UCLA psychologists have used brain-imaging techniques to study what happens to the human brain when it slips into unconsciousness. Their research, published Oct. 17 in the online journal PLOS Computational Biology, is an initial step toward developing a scientific definition of consciousness.
"In terms of brain function, the difference between being conscious and unconscious is a bit like the difference between driving from Los Angeles to New York in a straight line versus having to cover the same route hopping on and off several buses that force you to take a 'zig-zag' route and stop in several places," said lead study author Martin Monti, an assistant professor of psychology and neurosurgery at UCLA.
Monti and his colleagues used functional magnetic resonance imaging (fMRI) to study how the flow of information in the brains of 12 healthy volunteers changed as they lost consciousness under anesthesia with propofol. The participants ranged in age from 18 to 31 and were evenly divided between men and women.
The psychologists analyzed the "network properties" of the subjects' brains using a branch of mathematics known as graph theory, which is often used to study air-traffic patterns, information on the Internet and social groups, among other topics.
"It turns out that when we lose consciousness, the communication among areas of the brain becomes extremely inefficient, as if suddenly each area of the brain became very distant from every other, making it difficult for information to travel from one place to another," Monti said.
The finding shows that consciousness does not "live" in a particular place in our brain but rather "arises from the mode in which billions of neurons communicate with one another," he said.
When patients suffer severe brain damage and enter a coma or a vegetative state, Monti said, it is very possible that the sustained damage impairs their normal brain function and the emergence of consciousness in the same manner as was seen by the life scientists in the healthy volunteers under anesthesia.
"If this were indeed the case, we could imagine in the future using our technique to monitor whether interventions are helping patients recover consciousness," he said.
"It could, however, also be the case that losing consciousness because of brain injury affects brain function through different mechanisms," said Monti, whose research team is currently addressing this question in another study.
"As profoundly defining of our mind as consciousness is, without having a scientific definition of this phenomenon, it is extremely difficult to study," Monti noted. This study, he said, marks an initial step toward conducting neuroscience research on consciousness.
The research was conducted at Belgium's University Hospital of Liege.
Monti's expertise includes cognitive neuroscience, the relationship between language and thought, and how consciousness is lost and recovered after severe brain injury. He was part of a team of American and Israeli brain scientists who used fMRI on former Israeli Prime Minister Ariel Sharon in January 2013 to assess his brain responses.
Read more at Science Daily
Oct 19, 2013
Adolescence: When Drinking, Genes May Collide
Many negative effects of drinking, such as transitioning into heavy alcohol use, often take place during adolescence and can contribute to long-term negative health outcomes as well as the development of alcohol use disorders. A new study of adolescent drinking and its genetic and environmental influences has found that different trajectories of adolescent drinking are preceded by discernible gene-parenting interactions, specifically, the mu-opioid receptor (OPRM1) genotype and parental-rule-setting.
Results will be published in the March 2014 issue of Alcoholism: Clinical & Experimental Research and are currently available at Early View.
"Heavy drinking in adolescence can lead to alcohol-related problems and alcohol dependence later in life," said Carmen Van der Zwaluw, an assistant professor at Radboud University Nijmegen as well as corresponding author for the study. "It has been estimated that 40 percent of adult alcoholics were already heavy drinkers during adolescence. Thus, tackling heavy drinking in adolescence may prevent later alcohol-related problems."
Van der Zwaluw said that both the dopamine receptor D2 (DRD2) and OPRM1 genes are known to play a large role in the neuro-reward mechanisms associated with the feelings of pleasure that result from drinking, as well as from eating, having sex, and the use of other drugs.
"Different genotypes may result in different neural responses to alcohol or different motivations to drink," she said. "For example, OPRM1 G-allele carriers have been shown to experience more positive feelings after drinking, and to drink more often to enhance their mood than people with the OPRM1 AA genotype. In addition, we chose to examine the influence of parental alcohol-specific rules because research has shown that, more than general measures of parental monitoring, alcohol-specific rule-setting has a considerable and consistent effect on adolescents' drinking behavior."
Van der Zwaluw and her colleagues used data from the Dutch Family and Health study that consisted of six yearly waves, beginning in 2002 and including only adolescents born in the Netherlands. The final sample of 596 adolescents (50% boys) were on average 14.3 years old at Time 1 (T1), 15.3 at T2, 16.3 at T3, 17.7 at T4, 18.7 years at T5, and 19.7 years at T6. Saliva samples were collected in the fourth wave to enable genetic testing. Participants were subsequently divided into three distinct groups of adolescent drinkers; light drinkers (n=346), moderate drinkers (n=178), and heavy drinkers (n=72).
"It was found that adolescent drinkers could be discriminated into three groups: light, moderate, and heavy drinkers," said Van der Zwaluw. "Comparisons between these three groups showed that light drinkers were more often carriers of the OPRM1 AA 'non-risk' genotype, and reported stricter parental rules than moderate drinkers. In the heavy drinking group, the G-allele carriers, but not those with the AA-genotype, were largely affected by parental rules: more rules resulted in lower levels of alcohol use."
Van der Zwaluw explained that although evidence for the genetic liability of heavy alcohol use has been shown repeatedly, debate continues over which genes are responsible for this liability, what the causal mechanisms are, and whether and how it interacts with environmental factors. "Longitudinal studies examining the development of alcohol use over time, in a stage of life that often precedes serious alcohol-related problems, can shed more light on these issues," she said. "This paper confirms important findings of others; showing an association of the OPRM1 G-allele with adolescent alcohol use and an effect of parental rule-setting. Additionally, it adds to the literature by demonstrating that, depending on genotype, adolescents are differently affected by parental rules."
Read more at Science Daily
Results will be published in the March 2014 issue of Alcoholism: Clinical & Experimental Research and are currently available at Early View.
"Heavy drinking in adolescence can lead to alcohol-related problems and alcohol dependence later in life," said Carmen Van der Zwaluw, an assistant professor at Radboud University Nijmegen as well as corresponding author for the study. "It has been estimated that 40 percent of adult alcoholics were already heavy drinkers during adolescence. Thus, tackling heavy drinking in adolescence may prevent later alcohol-related problems."
Van der Zwaluw said that both the dopamine receptor D2 (DRD2) and OPRM1 genes are known to play a large role in the neuro-reward mechanisms associated with the feelings of pleasure that result from drinking, as well as from eating, having sex, and the use of other drugs.
"Different genotypes may result in different neural responses to alcohol or different motivations to drink," she said. "For example, OPRM1 G-allele carriers have been shown to experience more positive feelings after drinking, and to drink more often to enhance their mood than people with the OPRM1 AA genotype. In addition, we chose to examine the influence of parental alcohol-specific rules because research has shown that, more than general measures of parental monitoring, alcohol-specific rule-setting has a considerable and consistent effect on adolescents' drinking behavior."
Van der Zwaluw and her colleagues used data from the Dutch Family and Health study that consisted of six yearly waves, beginning in 2002 and including only adolescents born in the Netherlands. The final sample of 596 adolescents (50% boys) were on average 14.3 years old at Time 1 (T1), 15.3 at T2, 16.3 at T3, 17.7 at T4, 18.7 years at T5, and 19.7 years at T6. Saliva samples were collected in the fourth wave to enable genetic testing. Participants were subsequently divided into three distinct groups of adolescent drinkers; light drinkers (n=346), moderate drinkers (n=178), and heavy drinkers (n=72).
"It was found that adolescent drinkers could be discriminated into three groups: light, moderate, and heavy drinkers," said Van der Zwaluw. "Comparisons between these three groups showed that light drinkers were more often carriers of the OPRM1 AA 'non-risk' genotype, and reported stricter parental rules than moderate drinkers. In the heavy drinking group, the G-allele carriers, but not those with the AA-genotype, were largely affected by parental rules: more rules resulted in lower levels of alcohol use."
Van der Zwaluw explained that although evidence for the genetic liability of heavy alcohol use has been shown repeatedly, debate continues over which genes are responsible for this liability, what the causal mechanisms are, and whether and how it interacts with environmental factors. "Longitudinal studies examining the development of alcohol use over time, in a stage of life that often precedes serious alcohol-related problems, can shed more light on these issues," she said. "This paper confirms important findings of others; showing an association of the OPRM1 G-allele with adolescent alcohol use and an effect of parental rule-setting. Additionally, it adds to the literature by demonstrating that, depending on genotype, adolescents are differently affected by parental rules."
Read more at Science Daily
Oct 18, 2013
Gravitational Waves Help Us Understand Black-Hole Weight Gain
A paper in today's issue of Science pits the front-running ideas about the growth of supermassive black holes against observational data -- a limit on the strength of gravitational waves, obtained with CSIRO's Parkes radio telescope in eastern Australia.
"This is the first time we've been able to use information about gravitational waves to study another aspect of the Universe -- the growth of massive black holes," co-author Dr Ramesh Bhat from the Curtin University node of the International Centre for Radio Astronomy Research (ICRAR) said.
"Black holes are almost impossible to observe directly, but armed with this powerful new tool we're in for some exciting times in astronomy. One model for how black holes grow has already been discounted, and now we're going to start looking at the others."
The study was jointly led by Dr Ryan Shannon, a Postdoctoral Fellow with CSIRO, and Mr Vikram Ravi, a PhD student co-supervised by the University of Melbourne and CSIRO.
Einstein predicted gravitational waves -- ripples in space-time, generated by massive bodies changing speed or direction, bodies like pairs of black holes orbiting each other.
When galaxies merge, their central black holes are doomed to meet. They first waltz together then enter a desperate embrace and merge.
"When the black holes get close to meeting they emit gravitational waves at just the frequency that we should be able to detect," Dr Bhat said.
Played out again and again across the Universe, such encounters create a background of gravitational waves, like the noise from a restless crowd.
Astronomers have been searching for gravitational waves with the Parkes radio telescope and a set of 20 small, spinning stars called pulsars.
Pulsars act as extremely precise clocks in space. The arrival time of their pulses on Earth are measured with exquisite precision, to within a tenth of a microsecond.
When the waves roll through an area of space-time, they temporarily swell or shrink the distances between objects in that region, altering the arrival time of the pulses on Earth.
The Parkes Pulsar Timing Array (PPTA), and an earlier collaboration between CSIRO and Swinburne University, together provide nearly 20 years worth of timing data. This isn't long enough to detect gravitational waves outright, but the team say they're now in the right ballpark.
"The PPTA results are showing us how low the background rate of gravitational waves is," said Dr Bhat.
"The strength of the gravitational wave background depends on how often supermassive black holes spiral together and merge, how massive they are, and how far away they are. So if the background is low, that puts a limit on one or more of those factors."
Armed with the PPTA data, the researchers tested four models of black-hole growth. They effectively ruled out black holes gaining mass only through mergers, but the other three models are still a possibility.
Read more at Science Daily
Elusive Goblin Shark Has World’s Most Terrifying Jaws
But in the deep seas around the world swims a true goblin king with no interest in righteous hairstyles: the mysterious goblin shark, whose spring-loaded jaws are surely the animal kingdom’s most incredible chompers. Freaky freaky, as Bowie might say.
First described in 1898, the goblin shark had already been known to Japanese fishermen, who called it tengu-zame, tengu being a mythical goblin with an extremely long nose that looked a bit like Pinocchio, except like Jareth it kidnapped children instead of teaching them not to lie. The shark, which grows up to 12.5 feet long, swims at depths of over 4,000 feet and remains poorly understood, though with each new specimen we’re building a better picture of its incredible adaptations to the deep-sea lifestyle.
Most dramatic, of course, are its highly protrusive jaws packed with needle-like teeth meant to trap, not slice. Sharks are able to project their mouths in this manner because the jaw is suspended by ligaments and cartilage instead of being fused to the skull. And the goblin shark takes this to the extreme with a jaw that pretty much looks like it’s trying to escape from the animal’s face.
“Goblin sharks have a very large mouth relative to their size,” added Duffy, and the skin and muscles that comprise it are very loose, “allowing it to expand considerably when the mouth is opened and the jaws protruded.” The rapid expansion “probably creates a vacuum that sucks prey into the shark’s mouth.” (See the first footage of the goblin feeding in the Shark Week video below.)
Aiding this vacuum effect is the goblin shark’s highly developed, highly mobile basihyal — a structure analogous to a tongue, except made out of cartilage — making the creature sort of like the Gene Simmons of the deep. As the jaws fire out, the giant basihyal is depressed, providing even more suction, though not substantially more rock and roll, as far as scientists can tell.
Such a large mouth, according to Duffy, is an adaptation to an environment that’s poor in food choices, allowing “consumption of a wide range of prey sizes from small crustaceans to large-bodied squid and fish.” We see this mirrored in many other deep-sea predators, from the fangtooth to the wait-a-second-this-shouldn’t-exist gulper eel.
Though we can’t yet say for certain that the goblin shark does the same, we can confidently assume it isn’t just wasting the shark family’s most remarkable sense: It’s likely following its nose, only it’s not hunting for Froot Loops, because they’d be super soggy down there.
“The elongated snout is filled with ampullae of Lorenzini,” said Duffy. “These are highly sensitive electroreceptors and probably help the goblin shark detect approaching prey, be it lantern fish or shrimps in the darkened water column, or small benthic fish resting or buried in the sea floor.”
Read more at Wired Science
Centuries-Old Manuscript Reveals Love for Richard III
Now, a nearly 600-year-old manuscript on display at the Yorkshire Museum reveals York's attitudes toward the medieval king while he was still alive. This is the first time the manuscript has been on display for the public, according to The Northern Echo.
"I advyse you, as honourably as your wisdomes can imagyne, to ressayve hym and the quene at their commyng, dispose you to do as well pageants with soch good speches as can goodly, thys short warnyng considered, be devised," read instructions from the King's secretary contained in the York House Books manuscript. The orders came in August 1483, as Richard III and his lords travelled to York.
The secretary went on to suggest that residents hang banners and tapestries along the streets, before adding that he was sure the residents of York already had it covered.
"Me nedeth not thus to advise you, for I doubte not ye have provided therfore better than I can advyse you," he wrote.
According to the House Books and other documents highlighted by the Richard III: Rumour and Reality Festival, which is ongoing until June 2014, the king was indeed met with great fanfare. Upon his death at the Battle of Bosworth in 1485, the city grieved.
"'King Richard late mercifully reigning upon us was thrugh grete treason of the duc of Northefolk and many othre that turned ayenst hyme, with many othre lordes and nobilles of this north parties, was pitiously slane and murdred to the grete hevynesse of this citie," the York House bookkeeper recorded.
Even now, York rallies around Richard III, with a number of Richard enthusiasts arguing that the king's remains should be reburied in the northern city. After Richard III's death in battle, his body was taken to Leicester, where it was stuffed into a hasty grave. In 2012, University of Leicester archaeologists rediscovered the grave, with the king's battle-bruised skeleton inside.
Read more at Discovery News
Biblical Theories, Conjectures and Other Heresies
Was Jesus Fictional?
Jesus Christ, founder of a faith that has endured for 2,000 years with a following of over one billion people, was a fiction, invented by Roman aristocrats to pacify the poor.
The astounding claim that Jesus was merely a propaganda tool has been made by American author and Biblical scholar Joseph Atwill, who plans to reveal proof of his hypothesis in a press conference on October 19. As Discovery News' Benjamin Radford notes: "Atwill believes that the story of Jesus was actually copied and created from the biography of the Roman emperor."
This isn't the first time that traditional Biblical scholarship has been challenged.
Man or Myth?
Tracing back to the 18th century, the earliest theories challenging the historical veracity of Jesus suggesting that he was in fact a combination of other mythological -- and often pagan -- traditions that share similar characteristics, such as virgin birth, sacrifice in death and resurrection.
Biblical and historical scholars, however, almost universally agree that Jesus was a living, breathing human being during the first century.
Married to Jesus?
Mary Magdalene, a former prostitute who Jesus saved from death by stoning, was one of Jesus' most committed followers. But was she also his wife?
Fans of Dan Brown's "The Da Vinci Code" may be familiar with this theory, which very nearly got a small boost last year thanks to the alleged discovery of a 1,600-year-old papyrus fragment. Karen L. King, a historian at Harvard Divinity school, identified and translated the scroll, which reads: "Jesus said to them, 'My wife... she will be able to be my disciple."
Although King herself cautioned the scroll did not necessarily mean Jesus had married, further research determined that the papyrus fragment, originally discovered in an antiques market, is a "clumsy forgery," according to Vatican experts.
Christ Kids
The fragment wasn't the only evidence of a possible union between Jesus and Mary Magdalene. A 2,000-year-old tomb discovered in Talpiot, Jerusalem, allegedly could have held the remains of Jesus and his family.
Based on this find, which was chronicled in the 2007 Discovery Channel documentary, "The Lost Tomb of Jesus," Jesus and Mary were not only married, but they had a son named Judah.
This theory is based on the inscriptions written on 10 limestone ossuaries (bone boxes), several of which contain names found in the New Testament: "Jesus son of Joseph," "Maria," "Mariamene e Mara," "Matthew," "Yose" and "Judah son of Jesus."
The tomb has stirred controversy among both scholars, who meet the claim with skepticism given the historic belief that Jesus never had a family, and the faithful, who reject the find given that it discredits the resurrection of Jesus.
On Thin Ice
After the image of the baby Jesus and Jesus on the cross, arguably the next most iconic image of Jesus is that of him walking on water.
While Christians take Jesus' water walk as a miracle, in 2006 Florida State University Professor of Oceanography Doron Nof came up with a much simpler explanation: Jesus walked on an isolated patch of ice.
As noted in the press release about the research, the study points to "a rare combination of optimal water and atmospheric conditions for development of a unique, localized freezing phenomenon" called "springs ice."
Parting of the Red Sea
The story of Jesus' water walk wasn't the first time that Nof put a Biblical miracle under a scientific lens.
In 1992, Nof came up with a theory for how Moses parted the Red Sea. He puts forward two possible explanations: strong winds along the Gulf of Suez pushing back the water, or a tsunami. According to his paper published in the Bulletin of the American Meteorological Society, the wind explanation is the most likely of the two.
Carl Drews, a software engineer with the National Center for Atmospheric Research, created a computer simulation in 2010 that drew upon language from the Bible to recreate the parting of the Red Sea. Drews echoed Nof's findings, suggesting that a strong wind may very well explain the temporarily receding shoreline, according to NPR.
Biblical scholars, however, contend that the crossing of the Israelites out of Egypt didn't take place on the Red Sea at all, but rather a Sea of Reeds, the location of which is disputed.
Samson the Sociopath
Samson, the famed Israelite of the Bible whose hair was the secret to his strength and the source of his downfall, was also likely a sociopath, according to University of California, San Diego researcher Eric Altschuler in 2001.
Credited with feats of strength including slaying a lion and moving the gates of Gaza, Samson also exhibited almost all of the symptoms of Antisocial Personality Disorder. Altschuler points to the following tales of Samson's questionable behavior as evidence for his diagnosis: "his failure to conform to social norms by torching the Philistines fields and then refusing arrest; ... his impulsivity as evidenced by his burning of the Philistine fields; his repeated involvement in physical fights, bullying, and cruelty to animals; ... and his lack of remorse, as evidenced by his gloating after the killing of 1,000 men."
In Altschuler's telling, Samson isn't so much a hero as he is a menace who was eventually brought under control by his fellow Israelites.
Read more at Discovery News
The astounding claim that Jesus was merely a propaganda tool has been made by American author and Biblical scholar Joseph Atwill, who plans to reveal proof of his hypothesis in a press conference on October 19. As Discovery News' Benjamin Radford notes: "Atwill believes that the story of Jesus was actually copied and created from the biography of the Roman emperor."
This isn't the first time that traditional Biblical scholarship has been challenged.
Man or Myth?
Biblical and historical scholars, however, almost universally agree that Jesus was a living, breathing human being during the first century.
Married to Jesus?
Fans of Dan Brown's "The Da Vinci Code" may be familiar with this theory, which very nearly got a small boost last year thanks to the alleged discovery of a 1,600-year-old papyrus fragment. Karen L. King, a historian at Harvard Divinity school, identified and translated the scroll, which reads: "Jesus said to them, 'My wife... she will be able to be my disciple."
Although King herself cautioned the scroll did not necessarily mean Jesus had married, further research determined that the papyrus fragment, originally discovered in an antiques market, is a "clumsy forgery," according to Vatican experts.
Christ Kids
Based on this find, which was chronicled in the 2007 Discovery Channel documentary, "The Lost Tomb of Jesus," Jesus and Mary were not only married, but they had a son named Judah.
This theory is based on the inscriptions written on 10 limestone ossuaries (bone boxes), several of which contain names found in the New Testament: "Jesus son of Joseph," "Maria," "Mariamene e Mara," "Matthew," "Yose" and "Judah son of Jesus."
The tomb has stirred controversy among both scholars, who meet the claim with skepticism given the historic belief that Jesus never had a family, and the faithful, who reject the find given that it discredits the resurrection of Jesus.
On Thin Ice
While Christians take Jesus' water walk as a miracle, in 2006 Florida State University Professor of Oceanography Doron Nof came up with a much simpler explanation: Jesus walked on an isolated patch of ice.
As noted in the press release about the research, the study points to "a rare combination of optimal water and atmospheric conditions for development of a unique, localized freezing phenomenon" called "springs ice."
Parting of the Red Sea
In 1992, Nof came up with a theory for how Moses parted the Red Sea. He puts forward two possible explanations: strong winds along the Gulf of Suez pushing back the water, or a tsunami. According to his paper published in the Bulletin of the American Meteorological Society, the wind explanation is the most likely of the two.
Carl Drews, a software engineer with the National Center for Atmospheric Research, created a computer simulation in 2010 that drew upon language from the Bible to recreate the parting of the Red Sea. Drews echoed Nof's findings, suggesting that a strong wind may very well explain the temporarily receding shoreline, according to NPR.
Biblical scholars, however, contend that the crossing of the Israelites out of Egypt didn't take place on the Red Sea at all, but rather a Sea of Reeds, the location of which is disputed.
Samson the Sociopath
Credited with feats of strength including slaying a lion and moving the gates of Gaza, Samson also exhibited almost all of the symptoms of Antisocial Personality Disorder. Altschuler points to the following tales of Samson's questionable behavior as evidence for his diagnosis: "his failure to conform to social norms by torching the Philistines fields and then refusing arrest; ... his impulsivity as evidenced by his burning of the Philistine fields; his repeated involvement in physical fights, bullying, and cruelty to animals; ... and his lack of remorse, as evidenced by his gloating after the killing of 1,000 men."
In Altschuler's telling, Samson isn't so much a hero as he is a menace who was eventually brought under control by his fellow Israelites.
Read more at Discovery News
Oct 17, 2013
Stonehenge Treasures Reveal Worshippers' Sophistication
Housed in a large, specially-designed high security and humidity-controlled exhibition facility inside the Wiltshire Museum in Devizes, 15 miles north of the megalithic stone circle, the objects make England’s largest collection of early Bronze-Age gold.
“Stonehenge is an iconic monument, but this is the first time that such a wide range of high status objects from the spectacular burials of the people who used it, has ever been put on permanent display,” David Dawson, director of the Wiltshire Museum.
Most of the 500 Neolithic objects on show were unearthed within a half mile radius of Stonehenge, including 30 gold pieces which were excavated in 1808 from a burial mound known as Bush Barrow.
Found by William Cunnington, Britain’s first professional archaeologist, the objects became known as the crown jewels of the “King of Stonehenge.”
Overlooking Stonehenge itself, the burial indeed contained the skeleton of a chieftain who lived almost 4,000 years ago. He was buried in regal splendor with the objects that showed his power and authority.
Among the treasures on display are a magnificent bronze dagger with a gold covered haft, a golden sheath for a dagger, a ceremonial axe, gold beads, necklaces, earrings, pendants and other gold jewellery, a unique jet disc (used to fasten a luxury garment), rare traces of ancient textiles and two of the finest prehistoric flint arrow head ever found.
“Many of the items may well have been worn by Bronze Age priests and chieftains as they worshiped inside Stonehenge,” Dawson said.
“Axes and daggers on display are identical to images of weapons carved into the giant stones of Stonehenge itself,” he added.
The exhibition’s centerpiece is the beautifully decorated gold lozenge found on the chest of the “King of Stonehenge.”
Although the purpose of the gold lozenge remains a mystery — interpretations have ranged from an elaborate button to an astronomical instrument — its precise decorations, made of impressed lines, reveals a detailed knowledge of mathematics and geometry.
“All this was done with the naked eye as there were no magnifying glasses or microscopes,” Dawson told London’s Times.
Read more at Discovery News
Is Being a Good Samaritan a Matter of Genes?
In Fort Lauderdale, Fla., after a woman lost control of her car on an Interstate freeway and flipped into a water-filled ditch, a man jumped in to rescue her from drowning. In Arizona, after a community college student lost a wallet containing her cash, credit cards, student ID and immigrant work permit, an unidentified person found it and dropped it off at her school's office. In Oklahoma, after a teenage skateboarder tumbled from his board and suffered a concussion, a man he didn't know found him by the side of the road and took him to get help.
What motivates people to stop and help others that they didn't previously know, with no apparent benefit to themselves?
Traditionally, we've viewed people who engage in prosocial behavior -- that is, voluntary acts performed to benefit others or society as a whole -- as being motivated by moral character or spiritual beliefs. But in recent years, increasing evidence has emerged to suggest that the tendency to be a do-gooder may be influenced by genes.
In a newly-published study in the journal Social Neuroscience, for example, researchers found that a single variation in a genotype seems to affect whether or not a person engages in prosocial acts. Individuals who have one variation of the genotype have a tendency toward social anxiety -- that is, unease around other people, and are less inclined to help others in ways that involve personal interaction.
Those who have another variation, in contrast, not only were less anxious, but also were more likely to be helpful. The genetic region involved is 5-HTTLPR, which regulates transport of serotonin, a neurotransmitter chemical in the brain. The researchers studied the genomes of 398 college students, and asked the subjects to fill out a questionnaire to provide information about their behavior and anxiety levels.
University of Missouri social psychologist Gustavo Carlo, one of the study's co-authors, said that the the genotype variation is just one "indirect pathway" that could lead a person to being a Good Samaritan. Another potential influence, he said, is the brain's ability to use dopamine, another brain chemical. Other genetic variations in brain chemistry may play a role as well.
"This is a really exciting area for research," Carlo said. "There are a lot of studies being done right now that focus on the micro-level biological processes associated with altruistic behavior."
Co-author Scott F. Stoltenberg, a researcher at the University of Nebraska-Lincoln's Behavior Genetics Laboratory, says the findings build on previous studies that suggest a link between relative levels of anxiety and prosocial behavior.
"It makes sense that people who have less social anxiety are more likely to help out," Stoltenberg explained. "When they're confronted with a situation where another person needs help, they don't have a problem going over to them and engaging." A person with social anxiety, in contrast, might experience so much discomfort that he or she would avoid the encounter.
Both serotonin and dopamine are neurotransmitters related to the sensations of pleasure and satisfaction, which may explain why people who perform selfless acts of generosity report that they feel good as a result.
Carlo cautioned that the study's findings don't necessarily mean that people with a genetic predisposition toward anxiety also lack empathy, the ability to care about others. While it may be more difficult for them to engage in public acts of prosocial behavior, they may instead make anonymous contributions to a person in need, or help in some other way that doesn't require personal interaction.
Why humans developed the capacity to be Good Samaritans is another widely-debated question. In the 1970s, evolutionary biologist Richard Dawkins, a believer in the notion that "genes are selfish," argued that prosocial behavior existed to ensure genetic continuity. His view was influenced by studies suggesting that organisms were most likely to help their own kin.
Read more at Discovery News
Out-of-Africa Skull May Trim Human Family Tree
The skull, dated to nearly 1.8 million years ago, is the earliest known human-like species outside of Africa ever found, according to a study published in the latest issue of Science.
It belonged to an adult male of the species Homo erectus, a.k.a. "Upright Man" and is called "Skull 5" because it was the fifth set of hominid remains recovered at the archeological site, Dmanisi, located in the Caucausus of the Republic of Georgia.
"All the Dmanisi individuals are around 1.77 million years old," co-author Christoph Zollikofer from the Anthropological Institute and Museum in Zurich, Switzerland, told Discovery News. "What is very special about Dmanisi Skull 5 is that it is the only known completely preserved and undeformed skull of an adult individual from these remote times."
Tim White, a professor of Integrative Biology at the University of California at Berkeley, told Discovery that these early members of our genus were fairly short in stature with large, projecting faces, big teeth and small brains. The latter confirms that big brains weren't needed to get humans out of Africa.
"They walked on two legs, and if you could look in on them, you might see them using primitive tech- stone tools- to remove meat and marrow from animal bones," said White. "You might also see them being killed and hauled off by a carnivore." (All five were found in underground dens where carnivores appear to have dragged their carcasses.)
Zollikofer, lead author David Lordkipanidze from the Georgian National Museum, and colleagues noted that the remains for the five Dmanisi individuals were very different. They attribute that to just normal variation within a single population. Moreover, they extended their comparisons to other documented Homo genus species and concluded that the variation was again reasonable for a single species.
They propose that Homo habilis, Homo rudolfensis, Homo ergaster and other early hominids from the same time were all misnamed and were really just members of the species Homo erectus. This bold theory would nearly wipe clean many early hominids.
Discovery News contacted multiple experts in early human history for their views, and received an earful of passionate, mixed opinions.
White and Dean Falk, an anthropologist at Florida State University, support the paper's conclusions. As Falk said, "I see no reason not to accept the authors' claim that the specimens all belong to one highly variable and highly sexually dimorphic species."
He further thinks that, although the Dmanisi individuals' brains were small, they were still in the process of slowly evolving into larger brains. That is significant, as some earlier studies have proposed that brain size suddenly took off around 2 million years ago.
Darren Curnoe, an associate professor in the School of Biological, Earth & Environmental Sciences at the University of New South Wales; Chris Stringer of the Natural History Museum, London; and Ian Tattersall of the American Museum of Natural History support the broader significance of the Dmanisi fossils, but doubt that all of the early Homo fossils can reasonably be lumped into an evolving Homo erectus lineage.
Tattersall said, "Paleoanthropologists are having a hard time letting go of the old idea that human evolution was a linear process, but fossils like this one from Dmanisi are making it ever clearer that hominid history has been one of diversity and evolutionary experimentation with the hominid potential."
Read more at Discovery News
Weird Out Of Whack Exoplanetary System Discovered
The Kepler observatory can detect these oscillations, much like it detected dips in target stars’ light due to planets passing by, or transiting, relative to the telescope’s line of sight.
Working both types of observations, scientists have now found the first multi-planet system that is tilted out of alignment with the host star.
“When we found this system, it was a major surprise. They didn’t form this way,” astronomer Daniel Huber, with NASA’s Ames Research Center in Moffett Field, Calif., told Discovery News.
The star, known as Kepler-56, is about 45 degrees out of alignment from the orbital plane of a pair of planets, which circle their parent star in 10- and 20 days respectively. Trying to determine what elbowed the planets out from the equatorial plane of their star led Huber and colleagues to a third, non-transiting, massive companion, which could be another planet or a star.
“We think it’s responsible for causing this misalignment,” Huber said.
The third, outer companion is inclined to the orbital plane of the inner planets. Scientists suspect its torque is tilting the orbital plane of the inner planets, with respect to the equatorial plane of the parent star.
Follow-up ground observations are underway to figure out the third body’s orbit and size, information scientists need to determine whether it is a planet, a brown dwarf star or another type of star.
“That is still a bit of an open question, but for the general conclusion of the theory of how this system formed it doesn’t really matter whether it’s a star or a planet. It just matters that you have a more massive companion in this outer orbit which can tilt the inner ones, which are much less massive,” Huber said.
The research has implications for understanding how planetary systems form and evolve. It also may help solve a long-standing mystery about how some giant planets settled into orbits far closer to their host stars than Mercury orbits the sun.
These so-called hot-Jupiters were the first planets discovered beyond the solar system.
“Some kind of dynamically disruption must have happened a long time ago that caused a planet to migrate so close to its host star,” Huber said.
The new research shows orbital upheavals are not just limited to hot-Jupiter systems.
Read more at Discovery News
Oct 16, 2013
Climate Change To Impact Every Inch of the Ocean
Previous studies addressing the effects of climate change on future ocean health have tended to focus on the effects of increased temperature and acidity on marine ecosystems. However, other oceanic conditions — including dissolved oxygen and productivity, or the abundance of tiny plant-like organisms that form the base of the marine food web — also play an important role in overall ocean health. As is the case on land, marine animals need oxygen and plant-life to survive.
A team of 29 international scientists based at the University of Hawaii, Honolulu, have now developed more comprehensive projections of future ocean health, which take into account temperature, acidity, dissolved oxygen and productivity. To develop these projections, the researchers compiled more than 80,000 existing modeled maps of oceanic change, many of which informed the latest Intergovernmental Panel on Climate Change (IPCC) report.
The team found that mangrove and coral reef ecosystems near the tropics will likely experience the smallest cumulative change by 2100, whereas cetaceans (the group of mammals that includes whales, dolphins and porpoises), as well as pinnipeds (such as seals and walruses) will face the largest amount of change.
"We already knew that coral reefs are very susceptible to temperature change, and our models show that they are going to be impacted the least," study co-author Camilo Mora, a researcher at the University of Hawaii, Honolulu, told LiveScience. "So you can imagine what it's going to be like for other ecosystems."
The team used the compiled maps to estimate the impact these changes will have on coastal human populations whose livelihoods depend on marine resources.
Researchers considered two different climate change scenarios: one in which humans significantly cut back carbon dioxide emissions and, as a result, global atmospheric carbon dioxide levels increase from the current 440 parts per million (ppm) to just 550 ppm; and one in which humans continue emitting carbon dioxide at the current rate, under a scenario known as "business as usual," which the IPCC projects will result in an atmospheric carbon dioxide accumulation of 900 ppm by the end of the century. (Parts per million is an indicator of the concentration of a chemical in, for example, air. So in this case, 440 ppm means that there are 440 molecules of carbon dioxide in every million molecules of air.)
Under the 550-ppm scenario, the team estimated that 1.4 billion people would face considerable local oceanic change by 2100. Of those people, 690 million will live in countries with medium to high ocean dependence — a metric the researchers developed of the extent to which a society's jobs, revenue and food depend on the ocean.
Under a business-as-usual scenario, 2 billion people will face considerable oceanic change by 2100, with 1.12 billion of them living in countries with medium to high dependence on the ocean. Of those 2 billion people, 870 million will live in low-income countries with few resources to adapt to the projected changes.
The team notes that these estimates are rough, and that the specific ways in which ecosystems and communities adjust to change will remain largely unknown until the changes unfold.
Mora likens this uncertainty to the uncertainty of falling off of a ladder: Some sort of injury is inevitable, but the exact body part or degree of injury remains unpredictable until a person hits the ground.
"Systems are very complex," Mora said. "You can't tell what species are going to go extinct, or the response of a specific species, but you can expect these changes to be quite massive."
Read more at Discovery News
'Mega-Clawed' Creature Had a Spider-Like Brain
The fossilized Alalcomenaeus is a type of arthropod known as a megacheiran (Greek for "large claws") that lived approximately 520 million years ago, during a period known as the Lower Cambrian. The creature was unearthed in the fossil-rich Chengjiang formation in southwest China.
Researchers studied the fossilized brain, the earliest known complete nervous system, and found similarities between the extinct creature's nervous system and the nervous systems of several modern arthropods, which suggest they may be ancestrally related.
Living arthropods are commonly separated into two major groups: chelicerates, which include spiders, horseshoe crabs and scorpions, and a group that includes insects, crustaceans and millipedes. The new findings shed light on the evolutionary processes that may have given rise to modern arthropods, and also provide clues about where these extinct mega-clawed creatures fit in the tree of life.
"We now know that the megacheirans had central nervous systems very similar to today's horseshoe crabs and scorpions," senior author Nicholas Strausfeld, a professor in the department of neuroscience at the University of Arizona in Tucson, said in a statement. "This means the ancestors of spiders and their kin lived side by side with the ancestors of crustaceans in the Lower Cambrian."
The newly identified creature measures a little over an inch long (3 centimeters), and has a segmented body with about a dozen pairs of attached limbs that enabled it to swim or crawl.
"Up front, it has a long pair of appendages that have scissorlike components — basically an elbow with scissors on the end," Strausfeld told LiveScience. "These are really weird appendages, and there has been a long debate about what they are and what they correspond to in modern animals."
Previously, researchers suggested megacheirans were related to chelicerates, since the extinct creature's scissorlike claws and the fangs of spiders and scorpions have similar structures, said Greg Edgecombe, a researcher at the Natural History Museum in London, England.
"They both have an 'elbow joint' in the same place, and they both have a similar arrangement of a fixed and movable finger at the tip," Edgecombe told LiveScience. "Because of these similarities, one of the main theories for what 'great appendage arthropods' are is that they were related to chelicerates. Thus, our findings from the nervous system gave an injection of new data to support an existing theory."
The researchers used CT scans to make 3D reconstructions of features of the fossilized nervous system. The scientists also used laser-scanning technology to map the distribution of chemical elements, such as iron and copper, in the specimen in order to outline different neural structures.
Though finding a well-preserved ancient nervous system is rare, the new study highlights the potential for similar discoveries, the researchers said.
"Finding ancient preservation of neural tissue allows us to analyze extinct animals using the same tools we use for living animals," Edgecombe said. "It suggests there should be more examples out there."
About a year ago, Edgecombe and his colleagues found a different fossilized brain that revealed unexpected similarity to the brains of modern crustaceans.
Read more at Discovery News
Dino Joints Key to Massive Size
One key to the dinos’ evolutionary ability to scale-up may have recently been found in their knees.
Sauropod joints handled the weight of the massive animals differently than the giant mammals, and that may have been one reason the sauropods could grow larger, according to a study published in PLOS ONE.
In the study, biologists examined how, as they evolved into larger forms, mammals developed bones with joints that fit into each other more exactly, a trait known as congruence. By fitting together better, the mammal bones reduced the possibility of stresses in unexpected parts of the joint. However, at the same time, the mammals developed thinner cartilage pads between their bones.
The study’s authors suggested there may have been a limit where the benefits of increasingly congruent bones proved insufficient without thick cartilage cushions. At that point, the mammals couldn’t evolve any larger because their joints may have lacked the physical ability to deal with the gigantic mammals’ weights.
Read more at Discovery News
Unexpected Victims of Climate Change
Moose
Polar bears serve as the poster children for climate change. But global warming also threatens many other species that don't get as much news coverage.
Moose in the Rocky Mountains become the latest climate change catastrophe icon recently, as their populations have plummeted with warming temperatures. But it's not just heat stress that is killing them off. Biologists are finding brain worms, liver flukes and ticks, as many as 150,000 on a single moose, are infecting the population to death.
Increased temperatures are allowing northern forest ticks to survive over the winter, when the blood-suckers and their eggs would normally die. This leaves an infected moose with no respite as the ticks breed again in the spring. The moose will continue to scratch and rub off its fur, develop anemia, and eventually die of emaciation.
Orangutan
Orangutans' populations on Borneo and Sumatra have declined by more than 80 percent during the last 75 years, according to the International Union for the Conservation of Nature (IUCN). Most of that decline resulted from hunting and habitat loss as the forests were logged for timber and to make room for oil palm plantations.
Climate change may further reduce the animals' homeland, according to a study in PLOS ONE. The orangutan lives most of its life swinging in the trees and the animals' forest home faces threats of drought and fire as climate change alters weather patterns.
Koala
The koala's picky eating habits may doom it as the planet's atmosphere changes. Koalas dine solely on the leaves of eucalyptus trees. Increasing levels of carbon dioxide in the air do speed up eucalyptus growth, but the leaves have lower nutritional value. Koalas need to eat more leaves to get the same amount of nutrition, according to the IUCN.
As it warms up Down Under, more forest fires and droughts threaten koalas' arboreal abodes. The IUCN named the koala as one of 10 flagship species, besides polar bears, that exemplify the effects of climate change.
Hawaiian Silversword
Like orangutans and koalas, the Haleakalā silversword (Argyroxiphium sandwicense macrocephalum) lives in a fragile habitat and would be in danger of disappearing even if the planet weren't changing. Livestock and flower-collectors nearly wiped out the plant early in the last century. Conservation programs helped the plant bounce back, but climate change has erased much of that progress, according to research in Global Change Biology. The population of the plant dropped from 65,000 in 1991 to 28,492 in 2010 as its highland habitat became warmer and dryer.
The silversword grows only on the volcanic slopes of Mount Haleakalā on the island of Maui. The plants can grow for nearly a century until it finally produces hundreds of vibrant reddish blossoms on a six-foot spike at the end of its life cycle. One to two million tourists hike to see the plants each year as they stand out against their bleak, lava-scourged surroundings.
Read more at Discovery News
Moose in the Rocky Mountains become the latest climate change catastrophe icon recently, as their populations have plummeted with warming temperatures. But it's not just heat stress that is killing them off. Biologists are finding brain worms, liver flukes and ticks, as many as 150,000 on a single moose, are infecting the population to death.
Increased temperatures are allowing northern forest ticks to survive over the winter, when the blood-suckers and their eggs would normally die. This leaves an infected moose with no respite as the ticks breed again in the spring. The moose will continue to scratch and rub off its fur, develop anemia, and eventually die of emaciation.
Orangutan
Climate change may further reduce the animals' homeland, according to a study in PLOS ONE. The orangutan lives most of its life swinging in the trees and the animals' forest home faces threats of drought and fire as climate change alters weather patterns.
Koala
As it warms up Down Under, more forest fires and droughts threaten koalas' arboreal abodes. The IUCN named the koala as one of 10 flagship species, besides polar bears, that exemplify the effects of climate change.
Hawaiian Silversword
The silversword grows only on the volcanic slopes of Mount Haleakalā on the island of Maui. The plants can grow for nearly a century until it finally produces hundreds of vibrant reddish blossoms on a six-foot spike at the end of its life cycle. One to two million tourists hike to see the plants each year as they stand out against their bleak, lava-scourged surroundings.
Read more at Discovery News
Oct 15, 2013
Women Leave Their Handprints On the Cave Wall
The assumption has been that hand prints, whether stencils -- paint blown around the hand -- or actual paint-dipped prints, were produced by men because other images on cave walls were often hunting scenes. The smaller handprints were assumed to be adolescent boys.
Dean Snow, emeritus professor of anthropology, came across the work of John Manning, a British biologist who about 10 years ago tried to use the relationships of various hand measurements to determine not only sex, but such things as sexual preference or susceptibility to heart disease. Snow wondered if he could apply this method to the handprints left in cave sites in France and Spain.
"Manning probably went way beyond what the data could infer, but the basic observation that men and women have differing finger ratios was interesting," said Snow. "I thought here was a neat little one off science problem that can be solved by applications of archaeological science."
Dean Snow, emeritus professor of anthropology, talks about Upper Paleolithic art on European cave walls.
When Snow saw a handprint in a book on Upper Paleolithic art, he realized that the image was female. A quick look at five other images found that two thirds were female.
Unfortunately, most cave art photographs lack size indication, making it difficult to determine relative size and the sex of the artist. Snow visited a number of caves and the few existing images with size indications. He also collected hand images from people with European and Mediterranean ancestry. He published his results in the current issue of American Antiquity.
Snow found he needed a two-step process for the modern hands to successfully differentiate men from women. He first measured the overall size of the hand using five different measurements. This separated the adult male hands from the rest. Snow found that step one was 79 percent successful in determining sex, but adolescent males were classified as female.
Step two compares the ratios of the index finger to the ring finger and the index finger to the pinky to distinguish between adolescent males and females. For the known hands, the success rate, though statistically significant, was only 60 percent. There is too much overlap between males and females in modern populations.
"I thought the fact that we had so much overlap in the modern world would make it impossible to determine the sex of the ancient handprints," said Snow. "But, old hands all fall at or beyond the extremes of the modern populations. Sexual dimorphism was greater then than it is now."
Sexual dimorphism implies that males and females differ. Not only were male hands larger, Snow found that development of the fingers, how long they are relative each other, also differs significantly.
The first step in the process showed that only 10 percent of the handprints on cave walls in Spain and France were left by adult males. The second step indicates that 15 percent were placed by adolescent males, leaving 75 percent of the handprints female.
Read more at Science Daily
Volcanic Eruption Creates Deadly Acid Lake
In the movie, volcanic gases quickly turn a placid lake into an acidic death trap as a family escapes burning-hot lava by boat, aided by a volcanologist played by Pierce Brosnan. Grandma sacrifices herself and jumps into the lake to push their dissolving aluminum boat the last few feet to safety.
For a film that gets some eruption science terrifyingly right, the lake's radical transformation has always been a sticking point. Volcanic gases belching from the lake bottom can't acidify an entire lake in a matter of hours, debunkers have shown. However, extremely acidic fluids could dissolve Grandma's legs and kill her from shock, as well as eat holes in the boat.
Now, it turns out there is also some truth behind the fictional volcanic chemistry.
Real-life acid trip
In 1996, volcanic blasts at Karymsky Lake in Russia's Kamchatka Peninsula created a toxic chemical soup in the formerly pristine lake, according to a study published Oct. 1 in Geophysical Research Letters. The eruption decimated the lake's ecosystem, killing off thousands of fish and trees.
The Kamchatka Peninsula is home to scores of steep-sided volcanoes, which line up like sentries along its eastern coast. Karymsky Lake nestles in the long-dormant Academy Nauk caldera, a hole in the Earth left behind when a massive eruption emptied out a magma chamber. Next door, about 3 miles (5 kilometers) north, rises Karymsky volcano, the most active volcano in Kamchatka.
Around midnight on Jan. 2, 1996, one day after a powerful earthquake, Karymsky volcano exploded, spewing ash and lava high into the air. Later that afternoon, the lake followed, with a strong underwater eruption. Eruptive pulses from the lake ejected columns of steam and ash into the air every five or six minutes for about 18 hours. (Scientists from the Institute of Volcanology and Seismology in Kamchatka watched from a safe distance, providing eyewitness accounts.)
"There was around 30 to 40 million tons of pyroclastic material and juvenile material erupted into the air, and this material was saturated with acidic fluids," said Yuri Taran, a senior researcher at the Institute of Geophysics at the National Autonomous University of Mexico and lead author of the new study.
Much of the ejected material collapsed back into the lake, stewing into a fetid mix of sodium, sulfate, calcium and magnesium. When scientists reached the lake, they discovered the pH had dropped from 7.5 to 3.2, in the range of grapefruit juice and vinegar, and the water's color was yellow-brown.
"Before the eruption, the lake was absolutely clear and after it was like an acidic hot spring," Taran told LiveScience's OurAmazingPlanet.
But unlike "Dante's Peak," the acidity didn't kill the thousands of salmon living in Karymsky Lake, Taran said. Death did come from below, but life in the lake first cooked to death, then was torn apart by tsunamis.
Here's what happened: The lake water steamed and boiled as superheated gas and lava broke through vents beneath the surface. Tsunamis up to 32 feet (20 meters) high pounded the shore with each new outburst, tearing out trees. New hot springs appeared. A small volcanic crater formed near the outlet of Karymsky River on the northern lake rim. Eventually, everything was covered with a layer of mud.
"The enormous waves, along with the sharp change in chemical composition and water temperature, led to the death of practically all life in the lake," researchers concluded in a 1998 account of the eruption published in the Proceedings of the International Symposium on Water Rock Interaction.
Despite the ecological catastrophe, Karymsky Lake is working its way back to normal.
The pH has returned to 7.54, measured during a 2012 research expedition by Taran and his colleagues. The water is clear. Still, the lake is about three times saltier than before the eruption. The new hot springs pump more minerals into the lake, keeping its salinity higher.
"Now it looks just the same, but it's not back to its original state," Taran said.
Read more at Discovery News
Rare Blood-Engorged Mosquito Fossil Found
Normally this wouldn't be newsworthy, and nobody would likely know or care about a long-dead insect in what is now northwest Montana. But somehow, the mosquito didn't immediately decompose — a fortuitous turn of events for modern-day scientists — and became fossilized over the course of many years, said Dale Greenwalt, a researcher at the National Museum of Natural History in Washington, D.C. Greenwalt discovered the mosquito fossil after it was given to the museum as a gift, and he immediately realized the specimen's rarity.
It is, in fact, the only blood-engorged mosquito fossil found, Greenwalt told LiveScience. The fossil is even stranger because it comes from shale, a type of rock formed from sediments deposited at the bottom of bodies of water, as opposed to amber, the age-old remains of dried tree sap, in which insect remnants are generally better preserved.
"The chances that such an insect would be preserved in shale is almost infinitesimally small," Greenwalt said.
In their study, Greenwalt and his collaborators bombarded the mosquito fossil with molecules of bismuth, a heavy metal, which vaporizes chemicals found in the fossil. These airborne chemicals are then analyzed by a mass spectrometer, a machine that can identify chemicals based on their atomic weights, Greenwalt said. The beauty of this technique, called time-of-flight secondary ion mass spectrometry, is that it doesn't destroy the sample — previously, similar techniques required grinding up portions of fossils, he added. The analysis revealed hidden porphyrins, organic compounds found in hemoglobin, the oxygen-carrying protein in blood, hidden in the fossilized mosquito's abdomen.
The finding may bring to mind the story of "Jurassic Park," a novel and movie in which scientists resurrect dinosaurs from DNA preserved in blood-engorged mosquitoes preserved in amber. Although this finding doesn't really make this fictitious story any more likely, it does show that complex organic molecules besides DNA can be preserved for a long time, Greenwalt said.
The discovery also shows that "blood-filled mosquitoes were already feeding at that time, suggesting that they were around much earlier and could have fed on dinosaurs," said George Poinar, a paleo-entomologist at Oregon State University, who wasn't involved in the research.
Greenwalt said he had no way of knowing exactly how the mosquito was preserved so well. Perhaps the most likely hypothesis is that the insect was trapped in a covering of water-suspended algae, which are capable of coating specimens in a sticky, gluelike material, before sinking to the bottom; this algae process has been shown to fossilize other types of insects, he said.
Researchers don't know what kind of animal the blood came from, since hemoglobin-derived porphyrins amongst different animals appear to be identical, Greenwalt said.
Read more at Discovery News
First 'Habitable Zone' Galactic Bulge Exoplanet Found
But don’t go having dreams of exotic getaways to the glistening lights of the center of our galaxy, this exoplanet is a huge gas giant world, about five times the mass of Jupiter. However, there is something (potentially) very exciting about this new discovery. Like Jupiter, this newly discovered giant exoplanet may possess small satellites; exomoons that could have life-giving potential.
This massive world was detected through “microlensing.” Microlensing events occur when a star passes in front of another, more distant, star. As the nearer star passes in front, its gravitational field — which is (according to general relativity) bending the surrounding spacetime — deflects the light from the more distant star. Like the lens in a magnifying glass, the starlight is magnified and Earth-bound observatories are able to spot a transient brightening. Information about the “lens” (the foreground star) and any planets in tow can then be deduced in the brightening’s “lightcurve.”
Detailed in a pre-print published on the arXiv, the microlensing event, known as “MOA-2011-BLG-293Lb,” was detected by all three microlensing surveys: the Microlensing Observations in Astrophysics (MOA — New Zealand/Japan), Optical Gravitational Lensing Experiment (OGLE — Poland) and Wise Observatory (Israel). Astronomers then decided to do followup observations of the event using the adaptive optics instrumentation of Hawaii-based Keck Observatory. Keck’s adaptive optics are capable of removing atmospheric aberrations and returning precise measurements of this transient brightening.
Measurements of the MOA-2011-BLG-293Lb’s lightcurve returned information about the lensing star, its planet, their masses and the star-planet distance. The star, determined to be a G-type dwarf star slightly less massive than the sun, is located only 1.1 AU (astronomical units) from the planet. This makes it highly likely (a probability of 53 percent) that the massive exoplanet is orbiting within the star’s habitable zone, albeit on the outer edge, near the star’s “snowline.” This is the first such discovery to be made of a world located in the galactic bulge.
The habitable zone around any star is the orbital distance at which it’s not “too hot” and not “too cold” for liquid water to exist on a hypothetical rocky planet’s surface. It is for this reason that the habitable zone is also nicknamed the “Goldilocks Zone” — it’s just right for liquid water to persist. Liquid water is the stuff believed to be essential for the evolution of life as we know it.
The search for exoplanets of approximately Earth-sized dimensions has been feverish over recent years, but unless we can find planets orbiting within habitable zones of their stars with the potential of possessing liquid water, the life-giving potential of those small worlds seems slim.
But, as the multinational team of astronomers who analyzed MOA-2011-BLG-293Lb hypothesize, the super-Jupiter could play host to its own system of exomoons that would also exist on the outer edge of the star’s habitable zone. Alas, microlensing surveys don’t have the sensitivity (yet) to detect these diminutive satellites, but it is a tantalizing thought.
“Indeed, although the data do not explicitly show any signature of a companion to the Jupiter planet, this possibility is not ruled out,” the researchers write. “The planet is apparently at the edge between the snow line and the habitable zone, but considering a potential greenhouse warming effect, the surface temperature of a possible companion (exomoon) can be suitable for habitability.”
Read more at Discovery News
Oct 14, 2013
Did Humans Arrive in Americas 30,000 Years Ago?
Historians commonly believe that humans first crossed to the Americans from Asia 12,000 years ago. But a new exhibit in Brazil features artifacts dating back as far as 30,000 years ago, 18,000 years earlier than previously believed.
100 items including cave paintings and ceramic art depicting animals, hunting expeditions and even sex scenes of the early Americans are on display in Brasilia, Brazil's capital.
The artifacts were found at the Serra da Capivara national park in Brazil’s northeastern Piaui state, which used to be a popular site for the hunter-gatherer civilization that created the artwork.
"To date, these are the oldest traces of human existence in the Americas," Franco-Brazilian archaeologist Niede Guidon who has headed a mission to carry out large-scale excavation of Piaui's interior since the 1970's told the AFP. "It's difficult to think there exists a site anywhere with a higher concentration of cave art."
In addition to the artwork, Guidon said charcoal remains of structured fires found at the site are among other traces of the Serra dwellers.
Some archaeologists disagree with Guidon that a few burnt flakes are not evidence of man-made fire hearths, but rather the remains of a natural stone formation.
Read more at Discovery News
Living Relatives of Iceman Mummy Found
Scientists from the Institute of Legal Medicine at Innsbruck Medical University analyzed DNA samples taken from 3,700 blood donors in the Tyrol region of Austria.
During their study, they discovered that 19 individuals share a particular genetic mutation with the 5,300-year-old mummy, whose full genome was published last year.
“These men and the Iceman had the same ancestors,” Walther Parson, the forensic scientist who carried out the study, told the Austrian Press Agency.
The researchers focused on parts of the human DNA which are generally inherited unchanged.
“In men it is the Y chromosomes and in females the mitochondria. Eventual changes arise due to mutations, which are then inherited further,” Parson explained.
People with the same mutations are categorized in haplogroups. Designed with letters, haplogroups allow researchers to trace early migratory routes since they are often associated with defined populations and geographical regions.
Indeed, Ötzi’s haplogroup is very rare in Europe.
“The Iceman had the halogroup G, sub category G-L91. In our research we found another 19 people with this genetic group and subgroup,” Parson said.
Having carried Y chromosome haplogroup analysis, Parson was able to trace only the male descendants of the Neolithic man.
So far the 19 individuals have not been informed of their genetic relationship to Ötzi.
Found in 1991 in a melting glacier in the Ötztal Alps (hence the name), the mummy is one of the most heavily investigated human corpses of all time.
Scientists discovered that Ötzi had brown eyes and very bad teeth, was lactose intolerant, had a genetic predisposition for an increased risk for coronary heart disease and probably had Lyme disease.
It’s certain he died a violent death: In 2007, CT scans showed that an arrowhead had lacerated his left subclavian artery, leading to fast bleeding.
Read more at Discovery News
US Parks Accidentally Fertilized By Air Pollution
Much of this accidental fertilization comes from ammonia that evaporated from agricultural chemicals and livestock urine, according to the study published in Atmospheric Chemistry and Physics. Power plant and vehicle emissions also contribute nitrogen in the form of nitrous oxides.
These nitrogen-containing gases enter the atmosphere, then fall back to earth in rain water or through other means.
“When we apply fertilizer in the United States, only about 10 percent of the nitrogen makes it into the food,” said lead author Daniel J. Jacob of Harvard University in a press release. “All the rest escapes, and most of it escapes through the atmosphere.”
Once that nitrogen escapes into the environment, it damages ecosystems.
In the east, the unwanted fertilizer most seriously affects the hardwood trees, such as oak, in Great Smoky Mountains National Park. The trees start to suffer when nitrogen input reaches 3 to 8 kilograms per hectare each year. However, the forest now receives far more than that, at 13.6 kilograms per hectare each year.
On the other side of the nation in Washington’s Mount Rainier National Park, nitrogen input levels have reached 6.7 kg/ha/year. Lichens, the base of the ecosystem, start to suffer when levels reach 2.5 to 7.1 kg/ha/year.
In bodies of water across the nation, excess nitrogen alters the acidity of the waters and fuels explosions of algae growth.
Controlling the environmental effects of accidental over-fertilization from air pollution poses a legal challenge, noted Jacob.
Read more at Discovery News
Top 10 Evolutionary Tricks for Pollinators
The Pollination Honeypot
Gifts of flowers can help humans in matters of the birds and the bees. However, flowers themselves often need reproductive help from birds and bees, not to mention bats, moths, lizards and primates.
Honeybees hog the spotlight of pollination fame, but many other species also help flowers find true love, or at least a few grains of pollen. These animals move pollen from one flower to another, fertilizing them, which allows them to form seeds.
Sugary Nectar
Tiny hummingbirds maintain their manic lifestyles by feeding on the sugary nectar within flowers. The bee hummingbird holds the record as the smallest living bird, at only 5-6 centimeters (2-2.5 inches). The birds burn energy quickly as they beat their wings up to 70 times per second in normal flight.
Plants attract hummingbirds using bright orange and red flowers with little odor. Hummingbird-pollinated flowers ooze extremely sugary nectar -- averaging 26 percent sugar, double the amount of a soft drink -- according to the Smithsonian National Zoo. Some flowers evolved to force a hungry hummingbird to brush its head on the pollen-laden stamens, a part of the flower. This turns the bird's head into a pollen postal service as the bird flits from flower to flower.
Reach for the Gold
In 1862, Charles Darwin predicted the existence of one of the most extreme pollinators after he received an orchid (Angraecum sesquipedale) with a foot-long tube leading to its nectar depository. Darwin predicted that an insect with an extremely long feeding structure, or proboscis, would eventually be discovered in the orchid's homeland of Madagascar.
In 1903, naturalists found Morgan's sphinx moth (Xanthopan morgani), a Madagascan moth with a proboscis that is just over 30 centimeters (one foot) long. Unfortunately, Darwin didn't survive to see the moth that fit his theory. He passed away two decades before the moth fluttered into a collector's clutches.
Fruity Flowers
Tequila exists thanks to bats' pollination. The nocturnal aviators help fertilize the agave plant, the source of tequila. Bats also pollinate more than 300 species of fruit, including mangoes, bananas and guavas, according to the U.S. Forest Service.
Some bats have evolved long tongues, similar to moths' proboscises, and the ability to hover, like hummingbirds. Bats outdo the birds and bugs by using their echolocation ability to find certain types of flowers, according to research in the Journal of Experimental Biology. Bat-pollinated flowers tend to be large, pale-colored and have a strong aroma of fermenting fruit.
Read more at Discovery News
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| A honeybee gathers nectar from a flower at a farm in the western Austrian village of Seefeld on May 14, 2013. |
Honeybees hog the spotlight of pollination fame, but many other species also help flowers find true love, or at least a few grains of pollen. These animals move pollen from one flower to another, fertilizing them, which allows them to form seeds.
Sugary Nectar
Plants attract hummingbirds using bright orange and red flowers with little odor. Hummingbird-pollinated flowers ooze extremely sugary nectar -- averaging 26 percent sugar, double the amount of a soft drink -- according to the Smithsonian National Zoo. Some flowers evolved to force a hungry hummingbird to brush its head on the pollen-laden stamens, a part of the flower. This turns the bird's head into a pollen postal service as the bird flits from flower to flower.
Reach for the Gold
In 1903, naturalists found Morgan's sphinx moth (Xanthopan morgani), a Madagascan moth with a proboscis that is just over 30 centimeters (one foot) long. Unfortunately, Darwin didn't survive to see the moth that fit his theory. He passed away two decades before the moth fluttered into a collector's clutches.
Fruity Flowers
Some bats have evolved long tongues, similar to moths' proboscises, and the ability to hover, like hummingbirds. Bats outdo the birds and bugs by using their echolocation ability to find certain types of flowers, according to research in the Journal of Experimental Biology. Bat-pollinated flowers tend to be large, pale-colored and have a strong aroma of fermenting fruit.
Read more at Discovery News
Oct 13, 2013
New Device Harnesses Sun and Sewage to Produce Hydrogen Fuel
A research team led by Yat Li, associate professor of chemistry at the University of California, Santa Cruz, developed the solar-microbial device and reported their results in a paper published in the American Chemical Society journal ACS Nano. The hybrid device combines a microbial fuel cell (MFC) and a type of solar cell called a photoelectrochemical cell (PEC). In the MFC component, bacteria degrade organic matter in the wastewater, generating electricity in the process. The biologically generated electricity is delivered to the PEC component to assist the solar-powered splitting of water (electrolysis) that generates hydrogen and oxygen.
Either a PEC or MFC device can be used alone to produce hydrogen gas. Both, however, require a small additional voltage (an "external bias") to overcome the thermodynamic energy barrier for proton reduction into hydrogen gas. The need to incorporate an additional electric power element adds significantly to the cost and complication of these types of energy conversion devices, especially at large scales. In comparison, Li's hybrid solar-microbial device is self-driven and self-sustained, because the combined energy from the organic matter (harvested by the MFC) and sunlight (captured by the PEC) is sufficient to drive electrolysis of water.
In effect, the MFC component can be regarded as a self-sustained "bio-battery" that provides extra voltage and energy to the PEC for hydrogen gas generation. "The only energy sources are wastewater and sunlight," Li said. "The successful demonstration of such a self-biased, sustainable microbial device for hydrogen generation could provide a new solution that can simultaneously address the need for wastewater treatment and the increasing demand for clean energy."
Microbial fuel cells rely on unusual bacteria, known as electrogenic bacteria, that are able to generate electricity by transferring metabolically-generated electrons across their cell membranes to an external electrode. Li's group collaborated with researchers at Lawrence Livermore National Laboratory (LLNL) who have been studying electrogenic bacteria and working to enhance MFC performance. Initial "proof-of-concept" tests of the solar-microbial (PEC-MFC) device used a well-studied strain of electrogenic bacteria grown in the lab on artificial growth medium. Subsequent tests used untreated municipal wastewater from the Livermore Water Reclamation Plant. The wastewater contained both rich organic nutrients and a diverse mix of microbes that feed on those nutrients, including naturally occurring strains of electrogenic bacteria.
When fed with wastewater and illuminated in a solar simulator, the PEC-MFC device showed continuous production of hydrogen gas at an average rate of 0.05 m3/day, according to LLNL researcher and coauthor Fang Qian. At the same time, the turbid black wastewater became clearer. The soluble chemical oxygen demand--a measure of the amount of organic compounds in water, widely used as a water quality test--declined by 67 percent over 48 hours.
The researchers also noted that hydrogen generation declined over time as the bacteria used up the organic matter in the wastewater. Replenishment of the wastewater in each feeding cycle led to complete restoration of electric current generation and hydrogen gas production.
Qian said the researchers are optimistic about the commercial potential for their invention. Currently they are planning to scale up the small laboratory device to make a larger 40-liter prototype continuously fed with municipal wastewater. If results from the 40-liter prototype are promising, they will test the device on site at the wastewater treatment plant.
Read more at Science Daily
Innate Virus-Killing Power Discovered in Mammals
Researchers led by Ding, who heads a lab in UC Riverside's Institute for Integrative Genome Biology, have discovered that, like plants and invertebrate animals, mammals use the RNA interference (RNAi) process to destroy viruses within their own cells.
Their findings will be published in the Oct. 11 issue of the journal Science.
Until now, scientists were unable to prove that mammals use RNAi for killing viruses, but ironically, it was Ding's earlier research into plants, nematodes and fruit flies that helped him find the key: viruses have been outwitting that innate protection in our cells by using proteins to suppress our virus-killing mechanism.
Remove the suppressor protein from the virus, Ding's research discovered, and the subject's body will quickly eliminate the virus using the RNAi process, which sends out small interfering RNAs (siRNAs) to kill the disease.
In their research on young mice, for instance, all the subjects died when they were infected with the Nodamura virus, but when Ding's researchers removed the suppressor protein called B2 from the virus, the infected mice began producing huge armies of the virus-attacking siRNAs and lived, unaffected by the otherwise lethal infection.
"Many have tried to do this, that is, find the viral siRNAs in mammals, but they could not find the key," said Ding. "The key was our prior knowledge of the B2 protein in the Nodamura virus, a virus few people know about. Other scientists asked me, 'What is the Nodamura virus?' They have been studying the more well-known human viruses, but Nodamura virus infection of mice proves to be the best model."
How did Ding know where to look? The China native was partly acting on a hunch that started when he was a graduate student at the Australia National University in the late 1980s. There, during a lecture, he learned that the genomes of viruses infecting plants and animals are actually very similar, even though plants and animals are very different.
That, and further discussions with his mentor Adrian Gibbs, an expert on molecular evolution of viruses and a fellow of the Australian Academy of Sciences, "made me think there must be a common anti-viral mechanism in plants and animals to keep their viruses similar," he said.
Ding produced the first evidence for that hypothesis while working with Bob Symons in the Waite Institute in South Australia, studying cucumber mosaic virus, a devastating, aphid-carried disease that infects more than 1,000 plant species, including many important crops.
Using computational analytical skills learned from Gibbs, Ding discovered a small gene in the virus other scientists had overlooked. He named the gene 2b and showed that it plays an essential role in helping the virus spread within the host plant. Based on his results, and published studies on the B2 protein of Flock house virus, an insect pathogen, Ding proposed in a 1995 paper that 2b and B2 proteins act by suppressing the host's antiviral defense.
Fueled by that idea, Ding moved to Singapore in 1996 to set up his own laboratory in the Institute of Molecular Agrobiology. There, in collaboration with a British group led by RNAi-expert David Baulcombe, Ding's group discovered that the 2b protein did indeed suppress the RNAi virus-fighting properties in plants. Further, the group found that the 2b proteins of the related viruses all have the suppressor activity even though they share limited sequence similarities.
Ding joined the faculty at UCR in December of 2000 to test the other half of his hypothesis: does the B2 protein of Flock house virus suppress RNAi in its animal host?
Although RNAi was known as a major antiviral mechanism in plants by that time, few believed it was also true in the animal kingdom, which was known to fight viral infections by many other well-defined mechanisms. Over the next five years, Ding used Flock house virus to discover that fruit flies and C. elegans nematodes have the same RNAi virus-killing properties as plants, but the B2 in the virus stop their RNAi defenses from working. Remove the B2, and the hosts produce massive amounts of siRNAs and rapidly destroy the virus.
The findings, which were featured in a Science cover story in 2002, showed that RNAi is a common antiviral defense in plants, insects and nematodes, and explained why viruses have to keep a protein to suppress that defense. It also took Ding deeper into his fundamental premise -- "If RNAi remains as an effective antiviral defense in plants, insects and nematodes after their independent evolution for hundred millions of years, why would it stop working with mammals?"
To answer this question, Ding decided to use a cousin of the Flock house virus -- Nodamura virus -- that is lethal to young mice. In collaboration with Ding, the lab of Olivier Voinnet at the Swiss Federal Institute of Technology in Zurich also reported in an accompanying paper the detection of viral siRNAs in cultured mouse embryonic stem cells infected by the Encephalomyocarditis virus. These findings have opened the door to new ways to combat dangerous human viruses.
Read more at Science Daily
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