Light: That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.Myosin Light Chains: The smaller subunits of MYOSINS that bind near the head groups of MYOSIN HEAVY CHAINS. The myosin light chains have a molecular weight of about 20 KDa and there are usually one essential and one regulatory pair of light chains associated with each heavy chain. Many myosin light chains that bind calcium are considered "calmodulin-like" proteins.Darkness: The absence of light.Light Signal Transduction: The conversion of absorbed light energy into molecular signals.Curing Lights, Dental: Light sources used to activate polymerization of light-cured DENTAL CEMENTS and DENTAL RESINS. Degree of cure and bond strength depends on exposure time, wavelength, and intensity of the curing light.Circadian Rhythm: The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs and stimuli, hormone secretion, sleeping, and feeding.Scattering, Radiation: The diversion of RADIATION (thermal, electromagnetic, or nuclear) from its original path as a result of interactions or collisions with atoms, molecules, or larger particles in the atmosphere or other media. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Ultraviolet Rays: That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-UV or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-UV or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants.Photoreceptor Cells: Specialized cells that detect and transduce light. They are classified into two types based on their light reception structure, the ciliary photoreceptors and the rhabdomeric photoreceptors with MICROVILLI. Ciliary photoreceptor cells use OPSINS that activate a PHOSPHODIESTERASE phosphodiesterase cascade. Rhabdomeric photoreceptor cells use opsins that activate a PHOSPHOLIPASE C cascade.Photosynthesis: The synthesis by organisms of organic chemical compounds, especially carbohydrates, from carbon dioxide using energy obtained from light rather than from the oxidation of chemical compounds. Photosynthesis comprises two separate processes: the light reactions and the dark reactions. In higher plants; GREEN ALGAE; and CYANOBACTERIA; NADPH and ATP formed by the light reactions drive the dark reactions which result in the fixation of carbon dioxide. (from Oxford Dictionary of Biochemistry and Molecular Biology, 2001)Myosin-Light-Chain Kinase: An enzyme that phosphorylates myosin light chains in the presence of ATP to yield myosin-light chain phosphate and ADP, and requires calcium and CALMODULIN. The 20-kDa light chain is phosphorylated more rapidly than any other acceptor, but light chains from other myosins and myosin itself can act as acceptors. The enzyme plays a central role in the regulation of smooth muscle contraction.Photoperiod: The time period of daily exposure that an organism receives from daylight or artificial light. It is believed that photoperiodic responses may affect the control of energy balance and thermoregulation.Dark Adaptation: Adjustment of the eyes under conditions of low light. The sensitivity of the eye to light is increased during dark adaptation.Microscopy, Electron: Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.Phytochrome: A blue-green biliprotein widely distributed in the plant kingdom.Color: The visually perceived property of objects created by absorption or reflection of specific wavelengths of light.Myosins: A diverse superfamily of proteins that function as translocating proteins. They share the common characteristics of being able to bind ACTINS and hydrolyze MgATP. Myosins generally consist of heavy chains which are involved in locomotion, and light chains which are involved in regulation. Within the structure of myosin heavy chain are three domains: the head, the neck and the tail. The head region of the heavy chain contains the actin binding domain and MgATPase domain which provides energy for locomotion. The neck region is involved in binding the light-chains. The tail region provides the anchoring point that maintains the position of the heavy chain. The superfamily of myosins is organized into structural classes based upon the type and arrangement of the subunits they contain.Adaptation, Ocular: The adjustment of the eye to variations in the intensity of light. Light adaptation is the adjustment of the eye when the light threshold is increased; DARK ADAPTATION when the light is greatly reduced. (From Cline et al., Dictionary of Visual Science, 4th ed)Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Retina: The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.Cryptochromes: Flavoproteins that function as circadian rhythm signaling proteins in ANIMALS and as blue-light photoreceptors in PLANTS. They are structurally-related to DNA PHOTOLYASES and it is believed that both classes of proteins may have originated from an earlier protein that played a role in protecting primitive organisms from the cyclical exposure to UV LIGHT.Chlorophyll: Porphyrin derivatives containing magnesium that act to convert light energy in photosynthetic organisms.Immunoglobulin lambda-Chains: One of the types of light chain subunits of the immunoglobulins with a molecular weight of approximately 22 kDa.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Photobiology: The branch of biology dealing with the effect of light on organisms.Reflex, Pupillary: Constriction of the pupil in response to light stimulation of the retina. It refers also to any reflex involving the iris, with resultant alteration of the diameter of the pupil. (Cline et al., Dictionary of Visual Science, 4th ed)PhotochemistryPhotic Stimulation: Investigative technique commonly used during ELECTROENCEPHALOGRAPHY in which a series of bright light flashes or visual patterns are used to elicit brain activity.Photochemotherapy: Therapy using oral or topical photosensitizing agents with subsequent exposure to light.Tumor Necrosis Factor Ligand Superfamily Member 14: A member of tumor necrosis factor superfamily found on activated LYMPHOCYTES and MONOCYTES. It occurs as transmembrane protein that can be cleaved to release a secreted form that specifically binds to LYMPHOTOXIN BETA RECEPTOR and TUMOR NECROSIS FACTOR RECEPTOR SUPERFAMILY, MEMBER 14.Melatonin: A biogenic amine that is found in animals and plants. In mammals, melatonin is produced by the PINEAL GLAND. Its secretion increases in darkness and decreases during exposure to light. Melatonin is implicated in the regulation of SLEEP, mood, and REPRODUCTION. Melatonin is also an effective antioxidant.Vision, Ocular: The process in which light signals are transformed by the PHOTORECEPTOR CELLS into electrical signals which can then be transmitted to the brain.Photosensitizing Agents: Drugs that are pharmacologically inactive but when exposed to ultraviolet radiation or sunlight are converted to their active metabolite to produce a beneficial reaction affecting the diseased tissue. These compounds can be administered topically or systemically and have been used therapeutically to treat psoriasis and various types of neoplasms.Photoreceptor Cells, Invertebrate: Specialized cells in the invertebrates that detect and transduce light. They are predominantly rhabdomeric with an array of photosensitive microvilli. Illumination depolarizes invertebrate photoreceptors by stimulating Na+ influx across the plasma membrane.Arabidopsis: A plant genus of the family BRASSICACEAE that contains ARABIDOPSIS PROTEINS and MADS DOMAIN PROTEINS. The species A. thaliana is used for experiments in classical plant genetics as well as molecular genetic studies in plant physiology, biochemistry, and development.Phytochrome B: A plant photo regulatory protein that exists in two forms that are reversibly interconvertible by LIGHT. In response to light it moves to the CELL NUCLEUS and regulates transcription of target genes. Phytochrome B plays an important role in shade avoidance and mediates plant de-etiolation in red light.Infrared Rays: That portion of the electromagnetic spectrum usually sensed as heat. Infrared wavelengths are longer than those of visible light, extending into the microwave frequencies. They are used therapeutically as heat, and also to warm food in restaurants.Microscopy, Polarization: Microscopy using polarized light in which phenomena due to the preferential orientation of optical properties with respect to the vibration plane of the polarized light are made visible and correlated parameters are made measurable.Rod Opsins: Photosensitive proteins expressed in the ROD PHOTORECEPTOR CELLS. They are the protein components of rod photoreceptor pigments such as RHODOPSIN.Microscopy: The use of instrumentation and techniques for visualizing material and details that cannot be seen by the unaided eye. It is usually done by enlarging images, transmitted by light or electron beams, with optical or magnetic lenses that magnify the entire image field. With scanning microscopy, images are generated by collecting output from the specimen in a point-by-point fashion, on a magnified scale, as it is scanned by a narrow beam of light or electrons, a laser, a conductive probe, or a topographical probe.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Clathrin Light Chains: The light chain subunits of clathrin.Kinetics: The rate dynamics in chemical or physical systems.Photochemical Processes: Chemical reactions effected by light.Phytochrome A: The primary plant photoreceptor responsible for perceiving and mediating responses to far-red light. It is a PROTEIN-SERINE-THREONINE KINASE that is translocated to the CELL NUCLEUS in response to light signals.Arabidopsis Proteins: Proteins that originate from plants species belonging to the genus ARABIDOPSIS. The most intensely studied species of Arabidopsis, Arabidopsis thaliana, is commonly used in laboratory experiments.Phototropism: The directional growth of organisms in response to light. In plants, aerial shoots usually grow towards light. The phototropic response is thought to be controlled by auxin (= AUXINS), a plant growth substance. (From Concise Dictionary of Biology, 1990)Photosystem II Protein Complex: A large multisubunit protein complex found in the THYLAKOID MEMBRANE. It uses light energy derived from LIGHT-HARVESTING PROTEIN COMPLEXES to catalyze the splitting of WATER into DIOXYGEN and of reducing equivalents of HYDROGEN.Hypocotyl: The region of the stem beneath the stalks of the seed leaves (cotyledons) and directly above the young root of the embryo plant. It grows rapidly in seedlings showing epigeal germination and lifts the cotyledons above the soil surface. In this region (the transition zone) the arrangement of vascular bundles in the root changes to that of the stem. (From Concise Dictionary of Biology, 1990)Retinal Rod Photoreceptor Cells: Photosensitive afferent neurons located in the peripheral retina, with their density increases radially away from the FOVEA CENTRALIS. Being much more sensitive to light than the RETINAL CONE CELLS, the rod cells are responsible for twilight vision (at scotopic intensities) as well as peripheral vision, but provide no color discrimination.Lasers: An optical source that emits photons in a coherent beam. Light Amplification by Stimulated Emission of Radiation (LASER) is brought about using devices that transform light of varying frequencies into a single intense, nearly nondivergent beam of monochromatic radiation. Lasers operate in the infrared, visible, ultraviolet, or X-ray regions of the spectrum.Optics and Photonics: A specialized field of physics and engineering involved in studying the behavior and properties of light and the technology of analyzing, generating, transmitting, and manipulating ELECTROMAGNETIC RADIATION in the visible, infrared, and ultraviolet range.Fluorescence: The property of emitting radiation while being irradiated. The radiation emitted is usually of longer wavelength than that incident or absorbed, e.g., a substance can be irradiated with invisible radiation and emit visible light. X-ray fluorescence is used in diagnosis.Photoreceptor Cells, Vertebrate: Specialized PHOTOTRANSDUCTION neurons in the vertebrates, such as the RETINAL ROD CELLS and the RETINAL CONE CELLS. Non-visual photoreceptor neurons have been reported in the deep brain, the PINEAL GLAND and organs of the circadian system.Light-Harvesting Protein Complexes: Complexes containing CHLOROPHYLL and other photosensitive molecules. They serve to capture energy in the form of PHOTONS and are generally found as components of the PHOTOSYSTEM I PROTEIN COMPLEX or the PHOTOSYSTEM II PROTEIN COMPLEX.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Photosynthetic Reaction Center Complex Proteins: Protein complexes that take part in the process of PHOTOSYNTHESIS. They are located within the THYLAKOID MEMBRANES of plant CHLOROPLASTS and a variety of structures in more primitive organisms. There are two major complexes involved in the photosynthetic process called PHOTOSYSTEM I and PHOTOSYSTEM II.Gene Expression Regulation, Plant: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in plants.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Chloroplasts: Plant cell inclusion bodies that contain the photosynthetic pigment CHLOROPHYLL, which is associated with the membrane of THYLAKOIDS. Chloroplasts occur in cells of leaves and young stems of plants. They are also found in some forms of PHYTOPLANKTON such as HAPTOPHYTA; DINOFLAGELLATES; DIATOMS; and CRYPTOPHYTA.Retinal Pigments: Photosensitive protein complexes of varied light absorption properties which are expressed in the PHOTORECEPTOR CELLS. They are OPSINS conjugated with VITAMIN A-based chromophores. Chromophores capture photons of light, leading to the activation of opsins and a biochemical cascade that ultimately excites the photoreceptor cells.Pupil: The aperture in the iris through which light passes.Refractometry: Measurement of the index of refraction (the ratio of the velocity of light or other radiation in the first of two media to its velocity in the second as it passes from one into the other).Radiation Injuries, Experimental: Experimentally produced harmful effects of ionizing or non-ionizing RADIATION in CHORDATA animals.Rabbits: The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.Retinal Degeneration: A retrogressive pathological change in the retina, focal or generalized, caused by genetic defects, inflammation, trauma, vascular disease, or aging. Degeneration affecting predominantly the macula lutea of the retina is MACULAR DEGENERATION. (Newell, Ophthalmology: Principles and Concepts, 7th ed, p304)Sunlight: Irradiation directly from the sun.Temperature: The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.Dose-Response Relationship, Radiation: The relationship between the dose of administered radiation and the response of the organism or tissue to the radiation.Halogens: A family of nonmetallic, generally electronegative, elements that form group 17 (formerly group VIIa) of the periodic table.Phosphorylation: The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.Seedling: Very young plant after GERMINATION of SEEDS.Plant Proteins: Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.Diuron: A pre-emergent herbicide.Hematoporphyrins: Iron-free derivatives of heme with 4 methyl groups, 2 hydroxyethyl groups and 2 propionic acid groups attached to the pyrrole rings. Some of these PHOTOSENSITIZING AGENTS are used in the PHOTOTHERAPY of malignant NEOPLASMS.Myosin Subfragments: Parts of the myosin molecule resulting from cleavage by proteolytic enzymes (PAPAIN; TRYPSIN; or CHYMOTRYPSIN) at well-localized regions. Study of these isolated fragments helps to delineate the functional roles of different parts of myosin. Two of the most common subfragments are myosin S-1 and myosin S-2. S-1 contains the heads of the heavy chains plus the light chains and S-2 contains part of the double-stranded, alpha-helical, heavy chain tail (myosin rod).Cyanobacteria: A phylum of oxygenic photosynthetic bacteria comprised of unicellular to multicellular bacteria possessing CHLOROPHYLL a and carrying out oxygenic PHOTOSYNTHESIS. Cyanobacteria are the only known organisms capable of fixing both CARBON DIOXIDE (in the presence of light) and NITROGEN. Cell morphology can include nitrogen-fixing heterocysts and/or resting cells called akinetes. Formerly called blue-green algae, cyanobacteria were traditionally treated as ALGAE.Chickens: Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.Calcium: A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.Luminescence: Emission of LIGHT when ELECTRONS return to the electronic ground state from an excited state and lose the energy as PHOTONS. It is sometimes called cool light in contrast to INCANDESCENCE. LUMINESCENT MEASUREMENTS take advantage of this type of light emitted from LUMINESCENT AGENTS.Immunoglobulin Light Chains, Surrogate: An immunolglobulin light chain-like protein composed of an IMMUNOGLOBULIN VARIABLE REGION-like peptide (such as light chain like lambda5 peptide) and an IMMUNOGLOBULIN CONSTANT REGION-like peptide (such as Vpreb1 peptide). Surrogate light chains associate with MU IMMUNOGLOBULIN HEAVY CHAINS in place of a conventional immunoglobulin light chains to form pre-B cell receptors.Protein Binding: The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.Seasonal Affective Disorder: A syndrome characterized by depressions that recur annually at the same time each year, usually during the winter months. Other symptoms include anxiety, irritability, decreased energy, increased appetite (carbohydrate cravings), increased duration of sleep, and weight gain. SAD (seasonal affective disorder) can be treated by daily exposure to bright artificial lights (PHOTOTHERAPY), during the season of recurrence.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.Spectrum Analysis: The measurement of the amplitude of the components of a complex waveform throughout the frequency range of the waveform. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Cattle: Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.Photometry: Measurement of the various properties of light.Semiconductors: Materials that have a limited and usually variable electrical conductivity. They are particularly useful for the production of solid-state electronic devices.Microscopy, Fluorescence: Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.Luminescent Measurements: Techniques used for determining the values of photometric parameters of light resulting from LUMINESCENCE.Mollusca: A phylum of the kingdom Metazoa. Mollusca have soft, unsegmented bodies with an anterior head, a dorsal visceral mass, and a ventral foot. Most are encased in a protective calcareous shell. It includes the classes GASTROPODA; BIVALVIA; CEPHALOPODA; Aplacophora; Scaphopoda; Polyplacophora; and Monoplacophora.Microscopy, Electron, Transmission: Electron microscopy in which the ELECTRONS or their reaction products that pass down through the specimen are imaged below the plane of the specimen.Biological Clocks: The physiological mechanisms that govern the rhythmic occurrence of certain biochemical, physiological, and behavioral phenomena.Photons: Discrete concentrations of energy, apparently massless elementary particles, that move at the speed of light. They are the unit or quantum of electromagnetic radiation. Photons are emitted when electrons move from one energy state to another. (From Hawley's Condensed Chemical Dictionary, 11th ed)Rod Cell Outer Segment: The portion of a retinal rod cell situated between the ROD INNER SEGMENT and the RETINAL PIGMENT EPITHELIUM. It contains a stack of photosensitive disk membranes laden with RHODOPSIN.Myosin-Light-Chain Phosphatase: A phosphoprotein phosphatase that is specific for MYOSIN LIGHT CHAINS. It is composed of three subunits, which include a catalytic subunit, a myosin binding subunit, and a third subunit of unknown function.Optical Processes: Behavior of LIGHT and its interactions with itself and materials.Pineal Gland: A light-sensitive neuroendocrine organ attached to the roof of the THIRD VENTRICLE of the brain. The pineal gland secretes MELATONIN, other BIOGENIC AMINES and NEUROPEPTIDES.Adaptation, Physiological: The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.Immunoglobulin Variable Region: That region of the immunoglobulin molecule that varies in its amino acid sequence and composition, and comprises the binding site for a specific antigen. It is located at the N-terminus of the Fab fragment of the immunoglobulin. It includes hypervariable regions (COMPLEMENTARITY DETERMINING REGIONS) and framework regions.Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.Ocular Physiological Phenomena: Processes and properties of the EYE as a whole or of any of its parts.Amyloidosis: A group of sporadic, familial and/or inherited, degenerative, and infectious disease processes, linked by the common theme of abnormal protein folding and deposition of AMYLOID. As the amyloid deposits enlarge they displace normal tissue structures, causing disruption of function. Various signs and symptoms depend on the location and size of the deposits.Immunoglobulin Heavy Chains: The largest of polypeptide chains comprising immunoglobulins. They contain 450 to 600 amino acid residues per chain, and have molecular weights of 51-72 kDa.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Thylakoids: Membranous cisternae of the CHLOROPLAST containing photosynthetic pigments, reaction centers, and the electron-transport chain. Each thylakoid consists of a flattened sac of membrane enclosing a narrow intra-thylakoid space (Lackie and Dow, Dictionary of Cell Biology, 2nd ed). Individual thylakoids are interconnected and tend to stack to form aggregates called grana. They are found in cyanobacteria and all plants.Photophobia: Abnormal sensitivity to light. This may occur as a manifestation of EYE DISEASES; MIGRAINE; SUBARACHNOID HEMORRHAGE; MENINGITIS; and other disorders. Photophobia may also occur in association with DEPRESSION and other MENTAL DISORDERS.Muscles: Contractile tissue that produces movement in animals.Xanthophylls: Oxygenated forms of carotenoids. They are usually derived from alpha and beta carotene.Photoreceptors, Plant: Plant proteins that mediate LIGHT SIGNAL TRANSDUCTION. They are involved in PHOTOTROPISM and other light adaption responses during plant growth and development . They include the phototropins, phytochromes (PHYTOCHROME), and members of the ubiquitous cryptochrome family.Plants: Multicellular, eukaryotic life forms of kingdom Plantae (sensu lato), comprising the VIRIDIPLANTAE; RHODOPHYTA; and GLAUCOPHYTA; all of which acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations.Photoreceptors, Microbial: Light absorbing proteins and protein prosthetic groups found in certain microorganisms. Some microbial photoreceptors initiate specific chemical reactions which signal a change in the environment, while others generate energy by pumping specific ions across a cellular membrane.Muscle, Smooth: Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Circadian Clocks: Biological mechanism that controls CIRCADIAN RHYTHM. Circadian clocks exist in the simplest form in cyanobacteria and as more complex systems in fungi, plants, and animals. In humans the system includes photoresponsive RETINAL GANGLION CELLS and the SUPRACHIASMATIC NUCLEUS that acts as the central oscillator.Spectrophotometry: The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Light-Curing of Dental Adhesives: The hardening or polymerization of bonding agents (DENTAL CEMENTS) via exposure to light.Phototropins: Blue-light receptors that regulate a range of physiological responses in PLANTS. Examples include: PHOTOTROPISM, light-induced stomatal opening, and CHLOROPLAST movements in response to changes in light intensity.Opsins: Photosensitive proteins in the membranes of PHOTORECEPTOR CELLS such as the rods and the cones. Opsins have varied light absorption properties and are members of the G-PROTEIN-COUPLED RECEPTORS family. Their ligands are VITAMIN A-based chromophores.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Species Specificity: The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.Spectrometry, Fluorescence: Measurement of the intensity and quality of fluorescence.Cotyledon: A part of the embryo in a seed plant. The number of cotyledons is an important feature in classifying plants. In seeds without an endosperm, they store food which is used in germination. In some plants, they emerge above the soil surface and become the first photosynthetic leaves. (From Concise Dictionary of Biology, 1990)Eye ProteinsTolonium Chloride: A phenothiazine that has been used as a hemostatic, a biological stain, and a dye for wool and silk. Tolonium chloride has also been used as a diagnostic aid for oral and gastric neoplasms and in the identification of the parathyroid gland in thyroid surgery.Molecular Weight: The sum of the weight of all the atoms in a molecule.DNA: A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).Birefringence: The property of nonisotropic media, such as crystals, whereby a single incident beam of light traverses the medium as two beams, each plane-polarized, the planes being at right angles to each other. (Cline et al., Dictionary of Visual Science, 4th ed)Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Photolysis: Chemical bond cleavage reactions resulting from absorption of radiant energy.Protein Conformation: The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).Equipment Design: Methods of creating machines and devices.Materials Testing: The testing of materials and devices, especially those used for PROSTHESES AND IMPLANTS; SUTURES; TISSUE ADHESIVES; etc., for hardness, strength, durability, safety, efficacy, and biocompatibility.Actins: Filamentous proteins that are the main constituent of the thin filaments of muscle fibers. The filaments (known also as filamentous or F-actin) can be dissociated into their globular subunits; each subunit is composed of a single polypeptide 375 amino acids long. This is known as globular or G-actin. In conjunction with MYOSINS, actin is responsible for the contraction and relaxation of muscle.Radiation Effects: The effects of ionizing and nonionizing radiation upon living organisms, organs and tissues, and their constituents, and upon physiologic processes. It includes the effect of irradiation on food, drugs, and chemicals.Acclimatization: Adaptation to a new environment or to a change in the old.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.

Biophysical characterization of the structure of the amino-terminal region of gp41 of HIV-1. Implications on viral fusion mechanism. (1/15260)

A peptide of 51 amino acids corresponding to the NH2-terminal region (5-55) of the glycoprotein gp41 of human immunodeficiency virus type 1 was synthesized to study its conformation and assembly. Nuclear magnetic resonance experiments indicated the sequence NH2-terminal to the leucine zipper-like domain of gp41 was induced into helix in the micellar solution, in agreement with circular dichroism data. Light scattering experiment showed that the peptide molecules self-assembled in water into trimeric structure on average. That the peptide molecules oligomerize in aqueous solution was supported by gel filtration and diffusion coefficient experiments. Molecular dynamics simulation based on the NMR data revealed a flexible region adjacent to the hydrophobic NH2 terminus of gp41. The biological significance of the present findings on the conformational flexibility and the propensity of oligomerization of the peptide may be envisioned by a proposed model for the interaction of gp41 with membranes during fusion process.  (+info)

Aggregation of deoxyhemoglobin S at low concentrations. (2/15260)

The self-association of deoxyhemoglobin S was measured in dilute solutions (0 to 5 g/dl) by Rayleigh light scattering at 630 nm and osmometry in 0.05 M potassium phosphate buffer (pH 7.35). Weight and number average molecular weights (Mw and Mn, respectively) and the second or higher virial coefficients, B' were determined. No experimentally significant differences were observed between oxy- and deoxy-Hb S up to the concentration of 2 g/dl; their apparent average molecular weights were within experimental error. Above that concentration, both Mn and Mw of deoxy-Hb S were significantly different from that of oxy-Hb S. The negative second viral coefficent of deoxy-Hb S, observed by both techniques, is consistent with the self-association of this protein. The lack of effect of 0.4 M propylurea on the state of aggregation and the significant influence of 0.1 M NaCl suggests that polar interactions are involved in formation of these aggregates.  (+info)

Improvement of systemic 5-aminolevulinic acid-based photodynamic therapy in vivo using light fractionation with a 75-minute interval. (3/15260)

We have studied different single and fractionated illumination schemes after systemic administration of 5-aminolevulinic acid (ALA) to Improve the response of nodular tumors to ALA-mediated photodynamic therapy. Tumors transplanted on the thigh of female WAG/Rij rats were transdermally illuminated with red light (633 nm) after systemic ALA administration (200 mg/kg). The effectiveness of each treatment scheme was determined from the tumor volume doubling time. A single illumination (100 J/cm2 at 100 mW/cm2, 2.5 h after ALA administration) yielded a doubling time of 6.6+/-1.2 days. This was significantly different from the untreated control (doubling time, 1.7+/-0.1 days). The only treatment scheme that yielded a significant improvement compared to all other schemes studied was illumination at both 1 and 2.5 h after ALA administration (both 100 J/cm2 at 100 mW/cm2) and resulted in a tumor volume doubling time of 18.9+/-2.9 days. A possible mechanism to explain this phenomenon is that the protoporphyrin IX formed after administration of ALA is photodegraded by the first illumination. In the 75-min interval, new porphyrin is formed enhancing the effect of the second illumination.  (+info)

The neuronal basis of a sensory analyser, the acridid movement detector system. I. Effects of simple incremental and decremental stimuli in light and dark adapted animals. (4/15260)

1. The response of the movement detector (MD) system to proportionally constant incremental and decremental stimuli has been studied at various degrees of light and dark adaptation. Action potentials in the descending contralateral movement detector neurone were taken as the indicator of response. 2. Over a range of at least six log10 units of adapting luminance, the MD system behaves as an ON/OFF unit, giving responses to both incremental and decremental changes in the illumination of a 5 degrees target. 3. With increasing amplitudes of stimuli, both the ON and OFF responses saturate rapidly. Saturation is reached sooner at higher levels of light adaptation. At all levels of light adaptation, the OFF response is greater than the ON. The ratio for saturating stimuli is approximately constant at around 3:2. 4. At the brightest adapting luminances used (20 000 cd/m2) the ON response is reduced but not lost. At the lowest (0-004 cd/m2) the OFF response to a 5 degrees disc fails, but can be regained by increasing the test area to 10 degrees. 5. From what is known of the retina of locusts and other insects, it is thought that light and dark adaptation in the MD system can be adequately explained by events at the retinula cell.  (+info)

Light-induced calcium influx into retinal axons is regulated by presynaptic nicotinic acetylcholine receptor activity in vivo. (5/15260)

Visual activity is thought to be a critical factor in controlling the development of central retinal projections. Neuronal activity increases cytosolic calcium, which was hypothesized to regulate process outgrowth in neurons. We performed an in vivo imaging study in the retinotectal system of albino Xenopus laevis tadpoles with the fluorescent calcium indicator calcium green 1 dextran (CaGD) to test the role of calcium in regulating axon arbor development. We find that visual stimulus to the retina increased CaGD fluorescence intensity in retinal ganglion cell (RGC) axon arbors within the optic tectum and that branch additions to retinotectal axon arbors correlated with a local rise in calcium in the parent branch. We find three types of responses to visual stimulus, which roughly correlate with the ON, OFF, and SUSTAINED response types of RGC reported by physiological criteria. Imaging in bandscan mode indicated that patterns of calcium transients were nonuniform throughout the axons. We tested whether the increase in calcium in the retinotectal axons required synaptic activity in the retina; intraocular application of tetrodotoxin (10 microM) or nifedipine (1 and 10 microM) blocked the stimulus-induced increase in RGC axonal fluorescence. A second series of pharmacological investigations was designed to determine the mechanism of the calcium elevation in the axon terminals within the optic tectum. Injection of bis-(o-aminophenoxy)-N,N,N',N'-tetraacetic acid-AM (BAPTA-AM) (20 mM) into the tectal ventricle reduced axonal calcium levels, supporting the idea that visual stimulation increases axonal calcium. Injection of BAPTA (20 mM) into the tectal ventricle to chelate extracellular calcium also attenuated the calcium response to visual stimulation, indicating that calcium enters the axon from the extracellular medium. Caffeine (10 mM) caused a large increase in axonal calcium, indicating that intracellular stores contribute to the calcium signal. Presynaptic nicotinic acetylcholine receptors (nAChRs) may play a role in axon arbor development and the formation of the topographic retinotectal projection. Injection of nicotine (10 microM) into the tectal ventricle significantly elevated RGC axonal calcium levels, whereas application of the nAChR antagonist alphaBTX (100 nM) reduced the stimulus-evoked rise in RGC calcium fluorescence. These data suggest that light stimulus to the retina increases calcium in the axon terminal arbors through a mechanism that includes influx through nAChRs and amplification by calcium-induced calcium release from intracellular calcium stores. Such a mechanism may contribute to developmental plasticity of the retinotectal system by influencing both axon arbor elaboration and the strength of synaptic transmission.  (+info)

Why and how is soft copy reading possible in clinical practice? (6/15260)

The properties of the human visual system (HVS) relevant to the diagnostic process are described after a brief introduction on the general problems and advantages of using soft copy for primary radiology interpretations. At various spatial and temporal frequencies the contrast sensitivity defines the spatial resolution of the eye-brain system and the sensitivity to flicker. The adaptation to the displayed radiological scene and the ambient illumination determine the dynamic range for the operation of the HVS. Although image display devices are determined mainly by state-of-the-art technology, analysis of the HVS may suggest technical characteristics for electronic displays that will help to optimize the display to the operation of the HVS. These include display size, spatial resolution, contrast resolution, luminance range, and noise, from which further consequences for the technical components of a monitor follow. It is emphasized that routine monitor quality control must be available in clinical practice. These image quality measures must be simple enough to be applied as part of the daily routine. These test instructions might also serve as elements of technical acceptance and constancy tests.  (+info)

Role of a novel photosystem II-associated carbonic anhydrase in photosynthetic carbon assimilation in Chlamydomonas reinhardtii. (7/15260)

Intracellular carbonic anhydrases (CA) in aquatic photosynthetic organisms are involved in the CO2-concentrating mechanism (CCM), which helps to overcome CO2 limitation in the environment. In the green alga Chlamydomonas reinhardtii, this CCM is initiated and maintained by the pH gradient created across the chloroplast thylakoid membranes by photosystem (PS) II-mediated electron transport. We show here that photosynthesis is stimulated by a novel, intracellular alpha-CA bound to the chloroplast thylakoids. It is associated with PSII on the lumenal side of the thylakoid membranes. We demonstrate that PSII in association with this lumenal CA operates to provide an ample flux of CO2 for carboxylation.  (+info)

The localisation of 2-carboxy-D-arabinitol 1-phosphate and inhibition of Rubisco in leaves of Phaseolus vulgaris L. (8/15260)

A recent controversial report suggests that the nocturnal inhibitor of Rubisco, 2-carboxy-D-arabinitol 1-phosphate (CAIP), does not bind to Rubisco in vivo and therefore that CA1P has no physiological relevance to photosynthetic regulation. It is now proved that a direct rapid assay can be used to distinguish between Rubisco-bound and free CA1P, as postulated in the controversial report. Application of this direct assay demonstrates that CA1P is bound to Rubisco in vivo in dark-adapted leaves. Furthermore, CA1P is shown to be in the chloroplasts of mesophyll cells. Thus, CA1P does play a physiological role in the regulation of Rubisco.  (+info)

*MYH7

The 9 nm alpha-helical neck region of each MHC-β head non-covalently binds two light chains, essential light chain (MYL3) and ... that dimerize and multimerize into a coiled-coil motif to form the light meromyosin (LMM), thick filament rod. ... regulatory light chain (MYL2). Approximately 300 myosin molecules constitute one thick filament. There are two isoforms of ...

*MYH1

Class II Myosins are hexameric proteins composed of a pair of myosin heavy chains (MYH) and two pairs of nonidentical light ...

*Photosynthesis

In the first stage, light-dependent reactions or light reactions capture the energy of light and use it to make the energy- ... Plants absorb light primarily using the pigment chlorophyll. The green part of the light spectrum is not absorbed but is ... These are the light-dependent 'photochemical' temperature-independent stage, and the light-independent, temperature-dependent ... Robert Emerson discovered two light reactions by testing plant productivity using different wavelengths of light. With the red ...

*Charged aerosol detector

The CAD, like other aerosol detectors (e.g., evaporative light scattering detectors (ELSD) and condensation nucleation light ... The CAD and evaporative light scattering detector (ELSD) are mass-flow sensitive detectors (response is proportional to mass of ...

*Free-running sleep

... including entrainment of the circadian clock to light-dark cycles, pupillary light responsiveness, and light-regulated hormone ... Study subjects are shielded from all time cues, often by a constant light protocol, by a constant dark protocol or by the use ... E]xposure to moderately bright light (~450 lux; ~1.2 W/m2) for the second or first half of the scheduled wake episode is ... Among blind people, the cause is the inability to register, and therefore to entrain to, light cues. The many blind people who ...

*Ballistic conduction

Non-ballistic electrons behave like light diffused in milk or reflected off a white wall or a piece of paper. Electrons can be ... A comparison with light provides an analogy between ballistic and non-ballistic conduction. Ballistic electrons behave like ... Like monochromatic light passing through milk, electrons undergo elastic interactions. Information about the state of the ... Electrons which undergo inelastic interaction are then similar to non-monochromatic light. For correct usage of this analogy ...

*Dynamic light scattering

In vertical/horizontal (VH) geometry the second polarizer allows light not in same direction as the incident light. When light ... A monochromatic light source, usually a laser, is shot through a polarizer and into a sample. The scattered light then goes ... The diffracted light from all of the molecules can either interfere constructively (light regions) or destructively (dark ... All of the molecules in the solution are being hit with the light and all of the molecules diffract the light in all directions ...

*MYL9

Myosin regulatory light polypeptide 9 is a protein that in humans is encoded by the MYL9 gene. Myosin, a structural component ... The protein encoded by this gene is a myosin light chain that may regulate muscle contraction by modulating the ATPase activity ... Higashihara M, Watanabe M, Usuda S, Miyazaki K (2008). "Smooth muscle type isoform of 20 kDa myosin light chain is expressed in ... The encoded protein binds calcium and is activated by myosin light chain kinase. Two transcript variants encoding different ...

*Light

... in particular about light beams visible from the side Light Fantastic (TV series) Light mill Light painting Light pollution ... Light pressure is equal to the power of the light beam divided by c, the speed of light. Due to the magnitude of c, the effect ... During the time it had "stopped" it had ceased to be light. The study of light and the interaction of light and matter is ... Media related to Light at Wikimedia Commons The dictionary definition of light at Wiktionary Quotations related to Light at ...

*Light (journal)

Light (formerly Light: A Quarterly of Light Verse) is an online journal which bills itself as "America's oldest and best-known ... 2. Nicol, Alfred (August 2, 2013), "A New Morning for Light" A New Morning for Light. Light. ... The verse in each issue begins with a feature on a writer of light verse. Sections in between vary from issue to issue, and ... Mella personally published the journal until 2008, when he founded the non-profit Foundation for Light Verse with a $500,000 ...

*Danny Light

Daniel Light (10 July 1948 - 18 October 2014) was a professional footballer who played as a forward. Light began his career at ... Danny Light at Post War English & Scottish Football League A-Z Player's Database Danny Light at holmesdale.net. ... "Danny Light". The Holmesdale Online. Retrieved 17 September 2013. "Danny Light". Colchester United: The Archive Database For ...

*Nordic Light

... International Festival of Photography (or just Nordic Light) is an international photo festival held annually in ... Morten M. Løberg, "Nordic Light i gang", Fotografi.no, 4 May 2011. (in Norwegian) Accessed 31 July 2011. Nordic Light. ... Kathryn Geard, "Nordic Light hedrer Tom Martinsen", Journalisten.no, 6 July 2007. (in Norwegian) Accessed 31 July 2011. ...

*Spire light

... (Fr. lucarne), the term given to the windows in a spire which are found in all periods of English Gothic ... 1911). "Spire Light". Encyclopædia Britannica. 25 (11th ed.). Cambridge University Press. p. 693. ...

*Dunkirk Light

Light List, Volume VII, Great Lakes (PDF). Light List. United States Coast Guard. 2009. p. 38. "ARLHS World List of Lights". ... Dunkirk Light, also known as Point Gratiot Light, is an active lighthouse located at Point Gratiot on Lake Erie in New York ... At the entrance to the park property is the South Buffalo North Side Light, formerly located in Buffalo Harbor. It was added to ... The lighthouse was established in 1826 and the current tower was first lit in 1875. The lighthouse was automated in 1960 and is ...

*Ocracoke Light

... is the oldest operating light station in North Carolina and the second oldest lighthouse still standing in the ... Various claims have been made about the light, including "the Ocracoke Light is the second oldest operating lighthouse in the ... Light List, Volume II, Atlantic Coast, Shrewsbury River, New Jersey to Little River, South Carolina (PDF). Light List. United ... Ocracoke /ˈoʊkrʌkoʊk/ Light was built in Hyde County, on Ocracoke Island, North Carolina in 1823 by Massachusetts builder Noah ...

*Natchez Light

... was a lighthouse on the Mississippi River that was built in 1825 and then destroyed in 1840 by a tornado. " ... "Foghorn Publishing ... Lighthouse Explorer Database ... Natchez Light". Lighthouse Digest. Retrieved 12 August 2016. ...

*Head Light

... is the third album by Trance Mission, released on October 21, 1996 through City of Tribes Records. All music ... "Head Light". Allmusic. Retrieved June 19, 2013. columnist (January 1997). Alternative Press: 85. Missing or empty ,title= (help ... Head Light at Discogs (list of releases). ...

*Alan Light

Starting in 2016 Light is one of the mainstay hosts of the newly created Volume music talk channel on Sirius XM. Light has also ... Light has worked as consultant for the Rock & Roll Hall of Fame. He was a judge for the 4th Annual Independent Music Awards in ... Alan Light (born August 4, 1966) is an American journalist who has been a rock critic for Rolling Stone and the editor-in-chief ... Light had been an intern at Rolling Stone during their 20th anniversary year while still a student. He later joined the staff ...

*Light Lake

... (60°42′S 45°39′W / 60.700°S 45.650°W / -60.700; -45.650Coordinates: 60°42′S 45°39′W / 60.700°S 45.650°W / - ... It was named by the UK Antarctic Place-Names Committee after British Antarctic Survey limnologist Jeremy J. Light, leader at ... "Light Lake". Geographic Names Information System. United States Geological Survey. Retrieved 2013-06-14. This article ... incorporates public domain material from the United States Geological Survey document "Light Lake" (content from the Geographic ...

*Sakonnet Light

Croix River, Maine to Shrewsbury River, New Jersey (PDF). Light List. United States Coast Guard. 2012. p. 166. "Historic Light ... The light was deactivated in 1954 after Hurricane Carol and was going to be destroyed, but local citizens protested, and ... Sakonnet Light, built in 1884, is a sparkplug lighthouse near Sakonnet Point, Little Compton, Rhode Island, on the eastern side ... "Sakonnet Point Light - History". New England Lighthouses: A Virtual Guild. Jeremy D'Entremont. Retrieved February 11, 2012. ...

*Shinnecock Light

Light List, Volume I, Atlantic Coast, St. Croix River, Maine to Shrewsbury River, New Jersey (PDF). Light List. United States ... Shinnecock Light was a lighthouse on the south side of Long Island, New York. The name comes from the Shinnecock Indian Nation ... Some time later the Coast Guard built a communication tower on the site and moved the light to the height of 75 feet (23 m) on ... p. 9. "Historic Light Station Information and Photography: New York". United States Coast Guard Historian's Office. Rowlett, ...

*Whaleback Light

Light List, Volume I, Atlantic Coast, St. Croix River, Maine to Shrewsbury River, New Jersey (PDF). Light List. United States ... The light is 59 feet (18 m) above mean sea level, and the tower, also housed the keeper's living quarters and a storage area. ... A light has been active at this location since 1820; the present tower was built in 1872. It was listed on the National ... The light was automated in 1963. The current lighthouse exhibits two white flashes every 10 seconds and is created by a modern ...

*Seguin Light

The light was listed on the National Register of Historic Places as Seguin Island Light Station in 1977. Seguin Island is a 64- ... Light List, Volume I, Atlantic Coast, St. Croix River, Maine to Shrewsbury River, New Jersey (PDF). Light List. United States ... With its light at 180 feet (55 m) above mean sea-level, the present tower, built in 1857, is its highest of the state's ... Seguin Light is a lighthouse on Seguin Island, in the Gulf of Maine south of the mouth of the Kennebec River, Maine. ...

*Triton Light

Light List, Volume II, Atlantic Coast, Shrewsbury River, New Jersey to Little River, South Carolina (PDF). Light List. United ... The characteristics of this light are FL (4+5) G 30s, that is Flashing Green light 4x, then 5x, every 30 seconds. The ... The Triton Light is a navigational beacon on the seawall of the United States Naval Academy in Annapolis, Maryland, where the ... The seawall on the Severn River from Triton Light north-west to the end of Simms Rd at College Creek is exactly 1/2 nautical ...

*Mukilteo Light

The Mukilteo Light is an operational navigation aid located on the east side of Possession Sound at Mukilteo, Snohomish County ... "Mukilteo Light". Lighthouse Digest. Lighthouse Explorer. Foghorn Publishing. Retrieved May 5, 2015. "National Register of ... McClary, Daryl C. (June 10, 2004). "Mukilteo Light Station". The Online Encyclopedia of Washington State History. HistoryLink. ... "Historic Overview of the Light Station". Mukilteo Historical Society. Retrieved May 5, 2015. Rowlett, Russ (October 19, 2014 ...
The invention relates to a light guide panel capable of distributing light beams incident from a light source to an entire surface thereof. The light guide panel has at least two through holes formed in a path of the incident light beams, apart in a predetermined interval from a light incident surface. The through holes are formed perpendicular to the path of the incident light beams, and lined along the light incident surface of the light guide panel. The light guide panel according to the present invention can improve uniformity of incident light without increasing the number or size of the light source, thereby distributing the incident light in a wider angle and decreasing a light mixing region. The light guide panel is produced in a simple manufacturing process, reducing the manufacturing costs.
The Shade Avoidance Syndrome in Arabidopsis: The Antagonistic Role of Phytochrome A and B Differentiates Vegetation Proximity and Canopy Shade. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
When chlorophyll a absorbs light energy, an electron gains energy and is excited. The excited electron is transferred to another molecule (called a primary electron acceptor). The chlorophyll molecule is oxidized (loss of electron) and has a positive charge. Photoactivation of chlorophyll a results in the splitting of water molecules and the transfer of energy to ATP and reduced nicotinamide adenine dinucleotide phosphate (NADP). The chemical reactions involved include: condensation reactions - responsible for water molecules splitting out, including phosphorylation (the addition of a phosphate group to an organic compound) oxidation/reduction (redox) reactions involving electron transfer Photosynthesis is a two stage process. 1. The Light dependent reactions, a light-dependent series of reactions which occur in the grana, and require the direct energy of light to make energy-carrier molecules that are used in the second process: light energy is trapped by chlorophyll to make ATP (ph. ...
The present invention provides an instrument adapted for alignment with a light beam, which instrument includes an instrument body having a point of entry of the light beam, a light conducting channel, and a sensing element carried by the instrument and being spaced from the point of entry of the light beam. The sensing element serves to provide indication of alignment or misalignment between the instrument and the light beam. The light beam travels inside the instrument along the light conducting channel extending from the point of entry to the sensing element. One or more light guiding devices are disposed inside the light conducting channel to increase precision of alignment between the instrument and the light beam. The light guiding device has a wall forming a guiding passage inside the guiding device. When disposed inside the instrument, the wall of the guiding device blocks non-aligned light beams from reaching the sensing element, while allowing the aligned light beams to propagate along a
Plants employ a variety of mechanisms to maximize photosynthetic potential under changing environmental conditions. For example, most plants can biochemically adapt to excessive light by altering the size of light harvesting complexes, dissipating excess energy as heat, scavenging reactive oxygen, and rapidly repairing damaged reaction center proteins (Niyogi, 1999). Developmental changes that occur in response to different light conditions include variations in leaf thickness, density of mesophyll cells, and changes in the orientation of the leaf blade (Boardman, 1977). These responses have been associated with improved photosynthetic potential and/or protection from photodamage. However, their relative importance can be species specific, indicating that some of these responses represent unique adaptive strategies. Another perhaps more ubiquitous plant response to varying light conditions is light-induced chloroplast movement, which has been documented in a large number of species, including ...
We have demonstrated the function of EML1 and its participation in the recovery of sensitivity under continuous illumination in UV- and blue-sensitive zebrafish cones. Sensitivity recovery in the first tens of seconds after the onset of adapting light was first reported in ERG studies of the flicker response of several mammalian and nonmammalian species (Muller-Limmroth and Andree, 1953). Studies of flicker ERG in frog suggested that the sensitivity recovery originates in cones (Owen and Sillman, 1973; Haynes and Sillman, 1986), which was directly demonstrated in single cell studies of turtle cones under continuous illumination (Normann and Perlman, 1979; Burkhardt, 1994). In humans, the cone-driven "b" wave in the ERG (Gouras and MacKay, 1989) and cone-driven psychophysical perception (Stockman et al., 2006, 2007) also exhibit slow sensitivity recovery under continuous illumination. However, the rate of this sensitivity recovery is slower than that measured in the nonmammalian photoreceptors, ...
Photosynthesis. Light dependant reaction. 1) light strikes the chlorophyll in photo system 2 this excites the electrons and boosts them to a higher energy level. 2) the electrons are accepted by an electron carrier in the thylokoid membrane (NADP becomes reduced). 3) The oxidised chlorophyll then removes electrons from water producing protons and oxygen this occurs in the thylokoid membrane. 4) as the electrons pass between the carriers they lose energy , this energy is then transferred to the proton pumps.The Protons are then pumped from the stroma to…. ...
Introduction. Photosynthesis Coursework Introduction Background Information Glucose can be converted to sucrose and carried to other parts of the plant in phloem vessels. Glucose can also be converted into starch and stored Light Sometimes light is a limiting factor. A plant may have lots of water and carbon dioxide, but it will not photosynthesize very fast if there is not enough light; increasing the light intensity will make photosynthesis faster. Carbon dioxide Sometimes the level of carbon dioxide is limiting. There may be plenty of light but the plant cannot photosynthesize because it has run out of carbon dioxide. Temperature Temperature can be a limiting factor too. The rate of photosynthesis will be limited if it is too cold for the enzymes to work properly. ...read more. Middle. Diagram Preliminary method I was going to do a method which involved counting the bubbles at different light intensities. I chose not to do this method as it is and inaccurate method to show volume of O2 ...
A light emitting diode (LED) warning signal light, the warning signal light comprising a plurality of light sources constructed and arranged with a reflector or cullminator, the LED light source being in electrical communication with a controller and a power supply, battery, or other electrical source. The warning signal light provides various colored light signals for independent use or use by an emergency vehicle. These light signals may include a strobe light, revolving light, an alternating light, a flashing light, a modulated light, a pulsating light, an oscillating light or any combination thereof. Additionally, the warning signal light may be capable of displaying symbols, reverse characters, or arrows. The controller may further be adapted to regulate or modulate the power intensity exposed to the illuminated LEDs to create a variable intensity light signal.
A light emitting diode (LED) warning signal light, the warning signal light comprising a plurality of light sources constructed and arranged with a reflector or cullminator, the LED light source being in electrical communication with a controller and a power supply, battery, or other electrical source. The warning signal light provides various colored light signals for independent use or use by an emergency vehicle. These light signals may include a strobe light, revolving light, an alternating light, a flashing light, a modulated light, a pulsating light, an oscillating light or any combination thereof. Additionally, the warning signal light may be capable of displaying symbols, reverse characters, or arrows. The controller may further be adapted to regulate or modulate the power intensity exposed to the illuminated LEDs to create a variable intensity light signal.
A new technique that stimulates heart muscle cells with low-energy light raises the possibility of a future light-controlled pacemaker, researchers have indicated.
The control of sleep/wakefulness is associated with the regulation of energy metabolism. The present experiment was designed to assess the effect of nocturnal blue light exposure on the control of sle
what are the products of light dependent reactions - 28 images - review for quiz on photosynthesis worland, the two steps of photosynthesis from openstax college, ppt photosynthesis powerpoint presentation id 1090782, science is cool, unit 6 photosynthesis cellular respiration ppt
Long daylength artificial light exposure associates with disorders and a potential physiological mechanism has been proposed. However, previous studies have examined no more than three artificial light treatments and limited metabolic parameters, which have been insufficient to demonstrate mechanical responses. Here, comprehensive physiological response curves were established and the physiological mechanism was strengthened. Chicks were illuminated for 12, 14, 16, 18, 20, or 22 h periods each day. A quadratic relationship between abdominal adipose weight (AAW) and light period suggested that long-term or short-term light exposure could decrease the amount of AAW. Quantitative relationships between physiological parameters and daily light period were also established in this study. The relationships between triglycerides (TG), cholesterol (TC), glucose (GLU), phosphorus (P) levels and daily light period could be described by quadratic regression models. TG levels, AAW and BW positively correlated with
Novel visible-light-responsive photocatalysts (CsBi2Nb5O16 and CsBiNb2O7) were prepared using a conventional solid-state reaction method. CsBiNb2O7 and CsBi2Nb5O16 belong to a layered perovskite structure and a defective pyrochlore structure, respectively. These prepared samples have photocatalytic properties to decompose 2-propanol under visible light irradiation.
A light clock measures time by having a light pulse source initiating a light pulse which travels a preset distance in an open or closed loop. A counter is increases incrementally upon detection of the light pulse by a light pulse detector. Each increment is a time interval, which is determined by the preset distance divided by the speed of the light pulse. If the loop is an open loop, another light pulse may be initiated upon detection of the previous light pulse. If the loop is a closed loop, no further light pulse initiation beyond the initial light pulse is required, but, when necessary, a light pulse amplifier is used to amplify the light pulse for the next cycle around the closed loop in the light pulse transmission device.
Plants do not only gain energy from light, they also use light as a source of information in order to adapt growth and development to environmental conditions. They have a range of photoreceptors to detect different aspects of their light environment, such as the light intensity and spectral composition, the direction of the light gradient, or temporal light patterns (Kami et al., 2010). Cryptochromes, phototropins, members of the ZEITLUPE (ZTL) family, and UV RESISTANCE LOCUS 8 (UVR8) monitor the blue (B) and UV-B range of the light spectrum, whereas phytochromes (PHYs) are essential for the perception of red (R) and far-red (FR) light (Kami et al., 2010; Heijde and Ulm, 2012). Phytochromes can exist in two different states, the inactive Pr form with maximal absorption in R light, and the active or Pfr form of phytochromes, which has an absorption peak in FR light. By absorption of light, these forms reversibly convert into each other, resulting in an equilibrium with a wavelength-specific ...
Your eyes are sensitive to a narrow band of frequencies referred to as the, "visible light spectrum." Visible light-light capable of being seen by the human eye -consists of wavelengths of varying lengths.. Blue light has a very short wavelength and is detectable by the human eye. Not only does it provide basic illumination to our worlds, blue light also helps to increase feelings of well-being. But exposure to large amounts of blue light can be harmful to the eyes.. The plethora of electronic devices in use today, such as cell phones, tablets, and laptop computers, has drastically increased our exposure to blue light. Another source of blue light is energy efficient technology in the form of fluorescent light bulbs and LED lights. Research has determined that the lens inside the eye, and the pigment in the back of the eye, offer some protection against blue light. But this protective mechanism only lasts for short period of exposure to the intense blue light, and during daylight hours.. Perhaps ...
The signal transduction machinery activated by PHY requires transcription factors such as PIF, HY5 and LAF1, which act in the de-etiolation process (Chattopadhyay et al., 1998; Ballesteros et al., 2001; Tepperman et al., 2001; Al-Sady et al., 2006). Recently, studies on phytochrome-regulated gene expression by means of microarray analyses showed that many other transcription factors are also early over-expressed through PHYA and PHYB (Quail, 2007).. It has been shown that PHYA, but not PHYB, plays a role in the transcriptional induction of phytoene synthase (psy) in Arabidopsis (von Lintig et al., 1997), by promoting the binding of HY5 to white, blue, red and far red light respon-sive elements (LREs) located in its promoter (Figure 2). LREs are described to be sufficient to confer responsiveness to light in promoters that are not induced normally by light (Roa-Rodríguez, 2003). The most common type of LREs that are present in genes activated by light are the ATCTA element, and the Gl (CACGAG) ...
Algal-derived compounds allow us to make assumptions about environmental conditions in the past. In order to better understand how organisms record environmental conditions, we grew microscopic marine algae at different light intensities, salinities, and alkalinities in a temperature-controlled environment. We determined how these environmental parameters affected specific algal-derived compounds, especially their relative deuterium content, which seems to be mainly affected by salinity ...
To keep track of fluctuations in spectral composition and intensity of incoming sunlight, plants engage a plethora of photosensory pigments. Absorption of light by these photoreceptors sets in motion signaling cascades that ultimately influence the plants physiology. Many light-controlled processes are based on modulation of gene activity in response to changes in irradiation. The molecular basis of this regulation and the downstream components transducing signals from the photoreceptors are not fully understood yet, but recent evidence suggests that some of those routes are rather short. The phytochrome photoreceptors have been found to influence light-responsive promoters by direct contact with transcription factors. Additionally, the cryptochrome blue-light receptors directly interact with a key repressor of photomorphogenesis, suggesting that light activation of photoreceptors could initiate photomorphogenesis through posttranslational regulation. This review focuses on recent insights into ...
Photosynthesis is most efficient at light wavelengths between 400 and 500 nanometers and 600 to 700 nanometers. The green pigment, chlorophyll, restricts the efficiency of photosynthesis....
Blue light is part of the visible light spectrum, with wavelengths of about 415 nm to 495 nm. Blue light can be divided into two bands: blue-violet light (415-455 nm) and blue-turquoise light (465-495 nm).3 When light in the blueviolet range hits the eye, a process unique to this band of wavelength occurs. During the visual cycle, when opsin starts the process of phototransduction, certain intermediate products are produced that can also bind opsin and accept more photons within this range of wavelength, resulting in photoreversal that occurs faster than the normal visual cycle. This photoreversal enables the eye to absorb more blue light than any other kind of light.4. Photons of light are small units of energy, too much of which can result in uncoupling of cellular oxidative phosphorylation, which produces reactive oxygen species (ROS) that disrupt membranous structures of the photoreceptor outer segments and consequently damage delicate RPE cells. This damage causes incomplete phagocytosis ...
Membrane proteins are of significant importance, performing a variety of biological functions including pumps, channels, and receptors. Thus, membrane proteins represent attractive candidates as drug targets. Bacteriorhodopsin (bR), the most widely studied membrane protein, consists of seven transmembrane helical segments and functions which can work as a proton pump in Halobacterium Salinarium. In the present study, the reversible control of bR conformation with simple light illumination is examined, providing a protocol to probe membrane protein folding (a challenge even to this day due to the large, aggregation-prone hydrophobic regions of membrane proteins compared to soluble proteins). Two general methodologies are utilized to control membrane protein folding, including (1) saturation of the natural lipids with a photoresponsive surfactant resulting in partitioning of the protein into detergent-lipid mixed micelles in the unfolded state, and (2) the development of artificial bilayers ...
Membrane proteins are of significant importance, performing a variety of biological functions including pumps, channels, and receptors. Thus, membrane proteins represent attractive candidates as drug targets. Bacteriorhodopsin (bR), the most widely studied membrane protein, consists of seven transmembrane helical segments and functions which can work as a proton pump in Halobacterium Salinarium. In the present study, the reversible control of bR conformation with simple light illumination is examined, providing a protocol to probe membrane protein folding (a challenge even to this day due to the large, aggregation-prone hydrophobic regions of membrane proteins compared to soluble proteins). Two general methodologies are utilized to control membrane protein folding, including (1) saturation of the natural lipids with a photoresponsive surfactant resulting in partitioning of the protein into detergent-lipid mixed micelles in the unfolded state, and (2) the development of artificial bilayers ...
I have been studying research in the area of natural light and its interaction on the human brain. An important point to make is that appropriate exposure to natural light has positive effects on our circadian rhythm and in turn promotes many aspects of health.. We evolved from exposure to natural day lighting. The sun provides a specific wavelength (blue range) in the early morning that lasts until early afternoon. At that point a different light wavelength is produced (red to orange range). We recently discovered that the retina has a specific photoreceptor that detects light and sends it to a special part of the brain known as the suprachiasm, located near the hypothalamus. Once the suprachiasm is triggered, it sets off the hypothalamus, the master gland that in turn triggers the pituitary, thyroid, and adrenal glands of the brain and body. The hormonal reaction to light is what causes and promotes the diverse actions of the body and health.. The blue range of light helps our bodies become ...
Imagine for a moment that we are a new seedling of some kind of plant chilling on a forest floor. There are lots of other plants around us taking up light that we need. In nature, due to the characteristics of their wavelengths, blue light is absorbed first by plants, then red light, then far-red light. So, if there are other taller plants around us, they will be taking up all the blue light, while letting us have a more of the red light. If we are getting a lot of this red light early in our life, this tells our photoreceptors that there are lots of taller plants around us (or that were still in the soil), and we need to grow taller. So, we, the plant, invest growth in our shoots and stems, mostly forgoing growth in leaves (for now) until it can eclipse the plants around us and get to that sweet, sweet blue light in the heavens above.. If you begin growing a seedling and it is getting too tall and wiry for your liking and not producing any leaves, this is likely because its getting too much ...
Fig. 1: Retinal degeneration: a new model of blue-light induced damage Light microscopy photographs (magnification x400). Trichrome Masson staining of sagittal section of retina 14 days after blue light exposure. Approximately four rows of photoreceptor nuclei remaining and inner and outer segments were disrupted (Iris Pharma, France).. Blue light may damage the retina in a number of ways involving different chromophores and cellular events; however, retinal damage by photo chemical mechanism is most likely to be of relevance in the development of AMD. Photochemical reactions occur in normal ambient conditions and involve a reaction between energetic photons and an absorbing molecule in the presence of oxygen leading to the generation of reactive oxygen species (ROS) that are highly toxic to the retina.. Short-term exposure (up to about 12 hours) to relatively intense blue light, referred to as "blue light hazard", can produce damage at the level of RPE in primates. [9] The dependence of this ...
Fig. 1: Retinal degeneration: a new model of blue-light induced damage Light microscopy photographs (magnification x400). Trichrome Masson staining of sagittal section of retina 14 days after blue light exposure. Approximately four rows of photoreceptor nuclei remaining and inner and outer segments were disrupted (Iris Pharma, France).. Blue light may damage the retina in a number of ways involving different chromophores and cellular events; however, retinal damage by photo chemical mechanism is most likely to be of relevance in the development of AMD. Photochemical reactions occur in normal ambient conditions and involve a reaction between energetic photons and an absorbing molecule in the presence of oxygen leading to the generation of reactive oxygen species (ROS) that are highly toxic to the retina.. Short-term exposure (up to about 12 hours) to relatively intense blue light, referred to as "blue light hazard", can produce damage at the level of RPE in primates. [9] The dependence of this ...
A fluorimeter comprises an excitation optical system projecting the excitation light having a selected wavelength for a sample to said sample, a sample cell for accommodating the sample; fluorescent light sensors for sensing the fluorescent light emitted from the sample; a transmission light sensor for sensing the light transmitted through the sample; and an arithmetic divider which divides the output of the fluorescent light sensor by the output of the transmission light sensor, and provides a signal representing the intensity of the fluorescent light which is corrected against the variation of the excitation light intensity.
Mracek, Philipp; Pagano, Chrstina; Fröhlich, Nadine; Idda, M. Laura; Cuesta, Ines H.; Lopez-Olmeda, Jose Fernando; Sánchez-Vázquez, F. Javier; Daniela Vallone, Daniela; Foulkes, Nicholas S ...
BACKGROUND Ultraviolet (UV) B irradiation causes visible erythema, which has been linked with DNA damage. However, besides such direct photochemical conformation changes, UVB also induces many indirect photochemical effects in the skin. Lipid peroxidation (LPO) is in this context one of the major pathways by which photo-oxidative stress disturbs cell signalling and promotes photocarcinogenesis and photoageing. So far we lack techniques for visualizing photo-oxidative stress in the skin. Furthermore, LPO has never been linked with individually acquired UVB doses measured by personal dosimetry. OBJECTIVES Measuring the skin reaction and photo-oxidative damage by LPO in vivo after UVB exposure in a pilot study surveyed by personal dosimetry in order to allow for a correlation analysis of acquired dose, skin reaction and amount of LPO. METHODS UVB exposure was measured with the opto-electronic X2000-1 (Gigahertz Optik, Puchheim, Germany) and the biological DLR Biofilm (German Aerospace Center DLR,
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Curing lights are commonly used by dentists in order to harden the resins or materials inserted to fill teeth or to apply appliance bonding. The lights are also used to activate teeth whitening and cleaning solutions. The chemical components contained within bonding, filling, cleaning or whitening materials are created to react with the special wavelength. Once exposed to the light for a brief number of seconds, the compound or solution activates. Along with hardening the dental material, curing lights also ensure the resin cures and adheres appropriately. This is important for adhesives when affixing braces or implants to teeth. The lights are also used to cure sealants in order to reduce the possibility of cracking.. The modern technology involves the use of lights equipped with at least one LED bulb, which emits light at a specified wavelength. Some lights might conversely contain a normal white light bulb. However, the white light passes through a filter, which creates the desired ...
The sensitivity of molecular, endocrine, and neurobehavioral performance to short-wavelength photic stimuli at night has been demonstrated by several groups (5, 8, 38, 48, 61). We and others have demonstrated previously that exposure at night to polychromatic white light from which short-wavelength light (,530 nm) has been filtered prevents melatonin suppression in humans (28, 29, 52). The present study extended these findings, demonstrating that completely filtering short wavelengths ,480 nm from nocturnal light not only attenuates the suppression of melatonin but also prevents alterations in cortisol secretion and clock gene expression in humans. Furthermore, completely filtering short wavelengths ,460 nm or partially filtering short wavelengths ,480 nm by ≤70% did not attenuate the physiological changes induced by nocturnal light exposure. These findings are consistent with our observations in rats (46) that a narrow band of light wavelengths between 470 and 480 nm is responsible for the ...
Principal Investigator:NAGATA Toshiyuki,大野 哮司, Project Period (FY):1991 - 1994, Research Category:Grant-in-Aid for Scientific Research on Priority Areas
SECTION III - GLOSSARY. ACOUSTO-OPTIC. The effect, on the properties of a beam of light, by sound energy, interacting with the light within a volume of matter.. ACTIVE MEDIA. The material, in which most of the atoms can be placed in an excited state (i.e., population inversion state), so that an electromagnetic wave of the proper frequency passing through it can stimulate a cascade of photons.. BIREFRINGENT. The property of dividing a ray of light into two polarized rays (known as the ordinary and extraordinary rays), the directions of polarization of the rays being at right angles to each other.. COHERENT LIGHT. A single frequency of light. A light beam in which the electric vector at any point in it is related to that at any other point by a definite, continuous sinusoidal function.. DIFFRACTION. The bending of a light ray in passing the edge formed by contiguous opaque and transparent areas.. ELECTRO-OPTIC. The effect, on the properties of a beam of light, by an electrical field, interacting ...
A dental curing light includes a body, one or more LEDs configured to emit a first spectrum of light having a relatively short first peak wavelength (e.g., UV) disposed on the body, and a fluorescing lens that converts at least a portion of the first spectrum of light into a second spectrum of light having a second peak wavelength that is longer than the first peak wavelength. The second spectrum of light is selected so as to match the curing spectrum of a desired light-curable dental composition. In a preferred embodiment, the body comprises an elongate wand having a proximal end and distal end. The LEDs may be disposed at or near the distal end of the elongate wand.
Growth factor array results showed that NHEK responded to blue light exposure by increasing secretion of several growth factors including insulin-like growth factor binding protein-1, amphiregulin, epidermal growth factor and fibroblast growth factor-b. Likewise, mitochondrial dehydrogenase activity and cell proliferation were enhanced in NHEK. In contrast, HGF did not respond to blue light exposure significantly in any of the parameters tested.. These results show that NHEK cells responded robustly to a single, small dose of light by increasing their mitochondrial activity, DNA synthesis, and production of growth factors. Together, these data suggest that blue light may be useful to enhance epithelial cell growth in a wound site.. This is a summary of abstract #488, "A Novel In Vitro Model for Light-Induced Wound Healing," to be presented by C. Millan at 3:30 p.m. on Thursday, March 4, 2010, in Exhibit Hall D of the Walter E. Washington Convention Center, during the 39th Annual Meeting of the ...
The Photon Pod is a collaborative research project between Phillips, Cantifix and Oxford University to study the effects of various lights on health and wellbeing.
The invention is directed to an apparatus (20) for determining surface topology of a teeth portion (26), comprising a probing member (90) with a sensing face; an illumination unit (28, 32, 34, 38) for providing an array of incident light beams transmitted towards the teeth portion (26) along an optical path through said probing unit (90) to generate illuminated spots on said portion; a light focusing optics (42, 44) defining one or more focal planes forward said probing face at a position changeable by said optics, each light beam having its focus on one of said one or more focal plane; a translation mechanism (70, 72) coupled to said focusing optics for displacing said focal plane relative to the teeth segment (26) along an axis (Z) defined by the propagation of the incident light beams (48); a detector (60) having an array of sensing elements (68) for measuring intensity of each of a plurality of light beams returning from said spots propagating through an optical path opposite to that of the incident
Scientists now realize that fluorescent light bulbs emit ultraviolet (UV) radiation, which is known to cause wrinkles and other signs of photoaging skin damage, such as blotchy skin pigmentation. Many years ago, I figured that out on my own after noticing Id get a mild sunburn after working in my shop when it was illuminated by fluorescent bulbs but not when Id be in there for an even longer time with the lights off, with illumination provided by light filtering in through the windows and especially the open 16-foot-wide door. (Parenthetical comment: Since sunlight contains UV, I suspect the diffused sunlight entering my garage was largely scrubbed of UV by trees, grass, and other plants.) Id also not burn when I worked under even brighter incandescent lighting.. Thus, you should add UV light exposure to the list of problems attributable to fluorescent lights, such as almost inevitable exposure to highly toxic mercury (see my article, How fluorescent bulbs turn us into sheeple/Where has all ...
Glial cells play an important role in the maintenance of normal structure and function of the neural components of the central nervous system. The Müller cells are one of the macroglial elements in the retina and their wide-ranging roles are responsible for the protection and proper functioning of the photoreceptors. In the present study, we aimed to test the effects of pretreatment with 670 nm red light on Müller cells in the light-induced model of retinal degeneration. Adult Sprague-Dawley albino rats were treated with 670 nm red light, from an LED source prior to exposure to bright (1000 lux) continuous light for 24 h. Müller cell-specific markers were used to assess structural and functional changes in this cell type 1 week after contact with damaging light. Changes in gene (Edn2, LIF, TNF-α) and protein (S100β, Vimentin, LIF, iNOS, GS, Cyclin-D1) levels and localization were evaluated using RT-qPCR, and immunohistochemistry. Our results showed that 670 nm light pretreatment ameliorates ...
Previous investigators have reported an increase in numbers of amacrine synapses in the inner plexiform layer (IPL) of the rat retina following light deprivation, and an increase in amacrine along with a decrease in bipolar synapses following light damage. Since there are several points of disagreement between the published reports on this subject we undertook a more detailed study of the effects of light deprivation and light damage on the retina. Four groups of eight male albino rat pups (14 days old) were raised for eight weeks under different conditions: (1) unsutured, bright light reared (UB); (2) bilaterally lid-sutured, bright light reared (SB); (3) unsutured, low light reared (UL); and (4) bilaterally lid-sutured, dark reared (SD). The intensity of the light given the UL group was equated with that striking the corneas of the SB group. Light microscopy showed that the retinas of the SB as well as the UB groups had almost complete degeneration of the outer retinal layers, indicating that ...
Figure S1. PIF5 binds with different frequency to various E-box sequences in vivo. PIF5 binding sites that were assigned to a gene locus were chosen. For each binding site the most central E-box was detected. Sequences with two E-boxes with the same distance to the peak summit were discarded from the analysis. E-box sequences were then counted and sense and antisense sequences as well as their reverse complements were grouped.. Figure S2. Chromatin Immunoprecipitation (ChIP) of PIF5-HA after 2 hours in low R/FR. Immunoprecipitated DNA was quantified by Q-PCR using primers in the promoter region containing a G-box or control region (minimum 1 kb 3 or 5 from the peak region). Data are average of technical triplicates of the Q-PCR. (A / B) Col and/or PIF5-HA lines were grown for 7 days in constant light conditions before being shifted for 2 hours in low R/FR conditions. (C) PIF5-HA lines were grown for 14 days in constant light conditions before being shifted for 2 hours in low R/FR ...
When it comes to bike lights I think the main issue is; How much attention can a bike light garner? Im of the opinion that if a bike light ( or lights ) are bright enough and clearly visible ( to anyone not drugged or not looking straight ahead ) there is a much better chance that the person who saw the light(s) will take measures not to hit the person with the light(s). The better your light strategy..ie..brighter lights, multiple lamps for a larger signature, the better your chances of being seen in low light conditions THUS lowering your chances of being hit my a motorist. I dont need a rocket scientist to tell me that my 200 lumen/blinking seat post lamp coupled with my 70 lumen flasher on my helmet is going to get me seen better than the guy riding wearing dark clothing and using only reflectors on the pedals. Now if the guy with no lights makes it home he lives to see another day. Good for him. That said Ill take my chances using my common sense and he can take his chances with his ...
The present light bulb includes a wide angle dispersed light which uses, as a source of light dispersion, crystalline particulate material incorporated into the molded or formed material of the light bulb. The crystalline particulate material can be incorporated into the light bulb material prior to the molding or forming process or it can be later applied to the surfaces of the light bulb. The crystalline particulate material are chosen to provide high reflectivity and dispersion qualities for the parts of the light bulb and are further chosen and incorporated according to the function of the particular piece or part therein incorporated. A light tuning element may also be used to further enhance the light dispersion qualities of the light bulb. Methods for making the present light bulb are also provided.
If you are looking for a quality replacement LED light for your car, this T10 / BA9S / Bicuspid 8W 400lm 48-SMD5050 LED White Light Car Reading Light / Panel Light is your best choice! Made with 48 SMD5050 LEDs, it gives off ultra bright white light up to 400 lumens with extremely low power consumption. It is also very easy to install. You can directly install it into any T10 or BA9S or bicuspid socket of car interior lights like reading light or panel light without extra wiring and tools. Click and order now ...
Join Lee Lanier for an in-depth discussion in this video Creating light effects, part of VFX Techniques: Crowd Replication with After Effects
Hi everyone ; I started new scifi concept works a few days a go. The concept main think is the woman who stand with her mechas after the mecha arena fight. This mecha is not kind of space type. More like brutal arena fight mecha. And that woman suit is made by vinyl. Im stiil work o this concept. Add these details next days * Some grease effect on mecha * More light effects inside of mecha * color light effects on vinyl suit * neon Score panel top side and light effects Im
A variety of optical probes and optical methods have utility in the examination of various materials, especially materials in the interior of cavities having restricted access through orifices or passageways. An optical probe useful, for example, in examining the epithelia and other tissues of anatomical structures within the body cavities and tubular organs and viscera of mammals is elongated and includes an optical window ( 240, 302, 1002 ), a light source ( 222, 312, 314, 510, 520, 1020, 1200, 1400, 1700 ), a spatial mixer ( 224, 304, 2004, 2104, 2204, 2304 ), and a light collector ( 210, 320, 720, 1120 ). The light from the light source is mixed in the spatial mixer, thereby removing any reflected images and irradiation artifacts to achieving uniform diffuse light in the vicinity of the optical window. The light collector receives light from the target through the spatial mixer, but the field of view of the light collector excludes any residual reflections and fluorescence from the spatial
Plants derive their energy through a process called photosynthesis. This is a chemical reaction that converts carbon dioxide into sugars using light energy. Plants are most receptive to light ...
The Emerald Tablets say:. Thy Light, O man, is the great Light, shining through the shadow of flesh. Free must thou rise from the darkness before thou art One with the Light. Light is life, for without the great Light nothing can ever exist. Know ye, that in all formed matter, the heart of Light always exists. Aye, even though bound in the darkness, inherent Light always exists.. Ever his destiny shall lead him onward until he is One with the Light. Aye, though his way lies midst the shadows, ever before him glows the Great Light. Dark though the way be yet shall he conquer the shadows that flow around him like night.. Far in the future, I see man as Light-born, free from the darkness that fetters the Soul, living in Light without the bounds of the darkness to cover the Light that is Light of their Soul.. Hear ye the Word that shall fill thee with Life. Hear ye the Word that shall banish the darkness. Hear ye the voice that shall banish the night.. When at the end of thy work appointed, thou may ...
Newswise - Biologists and psychologists know that light affects mood, but a new University of Virginia study indicates that light may also play a role in modulating fear and anxiety. Psychologist Brian Wiltgen and biologists Ignacio Provencio and Daniel Warthen of U.Va.s College of Arts & Sciences worked together to combine studies of fear with…
Photosynthesis is much more important to humans than we would imagine. It affects everything in the biological chain, either directly or indirectly. How the process is affected with slight changes is also integral in our understanding of how we can better harness the process for desired environmental results.
Chris Stoll - Hypno (Diego Costa Remix) (Diego Costa Remix), eNc (Irl) - Diversion (Thomas Stoffer Remix), Following Light - Salutary (Ilya Geruss Color Of The Night Mix), Following Light, Razzer - Esc (Magnetic Brothers Remix), Ignacio Toledo - Ozone (Original Mix), K.Oshkin - You Still Alive (Following Light Remix), Matt Hieu - Big Happy Family (Mantij In Tokio Remix), Matthew Matheson - Liquid Melody (Following Light Remix), Mozaiek - Forest (Original Mix), Neptun 505 - Resonance (Original Mix)
Experimental animals. Experiments were performed using Wistar rats, C57BL/6J mice, and p75NTR knock-out mice (purchased from the Jackson Laboratory) in accordance with the ARVO statement for the Use of Animals in Vision Research. Animals were maintained in either a 12 hr light/dark cycle (LD 12:12) or 24 hr of constant illumination. Light intensity inside the cages ranged from 100 to 200 lux under LD 12:12, whereas 800-1300 lux was used for 24 hr of constant illumination to effect light-induced retinal degeneration (Harada et al., 1996, 1998a).. Immunohistochemistry. Rats were anesthetized with diethylether and perfused transcardially with saline, followed by 4% paraformaldehyde in 0.1 m phosphate buffer containing 0.5% picric acid at room temperature. Rat eyes were removed and postfixed overnight in the same fixative and then embedded in paraffin. The posterior portion of the eye was sectioned sagittally at 7 μm thickness, mounted, and stained with hematoxylin and eosin. For ...
I m confused about cyclic and non-cyclic photophosporilation. Do they happen at the same time? And what connects them? Thanks a lot for the help...
An alternative approach was planned during the early stages of the project: the combination of LuxAB with another protein: YFP from Vibrio fischeri. This would shift the wavelength produced by LuxAB towards the green regions of the spectrum, to activate our green light sensor. During our discussions with UNAM-Genomics Mexico we realised that they planned on making the same part, so we stopped working on it, planning on testing its combination with our green light sensor later on. We unfortunately have not yet reached that stage, but the part is available in the registry as BBa_K360010.. In addition to the above, we created a codon-optimised mutant of the firefly luciferase, reported by Fujii et al. (2007) to be 12.5 times brighter than the wildtype. This may help to alleviate the problems foreseen with a lack of luminescence intensity failing to activate the light sensors of the corresponding wavelength.. LUCIE (LUCiferase with Intense Emission) has three mutations compared to the wild type: ...
Learn about the health impacts fluorescent lights can have, affecting your productivity, welfare, and body. See what solutions are available.
The invention relates to a method and an apparatus for controlling light from a light source (1) to a lighting location. A preferred embodiment of the invention comprises precisely one central light source (1) which is connected to a plurality of light guides (4) via a control unit (3), each of said light guides being terminated at a remote point. The control unit comprises a plurality of electrically controlled microshutters (14, 15), each of which has at least two states, an open state and a closed state, from which the light is conducted further on to the light location or locations via optical guides in the open state of the diaphragms. The light may thus be distributed by means of the control unit (3) to the individual light guides (4) in response to control signals supplied to the control unit.
Almost all our food, feed, fuel and fiber ultimately derive from plants. Plant growth depends on photosynthesis, the process in which light energy is harnessed for the synthesis of high-energy carbon compounds. In order to capture light, plants have evolved unique ways of building cells, tissues and organs, a highly diverse metabolism, and a life-long continuation of versatile growth and development. Plants possess numerous photoreceptors enabling them to sense changes in the amount, spectral composition (color), photoperiod and direction of light. The central goal of our research is to understand how plants manage to gain access to direct sunlight when this resource becomes limiting. This occurs at high plant density leading to specific growth and developmental strategies such as the Shade Avoidance Syndrome (SAS) and Phototropism. We use the model plant Arabidopsis thaliana to study the molecular events leading from light perception to the physiological responses elicited by unfavorable light ...
Researchers have succeeded in developing a complex molecular motor that can work in one direction and its opposite. The system can even be controlled precisely, in the same way as a gearbox.
The field of photonics starts with the efficient generation of light. The generation of efficient yet highly controllable light can indeed be accomplished with light-emitting diodes (LEDs), which are, in principle, capable of generating white light with a 20 times greater efficiency than conventional light bulbs. Deployed on a global scale to replace conventional sources, such solid-state light sources will result in enormous benefits that, over a period of 10 years, include (1) gigantic energy savings of 1.9 x 10*20 joule, (2) a very substantial reduction in global-warming CO2 emissions, (3) a strong reduction in the emission of pollutants such as acid-rain-causing SO2, mercury (Hg), and uranium (U), and (4) financial savings exceeding a trillion (10*12) US$. These benefits can be accomplished by the "replacement paradigm" in which conventional light sources are replaced by more energy efficient, more durable, and non-toxic light sources. However, it will be shown that solid-state light sources ...
It is an object of the present invention to provide a light emitting element which can be driven at a low voltage. Other objects of the present invention are to provide a light emitting element with a high luminescent efficiency; a light emitting element with a high luminance; a light emitting element having long-life luminescence; a light emitting element and an electronic device having reduced power consumption; and a light emitting element and an electronic device which can be manufactured at low cost. The light emitting element has a light emitting layer and a barrier layer between a first electrode and a second electrode, the light emitting layer contains a base material and an impurity element, and the barrier layer is provided so as to be in contact with the first electrode. Light emission is obtained when a voltage is applied such that a potential of the second electrode becomes higher than a potential of the first electrode.
A symbol reader which projects an illumination window or field that is the same size as a field of view of a sensor used to read a symbol. The illumination window is aligned with the field of view of the sensor. The window or field can provide an area of relatively constant illumination or edges of the window or field can be at a higher illumination creating an outline or capture border. The outline alone can be projected when the ambient light level is sufficient for capture of the symbol. The window or field can be created by projecting light from various light sources.
Get an answer for Describe how light is transduced to action potentials in the retina of the eye, including the roles of retinal, opsin, and the dark current and bleaching reaction. and find homework help for other Science questions at eNotes
The current study, in which Dr. Fuad Fares and Adina Yokler, Orna Harel and Hagit Schwimmer also participated, set out to establish or refute this hypothesis. In order to do so, four groups of lab mice injected with cancerous cells were examined: one group was exposed to "long days" of 16 hours of light and 8 hours of darkness, simulating exposure to artificial light beyond the natural number of light hours in a day; a second group was exposed to the same "long days" but were treated with melatonin; a third group was exposed to "short days" of 8 light hours and 16 dark hours; and a fourth group was exposed to the same "short days" but during the dark hours was exposed to a half-hour interval of light.. The results show once again the clear link between LAN and cancer: the cancerous growths in mice exposed to "short days" were smallest (0.85 cubic cm. average), while those mice exposed to the interval of LAN during dark hours had larger growths (1.84 cubic cm. average) and those exposed to "long ...
RoombaPhotovore: Turns your Roomba into a light follower by controlling it via IR. * Uses a 38 KHz carrier generated by directly setting timer 2s registers. * Author: Tom Lauwers, [email protected] * Date: 1/3/2011 * * Modified: 01/24/2012 by Max Eliaser of OReilly Media, Inc. * Capitalize preprocessor macro names. * Add LEFT_LIGHT_PIN, RIGHT_LIGHT_PIN, LIGHT_THRESHOLD, LIGHT_DIFF_THRESHOLD, and IR_OUTPUT_PIN * macros where previously there had been hardcoded numbers. */ // The length of the raw IR signals #define SIGNAL_LENGTH 15 // The pins for the LED and photoresistors #define IR_OUTPUT_PIN 11 #define LEFT_LIGHT_PIN 0 #define RIGHT_LIGHT_PIN 1 // Twiddle this to adjust for the peculiarities of your photoresistors and the ambient light levels #define LIGHT_THRESHOLD 800 // was originally 100; I changed it to 800 to compensate for a bright room // Twiddle this to adjust how different the photoresistors should be to trigger a turn #define LIGHT_DIFF_THRESHOLD 100 // Arrays ...
We evaluated the effect of different light combinations on powdery mildew resistance and growth of melon seedlings. Light-emitting diodes were used as the light source and there were five light combinations: white light (420-680 nm); blue light (460 nm); red light (635 nm); RB31 (ratio of red and blue light, 3: 1); and RB71 (ratio of red and blue light, 7: 1). Compared with other treatments, blue light significantly decreased the incidence of powdery mildew in leaves of melon seedlings. Under blue light, H2O2 showed higher accumulation, and the content of phenolics, flavonoid and tannins, as well as expression of the genes involved in synthesis of these substances, significantly increased compared with other treatments before and after infection ...
As mentioned earlier, visible light is made up of the wavelengths that range from 400 nm to 700 nm. Each wavelength is characterized by a unique color, with violet on one end (adjacent to ultraviolet light) and red on the other (adjacent to infrared light). When all these wavelengths are combined together, they make up what is known as white light. You can separate these wavelengths (and the corresponding colors) by letting them pass through either a prism or a diffraction grating. The magnificent array of colors that we see in a rainbow, on a diamond, or even a peacocks tail are examples of this separation. All phenomena of visible light such as reflection, refraction, interference, and diffraction are also exhibited by non-visible wavelengths. Hence, by understanding these phenomena, and applying them to the non-visible wavelengths, scientists were able to unearth many of natures secrets. In fact, if we trace back the roots of modern physics, particularly the wave-particle duality of matter, ...
The research carried out by honours students Blake Williamson and Oliver Webb, also showed drivers are more inclined to jump red lights in areas of slower lower speed limits.. Between 2010-2012 and there were 665 crashes in New Zealand after cars failed to stop at red lights, involving nine fatalities. Numerous studies have investigated the behaviour of drivers that run red lights, Williamson says.. "Vehicle speed, road conditions, time of day, direction of movement and type of vehicle can all impact on why a large number of drivers run red lights. Little research has been carried out involving differences in sunlight levels during peak times and the subsequent effect they may have on red light running behaviour.. "To investigate further, we studied three intersections with traffics lights in Christchurch. Each intersection had a unique speed limit. One survey for each intersection was carried out during the autumn month of May and the same process repeated in the darker winter month of July. ...
A light emitting device includes a substrate; a light emitting element disposed on the substrate; and a wavelength conversion member disposed on or above the substrate, the wavelength conversion member covering the light emitting element spacing apart therefrom, and having a level difference at an outer peripheral portion of a lower end of the wavelength conversion member, the lower end being joined to the substrate via a light transmitting member. In addition, the light emitting device includes a light blocking member disposed on the substrate and disposed between the light emitting element and the light transmitting member. Further, the wavelength conversion member is configured so that the lower end thereof extends from a top of the light transmitting member to a side of the light transmitting member.
This is the best bicycle light I have ever found!! I really like how easy this light is to mount and to remove from the bike. The Lumenx Mountain Bike Light has many features that I really like. I grew up riding bikes with my family and these lights have come a long way from what the bicycle lights used to be. The new version of bicycle light made by Lumenx is a very sleek design and not too bulky. It has many great features like being able to zoom in or out and make the light wider or smaller. This is great for riding at night when you want to be able to see more of your surroundings. Besides having the zoom feature this front light also has a solid "on" setting or a "flash" setting. The flash setting helps people notice you more at night and is also a great safety feature when riding at night. Lumenx Mountain Bike Light also comes out of the mount and can be used as a flashlight in the case of an emergency. The red back light also has 2 settings, and "on" or "flash" setting. Also great for ...
BackgroundPlants have evolved complex mechanisms to adapt growth and development to the light environment. The COP1/SPA complex is a key repressor of photomorphogenesis in dark-grown Arabidopsis plants and acts as an E3 ubiquitin ligase to ubiquitinate transcription factors involved in the light response. In the light, COP1/SPA activity is inhibited by photoreceptors, thereby allowing accumulation of these transcription factors and a subsequent light response. Previous results have shown that the four members of the SPA family exhibit partially divergent functions. In particular, SPA1 and SPA2 strongly differ in their responsiveness to light, while they have indistinguishable activities in darkness. The much higher light-responsiveness of SPA2 is partially explained by the much stronger light-induced degradation of SPA2 when compared to SPA1. Here, we have conducted SPA1/SPA2 domain swap experiments to identify the protein domain(s) responsible for the functional divergence between SPA1 and ...
Light and brassinosteroids (BRs) have been proved to be crucial in regulating plant growth and development; however, the mechanism of how they synergistically function is still largely unknown. To explore the underlying mechanisms in photomorphogenesis, genome-wide analyses were carried out through examining the gene expressions of the dark-grown WT or BR biosynthesis-defective mutant det2 seedlings in the presence of light stimuli or exogenous Brassinolide (BL). Results showed that BR deficiency stimulates, while BL treatment suppresses, the expressions of light-responsive genes and photomorphogenesis, confirming the negative effects of BR in photomorphogenesis. This is consistent with the specific effects of BR on the expression of genes involved in cell wall modification, cellular metabolism and energy utilization during dark-light transition. Further analysis revealed that hormone biosynthesis and signaling-related genes, especially those of auxin, were altered under BL treatment or light ...
Red Scaly Skin in Light-exposed Areas: Nutritional deficiencies can cause several health problems such as stunted bone growth, skin problems, digestive problems, dementia and more.
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All manner of artificial light sources are now being used to grow plants indoors, but not all of them are created equal.. Here you can see the output spectrum of a few of the most popular grow lighting technologies.. As you can see, compact fluorescent lights operate mainly in the blue end of the spectrum, which is predominantly used for the seed-to-vegetative stages of plant growth. High pressure sodium lights are the most commonly used for flowering and harvest stages of plant growth. Their strength lies in their sheer power and strong output in the amber range, into the red frequencies.. Also shown is one of the more popular LED grow lights. You can see it is very strong in the red frequencies and somewhat strong in the blues. This belief that only reds and blues from LED grow lights is necessary for plant growth is a common misconception, based on very old data, and taken out of context.. ...
Induction of sleep by acute light in Opa1+/+ and Opa1+/− mice.(A) The average immobility-defined sleep is plotted against zeitgeber time in a normal 12∶12 h
The Project Yellow Light Billboard Design Contest Scholarship is available to high school juniors and seniors and full - time undergraduate students. To be considered, you must design a billboard ...
A system for directing light in an interactive display system so as to perform multiple functions. In addition to projecting images on the interactive display system, the system is used to distribute infrared (IR) light onto the display surface, and/or to receive and focus received IR light reflected from a physical object on the display surface. A light separating system separates a multi-waveband light from a source into a predominantly visible light and a predominantly non-visible light, the latter being redirected around visible light modulators and recombined with the modulated visible light for projection onto the display surface by a lensing system. In addition, or in the alternative, the light separating system separates predominantly non-visible light reflected from an object adjacent to the surface, from light produced by the source, directing only the non-visible light received to the light sensor used to image the display surface.
Buy Generic Round Shape LED Light Up Coasters Light Flash Cup Mat - Black Shell + White Light for KSh 439 (19/12/2017) online at Jumia Kenya✔ Best service✔ Enjoy payment on delivery✔
Delivering seizure-triggering images to epileptics through Twitter is a crime. But most of us, even the Twitter trolls, dont know why such flashes of light affect the brain.
In one embodiment, apparatus is provided with a light source, an optic element, at least one photosensor, and a control system. The optic element has a reflective material on a surface thereof, and is positioned to receive and reflect light emitted by the light source. The at least one photosensor is mounted to the surface of the optic element on which the reflective material resides, over a portion of the optic element on which the reflective material does not reside. The control system is operably associated with both the photosensor(s) and the light source, to regulate the light sources light output in accordance with measurements received from the photosensor(s).
Light during the day and darkness during the night is supporting a good night of sleep and a day full of energy. Most people recognize they feel much more energetic during a bright, sunny, day and often enjoy a sound sleep afterwards. Dark, gloomy days, especially in winter may induce feelings of lethargy, low spirit and sleepiness.. The reason why some people experience mild changes in energy levels, sleep need, and mood in winter, and others do not, is not really known. Whether it actually is the lack of light that is causing the symptoms is also unclear. What is known is that light exposure through the eyes, either by the sun or by an artificial light source, is able to counteract reduced feelings of well being.. In people experiencing seasonal changes, bright light during the short winter days, and in particular during the morning hours, may fight the low energy levels and improve mood. Already 30 minutes of light is capable of increasing subjective energy levels.. If one recognizes the ...
Posted by Marta Lisa on Aug 14, 2017 in Uncategorized , Comments Off on Light and Neuroprotection - Parkinsons and Beyond. This is a really wonderful review of how light is received by the body both directly and indirectly to help with cell regeneration in the brain and entire body. Impact Factor for 2016 is 1.769 Click here to view optimized website for mobile devices Journal is indexed with PubMed and Science Citation Index Expanded Table of Contents PERSPECTIVE Year : 2017 , Volume : 12 , Issue : 4 , Page : 574-575 Why and how does light therapy offer neuroprotection in Parkinsons disease? John Mitrofanis Ph.D. Department of Anatomy F13, University of.... read more ...
High-pressure sodium lights have a better color rendition than low-pressure sodium lights. The high-pressure lights produce a more desirable golden to white light, while the color produced by low-pressure lights is yellow to orange. High-pressure sodium lights are more popular than low-pressure lights because of this significant color difference.. ...
Excessive exposure to blue light has also been shown to be harmful to the eyes. The short wavelength of the blue light is very energy-intensive for the eyes. Some studies have shown that the blue light causes damage to the retina and the macula. There are even doctors talking about a generation of macular degeneration due to excessive screen exposure. Worth adding are our childrens eyes are even more sensitive to blue light.. My solutions. • Be sure to get more natural light to restore the natural rythm. Be sure to go out when it is sunny. I usually try to catch some morning sun if possible.. • Reduce screen and TV time. Get fixed routines about how much screen time you allow yourself.. • Block blue light with glasses and screen filters. Blue blocking glasses are something I use every day especially in the afternoon. There are many apps that can help reduce the blue light from mobile phone or computer. I use F.lux on my computer and always have the mobile in night-shift mode. • Replace ...
The freeMD virtual doctor has found 40 conditions that can cause Bowels Have Become Light and Urine is Abnormally Light. There are 7 somewhat common conditions that can cause Bowels Have Become Light and Urine is Abnormally Light. There are 5 uncommon conditions that can cause Bowels Have Become Light and Urine is Abnormally Light. There are 28 rare conditions that can cause Bowels Have Become Light and Urine is Abnormally Light.
neat concept, although it seems the closing is entirely counter-productive day or night.. efficient street lights should always point down, with no light lost in the upward direction, which causes light pollution.. likewise, efficient solar panels should never really "close up," just follow the direction of the sun.. so basically if the tops of these street lights were more like stationary orbs, or slightly flattened orbs, where the upper hemispheres collect light and the lower hemispheres distribute light, then a portion of the solar collectors would always be facing the sun during the day, and light would radiate downward and outward at night. ...
Hazards: Do not look directly into the laser light. Chemicals and Solutions: Materials: laser. record. Procedure: Dim the lights in the room and shine the laser on the screen to show students the point of light. Now shine the laser on a record such that the light bounces off the record and on to the screen. A line of spots will be seen. Hint: Discussion: When the light hits the grooves in the record it is scattered and interference occurs among the resulting light waves. Both constructive and destructive interference occurs leading to a pattern of dark spaces and light spots. ...
Light chains associated with normal serum immunoglobulin can be resolved into a finite number of discrete focusing bands by isoelectric focusing. Four distinct light chain patterns can be distinguished among the inbred mouse strains. In the present studies inheritance of the characteristic light chain patterns has been studied in the AKXL recombinant inbred lines (derived from C57L/J and AKR/J parental lines) and in the inbred Ly-2a,3a congenic line B6.PL-Ly-2aLy-3a/Cy as well as in individual backcross animals of an incipient Ly-2a,3a congenic strain. Virtually complete concordance was observed for the expression of light chains characteristic of phenotype B (AKR-J-like) and the expression of the Ly-2a,3a allele. This observation indicates that a locus controlling light chain structure and/or expression is closely linked (less than 2.6 map units) to the Ly-2,3 locus on mouse Chromosome 6. The locus controlling normal light chain IF-patterns has been designated Ef1.
Intels new research prototype demonstrates that light beams can be used to replace electrons to transport data in computers of the future.
Transformants are often growing the wrong colour. LovTap controls the production of RFP in the cells. When LovTap is inactive (i.e. in the dark), the cells should be producing RFP and hence should be growing red. When LovTap is active (i.e. in white or blue light), the cells stop producing RFP and hence chould produce white colonies. At the moment some cells in the light are still growing red, although some are definitely growing white, and vice versa in the dark. One suggestion was that the plasmids are unstable and dividing randomly, altering the intensity of the colour in some cells. Attempts to stabilise the colours of the colonies are ongoing (see the video in the gallery which demonstrates one of the innovative methods of providing proper culture conditions).. ...
Purpose : The intrinsic photosensitive retinal ganglion cells (ipRGCs) are known to integrate the light signals over time in order to synchronize the circadian rhythm. We tested the hypothesis that the pupillary light response (PLR) is larger as result of intermittent light stimuli compared to continuous light exposure. Methods : PLR was recorded in 36 healthy subjects, one patient with choroideremia (rod-cone degeneration) and one glaucoma patient (melanopsin dysfunction) using three different pupillometry protocols. Each protocol began with five minutes of dark-adaptation. Protocol-1 consisted of 20 s continuous illumination (463 nm, 100 lux) followed by post-illumination pupillary response (PIPR) recording in 40 s. Protocol-2 included seven sequences of 5 s light-on and 5 s light-off, followed by PIPR recording in 40 s. Protocol-3 consisted of three sequences of 10 s light-on and 40 s light-off periods. Maximum contraction amplitude during the illumination period constituted the mixed ...
Exposure to constant light has a range of negative effects on behaviour and physiology, including reduced immune function in both vertebrates and invertebrates. It is proposed that the associated suppression of melatonin (a ubiquitous hormone and powerful antioxidant) in response to the presence of light at night could be an underlying mechanistic link driving the changes to immune function. Here, we investigated the relationship between constant illumination, melatonin and immune function, using a model invertebrate species, the Australian black field cricket, Teleogryllus commodus. Crickets were reared under either a 12 h light: 12 h dark regimen or a constant 24 h light regimen. Circulating melatonin concentration and immune function (haemocyte concentration, lytic activity and phenoloxidase (PO) activity) were assessed in individual adult crickets through the analysis of haemolymph. Constant illumination reduced melatonin and had a negative impact on haemocyte concentrations and lytic activity, but
PURPOSE: To compare retinal light damage in rats with either normal or reduced levels of rod outer segment (ROS) docosahexaenoic acid. METHODS: Weanling male albino rats were maintained in a weak cyclic light environment and fed either a nonpurified control diet or a purified diet deficient in the linolenic acid precursor of docosahexaenoic acid (DHA). Half the rats on the deficient diet were given linseed oil, containing more than 50 mol% linolenic acid, once a week to maintain ROS DHA at near normal levels. Diets and linseed oil supplementation were continued for 7 to 12 weeks. To replenish DHA in their ROS, some 10-week-old rats on the deficient diet were given linseed oil three times a week for up to 3 additional weeks. Groups of animals were killed at various times for ROS fatty acid determinations or were exposed to intense green light using intermittent or hyperthermic light treatments. The extent of retinal light damage was determined biochemically by rhodopsin or photoreceptor cell DNA ...
This page includes the following topics and synonyms: Pupillary Light Reflex, Swinging Flashlight Test, Marcus Gunn Pupil, Direct Light Reflex, Consensual Light Reflex, Direct Light Pupillary Reflex Loss, Relative Afferent Pupillary Defect, Afferent Pupillary Defect.
The aphototropic mutant line ptrll6 of the moss Ceratodon purpureus shows characteristics of a deficiency in the phytochrome chromophore. Photoreversibility measurements indicate an approximately 20 time lower concentration of spectrally active phytochrome compared to wild-type, whereas normal phytochrome apoprotein levels are found on immunoblots. Feeding with the tetrapyrroles biliverdin, the proposed precursor of the phytochrome chromophore, or phycocyanobilin, which may replace the phytochrome chromophore, resulted in the rescue of ptrll6 phototropism.. The ptrll6 mutant and the phenotypically-related mutant ptrl contain lower chlorophyll levels than the wild-type. Chlorophyll content of wildtype and mutant tissue grown under different light conditions was estimated using conventional spectrophotometry of extracts and fluorimetrically, on single apical cells. Dark-grown tissue contained about 100 times less chlorophyll than tissue grown under standard white light conditions. Red light given ...
Phytochrome B (phyB) is the major photoreceptor that senses a reduction in the R:FR ratio, and controls the initial appearance of SAS phenotypes...SAS responses to low R:FR (increased petiole elongation and leaf hyponasty) depend on increased auxin biosynthesis through the TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS 1 (TAA1) pathway, and polar auxin transport by the auxin efflux carrier PIN3. Increased gibberellin (GA) production, perhaps in response to increased auxin, is also required for the expression of petiole elongation responses to low R:FR...Increased GA production triggers degradation by the 26S proteasome of DELLA proteins, a group of five nuclear proteins that redundantly repress growth. DELLA proteins bind to and inactivate PHYTOCHROME INTERACTING FACTORS (PIFs), which are growth-promoting transcription factors involved in the elicitation of SAS responses to low R:FR...plants can present strong SAS-like responses to blue light attenuation...blue light responses required cry1, and ...
The ndhB- and psaE- mutants of the cyanobacterium Synechocystis sp. PCC 6803 are partly deficient in PSI-driven cyclic electron transport. We compared photoinhibition in these mutants to the wild type to test the hypothesis that PSI cyclic electron transport protects against photoinhibition. Photoinhibitory treatment greatly accelerated PSI cyclic electron transport in the wild type and also in both the mutants. The psaE- mutant showed rates of PSI cyclic electron transport similar to the wild type under all conditions tested. The ndhB- mutant showed much lower rates of PSI cyclic electron transport than the wild type following brief dark adaptation but exceeded wild type rates after exposure to photoinhibitory light. The wild type and both mutants showed similar rates of photoinhibition damage and photoinhibition repair at PSII. Photoinhibition at PSI was much slower than at PSII and was also similar between the wild type and both mutants, despite the known instability of PSI in the psaE- ...
The effects of cadmium (from 7.5 to 75 lM) on chloroplasts of rice were studied at the structural and biochemical level. Loss of pigments, reduction of thylakoids and decrease in oxygen evolution and Fv/Fm ratio occur in leaves following cadmium treatment. However, the amount of photosystem II reaction center proteins and that of its light harvesting complex is not affected, indicating that cadmium does not adversely influence the structural organization of this photosystem. In thylakoids isolated from cadmium-treated plants a loss in the capability to reduce 2,6- hlorophenolindophenol is observed, which is partially restored if diphenylcarbazide is used as an electron donor, indicating that cadmium affects water splitting activity. In thylakoids isolated from control plants and treated with cadmium, diphenylcarbazide preserves most of the photosystem II activity lost after incubation with cadmium; most of the S2 multiline electron paramagnetic resonance signal from the manganese cluster is ...

Light-year - WikipediaLight-year - Wikipedia

Units such as the light-minute, light-hour and light-day are sometimes used in popular science publications. The light-month, ... "Gly" for a gigalight-year (1,000,000,000 light years)[19]. History[edit]. The light-year unit appeared a few years after the ... Light travels approximately one foot in a nanosecond; the term "light-foot" is sometimes used as an informal measure of time.[ ... The Universe within 12.5 Light Years: The Nearest Stars *^ a b c d e International Astronomical Union, Measuring the Universe: ...
more infohttps://en.wikipedia.org/wiki/Light-year

Red Light AccidentRed Light Accident

Louis :: Thousands of people in the U.S. are injured or killed because someone ran a red light. In fact, it is the leading ... Red Light Accident. Thousands of people in the U.S. are injured or killed because someone ran a red light. In fact, it is the ... Louis Red Light Accident Lawyer. If you or a loved one have been injured due to another driver running a red light, contact The ... Red Light Accidents. When a person approaches an intersection with a green light, they assume it is safe to proceed. However, ...
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Youre a Dim Bulb (And I mean that in the best possible way) - The Loom : The LoomYou're a Dim Bulb (And I mean that in the best possible way) - The Loom : The Loom

You know what its called when more than 1% of the neurons in your brain fire at once? A seizure.. Also, its really a mistake to equate synaptic events with calculations in a computer. Synaptic events are much, much simpler. When computer scientists talk about a "calculation", they usually mean an amount of computation that takes one clock cycle, which might be to add two long numbers, or decide if one number is bigger or smaller than 0. To the extent we understand what computations synapses compute, theyre probably, at least mostly, small portions of an addition. The simplest model of a neuron basically computes "if the sum of the average firing rate of my input neurons is more than X, fire". Any single synaptic event affecting that neuron is likely to be one of probably thousands of such events that is involved in that computation…. On the other hand, 1% of the neurons in your brain can compute that kind of rule simultaneously, while your desktop computer can compute only one or two things ...
more infohttp://blogs.discovermagazine.com/loom/2006/03/23/youre-a-dim-bulb-and-i-mean-that-in-the-best-possible-way/

Rapid genetic evolution linked to lighter skin pigmentation in a southern African populationRapid genetic evolution linked to lighter skin pigmentation in a southern African population

Populations of indigenous people in southern Africa carry a gene that causes lighter skin, and scientists have now identified ... Gene plays a role in lighter skin pigmentation. Individuals who carry two copies of the lighter pigmentation gene are 14 ... Fish gene sheds light on human skin color variation mystery. December 16, 2005 The genetic determination of human skin color is ... Researchers shed new light on the origins of modern humans. March 20, 2019 Researchers from the University of Huddersfield, ...
more infohttps://phys.org/news/2018-12-rapid-genetic-evolution-linked-lighter.html

The Science of Light : Light in ColorThe Science of Light : Light in Color

Colored Shadows (Requires Java.) Funny things happen when colored lights cast shadows. You will use a simulation of such lights ... You will look at light, separated into a spectrum, and figure out the elements from the spectral lines you see. ...
more infohttp://www.learner.org/teacherslab/science/light/color/index.html

Light - WikipediaLight - Wikipedia

Light pressure is equal to the power of the light beam divided by c, the speed of light. Due to the magnitude of c, the effect ... Speed of light. Main article: Speed of light. The speed of light in a vacuum is defined to be exactly 299,792,458 m/s (approx. ... Light sources. Further information: List of light sources. There are many sources of light. A body at a given temperature emits ... Visible light waves are less than 700 nanometers long and impart energy in the form of photons, the quanta of light. Shown ...
more infohttps://en.wikipedia.org/wiki/Light

Light paintingsLight paintings

An artist has used the great outdoors as his canvas - painting spectacular scenes by using nothing except LIGHTS. Jeremy ...
more infohttps://www.yahoo.com/news/photos/light-paintings-1392058418-slideshow/?.tsrc=vmus&ref=gs

Spook LightSpook Light

Newspaper articles about the Spook Light. Other Spook Lights around the world. Stories about the Spook Light. ... Directions to the Spook Light from Joplin, Missouri, Neosho, Missouri and Miami, Oklahoma. ... Spook Light Updates. Visit Real Spook Light on Facebook, Twitter, and YouTube you can also contact the Real Spook Light by ... The Hornet Spook Light is not the only strange light around. There are others in the US and around the world. click here to see ...
more infohttps://sites.google.com/site/realspooklight/

Angelz LightAngelz Light

... She led her life with gentle hands. Soft and warm, soothing to the touch. The silver in her hair sparkled with ... When she spoke the smile on her lips light up our hearts and our lives.. Those who would remember her heart, carry her gracious ...
more infohttp://www.angelfire.com/in2/angelz/angelzlight.html

Light PartyLight Party

Its the annual Emmanuel Light Party in the Hall, on Tuesday 30th October 2018, from 4 to 5.30pm. Use the form to register one ...
more infohttps://docs.google.com/forms/d/e/1FAIpQLScrxlsQE0Xhiiz1bw0fkbjcKBf3NllpRGRNJIWuFKUb4mQ1wQ/viewform

Risen light
	
			Risen light

The difference is in the light. In Moria Gandalf evoked light. Light was conjoured and held in the wizard s staff. Light though ... Light can only be victorious if it is carried into battle, not as a weapon but as an inspiration. All light seems attracted to ... Light falls down onto the wizard yet at the same time rises like a column above him.. The light flowing from Gandalf seems to ... The horse and rider on the edge of the picture are picked out in a bluish light, it s source is the reflection of Gandalf. ...
more infohttp://www.angelfire.com/film/stormcrow/whitelight.html

light - Wiktionarylight - Wiktionary

... "light"), German Licht ("light"). Related also to Swedish ljus ("light"), Icelandic ljós ("light"), Latin lūx ("light"), Russian ... light (third-person singular simple present lights, present participle lighting, simple past and past participle lit or lighted ... light (third-person singular simple present lights, present participle lighting, simple past and past participle lit or lighted ... light (comparative lighter, superlative lightest). *Of low weight; not heavy. My bag was much lighter once I had dropped off ...
more infohttps://en.wiktionary.org/wiki/light

Kaurit® LightKaurit® Light

Die Präsentation zeigt die Vorteile von Kaurit® Light verglichen mit regulären Holzplatten und erklärt seine Technol… ... 4. Kaurit® LightVorteile im Überblick Kaurit® Light spart 30% Gewicht Kaurit® Light spart 35% Holz Kaurit® Light spart ... Light Platten der Kaurit® Light Platten  Kaurit® Light Platten sind besonders geeignet für Feuchträume. ... Kaurit® Light * 1. Kaurit® Light-der leichteHolzwerkstoff * 2. Kaurit® LightBündelung von BASF KernkompetenzenKompetenz in der ...
more infohttps://www.slideshare.net/basf/kaurit-light

light saillight sail

Bill Nyes New Light Sail Is Bigger and Better... The Planetary Society has revealed the LightSail 2, scheduled to lau… ... We could hear alien light sails, but someday they might hear ours. ...
more infohttps://www.popularmechanics.com/content/light-sail/

Bud LightBud Light

... * TV The Bud Knight Lives: Anheuser Revives Ad Mascot After Super Bowl Demise 6 months ago ... ESPN, Bud Light Turn Ad Character Into New Rookie for NFL Draft 1 year ago ...
more infohttps://variety.com/t/bud-light/

Light readingLight reading

... Which e-reader performs best under the suns intense rays? We slather on some SPF and take four devices to a ... At 10.2 ounces, the Kindle is the lightest e-reader I tried-holding it in one hand and drinking a beer with the other is a snap ... Sun test Of all the electronic ink e-readers I tested, the Daily is most difficult to read in bright light (but still pretty ...
more infohttps://www.timeout.com/chicago/books/light-reading

Light curveLight curve

In astronomy, a light curve is a graph of light intensity of a celestial object or region, as a function of time. The light is ... The point on the curve where these two differing slopes meet is called the light saturation point and is where the light- ... Thus, astronomers measure the amount of light produced by an object as a function of time (the light curve). The time ... In botany, a light curve shows the photosynthetic response of leaf tissue or algal communities to varying light intensities. ...
more infohttp://www.princeton.edu/~achaney/tmve/wiki100k/docs/Light_curve.html

Travelling light - TelegraphTravelling light - Telegraph

Getting ready for a summer break but cant live without your essentials? No problem. Weve found a selection of goodies that will keep you covered a fortnight or longer
more infohttp://www.telegraph.co.uk/news/health/pictures/3354868/Travelling-light.html

First...'First...

near first light, thick arms cradling rolls. and crusty loaves, a gift for late-returning revelers,. for the derelict who ...
more infohttp://www.slate.com/articles/arts/poem/2002/12/first_light.html

Phoenix LightPhoenix Light

... The Phoenix Light is similar in size, shape and weight to the Budd Light. It uses a standard 9-volt battery. It ... As with the Budd Light, the Phoenix Light can be viewed by night vision goggles, but not the FLIR system. Air-to-Ground and ... The Phoenix Lights innovation is a programmable coded flashing signal that can be easily entered and changed by the soldier in ... http://www.fas.org/man/dod-101/sys/land/phoenix-light.htm. Maintained by Robert Sherman. Originally created by John Pike. ...
more infohttps://fas.org/man/dod-101/sys/land/phoenix-light.htm

Ambient Light EventsAmbient Light Events

When the current light level changes, the user agent MUST queue a task to fire a device light event at the top-level browsing ... The light-level media feature [. MEDIAQUERIES4. ] provides more granular, less precise, information about the ambient light ... current light level. is a value that represents the ambient light levels around the hosting device in lux units. ... This specification defines a means to receive events that correspond to a light sensor detecting the presence of a light. ...
more infohttp://www.w3.org/TR/2015/WD-ambient-light-20150903/

Ultraviolet LightUltraviolet Light

Uv light water treatment camping Diy repair bmw Homemade led lamp for nails price Buy uv light brisbane weather Uv light ... Use the form below to delete this Soldiers Machine Gun Army Weapons M249 Light image from our index. Use the form below to ... ... Use the form below to delete this BREN Light Machine Gun Description Use And Mechanism UK0000 Mycity image from our index. ... Dying Light: The Following - Enhanced Edition will be available from digital stores a.... ...
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Ultraviolet LightUltraviolet Light

... tlo Uv curing light safety 2014 Light concept nails anchorage Lamps plus pleasant hill ca Uv light for nails cancer Repair your ... glue Bonding aluminium to glass fibre Light uv Uvc bulbs pond filters work Opi axxium ax900 gel nail uv lamp light red Light ... Ultraviolet tube lights journey. What is the best glue for glass yard art wholesale ... SpectraLight UV systems use remarkable, innovative technology that incorporates ultraviolet light to create a swimming pool, ...
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Light showLight show

Dazzling light shows and fireworks illuminate Qingdao Beer City of the coastal citys Huangdao district on Aug 4 at the opening ...
more infohttp://www.chinadaily.com.cn/m/qingdao/2017-08/10/content_30423868.htm
  • There is no research that shows exposure to light boxes can harm the retina or cause or accelerate eye disease. (unh.edu)
  • The light box encases a set of fluorescent bulbs or tubes that are covered with a plastic screen that helps block out potentially harmful ultraviolet (UV) rays. (unh.edu)
  • For optimal results, you sit directly in front of the light box (about 23 inches is optimal) with your eyes open. (unh.edu)
  • For most people, light therapy is best used in the morning, after first waking up. (unh.edu)
  • Visible light is usually defined as having wavelengths in the range of 400-700 nanometres (nm), or 4.00 × 10 −7 to 7.00 × 10 −7 m, between the infrared (with longer wavelengths) and the ultraviolet (with shorter wavelengths). (wikipedia.org)
  • Generally, EM radiation, or EMR (the designation "radiation" excludes static electric and magnetic and near fields ), is classified by wavelength into radio, microwave , infrared , the visible region that we perceive as light, ultraviolet , X-rays and gamma rays . (wikipedia.org)
  • Above the range of visible light, ultraviolet light becomes invisible to humans, mostly because it is absorbed by the cornea below 360 nanometers and the internal lens below 400. (wikipedia.org)
  • Many animals with eyes that do not require lenses (such as insects and shrimp) are able to detect ultraviolet, by quantum photon-absorption mechanisms, in much the same chemical way that humans detect visible light. (wikipedia.org)
  • Nearby shorter and longer wavelength ranges, although not visible, are commonly called ultraviolet and infrared light. (wiktionary.org)
  • SpectraLight UV systems use remarkable, innovative technology that incorporates ultraviolet light to create a swimming pool, spa, or pool and spa combination that is safer, healthier, and easer to maintain than traditional sanitizing methods. (amazonaws.com)
  • Sections in between vary from issue to issue, and have included "Spectrum" roundups on types of light verse (Little Willies, "impossible rhymes," etc. (wikipedia.org)
  • The point on the curve where these two differing slopes meet is called the light saturation point and is where the light-dependent reactions are producing more ATP and NADPH than can be utilized by the light-independent reactions . (princeton.edu)
  • Shown above is the relative magnetic flux of a light wave, stronger at the peaks and weaker at the nodes. (wikipedia.org)
  • The time separation of peaks in the light curve gives an estimate of the rotational period of the object. (princeton.edu)
  • For example, an asymmetrical asteroid's light curve generally has more pronounced peaks, while a more spherical object's light curve will be flatter. (princeton.edu)
  • While light skin is often associated with European ancestry, even in South Africa, the present-day Khoekhoe and San did not experience enough recent migration to account for the frequency of the gene. (phys.org)
  • The light is usually in a particular frequency interval or band. (princeton.edu)
  • Here the stripped panelling was warmly gold and the pictures, mostly of the English school, were mellow and gentle in the afternoon light . (wiktionary.org)
  • Tony and Emmy Award winner Judith Light made her professional stage debut in 1970 and made her Broadway debut in the 1975 revival of A Doll's House (1973) starring [nm0880521 and Sam Waterston . (imdb.com)
  • Populations of indigenous people in southern Africa carry a gene that causes lighter skin, and scientists have now identified the rapid evolution of this gene in recent human history. (phys.org)
  • Different physicists have attempted to measure the speed of light throughout history. (wikipedia.org)
  • The light-year is a unit of length used to express astronomical distances and measures about 9.46 trillion kilometres or 5.88 trillion miles . (wikipedia.org)
  • Because it includes the word " year ", the term light-year is sometimes misinterpreted as a unit of time. (wikipedia.org)
  • The light-year is most often used when expressing distances to stars and other distances on a galactic scale, especially in nonspecialist and popular science publications. (wikipedia.org)
  • Before 1984, the tropical year (not the Julian year) and a measured (not defined) speed of light were included in the IAU (1964) System of Astronomical Constants, used from 1968 to 1983. (wikipedia.org)
  • 7015946052840500000♠ 9.460 528 405 × 10 15 m , is the product of the J1900.0 mean tropical year and the defined speed of light. (wikipedia.org)
  • The light-year unit appeared a few years after the first successful measurement of the distance to a star other than the Sun, by Friedrich Bessel in 1838. (wikipedia.org)
  • He recognized that his readers would enjoy the mental picture of the approximate transit time for light, but he refrained from using the light-year as a unit. (wikipedia.org)
  • Thousands of people run red lights every year. (hoffmannpersonalinjury.com)
  • Frequent consideration of a thing [ … ] shows it in its several lights and various ways of appearance. (wiktionary.org)
  • In botany , a light curve shows the photosynthetic response of leaf tissue or algal communities to varying light intensities. (princeton.edu)
  • Dazzling light shows and fireworks illuminate Qingdao Beer City of the coastal city's Huangdao district on Aug 4 at the opening ceremony of the 2017 Qingdao International Beer Festival. (chinadaily.com.cn)
  • Bessel added that light employs 10.3 years to traverse this distance. (wikipedia.org)
  • He may have resented expressing distances in light-years because it would deteriorate the accuracy of his parallax data due to multiplying with the uncertain parameter of the speed of light. (wikipedia.org)
  • The gene that causes lighter skin pigmentation, SLC24A5, was introduced from eastern African to southern African populations just 2,000 years ago. (phys.org)
  • UC Davis anthropologist Brenna Henn and colleagues have shown that a gene for lighter skin spread rapidly among people in southern Africa in the last 2,000 years. (phys.org)
  • While the biological cause of the selective event merits further investigation, we have demonstrated an unusual rapid case of selection for lighter skin pigmentation based on a recently introduced allele less that 2,000 years ago, the first case of pigmentation adaptation from migration in humans," the paper concludes. (phys.org)
  • Magoon's governorship in Cuba was viewed in a negative light by many Cuban historians for years thereafter. (wiktionary.org)
  • Individuals who carry two copies of the lighter pigmentation gene are 14 percent lighter-skinned than the population average, the researchers said. (phys.org)
  • beside the hive-domed ovens of Chaldea and of Ur- near first light, thick arms cradling rolls and crusty loaves, a gift for late-returning revelers, for the derelict who washes in the creek under the bridge his daily bread at daybreak. (slate.com)
  • Light curves can be periodic, as in the case of eclipsing binaries , cepheid variables and other periodic variables, or aperiodic , like the light curve of a nova , a cataclysmic variable star , a supernova or a microlensing event . (princeton.edu)
  • When a wave of light is transformed and absorbed as a photon, the energy of the wave instantly collapses to a single location, and this location is where the photon "arrives. (wikipedia.org)
  • With the development of electric lights and power systems , electric lighting has effectively replaced firelight. (wikipedia.org)
  • For all that, the rapid arrival of electric light to Indian villages is long overdue. (wiktionary.org)
  • Use the form below to delete this BREN Light Machine Gun Description Use And Mechanism UK0000 Mycity image from our index. (amazonaws.com)
  • Use the form below to delete this Soldiers Machine Gun Army Weapons M249 Light image from our index. (amazonaws.com)
  • The fixed value of the speed of light in SI units results from the fact that the metre is now defined in terms of the speed of light. (wikipedia.org)
  • Sun test Of all the electronic ink e-readers I tested, the Daily is most difficult to read in bright light (but still pretty readable): The contrast between background and ink isn't so sharp and the screen is a bit too shiny. (timeout.com)
  • The study of light, known as optics , is an important research area in modern physics. (wikipedia.org)
  • The study of the light curve, together with other observations, can yield considerable information about the physical process that produces it or constrain the physical theories about it. (princeton.edu)
  • Visit Real Spook Light on Facebook , Twitter , and YouTube you can also contact the Real Spook Light by messaging us on facebook with any questions, comments, corrections or additions. (google.com)
  • The calm that comes over me when I'm curled up under the covers with my trusty book light. (google.com)
  • The verse in each issue begins with a feature on a writer of light verse. (wikipedia.org)