Scientists Urge New Approaches to Plant Research

You'd be amazed at how much you can learn from a plant.

In a paper published this week in the journal Science, a Michigan State University professor and a colleague discuss why if humans are to survive as a species, we must turn more to plants for any number of valuable lessons.

"Metabolism of plants provides humans with fiber, fuel, food and therapeutics," said Robert Last, an MSU professor of biochemistry and molecular biology. "As the human population grows and nonrenewable energy sources diminish, we need to rely increasingly on plants and to increase the sustainability of agriculture."

However, Last and co-author Ron Milo of the Weizmann Institute of Science point out that despite decades of plant genetic engineering, there are relatively few types of commercial products originating from this body of work.

"This is in part because we do not understand enough about the vastly complex set of metabolic reactions that plants employ," Last said. "It's like designing and building a bridge armed only with satellite images of existing bridges."

The authors say that perhaps the best approach is to bring together a variety of disciplines -- not just plant scientists -- to study how plants operate.

They also suggest looking hard at what brought plants to the place they are today -- evolution.

"We think that understanding design principles of plant metabolism will be aided by considering how hundreds of millions of years of evolution has led to well-conserved examples of metabolic pathways," Last said.

One of the amazing aspects of plant metabolism is this: It must continuously strike a balance between evolving to meet an ever-changing environment while maintaining the internal stability needed to carry on life as it knows it.

In addition, the authors point out that plants experiment with specialized (also called secondary) metabolism which can produce novel chemicals that are used to defend against pathogens and herbivores.

"Humans benefit from this 'arms race' because some of these compounds have important therapeutic properties," Last said. "Unfortunately, design principles are not so well studied in these rapidly evolving metabolic processes. Using new approaches, including considering optimality principles, will lead to advances in medicinal chemistry as well as creating more and healthier food."

Read more at Science Daily

Moderate Doses of Alcohol Increase Social Bonding in Groups

A new study led by University of Pittsburgh researchers reveals that moderate amounts of alcohol -- consumed in a social setting -- can enhance positive emotions and social bonding and relieve negative emotions among those drinking.

While it is usually taken for granted that people drink to reduce stress and enhance positive feelings, many studies have shown that alcohol consumption has an opposite effect. In a new paper titled "Alcohol and Group Formation: A Multimodal Investigation of the Effects of Alcohol on Emotion and Social Bonding," research shows that moderate doses of alcohol have a powerful effect on both male and female social drinkers when they are in a group.

The paper is published online in Psychological Science.

According to the researchers, previous alcohol studies testing the impact of alcohol on emotions involved social drinkers consuming alcohol in isolation rather than in groups.

"Those studies may have failed to create realistic conditions for studying this highly social drug," said Michael A. Sayette, lead author and professor of psychology in Pitt's Kenneth P. Dietrich School of Arts and Sciences. "We felt that many of the most significant effects of alcohol would more likely be revealed in an experiment using a social setting."

Sayette and his colleagues assembled various small groups using 720 male and female participants, a larger sample than in previous alcohol studies. Researchers assessed individual and group interactions using the Facial Action Coding System (FACS) and the Grouptalk model for speech behavior.

They concluded that alcohol stimulates social bonding, increases the amount of time people spend talking to one another, and reduces displays of negative emotions. According to Sayette, the paper introduces into the alcohol literature new measures of facial expression and speech behavior that offer a sensitive and comprehensive assessment of social bonding.

Sayette and eight colleagues took special care in the methods they employed to form the groups. Each participant was randomly assigned to a group of three unacquainted "strangers." Each group was instructed to drink an alcoholic beverage, a placebo, or a nonalcoholic control beverage. Twenty groups representing each gender composition (three males; one female and two males; two males and one female; and three females) were assigned to the three different beverage scenarios. Group members sat around a circular table and consumed three drinks over a 36-minute time span. Each session was video recorded, and the duration and sequence of the participants' facial and speech behaviors were systematically coded frame by frame.

Results showed that alcohol not only increased the frequency of "true" smiles, but also enhanced the coordination of these smiles. In other words, alcohol enhanced the likelihood of "golden moments," with groups provided alcohol being more likely than those offered nonalcoholic beverages to have all three group members smile simultaneously. Participants in alcohol-drinking groups also likely reported greater social bonding than did the nonalcohol-drinking groups and were more likely to have all three members stay involved in the discussion.

"By demonstrating the sensitivity of our group formation paradigm for studying the rewarding effects of alcohol," said Sayette, "we can begin to ask questions of great interest to alcohol researchers -- Why does alcohol make us feel better in group settings? Is there evidence to suggest a particular participant may be vulnerable to developing a problem with alcohol?"

The new research sets the stage for evaluation of potential associations between socioemotional responses to alcohol and individual differences in personality, family history of alcoholism, and genetic vulnerability.

Read more at Science Daily

First-Ever Changes in an Exoplanet Atmosphere Detected

An international team of astronomers using data from NASA's Hubble Space Telescope has made an unparalleled observation, detecting significant changes in the atmosphere of a planet located beyond our solar system.

The scientists conclude the atmospheric variations occurred in response to a powerful eruption on the planet's host star, an event observed by NASA's Swift satellite.

"The multiwavelength coverage by Hubble and Swift has given us an unprecedented view of the interaction between a flare on an active star and the atmosphere of a giant planet," said lead researcher Alain Lecavelier des Etangs at the Paris Institute of Astrophysics (IAP), part of the French National Scientific Research Center located at Pierre and Marie Curie University in Paris.

The exoplanet is HD 189733b, a gas giant similar to Jupiter, but about 14 percent larger and more massive. The planet circles its star at a distance of only 3 million miles, or about 30 times closer than Earth's distance from the sun, and completes an orbit every 2.2 days. Its star, named HD 189733A, is about 80 percent the size and mass of our sun.

Astronomers classify the planet as a "hot Jupiter." Previous Hubble observations show that the planet's deep atmosphere reaches a temperature of about 1,900 degrees Fahrenheit (1,030 C).

HD 189733b periodically passes across, or transits, its parent star, and these events give astronomers an opportunity to probe its atmosphere and environment. In a previous study, a group led by Lecavelier des Etangs used Hubble to show that hydrogen gas was escaping from the planet's upper atmosphere. The finding made HD 189733b only the second-known "evaporating" exoplanet at the time.

The system is just 63 light-years away, so close that its star can be seen with binoculars near the famous Dumbbell Nebula. This makes HD 189733b an ideal target for studying the processes that drive atmospheric escape.

"Astronomers have been debating the details of atmospheric evaporation for years, and studying HD 189733b is our best opportunity for understanding the process," said Vincent Bourrier, a doctoral student at IAP and a team member on the new study.

When HD 189733b transits its star, some of the star's light passes through the planet's atmosphere. This interaction imprints information on the composition and motion of the planet's atmosphere into the star's light.

In April 2010, the researchers observed a single transit using Hubble's Space Telescope Imaging Spectrograph (STIS), but they detected no trace of the planet's atmosphere. Follow-up STIS observations in September 2011 showed a surprising reversal, with striking evidence that a plume of gas was streaming away from the exoplanet.

The researchers determined that at least 1,000 tons of gas was leaving the planet's atmosphere every second. The hydrogen atoms were racing away at speeds greater than 300,000 mph. The findings will appear in an upcoming issue of the journal Astronomy & Astrophysics.

Because X-rays and extreme ultraviolet starlight heat the planet's atmosphere and likely drive its escape, the team also monitored the star with Swift's X-ray Telescope (XRT). On Sept. 7, 2011, just eight hours before Hubble was scheduled to observe the transit, Swift was monitoring the star when it unleashed a powerful flare. It brightened by 3.6 times in X-rays, a spike occurring atop emission levels that already were greater than the sun's.

"The planet's close proximity to the star means it was struck by a blast of X-rays tens of thousands of times stronger than the Earth suffers even during an X-class solar flare, the strongest category," said co-author Peter Wheatley, a physicist at the University of Warwick in England.

Read more at Science Daily

An Astronomical Tour in the Realm of Galaxies

The summer skies aren't always the obvious time to go galaxy hunting because the combination of faint objects, bright skies and longer days can make finding them a little tricky.

However, those of you in the Northern Hemisphere prepared to stay up late until the sky properly darkens will be treated to a few galactic treasures in the skies of July and August.

Obviously placed due south during local midnight is our own galaxy, the Milky Way, making a excellent place to start our tour of deep space. We live inside the Milky Way at a distance of around 30,000 light-years from the galactic core -- this is why our galaxy appears in our sky as a band of light.

The Milky Way is believed to be a "barred spiral galaxy" around 100,000 light years across with up to 400 billion stars. Because of the obscuring dust and foreground stars, it's not easy to spot galaxies in the direction of the Milky Way so we have to look due east and west ("up" and "down" from the galactic disk) to see external galaxies.

Over in the far west are the constellations of Virgo, Coma Berenices and Canes Venatici that are home to some great galaxy clusters. There are three bright galaxies to look out for in the western sky and they can be found from the easily recognizable Plough (or "Big Dipper"), part of the much larger Ursa Major constellation.

Starting from Alkaid, the end star of the Big Dipper's handle, head no more than 5 degrees (a clenched fist at arm's length measures 10 degrees, so its half that distance) in the same direction that takes you parallel with the nearest two stars of the bowl and you will find a beautiful example of interacting galaxies called the Whirlpool Galaxy and NGC5195. From a dark site it can be just about detected in binoculars, but telescopes with 10 centimeter (4 inch) aperture or more are needed to be able to detect the spiral arms. Anything larger should show the two galaxies with ease with an increasing level of detail.

Now identify the stars at the bottom left of the bowl, Phecda and Dubhe at the upper right. Imagine a line between them and extend the line on further due north for about the same distance. There are two galaxies here; M81, which is a bright spiral galaxy easily detectable in binoculars and any telescope larger than 15 cm (6") will pick out its spiral arms. It's estimated to be 12 million light years away and is gravitationally bound with its neighbour M82. This irregular galaxy is fainter than M81 but can still be seen in binoculars in the same field of view as M82.

Turning to the north-east now and the great square of the constellation Pegasus is rising. Its north-east corner star is also the starting point for the constellation of Andromeda. Move further east by Delta Andromedae and Mirach and then up by another two fainter stars and just to the north west of Nu Andromedae is the famous Andromeda Galaxy. An easy target for the naked eye under dark skies it's the nearest major galaxy to our own. Even small telescopes reveal its two companion galaxies M32 and M110.

Read more at Discovery News

Voyager 1: The Little Spacecraft That Could

Voyager 1, the spacecraft that launched on a tour of the solar on Sept. 5, 1977, is getting ready to enter interplanetary space.

The spacecraft's journey started in 1966 when Gary Flandro, then a graduate student working at NASA's Jet Propulsion Laboratory, discovered that the planets were about to align. Not just for him, but for the whole solar system.

He found that in the late 1970s and early 1980s, Jupiter, Saturn, Uranus, Neptune, and Pluto would be at the right relative positions in their orbits that a spacecraft could visit each of them on a grand tour. The secret was gravity assists, using the planets' gravity to slingshot the spacecraft from one to the next.

To take advantage of the opportunity, NASA developed the twin Voyager spacecraft. Both would fly by Jupiter and Saturn, adding valuable scientific data to what was then a very scant knowledge of the outer solar system. Ground-based studies revealed the planets' most basic properties, and hinted that there were fascinating discoveries still to make.

In the early 1970s, Pioneer 10 and Pioneer 11 made the first flybys of the gas giants and their instruments began revealing just how complex those worlds are.

With this as the background, Voyager wasn't just a great opportunity, it was the logical next step is understanding our solar system.

Voyager 2, which was actually the first to launch on August 20, 1977, ended up with more opportunities on its trajectory. After flying by Jupiter and Saturn, it would be in the right place to continue its mission and fly by Uranus.

Voyager 1 was a little more limited. Its orientation after flying by Saturn would send it out of the ecliptic, the plane where all the planets orbit the sun.

But even without another planetary target, Voyager 1 would keep on going. It would, as the 1977 pre-launch press kit described, continue "outward from the solar system and across the boundary of the wind of charged particles (solar wind) that streams outward from the Sun, thus penetrating into interstellar space." At the time, there was no concrete plan to keep in touch with the spacecraft after it left Saturn.

On Nov. 12, 1980, Voyager 1 began its trip out of the solar system. The spacecraft was on its path "searching for the outer limit of the solar wind –- that presumed boundary... where the influence of the sun gives way," as NASA described it in a 1980 press release. It kept on going, and NASA hasn't lost touch despite arguments that its continuing budget spent on the mission every year could be put to "better use."

Currently, Voyager 1 is at the furthest reaches of our solar system more than 107 times as far as the Earth is from the sun. Data suggests that the spacecraft is in a region where the environment is changing rapidly and that the protective sphere of the sun's magnetic field -- the heliosphere -- is failing. More cosmic rays seem to be hitting the spacecraft without the cushioning effect of the heliosphere.

From the edges of the solar system, it takes a signal traveling from the spacecraft fifteen hours to reach Earth. Voyager 2 isn't too far behind. It flew by Uranus and Neptune in the 1980s before slipping below the ecliptic. Both have since returned stunning portraits of the whole solar system.

Read more at Discovery News

The Science Behind Saturday's Leap Second

This Saturday, June 30, expect a lengthier day, as an extra leap second will be added to Earthlings' clocks.

What's behind this leap second? The ever-so-slight slowing of Earth's rotation, or the 24-hour spin that brings the sun into our skies every morning.

Historically, humans based time on the average rotation of the Earth relative to other celestial bodies, with the second defined by this frame of reference. However, the invention of atomic clocks — accurate to about one second in 200 million years — brought about a definition of a second independent of Earth's rotation. Instead, they're based on a consistent signal emitted by electrons changing energy states within an atom.

Earth has been falling behind the atomic time at a rate of about 2 milliseconds per day, currently trailing the atomic time by six-tenths of a second. Every now and then a leap second must be added to atomic clocks (and thus all of our clocks) to keep in sync with Earth's oddball rotation.

This Saturday will mark the 25th time a leap second has been added since the practice started in 1972. The most recent leap second occurred in 2008 on New Year's Eve.

Read more at Discovery News

Maya Archaeologists Unearth New 2012 Monument With 'End Date' of Dec. 21, 2012

Archaeologists working at the site of La Corona in Guatemala have discovered a 1,300-year-old-year Maya text that provides only the second known reference to the so-called "end date" of the Maya calendar, December 21, 2012. The discovery, one of the most significant hieroglyphic finds in decades, was announced June 28 at the National Palace in Guatemala.

"This text talks about ancient political history rather than prophecy," says Marcello A. Canuto, director of Tulane's Middle American Research Institute and co-director of the excavations at La Corona.

Since 2008, Canuto and Tomás Barrientos of the Universidad del Valle de Guatemala have directed excavations at La Corona, a site previously ravaged by looters.

"Last year, we realized that looters of a particular building had discarded some carved stones because they were too eroded to sell on the antiquities black market," said Barrientos, "so we knew they found something important, but we also thought they might have missed something."

What Canuto and Barrientos found was the longest text ever discovered in Guatemala. Carved on staircase steps, it records 200 years of La Corona history, states David Stuart, director of the Mesoamerica Center at The University of Texas at Austin, who was part of a 1997 expedition that first explored the site.

While deciphering these new finds in May, Stuart recognized the 2012 reference on a stairway block bearing 56 delicately carved hieroglyphs. It commemorated a royal visit to La Corona in AD 696 by the most powerful Maya ruler of that time, Yuknoom Yich'aak K'ahk' of Calakmul, only a few months after his defeat by long-standing rival Tikal in AD 695. Thought by scholars to have been killed in this battle, this ruler was visiting allies and allaying their fears after his defeat.

"This was a time of great political turmoil in the Maya region and this king felt compelled to allude to a larger cycle of time that happens to end in 2012," says Stuart.

So, rather than prophesy, the 2012 reference places this king's troubled reign and accomplishments into a larger cosmological framework.

Read more at Science Daily

Ancient 'Cow Woman' Skeleton Called Bizarre

The skeleton of a 1,400-year-old Anglo-Saxon woman buried alongside a cow has emerged from a former children's playground near Cambridge in England, making the "cow woman" an extraordinary unique find.

Described as "hugely exciting" and "bizarre," the burial was uncovered by students from Manchester Metropolitan University and the University of Central Lancashire.

The find is believed to be the only one of its kind ever found in Europe.

"Usually it is warrior men who are discovered buried with their animals. Never before have we found a woman buried alongside a cow," Faye Simpson, of the Department of History at Manchester Metropolitan University, said.

Simpson and colleague Duncan Sayer, from the University of Central Lancashire, believe the burial indicates the woman enjoyed a high social status within her community.

"A cow is symbolic of economic and domestic power. In the 5th century this animal was a very important to a community’s survival, so to sacrifice one is highly significant. Such a unique burial indicates the woman's role as regional elite," Simpson told Discovery News.

According to the researchers, the community would have wanted to give the woman something really important to show respect -- something they wouldn't have done for just anybody.

"She was buried in the late 5th century, a significant period after the Roman occupation. The burial demonstrates that the reordering of social boundaries could include important matriarchal figures," Simpson said.

Read more at Discovery News

Slug-Like Animal Resets Date of Animal Life

Researchers have found the first physical proof that animals existed 585 million years ago, which is 30 million years earlier than previously documented, according to a new paper in the journal Science.

The proof isn't much to look at for the untrained eye. It resembles a mark left behind by someone dragging a stick across the ground. But the above image actually shows a fossilized track of a primitive slug-like animal, University of Alberta geologists Ernesto Pecoits and Natalie Aubet conclude. The animal measured about 1/4 of an inch long.

The pattern of the track indicates that the prehistoric slug-ish species likely was searching for organic material to eat in silty sediment. This sediment was at the bottom of a shallow ocean in what is now Uruguay.

The primitive creature was a bilaterian. These animals are bilaterally symmetrical, with their top side  distinguishable from the bottom side.

The track was dated by studying an igneous rock that intruded into siltstone in the area where the tracks were found. Studying the track itself wasn't too complicated, but the dating process took more than two years and involved feedback from a bunch of peer review scientists. The researchers even had to travel back to Uruguay to collect additional samples of the fossilized rock. A technique called mass spectrometry permitted its analysis.

Most early animal life is known to us through such tracks, since the soft bodies of most creatures would long have eroded away.

Read more at Discovery News

Dinosaurs May Have Been Warm-Blooded

Dinosaurs may not have been the slow, sunbathing reptiles researchers used to think. In fact, they may have been warm-blooded, new research suggests.

The researchers studied the "growth lines" on animal bones, which are similar to the growth rings in tree trunks. During slow-growing times like during the winter, they are darker and narrower, while in fast-growing times the bones have lighter, wider bands.

Figuring out if dinosaurs were warm-blooded endotherms (made their own body heat) or were "cold-blooded" ectotherms that relied on outside sources of warmth could illuminate a lot about how they lived, grew and evolved. How warm an animal is has an impact on their metabolism, and therefore how quickly they can grow and have babies.

Of bones and blood

Previously, scientists had thought that growth lines showed up only on the bones of cold-blooded animals, since these animals grow in fits and starts. Warm-blooded animals, like mammals and birds, are assumed to grow continuously, because they keep their temperatures up and have high metabolic rates, continually making energy to grow.

As such, researchers took the growth lines on dinosaur bones as evidence of their cold-bloodedness. Until now.

In this study, the researchers compared the bone lines from the leg bones of more than 100 wild ruminants (warm-blooded mammals like sheep and cows that have multiple stomachs) with seasonal rainfall and temperature cycles and with the animal's core body temperature and resting metabolic rate. The researchers showed that these warm-blooded animals also have bone growth lines indicating fast, yet interrupted yearly growth that depended on how long the "unfavorable" season lasted.

Hot dinos

The growth lines they found on the ruminants were similar to those seen in previous studies of dinosaur bones — indicating that both ruminants and dinosaurs have periods of high growth punctuated by "unfavorable" seasons with limited resources and little growth. This means that dinosaurs were likely warm-blooded like the ruminants.

"The argument we are giving in our paper, rather in favor of endothermy in dinosaurs, is that between the growth and rest lines, there's always a big region of highly vascularized [infiltrated with blood vessels] tissue that indicates very high growth rates," study researcher Meike Köhler, of the Autonomous University of Barcelona in Spain, told LiveScience. "This is typical in dinosaurs and very different from reptiles, which have slow growth between the rest lines."

Sauropods were the only dinosaurs where researchers haven't seen growth lines similar to those of ruminants. Previous studies of their teeth indicate they would have had high body temperatures as well, though they might have been big enough for their mass to generate that heat — what researchers call a "gigantotherm." Researchers don't know what their growth lines would have looked like, since no animals alive today are gigantotherms.

Fast growth?

This indicates that "dinosaursalso had very fast growth rates and needed to eat a lot and maintain high generation of heat internally," Kohler said, so they were most likely warm-blooded.

Read more at Discovery News