Protection for humans on Mars

ScienceDaily (Sep. 18, 2012) ? For six weeks NASA's Mars rover Curiosity has been working on the Red Planet. NASA also plans to send humans to Mars within the next 20 years. On the flight and during the stay on Moon or Mars the astronauts have to be protected against long exposure to cosmic radiation that might cause cancer.

On behalf of the European Space Agency ESA the GSI Helmholtzzentrum f?r Schwerionenforschung GmbH tests whether Moon and Mars regolith can be used to build shieldings for ground stations.

On Earth the atmosphere and the magnetic field weaken cosmic rays. But on Moon and Mars they pelt down unhamperdly. The cosmic radiation can harm astronauts and could cause cancer in the long run as a result of damage in DNA and cells.

Chiara La Tessa is manager of experiments in GSI biophysics. She explains why Moon or Mars ground stations would not be built from terrestrial high tech material: "In space travels every gram counts. Transporting building material through space would lead to a cost explosion. That is why ground stations would basically be built from Moon and Mars regolith -- especially the shielding. We know from the analyses done by rovers what the local sand and stones consist of. With this information one can produce Moon and Mars regolith on Earth and we test it for its properties." As cosmic rays are nothing else but fast ions that were accelerated by star explosions they can be simulated by an accelerator. The GSI facility is one of the few able to reproduce cosmic rays in an original way.

After the GSI team tested how well the stone slabs can protect against radiation in the American accelerator laboratory in Brookhaven, they now explore how many neutrons are produced in the materials when radiated.

If cosmic rays strike the stones with full speed they smash some atomic nuclei to pieces. The resulting free neutrons have a different effect on the human body than cosmic radiation. Depending on their speed they might even be more harmful.

At GSI the scientists now tested how strong the neutron effect is in Moon and Mars regolith and how far it passes through the material. ?I cannot estimate how the material is going to react to the radiation yet," says La Tessa. ?Will many neutrons be produced? How many fast and how many slow ones? This we will know when we analyzed our experiment data."

The tests funded by ESA were coordinated by Thales Alenia Space Italia. The prime contractor of ESA's project also designed the test plan in cooperation with GSI, chose the materials and evaluats the results.

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The above story is reprinted from materials provided by Helmholtz Association of German Research Centres.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Source: http://feeds.sciencedaily.com/~r/sciencedaily/top_news/top_technology/~3/tuQMLKdCpZw/120918121545.htm

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Nano-velcro clasps heavy metal molecules in its grips

ScienceDaily (Sep. 9, 2012) ? Researchers develop nano-strips for inexpensive testing of mercury levels in our lakes and oceans with unprecedented sensitivity

Mercury, when dumped in lakes and rivers, accumulates in fish, and often ends up on our plates. A Swiss-American team of researchers led by Francesco Stellacci at the Ecole Polytechnique F?d?rale de Lausanne (EPFL) and Bartosz Grzybowski at Northwestern University has devised a simple, inexpensive system based on nanoparticles, a kind of nano-velcro, to detect and trap this toxic pollutant as well as others. The particles are covered with tiny hairs that can grab onto toxic heavy metals such as mercury and cadmium. This technology makes it possible to easily and inexpensively test for these substances in water and, more importantly, in the fish that we eat. Their new method can measure methyl mercury, the most common form of mercury pollution, at unprecedentedly small attomolar concentrations. The system is outlined in an article appearing September 9, 2012 in the journal Nature Materials.

Methyl mercury, toxic and difficult to monitor

Researchers are particularly interested in detecting mercury. Its most common form, methyl mercury, accumulates as one goes up the food chain, reaching its highest levels in large predatory fish such as tuna and swordfish. In the US, France and Canada, public health authorities advise pregnant women to limit fish consumption because mercury can compromise nervous system development in the developing fetus.

"The problem is that current monitoring techniques are too expensive and complex," explains Constellium Chair holder at EPFL and co-author Francesco Stellacci. "We periodically test levels of mercury in drinking water, and if those results are good, we make the assumption that levels are acceptable in between those testing periods." But industrial discharge fluctuates.

A simple, inexpensive new technology

The technology developed by the Swiss-American team is simple to use. A strip of glass covered with a film of "hairy" nanoparticles is dipped into the water. When an ion -- a positively charged particle, such as a methyl mercury or cadmium ion -- gets in between two hairs, the hairs close up, trapping the pollutant.

A voltage-measuring device reveals the result; the more ions there are trapped in the nano-velcro, the more electricity it will conduct. So to calculate the number of trapped particles, all one needs to do is measure the voltage across the nanostructure.

By varying the length of the nano-hairs, the scientists can target a particular kind of pollutant. "The procedure is empirical," explains Stellacci. Methyl mercury, fortunately, has properties that make it extremely easy to trap without accidentally trapping other substances at the same time; thus the results are very reliable.

The interesting aspect of this approach is that the 'reading' glass strip could costs less than 10 dollars, while the measurement device will cost only a few hundreds of dollars. The analysis can be done in the field, so the results are immediately available. "With a conventional method, you have to send samples to the laboratory, and the analysis equipment costs several million dollars," notes Stellacci.

Convincing tests in Lake Michigan and Florida

The researchers tested the system in Lake Michigan, near Chicago. Despite the high level of industry in the region, mercury levels were extremely low. "The goal was to compare our measurements to FDA measurements done using conventional methods," explains Stellacci. "Our results fell within an acceptable range."

A mosquito fish from the Everglades in Florida was also tested. This species is not very high on the food chain and thus does not accumulate high levels of mercury in its tissues. "We measured tissue that had been dissolved in acid. The goal was to see if we could detect even minuscule quantities." says Bartosz Grzybowski, Burgess Professor of Chemistry and Director of Non-Equilibrium Energy Research Center at Northwestern University. The United States Geological Survey reported near-identical results after analyzing the same sample.

From quantum to real applications

"I think it is quite incredible," Grzybowski adds, "how the complex principles of quantum tunneling underlying our device translate into such an accurate and practically useful device. It is also notable that our system -- through some relatively simple chemical modifications -- can be readily adapted to detect other toxic species" Researchers have already demonstrated the detection of cadmium with a very high femtomolar sensitivity.

"With this technology, it will be possible to conduct tests on a much larger scale in the field, or even in fish before they are put on the market," says lead author Eun Seon Cho. This is a necessary public health measure, given the toxic nature of methyl mercury and the extremely complex manner in which it spreads in the environment and accumulates in living tissues.

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The above story is reprinted from materials provided by Ecole Polytechnique F?d?rale de Lausanne, via EurekAlert!, a service of AAAS.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. Eun Seon Cho, Jiwon Kim, Baudilio Tejerina, Thomas M. Hermans, Hao Jiang, Hideyuki Nakanishi, Miao Yu, Alexander Z. Patashinski, Sharon C. Glotzer, Francesco Stellacci, Bartosz A. Grzybowski. Ultrasensitive detection of toxic cations through changes in the tunnelling current across films of striped nanoparticles. Nature Materials, 2012; DOI: 10.1038/nmat3406

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Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Source: http://feeds.sciencedaily.com/~r/sciencedaily/top_news/~3/42J8FlBVghc/120909150355.htm

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short-domains.de ? Mental Disorder and Criminal Law ...

Gepostet am 30.08.2012 von shortdomains

The death penalty has long played a central role in jurisprudence, in terms of identifying the most serious offenses and the most culpable offenders, as well as understanding the mental conditions that may exclude an offender from such a sentence. More recently, the debate has intensified on competency to face [execution], the effects of psychological impairment on that competency, and the role of expert witnesses in establishing criminal culpability. The edited volume, Mental Disorder and Criminal Law authoritatively blends empirical findings and legal expertise with sophisticated reasoning and ethical analysis to promote a deeper understanding of these complex issues at the interface of legal and psychological domains. In short, it explores the concept of (as termed by one chapter author) protecting well-being while pursuing justice. Contributors to this important volume:

• Examine the effects of depression at different stages of legal procedure.
• Offer proposed criteria for [prohibiting] capital punishment [of] the severely mentally ill
• Identify moral and procedural concerns in the use of child victims as witnesses.
• Analyze the balance between present responsibility and future risk.
• Untangle clinical and ethical issues for clinicians involved in capital sentencing.
• Clarify the process of psychological evaluation of competence to be executed.
• Review degrees of psychopathy in the context of criminal culpability.

A practice-enhancing reference for forensic psychiatrists and psychologists, and legal professionals, Mental Disorder and Criminal Law challenges readers to reexamine the life-and-death questions at the core of their work.

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Kategorie: Psychologie > P?dagogik > Forensische Psychologie

Artikelnummer: 9780387848457

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Source: http://www.short-domains.de/2012/08/30/mental-disorder-and-criminal-law-responsibility-punishment-and-competence/

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