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How Babies Learn Language

2010-04-27T13:34:00.000+05:30

During the first year of a child's life, parents and care takers are concerned with its physical development; during the second year they watch the baby's language development very carefully. It is interesting just how easily children learn language. Children who are just three or four years old, who cannot yet tie their shoelaces, are able to speak in full sentences without any specific language training.

The current view of child language development is that it is an instinct—something as natural as eating or sleeping. According to experts in this area, this language instinct is innate—something each of us is born with. But this prevailing view has not always enjoyed widespread acceptance.

In the middle of last century, experts of the time, including a renowned professor at Harvard University in the United States, regarded child language development as the process of learning through mere repetition. Language "habits" developed as young children were rewarded for repeating language correctly and ignored or punished when they used incorrect forms of language. Over time, a child, according to this theory, would learn language much like a dog might learn to behave properly through training.

Yet even though the modern view holds that language is instinctive, experts like Assistant Professor Lise Eliot are convinced that the interaction a child has with its’ parents and care givers is crucial to its development. The language of the parents and caregivers acts as models for the developing child. In fact, a baby's day-to-day experience is so important that the child will learn to speak in a manner very similar to the model speakers it hears.

Given that the models parents provide are so important, it is interesting to consider the role of "baby talk" in the child's language development. Baby talk is the language produced by an adult speaker who is trying to exaggerate certain aspects of the language to capture the attention of a young baby.

Dr. Roberta Golinkoff believes that babies benefit from baby talk.

Experiments show that immediately after birth babies respond more to infant-directed talk than they do to adult-directed talk. When using baby talk, people exaggerate their facial expressions, which help the baby to begin to understand what is being communicated. She also notes that the exaggerated nature and repetition of baby talk helps infants to learn the difference between sounds. Since babies have a great deal of information to process, baby talk helps.

Although there is concern that baby talk may persist too long, Dr. Golinkoff says that it stops being used as the child gets older, that is, when the child is better able to communicate with the parents.

Professor Jusczyk has made a particular study of babies' ability to recognize sounds, and says they recognize the sound of their own names as early as four and a half months. Babies know the meaning of Mummy and Daddy by about six months, which is earlier than was previously believed. By about nine months, babies begin recognizing frequent patterns in language. A baby will listen longer to the sounds that occur frequently, so it is good to frequently call the infant by its name.

An experiment at Johns Hopkins University in USA, in which researchers went to the homes of 16 nine-month-olds, confirms this view. The researchers arranged their visits for ten days out of a two week period. During each visit the researcher played an audio tape that included the same three stories. The stories included odd words such as "python" or "hornbill", words that were unlikely to be encountered in the babies' everyday experience. After a couple of weeks during which nothing was done, the babies were brought to the research lab, where they listened to two recorded lists of words. The first list included words heard in the story. The second included similar words, but not the exact ones that were used in the stories.

Jusczyk found the babies listened longer to the words that had appeared in the stories, which indicated that the babies had extracted individual words from the story. When a control group of 16 nine-month-olds, who had not heard the stories, listened to the two groups of words, they showed no preference for either list.

This does not mean that the babies actually understand the meanings of the words, just the sound patterns. It supports the idea that people are born to speak, and have the capacity to learn language from the day they are born. This ability is enhanced if they are involved in conversation. And, significantly, Dr Eliot reminds parents that babies and toddlers need to feel they are communicating. Clearly, sitting in front of the television is not enough; the baby must be having an interaction with another speaker.

Forex scam

2009-05-18T10:30:00.001+05:30

A forex (or foreign exchange) scam is any trading scheme used to defraud individual traders by convincing them that they can expect to gain a high profit by trading in the foreign exchange market. Currency trading "has become the fraud du jour" as of early 2008, according to Michael Dunn of the U.S. Commodity Futures Trading Commission. [1] But "the market has long been plagued by swindlers preying on the gullible," according to the New York Times [2]. "The average individual foreign-exchange-trading victim loses about $15,000, according to CFTC records" according to The Wall Street Journal. [3] The North American Securities Administrators Association says that "off-exchange forex trading by retail investors is at best extremely risky, and at worst, outright fraud." [4]

“In a typical case, investors may be promised tens of thousands of dollars in profits in just a few weeks or months, with an initial investment of only $5,000. Often, the investor’s money is never actually placed in the market through a legitimate dealer, but simply diverted – stolen – for the personal benefit of the con artists.”[5]

In August, 2008 the CFTC set up a special task force to deal with growing foreign exchange fraud.”[6]

The forex market is a zero-sum game[7] , meaning that whatever one trader gains, another loses, except that brokerage commissions and other transaction costs are subtracted from the results of all traders, technically making forex a "negative-sum" game.

These scams might include churning of customer accounts for the purpose of generating commissions, selling software that is supposed to guide the customer to large profits, [8] improperly managed "managed accounts", [9] false advertising, [10] Ponzi schemes and outright fraud. [4] [11] It also refers to any retail forex broker who indicates that trading foreign exchange is a low risk, high profit investment. [12]

The U.S. Commodity Futures Trading Commission (CFTC), which loosely regulates the foreign exchange market in the United States, has noted an increase in the amount of unscrupulous activity in the non-bank foreign exchange industry.[13]

An official of the National Futures Association was quoted [14] as saying, "Retail forex trading has increased dramatically over the past few years. Unfortunately, the amount of forex fraud has also increased dramatically..." Between 2001 and 2006 the U.S. Commodity Futures Trading Commission has prosecuted more than 80 cases involving the defrauding of more than 23,000 customers who lost $350 million. From 2001 to 2007, about 26,000 people lost $460 million in forex frauds. [1] CNN quoted Godfried De Vidts, President of the Financial Markets Association, a European body, as saying, "Banks have a duty to protect their customers and they should make sure customers understand what they are doing. Now if people go online, on non-bank portals, how is this control being done?"

From Wikipedia, the free encyclopedia

Quality Factors in Foods

2009-05-14T10:41:00.000+05:30

In countries where food is abundant, people choose foods based on a number of factors which can in sum be thought of as "quality." Quality has been defined as degree of excellence and includes such things as taste, appearance, and nutritional content. We might also say that quality is the composite of characteristics that have significance and make for acceptability. Acceptability, however, can be highly subjective. Quality and price need not go together, but food manufacturers know that they generally can get a higher price for or can sell a larger quantity of products with superior quality. Often "value" is thought of as a composite of cost and quality. More expensive foods can be a good value if their quality is very high. The nutrient value of the different grades of canned fruits and vegetables is similar for all practical purposes, yet the price can vary as much as threefold depending on other attributes of quality. This is why processors will go to extremes to control quality.

When we select foods and when we eat, we use all of our physical senses, including sight, touch, smell, taste, and even hearing. The snap of a potato chip, the crackle of a breakfast cereal, and crunch of celery are textural characteristics, but we also hear them. Food quality detectable by our senses can be divided into three main categories: appearance factors, textural factors, and flavor factors.

Appearance factors include such things as size, shape, wholeness, different forms of damage, gloss, transparency, color, and consistency. For example, apple juice is sold both as cloudy and clear juice. Each has a different appearance and is often thought of as a somewhat different product.

Textural factors include handfeel and mouthfeel of firmness, softness, juiciness, chewiness, grittiness. The texture of a food is often a major determinant of how little or well we like a food. For example, many people do not like cooked liver because of its texture. Texture of foods can be measured with sophisticated mechanical testing machines.

Flavor factors include both sensations perceived by the tongue which include sweet, salty, sour, and bitter, and aromas perceived by the nose. The former are often referred to as "flavors" and the latter "aromas," although these terms are often used interchangeably. Flavor and aroma are often subjective, difficult to measure accurately, and difficult to get a group of people to agree. A part of food science called sensory science is dedicated to finding ways to use humans to accurately describe the flavors and other sensory properties of foods. There are hundreds of descriptive terms that have been invented to describe flavor, depending on the type of food. Expert tea tasters have a language all of their own, which has been passed down to members of their guild from generation to generation. This is true of wine tasters as well.

Source:- Potter N. Norman, Hotchkiss H. Joseph. 2006. Food Science, Fifth edition. CBS publishers & Distributors, New Delhi.

The World's Healthiest Foods

2008-09-12T14:37:00.004+05:30

Bananas

Wonderfully sweet with firm and creamy flesh, bananas come prepackaged in their own yellow jackets and are available for harvest throughout the year.

The banana plant grows 10 to 26 feet and belongs to the same family as the lily and the orchid. The cluster of fruits contain anywhere from 50 to 150 bananas with individual fruits grouped in bunches, known as "hands," containing 10 to 25 bananas.

This chart graphically details the %DV that a serving of Bananas provides for each of the nutrients of which it is a good, very good, or excellent source according to our Food Rating System. Additional information about the amount of these nutrients provided by Bananas can be found in the Food Rating System Chart. A link that takes you to the In-Depth Nutritional Profile for Bananas, featuring information over 80 nutrients, can be found under the Food Rating System Chart.

Health Benefits

Creamy, rich, and sweet, bananas are a favorite food for everyone from infants to elders. Sports enthusiasts appreciate the potassium-power delivered by this high energy fruit.

Cardiovascular Protection from Potassium and Fiber

Bananas are one of our best sources of potassium, an essential mineral for maintaining normal blood pressure and heart function. Since the average banana contains a whopping 467 mg of potassium and only 1 mg of sodium, a banana a day may help to prevent high blood pressure and protect against atherosclerosis.

The effectiveness of potassium-rich foods such as bananas in lowering blood pressure has been demonstrated by a number of studies. For example, researchers tracked over 40,000 American male health professionals over four years to determine the effects of diet on blood pressure. Men who ate diets higher in potassium-rich foods, as well as foods high in magnesium and cereal fiber, had a substantially reduced risk of stroke.

A study published in the Archives of Internal Medicine also confirms that eating high fiber foods, such as bananas, helps prevent heart disease. Almost 10,000 American adults participated in this study and were followed for 19 years. People eating the most fiber, 21 grams per day, had 12% less coronary heart disease (CHD) and 11% less cardiovascular disease (CVD) compared to those eating the least, 5 grams daily. Those eating the most water-soluble dietary fiber fared even better with a 15% reduction in risk of CHD and a 10% risk reduction in CVD.

In addition to these cardiovascular benefits, the potassium found in bananas may also help to promote bone health. Potassium may counteract the increased urinary calcium loss caused by the high-salt diets typical of most Americans, thus helping to prevent bones from thinning out at a fast rate.

Soothing Protection from Ulcers

Bananas have long been recognized for their antacid effects that protect against stomach ulcers and ulcer damage. In one study, a simple mixture of banana and milk significantly suppressed acid secretion. In an animal study, researchers found that fresh bananas protected the animals' stomachs from wounds.

Bananas work their protective magic in two ways: First, substances in bananas help activate the cells that compose the stomach lining, so they produce a thicker protective mucus barrier against stomach acids. Second, other compounds in bananas called protease inhibitors help eliminate bacteria in the stomach that have been pinpointed as a primary cause of stomach ulcers.

Improving Elimination

Bananas are a smart move if you suffer from elimination problems. A bout of diarrhea can quickly deplete your body of important electrolytes. Bananas can replenish your stores of potassium, one of the most important electrolytes, which helps regulate heart function as well as fluid balance.

In addition, bananas contain pectin, a soluble fiber (called a hydrocolloid) that can help normalize movement through the digestive tract and ease constipation. Bananas also contain resistant starch, but this amount varies depending on their degree of ripeness. In their lesser ripe stages, bananas score as low as 30 on the glycemic index (below 50 would be considered low). In their riper stages, this number usually rises to a moderate level in the 60's. All of the above features help place banana in a more favorable digestive light than might otherwise be expected for a sugary fruit.

Protect Your Eyesight

Your mother may have told you carrots would keep your eyes bright as a child, but as an adult, it looks like fruit is even more important for keeping your sight. Data reported in a study published in the Archives of Ophthalmology indicates that eating 3 or more servings of fruit per day may lower your risk of age-related macular degeneration (ARMD), the primary cause of vision loss in older adults, by 36%, compared to persons who consume less than 1.5 servings of fruit daily.

In this study, which involved over over 100,000 women and men, researchers evaluated the effect of study participants' consumption of fruits; vegetables; the antioxidant vitamins A, C, and E; and carotenoids on the development of early ARMD or neovascular ARMD, a more severe form of the illness associated with vision loss. Food intake information was collected periodically for up to 18 years for women and 12 years for men.

While, surprisingly, intakes of vegetables, antioxidant vitamins and carotenoids were not strongly related to incidence of either form of ARMD, fruit intake was definitely protective against the severe form of this vision-destroying disease.

Three servings of fruit may sound like a lot to eat each day, but by simply tossing a banana into your morning smoothie or slicing it over your cereal, topping off a cup of yogurt or green salad with a half cup of berries, and snacking on an apple, plum, nectarine or pear, you've reached this goal.

Build Better Bones with Bananas

Build better bones by eating bananas? Yes, enjoying bananas frequently as part of your healthy way of eating can help improve your body's ability to absorb calcium via several mechanisms.

Bananas are an exceptionally rich source of fructooligosaccharide, a compound called a prebiotic because it nourishes probiotic (friendly) bacteria in the colon. These beneficial bacteria produce vitamins and digestive enzymes that improve our ability to absorb nutrients, plus compounds that protect us against unfriendly microorganisms. When fructooligosaccharides are fermented by these friendly bacteria, not only do numbers of probiotic bacteria increase, but so does the body's ability to absorb calcium. In addition, gastrointestinal transit time is lessened, decreasing the risk of colon cancer.

Green bananas contain indigestible (to humans) short chain fatty acids (SCFAs) that are a favorite food of the cells that make up the lining of the intestines. When these cells are well-nourished and healthy, the body's ability to absorb nutrients such as calcium can increase dramatically.

Research published in Digestive Diseases and Sciences underscores just how much bananas can improve nutrient absorption. In this study, 57 male babies (5-12 months) with persistent diarrhea of at least 14 days duration were given a week's treatment with a rice-based diet containing either green banana, apple pectin or the rice diet alone. Treatment with both green banana and apple pectin resulted in a 50% reduction in stool weights, indicating that the babies were absorbing significantly more nutrients.

Also, to check how well their intestines were able to absorb nutrients, the babies were given a drink containing lactulose and mannitol. Lactulose is a compound that should be absorbed, while mannitol is one that should not be. When the intestines are too permeable, a condition clinicians call "leaky gut," too little lactulose and too much mannitol are absorbed. After just one week of being given the green banana-rice diet, the babies' were absorbing much more lactulose and little mannitol, showing that their intestines were now functioning properly.

Some banana cultivars are also rich in provitamin A carotenoids, which have been shown to protect against chronic disease, including certain cancers, cardiovascular disease, and diabetes. How to identify which bananas contain the most carotenoids? Check the color of their edible flesh. Bananas whose flesh is more golden contain the most carotenoids.

Promote Kidney Health through Regular and Moderated Intake

About 190,000 cases of kidney cancer are diagnosed each year. Risk factors include smoking, high blood pressure, obesity, and exposure to toxic chemicals such as asbestos and cadmium.

Dietary factors can be related to kidney disease in a preventive way. Research published in the International Journal of Cancer suggests that regular, moderated consumption of whole fruits and vegetables, especially bananas, can be protective. The results of this large population based prospective study (13.4 years) of 61,000 women aged 40-76, show that women eating more than 75 servings of fruits and vegetables per month (which translates into 2.5 per day) cut their risk of kidney cancer 40%. Among the fruits, bananas were especially protective. Women eating bananas four to six times a week halved their risk of developing the disease compared to those who did not eat this fruit.

Salads, eaten at least once a day, were associated with a 40% decreased risk. Among vegetables, frequent consumption of root vegetables and white cabbage offered the most protection, providing a 50-65% decrease in risk.

The conclusion drawn by the researchers: routine and moderated consumption of fruits and vegetables, especially bananas, cabbage and root vegetables, may reduce risk of kidney cancer. Why these foods? Bananas and many root vegetables contain especially high amounts of antioxidant phenolic compounds. Cabbage is rich in sulfur compounds necessary for efficient and effective detoxification of potential carcinogens. This mixture of phytonutrients may have been particularly helpful in protecting kidney function.

The benefits of regular and moderated fruit intake need to be contrasted, however, with the increased risks that stem from very high consumption of fruit juices. In several studies examining diet and renal (kidney) cancer, very high consumption of fruit juices is associated with increased cancer risk. Since most fruit juice consumption involves highly processed fruits and stands in sharp contrast to consumption of whole, natural foods, this finding is not surprising. The reasons for avoiding high intake of fruit juice are not limited to increased risk of kidney disease, but also to problems involved with excessive sugar intake and excessive calorie intake from non-whole foods. Moderate amounts of fruit juice - especially juice containing as much of the whole fruit as possible, for example, pulp or skin - are still recommended, since these limited amounts in a balanced diet appear to be protective against kidney cancer.

Description

Bananas are elliptically shaped fruits "prepackaged" by Nature, featuring a firm, creamy flesh gift-wrapped inside a thick inedible peel. The banana plant grows 10 to 26 feet in height and belongs to the family Musaceae. Banana fruits grow in clusters of 50 to 150, with individual fruits grouped in bunches, known as "hands," of 10 to 25 bananas.

Bananas abound in hundreds of edible varieties that fall under two distinct species: the sweet banana (Musa sapienta, Musa nana) and the plantain banana (Musa paradisiacal). Sweet bananas vary in size and color.

While we are accustomed to thinking of sweet bananas as having yellow skins, they can also feature red, pink, purple and black tones when ripe. Their flavor and texture range with some varieties being sweet while others have starchier characteristics. In the United States, the most familiar varieties are Big Michael, Martinique and Cavendish. Plantain bananas are usually cooked and considered more like a vegetable due to their starchier qualities; they have a higher beta-carotene concentration than most sweet bananas.

History

Bananas are thought to have originated in Malaysia around 4,000 years ago. From there, they spread throughout the Philippines and India, where in 327 B.C. Alexander the Great's army recorded them being grown.

Bananas were introduced to Africa by Arabian traders and discovered there in 1482 A.D. by Portuguese explorers who took them to the Americas, the place where the majority of bananas are now produced.

Bananas were not brought to the United States for sale in markets until the latter part of the 19th century and were initially only enjoyed by people in the seacoast towns where the banana schooners docked; because of the fruit's fragility, they were unable to be transported far.

Since the development of refrigeration and rapid transport in the 20th century, bananas have become widely available. Today, bananas grow in most tropical and subtropical regions with the main commercial producers including Costa Rica, Mexico, Ecuador and Brazil.

How to Select and Store

Since bananas are picked off the tree while they're still green, it's not unusual to see them this color in the store. Base your choice of bananas depending upon when you want to consume them. Bananas with more green coloration will take longer to ripen than those more yellow in hue and/or with brown spots.

Bananas should be firm, but not too hard, bright in appearance, and free from bruises or other injuries. Their stems and tips should be intact. The size of the banana does not affect its quality, so simply choose the size that best meets your needs.

While bananas look resilient, they're actually very fragile and care should be taken in their storage. They should be left to ripen at room temperature and should not be subjected to overly hot or cold temperatures. Unripe bananas should not be placed in the refrigerator as this will interrupt the ripening process to such an extent that it will not be able to resume even if the bananas are returned to room temperature.

If you need to hasten the ripening process, you can place bananas in a paper bag or wrap them in newspaper, adding an apple to accelerate the process. Ripe bananas that will not be consumed for a few days can be placed in the refrigerator. While their peel may darken, the flesh will not be affected. For maximum flavor when consuming refrigerated bananas, remove them from the refrigerator and allow them to come back to room temperature.

For the most antioxidants, eat fully ripened fruit:

Research conducted at the University of Innsbruck in Austria suggests that as fruits fully ripen, almost to the point of spoilage, their antioxidant levels actually increase.

Key to the process is the change in color that occurs as fruits ripen, a similar process to that seen in the fall when leaves turn from green to red to yellow to brown— a color change caused by the breakdown and disappearance of chlorophyll, which gives leaves and fruits their green color.

Until now, no one really knew what happened to chlorophyll during this process, but lead researcher, Bernard Kräutler, and his team, working together with botanists over the past several years, has identified the first decomposition products in leaves: colorless, polar NCCs (nonfluorescing chlorophyll catabolytes), that contain four pyrrole rings - like chlorophyll and heme.

After examining apples and pears, the scientists discovered that NCCs replace the chlorophyll not only in the leaves of fruit trees, but in their very ripe fruits, especially in the peel and flesh immediately below it.

"When chlorophyll is released from its protein complexes in the decomposition process, it has a phototoxic effect: when irradiated with light, it absorbs energy and can transfer it to other substances. For example, it can transform oxygen into a highly reactive, destructive form," report the researchers. However, NCCs have just the opposite effect. Extremely powerful antioxidants, they play an important protective role for the plant, and when consumed as part of the human diet, NCCs deliver the same potent antioxidant protection within our bodies. Angew Chem Int Ed Engl. 2007 Nov 19;46(45):8699-8702.

Bananas can also be frozen and will keep for about 2 months. Either purée them before freezing or simply remove the peel and wrap the bananas in plastic wrap. To prevent discoloration, add some lemon juice before freezing.

How to Enjoy

In addition to being eaten raw, bananas are a wonderful addition to a variety of recipes from salads to baked goods.

A few quick serving ideas:

A peanut butter and banana sandwich drizzled with honey is an all-time favorite comfort food for children and adults alike.

Add chopped bananas, walnuts and maple syrup to oatmeal or porridge.

Try our Tropical Breakfast Risotto in the Recipe File

Safety

Bananas and Latex Allergy

Like avocados and chestnuts, bananas and plantain contain substances called chitinases that are associated with the latex-fruit allergy syndrome. There is strong evidence of the cross-reaction between latex and these foods. If you have a latex allergy, you may very likely be allergic to these foods as well. Processing the fruit with ethylene gas increases these enzymes; organic produce not treated with gas will have fewer allergy-causing compounds. In addition, cooking the food may deactivate the enzymes.

Nutritional Profile

Bananas are a very good source of vitamin B6 and a good source of vitamin C, potassium, dietary fiber, and manganese.

For an in-depth nutritional profile click here: Banana.

In-Depth Nutritional Profile

In addition to the nutrients highlighted in our ratings chart, an in-depth nutritional profile for Bananas is also available. This profile includes information on a full array of nutrients, including carbohydrates, sugar, soluble and insoluble fiber, sodium, vitamins, minerals, fatty acids, amino acids and more.

Introduction to Food Rating System Chart

In order to better help you identify foods that feature a high concentration of nutrients for the calories they contain, we created a Food Rating System. This system allows us to highlight the foods that are especially rich in particular nutrients. The following chart shows the nutrients for which this food is either an excellent, very good, or good source (below the chart you will find a table that explains these qualifications). If a nutrient is not listed in the chart, it does not necessarily mean that the food doesn't contain it. It simply means that the nutrient is not provided in a sufficient amount or concentration to meet our rating criteria. (To view this food's in-depth nutritional profile that includes values for dozens of nutrients - not just the ones rated as excellent, very good, or good - please use the link below the chart.) To read this chart accurately, you'll need to glance up in the top left corner where you will find the name of the food and the serving size we used to calculate the food's nutrient composition. This serving size will tell you how much of the food you need to eat to obtain the amount of nutrients found in the chart. Now, returning to the chart itself, you can look next to the nutrient name in order to find the nutrient amount it offers, the percent Daily Value (DV%) that this amount represents, the nutrient density that we calculated for this food and nutrient, and the rating we established in our rating system. For most of our nutrient ratings, we adopted the government standards for food labeling that are found in the U.S. Food and Drug Administration's "Reference Values for Nutrition Labeling." Read more background information and details of our rating system.

Banana 1.00 each 118.00 grams 108.56 calories
Nutrient	Amount	DV (%)	Nutrient Density	World's Healthiest Foods Rating
vitamin B6 (pyridoxine)	0.68 mg	34.0	5.6	very good
vitamin C	10.74 mg	17.9	3.0	good
potassium	467.28 mg	13.4	2.2	good
dietary fiber	2.83 g	11.3	1.9	good
manganese	0.18 mg	9.0	1.5	good

World's Healthiest Foods Rating	Rule
excellent	DV>=75%	OR	Density>=7.6	AND	DV>=10%
very good	DV>=50%	OR	Density>=3.4	AND	DV>=5%
good	DV>=25%	OR	Density>=1.5	AND	DV>=2.5%

In-Depth Nutritional Profile for Bananas

The World's Healthiest foods

2008-09-04T10:19:00.003+05:30

Carrots

Easy to pack and perfect as crudités for that favorite dip, the crunchy texture and sweet taste of carrots is popular among both adults and children. Although they are shipped around the country from California throughout the year, locally grown carrots are in season in the summer and fall when they are the freshest and most flavorful.

The carrot has a thick, fleshy, deeply colored root, which grows underground, and feathery green leaves that emerge above ground. It is known scientifically as Daucus carota, a name that can be traced back to ancient Roman writings of the 3rd century. Carrots belong to the Umbelliferae family along with parsnips, fennel caraway, cumin and dill which all have the umbrella-like flower clusters that characterize this family of plants.

This chart graphically details the %DV that a serving of Carrots provides for each of the nutrients of which it is a good, very good, or excellent source according to our Food Rating System. Additional information about the amount of these nutrients provided by Carrots can be found in the Food Rating System Chart. A link that takes you to the In-Depth Nutritional Profile for Carrots, featuring information over 80 nutrients, can be found under the Food Rating System Chart.

Health Benefits

Carrots are an excellent source of antioxidant compounds, and the richest vegetable source of the pro-vitamin A carotenes. Carrots' antioxidant compounds help protect against cardiovascular disease and cancer and also promote good vision, especially night vision.

Carotenoids and Heart Disease

When six epidemiological studies that looked at the association of diets high in carotenoids and heart disease were reviewed, the research demonstrated that high-carotenoid diets are associated with a reduced risk of heart disease. In one study that examined the diets of 1,300 elderly persons in Massachusetts, those who had at least one serving of carrots and/or squash each day had a 60% reduction in their risk of heart attacks compared to those who ate less than one serving of these carotenoid-rich foods per day.

Better Vision

Beta-carotene helps to protect vision, especially night vision. After beta-carotene is converted to vitamin A in the liver, it travels to the retina where it is transformed into rhodopsin, a purple pigment that is necessary for night-vision. Plus beta-carotene's powerful antioxidant actions help provide protection against macular degeneration and the development of senile cataracts, the leading cause of blindness in the elderly.

Carotenoids and Optimal Health

Carrots are by far one of the richest source of carotenoids-just one cup provides 16,679 IUs of beta-carotene and 3,432 REs (retinol equivalents), or roughly 686.3% the RDA for vitamin A. High carotenoid intake has been linked with a 20% decrease in postmenopausal breast cancer and an up to 50% decrease in the incidence of cancers of the bladder, cervix, prostate, colon, larynx, and esophagus. Extensive human studies suggest that a diet including as little as one carrot per day could conceivably cut the rate of lung cancer in half. Remember the study in which heavy long-term cigarette smokers were given synthetic beta-carotene, and it did not appear to prevent them from developing lung cancer? Well, not only is synthetic beta-carotene not biochemically identical to the real stuff found in carrots, but scientists now think that carrots' protective effects are the result of a team effort among several substances abundant in carrots, including alpha-carotene-another, less publicized carotenoid. A recent National Cancer Institute study found lung cancer occurence was higher in men whose diets did not supply a healthy intake of alpha-carotene.

Carotenoids and Blood Sugar

Intake of foods such as carrots that are rich in carotenoids may be beneficial to blood sugar regulation. Research has suggested that physiological levels, as well as dietary intake, of carotenoids may be inversely associated with insulin resistance and high blood sugar levels.

Falcarinol in Carrots Promote Colon Health

Although best known for their high content of beta carotene, carrots also contain a phytonutrient called falcarinol that may be responsible for the recognized epidemiological association between frequently eating carrots and a reduced risk of cancers.

Falcarinol provides protection against colon cancer, suggests a study published in the Journal of Agricultural and Food Chemistry. Three groups of laboratory animals in whom precancerous colon lesions (aberrant crypt foci) had been chemically-induced were fed a standard diet, one supplemented with freeze-dried carrots naturally containing falcarinol, or one supplemented with an extract of falcarinol. After 18 weeks, precancerous lesions in the animals given diets containing carrots or falcarinol were much smaller than those in the control animals, and far fewer of the lesions had grown in size or progressed to become tumors.

Promote Lung Health

If you or someone you love is a smoker, or if you are frequently exposed to secondhand smoke, then making vitamin A-rich foods, such as carrots, part of your healthy way of eating may save your life, suggests research conducted at Kansas State University.

While studying the relationship between vitamin A, lung inflammation, and emphysema, Richard Baybutt, associate professor of nutrition at Kansas State, made a surprising discovery: a common carcinogen in cigarette smoke, benzo(a)pyrene, induces vitamin A deficiency.

Baybutt's earlier research had shown that laboratory animals fed a vitamin A-deficient diet developed emphysema. His latest animal studies indicate that not only does the benzo(a)pyrene in cigarette smoke cause vitamin A deficiency, but that a diet rich in vitamin A can help counter this effect, thus greatly reducing emphysema.

Baybutt believes vitamin A's protective effects may help explain why some smokers do not develop emphysema. "There are a lot of people who live to be 90 years old and are smokers," he said. "Why? Probably because of their diet…The implications are that those who start smoking at an early age are more likely to become vitamin A deficient and develop complications associated with cancer and emphysema. And if they have a poor diet, forget it." If you or someone you love smokes, or if your work necessitates exposure to second hand smoke, protect yourself by making sure the World's Healthiest Foods rich in vitamin A (carrot's beta-carotene is converted in the body into vitamin A) are a daily part of your healthy way of eating.

Description

Carrots? The favorite food of Bugs Bunny hardly needs a description for they are well known and loved by even the youngest children in many countries. Carrots benefits are legendary. Bet your mother told you that eating carrots would keep your eyesight bright.

While we usually associate carrots with the color orange, in fact, carrots grow in a host of other colors including white, yellow, red, or purple, the latter being the color of the original variety. The carrot is a plant with a thick, fleshy, deeply colored root, which grows underground, and feathery green leaves that emerge above ground. It is known scientifically as Daucus carota, a name that can be traced back to ancient Roman writings of the 3rd century.

Carrots belong to the Umbelliferae family, named after the umbrella like flower clusters that plants in this family produce. As such, carrots are related to parsnips, fennel caraway, cumin and dill. There are over 100 different varieties that vary in size and color. Carrots can be as small as two inches or as long as three feet, ranging in diameter from one-half of an inch to over two inches. Carrot roots have a crunchy texture and a sweet and minty aromatic taste, while the greens are fresh tasting and slightly bitter.

History

The carrot can trace its ancestry back thousands of years, originally having been cultivated in central Asian and Middle Eastern countries. These original carrots looked different from those that we are accustomed to today, featuring deep purple coloring, ranging from lavender to deep eggplant. This coloration was a reflection of the anthocyanin phytonutrient pigments these carrots had. In pre-Hellenic times, a yellow-rooted carrot variety appeared in Afghanistan and was further cultivated and developed into an earlier version of the carrot we known today. Both types of carrots spread throughout the Mediterranean region and were adopted by the ancient Greeks and Romans for their medicinal use.

It seems that carrots did not become a popular vegetable in Europe until the Renaissance. This was probably related to the fact that the early varieties had a tough and fibrous texture. Centuries later, beginning in the 17th century, agriculturists in Europe started cultivating different varieties of carrots, developing an orange-colored carrot that had a more pleasing texture than its predecessor. Europeans favored the growing of this one over the purple variety, which was and still is widely grown in other areas of the world, including southern Asia and North Africa. Carrots were subsequently introduced into the North American colonies. Owing to its heightened popularity, in the early 1800s, the carrot became the first vegetable to be canned. Today, the United States, France, England, Poland, China and Japan are among the largest producers of carrots.

How to Select and Store

Carrot roots should be firm, smooth, relatively straight and bright in color. The deeper the orange-color, the more beta-carotene is present in the carrot. Avoid carrots that are excessively cracked or forked as well as those that are limp or rubbery. In addition, if the carrots do not have their tops attached, look at the stem end and ensure that it is not darkly colored as this is also a sign of age. If the green tops are attached, they should be brightly colored, feathery and not wilted. Since the sugars are concentrated in the carrots' core, generally those with larger diameters will have a larger core and therefore be sweeter.

Carrots are hardy vegetables that will keep longer than many others if stored properly. The trick to preserving the freshness of carrot roots is to minimize the amount of moisture they lose. To do this, make sure to store them in the coolest part of the refrigerator in a plastic bag or wrapped in a paper towel, which will reduce the amount of condensation that is able to form. They should be able to keep fresh for about two weeks. Carrots should also be stored away from apples, pears, potatoes and other fruits and vegetables that produce ethylene gas since it will cause them to become bitter.

If you purchase carrot roots with attached green tops, the tops should be cut off before storing in the refrigerator since they will cause the carrots to wilt prematurely as they pull moisture from the roots. While the tops can be stored in the refrigerator, kept moist by being wrapped in a damp paper, they should really be used soon after purchase since they are fragile and will quickly begin to wilt.

How to Enjoy

For some of our favorite recipes, click Recipes.

Tips for Preparing Carrots:

Wash carrot roots and gently scrub them with a vegetable brush right before eating. Unless the carrots are old, thick or not grown organically, it is not necessary to peel them. If they are not organically grown, peel them; most all conventionally grown carrots are grown using pesticides and other chemicals. If the stem end is green, it should be cut away as it will be bitter. Depending upon the recipe or your personal preference, carrots can be left whole or julienned, grated, shredded or sliced into sticks or rounds.

Carrots are delicious eaten raw or cooked. Beta-carotene is not destroyed by cooking; in fact, cooking breaks down the fiber, making this nutrient and carrots' sugars more available, thus also making them taste sweeter. Take care not to overcook carrots, however, to ensure that they retain their maximum flavor and nutritional content.

A f\Few Quick Serving Ideas:

Shredded raw carrots and chopped carrot greens make great additions to salads.

Combine shredded carrots, beets and apples, and eat as a salad.

For quick, nutritious soup that can be served hot or cold, purée boiled carrots and potatoes in a blender or food processor, and add herbs and spices to taste.

Spiced carrot sticks are a flavorful variation on an old favorite at parties or at the dinner table. Soak carrot sticks in hot water spiced with cayenne, coriander seeds and salt. Allow to cool, drain and serve.

Combine freshly squeezed carrot juice with soymilk and bananas to make a nutrient-dense breakfast shake.

Safety

Carrots and Carotoderma

Excessive consumption of carotene-rich foods may lead to a condition called carotoderma in which the palms or other skin develops a yellow or orange cast. This yellowing of the skin is presumably related to carotenemia, excessive levels of carotene in the blood. The health impact of carotenemia is not well researched. Eating or juicing high amounts of foods rich in carotene, like carrots, may over tax the body's ability to convert these foods to vitamin A. The body slowly converts carotene to vitamin A, and extra carotene is stored, usually in the palms, soles or behind the ears. If the cause of the carotenemia is eating excessively high amounts of foods like carrots, the condition will usually disappear after reducing consumption.

Nutritional Profile

Carrots are an excellent source of vitamin A. In addition, they are a very good source of vitamin C, vitamin K, dietary fiber and potassium.

For an in-depth nutritional profile click here: Carrots.

In-Depth Nutritional Profile

In addition to the nutrients highlighted in our ratings chart, an in-depth nutritional profile for Carrots is also available. This profile includes information on a full array of nutrients, including carbohydrates, sugar, soluble and insoluble fiber, sodium, vitamins, minerals, fatty acids, amino acids and more.

Introduction to Food Rating System Chart

The following chart shows the nutrients for which this food is either an excellent, very good or good source. Next to the nutrient name you will find the following information: the amount of the nutrient that is included in the noted serving of this food; the %Daily Value (DV) that that amount represents; the nutrient density rating; and the food's World's Healthiest Foods Rating. Underneath the chart is a table that summarizes how the ratings were devised. Read detailed information on our Food and Recipe Rating System.

Carrots, raw 1.00 cup 122.00 grams 52.46 calories
Nutrient	Amount	DV (%)	Nutrient Density	World's Healthiest Foods Rating
vitamin A	34317.40 IU	686.3	235.5	excellent
vitamin K	16.10 mcg	20.1	6.9	very good
vitamin C	11.35 mg	18.9	6.5	very good
dietary fiber	3.66 g	14.6	5.0	very good
potassium	394.06 mg	11.3	3.9	very good
vitamin B6 (pyridoxine)	0.18 mg	9.0	3.1	good
manganese	0.17 mg	8.5	2.9	good
molybdenum	6.10 mcg	8.1	2.8	good
vitamin B1 (thiamin)	0.12 mg	8.0	2.7	good
vitamin B3 (niacin)	1.13 mg	5.6	1.9	good
phosphorus	53.68 mg	5.4	1.8	good
magnesium	18.30 mg	4.6	1.6	good
folate	17.08 mcg	4.3	1.5	good

World's Healthiest Foods Rating	Rule
excellent	DV>=75%	OR	Density>=7.6	AND	DV>=10%
very good	DV>=50%	OR	Density>=3.4	AND	DV>=5%
good	DV>=25%	OR	Density>=1.5	AND	DV>=2.5%

Computer Power Management

2008-07-02T09:22:00.003+05:30

Low power consumption is an important goal in designing modern electronic systems. Most previous studies of low-power techniques focused on either hardware or software to reduce power consumption. “Power Management” is an effective approach to reduce power consumption by various electronic systems without any significant degrading of their performances.

What is “Power Management”?

Power management is a process that allows computers and monitors to enter low-power states when sitting idle. The low power modes of inactive computers can involve reducing central processing unit power consumption or spinning down the hard disk. Inactive monitors with enabled power management enter low-power modes by turning off monitor output.

Power management does not reduce the performance of computers and monitors. It simply adds features to reduce their power consumption at the time when they are not in use. Most power management savings come from reducing power when the machine is not fully active by adding low-power or “sleep” modes that kick in when idle. “Sleep” modes usually involve slowing the clock rate of the central processing unit, and may include spinning down the hard disk, turning off entire system components such as video cards, sound cards or disk controllers.

Why Power Management is essential?

Worldwide, computers and monitors in commercial and industrial settings use millions of kilowatts of electricity each day. Two simple steps can save more than half of this energy.

· Enable power management functions that place computers and monitors in low-power mode during periods of inactivity.

· Turning off computers and monitors after work.

When using energy efficient machines, they save money on electricity as well as reduce pollution from power plants. In addition to the environmental benefits of reducing energy consumption, power management can improve equipment reliability by reducing waste heat.

History of the Power Management

In the early days of personal computing, under operating systems like DOS and CP/M (Control Program / Monitor or Control Program for Microcomputers) operating systems, there was no such an operation called power management. Those computers either used 100% of their power requirements or were switched off. Personal computer power management history dates back at least to 1989, when Intel produced processors with technology to allow the central processing unit (CPU) to slow down, suspend, or shut down part or all of the system platform, or even the CPU itself, to preserve and extend battery life. The increasing importance of power management reflects the increasing number of PCs in use and their transition to tools that go wherever people go.

PC power management was first introduced in laptop computers to allow longer operating times while running on battery power. Later it was brought into the desktop PC market. Many early power management systems had long recovery times, awkward configuration methods and low energy savings. However, power management has improved rapidly, becoming more powerful, reliable and easier to use. It also now delivers considerably more energy savings. In 1993 Intel and Microsoft introduced Advanced Power Management (APM) which becoming an industry standard. The APM protocol supports power management by defining how power management commands are communicated within the PC system.

How does Power Management work?

As the following figure shows, computers are logically organized as a hierarchy of layers. Those at the top are the software that the user directly interacts with. Those closer to the bottom direct the physical control of electrical signals. Power management can involve the application software and the operating system (sometimes these are not involved), and always requires action by the firmware (BIOS), processor and peripheral hardware.

The BIOS (Basic Input/Output System) is a combination of hardware and firmware (software in read-only memory), distinct from the operating system, that intermediates between the processor and other parts of the system. In the first generation of power management (machines built through 1993 or 1994), it was controlled only by the BIOS. As of 1996, the BIOS is still a key component, but more of the configuration and control is rising into the operating system and occasionally into application software. However, control signals must still pass through each intermediate layer for action to occur.

Figure 1: PC Power Management key components and communication paths

In the above figure, the numbers indicate the various steps in initiating power management. It shows the communication paths which allow power management to occur.

Number 2 The BIOS send periodic signals (about once per second) to the operating system to begin power management

Number 3 If this signal is passed through by the operating system, it will trigger the start of the power management timers in the BIOS. The operating system will only pass the signal through if it detects no activity from the application software

Number 4 If there is no activity, the operating passes the signal back to the BIOS, which begins a timer

Number 1 The BIOS continues to monitor keyboard and mouse activity

Number 5 After a specified time with no activity, the BIOS will initiate power management by sending appropriate messages to some or all of the hard disk, peripheral cards, processor, and video card

After initiating a change in mode, the BIOS begins another timer which indicates when to initiate the next power management mode. If at any time the BIOS receives an interrupt request (keyboard, mouse, or network activity), the BIOS will signal the required peripheral cards, processor, and video card to return to an active mode (usually only a demand for hard disk activity will cause the hard disk to spin up). Examples of peripheral cards include network interfaces and CD-ROM drives.

Power management has four major components for the following activities.

1. To monitor activity levels of the processor, input devices (such as the keyboard and mouse), and communication peripherals (network or modem).

2. To utilize timers to decide when to initiate the shift to a lower power mode.

3. To changes the power management status need to be communicated to the correct device and actually occur.

4. To recognize when activity resumes and return to a higher power (or full-power) mode.

PC Power Management modes

Before the release of Windows 95, Microsoft operating system software was only minimally involved in desktop PC power management (and application software was only used for monitor power management, not for controlling the PC itself). Thus the BIOS was, and remains, a critical component. Three companies dominate the production of BIOS systems used in x86-based PCs. This means that computers from different manufacturers may use the same power management. The following activities applies to Advanced Power Management (APM), and not necessarily to early (1993 and earlier) implementations of power management. To enter APM modes, they must be enabled, and the specified amount of time must pass without activity. Note that hibernate is not an APM mode.

Full-on Mode:

· All components fully powered; no power management occurring.

APM Enable Mode:

· CPU is slowed or stopped (depending on BIOS); all other devices still draw full power.

· Some systems have a ‘doze’ mode that is similar to APM Enabled.

PC Savings: 0-25% Recovery time: instantaneous

APM Standby Mode:

· CPU may be stopped depending on operation or activity; most devices are in low power mode.

· Monitor enters its first power management mode.

· Activity can trigger a return to enabled or full-on, depending on the system and activity.

PC Savings: 20-30%

Monitor Savings: 60-90%

APM Suspend Mode:

· CPU is stopped; most power-managed devices are not powered (network card may stay on).

· Maximum power savings under APM.

· Activity can trigger a return to standby, doze or full-on, depending on the BIOS

PC Savings: 25-45%

Monitor Savings: 0-10% Recovery time: 3 to 10 seconds

Hard Disk Power Down : (this is not an APM mode)

· Hard disk spin in stopped; this is independent of other power management (hence not a system mode), so that the remainder of the system can be fully operational or power down.

· Disk control electronics are still powered to facilitate quick reactivation

PC Savings: 10%

Recovery time: 3–10 seconds (disk savings independent of other savings)

Hibernate: (this is not an APM mode)

· All memory contents and system state saved to disk.

· System resistant to power loss

PC Savings: 90-100% Recovery Time: 15-60 seconds

Workstation Savings: 95% Recovery Time: <60>

Off Mode

· No operational parameters are saved

· System resets and starts at full-on mode

· Most systems use no power (a few draw a small amount).

PC Power Management with Networks

Maintaining network connections during power management was a problem for many earlier systems. Some new systems continue to have problems with this, but many have been tested to work properly under common networking systems. Currently, most power management problems with networked PCs are a result of the way the network operating system works rather than with the PC hardware.

Monitor Power Management

Even though the PC must be the initiator, power management has been more successful in monitors than in PCs. Compared to power managing PCs, monitors are usually simpler, have much more energy savings potential, power manage more reliably, and are less likely to interfere with operation or network connections. Because of this, it is even more important to enable monitors for power management than it is to enable PCs.

Monitor power management is in most cases independent of PC power management in that the monitor can power down even if the PC doesn’t, and vice-versa. However, the monitor is still dependent on the PC for power management initiation. This is necessary since the monitor does not directly receive the activity information needed to know when to begin and end power management. Once the first low-power mode is entered, however, the monitor has an internal timer and will shift to succeeding low-power modes even if the PC doesn’t send additional signals. While delay times may differ, for the most part, the monitor and PC are driven by the same activity for beginning and ending low-power modes (though network activity is an exception to this).

The structure of monitor power management control is shown in Figure 1. The PC always initiates the process, with the initial timers within the BIOS, or special software that comes with the video card. Successive power management modes can be activated by either the PC's timer or the monitor's internal timer.

Some PCs have a “convenience” electrical outlet on the back for plugging in the monitor. PCs that can switch off the power to this outlet allow energy savings from monitors that can't power manage on their own. In addition, if the monitor is plugged into the PC (whether the outlet is power-managed or not), then the monitor will be switched off when the PC is switched off (otherwise they often remain on, albeit with a blank screen).

Potential Barriers to Power Management

Even though a computer or monitor may have power management features, power management may not always operate effectively. There are many reasons why power management can be defeated in systems that have the feature.

Software Interactions

Some application software can interfere with power management, depending on how it is configured and the particular machine it is used on. One example is the ‘auto-save’ feature on many word processors and spreadsheets. If the feature saves the document even if no changes have been made, this will unnecessarily cause the processor and hard disk to stay awake, defeating power management partially or entirely.

Some screensavers will periodically load complex images from the hard disk, keeping the disk from powering down. A screensaver can keep the monitor and processor from power managing, unless set to a specific power management mode; many screensavers lack a power management mode and so need to be turned off for power management to occur.

Upgrades

Power management capabilities may change when PCs are upgraded by replacing the processor, the motherboard, or add-on cards (e.g. the network interface). Software upgrades of operating systems or utility software can cause power management to be disabled. Before upgrading many similar machines, determine if the proposed change interferes with power management. If it does, consider looking for alternatives that do not.

Networks

Computer networks pose special challenges for power management. Once a PC is connected to a network, the user may want to access the machine remotely, others may rely on being able to connect to it at any time, and services such as disk backups may operate during nights or weekends. This can mean that the simplest power management strategy, simply turning the machine off, can no longer be used for the PC (though the monitor can and should be turned off). Remote access by modem has the same effect as does a computer set up to receive faxes.

Future Directions of the Power Management

Power Management in Monitors

There are several important emerging monitor technologies that offer some relief in the historical increase in power. Most of today's monitors are Cathode Ray Tubes (CRTs). The two technologies that show promise in gaining significant market share in the near future are Liquid Crystal Display technologies, and thin CRTs.

Flat-panel displays used with today's laptop computers use far less power than CRTs, but currently their high cost limits their use with desktop PCs. This is changing as manufacturers seek to bring costs down and build larger displays.

Power Management in PCs

Not only power management for PCs for periods when they are not fully active, there are also opportunities to reduce active power. Active power can be lowered with techniques such as reducing the chip count through more integration of functions, lowering the power supply voltage, using a more efficient power supply, or switching to smaller (less energy-intensive) expansion cards.

Cholesterol and Heart Disease

2008-06-11T10:44:00.000+05:30

In recent times there have been a number of newspaper and other articles about fats in the diet, their effects on the increase in serum cholesterol level and resulting coronary Heart Disease (CHD). the discussion has mainly focussed on the intake of saturated fats and CHD. It is special concern to us the large amount of coconut and coconut oil that are used in Sri Lankan meals.

What is CHOLESTEROL?

Cholesterol is a type of essential fat that is needed by the body and is found i9n small amounts in the human body and in animals. Consequently it is found in small quantities in animal food products such as meat, milk, eggs etc. the major portion of cholesterol is synthesised in our liver and only a little comes from the diet. Cholesterol is not found in any plants. Coconut oil like other vegetable oils, does not have cholesterol. In the blood, cholesterol and fatty acids are carried by proteins. These ‘fat-protein’ molecules are called lipoproteins. These are two types of lipoproteins, the HDL (High Density Lipoprotein) cholesterol and LDL (Low Density Lipoprotein) cholesterol. The normal level of serum cholesterol is 200 mg/100 ml. high levels of cholesterol in blood is a matter for concern. Cholesterol deposition in the blood vessels is facilitated by LDL cholesterol, causing the thinning of arteries and blocking the free flow of blood into the heart muscles, resulting in CHD. HDL cholesterol on the other hand acts as a scavenger of cholesterol.

Synthesis of cholesterol in the liver is influenced by our diet. The type and amount of fatty acids and the content of cholesterol in the foods we eat, affects the types and levels of cholesterol in the blood. It has been accepted that high contents of cholesterol and saturated fatty acids in the food cause elevated cholesterol levels in the blood. Foods such as butter, cheese and pork increase the synthesis of cholesterol because of the high content of long chain saturated fatty acids that are found in these foods.

Where do we stand with regard to coconut oil?

The predominant fatty acids in coconut oil are saturated;

This has for a long time let to the belief that coconut oil is an unhealthy fat that can result in CHD. The reason for this belief is mainly the result of that experiment carried out using hydrogenated coconut oil, which showed elevation of serum cholesterol in the subjects used for the experiment.

Recently however there has been reassessment of previous experiment data and the present thinking is that coconut oil, is after all, not so bad. Nutritionist believes that even tough coconut oil has a large proportion of saturated fatty acids (91.6%) that these are mostly of the medium chain (carbon atoms 6 to 12 in the chain) fatty acid types. Lauric, Myristic and other medium chain fatty acid account for 60 to 70% of the saturated fatty acids. The medium chain fatty acids are easily broken down to give energy and do not remain available in the blood to result in an increase of LDL cholesterol, This however is not the casa with long chain fatty acids as found in animal fats.

Hydrogenated coconut oil however is not so good because not only is the oil further saturated but the nature of the essential fatty acids is also changed from ‘Cis’ to ‘Trans’ fatty acids. The body cannot use Trans-linoleic acids as essential fatty acids. There is also evidence to show that ‘Trans’ fatty acids are injurious to health.

The polyunsaturated also should be eaten for the essential fatty acids.

It must be remembered that where CHD is concerned, cholesterol is only one factor, others being obesity, high blood pressure, smoking and diabetes mellitus.

Natural Compound Improves Apples’ Red Colour

2008-06-10T11:31:00.000+05:30

Methyl jasmonate (MJ) has many functions. The natural compound derived from plant oils – especially jasmine and honeysuckle oils – helps plants muster pest-defence proteins. Incorporated into cosmetic products, it produces a sweet, flowery aroma. Now, spraying MJ onto apples before harvest may improve uniformity and depth of red colouring in the fruit’s peel, new research suggests.

“Applying MJ increases the total percentage of the crop having uniform red colour, and important grading issue for domestic and export markets,” says Agricultural Research Service plant pathologist James Mattheis.

The approach draws on published research showing that when apples are exposed to natural or artificial light, MJ activities processes in the peel that produce anthocyanin pigments. MJ also breaks down the peel’s green chlorophyll, though light isn’t required.

“Application timing is important; treat too early in the season, and the colour can face by harvest,” says Mattheis, who heads ARS’ Tree Fruit Research Laboratory in Wenatchee, Washington, a state forecast to produce 88.8 million boxes of fresh-market apples this year.

Through research is ongoing, ARS in May 2002 applied for patent protection (10/146,687) on the treatment, since no similar products are currently marketed, notes Mattheis, whose research team includes graduate student Dave Rudell and food technologist Xuetong Fan.

One particular use for MJ may be ensuring a more uniform red colour on Fugi apples that have spent much of the growing season enclosed within opaque bags. In the United States and Japan, where Fujis originated, bagging is practiced to enhance the apple’s red colour or close to harvest. Starting in late June, more than a month after a Fuji’s flowers have bloomed, two overlapping bags are placed around the immature fruit by hand and keep in place until a few weeks before harvest (late September to early October in Washington). Even after the bags are removed, the red colour continues to develop, albeit unevenly. Spraying MJ helps correct for this by promoting red colour development on all sides of the apple, Mattheis notes.

MJ also works on such popular varieties as Red Delicious and Gala. “We didn’t see any significant change in eating quality compared to untreated fruit,” says Mattheis of lab and orchard studies in which apples were treated with a water-based emulsion containing a sufficient and 2 percent or less MJ.

Other positives: MJ also works on harvested fruit for degreening, and is already classified by the Food and Drug Administration as a generally Recognized As Safe substance. Despite its promise, MJ needs further evaluation. Too much can harm he fruit, and at about $43 an ounce, the economics of orchard-scale treatments are uncertain.

“We’re still not totally there in terms of minimizing the variability,” Mattheis says, “We’re still trying to improve MJ formation and timing and better understand the factors that influence success with this treatment.”

But if the approach bears fruit in terms of consistency and cont, apple growers could get a head-start on improving their crop’s marketability.

Flash Memory

2008-06-05T11:09:00.002+05:30

Computerized systems, from simple appliances to complex networks, consists of many different parts such as processors, printed circuit boards, drives, keyboards and mouse, switches, modems, memory, displays, software, etc. that are essential for the smooth functioning of the system. Among those parts, memory is a very important and mandatory factor that need by almost all the computer systems.

Computer memory can be considered as a location where information is stored, that can be utilized by the operating system, software programs, hardware devices and by the user. There are two types of memory as volatile memory and non-volatile memory on the basis of their information retention ability. Volatile memory is memory that loses its contents when the computer or hardware device loses power. Computer RAM (Random Access Memory) is a good example of a volatile memory. Non-volatile memory, (sometimes abbreviated as NVRAM) is memory that keeps its contents even if the power is lost. CMOS (Complementary metal-oxide semiconductor) is a good example of a non-volatile memory.

Memory is capable of retaining digital information under certain conditions. This retained material might be operational code or data files or a combination of the two. An ideal memory subsystem optimises density, preserves critical material in a non-volatile condition, is easy to program and re-program, can be read fast, and is cost-effective for the application. Some memory technologies meet one or more of these requirements very well, but there are limitations that can prevent the product from becoming a genuine solution, especially in newer applications.

Non-volatile memory

Non-volatile memory is the type of computer memory that can retain the stored information even when not powered. Read-only memory, flash memory, most types of magnetic computer storage devices (e.g. hard disks, floppy disk drives, and magnetic tape), optical disc drives, and early computer storage methods such as paper tape and punch cards are some examples of non-volatile memory.

Non-volatile memory is typically used for the task of secondary storage or long-term persistent storage. The most widely used form of primary storage today is a volatile form of random access memory (RAM). When the computer is shut down, anything contained in RAM gets lost. Unfortunately, most forms of non-volatile memory have limitations that make them unsuitable for use as primary storage. Typically, non-volatile memory either costs more or performs worse than volatile random access memory. But, in terms of secondary storage, non-volatile memory plays a major role.

Several companies are working on developing non-volatile memory systems comparable in speed and capacity to volatile RAM. For instance, IBM is currently developing MRAM (Magnetic RAM). Not only would such technology save energy, but it would allow for computers that could be turned on and off almost instantly, bypassing the slow start-up and shutdown sequence.

Non-volatile data storage can be categorized in electrically addressed systems random access memory and mechanically addressed systems hard disks, optical disc, magnetic tape, holographic memory and such. Electrically addressed systems are expensive, but fast, whereas mechanically addressed systems have a low price per bit, but are slow. Non-volatile memory may one day eliminate the need for comparatively slow forms of secondary storage systems, which include hard disks.

Electrically addressed non-volatile memories based on charge storage can be categorised according to their write mechanism as follows.

Mask-programmed ROM

The mask-programmed ROM was one of the earliest forms of non-volatile read-only memory. It was pre-wired at the design stage to contain specific data. Once the mask was used to manufacture the integrated circuits, the data was cast in stone and could not be changed. Whatever '1's and '0's were in memory when it left the factory were there for life. The mask ROM was therefore useful only for large-volume production, such as for read-only memories containing the start-up code in early microcomputers. Due to the very high initial cost and inability to make revisions, the mask ROM is rarely if ever used in new designs.

Programmable ROM (PROM)

The next approach was to create a chip which was initially blank. The resultant was the programmable ROM. Originally it contained silicon or metal fuses, which would be selectively "blown" or destroyed by a device programmer or PROM programmer in order to change '0's to '1's. Once the bits were changed, there was no way to restore them to their original condition. Therefore, even though the Programmable ROM was non-volatile, still it was somewhat inflexible.

Erasable PROMs (EPROM)

The original erasable non-volatile memories were EPROM's. These could be readily identified by the distinctive quartz window in the centre of the chip package. There are two classes of non-volatile memory chips based on EPROM technology, the UV-erase EPROMs and one-time programmable ROMs.

UV-erase EPROM

These operated by trapping an electrical charge on the gate of a field-effect transistor in order to change a '1' to a '0' in memory. To remove the charge, the chip should be placed under an intense short-wavelength fluorescent ultraviolet lamp for 20-30 minutes. This action will return the entire chip to its original blank (all '1's) state.

OTP (one-time programmable) ROM

An OTP is electrically an EPROM, but with the quartz window physically missing. Like the fuse PROM it can be written once, but cannot be erased. It has largely replaced PROM chips in electronic production as an EPROM with no window is inexpensive to manufacture and can be programmed using identical equipment to that used to write to the UV-window EPROM.

Electrically Erasable PROM (EEPROM)

Electrically erasable PROM's have the advantage of being able to selectively erase any part of the chip without the need to erase the entire chip and without the need to remove the chip from the circuit. While an erase and rewrite of a location appears nearly instantaneous to the user, the write process is slightly slower than the read process. The chip can be read at full system speeds.

The limited number of times a single location can be rewritten is usually in the range of 10,000-100,000. The capacity of an EEPROM also tends to be smaller than that of other non-volatile memories. However, EEPROMs are useful for storing settings or configuration for devices ranging from dial-up modems to satellite receivers.

Flash Memory

The flash memory chip is a close relative to the EEPROM. It differs in that it can only be erased one "block" or "page" at a time. Capacity is substantially larger than that of an EEPROM, making these chips a popular choice for digital cameras and desktop PC BIOS chips.

Battery-Backed Static RAM

This is a volatile memory chip to which a battery has been added in order to preserve the contents in the absence of external power. These used to be typically manufactured with CMOS technology to minimise power consumption. A lithium cell can easily power a small memory for a few years. It is now common to use SDRAM with a Lithium ion battery. It is possible to preserve a gigabyte of such memory for days. The settings from the BIOS menus which appear on start-up on most desktop PCs are stored in battery-backed CMOS static RAM as a battery must already be present on the mainboard to keep the real-time clock running when the computer is not in use.

Mechanically addressed systems

Tape, Hard disk, Optical disk, Nanodrive, Holographic storage are some of the mechanically addressed systems.

What is Flash Memory?

Flash memory is a type of non-volatile computer memory that can be electrically erased and reprogrammed. It is a technology that is primarily used in memory cards and USB flash drives (thumb drives, handy drive, memory stick, flash stick, jump drive), which are used for general storage and transfer of data between computers and other digital products. It is a specific type of EEPROM that is erased and programmed in large blocks. In early flash the entire chip had to be erased at once. Flash memory costs far less than byte-programmable EEPROM and therefore has become the dominant technology wherever a significant amount of non-volatile, solid-state storage is needed. Examples of applications include PDAs and laptop computers, digital audio players, digital cameras and mobile phones. It has also gained some popularity in the game console market, where it is often used instead of EEPROMs or battery-powered static RAM (SRAM) for game save data.

Flash memory stores information in an array of floating gate transistors called 'cells' each of which traditionally stores one bit of information. The two major types of flash memory are known as NOR architecture and NAND architecture.

NOR Flash Memory

NOR, named after the specific data mapping technology (Not OR), is a high-speed Flash technology. NOR Flash memory provides high-speed random-access capabilities, being able to read and write data in specific locations in the memory without having to access the memory in sequential mode. NOR Flash allows the retrieval of data as small as a single byte. NOR Flash excels in applications where data is randomly retrieved or written. NOR is most often found built into cellular phones (to store the phone’s operating system) and PDAs and is also used in computers to store the BIOS program that runs to provide the start-up functionality.

NAND Flash Memory

NAND Flash was invented after NOR Flash, and is named after the specific mapping technology used for data (Not AND). NAND Flash memory reads and writes in high speed sequential mode, handling data in small block sizes (“pages”). NAND Flash can retrieve or write data as single pages, but cannot retrieve individual bytes like NOR Flash. NAND Flash memory is commonly found in solid-state hard drives, audio and video Flash media devices, television set-top boxes, digital cameras, cell phones (for data storage) and other devices where data is generally written or read sequentially. For example, most digital cameras use NAND-Flash based digital film, as pictures are usually taken and stored sequentially.

NAND-Flash is also more efficient when pictures are read back, as it transfers whole pages of data very quickly. As a sequential storage medium, NAND Flash is ideal for data storage. NAND Flash memory is less expensive than NOR Flash memory, and can accommodate more storage capacity in the same die size.

Flash memory which stores a single bit per cell (e.g., a value of “0” or “1” per cell) is known as Single-Level Cell (SLC) Flash. Newer flash memory devices, sometimes referred to as Multi-Level Cell devices, can store more than one bit per cell, by using more than two levels of electrical charges, placed on the floating gate of a cell.

General Flash characteristics

Although flash shares many characteristics with EPROM and EEPROM, current-generation flash differs in that ERASE operations are done in blocks. Flash, EPROM and EEPROM all must be erased before being written. When erasing EPROM, the entire chip is erased with a UV light source. EEPROM is automatically erased before a WRITE on a byte basis. Flash is either erased in blocks (boot block or sectored erase block flash) or the entire chip at once (bulk erase flash).

Boot block devices have erase blocks that vary in size from 4KB to 128KB. Sectored erase block flash has blocks of equal size, some with no additional hardware protection. This configuration is suited for mass storage or firmware applications. Although flash is erased on a block basis, WRITE and READ operations are done on a random byte or word basis.

Flash Cell Structure

Most flash devices share basically the same cell structure as the EPROM cell. Both the flash and EPROM cells are dual polysilicon (poly), floating-gate CMOS field effect transistors. The first poly layer is isolated from the control gate by an interpoly dielectric layer and from the substrate by a thin oxide layer.

This isolation allows the first poly layer (floating gate) to store charge. The second poly layer is connected to the wordline and functions as the control gate. However, there are two main differences between a flash cell and an EPROM cell that allow for electrical erase of the flash cell. Flash has a thinner oxide layer of approximately 100 angstroms to enable Fowler-Nordheim tunneling of electrons from the floating gate during an ERASE. In addition, flash has a deeper source diffusion to further enhance ERASE performance.

How flash Cell Works?

Automated write and erase

One feature that many current-generation flash devices have is an on-chip state machine that automates WRITE and ERASE. First-generation flash and EPROM typically require the host system or programmer to execute complex algorithms to write and erase. These algorithms are required to write any flash cell, but on current-generation flash the algorithms are executed internally by a state machine. This frees the host system to do other tasks while the state machine writes or erases the flash memory and simplifies designing of flash by reducing software overhead necessary to write or erase the device.

During a WRITE, the state machine controls the WRITE pulse timing to the cell, tracks the number of pulses issued, controls the voltages applied to the cell and verifies that the data was written correctly. When executing an ERASE, the state machine first writes all locations within the block to “0” so that each cell contains uniform charge. The state machine then issues the ERASE pulses to the cells within the block and monitors the ERASE for completion. At any time during a WRITE or ERASE, the status register may be read to monitor the WRITE or ERASE in progress or to check for the completion of the WRITE or ERASE cycle.

WRITE

Flash and EPROM implement hot electron injection to place charge on the floating gate during a WRITE. During a WRITE, a high programming voltage (V_PP = 12V) is placed on the control gate. This forces an inversion region to form in the p-type substrate. The drain voltage is increased to approximately half the control gate voltage (6 volts) while the source is grounded (0 volts), increasing the voltage drop between the drain and source. (Figure 2.) With the inversion region formed, the current between drain and source increases. The resulting high electron flow from source to drain increases the kinetic energy of the electrons. This causes the electrons to gain enough energy to overcome the oxide barrier and collect on the floating gate.

After the WRITE is completed, the negative charge on the floating gate raises the cell’s threshold voltage (V_T) above the wordline logic 1 voltage. When a written cell’s wordline is brought to a logic 1 during a READ, the cell will not turn on. The sense amps detect and amplify the cell current and output a “0” for a written cell.

ERASE

Flash employs “Fowler-Nordheim tunnelling” (a process whereby electrons tunnel through a barrier in the presence of a high electric field) to remove charge from the floating gate to bring it to the erased state. Using high-voltage source erase, the source is brought to a high voltage (V_PP = 12V), the control gate grounded (0 volts) and the drain left unconnected. (Figure 3.) The large positive voltage on the source, as compared to the floating gate, attracts the negatively charged electrons from the floating gate to the source through the thin oxide. Because the drain is not connected, the ERASE function is a much lower current-per-cell operation than a WRITE that uses hot electron injection.

After the ERASE is completed, the lack of charge on the floating gate lowers the cell’s V_Tbelow the wordline logic 1 voltage. When an erased cell’s wordline is brought to a logic 1 during a READ, the transistor will turn on and conduct more current than a written cell. Some flash devices use Fowler-Nordheim tunneling for WRITEs as well as ERASEs.

Array architecture

Flash products are available in symmetrical as well as asymmetrical blocking architecture. The flexible blocking architecture enables system integration of code and data within a single flash device.

READING

During a READ of a byte or word of data, the addressed row (wordline) is brought to a logic 1 level (> V_T of an erased cell). This condition turns on erased cells which allow current to flow from drain to source, while written cells remain in the off state with little current flow from drain to source. The cell current is detected by the sense amps and amplified to the appropriate logic level to the outputs. All other wordlines within the array remain low. Because only one wordline needs to be controlled at a time during a READ, the decode overhead is minimized. As a result, high random-access READ performance is achieved with the NOR architecture.

Flash memory devices

There are many products can be identified that use the flash technology. USB flash drive is a device commonly used by most of the people in there day to day life in many activities. Therefore it is important that studying the functioning and features with the USB flash drive.

USB flash drive

They are NAND-type flash memory data storage devices integrated with a USB (universal serial bus) interface. They are typically small, lightweight, removable and rewritable. Capacity is limited only by current flash memory densities, although cost per megabyte may increase rapidly at higher capacities due to the expensive components.

USB flash drives offer potential advantages over other portable storage devices, particularly the floppy disk. They are more compact, generally faster, hold more data, and are more reliable (due to both their lack of moving parts, and their more durable design) than floppy disks. These types of drives use the USB mass storage standard, supported natively by modern operating systems such as Linux, Mac OS X, Unix, and Windows.

A flash drive consists of a small printed circuit board encased in a plastic or metal casing, making the drive sturdy enough to be carried about in a pocket, as a key fob, or on a lanyard. Only the USB connector protrudes from this protection, and is usually covered by a removable cap. Most flash drives use a standard type-A USB connection allowing them to be connected directly to a port on a personal computer.

To access the data stored in a flash drive, the drive must be connected to a computer, either by plugging it into a USB host controller built into the computer, or into a USB hub. Flash drives are active only when plugged into a USB connection and draw all necessary power from the supply provided by that connection. However, some flash drives, especially high-speed drives utilizing the USB 2.0 standard, may require more power than the limited amount provided by a bus-powered USB hub, such as those built into some computer keyboards or monitors. These drives will not work unless plugged directly into a host controller or a self-powered hub.

Components of a USB flash drive

One end of the device is fitted with a single male type-A USB connector. Inside the plastic casing is a small printed circuit board. Mounted on this board is some simple power circuitry and a small number of surface-mounted integrated circuits (ICs). Typically, one of these ICs provides an interface to the USB port, another drives the onboard memory, and the other is the flash memory.

Essential components

There are typically four parts to a flash drive:

Male type-A USB connector - provides an interface to the host computer.
USB mass storage controller - implements the USB host controller and provides a linear interface to block-oriented serial flash devices while hiding the complexities of block-orientation, block erasure, and wear levelling, or wear balancing. The controller contains a small RISC microprocessor and a small amount of on-chip ROM and RAM.
NAND flash memory chip - stores data. NAND flash is typically also used in digital cameras.
Crystal oscillator - produces the device's main 12 MHz clock signal and controls the device's data output through a phase-locked loop.

The typical device may also include:

Jumpers and test pins - for testing during the flash drive's manufacturing or loading code into the microprocessor.
LEDs - indicate data transfers or data reads and writes.
Write-protect switches - indicate whether the device should be in "write-protection" mode.
Unpopulated space - provides space to include a second memory chip. Having this second space allows the manufacturer to develop only one printed circuit board that can be used for more than one storage size device, to meet the needs of the market.
USB connector cover or cap - reduces the risk of damage due to static electricity, and improves overall device appearance. Some flash drives do not feature a cap, but instead have retractable USB connectors. Other flash drives have a "swivel" cap that is permanently connected to the drive itself and eliminates the chance of losing the cap.
Transport aid - In some cases, the cap or the main body contains a hole suitable for connection to a key chain or lanyard or to otherwise aid transport and storage of the USB flash device.

USB flash drives have been integrated into other things such as a watch or a pen.

Common uses of a USB flash drive

Personal data transport

The most common use of flash drives is to transport and store personal files such as documents, pictures and video. Individuals also store medical alert information for use in emergencies and for disaster preparation.

Computer repair

Flash drives are useful in the PC repair field as a means to transfer recovery and antivirus software to infected PCs, while allowing a portion of the host machine's data to be archived in case of emergency.

System administration

Flash drives are particularly popular among system and network administrators, who load them with configuration information and software used for system maintenance, troubleshooting, and recovery.

Application carriers

Flash drives are used to carry applications that run on the host computer without requiring installation. U3, backed by flash drive vendors, offers an API to flash drive-specific functions. “airWRX” is an application framework that runs from a flash drive and turns its PC host and other nearby PCs into a multi-screen, web-like work environment.

Audio players

Many companies make solid state digital audio players in a small form factor, essentially producing flash drives with sound output and a simple user interface. Probably the best-known of these has been Apple Computer's “iPod shuffle”, and the Creative Labs “MuVo”.

To boot operating systems

In a way similar to that used in LiveCD, one can launch any operating system from a bootable flash drive, known as a “LiveUSB”.

Windows Vista ReadyBoost

In Windows Vista, the “ReadyBoost” feature allows use of a flash drive to augment system memory.

Strengths and weaknesses of Flash Memory Devices

Many Flash Memory devices are nearly impervious to the scratches and dust that were problematic for previous forms of portable storage, such as compact discs and floppy disks. Their durable solid-state design means they often survive casual abuse. This makes them ideal for transporting personal data or work files from one location to another, such as from home to office or for carrying around personal data that the user typically wants to access in a variety of places. The near ubiquity of USB support on modern computers means that such a drive will work in most places. A drawback to the small size is that they are easy to misplace, leave behind, or otherwise lose.

Flash memory devices are relatively dense form of storage, where even the cheapest will store dozens of floppy disks worth of data. Some can hold more data than a CD (700 MB). Top of the line flash drives can store more data than a double-sided dual-layer DVD - even 64 GB and more.

USB Flash drives implement the USB mass storage device class, meaning that most modern operating systems can read and write to flash drives without any additional device drivers. The flash drives present a simple block-structured logical unit to the host operating system, hiding the individual complex implementation details of the various underlying flash memory devices. The operating system can use whatever type of file system or block addressing scheme it wants. Some computers have the ability to boot up from flash drives.

All flash memory devices can sustain only a limited number of write and erase cycles before failure. Mid-range flash devices under normal conditions will support several hundred thousand cycles, although write operations will gradually slow as the device ages. This should be a consideration when using a flash drive to run application software or an operating system. To address this, as well as space limitations, some developers have produced special versions of operating systems (such as Linux) or commonplace applications (such as Mozilla Firefox) designed to run from flash drives. These are typically optimized for size and configured to place temporary or intermediate files in the computer's main RAM memory rather than store them temporarily on the flash drive.

Most USB flash drives do not include a write-protect mechanism. Such a switch on the housing of the drive itself would keep the host computer from writing or modifying data on the drive. Write-protection would make a device suitable for repairing virus-contaminated host computers without infecting the USB flash drive itself.

Flash devices are much more tolerant of abuse than mechanical drives, but can still be damaged or have data corrupted by severe physical impacts. Improperly wired USB ports can also destroy the circuitry of a flash drive, a danger in home-built desktop PCs.

Comparison to other portable memory forms:

Flash storage devices are often compared to other common, portable, swappable data storage devices, such as floppy disks, Zip disks, miniCD / miniDVD, CD-R/CD-RW and DVD-RW discs.

Floppy disks were the first popular method of file transport, but have been almost completely phased out due to their low capacity, low speed, and low durability. Virtually all new computers no longer include floppy drives, and do include USB ports, the Apple iMac being the first to ship this way. However, floppy disks are still in use because of their low cost; they are often the easiest or only way to share files with older systems; floppy drives can be added to new systems either internally or externally.

Attempts to extend the floppy standard (such as the Imation SuperDisk) were not successful because of a reputation for unreliability and the lack of a single standard for PC vendors to adopt. The Iomega Zip drive enjoyed some popularity, but never reached the point of ubiquity in computers. Also, the larger sizes of Zip (now up to 750 MB) cannot be read on older drives. Unless one were to carry an external drive, their usefulness as a means of moving data was rather limited. The cost per megabyte was fairly high, with individual disks. Because moving parts are involved and the material used for creating the storage medium in Zip disks is similar to that used in floppy disks, Zip disks have a high risk of failure and data loss compared to flash drives. Larger removable storage media, like Iomega's Jaz drive, had even higher costs for both drives and media, and as such were not pervasively adopted as a floppy alternative.

CD-R and CD-RW are swappable storage media alternatives. Unlike Zip and floppy drives, DVD and CD recorders are now common in personal computer systems. CD-Rs can be written to only once. But CD-RWs are rated at up to 1,000 erase/write cycles, and modern NAND-based flash drives often last for 500,000 or more erase/write cycles. Optical storage devices also usually are slower than their flash-based counterparts. And, compact discs with a 12 cm diameter can be inconveniently large and, unlike flash drives, cannot fit into a pocket or hang from a key chain. There are smaller CD-R media such as business card CD-Rs, which have the same dimensions as a credit card, and (slightly less convenient but have more storage) 8 cm CD-Rs. But these are harder to obtain and generally more expensive than the standard 12 cm version. There also is no standard file system for rewritable optical media. Packet-writing utilities like DirectCD and InCD exist but produce discs that are not universally readable, despite their claiming to be based on the UDF standard. The upcoming Mount Rainier standard addresses this shortcoming in CD-RW media, but it still is not supported by most DVD and CD recorders or major operating systems. As a result, CDs/DVDs are a good way to record a great deal of information cheaply but not good for making ongoing small changes to a large collection of information; flash drives' ability to do this is their major advantage.

USB Flash drives and Security

Some flash drives feature encryption of the data stored on them, generally using full disk encryption below the file system. This prevents an unauthorized person from accessing the data stored on it. The disadvantage is that the drive is accessible only in the minority of computers which have compatible encryption software, for which no portable standard is widely deployed.

Some encryption applications allow running without installation. The executable files can be stored on the USB drive, together with the encrypted file image. The encrypted partition can be accessed on any computer running Microsoft Windows. Other flash drives allow the user to configure secure and public partitions of different sizes. Executable files for Windows, Macintosh, and Linux may be on the drive, depending on manufacturer support. Some security software may require administrative rights on the host PC to access data.

Newer flash drives support biometric fingerprinting to confirm the user's identity. As of mid-2005, this was a relatively costly alternative to standard password protection offered on many new USB flash storage d

evices. Most fingerprint scanning drives rely upon the host operating system to validate the fingerprint via a software driver, restricting the drive to Microsoft Windows computers.

Some manufacturers deploy physical authentication tokens in the form of a flash drive. These are used to control access to a sensitive system by containing encryption keys or, more commonly, communicating with security software on the target machine. The system is designed so the target machine will not operate except when the flash drive device is plugged into it. Some of these "PC lock" devices also function as normal flash drives when plugged into other machines.

All such forms of data protection security involve an increased risk of loss of access to the data by the legitimate owner/user.

Flavour Saver

2008-06-04T11:12:00.000+05:30

New Algicide to help keep Catfish tasting good

Blue-green algae give catfish farmers the blues.

Certain types of blue-green algae, or Cyanobacteria, produce off-flavour compounds that can give catfish a muddy or earthy taste, which keeps them from being marketable. Affected fish are held in ponds for costly weeks until the compounds leave their bodies.

Currently, catfish farmers choose between two chemical solutions for fighting the algal menace. Copper sulphate is the only algicide approved by the U.S. Environmental Protection Agency for such use on a permanent basis. Diuron, a herbicide containing chlorine, is used with government permission that must be renewed yearly.

These chemicals control the cyanobacteria, but can be toxic to most phytoplankton, including green algae. Green algae do not cause off-flavours, and they play a significant role as a base for aquatic food chains and as oxygenators for pond water.

Better help may be on the horizon for many catfish farmers in the form of a natural-based algicide that kills blue-green algae but is much safer for other pond life.

The new algicide, the subject of a patent application, uses a product derivative based on the natural compound anthraquinone, found in rye grass (Lolium perenne). It was discovered by scientists at Agriculture Research Service Natural Products Utilization Research Unit in Oxford, Mississippi, in collaboration with biochemist Dhammika Nanayakkara at the University of Mississippi’s National Centre for Natural Products Research.

According to Agriculture Research Service microbiologist Kevin Schrader, the project’s lead scientist, the algicide is ready for additional testing in catfish-filled ponds. It has shown great potential against its target in laboratory tests using microplates and in large fibreglass enclosures known as limnocorrals placed in catfish ponds. Also, catfish exposed to it in aquarium tests stayed healthy, Schrader says.

Agriculture Research Service is seeing a commercial partner to fully develop and commercialize the technology.

The algicide targets Oscillatoria perornata, a species of cyanobacteria prevalent in Mississippi. (That state is home to half of the nation’s catfish farms). O. perornata produces the musty compound 2-methylisoborneol, which in turn gives catfish the muddy type of off-flavor.

Pond testing against O. perornata will continue to take place in four quarter-acre ponds in Stoneville, Mississippi, at the Thad Cochran National Warmwater Aquaculture Centre, in collaboration with fisheries biologist Craig Tucker of Mississippi State University’s Delta Research and extension Centre.

In laboratory tests, the algicide, which if approved may be available in 2 to 3 years, was 40 times less lethal to green algae than Diuron. Also, it rapidly dissipated from the pond water after application, whereas Diuron can be detected for days or weeks after application.

Off-flavour problems cause the $2 billion-a-year catfish farming industry as much as $50 million in losses annually.

Alzheimer’s Disease

2008-06-02T14:09:00.000+05:30

The relationship of aluminium with Alzheimer’s disease is shrouded in controversy. At the second international symposium on geochemistry and health in London in April 1987, many specialists from the medical profession showed definite evidence of aluminium accumulation on the senile plaque cores of the brain of those suffering from the dementia termed Alzheimer’s disease.

In a well illustrated case study from Guam where the percentage of Alzheimer’s disease is very high, Prof. Dan Perl from Mount Sinai Medical School, New York showed the abundance of aluminium as well as silicon in the senile plaque cores, using laser mass spectroscopy.

Even though one cannot yet attribute a causal effect to aluminium, the observations on aluminium accumulation has led to investigation on the possible role of aluminium in the etiology of Alzheimer’s disease.

The recent work of Prof. Keerthi Tennakone and his team from Ruhuna University and IFS, published in the prestigious journal Nature was also highlighted in the symposium and this brought in a whole new dimension to the problem of aluminium uptake by the human body. Prof. Tennakone and his team discovered that even trace quantities of fluoride ions can catalyse the dissolution of metallic aluminium from cooking utensils.

Their work showed that even one part per million of fluoride present in the water may help in extracting dangerous concentrations of aluminium.

This discovery has understandably caused concern among the general public and the environmental geochemists have now yet another intriguing problem before them, ie. to probe the environmental geochemistry of aluminium and its relationship (if any) on the prevalence of Alzheimer’s disease, bearing in mind that aluminium is one of the most abundant elements in the environment and that fluoride-rich waters are also abundant, particularly in the dry zone.

The water factor and your heart

2008-06-02T09:54:00.000+05:30

An awareness of the relationship between environmental geochemistry and the health of man, animals and plants is now being increasingly developed world-wide.

It is also realized that this is a complex problem requiring controlled interactive studies involving geochemists, epidemiologists, ecologists, medical and veterinary practitioners and others.

In a recent publication on Environmental Geochemistry and Health, by the Royal Society, it was stated that, “trace element toxicities and deficiencies in man are especially difficult to relate to the environment in developed countries. However, there are good expectations that direct evidence can be obtained more readily in developing countries and research in such territories is to be encouraged.”

Sri Lanka affords an almost ideal opportunity for the researcher on environmental geochemistry and health in view of the fact that the vast majority of the population of Sri Lanka live in intimate association with the actual physical environment.

This is to say that most people depend on the soil, water, plants and air in the immediate environment for their sustenance. A person who has been drinking water from his garden well for over 60 years and eaten food from plants grown on the soil of his garden will surely have his general health and the trace element budget of his body be governed to a very great extent by the environmental chemistry of the particular water and soil.

This idea can be extended to larger geographical regions and the incidence of certain diseases can therefore be corrected with elemental distributions in the physical environment. Environmental geochemistry is therefore now developing into a very useful tool in investigating regional health problems.

It must be noted that whereas much emphasis is laid on the pollution of the physical environment by man, the effect of the chemistry of the natural environment on the health of a population is also of equal importance. What is required is therefore a much closer interaction between geochemists on the one hand and on the other, professionals such as medical practitioners, epidemiologists and ecologists on the other, working on joint projects.

At the Royal Society meeting mentioned earlier, the clear need to differentiate between hazards due to the natural distribution of elements and due to those introduced by man’s activities was noted.
Water hardness

What level of lead could be expected be taken up by plants grown in a market garden close to a major road?

In Sri Lanka there are many and interesting geochemical situations that need detailed investigation. A few case studies can be highlighted here.

A very interesting relationship that has been observed in many countries is the negative correlation of cardiovascular disease incidence with water hardness, of that area. Deficiencies or excess in the content or availability of trace elements on the rocks and soils, or in water flowing through them, is often considered to be a possible cause of certain diseases, including cardiovascular diseases.

Several investigations have revealed that higher cardiovascular pathology is almost consistently associated with environments (rocks, soils or water) that are generally deficient in trace elements.

In Sri Lanka, the Northern Province, underlaid mostly by sedimentary limestone formations, has the highest water hardness as well as the total dissolved solids (TDS). Interestingly, it is this area in Sri Lanka which has the lowest cardiovascular disease rate.

Areas in the Central Highlands, on the other hand, have soft water and low total dissolved solids contents. Some of the highest cardiovascular death rates, are also found in these mineral deficient groundwater regions. Even though hardwater itself may not be the factor controlling cardiovascular diseases, epidemiological studies have consistently shown that there is a ‘water factor’ associated with hardwater the lack of which may be etiologically important.

The ‘water factor’ may well be a single trace element, a cluster or even, an indirect relationship. Looking for the water factor presents a special challenge to the geochemist and the epidemiologist. If the relation is causal and if the factor in the water can be determined and altered in a beneficial direction, a definite preventive health possibility could well be at hand.

FOOD ADITIVES

2008-05-28T13:04:00.000+05:30

Food additives are intentionally added substances to food. These are normally added in small quantities and are not consumed as foods by themselves. These serve as aids in the preparation and processing of food, to improve quality, appearance, taste, odour, texture, consistency, acidity or alkalinity etc.

Food additives aid the manufacturers but the benefits to the consumer are often debated.

Food additives may be classified as follows:-

1. Preservatives

2. Anti-oxidents

3. Permitted colours

4. Sweetening agents

5. Emulsifiers and Stabilizers

6. Anti-caking agents

7. Firming agents – humectants

8. Acids, Buffers and Bases

These do not include vitamins, herbs and spices and contaminants arising from agricultural practice etc.

Food laws stipulate that labels must list all ingredients in descending order of proportion by weight. Thus food additives appear almost at the end of the list as a code number. These numbers are based on an internationally accepted system replacing long chemical names. The prefix letter E appearing before the number indicate that it has been approved by the European Community e.g. E220 refers to Sulphur dioxide.

Adverse reactions to food additives occur only in a small proportion of the population. Such people could avoid these on recognising the presence of the particular additive from the label.

Preservatives

Preservatives means a substance which when added to food is capable of inhibiting, retarding or arresting the process of fermentation, acidification or other decomposition of food. These acts as antimicrobial agents and inactivate or inhibit the growth of moulds and bacteria in foods.

The preservative regulations permit the presence of only specified preservative within prescribed limits in some foods.

Sulphur dioxide in the form of gas, in solution as sulphurous acid or as sodium, potassium and calcium sulphite is commonly used as a preservative in fruit juices, jams, cider, bear etc. while benzoic acid derivatives are also used in fruit juices, diabetic jams, bear etc. weight by weight benzoic acid is only half as effective as sulphur dioxide.

Sodium nitrate and sodium nitrite are permitted within maximum limits in cured meat, salami, bacon and ham and some cheese. Added nitrates and nitrites are prohibited in all infant foods. These have the potentiality of forming the carcinogenic nitrosoamines, which are harmful to all including infants.

Propionic acid is a permitted preservative in flour confectionary Christmas pudding and in bread within maximum limits. However, it is banned in Germany. Sorbic acid is also permitted in flour confectionary, cheese, cider, yoghurt, curd and some ready to drink beverages.

Biphenyls, 2-hydroxy biphenyls and 2-thiaxol-4-benzimidazole are permitted in citrus fruits.

The abusive and unlawful use of formalin as a preservative in fish and malathion in cereals and pulses have occurred in some developing countries. Malathion is freely available in tropical countries as it is now widely used for spraying against malarial vectors.

Table 1 presents a summary of the permitted preservatives in specified foods and maximum allowed levels in mg/kg.

Specified food	Permitted Preservative	Maximum allowed level mg/kg
1. Beer	SO₂, Benzoic acid or other derivatives of Benzoic acid	70
2. Bread	Propionic acid	3000
3. Cheese	Sorbic acid	1000
4. Cider Wines	SO₂ or Sorbic acid "	200 350
5. Desiccated Coconut	SO₂	50
6. Flour Confectionery	Propionic or Sorbic acid	1000
7. fresh fruits a) Citrus b) Grapes	Biphenyl 2-Hydroxy Biphenyl 2-Thiaxol-4-yl benzimidazole SO₂	70 12 20 15
8. Fruit Juices	SO₂ Benzoic acid or derivatives	350 800
9. Jams	Residual SO₂	100
10. Diabetic Jams	SO₂	100
11. Sausages	SO₂	450
12. Meat cured	NaNO₃ NaNO₂	500 200
13. Ready to drink beverages	SO₂ Benzoic acid or derivatives Sorbic acid	70 160 200
14. Yoghurt	Sorbic acid SO₂ Benzoic acid or derivatives	300 60 120
15. Curd	Sorbic acid	300

Antioxidants

Antioxidants are substances capable of delaying, retarding or preventing the development in food of rancidity or other flavour deteriorations and spoilage due to oxidation and prolonging shelf-life.

Ethyl, propyl, octyl and dodecyl gallates are commonly used antioxidants with a maximum permitted level of 100 mg/kg in edible oils and fats, ghee and margarine while the amount for butter fat used for manufacturing purposes is reduced to 80 mg/kg.

Butylated hydroxy anisole (BHA) or butylated hydroxy toluene (BHT) or a mixture of both are allowed in edible oils, fats, margarine and ghee to a limit of 200 mg/kg while the limit for butterfat used for manufacturing purposes is 160 mg/kg. Gallates, BHA and BHT are prohibited in baby foods. These included 1-ascorbic acid and tocopherols which also serve as antioxidants.

Colouring matters

Colours are as turmeric and saffron have been used in food from ancient times to please consumers. However, regulations had to be brought in to prevent the diaguise of inferior products, the use of metallic coloured salts and non-permitted coal-tar dyes in foods. Poisonous copper sulphate had been used to colour pickles, alum to whiten bread, plant extracts to colour beer and molasses, dyes to spent tea leaves, yellow colour to mask adulterated milk etc.

Only permitted colours which satisfy purity criteria are now allowed in specified foods. Regulations exist for these purposes. Also when colour is added to any food the label must state “Artificially Coloured”.

Among the red permitted colours are carmoisine, fast red E, ponceau 4R, and erythrosine BS. The blue colours are indigo-carmine, brilliant blue FCF while the green colours are S and green FCF. The yellow colours are tartrazine, amaranth and sunset yellow. Amaranth has been banned in the USA.

Raw or unprocessed meat, poultry, fish, fruits and vegetables, tea, coffee beans, ground coffee, coffee extract, bread, cream, condensed milk, dried milk, cheese and butter are not permitted to have added colours. Butter may however contain annatto and carotene. Colours are also prohibited in baby foods.

Sweetening agents

Sugars are high energy foods and these have been replaced by very low energy and non nutritional artificial sweeteners such as saccharine, cyclamates and aspartame. Saccharine and cyclamates have been accepted for carbonated drinks, gelatine deserts, pudding mixtures, jams, jellies, diet jams, cordials, custard and soft drinks. These artificial sweeteners are not permitted in baby foods.

Cyclamates still remain banned in the USA although some attempts have been made to remove this band.

Acesulfame – K is an approved sweetener in more than 20 countries

Genetic engineering has yielded some promising peptide sweeteners.

Other less sweetening agents that yield bulk in sugar free products used for special diets and by diabetics are sorbitol, mannitol and polyhydric alcohols. Thaumatin, which is 3000 times sweeter than sucrose is also a permitted sweetener in some countries. It is found in the fruit of a West African plant called Katemfe.

Non- nutritive sweeteners in food regulations limit the amount allowed in foods.

Analytical methods which include TLC, spectrophotometry and HPLC are available for the detection and estimation of artificial sweeteners.

Emulsifiers and Stabilizers

Any substance which is capable of aiding the formation of a stable mixture of two otherwise immiscible substances such as oils, fats and water is called and emulsifier and any substance that helps to maintain an emulsion which has been formed is called a stabilizer.

Edible gums and agar were used in the early days but they have been replaced now by lecithin, polyphosphates, cellulose esters, poly and partial glycerol esters, propylene glycol esters, carboxy methyl cellulose, stearyl tartrate and monostearin sodium sulphoacetate etc. These are used in bread, flour confectionery, ice-cream, margarine, chocolate, sugar confectionary, processed meats, sauces, dessert mixtures.

Wood resin or ester gum used in beverages and chewing gum and derived from the stumps of longleaf pine are a complex mixture of tri and diglycerol esters of resin acids.

Food regulations specify permitted emulsifiers and stabilizers with limits in foods and also prescribe purity criteria fro emulsifiers and stabilizers.

TLC, HPLC and GLC methods including colorimetric methods are available for the detection and estimation of emulsifiers and stabilizers.

Anti-caking agents: these are substances that ensure a free flow when poured from containers e.g. salt. Magnesium carbonate amounting to 0.3-1% is added to salt to health the free running properties. Phosphates, silicates and fatty acid salts are also used in other foods but the maximum total amount allowed is 20g/kg.

Firming agents and humectants: these enhance the texture and uniform consistency of the food. Humectants prevent foods from drying out. Glycerine, lacitol, mannitol and propylene glycol are common humectants.

Thickeners used in present day foods are modified starches, carrageenan etc. carrageenan is a plant gum derived from a variety of sea weed. It was also called Irish moss and named after a town carragheen in Ireland.

Acids, buffers and bases: these are added to maintain a constant pH level in foods.

Flavour enhancers and flavourings are used for improving the existing flavour or aroma of the food and to retain losses during processing and to make the food more palatable.

Glutamates, ribonucleotides and protein hydrolysates are used as flavour enhancers in soup mixes, sauces and meat products. Ribonucleotides include disodium inosinate and disodium guanylate.

Monosodium glutamate (MSG) is a common flavour enhancer used in Chinese restaurants. MSG is the sodium salt of glutamic acid, one of the most common amino acid found in foods. One fifth of the body’s protein is a glutamate. MSG, besides being a flavour enhancer has also a basic taste named “umane”. Excessive amounts of MSG cause the Chinese restaurant syndrome or Kwok’s Quease which includes headaches, dizziness, muscle tightening, nausea, weakness of upper arm, pains in the neck etc. MSG is prohibited in baby foods. Allergies to MSG exists, as in many other foods.

Apart from food additives already included above, there are others such as enzymes which act as catalysts. These may also act as tenderizers, flavour enhancers, stabilizers, antioxidants and preservatives.

Foods with added flavours, natural of synthetic should be labelled accordingly.

The list of food additives are increasing every year and adequate safeguards are needed. There is a joint FAO/WHO expert committee on Food additives to monitor new additives and to recommend or not their use including establishments of safety limits. The safety limits are included in the food standards established by Codex Alimentarius Commission of the FAO.

Consumers demand more additive free foods, but the food industry rely heavily on additives. Food additives, while serving the purpose for which they are added, should be safe and beneficial to the consumer.

Global Warming

2008-05-28T12:43:00.000+05:30

Global warming is a concept that denotes the temperature increase in the earth’s atmosphere due to the huge emissions of carbon dioxide emitted by human activity, mostly through the inconsiderate combustion of fossil fuels, such as oil and coal. Although climate scientists have been warning against the potentially disastrous effects of global warming for decades, no large-scale counter-measures have been taken so far. Scientists say that global warming will cause increasingly extreme weather patterns: greater heat, greater cold, stronger wind, more or les rain. The increasing warmer temperatures are causing the ice caps in the North and South Poles to melt, which results in rising sea levels. A recent research project that analyzed trapped air in the Antarctic ice core concluded that the present levels of CO₂ are the highest in 800,000 years, that the fastest increase during that period was during the last seventeen years, and that a similar hike in CO₂ levels has never happened in less than a thousand year period up to now. One of the researchers involved said that there is nothing in the ice core that gives us any reason for comfort and that changes of CO₂ levels in the past have always been accompanied by climate change. Although skeptics, especially in the USA, doubt that human activity is responsible for global warming, suggesting that it could be natural occurrence, leading climate scientists and politicians such as AL Gore and Tony Blair connect global warming to the ever increasing combustion of fossil fuels.

Global warming is a global problem in the sense that it is caused globally and has effects globally. The emission of CO₂ in one area of the world will have effects on the climate everywhere. Thus, even if the emission of CO₂ is reduced in Europe, the great increase of CO₂ emissions in rapidly developing countries such as India or China will cause this reduction to have no effect.

The Prime Minister of Britain, Tony Blair, said that the world was facing “nothing more serious, more urgent, or more demanding of leadership” than climate change. Speaking at the launching of a major economic report commissioned by British Treasury, Blair said there was “overwhelming scientific evidence” that climate change was taking place and that the consequences of failing to act would be “disastrous”. According to the report, “Our actions over the coming decades could create risks of major disruption to economic and social activity, later in this century and in the next, on a scale similar to those associated with the great wars and the economic depression of the first half of the 20^th century.”

A recent UN report, the Global Biodiversity outlook, states the need for unprecedented effort to slow down the decline in the richness of natural systems throughout the world. More species of animals and plants are becoming extinct now than at any time since the demise of the dinosaurs sixty five million years ago. And this is all due to human activity. The misuse of modern technology causes our natural environment to collapse in such a way that eventually it might not be able to support people anymore.

Recently, I had first hand experience of the effects of global warming when visiting Europe. When I grew up in the Netherlands, it was a cool and drizzly country even in summer. However, when I was there at the end of June, a tropical heat wave started to envelope the whole of Northern Europe, and in some areas temperatures soared above 35?c.These extreme heat waves were unknown in Northern Europe until few years ago. When the heat wave was over, unprecedented tropical rainstorms inundated streets .At the time of writing this article, at the end of October, 2006, the temperatures are still unusually high in the Netherlands. The trees still carry their leaves, which would normally only be found in distant southern European areas with mild winters and warm summers, have started to appear in the Netherlands during the last few years. Due to the warmer weather, southern creatures find conditions suitable in the north and rapidly move up. Another consequence of the heat waves in Europe was that yields of crops were affected, and consequently the prices of certain foods such a milk and bread went up. With a large part of the Netherlands being land below sea level that is only protected by dykes from the sea, Dutch government organizations are naturally taking global warming seriously. Serious plans have been made on how to deal with drastically rising sea levels, and what to do when the large rives that flow through the Netherlands overflow due to rapidly melting snow in the Alps in spring and heavy rains in summer. In Switzerland, where I also went, I was told that the glaciers on the mountains are disappearing, and where there previously was ice and snow on the mountains during the summer, now there is none.

Recent plans for shifting over from fossil fuels to nuclear power would increase the risk of nuclear disasters, and besides this, the building, maintaining, and especially the decommissioning of nuclear plants and the storage of nuclear waste uses tremendous amounts of energy obtained from fossil fuels. The is no guarantee that future societies, which might not have the same resources as we have now, will be able to handle nuclear waste left over from us. Moreover, uranium is an even more limited resource than oil, and economically viable extraction might finish within twenty years. Alternative energy sources, such as wind and solar power, are attractive alternatives, but, as these technologies don’t create large-scale industries and income for governments, their introduction has been slow.

Among the family and friends I talked to in the Netherlands there was a general acknowledgment that the climate is changing: however, when one touches upon the causes and results of it, then a visible uneasiness arises, and the topic is changed. For many, it is difficult to accept that human activity can change the climate. Weather has always been something that has been considered unpredictable and uncontrollable. In pre-modern times, and still, in traditional cultures, it was supposed that gods who controlled the weather, and the only thing that humans could do was to try to placate such gods by making offerings. With the rise of the scientific technological worldview, the consequent belief in an all-controlling god responsible for the weather vanished. Statistical research in Netherlands has shown that when fertilizers and pesticides first started to be used on large scale in the 1950s, church attendance in farming communities drastically dropped because farmers no longer needed to solicit the help of God for a successful harvest, Even then, although the weather could be predicted to a fairly accurate degree, it was not believed that humans could influence or control the weather. Now, however, it has become apparent that humans are responsible for the increasingly extreme weather patterns that are appearing in many parts of the world. A reasonable argument for this possibility is that, if people are responsible for such drastic changes in the natural world as the holes in the ozone layer in the stratosphere, the drying up of the Aral Sea in the former then why couldn’t people cause atmosphere to heat up?

Most people don’t want to think about the prospect of having to live in a world with increasingly extreme weather conditions combined with increasingly limited natural resources to compensate for the calamities such as floods, famines, mass refugee movements, and warscaused by it.

In the case of global warming, although the effects seem at first unclear and slow, scientists are warnings us, once it has started, there will be no way it can be stopped. The carbon dioxide and methane now put in to the atmosphere will not leave it for decades. The comfortable view that technology is eventually going to solve all problems can be considered a wrong view. It is wrong in the sense that is the nature of the world to be uncontrollable. New problems will always crop up. Due to a wrong, unrestrained use of technology, modern humanity could end up off worse-off than is les technologically advanced, but perhaps more sensible and content ancestors.