Thursday, December 29, 2011

Inflammation

As important as your body’s physical barriers are, they can’t repel all invaders. Minor cuts in your skin open a brief, tantalizing entryway to your body’s nutrient-rich interior. Tiny germs can eventually make their way through the thickest mucous coating. And while the acid in your stomach is strong enough to pickle steel, crafty microbes can survive or slip through it to your much more hospitable intestines. (For example, H. pylori, the culprit behind most heartburn-causing stomach ulcers, secretes an acid-neutralizing enzyme that protects the microbe until it gets a chance to worm its way into your stomach walls.)
When a pathogen breaches your body’s first line of defense, the lowly foot soldiers of your immune system meet it within minutes. One of your best defenders is the macrophage (which translates as “big eater”), a swollen blob of a cell that sucks in almost any foreign particle that crosses its path, including dead cells, debris, and pathogens. Once enveloped, a battery of powerful chemicals attacks the foreign particle, destroying it in minutes. A typical macrophage may swallow some hundred bacteria before it dies, finally done in by its own toxic chemicals.

A macrophage is a type of white blood cell. All white blood cells are immune system soldiers—they simply use different tactics.

For its first strike to be successful, your body needs to respond quickly and with overwhelming force. It’s not enough to wait until wandering macrophages stumble across new invaders. Your body needs to summon its defensive forces in a hurry.

Its trick is the inflammation response, your immune system’s call to arms. Your body triggers inflammation when it detects damaged tissue, intense heat, dangerous chemicals, or potential attackers. The first effect of the inflammation response is increased blood flow—your blood vessels dilate and gaps open in your cell walls so the blood can pour into the surrounding tissue. As the blood rushes in, you feel the resulting swelling, as well as pain (because the swollen tissues press on nearby nerves that carry pain signals) and heat (because of the influx of heated blood).

The main goal of the inflammation response is to stock the affected area with your body’s immune system soldiers. In addition, the added blood increases the heat, which spurs your macrophages to work harder and can alter the delicate balance of chemical reactions in the invading pathogens, throwing them off balance. (Your body uses a fever—a sudden spike in body temperature—with much the same effect when battling more stubborn enemies.)

The only time you see your white blood cells is when pus oozes from a wound. This creamy, yellow substance contains the detritus of biological warfare—brokendown tissue cells, living and dead pathogens, and scores of dead white blood cells.

Source of Information : Oreilly - Your Body Missing Manual

Sunday, December 25, 2011

A Tale of Math Treasure

An exhibition traces the reconstruction of a long-missing collection of writings by Archimedes

There is much cheesy lore about the ancient Greek mathematician Archimedes of Syracuse: that he popularized the word “eureka”; that he used mirrors to set Roman ships on fire; that a Roman soldier killed him in 212 B.C. while he was tracing diagrams in the sand. Not only is the lore probably untrue, historians say, but it also fails to capture the true significance of his achievements, which spanned mathematics, science and engineering and inspired the likes of Leonardo da Vinci, Galileo and Isaac Newton. Some credit him with having essentially invented the basic ideas of calculus. An exhibit opening in October at the Walters Art Museum in Baltimore will showcase a decade-long effort to restore some of his longlost texts and unearth some of his previously unknown contributions. “Lost and Found: The Secrets of Archimedes” focuses on a parchment book known as the Archimedes Palimpsest.

At one point in history, all of Archimedes’ works that survived through the Dark Ages were contained in just three tomes made by 10th-century copyists in Constantinople. One, called Codex C, disappeared some time after Western European armies sacked the Byzantine capital in 1204. Then, in 1906, Danish philologist Johan Ludvig Heiberg found a book of prayers at a monastery in the city and noticed that it was a palimpsest—meaning that the parchment had been recycled by cutting up the pages of older books and scraping them clean. Among those older books, Heiberg realized, was Codex C. Armed with a magnifying lens, Heiberg painstakingly transcribed what he could read of the older text, including parts of two treatises that no other eyes had seen in modern times. One was the “Method of Mechanical

Theorems,” which describes the law of the lever and a technique to calculate a body’s center of gravity—essentially the one still used today. Another, called the “Stomachion,” appeared to be about a tangramlike game. Soon, the book disappeared again before resurfacing in 1998 at an auction in New York City. There an anonymous collector bought it for $2 million and lent it to the Walters museum. When the palimpsest reemerged, says Will Noel, who is its curator, “it was in appalling condition.” As the exhibition will display on panels and videos, imaging experts were able to map much of the hidden text using high-tech tools—including x-rays from a particle accelerator— and to make it available to scholars. Reviel Netz, a historian of mathematics at Stanford University, discovered by reading the “Method of Mechanical Theorems” that Archimedes treated infinity as a number, which constituted something of a philosophical leap. Netz was also the first scholar to do a thorough study of the diagrams, which he says are likely to be faithful reproductions of the author’s original drawings and give crucial insights into his thinking. These will be on display, but the studies go on. Netz is now transcribing the texts contained in the palimpsest, which he estimates at about 50,000 words, most written in a shorthand typical of medieval copyists. He plans to publish a critical edition in the original Greek. “It will take probably several decades to translate it into English,” he says.

Source of Information : Scientific American Magazine

Wednesday, December 21, 2011

How Many Glasses of Water a Day?

It’s the question that everyone seems to ask. And if you follow the standard advice (drink 8 to 10 glasses of water every day), your next request will be for directions to the restroom. Because unless you’re a strenuous exercise or a desert dweller, you’re unlikely to need that much water—and unless you’re carrying a horse’s bladder, you won’t hold onto it for long.

No one’s quite sure where the 8-to-10 glasses factoid started. However, medical professionals do agree on quite a few things about fluids:

• Six glasses is usually enough. If you must count, 6 glasses of water a day is probably a good rule of thumb (not a bare minimum). But the average person, doing gentle activity in a gentle climate, can probably get all the fluid they need from solid food alone (although it’s not recommended).

• Follow your thirst. Your need for water varies greatly depending on your activity level. Fortunately, your body is surprisingly good at telling you when to drink. And the idea that we’re chronically (and unknowingly) dehydrated is little more than science fiction.

• Don’t fear coffee and tea. Despite the diuretic properties of caffeine, you’ll still retain a large amount of the fluid in every cup—and even more if you’re a regular drinker of caffeinated beverages.

• Dehydration may worsen constipation. If you’re straining to pass stool, you might benefit from increasing your water intake a bit. However, results vary, and a more likely cause of constipation is inadequate fiber in your diet.

So why are we so easily misled by drinking myths that don’t hold water? Quite simply, in the era of modern science, we’re used to hearing (and accepting) startling facts. But when it comes to water, medical research is in an unusual position: proving that our common sense was right all along.

Source of Information : Oreilly - Your Body Missing Manual

Friday, December 16, 2011

What Are Probiotics and Prebiotics?

Probiotics are live microorganisms (bacteria or yeast) that are particularly well-suited to your digestive system. For example, lactic acid bacteria is a common probiotic that gives sourdough and yogurt their characteristic sour flavor. In your colon, lactic acid bacteria digest the sugar known as lactose and may even prevent inflammation and inhibit cancer.

However, there’s a catch. As you’ve seen, your large intestine is quite far down in your digestive system. For a probiotic to make it to its new home, it needs to pass through the inhospitable acidic environment of your stomach. Pharmaceutical companies are experimenting with special coatings that help probiotics make the hazardous journey intact, but in the meantime it’s hard to tell how effective probiotic-fortified foods really are.

Prebiotics are substances that your healthy, colon-dwelling bacteria like to munch on. Supply these bacteria with more prebiotics, and you can encourage a small population to grow. Prebiotics are naturally present in fruits and vegetables, but don’t expect to find any in a box of macaroni and cheese.

The bottom line is that both probiotics and prebiotics are based on valid nutritional science that recognizes the value of good gut bacteria. But their success as products is less clear, and it’s a good guess that you’ll get more benefit from a diet that emphasizes fruits and vegetables than one that focuses on convenience foods and nutritionally fortified drinks, no matter what miraculous new additives manufacturers toss in.

Source of Information : Oreilly - Your Body Missing Manual

Tuesday, December 13, 2011

The Trouble with Armor

The steel plates worn by medieval soldiers may have led to their wearers’ demise

On August 13, 1415, the 27-year-old English king Henry V led his army into France. Within two months dysentery had killed perhaps a quarter of his men, while a French army four times its size blocked escape to Calais and across the English Channel. Winter approached; food grew scarce. Yet in one of the most remarkable upsets in military history, a force of fewer than 7,000 English soldiers— most of them lightly armed archers—repulsed 20,000 to 30,000 heavily armored French men-at-arms near the village of Agincourt, killing thousands. Shakespeare’s play Henry V attributed the victory to the power of Henry’s inspirational rhetoric; the renowned military historian John Keegan has credited the self-defeating crush of the French charge. But a study by exercise physiologists now suggests a new reason for the slaughter: suits of armor might not be all that great for fighting.

Researchers at the University of Leeds in England placed armor-clad volunteers on a treadmill and monitored their oxygen consumption. The armor commonly used in the 15th century weighed anywhere from 30 to 50 kilograms, spread from head to hand to toe. Because of the distributed mass, volunteers had to summon great effort to swing steel-plated legs through each stride. In addition, breastplates forced quick, shallow breaths. The researchers found that the suits of armor doubled volunteers’ metabolic requirements, compared with an increase of only about 70 percent for the same amount of weight carried in a backpack.

Of course, medieval battles did not happen on treadmills. The fields at Agincourt were thick with mud, having recently been plowed for winter wheat and soaked in a heavy October shower. The French charged across 300 yards of this slop, all while suffering fire from the English archers. Combine the effort required to run in armor with that needed to slog through mud, says Graham Askew, one of the study’s leaders, and you’d expect at least a fourfold increase in energy expenditure—enough, it seems, to change history.

Source of Information : Scientific American Magazine

Thursday, December 8, 2011

Why Don’t Mexicans Get Traveler’s Diarrhea?

If you’re a citizen of the world, you’ve probably met up with that uncomfortable phenomenon known as traveler’s diarrhea—a short episode of diarrhea that strikes thosebrave enough to visit local places and enjoy local cuisine. The odd part is that traveler’s diarrhea seems to affect only travelers. Native people can eat the same foods and emerge unscathed.

The first thing to understand is that traveler’s diarrhea needs a certain level of sanitary sloppiness to occur. In particular, it only happens if there’s some way for bacteria to pass from another person’s (or an animal’s) feces into your environment. For this reason, traveler’s diarrhea happens much less often to visitors of most first-world countries. (Although Mexicans do occasionally get diarrhea when visiting the U.S., which they call“Washington’s Revenge.”)

However, this doesn’t explain why locals have a much-reduced rate of diarrhea. The answer is that, because of near-continuous exposure, their digestive systems have gradually grown to recognize and tolerate strains of bacteria that other people can’t handle. No one knows how long this immunity takes to develop or how long it holds up, but a study in Nepal found that American adults needed 7 years of local life to adjust, and they lost their tolerance after only a few months back home.

Interestingly, enterprising travelers can use one approach for instant immunity. If you’re worried about E. coli (which is the most common culprit in Mexico), you can buy a vaccine called Dukoral that gives you temporary immunity. To get Dukoral, head to your local pharmacy or check with a travel clinic, which can also identify the gastrointestinal dangers in different parts of the world.

Source of Information : Oreilly - Your Body Missing Manual

Tuesday, December 6, 2011

Instant Health Checks for Buildings and Bridges

Sensors can detect damage that may be invisible to the naked eye

During 2011’s deadly onslaught of earthquakes, floods and tornadoes, countless buildings had to be evacuated while workers checked to make sure they were stable. The events served as a reminder that most structures are still inspected by a decidedly low-tech method: the naked eye. To speed the process and make it more accurate, investigators are researching electronic skins, evolutionary algorithms and other systems that can monitor the integrity of bridges, buildings, dams and other structures in real time. To automatically detect tiny faults and relay their precise locations, civil engineer Simon Laflamme of the Massachusetts Institute of Technology and his colleagues are devising a “sensing skin”—flexible patches that glue to areas where cracks are likely to occur and continuously monitor them. The formation of a crack would cause a tiny movement in the concrete under a patch, causing a change in the electrical charge stored in the sensing skin, which is made of stretchable plastic mixed with titanium oxide. Every day a computer attached to a collection of patches would send out a current to measure each patch’s charge, a system that Laflamme and his colleagues detail in the Journal of Materials Chemistry

Another engineer is applying a similar concept to bridges. To monitor deterioration inside suspension bridge cables, Raimondo Betti of Columbia University and his collaborators are testing 40 sensors in cables in New York City’s Manhattan Bridge (above). The sensors track temperature, humidity and corrosion rate.

Although these sensors can detect damage that occurs after they have been installed, what about damage a structure had beforehand? Roboticist Hod Lipson of Cornell University and his colleagues have developed a computer model that simulates an intact structure and runs algorithms that evolve this model until it matches data that sensors provide, which can reveal a broader scope of damage.

Others are not yet convinced of these projects’ benefits. “There does not exist, yet, enough research and data that economically support continuous and timely maintenance,” Laflamme says. Another concern might be the yet to be studied long-term performance of the systems, especially in harsh environments—a matter for future research.

Source of Information : Scientific American Magazine

Wednesday, November 30, 2011

Diet Advice from Your Small Intestine

One of your digestive system’s limitations is that the body parts in charge of picking, identifying, and enjoying what you eat (your brain and your mouth) sit a great distance away from the parts that actually process and absorb your meal (mainly, your small intestine). So it’s no wonder that this system so often slips out of sync, sending you hurtling straight into dietary trouble.
The real problem is that your brain and mouth follow a somewhat outdated ingredient list. They’re always searching for the immediate gratification of sweet, calorie-dense foods. The rest of your digestive system simply processes whatever it gets. In 100,000 years of human evolution, it never occurred to anyone that people might somehow be able to consume vastly more food than they need.

The only antidote to the rampant abuses of modern eating is to simplify your diet with a few common-sense principles. And now that your small intestine has broken your breakfast down into its essential parts—protein, fat, and sugar—it’s easier to pick out these principles, and to separate what your body eats from what it needs. Here’s what your small intestine would ask for if it had a voice:

• Natural, unprocessed foods. Industrial processing—the sort of thing that changes a box of ordinary rice into a package of breakfast cereal— amounts to pre-digestion. It takes responsibility for breaking down foods away from your small intestine, and it can eliminate trace elements of hundreds of different nutrients—all for a product that tastes like flavored packing material.

• Plant-based foods, with small quantities of meat. Unless you’re a weight-training athlete, your body can get all the protein it needs from two servings of meat per day. (That’s a piece of chicken, beef, or fish that’s the size of the palm of your hand, without the fingers.) Dieticians often suggest treating meat as a condiment—in other words, as something you add to flavor a nutrient-rich plate of vegetables.

• A rich variety. Rather than obsess about the nutritional merits of squash versus sweet potatoes, strive to incorporate a range of healthy food into your diet. Highly varied dining offers another benefit: The sheer amount of healthy food tends to crowd out other, less desirable foods.

• More complex carbohydrates, less sugar. Your mouth, stomach, and small intestine eventually break down all carbohydrates into sugar. The more refined the carbohydrate, the faster the conversion, and the quicker you absorb it. This is a problem, because your digestive system is all about pacing (as demonstrated by the careful, one-squirt-ata- time food transmission from your stomach to your small intestine). Heavily refined foods leave your stomach more quickly, which reduces your body’s ability to pace itself and leads to see-sawing levels of blood sugar that your liver must work hard to adjust. But if you fill up with complex carbohydrates like vegetables, whole wheat flour, and brown rice, you’ll have a tankful of food that will fuel you with a slow, steady supply of sugar for hours to come.

• Water. If your food comes premixed with fluid, you need less saliva and gastric juice to create the creamy paste your digestive system expects. And although well-meaning nutritionists sometimes warn heavy drinkers (of water) that they can dilute their gastric acids at mealtime, the effect is minor and has little effect on the average stomach.

Source of Information : Oreilly - Your Body Missing Manual

Monday, November 28, 2011

Clearing the Smoke Marijuana remains tightly controlled, even though its compounds show promise

Preliminary clinical trials show marijuana might be useful for pain, nausea and weight loss in cancer and HIV/AIDS and for muscle spasms in multiple sclerosis. Medical marijuana studies in the U.S. are dwindling fast, however, as funding for research in California—the only state to support research on the whole cannabis plant—comes to an end this year and federal regulations on obtaining marijuana for study remain tight.

In July the Drug Enforcement Administration denied a petition, first filed in 2002 and supported by the American Medical Association, to change marijuana’s current classification. So marijuana remains in the administration’s most tightly controlled category, Schedule I, defined as drugs that “have a high potential for abuse” and “have no currently accepted medical use in treatment in the U.S.” Many medical cannabis proponents see a catch-22 in the U.S.’s marijuana control. One of the DEA’s reasons for keeping marijuana in Schedule I is that the drug does not have enough clinical trials showing its benefits. Yet the classification may limit research by making marijuana difficult for investigators to obtain.

Even as prospects for whole-plant marijuana research dim, those who study isolated compounds from marijuana— which incorporates more than 400 different types of molecules—have an easier time. The drug’s main active chemical, delta 9-tetrahydrocannabinol (THC), is already FDA-approved for nausea and weight loss in cancer and HIV/AIDS patients. The Mayo Clinic is investigating the compound, trade-named Marinol, as a treatment for irritable bowel syndrome. Researchers at Brigham and Women’s Hospital in Boston are studying Marinol for chronic pain.

Compared with smoked or vaporized marijuana, isolated cannabis compounds are more likely to reach federal approval, experts say. Pharmaceutical companies are more likely to develop individual compounds because they are easier to standardize and patent. The results should be similar to inhaled marijuana, says Mahmoud ElSohly, a marijuana chemistry researcher at the University of Mississippi, whose lab grows the nation’s only research-grade marijuana.

Other investigators say a turn away from whole-plant research would shortchange patients because the many compounds in marijuana work together to produce a better effect than any one compound alone. Inhaling plant material may also provide a faster-acting therapy than taking Marinol by mouth. While ElSohly agrees that other marijuana compounds can enhance THC, he thinks just a few chemicals should re-create most of marijuana’s benefits.

Source of Information : Scientific American Magazine

Friday, November 25, 2011

Purposefully Indigestible

Depending on your meal, your small intestine may contain quite a bit of undigested food. (This isn’t the case with the simple breakfast example because it’s short on plant matter and other sources of fiber.) In modest quantities, this undigested food benefits your digestive system and eases the passage of your meal as it scrapes through your narrow intestinal passageways. We call it fiber. One example of indigestible food is cellulose, a compound that helps form the structure of green plants.

In the dieting world, there’s a completely different class of indigestible food substances that masquerade as the sugar and fats our mouths expect, while dodging the absorption step in the small intestine. One example, sucralose (which is known commercially as Splenda), is a subtly modified version of sugar that triggers the sweet taste buds on your tongue, but can’t be broken down by the carbohydrate-processing enzymes in your body. Another example is olestra, an altered fat molecule that has the same mouth feel as fat but passes unhindered through your small intestine. (Eat olestra in great quantities, and you’ll have a significant amount of unneeded matter moving through your system, potentially leading to the abdominal cramping and loose stools mentioned in the package warning label.) These two indigestible foods are examples of food science at its creative best—and potential health concerns.

The key concern for most sugar and fat replacements is not toxic side effects, but the way they allow non-foods with no nutritional value to take up valuable stomach space. Dieters caught up in the excitement of eating without weight gain may forget that their calorie-free potato chips are displacing real foods, and in the process robbing their bodies of the vitamins, minerals, and other nutrients they need.

Source of Information : Oreilly - Your Body Missing Manual

Tuesday, November 22, 2011

Is It Safe to Drink?

The government may not be doing enough to regulate contaminants in tap water

More than 6,000 chemicals pollute U.S. drinking water, yet the U.S. Environmental Protection Agency has added only one new pollutant to its regulatory roster in the past 15 years. Environmental groups have long raised questions about this track record, and the U.S. Government Accountability Office recently joined the chorus, releasing a report that charges the agency with taking actions that have “impeded... progress in helping assure the public of safe drinking water.”

Among other things, the GAO report says, the EPA relies on flawed data. To determine the level of a particular pollutant in drinking water—which the EPA does before making a regulatory ruling on it—the agency relies on analytic testing methods so insensitive that they cannot identify the contaminants at levels expected to cause health effects. In addition, since 1996 the EPA has been required to make regulatory decisions about five new pollutants each year, ruling on those that might pose the biggest threats to public health. The GAO report asserts that the agency has been ruling only on the “low-hanging fruit”—contaminants for which regulatory decisions are easy rather than those that might be the most dangerous.

“They’re not actually doing anything to protect public health,” says Mae Wu, an attorney at the Natural Resources Defense Council. For its part, the EPA has pledged to review the nation’s drinking-water standards and to add at least 16 new contaminants to the list of those it regulates. This past February the agency reversed a longstanding decision to not regulate the rocket-fuel ingredient perchlorate, making the chemical the first new drinking-water contaminant to be regulated since 1996. In its response to the GAO, the EPA stated that “no action” was necessary to better prioritize the contaminants on which the agency will rule in the future, nor did it acknowledge the need for improvements in data collection. The agency did, however, agree to consider improving its methods for alerting the public when there are drinking- water advisories.

Source of Information : Scientific American Magazine

Wednesday, November 16, 2011

The Great Absorber

Your small intestine has two important responsibilities. First, it finishes digesting your meal, further breaking down its proteins, fats, and starches into simpler compounds. To perform this task, it gets help from several accessory organs, including your pancreas, liver, and gallbladder. Second, your small intestine absorbs your meal’s final, fully digested nutrients, pulling them out of the pasty digestive solution and passing them directly into your bloodstream, making them available to the rest of your body. The easiest way to understand what’s going on in your small intestine is to consider the different types of food it processes:
• Carbohydrates. Several hours ago, you began to digest your breakfast toast in the relatively easygoing environment of your mouth. Now, deep in your abdomen, the process continues with a new series of more powerful enzymes that shatter the remnants of your toast into simple sugars. Your body secretes these enzymes from your pancreas—a plain looking slab of an organ that squirts digestive juices into your small intestine.

• Proteins. More recently, your stomach started working on the proteins in your eggs and sausage. Your small intestine finishes the job, again with the help of enzymes from your pancreas. The end results are amino acids—fundamental building blocks your body uses to assemble hundreds of thousands of different biological compounds.

• Fats. Your body has to break these down into fatty acids. Once again, the pancreas secretes the enzymes your small intestine needs to do the job. However, before these enzymes can get to work, your body needs a way to break the big, greasy globules of fat into tiny droplets, in much the same way that dish detergent dissolves the oil from last night’s deep-fried chicken. Two organs solve the problem. First, the liver—a multifaceted organ whose main responsibility is filtering blood—creates bile that does the trick. Second, the gallbladder—a kiwi-sized organ that looks like an unremarkable green pouch—stores and concentrates this bile between meals.

Once your body breaks down these nutrients, they seep through your thin intestinal walls, along with various vitamins and minerals. To make this process easier, thin folds lined with tiny hairs cover your small intestine. These details help increase your small intestine’s surface area to promote nutrient absorption.

With the pancreas’s high-powered digestive abilities, you might wonder why it doesn’t eat itself. The trick is that the pancreas releases harmless, inactive enzymes. These enzymes switch themselves on when they meet up with the strong acids in the partly digested food in your intestine.

Source of Information : Oreilly - Your Body Missing Manual

Thursday, November 10, 2011

Using Intestines from the Animal Kingdom

Your intestines are quite important, and you’d be ill advised to part with a single foot of the stretchy tubing. However, it just so happens that the resilient tissue that lines your gut lends itself to a host of arts and crafts. Humans have capitalized on this with the help of other animals. In fact, we’re downright notorious in the animal kingdom for putting the intestines of other species to work in a variety of creative ways. Here are some examples:
• Cheese-making. Cow, sheep, and goat guts contain rennet, an important additive in the cheese-making process. Presumably, ancient man discovered this while making cheese in a convenient sack—the stomach of a dead animal.

• Music-playing. For centuries, craftsman fitted violins and other stringed instruments with tough fibers made from animal intestines. Although silk, nylon, and steel are more common today, some top-caliber musicians insist that nothing can match the sound of fresh sheep gut.

• Food. Natural sausage casings (the thin, plasticky substance that wraps your breakfast sausage) use animal gut from a pig, cow, or sheep.

• Sex. The world’s oldest known condoms (dating back to about 1640) were made from sheep intestines. They were quite expensive, which probably accounts for the roaring trade in washed, second-hand condoms that prevailed at the time.

Source of Information : Oreilly - Your Body Missing Manual

Saturday, November 5, 2011

Fasting and Detoxifying

Fasting is the age-old practice of limiting food and drink, often as part of religious festivals. Some fasts restrict all food, while others allow a stripped-down diet. Fasts may also go hand-in-hand with non-food restrictions, such as religious rules forbidding fighting, lying, and sex. (Fasts are notorious for lumping sin and pleasure together into one giant category of forbidden pastimes.)

The benefits of fasting aren’t digestive. Supporters point out how practicing selfrestraint (and enduring a little borborygmus) develops inner will. They’re less likely to point out the way fasting increases carnal pleasures post-fast. Much in the same way that you feel good when you stop striking your head against a tree, the end of a fast brings a heightened appreciation of everything you temporarily sacrificed. More controversially, fasts are sometimes studied as a way to improve health. Some studies suggest that occasional fasting or lifelong calorie restriction can boost life expectancy.

One possible reason for this phenomenon (if it actually exists) is that gentle stress may prompt the body to fire up certain beneficial repair processes. Or it may simply be that less food means less of all the ills of the modern diet—from excess sugar to runaway fat.

The score for so-called detoxifying diets is far less promising. Promoters suggest that extreme fasting, bizarre diet restrictions, or colon “cleansing” can purge toxins from your body. The idea is alluring— after all, who wouldn’t like to atone for a lifetime of dietary sin and return the body to a pristine, unpolluted state? However, the science is about as solid as a bowl of low-calorie Jell-O.

Source of Information : Oreilly - Your Body Missing Manual

Monday, October 31, 2011

WHO? WHAT? WHEN? WHERE? HOW? WHY?

A good science article answers all these questions. Especially it answers the question ‘why?’, explaining to the reader the reason the research was carried out, and why it is important to humanity. The reason why is often taken for granted in scientific writing, which is a big mistake when writing for a wider audience.

Each question helps to establish the meaning of the science to the reader. ‘Who’, for example, explains who is affected by the science, and who performed it. This conveys both its relevance to society or industry, and its trustworthiness, embodied in the name of the research institute or corporation. ‘What’ explains what was actually done. ‘When’ conveys to the reader whether this is new knowledge, or ‘news’. ‘Where’ is important because people habitually think of their own locality first, and science performed locally by local researchers addressing local problems is of much greater interest than science performed in some other country by and for people they have never heard of. ‘How’ explains how the science was actually performed and how it affects the community.

Source of Information : CSIRO-Open Science Sharing Knowledge in the Global Century 

Thursday, October 27, 2011

JARGON AND BUREAUCRATESE

Scientists use language in very particular ways in order to convey specialized meanings. This works fine among the peer group but it can lead to confusion, ambiguity and misinterpretation externally. Because science itself is concerned with being as precise as possible, it is a great shame if it\ loses precision because its audience misunderstands what they are told. In science, new words are often coined to describe new phenomena, or else old words are given new meanings to which the public is not privy. Scientists sometimes forget this.

For example, a soil scientist may refer unthinkingly to a soil layer as a ‘horizon’, whereas his lay audience may wonder what that line the sun goes behind is doing at the bottom of a hole. This is a case of one word having two (or more) meanings: technical and general. Classically, scientists often refer to their ‘models’, blithely unaware that many people in society think a model is an elegant person sporting stylish clothes, or alternatively, a small plastic aeroplane. In the sentence ‘We are using a new model to predict rabbit populations…’ the average person may be puzzled why the scientist would employ a mannequin to forecast rabbit plagues – and probably wonder how the scientist came by such a generous budget!

Scientific terms slip off the tongue, or the keyboard, very easily, and great care must be taken to avoid them or at least to translate them for the audience. Is a base an electron pair, a headquarters or the bottom of something? Is a phase part of a waveform cycle or a period in your life? Is a port the plughole in a computer, a place for ships to dock or a fortified wine? Is a bond a chemical link, a financial instrument or a manacle? Context will usually supply the answer, but one can never be sure what all readers will make of it and science writing must always be scanned carefully for such ambiguities.

A good test for whether a word is jargon is to imagine oneself standing at the supermarket checkout and saying the word to each person as they come past the cash register. How many would be able to provide even a rough explanation of the meaning? If the answer is ‘not many’, then the term should be avoided and a more common term used.

Avoiding scientific jargon is not as hard as it seems, as articles written for the public, for government and even industry usually focus on the application of the science, not on the science itself. It is nearly always possible to describe the application of science in plain language. Nevertheless, scientists sometimes complain that the translation of science into plain language ‘devalues’ it or ‘dumbs it down’. However, if the use of scientific terminology will only cause the audience to misunderstand – or, worse, completely misinterpret what is being said – then it makes no sense to use it, as the result will only be confusion. Scientists should never expect people outside their discipline to understand the exact meaning they ascribe to a specialised term – even an apparently simple one like ‘model’. Every effort should be made to re-phrase the language so that it has meaning for the audience. This sometimes takes more time and effort than some researchers can spare, and is the reason for the growing value of the skilled communicator as a messenger and interpreter between science and society.

Another challenge for the science writer turning scientific reports or articles into stuff the public can understand is ‘bureaucratese’: the leaden language of the public servant. Nowadays science is often twice as difficult to understand because it mingles scientific jargon with bureaucratese. This language is supposed to be dispassionate, but in fact it is usually clumsy, verbose and hard to read. It too favours the passive and the subjunctive, as well as a whole lexicon of specialist terms intended to exclude the uninitiated. Indeed, bureaucratese is often deliberately designed not to be understood, or else to be ambiguous, in order to withhold knowledge (and power) rather than share it. Because a great deal of science happens in bureaucracies – in universities, research agencies or government departments – the two languages often become horribly intermingled, resulting in a disaster for clarity and for the communication of science. In writing about science, it is very important to purge bureaucratic language as well as technical terms.

A nasty bureaucratic habit is to refer to everything by its initials or its acronym. This is fine if you know what it means – but is simply gobbledegook to the general public. Acronyms are bad in several ways: first, because they are meaningless by themselves and cannot even be looked up in a dictionary; second, because the phrase from which the initials are drawn is usually badly chosen and not easy to guess; third, because acronyms break the flow of meaning by forcing the reader to pause and puzzle over them; and fourth, because they sneer at the person who has not been initiated into the secret of their meaning.

A related phenomenon, even where the acronym is explained, is ‘alphabet soup’ – the excessive use of initials, as in the following example:

The FAIMMS sensor network will utilise leading edge technology to provide real-time 3D profiles of reef systems at seven sites along the Great Barrier Reef (GBR). AIMS is the national operator of FAIMMS, which is one of the components of the Great Barrier Reef Ocean Observing System (GBROOS), for which AIMS is also responsible. GBROOS is part of a nation-wide collaborative program, the Integrated Marine Observing System (IMOS), designed to observe the oceans around Australia.

It is possible for the general reader to fathom what is meant here, but the over-reliance on obscure abbreviations creates constant hiccups in the flow of meaning and should be avoided.

Another common vice of scientific (and bureaucratic) writing is to attach too many adjectives to a single noun. Sometimes as many as five, and even seven, adjectives may be piled onto one poor, struggling, inoffensive little noun. The words ‘one’, ‘poor’, ‘struggling’, ‘inoffensive’ and ‘little’ are the adjectives that describe the word ‘noun’. The use of such strings can perplex the reader, who has to decide which adjective is the most important in the context, and how each adjective affects all the others. The use of too many adjectives to over-describe an object is bad writing and unnecessary. If the adjectives are essential they can be distributed over several sentences. In reality, however, most of them can be left out without losing meaning. This improves both clarity and ease of reading. When pruning one’s work, it is good practice to remove all adjectives. Then go back and see which ones are truly vital and allow these alone to stand.

Source of Information : CSIRO-Open Science Sharing Knowledge in the Global Century 

Tuesday, October 18, 2011

STRUCTURING THE ARTICLE

The traditional scientific journal article begins with a few general statements about things that are usually well-known or accepted. It then outlines the background to the research, provides a description of the experiments carried out and their methods, reports and discusses the results, then finally draws a conclusion from them and discusses its wider implications. The reader must work their way through each of these steps in order to be rewarded with the finding.

A science article written for the media or a lay audience, on the other hand, adopts almost exactly the opposite structure. It reports the main finding and its impact on society in the very first sentence, then explains who did the research and why, adds further detail and finally, if there is room, goes on to discuss what most scientists would see as the main game – the research itself. This is because audiences are usually more concerned about how the science affects them directly than they are with the method by which it was achieved. They are users of science, not its practitioners.

In journalism, the conclusion is nearly always presented first and the rest of the article then expands on this, providing the reader with the supporting evidence for the initial claim and the background to it. This structure has since become common in many forms of reporting: corporate and government reports, for example, present their findings in an executive summary – often a series of terse bullet points – so the busy reader can seize the essence without having to wade through the detail. In journalism, most readers read the first few paragraphs, but few make their way to the end of the article. If important information is placed here it will be lost (or even cut out completely by the editor).

This ‘upside down pyramid’ article structure, with the most important fact first, achieves a much higher impact on the reader and is likely to stick in their mind longer. Where there are several important findings from the research, the article will present them one at a time in the first few paragraphs, rather than risk obscuring or losing some key points by running them all together.

Scientists often assume the reason they are doing their work is selfevident, but this is often not the case. A good science article therefore makes clear, in its opening paragraphs, why the research is being carried out – to save lives, prevent environmental damage, improve industrial productivity, and so on. Indeed, it is on this simple fact that the importance of the article and its chances of publication depend. If it is omitted, the relevance of the science to the reader may well be lost. The editor may regard the story as unimportant and ‘put it on the spike’ (discard it).

The credibility of science with the public often depends on who performed it, so the science article identifies the researchers and institutions involved early on. This is a sign to the reader – who may be unfamiliar with journals and peer review – how trustworthy the information is. However, a good article or media story does not waste space on long wordy names, titles or teams.

A good science article often goes directly to the meaning of the science to society, rather than to the science itself. This is especially the case with a new technology or piece of applied science. The exception would be a ‘blue sky’ discovery, or findings from fields such as astronomy or palaeontology without immediate practical application. In these cases, the article will dwell on the sheer wonder or novelty of what has been found and seek to engage the reader through their curiosity about the natural world.

To engage the reader at the outset it is vital to choose a strong heading. Unlike a scientific paper, where the heading often describes the research, a heading in the media, a press release, a book or a report is intended to catch the eye and capture the attention of the reader – not to inform them. It is usually concerned with the impact of the science, not with the science itself. It is an advertisement for what follows, not a synopsis of it. For this reason, a strong heading is usually short – three to five words work best. An attractive heading may also use mystery, humour or an unusual word to attract the reader. All it needs to do is entice them into reading the first paragraph, which then delivers the main message of interest and lures them to read on.

An effective piece of science writing often has only one idea per sentence. As mentioned above, this gives the reader time to digest important facts. Where high impact is required, occasionally use only a single sentence per paragraph.

The white space between the paragraphs emphasises the point being made in a delicate way, without using exclamation marks, underlining, bold type or italics. In fact, the last three can offend the reader, as they are the typological equivalent of shouting at them (like using CAPS in an email).

Good science writing is usually very economical in its use of language. It compensates for complexity by elegance and simplicity of expression and choice of words. It avoids pomposity or talking down to the reader. It goes directly to the wider significance of the research and why it was done. It explains its relevance to the general reader, rather than to science. It seeks to convey a sense of wonder, where appropriate, but does not exaggerate or overstate. It is checked with the scientist, to ensure accuracy. If there is room, it refers to doubts, criticisms and alternative interpretations of the science.

Source of Information : CSIRO-Open Science Sharing Knowledge in the Global Century 

Wednesday, October 12, 2011

CURING OLD VICES

Common vices in science writing include the use of the passive voice instead of the active, the use of the subjunctive mood instead of the present or future tense, the over-use of adjectives to describe a single noun, and the use of professional terminology or ‘jargon’. It is quite easy to purge oneself of these bad habits without having to go back to school to study grammar and syntax.

A great deal of science is written in the passive voice, rather than the active. The active expresses the action directly: ‘We pursued the research’. The passive focuses on the object being acted on: ‘The research was pursued by us’. The reason for overusing the passive voice probably lies in the desire of scientists to appear objective and impersonal when describing experiments and their results. However, science uses the passive to gruesome excess; this makes the writing ponderous and less easily digested than it should be. It adds unnecessary words – in the above example, 50 per cent more words are used by the passive. Writing for the public should avoid the passive voice as far as possible (e.g. instead of saying ‘The passive voice should be avoided in writing for the public …’.). Even scientific editors no longer favour the passive. Search for it in your writing and convert it ruthlessly to the active voice. Your prose will sparkle with new vigour and directness.

For example: ‘In this study the chemodynamics of heavy metals in soils were investigated.’ Why not simply ‘In this study we investigated the chemodynamics of heavy metals in soils’? Or instead of ‘A new treatment for diabetes has been developed by Australian scientists’, just write ‘Australian scientists have developed a new treatment for diabetes.’

The use of the subjunctive mood is a common feature of science writing, which makes it more turgid and its meaning more vague and uncertain to the reader. Without getting into technicalities, the subjunctive is characterised by the use of words like ‘would’, ‘could’, ‘should’, ‘may’ and ‘might’. These are often preferred by scientists to the use of the present tense (is, are) or the future tense (will, shall). However, they increase uncertainty in the reader as to what is meant – and removing them often does little damage to the sense. For example, in the sentence ‘Heavy metals could pollute soil or groundwater … ’ the word ‘could’ can be omitted: ‘Heavy metals pollute soil or groundwater … ’ This is simply a cleaner, more direct way of writing, which avoids the subjunctive but does not significantly alter the intended meaning. It expresses the meaning more directly and with less uncertainty.

Of course, science often wants to convey a degree of uncertainty, and this is the reason for the ubiquitous ‘could’ and ‘would’. However, this is often faulty reasoning on the part of the writer. Uncertainty can be conveyed directly by stating that the conclusion is not certain, or open to different interpretations, and explaining why. This is more direct and honest than using syntax to obscure the meaning, and the reader will appreciate it. Where it is unavoidable, the word ‘may’ is often preferable: ‘The universe may end, not in a bang but a whimper … ’

Source of Information : CSIRO-Open Science Sharing Knowledge in the Global Century 

Monday, October 3, 2011

Heartburn

While your stomach churns, two valves keep its contents tightly contained. This is important, because the mixture of food and gastric juices is highly acidic and decidedly unwelcome in other parts of your body. If the topmost valve fails and the acidic mixture escapes up your esophagus, the result is heartburn. As you already know, heartburn has nothing to do with your heart, although the burning chest pain can mimic heart trouble. To avoid heartburn, try these tips:

• Elevate yourself. Sit up after a meal, and use pillows or a wedge to prop your upper body while you sleep. This enlists the aid of gravity. (Also, it’s a good idea to avoid eating before you plan to lie down, such as in the 2 hours before bed.)

• Eat small portions. When your stomach is swollen with food, it’s easier for the acidic mixture to burst loose.

• Avoid trigger foods. Most heartburn sufferers can pinpoint problem foods that cause excess acid production. Your list won’t be the same as someone else’s, and potential problem foods—such as spicy meals, acidic fruit drinks, and fizzy soda pop—may be either harmless or exquisitely painful once they’re in your stomach.

• Don’t squeeze. The stomach is a soft pouch. Restrictive clothing, a tight belt, or a hefty layer of subcutaneous fat can put pressure on your stomach, encouraging it to squeeze open like a tube of toothpaste.

If you suffer from an occasional bout of heartburn, your best bet is to treat it with an over-the-counter antacid. Avoid milk—although it can temporarily soothe the stomach, the proteins it contains will soon stimulate increased acid production and possibly make your heartburn worse.

Finally, don’t ignore persistent heartburn. If heartburn strikes two or three times a week for more than 4 weeks, it’s time to bring in a doctor to check for more serious chronic problems. And if you have heartburn that gets worse before meals and fades away as you eat, it may be the sign of an ulcer (a tiny sore in the lining of your stomach), which doctors can often treat with a simple course of antibiotics.

Source of Information : Oreilly - Your Body Missing Manual

Thursday, September 29, 2011

The Gastric Storage Tank

Your stomach is a temporary storage tank. Empty, it holds less than a child’s juice box does. Swollen with food, it expands a staggering 30 to 50 times— large enough to accommodate nearly a gallon of food and drink.

Your stomach is also a muscle—one that few of us have trouble exercising. It expands and contracts continually, kneading, twisting, compressing, and mixing your food with powerful gastric juices that help digest it. The more food you put in your stomach, the more vigorous the mixing. When your stomach is empty, you might hear the noisy rumbles that biologists call borborygmus (pronounced “bore-bo-rig-mus”), but you call growling.

As your stomach churns your food, the meal gradually takes on the consistency of a creamy paste. Roughly three times a minute, your stomach squirts out a small eyedropper’s worth of this paste into your small intestine (which is the next stage in the digestive journey). In this way, your stomach slowly works through your breakfast, preparing it for further digestion, being careful not to hurry the job and overwhelm your intestines.

Your stomach passes along almost all the food it receives. However, some substances can dissolve through the thick coating of mucus that lines your stomach and enter your blood. Examples include alcohol and certain drugs, like aspirin.

It usually takes 2 to 4 hours for your stomach to empty itself. Fluids and carbohydrates pass through it quite quickly, while protein takes longer, and fat forms an oily layer that’s digested still more slowly. Large, fatty meals can linger for 6 hours or more. In the sample breakfast meal used here, the last holdout is the sausage, which supplies half of its calories from fat. For that reason, the sausage is also the most likely part of your meal to return as heartburn

Ideally, you’ll eat food that won’t race through your system or overstay its welcome. If you eat meals that have a dash of unsaturated fat and a good dose of fiber, you’ll process them steadily but gradually, and you’ll feel full longer. You’ll also avoid the sudden sugar rush and insulin release that raw carbohydrates cause—a process that can, over the years, encourage diabetes.

Source of Information : Oreilly - Your Body Missing Manual

Tuesday, September 20, 2011

Saliva

Saliva is a watery, frothy substance that your mouth manufactures continuously. It trickles out through glands scattered around your mouth, cheeks, and throat, but most of it seeps up from under your tongue. You produce a small milk-carton’s worth (1 liter) of the stuff every day, most obviously when you eat, and hardly at all when you sleep.

Saliva cleans your teeth, lubricates your mouth, and protects the tender tissues inside. It also dissolves the substances in your food so they can reach your taste buds. In fact, without saliva, your favorite meal would be as appetizing as a stick of chalk.

Saliva also contains enzymes that start breaking down the long chains of complex carbohydrates in your food. (Enzymes are special compounds your body builds and then uses to carry out complex chemical reactions, like digestion.) For example, in the breakfast meal you’re chewing right now, enzymes split some of the starches in your toast. It’s all a bit of a preview to the heavy-duty digestion that takes place lower down the digestive tract. Saliva also moistens your food so your teeth can compact it into a small, soggy ball that’s ready to shoot down your throat and into your stomach.

Once your teeth and salivary glands have done their work, it’s time to swallow hard and move on. Your meal has now entered the winding passages of your digestive tract, where it will remain for the rest of its journey.

Although saliva includes its own natural antibacterial agents, opinions differ about whether the distinctly icky practice of licking wounds is healthy or dangerous. One thing is certain: Putting your tongue to a cut introduces not just antibacterial substances, but a huge family of mouth-dwelling bacteria, too—some of which can cause real trouble if they make their way deeper into your body.

Source of Information : Oreilly - Your Body Missing Manual

Wednesday, September 14, 2011

Bad Breath

Basic dental hygiene removes particles of trapped food that can create an unpleasant mouth odor as the food decays. But a variety of other things can contribute to bad breath, such as:

• Dry mouth. Without the cleansing power of saliva, dead cells build up and decay in your mouth. This is the source of the phenomenon called morning breath, and it’s particularly bad if you sleep with your mouth dangling open.

• Digested food. Certain foods, like garlic, have volatile oils that can stink up your airways. There’s no way to rid yourself of these odors, because the odor begins after you absorb and process the food—and it actually seeps out of your lungs. Fortunately, the scent should die down in 24 hours. In the meantime, you can try to mask it by chewing on a clove, some mint, or a sprig of parsely (and hope that this combination doesn’t create a still more objectionable smell).

• Dental problems. When bacteria works itself into places it shouldn’t be—such as the pockets between your teeth and gums—it’s impossible to remove on your own. The problem usually begins with poor dental hygiene, and you can only fix it with a trip to the dentist.

• Diseases. Certain medical conditions can produce strange or offensive smells. For example, untreated diabetes can cause a fruity smell. Kidney failure can cause an ammonia-like smell. If you suddenly develop a new and unpleasant mouth odor, check it out with your doctor.

Source of Information : Oreilly - Your Body Missing Manual

Tuesday, September 6, 2011

Mouth Maintenance

Different animals have very different ways of producing and maintaining their teeth. Sharks grow a limitless supply and never need to see a dentist. Elephants get a lifetime allotment of just 24 teeth and use no more than six at a time. As an elephant grinds its way through its tough, plant-based diet, its front teeth wear down and eventually fall out, making room for its back teeth to move forward as replacements. When an old elephant goes through all of its teeth, it starves to death.

Humans aren’t quite as bad off—if we lose our limited set of 32 teeth, we can survive on protein shakes and peach ice cream. But if you want to bite your way through chocolate bars and ciabatta bread well into your nineties, you need to make sure your dental hardware doesn’t end up as used and abused as a mouthful of elephant teeth.

Here’s what you need to know to maintain healthy teeth:

• Brushing. It’s not necessary (or helpful) to attack your teeth with sandblasting force. Instead, a gentle 3- to 4-minute brushing does the trick. (Most people think they brush even longer, but the average brushing session lasts just 60 seconds.) Twice a day is the official tooth-brushing recommendation, but dentists really want you to clean your teeth after every meal. Modern research suggests you wait 20 minutes after a meal before you brush. Immediate brushing attacks your teeth when they’re at their softest—weakened by the acids in your food.

• Flossing. Studies suggest that proper flossing might do more for your teeth than brushing. Flossing once a day won’t bankrupt your dentist, but it will remove tiny particles of food between your teeth and reduce the sticky buildup of plaque. To get the most out of flossing, however, you need impeccable technique. Particularly important is flossing gently under your gumline, as shown in the picture below. For a step-bystep walkthrough, point your Web browser to http://tinyurl.com/cltjjy. Too pressed for time to clean your teeth with a strip of floss? As sardonic dentists often remark, you need to floss only the teeth you want to keep.

• Whitening. Stained, discolored teeth get little love. But recently, tooth fashion has switched from cloud white to glistening-Chiclets white, and the effect can be as glaringly unnatural as a nose job on Cyrano de Bergerac. If you really want a brighter shade of white, skip whitening toothpastes—most of them simply include abrasives that can grind away some surface marks. However, home whitening kits and custom dental appliances can produce better results, so talk to your dentist about what sort of whitening product would be most effective for you. This is particularly important if you’ve had any serious dental work.

• Gum disease. The real danger of poor dental hygiene isn’t cavities (which are usually easy to patch), but gum disease. Gum disease occurs when the same bacteria that attack your teeth slip under your gumline, damaging your gums (in which case it’s called gingivitis) or into your teeth’s supporting tissues and bone (in which case it’s called periodontitis). The former can make your gums swell and bleed, and can trigger bad breath. The latter can destabilize your teeth and lead to a set of dentures.

• Fluoride. Conspiracy theorists aside, fluoride plays an important role in strengthening tooth enamel, especially early in life. Countless studies have nearly always agreed about fluoride’s cavity-preventive abilities and its lack of side effects, which is why it’s so often included in municipal water supplies or (in many non–English-speaking countries) added to table salt. The only catch is that too much fluoride can stain the teeth of young children, but that won’t happen unless they abuse fluoridated mouthwashes or eat entire tubes of toothpaste. (Incidentally, in the 1950s, far-right activists opposed fluoridation and vaccination, believing both were part of a shadowy conspiracy to impose a communist regime on America. So consider yourself forewarned.)

There’s a more controversial ingredient in some toothpastes: triclosan, an antibiotic that coats the teeth. Studies confirm that it’s an effective tool against the bacterial marauders that live in your mouth and cause plaque. However, some health experts worry that it could lead to bacterial resistance —in other words, the presence of triclosan could encourage harmful bacteria to evolve into a super-species that’s immune to the usual antibiotic weaponry. If you’re looking to give your teeth an antibiotic boost—or if you just want to avoid this high-powered ingredient—check the label. Colgate Total is the best-known toothpaste to include triclosan.

Source of Information : Oreilly - Your Body Missing Manual

Wednesday, August 31, 2011

Do You Need Thirty Chews?

Few of us count the number of times we chew before swallowing a morsel of food (and those who do aren’t much fun at dinner parties). Still, the age-old question remains: Can swallowing half-chewed chunks of food harm your digestive system? The answer, it turns out, is fairly sensible. You should chew your food until it becomes an easily swallowable, broken-down paste. (One rule of thumb is that the texture shouldn’t be recognizable. For example, if your potatoes still have skin on them and your broccoli still has a stalk attached, they’re not ready to swallow.)

Basic chewing has several benefits. First, it triggers activity in other parts of your digestive system, like your stomach, preparing them for the work ahead. It also helps the rest of your digestion work more smoothly, because your digestive system doesn’t need to struggle to extract the nutrients from large, tough chunks of food. Finally, chewing forces you to eat more slowly, which can reduce the chance that you’ll choke or overeat, and improves your mealtime enjoyment (and dinnertime popularity). However, there’s no reason to get obsessive about it. For example, the infamous motherly advice to count
30 chews will turn all but the most overcooked steak into something not unlike a wad of pulp from a paper mill—and who wants to swallow that?

Incidentally, extreme chewing was the foundation of a wildly popular Victorian-era diet. Horace Fletcher (also known as “The Great Masticator”) became a millionaire by championing obsessive chewing as a way to avoid constipation and other digestive ills. His strict advice was to chew each mouthful more than 30 times over the course of a half minute, and then tilt your head back to let the result trickle down your throat. You were to spit out any remaining chunks. The side effects included long meal times, dramatic weight loss, and a sore jaw.

Source of Information : Oreilly - Your Body Missing Manual

Wednesday, August 24, 2011

Cardio Exercise

The perfect complement to strength training is cardio exercise. A regimen of regular cardio exercise improves the function of your lungs, heart, and blood vessels. Over time, it gives you greater endurance for heart-pumping tasks like running, dancing, and swimming. It also reduces your risk of a whole medical manual of health problems, from diabetes to depression. It might even help you dodge a coronary catastrophe.

Getting cardio exercise is cheap and easy. You don’t need special equipment or expert advice. You simply need to do something tiring (say, jumping up and down in one spot, or dancing around in your pajamas). Do it until you start breathing heavily, and then keep at it for at least 20 more minutes. This may not sound glamorous (in fact, if you pick the pajama option, it’s downright embarrassing), but the science is sound.

The best approach to cardio exercise is to follow a regular regimen three times a week. But—surprisingly—research shows that even a single session each week has a positive effect on heart health. This finding kicks the legs out of your last good excuse to stay on the sofa.

There are two basic types of cardio exercisers—those who like slow and steady activity (say, a brisk 1-hour walk), and those who prefer shorter bursts of higher intensity work (say, 20 minutes in a hard-driving aerobics class). Both approaches are effective, and both help you burn calories and strengthen your heart. The key is to pick the right duration for your activity. If you opt for a high-intensity workout, 20 or 30 minutes is enough. A more leisurely activity requires twice that time.


Types of Cardio Exercise
If you get tired of having your friends and family laugh at your impromptu jumping jacks, you can try a more traditional form of aerobic exercise. Here are some of the most popular:

• Running. Requiring nothing more than time and a decent pair of running shoes, running is the most straightforward way to get your heart pumping. It’s also a marvelously adaptable exercise you can tailor to any fitness level. To go easy on yourself, alternate between brisk walking and a light jog. For hard-core training, maintain a steady jog with bursts of flat-out sprinting.

Running isn’t for people with joint problems because the impact of your feet striking the ground can put excess stress on your knees and ankles. However, if your joints are currently pain-free don’t worry about running. Recent research suggests that healthy runners don’t suffer from a greater incidence of joint problems than other exercisers.

• Jumping rope. Like running, rope skipping is a highly portable way to get intense aerobic exercise wherever you go. You can’t slip an entire gym in your pocket, but there’s always room for a jump rope.

• Swimming. If you have a pool handy, you can use swimming as a fullbody, low-impact form of exercise. Because it’s so gentle on the joints, many people like to alternate swimming with other types of cardio exercise to create a weekly workout program.

• Bicycling. Like running, cycling is an activity you can do either indoors (on a machine) or outside (on the street). As a side benefit, the effort of keeping yourself balanced on two wheels strengthens the muscles throughout your body.

• Cross-country skiing. It’s one of the most intense forms of full-body aerobic exercise around. Cross-country skiing has obvious disadvantages— for instance, you need a snowy trail and a lot of equipment— and newbies will find it extremely challenging. But it makes an excellent excuse to book that Nordic vacation.

• Step aerobics. Any aerobic workout routine can deliver the goods, but step aerobics stands out from the late-night infomercial gimmicks. Two decades after its creation, the basic idea (performing choreographed movements using a raised platform) remains wildly popular. Done right, step aerobics has the perfect mix of low-impact exercise and intense effort. To get started, you can try an exercise DVD. Or better yet, join a class at your local fitness club or community center.

• Gym equipment. Purists might say that a treadmill gives you all the effort of running with none of the scenery, but exercise equipment is the perfect solution for many casual exercisers. And even if the convenience of treadmills, steppers, and elliptical trainers doesn’t seduce you, you just might fall for the shiny electronic gadgetry (such as programmed courses and integrated heart-rate monitoring). If not, there’s always the wall-mounted television.

The experts agree—the best way to choose a cardio exercise is to forget about calories per minute and pick something you enjoy doing and can easily integrate into your daily routine. This gives you the best chance of maintaining a regular routine—and regularity is far more important than the type of exercise you choose.

Source of Information : Oreilly - Your Body Missing Manual

Thursday, August 18, 2011

Heart Attack Prevention

With its complications and uncomfortably high odds of lasting heart damage and death, a heart attack clearly tops the list of Life-Changing Experiences Worth Avoiding. But considering that heart disease is the single most common cause of death (at least in the U.S.), is it really possible to avoid cardiac calamity?

Surprisingly, there’s a lot you can do to stay out of harm’s way. Stay active, lose excess weight, and avoid stress is a good start. But if these practices aren’t doing enough in later life, it’s critically important to step up your game. In other words, forget your good intentions—your doctor needs to check your blood pressure and blood cholesterol, and use the full arsenal of modern medicine if these numbers are dangerously high. (As you’ve already seen, high blood pressure damages the delicate inner lining of your arteries. Excess cholesterol becomes trapped in artery walls, kick-starting the inflammatory process that leads to potentially dangerous plaque.)

If you’re not convinced, consider this startling statistic: a 50-year-old man who doesn’t smoke or have diabetes, and who keeps his cholesterol and blood pressure in the recommended range, has just a 5-percent chance of a serious heart event over the next half-century. But if he violates any one of these conditions, his chances rise tenfold, hitting 50 percent. Unsurprisingly, the vast majority of 50-year-olds fall into the second, far riskier category. They remain apparently healthy even as their cholesterol level and blood pressure creep up, laying the groundwork for the Big One.


A Heart Attack on a Stick
There’s one more critical step to prevent a heart attack: Stay away from cigarettes. Their effect on heart health rivals the destruction they wreak in your lungs. In fact, if you’re a chronic smoker, you’ll realize greater benefits from kicking the cigarette habit than you will from starting a hard-core workout regimen and adopting a strict health-food diet. The way cigarettes work their damage isn’t entirely clear, but smoking seems to doom your circulatory system in several ways, reducing the supply of oxygen to the heart, raising blood pressure, increasing the level of dangerous LDL, and making blood more likely to clot. Altogether, it’s a cocktail of heart trouble that’s far more potent than a daily Big Mac.

If you’re still not convinced, consider these grim facts:

» Heavy smokers have double the risk of stroke, and two to four times the risk of a heart attack.

» When a heart attack strikes, heavy smokers are nearly twice as likely to die.

» Even light smokers (those who smoke one to nine cigs a day) are at a third higher risk for a heart attack.

Source of Information : Oreilly - Your Body Missing Manual

Wednesday, August 10, 2011

Case Study: Boreal—Earth’s Northern Woods

Forests that cover the northern regions of Canada, Russia, China, Scandinavia, and southern Alaska make up the boreal forests, or taiga. (Smaller areas of Japan, Korea, and Mongolia also contain boreal forest.) They include a band of growth between 45° and 57° north latitudes and form an almost continuous ring at the top of the globe. Boreal forests hold little tree diversity compared with tropical rain forests: They contain only a limited variety of coniferous trees that retain needles year-round and have a short growing season of about 130 days. Boreal forests nevertheless support extensive food webs of plants, mammals, birds, insects, and fish. They also act as a northern watershed by containing numerous lakes, rivers, wetlands, bogs, and marshes.

The boreal forests serve the Earth in the following additional ways: (1) as a carbon reservoir for storing carbon not released into the atmosphere; (2) in filtering millions of gallons of water each day; and (3) by providing resources for resident people that use the forest for hunting, trapping, and fishing. The boreal forests also contain vast potential commercial potential because of their timber, oil, gas, minerals, and hydroelectric power resources, so they have become a central point of interest of both industry and environmentalists.

Large oil and natural gas reserves under the forests of Alaska, Canada, and Russia represent the number-one threat to the future of boreal forests. Fossil fuel reserves in other parts of the world will someday run dry, and countries such as the United States desire a reliable supply of domestic fuel, which the boreal region holds. In addition to the United States, Canada, China, Russia, and Norway have all eyed their own boreal forests for oil exploration.

Global warming also threatens boreal forests because as temperatures rise the health of the cold-tolerant trees may decline, and disease and parasites gain opportunity to infect them. At the same time, warmer temperatures have already made temperate deciduous forests to the south drift north toward the boreal habitat. The warmer temperatures therefore threaten boreal growth from the south, and melting glaciers and polar ice may cause flooding from the north.

Environmental organizations have tried to protect boreal forests from the destruction that has occurred in poorly managed tropical forests. In the United States and Canada, the following organizations act as watchdogs over boreal forests by monitoring the mining, oil drilling, and logging industries and by participating in global warming talks: the Northern Alaska Environmental Center; the Sierra Club; the Nature Conservancy; the Alaska Department of Fish and Game; and the Natural Resources Defense Council; and Nature Canada.

Forests in Siberia and eastern Russia suffer added threats because of the way they have been managed, and have endured several consecutive seasons marked by wildfires, insect outbreaks, and overgrowth that keeps seedlings from maturing. Enterprises that once operated farms under socialism now own much of Russia’s forestland. These owners may view forests as a community resource to be depleted for building personal wealth without much regard for sustainable methods. For example, the Federal Forest Service of Russia for many years controlled more than 90 percent of Russia’s forests and has shown interest in conservation, but this agency also ran about 20 percent of the country’s logging. The agency furthermore has released no information on forest area land or logging activities, so environmentalist groups such as Greenpeace Russia and the Taiga Rescue Network found it difficult to design conservation action plans.

Environmentalists suspect that forest management in Russia has not been optimal. Fedor Pecar, chief of the Irkutsk airbase in Russia told Greenpeace in 2007, “This year there are more of them [fires] than in all of the previous years. One may think that now everything is being burnt off: fields and old straw. Almost half of the fires were caused by this. The villagers burn off private meadows and they are doing it recklessly and carelessly. Thus not only forest, but also buildings and houses catch fire. . . .” In 2000 Russian President Vladimir Putin signed a decree abolishing the Federal Forest Service, the only federal agency with interests in protecting the boreal forests. Fortunately, Russia’s boreal forests are very remote, and logging them would be an expense that for the present has kept them safe from large-scale destruction.

The world’s boreal forests will not be safe forever if the timber and fossil fuel industries need new places to explore. Boreal forests the world over will require careful monitoring and strong legal protections for their survival.

Source of Information : Green Technology Conservation Protecting Our Plant Resources

Tuesday, August 2, 2011

Forest Roads

Timber companies must have roads that lead to harvesting sites to allow heavy equipment and emergency vehicles into and out of the forest. The companies usually build these logging roads themselves to meet these needs. But the road-building and the completed roads create a major disruption to forest ecosystems. In addition to the noise and dirt created during road-building, smooth-surface or packed gravel roads make forests vulnerable to the following occurrences:

» increased erosion and sediment runoff
» habitat fragmentation
» biodiversity loss
» enhanced exposure to invasive species, pests, and diseases
» disrupted migration routes by wildlife, reptiles, and amphibians
» wildlife mortalities on roads
» opening of once-inaccessible forests to hunters, off-road vehicles, and illegal farming or logging
» opening of territory to mining and farming

At present, logging roads and helicopter landing areas built on public lands cause those lands to lose federal protection as wilderness areas. In 1997 President Bill Clinton tried to reverse this policy by passing what came to be known as the “Roadless Rule,” which authorized the U.S. Forest Service to obliterate hundreds of miles of abandoned logging roads and halt construction on others. At the time, Forest Service officer Bob McDowell in Lake Tahoe, California, told the Tahoe Daily Tribune, “The kinds of roads that we will obliterate are the roads that don’t go anywhere—old logging roads and landing areas. The ultimate goal is to re-contour some roads, to make the road bed disappear.” The recovery of the land under the Roadless Rule has progressed very slowly, and thousands of miles of abandoned logging roads remain in North American forests. Some states, such as Idaho and Alaska, have challenged the Roadless Rule for putting too severe a restriction on their forest management. For example, at the close of 2003, Alaska had successfully won the right from the USDA and the Department of Justice to exclude the Tongass National Forest from the Roadless Rule.

The effect of abandoned and overgrown roads has not been determined. Scientist Eric Sanderson of the Wildlife Conservation Society said in 2005, “Roads are terrific at providing human access to areas, but unfortunately they bring with that access a host of ecological problems.” The timber industry countered that forest roads were necessary to serve local communities in times of wildfire, meaning an out-of-control fire. In 2005 President George W. Bush did away with the Roadless Rule to allow greater access for mining and logging in the nation’s forests. Chris West spoke for the American Forest Resource Council in support of the White House’s decision and to calm the public’s fears over road expansion: “Despite the environmental rhetoric, chain saws, bulldozers and drilling rigs are not gassing up to enter roadless areas.” The case study “Boreal—Earth’s Northern Woods” discusses how roads and other human activities in the forest have kept this debate alive.

Source of Information : Green Technology Conservation Protecting Our Plant Resources

Monday, July 25, 2011

Timber Harvesting

Tree harvesting in the past meant the removal of all trees of any size and regardless of value. Logging companies clear-cut the landscape, which not only destroys the forest but also eliminates ecosystems. Even animals inhabiting the uncut adjacent forest must contend with the increased activity and noise coming from the clear-cutting zone. Clear-cutting also makes the harvested land vulnerable to soil erosion, floods streams, increases silt levels in streams that harm aquatic life, and makes landslides more likely.

During 2007 in Oregon, storms caused landslides in two clear-cut areas and torrents of mud and debris overwhelmed homes and vehicles and covered a state highway. While no humans were killed, several received injuries, and the damage to wildlife has not been fully resolved. Stephen Hobbs of the Oregon Board of Forestry described the event as a rare quirk of nature. He told the Oregonian, “Mother Nature threw a curveball at us. It was a pretty intense storm event, so you’re going to have unexpected things happen.” Despite these assurances, other people suspect that clear-cutting creates a danger to human and animal life. The University of Washington professor David Montgomery told the Olympian in 2008, “As a geologist, I see no surprises here. When you clear-cut potentially unstable slopes, you increase the risk of landslides up to tenfold.” These differences of opinion on the harm of clear-cutting and other tree harvesting methods continue.

In addition to the harvesting method loggers choose, all harvesting sites require roads built into the forest to give equipment access and allow logging trucks to transport the logs out of the forest. Roads help the overall efficiency of logging, and timber companies cannot do their job without them, but forest roads also harm ecosystems by fragmenting habitat, driving out animal species, and giving access to invasive species.

Once loggers reach the logging site, they can use any of a variety of harvesting methods, described in the table on the next page. Over the long term it is in the best interests of loggers to choose a method that sustains their industry but also conserves forests for future generations.

Logging comprises any of the harvesting methods described in the table below, plus the methods used for felling the trees and the yarding methods for taking the logs out of the forest. Tree cutting can be done in two ways: conventional sawing or mechanical logging. Sawing cuts the full length of trees to the stump close to the ground, while mechanical cutting removes trees using a piece of equipment called a feller (or faller). An operator drives a feller up to the tree to be removed and a blade or saw at the end of the feller’s arm cuts the tree, usually leaving a taller stump than the sawing method.

For centuries, horse-drawn wagons hauled logs out of the forest. This required little road-building and made little noise. In the 1800s horse or oxen teams dragged logs to specialized narrow logging railroads or, in areas where railroads could not reach, to mountain streams where workers transferred the logs to another conveyance, a process called offloading. Gravity simply carried the harvest downstream to a collection point at the bottom of the mountain. Dragging logs downhill to a train or stream soon proved to be inefficient because every forest snag or stump acted as a fishhook and grabbed at each log on the journey. Loggers soon learned that dragging logs uphill by cable to a mountaintop railroad track was the best approach. This so-called uphill logging or skyline logging evolved into the helicopter logging used by many timber operations today in difficult-to-reach terrain. Though horses still haul timber in parts of the world, today most operations use trucks, cables, and helicopters.

Timber harvests consist of whole logs, called roundwood, which means logs denuded of branches and bark. These harvests are of three main types: (1) hardwoods from broadleaf, deciduous trees; (2) softwoods from gymnosperm trees, including pine, spruce, fir, and juniper; or (3) pulpwood, which is any wood harvested for papermaking.

Source of Information : Green Technology Conservation Protecting Our Plant Resources

Thursday, July 21, 2011

Old-Growth Forest Ecosystems

Old-growth forests consist of trees that have never been cut so have never been forced to regrow. These primary forests contain the original growth of a tree population and therefore they contain the oldest and most mature trees found in the forest biome. Old-growth trees arise at the latest stage of forest ecological succession, and because of this they contain a mixture of species and a variety of sizes. They also contain dead trees that have fallen and begun to decay, broken branches, snags, and several canopy layers. All of these things create specialized habitats for a variety of animal life, plants, and fungi. Old-growth forests contain very complex ecosystems with many interrelationships between species, and of course, this enhances biodiversity.

The unique characteristics of old-growth forests sometimes provide habitat for species that cannot live anywhere else. Some of these specialized habitats include hollowed trees, tree cavities, decaying logs, the canopy, the understory, moist soil, and bark. In dense old-growth forests, the top of the canopy receives direct sunlight for the life in that habitat, while creatures near the forest floor live in dark, shaded surroundings. Animal diversity in old-growth forests includes moose, bear, weasel, lynx, fox, wolf, deer, bobcat, mountain lion, chipmunks, squirrels, shrews, bats, woodpeckers, owls, and hawks. This represents only a partial list and does not account for the microbes, insects, invertebrates, amphibians, reptiles, songbirds, and aquatic species that also live in old-growth forests. Vines, ferns, shrubs, mosses, lichens, and some grasses dominate the plant diversity. A typical old-growth forest in the Pacific Northwest contains giant redwoods, Douglas fir, spruce, and possibly hemlock and cedar. Each 2.5 acres (0.01 km) contain about 20 large trees at least 300 years old, many measuring over three feet (1 m) in diameter.

The health of an old-growth forest depends on fires caused by natural circumstances, such as lightning strikes. Frequent, short-lived ground fires reduce competing vegetation and degrade dead wood, which hastens the return of nutrients to the soil. Fires also thin out the densest growth and open more space for sunlight to reach places that had been cut off from light. Though fires may temporarily destroy some wildlife habitat, fires also create new habitat. For instance, some small mammals may prefer the plants and grasses that first break through the earth after a fire, and only ground fires afford this opportunity.

Old-growth forests and their ecosystems have remained largely a mystery despite the studies that have been conducted in them. They have outlived generations of humans, and they surely contain undiscovered species as well as ecosystems that have not been fully identified. These forests survived from a time when humans did not affect seemingly every corner of the Earth. For that reason alone, they deserve respect within the world of living things.

Source of Information : Green Technology Conservation Protecting Our Plant Resources

Wednesday, July 13, 2011

Tempe rate and Boreal Forest Loss

Forest evaluation takes place by two main methods: aerial surveys and satellite imagery and on-the-ground field studies. Aerial surveys gather information on forested regions such as the Blue Ridge Mountains. Satellite images help scientists view much larger expanses such as the total area forests occupy on a continent. Scientists who conduct field surveys gather detailed information by observing forest ecosystems up close. Field surveys typically collect data on the following topics in assessing forest health:

» grass and wildflower ground cover
» wildlife diversity
» densities of small, stunted trees
» numbers of large, old-growth trees
» increased old-growth mortality rates due to thickets of small trees
» large-scale insect or other parasite infestation
» pathogens in rain runoff
» shift from low-intensity ground/grass fires to fast and large canopy fires, called crown fires

The FAO report states that the net rate of global forest destruction has slowed in some places, which is an encouraging sign, but overall the world continues to lose forests. For instance, aerial and satellite studies have revealed that forest area has increased a small amount (less than 0.1 percent) in Europe and parts of Asia in the past 15 to 20 years. During the same period, the total area of North American forests did not increase, but their destruction was greatly diminished. Both of these trends suggest that Europe and most of North America have put significant effort into forest conservation. Only Mexico, which loses about 0.5 percent of its trees annually, and select parts of Asia have continued losing temperate forests with no sign of slowing.

The United States destroyed most of its old-growth forests by 1920, especially in the East and Midwest, where secondary forests have now replaced them. Sections of the West and Alaska still experience large losses, however, to the point where plant and animal diversity now differs from the diversity that sustained Native Americans before European settlers arrived. Between 1600 and 1800, eastern settlements began removing trees for lumber, and the need for wood grew as the settlements became cities. When settlers migrated west, more trees came down for building houses, barns, and fencing. In the 1800s railroads crisscrossed the continent, and the new tracks demanded a constant supply of wood for railroad ties. Today lumber and paper make up the main uses of the country’s timber harvest, but trees supply other non wood products.

How has Europe managed to increase the amount of its forested land, especially in one of the most densely populated parts of the world? European countries have taken the lead in exploring sustainable methods in forest management. For example, in Europe tree plantations that restore destroyed forests tend to contain plantings of native trees interspersed with monoculture. This mixture of natural and artificial conditions allows a secondary forest to grow quickly, yet it retains some of the biodiversity of the original forest. Primary forest makes up only 4 percent of Europe’s forest area, so these secondary forests represent the continent’s best hope of reversing decades of deforestation. In North America primary forests account for almost 45 percent of total forests, mostly in Canada, and 12 percent of those primary forests have now been entered into conservation programs. The goal is to emulate Europe and begin rebuilding forested area.

Alaska has presented the American public with a unique situation regarding deforestation. Alaska’s large expanses of forest have been tempting the timber industry for many years, and the state now supports an active logging industry; about 5 percent of Alaskans are employed by the timber industry. But increased logging and further destruction of forest tracts due to new oil exploration have drawn increasingly heated debate. Laurie Cooper of the Alaska Wilderness League told the Los Angeles Times in 2008, “We’re at a crucial time right now to make sure we’re looking at a future that retains some of this landscape and some of this way of life for future generations.”

Alaska contains two principal types of forests: coastal rain forest and interior boreal forest. Most of the timber activity takes place in the coastal regions, and of the total forests available for logging, the federal government owns 51 percent, the state and local governments own 25 percent, and private owners hold about 24 percent. Alaska Native corporations make up 99 percent of all private forest landowners. Alaska also contains the nation’s largest and second-largest national forests: the Tongass National Forest, containing 16.8 million acres (68,000 km2), and the Chugach National Forest, with 5.9 million acres (24,000 km2). Logging presently occurs in a small portion of each of these forests, but Tongass has of late become a focal point in a debate on the possible expansion of Alaska’s logging.

In January 2008, President George W. Bush approved a plan to open an additional 3 million acres (12,140 km2) of Tongass National Forest to the timber industry. Though the decision sought to relieve financial stress in Alaska’s economy, environmentalists pointed out that logging may not help the economy much. Tom Waldo, attorney for the environmental group Earthjustice, warned in a New York Times article that logging may harm Alaska more than help it: “It leaves 2.4 million acres [9,712 km] of wild, roadless backcountry areas open to clear-cutting and new logging roads.” Meanwhile, the logging industry contributes only about 1 percent of Alaska’s economy.

The Pacific Northwest has had similar questions on the extent with which logging should take place, especially when local mill towns depend on timber for their income. One question that turned into a serious argument between the timber industry and environmentalists came in 1986, when the northern spotted owl was placed on the endangered species list. Spotted owls prefer habitat of old-growth forests like the kind that stretch from northern California to Canada. Listing the owl as threatened pitted conservationists against people whose livelihoods depended on logging. Many of these forests now receive federal protection as habitat for the owl, and the mill towns have slowly found income in nonforest pursuits, including tourism.

Temperate forests have not had the controversies that characterize the forests in Alaska or the Pacific Northwest, so the public has perhaps overlooked the dire condition of these forests. Part of this complacency comes from the fact that forests are a renewable resource: The trees grow back after they have been cut. But the time required to replace a forest is hundreds of years, depending on the type of trees growing there. Julia Bonds of the Coal River Mountain Watch in Appalachia said in a 2003 interview on mining and logging in the area of West Virginia where she grew up, “It’s [mountaintop mining] not only turning the mountaintops into wastelands, but the valleys as well. The wonderful and valuable hardwood forests are being destroyed, and they will not return for over 600 years, if ever. Our beautiful mountain streams have been devastated.” The temperate forested land in the United States has now stabilized, but that may be little comfort to people who remember when these forests stretched for hundreds of miles. The worth of forests is explored further in the sidebar “Old-Growth Forest Ecosystems.”

The United States has been able to stabilize its forested land area by reversing its commerce in wood products. The United States exported lumber for decades until the start of the 1990s, when imports began to outweigh exports. Today the value of U.S. wood product imports is double the value of its exports. In other words, the United States spares its forests by relying on wood products from other countries. In addition to primary wood products (raw lumber), the United States imports a large quantity of its secondary wood products, such as furniture.

Source of Information : Green Technology Conservation Protecting Our Plant Resources

Tuesday, July 5, 2011

Temperate and Boreal Forest Preservation

Temperate and boreal forests differ from tropical forests in that they grow at latitudes of cool to cold winters and live in places that receive seasonal variation. Like tropical forests, temperate and boreal forests have been greatly reduced from their original area on Earth. While tropical forests have lost an estimated 50 percent of their area, a very small percentage of temperate forests and boreal forests remain from their original population.

The temperate forests that remain in eastern North America, northeastern Asia, and Europe share the following characteristics: varied temperature from below zero to 85°F (30°C); even precipitation throughout the year; moderately dense canopy with partial light penetration; fertile soil; and seven to 10 tree species per square mile (three to four species per km).

Temperate forests contain plant, tree, and animal diversity, and they occupy moderate climates with a long growing season. These factors have made temperate forests attractive to generations of people for timber and hunting. Due to their location in temperate climates, cities and towns have grown up near temperate forests, so the trees have been accessible for logging. As towns expanded, the forests became fragmented, which worsened the conditions for the forest ecosystem.

Boreal forests, also called taiga, occupy the largest biome on the Earth's land surface and grow in the northern parts of North America, Europe, and Asia. These forests contain the following characteristics: cold climates with precipitation mainly as snow; sparse canopy that permits moderate light penetration; nutrient-poor soil; trees that are mainly cold-tolerant evergreen conifers; and animal diversity that may be greater than plant diversity. Though boreal forests occupy places remote from many urban centers, they have been severely reduced by centuries of logging and are in jeopardy of disappearing within a few generations.

Globalization of economic markets combined with population growth has put pressure on all the world's forests, but these things occur unevenly across the face of the globe. Because temperate forests occur near population centers, throughout history they have been cut down at a faster rate than the remote boreal forests. Regardless of how these forests have been accessed and harvested, temperate and boreal forests require the same dedicated protection as forests in the Tropics. Though local efforts can protect some tropical forests, temperate and boreal forests will likely need the oversight of governments and international organizations. These forests lie in industrialized countries where big businesses and government have often worked in close association. The international Food and Agriculture Organization of the United Nations (FAO) stated in its recent report State of the World's Forests 2007, 「 『What happens to forests' will be largely determined by 『what happens outside forests'.」 In other words, small local communities may no longer have the power to protect the remaining forests and the success or failure of conservation will rest with strong leadership.

Source of Information : Green Technology Conservation Protecting Our Plant Resources