The flow of molten material in our planet’s outer core is the prime source of Earth’s magnetic field.  http://louisyjysheehan.blogspot.com  That flow can fluctuate rapidly over large areas, recent data suggest, so geophysical models that estimate how the magnetic field evolves over time should account for such variations.

Earth’s outer core, a molten mix of iron and other metals that is no more viscous than water, flows at an average speed of about 20 kilometers per year. Because that material contains charged particles, its flow produces the planet’s magnetic field, says Nils Olsen, a geophysicist at the Danish National Space Center in Copenhagen.

Most large-scale variations in Earth’s magnetic field take place over long periods. Data gathered by satellites since 1999, however, as well as measurements taken by ground-based observatories, indicate that changes in the magnetic field’s strength can take place over small areas at a rather quick pace — twitches that researchers have dubbed geomagnetic jerks.

Instruments have detected two such jerks in the past decade. In one, which occurred in mid-2003, changes in the magnetic field were most evident in southern Asia, says Olsen. Variations noted during the other, in late 2004, were strongest in the region stretching from the South Atlantic to the southwestern Indian Ocean. The rate of field change in each case measured, at its peak, just 0.004 percent per year, he notes.

These small blips nevertheless betray large and rapid changes in the flow of molten material along the surface of the outer core, Olsen and Mioara Mandea, a geophysicist at the National Research Center for Geosciences in Potsdam, Germany, report online May 18 in Nature Geoscience.

Each of the flow changes inferred from the magnetic field data covered less than a quarter of the Earth’s surface and lasted no more than a few months. Such changes in the flow of outer core material are akin to ocean eddies, says Olsen. The new findings suggest that geophysical models used to simulate variations in the planet’s magnetic field strength should include the possibility of short-term changes in the flow of core material.

Thanks to better screening, prevention and treatment, death rates from cancer in the United States have declined steadily in recent decades. But a new study finds that while college graduates have benefited from this trend, people who didn’t finish high school have lagged behind and even missed out on some of these gains.  http://Louis-J-Sheehan.de

Much of the discrepancy stems from differences between the groups in taking preventive measures such as quitting smoking or using cancer screening options, says study coauthor Ahmedin Jemal, an epidemiologist at the American Cancer Society in Atlanta.

But a lot can also be traced to the fact that 47 million people in the United States are uninsured, he says. Education levels closely track with socioeconomic levels, and that means access to good health care and insurance coverage to pay for it, he says.

Jemal and his colleagues analyzed data collected by the National Center for Health Statistics, part of the Centers for Disease Control and Prevention, from death certificates filed in 37 states and the District of Columbia. The research team concentrated on people ages 25 to 64 who had died from 1993 to 2001, calculating mortality rates during that time period for the four most common cancers—lung, colorectal, breast and prostate. The sampling of the non-Hispanic population included more than 500,000 deaths.

The researchers report in the July 16 Journal of the National Cancer Institute that while some death rates fell dramatically between these time posts, significant differences emerged across the board based on educational background. For example, the death rate from lung cancer over that span dropped by 5 percent annually in white men and 7 percent annually in black men who had been through college.  http://Louis-J-Sheehan.de  But among men who had dropped out of high school, the lung cancer death rate remained largely unchanged in whites and dropped less than 1 percent a year in blacks.

Meanwhile, colorectal cancer fell significantly over that time in men and women, black and white, who had gone to college, but not in their counterparts who hadn’t finished high school.

Other research shows that roughly 50 percent or more of highly educated people get regular colonoscopies that can catch and remove colorectal cancer early, but that among poorly educated people the number is closer to 30 percent, Jemal says. “The difference by education is mind-boggling,” he says.  http://Louis-J-Sheehan.de

Among whites, breast cancer death rates declined broadly, and women with more education showed greater decreases. But among black women, only those with four years of college showed clear declines.

In men, prostate cancer deaths showed a strong education-related decline among white men, but less of a decline for black men.

Much of the effect seen in this study could reflect access to health care, says health economist Cathy Bradley of Virginia Commonwealth University in Richmond. But another factor could play an equally important role, she says.

“I think education is a marker for something else,” she says. “People who invest in an education also invest in their health and place a higher value on the future than on the present.” Hypothetically, this prioritizing would be reflected in lifestyle, and these people might even seek out jobs with better insurance plans.

In contrast, people who don’t invest in the future, as in a high school diploma or a college degree, may place more value on the present, she says. Because cancer is an invisible disease whose causes have little immediate impact, these people may concentrate on satisfying immediate needs and show less regard for future risks.

Two main factors contribute to keyboard filth: cleaning them is difficult, and people rarely remember to do it. Wilson and his team tackled both problems. First, it’s hard to get into a traditional keyboard’s dirty and germ-filled crevices, so the new design is flat, allowing it to be wiped down in a flash. And while you might only clean your keyboard when a story like this reminds you what a bacteria trap it can be, Wilson’s team programmed their keyboard to nag—a warning light comes on after a few hours, reminding the cleaning staff to disinfect it.  http://louis6j6sheehan.blogspot.com

British hospitals everywhere will soon be trying out the flat keyboard, and those old tough-to-clean models couldn’t be gone soon enough. While normal British offices could have 150 times the recommended limit of bacteria on their keyboards, Wilson says, hospitals are worse: Doctors and nurses are cognizant that they need to wash their hands between patients, but they aren’t so diligent in cleaning up between working with a patient and typing on a computer. But, he says, using the new keyboards and cleaning them every 12 hours can cut the bacterial load by 70 percent.

If you’re stuck with an old-style keyboard, though, don’t despair—there are always Q-tips and alcohol. Or, if you don’t have time for such a meticulous process, you could just throw your keyboard in the dishwasher. We are not advocating this, however, so do so at your own risk.

Water on Mars was once widespread and long-lasting, providing environments with the potential to support life, a new study finds.

Previously, scientists had strong evidence that liquid water chemically altered the Red Planet’s crust at certain times and locations. Those locations hold the mineral traces of water and preserve in the rock the planet’s past organic chemistry, says Scott Murchie, co-author of the new paper published in the July 17 Nature.

Those locations are also “really important” because the rocks there could hold possible evidence of past life, says Murchie, of the Johns Hopkins University Applied Physics Laboratory in Laurel, Md.  http://louisjjjsheehan.blogspot.com

Using the Compact Reconnaissance Imaging Spectrometer for Mars, or CRISM, and other instruments aboard NASA’s Mars Reconnaissance Orbiter, the team looked for specific types of phyllosilicates, or clay-like minerals, that can form only in the presence of water. The team suggests the water was present early in the solar system’s history, between 4.6 billion and 3.8 billion years ago, based on where in the planet’s rocky layers the minerals occur.

Scientists previously identified a few types of these minerals at about 100 sites, but the sensitivity of CRISM picked up a large variety of the phyllosilicates at thousands of locations across Mars’ southern highlands.  http://louisjjjsheehan.blogspot.com

“Finding all these different water-based minerals at all these locations really blows the doors off Mars research,” says University of Paris’ Joseph Michalski, a Mars researcher who was not involved in the study. But, he adds, it all will take years of scientific study and debate to understand what these sites mean for the history of Mars, and whether these sites hosted life.

Scientists use X-rays to peer into a person's body, and a new X-ray imaging technique does the same for individual cells. 
http://louis1j1sheehan1.blogspot.com

“You should be able to image most macromolecular assemblies inside the cell”, such as proteins and DNA, says Pierre Thibault, a physicist at the Paul Scherrer Institute in Villigen, Switzerland who leads the team that reports the new technique in the July 18 Science.

Also, “it’s certainly a very important tool for nanotechnology,” Thibault says. The best light microscopes can’t distinguish features smaller than 200 nanometers. But images made with the new technique, called scanning X-ray diffraction microscopy, reveal features as small as 10 nanometers. 
http://louis1j1sheehan1.blogspot.com

Electron microscopes can “see” details as small as 0.2 nanometers, but since electrons don’t penetrate far into most materials, only the surface gets imaged. X-rays penetrate materials much better, allowing the new technique to peer into objects tens of thousands of nanometers thick — about the size of most plant or animal cells.

“It’s an important development,” comments Jianwei Miao, a physicist at the University of California, Los Angeles who helped pioneer a related X-ray imaging technique. “The image is much better quality compared to previous ones.”

To make an image, Thibault and his colleagues scanned a specimen with an X-ray beam focused into a spot 300 nanometers across. For each point in the specimen, a high-speed photon detector recorded the X-rays that had passed through the specimen and spread out into a diffraction pattern — akin to the rainbow produced by a prism. Using the series of diffraction patterns, the scientists could mathematically reconstruct the image.

Louis J. Sheehan

At more than 14 billion kilometers from the sun, Voyager 1 is farther from Earth than any other man-made object, yet the spacecraft is still within range of NASA's budget ax. The agency's new focus on human exploration--including the resumption of space shuttle flights scheduled for this month--is pulling funds from the unmanned spacecraft that study Earth, the sun and the outer reaches of the solar system.

In addition to devoting 40 percent of its $16.5-billion budget to the shuttle and the International Space Station, NASA has earmarked $753 million for the design of the Crew Exploration Vehicle, which will carry astronauts into orbit after the shuttle is retired in 2010. To help pay for this effort, the agency has proposed deep cuts to its Earth-Sun System Division, which operates Voyagers 1 and 2 and a dozen other probes that have completed their primary missions but are still yielding valuable data. Ordered to lop $20 million from the $75-million budget for the missions, the division will hold a review this fall to determine which spacecraft must be sacrificed. Potential victims include solar observatories (such as Ulysses and TRACE) as well as probes that investigate space weather around Earth (such as Polar, FAST, Geotail and Wind). To keep the craft running until the review, NASA has delayed funding research proposals to analyze the data from the missions.

The uproar over the Voyagers has been the loudest. Launched in 1977, the twin probes explored Jupiter, Saturn, Uranus and Neptune and can continue operating until they use up their plutonium fuel about 15 years from now. In 2002 Voyager 1 reported a surge in particle counts; the craft may have temporarily crossed the termination shock, the turbulent boundary where the solar wind begins to merge with the interstellar medium. The probe recently detected new signs of turbulence, and project scientists insist that canceling the $4.2-million-a-year program would be folly. Says Stamatios Krimigis, lead investigator for Voyager's low-energy particle detector: "It's like Columbus sighting land and then saying, 'Okay, let's go back.'"

Meteorologists and geologists are up in arms, too. In April a National Research Council (NRC) report declared that NASA's system of Earth-observing satellites "is at risk of collapse." Half a dozen missions have been canceled, downsized or delayed. In some cases, the cutbacks threaten to create gaps in environmental records that NASA has been compiling for decades. For example, the agency had originally intended to launch the Landsat Data Continuity Mission to succeed the aging Landsat 7 satellite, which tracks everything from deforestation in the tropics to collapsing ice sheets in Antarctica. But now NASA plans to build only the Landsat imagers and place them on weather satellites operated by the National Oceanic and Atmospheric Administration. The delay will almost certainly cause a data gap--Landsat 7, which was launched in 1999, is already faltering, and the first of the NOAA satellites will probably not go up until at least 2009. What is more, researchers warn that the NOAA satellites will be large and hence prone to vibrations, which may ruin the quality of the Landsat images.

The budget pressures are also slowing the effort to understand climate change. The future of the Glory mission, which would make the first global measurements of soot and dust to determine their impact on climate, is now uncertain; its instruments may be reassigned to one of the NOAA satellites. "Pushing all these things back is not okay," says Richard A. Anthes, a hurricane expert who co-chaired the NRC panel. "We can't afford not to observe Earth."

The scientific community is clearly hoping that NASA's new administrator, Mike Griffin, will reverse some of the cuts to research missions. Before taking the top job at NASA, Griffin headed the space department at Johns Hopkins University's Applied Physics Laboratory. Krimigis, who held the same position before Griffin, has faith in his colleague. "I know Griffin--I interviewed him for this job," Krimigis says. "I'm quite confident he'll do the right thing."

Louis J. Sheehan

A common belly bug once thought to be harmful may have beneficial effects early in life. Researchers at the New York University (N.Y.U.) Langone Medical Center have found that a lack of Helicobacter pylori—a microbe that thrives in the human stomach—may be linked to childhood asthma and other allergies.

They report in The Journal of Infectious Diseases that children ages three to 13 years were 59 percent less likely to have asthma and 69 percent less likely to have hay fever and other childhood allergies if they tested positive for the bacterium. The question is whether the benefits outweigh the potential risks later in life. H. pylori has been linked to the development of peptic ulcers and gastric cancer in adults after their third decade.

The finding suggests that doctors may even consider introducing the bacteria to kids whose natural supplies have been destroyed, says study co-author Martin Blaser, an N.Y.U. infectious disease specialist.

"In the future, physicians may give children a mix of H. pylori strains to optimize their health early in life, and then use antibiotics to eradicate the organism in a patient's 40s," Blaser says.

H. pylori is acquired during childhood, usually from close contact with parents and siblings. Beginning in the early 20th century, clean water, smaller families, better nutrition and the widespread use of antibiotics in industrialized nations led to a dramatic decline in this microbe. Only about 5 percent of children in this study who were under 10 years of age were found to harbor H. pylori compared with developing nations, where most children test positive.

During the second half of the 20th century, there was a spike in asthma rates, particularly in countries where the bacteria were disappearing; in the U.S., for instance, asthma rates for children below the age of 17 jumped from 3.6 percent in 1980 to 8.9 percent in 2005.

Blaser says the microbe has been residing in the human stomach for at least 50,000 years. When present, it dominates the microbial ecosystem of the gut and interacts with the stomach lining's cells. The immune system cannot eliminate the organism, but "it has learned to live with it by regulating the inflammatory responses induced by H. pylori," he notes.

The study echoes previous findings that suggest that H. pylori can benefit people harboring it, according to William Tremaine, a professor of medicine at the Mayo Clinic in Rochester, Minn, who was not involved in the study. For example, children with inflammatory bowel disease tend to test positive for the microbe less often than other children. All of that may mean that in the recent past, "H. pylori may have offered a survival advantage by blocking the onset of debilitating and potentially fatal diseases that start earlier in life than gastric cancer," Tremaine wrote in an e-mail.

Future studies will examine if H. pylori interactions in the stomach play a direct role in tempering broader immune responses to environmental allergens. As Hidekazu Suzuki, an associate professor at the Keio University School of Medicine in Tokyo, who was not involved in the study, notes in an e-mail, this work suggests a "new trend for the basic and clinical research of H. pylori-associated diseases."

A letter from Gen. Gilmer states that the Danville Railroad will not be fully repaired before the last of this month. But there is a good wagon road, and the army can be supplied by wagons when the cars cannot run, sonic 25 miles.

            There is an idle rumor that Wilmington has been taken by the enemy. This, indeed, would hurt us. But we get neither letters nor dispatches from beyond Petersburg.

            Last week, when the local forces were recalled, one of the clerks in the Treasury Department, upon being dismissed, fell upon his lieutenant, who had insulted him while in the military service, and as a civilian, gave him a beating. To-day the officer, after consulting his lieutenant-colonel commanding, and, it is said, the Secretary of War, sent a subaltern to the department to arrest the clerk, who resisted. http://louis9j9sheehan9esquire.blogspot.comThe subaltern said he acted by authority of the lieutenant-colonel and the Secretary of War, and would arrest him and throw him in prison, if he had to come with force enough to pull down the building. To all this the Secretary of the Treasury demurred, and made a formal complaint to the President, who most indignantly indorsed on the paper that the conduct of the officer was “very reprehensible,” that if when the offense was committed, the battalion had been dismissed, the military authority of the officers ceased, and as civil officers, all were on the same footing.  http://louis9j9sheehan9esquire.blogspot.com  He ordered the Secretary to make this known to the officers, etc. None believe now that the President ever threatened to turn the clerks out of office, as represented, nor wished them put in the army, as hinted.