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Vertisols of the world A more detailed map of the global distribution of Vertisols. A vertisol is a Soil Order in the USDA soil taxonomy [1] and a Reference Soil Group in the World Reference Base for Soil Resources (WRB). [2] It is also defined in many other soil classification systems. In the Australian Soil Classification it is called ...
Expansive clay, also called expansive soil, is a clay soil prone to large volume changes (swelling and shrinking) directly related to changes in water content. [1] Soils with a high content of expansive minerals can form deep cracks in drier seasons or years; such soils are called vertisols.
Due to the physical and chemical properties of some clays [4] (such as the Lias Group) large swelling occurs when water is absorbed. Conversely when the water dries up these clays contract (shrink). The presence of these clay minerals is what allows soils to have the capacity to shrink and swell.
Chemical properties can be contrasted with physical properties, which can be discerned without changing the substance's structure. However, for many properties within the scope of physical chemistry , and other disciplines at the boundary between chemistry and physics , the distinction may be a matter of researcher's perspective .
Activin and inhibin are two closely related protein complexes that have almost directly opposite biological effects. Identified in 1986, [1] [2] activin enhances FSH biosynthesis and secretion, and participates in the regulation of the menstrual cycle.
Tillage And Manure Interactive Effects On Soil Aggregates Dynamics, Soil Organic Carbon Accumulation And By Pass Flow In Vertisols; Development of Efficient Spraying System To Reduce Spray Losses; Development of spectral reflectance based prototype of variable rate urea application system for top dressing in rice and wheat crops.
When women undergo cyclic changes or different hormonal transition phases (menopause, pregnancy, adolescence), there are changes in their progesterone levels. [90] Therefore, females have an increased biological vulnerability to nicotine's reinforcing effects compared to males and progesterone may be used to counter this enhanced vulnerability.
Levels of estradiol in premenopausal women are highly variable throughout the menstrual cycle and reference ranges widely vary from source to source. [62] Estradiol levels are minimal and according to most laboratories range from 20 to 80 pg/mL during the early to mid follicular phase (or the first week of the menstrual cycle, also known as ...