Oct 26, 2014

Keeping Your Arteries Healthy

The well-being of your arteries depends on a healthy endothelium, the inner lining of your blood vessels. “Endothelial cells are the prima donnas within the blood vessels. They control almost every activity that occurs in the vessels, and they’re fundamentally altered with age,” Dr. Lakatta says. “People who maintain a healthy endothelium as they get older and those who make an effort to do things that promote the repair of injured endothelium can reduce the risk of heart attacks and strokes caused by atherosclerosis or hypertension.”

Although scientists still have much to learn about the endothelium and what can be done to keep it healthy, a number of studies suggest that certain modifiable risk factors can have an important impact on the cardiovascular system. For instance, regular moderate exercise, such as running, walking, or swimming can reduce body fat, increase lean muscle mass, decrease blood pressure, increase HDL cholesterol (the “good” cholesterol) levels, and lessen the extent of arterial stiffening. All of these exercise-induced changes can have a positive influence on endothelial cells.

Oct 18, 2014

Astrobiology

Astrobiology is the study of the origin, evolution, distribution, and future of life in the universe: extraterrestrial life and life on Earth. This interdisciplinary field encompasses the search for habitable environments in our Solar System and habitable planets outside our Solar System, the search for evidence of prebiotic chemistry, laboratory and field research into the origins and early evolution of life on Earth, and studies of the potential for life to adapt to challenges on Earth and in outer space. Astrobiology addresses the question of whether life exists beyond Earth, and how humans can detect it if it does. (The term exobiology is similar but more specific — it covers the search for life beyond Earth, and the effects of extraterrestrial environments on living things.)

Astrobiology makes use of physics, chemistry, astronomy, biology, molecular biology, ecology, planetary science, geography, and geology to investigate the possibility of life on other worlds and help recognize biospheres that might be different from the biosphere on Earth. Astrobiology concerns itself with interpretation of existing scientific data; given more detailed and reliable data from other parts of the universe, the roots of astrobiology itself — physics, chemistry and biology — may have their theoretical bases challenged. Although speculation is entertained to give context, astrobiology concerns itself primarily with hypotheses that fit firmly into existing scientific theories. 
(Wikipedia Encyclopedia)

Oct 11, 2014

Consciousness

Consciousness is defined in the dictionary as: 1. the state of being conscious; awareness of one's own existence, sensations, thoughts, surroundings, etc.  2. the thoughts and feelings, collectively, of an individual or of an aggregate of people: the moral consciousness of a nation.3. full activity of the mind and senses, as in waking life: to regain consciousness after fainting. 4. awareness of something for what it is; internal knowledge: consciousness of wrongdoing. 5. concern, interest, or acute awareness: class consciousness. 6. the mental activity of which a person is aware as contrasted with unconscious mental processes. 7. Philosophy. the mind or the mental faculties as characterized by thought, feelings, and volition. Idioms: raise one's consciousness: to increase one's awareness and understanding of one's own needs, behavior, attitudes, etc., especially as a member of a particular social or political group.

Psychologists define consciousness as the quality or state of awareness, or, of being aware of an external object or something within oneself. The English philosopher John Locke defined it as “the perception of what passes in a man's own mind.” It is also defined as: sentience, awareness, subjectivity, the ability to experience or to feel, wakefulness, having a sense of selfhood, and the executive control system of the mind. Despite the difficulty in definition, many philosophers believe that there is a broadly shared underlying intuition about what consciousness is.  As Max Velmans and Susan Schneider wrote in The Blackwell Companion to Consciousness: "Anything that we are aware of at a given moment forms part of our consciousness, making conscious experience at once the most familiar and most mysterious aspect of our lives."

Oct 4, 2014

Eye Anatomy

The eye comprises three main outer layers and an inner chamber, which is filled with a thick, clear fluid, known as vitreous humor. ('The Human Brain Book', by Rita Carter)