Monday, November 27, 2006
Non-fiction
Non-fiction is an account or representation of a subject which is presented as fact. This presentation may be accurate or not; that is, it can give either a true or a false account of the subject in question. However, it is generally assumed that the authors of such accounts believe them to be truthful at the time of their composition. Non-fiction is one of the two main divisions in writing, particularly used in libraries, the other being fiction. However, non-fiction need not be written text necessarily, since pictures and film can also purport to present a factual account of a subject.
Essays, journals, documentaries, scientific papers, photographs, biographies, textbooks, blueprints, technical documentation, user manuals, diagrams and journalism are all common examples of non-fiction works, and fiction within any of these works is usually regarded as dishonest. Other works can legitimately be either fiction or non-fiction, such as letters, magazine articles, histories, websites, speeches and travelogues. Although they are mostly either one or the other it is not uncommon for there to be a blend of both, particularly non-fiction with a dash of fiction for added spice.
Monday, November 20, 2006
Pitch
In music, pitch is the psychological associate of the fundamental frequency of a note. The note an above middle C played on any instrument is perceived to be of the same pitch as a pure tone of 440 Hz, but does not essentially contain a partial having that frequency. Furthermore, a slight change in frequency need not lead to a perceived change in pitch, but a change in pitch implies a change in frequency. In fact, the just perceptible difference is about five cents, but varies over the range of hearing and is more precise when the two pitches are played at the same time. Like other human stimuli, the perception of pitch also can be explained by the Weber-Fechner law.
Pitch also depends on the amplitude of the sound, especially at low frequencies. For instance, a low bass note will sound lower in pitch if it is louder. Like other senses, the comparative perception of pitch can be fooled, resulting in "audio illusions". There are several of these, such as the tritone paradox, but most especially the Shepard scale, where a continuous or discrete sequence of specially formed tones can be made to sound as if the sequence continues ascending or descending forever.
Friday, November 10, 2006
Lipstick
Lipstick is a cosmetic product for the lips that is richer in color and texture than lip gloss, primarily used to apply color to the lips. Most lipsticks are red or reddish, simulating the appearance of sexual arousal, which naturally increases blood flow and reddens the lips, intending to make the wearer more sexually attractive. With modern pigments, however, lipstick is available in a massive and varied selection of colors and shades.A typical lipstick contains many chemical ingredients, principally pigments, oils, waxes, and emollients. Perfume and/or flavoring may be added to cover the odors and tastes of the other ingredients.
Lipstick does not have a particular origin. However, it is known to have been used around 5000 years ago in ancient Babylon, when semi-precious jewels were crushed and applied to the lips and occasionally around the eyes. Ancient Egyptians extracted purplish-red dye from fucus-algin, 0.01% iodine, and some bromine mannite, which resulted in serious illness. Cleopatra had her lipstick made from crushed carmine beetles, which gave a deep red pigment, and ants for a base. Lipsticks with shimmering effects were initially made using a substance found in fish scales called pearlescence.
Thursday, November 02, 2006
Immunology
Immunology is a broad branch of biomedical science that covers the study of all aspects of the immune system in all organisms. It deals with, among other things, the physiological functioning of the immune system in states of both health and disease; malfunctions of the immune system in immunological disorders autoimmune diseases, hypersensitivities, immune deficiency, allograft rejection; the physical, chemical and physiological characteristics of the components of the immune system in vitro, in situ, and in vivo. Immunology has various applications in several disciplines of science, and as such is further divided.
Classical immunology ties in with the fields of epidemiology and medicine. It studies the relationship between the body systems, pathogens, and immunity. The earliest written mention of immunity can be traced back to the plague of Athens in 430 BCE. Thucydides noted that people who had recovered from a previous bout of the disease could nurse the sick without contracting the illness a second time. Many other ancient societies have references to this phenomenon, but it was not until the 19th and 20th centuries before the concept developed into scientific theory.
The study of the molecular and cellular components that comprise the immune system, including their function and interaction, is the central science of immunology. The immune system has been divided into a more primitive innate immune system, and acquired or adaptive immune system of vertebrates, the latter of which is further divided into humoral and cellular components.
