Author Archives: Bora Zivkovic

In A Technical Tour De Force, Scientists Take A Global View Of The Epigenome:

A collaboration between researchers at the Salk Institute for Biological Studies and the University of California at Los Angeles captured the genome-wide DNA methylation pattern of the plant Arabidopsis thaliana – the “laboratory rat” of the plant world – in one big sweep.
“In a single experiment we recapitulated 20 years worth of anecdotal findings and then some,” says senior author Joseph Ecker, Ph.D., a professor in the Salk Institute’s Plant Biology Laboratory. “Previously, only a hand full of plant genes were known to be regulated by methylation. In addition to those, we found hundreds of others.”

Feelings Matter Less To Teenagers, Neuroscientist Says:

Teenagers take less account than adults of people’s feelings and, often, even fail to think about their own, according to a UCL neuroscientist. The results, presented at the BA Festival of Science today, show that teenagers hardly use the area of the brain that is involved in thinking about other people’s emotions and thoughts, when considering a course of action.
Many areas of the brain alter dramatically during adolescence. One area in development well beyond the teenage years is the medial prefrontal cortex, a large region at the front of the brain associated with higher-level thinking, empathy, guilt and understanding other people’s motivations. Scientists have now found that, when making decisions about what action to take, the medial prefrontal cortex is under-used by teenagers. Instead, a posterior area of the brain, involved in perceiving and imagining actions, takes over.
———————snip———————
While children start to think about other people’s mental states at around age five, this new data shows that the neural basis of this ability continues to develop and mature well past early childhood.
A second piece of research presented at the festival shows that teenagers are also less adept at taking someone else’s perspective and deciding how they would feel in another person’s shoes.
———————snip———————
“Whatever the reasons, it is clear that teenagers are dealing with, not only massive hormonal shifts, but also substantial neural changes. These changes do not happen gradually and steadily between the ages of 0–18. They come on in great spurts and puberty is one of the most dramatic developmental stages.”

Fast-freeze Snapshot Yields New Picture Of Nerve-muscle Junction:

When nerve cells excite muscle fibers to flex, getting synaptic proteins and components into the right place can mean the difference between feats of strength or lapses of drowsy lethargy.
Several proteins that have been shown to be major players in synaptic transmission have now been studied using a flash-freeze physical-fixation technique that reveals new details of their location and function in neuromuscular synapses. The technique was used with tiny, one-millimeter-long nematode worms, a lab animal widely studied by neuroscientists.

Global Changes Alter The Timing Of Plant Growth, Scientists Say:

Different plant species mature at different times. Scientists studying plant communities in natural habitats call this phenomenon “complementarity.” It allows species to co-exist because it reduces overlap in the time period when species compete for limited resources. Now, in a study posted online the week of Sept. 4 in Proceedings of the National Academy of Sciences, ecologists working at Stanford’s Jasper Ridge Biological Preserve report evidence that climate change may al ter this delicate balance.

Mother Deer Cannot Recognize The Calls Of Their Own Offspring But Sheep And Reindeer Can:

In a new study from the American Naturalist, researchers from the University of Zurich studied vocal communication between fallow deer mothers and their offspring. They found that only adult females have individually distinctive calls, meaning that fawns are able to distinguish their mother’s calls from those of other females, but mothers are not able to distinguish between the calls of their own offspring and other fawns. This is in contrast to pre vious studies and provides a novel insight into parent-offspring recognition mechanisms.

Good Times Ahead For Dinosaur Hunters, According To Dinosaur Census:

The golden age of dinosaur discovery is yet upon us, according to Peter Dodson at the University of Pennsylvania. Dodson revises his groundbreaking 1990 census on the diversity of discoverable dinosaurs upward by 50 percent, offering a brighter outlook about the number of dinosaurs waiting to be found. His findings also add evidence that dinosaur populations were stable, and not on the decline, in the time shortly before their extinction 65 million years ago.

Designer Babies: What Would You Do For A ‘Healthy’ Baby?:

The well-educated are significantly more open to the idea of “designing” babies than the poorly educated, according to a new study by psychologists at the University of East Anglia.

New Generation Of Super Microscopes Poised For Scientific Use:

Super-high resolution optical microscopes, with powers that seemed physically impossible a decade ago, are poised to open a new era in imaging in molecular biology, according to a report scheduled for the Sept. 4 issue of Chemical & Engineering News.

Proteins Necessary For Brain Development Found To Be Critical For Long-term Memory:

A type of protein crucial for the growth of brain cells during development appears to be equally important for the formation of long-term memories, according to researchers at UC Irvine. The findings could lead to a better understanding of, and treatments for, cognitive decline associated with normal aging and diseases such as Alzheimer’s.

Eating Protein Boosts Hormone That Staves Off Hunger:

The amount of a hunger-fighting hormone can be increased by eating a higher protein diet, researchers report in the September issue of the journal Cell Metabolism, published by Cell Press. The hormone, known as peptide YY (PYY), was earlier found by the researchers to reduce food intake by a third in both normal-weight and obese people when given by injection.

Edible Coatings: The Packaging Of The Future?:

One of the most popular alternatives in the last few years is the edible coating — a transparent film that covers the food item and acts as a barrier to humidity and oxygen. Moreover, these films can be used as a host for additives in the conservation of the properties of the product or simply in order to improve its appearance.

Anticipation Plays A Powerful Role In Human Memory, Brain Study Finds:

Psychologists have long known that memories of disturbing emotional events — such as an act of violence or the unexpected death of a loved one — are more vivid and deeply imprinted in the brain than mundane recollections of everyday matters.

Cracking The Real Da Vinci Code: What Happens In The Artist’s Brain?:

The brain of the artist is one of the most exciting workplaces, and now an art historian at the University of East Anglia has joined forces with a leading neuroscientist to unravel its complexities.

Mind-body Connection: How Central Nervous System Regulates Arthritis:

In a unique approach to inflammation research, a study by researchers at UCSD School of Medicine shows that, in a model of rheumatoid arthritis, inflammation in the joints can be sensed and modulated by the central nervous system (CNS). The research suggests that the CNS can profoundly influence immune responses, and may even contribute to understanding so-called placebo effects and the role of stress in inflammatory diseases.

After Insects Attack, Plants Bunker Sugars For Later Regrowth:

Using radioactive carbon and genetically modified native tobacco plants, Max Planck Society scientists and colleagues have discovered the first gene mediating tolerance to herbivore attack.

Scientists Link Immune Response To ‘Ghost’ Parasites And Severely Congested Sinuses:

Although it’s unclear why it’s so, scientists at Johns Hopkins have linked a gene that allows for the chemical breakdown of the tough, protective casing that houses insects and worms to the severe congestion and polyp formation typical of chronic sinusitis.

Scientists Explore How Complex Organs Develop From A Simple Bud:

The current issue of Differentiation, guest-edited by Brigid Hogan, highlights several scientific investigations into the complex biological mechanism known as branching morphogenesis. Through a series of seven laboratory reviews, important insights governing this process during animal development are revealed. The articles analyze how branching morphogenesis occurs in different organ systems in the same species. They also compare the process between simple and complex organisms.

How Did Our Ancestors’ Minds Really Work?:

How did our evolutionary ancestors make sense of their world? What strategies did they use, for example, to find food? Fossils do not preserve thoughts, so we have so far been unable to glean any insights into the cognitive structure of our ancestors.
However, in a study recently published in Current Biology (September 5, 2006), researchers at the Max Planck Institute for Psycholinguistics and their colleagues at the Max Planck Institute for Evolutionary Anthropology were able to find answers to these questions using an alternative research method: comparative psychological research. In this way, they discovered that some of the strategies shaped by evolution are evidently masked very early on by the cognitive development process unique to humans.
Being able to remember and relocate particular places where there is food is an asset to any species. There are two basic strategies for remembering the location of something: either remembering the features of the item (it was a tree, a stone, etc.), or knowing the spatial placement (left, right, middle, etc.). All animal species tested so far – from goldfish, pigeons and rats though to humans – seem to employ both strategies. However, if the type of recall task is designed so that the two strategies are in opposition, then some species (e.g. fish, rats and dogs) have a preference for locational strategies, while others (e.g. toads, chickens and children) favor those which use distinctive features.
Until now, no studies had systematically investigated these preferences along the phylogenetic tree. Recently, however, Daniel Haun and his colleagues have carried out the first research of its kind into the cognitive preferences of a whole biological family, the hominids. They compared the five species of great apes – orangutans, gorillas, bonobos, chimpanzees and humans – to establish which cognitive strategies they prefer in order to uncover hidden characteristics.

Landscape Corridors Promote Plant Diversity By Preventing Species Loss:

Landscape corridors – thin strips of habitat that connect isolated patches of habitat — are lifelines for native plants that live in the connected patches and therefore are a useful tool for conserving biodiversity. That’s the result of the first replicated, large-scale study of plants and how they survive in both connected patches of habitat — those utilizing landscape corridors — and unconnected patches.

I’ve heard a lot about this study (and several others at the same site) over the years because Nick and Ellen are my friends and colleagues – I am so excited they got this into Science
‘Stress And The City’: Urban Birds Keep Cool:

Ornithologists of the Max Planck Society demonstrate that urban birds are more resistant to acute stress than forest dwelling birds. This reduced reactivity probably has a genetic basis and could be the result of the urban-specific selection pressures to which urban blackbirds are exposed.

Mayo Clinic Discovers New Type Of Sleep Apnea:

Researchers at Mayo Clinic have identified a new type of sleep apnea they call “complex sleep apnea.” The newly discovered type, complex sleep apnea, is a combination of both obstructive and central sleep apneas.

Deer-free Areas May Be Haven For Ticks, Disease:

Excluding deer could be a counterproductive strategy for controlling tick-borne infections, because the absence of deer from small areas may lead to an increase in ticks, rapidly turning the area into a potential disease hotspot, according to a team of U.S. and Italian researchers.

‘Portion Distortion’ May Contribute To Expanding Waistlines, Study Reports:

New research shows that people’s perceptions of normal portion sizes have changed in the past 20 years. A study out of Rutgers published in the September issue of the Journal of the American Dietetic Association reports that Portion Distortion may be the cause. This phenomenon occurs when consumers perceive large portion sizes as appropriate amounts to eat at a single eating occasion.

Scientists Identify Compounds That Stimulate Stem Cell Growth In The Brain:

Harvard scientists have identified key compounds that stimulate stem cell growth in the brain, which may one day lead to restored function for people affected by Parkinson’s disease, strokes, multiple sclerosis and a wide range of neurological disorders. These findings, which appear in the September 2006 issue of the FASEB Journal, provide important clues as to which compounds may be responsible for causing key brain cells, neurons, to regenerate and ultimately restore brain function.

New Parks To Protect Animals Seen As Feasible:

Many “gap” locations worldwide — identified in previous research as lacking conservation protection yet harboring imperiled animal species — are ripe for conservation efforts, because they have a sparse human population and large tracts of conservation-compatible habitat, and are unattractive for agriculture.

A Switch Between Life And Death:

Cells in an embryo divide at an amazing rate to build a whole body, but this growth needs to be controlled. Controlling growth requires that some cells divide while others die; their fates are determined by signals that are passed from molecule to molecule within the cell. Researchers at the European Molecular Biology Laboratory (EMBL) in Heidelberg have now discovered how one of these signaling pathways controls the life and death of cells in the fruit fly.

Scientists Crack Genetic Secrets Of Human Egg:

Scientists at Michigan State University report this week in the Proceedings of the National Academy of Sciences that they have identified genes unique to the human egg. The identification opens the way to understanding these genes’ functions, which may lead to solving problems from infertility to degenerative diseases.

High Levels Of Pollutants May Decrease Sexual Organ Size In Polar Bears:

Exposure to high levels of environmental pollutants called organohalogen compounds (OHCs) seems to reduce the size of sexual organs in male and female polar bears, researchers report in an article scheduled for the Sept. 15 issue of the ACS journal, Environmental Science & Technology. OHCs include dioxins, polychlorinated biphenyls and some pesticides.

Researchers Map Out Networks That Determine Cell Fate:

A two-step process appears to regulate cell fate decisions for many types of developing cells. For some differentiating stem cells, the first step leads not to a final decision but to a new choice. In response to the initial chemical signal, these cells take on the genetic signatures of two different cell types. It often requires a second signal for them to commit to a single cellular identity.

Social Imitation In Neonatal Monkeys:

Humans do it. Chimps do it. Why shouldn’t monkeys do it, too? Mimicry exists throughout the animal kingdom, but imitation with a purpose — matching one’s behavior to others’ as a form of social learning — has been seen only in great apes. It’s generally believed that monkeys do not imitate in this way. However, the discovery that rhesus monkeys have “mirror neurons” — neurons that fire both when monkeys watch another animal perform an action and when they perform the same action — suggests they possess the common neural framework for perception and action that is associated with imitation.

Spread Of Plant Diseases By Insects Can Be Described By Equations That Model Interplanetary Gravity:

Researchers from Penn State University and the University of Virginia show that the spread of diseases by insects can be described by equations similar to those that describe the force of gravity between planetary objects. Their findings are detailed in the September issue of the American Naturalist.

Researcher Studies Gene Families To Explore Diversity And Evolution:

Iowa State University theoretical biologist Stephen Proulx uses tools and computer models to determine how environmental and evolutionary factors structure a genome. One path to diversity in a genome involves the proliferation of genes into multi-gene families. In a recent paper in the journal Evolution, Proulx and a colleague show that the process of gene family expansion can begin even before a gene is duplicated.

Iron Critical To Ocean Productivity, Carbon Uptake:

A new study has found that large segments of the Pacific Ocean lack sufficient iron to trigger healthy phytoplankton growth and the absence of the mineral stresses these microscopic ocean plants, triggering them to produce additional pigments that make ocean productivity appear more robust than it really is. The tropical Pacific Ocean may photosynthesize 1-2 billion tons less atmospheric carbon dioxide than was previously thought.