September 16, 2011

Why Laughter May Be the Best Pain Medicine

Laughter with friends releases endorphins, the brain's "feel-good" chemicals

Laughing with friends releases feel-good brain chemicals, which also relieve pain, new research indicates.
Until now, scientists haven't proven that like exercise and other activities, laughing causes a release of so-called endorphins.
"Very little research has been done into why we laugh and what role it plays in society," study researcher Robin Dunbar, of the University of Oxford, said in a statement. "We think that it is the bonding effects of the endorphin rush that explain why laughter plays such an important role in our social lives."

Leia Mais…

U.K. Researchers to Test "Artificial Volcano" for Geoengineering the Climate

An experiment starting next month in the U.K. will pump water one kilometer into the air to test a new climate-cooling method that eventually could deliver sunlight-reflective sulfate particles into the stratosphere

Next month, researchers in the U.K. will start to pump water nearly a kilometer up into the atmosphere, by way of a suspended hose.

The experiment is the first major test of a piping system that could one day spew sulfate particles into the stratosphere at an altitude of 20 kilometers, supported by a stadium-size hydrogen balloon. The goal is geoengineering, or the "deliberate, large-scale manipulation of the planetary environment" in the words of the Royal Society of London, which provides scientific advice to policymakers. In this case, researchers are attempting to re-create the effects of volcanic eruptions to artificially cool Earth.

                      Volcanic eruptions, like this one at Mount Pinatubo eruption in 1991, are known to have global cooling effects. In October, researchers will test a man-made volcano that might eventually be used as a temporary defense against the devastating effects of climate  change. Image: Wikimedia Commons

The $30,000 test, part of a project called Stratospheric Particle Injection for Climate Engineering (SPICE), is inspired by the 1991 eruption of Mount Pinatubo in the Philippines. That volcano spewed 20 million tons of sulfate particles into the atmosphere, cooling Earth by 0.5 degree Celsius for 18 months. If the British feasibility tests are successful, the balloon-and-hose contraption could be used to inject additional particles into the stratosphere, thereby reflecting more of the sun's energy back into space, and hopefully curbing some of the effects of global warming.
"This is one of the first times that people have taken geoengineering out of the lab and into the field," lead scientist Matthew Watson said Tuesday during a press conference in London. "We are still decades away—and I do mean decades—from doing real geoengineering." Watson said his team still needs to determine which substances would work best at reflecting light, how much is needed to have an effect, and the possible unintended consequences of injecting the particles into the atmosphere, such as acid rain, ozone depletion or weather pattern disruption.
October's tests will mainly focus on whether the balloon-and-hose design could be an effective method to deliver the sunlight-reflecting particles. At an airfield in Norfolk, England, that is no longer in use, a helium blimp will hoist a regular pressure-washer hose one kilometer off the ground. An off-the-shelf pressure washer will pump up 1.8 liters of tap water per minute, to a maximum of 190 liters, says Hunt, which will evaporate or fall down to the ground locally. The researchers will monitor the performance of the system, and use the data to design the larger 20-kilometer-high setup.
In the past scientists have proposed similar atmospheric delivery methods using guns, airplanes, rockets and chimneys. In 2009 Russian scientists even tested airplane delivery on a small scale. But Hugh Hunt, a SPICE engineer at the University of Cambridge, said the balloon-and-hose design appears to be the most cost-effective option. Even when scaled up, the team expects the simple design to cost around $5 billion, in comparison with the $100 billion needed to launch thousands of high-altitude aircraft.
The water tests are expected to be harmless, but several environmental groups have criticized the plan—and geoengineering in general. Last year, the United Nation's Convention on Biological Diversity issued a statement forbidding geoengineering research that may impact biodiversity. The U.K. accepted that statement, but the SPICE experiment does not violate any international agreements due to its small scale, says Jason Blackstock, a physicist at Canada's Center for International Governance Innovation.
Whereas Hunt agrees that such research is lacking, he said that the team needs real measurements in order to see if the tethered balloon design is viable. "If not now, then when would you start?" he asks. "This year, next year? Or maybe wait until a large block of ice falls off of Greenland? My choice is to have all the tools carefully thought through, so that we don't have to rush into anything."
To avoid dangerous climate change, some scientists estimate that global CO2 emissions must be cut by at least 80 percent by the end of the century. Geoengineering will not help achieve that long-term target, but the cooling effects of large sulfate clouds are nearly instantaneous, making geoengineering potentially valuable in the event of acute climate crises such as the melting of Arctic sea ice, which could further accelerate global warming over the decades.
The researchers made it clear in Tuesday's press conference that they do not advocate using geoengineering as an excuse for humanity to continue recklessly emitting carbon dioxide and other greenhouse gases. "[Geoengineering] should be considered as an emergency remediation while we wean ourselves off carbon," Watson said. "The question you have to ask is, is it worse without mitigation or with it? And that answer isn't obvious yet."

Nevertheless, the Canada-based Action Group on Erosion, Technology and Concentration (ETC) is calling the tests internationally irresponsible. In a written statement, they called on the British government to shut down the project, adding: "This experiment is only phase one of a much bigger plan that could have devastating consequences, including large changes in weather patterns such as deadly droughts."
Alan Robock, a Rutgers University meteorologist, shares some of those concerns. He has created computer simulations indicating that sulfate clouds could potentially weaken the Asian and African summer monsoons, reducing rain that irrigates the food crops of billions of people. It is premature to conduct such field experiments, Robock says. More computer modeling should be done first, he adds, to determine how injected particles might interact with the ozone layer and the hydrologic cycle.

Leia Mais…

QR Tags Can Be Rigged to Attack Smart Phones

A blogger has demonstrated how these innocuous tags can be made into cyber-crime weapons

You've probably seen QR tags thousands of times, from advertisements in the subway to coupon flyer in the mail to products in the supermarket. They look like stamp-size bar codes, a grid of small black-and-white rectangles and squares, usually with bigger black squares in the corners.
A marketer's dream-come-true, these tiny images are capable of storing and transmitting loads of data directly to the smartphones of interested customers. When a person scans a QR tag with a smartphone, the tag can do any number of things, including taking the user right to the product's website.

                                                    Image: Digitmedia, courtesy Flickr
                                            [How to Protect Your Smartphone From Malware]

But like any technology, they can also be manipulated to bite the hands — or phones — that feed them. On the mobile security blog Kaotico Neutral, researcher Augusto Pereyra demonstrated how these innocuous QR tags can be made into cybercrime weapons.

QR tags are touted for their convenience, but it's that same convenience — coupled with their increasing prevalence — that Pereyra believes could allow them to become dangerous attack vectors. Popular QR tag-scanning software, such as ScanLife, automatically takes mobile browsers to the site embedded within the tag, and while it makes the process quick, it does nothing for its safety.

"This is a serious problem since this is the equivalent of clicking a link with your eyes closed," Pereyra wrote.
Tim Armstrong, researcher for the security firm Kaspersky Lab, said this streamlined process creates a "run first, ask questions later" mentality that benefits attackers.

An attack like his could easily be scaled up, Pereyra said, simply by printing the rigged QR tags and pasting them atop already-existing tags on posters in public places.
As companies and marketers take advantage of the power and ubiquity of mobile devices, and it becomes easier for consumers to carry out financial transactions via smartphones, researchers suspect online attackers will attempt to gain their own foothold in the market.

Leia Mais…

August 23, 2011

Ultra-Violet Radiation (UVR) From Tube Light

বর্তমানে একটি জনস্বাস্থ্যমূলক প্রসঙ্গ বারবার উঠে আসছে। তা হল tube light বা fluorescent lamp হতে নির্গত ultraviolet radiation (UVR) শরীরের জন্য ক্ষতিকর কিনা। কারণ UVR হল skin cancer এর জন্য দায়ি, যা মানব স্বাস্থ্যের জন্য হুমকিস্বরূপ। Tube light বা fluorescent lamp হতে নির্গত UVR
নিম্ন চাপীয় mercury বাষ্প হতে উৎপন্ন হয়। যখন electrical discharge mercury বাষ্পের মধ্য দিয়ে চালিত হয় তখন UVR উৎপন্ন হয়অধিকাংশ নির্গত শক্তির wavelength হল 254 nm ইহা UV-C spectrum (180-280 nm) এর মধ্যে অবস্থিত। Fluorescent bulb এর ক্ষেত্রে 254 nm এর  radiation ব্যবহৃত হয় phosphor কে উত্তেজিত করতে, যা bulb এর glass envelope এর ভিতরের দিকে প্রলেপ হিসেবে থাকে। পরবর্তিতে phosphor visible wavelength এর আলো নিঃসরণ করে (বিভিন্ন phosphor বিভিন্ন রঙ সৃষ্টি করে) এবং যে সকল UV-C রশ্নি phosphor শোষণ করে না তা glass wall দ্বারা শোষিত হয়। আবার mercury discharge অন্নান্য wavelength এর যেমন 365 nm এর আলোও নিঃসরণ করে যা UV-A spectrum (315-400 nm) এর মধ্যে অবস্থিত। এই UV-A radiation phosphor দ্বারা শোষিত হয়না এবং অধিকাংশই lamp wall ভেদ করে পরিবেশে মুক্ত হয়।১৯৮৮ সালে NRPB বিস্তারিত গবেষণা চালায় UVR এর উপর। তারা ক্ষতিকর প্রভাব যেমন photokeratitis, erythema ইত্যাদির জন্য মাত্রা  নির্ধারণ করে। এছাড়া non-melanoma skin cancer (NMSC) এর সাথেও UVR এর সংশ্লিষ্টতা দেখানো হয়

Leia Mais…

June 22, 2011

Who Is The Father Of Physics?

Physics is the field of science which studies the natural world and the laws on which it works. It is considered as the most fundamental of the sciences from which the other branches like chemistry, biology and application oriented fields like engineering and medicine originate. Physics has been studied by man since ancient times in various ways with a number of eminent personalities contributing a great deal to the field.

Physics though it employs mathematical means to comprehend various concepts which are then subjected to tests or experiments also has a philosophical aspect about it. The ancient Greek philosopher Thales (6th century BC) is widely regarded as the father of physics. He is credited with being the first to study the heavens; some of his achievements include predicting a solar eclipse, construction of an almanac and his statement that all 'things' are formed of one primary element.

Some important philosopher physicists of the period include Aristotle, Democritus and Archimedes. The father of Modern Physics is considered to be the Italian physicist Galileo Galilei most famous for his assertion of the heliocentric view of the solar system.
Some famous physicists of the modern period are Sir Isaac Newton, Johannes Kepler, Benjamin Franklin, Michael Faraday, Nikolai Tesla, Niels Bohr and Albert Einstein among others.

Leia Mais…