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An oxygen minimum zone (OMZ) is characterized as an oxygen-deficient layer in the world's oceans. Typically found between 200m to 1500m deep below regions of high productivity, such as the western coasts of continents. [1] OMZs can be seasonal following the spring-summer upwelling season. Upwelling of nutrient-rich water leads to high ...
Oxygen began building up in the atmosphere at approximately 1.85 Ga. At current rates of primary production, today's concentration of oxygen could be produced by photosynthetic organisms in 2,000 years. [ 4] In the absence of plants, the rate of oxygen production by photosynthesis was slower in the Precambrian, and the concentrations of O 2 ...
Photosynthesis ( / ˌfoʊtəˈsɪnθəsɪs / FOH-tə-SINTH-ə-sis) [ 1] is a system of biological processes by which photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical energy necessary to fuel their metabolism.
While it’s certainly sobering that cardiovascular disease is the number one cause of death in this country, the good news is that this is a health condition that’s largely avoidable.
Human nutrition deals with the provision of essential nutrients in food that are necessary to support human life and good health. [ 1] Poor nutrition is a chronic problem often linked to poverty, food security, or a poor understanding of nutritional requirements. [ 2]
The oxygen cycle is the biogeochemical cycle of oxygen atoms between different oxidation states in ions, oxides, and molecules through redox reactions within and between the spheres/reservoirs of the planet Earth. [ 1] The word oxygen in the literature typically refers to the most common oxygen allotrope, elemental/diatomic oxygen (O 2 ), as it ...
A table or chart of nuclides is a two-dimensional graph of isotopes of the elements, in which one axis represents the number of neutrons (symbol N) and the other represents the number of protons (atomic number, symbol Z) in the atomic nucleus. Each point plotted on the graph thus represents a nuclide of a known or hypothetical chemical element.
Oxygen-18, 18 O. O, Ω [1]) is a natural, stable isotope of oxygen and one of the environmental isotopes . O is an important precursor for the production of fluorodeoxyglucose (FDG) used in positron emission tomography (PET). Generally, in the radiopharmaceutical industry, enriched water ( H. 2Ω) is bombarded with hydrogen ions in either a ...