Genetic testing may not be the best way to study one's ancestry

Darkfrog submitted, created time 1 month 3 weeks (www.nature.com)

In recent years, companies providing personal genetic exams have sprung up like mushrooms. For a fee and a cheek swab, they can will identify the client's countries of ancestry, even to specific regions.

However, Charmaine Royal of the the Duke Institute for Genome Sciences has serious reservations:

"The general limitation, I'd say, of all of these tests, is that they can't pinpoint with 100% accuracy who your ancestors may or may not be. Some people are concerned that the biogeographical ancestry test reifies the notion of race

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Tracing Humanity's Path

jerry submitted, created time 7 months 2 weeks (sciencenow.sciencemag.org)

Most researchers agree that modern humans got their start in Africa and then spread throughout the world beginning about 50,000 years ago. But scientists are still working out the details of how the planet was peopled, such as who went where, and when. A new study, employing sophisticated modeling techniques, confirms the prevailing Out of Africa model but also comes up with some surprises, including evidence that the Americas' first human inhabitants arrived in multiple waves.

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U.S.-Mexico border fence may trap jaguars as well as immigrants

Darkfrog submitted, created time 11 months 2 weeks (sciencenow.sciencemag.org)

This is fascinating. I never knew that any jaguars at all lived in the United States, let alone as far northeast as North Carolina!

Now this isn't a message of doom for all jaguars everywhere, just the eleven males who've been spotted in the Southwest over the past few years. Now, while the government's decision to not implement a recovery plan technically violates the Endangered Species Act, I find that I can see their point. For so few animals, any efforts toward the conservation of jaguars would be better spent elsewhere.

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American Rice: Out of Africa

Polarity reveals intrinsic cell chirality

channel submitted, created time 1 year 7 months (www.pnas.org)

Like blood neutrophils, dHL60 cells respond to a uniform concentration of attractant by polarizing in apparently random directions. How each cell chooses its own direction is unknown. We now find that an arrow drawn from the center of the nucleus of an unpolarized cell to its centrosome strongly predicts the subsequent direction of attractant-induced polarity: Of 60 cells that polarized in response to uniform f-Met-Leu-Phe (fMLP), 42 polarized to the left of this arrow, 6 polarized to the right, and 12 polarized directly toward or away from the centrosome.

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Warming World Threatens Migratory Birds

fiona submitted, created time 1 year 7 months (hosted.ap.org)

"Disoriented by erratic weather, birds are changing migration habits and routes to adjust to warmer winters, disappearing feeding grounds and shrinking wetlands, a migration expert says."

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Lysosomal Cysteine Proteinase Cathepsin S as a Potential Target for Anti-Cancer Therapy

IQGAP1 Regulates Adult Neural Progenitors In Vivo and Vascular Endothelial Growth Factor-Triggered Neural Progenitor Migration In Vitro

badboy submitted, created time 1 year 8 months (www.jneurosci.org)

"In the germinative zone of the adult rodent brain, neural progenitors migrate into niches delimited by astrocyte processes and differentiate into neuronal precursors."

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Study Reveals Real Reason Birds Migrate

channel submitted, created time 1 year 10 months (www.livescience.com)

Why birds migrate? It’s food scarcity, not dietary preferences, that motivates birds to migrate thousands of miles back and forth between breeding and non-breeding areas each year, new research shows. No matter you are a birds or a human-being, when faced with food scarcity, you have two options, forage with other or migrate, which one would you choose first?

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Modelling the impact of migration on the HIV epidemic in South Africa.

athena submitted, created time 1 year 10 months (www.aidsonline.com)

"Migration primarily influences HIV spread by increasing high-risk sexual behaviour, rather than by connecting areas of low and high risk. Frequent return of migrants is an important risk factor when coupled with increased sexual risk behaviour. Accordingly, intervention programmes in South Africa need to target the sexual behaviour of short-term migrants specifically, even though these individuals may be more difficult to identify."

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