Exercise may prevent stress on telomeres, a measure of cell health

Jennifer O’Brien – UCSF scientists are reporting several studies showing that psychological stress leads to shorter telomeres – the protective caps on the ends of chromosomes that are a measure of cell age and, thus, health. The findings also suggest that exercise may prevent this damage.

The team focused on three groups: post-menopausal women who were the primary caregivers for a family member with dementia; young to middle-aged adults with post-traumatic stress disorder; and healthy, non-smoking women ages 50 to 65 years.

They examined telomeres in leukocytes, or white blood cells, of the immune system, which defends the body against both infectious agents and cell damage.

“Our findings suggest that traumatic and chronic stressful life events are associated with shortening of telomeres in cells of the immune system, but that physical activity may moderate this impact,” said co-author Jue Lin, PhD, associate research biochemist in the laboratory of senior author and Nobel laureate Elizabeth Blackburn, PhD, professor of biochemistry and biophysics at UCSF.

Lin presented the findings in a poster session on Monday, April 4, 2011, at the AACR 102nd Annual Meeting 2011.

Telomeres are tiny units of DNA at the ends of chromosomes that protect and stabilize chromosomes. Every time a cell divides, some telomeres drop off. After a certain number of cell divisions, which varies depending on the cell type, the telomeres reach a critical length and the cell typically dies. Sometimes, however, the cells cease to divide and are subjected to genomic instability, promoting inflammation in the body.

Scientists have known for more than a decade that the length of telomeres in immune system cells is a marker of cell aging. In recent years, they have discovered that shorter telomeres are associated with a broad range of aging-related diseases and are predictive of incidence and poor prognosis of cardiovascular disease and a variety of cancers.

A 2004 study led by Blackburn and UCSF colleague Elissa Epel, PhD, associate professor of psychiatry, suggested that psychological stress may impact the length of telomeres in immune system cells. They reported that the perception of psychological stress in female caregivers of chronically sick children was related to shorter telomeres in lymphocytes, key cells of the immune system. This offered the first evidence that telomere maintenance potentially mediates the well documented detrimental effects of stress on health. …

via Exercise may prevent stress on telomeres, a measure of cell health.

Addressing the nuclear waste issue

Researchers from Northwestern University and Argonne National Laboratory have an enhanced understanding of a common freshwater alga and its remarkable ability to remove strontium from water. Insight into this mechanism ultimately could help scientists design methods to remove radioactive strontium from existing nuclear waste.

Strontium 90, a major waste component, is one of the more dangerous radioactive fission materials created within a nuclear reactor. It is present in the approximately 80 million gallons of radioactive waste sludge stored in the United States alone.

The researchers are the first to show quantitatively how Closterium moniliferum, one of the bright green algae often seen in ponds, sequesters strontium (in the form of barium-strontium-sulfate crystals). They are using this understanding to think about a practical sequestration system for nuclear waste that maximizes strontium removal. The possibilities include using the algae for direct bioremediation of waste or accidental spills in the environment or designing a new process for waste treatment inspired by how the algae work.

The results are published by the journal ChemSusChem, a sister journal of Angewandte Chemie.

“Nuclear waste cleanup is a problem we have to solve,” said senior author Derk Joester, who experienced Chernobyl’s radioactive fallout when he was a teenager living in southern Germany. “Even if all the nuclear reactors were to shut down tomorrow, the existing volume of waste is great, and it is costly to store. We need to isolate highly radioactive ‘high-level’ waste from ‘low-level’ waste. The algae offer a mechanism for doing this, which we would like to understand and optimize.”

Even though strontium 90 doesn’t appear to be a significant environmental threat following the nuclear accident in Japan, the radioactive isotope will need to be dealt with during the power plant and nuclear waste cleanup, Joester said. …

via Addressing the nuclear waste issue.

Resource scarcity is not a necessity

Economic theory assumes resource scarcity as an important premise, and there is a general consensus that scarce resources are best allocated by means of a market. However, a new doctoral thesis from the University of Gothenburg, Sweden, shows that there may be alternative solutions to the allocation problem.

Economic theory generally assumes that there will never be enough food, water, cars, money etc. to satisfy people’s wants. This means that inequalities, conflict and poverty are inevitable parts of society. Many economists feel that scarcity is best dealt with through the presence of a market – the highest bidders gain access to a society’s scarce resources.

Yet, economic sociologists do not necessarily see resource scarcity as inevitable, and neither do they always agree with the mainstream solution to the economic problem. There are indeed enough resources, they might argue, but people are for various reasons denied access. For example, there is enough food in the world, but people are still starving. Why is that?

‘The market as an allocation mechanism has not been able to distribute food to everyone – every sixth person in the world does not have access to enough food,’ says Adel Daoud, author of the thesis.

So, do we need the market?

‘Maybe we do, given the present economic system, but we should at the same time ask ourselves whether any alternative allocation models could help us manage the world’s resources better, not least considering the climate threat. A so-called economic democracy could be one such solution. In an economic democracy, citizens get to have a say about what and how much of various products and services should be produced,’ says Daoud.

One of the main contributions of the thesis is to show the importance of using alternative perspectives, such as economic sociology, to deal with the notion of resource scarcity rather than simply seeing scarcity as inevitable. …

via Resource scarcity is not a necessity.

Genetic changes behind sweet tooth

The substance ghrelin plays an important role in various addictions, such as alcoholism and binge-eating. It also impacts on sugar consumption, which is due, in part, to genetic factors, reveals new research from the University of Gothenburg, Sweden.

Ghrelin is a neuropeptide that both activates the brain’s reward system and increases appetite. This means that when we are hungry, levels of ghrelin increase, activating the brain’s reward system, and this, in turn, increases our motivation to look for food. Previous research from the Sahlgrenska Academy has linked ghrelin to the development of various dependencies, such as drug addiction and alcoholism.

In a new study published in the online version of the journal Plos One, researchers examined the genes of 579 individuals chosen from the general public. It emerged that people with certain changes in the ghrelin gene consume more sugar than their peers who do not have these changes. This link was also seen in people who consumed large amounts of both sugar and alcohol.

Trials have also been carried out using rats, where the researchers found that when ghrelin was blocked the rats reduced their consumption of sugar and were less motivated to hunt for sugar.

“This shows that ghrelin is a strong driver when it comes to tracking down rewarding substances such as sugar or alcohol,” says researcher Elisabet Jerlhag from the Sahlgrenska Academy’s Department of Pharmacology.

These results go hand in hand with the researchers’ previous findings which showed that substances that block the ghrelin system reduce the positive effects of addictive drugs and that changes in the ghrelin gene are associated with high alcohol consumption, weight gain in alcoholics and smoking.

The researchers are now a step closer to understanding what happens in the brain and the body in different types of addictive behavior. Understanding these mechanisms means that new drugs can be developed to block the ghrelin system and used to treat patients who are addicted to alcohol or who suffer from binge-eating disorders.

via Genetic changes behind sweet tooth.

Protein adaptation shows that life on early earth lived in a hot, acidic environment

A new study reveals that a group of ancient enzymes adapted to substantial changes in ocean temperature and acidity during the last four billion years, providing evidence that life on Early Earth evolved from a much hotter, more acidic environment to the cooler, less acidic global environment that exists today.The study found that a group of ancient enzymes known as thioredoxin were chemically stable at temperatures up to 32 degrees Celsius (58 degrees Fahrenheit) higher than their modern counterparts. The enzymes, which were several billion years old, also showed increased activity at lower pH levels — which correspond to greater acidity.

“This study shows that a group of ubiquitous proteins operated in a hot, acidic environment during early life, which supports the view that the environment progressively cooled and became more alkaline between four billion and 500 million years ago,” said Eric Gaucher, an associate professor in the School of Biology at the Georgia Institute of Technology.

The study, which was published April 3 in the advance online edition of the journal Nature Structural & Molecular Biology, was conducted by an international team of researchers from Georgia Tech, Columbia University and the Universidad de Granada in Spain.

Major funding for this study was provided by two grants from the National Aeronautics and Space Administration to Georgia Tech, a grant from the National Institutes of Health to Columbia University, and a grant from the Spanish Ministry of Science and Innovation to the Universidad de Granada.

Using a technique called ancestral sequence reconstruction, Gaucher and Georgia Tech biology graduate student Zi-Ming Zhao reconstructed seven ancient thioredoxin enzymes from the three domains of life — archaea, bacteria and eukaryote — that date back between one and four billion years old.

To resurrect these enzymes, which are found in nearly all known modern organisms and are essential for life in mammals, the researchers first constructed a family tree of the more than 200 thioredoxin sequences available from the three domains of life. Then they reconstructed the sequences of the ancestral thioredoxin enzymes using statistical methods based on maximum likelihood. Finally, they synthesized the genes that encoded these sequences, expressed the ancient proteins in the cells of modern Escherichia coli bacteria and then purified the proteins.

“By resurrecting proteins, we are able to gather valuable information about the adaptation of extinct forms of life to climatic, ecological and physiological alterations that cannot be uncovered through fossil record examinations,” said Gaucher …

via Protein adaptation shows that life on early earth lived in a hot, acidic environment.

Men who lose their jobs at greater risk of dying prematurely

Research by McGill Sociology Professor Eran Shor, working in collaboration with researchers from Stony Brook University, has revealed that unemployment increases the risk of premature mortality by 63 per cent. Shor reached these conclusions by surveying existing research covering 20 million people in 15 (mainly western) countries, over the last 40 years.

One surprising finding was that, in spite of expectations that a better health-care system might contribute to lower mortality rates, the correlation between unemployment and a higher risk of death was the same in all the countries covered by the study.

The truly groundbreaking aspect of the research is that it suggests that there is a causal relationship between unemployment and a higher risk of death.

“Until now, one of the big questions in the literature has been about whether pre-existing health conditions, such as diabetes or heart problems, or behaviours such as smoking, drinking or drug use, lead to both unemployment and a greater risk of death,” Shor said. “What’s interesting about our work is that we found that preexisting health conditions had no effect, suggesting that the unemployment-mortality relationship is quite likely a causal one. This probably has to do with unemployment causing stress and negatively affecting one’s socioeconomic status, which in turn leads to poorer health and higher mortality rates.”

The research also showed that unemployment increases men’s mortality risk more than it does women’s mortality risk (78 per cent vs. 37 per cent respectively).The research also showed that there is a much higher correlation between unemployment and mortality for men than for women (78 per cent vs. 37 per cent). The risk of death is particularly high for those who are under the age of 50.

“We suspect that even today, not having a job is more stressful for men than for women.” Shor said. “When a man loses his job, it still often means that the family will become poorer and suffer in various ways, which in turn can have a huge impact on a man’s health by leading to both increased smoking, drinking or eating and by reducing the availability of healthy nutrition and health care services.” …

via Men who lose their jobs at greater risk of dying prematurely.

Hidden in a cave: First ever portrait of Jesus found in 1 of 70 ancient books?

Nick Pryer – The image is eerily familiar: a bearded young man with flowing curly hair. After lying for nearly 2,000 years hidden in a cave in the Holy Land, the fine detail is difficult to determine. But in a certain light it is not difficult to interpret the marks around the figure’s brow as a crown of thorns.
The extraordinary picture of one of the recently discovered hoard of up to 70 lead codices – booklets – found in a cave in the hills overlooking the Sea of Galilee is one reason Bible historians are clamouring to get their hands on the ancient artefacts.

If genuine, this could be the first-ever portrait of Jesus Christ, possibly even created in the lifetime of those who knew him. ..

via Hidden in a cave: First ever portrait of Jesus found in 1 of 70 ancient books? | Mail Online.

The reason this image is “eerily familiar” is because it looks like one of the Pirates of the Caribbean.

Crown of thorns? I think you are imagining things there, but how about those three horns coming out of his head? Hard to miss those. And what about that pointy elf ear?

I’ll be interested to hear what the translation says is written under the face if this continues to play out as a real artifact.

It looks to me like this grinning person has a short triangular nose.

Ancient Greek Computer Had Surprising Sun Tracker

The world’s oldest astronomical calculator is famous for having intricate gear systems centuries ahead of their time. But new work shows the Antikythera mechanism used pure geometry, as well as flashy gears to track celestial bodies’ motion through the heavens.

The device, a 2,000-year-old assemblage of gears and wheels that matched 19th century clocks in precision and complexity, was salvaged from a shipwreck off the Greek island of Antikythera in 1901.

Called the Antikythera mechanism, the machine gracefully kept track of the day of the year, the positions of the sun and the moon, and perhaps the other planets. It also predicted eclipses and kept track of upcoming Olympic games.

Most of the mechanism’s calculations were driven by a series of 37 interlocking dials, which may have been manipulated by a hand crank. The front of the mechanism had a clock-like face that denoted the calendar date in two concentric circles, one showing the signs of the Greek zodiac, and one carrying the Egyptian months of the year.

Three hands denoting the date and the position of the sun and the moon moved through the zodiac and the months as the gears turned.

“It’s a pretty elaborate piece of machinery,” said science historian James Evans of the University of Puget Sound in a presentation at the University of Washington in Seattle on March 31. “Nobody would ever have guessed that there could be something this complex in the second century [BC].”

Earlier research showed the device also accounted for a subtle weirdness in the motion of the moon. Because the moon’s orbit around the Earth is an ellipse, not a perfect circle, the moon seems to speed up and slow down over the course of a month. In 2006, Tony Freeth of Cardiff University and colleagues showed that a clever configuration of two overlapping gears, with the top gear laid off-center from the bottom gear, could give the moon’s marker its irregular speed.

Because of the Earth’s elliptical orbit around the sun, the sun makes a similarly variable trip across the sky, speeding up and slowing down over the course of the year. But the effect is much more subtle than for the moon.

“It’d be very hard with gears to mimic an effect so small,” Evans said. Also, if there were any extra gears related to the sun’s movement in the original mechanism, none emerged from the shipwreck.

Evans and colleagues suggested a simpler way to make the sun dial appear to change speed: Stretch the zodiac. If the spaces on the front wheel of the mechanism were of different widths, Evans reasoned, then the hand representing the sun would take longer to travel through the part of the year lumped under the zodiac sign of Taurus than through Libra.

The delay would make the sun look like it was moving slower at some times of year and faster at others, even though the gears turning the hand moved at a constant speed.

To check this idea, the researchers examined X-ray images of the Antikythera mechanism, parts of which were badly corroded. In a paper last year in the Journal for the History of Astronomy (which Evans co-edits), the team analyzed 69 degrees of the circle that was preserved well enough for the zodiac names and markings to be read. Since then, the team has extended the study to 88 degrees of the circle.

They found that the two circles representing the zodiac and the Egyptian calendar were divided differently, and in just the right way to account for the sun’s irregular speed. …

via Ancient Greek Computer Had Surprising Sun Tracker | Wired Science | Wired.com.

Mangroves excel at storing carbon

Tropical mangrove trees are better at storing carbon dioxide than most other forests, and cutting them down unleashes more greenhouse gas than deforestation elsewhere, say scientists.

Mangroves are so efficient at keeping carbon dioxide out of the atmosphere that when they are destroyed, they release as much as 10 per cent of all emissions worldwide attributable to deforestation – even though mangroves account for just 0.7 per cent of the tropical forest area, says researchers.

Daniel Donato, of the US Agriculture Department’s Forest Service and lead author of a study published in the journal Nature Geoscience, says mangroves store two to four times the carbon that tropical rainforests do.

“Mangroves store a lot of carbon, much more so than most forests on Earth, on a per hectare basis,” says Donato. “Since they store so much carbon, there’s probably a lot being released from all the mangrove deforestation that’s going on.”

Mangroves live where many people want to live, along ocean coastlines in the tropics, and their areal extent – the amount of land they grow on – has declined by 30 per cent to 50 per cent over the last 50 years, the study found.

Coastal development, aquaculture and over-harvesting have all contributed to mangrove deforestation. Rising sea levels expected this century are also a threat, the study says.

Besides storing carbon, mangrove forests act as fisheries, keep sediment in place, produce fibre and protect inhabited areas against storms and tsunamis, the researchers say.

Coastal mangrove forests and the ecological services they provide could be gone in as little as 100 years, according to the researchers.

Part of the reason for mangroves’ efficiency in keeping carbon locked away lies in their location in tidal zones, where their roots are often covered with sea water.

They need complex root systems to keep them breathing even when the tides come in, says Donato. This same complexity traps sediment that comes in from rivers and it builds up. …

via Mangroves excel at storing carbon › News in Science (ABC Science).

Mysteries, military bases & monks: RT goes deeper underground

YouTube – Mysteries, military bases & monks: RT goes deeper underground.