1  |  2  |  3  |  4  |  5  |  6  |  7  |  8  |  9  |  10  |  11  |  12  |  13  |  14  |  15  |  16  |  17  |  18  |  19  |  20  |  21  |  22  |  23  |  24  |  25  |  26  |  27  |  28  |  29  |  30  |  31  |  32  |  33  |  34  |  35  |  36  |  37  |  38  |  39  |  40  |  41  |  42  |  43  |  44  |  45  |  46  |  47  |  48  |  49  |  50  |  51  |  52  |  53  |  54  |  55  |  56  |  57  |  58  |  59  |  60  |  61  |  62  |  63  |  64  |  65  |  66  |  67  |  68  |  69  |  70  |  71  |  72  |  73  |  74  |  75  |  76  |  77  |  78  |  79  |  80  |  81  |  82  |  83  |  84  |  85  |  86  |  87  |  88  |  89  |  90  |  91  |  92  |  93  |  94  |  95  |  96  |  97  |  98  |  99  |  100  |  101  |  102  |  103  |  104  |  105  |  106  |  107  |  108  |  109  |  110  |  111  |  112  |  113  |  114  |  115  |  116  |  117  |  118  |  119  |  120  |  121  |  122  |  123  |  124  |  125  |  126  |  127  |  128  |  129  |  130  |  131  |  132  |  133  |  134  |  135  |  136  |  137  |  138  |  139  |  140  |  141  |  142  |  143  |  144  |  145  |  146  |  147  |  148  |  149  |  150  |  151  |  152  |  153  |  154  |  155  |  156  |  157  |  158  |  159  |  160  |  161  |  162  |  163  |  164  |  165  |  166  |  167  |  168  |  169  |  170  |  171  |  172  |  173  |  174  |  175  |  176  |  177  |  178  |  179  |  180  |  181  |  182  |  183  |  184  |  185  |  186  |  187  |  188  |  189  |  190  |  191  |  192  |  193  |  194  |  195  |  196  |  197  |  198  |  199  |  200  |  201  |  202  |  203  |  204  |  205  |  206  |  207  |  208  |  209  |  210  |  211  |  212  |  213  |  214  |  215  |  216  |  217  |  218  |  219  |  220  |  221  |  222  |  223  |  224  |  225  |  226  |  227  |  228  |  229  |  230  |  231  |  232  |  233  |  234  |  235  |  236  |  237  |  238  |  239  |  240  |  241  |  242  |  243  |  244 

January 03, 2013

Was atmospheric lead responsible for America's violent crime rates?

America's Real Criminal Element: Lead | Mother Jones
It was leaded gasoline. And if you chart the rise and fall of atmospheric lead caused by the rise and fall of leaded gasoline consumption, you get a pretty simple upside-down U: Lead emissions from tailpipes rose steadily from the early '40s through the early '70s, nearly quadrupling over that period. Then, as unleaded gasoline began to replace leaded gasoline, emissions plummeted. Intriguingly, violent crime rates followed the same upside-down U pattern. The only thing different was the time period: Crime rates rose dramatically in the '60s through the '80s, and then began dropping steadily starting in the early '90s. The two curves looked eerily identical, but were offset by about 20 years. So Nevin dove in further, digging up detailed data on lead emissions and crime rates to see if the similarity of the curves was as good as it seemed. It turned out to be even better: In a 2000 paper (PDF) he concluded that if you add a lag time of 23 years, lead emissions from automobiles explain 90 percent of the variation in violent crime in America. Toddlers who ingested high levels of lead in the '40s and '50s really were more likely to become violent criminals in the '60s, '70s, and '80s. And with that we have our molecule: tetraethyl lead, the gasoline additive invented by General Motors in the 1920s to prevent knocking and pinging in high-performance engines. As auto sales boomed after World War II, and drivers in powerful new cars increasingly asked service station attendants to "fill 'er up with ethyl," they were unwittingly creating a crime wave two decades later. . . .

January 02, 2013

NASA considering lassoing an asteroid to the moon

NASA mulls plan to drag asteroid into moon's orbit - space - 02 January 2013 - New Scientist
Who says NASA has lost interest in the moon? Along with rumours of a hovering lunar base, there are reports that the agency is considering a proposal to capture an asteroid and drag it into the moon's orbit. Researchers with the Keck Institute for Space Studies in California have confirmed that NASA is mulling over their plan to build a robotic spacecraft to grab a small asteroid and place it in high lunar orbit. The mission would cost about $2.6 billion – slightly more than NASA's Curiosity Mars rover – and could be completed by the 2020s. For now, NASA's only official plans for human spaceflight involve sending a crewed capsule, called Orion, around the moon. The Obama administration has said it also wants to send astronauts to a near-Earth asteroid. One proposed target, chosen because of its scientific value and favourable launch windows for a rendezvous, is a space rock called 1999 AO10. The mission would take about half a year, exposing astronauts to long-term radiation beyond Earth's protective magnetic field and taking them beyond the reach of any possible rescue. Robotically bringing an asteroid to the moon instead would be a more attractive first step, the Keck researchers conclude, because an object orbiting the moon would be in easier reach of robotic probes and maybe even humans.

Physicians in China treat addictions by destroying the brain’s pleasure center

Physicians in China treat addictions by destroying the brain's pleasure center
The authors [of a new study], led by Guodong Gao, claim that the surgery is "a feasible method for alleviating psychological dependence on opiate drugs." At the same time, they report that more than half of the 60 patients had lasting side effects, including memory problems and loss of motivation. Within five years, 53% had relapsed and were addicted again to opiates, leaving 47% drug free. Conventional treatment only results in significant recovery in about 30-40% of cases, so the procedure apparently improves on that, but experts do not believe that such a small increase in benefit is worth the tremendous risk the surgery poses. Even the most successful brain surgeries carry risk of infection, disability and death since opening the skull and cutting brain tissue for any reason is both dangerous and unpredictable. And the Chinese researchers report that 21% of the patients they studied experienced memory deficits after the surgery and 18% had "weakened motivation," including at least one report of lack of sexual desire. The authors claim, however, that "all of these patients reported that their [adverse results] were tolerable." In addition, 53% of patients had a change in personality, but the authors describe the majority of these changes as "mildness oriented," presumably meaning that they became more compliant. Around 7%, however, became more impulsive. The surgery is actually performed while patients are awake in order to minimize the chances of destroying regions necessary for sensation, consciousness or movement. Surgeons use heat to kill cells in small sections of both sides of the brain's nucleus accumbens. That region is saturated with neurons containing dopamine and endogenous opioids, which are involved in pleasure and desire related both to drugs and to ordinary experiences like eating, love and sex.