Examples of homeostasis include the regulation of body temperature, the pH of extracellular fluid, or the concentrations of sodium, potassium and calcium ions as well as that of glucose in the blood plasma, despite changes in the environment, diet, or level of activity.
Blue-collar workers perform labor jobs and typically work with their hands. The skills necessary for blue-collar work vary by occupation. Some blue-collar occupations require highly skilled personnel who are formally trained and certified.
Positions within the Federal Government are classified by occupational series, grade or pay level, and pay plan. Pay plans identify the pay system under which the position is covered. Many white-collar employees are paid under the General Schedule (GS), which is regulated by title 5 and administered by OPM. GS positions, including other white-collar positions, are paid annual salaries.