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A harmless variant or derivative of a pathogen that stimulates a host's immune system to mount defenses against the pathogen; Substance designed to trigger formation of antibodies without inducing disease.
A membrane-enclosed sac taking up most of the interior of a mature plant cell and containing a variety of substances important in plant reproduction, growth, and development.
Part of the female reproductive system between the uterus and the outside opening
The outermost energy shell of an atom, containing the valence electrons involved in the chemical reactions of that atom
1. Value (in psychology)
Preciseness and exactitude of statistical results.
Any disease affecting any of the four valves of the heart that ensure that blood flows in the correct direction.
Van der Waals dispersion force or Van der Waals interactions
Weak attractions between molecules or parts of molecules that are brought about by localized charge fluctuations; the weakest of the imtermolecular forces.
Artificial vanilla flavouring frequently used as an ingredient in chocolate.
The change from a liquid to a gas; evaporation.
A symbol used to represent a value.
Variable-number-of-tandem-repeats (VNTR) locus
Locus that is hypervariable because of tandemly repeated DNA sequences.
The proportion of individuals with a specific genotype and environmental conditions who manifest that genotype at the phenotype level.
A region in an immunoglobin molecule that shows many sequence differences between antibodies of different specificities; the part of the antibody that binds to the antigen.
Variable surface glycoprotein (VSG)
One of a battery of antigenic determinants expressed by a microorganism to elude immune detection.
A statistical measure of the dispersion of a set of values about its mean; a measure of the variability of the data.
The variance model is one of four least squares linear regression types. The four types of linear regression are the linear, exponential, logarithmic, and the power line fits.
The variance expression of the response, computed as a function of the mean response of a variance line, is either the variance or the coefficient of variation (CV) of the responses at a single point.
A variance line is an equation which describes the average variance of a response point as a function of the mean of that response. The response variance is computed from the means and variances of the reference assay responses. The heteroscedasticity of the test method, the random error, and the systematic error are the principle elements contributing to the variance line.
Diversity among the members of a population.Variation among individuals can exist at many levels, including genetic, physiologic and behavioral.
Dilated and twisted veins of the testis . Manifests itself as a swelling on the side of the scrotum which may look and feel like a "bag of worms". May be surgically corrected if causing discomfort. This condition may also cause reduced sperm count and male sterility due to sluggish blood flow elevating testicular temperature.
The occurrence within a tissue of sectors or clones with differing phenotypes. Patchiness; a type of position effect that results when particular loci are contiguous with heterochromatin.
Containing or concerning vessels that conduct fluid.
Membrane-bound fluid-filled space within a cell. In most plant cells, there is a single large vacuole filling most of the cell's volume.
Vas deferens (Plural = vas deferentia)
The tube in the male reproductive system in which sperm travel from the epididymis to the urethra.
Vector (in mathematics & physics)
A quantity that is determined by its magnitude and direction: forces and fields.
Vector (in molecular biology)
In recombinant DNA, a small, self-replicating DNA molecule, or a portion thereof, into which a DNA segment can be spliced and introduced into a cell; generally a plasmid or a virus. An agent used as a vehicle to introduce recombinant DNA into a host cell; The DNA "vehicle" used to carry experimental DNA and to clone it.
Transmission of microorganisms via an intermediate host (flea, mosquito, tick, etc.)
In contrast to the dormant spore, which has no metabolic activity until activated when food is cooked, the vegetative cell is in an active metabolic state in which the bacteria are growing and multiplying at a rate depending on the food temperature, acidity, water, additives, etc.
Active state of a bacterium where the cell takes in nourishment grows
The solution in which a drug is administered. The solvent used to dissolve drugs often water or isotonic (0.9%) saline solution. May itself be administered to some animals in a control experiment. See also placebo.
Transmission of microorganisms by an inanimate object, such as equipment used in treating the patient.
A vessel that returns blood to the heart.
The rate of change of distance with respect to time. The first derivative of the position function.
A large vein that brings blood from the tissues to the right atrium of the four-chambered mammalian heart. The superior vena cava collects blood from the forelimbs, head, and anterior or upper trunk; the inferior vena cava collects blood from the posterior body region.
Of the blood vessels that drain tissues and return blood to the heart.
A small hole drilled through an earmold to allow the passage of air and to modify sound reaching the eardrum.
Any method of increasing contact between the respiratory medium and the respiratory surface.
Pertaining to the undersurface of an animal that holds its body in a horizontal position; to the front surface of an animal that holds its body erect..
In the spinal cord the ventral region of the central butterfly-shaped region that appears gray in histology. The ventral horn contains the motor nerve cell bodies (whose axons run out of the spinal cord to control various target muscle structures).
1. Fluid filled spaces in the brain.
A very small vein.
Impaired control of proper sequencing of muscles used in speech (tongue, lips, jaw muscles, vocal cords). The muscles are not weak but their control is defective. Speech is labored and characterized by sound reversals, additions and word approximations.
A common speech disorder in which a person is unable to produce the sequential, rapid, and precise movements required for speech. Nothing is wrong with the vocal apparatus, but the brain cannot give correct instructions for the motor movements involved in speech. This disorder is characterized by many omissions. Some verbally dyspraxia children speak only in vowels, making their speech nearly intelligible, and have very slow, halting speech with many false starts before the right sounds are produced. Their speech errors may be similar to those of children with phonological impairment.
The excessive use of speech (wordiness) in which individuals use words that have little meaning to them.
The preferred plural of vertebra . (The alternate plural is vertebras.) See also: Cervical vertebrae ; Coccygeal vertebrae ; Lumbar vertebrae ; Sacral vertebrae ; and Thoracic vertebrae .
The point on an angle where the two sides intersect.
Intracellular membrane-bound sac.
The backbone. In nearly all vertebrates, it forms the supporting axis of the body and protects the spinal cord.
A chordate animal with a backbone: the mammals, birds, reptiles, amphibians, and various classes of fishes.
Generic term for any repair or reconstruction of a vertebral body. Titanium vertebral cages or bone allografts are common ways of replacing damaged vertebral bodies.
A small, intracellular membrane-bound sac.
A tube in the body that carries fluids: blood vessels or lymph vessels.
Pertaining to the vestibular system in the middle ear (consisting of three semi-circular canals and two otolith organs) and the brain which senses movements of the head. Disorders of the vestibular system can lead to dizziness, poor regulation of postural muscle tone and inability to detect quick movements of the head.
A type of homologous structure that is rudimentary and of marginal or no use to the organism
The ability to survive to adulthood.
Speciation which occurs as a result of the separation and subsequent isolation of portions of an orginal population.
Videoswallow study (Also may be referred to as a modified barium swallow study or oral-pharyngeal motility
A videofluoroscopic study from which a detailed analysis of the structures and function of the oral and pharyngeal mechanisms during the feeding and swallowing processes can be obtained.
Villus (Plural = villi)
In vertebrates, one of the minute, fingerlike projections lining the small intestine that serve to increase the absorptive surface area of the intestine.
Vineland Social Maturity Scale
A standardized assessment procedure for evaluating adaptive behavior.
A viral gene that contributes to malignancies in vertebrate hosts.
A virus particle.
A plant pathogen composed of molecules of naked RNA only several hundred nucleotides long; Infective forms of nucleic acid without a protective coat of protein; Unencapsulated small single-stranded self-splicing RNA molecules.
Pathogenic or poisonous potential of bacteria, fungi, or other agents.
A phage that cannot become a prophage; infection by such a phage always leads to lysis of the host cell.
A submicroscopic, noncellular particle composed of a nucleic acid core and a protein coat (capsid); parasitic; reproduces only within a host cell.
The collective term for the internal organs of an animal.
Visceral arches (also known as branchial arches, gill arches, or pharyngeal arches)
Columns of mesenchyme found in the neck of the developing vertebrate embryo derived from cranial neural crest.
Smooth muscle found in the walls of the digestive tract, bladder, arteries, and other internal organs.
An instrument for rapid and accurate determination of the viscosity of a fluid.
The internal friction of a fluid; Having a relatively high resistance to flow.
That portion of the electromagnetic spectrum detected as various colors by the human eye, ranging in wavelength from about 400 nm to about 700 nm.
The clarity or sharpness of vision.
The ability to identify an object from an incomplete image.
Visual figure ground
Differentiating an object from its surrounding background and hold the image while scanning the total pattern.
Visually following an object as it moves through space.
The maximum volume of air that can be exhaled after a maximal inspiration.
The belief that natural phenomena are governed by a life force outside the realm of physical and chemical laws.
Name that is given to 13 organic substances which are essential in the diet because they cannot be manufactured by the body.
A fat soluble vitamin that can be found in some foods but is mostly made by the skin when exposed to ultraviolet rays from the Sun. The two major forms are D2 and D3. Active vitamin D functions as a hormone because it sends messages to the intestines to increase the absorption of calcium and phosphorus. Vitamin D deficiency is known to cause several bone diseases, including rickets and osteoporosis.
transparent, semigelatinous fluid in the chamber filling the cavity behind the crystalline lens of the eye
Referring to a type of development in which the young are born alive after having been nourished in the uterus by blood from the placenta.
The joining of a variable (V) gene segment and a joining (J) gene segment in the first step of the formation of a functioning immunoglobulin gene.
A thickening at a specific locale on a true vocal cord.
Speech impairments characterized by either an inappropriate pitch (too high, too low, never changing or interrupted by breaks); loudness
An imaging technique (X-ray) displaying the urethra and bladder while urinating.
Differences in potential (or electric state) related to the electrical forces that 'push' charges through a conductor.
Voltage-gated ion channels
Membrane ion channels that open and close in response to changes in membrane potential (voltage)
Measurement of space.
Heating by internal energy generation throughout the volume of a material
An abbreviation for "volume element" or "volume cell."