Archive for the ‘University of Rochester Medical Center in New York’ Category


Doctoral student Joseph Choi demonstrates a multidirectional ‘perfect paraxial’ cloak using 4 lenses.


Choi uses his hand to further demonstrate his device.


A laser shows the paths that light rays travel through the system, showing regions that can be used for cloaking an object.

Scientists at the University of Rochester have discovered a way to hide large objects from sight using inexpensive and readily available lenses.

Cloaking is the process by which an object becomes hidden from view, while everything else around the cloaked object appears undisturbed.

“A lot of people have worked on a lot of different aspects of optical cloaking for years,” John Howell, a professor of physics at the upstate New York school, said on Friday.

The so-called Rochester Cloak is not really a tangible cloak at all. Rather the device looks like equipment used by an optometrist. When an object is placed behind the layered lenses it seems to disappear.

Previous cloaking methods have been complicated, expensive, and not able to hide objects in three dimensions when viewed at varying angles, they say.

“From what, we know this is the first cloaking device that provides three-dimensional, continuously multidirectional cloaking,” said Joseph Choi, a graduate student who helped develop the method at Rochester, which is renowned for its optical research.

In their tests, the researchers have cloaked a hand, a face, and a ruler – making each object appear “invisible” while the image behind the hidden object remains in view. The implications for the discovery are endless, they say.

“I imagine this could be used to cloak a trailer on the back of a semi-truck so the driver can see directly behind him,” Choi said. “It can be used for surgery, in the military, in interior design, art.”

Howell said the Rochester Cloak, like the fictitious cloak described in the pages of the Harry Potter series, causes no distortion of the background object.

Building the device does not break the bank either. It cost Howell and Choi a little over $US1000 ($1140) in materials to create it and they believe it can be done even cheaper.

Although a patent is pending, they have released simple instructions on how to create a Rochester Cloak at home for under $US100 (114).

There is also a one-minute video about the project on YouTube.

http://www.smh.com.au/technology/sci-tech/scientists-unveil-invisibility-cloak-to-rival-harry-potters-20140927-10n1dp.html

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In a first-of-its-kind study, researchers have developed a blood test for Alzheimer’s disease that predicts with astonishing accuracy whether a healthy person will develop the disease.

Though much work still needs to be done, it is hoped the test will someday be available in doctors’ offices, since the only methods for predicting Alzheimer’s right now, such as PET scans and spinal taps, are expensive, impractical, often unreliable and sometimes risky.

“This is a potential game-changer,” said Dr. Howard Federoff, senior author of the report and a neurologist at Georgetown University Medical Center. “My level of enthusiasm is very high.”

The study was published in Nature Medicine.

In the beginning, the researchers knew they wanted to find a blood test to detect Alzheimer’s but didn’t know what specifically to look for. Should they examine patients’ DNA? Their RNA? Or should they look for the byproducts of DNA and RNA, such as fats and proteins?

They decided to start with fats, since it was the easiest and least expensive. They drew blood from hundreds of healthy people over age 70 living near Rochester, New York, and Irvine, California. Five years later, 28 of the seniors had developed Alzheimer’s disease or the mild cognitive problems that usually precede it.

Scouring more than 100 fats, or lipids, for what might set this group apart, they found that these 28 seniors had low levels of 10 particular lipids, compared with healthy seniors.

To confirm their findings, the researchers then looked at the blood of 54 other patients who had Alzheimer’s or mild cognitive impairment. This group also had low levels of the lipids.

Overall, the blood test predicted who would get Alzheimer’s or mild cognitive impairment with over 90% accuracy.

“We were surprised,” said Mark Mapstone, a neuropsychologist at the University of Rochester Medical Center and lead author of the study. “But it turns out that it appears we were looking in the right place.”

The beauty of this test, Mapstone says, is that it caught Alzheimer’s before the patient even had symptoms, suggesting that the disease process begins long before people’s memories start failing. He says that perhaps the lipid levels started decreasing at the same time as brain cells started dying.

He and his team plan to try out this test in people in their 40s and 50s. If that works, he says, that would be the “holy grail,” because then researchers could try experimental drugs and treatments in a group that’s almost sure to get the disease. That would speed research along immensely.

Plus, people could get a heads up that they were probably destined to get Alzheimer’s. Although some people might not want to know that they’re destined for a horrible disease, others might be grateful for the warning.

Federoff said he would want to know whether he was on his way to getting the disease, even though there’s nothing he could do about it. He might want to take a family trip he’d been thinking about or might want to appoint a successor at work.

“I would make sure that things that are important to me get done,” he said.

But, Federoff added, others might not want to know they were about to get a devastating disease they were powerless to stop.

“I think it’s a very personal decision,” Federoff said. “It would have to be thought through on multiple dimensions. Patients and their families would have to be counseled.”

Other research teams are looking at other possible tests for Alzheimer’s. The need for a screening test of some kind for Alzheimer’s has never been greater: A report released last week says the disease claims the lives of perhaps a half a million Americans, making it nearly as deadly as heart disease and cancer.

If any of these tests work out — and that’s still an if — it would take years to make it to doctors’ offices, since the test would need to be validated by other labs and with larger groups of people. Thee test developed by the Georgetown and Rochester researchers, for example, was used mainly in white people, and it might not work as well with other groups.

Heather Snyder, a spokeswoman for the Alzheimer’s Association, said the study was well done but much work is still needed.

“It’s an interesting paper. It’s an intriguing study. But it is very preliminary,” she said.http://www.cnn.com/2014/03/09/health/alzheimers-blood-test/index.html?hpt=hp_t2

 

SHANGHAI, CHINA—Mrs. Y’s death would have stumped many experts. A young mother and loyal wife, the rural Chinese woman showed none of the standard risk factors for suicide. She was not apparently depressed or mentally ill. Villagers said she exuded happiness and voiced few complaints. But when a neighbor publicly accused Mrs. Y of stealing eggs from her henhouse, the shame was unbearable. Mrs. Y rushed home and downed a bottle of pesticide. “A person cannot live without face,” she cried before she died. “I will die to prove that I did not steal her eggs.”

Decades of research in Western countries have positioned mental illness as an overwhelming predictor of suicide, figuring in more than 90% of such deaths. Another big risk factor is gender: Men commit suicide at much higher rates than women, by a ratio of nearly 4 to 1 in the United States, according to the U.S. Centers for Disease Control and Prevention. Other common correlates include city life and divorce. But in China, says Jie Zhang, a sociologist at the State University of New York, Buffalo State, the case of Mrs. Y is “a very typical scenario.”

Zhang oversaw interviews with Mrs. Y’s family and acquaintances while researching the prevalence of mental illness among suicide victims aged 15 to 34 in rural China. Through psychological autopsies—detailed assessments after death—Zhang and coauthors found that only 48% of 392 victims had a mental illness, they reported in the July 2010 issue of the American Journal of Psychiatry. An earlier study of Chinese suicide victims put the prevalence of mental disorders at 63%—still nowhere near as high as accepted models of suicide prevention would predict. Meanwhile, other standard risk factors simply don’t hold true, or are even reversed, in China. Chinese women commit suicide at unusually high rates; rural residents kill themselves more frequently than city dwellers do; and marriage may make a person more, rather than less, volatile.

Such differences matter because China accounts for an estimated 22% of global suicides, or roughly 200,000 deaths every year. In India, meanwhile, some 187,000 people took their own lives in 2010—twice as many as died from HIV/AIDS. By comparison, the World Health Organization (WHO) estimates that suicides in high-income countries total only 140,000 a year. Suicide rates in Japan and South Korea, however, are similar to China’s (see p. 1026), suggesting that this is a regional public health issue. And yet suicide in Asia is poorly understood. “Suicide has not gotten the attention it deserves vis-à-vis its disease burden,” says Prabhat Jha, director of the Centre for Global Health Research in Toronto, Canada.

Emerging research from developing countries like China and India is now filling that gap—and overturning prevailing notions. “The focus of the study of suicide in the West is psychiatry,” Zhang says. While mental illness remains an important correlate in Asia, he says, researchers may learn more from a victim’s family, religion, education, and personality. New findings, Zhang says, suggest that some researchers may have misread correlation as causation: In both the East and the West, “mental illness might not be the real cause of suicide.”

Distressing data

Reliable data on suicide across Asia were once maddeningly scarce. In Thailand until 2003, there was no requirement that the reported cause of death be medically validated—a flaw that rendered the country’s suicide data inaccurate. In India, suicide is a crime, which means it often goes unreported. But the Thai government now has a more accurate reporting system for mortality figures, while Indian researchers are benefiting from the Million Death Study, an effort to catalog causes of death for 1 million Indians in a 16-year survey relying on interviews with family members (Science, 15 June, p. 1372). The study has already produced a disturbing revelation about reported suicide rates. “When we compare our data with police reports, you find undercounts of at least 25% in men and 36% in women,” says Jha, the study’s lead investigator.

New insights from China are particularly instructive. Because suicide carries a stigma, the Chinese government withheld data on the topic until the late 1980s. When information finally came out, it quickly became clear that the country had a serious problem. In 1990, for example, the World Bank’s Global Burden of Disease Study estimated there were 343,000 suicides in China—or 30 per 100,000 people. The U.S. rate for the same year was 12 per 100,000.

But other reports gave different figures, prompting a debate on sources. WHO’s extrapolated total was based on data that China had reported from stations covering only 10% of the population, skewed toward urban residents. As researchers focused on the problem, they arrived at more reliable figures—but also unearthed more mysteries. In an analysis in The Lancet in 2002, a group led by Michael Phillips of Shanghai Mental Health Center and Emory University School of Medicine in Atlanta estimated that from 1995 to 1999, Chinese women killed themselves more frequently than men—by a ratio of 5 to 4. “There was originally disbelief about the very different gender ratio in China,” Phillips says, although later it was accepted.

Today, the suicide sex ratio in China is roughly 1 to 1, still a significant departure from the overall U.S. male-to-female ratio of 4 to 1. In India, the male-to-female suicide ratio is 1.5 to 1, although in the 15 to 29 age group it is close to equal. And yet, WHO estimates the global sex ratio at three men to one woman. (With colleague Cheng Hui, Phillips recently used Chinese and Indian figures to lower that estimate to 1.67 to 1.) Among young adults in India, suicide is second only to maternal mortality as a cause of death for women, according to the Million Death Survey.

In both China and India, cases like Mrs. Y’s involving no apparent mental illness are common. In India, suicide is most prevalent among teenagers and young adults—the cohort that is entering the workforce, marrying, and facing new life stresses. This contrasts with the Western pattern of high suicide rates among the middle-aged, suggesting that although “there might well be some underlying psychiatric conditions, the main drivers of [suicide in India] are probably chiefly social conditions,” Jha says. While cautioning that detailed psychological autopsies are still needed in India, he says, “it’s a reasonable assumption that many of these young folks are not mentally ill.”

Convincing researchers outside Asia may prove an uphill battle. Matthew Miller, a suicide researcher at the Harvard Injury Control Research Center in Boston, says that mental illness may be underdiagnosed in Asia for reasons that aren’t fully understood. That could throw off correlation studies. Phillips, who has worked in China for over 20 years, agrees that underdiagnosis is a problem, and that “many Western researchers still believe that we are just missing cases.” But he rejects that explanation. Even accounting for underdiagnosis, he says, the finding of a lower rate of mental illness among suicide victims has held up in multiple studies. Many Chinese suicide victims, he adds, are “most certainly severely distressed, but they don’t meet the criteria of a formal mental illness.”

Lethal weapons

Assuming that suicide risk is shaped by different factors in Asia, researchers are striving to uncover the roots. One clue may lie in the high proportion of unplanned Chinese suicides. In a 2002 survey of 306 Chinese patients who had been hospitalized for at least 6 hours following a suicide attempt, Phillips and colleagues found that 35% had contemplated suicide for less than 10 minutes—and 54% for less than 2 hours. Impulsiveness among suicide victims in Asia “tends to be higher than in the West,” says Paul Yip, director of the Hong Kong Jockey Club Centre for Suicide Research and Prevention at the University of Hong Kong and one of the authors of a recent WHO report on suicide in Asia. Although impulsive personality traits are sometimes linked to illnesses like bipolar disorder, studies in China have not uncovered full-fledged personality disorders in impulsive suicide victims.

In a tragic twist, impulsive victims in Asia tend to favor highly fatal methods. After interviewing family members and friends of 505 Chinese suicide victims, Kenneth Conner, a psychiatric researcher at the University of Rochester Medical Center in New York, and colleagues reported in 2005 that those who had ingested pesticides were more likely to have acted rashly than were those who used other methods such as hanging or drowning. Pesticides are a leading cause of suicide death in China and India, and the cause of roughly half of suicides worldwide. Pesticides may also explain Asia’s unusual suicide sex ratio, Jha says. In the West, women attempt suicide just as frequently as men do, but they tend to down sleeping pills—and often survive.

The trends in Asia point to a need for innovative prevention strategies. Zhang believes efforts should focus less on mental illness and more on “educating people to have realistic goals in life and teaching them to cope with crisis.” Front and center should be universities and rural women’s organizations, both of which already have active suicide prevention programs in China, he says. Such community-based approaches appear to have been effective in Hong Kong, Yip says. Over the past decade, the territory has rolled out programs for schoolchildren on dealing with stress and outreach groups for older adults. Its suicide rate has fallen 27% since 2003.

But resources in many Asian countries are limited. The vast majority of cities in China and India still do not have 24-hour suicide prevention hotlines. That may make what scholars call means restriction—reducing access to tools commonly used in suicide—a better goal. In Sri Lanka, pesticides once accounted for two-thirds of suicide deaths. Then in 1995, the government took steps to ban the most toxic pesticides. The suicide rate plummeted by 50% in the following decade.

The varying degrees to which mental illness and suicide correlate in East and West may ultimately be beside the point, argues Zhang, who believes a third factor may be the trigger in both regions. Strain theory, which posits that societal pressures, rather than inborn traits, contribute to crime, can help explain suicide, he believes. “Psychological strains usually precede a suicidal behavior, and they also happen before an individual becomes mentally ill.”

When a person is pulled by two or more conflicting pressures, Zhang says, as with “a girl who receives Confucian values at home and then goes to school and learns about modern values and gender equality,” she may be more prone to suicide. Other situational stresses may include a sudden crisis faced by a rural woman lacking coping mechanisms—such as the case of Mrs. Y—or an incident that forces a young man to confront a gap between his aspirations and reality. Zhang found that strain theory held up for his study subjects in rural China. He plans to probe whether it also applies to older Chinese.

Ultimately, Zhang hopes to test strain theory on Americans. The U.S. National Institutes of Health “spends millions and millions of dollars every year on treating mental illness to prevent suicide,” he says. “But no matter how much money we spend, how many psychiatrists we train, or how much work we do in psychiatric clinics, the U.S. suicide rate doesn’t decrease.” It has hovered around 10 to 12 suicides per 100,000 people since 1960.

Such research may be the tip of the iceberg when it comes to debunking long-held ideas about behavior disorders. Alcoholism is another area ripe for exploration, Cheng says: The profile of alcoholics in China contrasts sharply with that in the West. Because of social pressure to drink, Chinese alcoholics are far more likely to be working and married than American counterparts, who are often unemployed and divorced, she says. Suicide, Cheng muses, “is just another example of how environment can change behavior.”

http://www.sciencemag.org/content/338/6110/1025.full