Since at least 1936 it has been known that BPA mimics estrogens, binding to the same receptors throughout the human body as natural female hormones. And tests have shown that the chemical can promote as well as decrease sperm count in rats, among other effects. These findings have raised questions about the potential health risks of BPA, especially in the wake of hosts of studies showing that it leaches from plastics and resins when they are exposed to hard use or high temperatures (as in microwaves or dis
Because what we see is that the basic plan of that limb—one bone in the upper limb, two bones in the lower limb, wrists that twist, a series of five or fewer digits—has been elaborated to give you everything from the wing of the bat for soaring, to a flipper of a porpoise for swimming and navigating the oceans, to a hand for grasping or playing the piano, to a mole&aposs limb for digging. The enormous differences in limb use have enabled subsequent animals—amphibians, birds, mammals—to d
New research has found that babies born to fathers under the age 25 or over 51 are at higher risk of developing autism and other social disorders. The study, conducted by the Seaver Autism Center for Research and Treatment at Mount Sinai, found that these children are actually more advanced than their peers as infants, but then fall behind by the time they hit their teenage years.
Scientific theories are, in essence, conceptual models that explain some phenomenon. They are “nets cast to catch what we call ‘the world’…we endeavor to make the mesh ever finer and finer” (Popper, 1959, p. 59). Indeed, much of science is fundamentally concerned with developing and testing theories, hypotheses, models, conjectures, or conceptual frameworks that can explain aspects of the physical and social world. Examples of well-known scientific theories include evolution,
Mutations on three genes are known to cause a rare form of Alzheimer’s disease that accounts for less than 1 percent of cases. When a person has one of these mutations, he or she has a 95 to 100 percent chance of developing Alzheimer’s. hopes to slow or stop the development of Alzheimer’s in these individuals with experimental drugs. Two drugs, gantenerumab and solanezumab, are currently being tested. Both are designed to help remove excess beta-amyloid in the brain. The brain changes of people with