Twin reversed arterial perfusionThe Otwell Twins: The Otwell Twins are an American singing duo made up of identical twin brothers Roger and David, born August 2, 1956, in Tulia, Texas. They are best known as members of The Lawrence Welk Show from 1977-1982.Monochorionic twinsParasitic twin: A parasitic twin (also known as an asymmetrical or unequal conjoined twin) is the result of the processes that also produce vanishing twins and conjoined twins, and may represent a continuum between the two. Parasitic twins occur when a twin embryo begins developing in utero, but the pair does not fully separate, and one embryo maintains dominant development at the expense of the other.Heritability: Heritability is a statistic used in breeding and genetics works that estimates how much variation in a phenotypic trait in a population is due to genetic variation among individuals in that population. It is calculated with the following equation (for broad-sense heritability): H^2 = VG/VP.Twin-to-twin transfusion syndromePrenatal nutrition: Nutrition and weight management before and during :pregnancy has a profound effect on the development of infants. This is a rather critical time for healthy fetal development as infants rely heavily on maternal stores and nutrient for optimal growth and health outcome later in life.Selective reduction: Selective reduction (or multifetal pregnancy reduction or MFPR) is the practice of reducing the number of fetuses in a multifetal pregnancy, say quadruplets, to a twin or singleton pregnancy.Evolution in Variable EnvironmentGestational age: Gestational age (or menstrual age) is a measure of the age of a pregnancy where the origin is the woman's last normal menstrual period (LMP), or the corresponding age as estimated by other methods. Such methods include adding 14 days to a known duration since fertilization (as is possible in in vitro fertilization), or by obstetric ultrasonography.Chorion (egg): The chorion is the outermost membrane around the embryo in mammals, birds and reptiles. It develops from an outer fold on the surface of the yolk sac, which lies outside the vitteline envelope and is developed by the follicle cells while the egg is in the ovary.David FulkerBirth weight: Birth weight is the body weight of a baby at its birth.Definitions from Georgia Department of Public Health.Harold LockwoodDisease registry: Disease or patient registries are collections of secondary data related to patients with a specific diagnosis, condition, or procedure, and they play an important role in post marketing surveillance of pharmaceuticals. Registries are different from indexes in that they contain more extensive data.FetoscopyGenain quadruplets: The Genain quadruplets (born in 1930) are a set of identical quadruplet sisters. All four developed schizophrenia, suggesting a large genetic component to the cause of the disease.PolyhydramniosAarhus Faculty of Health Sciences (Aarhus University): The Aarhus Faculty of Health Sciences is a faculty of Aarhus University. The Aarhus Faculty of Health Sciences became a reality after Aarhus University was divided into four new main academic areas which came into effect on 1 January 2011.Phenotype microarray: The phenotype microarray approach is a technology for high-throughput phenotyping of cells.Climate change in Sweden: The issue of climate change has received significant public and political attention in Sweden and the mitigation of its effects has been high on the agenda of the two latest Governments of Sweden, the previous Cabinet of Göran Persson (-2006) and the current Cabinet of Fredrik Reinfeldt (2006-). Sweden aims for an energy supply system with zero net atmospheric greenhouse gas emissions by 2050.