GET Rs500 GIFT VOUCHER ONLY FOR REGISTERING

Yes. You heard it right.Not only that you will earn Rs 2025 after completing an offer which will take only 5 minutes. You will be able to send free SMS to anyone anywhere and get paid emails alsoWhat are you waiting for? click ...

http://www.youmint.com/network-vishakvishwa

YOU ARE NOT GONNA BELIEVE THIS ... DOWNLOAD THIS EXTRAORDINARY PICTURE

You are not going to believe your eyes.Download and have a look at this absolutely brilliant and extraordinary picture.Try it out !!!!.If you dont you are missing something.


http://uploadbox.com/files/ecc92260b0

WHY DOES FOOD GET SPOILED ???

Food, just like humans, gradually deteriorates because of a natural aging process. However, there are a few things we can do that will have a positive effect on the shelf life and safety of our food. Some preservation is done at the food manufacturing level and some occurs naturally, but a better understanding of the processes may help you extend the shelf life. Preservation methods and storage conditions must be designed to reduce the rate of decomposition and protect the safety, appearance and taste of our food.

The causes of food spoilage - Once food is harvested or slaughtered, its plant or animal tissue soon starts to decay. Microorganisms, such as fungi (molds & yeasts), spoilage bacteria, and their enzymes usually cause the spoilage process. Not all these changes in food are undesirable. Some people like aged beef and cheeses or very ripe fruit. The production of wine and beer involves conversion of sugars to alcohol, while souring of milk is essential in the production of cheese.

However, it is important to remember that some of the conditions that accelerate spoilage, such as inappropriate temperature and moisture control, also encourage the growth of pathogenic microorganisms that cause foodborne illness. Consequently, spoiled food is not just an issue of quality, it is also often a question of food safety.

• Mold & Yeast: Corn, nuts, breads, meat, cheeses, fruits and vegetables are all affected by mold. Do not try to salvage cheese that shows visible mold by cutting it away, unless of course it is a natural part of the cheese (i.e. bleu cheese, Brie, or Camembert). Mold forms a network of microscopic strands that extend into the foods which could cause allergic reactions or illness, so discarding them is the safest option. Most cheeses do not improve with age. Deli meats are the same. Yeast can cause discoloration, slime, and odors on sweet, acidic refrigerated foods or jams/jellies.
• Bacteria: Some spoilage bacteria are also pathogenic (disease causing). For example, Clostridium perfringens (a common cause of spoilage in meat & poultry) and Bacillus cereus (spoils milk & cream) are also responsible for causing foodborne illness. Most foods are subject to bacterial growth.
• Enzymes: Enzymes are naturally present in the cells of microorganisms that break down animal and plant foods. Breakdown continues until blanching or cooking inactivates the enzymes.

Other causes of spoilage include: 1) the bruising or piercing of vegetables, fruits or vacuum packaged food by rough handling; 2) oxidation (changes the taste or texture when exposed to oxygen) or freezer burn; 3) pest infestation as a result of poor receiving control, storage, rotation or cleaning; 4) adulteration through addition of leftover, inferior or undesirable food or ingredients to fresh food.

Detecting spoilage relies on being aware of the typical indicators, such as appearance (discoloration or slime), texture, smell or taste (obviously not recommended if any of the others are present).

Bottom line prevention - When in doubt, throw it out. Food spoilage affects your bottom line in food waste dollars. Prevention includes good receiving inspection practices, following the manufacturer's instructions, unfailing temperature recording and control, being observant and of course good sanitation and personal hygiene by food handlers.

WHY DO EARTHQUAKES OCCUR?

Earthquakes are usually caused when rock underground suddenly breaks along a fault. This sudden release of energy causes the seismic waves that make the ground shake. When two blocks of rock or two plates are rubbing against each other, they stick a little. They don't just slide smoothly; the rocks catch on each other. The rocks are still pushing against each other, but not moving. After a while, the rocks break because of all the pressure that's built up. When the rocks break, the earthquake occurs. During the earthquake and afterward, the plates or blocks of rock start moving, and they continue to move until they get stuck again. The spot underground where the rock breaks is called the focus of the earthquake. The place right above the focus (on top of the ground) is called the epicenter of the earthquake.

1. Break a block of foam rubber in half.
2. Put the pieces on a smooth table.
3. Put the rough edges of the foam rubber pieces together.
4. While pushing the two pieces together lightly, push one piece away from you along the table top while pulling the other piece toward you. See how they stick?
5. Keep pushing and pulling smoothly.
   
   Soon a little bit of foam rubber along the crack (the fault) will break and the two pieces will suddenly slip past each other. That sudden breaking of the foam rubber is the earthquake. That's just what happens along a strike-slip fault.

Earthquake-like seismic waves can also be caused by explosions underground. These explosions may be set off to break rock while making tunnels for roads, railroads, subways, or mines. These explosions, however, don't cause very strong seismic waves. You may not even feel them. Sometimes seismic waves occur when the roof or walls of a mine collapse. These can sometimes be felt by people near the mine. The largest underground explosions, from tests of nuclear warheads (bombs), can create seismic waves very much like large earthquakes. This fact has been exploited as a means to enforce the global nuclear test ban, because no nuclear warhead can be detonated on earth without producing such seismic waves.

WHY DO CUT ONIONS BRING TEARS?

We all know that onions can cause us to tear up when we cut them. But why does this happen?

As always, we turn to our best friend when we need a logical explanation - Science!

Within each variety of vegetables belonging to the Allium family resides a class of organic molecules called amino acid sulfoxides. These molecules help give the onions their specific bitter flavors.

Within the tissues of these same onions are enzymes called allinases. When these enzymes are released, be it through slicing, crushing, piercing, whatever, they react with the amino acid sulfoxides, converting them to sulfenic acids (RSOH). The sulfenic acids are very unstable, and often will often re-arrange their molecular structure to form syn-propanethial-S-oxide(H₇O₃S₂). It is this chemical that causes tearing.

There are several ways to prevent or mitigate the causes of tearing. One, you could have brain surgery that would block any sensory information sent from the ciliary nerve. However, that may be a tad impractical.

Water is the best route. Cutting onions under water, or soaking the onions prior to slicing will work. Choosing onions with higher water content can also lessen the tearing. This means purchasing onions that haven't been dry cured. Any "named" onions, such as "Vidalia" or "Walla Walla", will do. Dry cured onions inlcude the generic white, yellow, and red onions.

If the only options available to you are the generic whites, yellows, and reds, it would be the white onions which should have higher water content, and red onions having the least amount.

Another way to prevent or lessen tearing is to preventing an excessive amount of allinases from being released. The best way to do that is to cut the onion in such a way that minimally damages the tissue. In other words - the sharper the knife the better.

Finally, cut the onions in a well ventilated area. The vapors released from the onion can be dispersed quickly with a fan in the area.

So all of you out there cutting red onions with a butter knife in a windowless room, cut it out. You're only asking for trouble.

WHY DO DREAMS OCCUR?

Two different schools of thought exist as to why we dream: the physiological school, and the psychological school.

Both, however, agree that we dream during the REM, or rapid eye movement, phase of sleep. During this phase of sleep, our closed eyes dart rapidly about, our brain activity peaks, and our muscles suffer temporary paralysis.

The physiological theory centers upon how our body, specifically our brains, function during the REM phase of sleep. Proponents of this theory believe that we dream to exercise the synapses, or pathways, between brain cells, and that dreaming takes over where the active and awake brain leaves off. When awake, our brains constantly transmit and receive messages, which course through our billions of brain cells to their appropriate destinations, and keep our bodies in perpetual motion. Dreams replace this function.

Two underpinning physiological facts go towards supporting this theory of dreams. The first lies in the fact that the first two or so years of ones life, the most formative ones for learning, are also the ones in which the most REM sleep occurs. It follows that during this time of the greatest REM sleep, we experience the greatest number of dreams. The second physiological fact that lends credence to this theory is that our brain waves during REM sleep, as recorded by machines measuring the brain's electrical activity, are almost identical in nature to the brain waves during the hours we spend awake. This is not the case during the other phases of sleep.

Psychological theorists of dreams focus upon our thoughts and emotions, and speculate that dreams deal with immediate concerns in our lives, such as unfinished business from the day, or concerns we are incapable of handling during the course of the day. Dreams can, in fact, teach us things about ourselves that we are unaware of.

Connections between dreams that the human psyche have been made by many people over thousands of years. The famous Greek philosopher, Aristotle wrote in his "Parva Naturalia," over 2,200 years ago, of a connection between dreams, waking experiences, and emotional needs.

Others have delved into more complicated explanations for dreams, such as the prophetic nature of dreams written of in the Bible, which was and is a belief held by many cultures. Sigmund Freud, one of the fathers of modern psychology, believed dreams to be symbolic of any number of things buried deep within our minds and our memories.

Until someone proves or disproves one of these theories, or poses an alternate one, we are left at square one. Our knowledge as to what causes us to dream is limited to the fact that we do dream, and that dreams occur during the REM phase of sleep. Sweet dreams!

WHY DO BIRDS MIGRATE ?

Why do some birds fly thousands of miles back and forth between breeding and non-breeding areas every year whereas others never travel at all?

---

One textbook explanation suggests either eating fruit or living in non-forested environments were the precursors needed to evolve migratory behavior.

Not so, report a pair of ecologists from The University of Arizona in Tucson. The pressure to migrate comes from seasonal food scarcity.

"It's not just whether you eat insects, fruit, nectar or candy bars or where you eat them -- it matters how reliable that food source is from day-to-day," said W. Alice Boyle. "For example, some really long-distance migrants like arctic terns are not fruit-eaters."

Boyle, an adjunct lecturer in UA's department of ecology and evolutionary biology and co-author Courtney J. Conway, a UA assistant professor of natural resources and a research scientist with the U.S. Geological Survey, report their findings in the March 2007 issue of American Naturalist.

To figure out the underlying pressures that drive some birds to leave home for the season, the team wanted to examine a related set of species and compare their size, food type, habitat, migratory behavior and whether they fed in flocks.

Boyle and Conway focused on 379 species of New World flycatchers from the suborder Tyranni. One of the largest groups of New World birds, the Tyranni includes kingbirds, flycatchers, phoebes and such southern Arizona birdwatchers' delights as vermillion flycatchers and rose-throated becards. Tropical members include manakins and cotingas.

First the scientists had to construct the first "supertree" for New World flycatchers.

"No one has ever compiled all those birds together into one megafamily tree," Boyle said, adding that "supertree" is a technical term among evolutionary biologists.

Having the tree let the researchers compare a variety of traits across the many species of Tyranni by using a computer analysis called phylogenetic independent contrasts.

The technique allowed the scientists to sort out whether a bird was migratory because that's what species on their side of the family tree always did or whether the bird's travel habits had some ecological correlates.

Food scarcity was the number one issue that predicted a species' migratory behavior, the team found. Boyle said, "Food availability is the underlying process, not diet and habitat."

One strategy for dealing seasonal changes in food availability is migration. The team also found that species that forage in flocks are less likely to migrate.

"If you are faced with food scarcity, you have two options," Boyle said. "You can either forage with other birds or you can migrate."

When birds band together to search for food, the group is more likely to find a new patch of food than is one lone individual, she said. "Flocking can be an alternative way to deal with food shortages."

A universal assumption about bird migration has been that short-distance migration is an evolutionary stepping stone to long-distance migration. The team's work contradicts that idea by showing that short-distance migrants are inherently different from their globe-trotting cousins.

The National Science Foundation and the Natural Sciences and Engineering Research Council of Canada funded the work.

WHY DO BATS HANG UPSIDE DOWN ?

Because they need to put their feet up ;-).

Since bats are the only mammals who can fly, with wingspans ranging from 6" to 6', they failed to make great strides in the walking-about, or in the standing departments. Their legs and feet are simply not strong enough to support these functions for great lengths of time.

For this very reason, bats, when in their bat caves, or roosting in trees, take the weight off of their tired limbs by hanging upside down. Their breast-feeding babes, born live, as are all mammal offspring, have no choice but to hang in limbo with mom. Together, they reap the benefits of downward gravitational pull.

Bats also invert our common beliefs regarding their eyesight. The bat, a nocturnal creature, hunts its prey at night, and rests up (or down, as is the case) for the evening's events by day. One would be incorrect in assuming that the bat has keen night vision, to assist it in its feeding frenzy. Not so.

The bat employs an echo system, whereby it tosses out a high-frequency sound, one inaubible to the human ear, which in turn strikes a target, and then bounces back to the bat, thereby letting it know what lies ahead. Were it not for the bat's radar, we would hear even more bumps in the night than we already do.

Why don't Birds on a wire get a shock?

Now how is that possible? The fact is, for a living creature to get a ‘shock’ there has to be a substantial flow of current through the body. However, there is barely any current running through the bird’s body for two reasons. Firstly, the bird not only forms a circuit with the wire, but it also offers a high resistance to current, so the current passes through the wire instead of the bird.

It’s a bit like this, would you prefer going on a smooth road or a road full of potholes? The answer is obvious and just like you, the current prefers taking the easier path. All objects offer some amount of resistance to the flow of current, depending on the material.

This is just one of the reasons why birds don’t get shock, however the more important reason why current does not pass through the bird is, there is barely any, if at all, voltage difference across the bird. Current flow is actually just the flow of minute charged particles that are invisible to the naked eye. These charged particles need an energy input in order for them to get transferred. The amount of energy needed to move the charges from one point to another is measured in terms of the potential difference between the two points.

A bird perched on high-tension wires has both its feet placed firmly on the same wire, so the net potential difference from one end of the bird to the other is, for all purposes, next to nil.

In order for current to flow through the bird, there must be a sizeable difference in voltage across the body. While the potential difference between the wire and Earth may be thousands of volts, the potential difference between the bird's two feet is extremely tiny and so a very small current flows through the bird which can barely be registered.

If the bird were to touch the wire and simultaneously another wire, it would receive a mild shock. On the other hand if it were to touch the wire and some other object connected to the ground, it would receive a deadly shock, the greater the potential difference, the greater is the current flow

WHY IS THE SKY BLUE?

The blue color of the sky is due to Rayleigh scattering. As light moves through the atmosphere, most of the longer wavelengths pass straight through. Little of the red, orange and yellow light is affected by the air.

However, much of the shorter wavelength light is absorbed by the gas molecules. The absorbed blue light is then radiated in different directions. It gets scattered all around the sky. Whichever direction you look, some of this scattered blue light reaches you. Since you see the blue light from everywhere overhead, the sky looks blue.

Blue sky from scattered light



As you look closer to the horizon, the sky appears much paler in color. To reach you, the scattered blue light must pass through more air. Some of it gets scattered away again in other directions. Less blue light reaches your eyes. The color of the sky near the horizon appears paler or white.

Sky paler at horizon

Why do we get HEADACHES ?????

When i asked this question to my friend, he said "DUE TO LESS FLOW OF BLOOD TO OUR BRAIN" , this is a COMMON answer told by many people ...Actually this is only one of the reasons causing head aches !!!

Headaches are one of the most common medical complaints -- nearly everyone gets a headache at some point. Over 45 million Americans (about one in six) suffer chronic headaches each year. Headaches therefore have a big economic impact -- when you have a throbbing pain in your head, it's hard to work. The cost of these headaches in absenteeism and medical expenses is estimated as high as $50 billion per year.

A headache is a pain sensed in the nerves and muscles of the head and neck, as well as the meninges (the membranous coverings of the brain and spinal cord). Your brain itself cannot sense pain, so a headache has nothing to do with your brain hurting. It is really a pain somewhere around your brain, being picked up by nerve endings located in your head.

There are two main reasons why people get headaches, and doctors therefore classify headaches into two broad categories: primary and secondary.

Primary headaches are not associated with any underlying medical condition.

Secondary headaches are associated with medical conditions like infections, fever, head injury, hypoglycemia, tumors, dental conditions or increased pressure in the skull and/or sinuses (sinus headaches).
There are three main causes for primary headaches:

Migraine - Migraine headaches can be caused by reduced blood flow to various areas of the cerebral cortex.
Symptoms of migraines include sensitivity to light and noise, nausea, vomiting and intense throbbing pain that is usually on one side of the head.
A neurotransmitter, serotonin, is thought to be involved in migraines because many of the drugs used to treat migraines alter the binding of serotonin to various receptors.
Tension - Tension headaches are caused by muscular strains in the head and neck and/or emotional stress.
Tension headaches are usually dull, steady, aching pains on both sides of the head.
Sometimes, tension headaches develop into throbbing pains, leading researchers to believe that they may be closely related to migraines.
Eye strain (poor vision) can trigger frequent tension headaches.
Cluster - Cluster headaches are headaches that occur repeatedly over a period of weeks or even months.
Cluster-headache pain usually occurs on one side of the head and is centered around the eye.
The causes of cluster headaches are unknown, but may be related to changes in blood flow because substances that affect blood flow, such as alcohol, can trigger cluster headaches.
­­
­Primary headaches can also be caused by too much blood flow. For example, if you have read How Caffeine Works, you know that caffeine reduces blood flow in the brain. Some pain relievers contain caffeine to take advantage of this effect. If you have been taking caffeine every day and you stop, you can get an incredible headache because of the increased blood flow in your brain.

Secondary headaches result from some other problem with your body. For example, How Viruses Work talks about why you get a headache (and other pains) when you have the flu. Once you eliminate the disease, you eliminate the secondary headaches.

WHY doesnt the stomach digest itself ???

If you were to put a piece of zinc into a cup of gastric acid, the zinc would dissolve. It's therefore not surprising that the stomach's digestive juices can make short work of anything we deliberately feed to it. So its logical to ask this question, "what if the digestive juices digest the skin cells of our stomach ???"

The answer is :
In a manner of speaking, it does. The stomach is lined with a dense layer of cells, called epithelial cells, which continually SACRIFICE themselves in order to protect deeper layers of the stomach wall. Each minute, the surface lining sheds some 500,000 cells, and it completely replaces itself in three days.





The main components of digestive juices are a protein-digesting enzyme called pepsin and hydrochloric acid. The pepsin is relatively harmless, but hydrochloric acid is extremely caustic and can dissolve tissue in hours. If too much is secreted, the regenerative properties of the epithelial cells may be overcome, the wall breached, and an ulcer produced.

Not only the epithelial tissue is present to protect but there is MUCOUS CELLS which does alkaline mucous secretions which again protects our stomach lining ...This picture shows the mucous cells present in our stomach !!!