Effective population sizeThe effective population size (Ne) is a number that, in some simplified scenarios, corresponds to the number of breeding individuals in the population. More generally, Ne is the number of individuals that an idealised population would need to have in order for some specified quantity of interest (typically change of genetic diversity or inbreeding rates) to be the same as in the real population. Idealised populations are based on unrealistic but convenient simplifications such as random mating, simultaneous birth of each new generation, constant population size, and equal numbers of children per parent.
Politics of BrazilThe politics of Brazil take place in a framework of a federal presidential representative democratic republic, whereby the President is both head of state and head of government, and of a multi-party system. The political and administrative organization of Brazil comprises the federal government, the 26 states and a federal district, and the municipalities. The federal government exercises control over the central government and is divided into three independent branches: executive, legislative and judicial.
New UrbanismNew Urbanism is an urban design movement that promotes environmentally friendly habits by creating walkable neighbourhoods containing a wide range of housing and job types. It arose in the United States in the early 1980s, and has gradually influenced many aspects of real estate development, urban planning, and municipal land-use strategies. New Urbanism attempts to address the ills associated with urban sprawl and post-Second World War suburban development.
Urban densityUrban density is a term used in urban planning and urban design to refer to the number of people inhabiting a given urbanized area. As such it is to be distinguished from other measures of population density. Urban density is considered an important factor in understanding how cities function. Research related to urban density occurs across diverse areas, including economics, health, innovation, psychology and geography as well as sustainability.
Urban areaAn urban area, built-up area or urban agglomeration is a human settlement with a high population-density and an infrastructure of built environment. This is the core of a metropolitan statistical area in the United States, if it contains a population of more than 50,000. Urban areas originate through urbanization, and researchers categorize them as cities, towns, conurbations or suburbs. In urbanism, the term "urban area" contrasts to rural areas such as villages and hamlets; in urban sociology or urban anthropology it contrasts with natural environment.
Urban economicsUrban economics is broadly the economic study of urban areas; as such, it involves using the tools of economics to analyze urban issues such as crime, education, public transit, housing, and local government finance. More specifically, it is a branch of microeconomics that studies the urban spatial structure and the location of households and firms . Historically, much like economics generally, urban economics was influenced by multiple schools of thought, including original institutional economics and Marxist economics.
Urban historyUrban history is a field of history that examines the historical nature of cities and towns, and the process of urbanization. The approach is often multidisciplinary, crossing boundaries into fields like social history, architectural history, urban sociology, urban geography, business history, and archaeology. Urbanization and industrialization were popular themes for 20th-century historians, often tied to an implicit model of modernization, or the transformation of rural traditional societies.
Urban reforestationUrban reforestation is the practice of planting trees, typically on a large scale, in urban environments. It may also include urban horticulture and urban farming. Reasons for practicing urban reforestation include urban beautification; increasing shade; modifying the urban climate; improving air quality, such as by sequestering carbon dioxide; and restoration of urban forests after a natural disaster. Increased shade from urban reforestation can also lead to decreased energy costs, as heat from the sun is blocked from heating structures that use air conditioning.
MunicipalityA municipality is usually a single administrative division having corporate status and powers of self-government or jurisdiction as granted by national and regional laws to which it is subordinate. The term municipality may also mean the governing body of a given municipality. A municipality is a general-purpose administrative subdivision, as opposed to a special-purpose district. The term is derived from French municipalité and Latin municipalis.
Small population sizeSmall populations can behave differently from larger populations. They are often the result of population bottlenecks from larger populations, leading to loss of heterozygosity and reduced genetic diversity and loss or fixation of alleles and shifts in allele frequencies. A small population is then more susceptible to demographic and genetic stochastic events, which can impact the long-term survival of the population. Therefore, small populations are often considered at risk of endangerment or extinction, and are often of conservation concern.
