Archive for the ‘Northwestern University’ Category

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Delaying fatherhood may offer survival advantages, say US scientists who have found children with older fathers and grandfathers appear to be “genetically programmed” to live longer.

The genetic make-up of sperm changes as a man ages and develops DNA code that favours a longer life – a trait he then passes to his children. The team found the link after analysing the DNA of 1,779 young adults. Their work appears in Proceedings of the National Academy of Sciences.

Experts have known for some time that lifespan is linked to the length of structures known as telomeres that sit at the end of the chromosomes that house our genetic code, DNA. Generally, a shorter telomere length means a shorter life expectancy. Like the plastic tips on shoelaces, telomeres protect chromosomal ends from damage. But in most cells, they shorten with age until the cells are no longer able to replicate.

However, scientists have discovered that in sperm, telomeres lengthen with age. And since men pass on their DNA to their children via sperm, these long telomeres can be inherited by the next generation. Dr Dan Eisenberg and colleagues from the Department of Anthropology at Northwestern University studied telomere inheritance in a group of young people living in the Philippines.

Telomeres, measured in blood samples, were longer in individuals whose fathers were older when they were born. The telomere lengthening seen with each year that the men delayed fatherhood was equal to the yearly shortening of telomere length that occurs in middle-aged adults. Telomere lengthening was even greater if the child’s paternal grandfather had also been older when he became a father. Although delaying fatherhood increases the risk of miscarriage, the researchers believe there may be long-term health benefits.

Inheriting longer telomeres will be particularly beneficial for tissues and biological functions that involve rapid cell growth and turnover – such as the immune system, gut and skin – the scientists believe. And it could have significant implications for general population health. “As paternal ancestors delay reproduction, longer telomere length will be passed to offspring, which could allow lifespan to be extended as populations survive to reproduce at older ages.”

Prof Thomas von Zglinicki, an expert in cellular ageing at Newcastle University, said more research was needed.

“Very few of the studies that linked telomere length to health in late life have studied the impact, if any, of paternal age. It is still completely unclear whether telomere length at conception (or birth) or rate of telomere loss with age is more important for age-related morbidity and mortality risk in humans. “The authors did not examine health status in the first generation offspring. It might be possible that the advantage of receiving long telomeres from an old father is more than offset by the disadvantage of higher levels of general DNA damage and mutations in sperm,” he said.

http://www.bbc.co.uk/news/health-18392873

Thanks to Kebmodee for bringing this to the attention of the It’s Interesting community.

drone-proof-burqa
As debate over the use of unmanned aerial vehicles in the U.S. rages on, a fashion designer introduces clothing that blocks drone-mounted infrared cameras.

As the U.S. government draws up plans to use surveillance drones in domestic airspace, opposition to what many consider an unwarranted and significant invasion of privacy is mounting across the country, from rural Virginia to techopolis Seattle. Although officials debate anti-drone legislation at federal, state and local levels, one man is fighting back with high-tech apparel.

A New York City privacy advocate-turned-urban-guerilla fashion designer is selling garments designed to make their wearers invisible to infrared surveillance cameras, particularly those on drones. And although Adam Harvey admits that his three-item Stealth Wear line of scarves and capes is more of a political statement than a money-making venture, the science behind the fashion is quite sound.

“Fighting drones is not my full-time job, but it could be,” says Harvey, an instructor of physical computing at Manhattan’s School of Visual Arts and the creator of the CV Dazzle project, which seeks to develop makeup and hairstyles that camouflage people from face-recognition cameras and software.

Harvey’s newest medium, metalized fabric, has been around for more than 20 years. It holds in body heat that would burn bright for infrared cameras—a characteristic that could prove attractive to those who do not want unmanned aerial vehicles spying on them.

Metalized fabric
Metal is very good at absorbing and scattering infrared light, says Cheng Sun, a Northwestern University assistant professor of mechanical engineering. In that sense there is nothing exotic in how metalized fabric works—it “would strongly attenuate the [infrared] light,” he says. The metal would dissipate heat to surroundings as well, making the wearer harder to pinpoint.

To date, the fabric has primarily been used in tape and gaskets to protect electronics and communications equipment from static electricity and electromagnetic interference, according to Larry Creasy, director of technology for metalized fabric-maker Laird Technologies, based in Saint Louis.

Here’s how metalizing works, at least at Laird: Woven fabric, commonly nylon or polyester, is coated with a special catalyst—a precious metal Creasy declined to specify—that helps copper bind to the fiber. Once dry, the fabric is submerged in a copper sulfate–plating bath and dried. A nickel sulfamate bath follows to help the finished fabric withstand the elements and abrasions. The result is a flexible, breathable fabric that can be cut with ordinary tools but that protects against electromagnetic interference and masks infrared radiation, Creasy says. The process adds weight to the original fabric. An untreated square yard of nylon weighs about 42.5 grams. Treated, the same patch weighs more than 70 grams.

The fashion
Harvey’s fabric is coated with copper, nickel and silver, a combination that gives his scarves, head-and-shoulders cloak and thigh-length “burqa” a silvery and “luxurious” feel. The material blocks cell signals, as well, adding an element of risk to tweeting, texting and other mobile activities, as the wearer must break cover to communicate.

Stealth Wear is sold only via a U.K. Web site. The burqa goes for about $2,300, the “hoodie” is $481 and the scarf is $565—luxury items, but so, too, is privacy today, Harvey says.

The impetus
The high cost and limited availability are significant drawbacks—Harvey says he’s only sold one Stealth Wear item online, a scarf. But the Federal Aviation Administration (FAA) predicts 10,000 commercial drones will ply domestic airspace by 2017—almost twice the that of the U.S. Air Force’s current fleet of unmanned aircraft. The number of drones flying in the U.S. today is hard to pin down because not every company and agency that gets FAA approval to fly a drone actually puts one in the air. In fact, 1,428 private-sector and government requests have been approved since 2007, according to the FAA. A Los Angeles Times report states that 327 of those permits are still active. Meanwhile, President Obama signed a law in February 2012 that gives the FAA until September 2015 to draw up rules that dictate how law enforcement, the military and other entities may use drones in U.S. airspace.

As of October 2012, 81 law agencies, universities, an Indian tribal agency and other entities had applied to the FAA to fly drones, according to documents released by the FAA to the Electronic Freedom Frontier following a Freedom of Information Act lawsuit. Government entities as diverse as the U.S. Department of State and Otter Tail County, Minn., are among them.

Discomfort rising
Although Harvey’s anti-drone fashions are not currently flying off the shelves, he could soon find himself leading a seller’s market if recent events are any metric:

•The Charlottesville, Va., city council has passed a watered-down ordinance that asks the federal and commonwealth governments not to use drone-derived information in court. Proponents had sought to make the city drone-free (pdf).

•Virginia, Minnesota, Oregon, Montana, Arizona (pdf) and Idaho legislators are trying to at least regulate or even prohibit, drones in their skies.

•Seattle Mayor Mike McGinn returned the city’s two surveillance drones after a hostile public reception.

•A bipartisan pair of U.S. Representatives has introduced legislation to limit information-gathering by government-operated drones as well as prohibit weapons on law-enforcement and privately owned unmanned aerial vehicles.

Drone advocates defend the use of the technology as a surveillance tool. “We clearly need to do a better job of educating people about the domestic use of drones,” says Ben Gielow, government relations manager for the Association for Unmanned Vehicle Systems International. Gielow says U.S. voters must decide the acceptability of data collection from all sources, adding, “Ultimately, an unmanned aircraft is no different than gathering data from the GPS on your phone or from satellites.”

GPS does not use infrared cameras, however, and satellites are not at the center the current privacy debate brewing in Washington—factors that could make Harvey’s designs all the more fashionable.

http://www.scientificamerican.com/article.cfm?id=drone-proof-anti-infrared-apparel&page=2

sn-sleep

Hitting the wall in the middle of a busy work day is nothing unusual, and a caffeine jolt is all it takes to snap most of us back into action. But people with certain sleep disorders battle a powerful urge to doze throughout the day, even after sleeping 10 hours or more at night. For them, caffeine doesn’t touch the problem, and more potent prescription stimulants aren’t much better. Now, a study with a small group of patients suggests that their condition may have a surprising source: a naturally occurring compound that works on the brain much like the key ingredients in chill pills such as Valium and Xanax.

The condition is known as primary hypersomnia, and it differs from the better known sleep disorder narcolepsy in that patients tend to have more persistent daytime sleepiness instead of sudden “sleep attacks.” The unknown cause and lack of treatment for primary hypersomnia has long frustrated David Rye, a neurologist at Emory University in Atlanta. “A third of our patients are on disability,” he says, “and these are 20- and 30-year-old people.”

Rye and colleagues began the new study with a hunch about what was going on. Several drugs used to treat insomnia promote sleep by targeting receptors for GABA, a neurotransmitter that dampens neural activity. Rye hypothesized that his hypersomnia patients might have some unknown compound in their brains that does something similar, enhancing the activity of so-called GABAA receptors. To try to find this mystery compound, he and his colleagues performed spinal taps on 32 hypersomnia patients and collected cerebrospinal fluid (CSF), the liquid that bathes and insulates the brain and spinal cord. Then they added the patients’ CSF to cells genetically engineered to produce GABAA receptors, and looked for tiny electric currents that would indicate that the receptors had been activated.

In that first pass, nothing happened. However, when the researchers added the CSF and a bit of GABA to the cells, they saw an electrical response that was nearly twice as big as that caused by GABA alone. All of this suggests that the patients’ CSF doesn’t activate GABAA receptors directly, but it does make the receptors almost twice as sensitive to GABA, the researchers report today in Science Translational Medicine. This effect is similar to that of drugs called benzodiazepines, the active ingredients in antianxiety drugs such as Valium. It did not occur when the researchers treated the cells with CSF from people with normal sleep patterns.

Follow-up experiments suggested that the soporific compound in the patients’ CSF is a peptide or small protein, presumably made by the brain, but otherwise its identity remains a mystery.

The idea that endogenous benzodiazepinelike compounds could cause hypersomnia was proposed in the early 1990s by Elio Lugaresi, a pioneering Italian sleep clinician, says Clifford Saper, a neuroscientist at Harvard Medical School in Boston. But several of Lugaresi’s patients later turned out to be taking benzodiazepines, which undermined his argument, and the idea fell out of favor. Saper says the new work makes a “pretty strong case.”

Based on these results, Rye and his colleagues designed a pilot study with seven patients using a drug called flumazenil, which counteracts benzodiazepines and is often used to treat people who overdose on those drugs. After an injection of flumazenil, the patients improved to near-normal levels on several measures of alertness and vigilance, the researchers report. Rye says these effects lasted up to a couple hours.

In hopes of longer-lasting benefits, the researchers persuaded the pharmaceutical company Hoffmann-La Roche, which makes the drug, to donate a powdered form that can be incorporated into dissolvable tablets taken under the tongue and a cream applied to the skin. One 30-something patient has been taking these formulations for 4 years and has improved dramatically, the researchers report in the paper. She has resumed her career as an attorney, from which her hypersomnia had forced her to take a leave of absence.

The findings are “certainly provocative,” Saper says, although they’ll have to be replicated in a larger, double-blind trial to be truly convincing.

Even so, says Phyllis Zee, a neurologist at Northwestern University in Evanston, Illinois: “This gives us a new window into thinking about treatments” for primary hypersomnia. “These patients don’t respond well to stimulants,” Zee says, so a better strategy may be to inhibit the sleep-promoting effects of GABA—or as Rye puts it, releasing the parking brake instead of pressing the accelerator.

The next steps are clear, Rye says: Identify the mystery compound, figure out a faster way to detect it, and conduct a larger clinical trial to test the benefits of flumazenil. However, the researchers first need someone to fund such a study. So far, Rye says, they’ve gotten no takers.

http://news.sciencemag.org/sciencenow/2012/11/putting-themselves-to-sleep.html

interview_2412938b

Employers are more likely to hire people they fancy, researchers claim, as they find “leisure pursuits, background and self-presentation” are more important than skills.

Women in the workplace have fought a long battle to prove their skills, experience and CV are the only keys to their success.

But their efforts may have been in vain, as a study find good looks, a winning smile and a little gentle flirtation may be the key to securing a job after all.

Bosses would rather hire someone they find attractive and enjoy spending time with than the perfectly-qualified candidate, it has been claimed.

They would rather employ someone “who will be their friend or maybe even their romantic partner”, with whom they feel a “spark”, researchers have suggested.

A study, conducted by American sociologists, has found interviewers at banking, law and management consultancy firms consistently prefer applicants they “feel good around”.

More than half of employers claim attractiveness, the right social background and how candidates spend their leisure time are the most important considerations when hiring, it is claimed.

Dr Lauren Rivera, from Northwestern University in the United States, found interviewers often put their personal feelings of comfort, acceptance and excitement first.

Half of those studied ranked “cultural fit” as the most important criterion at job interview stage, meaning they were more likely to hire someone with the same “leisure pursuits, background and self-presentation” as current staff.

“Of course employers are looking for people who have the baseline of skills to effectively do the job,” she said.

“But, beyond that, employers really want people who they will bond with, who they will feel good around, who will be their friend and maybe even their romantic partner.

“As a result, employers don’t necessarily hire the most skilled candidates.”

The study, based on 120 interviews and published in the American Sociological Review, is the first investigation of its kind into whether shared culture between employers and job candidates matters.

Dr Rivera said: “It is important to note this does not mean employers are hiring unqualified people.

“But my findings demonstrate that – in many respects – employers hire in a manner more closely resembling the choice of friends or romantic partners than how one might expect employers to select new workers.

“When you look at the decision to date or marry someone what you think about is commonalities. Do you have a similar level of education? Did you go to a similar calibre school? Do you enjoy similar activities? Are you excited to talk to each other? Do you feel the spark?

“These types of things are salient at least to the employers I’ve studied.”

In studying graduate and undergraduate employment programmes, she also noted significant differences in the way different social classes approached interviews.

“Evaluators are predominately white, Ivy League-educated, upper-middle or upper class men and women who tend to have more stereotypically masculine leisure pursuits and favour extracurricular activities associated with people of their background,” she said.

“Given less affluent students are more likely to believe achievement in the classroom rather than on the field or in the concert hall matters most for future success and focus their energies accordingly, the types of cultural similarities valued in elite firms’ hiring processes has the potential to create inequalities in access to elite jobs based on parental socioeconomic status.”

http://www.telegraph.co.uk/news/newstopics/howaboutthat/9710004/Bosses-more-likely-to-hire-someone-they-fancy-study-finds.html