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The earliest recorded observation of this behavior in plants dates back to 324 BC when Androsthenes of Thasos, a companion to Alexander the Great, noted the opening and closing of tamarind tree leaves from day to night. [15] Carl Linnaeus (1729) proposed that this was the plants sleeping, but this idea has been widely contested.
In nuclear medicine, radioisotopes are used for diagnosis, treatment, and research. Radioactive chemical tracers emitting gamma rays or positrons can provide diagnostic information about internal anatomy and the functioning of specific organs, including the human brain .
Glovebox. Radiochemistry is the chemistry of radioactive materials, where radioactive isotopes of elements are used to study the properties and chemical reactions of non-radioactive isotopes (often within radiochemistry the absence of radioactivity leads to a substance being described as being inactive as the isotopes are stable).
Environmental toxicants and fetal development is the impact of different toxic substances from the environment on the development of the fetus.This article deals with potential adverse effects of environmental toxicants on the prenatal development of both the embryo or fetus, as well as pregnancy complications.
Noxious weeds can be deadly for humans, animals and other plants in your garden. Here’s how to identify a plants before you get hurt. You may have poison in your garden.
There is a zone of the atmosphere in which ozone absorbs some 98% of non-ionizing but dangerous UV-C and UV-B. This ozone layer starts at about 20 miles (32 km) and extends upward. Some of the ultraviolet spectrum that does reach the ground is non-ionizing, but is still biologically hazardous due to the ability of single photons of this energy ...
Many of the fission products are either non-radioactive or only short-lived radioisotopes, but a considerable number are medium to long-lived radioisotopes such as 90 Sr, 137 Cs, 99 Tc and 129 I. Research has been conducted by several different countries into segregating the rare isotopes in fission waste including the "fission platinoids" (Ru ...
Today, there is concern about contamination of the soil with strontium-90 and caesium-137, which have half-lives of about 30 years. The highest levels of caesium-137 are found in the surface layers of the soil where they are absorbed by plants, insects and mushrooms, which then enter the local food supply [50]). Some scientists fear that ...