Tuesday, January 29, 2013

Simulations' Achille's heel

Jan. 29, 2013 ? What can go wrong when computer simulations are applied outside their original context? In an article about to be published in EPJ Plus, Daan Frenkel from the University of Cambridge, UK, outlines the many pitfalls associated with simulation methods such as Monte Carlo algorithms or other commonly used molecular dynamics approaches.

The context of this paper is the exponential development of computing power in the past 60 years, estimated to have increased by a factor of 10152, in line with Moore's law. Today, short simulations can reproduce a system the size of a bacterium.

The author outlines diverse examples of issues arising when seemingly simple simulation methods are not applied with the due level of care. For example, simulations of small-scale systems, such as cubic boxes representing a unit cell as part of a crystal or liquid crystal, display effects that are linked to the fact that the sample is of finite size. Therefore, these simulations can only imitate, not reproduce, macroscopic effects unless effects that occur at microscopic scale, such as surface effects, are effectively removed. This is typically done by using periodic repetition of a small system in all directions.

Frenkel also focuses on methods that, at first blush, appear reasonable, but are flawed and are akin to attempting to compare apples and oranges. For example, computing a mechanical property of a system -- say the potential energy -- using a Monte Carlo simulation, which can be based on thermal averages, does not allow us to compute the thermal properties of such a system -- such as entropy -- in terms of thermal averages. Finally, the article also takes great care to debunk common myths and misconceptions pertaining to simulations, for instance, newer simulation methods are not necessarily better than older ones.

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The above story is reprinted from materials provided by Springer Science+Business Media, via AlphaGalileo.

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


Journal Reference:

  1. D. Frenkel. Simulations: The dark side. The European Physical Journal Plus, 2013; 128 (1) DOI: 10.1140/epjp/i2013-13010-8

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

Source: http://feeds.sciencedaily.com/~r/sciencedaily/top_news/top_technology/~3/VdK1EE1jwwY/130129080222.htm

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Ringadoc Raises $1.2M From Founders Fund?s FF Angel To Connect Doctors With Patients On-Demand

Screen shot 2013-01-29 at 12.58.41 PMRingadoc has a pretty big vision: To be the "frontline of primary care," to let anyone and everyone pay a flat fee to instantly talk to a real doctor at any hour of the day. In pursuit of perfecting on-demand medicine, the startup announced today that it has raised $1.2 million in seed financing, led by Founders Fund's seed vehicle, FF Angel. The raise marks the close of the second half of its seed funding, following the $750K the startup announced last June from Founders Fund, bringing its total to just over $1.2 million.

Source: http://feedproxy.google.com/~r/Techcrunch/~3/_AjSzEckp5U/

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Link found between insulin sensitivity, cells' powerhouses: Mice with mitochondrial mutation live longer, have less fat

Jan. 28, 2013 ? If findings of a new study in mice are any indication, it might be possible to fine-tune cellular powerhouses called mitochondria, tweaking one aspect to increase insulin sensitivity, reduce body and fat mass, and even extend life. Exploiting this target could one day lead to novel treatments for type 2 diabetes -- an endocrine system disease that affects 8 percent of the U.S. population. The research also points to promising new avenues of investigation in the biology of aging.

The study, reported in The FASEB Journal by authors from the School of Medicine at the UT Health Science Center San Antonio and the university's Barshop Institute for Longevity and Aging Studies, found that diminished activity of a protein complex involved in mitochondrial function was associated with healthy changes in the mice. The median life span of this strain of mice is 20 percent longer.

Paradoxical

"This is an unexpected finding because you would think that something that decreases mitochondrial function would have a damaging effect, but instead we saw an increase in life span and beneficial metabolic effects," said lead author Deepa Sathyaseelan, Ph.D., research assistant professor of cellular and structural biology in the School of Medicine.

"The most important thing we noticed is reduced body weight and decreased fat mass in the mice," Dr. Sathyaseelan said. "We found that this decreased fat mass is due to increased fat utilization."

Fat utilization

Mitochondria produce an energy source called ATP that is necessary for the functions of life, everything from breathing to thinking. Additionally the cellular powerhouses are a major site of fat utilization, said study senior author Holly Van Remmen, Ph.D., professor of cellular and structural biology. Fat is an endocrine organ that performs many functions, and having it in the correct proportions is important for the body. Too much or too little fat is harmful.

The scientists also observed that mice with the mutation, in contrast to control animals, make greater numbers of new mitochondria. This is important because cells are constantly remodeling themselves, including mitochondrial overhaul.

Age-related

Mitochondrial dysfunction occurs with age and is associated with many age-related diseases such as type 2 diabetes, heart disease and cancer. Dr. Sathyaseelan said the study "opens the door to new clues about how mitochondrial function might modulate insulin sensitivity," representing an important step for diabetes research.

Type 2 diabetes involves abnormalities with insulin, a hormone secreted by beta cells in the pancreas. Insulin helps the body store and use sugar from food, but in type 2 diabetes the body is insulin resistant, that is, it inefficiently responds to the hormone. With time the beta cells in diabetic patients start to die, resulting in less insulin to handle the demands. Levels of the hormone become progressively lower and sugar levels are increased progressively, damaging blood vessels and organs.

Understanding longevity

"I would also like to point out that these mice live longer," Dr. Van Remmen said. "For us they are very important from an aging standpoint. We want to understand how these animals can have added longevity, yet have a 60 percent reduction in a protein complex involved in mitochondrial function."

Dr. Sathyaseelan noted that life extension in association with decrease of the complex's activity is seen across species, including roundworms and flies. Shane Rea, Ph.D., assistant professor of physiology at the Barshop Institute, is one of the first to make this discovery in the worms.

The Barshop Institute team obtained the study mice from an Italian institute where studies are ongoing. Dr. Sathyaseelan recently received a two-year, $140,000 grant from the American Heart Association to understand how mitochondrial dysfunction is related to insulin sensitivity.

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Story Source:

The above story is reprinted from materials provided by University of Texas Health Science Center at San Antonio, via EurekAlert!, a service of AAAS.

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


Journal Reference:

  1. S. S. Deepa, D. Pulliam, S. Hill, Y. Shi, M. E. Walsh, A. Salmon, L. Sloane, N. Zhang, M. Zeviani, C. Viscomi, N. Musi, H. Van Remmen. Improved insulin sensitivity associated with reduced mitochondrial complex IV assembly and activity. The FASEB Journal, 2012; DOI: 10.1096/fj.12-221879

Note: If no author is given, the source is cited instead.

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.

Source: http://feeds.sciencedaily.com/~r/sciencedaily/top_news/~3/rk2jSNJXv1k/130129100255.htm

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Fragile economy, other global woes dominated Davos

DAVOS, Switzerland (AP) ? The fragile state of the global economy and a host of other woes ? from Syria's escalating war to the rocky fallout from the Arab Spring ? dominated the annual meeting of the global elite at Davos, casting a sense of uncertainty and foreboding over what lies ahead.

Much of the overt glitz and glamor that was long a feature of the World Economic Forum was absent this year, a decision founder Klaus Schwab said reflected the serious issues confronting the planet.

As more than 2,500 global movers and shakers headed home Sunday, there was broad agreement that things are beginning to look up on the economic front ? at least in China, Africa, and emerging markets, but not in Japan, Europe, and the United States.

Source: http://news.yahoo.com/fragile-economy-other-global-woes-dominated-davos-154125358--finance.html

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Monday, January 28, 2013

Iran says it successfully sent a monkey into space

In this undated image taken from AP Television, scientists in Iran surround a monkey ahead of a space launch. Iran said it had successfully sent the monkey into space on Monday, Jan. 28, 2013, describing the launch as another step toward Tehran's goal of a manned space flight. According to a brief report on state TV, the monkey was sent up to a height of 120 kilometers (72 miles) on board a rocket dubbed Pishgam, or Pioneer in Farsi. (AP Photo/AP Video)

In this undated image taken from AP Television, scientists in Iran surround a monkey ahead of a space launch. Iran said it had successfully sent the monkey into space on Monday, Jan. 28, 2013, describing the launch as another step toward Tehran's goal of a manned space flight. According to a brief report on state TV, the monkey was sent up to a height of 120 kilometers (72 miles) on board a rocket dubbed Pishgam, or Pioneer in Farsi. (AP Photo/AP Video)

(AP) ? A gray-tufted monkey strapped in a pod resembling an infant's car seat rode an Iranian rocket into space and returned safely, officials said Monday in what was described as a step toward Tehran's goal of a manned space flight.

The mission also touched on concerns that advances in Iran's rocket expertise could be channeled into military use for long-range weapons that might one day carry nuclear warheads. Iran says it does not seek atomic weapons.

Launching a live animal into space ? as the U.S. and the Soviet Union did more than a half-century ago in the infancy of their programs ? may boost a country's stature. But John Logsden, a space policy professor emeritus at George Washington University, said Iran's achievement should draw no concern.

"A slight monkey on a suborbital flight is nothing to get too excited about," he said. "They already had the capability to launch warheads in their region."

U.S. State Department spokeswoman Victoria Nuland said the U.S. had no way to confirm the monkey's voyage, but that it was concerned by the reports because "any space launch vehicle capable of placing an object in orbit is directly relevant to the development of long-range ballistic missiles."

The U.N. Security Council has expressly forbidden Iran from such ballistic missile activity, Nuland added.

In June 2010, the Security Council banned Iran from pursuing "any activity related to ballistic missiles capable of delivering nuclear weapons."

With its ambitious aerospace program, Iran has said it wants to become a technological leader for the Islamic world.

It's not the first time Iran has announced it had rocketed a live creature out of the Earth's atmosphere. The country sent a mouse, a turtle and some worms into space in 2010, officials said.

But the purported successful voyage of the small monkey, shown wearing a protective vest, put Iran among just a handful of nations that have sent a primate into space in a mission seen as a precursor of human spaceflight. No name was given for the monkey.

Earlier this month, the director of Iran's space agency, Hamid Fazeli, said Iran wanted to launch its first manned space mission in as soon as five years ? a goal that stretches back to the shah's fascination with NASA years before the 1979 Islamic Revolution.

"Iran is on its way to send a man into space," said Iran's Defense Minister Gen. Ahmad Vahidi in comments posted on the ministry's website.

He added that the capsule "returned to Earth safely at the expected speed, together with the monkey inside," without giving further details.

According to state TV, the rocket dubbed "Pishgam," or "Pioneer" in Farsi, reached a height of 120 kilometers (72 miles), pushing into the threshold of space.

Iran's state TV broadcast its first video pictures showing Iranian scientists fixing the seated monkey into the rocket before the launch. It did not give any details on the timing or location of the launch.

Still images also showed the monkey wearing a type of molded body protection and being strapped tightly into a red plastic seat. The monkey was shown immobilized with straps and his face poked through a purple shield that covered his head and upper body.

Fazel said the monkey parachuted safely with the remaining last stage of the rocket. The TV also showed experts walking to the site in the middle of a desert where the monkey landed.

Fazel told the state TV that Iran will launch a bigger rocket together with a larger animal to obtain greater safety assurances before sending a man into space.

For Iran, its aerospace program is a source of national pride at a time of slumping economic fortunes from Western sanctions. It's also one of the pillars of Iran's aspirations to be seen as the technological hub for Islamic and developing countries.

Iran's Supreme Leader, Ayatollah Ali Khamenei, and others repeatedly describe scientific progress ? including Iran's uranium enrichment labs ? as a patriotic duty in response to Western economic and diplomatic pressures.

Iran's rocket technology alarms the West as giving it intercontinental reach for a possible arsenal. Already, conventional Iranian missiles are capable of reaching Israel and U.S. military bases in the Persian Gulf.

Iran insists it only seeks nuclear reactors for energy and medical applications. But authorities also say there can be no retreat from homegrown technological development in all fields ? from peaceful nuclear research to military surveillance drones.

Tehran has announced several successful launches of satellites, dating back to 2005 in a joint project with Russia.

In November, the head of Iran's powerful parliamentary committee on security and foreign policy, Alaeddin Boroujerdi, warned that "no power can prevent Iran's progress in scientific and nuclear science fields."

Similar statements were made last year when Iran announced plans for a new space center.

Few details have emerged on the new facility, but Iran already has a major satellite launch complex near Semnan, about 200 kilometers (125 miles) east of Tehran. A satellite monitoring facility is located outside Mahdasht, about 70 kilometers (40 miles) west of the Iranian capital.

Iran says it wants to put its own satellites into orbit to monitor natural disasters in the earthquake-prone nation, improve telecommunications and expand military surveillance in the region.

The mission involving the monkey drew historical links to the earliest years of the space race in the 1950s when both the U.S. and the Soviet Union tested rockets with animals on board, including American capsules carrying monkeys and Moscow's holding dogs. Many of the animals on the early flights perished because of equipment failure or technology unable to cope with re-entry from sub-orbit.

Later in the 1960s, the U.S. and Soviets sent animals into orbit for further biological tests on space flight and other nations, including France and China, sent animals on rocket flights.

"They're following the path that we followed more than half a century ago," Logsdon said, adding that Iran is probably ahead of India in terms of space ability, but behind its arch foe Israel.

People for the Ethical Treatment of Animals said it was "appalled" by photos of what it described as a "visibly terrified monkey crudely strapped into a restraint device."

It said it had urged Iran in 2011 not to send a primate into space.

"Iran is repeating the wasteful and cruel mistakes that marked the darkest days of the space race," PETA said in a statement.

____

Science Writer Seth Borenstein and Bradley Klapper in Washington contributed to this report.

Associated Press

Source: http://hosted2.ap.org/APDEFAULT/cae69a7523db45408eeb2b3a98c0c9c5/Article_2013-01-28-Iran-Space%20Monkey/id-555aa0dca5664bdaa1a7c98d225e7b54

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Wednesday, January 16, 2013

THE RESET: Gun control joins long list of battles

President Barack Obama, accompanied by Vice President Joe Biden, left, hugs eight-year-old letter writer Grant Fritz during a news conference on proposals to reduce gun violence, Wednesday, Jan. 16, 2013, in the South Court Auditorium at the White House in Washington. Obama and Biden were joined by law enforcement officials, lawmakers and children who wrote the president about gun violence following the shooting at an elementary school in Newtown, Conn., last month. (AP Photo/Susan Walsh)

President Barack Obama, accompanied by Vice President Joe Biden, left, hugs eight-year-old letter writer Grant Fritz during a news conference on proposals to reduce gun violence, Wednesday, Jan. 16, 2013, in the South Court Auditorium at the White House in Washington. Obama and Biden were joined by law enforcement officials, lawmakers and children who wrote the president about gun violence following the shooting at an elementary school in Newtown, Conn., last month. (AP Photo/Susan Walsh)

A convention attendee looks through the sight of a Sig Sauer semiautomatic rifle at the 35th annual SHOT Show, Tuesday, Jan. 15, 2013, in Las Vegas. The National Shooting Sports Foundation was focusing its trade show on products and services new to what it calls a $4.1 billion industry, with a nod to a raging national debate over assault weapons. (AP Photo/Julie Jacobson)

FILE - In a Friday, Jan. 4, 2013 file photo, a sign is posted for an upcoming gun show, in Leesport, Pa. Nearly six in 10 Americans want stricter gun laws in the aftermath of last month's deadly school shooting in Connecticut, with majorities favoring a nationwide ban on military-style, rapid-fire weapons and limits on gun violence depicted in video games and movies and on TV, according to a new Associated Press-GfK poll. A lopsided 84 percent of adults would like to see the establishment of a federal standard for background checks for people buying guns at gun shows, the poll showed. President Barack Obama was set Wednesday, Jan. 16, 2013 to unveil a wide-ranging package of steps for reducing gun violence expected to include a proposed ban on assault weapons, limits on the capacity of ammunition magazines and universal background checks for gun sales. (AP Photo/Matt Rourke)

Leading up to President Barack Obama's second inauguration, strong emotions are emanating from both sides of the aisle on a range of subjects in today's highly charged political environment of Washington.

There are raging battles over the national debt ceiling, taxes, spending cuts and immigration overhaul ? no shortage of hot-button issues awaiting Obama and a deeply divided Congress.

The president has now formally added to the list gun control, which wasn't even a major part of his second-term agenda until last month's deadly shooting rampage at an elementary school in Connecticut that claimed the lives of 20 children and six adults.

Obama unveiled a tough package of measures Wednesday to curb what he said was "an epidemic" of gun violence. They include proposed legislation to ban the sale of certain semiautomatic rifles and high-capacity ammunition magazines and to expand background checks. He also announced a raft of 23 steps that he could take by executive action alone without requiring congressional consent.

The legislative part of his package drew predictable and heavy opposition from the gun lobby and Republicans and is even drawing resistance from some members of his own party.

Senate Majority Leader Harry Reid, D-Nev., for instance, says that while an assault-style weapons ban might pass the Senate, he doubts it could pass the Republican-led House. Reid said immigration tops his priority list after the upcoming fiscal fights? not gun control.

The heavy sentiment in Congress against sweeping changes to gun laws runs counter to polls showing that a majority of Americans support tighter gun restrictions.

A new AP-GfK poll shows that 58 percent of Americans favor strengthening gun laws and 85 percent favor background checks for gun-show purchases.

Obama acknowledges the difficulty of making headway against the ingrained gun lobby and its congressional backers.

But, he said Wednesday, "If there's even one life that can be saved, then we have an obligation to try it. And I'm going do to my part.".

___

Follow Tom Raum on Twitter: http://www.twitter.com/tomraum

Associated Press

Source: http://hosted2.ap.org/APDEFAULT/386c25518f464186bf7a2ac026580ce7/Article_2013-01-16-US-The-Reset/id-cde00f8166bd4e3bab827217625be8bd

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Finland's Katainen: EU without UK like "fish without chips"

BRUSSELS (Reuters) - Existing banking problems in countries such as Ireland and Spain have to be kept separate from future bank crises, Finnish Prime Minister Jyrki Katainen said on Wednesday, reigniting a debate about the treatment of "legacy" bank assets.

In an interview, Katainen said he expected Britain to remain in the European Union, with "major British politicians and the people" convinced that Britain should be at the heart of Europe.

"The European Union without Britain is pretty much the same as fish without chips. It's not a meal anymore," he said.

Katainen also emphasised the need for a strong and comprehensive system for resolving bad banks in Europe, saying the mentality of leaders had to shift from bailing out banks to ensuring that investors and owners of banks were 'bailed in'.

Only then would taxpayers be protected from having to carry the cost of bailouts, and the link could be broken between the debts of problem banks and the debts of sovereign countries.

(Writing by Luke Baker, reporting by Luke Baker and Ethan Bilby)

Source: http://news.yahoo.com/finlands-katainen-eu-without-uk-fish-without-chips-123638827--sector.html

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