Friday, February 12, 2016
Researchers have found that despite the complexity of the US population, individuals know their ancestral origins, and that self-reported ethnicity and race is a reliable indicator of genetic ancestry
In one genetic study, 98.7% turned out on their DNA test to be primarily what they self-identified as and among those who identified as non-Hispanic white, 427 out of 430 had their self-identifications confirmed by the genome analysis as of European ancestry.
Thursday, February 11, 2016
The first study to look at dementia risk in a population representing the diversity of the United States finds dementia incidence to be highest in African Americans and lowest in Asian Americans
The rate of occurrence of dementia in African Americans was found to be 65% higher than Asian Americans. The scientists compared dementia incidence across six racial and ethnic groups – Whites, Asian-Americans, Latinos, African Americans, American Indians/Alaskan Natives, and Pacific Islanders. "Most research on disparities in dementia includes only one to two racial and ethnic groups, for example only Whites and African Americans," said study first author Elizabeth Rose Mayeda, Ph.D., Postdoctoral Fellow at University of California, San Francisco in the Department of Epidemiology and Biostatistics. "Our study is the only work that compares dementia for these six racial and ethnic groups representing the aging demographic of the United States in a single study population. It is also the first study to look at incidence of dementia in Pacific Islanders and American Indians." The researchers found that dementia incidence over the 14-year study period ranged from an average annual rate of 26.6 cases of dementia per 1,000 people for African-Americans, and 22.2 cases per 1,000 people for American Indians/Alaskan Natives, to 15.2 cases per 1,000 people for Asian-Americans. In between were Latinos and Pacific Islanders with an average annual rate of 19.6 cases per 1,000 people, and whites with 19.3 per 1,000. Using the observed dementia incidence rates and a widely accepted method of calculating a person's lifetime risk for developing a disease, the researchers estimated the percentage of individuals free of dementia before age 65 in each racial and ethnic group who can expect to be diagnosed with dementia over the next 25 years. The projections were 38% of African Americans, 35% of American Indians/Alaskan Natives, 32% of Latinos, 25% of Pacific Islanders, 30% of Whites, and 28% of Asian Americans.
Saturday, February 6, 2016
An Iraqi migrant raped a 10-year-old boy at a swimming pool in Vienna and told police that it was a "sexual emergency" because he hadn't had sex in months
A 10-year-old boy was so brutally raped by an Iraqi migrant in a swimming pool cubicle that he had to be hospitalized for his injuries. A lifeguard immediately called an ambulance after the boy went to him in floods of tears, while the Iraqi was entertaining himself by repeatedly jumping off the three-meter diving board. Police arrested him on the spot at the pool in Vienna, and during an interrogation, he told them that it was a "sexual emergency" as he had not had sex in four months. The migrant, who had entered the country through the Balkans on September 5, 2015 official records show, said that he could not help himself as he had an "excess sexual energy".
Thursday, February 4, 2016
DNA evidence lifted from the ancient bones and teeth of people who lived in Europe from the Late Pleistocene to the early Holocene - spanning almost 30,000 years of European prehistory - has offered some surprises
Perhaps most notably, the evidence shows a major shift in the population around 14,500 years ago, during a period of severe climatic instability. "We uncovered a completely unknown chapter of human history: a major population turnover in Europe at the end of the last Ice Age," says leading author Johannes Krause of the Max Planck Institute for the Science of Human History in Germany. The researchers pieced this missing history together by reconstructing the mitochondrial genomes of 35 hunter-gatherer individuals who lived in Italy, Germany, Belgium, France, the Czech Republic, and Romania from 35,000 to 7,000 years ago. Mitochondria are organelles within cells that carry their own DNA and can be used to infer patterns of maternal ancestry. "There has been a real lack of genetic data from this time period, so consequently we knew very little about the population structure or dynamics of the first modern humans in Europe," Krause says. The new data show that the mitochondrial DNA of three individuals who lived in present-day Belgium and France before the coldest period in the last Ice Age - the Last Glacial Maximum - belonged to haplogroup M. This is remarkable because the M haplogroup is effectively absent in modern Europeans but is extremely common in modern Asian, Australasian, and Native American populations. The absence of the M haplogroup and its presence in other parts of the world had previously led to the argument that non-African people dispersed on multiple occasions to spread across Eurasia and Australasia. The researchers say that the discovery of this maternal lineage in Europe in the ancient past now suggests instead that all non-Africans dispersed rapidly from a single population, at a time they place around 50,000 years ago. Then, at some later stage, the M haplogroup was apparently lost from Europe. "When the Last Glacial Maximum began around 25,000 years ago, hunter-gatherer populations retreated south to a number of putative refugia, and the consequent genetic bottleneck probably resulted in the loss of this haplogroup," explains first author of the study Cosimo Posth of Germany's University of Tübingen. The researchers say that their biggest surprise, however, was evidence of a major turnover of the population in Europe around 14,500 years ago, as the climate began to warm. "Our model suggests that during this period of climatic upheaval, the descendants of the hunter-gatherers who survived through the Last Glacial Maximum were largely replaced by a population from another source," says Adam Powell, another senior author at the Max Planck Institute for the Science of Human History. The researchers say that the next step is to construct a more comprehensive picture of the past by analyzing the complete genomes of these ancient individuals along with additional specimens representing more times and places.