ScienceDaily: Top Science News

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• Fossilized human feces from 14th century contain antibiotic resistance genes
• Trigger found for most common form of intellectual disability, autism
• 10,000 years on the Bering Land Bridge: Ancestors of Native Americans paused en route from Asia
• Bisphenol A (BPA) at very low levels can adversely affect developing organs in primates
• Prenatal Nicotine Exposure May Lead to ADHD in Future Generations
• Ancient 'great leap forward' for life in the open ocean: Cyanobacteria sheds light on how complex life evolved on earth
• Study uncovers why autism is more common in males
• Big thaw projected for Antarctic sea ice: Ross Sea will reverse current trend, be largely ice free in summer by 2100
• Closest, brightest supernova in decades is also a little weird
• Why dark chocolate is good for your heart
• Father's age tied to higher rates of psychiatric, academic problems in kids
• Watching how the brain works with new live imaging

Fossilized human feces from 14th century contain antibiotic resistance genes Posted: 27 Feb 2014 01:45 PM PST A team of French investigators has discovered viruses containing genes for antibiotic resistance in a fossilized fecal sample from 14th century Belgium, long before antibiotics were used in medicine.

Trigger found for most common form of intellectual disability, autism Posted: 27 Feb 2014 11:26 AM PST The most common genetic form of mental retardation and autism occurs because of a mechanism that shuts off the gene associated with the disease, new research concludes. The findings also show that a drug that blocks this silencing mechanism can prevent fragile X syndrome -- suggesting similar therapy is possible for 20 other diseases that range from mental retardation to multisystem failure. Fragile X syndrome occurs mostly in boys, causing intellectual disability as well as telltale physical, behavioral and emotional traits.

10,000 years on the Bering Land Bridge: Ancestors of Native Americans paused en route from Asia Posted: 27 Feb 2014 11:18 AM PST Genetic and environmental evidence indicates that after the ancestors of Native Americans left Asia, they spent 10,000 years on a land bridge that once linked Siberia and Alaska. Archaeological evidence is lacking because it drowned when sea levels rose.

Bisphenol A (BPA) at very low levels can adversely affect developing organs in primates Posted: 27 Feb 2014 10:48 AM PST Bisphenol A is a chemical that is used in a wide variety of consumer products and exhibits hormone-like properties. Fetuses, infants, children or adults exposed to the chemical have been shown to exhibit numerous abnormalities, including cancer, as well as reproductive, immune and brain-behavior problems. Now, researchers have determined that daily exposure to very low concentrations of Bisphenol A by pregnant females also can cause fetal abnormalities in primates.

Prenatal Nicotine Exposure May Lead to ADHD in Future Generations Posted: 27 Feb 2014 10:47 AM PST Prenatal exposure to nicotine could manifest as attention deficit hyperactivity disorder in children born a generation later, according to a new study. Researchers have found evidence that ADHD associated with nicotine can be passed across generations. In other words, your child's ADHD might be an environmentally induced health condition inherited from your grandmother, who may have smoked cigarettes during pregnancy a long time ago. And the fact that you never smoked may be irrelevant for your child's ADHD.

Ancient 'great leap forward' for life in the open ocean: Cyanobacteria sheds light on how complex life evolved on earth Posted: 27 Feb 2014 09:55 AM PST Plankton in the Earth's oceans received a huge boost when microorganisms capable of creating soluble nitrogen 'fertilizer' directly from the atmosphere diversified and spread throughout the open ocean. This event occurred at around 800 million years ago and it changed forever how carbon was cycled in the ocean.

Study uncovers why autism is more common in males Posted: 27 Feb 2014 09:52 AM PST Males are at greater risk for neurodevelopmental disorders, such as autism spectrum disorder, than females, but the underlying reasons have been unclear. A large cohort study provides compelling evidence in support of the 'female protective model,' which proposes that females require more extreme genetic mutations than do males to push them over the diagnostic threshold for neurodevelopmental disorders. Researchers found that females diagnosed with a neurodevelopmental disorder or ASD had a greater number of harmful CNVs than did males diagnosed with the same disorder. Moreover, females diagnosed with ASD had a greater number of harmful SNVs than did males with ASD. These findings suggest that the female brain requires more extreme genetic alterations than does the male brain to produce symptoms of ASD or neurodevelopmental disorders.

Big thaw projected for Antarctic sea ice: Ross Sea will reverse current trend, be largely ice free in summer by 2100 Posted: 27 Feb 2014 08:55 AM PST A new modeling study suggests that a recent observed increase in summer sea-ice cover in Antarctica's Ross Sea is likely short-lived, with the area projected to lose more than half its summer sea ice by 2050 and more than three quarters by 2100. These changes will significantly impact marine life in what is one of the world's most productive and unspoiled marine ecosystems.

Closest, brightest supernova in decades is also a little weird Posted: 27 Feb 2014 06:24 AM PST The closest and brightest supernova in decades, SN 2014J, brightens faster than expected for Type Ia supernovae, the exploding stars used to measure cosmic distances, according to astronomers. Another recent supernova also brightened faster than expected, suggesting that there is unsuspected new physics going on inside these exploding stars. The finding may also help physicists improve their use of these supernovae to measure cosmic distance.

Why dark chocolate is good for your heart Posted: 27 Feb 2014 06:21 AM PST It might seem too good to be true, but dark chocolate is good for you and scientists now know why. Dark chocolate helps restore flexibility to arteries while also preventing white blood cells from sticking to the walls of blood vessels. Both arterial stiffness and white blood cell adhesion are known factors that play a significant role in atherosclerosis. What's more, the scientists also found that increasing the flavanol content of dark chocolate did not change this effect.

Father's age tied to higher rates of psychiatric, academic problems in kids Posted: 26 Feb 2014 01:53 PM PST Advancing paternal age can lead to higher rates of psychiatric and academic problems in offspring than previously estimated. Compared to a children born to a 24-year-old father, children born to a 45-year-old father are 3.5 times more likely to have autism, 13 times more likely to have ADHD, twice as likely to have psychotic disorders and 25 times more likely to have bipolar disorder.

Watching how the brain works with new live imaging Posted: 24 Feb 2014 09:42 AM PST For the first time, a group of scientists has been able to observe intact interactions between proteins, directly in the brain of a live animal. The new live imaging approach will allow scientists to visualize the interactions of proteins in the brain of an animal, along different points throughout its development, explains the lead author, who likens protein interactions to the way organisms associate with each other. Previous methods required chemical or physical treatments that most likely disturb or even kill the cells. That made it impossible to study the protein interactions in their natural environment.

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