Category Archives: Science

The Next Big Step Toward Atom-Specific Dynamical Chemistry

*Berkeley Lab scientists push chemistry to the edge, testing plans for a new generation of light sources*

For Ali Belkacem of Berkeley Lab’s Chemical Sciences Division, “What is chemistry?” is not a rhetorical question.

“Chemistry is inherently dynamical,” he answers. “That means, to make inroads in understanding – and ultimately control – we have to understand how atoms combine to form molecules; how electrons and nuclei couple; how molecules interact, react, and transform; how electrical charges flow; and how different forms of energy move within a molecule or across molecular boundaries.” The list ends with a final and most important question: “How do all these things behave in a correlated way, ‘dynamically’ in time and space, both at the electron and atomic levels?” (more…)

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50-Million-Year-Old Cricket and Katydid Fossils From Colorado Hint at Origin of Insect Hearing

*The team scoured more than 500 museum drawers of Green River fossils for crickets and katydids with intact front legs, looking for evidence of ears.*

How did insects get their hearing? A new study of 50-million-year-old cricket and katydid fossils sporting some of the best preserved fossil insect ears described to date are helping to trace the evolution of the insect ear.

According to paleontologist Dena Smith of the University of Colorado Boulder’s Museum of Natural History and University of Illinois Professor Roy Plotnick, who collaborated on the new study at the National Evolutionary Synthesis Center, or NESCent, in Durham, N.C., insects hear with help from some very unusual ears. (more…)

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To Turn Up The Heat in Chilies, Just Add Water

Biologists have learned in recent years that wild chilies develop their trademark pungency, or heat, as a defense against a fungus that could destroy their seeds. But that doesn’t explain why some chilies are hot and others are not.

New research provides an answer: Hot chilies growing in dry areas need more water to produce as many seeds as non-pungent plants, but the Fusarium fungus is less of a threat in dryer environments so chilies in those areas are less likely to turn up the heat. In wetter regions, where Fusarium thrives, wild chilies build up their reserves of spicy capsaicin in self-defense. (more…)

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Prehistoric Predators with Supersized Teeth Had Beefier Arm Bones

*Combination of colossal canines and forceful forelimbs arose repeatedly over time*

The toothiest prehistoric predators also had beefier arm bones, according to results of a study published today in the journal Paleobiology.

Saber-toothed tigers may come to mind, but these extinct cats weren’t the only animals with fearsome fangs.

Take the false saber-toothed cats–also known as nimravids–and their catlike cousins, a family of carnivores called the barbourofelids. (more…)

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First Person: How We Discovered Fluoride Riboswitches

Scientific discoveries come through many different means. Breakthroughs can result from purposefully-executed research projects that are perhaps punctuated with unexpected flashes of insight. In rare cases, discoveries occur through a chain of highly improbable, very lucky, occurrences. (more…)

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North American Mammal Evolution Tracks with Climate Change

*Climate changes profoundly influenced the rise and fall of six distinct, successive waves of mammal species diversity in North America over the last 65 million years, shows a novel statistical analysis led by Brown University evolutionary biologists. Warming and cooling periods, in two cases confounded by species migrations, marked the transition from one dominant grouping to the next.*

PROVIDENCE, R.I. [Brown University] — History often seems to happen in waves — fashion and musical tastes turn over every decade and empires give way to new ones over centuries. A similar pattern characterizes the last 65 million years of natural history in North America, where a novel quantitative analysis has identified six distinct, consecutive waves of mammal species diversity or “evolutionary faunas.” What force of history determined the destiny of these groupings? The numbers say it was typically climate change.

“Although we’ve always known in a general way that mammals respond to climatic change over time, there has been controversy as to whether this can be demonstrated in a quantitative fashion,” said Christine Janis, professor of evolutionary biology at Brown University. “We show that the rise and fall of these faunas is indeed correlated with climatic change — the rise or fall of global paleotemperatures — and also influenced by other more local perturbations such as immigration events.” (more…)

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Children Don’t Give Words Special Power to Categorize Their World

COLUMBUS, Ohio – New research challenges the conventional thinking that young children use language just as adults do to help classify and understand objects in the world around them.

In a new study involving 4- to 5-year-old children, researchers found that the labels adults use to classify items – words like “dog” or “pencil” – don’t have the same ability to influence the thinking of children. (more…)

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