Population dynamicsPopulation dynamics is the type of mathematics used to model and study the size and age composition of populations as dynamical systems. Population dynamics has traditionally been the dominant branch of mathematical biology, which has a history of more than 220 years, although over the last century the scope of mathematical biology has greatly expanded. The beginning of population dynamics is widely regarded as the work of Malthus, formulated as the Malthusian growth model.
Gender roleA gender role, also known as a sex role, is a social role encompassing a range of behaviors and attitudes that are generally considered acceptable, appropriate, or desirable for a person based on that person's sex. Gender roles are usually centered on conceptions of masculinity and femininity, although there are exceptions and variations. The specifics regarding these gendered expectations may vary among cultures, while other characteristics may be common throughout a range of cultures.
Le Ton beau de MarotLe Ton beau de Marot: In Praise of the Music of Language is a 1997 book by Douglas Hofstadter in which he explores the meaning, strengths, failings and beauty of translation. The book is a long and detailed examination of one short translation of a minor French poem and, through that, an examination of the mysteries of translation (and indeed more generally, language and consciousness) itself. Hofstadter himself refers to it as "my ruminations on the art of translation".
Heavy metalsHeavy metals are generally defined as metals with relatively high densities, atomic weights, or atomic numbers. The criteria used, and whether metalloids are included, vary depending on the author and context. In metallurgy, for example, a heavy metal may be defined on the basis of density, whereas in physics the distinguishing criterion might be atomic number, while a chemist would likely be more concerned with chemical behaviour. More specific definitions have been published, none of which have been widely accepted.
Sustainable agricultureSustainable agriculture is farming in sustainable ways meeting society's present food and textile needs, without compromising the ability for current or future generations to meet their needs. It can be based on an understanding of ecosystem services. There are many methods to increase the sustainability of agriculture. When developing agriculture within sustainable food systems, it is important to develop flexible business process and farming practices.
MetalA metal (from Ancient Greek μέταλλον métallon 'mine, quarry, metal') is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typically ductile (can be drawn into wires) and malleable (they can be hammered into thin sheets). These properties are the result of the metallic bond between the atoms or molecules of the metal. A metal may be a chemical element such as iron; an alloy such as stainless steel; or a molecular compound such as polymeric sulfur nitride.
Sociology of genderSociology of gender is a prominent subfield of sociology. Social interaction directly correlated with sociology regarding social structure. One of the most important social structures is status. This is determined based on position that an individual possesses which effects how they will be treated by society. One of the most important statuses an individual claims is gender. Public discourse and the academic literature generally use the term gender for the perceived or projected (self-identified) masculinity or femininity of a person.
Third genderThird gender is a concept in which individuals are categorized, either by themselves or by society, as neither man nor woman. It is also a social category present in societies that recognize three or more genders. The term third is usually understood to mean "other", though some anthropologists and sociologists have described fourth and fifth genders. The state of personally identifying as, or being identified by society as, a man, a woman, or other is usually also defined by the individual's gender identity and gender role in the particular culture in which they live.
Precious metalPrecious metals are rare, naturally occurring metallic chemical elements of high economic value. Chemically, the precious metals tend to be less reactive than most elements (see noble metal). They are usually ductile and have a high lustre. Historically, precious metals were important as currency but are now regarded mainly as investment and industrial raw materials. Gold, silver, platinum, and palladium each have an ISO 4217 currency code. The best known precious metals are the coinage metals, which are gold and silver.
Population declinePopulation decline, also known as depopulation, is a reduction in a human population size. Over the long term, stretching from prehistory to the present, Earth's total human population has continued to grow; however, current projections suggest that this long-term trend of steady population growth may be coming to an end. Until the beginning of the Industrial Revolution, the global population grew very slowly, at about 0.04% per year. After about 1800, the growth rate accelerated to a peak of 2.
Gender varianceGender variance or gender nonconformity is behavior or gender expression by an individual that does not match masculine or feminine gender norms. A gender-nonconforming person may be variant in their gender identity, being transgender or non-binary, or they may be cisgender. In the case of transgender people, they may be perceived, or perceive themselves as, gender-nonconforming before transitioning, but might not be perceived as such after transitioning.
Gender neutrality in languages with gendered third-person pronounsA third-person pronoun is a pronoun that refers to an entity other than the speaker or listener. Some languages with gender-specific pronouns have them as part of a grammatical gender system, a system of agreement where most or all nouns have a value for this grammatical category. A few languages with gender-specific pronouns, such as English, Afrikaans, Defaka, Khmu, Malayalam, Tamil, and Yazgulyam, lack grammatical gender; in such languages, gender usually adheres to "natural gender", which is often based on biological sex.
