Wednesday, June 27, 2007

Health

Health is the level of functional and metabolic effectiveness of an organism at both the micro and macro level. In the medical field, health is commonly defined as an organism's skill to efficiently respond to challenges and effectively restore and maintain a state of balance, known as homeostasis.

Another widely established definition of health is that of the World Health Organization which states that health is a state of complete physical, mental and social well-being and not merely the nonattendance of disease or infirmity .In more recent years, this statement has been customized to include the ability to lead a socially and economically productive life. The definition is not without criticism, as some argue that health cannot be defined as a state at all, but must be seen as a process of incessant adjustment to the changing demands of living and of the changing meaning we give to life.

Wednesday, June 20, 2007

Color

Color is the visual perceptual possessions corresponding in humans to the categories called red, yellow, white, etc. Color derives from spectrum of light distribution of light energy versus wavelength interacting in the eye with the spectral sensitivities of the light receptors. Color categories and physical condition of color are also associated with objects, materials, light sources, etc., based on their physical properties such as light absorption, reflection, or emission spectra.

Typically, only features of the composition of light that are visible by humans wavelength spectrum from 400 nm to 700 nm, roughly are included, thereby objectively relating the psychological phenomenon of color to its physical specification. Because perception of color stems from the varying sensitivity of different types of cone cells in the retina to different parts of the spectrum, colors may be defined and quantify by the degree to which they stimulate these cells. These physical or physiological quantifications of color, however, do not fully clarify the psychophysical perception of color appearance.

The science of color is sometimes called chromatics. It includes the perception of color by the human eye and brain, the origin of color in materials, color theory in art, and the physics of electromagnetic emission in the visible range that is, what we commonly refer to simply as light.

Thursday, June 07, 2007

Cosmetics

Cosmetics or make-up are substances used to enhance the beauty of the human body. Cosmetics include lotions, powders, lipstick and many other types of products. Their use is widespread, especially among women in Western countries. The manufacture of cosmetics is currently dominated by a small number of multinational corporations that originated in the early 20th century, but the distribution and sale of cosmetics is spread among a wide range of different businesses.