Wednesday, August 11, 2010

CAN YOU ASK A PIG IF HIS GLASS IS HALF FULL?

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Babe may be the most famous sensitive pig in the world but new research from Newcastle University suggests he is by no means the only one.

Experts from the university’s School of Agriculture, Food and Rural Development have shown for the first time that a pig’s mood mirrors how content he is, highlighting that pigs are capable of complex emotions which are directly influenced by the environment in which they live.

Led by Dr Catherine Douglas, the team has employed a technique to ‘ask’ pigs if they are feeling optimistic or pessimistic about life as a result of the way in which they live.

In an experiment reminiscent of Pavlov’s dogs, the Newcastle team taught the pigs to associate a note on a glockenspiel with a treat – an apple – and a dog training ‘clicker’ with something unpleasant – in this case rustling a plastic bag.

The next step was to place half the pigs in an enriched environment – more space, freedom to roam in straw and play with ‘pig’ toys – while the other half were placed in a smaller, boring environment– no straw and only one non-interactive toy.

The team then played an ambiguous noise – a squeak – and studied how the pigs responded. Dr Douglas said the results were compelling.

“We found that almost without exception, the pigs in the enriched environment were optimistic about what this new noise could mean and approached expecting to get the treat,” she said. “In contrast, the pigs in the boring environment were pessimistic about this new strange noise and, fearing it might be the mildly unpleasant plastic bag, did not approach for a treat.

“It’s a response we see all the time in humans where how we are feeling affects our judgement of ambiguous events. For example, if you’re having a bad day -feeling stressed and low - and you’re presented with an ambiguous cue such as your boss calling you into their office, the first thing that goes through your head is what have I done wrong? We call this a negative cognitive bias. But on a good day you greet the same ambiguous event far more positively, you might strut in expecting a slap on the back and a pay rise.

“This ‘glass half empty versus glass half full’ interpretation of life reflects our complex emotional states, and our study shows that we can get the same information from pigs. We can use this technique to finally answer important questions about animal welfare in relation to a range of farm environments, for pigs and potentially other farm animals.”

The research, funded by Universities Federation for Animal Welfare (UFAW) was presented at the organisation’s annual conference in York.

Quality of life of our farm animals is becoming increasingly important to consumers, scientists and government and the study is part of ongoing research at Newcastle to further our understanding of animal welfare and improve the lives of farmed stock.

Sandra Edwards, professor of agriculture at Newcastle University and one of the UK’s leading experts in pig welfare, said the next step would be to refine and further validate the methodology so it could be used to help scientists determine what is really important to the pig for its well-being.

“Historically, animal welfare research looked only at alleviating suffering. Now the UK industry itself is going beyond a minimum standard and funding research to explore measuring, and then promoting, quality of life,” she explained.

“Although techniques exist to measure stress, in the past we haven’t been able to directly ask a pig if it is happy or not. Instead we have assessed production systems based purely on human perceptions and our best interpretations of behaviour.

“Our research, for the first time, provides an insight into pigs' subjective emotional state and this will help scientists and farmers to continue to improve the lives of their pigs in the future.”

Dr Douglas said that in their experiments they deliberately used only environments which could be easily and sustainably introduced in commercial systems.

“UK farmers have some very difficult decisions to make in order to compete in the global market and to suggest that we make all pig farms free range is simply not practical, possible or necessarily desirable,” she explained.
“Unfortunately, consumers buying cheap imports have the biggest impact on animal welfare and this puts pressure on UK farmers who, as a rule, do their utmost to ensure good welfare of the UK pig herd.

“In our experiments the enriched environment was also a widespread commercial housing system, so a ‘happy pigs’ system already exists on many farms across the UK.”

(Photo: Newcastle U.)

Newcastle University

PREDICTIONS OF COAL, CO2 PRODUCTION FLAWED, SAYS LATEST RESEARCH

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The CO2 emission estimates used for government policy decisions assume unlimited coal and fossil fuel production for the next 100 years, an unrealistic premise which skews climate change models and proposed solutions, according to new research published by Tad Patzek, chair of the Petroleum and Geosystems Engineering Department at The University of Texas at Austin.

Based on widely accepted studies predicting coal production will peak and decline after 2011, Patzek warns climate change predictions should be revised to account for this inevitable peak and decline. His research appears in the internationally peer-reviewed journal, Energy, The International Journal.

"Governments worldwide are basing their policy decisions on the uninterrupted increase of coal and oil production worldwide," says Patzek. "These policy decisions will be inherently in error, and will lead to expensive and false technological solutions."

Under the 40 different U.S. Intergovernmental Panel on Climate Change (IPCC) scenarios, Patzek found 36 of the 40 scenarios predicted future carbon production and CO2 emissions at today's rate of coal production. Credible forecasts of coal production, by contrast, predict a 50 percent reduction over the next 50 years.

"Most of the IPCC scenario writers accepted the common myth of 200-400 years of coal supply, and now their 'eternal' (100 years plus) growth of carbon dioxide emissions in turn is a part of the commonly accepted social myth," says Patzek. "It seems, therefore, that the present attempt to inject some geophysics into the debate will be an uphill battle."

Patzek evaluated the accuracy of each of the 40 IPCC scenarios based on diminishing coal and fossil fuel resources. His full report was published in the August issue of Energy, The International Journal with co-author, Dr. Gregory Croft, who was Patzek's last Ph.D. student at the Department of Civil and Environmental Engineering at the University of California, Berkeley.

"The IPCC carbon estimates, which are used by all major decision makers, are based on economic and policy considerations that appear to be unconstrained by geophysics," says Patzek. "The value of our approach is that it provides a reality check on the magnitude of carbon emissions."

The paper provides a physical model of historical and future production of coal worldwide. The model demonstrates that despite enormous coal deposits globally, coal production rates will decline because the deposits show increasing inaccessibility and decreasing coal seam thickness, according to the research.

"The current global hysteria around carbon capture and sequestration is leading to desperately poor government policies," says Patzek. "For instance, large-scale subsurface sequestration of CO2 will decrease power plant efficiency by up to 50 percent. The same resources could be spent more wisely on increasing U.S. coal-fired power plant efficiency by 50 percent from the current 32 percent."

The University of Texas at Austin

PROTEINS LINKED TO LONGEVITY ALSO LINKED TO ALZHEIMER’S

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Sirtuins appear to control production of the devastating protein fragments that form plaques in the brains of Alzheimer’s patients.

Over the past 20 years, scientists have learned that proteins called sirtuins play a vital role in longevity and stress response in organisms as diverse as humans, yeast and mice. A new paper from MIT biologists now reveals a surprising additional role for sirtuins: They appear to suppress the production of amyloid beta proteins, which form plaques in the brains of Alzheimer’s patients.

The finding, reported in the July 23 issue of Cell, suggests that targeting sirtuins could offer a promising new approach to treating Alzheimer’s, says Professor Leonard Guarente, leader of the research team.

Guarente and his colleagues showed that boosting the activity of a sirtuin called SIRT1 stifled the production of amyloid beta proteins and enhanced brain function in mice engineered to express Alzheimer’s symptoms. This marks the first time sirtuins have been linked to those proteins.

Several drug companies are now developing and testing compounds that enhance sirtuin activity. Guarente, who consults for one of those companies, Sirtris (a unit of GlaxoSmithKline), believes that sirtuin activators may eventually prove useful against Alzheimer’s, which affects up to one-third of people who reach age 80.

Though amyloid plaques are a defining feature of Alzheimer’s disease, many researchers now believe that the symptoms are caused by smaller clumps of two or three amyloid beta (A-beta) fragments, not the larger plaques.

A-beta peptides form when proteins called amyloid precursor proteins (APPs) are broken into smaller pieces. However, APPs can also be cleaved at other sites, producing harmless protein fragments. APP’s normal function is unknown, but it has been established that people with a gene mutation that stimulates overproduction of APP are more likely to develop Alzheimer’s at an early age (before age 65).

Another mutation that stimulates early-onset Alzheimer’s (which accounts for 5 to 10 percent of cases) occurs in the gene for the enzyme that cleaves APP into A-beta peptides. Although those genes for early-onset Alzheimer’s have been identified, “with late-onset Alzheimer’s, we still don’t know why some people get it and other people don’t,” says Guarente.

Guarente, who first discovered the life-extending ability of sirtuins 20 years ago, started studying their role in Alzheimer’s after some recent studies showed that the gene that produces sirtuins, SIRT1, appears to protect mice from the effects of Alzheimer’s disease. When those studies came out, “I thought that the mice with extra SIRT1 probably had just as much A-beta, but that SIRT1 was protecting them against it,” Guarente recalls. “It turns out that they were actually making less A-beta peptide.”

In the Cell paper, Guarente and his colleagues showed that SIRT1 activates the production of an enzyme (alpha-secretase) that carves APPs into harmless fragments, preventing the formation of Alzheimer’s-associated amyloid peptides. Mice engineered to produce excess sirtuins had reduced peptide levels, while mice with SIRT1 knocked out showed elevated peptide levels.

Furthermore, learning and memory deficits in the Alzheimer’s mice were improved when SIRT1 was overproduced and worsened when the gene was deleted. The researchers also found that SIRT1 activates the so-called notch-signaling pathway via the elevated levels of alpha-secretase, which protects neurons and helps maintain brain function.

The research, funded by the American Parkinson Disease Association, National Institutes of Health and the Paul F. Glenn Foundation, demonstrates that drugs that activate SIRT1 in the brain may be a promising approach to treating Alzheimer’s, says Guarente. Any such drug would have to be able to cross the blood-brain barrier, which prevents large molecules from diffusing into the brain.

Sirtris, a company co-founded by Guarente and then bought by GlaxoSmithKline, is now testing SIRT1 activators in a clinical trial for diabetes. Guarente believes that related drugs could have an impact on a range of neurodegenerative diseases, as well as diabetes and other diseases of aging.

However, any potential drug for Alzheimer’s would likely take several years to reach clinical trials, because of the need to find a drug that crosses the blood-brain barrier, says Guarente.

Rudolph Tanzi, professor of neurology at Harvard Medical School, says the new findings also suggest another approach: targeting one specific aspect of SIRT1’s activity. Tanzi’s lab recently found that mutations in the gene that produces alpha-secretase (ADAM10) are associated with late-onset Alzheimer’s disease.

“If this is how SIRT1 protects against Alzheimer’s — by turning on ADAM10 — you could try finding a drug that specifically addresses that mechanism,” instead of globally activating SIRT1, says Tanzi.

(Photo: Donna Coveney)

Massachusetts Institute of Technology

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