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মঙ্গলবার, ৮ মে, ২০১২

Sunscreen ingredient may increase skin cancer risk

ScienceDaily (May 7, 2012) ? As vacationers prepare to spend time outdoors this summer, many of them will pack plenty of sunscreen in hopes it will protect their bodies from overexposure, and possibly from skin cancer. But researchers at Missouri University of Science and Technology are discovering that sunscreen may not be so safe after all.

Cell toxicity studies by Dr. Yinfa Ma, Curators' Teaching Professor of chemistry at Missouri S&T, and his graduate student Qingbo Yang, suggest that when exposed to sunlight, zinc oxide, a common ingredient in sunscreens, undergoes a chemical reaction that may release unstable molecules known as free radicals. Free radicals seek to bond with other molecules, but in the process, they can damage cells or the DNA contained within those cells. This in turn could increase the risk of skin cancer.

Ma also found that the longer zinc oxide is exposed to sunlight, the greater the potential damage to human cells.

"Zinc oxide may generate free radicals when exposed to UV (ultraviolet) sunlight," May says, "and those free radicals can kill cells."

Ma studied how human lung cells immersed in a solution containing nano-particles of zinc oxide react when exposed to different types of light over numerous time frames. Using a control group of cells that were not immersed in the zinc oxide solution, Ma compared the results of light exposure on the various groups of cells. He found that zinc oxide-exposed cells deteriorated more rapidly than those not immersed in the chemical compound.

Even when exposed to visible light only, the lung cells suspended in zinc oxide deteriorated. But for cells exposed to ultraviolet rays, Ma found that "cell viability decreases dramatically."

When exposed to ultraviolet long-wave light (ultraviolet A or UVA) for 3 hours, half of the lung cells in the zinc oxide solution died. After 12 hours, 90 percent of the cells in that solution died, Ma found.

Why does zinc oxide, an ingredient used in sunscreen to help block harmful UV rays, cause cells to deteriorate when exposed to sunlight? According to Ma, when the zinc oxide nano-particles in the solution absorb the UV rays, the reaction releases electrons, which in turn may produce unstable free radical molecules in the zinc oxide solution. Those free radical molecules then bond with other molecules and act as parasites, damaging the other molecules in the process.

Ma and his colleagues at Missouri S&T published their initial research results in the January 2009 edition of the Journal of Nanoparticle Research. The paper, titled "Toxicity of nano- and micro-sized ZnO particles in human lung epithelial cells," was the first comprehensive study ever published on this subject. Lead author Weisheng Lin was Ma's Ph.D. student at the time. Other authors of the paper were Chuan-Chin Huang, a graduate student in biological sciences at the time, and two members of S&T's biological sciences faculty, Dr. Katie Shannon (assistant professor) and Dr. Yue-Wern Huang (associate professor).

Now, Ma is preparing to publish his latest research results in the journal Toxicology and Applied Pharmacology. A publication date has not been determined.

Ma's research on zinc oxide's effect on cells is still in the early stages, so he cautions people from drawing conclusions about the safety or dangers of sunscreen based on this preliminary research.

"More extensive study is still needed," May says. "This is just the first step."

For instance, Ma plans to conduct electron spin resonance tests to see whether zinc oxide truly does generate free radicals, as he suspects. In addition, clinical trials will be needed before any conclusive evidence may be drawn from his studies.

In the meantime, Ma advises sunbathers to use sunscreen and to limit their exposure to the sun.

"I still would advise people to wear sunscreen," he says. "Sunscreen is better than no protection at all."

Besides sunscreen, zinc oxide is used in many commercial products, including plastics, paints, ointments and sealants.

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The above story is reprinted from materials provided by Missouri University of Science and Technology, via Newswise.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

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Putin pledges unity while police round up protesters

MOSCOW (Reuters) - Vladimir Putin took the oath as Russia's president on Monday with a ringing appeal for unity at the start of a six-year term in which he faces growing dissent, economic problems and bitter political rivalries.

Parliament is expected to approve to his ally Dmitry Medvedev, 46, as prime minister on Tuesday, completing a job swap that has left many Russians feeling disenfranchised two decades after the Soviet Union collapsed.

Outside the Kremlin's high red walls, riot police prevented protests by rounding up about 300 people, including men and women in cafes who were wearing the white ribbons symbolizing opposition to Putin, a day after detaining more than 400 during clashes.

But in the Kremlin, 2,000 dignitaries applauded Putin's every step down the red carpet into a vast hall with gilded columns, the throne room of tsars, where he was sworn in with his right hand resting on the red-bound Russian constitution.

"We will achieve our goals if we are a single, united people, if we hold our fatherland dear, strengthen Russian democracy, constitutional rights and freedoms," Putin said in a five-minute speech after taking the oath for the third time.

"I will do all I can to justify the faith of millions of our citizens. I consider it to be the meaning of my whole life and my obligation to serve my fatherland and our people."

The Kremlin's bells pealed, and the national anthem blared at the end of a ceremony which was followed by the head of the Russian Orthodox Church blessing Putin and the president taking charge of the nuclear suitcase.

Although he has remained Russia's dominant leader for the past four years as prime minister, Putin, 59, has now taken back the formal reins of power he ceded to Medvedev in 2008 after eight years as president.

AUTHORITY WEAKENED

Putin is returning with his authority weakened by months of protests that have polarized Russia and left the former KGB spy facing a battle to reassert himself or risk being sidelined by the business and political elites whose backing is vital.

"We want to, and we will, live in a democratic country," Putin declared, evoking patriotic images of Russia as a great nation and urging people to show a sense of responsibility and national pride to make the country stronger.

Putin made no mention of the protest movement in his speech and no promises of political reform in a series of decrees he signed after the ceremony, most of them focused on economic goals and efforts to improve living standards.

Despite his pledge, riot police, nervous after battling protesters at an anti-Putin rally on Sunday, cracked down on the slightest sign of dissent on the streets of central Moscow, many of which were almost empty.

At least 22 protesters were led away when a crowd of more than 100 started shouting "Russia without Putin" near two luxury hotels 500 m (yards) from the Kremlin.

"This shows that Putin is scared of dissatisfied citizens. Although there are not so many of us, there are not so few either," said 18-year-old student Pavel Kopilkov.

Dozens of others were detained by police on a boulevard near the route of Putin's motorcade to the ceremony, including some who had been sitting outside a French bistro wearing the white ribbon of protest on their jackets and coats.

A Reuters correspondent saw tables and chairs being overturned as the people were hauled away.

"This is shameful. This is not how you celebrate a holiday - this is how you celebrate seizing power," liberal opposition leader Boris Nemtsov said shortly before he was detained.

Police moved in quickly several times through the day as activists sought to gather in various locations for protests, pressing against crowds and detaining people.

Moscow police said 300 had been detained, but that the number included some people who were released and then detained when attempting to protest again.

In Putin's hometown of St Petersburg, police detained a few protesters in a crowd of dozens on the central Palace Square.

PUTIN UNDER PRESSURE

Although the protests, sparked by allegations of electoral fraud, had lost momentum before Sunday's rally, they have given birth to a civil society that will press on with attempts to undermine Putin's authority by contesting local elections.

Many of the protesters are angry that Putin is extending his 12-year domination of Russia and fear he will stifle political and economic reform in his third term as president.

He is under pressure to show he can adapt to the new political landscape. Few think he has changed much, if at all.

He has eased up on the choreographed macho antics that long burnished his image in Russia, such as riding horseback barechested and shooting a tiger with a tranquilizer gun.

Harder to shake off will be his habit of seeking total control, as political rivals begin to gain status and a rising middle class demands more political freedom.

He has to quell rivalries between liberals and conservatives battling for positions in the new cabinet under Medvedev, who is swapping jobs with Putin. The outcome of the struggle could help determine how far reforms go to improve the investment climate.

The $1.9 trillion economy is in better shape than that of most European countries, but is vulnerable to any drop in the price of oil, the main export commodity. The budget is under pressure from Putin's lavish pre-election spending promises.

Putin has said he wants to attract more foreign investment by improving the business climate, reduce corruption and red tape, and end Russia's heavy dependence on energy exports.

He called for the creation of a "new economy" in the speech and reiterated those goals in economic decrees signed on Monday, but critics say he has had plenty of time to tackle the persistent problems in his years in power.

He set out aims on a range of issues in other decrees, from higher wages for teachers and other state workers to better weapons for the military and a decrease in Russia's death rate.

As in the past, he is likely to use tough anti-Western rhetoric on foreign policy to drum up support if times get tough in Russia. But he never yielded his strong influence over foreign policy as premier, so a major policy shift is unlikely.

Putin struck familiar chords in a decree on foreign policy, emphasizing opposition to interference in the internal affairs of sovereign states and saying Moscow wants "strategic" ties with the United States but will not tolerate meddling.

(Additional reporting by Alissa de Carbonnel, Gleb Bryanski and Steve Gutterman; Editing by Louise Ireland)

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Important Tips For Surviving the Inevitable Robot Uprising [Video]

Click here to read Important Tips For Surviving the Inevitable Robot Uprising

Like it or not, one day all of the robots we've designed and built are going to turn on us. Roombas, Aibos, even those arms working in factories are going to realize they're better off without man. But that doesn't mean we can't fight them back into submission. More »

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সোমবার, ৭ মে, ২০১২

FBI had been investigating Arizona neo-Nazi before shooting

[ [ [['A picture is worth a thousand words', 5]], 'http://news.yahoo.com/why-facebook-bought-instagram-4-theories-160400376.html', '[Related: Why Facebook bought Instagram: 4 theories]', ' ', '630', ' ', ' ', ], [ [['He was in shock and still strapped to his seat', 9]], 'http://contributor.yahoo.com/join/yahoonews_virginiabeach', '[Did you witness the jet crash? Share your story with Yahoo! News]', ' ', '630', ' ', ' ', ], [ [['A JetBlue flight from New York to Las Vegas', 3]], 'http://yhoo.it/GV9zpj', '[Related: View photos of the JetBlue plane in Amarillo]', ' ', '630', ' ', ' ', ], [ [['Dick Clark', 11]], 'http://news.yahoo.com/photos/dick-clark-dies-at-82-slideshow/', 'Click image to see more photos', 'http://l.yimg.com/a/p/us/news/editorial/c/21/c217c61aa2d5872244c08caa13c16ec5.jpeg', '500', ' ', 'Reuters', ], [ [['the 28-year-old neighborhood watchman who shot and killed', 15]], 'http://news.yahoo.com/photos/white-house-stays-out-of-teen-s-killing-slideshow/', 'Click image to see more photos', 'http://l.yimg.com/cv/ip/ap/default/120411/martinzimmermen.jpg', '630', ' ', 'AP', ], [ [['Titanic', 7]], 'http://news.yahoo.com/titanic-anniversary/', ' ', 'http://l.yimg.com/a/p/us/news/editorial/b/4e/b4e5ad9f00b5dfeeec2226d53e173569.jpeg', '550', ' ', ' ', ], [ [['He was in shock and still strapped to his seat', 6]], 'http://news.yahoo.com/photos/navy-jet-crashes-in-virginia-slideshow/', 'Click image to see more photos', 'http://l.yimg.com/cv/ip/ap/default/120406/jet_ap.jpg', '630', ' ', 'AP', ], [ [['xxxxxxxxxxxx', 11]], 'http://news.yahoo.com/photos/russian-grannies-win-bid-to-sing-at-eurovision-1331223625-slideshow/', 'Click image to see more photos', 'http://l.yimg.com/a/p/us/news/editorial/1/56/156d92f2760dcd3e75bcd649a8b85fcf.jpeg', '500', ' ', 'AP', ] ]

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Bird Supply Basics ? What to Look For in Your Bird Cage ? Bird ...

People who keep pets absolutely love and adore them, especially those who have feathered pets. You might feed your bird regularly, play with it, make it sing; make it speak but have you ever thought about how comfortable the bird is inside its cage? The cage to a bird is like a house to your average human. The fact that the bird is not going to be let out of the cage makes it all the more important for us to choose the right and comfortable cage for the birds.

It is important to provide them with adequate living space. Today, there are several bird cages that come in a variety of shapes, sizes, models and colors. There are innumerable and endless choices but the trick lies in choosing the best one for your particular type of feathered pet. Given below are the most important things to be kept in mind when you buy a cage for your bird.

The location and placement of the cage is very important. If you are scared that your bird might fly away or be restless when the cage is placed near the window, then an apt place should be chosen inside the house itself. This place should not be secluded and should be such that the bird has you and other folks around it and thereby enabling it to develop socially. Once the location is chosen, the shop keeper can give you the apt choice of cages for that location.

The next thing to be looked into is SIZE. Simple logic works here- large birds require big cages and their smaller counterparts require small ones. That does not mean that a small bird like canaries can be kept in cages that are barely bigger than the bird itself. There should be enough space in the cage for the bird to move around. When confined to small spaces, birds tend to get irritated and therefore they might screech, make lot of noise, peck, pluck their own feathers etc. It is important to choose the size of the cage with great care.

Next thing to be looked at is the bars of the cage. Small birds require bars not more than half an inch apart. Several times people have encountered incidents of birds escaping through the bars and also birds getting stuck in between bars. It is also important to decide on having horizontal or vertical bars. Large birds are to be kept in horizontal barred cages as that lets the birds climb up the bars a bit and exercise every now and then.

The shape of the cage is also extremely important. Imagine yourself living in a perfect sphere or circular house- enough to make your head spin? Birds have the same reaction too. Round cages affect them psychologically and therefore the most preferred shapes of cages are angled ones, rectangular or square. These can be styled inside with small mounds; stands etc where the birds can perch up and have some movement.

Today, craftsmanship also finds a place while choosing cages. Cages with fancy stands, perches etc are in demand. One the cage is brought be sure to clean it and check it any sharp items or anything harmful to the bird. Fill it colorful toys, soft accessories and also have a stylish small bird bath inside with a food tray where you can serve food to your lovely feathered friend.

Shop for Pet Bird & Parrot Supplies, Bird Food, Bird Carriers, Bird Stands & Toys and Hard to Find Bird Items at Chirp n Squawk Bird Supplies. Chirp n Squawk Bird Supplies are specialists for all kinds of pet bird and parrot supplies.

Author: Scott Miscall
Article Source: EzineArticles.com
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NASA's commercial crew partner boeing completes parachute test

ScienceDaily (May 5, 2012) ? The Boeing Company successfully completed the second parachute drop test for its Crew Space Transportation (CST) spacecraft May 2, 2012, part of its effort to develop commercial crew transportation capabilities that could ferry U.S. astronauts to and from low-Earth orbit (LEO) and the International Space Station.

A helicopter lifted the CST-100 crew capsule to about 10,000 feet above the Delmar Dry Lake Bed near Alamo, Nev. A drogue parachute deployment sequence was initiated, followed by deployment of the main parachute. The capsule descended to a smooth ground landing, cushioned by six inflated air bags. The test demonstrated the performance of the entire landing system.

"Boeing's parachute demonstrations are a clear sign NASA is moving in the right direction of enabling the American aerospace transportation industry to flourish under this partnership," NASA's Commercial Crew Program Manager Ed Mango said. "The investments we're making now are enabling this new path forward of getting our crews to LEO and potentially the space station as soon as possible."

Boeing's CST system is designed to be a reusable, capsule-shaped spacecraft capable of taking up to seven people, or a combination of people and cargo, to and from low-Earth orbit, including the space station. HDT Airborne Systems of Solon, Ohio, designed, fabricated and integrated the parachute system, including the two drogue parachutes. ILC Dover of Frederica, Del., designed and fabricated the landing air bag system.

The first test, on April 3, validated the architecture and deployment of the parachute system, characterized pyrotechnic shock loads, confirmed parachute size and design, and identified potential forward compartment packaging and deployment issues. The company inspected and re-packed the full parachute system for this second test.

"This second parachute drop test validates Boeing's innovative system architecture and deployment plan," said John Mulholland, vice president and program manager of Boeing Commercial Programs. "Boeing's completion of this milestone reaffirms our commitment to provide safe, reliable and affordable crewed access to space."

The company has scheduled additional tests to be performed in 2012 that will provide more data on elements of the spacecraft's design.

Boeing's spacecraft was designed to be compatible with a variety of expendable launch vehicles. The company selected United Launch Alliance's Atlas V rocket for initial CST-100 test flights.

All of NASA's industry partners, including Boeing, continue to meet their established milestones in developing commercial crew transportation capabilities.