sid_melo blogreen: 11/08/14

sábado, 8 de novembro de 2014

The cause and effect of migraines

A migraine is the most common type of headache that propels patients to seek care from their doctors. Roughly 30 million people living in the States suffer from migraine headaches, with women affected almost three times more often than men, according to statistics from the National Headache Foundation in Chicago.

"Hormonal changes are a big contributor to the higher female incidence," said Michael A. Moskowitz, MD, Professor of Neurology at Harvard Medical School at the Massachusetts General Hospital in Boston. "There are lines of evidence that support this from lab to clinical evidence and a decrease (although not abolished) incidence in post-menopausal females."

Migraine headaches can vary from person to person, but they typically last from four hours up to 72 hours. Some people get them several times per month, while others experience them much less frequently. Many migraine sufferers report throbbing or pulsating pain on one side of the head, blurred vision, sensitivity to light and sound, nausea, and vomiting. Roughly one in five migraine sufferers experience an aura, or visual or sensory disturbance, before the onset of the headache. Examples of an aura include: flashes of light, loss of vision, zig-zag lines, pins and needles in an arm or leg, and speech and language problems.

Several risk factors have been identified that increase a person's chance of having migraines:

• Family history: A significant majority of migraine sufferers have a family history of migraine attacks. For a person who has one or more first-degree relatives with migraine headaches, the likelihood rises substantially.

• Age: Migraines typically affect people between the ages of 15-55. Most people have had their first attack by 40 years old.

• Gender: Women are more likely to suffer from migraines than men.

• Certain medical conditions: depression, anxiety, stroke, epilepsy, and high blood pressure are all associated with migraine headaches.

• Hormonal changes: Women who suffer from migraines often find that the headaches have a pattern of recurrence just before or shortly after the onset of menstruation. The headaches may also change during pregnancy and/or menopause.

Migraines are vascular headaches but the exact cause is not fully understood. Some researchers believe that migraines occur when there are abnormal changes in the brain. When these changes occur, inflammation causes blood vessels to swell and press on nerves, which can result in pain.

Researchers have learned that certain triggers can set off migraine attacks. These triggers vary from person to person and can include: sleep disturbances, stress, weather changes, low blood sugar, dehydration, bright lights and loud noises, hormonal changes, foods that contain aspartame, foods that contain tyramine (fava beans, aged cheeses, soy products, etc.), caffeine, and alcohol.

Unfortunately, migraines have no known cure, but they can be managed effectively with the help of a health care provider. A variety of drugs can be used for pain relief and for prevention. Lifestyle changes are often recommended to identify and eliminate possible triggers that can set off an attack.

"Until recently there have been no treatments available to treat people who suffer from chronic migraines," said Moskowitz. "Recently, a new medication has become available specifically to treat chronic migraine headaches, called onabotulinumtoxinA (Botox). Chronic migraine sufferers can derive significant benefit from this new form of therapy."

Chronic migraine sufferers have also found relief in certain vitamins and other homeopathic remedies. But patients should check with their doctors for proper treatment protocols.

Story Source:

The above story is based on materials provided by Society for Women's Health Research (SWHR). Note: Materials may be edited for content and length.

Geroscience: Research strategy supports GSIG's efforts to integrate aging into chronic disease research

November 6, 2014

Buck Institute for Age Research

Scientists who have been successful in delaying mammalian aging with genetic, dietary and pharmacological approaches have developed a research strategy to expand Geroscience research directed at extending human healthspan. The strategy comes at a critical time, given the dramatic increase in the elderly population and a growing recognition that aging is the greatest risk factor for a majority of the chronic diseases that drive later-life disability and death.

The scientists took part in the first summit of the NIH Geroscience Interest Group (GSIG) held last year on the NIH campus. The National Institutes of Health is made up of 27 different components called Institutes and Centers. Each has its own specific research agenda. The GSIG is aimed at promoting new pathways for collaboration, both within the NIH and with its funded researchers, specifically within the context of aging. The NIH was created and organized long before scientists began seriously exploring the possibility of altering the aging process.

"We have high hopes that our research strategy will help move collaborative efforts to the next level," said Brian Kennedy, PhD, President and CEO of the Buck Institute and the lead author of the commentary. "What has come out of our work is a keen understanding that the factors driving aging are highly intertwined and that in order to extend healthspan we need an integrated approach to health and disease with the understanding that biological systems change with age."

The group focused on a limited set of short-and intermediate-term scientific goals that would accelerate Geroscience and launch novel approaches to reduce the impact of the healthcare burden associated with the chronic diseases of aging. The scientists call for Geroscience to be merged with ongoing research on human chronic disease states; an expansion of interventions that extend lifespan and healthspan; an elaboration of environmental and random factors driving aging; an integration of human genetic and epigenetic studies with animal models; a comparison and contrast of inflammation in aging and disease; and the development of new animal models of aging.

"Our current approach to researching and treating chronic diseases is inadequate and fragmentary," said Kennedy. "By the time chronic diseases are diagnosed, much damage is done and undoing it is difficult." Pointing out that 46 percent of Medicare spending is for people with six or more chronic conditions, Kennedy added, "Targeting aging may allow early intervention and allow us to maintain vigor and activity, while offsetting the economic burdens of a burgeoning aging population hampered by multiple chronic diseases."

Story Source:

The above story is based on materials provided by Buck Institute for Age Research. Note: Materials may be edited for content and length.

Journal Reference:

Brian K. Kennedy, Shelley L. Berger, Anne Brunet, Judith Campisi, Ana Maria Cuervo, Elissa S. Epel, Claudio Franceschi, Gordon J. Lithgow, Richard I. Morimoto, Jeffrey E. Pessin, Thomas A. Rando, Arlan Richardson, Eric E. Schadt, Tony Wyss-Coray, Felipe Sierra. Geroscience: Linking Aging to Chronic Disease. Cell, 2014; 159 (4): 709 DOI: 10.1016/j.cell.2014.10.039

First-in-class nasal spray demonstrates promise for migraine pain relief

Researchers are developing a novel prochlorperazine nasal spray formulation as a potential new treatment for migraines. This work is being presented at the 2014 American Association of Pharmaceutical Scientists (AAPS) Annual Meeting and Exposition in San Diego, Nov. 2-6.

Migraines are manifested by severe pain and headache that can last anywhere from four to seventy-two hours, accompanied by nausea, vomiting, and sensitivity to both light and sound. Of the 100 million people that experience headaches in the United States, 37 million of them suffer from migraines. According to the Migraine Research Foundation, migraine ranks in the top 20 of the world's most disabling medical diseases, with someone in the United States going to the emergency room every 10 seconds for treatment.

Venkata Yellepeddi, Ph.D., along with his colleagues from Roseman University of Health Sciences, developed a preservative-free device-driven prochlorperazine nasal spray that could prove useful for compounding pharmacists specifically in the field of pain medicine. "Prochloperazine is a dopamine receptor antagonist that is widely used as an anti-nausea medication. Comparative clinical studies have shown that prochloperazine provides better pain relief than other anti-migraine drugs such as sumatriptan, metoclopramide, and ketorolac," said Yellepeddi. "Currently, there are no marketed nasal spray formulations of prochlorperazine available for the treatment of migraine. Prochlorperazine is only available in tablet form, which has delayed onset of action." Yellepeddi and his team hypothesize that a nasal spray version of prochlorperazine will not only be effective, but fast acting and have better patient compliance overall. Furthermore, this novel product does not have any preservative-related adverse side effects, such as mucosal irritation which are normally seen with vehicles with preservatives such as benzalkonium chloride and potassium sorbate.

Yellepeddi used high performance liquid chromatography and microbiological assays to assess the stability of prochloperazine nasal spray. These studies demonstrated that the nasal spray was able to remain stable for up to 120 days with minimal degradation, therefore making it an effective treatment option for migraine patients.

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David Katzmaier

Body weight heavily influenced by gut microbes: Genes shape body weight by affecting gut microbes

By studying pairs of twins at King's Department of Twin Research, researchers identified a specific, little known bacterial family that is highly heritable and more common in individuals with low body weight. This microbe also protected against weight gain when transplanted into mice.

The results, published today in the journal Cell, could pave the way for personalised probiotic therapies that are optimised to reduce the risk of obesity-related diseases based on an individual's genetic make-up.

Previous research has linked both genetic variation and the composition of gut microbes to metabolic disease and obesity. Despite these shared effects, the relationship between human genetic variation and the diversity of gut microbes was presumed to be negligible.

In the study, funded by National Institutes of Health (NIH), researchers sequenced the genes of microbes found in more than 1,000 fecal samples from 416 pairs of twins. The abundances of specific types of microbes were found to be more similar in identical twins, who share 100 per cent of their genes, than in non-identical twins, who share on average only half of the genes that vary between people. These findings demonstrate that genes influence the composition of gut microbes.

The type of bacteria whose abundance was most heavily influenced by host genetics was a recently identified family called 'Christensenellaceae'. Members of this health-promoting bacterial family were more abundant in individuals with a low body weight than in obese individuals. Moreover, mice that were treated with this microbe gained less weight than untreated mice, suggesting that increasing the amounts of this microbe may help to prevent or reduce obesity.

Professor Tim Spector, Head of the Department of Twin Research and Genetic Epidemiology at King's College London, said: 'Our findings show that specific groups of microbes living in our gut could be protective against obesity -- and that their abundance is influenced by our genes. The human microbiome represents an exciting new target for dietary changes and treatments aimed at combating obesity.

'Twins have been incredibly valuable in uncovering these links -- but we now want to promote the use of microbiome testing more widely in the UK through the British Gut Project. This is a crowd-sourcing experiment that allows anyone with an interest in their diet and health to have their personal microbes tested genetically using a simple postal kit and a small donation via our website (www.britishgut.org). We want thousands to join up so we can continue to make major discoveries about the links between our gut and our health.'

Ruth Ley, Associate Professor at Cornell University in the United States, said: 'Up until now, variation in the abundances of gut microbes has been explained by diet, the environment, lifestyle, and health. This is the first study to firmly establish that certain types of gut microbes are heritable -- that their variation across a population is in part due to host genotype variation, not just environmental influences. These results will also help us find new predictors of disease and aid prevention.'

A cause of age-related inflammation found

November 6, 2014

Carnegie Institution

As animals age, their immune systems gradually deteriorate, a process called immunosenescence. It is associated with systemic inflammation and chronic inflammatory disorders, as well as with many cancers. The causes underlying this age-associated inflammation, and how it leads to diseases, are poorly understood. New work sheds light on one protein's involvement in suppressing immune responses in aging fruit flies.

Click to enlarge

This image shows a comparison of lamin-B in the fat bodies of 10-day-old and 50-day-old fruit flies.

As animals age, their immune systems gradually deteriorate, a process called immunosenescence. It is associated with systemic inflammation and chronic inflammatory disorders, as well as with many cancers. The causes underlying this age-associated inflammation, and how it leads to diseases, are poorly understood. New work in Carnegie's Yixian Zheng's lab sheds light on one protein's involvement in suppressing immune responses in aging fruit flies. It is published in Cell.

Insects have an immune organ called the fat body, which is roughly equivalent to the mammalian fat and liver. It is responsible for many immune functions. Zheng and her team--Carnegie's Haiyang Chen and Xiaobin Zheng--found that the fruit fly fat body experiences a great deal of inflammation in aged flies.

These inflamed fly fat bodies then secrete proteins that lead to a reduction in immune response of the gut. This reduction of the gut immune response causes the gut's stem cells to undergo excessive division and inappropriate differentiation, creating a condition called hyperplasia that shares features with the precancerous polyps found in human guts.

Zheng and her team found that the gradual reduction of a protein called lamin-B in the fat bodies of aging flies is the culprit behind fat body inflammation and the resulting hyperplastic gut, all of which falls under the umbrella of immunosenescence.

Lamin-B is part of the lamin family of proteins, which form the major structural component of the material that lines the inside of a cell's nucleus. Lamins have diverse functions, including suppressing gene expression, and they are found in an array of tissues and organs. In humans, diseases caused by mutations in lamins are called laminopathies and include premature aging.

B-type lamins have long been suspected to play a role in gene suppression by binding to segments of DNA. The team's work revealed that when the fruit fly fat body was depleted of lamin-B, the normal suppression of genes involved in the immune response is reversed, just as it would be in response to bacterial infection or injury, but in this case there is no apparent infection or injury. The un-suppressed immune response initiates the inflammation and resulting gut hyperplasia.

"Our findings have implications for mammals as well as for insects, as immune response genes in mammals also are known to have lamins present on them," Zheng explained. "We think that lamin-B might play an evolutionarily conserved role in suppressing inflammatory genes in immune organs in the absence of infection or injury and our work could provide insight into immunosenescence in humans."

Story Source:

The above story is based on materials provided by Carnegie Institution. Note: Materials may be edited for content and length.

Journal Reference:

Haiyang Chen, Xiaobin Zheng, Yixian Zheng. Age-Associated Loss of Lamin-B Leads to Systemic Inflammation and Gut Hyperplasia. Cell, 2014; 159 (4): 829 DOI: 10.1016/j.cell.2014.10.028

Synthetic biology for space exploration

Click to enlarge

Microbial-based biomanufacturing could be transformative once explorers arrive at an extraterrestrial site.

Does synthetic biology hold the key to manned space exploration of the Moon and Mars? Berkeley Lab researchers have used synthetic biology to produce an inexpensive and reliable microbial-based alternative to the world's most effective anti-malaria drug, and to develop clean, green and sustainable alternatives to gasoline, diesel and jet fuels. In the future, synthetic biology could also be used to make manned space missions more practical.

"Not only does synthetic biology promise to make the travel to extraterrestrial locations more practical and bearable, it could also be transformative once explorers arrive at their destination," says Adam Arkin, director of Berkeley Lab's Physical Biosciences Division (PBD) and a leading authority on synthetic and systems biology.

"During flight, the ability to augment fuel and other energy needs, to provide small amounts of needed materials, plus renewable, nutritional and taste-engineered food, and drugs-on-demand can save costs and increase astronaut health and welfare," Arkin says. "At an extraterrestrial base, synthetic biology could make even more effective use of the catalytic activities of diverse organisms."

Arkin is the senior author of a paper in the Journal of the Royal Society Interface that reports on a techno-economic analysis demonstrating "the significant utility of deploying non-traditional biological techniques to harness available volatiles and waste resources on manned long-duration space missions." The paper is titled "Towards Synthetic Biological Approaches to Resource Utilization on Space Missions." The lead and corresponding author is Amor Menezes, a postdoctoral scholar in Arkin's research group at the University of California (UC) Berkeley. Other co-authors are John Cumbers and John Hogan with the NASA Ames Research Center.

One of the biggest challenges to manned space missions is the expense. The NASA rule-of-thumb is that every unit mass of payload launched requires the support of an additional 99 units of mass, with "support" encompassing everything from fuel to oxygen to food and medicine for the astronauts, etc. Most of the current technologies now deployed or under development for providing this support are abiotic, meaning non-biological. Arkin, Menezes and their collaborators have shown that providing this support with technologies based on existing biological processes is a more than viable alternative.

"Because synthetic biology allows us to engineer biological processes to our advantage, we found in our analysis that technologies, when using common space metrics such as mass, power and volume, have the potential to provide substantial cost savings, especially in mass," Menezes says.

In their study, the authors looked at four target areas: fuel generation, food production, biopolymer synthesis, and pharmaceutical manufacture. They showed that for a 916 day manned mission to Mars, the use of microbial biomanufacturing capabilities could reduce the mass of fuel manufacturing by 56-percent, the mass of food-shipments by 38-percent, and the shipped mass to 3D-print a habitat for six by a whopping 85-percent. In addition, microbes could also completely replenish expired or irradiated stocks of pharmaceuticals, which would provide independence from unmanned re-supply spacecraft that take up to 210 days to arrive.

"Space has always provided a wonderful test of whether technology can meet strict engineering standards for both effect and safety," Arkin says. "NASA has worked decades to ensure that the specifications that new technologies must meet are rigorous and realistic, which allowed us to perform up-front techno-economic analysis."

The big advantage biological manufacturing holds over abiotic manufacturing is the remarkable ability of natural and engineered microbes to transform very simple starting substrates, such as carbon dioxide, water biomass or minerals, into materials that astronauts on long-term missions will need. This capability should prove especially useful for future extraterrestrial settlements.

"The mineral and carbon composition of other celestial bodies is different from the bulk of Earth, but the earth is diverse with many extreme environments that have some relationship to those that might be found at possible bases on the Moon or Mars," Arkin says. "Microbes could be used to greatly augment the materials available at a landing site, enable the biomanufacturing of food and pharmaceuticals, and possibly even modify and enrich local soils for agriculture in controlled environments."

The authors acknowledge that much of their analysis is speculative and that their calculations show a number of significant challenges to making biomanufacturing a feasible augmentation and replacement for abiotic technologies. However, they argue that the investment to overcome these barriers offers dramatic potential payoff for future space programs.

"We've got a long way to go since experimental proof-of-concept work in synthetic biology for space applications is just beginning, but long-duration manned missions are also a ways off," says Menezes. "Abiotic technologies were developed for many, many decades before they were successfully utilized in space, so of course biological technologies have some catching-up to do. However, this catching-up may not be that much, and in some cases, the biological technologies may already be superior to their abiotic counterparts."

This research was supported by the National Aeronautics and Space Administration (NASA) and the University of California, Santa Cruz.

New laws threaten Brazil's unique ecosystems

Brazil's globally significant ecosystems could be exposed to mining and dams if proposals currently being debated by the Brazilian Congress go ahead, according to researchers publishing in the journal Science this week.

The new report by a group of Brazilian and British researchers comes in the wake of Brazil´s recent presidential elections. It warns that new legislation could pose a serious threat to protected areas, weakening Brazil's international status as an environmental leader.

One of the proposals of particular concern is the call to open up 10% of the most strictly protected areas to mining. In a new analysis, the research shows that at least 20% of all Brazil´s most strictly protected areas and reserves for indigenous people overlap with areas that have been registered as under consideration for mining. In addition, many of the river systems associated with protected areas will be influenced by the construction of large hydroelectric dams.

The threat that this mining and hydropower poses to Brazil's ecosystems is not trivial. Areas of registered interest for mining include 34,117 km2 that are currently classified as strictly protected areas -- including National Parks, Biological Reserves and Wildlife Refuges. This is equivalent to an area the size of Switzerland. The situation is worse for indigenous lands, 28% of which, or 281,443 km2, overlap with areas of registered mining interest -- an area larger than the whole of the UK or the state of São Paulo.

In recent years Brazil has enjoyed increasing recognition as a world leader in combatting environmental destruction. Brazil´s protected area network is the largest in the world, while improved environmental governance in private lands has contributed to an 80% reduction in the rate of deforestation in the Brazilian Amazon over the last decade. Yet these new proposals could threaten these recent successes and undermine Brazil's reputation.

Dr Joice Ferreira, a scientist at Brazil´s agricultural research institute, Embrapa, and lead author of the study, said: "The purpose of this analysis is not to say that Brazil´s development should not benefit from its abundant natural resources, but that we should not squander our hard-won record of success and leadership in favor of fast-tracked and poorly planned development projects that leave a long legacy of environmental damage. It is possible to manage our development in a more sustainable way."

Co-author Dr Jos Barlow, a researcher at Lancaster University and a visiting professor in Brazil, said: "Rather than exploiting protected areas for short-term gains, Brazil should treasure them for the long-term benefits they can provide to society. The recent water shortages in the south east of Brazil emphasize the importance of protecting native vegetation across the country."

The authors of the study also warn that the proposals for minimizing and mitigating the environmental damage of large-scale development projects are so inadequate that even if only a fraction of these mining concessions were approved then the impacts could be enormous, especially in Brazil´s most threatened ecosystems.

Dr. Luiz Aragão a co-author of the study from Brazil´s federal space agency, INPE and the University of Exeter said: "Our concern is that even if the proposed mitigation actions were put in place they are oversimplified because they fail to take account of the indirect effects of mega-projects.

"These projects can involve thousands of workers and lead to rapid local population growth. This, combined with new roads and access routes, is a recipe for the emergence of new deforestation frontiers." explains Luiz.

The study highlights the fact that these worrying changes reflect an important shift in the support shown by Brazil´s federal government to environmental protection. These concerns come on the back of other recent changes, including the partial dismantling of Brazil´s protected area system to make way for development -- with some 44,100 km2 lost since 2008 due to downsizing or abolishment -- and the weakening of the Forest Code that gave an amnesty to landowners who deforested illegally in the past.

"Beyond the conservation and stewardship of its own biodiversity and environmental resources, so vital to the wellbeing of its citizens, Brazil plays a vital role in motivating and supporting the adoption of more sustainable development trajectories around the world," said Toby Gardner, of Stockholm Environment Institute, one of the authors of the study who has worked in the country for more than a decade. "Yet this standing is now in jeopardy."

Dr Joice Ferreira said: "The newly elected government has the chance to set the record straight and point Brazil firmly on a path of sustainable development. The authors of this report call on President Dilma and her government to ensure that individual development initiatives are subject to a comprehensive, socially inclusive, evidence-based and long-term cost-benefit analysis that compares potential environmental and social impacts against alternative development options. And also to ensure that Brazil´s renowned protected area network is given the resources it needs to manage our ecosystems sustainably.

"Above all we ask the Government to guarantee that important decisions regarding the management of Brazil´s natural resources involve the full and democratic participation of Brazilian society."

New research lights the way to super-fast computers

New research published today in the journal Nature Communications, has demonstrated how glass can be manipulated to create a material that will allow computers to transfer information using light. This development could significantly increase computer processing speeds and power in the future.

The research by the University of Surrey, in collaboration with the University of Cambridge and the University of Southampton, has found it is possible to change the electronic properties of amorphous chalcogenides, a glass material integral to data technologies such as CDs and DVDs. By using a technique called ion doping, the team of researchers have discovered a material that could use light to bring together different computing functions into one component, leading to all-optical systems.

Computers currently use electrons to transfer information and process applications. On the other hand, data sources such as the internet rely on optical systems; the transfer of information using light. Optical fibres are used to send information around the world at the speed of light, but these signals then have to be converted to electrical signals once they reach a computer, causing a significant slowdown in processing.

"The challenge is to find a single material that can effectively use and control light to carry information around a computer. Much like how the web uses light to deliver information, we want to use light to both deliver and process computer data," said project leader, Dr Richard Curry of the University of Surrey.

"This has eluded researchers for decades, but now we have now shown how a widely used glass can be manipulated to conduct negative electrons, as well as positive charges, creating what are known as 'pn-junction' devices. This should enable the material to act as a light source, a light guide and a light detector -- something that can carry and interpret optical information. In doing so, this could transform the computers of tomorrow, allowing them to effectively process information at much faster speeds."

The researchers expect that the results of this research will be integrated into computers within ten years. In the short term, the glass is already being developed and used in next-generation computer memory technology known as CRAM, which may ultimately be integrated with the advances reported.

Story Source:

The above story is based on materials provided by University of Surrey. Note: Materials may be edited for content and length.

Journal Reference:

Mark A. Hughes, Yanina Fedorenko, Behrad Gholipour, Jin Yao, Tae-Hoon Lee, Russell M. Gwilliam, Kevin P. Homewood, Steven Hinder, Daniel W. Hewak, Stephen R. Elliott, Richard J. Curry. n-type chalcogenides by ion implantation. Nature Communications, 2014; 5: 5346 DOI: 10.1038/ncomms6346

Denying problems when we don't like the political solutions: Why conservatives, liberals disagree so vehemently

There may be a scientific answer for why conservatives and liberals disagree so vehemently over the existence of issues like climate change and specific types of crime.

A new study from Duke University finds that people will evaluate scientific evidence based on whether they view its policy implications as politically desirable. If they don't, then they tend to deny the problem even exists.

"Logically, the proposed solution to a problem, such as an increase in government regulation or an extension of the free market, should not influence one's belief in the problem. However, we find it does," said co-author Troy Campbell, a Ph.D. candidate at Duke's Fuqua School of Business. "The cure can be more immediately threatening than the problem."

The study, "Solution Aversion: On the Relation Between Ideology and Motivated Disbelief," appears in the November issue of the Journal of Personality and Social Psychology.

The researchers conducted three experiments (with samples ranging from 120 to 188 participants) on three different issues -- climate change, air pollution that harms lungs, and crime.

"The goal was to test, in a scientifically controlled manner, the question: Does the desirability of a solution affect beliefs in the existence of the associated problem? In other words, does what we call 'solution aversion' exist?" Campbell said.

"We found the answer is yes. And we found it occurs in response to some of the most common solutions for popularly discussed problems."

For climate change, the researchers conducted an experiment to examine why more Republicans than Democrats seem to deny its existence, despite strong scientific evidence that supports it.

One explanation, they found, may have more to do with conservatives' general opposition to the most popular solution -- increasing government regulation -- than with any difference in fear of the climate change problem itself, as some have proposed.

Participants in the experiment, including both self-identified Republicans and Democrats, read a statement asserting that global temperatures will rise 3.2 degrees in the 21st century. They were then asked to evaluate a proposed policy solution to address the warming.

When the policy solution emphasized a tax on carbon emissions or some other form of government regulation, which is generally opposed by Republican ideology, only 22 percent of Republicans said they believed the temperatures would rise at least as much as indicated by the scientific statement they read.

But when the proposed policy solution emphasized the free market, such as with innovative green technology, 55 percent of Republicans agreed with the scientific statement.

For Democrats, the same experiment recorded no difference in their belief, regardless of the proposed solution to climate change.

"Recognizing this effect is helpful because it allows researchers to predict not just what problems people will deny, but who will likely deny each problem," said co-author Aaron Kay, an associate professor at Fuqua. "The more threatening a solution is to a person, the more likely that person is to deny the problem."

The researchers found liberal-leaning individuals exhibited a similar aversion to solutions they viewed as politically undesirable in an experiment involving violent home break-ins. When the proposed solution called for looser versus tighter gun-control laws, those with more liberal gun-control ideologies were more likely to downplay the frequency of violent home break-ins.

"We should not just view some people or group as anti-science, anti-fact or hyper-scared of any problems," Kay said. "Instead, we should understand that certain problems have particular solutions that threaten some people and groups more than others. When we realize this, we understand those who deny the problem more and we improve our ability to better communicate with them."

Campbell added that solution aversion can help explain why political divides become so divisive and intractable.

"We argue that the political divide over many issues is just that, it's political," Campbell said. "These divides are not explained by just one party being more anti-science, but the fact that in general people deny facts that threaten their ideologies, left, right or center."

The researchers noted there are additional factors that can influence how people see the policy implications of science. Additional research using larger samples and more specific methods would provide an even clearer picture, they said.

Does life satisfaction increase with age? Only in some places, new study finds

The study -- conducted by researchers from Princeton University's Woodrow Wilson School of Public and International Affairs, Stony Brook University and University College London -- highlights how residents of different regions across the world experience varying life-satisfaction levels and emotions as they age.

In the former Soviet Union and Eastern European countries, older residents reported very low rankings of life satisfaction compared with younger residents in those regions. This same pattern is seen in Latin America and Caribbean countries, though life satisfaction does not decrease as sharply as in the Eastern European countries. And in sub-Saharan Africa, life satisfaction is very low at all ages.

"Economic theory can predict a dip in well-being among the middle age in high-income, English-speaking countries," said co-author Angus Deaton, the Dwight D. Eisenhower Professor of Economics and International Affairs at the Wilson School. "What is interesting is that this pattern is not universal. Other regions, like the former Soviet Union, have been affected by the collapse of communism and other systems. Such events have affected the elderly who have lost a system that, however imperfect, gave meaning to their lives, and, in some cases, their pensions and health care."

The research team -- which includes Professor Andrew Steptoe of University College London and Arthur A. Stone, who conducted the research at Stony Brook but is now a professor at the University of Southern California -- also finds a two-way connection between physical health and well-being: poorer health leads to lower ratings of life satisfaction among the elderly, but higher life satisfaction seems to stave off physical health declines.

"Our findings suggest that health care systems should be concerned not only with illness and disability among the elderly but their psychological states as well," Deaton said.

Using data collected by the Gallup World Poll and the English Longitudinal Study of Ageing, the researchers looked at three measures of well-being: evaluative well-being, which focuses on evaluations of how satisfied people are with their lives; hedonic well-being, which is related to feelings or moods such as happiness, sadness and anger; and eudemonic well-being, which relates to judgments about the meaning and purpose of life. The researchers also looked at respondents' ratings of physical health and pain.

Evaluative well-being was captured from participants using a Cantril ladder scale. This measure of well-being, developed half a century ago by Princeton social researcher Hadley Cantril, asks participants to visualize a ladder with steps numbered from zero at the bottom (worst possible life) to 10 at the top (best possible life).

When looking at life satisfaction scores across the regions, the researchers confirmed a well-known "U-shaped curve" that bottoms out between the ages of 45 and 54 in high-income, English speaking countries. These countries include the United States, Canada, the United Kingdom, Ireland, Australia and New Zealand. This curve indicates that, in these countries, middle-age residents report the lowest levels of life satisfaction, which eventually bounces back up after age 54.

"This finding is almost expected," said Deaton. "This is the period at which wage rates typically peak and is the best time to work and earn the most, even at the expense of present well-being, so as to have increased wealth and well-being later in life."

Outside of these high-income, English-speaking countries, however, the same U-shaped curve is not seen. All other regions report decreasing life-satisfaction levels as people age, with the former Soviet Union and Eastern European countries having the sharpest declines. The researchers attribute this phenomenon to the transitions these countries have experienced. They note that not being happy, which is uncommon in high-income, English-speaking countries, is quite common among transition countries, particularly among the elderly.

"The findings undoubtedly show the recent experiences of the region and the distress that these events have brought to older people," Deaton said.

Gender, however, seems to make little difference. Men and women from the same regions have very similar levels of satisfaction, the researchers report.

Patterns in other measures of well-being

When looking at hedonic well-being -- emotions and moods -- across populations, the researchers find that older populations in high-income, English-speaking countries experience less stress, worry and anger than those who are middle-aged. A similar pattern is seen in the middle-income region of Latin America and Caribbean countries, where worry and stress peak in middle age, though not as sharply as in the Eastern European countries. And in sub-Saharan Africa, the researchers find that the prevalence of worry, stress and unhappiness increases just slightly with age.

In terms of gender, the differences between men and women in each region are slight. However, elderly women in former Soviet Union and Eastern European countries have substantially more worry, stress and pain than elderly men in those regions, regardless of the fact that the health of men in these countries has suffered more.

To determine survival rates among the elderly, the research team used data from the English Longitudinal Study of Ageing, and they compared it with data on eudemonic well-being, or purpose in life. What emerges is a bidirectional relationship; when elderly people feel they have a purpose, their rates of survival increase. The researchers found that the proportion of deaths was 29.3 percent in the lowest life-satisfaction grouping and only 9.3 percent in the highest life-satisfaction grouping.

"Even though the results do not unequivocally show that eudemonic well-being is causally linked with mortality, the findings do raise intriguing possibilities about positive well-being being implicated in reduced risk to health," the authors conclude.

In terms of physical pain, the fractions of young people reporting physical pain is similar across all regions, though the age-related trajectories for pain are much steeper in the former Soviet countries, sub-Saharan African and Latin America and Caribbean countries than in the high-income, English-speaking countries. Additionally, the pain divide between the old and young in former communist countries is much starker than the other regions.

While the research team agrees that progress is being made in terms of understanding how behavioral and biological elements play a role in subjective well-being, they agree that more work needs to be done.

"Investment in these research resources is essential," said Deaton. "Most studies are of high-income countries and not those with low or middle incomes. However, cross-national surveys such as the Gallup World Poll and others are beginning to re-address the balance."