Earth's Atmosphere

Read this interesting article.

- structure of the earth's atmosphere
- important elements (gases) in the atmosphere.

For Vietnamese terms pls view this page about "Cac tang khi quyen"
http://vi.wikipedia.org/wiki/C%E1%BA%A5u_tr%C3%BAc_kh%C3%AD_quy%E1%BB%83n

Scientists imagine earth’s atmosphere as an “ocean” of air hundreds of mile deep


The atmosphere of the earth exerts a lot of pressure, about 14.7 pounds per a square inch. This is normally referred to as atmospheric pressure. The air is composed of a mixture of several gases. Nitrogen is the most abundant followed by oxygen. Next to oxygen we have argon then carbon dioxide. After carbon dioxide is the “other” gases but I wont go into detail about those ones. Mixed in with theses gases is water vapor, which is the gaseous form of water. There are several important ingredients in the atmosphere. First there is oxygen, which is vital to human life, and then there is carbon dioxide, which is important to plants. Also there is water vapor in the air, which gives us precipitation, and also with the help of carbon dioxide it traps the heat of the sun within the atmosphere giving the earth a milder and more stable climate. The atmosphere is divided into to section based on the make-up. The two sections are the lower and the upper atmosphere. The lower atmosphere is referred to as the homosphere because it has a uniform mixture of gases. The upper layer of the atmosphere is referred to as the heterosphere because it has several layers of different gases. The atmosphere can be divided into several specific layers by density and temperature. The lowest layer of the atmosphere is called the troposphere also known as the “weather layer”. Next comes the tropopause, which is the upper boundary of the troposphere. The next layer is the stratosphere also called the jet stream because of its strong’ but steady winds with little or no change of weather. Above the stratosphere is the stratopause. In the stratopause lies the ozone layer, which protects the earth from the suns dangerous UV radiation. There are 3 types of radiation: first there is UVC, which is the most powerful and dangerous yet all of it is absorbed in the ozone layer. Next is UVB this type of radiation causes tanning and sunburn most but not all of it is absorbed by the ozone layer. Last but not least is UVA the least harmful and all it passes through the ozone layer with no trouble at all. Right above the ozone layer is the mesosphere, and above the mesosphere is the mesopause the mesopause is the coldest point in the atmosphere and averages to about negative 101-110 degrees Celsius (negative 150-165 degrees Fahrenheit) After the mesopause the temperature rises very quickly. The next layer in the atmosphere is the thermosphere named for its high temperature. Within the thermosphere and the mesosphere is the ionosphere and it is named that way because it is composed of many ions. Also in this same region the auroras occur they are known as the northern lights in the north and in the south the southern lights. After the thermosphere is the thermopause, which is the outer most boundary of the thermosphere. Last is the exosphere, which is the outermost layer of the atmosphere.

Heat or thermal energy that is absorbed differs from place to place. This so called heat from the sun is solar radiation. The solar radiation that reaches the earth is called insolation meaning incoming solar radiation. Our earth only receives about 47% of the suns solar radiation the rest is either reflected (37%) or absorbed by the atmosphere (18%). There are several factors affecting the earth’s insolation. First is cloudy weather because clouds are very reflective. Second is the length of daytime. Less daytime hours mean less insolation for the earth. Third is the angle of the sun’s rays. The more slanted the rays of the sun the longer it takes to heat up the earth. Last is the earth distance from the sun. When the earth is at perihelion, the closest point to the sun. It receives more insolation, but when it is at aphelion, the farthest point from the sun. The earth receives less insolation. The sun’s energy that enters the earth’s atmosphere is called the energy budget. This “energy” heats the land, water, and air.

So how does the earth contain this thermal energy? It is called the greenhouse effect. The water vapor and the carbon dioxide let the insolation in but they don’t let it escape out like the glass windows of a greenhouse. The thermal energy that the earth and its atmosphere receive from the sun is distributed several ways. One reason is because the land warms much faster then bodies of water and also the land cools faster then the bodies of water. Heat is distributed by radiation, which is heat transferred by electromagnetic waves, conduction which is direct contact between two objects, and also convection, which is the transfer of heat by moving currents of hot air, or fluids also called convection waves. Also winds are formed from convection. When rising air’s temperature heats up it’s compressed but does not have a heat loss this is called adiabatic heating; if there is no heat added and the temperature of the air-cools as it expands this is called adiabatic cooling So when masses of air rise, its temperature drops and as it sinks it heats back over and the process of cooling and heating are started over and over again.

When there is a higher than normal concentration of heat it will produce convection currents of rising air creating a low pressure called a low. If there is lower than normal heat concentration it will produce currents of sinking air creating a high pressure called a high. The way the earth rotates and causes changes in the course of the winds is called the Coriolis effect. It can be explained by two combined factors. First inertia the resistance to change in speed or direction keeps the winds in the same condition of motion. Second objects on earth’s rotating surface travel at different speeds. This causes two types of rotating winds. One is the cyclone this happens when the winds form a circulating spiral around the low. Second is the anticyclone this happens when winds form a wind system around a high. There are several wind zones in the earth. First there is the Intertropical Convergence Zone (ITCZ) this is where the winds of both the Northern and Southern hemisphere converge and rise. The next wind zone is the doldrums here there is little or periods of no wind and back then in the days of sailing vessels this was bad. Next comes the horse latitudes they are located about 30 degrees at both north and south latitudes. After the horse latitudes come the trade winds these winds blow toward the equator from the high-pressure regions of the horse latitudes.

Next come the polar easterlies these winds blow out of the northeast in the Northern Hemisphere and out of the southeast in the Southern Hemisphere together they make the polar easterlies. Another wind zone is the prevailing westerlies these winds come out of the southwest or the northwest. Last there is the jet stream these are high altitude winds concentrated in narrow, meandering bands of rapidly moving air that come mostly out of the west but it can come from all directions. Winds are normally named from the direction they come. There are also a few local winds. One is the monsoon or monsoon effect, which is when the winds reverse their direction from season to season. There is also the sea and land breeze the sea breeze brings cool air to the land during the day and at night it brings warm air to the land. The land breeze brings warm air farther inland during the day and at night it brings cool air further inland. Last is the mountain and valley breeze. During the day the cool mountain air warms as it travels to the valley and heats it. At night the warm valley air-cools and travels up the mountain and warms it.

Aloe Vera - The miracle Plant and the Real Boon by Nature

Aloe Vera is a miracle medicinal plant that has been used for health and beauty purposes since ancient times.



The miracle herb Aloe Vera is one of the real boons gifted by nature to human beings. One of the oldest known plants, it has been used in several millennia for various health and beauty purposes. Greeks, Egyptians, Indians, Mexicans, Japanese, Chinese, all loved to use the plant alike. Where Christopher Columbus and Alexander the Great used Aloe Vera to treat their soldier’s wound, beauty legends and Egyptian queens like Cleopatra and Nefertiti used it as a part of their regular beauty regimes.

A brief introduction of Aloe Vera- The plant derives it’s name “Aloe” from Arabic word “Alloeh” which means bitter, where as “Vera” in Latin means “true or genuine”. Due to it’s area of origin, plant is also referred as “Lily of desert” and due to it`s magical healing potency, it is called “the plant of immortality”, “Wand of Heaven” and the “First Aid plant”. In ancient Greece it was regarded as universal panacea. The very first reference to Aloe Vera in English was given by John Good yew in A.D. 1655 in a book that he translated from any other language. Although the species was described as “Aloe Vera” by Nicolas Laurens Burman in 1768 in his book “Flora Indica”. In India it is found mainly in Rajasthan, Andhra Pradesh, Gujarat, Maharashtra, and TamilNadu. It`s various common Indian names are - Hindi: Guarpatha, Ghikanvar, Sanskrit: Gritakumari, kumari, Malayalam: Kumari, Marathi: Korphod, Tamil: Chirukuttali, Telugu: Chinna Kalabanda, Oriya: Kumari, Canarese: Lolisara etc. Aloe Vera is a stem less or very short stemmed succulent plant that probably originated in African countries and gradually spread in tropical and sub tropical regions world wide, where weather conditions were not chilling. Today there are around 250 species of Aloe Vera found world wide, but only 4 or 5 are commonly used in medicines. The most common of them is Aloe Babandensis. Aloe Vera spreads by offsets and root sprouts. It`s leaves are green or gray-green, flashy, and thick with a serrated margin. Some varieties show white flecks on the upper and lower stem surface. The plant produces yellow flowers in summer which grows on a spike up to 90cm tall. Each leaf of Aloe Vera is made of three layers- (1) inner clear gel containing 99% of water, rest of this layer contains glucommannas, amino acids, lipids, sterols and vitamins. (2) Middle layer of latex which is bitter and contains anthraquinones and glycosides. (3) The outer thick layer or rind which synthesizes carbohydrates and proteins.

Medicinal properties and uses- Aloe Vera has almost all the chief nutrients that the human body requires. That’s why herbalists describe it as universal panacea. It contains almost 75 potentially active constituents like vitamins, minerals, enzymes, salicylic, lignin, sugars, acids and amino acids, saponins etc.

The plant is so rich in amino acids that it provides 20 out of 22 amino acids required by the human body. It contains vitamin A, C and E which acts as antioxidants. Besides, the plant is a good source of vitamin B12, chlorine and folic acid and enzymes. Aloe Vera is a rich source of minerals. Its leaves contain calcium, copper, magnesium, manganese, potassium, sodium, Zink, chromium, selenium etc. The plant also contains hormones like Auxins and gibberellins. These are the components that give the plant wound healing potency and have anti- inflammatory actions. Aloe Vera is considered very effective in treating the pancreas, kidney, liver stomach and small intestine diseases. It stimulates the immune system hence helps the body fighting various diseases caused by bacteria, viruses, and fungus.

Use in dermatology- Due to it’s special effects on skin, Aloe Vera is regarded as the queen plant by the dermatologists It stabilizes digestive system, therefore providing proper nourishment to the skin. It acts as a good cleanser for the skin by fighting extra amount of melanin. Aloe Vera gel helps to erase blemishes and dark spots that are generally caused as after pregnancy-effects on the face. It makes the skin pores clear and healthy and free from acne. It’s anti- aging potency is now well proved by the scientists. It’s anti-oxidant components help in fighting with age related changes. It also acts as a good moisturizer for the skin. Not only this, Aloe Vera products also work as a good conditioner for hair giving them proper nourishment.

Side effects- Although herbalists deny any serious side effects but in some cases it has showed some mild side effects like redness, burning, stinging sensation etc. According to doctors it is better to not take Aloe Vera orally during pregnancy and breastfeeding, because some of the components present in it may create some health complications for mother as well as the little baby.

Carbon capture technology tested

Read the article, also pay attention to compound words in bold.
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The 30-tonne test unit could pave the way for a much larger plant


New carbon capture technology is being tested for the first time in the UK on a working coal-fired power station.

A 30-tonne test unit will process 1,000 cubic metres of exhaust gas per hour from Longannet power station in Fife.

Carbon dioxide will be removed using chemicals and turned into a liquid, ready for storage underground.

Energy company ScottishPower wants to test technology which could lead to a full scale carbon capture plant becoming operational by 2014.

The UK government recently gave the go-ahead for a new generation of coal-fired power stations provided they were able to limit their CO2 emissions.

The scientists have focussed on the post-combustion method of carbon capture and storage (CCS) which aims to trap greenhouse emissions after fossil fuels have been burnt.

We believe that the UK can lead the world with CCS technology, creating new skills, jobs and opportunities for growth

Ignacio Galan
Chairman, Iberdrola
The plant, developed by Aker Clean Carbon, will enable them to assess the effectiveness of chemicals, known as amines, at removing CO2.

Researchers from the University of Edinburgh will join the project, testing three different types of amine solution over the next three months.

ScottishPower chief executive Nick Horler said: "This is the first time that CCS technology has been switched on and working at an operational coal-fired power station in the UK.

"It's a major step forward in delivering the reality of carbon-free fossil fuel electricity generation."

Research centre

ScottishPower's parent company Iberdrola said the UK would be its global centre of excellence for CCS development, bringing together academics, industry experts and engineers.

A professorship of CCS will be based at Edinburgh University, but other academic institutions will also be involved including Imperial College, London.

Iberdrola Chairman Ignacio Galan said: "We believe that the UK can lead the world with CCS technology, creating new skills, jobs and opportunities for growth.

"There is the potential to create an industry on the same scale as North Sea Oil, and we will invest in Scotland and the UK to help to realise this potential."

The Longannet power station opened in 1969 and is the second largest in the UK.

The station chimney is 183m tall, the second highest free-standing structure in Scotland.

Ice sheet melt threat reassessed

By Mark Kinver
Science and environment reporter, BBC News

The collapse of a major polar ice sheet will not raise global sea levels as much as previous projections suggest, a team of scientists has calculated.

Writing in Science, the researchers said that the demise of the West Antarctic Ice Sheet (WAIS) would result in a sea level rise of 3.3m (10 ft).

Previous estimates had forecast a rise in the region of five to six metres.

However, they added, the rise would still pose a serious threat to major coastal cities, such as New York.

"Sea level rise is considered to be the one of the most serious consequence of climate change," lead author Jonathan Bamber told the Science podcast.

"A sea level rise of just 1.5m would displace 17 million people in Bangladesh alone," he added.

"So it is of the utmost importance to understand the potential threats to coastlines and people living in coastal areas."

Threat reassessed

Professor Bamber, from the University of Bristol's Glaciology Centre, said that the WAIS posed "potentially one of the most serious threats".

The world has three ice sheets, Greenland, East Antarctica and West Antarctica, but it is the latter that is considered most vulnerable to climatic shifts.

"It has been hypothesised for more than 30 years now that the WAIS is inherently unstable," he explained.

"This instability means that the ice sheet could potentially rapidly collapse or rapidly put a lot of ice into the oceans."

When the idea first emerged in the late 1970s, it was estimated that global sea level would rise by five metres if the WAIS collapsed.

Current projections suggest that a complete collapse of WAIS would result in an increase of up to six metres.
But Professor Bamber said that no-one had revisited the calculation, despite new data sets becoming available, and scientists developing a better understanding of the dynamics in the vast ice sheets.

The original estimates were based on "very basic ice thickness data", he explained.

"Ice thickness data gives you information about the depth of the bedrock underneath the ice sheet.

"Over the past 30 years, we have acquired much more ice thickness data over the whole of Antarctica, particularly over West Antarctica.

"We also have much better surface topography. Those two data sets are critical in determining two things."

The first was knowing the volume of ice that could contribute to sea level rise, and the second was a better understanding of the proportion of WAIS that was potentially susceptible to this instability.

Instead of assuming that the entire WAIS would collapse, causing sea level to rise by up to six metres, Professor Bamber and colleagues used models based on glaciological theory to simulate how the 2.2 million-cubic-km ice sheet would respond.

"Our reassessment of West Antarctica's contribution to sea level rise if the ice sheet was to collapse is about 3.3 metres," he said.

"That is about half of the value that has been quoted up until now."

The team's study also calculated what regions were likely to experience the biggest increases in sea level.

"Sea level rise is not uniform across the world's oceans, partly as a result of disruptions to the Earth's gravity field," explained Professor Bamber.

"It turns out that the maximum increase in sea level rise is centred at a latitude of about 40 degrees along the Atlantic and Pacific seaboards of North America."

This would include cities such as San Francisco and New York.

These areas could expect increases of one-and-a-quarter times the global average, the team estimated.

In other words, if the global average was one metre, then places like New York could expect to see a rise of 1.25m.

Responding to Professor Bamber's paper in Science, British Antarctic Survey science leader Dr David Vaughan described the findings as "quite sound".

"But for me, the most crucial question is not solely about the total amount of ice in West Antarctica, because that might take several centuries to be lost to the ocean," he told BBC News.

"The crucial question is how much ice could be lost in 100-200 years; that's the sea level rise we have to understand and plan for.

"Even with this new assessment the loss of a fraction of WAIS over those timescales would have serious consequences and costs that we've only really just begun to understand."

Birds - Dance Moves

Birds show off their dance moves
By Rebecca Morelle
Science reporter, BBC News



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Snowball dances in time to his favourite Backstreet Boys song played at three different tempos

Some birds have a remarkable talent for dancing, two studies published in Current Biology suggest.

Footage revealed that some parrots have a near-perfect sense of rhythm; swaying their bodies, bobbing their heads and tapping their feet in time to a beat.

Previously, it was thought that only humans had the ability to groove.

The researchers believe the findings could help shed light on how our relationship with music and the capacity to dance came about.

One bird, Snowball, a sulphur-crested cockatoo (Cacatua galerita eleanora ), came to the researchers' attention after YouTube footage suggested he might have a certain prowess for dance - especially when listening to Everybody by the Backstreet Boys.


This is a capacity that everyone thought was uniquely human, but we've found evidence that some animals can keep a beat

Adena Schachner, Harvard University
Dr Aniruddh Patel, from The Neurosciences Institute in San Diego, said: "We found out that the previous owner usually listened to easy listening music, but he did have this one album, and he noticed Snowball bobbing his head to the Backstreet Boys".

To test Snowball's skill, the scientists filmed him as they played his favourite song at various tempos.

Dr Patel told the BBC: "We analysed these videos frame by frame, and we found he did synchronise - he did slow down and speed up in time with the music.

"It was really surprising that he had this flexibility."

Another group, led by Adena Schachner, from Harvard University, also looked at Snowball, as well as another bird, Alex, an African grey parrot (Psittacus erithacus ).

Dr Schachner said: "We brought some novel music that we knew Alex had never heard before - so there was no way he had been trained to dance to this music.

"We set up the camera and hit play, and we were shocked to see that Alex started dancing to the beat. He started to bob his head up and down."

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Alex is not as good a dancer as Snowball, but he was able to dance to songs he had not heard before

While Alex's dance routines were not as elaborate as Snowball's, analysis of the footage revealed that he was also able to match his movements with the music he was hearing.
Dr Schachner said: "This is a capacity that everyone thought was uniquely human, but we've found evidence that some animals can keep a beat."

Song and dance

The scientists believe that the parrots' apparent capacity for dance may be linked to another talent that they share with humans - the ability for vocal learning and vocal imitation.
They believe the part of the brain that evolved to allow us and a handful of other species, including dolphins, songbirds, elephants and some cetaceans, to learn and mimic different sounds may also be responsible for the ability to move in time to music.

YouTube footage suggested Asian elephants can dance
To test whether this might be the case, the researchers turned to a vast resource of animal footage - YouTube.

From more than 1,000 videos of different dancing animals, the team found only 33 films that showed animals moving in time to a musical beat.

Dr Patel said: "These 15 species were all vocal learners - 14 parrots and one Asian elephant."
After these initial studies, both teams now want to look more closely at different species' relationship with music.

Dr Patel told BBC News: "No other primates, besides humans, have vocal learning, so there is a strong prediction that no other primates could learn to synchronise to music, even with extensive training.

"However, there are other mammals that have a response to vocal learning - dolphins are a notable category, and I'd love to collaborate with dolphin researchers to find out if dolphins can move to a musical beat."


Dolphins have the ability to mimic sounds - but can they dance?
The scientists believe further research will also provide an insight into how our relationship with music evolved.

Dr Patel said: "Music is a true human universal - it is something we find in every single human culture.

"One of the questions we are asking is whether this is wired into our brains because of evolution, or is it because it builds on other brain systems.

"And this evidence builds on the fact that it is probably linked to other existing brains systems rather than being an adaptation in its own right."

He adds: "You see here a fundamental response to music seen in species that normally don't have a relationship to music in the world.

"They are clearly using a brain system that has a different day job, so to speak."

Swine Flu Pandemics

Mexico flu sparks worldwide fear

Mexico has ramped up its containment efforts
Mexican authorities have taken drastic measures to contain a new strain of the swine flu virus that has killed 81 and prompted fears of a global pandemic.

People are being urged to stay at home and maintain strict personal hygiene. Many schools, public buildings, bars and restaurants have been closed.

Non-fatal cases have been confirmed in the US and are likely in New Zealand.

The World Health Organization (WHO) has confirmed that at least some of the cases are a new strain of the virus.


SWINE FLU
Swine flu is a respiratory disease found in pigsHuman cases usually occur in those who have contact with pigs
Human-to-human transmission is rare and such cases are closely monitored


Q&A: Swine flu
UK monitoring swine flu outbreak
H1N1 is the same strain that causes seasonal flu outbreaks in humans, but the newly detected version contains genetic material from versions of flu which usually affect pigs and birds.

The respiratory virus - which infects pigs but only sporadically humans - is spread mainly through coughs and sneezes.

The WHO has warned the virus has the potential to become a pandemic.

Several countries in Asia and Latin America have begun screening airport passengers for symptoms.

Suspected outbreaks

Although all of the deaths so far have been in Mexico, the flu is spreading in the United States and suspected cases have been detected elsewhere:



Susan Watts, BBC Science editor



The next few days and weeks will be crucial.


One possibly hopeful sign is that of the eight cases in the US there has been only one hospitalisation, and no deaths.


So it may turn out that there is some other kind of infection at work in Mexico, as well as the new flu virus.





Read Susan's thoughts in full
Eleven confirmed infections in the US
In addition, eight suspected cases are being investigated at a New York City high school where about 200 students fell mildly ill with flu-like symptoms
Ten New Zealand students are among a group which travelled to Mexico have tested positive for influenza A - making it "likely", though not definite, that they are infected with swine flu, said Health Minister Tony Ryall
In France, a top health official told Le Parisien newspaper there were unconfirmed suspicions that two individuals who had just returned from Mexico may be carrying the virus
In Israel, medics are testing a 26-year-old man who has been taken to hospital with flu-like symptoms after returning from a trip to Mexico
But a UK hospital conducting tests for swine flu on a British Airways cabin crew member said the tests proved negative.
Mexico shutdown

The Mexican government, which has faced criticism for what some see as a slow reaction to this outbreak, is now taking an increasingly hard line to try to contain the virus, says the BBC's Stephen Gibbs in Mexico City.

Public buildings have been closed and hundreds of public events suspended.

There is a sense of chaos in hospitals and we do not know what to do

BBC reader Antonio Chavez, Mexico City


Read more experiences
Send us your comments
Schools in and around Mexico City have been closed until 6 May, and some 70% of bars and restaurants in the capital have been temporarily closed.

People are being strongly urged to avoid shaking hands, and the US embassy has advised visitors to the country to keep at least six feet (1.8m) from other people.

Mexico's Health Secretary, Jose Cordova, said a total of 1,324 people had been admitted to hospital with suspected symptoms since 13 April and were being tested for the virus.

"In that same period, 81 deaths were recorded probably linked to the virus but only in 20 cases we have the laboratory tests to confirm it," he said.

Mexico's President Felipe Calderon has announced emergency measures to deal with the situation.

They include powers to isolate individuals suspected of having the virus without fear of legal repercussions.


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In Mexico, face masks are handed out, while the head of the WHO voices concern

'International concern'

In the US, seven people in California, two people in Texas, and two people in Kansas have been infected with the new strain.

In New York, city health commissioner Dr Thomas Frieden said preliminary tests conducted on the ailing students showed they were possible cases of swine flu.

Further tests will clarify if it was the same strain that was detected in the other three states.

Following a meeting of its emergency committee on Saturday, the WHO said the virus had the potential to become a pandemic but it was too early to say whether that would happen.


FLU PANDEMICS
1918: The Spanish flu pandemic remains the most devastating outbreak of modern times - infecting up to 40% of the world's population and killing more than 50m people, with young adults particularly badly affected


1957: Asian flu killed two million people. Caused by a human form of the virus, H2N2, combining with a mutated strain found in wild ducks. The elderly were particularly vulnerable

1968: An outbreak first detected in Hong Kong, and caused by a strain known as H3N2, killed up to one million people globally, with those over 65 most likely to die
WHO Director General Margaret Chan said recent events constituted "a public health emergency of international concern" and that countries needed to co-operate in heightening surveillance.
The WHO is advising all countries to be vigilant for seasonally unusual flu or pneumonia-like symptoms among their populations - particularly among young healthy adults, a characteristic of past pandemics.

Officials said most of those killed so far in Mexico were young adults - rather than more vulnerable children and the elderly.

There is currently no vaccine for the new strain but severe cases can be treated with antiviral medication.

It is unclear how effective currently available flu vaccines would be at offering protection against the new strain, as it is genetically distinct from other flu strains.

Orchard Losses

Orchard losses 'threaten species'

Use of few or no chemicals makes orchards good wildlife habitat
Traditional fruit orchards are vanishing from England's landscape - with serious consequences for wildlife, conservationists have warned.

The National Trust says 60% have disappeared since the 1950s, putting local varieties of apples, cherries, pears, plums and damsons under threat.

It is launching a £536,000 drive to reverse the decline of the orchards.

Their trees provide important habitats for species such as the noble chafer beetle and lesser spotted woodpecker.

The orchards - some with as few as five trees - also offer sources of pollen and nectar to bees, which are thought to be declining partly because of a lack of suitable food.

Pressure from commercial fruit growers has led many small-scale producers to develop their orchards or convert them to other uses.

The BBC's Jon Kay explored orchards at the National Trust's Killerton House in Devon:


Standing in the grounds, you can see just how much wildlife is attracted to an orchard.


Above me, in the branches of the hundreds of apple trees, I can see blackbirds, blue tits, sparrows and crows enjoying the spring sunshine.


Buzzing about on the candy pink blossom are bees and wasps, gathering the first pollen.


And, on the ground, an array of bug life scuttles past my feet - beetles, ants and spiders thrive in the ground of a wild, traditional orchard like this.


There are almost 100 different varieties of apple trees here, with some fantastic local names such as Polly White Hair and Slack My Girdle.


In Pictures: Orchards under threat
The National Trust's head of nature conservation, Dr David Bullock, said traditional orchards had been "disappearing at an alarming rate over the last 60 years".

"We are in real danger of losing these unique habitats - and the wildlife, local fruit varieties and their rich heritage - and if we don't act in some cases we will not even know what local varieties of fruit have been lost," he said.

The trust has teamed up with government advisory body Natural England to launch the project to promote local fruit varieties.

It will undertake surveys to get a better understanding of the habitat, work to improve the condition of existing orchards and create new ones, and train people how to plant, prune and propagate trees.

Kate Merry has been appointed as orchard officer to champion the cause.

She said: "We now have a real opportunity to reverse the decline of traditional orchards and recognise the important role they play in our cultural and natural heritage; if we don't act there is a real danger they will not survive the 21st Century."

Trees in traditional orchards are widely spaced and the sites are often grazed by animals such as sheep, or cut for hay.

They provide a good habitat for wildlife because they are subject to low intensity management, with few or no chemicals used, and the trees are allowed to reach a stage where they are hollowed and gnarled.


The noble chafer beetle is among the rare species under threat
The noble chafer beetle makes its home in the dead wood of older fruit trees, while the lesser spotted woodpecker can also find nesting and feeding areas in the trees.

A survey by the National Trust last year of more than 100 traditional orchards in its care turned up a number of other species in the habitat, many of them rare.

At the Killerton estate in Devon, where the new programme has been launched, surveys found insects including the orchard park beetle and the apple tree lace bag. It also proved a feeding ground for long-eared bats.

Apples - including two varieties unique to the estate - are used to make cider and chutney, with the profits used to maintain the orchards.

Poul Christensen, acting chairman of Natural England, said: "Successful orchards are worth their weight in gold, not just for the valuable contribution they make to the economy but to the subsequent enhancement of these precious wildlife habitats."

In 2007, the government prioritised orchards as habitat to protect in recognition of their importance to wildlife.

Duck-like bill dinosaurs

Duck-billed dinosaur had big bite



Enlarge Image

A species of dinosaur that packed hundreds of teeth inside its giant beak has just been described by scientists.
The Gryposaurus, discovered in southern Utah, had a distinct duck-like bill and a powerful, strengthened jaw.

The two-legged creature, described in the Zoological Journal of the Linnean Society, was more than 10m (30ft) long.

Analysis suggests that the dinosaur, which lived in the Cretaceous forests of North America about 65-80 million years ago, was a successful herbivore.

"When you combine the 800 teeth with the very large, strong jaw and beak you have a very formidable plant eater," said Dr Terry Gates of the Utah Museum of Natural History, one of the authors on the paper.

Continental divide

Gryposaurus monumentensis was found in Grand Staircase-Escalante National Monument in Utah.

The park is a favoured destination for palaeontologists, who have previously found other new species in the area including a Velociraptor-like carnivore called Hagryphus and a species of tyrannosaur.




Enlarge Image


"We also have several other types of herbivores, including three new species of horned dinosaur, some domed dinosaurs and armoured dinosaurs," Dr Gates told the BBC World Service's Science in Action programme.

"There were lots of animals living in the ecosystem."

At the time, North America was thought to be split by a shallow sea, dividing the continent into two.

The new species is believed to have lived on the western landmass on a strip of land running between the waterway and a range of mountains to the west.

The recently described specimen was probably fossilised when it was covered by river sediments that now make up a series of sandstones and mudstones known as the Kaiparowits Formation.

Dietary choice

It was discovered in 2004 and analysis of its skull began in 2005.


Southern Utah is a favourite destination for palaeontologists

The specimen is the fourth species of Gryposaurus known today. The other three species were discovered in rocks of a similar age in Alberta, Canada and Montana in the US.

"This is a brand new and extremely important window into the world of dinosaurs," said Dr Scott Sampson, also of the Utah Museum of Natural History.

Although the new specimen is similar to other members of the genus, there are crucial differences.

"The snout is very robust indeed - it is much larger and much stronger-looking than any other duck-billed dinosaur," said Dr Gates.

"In addition, the angle of the snout is more vertical, which initially leads to a hypothesis that it had a stronger bite."

Combined with 300 teeth inside its beak, with a further 500 in its jaw ready to grow as replacements, the creature could have sliced through large amounts of fibrous or woody plant material, the researchers believe.

However, Dr Gates admits that researchers are still uncertain about the specifics of the creature's diet.

"We just don't know what this dinosaur ate," he said.

But whilst the food preferences of the toothy Gryposaurus monumentensis remain a mystery, the diet of other creatures alive at the time do not.

"We have duck-billed dinosaur bones with both raptor and tyrannosaur teeth marks on them, so we know they were getting eaten by the predators."


Vocabulary:
Herbivore: horned, domed, armourous dinosaurs
raptor
formidable plant eater
duck-like bill
duck-billed dinosaurs
two-legged creature
velociraptor (velo: 2, raptor: bird of prey)
Gryposaurus (Alberta, Canada, USA (Montana)
snout: robust, larger, stronger looking, more vertical so linked to having a big bite

Tyrannosaurus Rex found in China

Ancestor of T rex found in China

Tyrannosaurus rex may have had much smaller ancestors
Fossils found in China may give clues to the evolution of Tyrannosaurus rex.

Uncovered near the city of Jiayuguan, the fossil finds come from a novel tyrannosaur dubbed Xiongguanlong baimoensis.

The fossils date from the middle of the Cretaceous period, and may be a "missing link", tying the familiar big T rex to its much smaller ancestors.

The fossils show early signs of the features that became pronounced with later tyrannosaurs.

Paleontological knowledge about the family of dinosaurs known as tyrannosaurs is based around two distinct groups of fossils from different parts of the Cretaceous period, which ran from approximately 145 to 65 million years ago.

One group dates from an early part of the period, the Barremian, and the other is from tens of millions of years later.

Physical form

Before now it has been hard for palaeontologists to trace the lineage from one group to the other.

"We've got a 40-50 million year gap in which we have very little fossil record," said Peter Makovicky, associate curator at the Field Museum in Chicago, who helped to lead the US/Chinese team that uncovered the fossil.


Hadrosaurs - duck-billed dinosaurs - spread rapidly in the late Cretaceous
But, he said, X baimoensis was a "nice link" between those two groups.

"We're filling in that part of the fossil record," he said.

Writing in the Royal Society's journal Proceedings B, Dr Makovicky and colleagues suggest that X baimoensis is a "phylogenetic, morphological, and temporal link" between the two distinct groups of tyrannosaurs.

The fossil has some hallmarks of large tyrannosaurs such as a boxy skull, reinforced temple bones to support large jaw muscles, modified front nipping teeth and a stronger spine to support a large head.

But it also shows features absent from older tyrannosaurs, such as a long thin snout.

An adult would have stood about 1.5m tall at the hip and weighed about 270kg. By contrast, an adult T rex was about 4m tall at the hip and weighed more than 5 tonnes.

Wider net

The same edition of Proceedings B features papers about two other sets of dinosaur fossils.

One discovery was made in China by many of the palaeontologists who found the tyrannosaur. The samples found in the Yujingzi Basin came from a dinosaur that resembled the modern ostrich.

While many of these ornithomimosaurs have been found before, analysis of the bones of the new species, dubbed Beishanlong grandis, suggest it was one of the biggest.

The specimen found by the palaeontologists was thought to be 6m tall and weigh about 626kg.

Alongside in Proceedings B was work on the remains of a duck-billed dinosaur found in Uzbekistan called Levnesovia transoxiana.

Analysis of the fossils, by Hans-Dieter Sues of the Smithsonian in Washington and Alexander Averianov of the Russian Academy of Sciences, may shed light on the waves of expansion hadrosaurs undertook during the late Cretaceous.


Vocabulary:
Dinosaurs
Tyrannosaurs Rex
Xiongguanlong Baimoensis
Ornithomimosaurs
Hadrosaurs
Duck-billed dinosaurs

Cretaceous Period (Geologic Period)
Barremian Period

Jiayuguan
Yujingzi Basin

Paleontology
Paleontological knowledge

Phylogenetic
Morphological
Temporal link
Boxy skull
Reinforced temple bones
Large jaw muscles
Modified front nipping teeth
Stronger spine to support a larger head
Absent of long thin snout
Beishanlong Grandis

Rivers "drying-up"

World's major rivers 'drying up'
By Matt McGrath
BBC's environment reporter






Water levels in some of the world's most important rivers have declined significantly over the past 50 years, US researchers say.

They say the reduced flows are linked to climate change and will have a major impact as the human population grows.

The only area with a significant increase in water flows was the Arctic due to a greater snow and ice melting.

The study was published in the American Meteorological Society's (AMS) Journal of Climate.

Rainfall patterns 'altered'

From the Yellow river in northern China to the Ganges in India to the Colorado river in the United States - the US scientists say that the major sources of fresh water for much of the world's population are in decline.

The researchers analysed water flows in more than 900 rivers over a 50-year period to 2004.

They found that there was an overall decline in the amount of water flowing into the world's oceans.

Much of the reduction has been caused by human activities such as the building of dams and the diversion of water for agriculture.

But the researchers highlighted the contribution of climate change, saying that rising temperatures were altering rainfall patterns and increasing rates of evaporation.

The authors say they are concerned that the decline in freshwater sources will continue with serious repercussions for a growing global population.

While some major rivers, including the Brahmaputra in South Asia and the Yangtze in China, have larger water flows, there is concern that the increased volume comes from the melting of glaciers in the Himalayas.

This means that in future these rivers might decline significantly as the glaciers disappear.

Vocabulary and expressions:

Yellow river (China)
Ganges (India)
Colorado (USA)

Decline in fresh water
The reduced flows
overall decline in the amount of water flowing into the ocean
Reduction has been caused by human activities e.g building dams, diversion water for agriculture
Climate change - major cause
rising temperature
increase rates of water evaporation
Repercussion for growing global population

The Arctics
Yangtze (China)
Brahmaputra (South Asia)
snow
ice-melting
Glaciar melting
Hymalaya
fresh water decline in the future.

West Africa faces 'megadroughts'

West Africa faces 'megadroughts'
By Richard Black
Environment correspondent, BBC News website



A partially-submerged tree shows Lake Bosumtwi was shallower in the past
Severe droughts lasting centuries have happened often in West Africa's recent history, and another one is almost inevitable, researchers say.

Analysis of sediments in a Ghanaian lake shows the last of these "megadroughts" ended 250 years ago.

(mega: very big. megadroughts)

Writing in the journal Science, the researchers suggest man-made climate change may make the situation worse.

But, they say, the droughts are going to happen again anyway, and societies should begin planning for them.

"It's disconcerting - it suggests we're vulnerable to a longer-lasting drought than we've seen in our lifetime," said Tim Shanahan from the University of Texas in Austin, who led the research team.

What West Africa won't handle - and neither will California - is the 100-year-long, deep megadrought

Professor Michael Schlesinger
"If the region were to shift into one of these droughts it would be very difficult for people to adapt; and we need to develop an adaptation policy."

The region's most recent dry episode was the Sahel drought which claimed at least 100,000 lives, perhaps as many as one million, in the 1970s and 80s.

But the historical "megadroughts" were longer-lasting and even more devoid of precipitation, the researchers found.

Deep impact


The evidence comes from Lake Bosumtwi in southern Ghana, a deep lake formed in a meteorite impact crater.

Sediments laid down each year form neat, precise layers.

"Nothing lives at the bottom of the lake, so nothing disturbs these layers," said Professor Shanahan.

"Most lakes have this seasonal deposition, but it's rare in the tropics to find a lake where the bottom is undisturbed."

Wet and dry years are distinguished by the ratio of two oxygen isotopes in the sediment.


Layers of sediment preserve a record of rainfall


Droughts lasting a few decades occur regularly over the 3,000 years contained in this record.

They appear to be linked to the Atlantic Multidecadal Oscillation (AMO), a natural climatic cycle in which sea surface temperatures in the tropical Atlantic Ocean vary over time.

The Sahel drought coincided with a cool phase of the AMO. This changes wind patterns, and decreases the strength of the monsoon rains in this region.

However, the cause of the longer, multi-century droughts is not clear.

"That's one of the scary aspects - we have no idea what causes them," said Jonathan Overpeck from the University of Arizona, who oversaw the research effort.

"In Africa, we could cross the threshold, driving the system into one of these droughts, without even knowing why."

Money flows

Michael Schlesinger, who first characterised the AMO a decade ago but was not involved in the current study, suggested a similarity between the outlook for West Africa and the southwestern portion of the US.

There, research has also shown a history of shorter and longer droughts.

"There are two things that need to be done, one of which California and Arizona and so on have done - and that is put in the water collection and distribution infrastructure to deal with the short periods of not very intense water stress," the University of Illinois at Urbana-Champaign scientist told BBC News.


The southwestern US has seen prolonged dry weather
"What West Africa won't handle - and neither will California - is the 100-year-long, deep megadrought.

"The only way I can see of dealing with that is desalination; if push comes to shove and these megadroughts appear - and they will, and it'll probably be exacerbated by man-made global warming - that will be the only thing to do."

Whereas the southwestern US could afford desalination, it is not clear that West African countries could - nor do they all have the infrastructure to move water inland.

The possibility of man-made climate change causing worse droughts is an example of the impacts that many developing countries fear, and which causes them to seek money from richer countries to protect their societies and economies.

Professor Schlesinger is at one with Tim Shanahan's team in suggesting that human-induced climate change would be likely to make droughts more severe, although computer models of climate produce varying projections for rainfall change over the West African region.

But even without changing the chances of drought, rising temperatures worsen the region's outlook, suggested Professor Overpeck.

"Even if we were able to reduce greenhouse gas emissions somewhat, we would still probably have warming in this region of about 2-4C over the century, and that could make droughts much harder to adapt to when they occur," he said.

"What it's pointing to is the need to reduce greenhouse gas emissions; but you can't do it all with mitigation, just as you can't do it all with adaptation."

NB: Chú ý các tập hợp từ ghép in đậm. Cụm danh từ trong tiếng Anh có trật tự từ ngược với tiếng Việt. man-made N, human-made N, long-lasting N, human-induced N v.v.

Wanna read papers with me? Why not join now!

Pandas opt for low-cal sweeteners

Red pandas have surprised researchers by demonstrating a liking of artificial sweeteners.

The Journal of Heredity research was investigating the sweet taste preferences of carnivorous animals.

While some of them them ám chỉ ai nhỉ nếu không phải alf cụm từ carnivourous animals- thú ăn thịt đó - preferred natural sugars, only pandas favoured aspartame, neotame and sucralose. Trong khi hầu hết .... thì chỉ có ... là thích .... các thuật ngữ này đối lập với cụm từ natural sugars. Có thể dễ dàng đoán nghĩa của các từ kia, đúng không? Chẳng phải chúng là những loại đường nhân tạo hay sao! ồ dễ quá, đoán từ theo ngữ cảnh.

The researchers believe the ability to taste such molecules may have evolved because similar ones might exist among the panda's natural foods.

The receptors for sweet substances are formed from a pair of proteins, with the receptors' detailed shapes determining whether they react to natural or artificial sweeteners.

The team demonstrated in 2005 that the carnivore family Felidae - which includes the big cats and the domesticated variety - showed no preference for either natural sugars or sweeteners.

They went on to show that Felidae family animals only expressed one of the two genes that code for proteins that together form sweet receptors on animal tongues.

The new research investigated a number of animals in a similar taste test at two Swiss zoos, followed by genetic profiling. The animals included meerkats, ferrets, genets, mongoose, and lions as well as the pandas. Tên các con vật này có thể dễ dàng nhận biết hình dáng nếu bạn vào google.com.vn, click vào hình ảnh, tất cả chúng sẽ được hiện ra cho bạn chiêm ngưỡng. Hay quá đúng không, học từ online?!
Over the course of a day, the animals were allowed to choose from two water sources: plain water or water sweetened using one of six natural or six artificial sweeteners.

Message received

This is the essence of molecular science - asking a behavioural question and getting a molecular answer

Joseph Brand
Monell Chemical Senses Center
In keeping with the prior research, the lions showed no preference for water sweetened in any way.

All of the other animals showed some preference for at least one of the naturally sweetened water sources.

But pandas alone favoured the artificially sweetened water. Until now it was thought that only primates could taste aspartame, the pandas' favourite among the artificial sweeteners. Đoạn này cũng làm rõ nghĩa hơn các chất đường nhân tạo mà bạn gặp ở đoạn trên. Natural vs. artificial sweeteners

The researchers then looked at the genes that code for sweet receptors. Only the lions suffered from the "pseudogenisation" that prevents formation of the receptors; all of the others had some form of sweet receptors. (pseudo là một morpheme ngoại lai, có nghĩa là giả, không đúng.

However, the genetic analysis showed subtle differences in the fine structure of the pandas' receptors relative to all the other sweet-toothed animals.

"This may explain why the red panda is able to taste artificial sweeteners," said Xia Li, a researcher at the Monell Chemical Senses Center in Philadelphia and lead author of the study.

"What we don't know is why this particular animal has this unusual ability. Perhaps the red panda's unique sweet receptor evolved to allow this animal to detect some compound in its natural food that has a similar structure to these sweeteners."

The researchers will continue to study the fine interplay between the genes that code for sweet receptors, the molecules the receptors can bind to, and ultimately how that influences animals' diets.

"This is the essence of molecular science," said Monell's Joseph Brand, senior author of the research, "asking a behavioural question and getting a molecular answer."