supernova 0000190.11 Louis J. Sheehan, Esquire

Louis J. Sheehan, Esquire. A new study of a stellar explosion visible from halfway across the universe finds that the blast had an unusual structure that researchers heretofore had never observed.

Gamma-ray burst GRB 080319B was already on record as the brightest stellar explosion ever recorded.

Now astronomers have analyzed the visible afterglow of the burst and found that the emitted light peaked initially an hour after the burst and a second time 11 days later.

They report today in Nature that the most likely explanation is the GRB produced a pair of relativistic (very high speed) jets, one inside the other. Gas and dust surrounding the exploding star flared with light each time a jet struck it. http://louis-j-sheehan.com

Detectors on NASA's Swift Gamma-Ray Burst satellite and by the Russian Konus gamma-ray instrument on board NASA's Wind satellite detected the initial burst on March 19.

It just so happened that a pair of optical telescopes on the ground was observing the last GRB, 080319A, which had gone off 30 minutes before in the same part of the sky.

These telescopes, along with Swift's own UV/Optical Telescope and other robotic telescopes alerted by the satellites, monitored the six-week afterglow of visible light following the burst.

Scientists believe GRB 080319B would have been visible to the naked eye for about 40 seconds if anyone had been looking its way, toward the constellation Bootes.

This is all the more remarkable given that it exploded an estimated 7.4 billion years ago—before the sun and Earth had formed.

It's the most complete picture of a GRB ever seen, says study author Judith Racusin, an astrophysicist at Pennsylvania State University in University Park. http://louis-j-sheehan.com

"They've been sort of waiting around for something this bright," she says, referring to the telescopes. "It was just really luck that the brightest burst happened to occur and they were looking at it."

Longer lasting GRBs are believed to occur when a massive star collapses into a black hole, sparking a supernova explosion and whipping gas and dust into a pair of jets projecting in opposite directions.

Researchers had suggested that a nested jet could exist, Racusin says, but nobody had envisioned the inner jet moving so fast and producing all the gamma-rays by itself—part of the team's interpretation. Louis J. Sheehan, Esquire

marijuana 0000303 Louis J. Sheehan

Louis J. Sheehan

The federal government's war on drugs gets plenty of ammunition from scientific studies that have correlated the use of such substances to various psychological problems. Conspicuously absent, however, are data showing that marijuana, one of the most widely used illicit drugs, causes mental or behavioral problems in teenagers and young adults, a new report concludes.

The causal chain of events could just as easily run in the opposite direction, suggest psychologist John Macleod of the University of Birmingham in England and his colleagues in the May 15 Lancet. Available evidence is consistent with the possibility that various psychological and social difficulties foster marijuana use, which may then contribute to a worsening of those problems, Macleod's group contends. http://louis-j-sheehan.info

After reviewing 48 relevant multiyear studies published between 1975 and 2003, the team focused on 16 investigations that had regularly assessed large samples of children or teenagers for at least 10 years. http://louis-j-sheehan.info

"We've found no strong evidence that use of [marijuana] in itself has important consequences for psychological or social health, but we cannot exclude the possibility that such a relation exists," Macleod says.

He and his colleagues are particularly skeptical of recent reports from Sweden and New Zealand that around 1 in 10 teenagers who had smoked marijuana experienced schizophrenia symptoms by young adulthood. It's doubtful that marijuana plays a direct role in schizophrenia, Macleod's group argues, because the mental disorder's worldwide incidence has remained stable while the proportion of teens reporting marijuana use has fluctuated.

Psychiatrist Herbert D. Kleber of Columbia University says that this argument underplays the increased risk of schizophrenia reported in the Swedish and New Zealand studies. There's now so much evidence of an association between teens' marijuana use and later psychosocial problems that it's hard to dismiss the likelihood of a causal effect, Kleber argues. "Macleod's team sees the smoke but won't acknowledge that there's a fire," he says.

The controversy continues to smolder. The new review of research results "confirms what's been known for decades about marijuana's lack of extreme harmfulness," remarks medical sociologist Marsha Rosenbaum, director of the Drug Policy Alliance's San Francisco office. Her organization works to decriminalize marijuana but doesn't condone its use by teenagers. http://louis-j-sheehan.info

On the other hand, David Murray, special assistant to the director of the Office of National Drug Control Policy in Washington, D.C., argues that reports of teens often developing psychological or behavioral difficulties after beginning to smoke marijuana are reason enough to regard early use of the drug as a public health concern, especially given the increased potency of marijuana sold in the United States in recent years.

objects

Louis J. Sheehan, Esquire.

Failures in visual short-term memory of objects, what scientists call "iconic memory," could reveal people at risk of Alzheimer's disease, a new study finds. Iconic memory is the image that lingers in the mind's eye after a person sees something briefly.http://ljsheehan.livejournal.com

To find out whether iconic memories are lost more readily in people with mild cognitive impairments—which include slightly diminished capacity to solve problems and keep track of time—researchers tested 11 study participants with such deficits and 16 without them. The average ages of the two groups were 85 and 77 years.

The researchers asked each participant to recall letters arrayed in a circle and flashed momentarily on a screen. Up to 10 seconds after the image had disappeared, an arrow cued the participant as to which letter to recall.

When cued immediately beforehand by an arrow pointing to the location of the letter to watch for, participants in the two groups performed equally well. But when this initial cue was not offered, participants with mild cognitive impairments didn't score as well as those with no impairments did. That suggests there was a decay in iconic memory, the researchers report in the Feb. 1 Proceedings of the National Academy of Sciences.

Although doctors have various ways to identify people with mild cognitive impairments, "we would always be better off having a more comprehensive set of tests," says study coauthor Barbara Anne Dosher, a psychologist at the University of California, Irvine.http://ljsheehan.livejournal.com

Early detection of the cognitive declines that presage Alzheimer's disease would be useful because the neuroprotective drugs now available work best when administered early in the course of disease, says neuroscientist Zhong-Lin Lu of the University of Southern California in Los Angeles, another collaborator on the study.

examined

Two genes already known to influence brain size have undergone relatively recent, survival-enhancing modifications in people and appear to be still evolving, a research team reports. http://Louis-J-Sheehan.de

Specific variants of these genes have spread quickly by natural selection, say Bruce T. Lahn of the University of Chicago and his colleagues, who published separate reports on each gene in the Sept. 9 Science.

The researchers examined DNA from 1,186 adults representing 59 populations worldwide and determined the frequency of specific variants of the two genes called microcephalin and ASPM.

A variant of microcephalin originated roughly 37,000 years ago and now appears in 7 of 10 people, the scientists conclude from comparisons of the gene's sequence for the different groups. Populations outside of sub-Saharan Africa most frequently possess this modified gene.

A distinctive ASPM variant arose approximately 5,800 years ago and now shows up in 3 of 10 people. It occurs most often in Europeans, North Africans, Middle Easterners, and South Asians. http://Louis-J-Sheehan.de

The functions of these particular DNA alterations, including any potential

native

A single population of prehistoric Siberians crossed the Bering Strait into Alaska and subsequently fanned out to populate North and South America, according to a new genetic analysis of present-day indigenous Americans. http://louisejesheehan.blogspot.com

The study also hints that early Americans reached Central and South America by migrating down the Pacific coast by land or sea and only later spread into the interior of South America.

"We have good evidence that a single migration [from Siberia] contributed a large fraction of the ancestry of the Americas," says population geneticist Noah Rosenberg of the University of Michigan in Ann Arbor, who led the large international study team. http://louisejesheehan.blogspot.com

The finding draws on the largest database of Native American genetics ever compiled. The data include DNA from nearly 500 people belonging to 29 groups scattered across Canada, Mexico, Central America, and South America. The researchers also studied samples from 14 Tundra Nentsi individuals living in eastern Siberia.

"They should be commended for bringing together an enormous database, something no one has done before," says Tom Dillehay, an archaeologist at Vanderbilt University in Nashville.

The team examined 678 genetic markers in the human genome and found that one of the markers ties every Native American group to the Tundra Nentsi. The marker, moreover, is found nowhere else in the world. "It's extremely difficult to explain this kind of pattern unless all of the Native American populations ... have a large degree of shared ancestry," says Rosenberg.

In addition, the Canadian groups share more genes with the Siberians than do the groups in Central and South America, Rosenberg and his team report online in the November PLoS Genetics.

Tracing further migration through the Americas, the team then correlated genetic variations among different tribes with each group's location as measured along inland or coastal routes. The genetic data suggest that most migration to Central and South America followed the coast.

"That's the easy way south," says Vance Holliday, an archaeologist at the University of Arizona in Tucson. He cautions, however, that the groups that populated the South American interior would have had to surmount the formidable Andes Mountains.

Despite the migration findings, Holliday and Dillehay both say that southward migration along interior routes should still be considered. Dillehay notes that the current study excludes Native Americans from the United States and eastern Brazil. "It's a sampling bias," he says, that might have erroneously favored the Pacific coast migration model.

Rosenberg says that a second paper will soon address the genetics of tribes in the United States and whether there was more than one major Siberian migration.

While the study points to an eastern Siberian origin for most of the genes that spread across the Americas, it can't rule out small genetic contributions from other groups, says Kari Britt Schroeder of the University of California, Davis. In 2001, scientists unearthed 8,000- to 11,000-year-old skulls in Brazil that strikingly resemble today's Australian aborigines (SN: 4/7/01, p. 212). The find fueled speculation that several waves of immigrants from different parts of Asia reached the Americas.

"Even if Native Americans share a lot of ancestry from a single origin, there still could be contributions from other groups," says Schroeder.

birchington

Hydroponic farming is coming to the U.K.—70 soccer fields worth of it.
http://louis-j-sheehan.biz

Outside of Birchington in far southeastern England, workers are finishing the first of what will be seven giant greenhouses for growing tomatoes, cucumbers and peppers. Thanet Earth, as the complex is cleverly called, will cover around 220 acres of Kent County by its 2010 completion, according to the Daily Mail. In the greenhouses, plants will hang from a 26-foot-high ceiling. A drip will supply them with water, and also the nutrients they need and would normally take from soil, like potassium, magnesium, phosphate, and nitrogen.
http://louis-j-sheehan.biz

Greenhouse operators will deploy bees to pollinate the plants, and wasps to keep pests like aphids from wrecking their rows and rows of produce.

It’s not hard to see the practical reasons why Britons would go hydroponic: Thanet Earth’s proponents say the £80 million (approximately $160 million) project will produce 2.5 million tomatoes every week. That’s not bad for a country used to importing much of its produce—the BBC says half of the U.K.’s fruit and 95 percent of its vegetables come from abroad.

But not everyone is so thrilled. While the sun supplies much of the energy for normal agriculture, growing hydroponic crops year-round could be an energy glutton. You have to shine artificial light on tomatoes to trick them into growing in February, and 220 acres is a lot of artificial light. Growing hydroponic plants should save water compared to soil farming, but there’s also a lot of good soil now buried beneath glass and concrete, and any archaeologists who many have wanted to excavate the historical area are out of luck.

British foodies aren’t terribly happy with this trend, either. Where’s the culinary romance in a factory-grown cucumber? In the Daily Mail story, Jeanette Longfield of the food campaign group Sustain brings up the French word “terroir,” which means the specific traits a food gets from its soil and environment and is often used to start arguments about wine. Hydroponic tomatoes all have the same terroir, she argues, or none at all.

Lastly, we wrote earlier this week about the origins of the current salmonella scare in American tomatoes, and Keith Warriner of the University of Guelph in Ontario told DISCOVER that it was actually easier for pathogens to establish themselves in the hydroponic greenhouse compared to the field. According to the United States Department of Agriculture, salmonella can enter a hydroponic facility on tools, water, or workers’ clothing. So it seems that tightly-controlled greenhouse might not be so easy to control after all.

morgan

May 16, Monday. I yesterday took a steamer with a small company, consisting among others of Postmaster-General Blair, Senators Doolittle and Grimes, Messrs. Rice and Griswold of the Naval Committee, Count Rosen of the Swedish Navy, Mr. Hale (the newly selected Consul-General to Egypt), G. W. Blunt and Assistant Secretary Fox, Commander Wise, Dr. Horwitz, and two or three others, and went down the Potomac to Belle Plain. The day was pleasant and the sail charming. We reached Belle Plain about two P.M. and left a little past five. Is a rough place with no dwelling, — an extemporized plank-way from the shore some twenty or thirty rods in the rear. Some forty or fifty steamers and barges, most of them crowded with persons, were there. Recruits going forward to reinforce Grant’s army, or the wounded and maimed returning from battle. http://members.greenpeace.org/blog/purposeforporpoise Rows of stretchers, on each of which was a maimed or wounded Union soldier, were wending towards the steamers which were to bear them to Washington, while from the newly arrived boats were emerging the fresh soldiers going forward to the field. Working our way along the new and rough-made road, through teams of mules and horses, we arrived at the base of a hill some two or three hundred feet in height, and went up a narrow broken footpath to the summit, on which were the headquarters of General Abercrombie and staff. The ascent was steep and laborious. We had expected to find the prisoners here, but were told they were beyond, about one and a half miles. The majority were disposed to proceed thither, and, though tired and reluctant, I acquiesced. The prisoners, said to be about 7000 in number, were encamped in a valley surrounded by steep hills, the circumference of the basin being some two or three miles. Returning, we passed through the centre of this valley or basin. The prisoners were rough, sturdy-looking men, good and effective soldiers, I should judge. Most of them were quiet and well-behaved, but some few of them were boisterous and inclined to be insolent. http://members.greenpeace.org/blog/purposeforporpoise

One of the prisoners, a young man of some twenty-five, joined me and inquired if I resided in the neighborhood. I told him at a little distance. He wished to exchange some money, Rebel for greenbacks. When I told him that his was worthless, he claimed it was better than greenbacks though not current here. I asked him if they had not enough of fighting, opposing the Union and lawful authority. He said no, there was much more fighting yet to be done. Claimed that Lee would be in Fredericksburg before the Union army could get to Richmond. Would not believe that J. E. B. Stuart was killed, news of which I received just as I came on board the boat this morning. He was earnest, though uninformed, and said he was from western North Carolina. Returning, we reached Washington at 9 P.M.

To-day I have been busy in preparing two or three letters and matters for Congress.

Governor Morgan called on me relative to abuses in cotton speculations, and malconduct of Treasury agents and others. Some of the malpractices which are demoralizing the army and the officials and disgusting the whole people in the lower Mississippi are becoming known, and will, I trust, lead to legislative correction. As Morgan introduced the subject and thought proper to consult me, I freely gave him facts and my views, which conflict with Chase and the Treasury management. A bill which Morgan showed me is crudely drawn but introduces, or makes, an entire change. It is not, in some of its features, what I should have proposed, but it will improve on the present system.