Making sex cells from body cells

ISSUES of safety aside, the very idea of cloning people—of taking, say, a cell from the skin of a man or a woman and growing it into a new human being with exactly the same genes as its progenitor—is anathema to many. But what about taking such a cell and creating from it an egg or a sperm that can be used for in vitro fertilisation? That would enable infertile men and women, and gay couples, who wanted to raise children genetically related to both parents to do so, rather than relying on the assistance of an unrelated egg or sperm donor to start a family.

In people, this is not yet possible. But it is exactly what Katsuhiko Hayashi and his colleagues at Kyushu University, in Fukuoka, Japan, have done in mice. As they report this week in Nature, there are animals now scampering around cages in their laboratory whose maternal antecedents are egg cells derived not from the ovaries of their mothers, but from body cells (known as somatic cells), in this case from those mothers’ tails.

Nor does it stop there. In the past,…Continue reading
Source: Economist

Novel drugs for depression

IT STARTED out as LY110141. Its inventor, Eli Lilly, was not sure what to do with it. Eventually the company found that it seemed to make depressed people happier. So, with much publicity and clever branding, Prozac was born. Prozac would transform the treatment of depression and become the most widely prescribed antidepressant in history. Some users described it as “bottled sunshine”. It attained peak annual sales (in 1998) of $3 billion and at the last count had been used by 54m people in 90 countries. And, along the way, it embedded into the public consciousness a particular idea about how depression works—that it is caused by a chemical imbalance in the brain, which the drug corrects. Unfortunately, this idea seems to be only part of the story.

In science it is good to have a hypothesis to frame one’s thinking. The term “chemical imbalance” is just such a thing. It is a layman’s simplification of the monoamine hypothesis, which has been the prevalent explanation for depression for almost 50 years. Monoamines are a class of chemical that often act as messenger molecules (known technically as neurotransmitters) between nerve cells in the…Continue reading
Source: Economist

Stopping bridge collapses

Scoured away

ON AUGUST 2nd a century-old bridge carrying the road from Mumbai to Goa over the Savitri river collapsed (see picture), killing at least 20 people. The probable cause was that the river, swollen by monsoon rains, had scoured away the foundations of the bridge’s piers. Such erosion-induced collapses are not peculiar to India. In 2009 the Malahide viaduct, north of Dublin, failed similarly just after a train had crossed it. This was despite its having been inspected and pronounced safe a few days earlier. In America, meanwhile, foundation-scouring is reckoned to be the leading reason for bridge failure. Half of the 500 collapses that happened there between 1989 and 2000 were caused by it.

If detected early enough, foundation-scouring is easy to fix. Dumping rubble, known as riprap, into the water around a bridge’s piers stabilises the riverbed they are sunk into. But until now such detection has involved the deployment of teams of divers, which is expensive. Hence a search for technology which can substitute for the men and women in the wetsuits.

Ken Loh of the University of California, San Diego,…Continue reading
Source: Economist

Manufacturing ultracapacitors

ALMOST every week seems to bring reports in scientific journals of new electricity-storage devices—batteries and capacitors—being invented in laboratories around the world. The journey from bench-top to assembly line, though, is fraught with hazard and few of these ideas end up as products able to withstand the rough and tumble of industrial and consumer use. Fewer still hail from beyond the laboratories of North America, western Europe and Japan. But one which does is Skeleton Technologies’ ultracapacitor, which was developed, and is now being manufactured, in Estonia. 

Unlike batteries, which store energy chemically by squirrelling it away in the materials of their electrodes, capacitors store it physically as static electricity clinging to the surfaces of their equivalents of electrodes, which are known as plates. This static can be tapped or added to more swiftly than any chemical reaction can manage, so capacitors both store and discharge electricity more rapidly than batteries do. That makes them ideal for delivering short bursts of power. But they cannot accommodate nearly as much energy as batteries, so they soon run out of…Continue reading
Source: Economist

Prosthetic medicine

ARTIFICIAL limbs are nothing new. An ersatz toe, made of wood and leather and found attached to the mummified body of an Egyptian noblewoman in Cairo, in 2000, is thought to be between 2,500 and 3,000 years old. Things have moved on since then. Modern prostheses sport things like articulated fingers that can be controlled by picking up impulses from their wearer’s remaining nerves.

But a bionic limb receiving commands is only half the picture. To be a true replacement, it should also be able to send sensations back to its wearer, to enable him to control it precisely. And, in a study just published in Science Translational Medicine, a group of researchers led by Robert Gaunt, an engineer at the University of Pittsburgh, have taken an important step towards this goal. Their paper describes a way of restoring sensation by using implanted electrodes to stimulate a patient’s brain directly.

The patient in question is a 30-year-old man whose spinal cord was damaged in a car crash. He is not an amputee, but his injury means his brain and his hands can no longer communicate. Dr Gaunt’s aim was, first, to create an illusion in the patient’s brain that this was not the case, and then to use that illusion to send to that brain signals from an artificial hand which was equipped with sensors on its fingers.

Sensations from the…Continue reading
Source: Economist

Samsung’s meltdown

Source: Economist

Your class determines how you look at your fellow creatures

IN 2009 a team of psychologists at the University of California, Berkeley, who were studying people from different walks of life, noticed that those from the upper classes were less good than those from the lower at discerning emotions on the faces of others. This led them to speculate that such empathy weakens as you go up the social scale. The theory might be true. But a paper just published in Psychological Science, by Pia Dietze and Eric Knowles of New York University, offers an alternative hypothesis—that it is not the emotional sensitivity of patricians to plebs which is impaired, but their attention to them.

Dr Dietze and Dr Knowles began their study with an experiment that they told participants was a study of Google Glasses. However, in the time-honoured tradition of experimental psychologists, they were lying. The test was not of these pieces of apparatus (tiny video cameras hidden in pairs of spectacles, which let wearers take surreptitious footage of whatever they are looking at), but rather of the participants’ behaviour. Each of the 61 volunteers was asked to wear a Google Glass, walk for a block in New York and focus their…Continue reading
Source: Economist

Summoned by screams

Come into my parlour

THE botanical kingdom is rife with deceivers. Carrion flowers mimic the smell of rotten meat in order to attract scavenging beetles and flies and then cover them in pollen. Passion vines, beloved by some butterflies as food for their caterpillars, have yellow spots on their leaves that make them look as if they have already had an egg-laying visit from a gravid female. And numerous carnivorous plants lure insects with sweet odours, only to devour them. Now Stefan Dötterl and Annemarie Heiduk, of the Universities of Salzburg and Bayreuth respectively, think they have uncovered yet another form of deception. As they describe in Current Biology, a vegetable called the parachute plant uses chemical signals to trick carnivorous flies into believing the insects those flies prey on are lying wounded inside it.

At first sight parachute plants, which have cone-shaped flowers (see picture) decorated inside with needlelike inward-pointing hairs, look as though they might be carnivorous themselves. They are not, though they come close to it. Insects that enter a parachute-plant flower fall into…Continue reading
Source: Economist

Sounds like trouble

LINGUISTIC disorders of speech or of comprehension are awkward for anyone who suffers from them. For children, who are just beginning to make their way in society, they can be disastrous. Teasing, bullying, lack of friends and poor school performance may all follow from an inability to talk or listen normally. Early intervention and therapy, though, can make a big difference—if diagnosis comes quickly enough.

Often it does not. In America, 60% of such disorders go undiagnosed until a child goes to school. But Jen Gong and John Guttag of the Massachusetts Institute of Technology hope to change that. As they outlined at the Interspeech Conference in San Francisco in September, they have devised a method that, when refined, may yield an automated test which can spot the subtle clues, such as pauses during speech, that indicate a disorder to a professional ear but may not be obvious to parents.

Ms Gong and Dr Guttag, both computer scientists, wondered whether they could teach their machines to distinguish the speech of children with disorders from that of children without them. To this end, they first wrote an algorithm they hoped might do…Continue reading
Source: Economist

The internet of stings

Mr Krebs contemplates life

TO A layman, the phrase “Internet of Things” (IoT) probably conjures up a half-fantastic future in which refrigerators monitor their own contents and send orders direct to the grocer when the butter is running out, while tired commuters order baths to be drawn automatically using their smartphones as they approach their houses in their self-driving cars. Actually, though, a version of the IoT is already here. Wi-Fi hubs, smart televisions, digital video-recorders and the like are all part of a network of devices run by microprocessors that, just as much as desktop, laptop and tablet computers, form part of the internet—but with one crucial distinction. Unlike things immediately recognisable as computers, these devices are often designed with poor security, or even none at all. They are wide open to malicious hackers who might wish to misuse them. And there are already around 5 billion of them, according to Cisco, the world’s largest computer-networking company, with billions more to come in the years ahead.

One favourite trick of such hackers is the distributed denial of service attack, or…Continue reading
Source: Economist