Tag: biology

Music cuts across cultures: Certain aspects of our reactions to music universal

Music cuts across cultures: Certain aspects of our reactions to music universal

Machprinciple
http://machprinciple.com/music-cuts-across-cultures-certain-aspects-of-our-reactions-to-music-universal/

Musical-Wallpapers[1]

Whether you’re a Pygmy in the Congolese rainforest or a big-city hipster, certain aspects of music will touch you in the same ways—but others very differently, a study suggests.

“People have been trying to figure out for quite a while whether the way that we react to music is based on the culture that we come from or on some universal features of the music itself,” said co-researcher Stephen McAdams of McGill University in Montreal. “Now we know that it is actually a bit of both.”

The researchers traveled deep into the rainforest to play music to a very isolated people, the Mbenzélé Pygmies, who live without radio, television or electricity. They then compared how the Mbenzélé responded both to their own and to unfamiliar Western music, with how Canadians in downtown Montreal responded to the same pieces.

They found that the two groups were similar in their responses to how exciting or calming they found the music to be—but differed regarding whether specific pieces made them feel good or bad. The Pygmies tended to rate everything, even “scary” music, as making them happy, according to the study, published in the research journal Frontiers in Psychology.

The investigators played 19 short musical extracts (11 western and 8 Pygmy) of between about 30 and 90 seconds to 40 Pygmies and an equal number of Canadians. Because all the Mbenzélé Pygmies sing regularly for ceremonial purposes, the Canadians recruited for the study were all either amateur or professional musicians.

The Western music was designed to induce a range of emotions from calm to excited, and from happy to anxious or sad, and included both orchestral music and excerpts from three popular films (Psycho, Star Wars, and Schindler’s List).

The Pygmy pieces were all polyphonic (multiple-voiced) vocal pieces that are fairly upbeat and tend to be performed in ceremonial contexts to calm anger, or express comfort after a death, for example, or to bid good fortune before a hunting expedition leaves the village, or even to pacify a crying child.

The researchers used emoticons with smiling or frowning faces at each end of a continuum to get people to identify whether the music made them feel good or bad. They also asked participants to rate whether the music made them feel calm (close-eyed emoticon) or excited (open-eyed face). As participants listened, various measurements were also taken such as heart rate, rate of respiration, and amount of sweat on the palms.

“Our major discovery is that listeners from very different groups both responded to how exciting or calming they felt the music to be in similar ways,” said Hauke Egermann of the Technische Universität in Berlin, who did part of the research while at McGill University in Montreal. “This is probably due to certain low-level aspects of music such as tempo (or beat), pitch (how high or low the music is on the scale) and timbre (tone color or quality), but this will need further research.”

The main difference between Pygmy and Canadian listeners, the researchers said, was that the Canadians described themselves as feeling a much wider range of emotions as they listened to the Western music than the Pygmies felt when listening to either their own or Western music. This is probably attributable to the varying roles that music plays in each culture.

“Negative emotions are felt to disturb the harmony of the forest in Pygmy culture and are therefore dangerous,” said Nathalie Fernando of the University of Montreal’s Faculty of Music, who has been collecting and documenting Mbenzélé music-making for 10 years. “If a baby is crying, the Mbenzélé will sing a happy song. If the men are scared of going hunting, they will sing a happy song—in general music is used in this culture to evacuate all negative emotions, so it is not really surprising that the Mbenzélé feel that all the music they hear makes them feel good.”

source: http://www.world-science.net/

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Scientists study whale that lives 200 years for clues

Scientists study whale that lives 200 years for clues

Machprinciple
http://machprinciple.com/scientists-study-whale-that-lives-200-years-for-clues/

Sei whale, Azores, North Atlantic

A whale that can live over 200 years with little evidence of age-related disease may provide untapped insights into how to live a long and healthy life, biologists say.

In the Jan. 6 issue of the research journal Cell Reports, scientists present the bowhead whale’s complete genome and identify what they say are key differences with other mammals.

Changes in bowhead genes related to cell division, DNA repair, cancer, and aging may have helped increase its longevity and cancer resistance, according to the researchers.

“Our understanding of species’ differences in longevity is very poor, and thus our findings provide novel candidate genes for future studies,” said the study’s senior author, João Pedro de Magalhães of the University of Liverpool in the UK.

“My view is that species evolved different ‘tricks’ to have a longer lifespan, and by discovering the ‘tricks’ used by the bowhead we may be able to apply those findings to humans in order to fight age-related diseases.”

Also, he added, large whales with over 1,000 times more cells than humans don’t seem to have higher cancer risk, suggesting the whales have natural mechanisms that help suppress cancer.

Magalhães and his team plan to breed mice with various bowhead genes in hopes of determining the importance of different genes for longevity and resistance to diseases. They also note that because the bowhead’s genome is the first among large whales to be decoded, the new information may help reveal physiological adaptations related to large size.

Is warfare linked to evolution?

Machprinciple
http://machprinciple.com/is-warfare-linked-to-evolution/

Among an eastern African farming people, males who participate in livestock raids in youth may enjoy greater long-term “reproductive success,” a study has found.

The results could feed into a longstanding debate over whether warfare is a product of evolution. Evolutionary theory holds that characteristics of a species take root because they enhance survival and reproduction. Over generations, this causes advantageous features for an individual to spread throughout a population, while unhelpful characteristics die out.

In the new study, published in the journal Proceedings of the National Academy of Sciences this week, Luke Glowacki and Richard Wrangham of Harvard University traced the number of wives and children of 120 male members of the pastoralist Nyangatom people of Ethiopia and South Sudan.

In the short term, the authors found, men who engaged in livestock raids didn’t have more wives or children than non-raiders. This suggests that captured livestock aren’t directly used as leverage for marriage opportunities—rather they’re used by existing family members, the researchers said.

On the other hand, “elders who were identified as prolific raiders in their youth have more wives and children than other elders,” the authors wrote. “Our results suggest that in this cultural context raiding provides opportunities for increased reproductive success over the lifetime.”

“The causes of warfare in small-scale societies continue to be debated,” the authors added. “Most anthropological explanations have focused on causes that ignore the individual benefits warriors sometimes receive for participation.”

However, they added, “evolutionary anthropologists have commonly argued that warriors may receive fitness benefits,” or advantages that enhance their reproductive opportunities. “This hypothesis has a contentious history, in part because of concerns that a positive association between warfare and reproductive success may suggest biological” tendencies toward violence.

Glowacki and Wrangham also examined whether raiding and reproduction among the Nyangatom might be only coincidently related because both are related to a third factor—the man’s number of older siblings, which may enhance resources to leverage marriage opportunities. But the researchers concluded that this wasn’t the case.

Source : http://www.world-science.net/

Is warfare linked to evolution?

Machprinciple
http://machprinciple.com/is-warfare-linked-to-evolution/

Among an eastern African farming people, males who participate in livestock raids in youth may enjoy greater long-term “reproductive success,” a study has found.

The results could feed into a longstanding debate over whether warfare is a product of evolution. Evolutionary theory holds that characteristics of a species take root because they enhance survival and reproduction. Over generations, this causes advantageous features for an individual to spread throughout a population, while unhelpful characteristics die out.

In the new study, published in the journal Proceedings of the National Academy of Sciences this week, Luke Glowacki and Richard Wrangham of Harvard University traced the number of wives and children of 120 male members of the pastoralist Nyangatom people of Ethiopia and South Sudan.

In the short term, the authors found, men who engaged in livestock raids didn’t have more wives or children than non-raiders. This suggests that captured livestock aren’t directly used as leverage for marriage opportunities—rather they’re used by existing family members, the researchers said.

On the other hand, “elders who were identified as prolific raiders in their youth have more wives and children than other elders,” the authors wrote. “Our results suggest that in this cultural context raiding provides opportunities for increased reproductive success over the lifetime.”

“The causes of warfare in small-scale societies continue to be debated,” the authors added. “Most anthropological explanations have focused on causes that ignore the individual benefits warriors sometimes receive for participation.”

However, they added, “evolutionary anthropologists have commonly argued that warriors may receive fitness benefits,” or advantages that enhance their reproductive opportunities. “This hypothesis has a contentious history, in part because of concerns that a positive association between warfare and reproductive success may suggest biological” tendencies toward violence.

Glowacki and Wrangham also examined whether raiding and reproduction among the Nyangatom might be only coincidently related because both are related to a third factor—the man’s number of older siblings, which may enhance resources to leverage marriage opportunities. But the researchers concluded that this wasn’t the case.

Source : http://www.world-science.net/

Body Cameras On Cops can present violence

Body Cameras On Cops can present violence

Machprinciple
http://machprinciple.com/body-cameras-on-cops-can-present-violence/

rtr4gl8w[1]

Body cameras on police officers may reduce abusive behavior both by and against officers, a study has found.

Researchers from the University of Cambridge in the U.K. published the results of an experiment they conducted on the cameras’ effects in Rialto, Calif. in 2012. The year-long study found that use of force by camera-wearing police fell by 59 percent and reports against officers dropped by 87 percent against the previous year’s figures.

While the technology helps capture evidence for potential use in court, its greatest benefit may be preventing escalation to violence in the first place, the investigators said—in short, people tend to behave when they know they’re on camera.

However, the research team caution that the Rialto experiment is only a first step, and that more needs to be known about the impact of body-worn cameras before police departments are pressured into adopting the technology.

Vital questions remain, they explained, about how routine provision of digital video as evidence will affect prosecution expectations, and the storage technology and policies that the immense amounts of new data will require. President Obama recently promised to spend $75 million of federal funds on body-worn-video to address persistent protests over police killing unarmed black men.

Some question the merit of camera technology given that the officer responsible for killing Eric Garner—a 43-year-old black man suffocated during arrest for selling untaxed cigarettes—was acquitted by a grand jury even though a bystander filmed the altercation on a cell phone. Footage showed an illegal ‘chokehold’ placed on Garner who repeatedly states: “I can’t breathe.” (A medical examiner ruled the death a homicide).

For the Cambridge researchers, the Rialto results show that body-worn-cameras can reduce the need for such evidence by preventing excessive force in the first place.

“In the tragic case of Eric Garner, police weren’t aware of the camera and didn’t have to tell the suspect that he, and therefore they, were being filmed,” said Barak Ariel of Cambridge’s Institute of Criminology, who conducted the experiment with Cambridge colleague Alex Sutherland and Rialto police chief Tony Farrar.

“With institutional body-worn-camera use, an officer is obliged to issue a warning from the start that an encounter is being filmed, impacting the psyche of all involved by conveying a straightforward, pragmatic message: we are all being watched, videotaped and expected to follow the rules,” he said.

The idea behind body-worn-video, in which small high-definition cameras are strapped to a police officers’ torso or hat, is that every step of every police-public interaction—from the mundane to those involving deadly force—gets recorded to capture the closest approximation of actual events for evidence purposes, with only case-relevant data being stored.

In Rialto, police shifts over the course of a year were randomly assigned to be either with or without camera, with video covering over 50,000 hours of interactions. Ariel and colleagues are replicating the Rialto experiment with over 30 forces across the world, and early signs match the Rialto success, Ariel said.

Body-worn cameras seem very cost-effective: analysis from Rialto showed every dollar spent on the technology saved about four dollars on complaints litigations, the researchers added. But with technology becoming cheaper, the sheer volumes of data storage could become crippling.

“User licenses, storage space, ‘security costs’, maintenance and system upgrades can potentially translate into billions of dollars worldwide,” Ariel said.

And, if body-worn cameras become the norm, what might the cost be when video evidence isn’t available? “Historically, courtroom testimonies of response officers have carried tremendous weight, but prevalence of video might lead to reluctance to prosecute when there is no evidence from body-worn-cameras to corroborate the testimony of an officer, or even a victim,” said Ariel.

The study is published in the Journal of Quantitative Criminology.

Scientists may be able to restore the lost memories

Scientists may be able to restore the lost memories

Machprinciple
http://machprinciple.com/scientists-may-be-able-to-restore-the-lost-memories/

Memory-hippocampus-brain-631.jpg__800x600_q85_crop[1]

New UCLA research indicates that lost memories can be restored. It shows some rays of hope for patients in the early stages of Alzheimer’s disease.

For decades, most neuroscientists have believed that memories are stored at the synapses — the connections between brain cells, or neurons — which are destroyed by Alzheimer’s disease. The new study provides evidence contradicting this idea.

“Long-term memory is not stored at the synapse,” said David Glanzman, a senior author of the study, and a UCLA professor of integrative biology and physiology and of neurobiology. “That’s a radical idea, but that’s where the evidence leads. The nervous system appears to be able to regenerate lost synaptic connections. If you can restore the synaptic connections, the memory will come back. It won’t be easy, but I believe it’s possible.” The findings were published recently in eLife.

Glanzman’s research team studies a type of marine snail called Aplysia to understand the animal’s learning and memory. The Aplysia displays a defensive response to protect its gill from potential harm, and the researchers are especially interested in its withdrawal reflex and the sensory and motor neurons that produce it.

They enhanced the snail’s withdrawal reflex by giving it several mild electrical shocks on its tail. The enhancement lasts for days after a series of electrical shocks, which indicates the snail’s long-term memory. Glanzman explained that the shock causes the hormone serotonin to be released in the snail’s central nervous system.

Long-term memory is a function of the growth of new synaptic connections caused by the serotonin, said Glanzman, a member of UCLA’s Brain Research Institute. As long-term memories are formed, the brain creates new proteins that are involved in making new synapses. If that process is disrupted — for example by a concussion or other injury — the proteins may not be synthesized and long-term memories cannot form. (This is why people cannot remember what happened moments before a concussion.)

“If you train an animal on a task, inhibit its ability to produce proteins immediately after training, and then test it 24 hours later, the animal doesn’t remember the training,” Glanzman said. “However, if you train an animal, wait 24 hours, and then inject a protein synthesis inhibitor in its brain, the animal shows perfectly good memory 24 hours later. In other words, once memories are formed, if you temporarily disrupt protein synthesis, it doesn’t affect long-term memory. That’s true in the Aplysia and in human’s brains.” (This explains why people’s older memories typically survive following a concussion.)

Glanzman’s team found the same mechanism held true when studying the snail’s neurons in a Petri dish. The researchers placed the sensory and motor neurons that mediate the snail’s withdrawal reflex in a Petri dish, where the neurons re-formed the synaptic connections that existed when the neurons were inside the snail’s body. When serotonin was added to the dish, new synaptic connections formed between the sensory and motor neurons. But if the addition of serotonin was immediately followed by the addition of a substance that inhibits protein synthesis, the new synaptic growth was blocked; long-term memory could not be formed.

The researchers also wanted to understand whether synapses disappeared when memories did. To find out, they counted the number of synapses in the dish and then, 24 hours later, added a protein synthesis inhibitor. One day later, they re-counted the synapses.

What they found was that new synapses had grown and the synaptic connections between the neurons had been strengthened; late treatment with the protein synthesis inhibitor did not disrupt the long-term memory. The phenomenon is extremely similar to what happens in the snail’s nervous system during this type of simple learning, Glanzman said.

Next, the scientists added serotonin to a Petri dish containing a sensory neuron and motor neuron, waited 24 hours, and then added another brief pulse of serotonin — which served to remind the neurons of the original training — and immediately afterward add the protein synthesis inhibitor. This time, they found that synaptic growth and memory were erased. When they re-counted the synapses, they found that the number had reset to the number before the training, Glanzman said. This suggests that the “reminder” pulse of serotonin triggered a new round of memory consolidation, and that inhibiting protein synthesis during this “reconsolidation” erased the memory in the neurons.

If the prevailing wisdom were true — that memories are stored in the synapses — the researchers should have found that the lost synapses were the same ones that had grown in response to the serotonin. But that’s not what happened: Instead, they found that some of the new synapses were still present and some were gone, and that some of the original ones were gone, too.

Glanzman said there was no obvious pattern to which synapses stayed and which disappeared, which implied that memory is not stored in synapses.

When the scientists repeated the experiment in the snail, and then gave the animal a modest number of tail shocks — which do not produce long-term memory in a naive snail — the memory they thought had been completely erased returned. This implies that synaptic connections that were lost were apparently restored.

“That suggests that the memory is not in the synapses but somewhere else,” Glanzman said. “We think it’s in the nucleus of the neurons. We haven’t proved that, though.”

Glanzman said the research could have significant implications for people with Alzheimer’s disease. Specifically, just because the disease is known to destroy synapses in the brain doesn’t mean that memories are destroyed.

“As long as the neurons are still alive, the memory will still be there, which means you may be able to recover some of the lost memories in the early stages of Alzheimer’s,” he said.

Glanzman added that in the later stages of the disease, neurons die, which likely means that the memories cannot be recovered.

The cellular and molecular processes seem to be very similar between the marine snail and humans, even though the snail has approximately 20,000 neurons and humans have about 1 trillion.

Almost all the processes that are involved in memory in the snail also have been shown to be involved in memory in the brains of mammals, Glanzman said.

Glanzman’s demonstration that the NMDA receptor plays a critical role in learning in a simple animal like the marine snail was entirely unexpected at the time.

 

Crows are Much Smarter Than Previously Thought: Study

Crows are Much Smarter Than Previously Thought: Study

Machprinciple
http://machprinciple.com/crows-are-much-smarter-than-previously-thought-study/

House_crow_Bangalore_India[1]

Crows can reason by analogy, a study has found, showing an ability to recognize how different pairs of objects have similar relationships.

That means crows join humans, apes and monkeys in showing advanced “relational” thinking, according to the research. The crows also passed their test without training, except on a similar-but-easier task, the researchers said.

The crows’ feat is “phenomenal,” said Ed Wasserman, a University of Iowa psychologist and co-author of a report on the findings, though “it’s been done before with apes and monkeys.” Wasserman added that the crow brain is as “as special to birds as the brain of an ape is special to mammals.”

In the paper, published by Dec. 18 in the journal Current Biology, Wasserman and researchers at Lomonosov Moscow State University describe how they initially trained two hooded crows to win treats by matching pictures.

Later, they presented the birds with two cups, one empty and one with a treat. Each cup was covered with a card showing two pictures. The task was to choose the card where the pictured objects had the same relationship as those shown on a third, “sample” card.

For example, if the sample card displayed two same-sized squares, the crows might have to choose the card with two same-sized circles, rather than two different-sized circles.

The investigators said they were surprised to find that the crows could correctly perform this without specific training. Their previous game had involved exactly matching pictures rather than analogies.

“Honestly, if it was only by brute force that the crows showed this learning, then it would have been an impressive result. But this feat was spontaneous,” Wasserman said, although some background knowledge was present.

Anthony Wright, a neurobiologist at the University of Texas-Houston Medical School, said the discovery is on par with demonstrations of tool use by some birds, including crows.

“Analogical reasoning, matching relations to relations, has been considered to be among the more so-called ‘higher order’ abstract reasoning processes,” he said. “For decades such reasoning has been thought to be limited to humans and some great apes. The apparent spontaneity of this finding makes it all the more remarkable.”

Joel Fagot, director of research at the University of Aix-Marseille in France, agreed the results shatter the notion that “sophisticated forms of cognition can only be found in our ‘smart’ human species. Accumulated evidence suggests that animals can do more than expected.”

Wasserman concedes there will be skeptics and hopes the experiment will be repeated with more crows as well as other species. He suspects researchers will have more such surprises in store for science. “We have always sold animals short,” he said. “That human arrogance still permeates contemporary cognitive science.”

source : http://www.world-science.net/

Dinosaur-killer asteroid also nearly wiped out mammals

Dinosaur-killer asteroid also nearly wiped out mammals

Machprinciple
http://machprinciple.com/dinosaur-killer-asteroid-also-nearly-wiped-out-mammals/

life-on-earth-could-have-started-from-asteroid-impact-1-640x445-590x410[1]

The dinosaurs’ extinction 66 million years ago is thought to have opened the way for mammals to dominate the land. But a new study claims many of them died off too.

“If a few lucky species didn’t make it through, then mammals may have gone the way of the dinosaurs and we wouldn’t be here,” said Steve Brusatte of the University of Edinburgh in the U.K., one of the authors of a report on the findings.

Among mammals, the study argues, the brunt of the disaster seems to have hit a group known as metatherians—extinct relatives of living marsupials (“mammals with pouches,” such as opossums and kangaroos.) These thrived in the shadow of the dinosaurs during the Cretaceous period, just before the extinction.

The study, published in the research journal Zookeys, finds these once-abundant mammals nearly followed the dinosaurs into oblivion.

When a 10-km (6-mile)-wide asteroid struck what is now Mexico, unleashing a global cataclysm, some two-thirds of all metatherians living in North America perished, according to the researchers. These casualties, they said, included more than 90 percent of species living in the northern Great Plains, the best area in the world for preserving latest Cretaceous mammal fossils.

Metatherians, the scientists added, would never recover their previous diversity, which is why marsupials are rare today and largely restricted to areas in Australia and South America. Taking advantage of the metatherian demise were the placental mammals: species that give live birth to well-developed young. They are almost everywhere today and include everything from mice to men.

“It wasn’t only that dinosaurs died out, providing an opportunity for mammals to reign, but that many types of mammals, such as most metatherians, died out too—this allowed advanced placental mammals to rise to dominance,” said Thomas Williamson of the New Mexico Museum of Natural History and Science, lead author of the paper.

The study reviews the Cretaceous evolutionary history of metatherians and provides a family tree for these mammals based on the latest fossil records, which researchers said allowed them to study extinction patterns in unprecedented detail.

Source :  www.world-science.net

Curiosity readings point to mysterious, pulsing source of methane on Mars

Curiosity readings point to mysterious, pulsing source of methane on Mars

Machprinciple
http://machprinciple.com/curiosity-readings-point-to-mysterious-pulsing-source-of-methane-on-mars/

mars-life[1]

Levels of the organic gas methane are periodically spiking at the Gale Crater on Mars—suggesting something, possibly something alive, is creating the substance, scientists say.

Most of Earth’s methane production has a biological origin, but there are other ways methane, the simplest organic molecule, can arise naturally. Organic molecules are carbon-based and are essential ingredients for life.

The new findings, from the NASA Mars rover Curiosity, are published this week in the research journal Science.

Investigators said the findings suggest that the methane level in Mars’ atmosphere at the 154-km (96 mile) wide crater is generally lower than models predict, but that it spikes often. This implies the gas arises periodically from some nearby source, they added.

The scientists, from the NASA Jet Propulsion Laboratory in Pasadena, Calif. and other institutions, used 20 months of data collected by instruments on Curiosity to gauge levels of the gas at crater, near where the rover landed.

Their study found that the stable, background level of atmospheric methane is less than half of what was expected from known processes, such as the light-induced breakdown of dust and organic materials delivered to Mars by meteorites.

However, the researchers also found that this background level of methane spiked about tenfold, sometimes over the course of just 60 Martian days, which was surprising because the gas is expected to have a lifetime of about 300 years. The results suggest that methane is occasionally produced or vented near the crater, which is near the Martian equator, they added.

NASA originally chose Gale Crater, which has a mountain in the middle of it, as a landing site for the rover because there were signs of water in the area. The crater is believed to have formed with a meteor hit Mars in its early history, about 3.5 to 3.8 billion years ago.

The announcement comes just weeks after another report concluding that a Martian meteorite called Tissint contains organic molecules of possible biological origin.

[embedyt]http://www.youtube.com/watch?v=2PX6BXGHAGE[/embedyt]

source: http://www.world-science.net/

Herd mentality: Are we programmed to make bad decisions?

Herd mentality: Are we programmed to make bad decisions?

Machprinciple
http://machprinciple.com/herd-mentality-are-we-programmed-to-make-bad-decisions/

AP1[1]

A desire to be part of the “in crowd” is a result of our evolution—but can damage our ability to make good decisions, a new study proposes.

The research concludes that groups are less responsive to changes in their natural environment because individuals have evolved to be overly influenced by their neighbors. The investigators used mathematical models to examine how the use of social information has evolved within animal groups.

“Copying what other individuals do can be useful in many situations, such as what kind of phone to buy, or for animals, which way to move or whether a situation is dangerous,” said Colin Torney of the University of Exeter in the U.K., lead author of a paper on the findings.

But “the challenge is in evaluating personal beliefs when they contradict what others are doing. We showed that evolution will lead individuals to over use social information, and copy others too much… the result is that groups evolve to be unresponsive to changes in their environment and spend too much time copying one another, and not making their own decisions. “

The study is published in the Dec. 17 issue of the research journal Interface.

By using a simple model of decision-making in a changing environment, the team found that individuals overly rely on social information and evolve to be too readily influenced by their neighbors. The researchers suggest this is due to a “classic evolutionary conflict between individual and collective interest.”

“Our results suggest we shouldn’t expect social groups in nature to respond effectively to changing environments. Individuals that spend too much time copying their neighbors [are] likely to be the norm,” Torney said.