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Year end review and preview of 2017
Source: Economist
A breakthrough in miniaturising lidars for autonomous driving
EXPERIMENTAL self-driving cars continue to make regular forays onto the roads. After a trial in Pittsburgh, Uber, a taxi-hailing-app company, launched several of its “autonomous” vehicles onto the streets of San Francisco on December 14th—and promptly ran into a row with officials for not obtaining an operating permit, which Uber insists is unnecessary as the vehicles have a backup driver to take over if something goes wrong. General Motors said it would begin testing self-driving cars in Michigan. For these and other trials one thing is essential: providing the vehicles with a reliable form of vision.
As no man-made system can yet match a pair of human eyes and the image-processing power of a brain, compromises have to be made. This is why engineers use a belt-and-braces approach in equipping vehicles with sensors that can scan the road ahead. That way, just as your trousers will stay up if one or other of belt and braces fails, if one system misses a potential hazard, such as an oncoming car or a pedestrian, the others might spot it and direct the car to take evasive action.
Three of the sensory systems currently in use in…Continue reading
Source: Economist
A particle accelerator in the Middle East
THE hills 30km north-west of Amman, Jordan’s capital, are home to a miracle of scientific diplomacy called Sesame. Proposals to build this device, the world’s most politically fraught particle accelerator, date back nearly 20 years. The delay is understandable. Israel, Iran and the Palestinian Authority, three of the project’s nine members, are better known for conflict than collaboration. Turkey does not recognise the Republic of Cyprus, but both have worked together on the accelerator. As well as Jordan, the other members are Bahrain, Egypt and Pakistan. Nonetheless, Sesame, a type of machine called an electron synchrotron, is about to open for business. The first electrons are expected to complete their initial laps around its 133 metre circumference ring this month.
Electron synchrotrons are smaller cousins of proton synchrotrons such as the Large Hadron Collider (LHC), near Geneva. Instead of probing the frontiers of physics, they probe the structure of materials. Corralled by giant magnets, the electrons travelling around them emit radiation ranging in frequency from the infrared to X-rays. This can be used to look at anything from metals…Continue reading
Source: Economist
Scanning reveals what pregnancy does to a mother’s brain
AS ANY parent will tell you, once you have had children nothing is ever quite the same. Including, it seems, their mothers’ brains. In a paper just published in Nature Neuroscience, a team led by Elseline Hoekzema of the Universitat Autònoma de Barcelona, in Spain, describe for the first time how pregnancy alters women’s brains, rewiring them in ways that persist long after a child has been born.
Dr Hoekzema and her colleagues performed detailed brain scans on 65 female volunteers, none of whom had been pregnant before, but hoped to be in the near future, and a further 20 who had no such desire. About 15 months later, by which time 25 of their volunteers had carried babies to term, they repeated the process.
Comparing the scans showed significant reductions in the volume of grey matter in the brains of the new mothers. (Grey matter contains the main bodies of nerve cells; white matter, the brain’s other component, consists mostly of the nerve fibres that link those cells together.) The effect was reliable enough that it could be used by itself to predict, with perfect accuracy, which of the women had been pregnant and…Continue reading
Source: Economist
A long-sought vaccine against opioid drugs may now be on the cards
ANCIENT Egyptians, Sumerians, Greeks and many others knew the powers of opium poppies and employed them extensively. So, too, do modern doctors. Drugs derived from poppy juice, such as morphine, codeine, oxycodone and hydrocodone, known collectively as opioids, form the very foundation of pain management and are used in hospitals the world over.
Unfortunately, opioids are also highly addictive. Illicit consumption of them is reaching epidemic proportions—and not just among those who have wilfully chosen from the beginning to take such drugs recreationally. Many addicts were once prescribed an opioid legitimately, by a doctor, and then found that they could not stop. The upshot is a lot of premature deaths (see chart). Many researchers have therefore tried to find a way to deter those who have been given a brief taste of opioids from continuing to take them. Now one group, led by Kim Janda at the Scripps Research Institute in La Jolla, California, reports in ACS Chemical Biology that it has developed an anti-opioid vaccine.
Vaccines work by teaching the immune system to recognise a…Continue reading
Source: Economist
A new type of molecular medicine may be needed to halt cancers
ONE of the most important medical insights of recent decades is that cancers are triggered by genetic mutations. Cashing that insight in clinically, to improve treatments, has, however, been hard. A recent study of 2,600 patients at the M.D. Anderson Cancer Centre in Houston, Texas, showed that genetic analysis permitted only 6.4% of those suffering to be paired with a drug aimed specifically at the mutation deemed responsible. The reason is that there are only a few common cancer-triggering mutations, and drugs to deal with them. Other triggering mutations are numerous, but rare—so rare that no treatment is known nor, given the economics of drug discovery, is one likely to be sought.
Facts such as these have led many cancer biologists to question how useful the gene-led approach to understanding and treating cancer actually is. And some have gone further than mere questioning. One such is Andrea Califano of Columbia University, in New York. He observes that, regardless of the triggering mutation, the pattern of gene expression—and associated protein activity—that sustains a tumour is, for a given type of cancer, almost identical from patient to…Continue reading
Source: Economist
Using magnetism to take the sea’s temperature
“NOBODY really knows” was Donald Trump’s assessment of man-made global warming, in an interview on December 11th. As far as the atmosphere is concerned, that puts him at odds with most scientists who have studied the matter. They do know that the atmosphere is warming, and they also know by how much. But turn to the sea and Mr Trump has a point. Though the oceans are warming too, climatologists readily admit that they have only a rough idea how much heat is going into them, and how much is already there.
Many suspect that the heat capacity of seawater explains the climate pause of recent years, in which the rate of atmospheric warming has slowed. But without decent data, it is hard to be sure to what extent the oceans are acting as a heat sink that damps the temperature rise humanity is visiting upon the planet—and, equally important, how long they can keep that up.
This state of affairs will change, though, if a project described by Robert Tyler and Terence Sabaka to a meeting of the American Geophysical Union, held in San Francisco this week, is successful. Dr Tyler and Dr Sabaka, who work at the Goddard Space Flight Centre, in…Continue reading
Source: Economist
Why do some mammals have a bone in their penises?
PENILE stiffness is the stuff of smutty jokes. In Darwinian terms, though, it is no laughing matter. Intromission, the meeting of penis and vagina, is crucial to reproduction. With insufficient stiffness, intromission will not happen and the genes of the male will fail to make it into the next generation.
It is no surprise, therefore, that many male mammals have a bone, known as a baculum, in their penises to add to stiffness. What is surprising is that many others—men included—do not. What causes a baculum to evolve is not clear. But a study just published in the Proceedings of the Royal Society, by Matilda Brindle and Christopher Opie of University College London, has shed some light on the matter.
Ms Brindle and Dr Opie have reviewed what data there are about mammalian bacula, particularly those of primates and carnivores, and compared these with what is known about different species’ sex lives. They picked the primates and the carnivores in particular because both groups contain some species whose males have a baculum and others whose males do not. (The picture above is of a skeleton of an extinct wolf species, in…Continue reading
Source: Economist