Gene Frequency: The proportion of one particular in the total of all ALLELES for one genetic locus in a breeding POPULATION.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)Spectrophotometry: The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.Signal Processing, Computer-Assisted: Computer-assisted processing of electric, ultrasonic, or electronic signals to interpret function and activity.Fourier Analysis: Analysis based on the mathematical function first formulated by Jean-Baptiste-Joseph Fourier in 1807. The function, known as the Fourier transform, describes the sinusoidal pattern of any fluctuating pattern in the physical world in terms of its amplitude and its phase. It has broad applications in biomedicine, e.g., analysis of the x-ray crystallography data pivotal in identifying the double helical nature of DNA and in analysis of other molecules, including viruses, and the modified back-projection algorithm universally used in computerized tomography imaging, etc. (From Segen, The Dictionary of Modern Medicine, 1992)Sound Spectrography: The graphic registration of the frequency and intensity of sounds, such as speech, infant crying, and animal vocalizations.Acoustic Stimulation: Use of sound to elicit a response in the nervous system.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Magnetic Resonance Spectroscopy: Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).Spectrophotometry, Infrared: Spectrophotometry in the infrared region, usually for the purpose of chemical analysis through measurement of absorption spectra associated with rotational and vibrational energy levels of molecules. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Electroencephalography: Recording of electric currents developed in the brain by means of electrodes applied to the scalp, to the surface of the brain, or placed within the substance of the brain.Algorithms: A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.Spectral Karyotyping: The simultaneous identification of all chromosomes from a cell by fluorescence in situ hybridization (IN SITU HYBRIDIZATION, FLUORESCENCE) with chromosome-specific florescent probes that are discerned by their different emission spectra.Spectrum Analysis, Raman: Analysis of the intensity of Raman scattering of monochromatic light as a function of frequency of the scattered light.Auditory Threshold: The audibility limit of discriminating sound intensity and pitch.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.Pitch Perception: A dimension of auditory sensation varying with cycles per second of the sound stimulus.Spectrophotometry, Ultraviolet: Determination of the spectra of ultraviolet absorption by specific molecules in gases or liquids, for example Cl2, SO2, NO2, CS2, ozone, mercury vapor, and various unsaturated compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Auditory Perception: The process whereby auditory stimuli are selected, organized, and interpreted by the organism.Speech Acoustics: The acoustic aspects of speech in terms of frequency, intensity, and time.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.Light: That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.Microspectrophotometry: Analytical technique for studying substances present at enzyme concentrations in single cells, in situ, by measuring light absorption. Light from a tungsten strip lamp or xenon arc dispersed by a grating monochromator illuminates the optical system of a microscope. The absorbance of light is measured (in nanometers) by comparing the difference between the image of the sample and a reference image.Vibration: A continuing periodic change in displacement with respect to a fixed reference. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Genotype: The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.Alleles: Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.Color Perception: Mental processing of chromatic signals (COLOR VISION) from the eye by the VISUAL CORTEX where they are converted into symbolic representations. Color perception involves numerous neurons, and is influenced not only by the distribution of wavelengths from the viewed object, but also by its background color and brightness contrast at its boundary.Sound: A type of non-ionizing radiation in which energy is transmitted through solid, liquid, or gas as compression waves. Sound (acoustic or sonic) radiation with frequencies above the audible range is classified as ultrasonic. Sound radiation below the audible range is classified as infrasonic.Reproducibility of Results: The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.Spectrometry, Fluorescence: Measurement of the intensity and quality of fluorescence.Color: The visually perceived property of objects created by absorption or reflection of specific wavelengths of light.Psychoacoustics: The science pertaining to the interrelationship of psychologic phenomena and the individual's response to the physical properties of sound.Acoustics: The branch of physics that deals with sound and sound waves. In medicine it is often applied in procedures in speech and hearing studies. With regard to the environment, it refers to the characteristics of a room, auditorium, theatre, building, etc. that determines the audibility or fidelity of sounds in it. (From Random House Unabridged Dictionary, 2d ed)Tomography, Optical Coherence: An imaging method using LASERS that is used for mapping subsurface structure. When a reflective site in the sample is at the same optical path length (coherence) as the reference mirror, the detector observes interference fringes.Hearing: The ability or act of sensing and transducing ACOUSTIC STIMULATION to the CENTRAL NERVOUS SYSTEM. It is also called audition.Noise: Any sound which is unwanted or interferes with HEARING other sounds.Speech Perception: The process whereby an utterance is decoded into a representation in terms of linguistic units (sequences of phonetic segments which combine to form lexical and grammatical morphemes).Auditory Cortex: The region of the cerebral cortex that receives the auditory radiation from the MEDIAL GENICULATE BODY.Auditory Pathways: NEURAL PATHWAYS and connections within the CENTRAL NERVOUS SYSTEM, beginning at the hair cells of the ORGAN OF CORTI, continuing along the eighth cranial nerve, and terminating at the AUDITORY CORTEX.Polymorphism, Genetic: The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.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.Periodicity: The tendency of a phenomenon to recur at regular intervals; in biological systems, the recurrence of certain activities (including hormonal, cellular, neural) may be annual, seasonal, monthly, daily, or more frequently (ultradian).Autonomic Nervous System: The ENTERIC NERVOUS SYSTEM; PARASYMPATHETIC NERVOUS SYSTEM; and SYMPATHETIC NERVOUS SYSTEM taken together. Generally speaking, the autonomic nervous system regulates the internal environment during both peaceful activity and physical or emotional stress. Autonomic activity is controlled and integrated by the CENTRAL NERVOUS SYSTEM, especially the HYPOTHALAMUS and the SOLITARY NUCLEUS, which receive information relayed from VISCERAL AFFERENTS.Action Potentials: Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.Heart Rate: The number of times the HEART VENTRICLES contract per unit of time, usually per minute.Pitch Discrimination: The ability to differentiate tones.Color Vision: Function of the human eye that is used in bright illumination or in daylight (at photopic intensities). Photopic vision is performed by the three types of RETINAL CONE PHOTORECEPTORS with varied peak absorption wavelengths in the color spectrum (from violet to red, 400 - 700 nm).Mass Spectrometry: An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.Electric Stimulation: Use of electric potential or currents to elicit biological responses.Kinetics: The rate dynamics in chemical or physical systems.Perceptual Masking: The interference of one perceptual stimulus with another causing a decrease or lessening in perceptual effectiveness.Retinal Cone Photoreceptor Cells: Photosensitive afferent neurons located primarily within the FOVEA CENTRALIS of the MACULA LUTEA. There are three major types of cone cells (red, blue, and green) whose photopigments have different spectral sensitivity curves. Retinal cone cells operate in daylight vision (at photopic intensities) providing color recognition and central visual acuity.Evoked Potentials, Auditory: The electric response evoked in the CEREBRAL CORTEX by ACOUSTIC STIMULATION or stimulation of the AUDITORY PATHWAYS.Molecular Structure: The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.Computer Simulation: Computer-based representation of physical systems and phenomena such as chemical processes.Case-Control Studies: Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.Oscillometry: The measurement of frequency or oscillation changes.Sensitivity and Specificity: Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)Sound Localization: Ability to determine the specific location of a sound source.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.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Electrophysiology: The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.Vocalization, Animal: Sounds used in animal communication.Rod Opsins: Photosensitive proteins expressed in the ROD PHOTORECEPTOR CELLS. They are the protein components of rod photoreceptor pigments such as RHODOPSIN.Spectroscopy, Near-Infrared: A noninvasive technique that uses the differential absorption properties of hemoglobin and myoglobin to evaluate tissue oxygenation and indirectly can measure regional hemodynamics and blood flow. Near-infrared light (NIR) can propagate through tissues and at particular wavelengths is differentially absorbed by oxygenated vs. deoxygenated forms of hemoglobin and myoglobin. Illumination of intact tissue with NIR allows qualitative assessment of changes in the tissue concentration of these molecules. The analysis is also used to determine body composition.Analysis of Variance: A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.Electron Spin Resonance Spectroscopy: A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.Audiometry, Speech: Measurement of the ability to hear speech under various conditions of intensity and noise interference using sound-field as well as earphones and bone oscillators.Neurons: The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.Sensory Thresholds: The minimum amount of stimulus energy necessary to elicit a sensory response.Equipment Design: Methods of creating machines and devices.Photic Stimulation: Investigative technique commonly used during ELECTROENCEPHALOGRAPHY in which a series of bright light flashes or visual patterns are used to elicit brain activity.Audiometry, Pure-Tone: Measurement of hearing based on the use of pure tones of various frequencies and intensities as auditory stimuli.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Polymorphism, Single Nucleotide: A single nucleotide variation in a genetic sequence that occurs at appreciable frequency in the population.Cats: The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)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.Phonetics: The science or study of speech sounds and their production, transmission, and reception, and their analysis, classification, and transcription. (Random House Unabridged Dictionary, 2d ed)Haplotypes: The genetic constitution of individuals with respect to one member of a pair of allelic genes, or sets of genes that are closely linked and tend to be inherited together such as those of the MAJOR HISTOCOMPATIBILITY COMPLEX.Genetic Variation: Genotypic differences observed among individuals in a population.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.Cochlear Implants: Electronic hearing devices typically used for patients with normal outer and middle ear function, but defective inner ear function. In the COCHLEA, the hair cells (HAIR CELLS, VESTIBULAR) may be absent or damaged but there are residual nerve fibers. The device electrically stimulates the COCHLEAR NERVE to create sound sensation.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.Signal-To-Noise Ratio: The comparison of the quantity of meaningful data to the irrelevant or incorrect data.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)Artifacts: Any visible result of a procedure which is caused by the procedure itself and not by the entity being analyzed. Common examples include histological structures introduced by tissue processing, radiographic images of structures that are not naturally present in living tissue, and products of chemical reactions that occur during analysis.Circular Dichroism: A change from planar to elliptic polarization when an initially plane-polarized light wave traverses an optically active medium. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Fluorescent Dyes: Agents that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.Echolocation: An auditory orientation mechanism involving the emission of high frequency sounds which are reflected back to the emitter (animal).Color Vision Defects: Defects of color vision are mainly hereditary traits but can be secondary to acquired or developmental abnormalities in the CONES (RETINA). Severity of hereditary defects of color vision depends on the degree of mutation of the ROD OPSINS genes (on X CHROMOSOME and CHROMOSOME 3) that code the photopigments for red, green and blue.Flicker Fusion: The point or frequency at which all flicker of an intermittent light stimulus disappears.Models, Neurological: Theoretical representations that simulate the behavior or activity of the neurological system, processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.Nonlinear Dynamics: The study of systems which respond disproportionately (nonlinearly) to initial conditions or perturbing stimuli. Nonlinear systems may exhibit "chaos" which is classically characterized as sensitive dependence on initial conditions. Chaotic systems, while distinguished from more ordered periodic systems, are not random. When their behavior over time is appropriately displayed (in "phase space"), constraints are evident which are described by "strange attractors". Phase space representations of chaotic systems, or strange attractors, usually reveal fractal (FRACTALS) self-similarity across time scales. Natural, including biological, systems often display nonlinear dynamics and chaos.Mathematics: The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Speech Intelligibility: Ability to make speech sounds that are recognizable.Models, Theoretical: Theoretical representations that simulate the behavior or activity of systems, processes, or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.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.Image Processing, Computer-Assisted: A technique of inputting two-dimensional images into a computer and then enhancing or analyzing the imagery into a form that is more useful to the human observer.Phantoms, Imaging: Devices or objects in various imaging techniques used to visualize or enhance visualization by simulating conditions encountered in the procedure. Phantoms are used very often in procedures employing or measuring x-irradiation or radioactive material to evaluate performance. Phantoms often have properties similar to human tissue. Water demonstrates absorbing properties similar to normal tissue, hence water-filled phantoms are used to map radiation levels. Phantoms are used also as teaching aids to simulate real conditions with x-ray or ultrasonic machines. (From Iturralde, Dictionary and Handbook of Nuclear Medicine and Clinical Imaging, 1990)Transducers: Any device or element which converts an input signal into an output signal of a different form. Examples include the microphone, phonographic pickup, loudspeaker, barometer, photoelectric cell, automobile horn, doorbell, and underwater sound transducer. (McGraw Hill Dictionary of Scientific and Technical Terms, 4th ed)Inferior Colliculi: The posterior pair of the quadrigeminal bodies which contain centers for auditory function.Photometry: Measurement of the various properties of light.Pattern Recognition, Physiological: The analysis of a critical number of sensory stimuli or facts (the pattern) by physiological processes such as vision (PATTERN RECOGNITION, VISUAL), touch, or hearing.Contrast Sensitivity: The ability to detect sharp boundaries (stimuli) and to detect slight changes in luminance at regions without distinct contours. Psychophysical measurements of this visual function are used to evaluate visual acuity and to detect eye disease.Genetic Predisposition to Disease: A latent susceptibility to disease at the genetic level, which may be activated under certain conditions.Reference Values: The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.Cues: Signals for an action; that specific portion of a perceptual field or pattern of stimuli to which a subject has learned to respond.Molecular Conformation: The characteristic three-dimensional shape of a molecule.Equipment Failure Analysis: The evaluation of incidents involving the loss of function of a device. These evaluations are used for a variety of purposes such as to determine the failure rates, the causes of failures, costs of failures, and the reliability and maintainability of devices.Reaction Time: The time from the onset of a stimulus until a response is observed.Ultrasonics: A subfield of acoustics dealing in the radio frequency range higher than acoustic SOUND waves (approximately above 20 kilohertz). Ultrasonic radiation is used therapeutically (DIATHERMY and ULTRASONIC THERAPY) to generate HEAT and to selectively destroy tissues. It is also used in diagnostics, for example, ULTRASONOGRAPHY; ECHOENCEPHALOGRAPHY; and ECHOCARDIOGRAPHY, to visually display echoes received from irradiated tissues.Image Cytometry: A technique encompassing morphometry, densitometry, neural networks, and expert systems that has numerous clinical and research applications and is particularly useful in anatomic pathology for the study of malignant lesions. The most common current application of image cytometry is for DNA analysis, followed by quantitation of immunohistochemical staining.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).Oxidation-Reduction: A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).Risk Factors: An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.Principal Component Analysis: Mathematical procedure that transforms a number of possibly correlated variables into a smaller number of uncorrelated variables called principal components.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.Hydrogen-Ion Concentration: The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Models, Genetic: Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.Audiometry: The testing of the acuity of the sense of hearing to determine the thresholds of the lowest intensity levels at which an individual can hear a set of tones. The frequencies between 125 and 8000 Hz are used to test air conduction thresholds and the frequencies between 250 and 4000 Hz are used to test bone conduction thresholds.Biological Clocks: The physiological mechanisms that govern the rhythmic occurrence of certain biochemical, physiological, and behavioral phenomena.Chiroptera: Order of mammals whose members are adapted for flight. It includes bats, flying foxes, and fruit bats.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.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)Brain: The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.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.Prospective Studies: Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.Entropy: The measure of that part of the heat or energy of a system which is not available to perform work. Entropy increases in all natural (spontaneous and irreversible) processes. (From Dorland, 28th ed)Biophysics: The study of PHYSICAL PHENOMENA and PHYSICAL PROCESSES as applied to living things.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.Respiration: The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (= OXYGEN CONSUMPTION) or cell respiration (= CELL RESPIRATION).Calibration: Determination, by measurement or comparison with a standard, of the correct value of each scale reading on a meter or other measuring instrument; or determination of the settings of a control device that correspond to particular values of voltage, current, frequency or other output.Data Interpretation, Statistical: Application of statistical procedures to analyze specific observed or assumed facts from a particular study.Signal Detection, Psychological: Psychophysical technique that permits the estimation of the bias of the observer as well as detectability of the signal (i.e., stimulus) in any sensory modality. (From APA, Thesaurus of Psychological Index Terms, 8th ed.)Escherichia coli: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.Brain Waves: Wave-like oscillations of electric potential between parts of the brain recorded by EEG.Recombination, Genetic: Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.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.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.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).Tandem Mass Spectrometry: A mass spectrometry technique using two (MS/MS) or more mass analyzers. With two in tandem, the precursor ions are mass-selected by a first mass analyzer, and focused into a collision region where they are then fragmented into product ions which are then characterized by a second mass analyzer. A variety of techniques are used to separate the compounds, ionize them, and introduce them to the first mass analyzer. For example, for in GC-MS/MS, GAS CHROMATOGRAPHY-MASS SPECTROMETRY is involved in separating relatively small compounds by GAS CHROMATOGRAPHY prior to injecting them into an ionization chamber for the mass selection.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.Pigments, Biological: Any normal or abnormal coloring matter in PLANTS; ANIMALS or micro-organisms.Color Perception Tests: Type of vision test used to determine COLOR VISION DEFECTS.Psychophysics: The science dealing with the correlation of the physical characteristics of a stimulus, e.g., frequency or intensity, with the response to the stimulus, in order to assess the psychologic factors involved in the relationship.Electrocardiography: Recording of the moment-to-moment electromotive forces of the HEART as projected onto various sites on the body's surface, delineated as a scalar function of time. The recording is monitored by a tracing on slow moving chart paper or by observing it on a cardioscope, which is a CATHODE RAY TUBE DISPLAY.Brain Mapping: Imaging techniques used to colocalize sites of brain functions or physiological activity with brain structures.Models, Statistical: Statistical formulations or analyses which, when applied to data and found to fit the data, are then used to verify the assumptions and parameters used in the analysis. Examples of statistical models are the linear model, binomial model, polynomial model, two-parameter model, etc.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.Sleep Stages: Periods of sleep manifested by changes in EEG activity and certain behavioral correlates; includes Stage 1: sleep onset, drowsy sleep; Stage 2: light sleep; Stages 3 and 4: delta sleep, light sleep, deep sleep, telencephalic sleep.Retrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.Models, Chemical: Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.Electromyography: Recording of the changes in electric potential of muscle by means of surface or needle electrodes.Oxygen: An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.Water: A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Radio Waves: Electromagnetic waves with frequencies between about 3 kilohertz (very low frequency - VLF) and 300,000 megahertz (extremely high frequency - EHF). They are used in television and radio broadcasting, land and satellite communications systems, radionavigation, radiolocation, and DIATHERMY. The highest frequency radio waves are MICROWAVES.Genetics, Population: The discipline studying genetic composition of populations and effects of factors such as GENETIC SELECTION, population size, MUTATION, migration, and GENETIC DRIFT on the frequencies of various GENOTYPES and PHENOTYPES using a variety of GENETIC TECHNIQUES.Animal Communication: Communication between animals involving the giving off by one individual of some chemical or physical signal, that, on being received by another, influences its behavior.Alpha Rhythm: Brain waves characterized by a relatively high voltage or amplitude and a frequency of 8-13 Hz. They constitute the majority of waves recorded by EEG registering the activity of the parietal and occipital lobes when the individual is awake, but relaxed with the eyes closed.Software: Sequential operating programs and data which instruct the functioning of a digital computer.Adaptation, Physiological: The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.Age Factors: Age as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or the effect of a circumstance. It is used with human or animal concepts but should be differentiated from AGING, a physiological process, and TIME FACTORS which refers only to the passage of time.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.Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Heme: The color-furnishing portion of hemoglobin. It is found free in tissues and as the prosthetic group in many hemeproteins.Image Enhancement: Improvement of the quality of a picture by various techniques, including computer processing, digital filtering, echocardiographic techniques, light and ultrastructural MICROSCOPY, fluorescence spectrometry and microscopy, scintigraphy, and in vitro image processing at the molecular level.PhotochemistryEnergy Transfer: The transfer of energy of a given form among different scales of motion. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed). It includes the transfer of kinetic energy and the transfer of chemical energy. The transfer of chemical energy from one molecule to another depends on proximity of molecules so it is often used as in techniques to measure distance such as the use of FORSTER RESONANCE ENERGY TRANSFER.Lighting: The illumination of an environment and the arrangement of lights to achieve an effect or optimal visibility. Its application is in domestic or in public settings and in medical and non-medical environments.Baroreflex: A response by the BARORECEPTORS to increased BLOOD PRESSURE. Increased pressure stretches BLOOD VESSELS which activates the baroreceptors in the vessel walls. The net response of the CENTRAL NERVOUS SYSTEM is a reduction of central sympathetic outflow. This reduces blood pressure both by decreasing peripheral VASCULAR RESISTANCE and by lowering CARDIAC OUTPUT. Because the baroreceptors are tonically active, the baroreflex can compensate rapidly for both increases and decreases in blood pressure.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Cochlea: The part of the inner ear (LABYRINTH) that is concerned with hearing. It forms the anterior part of the labyrinth, as a snail-like structure that is situated almost horizontally anterior to the VESTIBULAR LABYRINTH.Delta Rhythm: Brain waves seen on EEG characterized by a high amplitude and a frequency of 4 Hz and below. They are considered the "deep sleep waves" observed during sleep in dreamless states, infancy, and in some brain disorders.Heterozygote: An individual having different alleles at one or more loci regarding a specific character.Synaptic Transmission: The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.Electrodes, Implanted: Surgically placed electric conductors through which ELECTRIC STIMULATION is delivered to or electrical activity is recorded from a specific point inside the body.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.Electromagnetic Fields: Fields representing the joint interplay of electric and magnetic forces.Image Interpretation, Computer-Assisted: Methods developed to aid in the interpretation of ultrasound, radiographic images, etc., for diagnosis of disease.Micronucleus Tests: Induction and quantitative measurement of chromosomal damage leading to the formation of micronuclei (MICRONUCLEI, CHROMOSOME-DEFECTIVE) in cells which have been exposed to genotoxic agents or IONIZING RADIATION.Ocular Physiological Phenomena: Processes and properties of the EYE as a whole or of any of its parts.Biophysical Phenomena: The physical characteristics and processes of biological systems.Wakefulness: A state in which there is an enhanced potential for sensitivity and an efficient responsiveness to external stimuli.Fractals: Patterns (real or mathematical) which look similar at different scales, for example the network of airways in the lung which shows similar branching patterns at progressively higher magnifications. Natural fractals are self-similar across a finite range of scales while mathematical fractals are the same across an infinite range. Many natural, including biological, structures are fractal (or fractal-like). Fractals are related to "chaos" (see NONLINEAR DYNAMICS) in that chaotic processes can produce fractal structures in nature, and appropriate representations of chaotic processes usually reveal self-similarity over time.Chromosome Aberrations: Abnormal number or structure of chromosomes. Chromosome aberrations may result in CHROMOSOME DISORDERS.Membrane Potentials: The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Evoked Potentials: Electrical responses recorded from nerve, muscle, SENSORY RECEPTOR, or area of the CENTRAL NERVOUS SYSTEM following stimulation. They range from less than a microvolt to several microvolts. The evoked potential can be auditory (EVOKED POTENTIALS, AUDITORY), somatosensory (EVOKED POTENTIALS, SOMATOSENSORY), visual (EVOKED POTENTIALS, VISUAL), or motor (EVOKED POTENTIALS, MOTOR), or other modalities that have been reported.Blood Pressure: PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.Time Perception: The ability to estimate periods of time lapsed or duration of time.Selection, Genetic: Differential and non-random reproduction of different genotypes, operating to alter the gene frequencies within a population.Linear Models: Statistical models in which the value of a parameter for a given value of a factor is assumed to be equal to a + bx, where a and b are constants. The models predict a linear regression.Theta Rhythm: Brain waves characterized by a frequency of 4-7 Hz, usually observed in the temporal lobes when the individual is awake, but relaxed and sleepy.Discrimination (Psychology): Differential response to different stimuli.Asian Continental Ancestry Group: Individuals whose ancestral origins are in the southeastern and eastern areas of the Asian continent.Polymorphism, Restriction Fragment Length: Variation occurring within a species in the presence or length of DNA fragment generated by a specific endonuclease at a specific site in the genome. Such variations are generated by mutations that create or abolish recognition sites for these enzymes or change the length of the fragment.Questionnaires: Predetermined sets of questions used to collect data - clinical data, social status, occupational group, etc. The term is often applied to a self-completed survey instrument.Chromatography, High Pressure Liquid: Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.Magnetic Resonance Imaging: Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.Sympathetic Nervous System: The thoracolumbar division of the autonomic nervous system. Sympathetic preganglionic fibers originate in neurons of the intermediolateral column of the spinal cord and project to the paravertebral and prevertebral ganglia, which in turn project to target organs. The sympathetic nervous system mediates the body's response to stressful situations, i.e., the fight or flight reactions. It often acts reciprocally to the parasympathetic system.
Spectral coordinates. Wavelength. 590-620 nm. Frequency. 505-480 THz. Colour coordinates. ...
... for determining the spectral content (i.e., the distribution of power over frequency) of a time series Statistical signal ... frequency domain, and complex frequency domain. This technology mainly discusses the modeling of linear time-invariant ... 2003). Time frequency signal analysis and processing a comprehensive reference (1 ed.). Amsterdam: Elsevier. ISBN 0-08-044335-4 ... Billings, S. A. (2013). Nonlinear System Identification: NARMAX Methods in the Time, Frequency, and Spatio-Temporal Domains. ...
Spectral reuse can therefore be limited. Visible and infrared light waves are much shorter than radio frequency waves. Their ... Radio frequencies (RF), from low frequencies through the microwave region, have wavelengths much longer than visible light. ... The apparent reduction in transmission, as frequency is increased, is an artifact of the change in the aperture of a given type ... On the other hand, the lower carrier frequencies are not able to support the high information bandwidths, which are required by ...
Higher frequencies are rejected. This interferogram's truncation determines the spectral resolution. It is also to be noted ... Only the frequencies corresponding to the zero Optical Path Difference (OPD) at the mirror, up to the farthest dots are sampled ... in 2005, but it had a very limited spectral resolution. In 2004, two French researchers, Etienne Le Coarer from Joseph Fourier ...
Li J, Levine MD, An X, Xu X, He H (2012). "Visual Saliency Based on Scale-Space Analysis in the Frequency Domain". IEEE Trans ... Hou X, Zhang L (2007). "Saliency Detection: A Spectral Residual Approach" (PDF). Ieee Cvpr. Li J, Levine MD, An X, Xu X, He H ( ... Gregoriou GG, Gotts SJ, Zhou H, Desimone R (Mar 2009). "High-frequency, long-range coupling between prefrontal and visual ... Gregoriou, GG (2009). "High-frequency, long-range coupling between prefrontal and visual cortex during attention". Science. 324 ...
a b c d e f g Spectral quantities given per unit frequency are denoted with suffix "ν" (Greek)-not to be confused with suffix " ... Spectral directional absorptance AΩ,ν. or. AΩ,λ N/A 1 Spectral radiance absorbed by a surface, divided by the spectral radiance ... Spectral flux density Ee,ν[nb 3] watt per square metre per hertz W⋅m−2⋅Hz−1 M⋅T−2 Irradiance of a surface per unit frequency or ... Spectral intensity Ie,Ω,ν[nb 3] watt per steradian per hertz W⋅sr−1⋅Hz−1 M⋅L2⋅T−2 Radiant intensity per unit frequency or ...
Hilbert spectral analysis (HSA) is a method for examining each IMF's instantaneous frequency as functions of time. The final ... 2008). "An amplitude-frequency study of turbulent scaling intermittency using Hilbert spectral analysis". Europhysics Letters. ... Hilbert transform Hilbert spectral analysis Hilbert spectrum Instantaneous frequency Nonlinear Wavelet transform Fourier ... "Time-frequency spectral analysis of TMS-evoked EEG oscillations by means of Hilbert-Huang transform". J Neurosci Methods. 198 ( ...
... time-frequency atom, pulsar, impulse, toneburst, tone pip, acoustic pixel, and others. In the frequency domain they may be ... Microtime is the level of "sonic" or aural "syntax" or the "time-varying distribution of...spectral energy.". Ryoji Ikeda ... Specifically this is shorter than one tenth of a second and longer than 10 milliseconds, including the audio frequency range ( ... 20 Hz to 20 kHz) and the infrasonic frequency range (below 20 Hz, rhythm). These sounds include transient audio phenomena and ...
A Spectral/temporal method for Robust Fundamental Frequency Tracking. The Journal of the Acoustical Society of America, 123 (6 ... Beat detection Frequency estimation Linear predictive coding D. Gerhard. Pitch Extraction and Fundamental Frequency: History ... However, during 50 ms, speech with higher fundamental frequencies may not necessarily have the same fundamental frequency ... and frequency domain processing utilizing spectral information to identify the pitch. Then, among the candidates estimated from ...
Spectral grids for WDM applications: DWDM frequency grid G.694.2 WDM用途のスペクトル・グリッド:CWDM 波長グリッド. Spectral grids for WDM ...
Very-high frequency ultrasonic imaging and spectral assays of the eye. Acoustical Imaging. 1997 May;23:107-112. Frederic L. ... High-frequency ultrasound spectral parameter imaging of anterior corneal scars. Contact Lens Association of Ophthalmologists ... High-frequency ultrasound imaging and spectral analysis in traumatic hyphema. Ophthalmology, 1993, Sept;100(9):1351-1357. Norma ... Comparison of very high-frequency ultrasound and spectral domain optical coherence tomography corneal and epithelial thickness ...
The figure shows how spectral resolution improves with increasing frequency. Saturation of paramagnetic centers occurs at a ... Therefore, the required parameters are: A high spectrometer frequency to maximize the Eq. 2. Common frequencies are discussed ... The higher spectral resolution over g-factor, which increases with irradiation frequency ν {\displaystyle \nu } and external ... the low-frequency peak is positive in first-derivative spectra, the high-frequency peak is negative, and the central peak is ...
Figure 3 shows the spectrogram of the audio file shown in Figure 1. Spectrogram is the square of STFT, time-varying spectral ... Fundamental frequency is the lowest frequency in harmonic series. In a periodic signal, the fundamental frequency is the ... Time-frequency analysis for music signals is one of the applications of time-frequency analysis. Musical sound can be more ... It displays frequencies on a uniform scale. However, musical scales are based on a logarithmic scale for frequencies. Therefore ...
... is the carrier frequency, f c {\displaystyle f_{c}} is the centroid frequency and θ is the angle between ki and v . When ... The spectral domain fringe signal, P O D T {\displaystyle P_{ODT}} is given by F O D T ( ν ) = 2 S 0 ( ν ) K r ( ν ) K s ( ν ) ... By calculating the phase change, the Doppler frequency shift f n {\displaystyle f_{n}} can be determined : f n = Δ Φ 2 π T ( 7 ... Then the light interferes with the light in the reference beam, causing a Doppler frequency shift F D {\displaystyle F_{D}} in ...
Spectral coordinates. Wavelength. 490-520 nm. Frequency. 610-575 THz. Common connotations. ... since the specific frequencies filtered out to produce that color affect how it interacts with other colors. Phthalocyanine ...
... in everyday environments spectral frequencies are more reliably carriers of environmental information than spectral amplitudies ... Physiologically, each spectral pitch depends on both temporal and spectral aspects (i.e. periodicity of the waveform and ... Virtual pitch is contrasted to spectral pitch, which is the pitch of a pure tone or spectral component. Virtual pitch is called ... The ear has evolved to separate spectral frequencies, because due to reflection and superposition ...
Technically, each individual frequency or band of frequencies could be considered an attribute. The seismic data is usually ... The application of these attributes is commonly called spectral decomposition. The starting point of spectral decomposition is ... a bandpass filter can be applied to view the amplitudes of seismic data at any frequency or range of frequencies. ... That is, thinner rock layers are much more apparent at higher frequencies and thicker rock layers are much more apparent at ...
Frequency analysis of its light curve shows no significant periods. BI Cygni is a red supergiant of spectral type M4 Iab. ...
Spectral radiance expresses radiance as a function of frequency or wavelength. Radiance is the integral of the spectral ... Spectral radiance in frequency of a surface, denoted Le,Ω,ν, is defined as L e , Ω , ν = ∂ L e , Ω ∂ ν , {\displaystyle L_{\ ... Spectral radiance is the radiance of a surface per unit frequency or wavelength, depending on whether the spectrum is taken as ... Spectral quantities given per unit frequency are denoted with suffix "ν" (Greek)-not to be confused with suffix "v" (for " ...
Walker D (2008). Recent developments in low frequency spectral analysis of passive seismic data. First break, 26, 69-77 " ... Passive seismic usually focuses on a low frequency signals (0 to 10 Hz) and is sometimes called the "low frequency" seismology ... The conclusions about the geological structure are based on the spectral analysis or on the mathematical reconstruction of the ... Passive seismic is the detection of natural low frequency earth movements, usually with the purpose of discerning geological ...
"Welch's power spectral density estimate - MATLAB pwelch". Spectral Plot, from the NIST Engineering Statistics Handbook. Short ... Smoothing is an averaging technique in frequency, instead of time. The smoothed periodogram is sometimes referred to as a ... In signal processing, a periodogram is an estimate of the spectral density of a signal. The term was coined by Arthur Schuster ... The definition of interest here is that the power spectral density of a continuous function, x ( t ) , {\displaystyle x(t),} is ...
The noise power spectral density in the frequency range of interest. The average noise power in the frequency range of interest ...
InP is used in high-power and high-frequency electronics[citation needed] because of its superior electron velocity with ... InP based components unlock this spectral range for important new applications. Optoelectronic Applications[edit]. InP based ... Today´s semiconductor technology allows the creation and detection of very high frequencies of 100 GHz and higher. Such ... Indium Phosphide: Transcending frequency and integration limits. Semiconductor TODAY Compounds&AdvancedSilicon • Vol. 1 • Issue ...
Frequency domain analysis is also called spectrum- or spectral analysis. Digital filters come in both IIR and FIR types. FIR ... There are some commonly used frequency domain transformations. For example, the cepstrum converts a signal to the frequency ... In practice, the sampling frequency is often significantly higher than twice the Nyquist frequency. Theoretical DSP analyses ... it captures both frequency and location information.The accuracy of the joint time-frequency resolution is limited by the ...
... low frequencies are limited by primary inductance and high frequencies by leakage inductance and capacitance. Another ... distortion and uneven spectral response is to be avoided. Some musicians also prefer the distortion characteristics of tubes ... The low frequency roll-off can be explained by many tube amplifiers having high output impedance compared to transistor designs ... The effect of dominant pole compensation is that gain is reduced at higher frequencies. There is increasingly less NFB at high ...
Frequency domain. *Spectral density estimation. *Fourier analysis. *Wavelet. *Whittle likelihood. Survival. Survival function. ...
Bispectral index Drummond JC, Brann CA, Perkins DE, Wolfe DE: "A comparison of median frequency, spectral edge frequency, a ... The spectral edge frequency or SEF is a measure used in signal processing. It is usually expressed as "SEF x", which stands for ... the frequency below which x percent of the total power of a given signal are located. (typically x is in the range 75 to 95.) ... frequency band power ratio, total power, and dominance shift in the determination of depth of anesthesia," Acta Anaesthesiol ...
Optical Spectral Structure and Frequency Coherence. By Ning Hua Zhu, Wei Li, Jian Hong Ke, Hong Guang Zhang, Jiang Wei Man and ... www.intechopen.com/embed/optoelectronic-devices-and-properties/optical-spectral-structure-and-frequency-coherence /,. Embed ... Optical Spectral Structure and Frequency Coherence, Optoelectronic Devices and Properties Oleg Sergiyenko, IntechOpen, DOI: ... Optical Spectral Structure and Frequency Coherence, Optoelectronic Devices and Properties Oleg Sergiyenko, IntechOpen, DOI: ...
Nonlinear Laplacian spectral analysis for time series with intermittency and low-frequency variability. Dimitrios Giannakis and ... Low-Frequency Modes.. These modes are characterized by high spectral power over interannual to interdecadal timescales. ... 1, plotted in the temporal and frequency domains. (A) Annual periodic mode, v1; (B) Leading low-frequency (PDO) mode, v3; (C) ... Nonlinear Laplacian spectral analysis for time series with intermittency and low-frequency variability ...
... Jungho Park, Ilwook Park ... S. Durvasula, "Natural frequencies and modes of skew membranes," The Journal of the Acoustical Society of America, vol. 44, no ... U. Lee, Spectral Element Method in Structural Dynamics, John Wiley & Sons, Singapore, 2009. ... U. Lee and J. Lee, "Spectral-element method for Levy-type plates subject to dynamic loads," Journal of Engineering Mechanics, ...
Relating Estimated Cyclic Spectral Peak Frequency to Measured Epilarynx Length Using Magnetic Resonance Imaging ... Conventional wisdom and common practice in acquisition and reconstruction of images from frequency data follow the basic ... time series, and the relationship between wavelet scale and Fourier frequency. New statistical significance tests for wavelet ... Conventional wisdom and common practice in acquisition and reconstruction of images from frequency data follow the basic ...
International Astronomical Union Spectral Lines of Most Importance Between 300 and 1000 GHz: The electromagnetic spectrum is a ... to be used in allocating frequency bands to the Radio Astronomy Service. Spectral lines between 300-1000 GHz are listed in ... Previous: Appendix C: International Astronomical Union Spectral Lines of Most Importance Below 300 GHz Page 241 Share Cite ... Handbook of Frequency Allocations and Spectrum Protection for Scientific Uses: Second Edition sets forth the principles for the ...
Spectral tomography with diffuse near-infrared light: inclusion of broadband frequency domain spectral data Author(s): Jia Wang ... Near-infrared (NIR) region-based spectroscopy is examined for accuracy with spectral recovery using frequency domain data at a ... The results indicate that broadband frequency domain data are required for maximal accuracy. A broadband frequency domain ... The 80-MHz pulsed signal is heterodyned with photomultiplier tube detection, to lower frequency for data acquisition. Tissue- ...
Extending the effective imaging depth in spectral domain optical coherence tomography by dual spatial frequency encoding Author ... OCT spectral interferogram corresponding to the shallow and deep depth of the sample will be shifted to the different frequency ... We present a spatial frequency domain multiplexing method for extending the imaging depth range of a SDOCT system without any ... Two galvo scanners with different pivot-offset distances in the reference arms are used for spatial frequency modulation and ...
... of the temporal effects and the restricted ability to control experimental conditions in order to obtain intrinsic spectral ... lineshapes in surface sum-frequency generation vibrational spectroscopy (SFG-VS) have limited its applications in surface and ... Unified treatment and measurement of the spectral resolution and temporal effects in frequency-resolved sum-frequency ... Unified treatment and measurement of the spectral resolution and temporal effects in frequency-resolved sum-frequency ...
Spectral harmonicity distinguishes two types of ictal phase-amplitude cross frequency couplings in patients candidate to ... Spectral harmonicity distinguishes two types of ictal phase-amplitude cross frequency couplings in patients candidate to ... Spectral harmonicity distinguishes two types of ictal phase-amplitude cross frequency couplings in patients candidate to ... Spectral harmonicity distinguishes two types of ictal phase-amplitude cross frequency couplings in patients candidate to ...
Spectral discrimination of breast pathologies in situusing spatial frequency domain imaging. ... and was generalized to all spectral parameters (n = 5) by:. J. =. ∑. i. =. 1. 5. ∑. j. =. 1. 5. P. i. P. j. J. ij. Open image ... Representative spectral parameter maps for tissue subtypes. Spectral parameter maps corresponding to the pathology subtypes: ... Diagnostic distributions of spectral parameters and immunohistochemistry correlates. (a-e) Boxplots of recovered spectral ...
In one embodiment, the signal is produced by spectrally filtering with a low pass filter, with the cross-over frequency being ... In this way, frequency cut-off of the sub-woofer low pass filter is frequency agile and can be spectrally modified bychanging ... Dynamic allocation of power supplied by a power supply and frequency agile spectral filtering of signals ... Dynamic allocation of power supplied by a power supply and frequency agile spectral filtering of signals ...
... ischemia causes a shift of the high-frequency spectral components of the local electrographic waveform to lower frequencies. ... Spectral analysis of canine epicardial electrogram. Short-term variations in the frequency content induced by myocardial ... Spectral analysis of canine epicardial electrogram. Short-term variations in the frequency content induced by myocardial ... Spectral analysis of canine epicardial electrogram. Short-term variations in the frequency content induced by myocardial ...
Imaging transverse flow velocity using spectral bandwidth of the doppler frequency shift in phase-resolved optical doppler ... Imaging transverse flow velocity using spectral bandwidth of the doppler frequency shift in phase-resolved optical doppler ... Spectral Doppler imaging of micro-vasculature response to laser irradiation also written by J. Stuart Nelson ... The Doppler bandwidth extracted from the standard deviation of the frequency shift in phase-resolved optical Doppler tomography ...
The spectral centroid of a signal is the midpoint of its spectral density function, i.e. the frequency that divides the ... Then the power spectral density can be defined as[11][12] S. x. x. (. ω. ). =. lim. T. →. ∞. E. [. ,. x. ^. (. ω. ). ,. 2. ]. ... The spectral density is a function of frequency, not a function of time. However, the spectral density of small windows of a ... To find the value of the energy spectral density S. x. x. (. f. ). {\displaystyle S_{xx}(f)}. at frequency f. {\displaystyle f} ...
... in both the spectral and spatial domains. We suggest that leveraging, rather than ignoring, such differences may prove useful ... In humans, spindles can be classified as either slow or fast, but large individual differences in spindle frequency as well as ... in both the spectral and spatial domains. We suggest that leveragi... ... In humans, spindles can be classified as either slow or fast, but large individual differences in spindle frequency as well as ...
Spectral display. See your audios frequency content with color and clarity. Digital Performer can display the spectral content ... The Spectrogram display can be invaluable in helping you effectively balance and manage the frequency content of your mix over ... Vertical position represents frequency; brightness represents intensity. This gives you a colorful, informative visual ... representation of the frequency content of your tracks within the context of surrounding tracks - and your entire mix. ...
Your method of sampling in frequency should be preserving that complex symmetric structure. If someone gives you the frequency ... Not the answer youre looking for? Browse other questions tagged frequency-spectrum denoising or ask your own question. ... My question is: is there a principled way to incorporate this knowledge into the spectral analysis algorithm that will estimate ... Evaluation of phase difference between two acquired signals (expected to be sine waves) with the same frequency ...
EVLA high frequency spectral line tutorial - IRC+10216 - calibration. From CASA Guides ... Because the sky frequencies are correct, and we set the rest frequency explicitly later in the deconvolution stage, this does ... Spectral Windows: (2 unique spectral windows and 1 unique polarization setups) SpwID #Chans Frame Ch1(MHz) ChanWid(kHz) TotBW( ... Note that the Rest Frequency and Systemic Velocity are wrong in the listobs log by a factor 10^6 and 1000, respectively, given ...
Spectral spindles frequency. Whence the appearance of two spatiotemporally distinguished types of spindles?. The observations ... OQ-2: What mechanism keeps spindle spectral frequency within so narrow limits, which are stable through the night for a given ... Spectral spindles frequency. Whence the appearance of two spatiotemporally distinguished types of spindles? ... Also the spindles appearing immediately after a K-complex had invariably faster spectral frequency than the sporadic spindles. ...
High Frequency Spectral Ultrasound Imaging to Detect Metastasis in Implanted Biomaterial Scaffolds *Grace G. Bushnell ...
... by strengthening the underlying neural pathways necessary for accurate representation of important temporal and spectral ... by strengthening the underlying neural pathways necessary for accurate representation of important temporal and spectral ... Aiken, S. J., and Picton, T. W. (2008). Envelope and spectral frequency-following responses to vowel sounds. Hear. Res. 245, 35 ... Spectral representation: fundamental frequency and harmonics. The neural encoding of the stimulus spectrum was calculated using ...
Plot responses against frequency ... Spectral filtering is used to reduce the out of band spectral ... It is also shown how the peak spectral density of the transmitted signal falls within the spectral mask to satisfy regulatory ... The high power amplifier model and the spectral filtering affect the out-of-band emissions in the spectral mask plot. For ... A high power amplifier (HPA) model is used, which introduces inband distortion and spectral regrowth. The spectral emission ...
Perform Spectral Analysis. Find Periodicity Using Frequency Analysis. Spectral analysis helps characterize oscillatory behavior ... Visualize, measure, analyze, and compare signals in the time, frequency, and time-frequency domains. ... Estimate the width of the frequency band that contains most of the power of a signal. For distorted signals, determine the ...
Spectral coordinates. Wavelength. 590-620 nm. Frequency. 505-480 THz. Colour coordinates. ...
  • With higher spectral resolution and accurate vibrational spectral lineshapes, it is shown that the parameters of the experimental SFG spectra can be used both to understand and to quantitatively reproduce the temporal effects in lower resolution SFG measurements. (rsc.org)
  • This spectral behaviour may lead to difficulty in distinguishing event-related peaks from ongoing brain activity in the electro- and magnetoencephalographic (EEG and MEG) signal spectra. (biomedcentral.com)
  • First, my thanks to Dr. Ullar Rannik for his interest and insights in my recent study of spectral corrections and associated eddy covariance flux loss (Massman, 2000, henceforth denoted by M2000). (usda.gov)
  • Intellon employs Orthogonal Frequency Division Multiplexing (OFDM) tone masking as opposed to other solutions which use a variable OFDM symbol length. (homeplug.org)
  • His comments are important and germane to the attenuation of low frequencies of the turbulent cospectra due to recursive filtering and block averaging. (usda.gov)
  • A simple analytical formula is developed for estimating the frequency attenuation of eddy covariance fluxes due to sensor response, path-length averaging, sensor separation, signal processing, and flux averaging periods. (usda.gov)
  • The key initial benefit to be the indentification and tagging of DNA losing self-organization by looking for harmonic intervals in it's spectral resonance which decay from the ideal PHI progression, inherent to it's micro AND macro geometry ( images at first links below). (goldenmean.info)
  • IPSCs arriving in pairs of either pyramidal or fast-spiking neurons during the Up state were highly synchronized and exhibited significant coherence at frequencies from 10 to 100 Hz, peaking at ∼40 Hz, suggesting both synchronous discharge of, and synaptic divergence from, nearby inhibitory neurons. (jneurosci.org)
  • After data filtering, image reconstruction and fusion the spatial frequency multiplexing SDOCT system can provide an approximately 1.9 fold increase in the effective ranging depth compared with that of a conventional single-reference-arm full-range SDOCT system. (spie.org)
  • The early sources of spectral emission lines were simply arc lamps or some other form of electrical discharge in a sealed tube of gas in which the pressure is kept low enough so that a significant portion of the radiation is emitted in the form of discrete lines. (britannica.com)
  • This study focused on synchronization abilities to music of finely-varying tempi and varying degrees of low-frequency spectral change/flux. (bsl.nl)
  • in particular, vertical movements of hip and feet were synchronized to the beat level when the music contained large amounts of low-frequency spectral flux and had a slower tempo, while synchronization of head and hands was more tightly coupled to the weak flux stimuli at the bar level. (bsl.nl)
  • Relationships between spectral flux, perceived rhythmic strength, and the propensity to move. (bsl.nl)
  • We are seeking to understand the underlying neural mechanisms that generate gamma-band spectral peaks in the cerebral cortex by studying gamma activity in the local field potential (LFP) in the primary visual cortex, V1. (jneurosci.org)
  • We present a spatial frequency domain multiplexing method for extending the imaging depth range of a SDOCT system without any expensive device. (spie.org)
  • Rick Lyons' article on "Spectral Flipping" at http://www.dsprelated.com/showarticle/37.php discusses methods of handling the inversion (as shown in Figure 1a and 1b) at the signal center frequency. (dsprelated.com)
  • Spectral line shapes of neutral helium 3889 Å(2 3 S-3 3 P) transition line are calculated by using several theoretical methods. (mdpi.com)
  • We propose instead that the source of the gamma-band spectral peak is the resonant V1 network driven by random inputs. (jneurosci.org)
  • We sought to overcome this limitation by examining the mechanisms of spike synchrony during the spontaneous generation of higher-frequency rhythmic activity during the active phase of the slow oscillation. (jneurosci.org)
  • In humans, spindles can be classified as either slow or fast, but large individual differences in spindle frequency as well as methodological difficulties have hindered progress towards understanding their function. (frontiersin.org)
  • Comparisons between MEG recorded actications in the spindle frequency range (12-16 Hz) in core states of NREM2 and awake (A) and NREM1 (B) states. (intechopen.com)
  • Computer simulations using 2-dimensional human atrial models with structural and ionic remodeling as in HF demonstrated that changes in AF activation frequency and dynamics were controlled by the interaction of electrical waves with clusters of fibrotic patches of various sizes and individual pulmonary vein ostia. (ahajournals.org)
  • Here we have characterized how AF frequency and dynamics on the endocardial surface of the PLA and pulmonary vein ostia (PVO) are affected by the amount, type (ie, diffuse versus patchy), and spatial distribution of fibrosis in failing hearts. (ahajournals.org)
  • It is our hypothesis that patchy rather than diffuse fibrosis contributes to wavebreak and intramural rotor formation, and governs the overall AF frequency and dynamics. (ahajournals.org)
  • Chain pairs of distortions together for sonic destruction at 64-bit precision, or split the signal into multiple bands and apply distortion independently to individual frequencies. (izotope.com)
  • The time locked index (TLI) measure was introduced to quantify the degree of harmonicity between frequency bands associated to the emergence of PAC during epileptic seizures. (biorxiv.org)