Author Archives: Bora Zivkovic

Bright Light Therapy Eases Bipolar Depression For Some:

Bright light therapy can ease bipolar depression in some patients, according to a study published in the journal Bipolar Disorders. Researchers from the University of Pittsburgh School of Medicine’s Western Psychiatric Institute and Clinic studied nine women with bipolar disorder to examine the effects of light therapy in the morning or at midday on mood symptoms.

Insect Attack May Have Finished Off Dinosaurs:

Asteroid impacts or massive volcanic flows might have occurred around the time dinosaurs became extinct, but a new arguemet is that the mightiest creatures the world has ever known may have been brought down by a tiny, much less dramatic force — biting, disease-carrying insects.

Predator Pressures Maintain Bees’ Social Life:

The complex organisation of some insect societies is thought to have developed to such a level that these animals can no longer survive on their own. New research suggests that rather than organisational, genetic, or biological complexity defining a ‘point of no return’ for social living, pressures of predation create advantages to not living alone.

Two Explosive Evolutionary Events Shaped Early History Of Multicellular Life:

Scientists have known for some time that most major groups of complex animals appeared in the fossils record during the Cambrian Explosion, a seemingly rapid evolutionary event that occurred 542 million years ago. Now Virginia Tech paleontologists, using rigorous analytical methods, have identified another explosive evolutionary event that occurred about 33 million years earlier among macroscopic life forms unrelated to the Cambrian animals. They dubbed this earlier event the “Avalon Explosion.”

Why Do Some Animals Live Longer Than Others?:

Why do some live longer than others? Researchers from Leiden University, the Netherlands, turned to tropical African butterflies to find the answer. “The definitive answer is still not known, but our results give an interesting new insight into the evolution of lifespan,” says Jeroen Pijpe, first author of a new article.

New Model Of Competitive Speciation Unifies Insights From Earlier Work:

Under which circumstances is sympatric speciation possible? An answer to this long-standing question of evolutionary biology has turned out to be challenging. In particular, models for the evolution of assortative mating under frequency-dependent disruptive selection necessarily depend on a large number of ecological and genetic factors.

Insects’ ‘Giant Leap’ Reconstructed By Founder Of Sociobiology:

The January 2008 issue of BioScience includes an article by biologist Edward O. Wilson that argues for a new perspective on the evolution of advanced social organization in some ants, bees, and wasps (Hymenoptera).

Fresh Fossil Evidence Of Eye Forerunner Uncovered:

Ancient armoured fish fossils from Australia present some of the first definite fossil evidence of a forerunner to the human eye, a scientist from The Australian National University says.

Parents Show Bias In Sibling Rivalry, Says Study:

Most parents would hotly deny favouring one child over another but new research suggests they may have little choice in the matter.

Lack Of Deep Sleep May Increase Risk Of Type 2 Diabetes:

Suppression of slow-wave sleep in healthy young adults significantly decreases their ability to regulate blood-sugar levels and increases the risk of type 2 diabetes, report researchers at the University of Chicago Medical Center.

Giraffes And Frogs Provide More Evidence Of New Species Hidden In Plain Sight:

Two new articles provide further evidence that we have hugely underestimated the number of species with which we share our planet. Today sophisticated genetic techniques mean that superficially identical animals previously classed as members of a single species, including the frogs and giraffes in these studies, could in fact come from several distinct ‘cryptic’ species.

Violent Sex Acts Boost Insect’s Immunity System:

The long-held idea that only vertebrates have sophisticated adaptive immune systems that can protect them for life against many pathogens after being infected by them just once has been revised in recent years. It turns out that many insects also have a form of immune memory that protects them against reinvasion by a pathogen they have previously encountered. This research was discussed at a conference on Innate Immunity and the Environment.

Nurses Working Extended Shifts, Are Tired At Work And Sleep Little Likely To Drive Drowsy:

Hospital staff nurses who work extended hours, work at night, struggle to remain awake at work, or obtain less sleep are more likely to experience a drowsy driving episode, according to a study published in the December 1 issue of the journal SLEEP.

Childhood Sleep-disordered Breathing Disproportionately Affects Obese And African-Americans:

As the obesity epidemic grows in the U.S., doctors are discovering more and more far reaching health concerns for overweight children. Sleep-disordered breathing (SDB), which can include various sleep behaviors ranging in severity from snoring to obstructive sleep apnea (OSA), disproportionately affects children who are overweight and African- American, according to a new study published in the December 2007 edition of Otolaryngology — Head and Neck Surgery. Obstructive sleep apnea (OSA) can pose serious health threats, including hypertension and higher risk for cardiac disease.

Restless Legs Syndrome Doubles Risk Of Stroke And Heart Disease, Study Shows:

People with restless legs syndrome (RLS) are twice as likely to have a stroke or heart disease compared to people without RLS, and the risk is greatest in those with the most frequent and severe symptoms, according to new research.

Holidays slightly altered the publication dates at PLoS this week, so I had to wait until Wednesday to bring you my picks from PLoS Biology, PLoS Medicine and PLoS ONE. Of course, look beyond my own picks and look at all the new articles to see what you are interested in:
Recurring Ethanol Exposure Induces Disinhibited Courtship in Drosophila:

Alcohol has a strong causal relationship with sexual arousal and disinhibited sexual behavior in humans; however, the physiological support for this notion is largely lacking and thus a suitable animal model to address this issue is instrumental. We investigated the effect of ethanol on sexual behavior in Drosophila. Wild-type males typically court females but not males; however, upon daily administration of ethanol, they exhibited active intermale courtship, which represents a novel type of behavioral disinhibition. The ethanol-treated males also developed behavioral sensitization, a form of plasticity associated with addiction, since their intermale courtship activity was progressively increased with additional ethanol experience. We identified three components crucial for the ethanol-induced courtship disinhibition: the transcription factor regulating male sex behavior Fruitless, the ABC guanine/tryptophan transporter White and the neuromodulator dopamine. fruitless mutant males normally display conspicuous intermale courtship; however, their courtship activity was not enhanced under ethanol. Likewise, white males showed negligible ethanol-induced intermale courtship, which was not only reinstated but also augmented by transgenic White expression. Moreover, inhibition of dopamine neurotransmission during ethanol exposure dramatically decreased ethanol-induced intermale courtship. Chronic ethanol exposure also affected a male’s sexual behavior toward females: it enhanced sexual arousal but reduced sexual performance. These findings provide novel insights into the physiological effects of ethanol on sexual behavior and behavioral plasticity.

Using fMRI Brain Activation to Identify Cognitive States Associated with Perception of Tools and Dwellings:

Previous studies have succeeded in identifying the cognitive state corresponding to the perception of a set of depicted categories, such as tools, by analyzing the accompanying pattern of brain activity, measured with fMRI. The current research focused on identifying the cognitive state associated with a 4s viewing of an individual line drawing (1 of 10 familiar objects, 5 tools and 5 dwellings, such as a hammer or a castle). Here we demonstrate the ability to reliably (1) identify which of the 10 drawings a participant was viewing, based on that participant’s characteristic whole-brain neural activation patterns, excluding visual areas; (2) identify the category of the object with even higher accuracy, based on that participant’s activation; and (3) identify, for the first time, both individual objects and the category of the object the participant was viewing, based only on other participants’ activation patterns. The voxels important for category identification were located similarly across participants, and distributed throughout the cortex, focused in ventral temporal perceptual areas but also including more frontal association areas (and somewhat left-lateralized). These findings indicate the presence of stable, distributed, communal, and identifiable neural states corresponding to object concepts.

Recognizing Student Misconceptions through Ed’s Tools and the Biology Concept Inventory:

Over the past decade, workers in physics education research have developed effective instructional methods and materials (e.g., workshop physics [1]; lecture demonstrations [2]; tutorials in introductory physics [3]) based on research into student thinking. A Socratic process of questioning and careful analysis of responses can reveal students’ thinking on a subject area, including misconceptions, prior conceptions, and conceptual lacunae. Applying this approach to biological concepts, we have built a software system, called Ed’s Tools, to capture and analyze student responses. Both instructors and researchers can use this system to obtain a more complete and nuanced picture of student understanding, which can then serve as the foundation on which to base subsequent instruction and the construction of concept inventories. We illustrate the value of the data obtained through this analysis by showing how it helped us trace the conceptual problems that students have in two subject areas, molecular biology and evolutionary biology, to a common cause: a fundamental misunderstanding of random processes.

In the Era of Systematic Reviews, Does the Size of an Individual Trial Still Matter:

Background to the debate: Systematic reviews that combine high-quality evidence from several trials are now widely considered to be at the top of the hierarchy of clinical evidence. Given the primacy of systematic reviews–and the fact that individual clinical trials rarely provide definitive answers to a clinical research question–some commentators question whether the sample size calculation for an individual trial still matters. Others point out that small trials can still be potentially misleading.

Adult Male Chimpanzees Don’t Stray Far From The Home:

When it comes to choosing a place to live, male chimpanzees in the wild don’t stray far from home, according to a new report. The researchers found that adult male chimps out on their own tend to follow in their mother’s footsteps, spending their days in the same familiar haunts where they grew up. Male chimpanzees are generally very social, but how they use space when they are alone might be critical to their survival, the researchers said.

Solving Another Mystery Of An Amazing Water Walker:

Walking on water may seem like a miracle to humans, but it is a ho-hum for the water strider and scientists who already solved the mystery of that amazing ability. Now researchers in Korea are reporting a long-sought explanation for the water strider’s baffling ability to leap onto a liquid surface without sinking.

Innovative Model Connects Circuit Theory To Wildlife Corridors:

Scientists at Northern Arizona University and the National Center for Ecological Analysis and Synthesis have developed a model that borrows from electronic circuit theory to predict gene flow across complex landscapes . Their approach could help biologists design better wildlife corridors, which are crucial to protecting threatened plant and animal populations.

Smelly Sounds: One Person Out Of Every 1,000 Has Synesthesia:

Surprising as it may seem, there are people who can smell sounds, see smells or hear colours. One person out of every thousand has synesthesia, a psychological phenomenon in which an individual can smell a sound or hear a color. Most of these people are not aware they are synesthetes: they think the way they experience the world is normal.

Sleep Chemical Central To Effectiveness Of Deep Brain Stimulation:

A brain chemical that makes us sleepy also appears to play a central role in the success of deep brain stimulation to ease symptoms in patients with Parkinson’s disease and other brain disorders. The surprising finding is outlined in a paper published online Dec. 23 in Nature Medicine. The work shows that adenosine, a brain chemical most widely known as the cause of drowsiness, is central to the effect of deep brain stimulation, or DBS. The technique is used to treat people affected by Parkinson’s disease and who have severe tremor, and it’s also being tested in people who have severe depression or obsessive-compulsive disorder.

On Fridays, I take a look at what’s new in PLoS Neglected Tropical Diseases, Pathogens, Computational Biology and Genetics. Here are some of my picks for this week:
Neglected Diseases and Poverty in “The Other America”: The Greatest Health Disparity in the United States?:

Large numbers of the poorest Americans living in the United States are suffering from some of the same parasitic infections that affect the poor in Africa, Asia, and Latin America.

The Long and Thorny Road to Publication in Quality Journals:

Within the “Ten Simple Rules” series in PLoS Computational Biology, Dr. Bourne suggests that for younger investigators it is better to publish one paper in a quality journal rather than having multiple papers in lesser journals [1]. While this is certainly advisable, it can be very difficult. Indeed, for young scientists or, more to the point, for researchers with a short record of publications, it may be almost impossible to make their work and themselves visible to a larger scientific community via higher impact journals. A not-too-small share of “seasoned” scientists will argue without malignity that “we experienced similar or the same” and “good researchers will eventually be recognized.” What they imply is that those who continue to provide good science shall be rewarded later, i.e., their papers will eventually find a home in quality journals, thus yielding better chances that the work will have impact. And yet, a much-cited case study ([2]; cited 264 times as of November 18, 2007, according to http://isiwebofknowledge.com/) may illustrate that the road to publication and recognition can be thorny and long for younger and less-recognized scientists.

Computational Biology in Argentina:

Sebastian Bassi and colleagues from the Universidad Nacional de Quilmes, Buenos Aires, reflect on the identity of the interdisciplinary field of computational biology both generally and specifically in their country, Argentina.

A Tribute to Marcy Carlson Speer, 1959-2007:

It is with great sadness that we say goodbye to Marcy Carlson Speer, who died on August 4, 2007, at the age of 47 after a two-year battle with breast cancer. Marcy was an extremely accomplished scientist who, at the time of her death, was the director of the Duke Center for Human Genetics and chief of the Division of Medical Genetics. During her career, she published 124 articles and 16 book chapters; the topics of her scholarly scientific work ranged from gene mapping and identification to method development in genetic epidemiology and authoritative book chapters on linkage analysis. Over her scientific career, Marcy was the recipient of 24 National Institutes of Health (NIH) grants; of these, she was principal investigator of 18.