American Public Health AssociationThe American Public Health Association (APHA) is a Washington, D.C.-based professional membership and advocacy organization for public health professionals in the United States. APHA is the largest professional organization of public health professionals in the United States and host the largest gathering of public health professionals in the world at their annual meeting and exhibition. In 1872, American Public Health Association was founded by a group of physicians, including Dr. Stephen Smith and Dr.
International migrationInternational migration occurs when people cross state boundaries and stay in the host state for some minimum length of the time. Migration occurs for many reasons. Many people leave their home countries in order to look for economic opportunities in another country. Others migrate to be with family members who have migrated or because of political conditions in their countries. Education is another reason for international migration, as students pursue their studies abroad, although this migration is often temporary, with a return to the home country after the studies are completed.
United States Public Health ServiceThe United States Public Health Service (USPHS or PHS) is a collection of agencies of the Department of Health and Human Services concerned with public health, containing nine out of the department's twelve operating divisions. The Assistant Secretary for Health oversees the PHS. The Public Health Service Commissioned Corps (PHSCC) is the federal uniformed service of the PHS, and is one of the eight uniformed services of the United States. PHS had its origins in the system of marine hospitals that originated in 1798.
Human migrationHuman migration is the movement of people from one place to another with intentions of settling, permanently or temporarily, at a new location (geographic region). The movement often occurs over long distances and from one country to another (external migration), but internal migration (within a single country) is also possible; indeed, this is the dominant form of human migration globally. Migration is often associated with better human capital at both individual and household level, and with better access to migration networks, facilitating a possible second move.
Circular migrationCircular migration or repeat migration is the temporary and usually repetitive movement of a migrant worker between home and host areas, typically for the purpose of employment. It represents an established pattern of population mobility, whether cross-country or rural-urban. There are several benefits associated with this migration pattern, including gains in financial capital, human capital, and social capital. There are also costs associated with circular migration, such as brain drain, poor working conditions, forced labor, and the inability to transfer acquired skills to home economies.
Population geneticsPopulation genetics is a subfield of genetics that deals with genetic differences within and among populations, and is a part of evolutionary biology. Studies in this branch of biology examine such phenomena as adaptation, speciation, and population structure. Population genetics was a vital ingredient in the emergence of the modern evolutionary synthesis. Its primary founders were Sewall Wright, J. B. S. Haldane and Ronald Fisher, who also laid the foundations for the related discipline of quantitative genetics.
Birth rateBirth rate, also known as natality, is the total number of live human births per 1,000 population for a given period divided by the length of the period in years. The number of live births is normally taken from a universal registration system for births; population counts from a census, and estimation through specialized demographic techniques. The birth rate (along with mortality and migration rates) is used to calculate population growth. The estimated average population may be taken as the mid-year population.
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.
Population ageingPopulation ageing is an increasing median age in a population because of declining fertility rates and rising life expectancy. Most countries have rising life expectancy and an ageing population, trends that emerged first in developed countries but are now seen in virtually all developing countries. That is the case for every country in the world except the 18 countries designated as "demographic outliers" by the United Nations. The aged population is currently at its highest level in human history.
Tertiary educationTertiary education, also referred to as third-level, third-stage or post-secondary education, is the educational level following the completion of secondary education. The World Bank, for example, defines tertiary education as including universities as well as trade schools and colleges. Higher education is taken to include undergraduate and postgraduate education, while vocational education beyond secondary education is known as further education in the United Kingdom, or included under the category of continuing education in the United States.
Secondary educationSecondary education or post-primary education covers two phases on the International Standard Classification of Education scale. Level 2 or lower secondary education (less commonly junior secondary education) is considered the second and final phase of basic education, and level 3 upper secondary education or senior secondary education is the stage before tertiary education. Every country aims to provide basic education, but the systems and terminology remain unique to them.
WomanA woman is an adult female human. Prior to adulthood, a female human is referred to as a girl (a female child or adolescent). The plural women is sometimes used in certain phrases such as "women's rights" to denote female humans regardless of age. Typically, women inherit a pair of X chromosomes, one from each parent, and are capable of pregnancy and giving birth from puberty until menopause. More generally, sex differentiation of the female fetus is governed by the lack of a present, or functioning, SRY-gene on either one of the respective sex chromosomes.
