Activity Cycles: Bouts of physical irritability or movement alternating with periods of quiescence. It includes biochemical activity and hormonal activity which may be cellular. These cycles are shorter than 24 hours and include sleep-wakefulness cycles and the periodic activation of the digestive system.Circadian Rhythm: The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs and stimuli, hormone secretion, sleeping, and feeding.Cell Cycle: The complex series of phenomena, occurring between the end of one CELL DIVISION and the end of the next, by which cellular material is duplicated and then divided between two daughter cells. The cell cycle includes INTERPHASE, which includes G0 PHASE; G1 PHASE; S PHASE; and G2 PHASE, and CELL DIVISION PHASE.Programming Languages: Specific languages used to prepare computer programs.Language Development: The gradual expansion in complexity and meaning of symbols and sounds as perceived and interpreted by the individual through a maturational and learning process. Stages in development include babbling, cooing, word imitation with cognition, and use of short sentences.Workflow: Description of pattern of recurrent functions or procedures frequently found in organizational processes, such as notification, decision, and action.Language Disorders: Conditions characterized by deficiencies of comprehension or expression of written and spoken forms of language. These include acquired and developmental disorders.Language Development Disorders: Conditions characterized by language abilities (comprehension and expression of speech and writing) that are below the expected level for a given age, generally in the absence of an intellectual impairment. These conditions may be associated with DEAFNESS; BRAIN DISEASES; MENTAL DISORDERS; or environmental factors.Sign Language: A system of hand gestures used for communication by the deaf or by people speaking different languages.Information Storage and Retrieval: Organized activities related to the storage, location, search, and retrieval of information.Adipogenesis: The differentiation of pre-adipocytes into mature ADIPOCYTES.Adipocytes: Cells in the body that store FATS, usually in the form of TRIGLYCERIDES. WHITE ADIPOCYTES are the predominant type and found mostly in the abdominal cavity and subcutaneous tissue. BROWN ADIPOCYTES are thermogenic cells that can be found in newborns of some species and hibernating mammals.Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.Transcription Factors: Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.PPAR gamma: A nuclear transcription factor. Heterodimerization with RETINOID X RECEPTOR ALPHA is important in regulation of GLUCOSE metabolism and CELL GROWTH PROCESSES. It is a target of THIAZOLIDINEDIONES for control of DIABETES MELLITUS.Cell Cycle Proteins: Proteins that control the CELL DIVISION CYCLE. This family of proteins includes a wide variety of classes, including CYCLIN-DEPENDENT KINASES, mitogen-activated kinases, CYCLINS, and PHOSPHOPROTEIN PHOSPHATASES as well as their putative substrates such as chromatin-associated proteins, CYTOSKELETAL PROTEINS, and TRANSCRIPTION FACTORS.Child Development Disorders, Pervasive: Severe distortions in the development of many basic psychological functions that are not normal for any stage in development. These distortions are manifested in sustained social impairment, speech abnormalities, and peculiar motor movements.Autistic Disorder: A disorder beginning in childhood. It is marked by the presence of markedly abnormal or impaired development in social interaction and communication and a markedly restricted repertoire of activity and interest. Manifestations of the disorder vary greatly depending on the developmental level and chronological age of the individual. (DSM-V)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.Gingival Overgrowth: Excessive growth of the gingiva either by an increase in the size of the constituent cells (GINGIVAL HYPERTROPHY) or by an increase in their number (GINGIVAL HYPERPLASIA). (From Jablonski's Dictionary of Dentistry, 1992, p574)Genes, cdc: Genes that code for proteins that regulate the CELL DIVISION CYCLE. These genes form a regulatory network that culminates in the onset of MITOSIS by activating the p34cdc2 protein (PROTEIN P34CDC2).Water Cycle: Circulation of water among various ecological systems, in various states, on, above, and below the surface of the earth.Climate Change: Any significant change in measures of climate (such as temperature, precipitation, or wind) lasting for an extended period (decades or longer). It may result from natural factors such as changes in the sun's intensity, natural processes within the climate system such as changes in ocean circulation, or human activities.Beginning of Human Life: The point at which religious ensoulment or PERSONHOOD is considered to begin.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)Weather: The state of the ATMOSPHERE over minutes to months.Climate: The longterm manifestations of WEATHER. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Achaete-Scute Complex Genome Region: A genomic region found in DROSOPHILA. The region contains genes encoding BASIC HELIX-LOOP-HELIX TRANSCRIPTION FACTORS that play a critical role in the regulation of pattern formation during EMBRYONIC DEVELOPMENT.Motorcycles: Two-wheeled, engine-driven vehicles.Bathing Beaches: Beaches, both natural and man-made, used for bathing and other activities.Head Protective Devices: Personal devices for protection of heads from impact, penetration from falling and flying objects, and from limited electric shock and burn.Accidents, Traffic: Accidents on streets, roads, and highways involving drivers, passengers, pedestrians, or vehicles. Traffic accidents refer to AUTOMOBILES (passenger cars, buses, and trucks), BICYCLING, and MOTORCYCLES but not OFF-ROAD MOTOR VEHICLES; RAILROADS nor snowmobiles.Off-Road Motor Vehicles: Motorized, recreational vehicles used on non-public roads. They include all-terrain vehicles, dirt-bikes, minibikes, motorbikes, trailbikes, and snowmobiles. Excludes MOTORCYCLES, which are considered public road vehicles.Menstrual Cycle: The period from onset of one menstrual bleeding (MENSTRUATION) to the next in an ovulating woman or female primate. The menstrual cycle is regulated by endocrine interactions of the HYPOTHALAMUS; the PITUITARY GLAND; the ovaries; and the genital tract. The menstrual cycle is divided by OVULATION into two phases. Based on the endocrine status of the OVARY, there is a FOLLICULAR PHASE and a LUTEAL PHASE. Based on the response in the ENDOMETRIUM, the menstrual cycle is divided into a proliferative and a secretory phase.Internet: A loose confederation of computer communication networks around the world. The networks that make up the Internet are connected through several backbone networks. The Internet grew out of the US Government ARPAnet project and was designed to facilitate information exchange.Governing Board: The group in which legal authority is vested for the control of health-related institutions and organizations.Specialty Boards: Organizations which certify physicians and dentists as specialists in various fields of medical and dental practice.Technology Assessment, Biomedical: Evaluation of biomedical technology in relation to cost, efficacy, utilization, etc., and its future impact on social, ethical, and legal systems.World War I: Global conflict primarily fought on European continent, that occurred between 1914 and 1918.Practice Guidelines as Topic: Directions or principles presenting current or future rules of policy for assisting health care practitioners in patient care decisions regarding diagnosis, therapy, or related clinical circumstances. The guidelines may be developed by government agencies at any level, institutions, professional societies, governing boards, or by the convening of expert panels. The guidelines form a basis for the evaluation of all aspects of health care and delivery.Great BritainFantasy: An imagined sequence of events or mental images, e.g., daydreams.Mitosis: A type of CELL NUCLEUS division by means of which the two daughter nuclei normally receive identical complements of the number of CHROMOSOMES of the somatic cells of the species.Love: Affection; in psychiatry commonly refers to pleasure, particularly as it applies to gratifying experiences between individuals.Students: Individuals enrolled in a school or formal educational program.Educational Measurement: The assessing of academic or educational achievement. It includes all aspects of testing and test construction.Students, Medical: Individuals enrolled in a school of medicine or a formal educational program in medicine.Politics: Activities concerned with governmental policies, functions, etc.Democracy: A system of government in which there is free and equal participation by the people in the political decision-making process.Civil Rights: Legal guarantee protecting the individual from attack on personal liberties, right to fair trial, right to vote, and freedom from discrimination on the basis of race, color, religion, sex, age, disability, or national origin. (from accessed 1/31/2003)Federal Government: The level of governmental organization and function at the national or country-wide level.Sociobiology: The comparative study of social organization in animals including humans, especially with regard to its genetic basis and evolutionary history. (Merriam-Webster's Collegiate Dictionary, 10th ed)Public Opinion: The attitude of a significant portion of a population toward any given proposition, based upon a measurable amount of factual evidence, and involving some degree of reflection, analysis, and reasoning.Physiognomy: An assessment of a person's personality based on their facial and other external features.