839 posts tagged Science
Less than 10% of human DNA has functional role, claim scientists
Large stretches may be no more than biological baggage, say researchers after comparing genome with that of other mammals
More than 90% of human DNA is doing nothing very useful, and large stretches may be no more than biological baggage that has built up over years of evolution, Oxford researchers claim. The scientists arrived at the figure after comparing the human genome with the genetic makeup of other mammals, ranging from dogs and mice to rhinos and horses. The researchers looked for sections of DNA that humans shared with the other animals, which split from our lineage at different points in history. When DNA is shared and conserved across species, it suggests that it does something valuable. Gerton Lunter, a senior scientist on the team, said that based on the comparisons, 8.2% of human DNA was “functional”, meaning that it played an important enough role to be conserved by evolution. “Scientifically speaking, we have no evidence that 92% of our genome is contributing to our biology at all,” Lunter told the Guardian. Researchers have known for some time that only 1% of human DNA is held in genes that are used to make crucial proteins to keep cells – and bodies – alive and healthy. The latest study, reported in the journal Plos Genetics, suggests that a further 7% of human DNA is equally vital, regulating where, when, and how genes are expressed. But if much of our DNA is so worthless, why do we still carry it around? “It’s not true that nature is parsimonious in terms of needing a small genome. Wheat has a much larger genome than we do,” Lunter said. “We haven’t been designed. We’ve evolved and that’s a messy process. This other DNA really is just filler. It’s not garbage. It might come in useful one day. But it’s not a burden.” (via Less than 10% of human DNA has functional role, claim scientists | Science | The Guardian)
Must watch the new acapella science : Eminemium Choose yourself-
If you had
Or one opportunity
To release all the energy you ever wanted
In one moment
Would you abuse it
Or use it for good?
Odds are, there’s a virus living inside your gut that has gone undetected by scientists for decades. A new study led by researchers at San Diego State University has found that more than half the world’s population is host to a newly described virus, named crAssphage, which infects one of the most common types of gut bacteria, Bacteroidetes. This phylum of bacteria is thought to be connected with obesity, diabetes and other gut-related diseases. The research appears today in Nature Communications. Robert A. Edwards, a bioinformatics professor at SDSU, and his colleagues stumbled upon the discovery quite by accident. Working with visiting researcher and corresponding author on the study Bas E. Dutilh, now at Radboud University Medical Center in The Netherlands, the researchers were using results from previous studies on gut-inhabiting viruses to screen for new viruses. In the DNA fecal samples from 12 different individuals, they noticed a particular cluster of viral DNA, about 97,000 base pairs long, that the samples all had in common. When Edwards and his colleagues checked this discovery against a comprehensive listing of known viruses, they came up empty. The researchers then screened for the virus across the database of the National Institute of Health’s Human Microbiome Project (HMP), and Argonne National Laboratory’s MG-RAST database, and again found it in abundance in samples derived from human feces. To prove that the viral DNA they discovered in their computer data actually exists in nature, fellow SDSU virologist John Mokili used a technique known as DNA amplification to locate the virus in the original samples used to build NIH’s database. “So we have a biological proof that the virus they found with the computer actually exists in the samples,” Mokili said. This was a new virus that about half the sampled people had in their bodies that nobody knew about. “It’s not unusual to go looking for a novel virus and find one,” Edwards said. “But it’s very unusual to find one that so many people have in common. The fact that it’s flown under the radar for so long is very strange.”
“I think I’ve only spent about ten percent of my energies on writing,” Pulitzer Prize-winning writer Katherine Anne Porter confessed in a 1963 interview. “The other ninety percent went to keeping my head above water.” While art may be a form of therapy for the rest of us, Porter’s is a sentiment far from uncommon among the creatively gifted who make that art. Why? When Nancy Andreasen took a standard IQ test in kindergarten, she was declared a “genius.” But she was born in the late 1930s, an era when her own mother admonished that no one would marry a woman with a Ph.D. Still, became a psychiatrist and a neuroscientist, and made understanding the brain’s creative capacity her life’s work. Having grown up seeped in ambivalence about her “diagnosis” of extraordinary intellectual and creative ability, Andreasen wondered about the social forces at work in the nature-nurture osmosis of genius, about how many people of natural genius were born throughout history whose genius was never manifested, suppressed by lack of nurture. “Half of the human beings in history are women,” she noted, “but we have had so few women recognized for their genius. How many were held back by societal influences, similar to the ones I encountered and dared to ignore?” (One need only look at the case of Benjamin Franklin and his sister to see Andreasen’s point.)
Albert Einstein was a genius, but he wasn’t the only one – why has his name come to mean something superhuman?
Before he died, Albert Einstein requested that his whole body be cremated as soon as possible after death, and his ashes scattered in an undisclosed location. He didn’t want his mortal remains to be turned into a shrine, but his request was only partially heeded. Einstein’s closest friend, the economist Otto Nathan, took possession of his ashes, but not before Thomas Harvey, the pathologist who performed the autopsy, removed his brain. Family and friends were aghast, but Harvey convinced Einstein’s son Hans Albert to give his reluctant permission after the fact. The eccentric doctor kept the brain in a glass jar of formalin inside a cider box under a cooler, until 1998, when he returned it to Princeton Hospital, and from time to time, he would send little chunks of it to interested scientists. Most of us will never be victims of brain-theft and ash hoarding, but Einstein’s status as the archetypical genius of modern times singled him out for special treatment. An ordinary person can live and die privately, but a genius – and his grey matter – belongs to the world. Even in his lifetime, which coincided with the first great flowering of mass media, Einstein was a celebrity, as famous for his wit and white shock of hair as he was for his science. Indeed, his life seems to have been timed perfectly to take advantage of the proliferations of newspapers and radio shows, whose reports often framed Einstein’s theories as being incomprehensible to anyone but the genius himself.
There’s no doubt that Einstein’s contributions to science were revolutionary. Before he came along, cosmology was a part of philosophy but, thanks to him, it’s become a branch of science, tasked with no less than a mathematical history and evolution of the Universe. Einstein’s work also led to the discovery of exotic physical phenomena such as black holes, gravitational waves, quantum entanglement, the Big Bang, and the Higgs boson. But despite this formidable scientific legacy, Einstein’s fame owes something more to our culture’s obsession with celebrity. In many ways, Einstein was well-suited for celebrity. Apart from his distinctive coif, he had a way with words and, as a result, he is frequently quoted, occasionally with bon mots he didn’t actually say. More than anything, Einstein possessed the distinctive mystique of genius, a sense that he was larger than life, or different from the rest of us in some fundamental way, which is why so many people were desperate to get hold of his brain. (via Why is Einstein the poster boy for genius? – Matthew Francis – Aeon)
An article published in the journal Nature looked into psychological therapy that causes brain changes within patients of mental disorders. Though neuroscience and clinical science are different and there is a “culture gap” between the two, the essay suggests that the two disciplines must be combined and explored together for the best results. Michelle Craske, Professor of Psychology at the University of California, said that they are unaware of how patients of mental disorder find relief after talking to a psychological therapist. He and his colleagues said that a fact finding was necessary. Worldwide, there are one in four mental health disorder cases, including depression, schizophrenia, post-traumatic stress disorder, obsessive-compulsive disorder and eating disorders. According to a study by Craske, Cambridge University Professor Emily Holmes and MIT Professor Ann Graybiel, “Psychological treatments hold the strongest evidence base for addressing many such conditions but they need improvement.” Psychological treatments are seen to be effective in most case, but in some conditions such as bipolar disorder, psychological treatments are seen to be ineffective or are in their infancy. The life report also threw light on the “culture gap” between neuroscientists and clinical scientists that has hindered the progress of mental health treatments. The authors of the report state that scientists from both disciplines must work together to advance the understanding and treatment of psychological disorders.
Humans are currently the most intelligent beings on the planet – the result of a long history of evolutionary pressure and adaptation. But could we some day design and build machines that surpass the human intellect? This is the concept of superintelligence, a growing area of research that aims to improve understanding of what such machines might be like, how they might come to exist, and what they would mean for humanity’s future. Oxford philosopher Nick Bostrom’s recent book Superintelligence: Paths, Dangers, Strategies discusses a variety of technological paths that could reach superintelligent artificial intelligence (AI), from mathematical approaches to the digital emulation of human brain tissue. And although it sounds like science fiction, a group of experts, including Stephen Hawking, wrote an article on the topic noting that “There is no physical law precluding particles from being organised in ways that perform even more advanced computations than the arrangements of particles in human brains.”
Brain as computer
The idea that the brain performs “computation” is widespread in cognitive science and AI since the brain deals in information, converting a pattern of input nerve signals to output nerve signals.
Another well-accepted theory is that physics is Turing-computable: that whatever goes on in a particular volume of space, including the space occupied by human brains could be simulated by a Turing machine, a kind of idealised information processor. Physical computers perform these same information-processing tasks, though they aren’t yet at the level of Turing’s hypothetical device.
These two ideas come together to give us the conclusion that intelligence itself is the result of physical computation. And, as Hawking and colleagues go on to argue, there is no reason to believe that the brain is the most intelligent possible computer.
In fact, the brain is limited by many factors, from its physical composition to its evolutionary past. Brains were not selected exclusively to be smart, but to generally maximise human reproductive fitness. Brains are not only tuned to the tasks of the hunter gatherer, but also designed to fit through the human birth canal; supercomputing clusters or data-centres have no such constraints.
Synthetic hardware has a number of advantages over the human brain both in speed and scale, but the software is what creates the intelligence. How could we possibly get smarter-than-human software?
If it feels hot to you now in the dog days of this summer, imagine a time when summertime Boston starts feeling like Miami and even Montana sizzles. Thanks to climate change, that day is coming by the end of the century, making it harder to avoid simmering temperatures. Summers in most of the U.S. are already warmer than they were in the 1970s. And climate models tell us that summers are going to keep getting hotter as greenhouse gas emissions continue. What will this warming feel like? Our new analysis of future summers illustrates just how dramatic warming is going to be by the end of this century if current emissions trends continue unabated. For our Blistering Future Summers interactive we have projected summer high temperatures for the end of this century for 1,001 cities, and then showed which city in the U.S. — or elsewhere in the world, if we couldn’t find one here — is experiencing those temperatures today. We’ve highlighted several striking examples on the interactive, but make sure to explore and find how much hotter summers will likely be in your city. By the end of the century, assuming the current emissions trends, Boston’s average summer high temperatures will be more than 10°F hotter than they are now, making it feel as balmy as North Miami Beach is today. Summers in Helena, Mont., will warm by nearly 12°F, making it feel like Riverside, Calif.
Love is the drug, scientists find
Cambridge University scientists find that those with drug addiction and sex addiction have similar neurological responses
When Roxy Music star Bryan Ferry declared that ”love is the drug” he may have been speaking the truth. Cambridge University scientists have found that sex and drug addiction may be two sides of the same neurological coin. When diagnosed sex addicts looked at explicit sexual images, it triggered brain activity very similar to that seen in people dependent on drugs. But the researchers caution that this does not suggest pornography is generally addictive. Lead scientist Dr Valerie Voon, from Cambridge University, said: ”The patients in our trial were all people who had substantial difficulties controlling their sexual behaviour and this was having significant consequences for them, affecting their lives and relationships. ”In many ways, they show similarities in their behaviour to patients with drug addictions. We wanted to see if these similarities were reflected in brain activity, too. ”There are clear differences in brain activity between patients who have compulsive sexual behaviour and healthy volunteers. These differences mirror those of drug addicts.” Previous studies have suggested that up to one in 25 adults may be affected by an obsession with sexual thoughts, feelings or behaviour they are unable to control. Public awareness of sex addiction has been raised by celebrities seeking help for the problem, including actors Michael Douglas and David Duchovny. The Cambridge scientists recruited 19 male sex addicts and played them short videos featuring either explicit pornographic scenes or people engaged in exciting sports such as skiing or skydiving. At the same time, the men’s brain activity was monitored using a functional magnetic resonance imaging (fMRI) scanner. The experiment was repeated with a matched group of volunteers not affected by sex addiction. Three regions of the brain were found to be especially more active in the brains of the sex addicts than in the healthy volunteers, the ventral striatum, dorsal anterior cingulate and amygdala. All three are also known to be activated in drug addicts stimulated by the sight of drug-taking paraphernalia. (via Love is the drug, scientists find - Telegraph)
The next couple of years will be make or break for the next big theory in physics called supersymmetry - SUSY for short. It might make way for a rival idea which predicts the existence of a ‘fifth force’ of nature. Next Spring, when the Large Hadron Collider (LHC) resumes its experiments, scientists will be looking for evidence of SUSY. It explains an awful lot that the current theory of particle physics does not. But there is a growing problem, provocatively expressed by Nobel Laureate George Smoot: “supersymmetry has got symmetry and it’s super but there is no experimental data to suggest it is correct.” According to the simplest versions of the theory, supersymmetric particles should have been discovered at the LHC by now. One set of null results prompted Prof Chris Parkes, of the LHCb to quip: “Supersymmetry may not be dead but these latest results have certainly put it into hospital”. But other forms of the theory are still very much in play.