Day: 12/09/2015

Penguin huddling found to be more complicated than thought

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emperor penguin
A team of researchers from several institutions in France and one in Germany has found that emperor penguin huddles are more complicated than has been thought by many in the science community. In their paper published in the journal Animal Behaviour, the team describes their study of the penguins over three separate breeding seasons and what they learned by looking at video of penguin huddling.

Male emperor huddling to keep themselves and eggs laid by an absent mate warm, has been made famous by the documentary March of the Penguins—they stand, seemingly stoically against the onslaught of bitter cold and frigid wind. Their actions seemed all the more interesting when it was learned that they shift about, moving members from the outside edges towards the center to share the burden of keeping warm. Now it appears that such images may be only part of the story. In this new research effort, the researchers discovered that penguin huddles don’t last very long because the penguins actually get too hot.

The team studied approximately 3000 emperor penguins living and huddling in Antarctica’s Pointe Géologie Archipelago colony over the years 2005 and 2006 and then again in 2008. In studying the video recordings they made, they discovered that huddling typically only lasted on average from twelve minutes to a few hours, and the average length of time an individual penguin spent in a huddle was just 50 minutes. They also found that temperatures inside the huddle could get hot, sometimes reaching nearly 100°F under certain conditions. What’s more, they discovered that it typically only took action by a single member to cause the huddle to disperse, and that the individual was generally one on the outside edges.

Backing up their theory that it was excessive heat that caused the huddles to disperse, the team found that soon after separating, a haze of warm air was released, and some of the penguins ate some snow, apparently attempting to cool off faster.

The team reports that they were surprised to discover that it was generally an outlier that instigated the breakup of huddles, but suggest that may have been because those in the center were trapped by the others around them.

 

Abstract
Social thermoregulation is a cooperative strategy in which animals actively aggregate to benefit from the warmth of conspecifics in response to low ambient temperatures. Emperor penguins, Aptenodytes forsteri, use this behaviour to ensure their survival and reproduction during the Antarctic winter. An emperor penguin colony consists of a dynamic mosaic of compact zones, the so-called huddles, included in a looser network of individuals. To maximize energy savings, birds should adjust their huddling behaviour according to environmental conditions. Here, we examined the dynamics of emperor penguin aggregations, based on photo and video records, in relation to climatic factors. Environmental temperature, wind and solar radiation were the main factors contributing to huddle formation. The analysis of individual movements showed that birds originating from loose aggregations continually joined huddles. Sometimes, a small number of birds induced a movement that propagated to the entire huddle, causing its breakup within 2 min and releasing birds, which then integrated into looser aggregations. Different parts of the colony therefore appeared to continually exchange individuals in response to environmental conditions. A likely explanation is that individuals in need of warmth join huddles, whereas individuals seeking to dissipate heat break huddles apart. The regular growth and decay of huddles operates as pulses through which birds gain, conserve or lose heat. Originally proposed to account for reducing energy expenditure, the concept of social thermoregulation appears to cover a highly dynamic phenomenon that fulfils a genuine regulatory function in emperor penguins.

Using hot sauce is a really easy way to improve your diet, say experts

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If you’re the type of person who breaks out the hot sauce at the start of every single meal, congratulations – you’re really onto something there. A slew of recent studies have been piecing together evidence that capsaicin – an active component of chili peppers – promotes a higher turnover of cells in the body, which could explain why eating spicy foods has been linked to a reduced risk of mortality and slowed cancer development.

“The bottom line is that any kind of vegetable material you consume will improve your health,” nutrition expert David Popovich from Massey University in New Zealand told TIME magazine. “But hot peppers are really beneficial for you, if you can take the spice.”

Popovich has been investigating the mechanism by which capsaicin appears to slow the growth of cancer cells in the lab. Back in 2006, researchers discovered that high doses of capsaicin could slow the growth of prostate cancer cells in mice by up to 80 percent, while leaving the healthy cells alone, and just a couple of months ago, a separate team demonstrated for the first time how this spicy compound binds to cancer cells and triggers changes in their internal structure.

It’s not yet known exactly how capsaicin is interacting with cancer cells to slow their growth, but scientists have observed it binding to the outer membrane and loging itself in, which appears to trigger chemical changes in the surface of the cell. “If you add enough of it, it actually causes the membranes to come apart,” Fiona MacDonald reported for us back in September.

Popovich has observed the slowed growth of cancer cells in his own lab, andtold Mandy Oaklander from TIME that the most popular hypothesis to explain what’s going on here is that the capsaicin is promoting a process known as apoptosis – programmed cell death that leads to a higher turnover of cells. It’s basically regulated cell suicide in the interest of cleaning up cells that are no longer needed.

“That’s one of the ways scientists think capsaicin and other active compounds in vegetables can prevent cancer development: by stimulating apoptotic cell death,” says Popovich.

While some researchers are investigating the potential of incorporating a concentrated form of capsaicin into a new anti-cancer drug, José de Jesús Ornelas-Paz from the Research Centre for Food and Development in Mexico told Oaklander the real benefits appear to come from the whole chili pepper – not just that one active ingredient.

“Pungent peppers are a cocktail of bioactive compounds,” he said. “Blending, cutting and cooking improve the release of [these compounds] from pepper tissue, increasing the amount available for absorption.”

Just as adding certain types of protein to a salad can actively improve your uptake of nutrients, research has shown that it’s not just what you eat, but how you eat it. According to Ornelas-Paz, because capsaicin is a fat-soluable compound, you should definitely try pairing it with a bit of fat or oil to help your body absorb it (which isn’t exactly difficult, unless you only like eating raw vegetables with your hot sauce).

As with many things to do with our diet, scientists still have to figure out the exact mechanism by which capsaicin could be altering our cells, but there’s enough evidence out there to suggest that it’s doing something beneficial. Back in August, a team from Harvard University published the results of a study that assessed the health of almost half a million Chinese adults, and found that those who ate spicy food six or seven times a week had a 14 percent lower mortality risk than those who seldom ate it.

So apply that spicy condiment with abandon until you’re blinded by the salty tears of too much hot sauce sweet, sweet vindication. You might look ridiculous, but at least you know you’ve got science on your side.

Playing 3-D video games can boost memory formation, study finds

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Playing 3-D video games can boost memory formation, UCI study finds
UCI professor of neurobiology & behavior Craig Stark, here holding a 3-D-printed model of his own hippocampus, says that “video games may be a nice, viable route” to maintaining cognitive health. 

Don’t put that controller down just yet. Playing three-dimensional video games – besides being lots of fun – can boost the formation of memories, according to University of California, Irvine neurobiologists.

Along with adding to the trove of research that shows these games can improve eye-hand coordination and , this finding shows the potential for novel virtual approaches to helping people who lose as they age or suffer from . Study results appear Dec. 9 in The Journal of Neuroscience.

For their research, Craig Stark and Dane Clemenson of UCI’s Center for the Neurobiology of Learning & Memory recruited non-gamer college students to play either a with a passive, two-dimensional environment (“Angry Birds”) or one with an intricate, 3-D setting (“Super Mario 3D World”) for 30 minutes per day over two weeks.

Before and after the two-week period, the students took memory tests that engaged the brain’s hippocampus, the region associated with complex learning and memory. They were given a series of pictures of everyday objects to study. Then they were shown images of the same objects, new ones and others that differed slightly from the original items and asked to categorize them. Recognition of the slightly altered images requires the hippocampus, Stark said, and his earlier research had demonstrated that the ability to do this clearly declines with age. This is a large part of why it’s so difficult to learn new names or remember where you put your keys as you get older.

Students playing the 3-D video game improved their scores on the memory test, while the 2-D gamers did not. The boost was not small either. Memory performance increased by about 12 percent, the same amount it normally decreases between the ages of 45 and 70.

In previous studies on rodents, postdoctoral scholar Clemenson and others showed that exploring the environment resulted in the growth of new neurons that became entrenched in the hippocampus’ memory circuit and increased neuronal signaling networks. Stark noted some commonalities between the 3-D game the humans played and the environment the rodents explored – qualities lacking in the 2-D game.
“First, the 3-D games have a few things the 2-D ones do not,” he said. “They’ve got a lot more spatial information in there to explore. Second, they’re much more complex, with a lot more information to learn. Either way, we know this kind of learning and memory not only stimulates but requires the hippocampus.”

Stark added that it’s unclear whether the overall amount of information and complexity in the 3-D game or the spatial relationships and exploration is stimulating the hippocampus. “This is one question we’re following up on,” he said.

Unlike typical brain training programs, the professor of & behavior pointed out, video games are not created with specific cognitive processes in mind but rather are designed to immerse users in the characters and adventure. They draw on many cognitive processes, including visual, spatial, emotional, motivational, attentional, critical thinking, problem-solving and working memory.

“It’s quite possible that by explicitly avoiding a narrow focus on a single … cognitive domain and by more closely paralleling natural experience, immersive video games may be better suited to provide enriching experiences that translate into functional gains,” Stark said.

The next step for him and his colleagues is to determine if environmental enrichment – either through 3-D video games or real-world exploration experiences – can reverse the hippocampal-dependent cognitive deficits present in older populations. This effort is funded by a $300,000 Dana Foundation grant.

“Can we use this video game approach to help improve hippocampus functioning?” Stark asked. “It’s often suggested that an active, engaged lifestyle can be a real factor in stemming cognitive aging. While we can’t all travel the world on vacation, we can do many other things to keep us cognitively engaged and active. Video games may be a nice, viable route.”

Physicists investigate unusual form of quantum mechanics

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In a new study, physicists at Penn State University have for the first time proposed a way to test a little-understood form of quantum mechanics called nonassociative quantum mechanics. So far, all other tests of quantum mechanics have dealt with the associative form, so the new test provides a way to explore this relatively obscure part of the theory.

quantum mechanics

“Nonassociative has been of mathematical interest for some time (and has recently shown up in certain models of String Theory), but it has been impossible to obtain a physical understanding,” coauthor Martin Bojowald at Penn State told Phys.org. “We have developed methods which allow us to do just that, and found a first application with a characteristic and instructive result. One of the features that makes this setting interesting is that much of the usual mathematical toolkit of quantum mechanics is inapplicable.”

Standard quantum mechanics is considered associative because mathematically it obeys the associative property. One of the fundamental concepts of standard quantum mechanics is the wave function, which gives the probability of finding a quantum system in a particular state. (The wave function is what determines the likelihood of Schrödinger’s cat being dead or alive, before the box is opened.) Mathematically, wave functions are vectors, and the mathematical operations involving vectors and the operators that act on them always obey the associative property (AB)C=A(BC), where the way that the parentheses are set doesn’t matter.

However, a few exotic quantum systems cannot be represented by wave functions, and so do not obey the associative property but instead are described by nonassociative algebra. One example of a nonassociative quantum system is a group of , which are hypothetical magnetic particles that have only a north or a south pole, not both like ordinary magnets.

In the new study, the physicists found theoretical evidence pointing to the existence of new, potentially observable, quantum effects that are not found in associative quantum mechanics. These new effects are predicted to cause a charged particle to move in a stable, circular motion in a situation where it otherwise would not in standard quantum mechanics.

More specifically, this situation involves the combination of a magnetic field with a linear force. If there is only a magnetic field, stable circular motion is possible also in standard quantum mechanics, but the linear force disrupts this motion. With the nonassociative effect, there is a new force that can compensate for the external linear force, making it again possible to have stable circular motion.

Although it would be difficult to experimentally realize a containing monopoles (as monopoles may not even exist), the scientists hope that the effects predicted here may be tested in the not-so-distant future.

“Fundamental monopoles are hypothetical, but there has recently been much research on constructing condensed matter systems consisting of quasi-particles which have properties similar to monopoles,” said coauthor Suddhasattwa Brahma. “In this setting, our new predictions may well be testable. Our equations have to be analyzed in more detail in order to see what should happen in the presence of magnetic fields realized in this context, and how strong the new effects would then be. This process may take a few years, but not much longer.”

Overall, the results could lead to a better understanding of nonassociative quantum mechanics. One of the intriguing consequences of the nonassociative property in quantum mechanics is a “triple” uncertainty relation.

“The usual uncertainty relation limits the precision of simultaneous measurements of position and momentum,” said coauthor Umut Büyükçam. “The triple one limits the precision of simultaneous measurements of all three components of the momentum vector, provided there are magnetic monopoles.

“Just as the standard uncertainty relation played an important role in the development of quantum mechanics, one can expect the triple uncertainty relation to be helpful in further improving our understanding of nonassociative quantum mechanics.”