Author Archives: Bora Zivkovic

A Roadmap for Migrating Neurons:

Politicians, pundits, and even your best friends occasionally do things that make you wonder how their brains are wired. The next time you have that thought, consider consulting a developmental neuroscientist: they work every day to understand the processes that wire up everyone’sbrains. It’s a mind-boggling job, because as an embryo develops, the connections within its brain ramify, becoming ever more complex. For example, consider the neural connections in the mammalian cerebellum. This distinctive structure is responsible for coordinating sensory and motor signals to produce fine motor control. This must be a complicated job–the cerebellum contains about half of the brain’s neurons.

Ethical Implications of Modifying Lethal Injection Protocols:

Lethal injection for execution has largely replaced other execution methods, in part due to the appearance of a peaceful death; however, available evidence indicates that some inmates actually suffer extreme pain. This has triggered legal challenges against lethal injection on the grounds that it violates the United States’ constitutional prohibition against cruel and unusual punishment. Some jurisdictions collect comprehensive data on executions and outcomes, and some have modified their lethal injection protocols. Recently, jurists and lethal injection advisory panels have recommended specific changes to be instituted for future executions. Such use of biomedical inquiry to evaluate, modify, and “improve” protocols resembles human experimentation and should be scrutinized against accepted norms for ethical conduct of research, particularly given the vulnerable nature of the prisoner population. Although the regulations governing prisoner research vary by jurisdiction, the ethical framework for the modification of lethal injection protocols should be made clear prior to further investigation into how to “improve the process.”

Gene Banks Pay Big Dividends to Agriculture, the Environment, and Human Welfare:

Nearly a century after the pioneering American apple tree purveyor Johnny Appleseed traveled from town to town planting nurseries in the Midwestern United States, Frans Nicholas Meijer left his Netherlands home to pursue a similar vocation as an “agricultural explorer” for the US Department of Agriculture. Over the course of his career, Meijer, who changed his name to Frank Meyer after reaching the New World, helped introduce over 2,500 foreign plants from Europe, Russia, and China, including the lemon that would bear his name. Starting with his first expedition for Asian plants in 1905, Meyer would encounter isolation, physical discomfort, disease, robbers, and revolutionaries in his quest to collect useful plants.

How Might Cocaine Interfere with Brain Development?:

Women addicted to cocaine often continue drug use through pregnancy, despite risks to the fetuses they are carrying. Multiple studies have attempted to identify the effects of cocaine and other commonly abused drugs on fetal brain development and behavior in clinical populations. The attribution of risk to specific drugs remains challenging, however, because women addicted to cocaine often use other illegal drugs as well as alcohol and tobacco. Moreover, they tend to have poor nutrition, low levels of prenatal care, and other problems that confound analysis.

Sheep’s Sex Determined By Diet Prior To Pregnancy:

Maternal diet influences the chances of having male or female offspring. New research has demonstrated that ewes fed a diet enriched with polyunsaturated fats for one month prior to conception have a significantly higher chance of giving birth to male offspring.

Fossilized Burrows 245 Million Years Old Suggest Lizard-like Creatures In Antarctica:

For the first time paleontologists have found fossilized burrows of tetrapods — any land vertebrates with four legs or leglike appendages — in Antarctica dating from the Early Triassic epoch, about 245 million years ago.

Caribbean Monk Seal Gone Extinct From Human Causes, NOAA Confirms:

After a five year review, NOAA’s Fisheries Service has determined that the Caribbean monk seal, which has not been seen for more than 50 years, has gone extinct — the first type of seal to go extinct from human causes.

Complex Synapses Drove Brain Evolution:

One of the great scientific challenges is to understand the design principles and origins of the human brain. New research has shed light on the evolutionary origins of the brain and how it evolved into the remarkably complex structure found in humans.

Scientific Information Largely Ignored When Forming Opinions About Stem Cell Research:

When forming attitudes about embryonic stem cell research, people are influenced by a number of things. But understanding science plays a negligible role for many people.

Plastic Brain Outsmarts Experts: Training Can Increase Fluid Intelligence, Once Thought To Be Fixed At Birth:

Can human beings rev up their intelligence quotients, or are they stuck with IQs set by their genes at birth? Until recently, nature seemed to be the clear winner over nurture.

Film Content, Editing, And Directing Style Affect Brain Activity, Neuroscientists Show:

Using advanced functional imaging methods, New York University neuroscientists have found that certain motion pictures can exert considerable control over brain activity. Moreover, the impact of films varies according to movie content, editing, and directing style. Because the study, which appears in Projections: The Journal for Movies and Mind, offers a quantitative neuroscientific assessment of the impact of different styles of filmmaking on viewers’ brains, it may serve as a valuable method for the film industry to better assess its products and offer a new method for exploring how the brain works.

Maternal Depression, Breastfeeding And A Lower Socioeconomic Status Can Affect Infants’ Sleep:

Maternal depression during pregnancy, breastfeeding and a lower socioeconomic status are all associated with less infant sleep duration in the first six months of life, according to a research abstract that will be presented on June 9 at SLEEP 2008, the 22nd Annual Meeting of the Associated Professional Sleep Societies (APSS).

Scientists Decipher The Neurological Basis Of Timely Movement:

Contrary to what one might imagine, the way in which each of us interacts with the world is not a simple matter of seeing (or touching, or smelling) and then reacting. Even the best baseball hitter eyeing a fastball does not swing at what he sees. The neurons and neural connections that make up our sensory systems are far too slow for this to work. “Everything we sense is a little bit in the past,” says Richard A. Andersen of the California Institute of Technology, who has now uncovered the trick the brain uses to get around this puzzling problem.

Persistent Man-made Chemical Pollutants Found In Deep-sea Octopods And Squids:

New evidence that chemical contaminants are finding their way into the deep-sea food web has been found in deep-sea squids and octopods, including the strange-looking “vampire squid”. These species are food for deep-diving toothed whales and other predators.

The Cormorant: ‘Black Plague’ Or An Example Of Successful Species Conservation?:

Europe requires a common management strategy for cormorants in order to reconcile nature conservation and fishing interests. An effective regulation of cormorant populations can only work at the European level, researchers from the Helmholtz Centre for Environmental Research (UFZ) write in the scientific journal Environmental Conservation. Furthermore, they suggest a five-step action plan, which would start with a consensus on the real numbers of animals and end in an international management plan.

New Catfish Species Named For Museum Mail Supervisor:

He’s not well known like President Bush and musician Neil Young, but Philadelphian Frank Gallagher now has something in common with them: He has a new species named after him.

Climate Change Hastens Extinction In Madagascar’s Reptiles And Amphibians:

New research from the American Museum of Natural History provides the first detailed study showing that global warming forces species to move up tropical mountains as their habitats shift upward. Christopher Raxworthy, Associate Curator in the Department of Herpetology, predicts that at least three species of amphibians and reptiles found in Madagascar’s mountainous north could go extinct between 2050 and 2100 because of habitat loss associated with rising global temperatures. These species, currently moving upslope to compensate for habitat loss at lower and warmer altitudes, will eventually have no place to move to.

Toxic Algal Blooms May Cause Seizures In California Sea Lions:

Scientists, reporting in the current issue of the online journal Marine Drugs, state that an increase of epileptic seizures and behavioral abnormalities in California sea lions can result from low-dose exposure to domoic acid as a fetus. The findings follow an analysis earlier this year led by Frances Gulland of the California Marine Mammal Center that showed this brain disturbance to be a newly recognized chronic disease.

Keeping Beer Fresher:

Scientists in Venezuela are reporting an advance in the centuries-old effort to preserve the fresh taste that beer drinkers value more than any other characteristic of that popular beverage.

Futuristic Linkage Of Animals And Electronics:

The same Global Positioning System (GPS) technology used to track vehicles is now being used to track cows.

Brown Argus Butterfly Sees Positive Effects Of Climate Change:

Global warming is generally thought to have a negative affect on the habitats of many animals and plants. Not for the Brown Argus butterfly, however. This insect seems to be bucking the trend and expanding its numbers quicker and more effectively, according to new research.

How To Construct A ‘Firefly’ Worm: Measuring Metabolism Of Entire Organism In Real Time:

For the first time, research describing a new modified luminescent worm allows scientists to measure – in real time – the metabolism of an entire living organism. The key behind this capacity relies in the fact that the luminescence is produced using the animal’s available energy, which reflects its metabolism that, as such, can be extrapolated from measuring the emitted light.

Fish 380 Million Years Old Found With Unborn Embryo:

In 2005, Museum Victoria’s expedition to the Gogo fossil sites in north Western Australia, led by Dr John Long, made a swag of spectacular fossil discoveries, including that of a complete fish, Gogonasus, showing unexpected features similar to early land animals.

Admiring Celebrities Can Help Improve Self-esteem:

A new study appearing in Personal Relationships shows how “connections” to celebrities, i.e. parasocial relationships, can allow people with low-self esteem to view themselves more positively.

Teenagers Attending College Less Likely To Engage In Risky Sexual Behavior:

Adolescents attending college six months after completing high school are significantly less likely to engage in risky sexual behavior than those who do not go to college, according to the first study to directly compare the two groups.

Spider Silk Can Be Stretchy Like Springs Or Like Rubber:

Spider silks are incredibly stretchy, but are they stretchy like elastic or springs? The answer lies in their amino acid content. Spider silks are made from proteins, and biologists have just discovered that the secret lies in the silk protein’s amino acid content. Spider silks with high proline contents behave like elastic rubber bands, while spider silks with low proline content behave like stretchy springs.

Scientists Uncover How Plant Roots Respond To Physical Forces Such As Gravity, Pressure, Or Touch:

Researchers at Washington University in St. Louis are the first to identify two proteins responsible for mechanosensitive ion channel activities in plant roots. Scientists have long known that plant cells respond to physical forces. Until now, however, the proteins controlling the ion channel response remained a mystery.

Human Viruses Appear To Be Making Wild Chimpanzees Sick:

After studying chimpanzees in the wilds of Tanzania’s Mahale Mountains National Park for the past year as part of a National Science Foundation (NSF) grant, Virginia Tech researcher Dr. Taranjit Kaur and her team have produced powerful scientific evidence that chimpanzees are becoming sick from viral infectious diseases they have likely contracted from humans.

Humans Have Ten Times More Bacteria Than Human Cells: How Do Microbial Communities Affect Human Health?:

The number of bacteria living within the body of the average healthy adult human are estimated to outnumber human cells 10 to 1. Changes in these microbial communities may be responsible for digestive disorders, skin diseases, gum disease and even obesity. Despite their vital imporance in human health and disease, these communities residing within us remain largely unstudied and a concerted research effort needs to be made to better understand them, say researchers June 3 at the 108th General Meeting of the American Society for Microbiology in Boston.

Unravelling The Mystery Of The Kitty Litter Parasite In Marine Mammals:

Researchers at California Polytechnic State University have discovered what may be a clue to the mystery of why marine mammals around the world are succumbing to a parasite that is typically only associated with cats. The key may just be the lowly anchovy, according to research presented today at the 108th General Meeting of the American Society for Microbiology in Boston.

New Way To Think About Earth’s First Cells:

A team of researchers at Harvard University have modeled in the laboratory a primitive cell, or protocell, that is capable of building, copying and containing DNA.

Estrogen Applied To Human Penis Could Block Spread Of HIV, Study Suggests:

In a world first, a University of Melbourne study has shown that topical oestrogen could help prevent HIV infection by blocking entry of the virus into the human penis.

This is funny – I start reading interesting stuff, really stuff that I find catchy regardless of where I work….and it’s all from PLoS ONE! We rock! The journal that some people regard as a repository for “boring, incremental stuff” is publishing all the most exciting papers around….just see these:
Transgenic Plants Don’t Hurt Beneficial Bugs, Entomologists Find:

Genetically modified (GM) plants that use Bt (Bacillus thuringiensis), a common soil bacterium, to kill pests won’t harm the pests’ natural enemies, according to new research by Cornell entomologists.

Honeybee Dance Breaks Down Cultural Barrier:

Asian and European honeybees can learn to understand one another’s dance languages despite having evolved different forms of communication, an international research team has shown for the first time.

Memory In Honeybees: What The Right And Left Antenna Tell The Left And Right Brain:

It is widely known that the right and left hemispheres of the brain perform different tasks. Lesions to the left hemisphere typically bring impairments in language production and comprehension, while lesions to the right hemisphere give rise to deficits in the visual-spatial perception, such as the inability to recognize familiar faces.

New Zealand Bird Outwits Alien Predators:

New research led by Dr Melanie Massaro and Dr Jim Briskie at the University of Canterbury, which found that the New Zealand bellbird is capable of changing its nesting behaviour to protect itself from predators, could be good news for island birds around the world at risk of extinction.

Parasitoid Turns Its Host Into A Bodyguard:

There are many examples of parasites that induce spectacular changes in the behaviour of their host. Flukes, for example, are thought to induce ants, their intermediate host, to move up onto blades of grass during the night and early morning. There, they firmly attach themselves to the substrate with their mandibles, and are thus consumed by grazing sheep, the fluke’s final host. In contrast, uninfected ants return to their nests during the night and the cooler parts of the day. As another example, terrestrial insects parasitized by hairworms commit suicide by jumping into water, where the adult worms reproduce.

Mammalian Neurogenesis Breaks Into The Most Static Brain Region:

Fifteen years ago, the discovery of adult neurogenesis (the production of new neurons) in the highly static, non-renewable mammalian brain was a breakthrough in neuroscience. Most emphasis was put on the possibility to figure out new strategies for brain repair against the threath of neurodegenerative diseases. Yet, unlike lower vetebrates, which are characterized by widespread postnatal neurogenesis, neurogenic sites in mammals are highly restricted within two very small regions. Hence, the fact that protracted neurogenesis in mammals is an exception rather than the rule slowes down hopes for generalized brain repair.

Substance In Red Wine, Resveratrol, Found To Keep Hearts Young:

How, scientists wonder, do the French get away with a clean bill of heart health despite a diet loaded with saturated fats? The answer to the so-called “French paradox” may be found in red wine. More specifically, it may reside in small doses of resveratrol, a natural constituent of grapes, pomegranates, red wine and other foods, according to a new study by an international team of researchers.

There are 56 new articles published in PLoS ONE a few minutes ago. Please comment, rate and send trackbacks. Here are some of my personal favourites of the week:
East Learns from West: Asiatic Honeybees Can Understand Dance Language of European Honeybees:

The honeybee waggle dance, through which foragers advertise the existence and location of a food source to their hive mates, is acknowledged as the only known form of symbolic communication in an invertebrate. However, the suggestion, that different species of honeybee might possess distinct ‘dialects’ of the waggle dance, remains controversial. Furthermore, it remains unclear whether different species of honeybee can learn from and communicate with each other. This study reports experiments using a mixed-species colony that is composed of the Asiatic bee Apis cerana cerana (Acc), and the European bee Apis mellifera ligustica (Aml). Using video recordings made at an observation hive, we first confirm that Acc and Aml have significantly different dance dialects, even when made to forage in identical environments. When reared in the same colony, these two species are able to communicate with each other: Acc foragers could decode the dances of Aml to successfully locate an indicated food source. We believe that this is the first report of successful symbolic communication between two honeybee species; our study hints at the possibility of social learning between the two honeybee species, and at the existence of a learning component in the honeybee dance language.

From Antenna to Antenna: Lateral Shift of Olfactory Memory Recall by Honeybees:

Honeybees, Apis mellifera, readily learn to associate odours with sugar rewards and we show here that recall of the olfactory memory, as demonstrated by the bee extending its proboscis when presented with the trained odour, involves first the right and then the left antenna. At 1-2 hour after training using both antennae, recall is possible mainly when the bee uses its right antenna but by 6 hours after training a lateral shift has occurred and the memory can now be recalled mainly when the left antenna is in use. Long-term memory one day after training is also accessed mainly via the left antenna. This time-dependent shift from right to left antenna is also seen as side biases in responding to odour presented to the bee’s left or right side. Hence, not only are the cellular events of memory formation similar in bees and vertebrate species but also the lateralized networks involved may be similar. These findings therefore seem to call for remarkable parallel evolution and suggest that the proper functioning of memory formation in a bilateral animal, either vertebrate or invertebrate, requires lateralization of processing.

Introduced Mammalian Predators Induce Behavioural Changes in Parental Care in an Endemic New Zealand Bird:

The introduction of predatory mammals to oceanic islands has led to the extinction of many endemic birds. Although introduced predators should favour changes that reduce predation risk in surviving bird species, the ability of island birds to respond to such novel changes remains unstudied. We tested whether novel predation risk imposed by introduced mammalian predators has altered the parental behaviour of the endemic New Zealand bellbird (Anthornis melanura). We examined parental behaviour of bellbirds at three woodland sites in New Zealand that differed in predation risk: 1) a mainland site with exotic predators present (high predation risk), 2) a mainland site with exotic predators experimentally removed (low risk recently) and, 3) an off-shore island where exotic predators were never introduced (low risk always). We also compared parental behaviour of bellbirds with two closely related Tasmanian honeyeaters (Phylidonyris spp.) that evolved with native nest predators (high risk always). Increased nest predation risk has been postulated to favour reduced parental activity, and we tested whether island bellbirds responded to variation in predation risk. We found that females spent more time on the nest per incubating bout with increased risk of predation, a strategy that minimised activity at the nest during incubation. Parental activity during the nestling period, measured as number of feeding visits/hr, also decreased with increasing nest predation risk across sites, and was lowest among the honeyeaters in Tasmania that evolved with native predators. These results demonstrate that some island birds are able to respond to increased risk of predation by novel predators in ways that appear adaptive. We suggest that conservation efforts may be more effective if they take advantage of the ability of island birds to respond to novel predators, especially when the elimination of exotic predators is not possible.

Parasitoid Increases Survival of Its Pupae by Inducing Hosts to Fight Predators:

Many true parasites and parasitoids modify the behaviour of their host, and these changes are thought to be to the benefit of the parasites. However, field tests of this hypothesis are scarce, and it is often unclear whether the host or the parasite profits from the behavioural changes, or even if parasitism is a cause or consequence of the behaviour. We show that braconid parasitoids (Glyptapanteles sp.) induce their caterpillar host (Thyrinteina leucocerae) to behave as a bodyguard of the parasitoid pupae. After parasitoid larvae exit from the host to pupate, the host stops feeding, remains close to the pupae, knocks off predators with violent head-swings, and dies before reaching adulthood. Unparasitized caterpillars do not show these behaviours. In the field, the presence of bodyguard hosts resulted in a two-fold reduction in mortality of parasitoid pupae. Hence, the behaviour appears to be parasitoid-induced and confers benefits exclusively to the parasitoid.

Visiting Sick People: Is It Really Detrimental to Our Health?:

Intuitively, keeping ones distance from a source of infection would appear to be the best way to limit the occurrence of disease. However, this overlooks the importance of repeated infections in maintaining efficient immune defenses. When acquired immunity has partly waned, re-exposure to the pathogenic agent may lead to mild disease that boosts the immune system. This prevents the total loss of immunity that would lead to classical disease in cases of re-infection. Here, using a mathematical model, we show that avoiding the pathogenic agent is detrimental in some situations, e.g. for pathogens that are highly transmissible, are not excessively lethal and that induce rapidly waning immunity. Reducing exposure to pathogenic agents is among the objectives of most, if not all, public health measures. A better understanding of the factors influencing the severity of a disease is required before applying measures that reduce the circulation of pathogenic agents.

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Evolution Of An Imprinted Domain In Mammals:

The normal human genome contains 46 chromosomes: 23 from the mother and 23 from the father. Thus, you have two copies of every gene (excluding some irregularity in the pair of sex chromosomes). In general, which parent contributes a chromosome has no effect on the expression of the genes found on it. Exceptions to this rule are caused by “genomic imprinting”–modification of DNA, which means that gene expression is influenced by which parent the gene came from. A new paper investigates the evolution of genomic imprinting in a specific region of the mammalian genome. The work, by Anne Ferguson-Smith and colleagues in the UK and Australia, shows that different regions became imprinted at different times during mammalian evolution.

Sad Children Out-perform Happy Children In Attention-to-detail Tasks:

Psychologists at the University of Virginia and the University of Plymouth (United Kingdom) have conducted experimental research that contrasts with the belief that happy children are the best learners. The findings show that where attention to detail is required, happy children may be at a disadvantage.

Bilateral Cochlear Implants: A Case When Two Are Definitely Superior To One:

A study of cochlear implant patients seen by Indiana University School of Medicine physicians is the first research to show evidence that cochlear implants in both ears significantly improves quality of life in patients with profound hearing loss and that the cost of the second implant is offset by its benefits.

Bikini-clad Women Make Men Impatient:

Images of sexy women tend to whet men’s sexual appetite. But stimulating new research in the Journal of Consumer Research says there’s more than meets the eye. A recent study shows that men who watched sexy videos or handled lingerie sought immediate gratification–even when they were making decisions about money, soda, and candy.

Strong Evidence For A Genetic Marker For Nearsightedness:

Research by Gu Zhu, M.D., and colleagues supports the theory that the refractive errors known as nearsightedness and farsightedness are primarily inherited. The group also identified the probable location—on the long arm of chromosome 5—of genes that help determine axial length, a key factor in these refractive errors. Axial length is a specific measurement from the front to back of the eye; this distance is longer than normal when a person is nearsighted and shorter than normal in a farsighted person.

Reforestation Using Exotic Plants Can Disturb Fertility Of Tropical Soils:

In many regions of the world, the impact of human activity on the environment intensified considerably over the past century. The high world population growth rate and the expansion of areas given over to crop production associated with climatic changes (longer periods of drought, irregular rainfall patterns) induced by global warming, have contributed to the acceleration of desertification.

The ‘Other’ Neglected Diseases in Global Public Health: Surgical Conditions in Sub-Saharan Africa:

Currently in sub-Saharan Africa, most patients with surgical problems that are routinely treatable in high-income countries never reach a health facility, or are treated at a facility with inadequate human or physical resources. These conditions lead to premature death or physical disability with a significant economic burden. Meanwhile, the last decade has seen the emergence of numerous “neglected tropical disease” (NTD) initiatives in global public health. As surgeons working with clinicians in sub-Saharan Africa, the momentum for NTDs causes us to ask: Shouldn’t surgical conditions also be considered “neglected”?
This article compares NTDs and surgical conditions in sub-Saharan Africa, considering their estimated burden and the cost-effectiveness of treatment, the scope of these conditions and associated global health disparities, and the effect of donor priorities on provision of surgical services. Lessons from NTD initiatives are analyzed among possible solutions to improving access to surgical services in sub-Saharan Africa.

The Ticket to Transport:

Cell nuclei are like gated communities–quite selective about who gets in. And understandably so, because if the wrong proteins showed up at the wrong time and place, the consequences could be disastrous. The standard procedure for moving large molecules that cannot diffuse from the cytoplasm into the nucleus is to use the transport proteins known as karyopherins as escorts. How do karyopherins know whether their cargo is a protein that ought to get in? By their ability to bind with recognition sites on the cargo: no recognition, no passage. The best known example is the canonical or classical nuclear localization signal (cNLS)–a specific sequence that, when added to a protein, drives its nuclear localization. But more recently, a new class of NLSs has been identified, known as a proline-tyrosine nuclear localization signal (PY-NLS). This new signal is recognized specifically by the highly conserved transporter molecule Karyopherinβ2.

Feasibility Of Preventing Malaria Parasite From Becoming Sexually Mature Demonstrated:

Researchers have demonstrated the possibility of preventing the human malaria parasite, Plasmodium falciparum, which is responsible for more than a million malaria deaths a year, from becoming sexually mature.

New Barn Swallow Study Reveals Image Makes The Bird:

In the world of birds, where fancy can be as fleeting as flight, the color of the bird apparently has a profound effect on more than just its image. A new study of barn swallows reveals it also affects the bird’s physiology.

Toad Research Could Leapfrog To New Muscle Model:

A toad sits at a pond’s edge eyeing a cricket on a blade of grass. In the blink of an eye, the toad snares the insect with its tongue. This deceptively simple, remarkably fast feeding action offers a new look at how muscles work.

Kew Gardens Provides Climate For Agricultural Change:

A device to help some of the most impoverished farmers in Africa maximise their crop yields is being tested at London’s Kew Gardens.

Factors That Make Bacteria More Modular Detailed:

Many bacteria break their metabolic processes into chunks. That may be logically tidy, but it’s often metabolically inefficient. Researchers have now figured out the factors that tend to make bacteria more modular.

A Great Lakes Mystery: The Case Of The Disappearing Species:

Throughout the overlooked depths of Lake Michigan and other Great Lakes, a small but important animal is rapidly disappearing.