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by unurth:

who: Iemza

location: Reims, France

who: jaz

location: buenos aires, argentina

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location: San Francisco, Cali

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by Physorg:

Sex with Neanderthals and another close relative — the recently discovered Denisovans — has endowed some human gene pools with beneficial versions of immune system genes, report researchers at the Stanford University School of Medicine in an article to be published online by the journal Science at the Science Express website on August 25.

Although modern humans, Neanderthals and Denisovans share a common ancestor in Africa, the groups split into separate, distinct populations approximately 400,000 years ago. The Neanderthal lineage migrated northwestward into West Asia and Europe, and the Denisovan lineage moved northeastward into East Asia. The ancestors of modern man stayed in Africa until 65,000 years or so ago, when they expanded into Eurasia and then encountered the other human-like groups. In some cases, the rendezvous were amorous in nature.

Last year, a partial genome sequence of Neanderthals, who died out approximately 30,000 years ago, revealed that these trysts left as much as 4 percent Neanderthal DNA in the genetic blueprint of some present-day humans. Last December, the genome of another human cousin, the extinct Denisovans, made clear that up to 6 percent of some people’s genomes are Denisovan in origin.

Now, a team of researchers led by Peter Parham, PhD, professor of structural biology and of microbiology and immunology, has found that these matings had a positive effect on modern human fitness. “The cross breeding wasn’t just a random event that happened, it gave something useful to the gene pool of the modern human,” said Parham, who is senior author on the study.

The useful gift was the introduction of new variants of immune system genes called the HLA class I genes, which are critical for our body’s ability to recognize and destroy pathogens. HLA genes are some of the most variable and adaptable genes in our genome, in part because the rapid evolution of viruses demands flexibility on the part of our immune system.

“The HLA gene system, with its diversity of variants, is like a magnifying glass,” said lead author Laurent Abi-Rached, PhD, explaining that it provides a lot more detail about the history of populations than typical gene families. Abi-Rached is a research associate in the Parham lab.

Denisovans' skeleton.

Prior to the sequencing of the Neanderthal and Denisovan genomes, Parham and his group had suspected that at least one HLA variant came from archaic humans. They determined that the variant known as HLA-B*73 is rare in present-day African populations but occurs with significant frequency in West Asian populations. The ethnic distribution of HLA-B*73 and its similarity across populations suggested that it came from a relatively recent co-mingling of modern human and archaic human DNA, which most likely would have happened outside of Africa. Parham’s team wanted to discern which archaic humans were the source of the HLA-B*73 gene type. In the last year they have found the answer in the genome sequence of a recently discovered human relative, the Denisovans, whose existence first came to light in 2008 with the discovery of an unfamiliar finger bone and tooth in a cave in Siberia.

By comparing the HLA genes of the archaic humans with modern humans, the researchers were able to show that the HLA-B*73 allele likely came from cross breeding with Denisovans. Little is known about what the Denisovans looked like (the finger bone and the tooth are the only known fossils), but the genome sequence extracted from the finger bone gives insight into where they overlapped with modern humans. Gene flow from the Denisovans into modern humans has left the highest frequency of the HLA-B*73 allele in populations in West Asia, the most likely site for the fortuitous mating to have taken place.

Even in West Asian populations, the HLA-B*73 variant never represents more than 5 percent of all known variants of that gene. However, other human HLA types that arose from ancient matings are found in much greater frequencies. “Certain traits coming from these archaic humans have become the dominant form,” said Parham. For example, another HLA gene type, called HLA-A*11, is absent from African populations, but represents up to 64 percent of variants in East Asia and Oceania, with the greatest frequency in people from Papua New Guinea. “The likely interpretation was that these HLA class variants provided an advantage to modern human and so rose to high frequencies,” Parham said.

A similar scenario is seen in some HLA gene types found in the Neanderthal genome, which was also sequenced from DNA extracted from ancient bones. These gene variants are common in European and Asian populations but rare in African populations. “We are finding frequencies in Asia and Europe that are far greater than whole genome estimates of archaic DNA in modern human genomes, which is 1 to 6 percent,” said Parham. Within one class of HLA gene, the researchers estimate that Europeans owe half of their variants to interbreeding with Neanderthals and Denisovans, Asians owe up to 80 percent and Papua New Guineans, up to 95 percent.

“This is not the pattern seen genome-wide,” said Abi-Rached. “The HLA system is unique in its diversity and the strength of natural selection acting on it, but it’s possible that other gene systems, particularly the ones under similar pressure for variation, could show a similar pattern.”

Physorg

Ah, human evolution at its finest.

by Reuters:

The report, issued on Thursday by the Institute of Medicine, part of the National Academies of Sciences, is the first comprehensive report on vaccine side effects since 1994.

Fears that vaccines might cause autism or other health problems have led some parents to skip vaccinating their children, despite repeated reassurances from health authorities. The concerns have also forced costly reformulations of many vaccines.

“We looked at more than 1,000 articles evaluating the epidemiological and biological evidence about whether vaccines cause side effects,” said committee chair Ellen Wright Clayton, professor of pediatrics and law, and director of the Center for Biomedical Ethics and Society at Vanderbilt University in Nashville.

“The big take-home message is that we found only a few cases in which vaccines can cause adverse side effects, and the vast majority of those are short-term and self-limiting,” she said in a telephone interview.

The report was commissioned by the U.S. Department of Health and Human Services to help guide the Vaccine Injury Compensation Program, which provides a pool of money to take care of children who experience side effects from vaccines.

The panel looked at eight common vaccines: the combination measles-mumps-rubella (MMR), the diphtheria-tetanus-acellular pertussis (DTaP), varicella for chickenpox, influenza, hepatitis B, meningococcal, tetanus-containing vaccines, and the human papillomavirus (HPV) vaccine.

Among the side effects vaccines can cause, Clayton said most are short-lived. The panel found that the MMR vaccine can cause seizures in people who develop high fevers after getting the vaccine, but these pass quickly. “They are scary to be sure, but they do not cause any long-term harm and they are not a sign the child will get epilepsy,” Clayton said.

Six vaccines — MMR, varicella, influenza, hepatitis B, meningococcal, and the tetanus-containing vaccines — also can trigger anaphylaxis, an allergic reaction that appears shortly after injection. But Clayton said this can be addressed with the requirement by doctors to have patients remain in the waiting room for 15 minutes after their shot to make sure they do not have an allergic reaction.

She said the report should help people who are seeking to file claims for vaccine side effects, but it should also reassure many people that vaccines are largely safe.

Reuters

Finally, a well-funded study to debunk the anti-vaccine crusaders. This case is officially closed.

by Medical Xpress:

In their original paper, Nicholas Christakis of Harvard and James Fowler of the University of California, San Diego claimed to have provided evidence of a “three-degrees-of-influence rule of social contagion” within networks such as families and friend groups where obesity characteristics could be transmitted socially. They went on to include other personal characteristics — divorce, smoking and even loneliness — in their social contagion theory, and their research took off in the media, accompanied by publication of their 2009 book “Connected” and appearances on the shows “Good Morning America” and “The Colbert Report.” Christakis built on his research to form a company, MedNetworks, which proposes to help pharmaceutical companies get doctors to prescribe more of their drugs.

When Lyons reviewed the evidence, he found not only a lack of statistical significance in the findings, but also that both the researchers and the reviewers did not realize that the statistical procedures Christakis and Fowler had used were inapplicable. Their methods, Lyons found, were fundamentally flawed.

Lyons is not arguing that social contagion, or peer pressure, doesn’t exist: He agrees that people influence each other. Rather, Lyons shows that the research did not support the paper’s contention that one could measure how much people influence one another, whether the people are one, two or three steps out in the network of family or friends. 

“The problem is that their methods were deeply flawed from bottom to top: The models used to analyze the sparse data contradict the data and the conclusions, and the method used to estimate the dubious models does not apply,” he said. “The statistical significance tests that were applied to the questionable estimates do not show the differences they have proposed.”

In the past 90 days, The New York Times , The Boston Globe , Slate and the Irish Medical Times , among numerous other media, have written about Lyons’ critique. The Strategy Research Initiative, a group that includes scholars from Harvard, Duke, Dartmouth, Columbia and Yale, now lists Lyons’ research as an “Exemplary Paper” in the area of Theoretical Critiques of Empirical Work.

Among those who have since joined Lyons in questioning the results are Columbia University professor of statistics Andrew Gelman and Oxford University professor of statistics in social sciences Tom Snijders. Other critiques have come from Hans Noel, Georgetown University, and Brendan Nyhan, Dartmouth, and from Carnegie Mellon University statistics professors Cosma Shalizi and Andrew Thomas.

“I tried to get high-profile journals interested in my critique, telling them about the wide interest the topic had, but to no avail,” he recalled. “I don’t think I got any special treatment; these were simply their policies. In fact, that’s one of my main points: From flawed statistics in research to poor-quality review to difficulty in publishing critiques, this is all too common. And that’s why I think these are important points, ones that I emphasize to my students when I teach statistics. They need to be wary.”

Medical Xpress

Plain and simple, correlation is not causation. 

It should be noted that the obesity researchers are/were working with pharmaceutical companies in increasing weight loss dosage for individuals.

by Time Magazine:

Indians hold cutouts of Hazare during a protest in support of his fight against corruption in Ahmadabad, August 17, 2011. AP

After 10 days of subsisting on nothing but water, the Indian anti-corruption crusader Anna Hazare relented Thursday evening, agreeing to end his fast on the condition that the Indian government would promise, in writing, to include the main points of his agenda in its final draft of a new anti-corruption bill. “I have sent a message to the prime minister,” Hazare told thousands of supports in New Delhi on Thursday evening. 

Prime Minister Manmohan Singh seemed to have gotten the message. He met with Rahul Gandhi, acting head of the Congress Party, on Friday morning. Shortly after his meeting with the Prime Minister, Gandhi stepped into the debate, ending a conspicuous silence during this week-long crisis of confidence in his party’s government. He thanked Hazare for bringing the issue of corruption to national attention but then questioned whether one law would make a difference. 

Until now, the government has appeared confused about whether to take a hard line against Hazare for disrupting the parliamentary process or try to co-opt his demands, adopting them as their own. At one point, a Congress Party spokesman accused Hazare himself of being corrupt. The government also held a series of meetings with Hazare’s group this week and an all-party meeting — none of which came to any conclusion. Meanwhile, the government has watched the 74-year-old’s failing health and growing public support with alarm. On Thursday, Singh made an emotional appeal to Hazare to call off his fast. 

Hazare surrounded by doctors and supporters while fasting. Google Images.

Rahul Gandhi’s entry onto the stage in this drama offers a little clarity. Few Congress Party politicians are willing to openly contradict Gandhi, scion of the Nehru-Gandhi family and a likely future prime minister. Gandhi has now made his position public, so it’s likely that the government will follow his lead: praise Hazare and empathize with anti-corruption sentiment but insist on the primacy of Parliament. Instead of a completely independent Lokpal, Gandhi proposed an office that would be “accountable to Parliament like the Election Commission” and suggested other reforms, like government funding of elections and reforms to end tax evasion.

Time Magazine

Recently, Indian police officers after arrested four politicians accusing them of abuse of power and other corruption charges. The fast has boosted the morale of India’s poor to protest against the heavily corrupted government. 

From the Middle East to the Far East, the fight to end corrupted governments lives on.

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by OpenClassroom:

OpenClassroom

Take advantage of the free Ivy league courses, while you can folks.

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