Phoebe S. Leboy, groundbreaking activist for women in STEM

Unlike carbon, water, and nitrogen, phosphorus is not present in the atmosphere as a gas. Instead, most phosphorus in the ecosystem exists as compounds, such as phosphate ions (PO43-), found in soil, water, sediment and rocks. Phosphorus is often a limiting nutrient (i.e., in short supply). Consequently, phosphorus is added to most agricultural fertilizers, which can cause environmental problems related to runoff in aquatic ecosystems.

Phasors are a powerful mathematical tool used to analyze alternating current (AC) circuits. They provide a complex number representation of sinusoids, with the magnitude of the phasor equating to the amplitude of the sinusoid and the angle of the phasor representing the phase measured from the positive x-axis.
One of the significant benefits of using phasors is that they simplify the analysis of AC circuits by eliminating the time dependence of the current and voltage. This transformation...

The stem cell niche is the dynamic microenvironment where stem cells reside. Inside these niches, the cells may remain undifferentiated, undergo high self-renewal, or become lineage-specific progenitors. Stem cells coexist with other niche cells, such as stromal cells. They also interact closely with the ECM. Cell-cell and cell-matrix communication occur via adhesion molecules or soluble factors that signal the stem cells and determine their fate. Stromal cells also provide survival signals to...

In 1653, the French philosopher and scientist Blaise Pascal published "Treatise on the Equilibrium of Liquids," which discussed the principles of static fluids. A static fluid is a fluid that is not in motion. When a fluid is not flowing, we say that the fluid is in static equilibrium. If the fluid is water, we say it is in hydrostatic equilibrium. For a fluid in static equilibrium, the net force on any part of the fluid must be zero; otherwise, the fluid will start to flow. Pascal observed...

Analyzing AC circuits in electrical systems is a fundamental aspect of electrical engineering. In these circuits, AC power is supplied from a distribution panel and wired to various household appliances in parallel. To perform a comprehensive analysis, electrical engineers use Kirchhoff's voltage and current laws, which are equally applicable in AC circuits as in DC circuits.
Kirchhoff's voltage law (KVL) states that the sum of phasor voltages around a closed loop in an AC circuit equals zero.

A hair follicle or HF is a small part of the skin that produces the hair shaft. Paul Gerson Unna was the first to observe a bulge in the human hair follicle's outer root sheath (ORS). The bulge is present between the sebaceous gland and the arrector pili muscle and is the niche for hair follicle stem cells (HFSCs). The bulge is also a niche for melanocyte stem cells, and their loss results in graying of hair. The HFSCs express Sox9 and Lhx2, which help them maintain stemness and prevent...