Pages

Thursday, December 28, 2006

Perception of sound

Sound is perceived through the sense of hearing. Humans and many animals use their ears to hear sound, but loud sounds and low frequency sounds can be supposed by other parts of the body through the sense of touch. Sounds are used in several ways, most notably for announcement through speech or, for example, music. Sound can also be used to acquire information about properties of the neighboring environment such as spatial characteristics and presence of other animals or objects. For example, bats use echolocation, ships and submarines use sonar, and humans can determine spatial information by the way in which they perceive sounds.

The range of frequencies that humans can hear well is between about 20 Hz and 16,000 Hz. This is by description the hearing range, but most people can hear above 16,000 Hz provided the sound pressure level is above the hearing threshold level. At 40,000 Hz and higher frequencies, for instance, this level is about 140 dB. The audible range varies by individual and, mostly in the upper part of the range, hearing damage accumulates with age. The ear is most sensitive to frequencies around 3,500 Hz. Sound above the hearing range is known as ultrasound and that below the hearing range as infrasound.


Halloween Costume

Thursday, December 21, 2006

Hinduism

Hinduism Dharma also known as Vaidika is a religion or philosophy that originated from the Indian subcontinent and nearby close areas. The term Hinduism is heterogeneous, as Hinduism consists of several schools of thought. It encompasses many religious rituals that widely vary in practice, as well as many diverse sects and philosophies. Many Hindus, influenced by Advaita philosophy, venerate an array of deities, considering them manifestations of the one supreme monistic Cosmic Spirit, Brahman, while many others focus on a singular concept of Brahman, as in Vaishnavism, Saivism and Shaktism.

Hinduism is the third major religion in the world, with approximately 900 million adherents, of whom approximately 890 million live in India. It is also the oldest known religion in the world today. Unlike many other religions, Hinduism has no main founder. It also has no single holy book — it has many, with all pointing to the same Truth - its original scriptures were the four Vedas, but as time has passed, many other scriptures have also emerged.


Halloween Costume

Sunday, December 17, 2006

Cellular differentiation

Cellular differentiation is a concept from developmental biology describing the process by which cells acquire a "type". The morphology of a cell may change considerably during differentiation, but the genetic material remains the same, with few exceptions.

A cell that is able to differentiate into many cell types is known as pluripotent. These cells are called stem cells in animals and meristematic cells in higher plants. A cell that is able to distinguish into all cell types is known as totipotent. In mammals, only the zygote and early embryonic cells are totipotent, while in plants, many differentiated cells can become totipotent with simple laboratory techniques.

In most multicellular organisms, not all cells are alike. For example, cells that make up the human skin are different from cells that make up the inner organs. Yet, all of the different cell types in the human body are all derived from a single fertilized egg cell through differentiation.


Halloween Costume

Sunday, December 10, 2006

Etymology of India

India, as a country and nation, has three principal names, in both official and popular usage, each of which is historically and culturally important. All three originally designated a single entity comprise all the modern nations of the Indian subcontinent. The first Article of the Constitution of India, which deals with the official name, states that "India, that is Bharat, shall be a union of states." Thus, not only in usage but officially India and Bharat are both accorded primary status? The name India is derived from the river Indus.

The innovative name of the river came from the fact that in the north-west of the subcontinent, there are seven main tributaries of the one river. The local inhabitants therefore called it Sapta-Sindhu, meaning the seven rivers. As the seven tributaries are part of the one river, the whole river system came to be known in time as Sindhu. In general, Sindhu also means any river or water body in Sanskrit.

Halloween Costumes

Thursday, December 07, 2006

Competition in education

Competition is also very obvious in education. On a global scale, national education systems, intending to bring out the best in the next generation, encourage competitiveness amongst students by scholarships. Countries like Singapore and the England have a gifted education programmed which caters to gifted students, prompting charge of academic elitism. Upon receipt of their academic results, students tend to compare their grades to see who is better. For severe cases, the pressure to perform in some countries is so high that it results in stigmatization of intellectually lacking students or even suicide as consequence of failing the exams, Japan being a prime example.
This resulted in critical revaluation of examinations as a whole by educationists . Critics of competition as opposed to excellence as a motivating factor in education systems, such as Alfie Kohn, assert that competition actually has a net negative influence on the achievement levels of students and that it "turns all of us into losers." Competitions also make up a large promoter of extracurricular activities that students partake in. Such competitions include TVO's broadcast Reach for the Top competition, FIRST Robotics and the University of Toronto Space Design Contest.


Halloween Costumes

Wednesday, November 29, 2006

Statue of Zeus at Olympia

The Statue of Zeus at Olympia is one of the classical Seven Wonders of the Ancient World. It was carved by the famed Classical sculptor Phidias circa 435 BC in Olympia, Greece.The seated statue occupied the whole width of the aisle of the temple that was built to house it, and was 40 feet tall. "It seems that if Zeus were to stand up," the geographer Strabo noted early in the 1st century BC, "he would unroof the temple." Zeus was carved from ivory then covered with gold plating and was seated on a magnificent throne of cedarwood, inlaid with ivory, gold, ebony, and precious stones. In Zeus' right hand there was a small statue of Nike, the goddess of victory, and in his left hand, a shining sceptre on which an eagle perched. Visitors like the Roman general Aemilius Paulus, the victor over Macedon, were moved to awe by the godlike majesty and splendor that Phidias had captured.

Halloween Costumes

Wednesday, November 22, 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.

Halloween Costumes

Monday, November 13, 2006

Abdominal pain

Abdominal pain can be one of the symptoms associated with transient disorders or serious disease. Making a definitive diagnosis of the cause of abdominal pain can be difficult, because many diseases can result in this symptom. Abdominal pain is a common problem. Most frequently the cause is benign and/or self-limited, but more serious causes may require urgent intervention.

Abdominal pain is traditionally described by its chronicity , its progression over time, its nature, its distribution , and by characterization of the factors that make it worse, or alleviate it.Due to the many organ systems in the abdomen, abdominal pain is a concern of general practitioners/family physicians, surgeons, internists, emergency medicine doctors, pediatricians, gastroenterologists, urologists and gynecologists. Occasionally, patients with rare causes can see a number of specialists before being diagnosed adequately .

Halloween Costumes

Sunday, November 05, 2006

Tornado

A tornado is a violently rotating column of air which is in contact with both a cumulonimbus cloud base and the surface of the earth. Tornadoes can come in many shapes, but are typically in the form of a visible condensation funnel, with the narrow end touching the earth. Often, a cloud of debris encircles the lower portion of the funnel.

Tornadoes can be the most destructive storms on earth. Most have winds of 110 mph or less, are approximately 250 feet across, and travel a mile or more before dissipating. However, some tornadoes can have winds of more than 300 mph be more than a mile across, and stay on the ground for dozens of miles.

They have been observed on every continent except Antarctica; however, a significant percentage of the world's tornadoes occur in the United States. This is mostly due to the unique geography of the country, which allows the conditions which breed strong, long-lived storms to occur many times a year. Other areas which often experience tornadoes are south-central Canada, northwestern Europe, east-central South America, South Africa, and south-central Asia.


Halloween Costumes

Monday, October 30, 2006

Dieting

Dieting is the practice of eating and drinking in a regulated fashion to achieve a particular, short-term objective.This is distinct from the more basic concept of diet, which addresses tie longer-term and more generic habit of nutritional consumption. For example, a vegan eats a diet completely without animal products, including milk; but while this is a diet, it is not dieting.The most common objective of dieting is loss of excess body fat. Some dieting is prescribed to achieve particular medical objectives, such as sodium-free diets, bland diets and soft food diets, while some dieting is actually designed to increase body fat and/or muscle weight gain.

Weight-loss diets restrict the intake of specific foods, or food in general, to reduce body weight. What works to reduce body weight for one person will not necessarily work for another, due to metabolic differences and lifestyle factors. Also, it's important to note that short-term dieting does not necessarily lead to weight loss in the long term. Reducing the body's food supply causes it to stockpile excess fat as a starvation response once normal eating is resumed - meaning crash dieting leads to small short-term weight loss, then an increase in weight shortly afterwards.

Halloween Costumes

Friday, October 20, 2006

Nature

Nature,in the broadest sense, is equivalent to the natural world, physical universe, material world or material universe.Nature refers to the phenomena of the physical world, and also to life in general. The term generally does not include manufactured objects and human interaction unless qualified in ways such as, e.g human nature or the whole of nature. Nature is also generally distinguished from the spiritual or supernatural. It ranges in scale from the subatomic to the galactic.

The word nature derives from the Latin word natura, or the course of things, natural character.Natura was a Latin translation of the Greek word physis, which originally related to the innate way in which plants and animals grow of their own accord, and to the Greek word for plants generally. The concept of nature as a whole, the physical universe, is a more recent development that gained increasingly wide use with the advent of modern scientific method in the last several centuries.

Within the various uses of the word today, "nature" may refer to the general realm of various types of living plants and animals, and in some cases to the processes associated with inanimate objects – the way that particular types of things exist and change of their own accord, such as the weather and geology of the Earth, and the matter and energy of which all these things are composed. It is often taken to mean the "natural environment" or wilderness – wild animals, rocks, forest, beaches, and in general those things that have not been substantially altered by human intervention, or which persist despite human intervention.


Halloween Costumes

Wednesday, October 04, 2006

Neuroscience

Neuroscience is a scientific discipline that studies the structure, function, development, genetics, biochemistry, physiology, pharmacology, and pathology of the nervous system. Traditionally it is seen as a branch of biological sciences. However, recently there has been of convergence of interest from many allied disciplines, including psychology, computer science, statistics, physics, and medicine. The scope of neuroscience has now broadened to include any systematic scientific experimental and theoretical investigation of the central and peripheral nervous system of biological organisms. The methodologies employed by neuroscientists have been enormously expanded, from biochemical and genetic analysis of dynamics of individual nerve cells and their molecular constituents to imaging representations of perceptual and motor tasks in the brain.

Furthermore, neuroscience is at the frontier of investigation of the brain and mind. The study of the brain is becoming the cornerstone in understanding how we perceive and interact with the external world and, in particular, how human experience and human biology influence each other.


Halloween Costumes

Saturday, September 09, 2006

Festival

A festival or fest is an event, usually staged by a local community, which centers on some theme, sometimes on some unique aspect of the community.Among many religions, a feast or festival is a set of celebrations in honour of God or gods. A feast and a festival are historically interchangeable. However, the term "feast" has also entered common secular parlance as a slang term for any large or elaborate meal. When used as in the meaning of a festival, most often refers to a religious festival rather than a film or art festival.

Festivals, of many types, serve to meet specific social needs and duties, as well as to provide entertainment. These times of celebration offer a sense of belonging for religious, social, or geographical groups. Modern festivals that focus on cultural or ethnic topics seek to inform members of their traditions. In past times, festivals were times when the elderly shared stories and transferred certain knowledge to the next generation. Historic feasts often provided a means for unity among families and for people to find mates. Select anniversaries have annual festivals to commemorate previous significant occurrences.


Halloween Costumes

Friday, September 08, 2006

Library

In the traditional sense of the word, a library is a collection of books and periodicals. It can refer to an individual's private collection, but more often it is a large collection that is funded and maintained by a city or institution. This collection is often used by people who choose not to — or cannot afford to — purchase an extensive collection themselves.
However, with the collection or invention of media other than books for storing information, many libraries are now also repositories and access points for maps, prints or other artwork, microfilm, microfiche, audio tapes, CDs, LPs, video tapes and DVDs, and provide public facilities to access CD-ROM and subscription databases and the Internet. Thus, modern libraries are increasingly being redefined as places to get unrestricted access to information in many formats and from many sources.
The term 'library' has itself acquired a secondary meaning: "a collection of useful material for common use", and in this sense is used in fields such as computer science, mathematics and statistics, electronics and biology.
More recently, libraries are understood as extending beyond the physical walls of a building, providing assistance in navigating and analyzing tremendous amounts of knowledge with a variety of digital tools.

Halloween Costumes

Monday, August 21, 2006

Vegetarian meat, dairy, and egg analogues

Some of the more traditional vegetarian meat analogues are based on centuries-old recipes for seitan (wheat gluten), other grains such as rice, mushrooms, legumes, tempeh, and/or pressed-tofu, with flavouring to make the finished product taste like chicken, beef, lamb, ham, sausage, seafood, etc. Some of the more-recent meat analogues include textured vegetable protein (TVP, which is a dry bulk commodity derived from soy), soy concentrate, Quorn, and modified defatted peanut flour to replace meat. TVP is produced more than any other meat analogue in most Western nations.
Examples of dairy analogues include those based primarily on processed rice, soy (tofu, soymilk, soy protein isolate), almond, cashew, gluten (such as with the first non-dairy creamers), nutritional yeast, or a combination of these, plus flavouring to make it taste like milk, cheeses, yogurt, mayonnaise, ice cream, cream cheese, sour cream, whipped cream, buttermilk, rarebit, or butter. Many dairy analogues contain casein, which is extracted dried milk proteins, when combined with soy and gluten, and are therefore not acceptable to vegans.
Examples of egg substitutes include tofu-scramblers, as well as Ener-G (primarily tapioca starch) and other similar products which recreate the leavening and binding effects of eggs in baked goods. Many people also use fruit products such as banana paste and applesauce as egg analogues in baking.


Halloween Costumes

Monday, August 14, 2006

mercer as a sergeant-major

He became a sergeant-major but nevertheless played in 26 wartime internationals, many of them as captain. The Everton manager Theo Kelly accused Mercer of not trying in an international against Scotland, but in reality Mercer had sustained a severe cartilage injury. After 14 with the club Mercer had to pay for the surgery himself even after consulting an orthopedic specialist and the Everton management refused to believe him. Understandably upset, Mercer moved in 1946 for £9,000 to Arsenal, although he commuted from Liverpool. Theo Kelly brought Mercer's boots to the transfer negotiations to prevent Mercer having a reason to go back to say goodbye to the other players at Everton.

Halloween Costumes

Friday, June 30, 2006

Pyromania

Pyromania is an obsession with fire and starting fires in an intentional fashion. In colloquial English, the synonym "firebug" or "firestarter" is sometimes used. Pyromaniacs are identified specifically as not having any other symptoms but obsession with fire causing their behavior. It is distinct from arson, and pyromaniacs are also distinct from those who start fires because of psychoses, for personal, monetary or political gain, or for acts of revenge. Pyromaniacs start fires to induce euphoria, and often tend to fixate on institutions of fire control: fire stations, firefighters, etc.

Starting in 1850, there have been many arguments as to the cause of pyromania. Whether the condition arises from mental illness or a moral deficiency has changed depending on the development of psychiatry and mental healthcare in general.


Halloween Costumes