Specific Gravity: The ratio of the density of a material to the density of some standard material, such as water or air, at a specified temperature.Gravity Sensing: Process whereby a cell, bodily structure, or organism (animal or plant) receives or detects a gravity stimulus. Gravity sensing plays an important role in the directional growth and development of an organism (GRAVITROPISM).Gravity, Altered: A change in, or manipulation of, gravitational force. This may be a natural or artificial effect.Gravitation: Acceleration produced by the mutual attraction of two masses, and of magnitude inversely proportional to the square of the distance between the two centers of mass. It is also the force imparted by the earth, moon, or a planet to an object near its surface. (From NASA Thesaurus, 1988)Tsuga: A plant genus in the family PINACEAE, order Pinales, class Pinopsida, division Coniferophyta. They are coniferous evergreen trees and should not be confused with hemlock plants (CICUTA and CONIUM).Urinalysis: Examination of urine by chemical, physical, or microscopic means. Routine urinalysis usually includes performing chemical screening tests, determining specific gravity, observing any unusual color or odor, screening for bacteriuria, and examining the sediment microscopically.Dehydration: The condition that results from excessive loss of water from a living organism.Acer: A plant genus of the family ACERACEAE, best known for trees with palmately lobed leaves.Urine: Liquid by-product of excretion produced in the kidneys, temporarily stored in the bladder until discharge through the URETHRA.Drinking: The consumption of liquids.Fagus: A plant genus of the family FAGACEAE.Brain Edema: Increased intracellular or extracellular fluid in brain tissue. Cytotoxic brain edema (swelling due to increased intracellular fluid) is indicative of a disturbance in cell metabolism, and is commonly associated with hypoxic or ischemic injuries (see HYPOXIA, BRAIN). An increase in extracellular fluid may be caused by increased brain capillary permeability (vasogenic edema), an osmotic gradient, local blockages in interstitial fluid pathways, or by obstruction of CSF flow (e.g., obstructive HYDROCEPHALUS). (From Childs Nerv Syst 1992 Sep; 8(6):301-6)Hypergravity: Condition wherein the force of gravity is greater than or is increased above that on the surface of the earth. This is expressed as being greater than 1 g.Silage: Fodder converted into succulent feed for livestock through processes of anaerobic fermentation (as in a silo).Reagent Strips: Narrow pieces of material impregnated or covered with a substance used to produce a chemical reaction. The strips are used in detecting, measuring, producing, etc., other substances. (From Dorland, 28th ed)Weightlessness: Condition in which no acceleration, whether due to gravity or any other force, can be detected by an observer within a system. It also means the absence of weight or the absence of the force of gravity acting on a body. Microgravity, gravitational force between 0 and 10 -6 g, is included here. (From NASA Thesaurus, 1988)Polyuria: Urination of a large volume of urine with an increase in urinary frequency, commonly seen in diabetes (DIABETES MELLITUS; DIABETES INSIPIDUS).Wood: A product of hard secondary xylem composed of CELLULOSE, hemicellulose, and LIGNANS, that is under the bark of trees and shrubs. It is used in construction and as a source of CHARCOAL and many other products.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).Air Sacs: Thin-walled sacs or spaces which function as a part of the respiratory system in birds, fishes, insects, and mammals.Silicone Oils: Organic siloxanes which are polymerized to the oily stage. The oils have low surface tension and density less than 1. They are used in industrial applications and in the treatment of retinal detachment, complicated by proliferative vitreoretinopathy.Drug Contamination: The presence of organisms, or any foreign material that makes a drug preparation impure.Hypogravity: Condition wherein the force of gravity is less than or is decreased below that on the surface of the earth. This is expressed as being between 0 and 1 g.Gravitropism: The directional growth of organisms in response to gravity. In plants, the main root is positively gravitropic (growing downwards) and a main stem is negatively gravitropic (growing upwards), irrespective of the positions in which they are placed. Plant gravitropism is thought to be controlled by auxin (AUXINS), a plant growth substance. (From Concise Dictionary of Biology, 1990)Poaceae: A large family of narrow-leaved herbaceous grasses of the order Cyperales, subclass Commelinidae, class Liliopsida (monocotyledons). Food grains (EDIBLE GRAIN) come from members of this family. RHINITIS, ALLERGIC, SEASONAL can be induced by POLLEN of many of the grasses.Rumen: The first stomach of ruminants. It lies on the left side of the body, occupying the whole of the left side of the abdomen and even stretching across the median plane of the body to the right side. It is capacious, divided into an upper and a lower sac, each of which has a blind sac at its posterior extremity. The rumen is lined by mucous membrane containing no digestive glands, but mucus-secreting glands are present in large numbers. Coarse, partially chewed food is stored and churned in the rumen until the animal finds circumstances convenient for rumination. When this occurs, little balls of food are regurgitated through the esophagus into the mouth, and are subjected to a second more thorough mastication, swallowed, and passed on into other parts of the compound stomach. (From Black's Veterinary Dictionary, 17th ed)Gastrointestinal Transit: Passage of food (sometimes in the form of a test meal) through the gastrointestinal tract as measured in minutes or hours. The rate of passage through the intestine is an indicator of small bowel function.