September 2, 2010

Evolution in Action: Lizard Moving From Eggs to Live Birth

National Geographic Daily News for September 1, 2010 reported on evolution in Australian lizzards.

Along the warm coastal lowlands of New South Wales (map), the yellow-bellied three-toed skink lays eggs to reproduce. But individuals of the same species living in the state's higher, colder mountains are almost all giving birth to live young.

Mammoth-Killer Impact Rejected

ScienceNOW for August 30, 2010 reported on a theory of an asteroid killing off mammoths.

Over the past 3 years, a loosely confederated group of researchers has argued that an asteroid or comet struck North America about 13,000 years ago, wiping out the woolly mammoth, the giant sloth, and other large animals. Experts say they have shot down most of the supposed evidence, but one finding remained: nano-scale diamond crystals that could have formed only under the extreme pressure of an impact. Now, a group of experts has dismissed this evidence as well, putting what many see as the final nail in the coffin of the mammoth-killer impact.

Evolution Rewritten, Again and Again

ScienceDaily for September 1, 2010 reported on fossiles and evolution.

This is especially true of the fossil record of human origins from their primate relatives. Even though early human fossils are immensely rare, and new discoveries make a big splash in the scientific literature and in the media, they sit randomly across the evolutionary tree of early humans. In other words, most discoveries of new fossil species simply fill in gaps in the fossil record that we already knew existed.
A World Science article is here.

Babies Born Past Term Associated With Increased Risk of Cerebral Palsy

ScienceDaily for September 1, 2010 reported on length of pregnancy and Cerebral Palsy.

Cerebral palsy (CP), the most common cause of physical disability in childhood, with limitations that persist throughout life, is characterized by nonprogressive disorders of movement and posture. "One of the strongest predictors of CP is preterm birth, with the risk of CP increasing steadily with earlier delivery. Although risk is lower among term births, about three-fourths of all infants with CP are born after 36 weeks. Within this range of term births, there are few data on the possible association of CP with gestational age," the authors write.

Infant's Gaze May Be an Early, but Subtle, Marker for Autism Risk

ScienceDaily for September 1, 2010 reported on a correlation between infrequent gazing by infants and risk of Autism.

Researchers found that, like the low risk group, the high-risk siblings exhibited typical levels of social gazing when their caregivers actively engaged them, such as pointing at the toy and expressing excitement. However, high-risk sibs spent less time looking to their caregivers and more time fixated on the non-social stimuli (toy or joystick) when the caregiver was not engaging them, which could indicate a disruption in development related to joint attention. Joint attention is often a core deficit for children with autism.

Increased Risk of Death in Men With Insomnia and a Short Sleep Duration

ScienceDaily for September 2, 2010 reported on sleep insomnia and death.

Compared to men without insomnia who slept for six hours or more, men with chronic insomnia who slept for less than six hours were four times more likely to die during the 14-year follow-up period (odds ratio = 4.33). Results were adjusted for potential confounders such as body mass index, smoking status, alcohol use, depression and obstructive sleep apnea. Further adjustments for hypertension and diabetes had little effect on the elevated mortality risk (OR = 4.00). No significant mortality risk was found in women with insomnia and a short sleep duration of less than six hours (OR = 0.36).
A National Geographic Daily News article is here.

Lower Blood Pressure May Preserve Kidney Function in Some Patients

ScienceDaily for September 2, 2010 reported on blood pressure and kidney disease.

Intensively treating hypertension in some African Americans with kidney disease by pushing blood pressure well below the current recommended goal may significantly decrease the number who lose kidney function and require dialysis, suggests a Johns Hopkins-led study publishing in the New England Journal of Medicine.

Stopping Smoking Cessation Treatments Too Soon May Reduce Odds of Success for 45 Percent of Smokers

ScienceDaily for September 2, 2010 reported on the effect of premature stopping of smoking.

Their findings published online in the journal Addiction suggest that current treatment theories that maintain any smoking after the planned target quit day predicts treatment failure need to be expanded to take into account a more dynamic quitting process. The team's analysis points to two types of successful quitters: those who quit immediately and remain abstinent through the end of treatment and those who are "delayed" in attaining abstinence but achieve success by the end of treatment.

September 1, 2010

Moderate Coffee Consumption Improves Aortic Distensibility in Hypertensive Elderly Individuals, Study Finds

ScienceDaily for September 1, 2010 reported on coffee and Aortic Distensibility.

Coffee consumption was particularly measured during the initial phase of the study because it is a deeply embedded social tradition within the Greek population, and also because of conflicting evidence of its impact on cardiovascular health. Doctor Christina Chrysohoou, the study coordinator, noted, "As far as the effect of coffee on hypertension is concerned, the pressor response to caffeine seems to be more pronounced in hypertensive or hypertension-prone subjects than in normo-tensive ones. For this reason, our study became focused on a sub-group of some 235 hypertensive subjects, and we measured the impact of daily coffee consumption using echocardiographic indices of aortic distensibility."

Diverse Diet of Veggies May Decrease Lung Cancer Risk

ScienceDaily for September 1, 2010 reported on veggies and cancer.

"Fruits and vegetables contain many different bioactive compounds, and it makes sense to assume that it is important that you not only eat the recommended amounts, but also consume a rich mix of these bioactive compounds by consuming a large variety," he said.

August 31, 2010

New Test Allows Individualized Profiles of Cigarette Smoking

ScienceDaily for August 25, 2010 reported on detection of chemicals in cigarette smoke.

A test for one of the thousands of chemicals in cigarette smoke has the potential for more accurately estimating smokers' mouth level exposure and may have applications for developing custom-tailored quitting approaches for the more than 43 million people in the United States who still smoke, and hundreds of millions elsewhere, scientists say.

Distant Star's Sound Waves Reveal Cycle Similar to the Sun's

ScienceDaily for August 27, 2010 reported on sound waves from a distant star.

In a bid to unlock longstanding mysteries of the Sun, including the impacts on Earth of its 11-year cycle, an international team of scientists has successfully probed a distant star. By monitoring the star's sound waves, the team has observed a magnetic cycle analogous to the Sun's solar cycle.

School-Based Intervention Successfully Lowers Drinking Rates in at Risk Children

ScienceDaily for August 31, 2010 reported on drinking rates of children.

The coming weeks mark the return to school for many of our youngest citizens. Sadly the satisfaction of making new friends and obtaining good test scores may be overshadowed by the prospect of substance abuse for some school-aged adolescents. The previous decade has witnessed a two-fold increase in both alcohol consumption and intoxication by adolescents age 12 to 17.

August 30, 2010

Cinnamon Extracts May Reduce Risk of Diabetes and Heart Disease, Study Suggests

The study demonstrated that the water-soluble cinnamon extract improved a number of antioxidant variables by as much as 13 to 23 percent, and improvement in antioxidant status was correlated with decreases in fasting glucose, according to Anderson.

August 29, 2010

Fluoride in Water Prevents Adult Tooth Loss, Study Suggests

ScienceDaily for August 28, 2010 reported on fluoridation of water and teeth-loss.

Pollick said that roughly 75 percent of people served by public water systems have fluoride added. The process uses small amounts of the naturally occurring mineral to increase concentrations to no more than one part per million typically.

August 28, 2010

Secondhand Smoke May Provoke Inflammatory Response in Lungs

ScienceDaily for August 27, 2010 reported on secondhand smoke.

Second-hand smoke is associated with a number of diseases and conditions, including cancer, heart disease, and emphysema. It is an irritant to lung tissue and blood vessels, but the processes through which the body reacts to second-hand smoke comprise a mystery scientists are only beginning to unravel.

Smoking Can Increase Depressive Symptoms in Teens, Study Finds

ScienceDaily for August 27, 2010 reported on smoking by teenagers and depression.

While some teenagers may puff on cigarettes to 'self-medicate' against the blues, scientists at the University of Toronto and the University of Montreal have found that smoking may actually increase depressive symptoms in some adolescents. Published in the journal Addictive Behaviors, the findings are part of the long-term Nicotine Dependence in Teens (NDIT) study based at the University of Montreal Hospital Research Centre.

Moms Who Don't Breastfeed More Likely to Develop Type 2 Diabetes, Study Finds

ScienceDaily for August 27, 2010 reported on breastfeeding and cancer.

"We have seen dramatic increases in the prevalence of type 2 diabetes over the last century," said Eleanor Bimla Schwarz, M.D., M.S., assistant professor of medicine, epidemiology, and obstetrics, gynecology and reproductive sciences at the University of Pittsburgh. "Diet and exercise are widely known to impact the risk of type 2 diabetes, but few people realize that breastfeeding also reduces mothers' risk of developing the disease later in life by decreasing maternal belly fat."