Cause of chemotherapy resistance in melanoma found

ScienceDaily (Sep. 17, 2012) — Researchers with UC Irvine's Chao Family Comprehensive Cancer Center have identified a major reason why melanoma is largely resistant to chemotherapy.

UCI dermatologist Dr. Anand Ganesan and colleagues found a genetic pathway in melanoma cells that inhibits the cellular mechanism for detecting DNA damage wrought by chemotherapy, thereby building up tolerance to cancer-killing drugs.

Targeting this pathway, comprising the genes RhoJ and Pak1, heralds a new approach to treating the deadly skin cancer, which claims nearly 10,000 U.S. lives each year. Study results appear online in Cancer Research, a journal of the American Association for Cancer Research.

"If we can find a way to turn off the pathway responsible for this resistance, melanoma tumors would suddenly become sensitive to therapies we've been using for the last 20 years," said Ganesan, assistant professor of dermatology and biological chemistry at UCI.

In pursuit of a cause for the chemo tolerance, he and his colleagues performed a genome-wide scan for genes controlling drug resistance in melanoma cells. Their search identified RhoJ, a gene normally involved in blood vessel growth. They saw that in response to drug-induced DNA damage in a melanoma cell, RhoJ activated another gene, Pak1, which initiated a molecular cascade suppressing the cell's ability to sense this damage -- and blocking the apoptosis process.

"Normally, such drug-induced DNA damage would result in cell death," Ganesan said. "But this blunting of DNA damage response allows melanoma cells to mutate and proliferate. Being capable of rapid adaptation and change is a hallmark feature of this challenging form of cancer and makes it very difficult to treat."

On the heels of this discovery, he and colleagues have begun exploring methods to inhibit the genes responsible for this DNA damage tolerance. What they come up with could one day supplement chemotherapy treatments for melanoma, Ganesan added.

Hsiang Ho, Jayavani Aruri, Rubina Kapadia and Hootan Mehr of UCI and Michael A. White of the University of Texas Southwestern Medical Center at Dallas participated in the study, which received support from the National Institutes of Health, the University of California Cancer Research Coordinating Committee, the American Cancer Society, Outrun the Sun Inc. and the Robert A. Welch Foundation.

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Journal Reference:

1. H. Ho, J. Aruri, R. Kapadia, H. Mehr, M. A. White, A. K. Ganesan. RhoJ and Pak Kinases Regulate Melanoma Chemoresistance by Suppressing Pathways that Sense DNA Damage. Cancer Research, 2012; DOI: 10.1158/0008-5472.CAN-12-0775

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18 Sep, 2012

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Hubble sees NGC 7090 — an actively star-forming galaxy

ScienceDaily (Sep. 17, 2012) — A new image portrays a beautiful view of the galaxy NGC 7090, as seen by the NASA/ESA Hubble Space Telescope. The galaxy is viewed edge-on from Earth, meaning we cannot easily see the spiral arms, which are full of young, hot stars.

However, a side-on view shows the galaxy's disc and the bulging central core, where typically a large group of cool old stars are packed in a compact, spheroidal region. In addition, there are two interesting features present in the image that are worth mentioning.

First, we are able to distinguish an intricate pattern of pinkish red regions over the whole galaxy. This indicates the presence of clouds of hydrogen gas. These structures trace the location of ongoing star formation, visual confirmation of recent studies that classify NGC 7090 as an actively star-forming galaxy.

Second, we observe dust lanes, depicted as dark regions inside the disc of the galaxy. In NGC 7090, these regions are mostly located in lower half of the galaxy, showing an intricate filamentary structure. Looking from the outside in through the whole disc, the light emitted from the bright center of the galaxy is absorbed by the dust, silhouetting the dusty regions against the bright light in the background.

Dust in our galaxy, the Milky Way, has been one of the worst enemies of observational astronomers for decades. But this does not mean that these regions are only blind spots in the sky. At near-infrared wavelengths -- slightly longer wavelengths than visible light -- this dust is largely transparent and astronomers are able to study what is really behind it. At still longer wavelengths, the realm of radio astronomy, the dust itself can actually be observed, letting astronomers study the structure and properties of dust clouds and their relationship with star formation.

Lying in the southern constellation of Indus (The Indian), NGC 7090 is located about thirty million light-years from the Sun. Astronomer John Herschel first observed this galaxy on October 4, 1834.

The image was taken using the Wide Field Channel of the Advanced Camera for Surveys aboard the Hubble Space Telescope and combines orange light (colored blue here), infrared (colored red) and emissions from glowing hydrogen gas (also in red).

A version of this image of NGC 7090 was entered into the Hubble's Hidden Treasures Image Processing Competition by contestant Rasid Tugral. Hidden Treasures is an initiative to invite astronomy enthusiasts to search the Hubble archive for stunning images that have never been seen by the general public. The competition is now closed and the list of winners is available here.

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18 Sep, 2012

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Improving memory for specific events can alleviate symptoms of depression

ScienceDaily (Sep. 17, 2012) — Hear the word "party" and memories of your 8th birthday sleepover or the big bash you attended last New Year's may come rushing to mind. But it's exactly these kinds of memories, embedded in a specific place and time, that people with depression have difficulty recalling.

Research has shown that people who suffer from, or are at risk of, depression have difficulty tapping into specific memories from their own past, an impairment that affects their ability to solve problems and leads them to focus on feelings of distress.

In a study forthcoming in Clinical Psychological Science, a new journal of the Association for Psychological Science, psychological scientists Hamid Neshat-Doost of the University of Isfahan, Iran, Laura Jobson of the University of East Anglia, Tim Dalgleish of the Cognition and Brain Sciences Unit, Medical Research Council, Cambridge and colleagues investigated whether a particular training program, Memory Specificity Training, might improve people's memory for past events and ameliorate their symptoms of depression.

In Iran, the researchers recruited 23 adolescent Afghani refugees who had lost their fathers in the war in Afghanistan and who showed symptoms of depression. Twelve of the adolescents were randomly assigned to participate in the memory training program and 11 were randomly assigned to a control group that received no training.

All of the adolescents completed a memory test in which they saw 18 positive, neutral, and negative words in Persian and were asked to recall a specific memory related to each word. Their responses were categorized as either a specific or a non-specific type of memory. They also completed questionnaires design to measure symptoms of depression and anxiety symptoms.

For five weeks, the adolescents assigned to the training attended a weekly 80-minute group session, in which they learned about different types of memory and memory recall, and practiced recalling specific memories after being given positive, neutral, and negative keywords.

At the end of the five weeks, both the training group and the control group were given the same memory test that they were given at the beginning of the study. And they took the memory test again as part of a follow-up visit two months later.

The adolescents who participated in the training were able to provide more specific memories after the training than those who did not receive intervention. They also showed fewer symptoms of depression than the control group at the two month follow-up. The researchers found that the relationship between participant group (training or control) and their symptoms of depression at follow-up could be accounted for by changes in specific memory recall over time.

These findings are promising because they suggest that a standalone training program that focuses on specific memory recall can actually improve depression symptoms.

Based on the results of this study, Jobson, Dalgleish, and colleagues conclude that, for individuals suffering from depression, "including a brief training component that targets memory recall as an adjunct to cognitive behavioral therapy or prior therapy may have beneficial effects on memory recall and mood."

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18 Sep, 2012

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Mobile launcher platforms prepped for new generation

ScienceDaily (Sep. 17, 2012) — NASA's trio of mobile launcher platforms (MLP) are being revamped to serve a variety of next-generation launch vehicles. The huge steel structures, which acted as launch bases for the Apollo/Saturn program and every space shuttle mission, will serve as the platforms that launch the next American-made vehicles to space.

Essentially a large steel box measuring 160 by 135 feet, a platform's surface features wide openings that align with a space-bound vehicle's engines and direct the blast into the flame trench below. Propellant lines and other utilities run throughout the structure. The two-story interior contains a variety of communications devices, control cabinets and other ground support equipment.

Throughout the past year, Kennedy Space Center's Ground Systems Development and Operations (GSDO) program has overseen the removal of much of the hardware used to support shuttle launches, making it available to the new 355-foot-tall mobile launcher in development for the agency's Space Launch System (SLS), a rocket that will launch NASA's Orion spacecraft and provide an entirely new capability for human exploration beyond Earth orbit.

"We're removing a lot of components -- cryogenic, pneumatic, mechanical, electrical, controls-type stuff for reuse on the new SLS mobile launcher as a cost savings," explained John Rigney, GSDO lead architect. "But at the same time, we wanted to keep the MLPs ready for any commercial entities that want to use them."

To accomplish this, the program carefully decided what hardware should be removed from the platforms in order to ensure two would remain available.

"It's kind of like taking parts off your car," Rigney said. "If I took the wheels off your car, and took the doors out of another car, and took the glass out of a third car, you'd say, 'Couldn't you leave one car that works?' We tried to think ahead."

Any hardware used in a solid-propulsion system was removed from MLP No. 2. Some of the electrical racks and control panels also were taken out.

"We tried to keep MLP-2 intact for a commercial entity with a liquid-fueled vehicle," said Mobile Launcher Technical Integrator Mike Canicatti. "We tried to pull off what we could that wasn't liquid-related, such as equipment that interacts with solid propellant, mostly pneumatic panels and control cabinets that feed the SRBs."

Conversely, the materials removed from MLP No. 3 leave the platform set to support a vehicle fueled by solid propellant.

MLP No. 1, the oldest of the three, is not intended to be used again, so the team planned carefully which pieces to save and which to leave with the structure.

"We didn't want to turn it over to [Kennedy's Center Operations directorate] with anything in it that had some value," Rigney said. "But at the same time, we didn't want to take everything out, because we'd have to store it and spend money to keep it. So we did the best we could and took out all the parts that were still good."

There are plans to use the hardware that's been pulled out of the platforms. Until then, the majority of the parts are being stored in the Vehicle Assembly Building, in the heart of Launch Complex 39.

The hands-on work to remove parts from the Mobile Launcher Platforms began earlier this year, one of many such activities under way to transition and retire the shuttle fleet. The job is expected to be complete by year's end.

The first test flight of NASA's Space Launch System, which will feature a configuration for a 70-metric-ton (77-ton) lift capacity, is scheduled for 2017.

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18 Sep, 2012

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Shrinking snow depth on Arctic sea ice threatens ringed seal habitat

ScienceDaily (Sep. 17, 2012) — As sea ice in the Arctic continues to shrink during this century, more than two thirds of the area with sufficient snow cover for ringed seals to reproduce also will disappear, challenging their survival, scientists report in a new study.

The ringed seal, currently under consideration for threatened species listing, builds caves to rear its young in snow drifts on sea ice. Snow depths must be on average at least 20 centimeters, or 8 inches, to enable drifts deep enough to support the caves.

"It's an absolute condition they need," said Cecilia Bitz, an associate professor of atmospheric sciences at the University of Washington. She's a co-author of the study, published in the journal Geophysical Research Letters.

But without sea ice, the platform that allows the snow to pile up disappears, ultimately reducing the area where the seals can raise their pups.

Bitz typically focuses on studying the area and thickness of sea ice. "But when a seal biologist telephoned and asked what our climate models predict for snow depth on the ice, I said, 'I have no idea,'" she said. "We had never looked."

That biologist was co-author Brendan Kelly of the National Science Foundation and he was curious about the snow depth trend because he was contributing to a governmental report in response to the petition to list the seals as threatened.

The researchers, including lead author and UW atmospheric sciences graduate student Paul Hezel, found that snowfall patterns will change during this century but the most important factor in determining snow depth on the ice will be the disappearance of the sea ice.

"The snowfall rate increases slightly in the middle of winter by the end of the century," Hezel said. However, at the same time sea ice is expected to start forming later in the year than it does now. The slightly heavier snowfall in the winter won't compensate for the fact that in the fall -- which is also when it snows the heaviest -- snow will drop into the ocean instead of piling up on the ice.

The researchers anticipate that the area of the Arctic that accumulates at least 20 centimeters of snow will decrease by almost 70 percent this century. With insufficient snow depth, caves won't hold up.

Other climate changes threaten those caves, too. For instance, the snow will melt earlier in the year than it does now, so it's possible the caves won't last until the young seals are old enough to venture out on their own. In addition, more precipitation will fall as rain, which soaks into the snow and can cause caves to collapse.

The research is important for more than just the ringed seals. "There are many other reasons to study snow cover," Hezel said. "It has a huge thermodynamic impact on the thickness of the ice."

Snow on sea ice in fall and winter acts like a blanket that slows the release of heat from the relatively warm ocean into the atmosphere. That means deeper snow tempers sea ice growth.

In the spring, snow has a different impact on the ice. Since snow is more reflective than ice, it creates a cooling effect on the surface. "So the presence of snow helps sustain the icepack into spring time," Hezel said.

To produce the study, the scientists examined 10 different climate models, looking at historic and future changes of things like sea ice area, precipitation, snowfall and snow depth on sea ice. The resulting prediction for declining snow depth on sea ice this century agreed across all of the models.

The new research comes too late to be cited in the report about ringed seals that was written by the National Oceanic and Atmospheric Administration in response to the petition to list the ringed seal as threatened. However, it confirms results that were based on a single model that Bitz provided for the report two years ago. NOAA expects to issue its final decision soon.

The UW scientists on this study were funded by the Office of Naval Research.

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The above story is reprinted from materials provided by University of Washington. The original article was written by Nancy Gohring.

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Journal Reference:

1. P. J. Hezel, X. Zhang, C. M. Bitz, B. P. Kelly, F. Massonnet. Projected decline in spring snow depth on Arctic sea ice caused by progressively later autumn open ocean freeze-up this century. Geophysical Research Letters, 2012; 39 (17) DOI: 10.1029/2012GL052794

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18 Sep, 2012

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Behavior issues are a bigger headache for children with migraines, research reveals

ScienceDaily (Sep. 17, 2012) — Kids who get migraine headaches are much more likely than other children to also have behavioral difficulties, including social and attention issues, and anxiety and depression. The more frequent the headaches, the greater the effect, according to research out now in the journal Cephalagia, published by SAGE.

Marco Arruda, director of the Glia Institute in São Paulo, Brazil, together with Marcelo Bigal of the Albert Einstein College of Medicine in New York studied 1,856 Brazilian children aged 5 to 11. The authors say that this is the first large, community based study of its kind to look at how children's behavioural and emotional symptoms correlate with migraine and tension-type headaches (TTH), and to incorporate data on headache frequency.

Children with or suffering from migraine had a much greater overall likelihood of abnormal behavioral scores than controls, especially in somatic, anxiety-depressive, social, attention, and internalizing domains. Children with TTH were affected in the same domains as migraine sufferers, but to a lesser degree.

The study used internationally validated headache questionnaires as well as the Child Behavior Checklist (CBCL) to assess emotional symptoms. The researchers trained school teachers in how to walk parents through questionnaires step by step.

For children with either migraine (23%) or TTH (29%), more frequent headaches correlated with increasingly abnormal scores on the behavior scale. The types of behavior most often seen were those characterized as internalizing -- behaviors directed towards the self. While less than a fifth of controls (19% of sample) have issues with internalizing behaviors, over half of migraine sufferers were affected. Externalizing behaviors, such as becoming more aggressive or breaking rules, were no more likely among the children with frequent attacks of headache than among the controls. The researchers suggested the CBCL may be underpowered to investigate the correlation between attention/hyperactivity and headaches in detail.

"As previously reported by others, we found that migraine was associated with social problems," said Arruda. "The 'social' domain identifies difficulties in social engagement as well as infantilized behavior for the age and this may be associated with important impact on the personal and social life."

"Providers should be aware of this possibility in children with migraines, in order to properly address the problem," he added.

Previous research has pointed to children with migraine being more likely than their peers to have other physical or psychological issues, including anxiety, depression, and attention and hyperactivity problems. But until now, few studies have examined the contrasts between TTH in children. Including headache frequency was also a missing part of the puzzle, the authors say.

Children often suffer from headaches, with migraine prevalence ranging from just over three percent to over one fifth of children as they progress from early childhood through to adolescence.

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Journal Reference:

1. Marco A Arruda and Marcelo E Bigal. Behavioral and emotional symptoms and primary headaches in children: A population-based study. Cephalalgia, 2012; DOI: 10.1177/0333102412454226

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17 Sep, 2012

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PARP inhibitors may have clinical utility in HER2-positive breast cancers

ScienceDaily (Sep. 17, 2012) — Poly (ADP-Ribose) polymerase (PARP) inhibitors, shown to have clinical activity when used alone in women with familial breast and ovarian cancers linked to BRCA mutations, may be a novel treatment strategy in women with HER2-positive breast cancers, according to the results of a study published in Cancer Research, a journal of the American Association for Cancer Research.

Currently, women with HER2-positive breast cancers are treated with therapies that target HER2. However, many women with this form of cancer either fail to ever respond to these targeted therapies or initially respond to them but then become resistant to their effects.

"Until now, PARP inhibitors have been shown to exhibit single agent activity only in tumors that are deficient in DNA repair, such as familial breast and ovarian cancers that are linked to BRCA mutations," said Eddy S. Yang, M.D., Ph.D., assistant professor in the department of radiation oncology at the University of Alabama-Birmingham.

According to Yang, only about 5 to 10 percent of all breast and ovarian cancers are BRCA-associated familial cancers, so researchers are currently trying to expand the patient population that might benefit from PARP inhibitors, which are generally well tolerated and have relatively few side effects.

"To do that, we were attempting to render nonfamilial cancers deficient in DNA repair," he said.

In prior studies, the Yang lab found that inhibiting the epidermal growth factor receptor (EGFR) pathway, which is commonly overactive in many tumor types, resulted in a DNA repair defect similar to that seen in familial cancers. They subsequently showed that this "forced" DNA repair defect increased tumor sensitivity to PARP inhibitors. Because HER2 and EGFR are in the same family of proteins, Yang and colleagues theorized that HER2-targeted therapies might force a similar DNA repair defect in HER2-positive tumors, increasing their sensitivity to PARP inhibitors.

They found that HER2-positive breast cancer cell lines were indeed sensitive to PARP inhibitors, both in culture and when transplanted into mice.

"However, the surprise was that these HER2-positive tumors were sensitive to PARP inhibitors alone, independent of a DNA repair defect," Yang said. "This means that there may be other mechanisms, outside of DNA repair, that dictate the sensitivity of a tumor to PARP inhibitors."

The researchers hope to further map out the reason why HER2-positive tumors are sensitive to PARP inhibitors. If better defined, the knowledge could ultimately broaden the clinical application for PARP inhibitors.

"Our research suggested that inhibition of NF-kB signaling is a possible cause of this sensitivity, but there may be other determinants as well," Yang said. "If we are able to find the determinants of sensitivity, we may be able to extrapolate our effects to other tumor types."

This research was supported by a career development award from the UAB Specialized Programs of Research Excellence (SPORE) in breast cancer (5P50CA089019-10), the Sidney Kimmel Foundation for Cancer Research Translational Scholar Award, the AACR-Genentech BioOncology Career Development Award for Cancer Research on the HER Family Pathway (Grant Number 12-20-18-YANG), the State of Alabama Investment Pool for Action (IMPACT) Award from the University of Alabama at Birmingham School of Medicine, and developmental support from the Comprehensive Cancer Center and Department of Radiation Oncology at the University of Alabama at Birmingham School of Medicine.

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Journal Reference:

1. E. S. Yang, S. Nowsheen, M. A. Rahman, R. S. Cook, F. Xia. Targeting BRCA1 localization to augment breast tumor sensitivity to poly(ADP-ribose) polymerase inhibition. Cancer Research, 2012; DOI: 10.1158/0008-5472.CAN-12-0934

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17 Sep, 2012

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Mobile phones and wireless networks: No evidence of health risk found, Norwegian experts find

ScienceDaily (Sep. 17, 2012) — There is no scientific evidence that low-level electromagnetic field exposure from mobile phones and other transmitting devices causes adverse health effects, according to a report presented by a Norwegian Expert Committee. In addition, the Committee provides advice to authorities about risk management and regulatory practice.

The Committee has assessed the health hazards from low-level electromagnetic fields generated by radio transmitters. These electromagnetic fields are found around mobile phones, wireless phones and networks, mobile phone base stations, broadcasting transmitters and other communications equipment. The Committee has evaluated the power of the fields, whether they pose a health risk, the current regulatory practice, and whether the threshold limit values for exposure are observed.

The report is entitled "Svake høyfrekvente elektromagnetiske felt -- en vurdering av helserisiko og forvaltningspraksis. FHI-rapport 2012:3" (In English: Low-level radiofrequency electromagnetic fields -- an assessment of health risks and evaluation of regulatory practice. NIPH report 2012:3). Published on September 13th, the report contains a Norwegian and English summary.

Studied electromagnetic fields below threshold limit values

The low-level electromagnetic fields generated when antennas in mobile phones and other wireless devices transmit radio signals are referred to as radiofrequency (RF) fields.

The health authorities have determined that the threshold limit values for electromagnetic fields around transmitters in mobile phones and other equipment should be the same as those recommended by the International Commission on Non-ionising Radiation Protection (ICNIRP). The threshold limit values are based on fields above a certain power that can cause harmful heating of tissue. The ICNIRP has not observed other adverse health effects under this level.

The threshold limit values for these fields are 50 times below the level that causes heating of human tissue or stimulation of nerve cells. Due to increasing public concerns, the government requested the appointment of an Expert Committee to assess whether such low-level electromagnetic fields could cause health effects.

The Norwegian Institute of Public Health was commissioned to appoint the Expert Committee by the Ministry of Health and Care Services and the Ministry of Transport and Communication. The Committee was chaired by Professor Jan Alexander, Assistant Director-General at the Institute.

Research indicates no health risk

The Committee has assessed a number of possible health effects from low-level electromagnetic fields and has evaluated the research in each area.

The group found no evidence that the low-level fields around mobile phones and other transmitters increase the risk of cancer, impair male fertility, cause other reproductive damage or lead to other diseases and adverse health effects, such as changes to the endocrine and immune systems.

No cancer risk found

Most studies concerning cancer have focused on the risk of cancer in the head and neck. The Committee found no scientific evidence for an association between mobile phone use and fast-growing brain tumours. So far, the effect on slow-growing tumours has been studied in people who have used mobile phones for up to 20 years. These studies show no association.

Only limited data exist for the other types of cancer in the head and neck area, as well as for leukaemia and lymphoma, but so far there is no evidence of an increased risk from mobile phone use. Cancer registries have not observed an increase in these tumours in the population since mobile phones were introduced.

Electromagnetic hypersensitivity

The Committee did not find that mobile phones and other equipment can cause health problems such as electromagnetic hypersensitivity.

Does this mean that electromagnetic hypersensitivity is an imaginary problem? "We have no grounds to say that the symptoms are imaginary. But a large number of studies suggest that these symptoms must have other causes than the physical effects of low-level electromagnetic fields around mobile phones, wireless transmitters and other wireless equipment. Research provides no evidence to support that interventions help, such as reducing the use of mobile phones or wireless networks. Our opinion is that patients with these health problems must be taken seriously by the health service and should be treated as other patients. There is a need for greater expertise in the health service for this group of patients," says Alexander.

Many people have found that holding a mobile phone to the head causes the area around the ear to become hot -- is this due to electromagnetic radiation? "The skin warms up slightly due to heat from the battery and not from the radio transmitter in the phone. The electromagnetic field will have very little or no heating effect. The body will remove the heat through normal blood flow, in the same way as the body otherwise regulates temperature."

Some mobile phone models transmitting at maximum power provide exposure that comes close to the threshold limit values. Even so, any heating due to electromagnetic fields would be negligible.

Advice: Show general caution

Since there are no uncertainties in the health risk assessment of low-level electromagnetic fields that warrant introduction of the precautionary principle, the Committee believes that general caution is sufficient. This means that exposure should not be higher than needed to achieve the intended purpose.

When comparing the power of the fields around different types of equipment, talking on a mobile phone tops the list, whilst wireless internet networks are at the bottom. Base stations and broadcasting transmitters also come low down in the list. An example of exercising general caution would be for the authorities to inform that hands-free kits will significantly reduce exposure from mobile phones.

Furthermore, the field strength around a mobile phone is lower when there is good coverage.

Little benefit from more research

The Committee has evaluated the assessments previously published by international expert groups, as well as recent individual studies. The material is very extensive. A number of studies were performed on cells and tissues in the laboratory, as well as in animals and humans. In addition, population studies and cancer registry studies were conducted in several countries.

Little uncertainty

There is always an element of uncertainty in all risk assessments. In this case, the Committee considers the uncertainty to be small. Some uncertainty is associated with high exposure over time, such as extensive use of mobile phones over several decades. Until now, this has been impossible to study. Cancer registries should follow the development of cancer incidence in the future and research should not cease. Studies of animals that have been exposed throughout life provide no evidence that low level RF fields cause cancer. It is unlikely that long-term use of mobile phones will cause health risks that are unknown today.

Regarding equipment that provides the lowest exposure, such as base stations, wireless networks, broadcasting transmitters and proximity to other mobile phones, the experts believe that the risk assessment has negligible uncertainty. In other words, it is reasonably certain that such equipment is not associated with health risks.

The report is approximately 200 pages long and includes Norwegian and English summaries. It can be downloaded in PDF format at http://www.fhi.no.

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17 Sep, 2012

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Only children are significantly more likely to be overweight, European study finds

ScienceDaily (Sep. 17, 2012) — Children who grow up without siblings have a more than 50 percent higher risk of being overweight or obese than children with siblings. This is the finding of a study of 12,700 children in eight European countries, including Sweden, published in Nutrition and Diabetes.

The University of Gothenburg, Sweden, was one of the participating universities in the study.

The study was conducted under the framework of the European research project Identification and prevention of Dietary and lifestyle-induced health EFfects In Children and infantS (IDEFICS), where researchers from various parts of Europe study diet, lifestyle and obesity and their health effects on children aged 2 to 9 years.

The study shows that only children have a more than 50 percent higher risk of obesity compared to their peers with siblings. The results were controlled for other influential factors, such as gender, birth weight and parental weight.

In the study, the children's measured BMI was linked to a parental questionnaire that included questions relating to the children's eating habits, television viewing habits and amount of outdoor play time.

"Our study shows that only children play outside less often, live in households with lower levels of education more often, and are more likely to have televisions in their bedrooms. But even when we take these factors into account, the correlation between singleton status and overweight is strong. Being an only child appears to be a risk factor for overweight independent of the factors we thought might explain the difference," says Monica Hunsberger, a researcher at the Sahlgrenska Academy, University of Gothenburg, who contributed to the study.

"The fact that only children are more susceptible to obesity may be due to differences in individual family environment and family structure that we were not able to measure in sufficient detail. To better understand the causality, a follow-up study of these families will start next year," says Lauren Lissner, a researcher at the Sahlgrenska Academy, University of Gothenburg.

Over 22 million children in Europe are estimated to be overweight. The study shows that obesity among children in general is three times more common in southern countries such as Italy, Spain and Cyprus than in Sweden and other northern countries.

Read more about IDEFICS: www.idefics.eu

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The above story is reprinted from materials provided by University of Gothenburg, via AlphaGalileo.

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. M Hunsberger, A Formisano, L A Reisch, K Bammann, L Moreno, S De Henauw, D Molnar, M Tornaritis, T Veidebaum, A Siani, L Lissner. Overweight in singletons compared to children with siblings: the IDEFICS study. Nutrition and Diabetes, 2012; 2 (7): e35 DOI: 10.1038/nutd.2012.8

Note: If no author is given, the source is cited instead.

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.

17 Sep, 2012

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Source: http://feeds.sciencedaily.com/~r/sciencedaily/~3/Rcd_6uAatYA/120917090022.htm
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World’s most powerful digital camera opens eye, records first images in hunt for dark energy

ScienceDaily (Sep. 17, 2012) — Eight billion years ago, rays of light from distant galaxies began their long journey to Earth. That ancient starlight has now found its way to a mountaintop in Chile, where the newly-constructed Dark Energy Camera, the most powerful sky-mapping machine ever created, has captured and recorded it for the first time.

That light may hold within it the answer to one of the biggest mysteries in physics -- why the expansion of the universe is speeding up.

Scientists in the international Dark Energy Survey collaboration announced this week that the Dark Energy Camera, the product of eight years of planning and construction by scientists, engineers, and technicians on three continents, has achieved first light. The first pictures of the southern sky were taken by the 570-megapixel camera on Sept. 12.

"The achievement of first light through the Dark Energy Camera begins a significant new era in our exploration of the cosmic frontier," said James Siegrist, associate director of science for high energy physics with the U.S. Department of Energy. "The results of this survey will bring us closer to understanding the mystery of dark energy, and what it means for the universe."

The Dark Energy Camera was constructed at the U.S. Department of Energy's (DOE) Fermi National Accelerator Laboratory in Batavia, Illinois, and mounted on the Victor M. Blanco telescope at the National Science Foundation's Cerro Tololo Inter-American Observatory (CTIO) in Chile, which is the southern branch of the U.S. National Optical Astronomy Observatory (NOAO). With this device, roughly the size of a phone booth, astronomers and physicists will probe the mystery of dark energy, the force they believe is causing the universe to expand faster and faster.

"The Dark Energy Survey will help us understand why the expansion of the universe is accelerating, rather than slowing due to gravity," said Brenna Flaugher, project manager and scientist at Fermilab. "It is extremely satisfying to see the efforts of all the people involved in this project finally come together."

The Dark Energy Camera is the most powerful survey instrument of its kind, able to see light from over 100,000 galaxies up to 8 billion light years away in each snapshot. The camera's array of 62 charged-coupled devices has an unprecedented sensitivity to very red light, and along with the Blanco telescope's large light-gathering mirror (which spans 13 feet across), will allow scientists from around the world to pursue investigations ranging from studies of asteroids in our own Solar System to the understanding of the origins and the fate of the universe.

"We're very excited to bring the Dark Energy Camera online and make it available for the astronomical community through NOAO's open access telescope allocation," said Chris Smith, director of the Cerro-Tololo Inter-American Observatory. "With it, we provide astronomers from all over the world a powerful new tool to explore the outstanding questions of our time, perhaps the most pressing of which is the nature of dark energy."

Scientists in the Dark Energy Survey collaboration will use the new camera to carry out the largest galaxy survey ever undertaken, and will use that data to carry out four probes of dark energy, studying galaxy clusters, supernovae, the large-scale clumping of galaxies and weak gravitational lensing. This will be the first time all four of these methods will be possible in a single experiment.

The Dark Energy Survey is expected to begin in December, after the camera is fully tested, and will take advantage of the excellent atmospheric conditions in the Chilean Andes to deliver pictures with the sharpest resolution seen in such a wide-field astronomy survey. In just its first few nights of testing, the camera has already delivered images with excellent and nearly uniform spatial resolution.

Over five years, the survey will create detailed color images of one-eighth of the sky, or 5,000 square degrees, to discover and measure 300 million galaxies, 100,000 galaxy clusters and 4,000 supernovae.

The Dark Energy Survey is supported by funding from the U.S. Department of Energy; the National Science Foundation; funding agencies in the United Kingdom, Spain, Brazil, Germany and Switzerland; and the participating DES institutions.

More information about the Dark Energy Survey, including the list of participating institutions, is available at the project website: www.darkenergysurvey.org.

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17 Sep, 2012

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Source: http://feeds.sciencedaily.com/~r/sciencedaily/~3/hAkNWkmg9bc/120917104651.htm
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