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)

  • 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. (biogeosciences.net)
  • This is a restricted class for coherent light generator systems wherein an assembly of electrical, mechanical, and optical components produces an intense, coherent, directional beam of light by stimulating electronic, ionic, or molecular transitions to lower energy levels. (uspto.gov)
  • What is the energy source for light dependent reactions? (answersdrive.com)
  • What is the first step in the light dependent reactions? (answersdrive.com)
  • The process, known as the Calvin cycle , uses products of the light-dependent reactions ( ATP and NADPH) and various enzymes. (answersdrive.com)
  • 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. (uspto.gov)
  • Light is absorbed and the energy is used to drive electrons from water to generate NADPH and to drive protons across a membrane. (answersdrive.com)
  • The effect, on the properties of a beam of light, by sound energy, interacting with the light within a volume of matter. (uspto.gov)
  • 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)
  • The Eve Light Switch transforms any single or multi-bulb setup into an intelligent lighting system, so can use your existing bulbs regardless of their shape, size, or color. (apple.com)
  • Ordinary light, such as that from a light bulb, has many wavelengths and spreads in all directions. (fda.gov)
  • Note: LED light bulb is polarity sensitive. (ebay.com)
  • The bulb is organic in operation, meaning it is basically two panels of phosphorescent diodes combined to release light. (ehow.com)
  • The process results in a superior white light that does not heat up the bulb and waste energy. (ehow.com)
  • What's The Best Light Bulb? (lifehacker.com)
  • Cree 60W Equivalent Soft White (2700K) A19 LED Light Bulb (4-Pack). (lifehacker.com)
  • Each BeOn bulb has backup power, so even in the event of a power outage or emergency you'll have some lighting, and if your other home safety appliances-like a smoke detector or carbon monoxide detector-goes off, the lights will respond as well so you can see your way out of the house. (lifehacker.com)
  • Moreover, it is expected that the lights will go out on one of the world's most ground-breaking inventions -- the incandescent bulb -- consigning its environmental profligacy of the past. (cnn.com)
  • And according to Greenpeace, halogen bulbs -- which on average last twice as long as regular bulbs -- account for about seven percent of light bulb sales in the UK. (cnn.com)
  • Light Weight Loudspeaker," SAE Technical Paper 920078, 1992, https://doi.org/10.4271/920078 . (sae.org)
  • METRO's light rail page is at https://www.ridemetro.org/Pages/Rail.aspx . (houstontx.gov)
  • [note As defined by the International Astronomical Union (IAU), a light-year is the distance that light travels in vacuum in one Julian year (365.25 days). (wikipedia.org)
  • This experiment didn't work because light travels too fast for him to measure over one mile. (amnh.org)
  • A light-year is the distance that light travels in one year, or about six trillion miles. (amnh.org)
  • In a vacuum, light travels at a constant speed of 186,000 miles per second. (amnh.org)
  • Light, of course, is more than color: it is energy, which travels at incredible speeds throughout the universe. (encyclopedia.com)
  • The Greeks recognized that light travels through air in rays, a term from geometry describing that part of a straight line that extends in one direction only. (encyclopedia.com)
  • light-year, in astronomy, unit of length equal to the distance light travels in one sidereal year . (infoplease.com)
  • I am now exploring the world of caustics - those magical patterns that are formed when a beam of light travels through transparent textured materials. (abduzeedo.com)
  • Polish developer Techland has announced that Dying Light: The Following - Enhanced Edition will be coming to PlayStation 4, Xbox One, and PC on February 9th, 2016. (amazonaws.com)
  • Dying Light: The Following - Enhanced Edition will be available from digital stores a. (amazonaws.com)
  • Dying Light is a first-person, action survival game set in a vast open world. (microsoft.com)
  • Dying Light gradually and gratifyingly evolves into a fast, hyper-violent celebration of vertical freedom and zombie destruction. (steampowered.com)
  • Techland's pedigree helps Dying Light become one of the better zombie games in recent years. (steampowered.com)
  • Dying Light: The Following - Enhanced Edition is the quintessential open world zombie game. (steampowered.com)
  • Fueled by the dedication of millions of fans who continue playing Dying Light, we've made supporting the game one of our priorities. (steampowered.com)
  • Available DLCs include crossover weapon packs that let you enjoy Left 4 Dead 2, Chivalry: Medieval Warfare, and Unturned gear in Dying Light. (steampowered.com)
  • The Saturn light used an array of 12 cool-white LEDs that provide lighting similar to natural daylight. (cdc.gov)
  • These fingerlike protrusions terminate in sandblasted crystal lobes which softly diffuse the light from enclosed LEDs. (behance.net)
  • LEDs are semi-conductors that convert electricity into light. (cnn.com)
  • The application of LEDs to such a wide range of products owes much, if not all, to the work of Professor Shuji Nakamura who in 1993 astonished the scientific community by creating the first successful blue light-emitting diode. (cnn.com)
  • exactly one year later Construction is quickly progressing on the $912 million facility, which will be the world's most brilliant light source. (scienceblogs.com)
  • The main source of light on Earth is the Sun . Sunlight provides the energy that green plants use to create sugars mostly in the form of starches , which release energy into the living things that digest them. (wikipedia.org)
  • To address these challenges, NIOSH researchers developed the Saturn LED area light with the main objectives of reducing glare and increasing floor illumination to improve the ability of miners to see floor tripping hazards. (cdc.gov)
  • White LED light is created by putting a coating of phosphor over a blue LED light. (cnn.com)
  • The phosphor absorbs most of the blue light but, at the moment still gives off quite a cold light, which remains unsuitable for the home. (cnn.com)
  • Light contains all colors, more colors than the ones our human eyes perceive. (angelfire.com)
  • Soundwaves act as a prism, separating colors from the light into a rainbow so to speak. (angelfire.com)
  • As the light flows through, the needed colors stick to this empty space. (angelfire.com)
  • To prove this, he directed a beam of white light through a prism, then allowed the diffused colors to enter another prism, at which point they recombined as white light. (encyclopedia.com)
  • Newton gave to the array of colors in visible light the term spectrum, (plural, "spectra") meaning the continuous distribution of properties in an ordered arrangement across an unbroken range. (encyclopedia.com)
  • Most of the times you see a firework of colors in space depending on the light around you, and the amount of pressure you press against the eyes. (abduzeedo.com)
  • EMR in the visible light region consists of quanta (called photons ) that are at the lower end of the energies that are capable of causing electronic excitation within molecules, which leads to changes in the bonding or chemistry of the molecule. (wikipedia.org)
  • This loudspeaker consists of a light-weight magnetic circuit with a higher magnetic-flux utilization rate and a high-rigidity light-weight frame. (sae.org)
  • One basic type of laser consists of a sealed tube, containing a pair of mirrors, and a laser medium that is excited by some form of energy to produce visible light, or invisible ultraviolet or infrared radiation. (fda.gov)
  • METRORail consists of three light-rail lines: The Red Line (North), Green Line (East End) and the Purple Line (Southeast). (houstontx.gov)
  • The study, released earlier this week , exposed breeding clownfish pairs to 12 hours of daylight followed by 12 hours under dim artificial lights. (forbes.com)
  • It appears that artificial lights can distract the young turtles from needed optical clues (e.g., the sky reflecting off the ocean) which would normally lead them to the sea shortly after hatching. (encyclopedia.com)
  • In physics , the term light sometimes refers to electromagnetic radiation of any wavelength, whether visible or not. (wikipedia.org)
  • The study of light, known as optics , is an important research area in modern physics. (wikipedia.org)
  • Though it was not as epochal as his contributions to mechanics, Newton's work in optics, an area of physics that studies the production and propagation of light, was certainly significant. (encyclopedia.com)
  • Ted Ducker, who goes by Outabounds on Flickr, has a simpler approach to light painting than Dennis Calvert (will link to Dennis Calvert slideshow). (slate.com)
  • I'm talking about the experiments of Alan Jaras, a "light photographer", on flickr. (abduzeedo.com)
  • A single area of light pollution could lead to impacts to surrounding reefs that are still relatively dark at night. (forbes.com)
  • Impacts of artificial light could spread to other reefs, while attracting young fish to an environment where their young likely won't hatch. (forbes.com)
  • Regulations on the type of light and orientation (facing down, rather than out), may help reduce impacts of light pollution on clownfish and other marine species. (forbes.com)
  • In fact, in this study, the researchers found that impacts on clownfish reproduction disappeared as soon as they returned the clownfish to normal light-dark cycles. (forbes.com)
  • 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)
  • 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 closest star to our Sun, Proxima Centauri, is about four light-years away. (amnh.org)
  • Magoon's governorship in Cuba was viewed in a negative light by many Cuban historians for years thereafter. (wiktionary.org)
  • Alpha Centauri and Proxima Centauri, the stars nearest our solar system, are about 4.3 light-years distant. (infoplease.com)
  • Although physicists had known for 50 years that under some conditions concentrated sound could produce flashes of light, it wasn't until a few years ago that Putterman's group put the topic back in the scientific forefront. (latimes.com)
  • Calvert began experimenting with light only about two years ago. (slate.com)
  • Like many of those now regarded as masters, he's only been playing with light for about two years. (slate.com)
  • Her hair is black as the inmost secret of light in a perfectly cut diamond, a perilous black, a secret light that must have been studied for many years before the anxious and disciplined craftsman could achieve the necessary balance between courage and skill to stroke the strange stone and take the one chance he would ever have to bring that secret to light. (poets.org)
  • His work, which won him the Millennium Prize in 2006, paved the way for what had been something of a holy grail for scientists over the years -- to find an LED which can provide white light that is suitable for use in our homes. (cnn.com)
  • These light levels simulate the artificial light exposure of near-shore reef communities, such as reefs just offshore a small city. (forbes.com)
  • Again, like all of Calvert's images, this effect was created entirely by playing with a long exposure and moving various lights around. (slate.com)
  • People with polymorphic light eruption are at greater risk of vitamin D deficiency, as a certain amount of sun exposure is needed to make your own vitamin D . Your GP will advise whether you need treatment with vitamin D supplements. (www.nhs.uk)
  • An ordinary light switch provides an example of a situation in which there is an excluded middle: there is nothing between "on" and "off. (encyclopedia.com)
  • The primary properties of visible light are intensity , propagation direction, frequency or wavelength spectrum , and polarization , while its speed in a vacuum , 299,792,458 meters per second, is one of the fundamental constants of nature. (wikipedia.org)
  • A Web developer in Culmann, Ala. (dry since Prohibition, Calvert tells me, until just recently), he found the tools he needed for his new hobby in the local Wal-Mart's camping and automotive sections: glow sticks, flashlights, electric tent lights, and other devices used by Alabamans to trick out their dashboards. (slate.com)
  • Various sources define visible light as narrowly as 420 to 680 to as broadly as 380 to 800 nm. (wikipedia.org)
  • The roof bolter light sources were compact fluorescent lamps shrouded by yellowish-orange polycarbonate globes intended to reduce glare and to protect the lamps. (cdc.gov)
  • This Sources Sought Synopsis focused solely on the need to explore cost-effective acquisition options to provide a productionized, weaponized, certified, and existing single-engine, turbo-prop, tandem-seat, pressurized, retractable tricycle gear Advanced Flight Trainer / Light Attack Aircraft (AFT/LAA) capability for ANAAC. (globalsecurity.org)
  • Though, multiple light sources,…with once source being the primary source of light,…can also make figures appear more dimensional. (lynda.com)
  • LED technology is different to the light sources we have had in the past,' Professor Narendran told CNN. (cnn.com)
  • 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)
  • Visit the Real Spook Light on Facebook for updates and discussions managed from 10 miles Southeast of Spook Light Road. (google.com)
  • Because it includes the word " year ", the term light-year is sometimes misinterpreted as a unit of time. (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)
  • The cells absorb the light, which accelerates tissue repair and speeds up recovery time. (angelfire.com)
  • As consciousness is acquired and the body prepared (I will add specific information about this later on as I get the time) the light will no longer have blockages (will write about those too) to go through in order to reach the human body. (angelfire.com)
  • He concluded that when Io was farther away, it was taking more time for its light to reach Earth, making it seem to appear later. (amnh.org)
  • Having developed the light using proven scientific principles, we hope to bring healthy illumination for night-time tasks. (google.com)
  • The idea was born out of the need to have a better, more patient-friendly night-time illumination for caregivers in hospital rooms (notorious for poor sleep and vulnerable to light disruption). (google.com)
  • At the foot of the pier stands a bridge that is only wide enough for a single car at a time, and drivers take turns with no light to direct them (apparently, Kronstadt only has one traffic light on the entire island). (huffingtonpost.com)
  • Those of you who nominated the LIFX noted that it's incredibly versatile, and since you can control the lighting in your home from your smartphone at any time, you can have the lights up in your home before you open the door, program different areas of your home to suit your tastes, and that the mobile apps are available for both iOS and Android, which is a nice perk. (lifehacker.com)
  • It lights instantly with power, so no warm-up time required. (lifehacker.com)
  • Historically, another important source of light for humans has been fire , from ancient campfires to modern kerosene lamps . (wikipedia.org)
  • this is wasted light reflecting off the water particles that form clouds. (encyclopedia.com)
  • Even without clouds, light shoots into the sky and reflects off of tiny airborne dust and moisture particles. (encyclopedia.com)
  • Galileo attempted to measure the speed of light in the seventeenth century. (wikipedia.org)
  • In the early 17th century, Galileo tried to measure the speed of light by flashing lanterns from hilltops about one mile apart. (amnh.org)
  • Our solar-powered lanterns and solar home systems provide light to over 80 million people. (ebay.com)
  • There are some pretty good pictures out there of this effect, and some feature blurred, colorful lights, which are just beautiful. (abduzeedo.com)
  • Wish you could visit the Spook Light but can't make the drive? (google.com)
  • But some materials (like air, glass, or water) can actually make light bend and slow down. (amnh.org)
  • Below, we'll look at some examples using four particularly common light verbs that have a variety of different meanings- do, make, get , and take . (thefreedictionary.com)
  • To make it worse, the light then usually turns on anyway. (apple.com)
  • They also make a great addition to your at-home emergency kit - keeping the light on even when the power goes out. (ebay.com)
  • Suddenly, in the center of the globe, you can just make out a steady blue light shining like a tiny star. (latimes.com)
  • So, for sound to make light requires an almost unbelievable concentration of energy. (latimes.com)
  • One of the coolest ideas is to make sweet light graffiti with this camera option. (abduzeedo.com)
  • As an illustrator obsessed with light…as an element of composition,…I can tell you that if you do incorporate…a light source in your work,…it's essential that you make it believable. (lynda.com)
  • Choosing a single light source,…and working in black and white, can make it easier. (lynda.com)
  • From the deepest recesses of the ocean to hundreds of miles above earth, Canon's renowned imaging technology enables researchers, professional photographers, cinematographers and even astronauts to shoot impactful, clear, crisp imagery, even in extremely low-light conditions. (canon.com)
  • Researchers at the National Institute for Occupational Safety and Health (NIOSH) have developed the Saturn LED area light that significantly improves illumination for roof bolting machines in underground mines, thereby enhancing safety by reducing injuries to miners. (cdc.gov)
  • In an effort to assess the magnitude of the light pollution problem, a comprehensive World Atlas of Artificial Night Sky Brightness was produced in 2001 by researchers at the University of Padua , Italy, and the National Oceanic and Atmospheric Administration (NOAA). (encyclopedia.com)
  • Although 'white light' is already in the marketplace, researchers worldwide are still refining its glow, with the aim of replicating the warmer light of the sun. (cnn.com)
  • d.light is a global leader in affordable solar lighting solutions for off-grid communities. (ebay.com)
  • Whatever the adventure, your d.light solar-powered lantern can handle it. (ebay.com)
  • Wisdom thinks, and makes a solar Drummond Light of a point of dull lime. (infoplease.com)
  • While the lasers themselves can cause injuries, laser light shows that are produced in accordance with FDA regulations keep hazardous lasers away from the audience. (fda.gov)
  • The light which puts out our eyes is darkness to us. (scienceblogs.com)
  • He ``hath called you out of darkness into his marvellous light'' is what I thought. (csmonitor.com)
  • Jesus said, ``I am the light of the world: he that followeth me shall not walk in darkness, but shall have the light of life. (csmonitor.com)
  • Mary Baker Eddy, the Discoverer and Founder of Christian Science, writes, ``Christianity causes men to turn naturally from matter to Spirit, as the flower turns from darkness to light. (csmonitor.com)
  • The Air Force issued its request for proposal to acquire a fleet of turboprop aircraft as part of its light attack effort. (military.com)
  • The new commander of SOCOM wants light attack aircraft to back his forces on the ground. (military.com)
  • The Air Force was supposed to publish a final RFP in December for a light attack aircraft, but it never happened. (military.com)
  • The U.S. Air Force has taken the initial steps to buy commercial, off-the-shelf aircraft for its light attack fleet. (military.com)
  • In April 2010, the US Air Force announced its intention to acquire a Light Air Support (LAS) aircraft for use by the Afghanistan National Army Air Corps (ANAAC) and other future customers. (globalsecurity.org)
  • The purpose of the contract was the acquisition of non-developmental Light Air Support Aircraft (LAS) for existing and future building partnership capacity nations. (globalsecurity.org)
  • Putterman turns on the electricity and turns off the room lights. (latimes.com)
  • The story of how the Ewing, N.J., company has developed ways to create light - by applying electricity through an active matrix to thinner-than-hair layers of molecules - offers a window into the high-risk world of turning ideas into commercial products. (philly.com)
  • They had developed ways to produce light by applying electricity to organic material. (philly.com)
  • For example, you can set your bathroom to soothing, dimmer light, and your office with brighter, more energetic lighting if you prefer. (lifehacker.com)
  • You can take this light we use to perceive the whole world and bend it in a way that creates science fiction and pure fantasy," he says. (slate.com)
  • ants in fact do use polarized light as a compass, augmenting the pedometric function of their legs. (britannica.com)