Showing posts with label Reveals. Show all posts
Showing posts with label Reveals. Show all posts

Tuesday, June 11, 2013

Report reveals steep increase in war amputations last fall

The majority of American soldiers undergoing amputation for war wounds last fall lost more than one limb, according to data presented Tuesday to the Defense Health Board, a committee of experts that advises the Defense Department on medical matters.

Military officials had previously released data showing that amputations, and especially multiple-limb losses, increased last year. The information presented to the 20-member board is the first evidence that the steepest increase occurred over the last four months of the year.

In September 2010, about two-thirds of all war-theater amputation operations involved a single limb (usually a leg) and one-third two or more limbs. The split was roughly 50-50 in October and November. In December, only one-quarter of amputation surgery involved only one limb; three-quarters involved the loss of two or more limbs.

The Marines, who make up 20 percent of the forces in Iraq and Afghanistan, were especially hard hit. Of the 66 wounded severely enough to be evacuated overseas in October, one-third lost a limb.

In the first seven years of the Iraq and Afghanistan wars, about 6 percent of seriously wounded soldiers underwent amputation.

Wounds to the genitals and lower urinary tract - known as genitourinary injuries - accounted for 11 percent of wounds over the last seven months of 2010, up from 4 percent in the previous 17 months, according to data presented by John B. Holcomb, a trauma surgeon and retired Army colonel.

The constellation of leg-and-genital wounds are in large part the consequence of stepping on improvised explosive devices - homemade mines - and are known as "dismounted IED injuries."

The data were assembled by Holcomb and two physicians at Landstuhl Regional Medical Center in Germany, where all seriously injured soldiers are taken on their way back to the United States.

The steep increase in both the rate and number of amputations clearly disturbed both Holcomb and members of the board, which met at a Hilton hotel near Dulles International Airport.

Holcomb, who spent two weeks at Landstuhl in December and is a former head of the U.S. Army Institute of Surgical Research, said he had heard of "unwritten pacts among young Marines that if they get their legs and genitals blown off they won't put tourniquets on but will let each other die on the battlefield."

Richard H. Carmona, who was U.S. surgeon general from 2002 to 2006 and is now on the board, said the information was "very disturbing."

He said it has made him ask: "What is the endgame here? Is the sacrifice we are asking of our young men and women worth the potential return? I have questions about that now."

Carmona, 61, served as an Army medic in Vietnam before going to college and medical school. He has a son who is an Army sergeant and is serving in Iraq.

Jay A. Johannigman, an Air Force colonel who has served multiple deployments as a trauma surgeon, said his stint at the military hospital at Bagram Airfield in Afghanistan last fall "was different" both personally and medically.

"We see the enormous price our young men and women are paying. It should not be for naught," he said. He didn't want to elaborate.

Why amputation-requiring injuries increased so much in recent months isn't entirely understood. It is partly a function of tactics that emphasize more foot patrols in rural areas. Some people have speculated the mines may be constructed specifically to cause the devastating wounds.

"Do the Marines know? Probably," said Frank Butler, a doctor and retired Navy captain who has spearheaded improvements in battlefield first aid over the last decade. "But they're not releasing a thing. And they shouldn't."


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Tuesday, April 23, 2013

New NASA Satellite Survey Reveals Dramatic Arctic Sea Ice Thinning


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NASA Orbiter Reveals Details of a Wetter Mars

Martian rocks containing a hydrated mineral similar to opal NASA's Mars Reconnaissance Orbiter has revealed Martian rocks containing a hydrated mineral similar to opal. Image credit: NASA/JPL-Caltech/Univ. of Arizona
Full image and caption October 28, 2008

PASADENA, Calif. -- NASA's Mars Reconnaissance Orbiter has observed a new category of minerals spread across large regions of Mars. This discovery suggests that liquid water remained on the planet's surface a billion years later than scientists believed, and it played an important role in shaping the planet's surface and possibly hosting life.

Researchers examining data from the orbiter's Compact Reconnaissance Imaging Spectrometer for Mars have found evidence of hydrated silica, commonly known as opal. The hydrated, or water-containing, mineral deposits are telltale signs of where and when water was present on ancient Mars.

"This is an exciting discovery because it extends the time range for liquid water on Mars, and the places where it might have supported life," said Scott Murchie, the spectrometer's principal investigator at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. "The identification of opaline silica tells us that water may have existed as recently as 2 billion years ago."

Until now, only two major groups of hydrated minerals, phyllosilicates and hydrated sulfates, had been observed by spacecraft orbiting Mars. Clay-like phyllosilicates formed more than 3.5 billion years ago where igneous rock came into long-term contact with water. During the next several hundred million years, until approximately 3 billion years ago, hydrated sulfates formed from the evaporation of salty and sometimes acidic water.

The newly discovered opaline silicates are the youngest of the three types of hydrated minerals. They formed where liquid water altered materials created by volcanic activity or meteorite impact on the Martian surface. One such location noted by scientists is the large Martian canyon system called Valles Marineris.

"We see numerous outcrops of opal-like minerals, commonly in thin layers extending for very long distances around the rim of Valles Marineris and sometimes within the canyon system itself," said Ralph Milliken of NASA's Jet Propulsion Laboratory in Pasadena, Calif.

Milliken is lead author of an article in the November issue of "Geology" that describes the identification of opaline silica. The study reveals that the minerals, which also were recently found in Gusev Crater by NASA's Mars rover Spirit, are widespread and occur in relatively young terrains.

In some locations, the orbiter's spectrometer observed opaline silica with iron sulfate minerals, either in or around dry river channels. This indicates the acidic water remained on the Martian surface for an extended period of time. Milliken and his colleagues believe that in these areas, low-temperature acidic water was involved in forming the opal. In areas where there is no clear evidence that the water was acidic, deposits may have formed under a wide range of conditions.

"What's important is that the longer liquid water existed on Mars, the longer the window during which Mars may have supported life," says Milliken. "The opaline silica deposits would be good places to explore to assess the potential for habitability on Mars, especially in these younger terrains."

The spectrometer collects 544 colors, or wavelengths, of reflected sunlight to detect minerals on the surface of Mars. Its highest resolution is about 20 times sharper than any previous look at the planet in near-infrared wavelengths.

NASA's Jet Propulsion Laboratory manages the Mars Reconnaissance Orbiter mission for NASA's Science Mission Directorate in Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The Applied Physics Laboratory led the effort to build the spectrometer and operates the instrument in coordination with an international team of researchers from universities, government and the private sector.

More information about the Mars Reconnaissance Orbiter is at http://www.nasa.gov/mro .

Media contacts: Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster@jpl.nasa.gov

Dwayne Brown 202-358-1726
NASA Headquarters, Washington
dwayne.c.brown@nasa.gov

Jennifer Huergo 240-228-5618
Johns Hopkins University Applied Physics Laboratory, Laurel, Md.
jennifer.huergo@jhuapl.edu

2008-198


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Thursday, April 18, 2013

[Report] Wnt Stabilization of β-Catenin Reveals Principles for Morphogen Receptor-Scaffold Assemblies

Sung-Eun Kim1,*, He Huang1,*,†, Ming Zhao2,*, Xinjun Zhang1, Aili Zhang2,4, Mikhail V. Semonov1,‡, Bryan T. MacDonald1, Xiaowu Zhang5, Jose Garcia Abreu1,3, Leilei Peng2, Xi He1,§

1F. M. Kirby Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA.
2College of Optical Sciences, University of Arizona, Tucson, AZ 85721, USA.
3Instituto de Ciencias Biomedicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
4School of Biomedical Engineering, Jiaotong University, Shanghai, China.
5Cell Signaling Technology, Danvers, MA 01923, USA. ?§Corresponding author. E-mail: xi.he{at}childrens.harvard.edu?* These authors contributed equally to this work.

?† Present address: Department of Pathology, University of Buffalo, Buffalo, NY 14203, USA.

?‡ Present address: Veterans Administration Hospital and Department of Pathology, Boston University, Bedford, MA 01730, USA.

Wnt signaling stabilizes ß-catenin through the LRP6 receptor signaling complex, which antagonizes the ß-catenin destruction complex. The Axin scaffold and associated glycogen synthase kinase-3 (GSK3) have central roles in both assemblies, but the transduction mechanism from the receptor to the destruction complex is contentious. We report that Wnt signaling is governed by phosphorylation regulation of Axin scaffolding function. Phosphorylation by GSK3 kept Axin activated (“open”) for ß-catenin interaction and poised for engagement of LRP6. Formation of the Wnt-induced LRP6-Axin signaling complex promoted Axin dephosphorylation by protein phosphatase-1 and inactivated (“closed”) Axin through an intramolecular interaction. Inactivation of Axin diminished its association with ß-catenin and LRP6, thereby inhibiting ß-catenin phosphorylation and enabling activated LRP6 to selectively recruit active Axin for inactivation reiteratively. Our findings reveal mechanisms for scaffold regulation and morphogen signaling.

Received for publication 5 November 2012. Accepted for publication 19 March 2013.


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