Issue - 643 (27)
1 Dec. - 7 Dec. 2015
Scientists create mosquito strain with malaria-blocking genes WASHINGTON Scientists aiming to take the bite out of malaria have produced a strain of mosquitoes carrying genes that block its transmission, with the idea that
they could breed with other members of their species in the wild and produce offspring that cannot spread the disease. The researchers said on Monday they used gene-editing, a genetic engineering technique in which DNA can be inserted, replaced or deleted from a genome, on a species called Anopheles stephensi that spreads malaria in urban India. They inserted DNA into the germ line, cells that pass on genes from generation to generation, of the species, creating mosquitoes with genes that prevent malaria
transmission by producing malaria-blocking antibodies that are passed on to 99.5 percent of offspring. Malaria is caused by parasites transmitted to people through
the bites of infected female mosquitoes. The goal is to release genetically modified mosquitoes to mate with wild mosquitoes so that their malariablocking genes enter the gene pool and eventually overrun the population, short-circuiting the species’ ability to infect people with the parasites. “It can spread through a population with great efficiency, increasing from 1 percent to more than 99 percent in 10 generations, or about one season for mosquitoes,” University of California-San Diego biologist Valentino Gantz
Spider webs act like crime scenes
said. University of California-San Diego biologist Ethan Bier called this a “potent tool in sustainable control of malaria,” as all the mosquitoes in a given region would carry anti-malarial genes. “We do not propose that this strategy alone will eradicate malaria,” University of CaliforniaIrvine molecular biologist Anthony James said. But in conjunction with treatment and preventive drugs, future vaccines, mosquito-blocking bed nets and eradication of mosquito-breeding sites, it could play a major role in sustaining the elimination of malaria, James said. Other scientists also have been working to create genetically engineered mosquitoes. One group last year said it created a strain carrying a gene leading nearly all offspring to be male, which could cause wild populations to plummet. “In contrast, our much more flexible system only prevents mosquitoes from carrying malaria but can be used to do no harm to the mosquito. So it should generate the least amount of ecological damage,” Bier said. The UN World Health Organization estimates there will be 214 million cases of malaria worldwide in 2015 and 438,000 deaths, most in subSaharan Africa. The research was published in the Proceedings of the National Academy of Sciences.
Man convicted of killing wife; posted Facebook photo of body
MIAMI A Florida man who killed his wife and posted a photo of the bloody corpse on Facebook was convicted on Wednesday of second-degree murder after failing to convince a jury that he shot her eight times in selfdefense.The jury verdict came in the third week of Derek Medina’s trial in the August 2013 killing of 27-year-old Jennifer Alfonso at their Miami home. Medina told police in a videotaped statement he shot his wife during an altercation in which she threatened him with a knife. Medina, who did not testify in his own defense, admitted in the police statement taking a cellphone photo of his dead wife’s body and uploading it on Facebook, along with a posting that said he expected to go to prison but was forced to kill her following years of physical abuse.Prosecutors put on evidence indicating that Medina had vowed to kill Alfonso if she tried to leave him, which she told friends she planned to do. They also pointed out that at 6 feet (1.83 meters) and about 200
pounds (91 kilograms), Medina could have easily overpowered his 5-foot-6 wife (1.68 meters) without shooting her.Alfonso’s mother, Carolyn Knox, burst into tears when the verdict was read after about six hours of jury deliberation over two days. She declined comment to reporters. Medina’s father, also named Derek Medina, would not comment.Medina showed absolutely no emotion as he was handcuffed and led back to jail, where he has been held since the killing. His attorney, Saam Zangeneh, said there will be an appeal.The second-degree murder conviction means that Medina, 33, faces a sentence of 25 years to life in prison.“No family should ever have to see their daughter killed and then exhibited worldwide on the Internet like some macabre trophy to a husband’s anger as was Jennifer Alfonso,” Rundle said. Trial testimony showed the couple began fighting in their upstairs bedroom because Medina had failed to wake up his wife early that morning to watch a movie, as he had promised.
US citizens can now own asteroids
New York Spiders’ silken webs are death traps for many insects. And now scientists have discovered DNA left on a web can be used to identify its owner and their victims, much like a crime scene. As well as revealing a spider’s last meal, the research could be used to monitor endangered species or to track down spider pests. While there are many methods of monitoring spider populations, the majority are time consuming and rely on experts being able to find and identify elusive species. This new method of analysing web DNA could make it easier for ecologists to pick out a species quickly from some 45,000 in number. The study, by
the University of Notre Dame, examined black widow spiders kept at Potawatomi Zoo, also in Indiana.Lead researcher Charles Xu, a Masters student in Evolutionary Biology, extracted, amplified, and sequenced mitochondrial DNA from spider web samples of the spiders.He found web DNA reveals which spider species made the web and what it had eaten in the weeks before.As the spiders in the experiment were fed on house crickets, Dr Xu detected traces of cricket DNA. The study, published in the journal Plos One, says: ‘Spider and prey DNA remained detectable at least 88 days after living organisms were no longer present on the web.’
WASHINGTON Private companies can now mine asteroids, after Barack Obama signed a major law that reverses decades of space law. US citizens are now able to obtain their own asteroids and mine resources out of them, and will be able to own the materials they find there. Until now, space has largely been treated as publicly-owned, meaning that nobody could claim commercial ownership of anything that was out there. The US government has now thrown out that understanding so that it can get rid of “unnecessary regulations” and make it easier for private American companies to explore space resources commercially. While people won’t actually be able to claim the rock or “celestial body” itself, they will be able to keep everything that they mine out of it. It is hoped that the new rules will allow people to harvest the often vast amounts of expensive resources that are inside of the asteroids that fly near our planet. In July, a rock with a platinum core passed that was worth £3.5 trillion passed by Earth. The new law is called the
US Commercial Space Launch Competitiveness Act. As well as giving the right to mine asteroids, it extends America’s
recognition of property rights in history”, and that it “establishes the same supportive framework that created the great
commitment to the International Space Station and makes it easier for to run a private space startup company. People won’t actually be able to claim the rock or “celestial body” itself, they will be able to keep everythi.It also requires that US authorities specify the way that asteroid mining will be regulated and organised. Planetary Resources, an American company that intends to make money by mining asteroids, said that the new law was the “single greatest
economies of history, and will encourage the sustained development of space”. Much of the ownership of space is regulated by the “Outer Space Treaty”, a document that was signed by the US and Russia among other countries in the 1960s. As well as saying that the moon and other celestial objects are part of the “common heritage of mankind”, it says that exploration must be peaceful and bans countries from putting weapons on the moon and other celestial bodies.