The polar bear rivals the Kodiak bear as the largest four-footed carnivore on Earth and can live up to 25 years. Although the polar bear?s coat appears white, each individual hair is actually a clear hollow tube that channels the sun?s energy directly to the bear?s skin and helps it stay warm. The polar bear?s entire body is furred, even the bottom of its paws. That helps prevent bears from slipping on the ice. The polar bear is classified as a marine mammal. Its feet are partially webbed for swimming, and its fur is water-repellent. A formidable predator, it has extremely sharp claws. Size :
Thursday, December 28, 2006
Polar Bear (ursus maritimus)
Diposkan oleh Sabudi Prasetyo di 11:42:00 PM
Label: Fauna
Tuesday, December 26, 2006
Carnivorous Plants
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Label: Flora
Bridges
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Label: Technology
All About Ozone
(Original Source : The Environmental Protection Agency, Fact Monster/Information Please® Database, © 2005 Pearson Education, Inc. All rights reserved., Photo Source : Yahoo! Image/wetteronline.de)
I. The Ozone Layer
The Earth's atmosphere is divided into several layers. The lowest region, the troposphere, extends from the Earth's surface up to about 10 kilometers (km) in altitude. The next layer, the stratosphere, continues from 10 km to about 50 km. Most atmospheric ozone is concentrated in a layer in the stratosphere, about 15–30 kilometers above the Earth's surface.
Ozone is a molecule containing three oxygen atoms. It is blue in color and has a strong odor. Normal oxygen, which we breathe, has two oxygen atoms and is colorless and odorless. Ozone is much less common than normal oxygen. Out of each 10 million air molecules, about 2 million are normal oxygen, but only 3 are ozone.
However, even the small amount of ozone plays a key role in the atmosphere. The ozone layer absorbs a portion of the radiation from the sun, preventing it from reaching the planet's surface. Most importantly, it absorbs the portion of ultraviolet light called UVB. UVB has been linked to many harmful effects, including various types of skin cancer, cataracts, and harm to some crops, certain materials, and some forms of marine life.
At any given time, ozone molecules are constantly formed and destroyed in the stratosphere. The total amount, however, remains relatively stable. While ozone concentrations vary naturally with sunspots, the seasons, and latitude, these processes are well understood and predictable. Each natural reduction in ozone levels has been followed by a recovery. Recently, however, convincing scientific evidence has shown that the ozone shield is being depleted well beyond changes due to natural processes.
II. Ozone Depletion
For over 50 years, chlorofluorocarbons, or CFCs, were thought of as miracle substances. They are stable, nonflammable, low in toxicity, and inexpensive to produce. Over time, CFCs found uses as refrigerants, solvents, foam blowing agents, and in other smaller applications. Other chlorine-containing compounds include methyl chloroform, a solvent, and carbon tetrachloride, an industrial chemical. Halons, extremely effective fire extinguishing agents, and methyl bromide, an effective produce and soil fumigant, contain bromine. All of these compounds have atmospheric lifetimes long enough to allow them to be transported by winds into the stratosphere. Because they release chlorine or bromine when they break down, they damage the protective ozone layer.
In the early 1970s, researchers began to investigate the effects of various chemicals on the ozone layer, particularly CFCs, which contain chlorine. They also examined the potential impacts of other chlorine sources. Chlorine from swimming pools, industrial plants, sea salt, and volcanoes does not reach the stratosphere. Chlorine compounds from these sources readily combine with water and repeated measurements show that they rain out of the troposphere very quickly. In contrast, CFCs are very stable and do not dissolve in rain. Thus, there are no natural processes that remove the CFCs from the lower atmosphere. Over time, winds drive the CFCs into the stratosphere.
The CFCs are so stable that only exposure to strong UV radiation breaks them down. When that happens, the CFC molecule releases atomic chlorine. One chlorine atom can destroy over 100,000 ozone molecules. The net effect is to destroy ozone faster than it is naturally created.
III. Ozone FAQ
What is the ozone layer and why is it important?
The ozone layer is a concentration of ozone molecules in the stratosphere. About 90% of the planet's ozone is in the ozone layer. The layer of the Earth's atmosphere that surrounds us is called the troposphere. The stratosphere, the next higher layer, extends about 10–50 kilometers above the Earth's surface. Stratospheric ozone is a naturally occurring gas that filters the sun's ultraviolet (UV) radiation. A diminished ozone layer allows more radiation to reach the Earth's surface. For people, overexposure to UV rays can lead to skin cancer, cataracts, and weakened immune systems. Increased UV can also lead to reduced crop yield, disruptions in the marine food chain, and other harmful effects.
How does ozone depletion occur?
It is caused by the release of chlorofluorocarbons (CFCs) and other ozone-depleting substances (ODS), which were used widely as refrigerants, insulating foams, and solvents. The discussion below focuses on CFCs, but is relevant to all ODS. Although CFCs are heavier than air, they are eventually carried into the stratosphere in a process that can take as long as 2 to 5 years.
When CFCs reach the stratosphere, the ultraviolet radiation from the sun causes them to break apart and release chlorine atoms, which react with ozone, starting chemical cycles of ozone destruction that deplete the ozone layer. One chlorine atom can break apart more than 100,000 ozone molecules.
Other chemicals that damage the ozone layer include methyl bromide (used as a pesticide) and halons (used in fire extinguishers). As methyl bromide and halons are broken apart, they release bromine atoms, which are 40 times more destructive to ozone molecules than chlorine atoms.
How do we know that natural sources are not responsible for ozone depletion?
While it is true that volcanoes and oceans release large amounts of chlorine, the chlorine from these sources is easily dissolved in water and washes out of the atmosphere in rain. In contrast, CFCs are not broken down in the lower atmosphere and do not dissolve in water. The chlorine in these human-made molecules does reach the stratosphere. Measurements show that the increase in stratospheric chlorine since 1985 matches the amount released from CFCs and other ozone-depleting substances produced and released by human activities.
What is being done about ozone depletion?
In 1978, the use of CFC propellants in spray cans was banned in the U.S. In the 1980s, the Antarctic “ozone hole” appeared and an international science assessment more strongly linked the release of CFCs and ozone depletion. It became evident that a stronger worldwide response was needed. In 1987, the Montreal Protocol was signed and the signatory nations committed themselves to a reduction in the use of CFCs and other ozone-depleting substances.
Since that time, the treaty has been amended to ban CFC production after 1995 in the developed countries, and later in developing. Today, over 160 countries have signed the treaty. Beginning January 1, 1996, only recycled and stockpiled CFCs will be available for use in developed countries like the US. This production phaseout is possible because of efforts to ensure that there will be substitute chemicals and technologies for all CFC uses.
Will the ozone layer recover? Can we make more ozone to fill in the hole?
The answers, in order, are: yes and no. We can't make enough ozone to replace what's been destroyed, but provided that we stop producing ozone-depleting substances, natural ozone production reactions should return the ozone layer to normal levels by about 2050. It is very important that the world comply with the Montreal Protocol; delays in ending production could result in additional damage and prolong the ozone layer's recovery.
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Label: Science
Night at the Museum
Starring: Ben Stiller, Carla Gugino, Kim Raver, Mickey Rooney and Dick Van Dyke
Directed by: Shawn Levy
Distributed by: 20th Century Fox Distribution, 20th Century Fox International
What's the Story?
Larry Daley (Ben Stiller) is a down-on-his-luck guy who gets a job as the night watchman at New York's Museum of Natural History. It's a boring job, until he accidentally unleashes an ancient curse and the exhibits start to come to life. Now he's got to keep a tiny Attila the Hun from fighting the ancient Romans, the cavemen from setting the place on fire, and the dinosaur bones from trampling everything.
Three Good Reasons
It's got the biggest names in comedy from three generations: Ben Stiller, Robin Williams and Dick Van Dyke.
Owen Wilson shows up as a miniature cowboy in his eighth on-screen collaboration with Stiller
Didn't you always wonder what those things in the museum were up to when everybody went home?
Williams plays a wax statue of President Theodore Roosevelt, who helps Stiller's character deal with the rampaging exhibits. Roosevelt's father, Theodore Roosevelt, Sr., was one of the founders of the American Museum of Natural History. The famous, Roman-style entrance to the museum is a monument to Teddy Roosevelt.
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Label: Movie
Thursday, December 21, 2006
Winter Solstice
(Original Source : by Ann-Marie Imbornoni, Fact Monster™ Database, © 2006 Pearson Education, Inc. All rights reserved.)
Thu., Dec. 21, 2006, marks the solstice—the beginning of winter in the Northern Hemisphere and summer in the Southern Hemisphere.
The precise moment of the 2006 solstice will be December 21, 2006 at 7:22 P.M. EST (Dec. 22, 00:22 UT).
In astronomy, the solstice is either of the two times a year when the Sun is at its greatest distance from the celestial equator, the great circle on the celestial sphere that is on the same plane as the earth's equator. In the Northern Hemisphere, the winter solstice occurs either December 21 or 22, when the sun shines directly over the tropic of Capricorn; the summer solstice occurs either June 21 or 22, when the sun shines directly over the tropic of Cancer. In the Southern Hemisphere, the winter and summer solstices are reversed.
Reason for the Seasons
The reason for the different seasons at opposite times of the year in the two hemispheres is that while the earth rotates about the sun, it also spins on its axis, which is tilted some 23.5 degrees towards the plane of its rotation. Because of this tilt, the Northern Hemisphere receives less direct sunlight (creating winter) while the Southern Hemisphere receives more direct sunlight (creating summer). As the Earth continues its orbit the hemisphere that is angled closest to the sun changes and the seasons are reversed.
Longest Night of the Year
The winter solstice marks the shortest day and the longest night of the year. The sun appears at its lowest point in the sky, and its noontime elevation appears to be the same for several days before and after the solstice. Hence the origin of the word solstice, which comes from Latin solstitium, from sol, “sun” and -stitium, “a stoppage.” Following the winter solstice, the days begin to grow longer and the nights shorter.
Diposkan oleh Sabudi Prasetyo di 4:04:00 PM
Label: Science
Virgin birth expected for Komodo Dragon (varanus komodoensis) in UK zoo
(Original Source : By Patricia Reaney, Wed Dec 20, 1:07 PM ET, Yahoo!NEWS )
LONDON (Reuters) - Flora, a pregnant Komodo dragon living in a British zoo, is expecting eight babies in what scientists said on Wednesday could be a Christmas virgin birth.
Flora has never mated, or even mixed, with a male dragon, and fertilized all the eggs herself, a process culminating in parthenogenesis, or virgin birth. Other lizards do this, but scientists only recently found that Komodo dragons do too.
"Nobody in their wildest dreams expected this. But you have a female dragon on her own. She produces a clutch of eggs and those eggs turn out to be fertile. It is nature finding a way," Kevin Buley of Chester Zoo in England said in an interview.
He said the incubating eggs could hatch around Christmas.Parthenogenesis has occurred in other lizard species, but Buley and his team said this was the first time it has been shown in Komodo dragons -- the world's largest lizards.
Scientists at Liverpool University in northern England discovered Flora had had no male help after doing genetic tests on three eggs that collapsed after being put in an incubator.
The tests on the embryos and on Flora, her sister and other dragons confirmed that Komodo dragons can reproduce through self-fertilization.
"Those genetic tests confirmed absolutely that Flora was both the mother and the father of the embryos. It completely blew us away because it (parthenogenesis) has never been seen in such a large species," Buley explained.
A Komodo dragon at London Zoo gave birth earlier this year after being separated from males for more than two years.
Scientists thought she had been able to store sperm from her earlier encounter with a male but, after hearing about Flora's eggs, researchers conducted tests which showed her eggs were also produced without male help.
"You have two institutions within a few short months of each other having a previously unheard of event. It is really quite unprecedented," said Buley.
The scientists, reporting the discovery in the science journal Nature, said it could help them understand how reptiles colonize new areas. A female dragon could, for instance, swim to another island and establish a new colony on her own.
"The genetics of self-fertilization in lizards means that all her hatchlings would have to be male. These would grow up to mate with their own mother and therefore, within one generation, there would potentially be a population able to reproduce normally on the new island," Buley added.
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Label: Fauna
A Green Tea Overview
(Original Source : The Salada Green Tea Website.//www.greentea.com, Photo Source : Yahoo! Image)
fact green tea. Thus it is unlikely that the harbor turned to a copper color! About ninety percent of the world's green tea is produced in China. While most of the world's black tea comes from countries such as Sri Lanka (Ceylon), India, Kenya, Indonesia and Argentina, these countries produce little, if any, green tea. Several hundred varieties of green tea are made in China alone. Some of the most popular include Gunpowder, Hyson, Imperial Green, and Gyokuro (Japan). A cup of green tea is generally much lighter than other teas. While Asian cultures have believed for centuries that green tea has properties beneficial to human health, modern science is just now discovering that this may be true. ManufactureDifferences between green, black, and oolong teas occur during the processing of the tea leaves. Plucking All types are normally hand plucked. Pluckers take only the bud and two leaves, as only young leaves produce good quality tea. Machine plucked tea is usually inferior. WitheringThe next step in manufacturing is withering. Tea leaves are laid out and allowed to wilt for several hours. Leaves are laid out in bamboo trays or in withering beds indoors. Withering reduces the moisture content in the leaves and prepares them for the next step. Withering can be omitted during the production of green tea, but is crucial in black tea manufacture. SteamingThis process differentiates green tea from other types. After withering, green tea leaves are immediately steamed, baked, or pan heated. This crucial step in green tea manufacture prevents the oxidation (fermentation) of the leaves so that they remain green.RollingGreen tea is very often hand rolled, but mechanical rollers are used as well. The rolling process gives the leaves their appearance. During green tea manufacture, leaves are usually steamed rolled and steamed alternatively. Tightly rolled leaves are an indication of good quality tea. FiringGreen tea leaves are given a final firing to dry the leaves and ensure no oxidation of the leaves occurs. The firing of leaves is done in ovens.
DIFFERENCES IN THE TEA PROCESSING METHODDifferences in the tea processing method create three basic tea types - green tea, black tea and oolong tea. The amount of oxidation, often referred to as fermentation, that the tea leaves undergo determines the basic tea type. It is the oxidation process that produces tea’s distinctive color and taste characteristics. All tea comes from the leaves of the Camellia Sinensis tree. Tea gardens pluck or prune the Camellia Sinensis year round and the plant more resembles a bush, but allowed to grow wild, it reaches heights of about thirty feet.
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Label: Health
Tuesday, December 19, 2006
Giant Panda (ailuropoda melanoleuca)
Emblem of hope for a nation and global biodiversity
The giant panda is universally loved, and of course has a special significance for WWF as it has been the organization's symbol since it was formed in 1961. Today, the giant panda's future remains uncertain. This peaceful, bamboo-eating member of the bear family faces a number of threats. Its forest habitat, in the mountainous areas of southwest China, is fragmented and giant panda populations are small and isolated from each other. Meanwhile, poaching remains an ever-present threat.Over 50 reserves created
By mid-2005, the Chinese government had established over 50 panda reserves, protecting more than 10,400km² and over 45 % of remaining giant panda habitat.
However, habitat destruction continues to pose a threat to the many pandas living outside
these areas, and poaching is a further problem. Today, only around 61% of the population, or about 980 pandas, are under protection in reserves. As China's economy continues its rapid development, it is more important than ever to ensure the giant panda's
survival.
WWF on the ground
WWF has been active in giant panda conservation since 1980, when it supported U.S. scientist Dr. George Schaller and his Chinese colleagues in field studies in the Wolong Nature Reserve. WWF was the first international conservation organization to work in China at the Chinese Government's invitation.
More recently, WWF has been helping the government of China to undertake its National
Conservation Programme for the giant panda and its habitat. This programme has made significant progress: Reserves for this species cover more than 16,000 km² of forest in and around their habitat. The latest survey (released in 2004) revealed that there are 1,600 individuals estimated to remain in the wild.
Physical Description
Species Description
Pandas have a white coat with black fur around their eyes, on their ears, muzzle, legs and shoulders. The unique physical features of the species include broad, flat molars and an enlarged wrist bone that functions as an opposable thumb - both of these adaptations are used for holding, crushing and eating bamboo.
Giant pandas are classified as bears and have the digestive system of a carnivore, but they have adapted to a vegetarian diet and depend almost exclusively on bamboo as afood source. Pandas live mainly on the ground but have the ability to climb trees as well. While the species does not hibernate, it often relocates to lower altitudes in the winter and spring.
Size
Giant pandas are about 150 cm long from nose to rump, with a 10-15 cm tail. A large adult panda can weigh about 100-150 kg, with males 10% larger and 20% heavier than females.
Colour
Distinctive black and white coat.
Habitat
Major habitat type
Temperate Broadleaf and Mixed Forests
Biogeographic realm
Palearctic
Range States
China
Geographical Location
Southwest China (Gansu, Shaanxi, and Sichuan Provinces) to the east of the Tibetan plateau.
Ecological Region
Temperate forest of the upper Yangtze
Why is this species important?
Panda habitat is found at the top of the Yangtze Basin, an ecoregion shared by both pandas and millions of people whose ancestors have utilized the region's natural resources for millenia. The Basin is the geographic and economic heart of China, and is one of the critical regions for biodiversity conservation in the world. Its diverse habitats contain many rare, endemic and endangered animal and plant species, the best known being the giant panda. Economic benefits derived from the Yangtze Basin include tourism, subsistence fisheries and agriculture, transport, hydropower and water resources.The survival of the panda and the protection of its habitat will ensure that people living in the region continue to reap ecosystem benefits for many generations.
Interesting Facts
A giant panda may consume 12-38 kg of bamboo a day to meet its energy requirements. (Original Source : WWF Website, Photo Source : en.wikipedia.org/wiki/Giant_panda#/media/File:Grosser_Panda.JPG)
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Label: Fauna