Science360 News Service: Combined

Commonly Used Pesticide Turns Honey Bees Into 'Picky Eaters'

Fri, 25 May 2012 07:00:00 GMT

Summary:

A small dose of a commonly used crop pesticide turns honey bees into "picky eaters" and affects their ability to recruit their nestmates to otherwise good sources of food.

Full Text:

Biologists at UC San Diego have discovered that a small dose of a commonly used crop pesticide turns honey bees into “picky eaters” and affects their ability to recruit their nestmates to otherwise good sources of food. The results of their experiments, detailed in this week's issue of the Journal of Experimental Biology, have implications for what pesticides should be applied to bee-pollinated crops and shed light on one of the main culprits suspected to be behind the recent declines in honey bee colonies.

Since 2006, beekeepers in North America and Europe have lost about one-third of their managed bee colonies each year due to "colony collapse disorder." While the exact cause is unknown, researchers believe pesticides have contributed to this decline. One group of crop pesticides, called "neonicotinoids," has received particular attention from beekeepers and researchers.

Image credit: Thinkstock

Tubes From Pollen Headed For An Egg Cell

Fri, 25 May 2012 07:00:00 GMT

Full Text:

Pictured here are pollen tubes emerging from pollen grains on the stylar surface of Austrobaileya scandens, a vine endemic to the Australian rainforest. The stigma is the part of the flower that receives pollen, and it can be very far from the egg.

The pollen tubes exit the pollen grain from a slit-like opening that can be most clearly seen in the pollen grain on the right side. The tubes are about 10 microns (one one hundredth of a millimeter) wide, but they can grow well over 6 millimeters to reach an egg, all in less than 24 hours after pollination, which is when this photo was taken.

Image credit: Joseph H. Williams, Department of Ecology and Evolution, University of Tennessee

Beetle-infested Pine Trees Contribute To Air Pollution And Haze In Forests

Thu, 24 May 2012 07:00:00 GMT

Summary:

The hordes of bark beetles that have bored their way through more than 6 billion trees in the western United States and British Columbia since the 1990s do more than kill stately pine, spruce and other trees.

Full Text:

Results of a new study find that these pests can make trees release up to 20 times more of the organic substances that foster haze and air pollution in forested areas.

A paper reporting the findings appears today in the journal Environmental Science & Technology, published by the American Chemical Society (ACS).

Image credit:

US Forest Service

A Torrent Of Crabs Running To The Sea

Thu, 24 May 2012 07:00:00 GMT

Full Text:

After a six-month dry season in coastal Panama, the first rains bring masses of bright red land crabs boiling out of their burrows in the forest and migrating to the shore. There, females lay fertilized eggs in the water. WHOI student Joanna Gyory discovered previously unknown parts of this species' life cycle.

Image credit: Joanna Gyory, Woods Hole Oceanographic Institution

Study Shows Availability Of Hydrogen Controls Chemical Structure Of Graphene Oxide

Wed, 23 May 2012 07:00:00 GMT

Summary:

Full Text:

A recent study shows that the availability of hydrogen plays a significant role in determining the chemical and structural makeup of graphene oxide, a material that has potential uses in nano-electronics, nano-electromechanical systems, sensing, composites, optics, catalysis and energy storage.The study also found that after the material is produced, its structural and chemical properties continue to evolve for more than a month as a result of continuing chemical reactions with hydrogen. Understanding the properties of graphene oxide – and how to control them – is important to realizing potential applications for the material.

Image credit: Gary Meek

Sea Sponge At Work

Wed, 23 May 2012 07:00:00 GMT

Full Text:

This image shows a sea sponge extracting water. Though often mistaken for plants, sea sponges are in fact dynamic, industrious animals that pump thousands of liters of water through their bodies in a single day.

Relationship Between Social Status And Wound-Healing In Wild Baboons

Tue, 22 May 2012 07:00:00 GMT

Summary:

Turns out it's not bad being top dog, or in this case, top baboon. A new study finds that high-ranking male baboons recover more quickly from injuries, and are less likely to become ill than other males.

Full Text:

Turns out it's not bad being top dog, or in this case, top baboon. Results of a study by University of Notre Dame biologist Beth Archie and colleagues from Princeton University and Duke University finds that high-ranking male baboons recover more quickly from injuries, and are less likely to become ill than other males. Archie, Jeanne Altman of Princeton and Susan Roberts of Duke examined health records from the Amboseli Baboon Research Project in Kenya. They published their results in this week's issue of the journal Proceedings of the National Academy of Sciences. The researchers found that high rank is associated with faster wound-healing.

Image credit: Elizabeth Miller

Lovely Lichens

Tue, 22 May 2012 07:00:00 GMT

Full Text:

Teloschistes crysophthalmus, a bright-orange, shrub-like epiphyte, is seen here growing on Fouquieria diguetii along the coast of Baja, Calif. Lichens are actually made up of two plants, an algae and a fungus, living in a symbiotic relationship. In desert environments, lichen will dry out completely and remain dormant until rain or dewfall provides enough moisture to make them active again. This ability allows lichens to survive some of the harshest environments on the planet. Because lichens are very sensitive to air pollution, scientists rely on them as a bioindicator species, like a natural environmental early warning system.

Image credit: ©Frank Bungartz, Ph.D., Arizona State University Lichen Herbarium

Pollination With Precision: How Flowers Do It

Mon, 21 May 2012 07:00:00 GMT

Summary:

Flowers make certain that gamete fusion has successfully occurred before other pollen grains are repelled. That allows the process of fertilization to continue if the first pollen grain turns out to have been a dud.

Full Text:

Brown University biologists report that flowers have evolved an elegant safeguard system to ensure that only the minimum necessary number of pollen tubes will reach each ovule. The discovery of how flowers manage the distribution of sperm among female gametes with industrial precision helps explain why the delicate beauties have reproduced prolifically enough to dominate the earth. In order for the flowers to succeed in pollination, exactly two fertile sperm should reach the two cells in each ovule — no more, no less. No ovule should be left out, either because too many tubes have gone elsewhere, or because the delivered sperm don't work. Mark Johnson, associate professor of biology at Brown and senior author on the paper detailing the discovery added that, "Until fusion has happened, there's no guarantee that you'll have successful seed formation.”

Image credit: Mike Cohea/Brown University

Bursts Of Stellar Turbulence

Mon, 21 May 2012 07:00:00 GMT

Full Text:

A slide depicting a 3-D mixing layer between two fluids of different densities in a gravitational field. Known as a Rayleigh-Taylor instability -- a type of turbulent mixing that occurs due to gravity, when a heavy gas is on top of a lighter one -- this mixing plays an essential role in stellar convection and is being studied in this context to help devise and validate statistical models of turbulent fluid mixing at the boundaries of convection zones in stars.

Image credit: Paul Woodward, Laboratory for Computational Science and Engineering, University of Minnesota

Ancient Giant Turtle Fossil Revealed

Fri, 18 May 2012 07:00:00 GMT

Summary:

Full Text:

Picture a turtle the size of a Smart car, with a shell large enough to double as a kiddie pool. Paleontologists from North Carolina State University have found just such a specimen – the fossilized remains of a 60-million-year-old South American giant that lived in what is now Colombia. The turtle in question is Carbonemys cofrinii, which means “coal turtle,” and is part of a group of side-necked turtles known as pelomedusoides. The fossil was named Carbonemys because it was discovered in 2005 in a coal mine that was part of northern Colombia’s Cerrejon formation. The specimen’s skull measures 24 centimeters, roughly the size of a regulation NFL football. The shell which was recovered nearby - and is believed to belong to the same species - measures 172 centimeters, or about 5 feet 7 inches, long. That’s the same height as Edwin Cadena, the NC State doctoral student who discovered the fossil.

Image credit: Liz Bradford

Cross Of Khaled

Fri, 18 May 2012 07:00:00 GMT

Full Text:

If you look at ice crystals that form on your window during the winter, you see something similar to what you see here. The ice crystallizes from a central point and grows outward into beautiful radial patterns. A similar behavior is seen in polymers that are cooled to a temperature where they can crystallize. The size of the crystalline structures is usually small, but with an optical microscope light, you can see them. If the light is polarized, like passing through polarized sunglasses, you see areas that are bright as well as dark. These areas tell you how the polymers are arranged. Here, an unusual crystallization of a block copolymer was studied where the different blocks crystallized at different temperatures. The bands arise from the crystals twisting like a barber pole from the central point.

Image credit: VISUAL, Materials Research Science and Engineering Center, University of Massachusetts, Amherst

OMG! Texting Ups Truthfulness, IPhone Study Suggests

Thu, 17 May 2012 07:00:00 GMT

Summary:

Text messaging is a surprisingly good way to get candid responses to sensitive questions, according to study.

Full Text:

Results of a new study suggest that people are more likely to disclose sensitive information via text messages than in voice interviews.

“This is sort of surprising," says lead researcher Fred Conrad, “since many people thought that texting would decrease the likelihood of disclosing sensitive information because it creates a persistent, visual record of questions and answers that others might see on your phone and in the cloud.”

Image credit: Thinkstock

Elephant Family

Thu, 17 May 2012 07:00:00 GMT

Full Text:

The African elephant is one of only two surviving genera of the Elephantidae family that once occurred in many parts of the earth. Genetic studies show that African elephants are actually comprised of two distinct species, Loxodonta africana (commonly referred to as savanna elephants) and Loxodonta cyclotis (commonly referred to as forest elephants). Although more closely related to the extinct mammoths, African elephants’ nearest and only surviving relatives are the Asian elephants, Elephas maximus.

Shown here, elephants roam the grasslands of the Mwaluganje Elephant Sanctuary located in Kenya. The sanctuary is the first community-owned conservation dedicated to protecting elephants. The sanctuary minimizes conflicts among humans and wildlife, enhances the cultural and economic well-being of the community, and upholds the highest standards of environmental protection.

Image credit: Janine Sides/State Dept.

Questions About Incredible Sea Turtle Migration Answered By Scientists

Wed, 16 May 2012 07:00:00 GMT

Summary:

Researchers reveal the most comprehensive perspective to date on precisely how young loggerhead sea turtles stay on course during one of the longest and most spectacular migrations on Earth.

Full Text:

Immediately after emerging from their underground nests on the lush beaches of eastern Florida, loggerhead sea turtles scramble into the sea and embark alone on a migration that takes them around the entire North Atlantic basin. Survivors of this epic migration eventually return to North America's coastal waters. The most comprehensive perspective to date on precisely how young loggerheads navigate their transoceanic migration was recently published in two complementary papers produced by a research team led by Kenneth J. Lohmann, a marine biologist at the University of North Carolina at Chapel Hill.

Image credit:

Kenneth Lohmann, Department of Biology, University of North Carolina at Chapel Hill

Orange-spotted Sea Clown

Wed, 16 May 2012 07:00:00 GMT

Full Text:

There are over 100 species of nudibranchia in California, and each has its own unique and interesting story. Many are brightly colored, but some blend into their surroundings or match their prey (upon which they may live). These are such beautiful creatures -- it is hard to imagine that some animals find them toxic. Shown here is a sea slug known as Triopha catalinae. It is just one of the thousands of species of "tidepool treasures" -- marine plants and animals found in the small bodies of water left by the ebbing tide that fill the rock basins and depressions along California's rocky shores.

Image credit: Genny Anderson, Santa Barbara City College

Cellular Secrets Of Plant Fatty Acid Production Understood

Tue, 15 May 2012 07:00:00 GMT

Summary:

Scientists have discovered three similar proteins that could soon translate into positive results for bio-renewable fuels, commodity chemicals like plastics, food security and nutrition and biomedicine.

Full Text:

A curious twist in a family of plant proteins called chalcone-isomerase recently was discovered by Salk Institute for Biological Studies scientist Joseph Noel and colleagues at Iowa State University led by Eve Wurtele. Pursuing basic scientific discovery, they found three similar proteins that could soon translate into positive results for bio-renewable fuels, commodity chemicals like plastics, food security and nutrition and biomedicine. The findings, reported recently in the advance online publication of the journal Nature, may lead to higher-yield crops and quantities of oils, help to address growing world demands for food and fuel, and mitigate environmental pressures on stressed ecosystems.

Image credit: Zina Deretsky, National Science Foundation

Antarctic Meteorite

Tue, 15 May 2012 07:00:00 GMT

Full Text:

This is a thin section of a meteorite from the Miller Range, Antarctica. Field researchers in Antarctica have returned with more than 17,500 meteorites over the 30-plus years that the extraterrestrial material has been collected from the frozen continent. Yet meteorite science is still in its infancy, and the collected rocks still hold plenty of surprises that could shape our understanding of the solar system, according to scientists involved in the search and characterization of the Antarctic meteorite collection.

Image credit:

Tim McCoy

Researchers Gain Greater Insight Into Earthquake Cycles

Mon, 14 May 2012 07:00:00 GMT

Summary:

Scientists have developed a dynamic computer model that is the first to show the full history of a fault segment. The model may allow researchers to forecast the range of potential earthquakes on a fault segment, which could be used to further assess seismic hazard and improve building designs.

Full Text:

Scientists at the California Institute of Technology have developed the first computer model of an earthquake-producing fault segment that reproduces, in a single physical framework, the available observations of both the fault's seismic (fast) and aseismic (slow) behavior. Models like this one may allow geoscientists to forecast the range of potential earthquakes on a fault segment, which could be used to further assess seismic hazard and improve building designs.

Image credit: Sylvain Barbot / Caltech

Spotted Salamander Eggs With Developing Larvae

Mon, 14 May 2012 07:00:00 GMT

Full Text:

Spotted salamander eggs with developing larvae are green from the presence of symbiotic algae. The algae provide oxygen that helps the salamander embryos develop and the embryos provide nutrients that facilitate growth of the algae.

Image credit:
Roger Hangarter, Indiana University Department of Biology