<descriptor thcode="2"><thesaurus thcode="2" name="USGS Thesaurus" scope="Topics and methods of scientific study carried out by USGS, with product types, scientific disciplines, geologic time, and types of institutional structure and activities.  Broad and shallow, used to help people find scientific information." creator="U.S. Geological Survey" rights="Public domain" edition="2.0" date="2020-01-09" codetype="number" prefix="topic" uri="https://www2.usgs.gov/science/USGSThesaurus" tblname="term" nonpref="nonpref" relterm="relterm" root_code="1" contact="pschweitzer"><category><term thcode="25" code="29" name="distinct labels" parent="26" scope="Preferred labels (descriptor texts) are distinct within the thesaurus. A concept can be specified either by its unique identifier (code) or by the text of its descriptor."/><term thcode="25" code="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/><term thcode="25" code="13" name="transitive" parent="12" scope="Narrower terms have an &quot;is a&quot; relationship with their broader terms, and generally can be described as part-of, type-of, or instance-of the broader term."/><term thcode="25" code="21" name="disciplines" parent="2" scope="Broad categories of human inquiry or activity, such as scientific disciplines."/><term thcode="25" code="20" name="methods" parent="2" scope="Actions taken to obtain or analyze information"/><term thcode="25" code="19" name="organizational functions" parent="2" scope="Things that organizations do, typically including various types of programs, projects, and services."/><term thcode="25" code="7" name="temporal" parent="2" scope="Terms indicate periods of time, such as chronostratigraphic units, named historical periods or intervals surrounding known historical events, or seasons."/><term thcode="25" code="5" name="theme" parent="2" scope="Terms indicate domains of human concern, such as scientific discipline, societal problems, or characteristics of earth, space, oceans, and living things."/><term thcode="25" code="29" name="distinct labels" parent="26" scope="Preferred labels (descriptor texts) are distinct within the thesaurus. A concept can be specified either by its unique identifier (code) or by the text of its descriptor."/><term thcode="25" code="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/><term thcode="25" code="13" name="transitive" parent="12" scope="Narrower terms have an &quot;is a&quot; relationship with their broader terms, and generally can be described as part-of, type-of, or instance-of the broader term."/><term thcode="25" code="21" name="disciplines" parent="2" scope="Broad categories of human inquiry or activity, such as scientific disciplines."/><term thcode="25" code="20" name="methods" parent="2" scope="Actions taken to obtain or analyze information"/><term thcode="25" code="19" name="organizational functions" parent="2" scope="Things that organizations do, typically including various types of programs, projects, and services."/><term thcode="25" code="7" name="temporal" parent="2" scope="Terms indicate periods of time, such as chronostratigraphic units, named historical periods or intervals surrounding known historical events, or seasons."/><term thcode="25" code="5" name="theme" parent="2" scope="Terms indicate domains of human concern, such as scientific discipline, societal problems, or characteristics of earth, space, oceans, and living things."/></category><altlabel><altlabel>USGSThesaurus</altlabel><altlabel>USGSThesaurus</altlabel></altlabel></thesaurus><term thcode="2" code="533" name="health and disease" parent="1174" scope="Normal and abnormal conditions of plant and animal bodies.  Covers both human and non-human health and disease topics. For human health and disease, use the narrower term 'environmental health (human)'."/><uf><usefor name="disease"/><usefor name="nutrition"/></uf><bt><term thcode="2" code="1174" name="topics" parent="1" scope="Themes, subjects, and concerns for which USGS information resources are relevant."/><term thcode="2" code="1" name="Categories" scope="Thematic terms for categorizing information resources.  This thesaurus is intended to support finding and understanding scientific information."/></bt><nt><term thcode="2" code="267" name="disease vectors" parent="533" scope="Organisms, such as insects, that transmit pathogens from one host to another."/><term thcode="2" code="345" name="environmental health (human)" parent="533" scope="Effects of the environment on human health."/><term thcode="2" code="1805" name="wildlife disease" parent="533" scope="Includes viral, bacterial, and fungal infections as well as exposure of organisms to dangerous chemicals or toxic substances."/><term thcode="2" code="1752" name="zoonotic diseases" parent="533" scope="Diseases of animals that can be communicated to humans"/></nt><rt><term thcode="2" code="77" name="bacteriology" parent="735" scope="Study of the single celled microorganisms known as bacteria."/><term thcode="2" code="334" name="endocrinology" parent="39" scope="Study of the collection of ductless glands that secrete hormones which influence growth, gender, sexual maturity, and other attributes."/><term thcode="2" code="540" name="histology" parent="39" scope="Branch of anatomy concerned with the microscopic structure of plant and animal tissue."/><term thcode="2" code="576" name="immunology" parent="39" scope="Branch of biology which studies the body's production of lymphocytes, antibodies, and macrophages in response to foreign substances or pathogenic organisms."/><term thcode="2" code="650" name="life sciences" parent="1019" scope="Branches of science that study living and fossil organisms."/><term thcode="2" code="871" name="parasitology" parent="650" scope="Branch of biology concerned with the study of organisms that, living on or in another organism, take nutrition from the host and often harm it."/><term thcode="2" code="876" name="pathology" parent="650" scope="Branch of biology concerned with the study of the causes, progress, symptoms, diagnosis, and effects of diseases."/><term thcode="2" code="1075" name="social sciences" parent="1019" scope="Sciences concerned with the structure and interrelationships of human societies, human institutions and organizations, and human culture over time."/></rt></descriptor>