Yearly Archives: 2007

Is there a new Tuberculosis vaccine in the making?
Another movie is being made about Ivory-Bill woodpeckers.
A new astronomical explanation for the cycles of extinctions.

Sleep-Wake Controls Identified: Implications For Coma Patients And Those Under Anesthesia:

How do we wake up? How do we shift from restful sleep to dreaming? Researchers at the University of Arkansas for Medical Sciences (UAMS) have discovered a new brain mechanism that just might explain how we do that. This new mechanism also may help us understand how certain anesthetics put us to sleep and how certain stimulants wake us up. In their first published study on this topic, researchers in the UAMS Center for Translational Neuroscience found that some neurons in the reticular activating system, a region of the brain that controls sleep-wake states, are electrically coupled.

Infant Hearing Test Results May Predict Sudden Infant Death Syndrome:

One of the greatest medical mysteries of our time has taken a leap forward in medical understanding with new study results announced by Dr. Daniel D. Rubens of Children’s Hospital and Regional Medical Center in Seattle. Rubens’ study published in July, 2007 in Early Human Development found all babies in a Rhode Island study group who died of Sudden Infant Death Syndrome (SIDS) universally shared the same distinctive difference in their newborn hearing test results for the right inner ear, when compared to infants who did not have SIDS.

Low Literacy Equals Early Death Sentence:

Not being able to read doesn’t just make it harder to navigate each day. Low literacy impairs people’s ability to obtain critical information about their health and can dramatically shorten their lives.

Obesity Is ‘Socially Contagious’:

Are your friends making you fat? Or keeping you slender? According to new research from Harvard and the University of California, San Diego, the short answer on both counts is “yes.” Appearing in the July 26 issue of the New England Journal of Medicine, a study coauthored by Nicholas Christakis of Harvard Medical School and James Fowler of UC San Diego suggests that obesity is “socially contagious,” spreading from person to person in a social network.

Hearing Colors And Seeing Sounds: How Real Is Synesthesia?:

In the psychological phenomenon known as “synesthesia,” individuals’ sensory systems are a bit more intertwined than usual. Some people, for example, report seeing colors when musical notes are played. One of the most common forms is grapheme-color synesthesia, in which letters or numbers (collectively called “graphemes”) are highlighted with particular colors. Although synesthesia has been well documented, it is unknown whether these experiences, reported as vivid and realistic, are actually being perceived or if they are a byproduct of some other psychological mechanism such as memory.

Context Affects Opinion About Novel Energy Sources:

Opinions people have about innovations are influenced by the context in which they form their opinion. For example, opinions about a novel energy source like biomass are influenced by thoughts regarding other energy sources. The less knowledge, interest or time people have, the stronger this effect. Sustainable energy options must therefore be promoted in the right context says Dutch researcher Wouter van den Hoogen.

Prenatal Stress Keeps Infants, Toddlers Up At Night, Study Says:

Anxious or depressed mothers-to-be are at increased risk of having children who will experience sleep problems in infancy and toddlerhood, finds a study that published this month in Early Human Development.

Resisting Peer Pressure: New Findings Shed Light On Adolescent Decision-making:

The capacity to resist peer pressure in early adolescence may depend on the strength of connections between certain areas of the brain, according to a study carried out by University of Nottingham researchers.

Humanitarians, You’re Not As Generous As You Think:

A new study out of Carnegie Mellon University reveals that people who regard themselves as humanitarians are even more likely than others to base donations to the poor on whether they believe poverty is a result of bad luck or bad choices.

Anger, Depression Much Higher Among Jailed Teen Girls Than Boys:

A new study reveals that girls in juvenile detention centers face surprisingly different psychological issues than average teen girls and, in some ways, more severe problems than incarcerated boys.

Learning A Second Language: Is It All In Your Head?:

Think you haven’t got the aptitude to learn a foreign language? New research led by Northwestern University neuroscientists suggests that the problem, quite literally, could be in your head. … Based on the size of Heschl’s Gyrus (HG), a brain structure that typically accounts for no more than 0.2 percent of entire brain volume, the researchers found they could predict — even before exposing study participants to an invented language — which participants would be more successful in learning 18 words in the “pseudo” language.

Why Do People Love Horror Movies? They Enjoy Being Scared:

A bedrock assumption in theories that explain and predict human behavior is people’s motivation to pursue pleasure and avoid pain. How can this be reconciled with the decision to engage in experiences known to elicit negative feelings, such as horror movies” It certainly seems counterintuitive that so many people would voluntarily immerse themselves in almost two hours of fear, disgust and terror. “Why do people pay for this?” “How is this enjoyable?”

How To Manipulate Perceptual Focus In Advertisements:

In a new study from the August issue of the Journal of Consumer Research, researchers from Northwestern University demonstrate how advertisements can be manipulated to cause overemphasis of a particular feature and increase the likelihood that a certain product is chosen. Their finding runs contrary to economic models, which assume that choices are based on stable preferences and should not be influenced by the inclusion of inferior options.

College Science Success Linked To Math And Same-subject Preparation:

Researchers at Harvard University and the University of Virginia have found that high school coursework in one of the sciences generally does not predict better college performance in other scientific disciplines. But there’s one notable exception: Students with the most rigorous high school preparation in mathematics perform significantly better in college courses in biology, chemistry, and physics.

Relational Uncertainty Sparks Negativity In Marital Conversations:

Spouses who experience doubts about their marriage, even weak doubts, make pessimistic judgments about their partner’s behavior in conversation. That’s the conclusion of researchers who have conducted the first study to examine the link between relational uncertainty and conversation within marriage.

Why We May Feel Guilty:

Guilt plays a vital role in the regulation of social behavior. That worried feeling in our gut often serves as the impetus for our stab at redemption. However, psychologists have trouble agreeing on the function of this complex emotion.

Electronic Eggs Used To Help Save Threatened African Bird:

This is an important summer for kori bustards at the Smithsonian’s National Zoo. Four chicks of this threatened African bird have hatched in June and July. Along with the bumper crop of baby birds is a bumper crop of new information for scientists working to preserve the species, thanks to an electronic egg that transmits real-time incubation data from the nest.

Reef Corals: How To Structure A Complex Body Plan:

Phenotypic flexibility enables multicellular organisms to adjust morphologies to variable environmental challenges. Such plastic variations are also documented in reef corals. Coral colonies are made of multiple genetically identical physiologically integrated modules (polyps).

Fossils Older Than Dinosaurs Reveal Pattern Of Early Animal Evolution On Earth:

The abundant diversity of characteristics within species likely helped fuel the proliferation and evolution of an odd-looking creature that emerged from an unprecedented explosion of life on Earth more than 500 million years ago. University of Chicago paleontologist Mark Webster reports this finding in the July 27 issue of the journal Science.

Curiosities: Why Do Flowers Smell, And Why Do Plants Smell, Too?:

The luscious aroma of flowers attracts lovers, and the biological role of that smell is similar: to attract pollinators. “Plants need to attract insects, bats and hummingbirds to transfer the pollen and create fertile seeds,” says Hugh Iltis, professor emeritus of botany at UW-Madison.

Mystery Of Mammalian Ears Solved:

A 30-year scientific debate over how specialized cells in the inner ear amplify sound in mammals appears to have been settled more in favor of bouncing cell bodies rather than vibrating, hair-like cilia, according to investigators at St. Jude Children’s Research Hospital.

In A Bug-eat-bug World, Researchers Use Unique Chinese Wasp To Battle Soybean Aphids:

The days of soybean aphids feasting on soybean fields may be numbered, thanks to a unique import from China. University of Minnesota scientists are field testing a beneficial insect, a stingless wasp from China also known as Binodoxys communis, that kills soybean aphids. A successful field test would be a major breakthrough in controlling a damaging crop pest. The U of M received permission from the federal government to conduct this test and is the leading institution in the testing.

Surprising New Species Of Light-harvesting Bacterium Discovered In Yellowstone:

In the hot springs of Yellowstone National Park, a team of researchers has discovered a novel bacterium that transforms light into chemical energy. The researchers also discovered that the new genus and species belongs to a new phylum, Acidobacteria — only the third time in the past 100 years that a new bacterial phylum has been added to the list of those with chlorophyll-producing members, of which there are now only six.

Humboldt Squid On The Move:

Over the last five years, large, predatory Humboldt squid have moved north from equatorial waters and invaded the sea off Central California, where they may be decimating populations of Pacific hake, an important commercial fish.

There are 31 new papers published on PLoS ONE this week, and here are some of my first, quick picks of titles that got my attention, but you should go and see them all, then rate, annotate and comment on them:
Stable Isotope Ratios in Hair and Teeth Reflect Biologic Rhythms by Otto Appenzeller, Clifford Qualls, Franca Barbic, Raffaello Furlan and Alberto Porta:

Biologic rhythms give insight into normal physiology and disease. They can be used as biomarkers for neuronal degenerations. We present a diverse data set to show that hair and teeth contain an extended record of biologic rhythms, and that analysis of these tissues could yield signals of neurodegenerations. We examined hair from mummified humans from South America, extinct mammals and modern animals and people, both healthy and diseased, and teeth of hominins. We also monitored heart-rate variability, a measure of a biologic rhythm, in some living subjects and analyzed it using power spectra. The samples were examined to determine variations in stable isotope ratios along the length of the hair and across growth-lines of the enamel in teeth. We found recurring circa-annual periods of slow and fast rhythms in hydrogen isotope ratios in hair and carbon and oxygen isotope ratios in teeth. The power spectra contained slow and fast frequency power, matching, in terms of normalized frequency, the spectra of heart rate variability found in our living subjects. Analysis of the power spectra of hydrogen isotope ratios in hair from a patient with neurodegeneration revealed the same spectral features seen in the patient’s heart-rate variability. Our study shows that spectral analysis of stable isotope ratios in readily available tissues such as hair could become a powerful diagnostic tool when effective treatments and neuroprotective drugs for neurodegenerative diseases become available. It also suggests that similar analyses of archaeological specimens could give insight into the physiology of ancient people and animals.

The Perils of Picky Eating: Dietary Breadth Is Related to Extinction Risk in Insectivorous Bats by Justin G. Boyles and Jonathan J. Storm:

Animals inhabiting small and specialized habitats tend to be more threatened by extinction than more generalist relatives. This study examined the diets of 44 bat species and found that those of conservation concern were also more likely to have a specialized food source. This correlation was independent of other known extinction risks, making dietary specialization an important factor for evaluating threats to insectivorous bats.

Vision and Foraging in Cormorants: More like Herons than Hawks? by Craig R. White, Norman Day, Patrick J. Butler and Graham R. Martin:

We measured the aquatic visual acuity of great cormorants under a range of viewing conditions (illuminance, target contrast, viewing distance) and found it to be unexpectedly poor. Cormorant visual acuity under a range of viewing conditions is in fact comparable to unaided humans under water, and very inferior to that of aerial predators. We present a prey detectability model based upon the known acuity of cormorants at different illuminances, target contrasts and viewing distances. This shows that cormorants are able to detect individual prey only at close range (less than 1 m). We conclude that cormorants are not the aquatic equivalent of hawks. Their efficient hunting involves the use of specialised foraging techniques which employ brief short-distance pursuit and/or rapid neck extension to capture prey that is visually detected or flushed only at short range. This technique appears to be driven proximately by the cormorant’s limited visual capacities, and is analogous to the foraging techniques employed by herons.

Population Bottlenecks Promote Cooperation in Bacterial Biofilms by Michael A. Brockhurst:

Population bottlenecks are assumed to play a key role in the maintenance of social traits in microbes. Ecological parameters such as colonisation or disturbances can favour cooperation through causing population bottlenecks that enhance genetic structuring (relatedness). However, the size of the population bottleneck is likely to play a crucial role in determining the success of cooperation. Relatedness is likely to increase with decreasing bottleneck size thus favouring the evolution of cooperation. I used an experimental evolution approach to test this prediction with biofilm formation by the bacterium Pseudomonas fluorescens as the cooperative trait. Replicate populations were exposed to disturbance events every four days under one of six population bottleneck treatments (from 103 to 108 bacterial cells). In line with predictions, the frequency of evolved cheats within the populations increased with increasing bottleneck size. This result highlights the importance of ecologically mediated population bottlenecks in the maintenance of social traits in microbes.

The US Anti-Prostitution Pledge: First Amendment Challenges and Public Health Priorities by Nicole Franck Masenior and Chris Beyrer:

In order for an HIV organization to receive funding from the United States, grantees must explicitly oppose prostitution.

Male Circumcision for Prevention of HIV Transmission: What the New Data Mean for HIV Prevention in the United States by Patrick S. Sullivan, Peter H. Kilmarx, Thomas A. Peterman, Allan W. Taylor, Allyn K. Nakashima, Mary L. Kamb, Lee Warner and Timothy D. Mastro:

Recent clinical trials in Africa found that male circumcision reduces the risk of acquiring HIV from heterosexual sex–what are the implications of these studies for the United States?

A Student-Led Campaign to Help Tackle Neglected Tropical Diseases by Sandeep P. Kishore and Prabhjot S. Dhadialla:

The authors propose that innovative student-led campaigns to address neglected diseases can and do make a practical difference.

Plasticity of Central Chemoreceptors: Effect of Bilateral Carotid Body Resection on Central CO2 Sensitivity by Albert Dahan, Diederik Nieuwenhuijs and Luc Teppema:

Bilateral carotid body resection in three individuals led to reduced sensitivity of central chemoreceptors to CO2, followed by a gradual return, providing evidence of central plasticity within the ventilatory control system.

Patient Adherence to Tuberculosis Treatment: A Systematic Review of Qualitative Research by Salla A. Munro, Simon A. Lewin, Helen J. Smith, Mark E. Engel, Atle Fretheim and Jimmy Volmink:

From a systematic review of qualitative research, Munro and coauthors found that a range of interacting factors can lead to patients deciding not to complete their course of tuberculosis treatment.

Did Pterosaurs Feed by Skimming? Physical Modelling and Anatomical Evaluation of an Unusual Feeding Method by Stuart Humphries, Richard H. C. Bonser, Mark P. Witton and David M. Martill:

Just because a component of an extinct animal resembles that of a living one does not necessarily imply that both were used for the same task. The lifestyles of pterosaurs, long-extinct flying reptiles that soared ancient skies above the dinosaurs, have long been the subject of debate among palaeontologists. Similarities between the skulls of living birds (black skimmers) that feed by skimming the water surface with their lower bill to catch small fish, and those of some pterosaurs have been used to argue that these ancient reptiles also fed in this way. We have addressed this question by measuring the drag experienced by model bird bills and pterosaur jaws and estimating how the energetic cost of feeding in this way would affect their ability to fly. Interestingly, we found that the costs of flight while feeding are considerably higher for black skimmers than previously thought, and that feeding in this way would be excessively costly for the majority of pterosaurs. We also examined pterosaur skulls for specialised skimming adaptations like those seen in modern skimmers, but found that pterosaurs have few suitable adaptations for this lifestyle. Our results counter the idea that some pterosaurs commonly used skimming as a foraging method and illustrate the pitfalls involved in extrapolating from living to extinct forms using only their morphology.

Proboscidean Mitogenomics: Chronology and Mode of Elephant Evolution Using Mastodon as Outgroup by Nadin Rohland, Anna-Sapfo Malaspinas, Joshua L. Pollack, Montgomery Slatkin, Paul Matheus and Michael Hofreiter:

We determined the complete mitochondrial genome of the mastodon (Mammut americanum), a recently extinct relative of the living elephants that diverged about 26 million years ago. We obtained the sequence from a tooth dated to 50,000-130,000 years ago, increasing the specimen age for which such palaeogenomic analyses have been done by almost a complete glacial cycle. Using this sequence, together with mitochondrial genome sequences from two African elephants, two Asian elephants, and two woolly mammoths (all of which have been previously sequenced), we show that mammoths are more closely related to Asian than to African elephants. Moreover, we used a calibration point lying outside the Elephantidae radiation (elephants and mammoths), which enabled us to estimate accurately the time of divergence of African elephants from Asian elephants and mammoths (about 7.6 million years ago) and the time of divergence between mammoths and Asian elephants (about 6.7 million years ago). These dates are strikingly similar to the divergence time for humans, chimpanzees, and gorillas, and raise the possibility that the speciation of mammoth and elephants and of humans and African great apes had a common cause. Despite the similarity in divergence times, the substitution rate within primates is more than twice as high as in proboscideans.

Paleontologists Study A Remarkably Well-preserved Baby Siberian Mammoth:

University of Michigan paleontologist Daniel Fisher just returned from Siberia where he spent a week as part of a six-member international team that examined the frozen, nearly intact remains of a 4-month-old female woolly mammoth.

Steroids, Not Songs, Spur Growth Of Brain Regions In Sparrows:

Neuroscientists are attempting to understand if structural changes in the brain are related to sensory experience or the performance of learned behavior, and now University of Washington researchers have found evidence that one species of songbird apparently has something in common with a few baseball sluggers. Both rely on steroids, birds to increase the size of song production areas of their brain and some players, apparently, to knock a fastball out of the park.

Feeding Habits Of Flying Reptiles Uncovered:

Scientists at the University of Sheffield, collaborating with colleagues at the Universities of Portsmouth and Reading, have taken a step back in time and provided a new insight into the lifestyle of a prehistoric flying reptile.

High-flying Honkers Have Superhuman Power:

They may seem deceptively innocuous mixed in with other waterfowl, but bar-headed geese can do with ease what most elite high altitude athletes can’t. Now a UBC zoologist is learning how. Native to South and Central Asia, bar-headed geese, named for the dark stripes on the backs of their heads, are often bred in captivity as domestic garden birds. In the wild, they migrate annually between India and the Tibetan plateau in China, flying over the world’s highest mountains on their way.

Mothers Invest More In Reproduction When Their Mates Are Attractive:

Animals in nature can behave according to basic rules of economics, such as investing in agreement with their expected payoff. A French team of behavioural ecologists demonstrated that, in the Peafowl, females paired with attractive males invested more resources in their eggs than females paired with unattractive males. They laid larger eggs and deposited more testosterone in egg yolk, potentially offering a better prospective to their offspring.

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