Tag: interesting science

Scientists study whale that lives 200 years for clues

Scientists study whale that lives 200 years for clues

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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?

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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/

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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.

Birds diversified in “big bang” after dinosaurs died out

Birds diversified in “big bang” after dinosaurs died out

Machprinciple
http://machprinciple.com/birds-diversified-in-big-bang-after-dinosaurs-died-out/

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A major new study sheds new light on how and when birds evolved and acquired features such as feathers, flight and song, scientists say.

The study charts a burst of evolution that took place after the dinosaurs suddenly died out, about 66 million years ago. Scientists say this burst occurred as new forms exploited opportunities left open by the absence of the dinosaurs, some of which were the ancestors of these same birds. Within 10 million years, researchers found, the avian explosion created representatives of nearly all the major bird lineages with us today.

The four-year project decoded and compared the entire genetic fingerprint of 48 bird species to represent all these lineages—including the woodpecker, owl, penguin, hummingbird and flamingo.

Researchers also compared these genomes with those of three other reptile species and humans.

They found that birdsong evolved separately at least twice. Parrots and songbirds gained the ability to learn and mimic vocal activity independently of hummingbirds, despite sharing many of the same genes.

The findings are considered important because some of brain processes that are involved in bird singing are also associated with human speech.

Birds are the most geographically diverse group of land animals. They help scientists investigate fundamental questions in biology and ecology and they are also a major global food resource, providing meat and eggs.

More than 200 scientists contributed to the Avian Phylogenomics Project, which was led by BGI in Shenzhen, China, the University of Copenhagen, Duke University in North Carolina, the Howard Hughes Medical Institute based in Chevy Chase, Md., and the Natural History Museum of Denmark. The findings are published in 23 scientific papers, including eight in the journal Science.

Building on this research, scientists at the National Avian Research Facility in Edinburgh have created 48 databases to share and expand on the information associated with the birds’ genomes. They hope that researchers from around the world will continue to upload their own data, offering further insights to the genetics of modern birds.

Such information is expected to be useful for helping scientists to understand why infectious diseases, such as bird flu, affect some species but not others.

“This is just the beginning. We hope that giving people the tools to explore this wealth of bird gene information in one place will stimulate further research,” said David Burt, acting director of the National Avian Research Facility at the University of Edinburgh’s Roslin Institute.

“Ultimately, we hope the research will bring important insights to help improve the health and welfare of wild and farmed birds.”

Source : www.world-science.net

Study: moving screen distracts hummingbird’s hovering skills

Study: moving screen distracts hummingbird’s hovering skills

Machprinciple
http://machprinciple.com/study-moving-screen-distracts-hummingbirds-hovering-skills/

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Hummingbirds’ remarkable ability to hover in place depends on a motionless field of view presenting itself to the tiny, nectar-feeding birds, according to new research.

University of British Columbia zoologists Benjamin Goller and Douglas Altshuler studied how the surprisingly intelligent birds—their pea-sized brains are very large for their body size—stay place while hovering.

The researchers projected moving spiral and striped patterns in front of free-flying hummingbirds trying to feed from a stationary feeder. Even minimal background pattern motion caused the hummingbirds to drift, according to the findings, published in the journal Proceedings of the National Academy of Sciences.

Giving the birds time to get used to the situation didn’t help them, the scientists found. Projecting a combination of moving and stationary patterns in front of the birds didn’t do much good either, though the birds were able to regain some stability.

Photos and video of the hummingbird experiment are available here.

“We were very surprised to see how strong and lasting the disruption was—birds with hovering and feeding abilities fine-tuned to the millimeter were off the mark by a centimeter,” ten times as much, said Goller. “We think the hummingbird’s brain is so precisely wired to process movement in its field of vision that it gets overwhelmed by even small stimuli during hovering.”

“Our brains interpret visual motion based on our current circumstances,” added Altshuler. “We react very differently to sideways movement in a parked car than while driving. Now we want to investigate how birds use vision during transitions from mode to mode, for example as they move from hovering to forward flight.”

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

Astronomers observe two stars about to merge into a supermassive star

Astronomers observe two stars about to merge into a supermassive star

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http://machprinciple.com/astronomers-observe-two-stars-about-to-merge-into-a-supermassive-star/

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Scientists are reporting the discovery of a pair of huge stars that are circling each other and are starting to merge.

Theoretical models predict that the biggest stars form by merging with other smaller stars, according to the researchers. These stars initially make up “binary” or “multiple” systems, in which two or more stars move around each other about a common central point.

The new study examines what scientists call the largest known system of binary stars that are expected to merge and that are still “main sequence” stars, meaning they’re in their active, fuel-burning phase.

The binary, known as MY Camelopardalis is also “eclipsing,” meaning that the stars sometimes block each other along the line of sight from Earth, say the researchers, who published their findings in the journal Astronomy & Astrophysics.

The scientists, who received help from amateur sky-watchers, also say the two stars are already touching, weigh the equivalent of 38 and 32 Suns, respectively, and take just 1.2 Earth days to circle each other. The stars are also believed to be slightly egg-shaped, as each distorts the other through its gravitational pull.

The stars—classified as “type O,” meaning the brightest, hottest, heaviest and bluest type—are also quite young and were already almost touching when they first formed, according to the group. And they’re expected to merge before they themselves change much further.

Stars which, like the Sun, move alone in their galaxy are a minority, said the researchers, from the University of Alicante in Spain and other institutions. Most stars spend their lives tied by gravity to one or more companion stars. MY Camelopardalis, in the constellation of the Giraffe, is the brightest star in a cluster known as Alicante 1. Researchers at the university have identified the group as a small stellar nursery, or star-forming region.

MY Camelopardalis was known for over half a century as just a single, huge star, but only a decade ago recognized as an eclipsing binary. The eclipsing property, in which one star blocks our view of the other, allows astronomers to study the system in detail as the light coming from the system changes in a regular way.

The astrophysicists studied this light using an instrument known as a spectrograph at the Calar Alto Observatory in Spain. Amateur astronomers helped by measuring the changes in the amount of light coming from the system.

Among other things, the researchers concluded that the points on the surfaces of the stars are moving at over a 10,000 miles (16,000 kilometers) a second; that the material in their outer layers is mixing; and that the stars are less than two million years old, so they haven’t had time to evolve since their birth.

While they’re expected to merge, it’s unclear exactly how this will play out. Some theoretical models suggest that the merger process is extremely fast, releasing a huge amount of energy in a kind of explosion. Other studies favor a less violent but still spectacular process.

Mars rock shows traces of biological activity

Mars rock shows traces of biological activity

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http://machprinciple.com/mars-rock-shows-traces-of-biological-activity/

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Did Mars ever have life? Might it still? A meteorite identified as coming from Mars has reignited the old debate. A study published this month argues that the rock contains traces of carbon with a likely biological origin, like coal, which comes from remains of long-ago plants.

“So far, there is no other theory that we find more compelling,” said study co-author Philippe Gillet, stressing that he’s open to being proven wrong.

Gillet and colleagues from China, Japan and Germany argue that the carbon could have gotten into the rock through contact with fluid rich in organic material. The study appears in the journal Meteoritic and Planetary Sciences

Thrown off Mars after an asteroid hit its surface, the meteorite, named Tissint, fell on the Moroccan desert on July 18, 2011, in view of several witnesses, the scientists said. Studies found the rock had small fissures filled with organic, carbon-containing matter.

The researchers carried out several analyses to conclude that the rock didn’t originate on Earth and that the carbon got into it before it left Mars. They took issue with a previous proposal that the carbon traces originated through the high-temperature crystallization of magma, or molten rock. Gillet and colleagues argue that more probably, liquids containing organic compounds of biological origin infiltrated Tissint’s “mother” rock at low temperatures, near the Martian surface.

These conclusions are supported by several properties of the meteorite’s carbon, such as its levels of so-called carbon-13 compared to carbon-12, they explained. This was found to be significantly lower than the ratio of carbon-13 in the carbon dioxide of Mars’s atmosphere, previously measured by the Phoenix and Curiosity rovers. Moreover, this difference corresponds perfectly with what is seen on Earth between a piece of coal and the carbon in the atmosphere, the scientists argue.

The researchers say the organic matter could also have reached Mars when very primitive meteorites, called carbonated chondrites, fell there, but probably not, because such meteorites contain very low levels of organic matter.

“Insisting on certainty is unwise, particularly on such a sensitive topic,” said Gillet, who directs the Earth and Planetary Sciences Laboratory at the École Polytechnique Fédérale de Lausanne, a Swiss institute of technology. “I’m completely open to the possibility that other studies might contradict our findings. However, our conclusions are such that they will rekindle the debate as to the possible existence of biological activity on Mars – at least in the past.”

Scientists found : Vultures evolved an extreme gut to cope with disgusting dietary habits

Scientists found : Vultures evolved an extreme gut to cope with disgusting dietary habits

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http://machprinciple.com/scientists-found-vultures-evolved-an-extreme-gut-to-cope-with-disgusting-dietary-habits/

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Some extreme adaptations—including very strong stomach acid—help vultures live on rotting, often poop-contaminated meat that would poison or kill most other animals, a study has found.

When vultures eat lunch they happily strip rotting carcasses to the bone. If a hide is too tough to bite through, they don’t hesitate to enter a carcass using other routes, including the back entrance—the anus. What ingredient this adds to the feast is not hard to see.

Yet the birds are apparently immune to the resulting cocktail of deadly microbes in their dinner such as Clostridia, Fuso- and Anthrax-bacteria.

“To investigate vultures’ ability to survive eating this putrid cocktail, we generated DNA profiles from the community of bacteria living on the face and gut of 50 vultures from the U.S.A.,” said researcher Lars Hestbjerg Hansen of Aarhus University in Denmark.

“Our findings enable us to reconstruct both the similarities, and differences, between the bacteria found in turkey vultures and black vultures, distributed widely in the Western Hemisphere.”

On average, the researchers found vultures’ facial skin contained DNA from 528 different types of microorganisms, but the gut revealed DNA from only 76 types. A lot of them are getting killed on the way down, said Roggenbuck and colleagues, whose findings are published in the journal Nature Communications.

“There has been strong adaptation in vultures when it comes to dealing with the toxic bacteria they digest. On one hand vultures have developed an extremely tough digestive system, which simply acts to destroy the majority of the dangerous bacteria they ingest,” he explained.

“On the other hand, vultures also appear to have developed a tolerance towards some of the deadly bacteria—species that would kill other animals actively seem to flourish in the vulture lower intestine.”

These observations, the researchers said, raise the question of whether the Clostridia and Fusobacteria in the gut simply outcompete the other bacteria without benefitting the bird, or in contrast, if their presence actually confers dietary advantages for the vultures. The results, they say, suggest it’s probably a bit of both—the surviving bacteria probably outcompete the other microbes, but also provide the birds with important nutrients by helping to break down the carrion.

The universe of microbes within the avian gut is not well understood but “it is not unreasonable to suppose that the relationship between birds and their microbes has been as important in avian evolution as the development of powered flight and song,” said Gary Graves of the Smithsonian Institution’s National Museum of Natural History in Washington, who participated in the work.

source : www.world-science.net

Largest known landslide occurred 21 million years ago

Largest known landslide occurred 21 million years ago

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http://machprinciple.com/largest-known-landslide-occurred-21-million-years-ago/

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An enormous landslide more than 21 million years ago in what is now Utah could be the largest known in all of Earth’s land areas, geologists are reporting.

The so-called Markagunt gravity slide covered an area greater than the state of Rhode Island within minutes—moving fast enough to melt rock into glass due to the immense friction, the researchers said. Any animals in the way would have been quickly mowed down.

Geologists previously knew about parts of the landslide, but in new work, geologist David Hacker of Kent State University in Ohio hiked through wilderness to find features indicating the slide was much bigger than previously realized. The findings are published in the November issue of the journal Geology.

The landslide took place in an area between what is now Bryce Canyon National Park and the town of Beaver, Utah, Hacker and colleagues said, and covered about 1,300 square miles (3,400 square km). That would make it one of the two largest known continental landslides (larger slides exist on the ocean floors).

Its rival in size, the “Heart Mountain slide,” which took place around 50 million years ago in northwest Wyoming, was discovered in the 1940s. The Markagunt slide could prove to be much larger, once it is better mapped, Hacker and colleagues said.

They suggest it occurred when not just one mountainside gave way, but a whole portion of a volcanic mountain range whose base had been pushed up higher and higher by molten rock, or magma, gathering beneath.

“Large-scale catastrophic collapses of volcanic fields such as these are rare but represent the largest known landslides on the surface of the Earth,” the authors wrote. The landslide was over 55 miles (90 km) long, Hacker added, though today, “looking at it, you wouldn’t even recognize it as a landslide.”

Understanding the mega-landslide could help geologists better understand these extreme events, he said. The Markagunt and the Heart Mountain slides document for the first time how large portions of ancient volcanic fields have collapsed, Hacker explained, representing “a new class of hazards in volcanic fields.”

Such events could theoretically happen in modern volcanic fields, or groups of volcanic mountains, such as the Cascade Mountains, which include Mt. St. Helens in Washington, he added. But many conditions must come together to produce a landslide. “We study events from the geologic past to better understand what could happen in the future,” said Hacker, who plans to continue mapping and analyzing the slide.

source: world-science.net