Diamonds Unlikely In Gas Giants Like Uranus

Daily Science Journal (Jul. 16, 2007) — A new study finds that diamonds probably don't crystallize in the atmospheres of planets such as Uranus and Neptune. The conclusion is contrary to recent speculation that small diamonds would spontaneously form in carbon rich layers of the gas giant planets. White dwarf stars, according to the study, are veritable diamond factories.

A simulated snapshot of crystallizing carbon atoms under Uranus-like conditions. (Credit: L. M. Ghiringhelli, C. Valeriani, E. J. Meijer and D. Frenkel, Physical Review Letters)

Physicists at the Universtiet van Amsterdam and the FOM Institute for Atomic and Molecular Physics in the Netherlands performed a numerical analysis showing that at the temperatures and pressures in gas giant planets like Uranus, arrangements of carbon atoms would be much more suitable for creating tiny bits of graphite rather than diamond.

In white dwarfs, on the other hand, the simulation shows that the conditions would cause the carbon atoms to line up in configurations that are much more amenable for diamond crystallization. The conclusion is consistent with the 2004 discovery of a cooling white dwarf star that appears to have a solid diamond core 4000 kilometers across.

Although diamond formation in the atmospheres of gas giants is not strictly impossible, the Dutch physicists say that the odds are exceedingly slim that a diamond could have formed under the conditions that exist in Uranus in the entire lifetime of the universe.

Adapted from materials provided by American Physical Society, via EurekAlert!, a service of AAAS.

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Urine Test Predicts Alzheimer's Disease

Daily Science Journal (Jul. 14, 2007) — (Philadelphia, PA) – A urine sample taken at the doctor's office can be the step in determining your chances of developing Alzheimer's disease (AD), according to researchers at the University of Pennsylvania School of Medicine. They have determined that a urine test can reliably detect free radical damage associated with people with Mild Cognitive Impairment (MCI) – a recognized precursor to AD. The test detects isoprostanes, fatty acids that are formed as the result of free radical damage in the brain – damage that correlates with clinical diagnosis of AD.

"This is the first noninvasive test that can predict a clinical diagnosis of Alzheimer's disease," said Domenico Praticò, MD, assistant professor in Penn's Department of Pharmacology. "Since there is no cure for Alzheimer's disease, physicians could slow the course of the disease if it is caught early enough."

Within four years of initial diagnosis, up to 50% of people with MCI develop Alzheimer's disease. As AD progresses, it attacks the brain and causes severe damage in the areas important for memory, judgement, and language. This destruction leads to other clinical complications and, eventually, death.

In the study, published in the June edition of Archives of Neurology, Praticò and his colleagues measured isoprostane in blood and urine samples obtained from 50 patients with a clinical diagnosis of AD, 33 patients with MCI, and 40 healthy volunteers. Two weeks later, a CSF sample and a second urine sample were taken from 28 of the AD patients, 17 of the MCI patients, and 18 of the control subjects. The researchers found significantly higher levels of isoprostane in CSF, blood, and urine of MCI and AD subjects than in the volunteers. Remarkably, the samples taken from the MCI subjects and the volunteers differed only in respect to their isoprostane levels.

"We found that patients with MCI have increased brain oxidative damage before the onset of AD – damage that can be detected in the form of isoprostanes in urine, as this study shows," said Praticò. "In fact, five MCI subjects, all with high isoprostane levels, converted to AD during follow-up."

Patients that are diagnosed with Mild Cognitive Impairment typically present their physicians with persistent memory loss that is not normal for someone of their age and education. Although their memory is impaired, MCI patients are capable of living largely independent lives. At this stage, it is difficult to determine whether a person with MCI will eventually have Alzheimer's or whether they will progress to a form of unrelated dementia.

A urine sample taken in the doctor's office may be a first point of decision in gauging the risk of developing AD. Further tests could then determine the severity of a patient's condition and course of treatment. For example, studies have shown that the transition from MCI to AD occurs fastest in people who have a gene called apoE4 and whose brain's hippocampus region is shown to be smaller as measured in an MRI scan.

"One hypothesis is that, in AD, healthy brain tissue is damaged by the local formation of large amounts of free radicals," said Praticò. "Isoprostanes are the byproducts of fats in the human body that were warped by free radical attack. They then accumulate in CSF, blood, and urine as the body works to get rid of them."

While at the moment this test is not yet clinically available, the team is working on the development of a version of it that could be broadly and easily performed.

Unlike a spinal tap, a urine test is simple to do and provides a painless and noninvasive way of assessing the situation. "The advantages are clear: with an easier test, doctors can diagnose the disease sooner and respond better to the patient's needs," said Praticò.

This research was supported by grants from the National Institutes of Health and the American Heart Association. Trial participants were selected at the Memory Disorders Clinic of Penn's Alzheimer's Disease Center.

Adapted from materials provided by University Of Pennsylvania Medical Center.

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Distress-prone People More Likely To Develop Memory Problems

Daily Science Journal (Jul. 12, 2007) — People who are easily distressed and have more negative emotions are more likely to develop memory problems than more easygoing people, according to a new study.

In the study, those who most often experience negative emotions such as depression and anxiety were 40 percent more likely to develop mild cognitive impairment than those who were least prone to negative emotions. Mild cognitive impairment is a transitional stage between normal aging and dementia. People with mild cognitive impairment have mild memory or cognitive problems, but have no significant disability.

Researchers analyzed the results from two larger studies, the Religious Orders Study and the Memory and Aging Project, which involved 1,256 people with no cognitive impairment. During up to 12 years of follow-up, 482 people developed mild cognitive impairment. Participants were evaluated on their level of proneness to distress and negative emotions by rating their level of agreement with statements such as "I am not a worrier," "I often feel tense and jittery," and "I often get angry at the way people treat me."

"People differ in how they tend to experience and deal with negative emotions and psychological distress, and the way people respond tends to stay the same throughout their adult lives," said study author Robert S. Wilson, PhD, of Rush University Medical Center in Chicago, IL. "These findings suggest that, over a lifetime, chronic experience of stress affects the area of the brain that governs stress response. Unfortunately, that part of the brain also regulates memory."

An earlier study by Wilson and his colleagues showed that people who are easily distressed are more likely to develop Alzheimer's disease than more easygoing people.

Wilson said several factors lead researchers to believe that proneness to stress is a risk factor for memory problems and not an early sign of disease. For example, while the level of distress does not appear to increase in old age, the changes in the brain related to memory problems and Alzheimer's disease do increase with age.

This research was published in the June 12, 2007, issue of Neurology®, the scientific journal of the American Academy of Neurology. The study was supported by grants from the National Institute on Aging and the Illinois Department of Public Health.

Adapted from materials provided by American Academy of Neurology.

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Cosmetic Surgery Techniques Can Enhance Thyroid Surgery Results

Daily Science Journal (Jul. 11, 2007) — Cosmetic surgery techniques, such as having a patient sit or stand while incision sites are marked so they blend into natural lines of the body, can improve the aesthetic result of thyroid surgery as well, researchers say.

Dr. David Terris, a pioneer in minimally invasive techniques that have dramatically reduced the size of the hallmark base-of-the-neck incisions. (Credit: Image courtesy of Medical College of Georgia)

"We have found that while keeping the management of the underlying thyroid problem as the first priority, we can still achieve a maximal cosmetic result," says Dr. David Terris, a pioneer in minimally invasive techniques that have dramatically reduced the size of the hallmark base-of-the-neck incisions.

Dr. Terris, who chairs the Medical College of Georgia Department of Otolaryngology-Head and Neck Surgery, wanted to know if cosmetic surgery principles he learned in the facial plastic surgery part of his training could further improve results.

He did a prospective analysis of 248 patients who required varying approaches to thyroid surgery, from a standard, several-inch-long neck incision to remove huge thyroids to minimally invasive techniques that cut the incision size in half to endoscopic approaches that reduce incision size half again. Patients were operated on at MCG Medical Center between September 2003 and June 2006.

Most thyroid patients requiring surgery are women – 198 women compared to 50 men in this new study published in the July issue of The Laryngoscope – and many are concerned with the cosmetic result, says Dr. Terris. "It matters to them how big the scar is, if it's even, if it's hidden in a skin crease, if the edges are nicely aligned."

All patients sat up to have their incision sites marked. "You want the incision to be in a location that corresponds to a cosmetically favorable area when you are upright at a dinner party, not stretched out on an operating room table," says Dr. Terris.

Other techniques applied included:

• Trimming traumatized edges at the incision sites. "Especially with the minimal-access techniques, the idea is to customize the incision to the size of the disease rather than one size fits all, which is how thyroid surgery was done just five or six years ago, with a big incision for everybody," says Dr. Terris. "Sometimes we still make big incisions, but more often, we make a smaller incision just big enough to get the thyroid out." Skin edges sometimes get frayed as surgeons remove large nodules from relatively small incisions. "Rather than make a bigger incision, we excise that edge so you have nice, fresh dges that come together quite well."
• Using surgical glues instead of sutures. "You can line up edges and get them accurately apposed without any risk of railroad-tracking using the glue," he says, referencing tracks left by traditional sutures or staples. "It's also convenient for patients because they don't have to come back on a certain date to get the stitches removed; they just peel it off."
• Minimizing trauma to surrounding skin. "The conventional way to get to the thyroid gland is to raise up the skin to the hyoid bone above the Adam's apple and down to the clavicles, then start working on the muscles in the throat that surround the thyroid gland, separate those, then get down to the gland." But all that raising of tissue, called flaps, means hoping it will lie back down as it's supposed to. "What we recognized is that you don't need to raise those flaps all the way up and all the way down. We make our incision, we go right down to the muscles, separate them, do the work we need to do, then close them. It saves time during surgery, it saves dissection and we are not creating a big space that we hope sticks back down."
• Minimizing use of drains. Drains to manage post-surgery oozing have been used pretty much since thyroid surgery was invented. "It used to be common, rather than removing the entire thyroid, to leave a little rind, if you will, of the thyroid behind," says Dr. Terris. The hope was the remaining tissue might reduce or even eliminate the need for thyroid medicine afterward. The reality is the patients ended up on medicine and the rind often caused oozing and sometimes recurrent disease. Now doctors take out the whole thyroid or all of one side, depending on the extent of the disease. Also today, minimally invasive techniques and other surgical improvements such as the thin, ultrasonic harmonic scalpel, have reduced overall surgical trauma. In the study, only 111 of the 248 patients got drains, 60 of whom had conventional thyroidectomy.

Researchers reported that only one of the 248 patients required additional treatment for their surgery scar; she received steroid injections for hypertrophic scarring.

"Although there continues to be enthusiasm for the use of these smaller incisions to accomplish thyroid surgery, it is likely that the application of well-known cosmetic principles is equally important to achieving optimal outcomes," Dr. Terris and his co-authors write.

Adapted from materials provided by Medical College of Georgia.

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Stellar Tiramisu: Astronomers Find Hints of Distant Planetary Pollution

Daily Science Journal (Jul. 10, 2007) — Looking at the chemical composition of stars that host planets, astronomers have found that while dwarf stars often show iron enrichment on their surface, giant stars do not. The astronomers think that the planetary debris falling onto the outer layer of the star produces a detectable effect in a dwarf star, but this pollution is diluted by the giant star and mixed into its interior.

Artist's impression of the structure of a solar-like star and a red giant. The two images are not to scale - the scale is given in the lower right corner. (Credit: Copyright ESO)

"It is a little bit like a Tiramisu or a Capuccino," says Luca Pasquini from ESO, lead-author of the paper reporting the results. "There is cocoa powder only on the top!'

Just a few years after the discovery of the first exoplanet it became evident that planets are preferentially found around stars that are enriched in iron. Planet-hosting stars are on average almost twice as rich in metals than their counterparts with no planetary system.

The immediate question is whether this richness in metals enhances planet formation, or whether it is caused by the presence of planets. The classic chicken and egg problem. In the first case, the stars would be metal-rich down to their centre. In the second case, debris from the planetary system would have polluted the star and only the external layers would be affected by this pollution.

When observing stars and taking spectra, astronomers indeed only see the outer layers and can't make sure the whole star has the same composition. When planetary debris fall onto a star, the material will stay in the outer parts, polluting it and leaving traces in the spectra taken.

A team of astronomers has decided to tackle this question by looking at a different kind of stars: red giants. These are stars that, as will the Sun in several billion years, have exhausted the hydrogen in their core. As a result, they have puffed up, becoming much larger and cooler.

Looking at the distribution of metals in fourteen planet-hosting giants, the astronomers found that their distribution was rather different from normal planet-hosting stars.

"We find that evolved stars are not enriched in metals, even when hosting planets," says Pasquini. "Thus, the anomalies found in planet-hosting stars seem to disappear when they get older and puff up!"

Looking at the various options, the astronomers conclude that the most likely explanation lies in the difference in the structure between red giants and solar-like stars: the size of the convective zone, the region where all the gas is completely mixed. In the Sun, this convective zone comprises only 2% of the star's mass. But in red giants, the convective zone is huge, encompassing 35 times more mass. The polluting material would thus be 35 times more diluted in a red giant than in a solar-like star.

"Although the interpretation of the data is not straightforward, the simplest explanation is that solar-like stars appear metal-rich because of the pollution of their atmospheres," says co-author Artie Hatzes, Director of the Thüringer Landessternwarte Tautenburg (Germany) where some of the data were obtained.

When the star was still surrounded by a proto-planetary disc, material enriched in more heavy elements would fall onto the star, thereby polluting its surface. The metal excess produced by this pollution, while visible in the thin atmospheres of solar-like stars, is completely diluted in the extended, massive atmospheres of the giants.

"Evolved stars hint to an external origin of enhanced metallicity in planet-hosting stars", by L. Pasquini et al. To appear in Astronomy and Astrophysics.

The team is composed of L. Pasquini and M.P. Döllinger (ESO), A. Weiss (Max-Planck-Institut für Astrophysik, Garching, Germany), L. Girardi (INAF-Osservatorio Astronomico di Padova, Italy), C. Chavero (Instituto de Astrofisica de Canarias, Tenerife, Spain, and Observatorio Nacional/MCT, Rio de Janeiro, Brasil), A. P. Hatzes (Thüringer Landessternwarte Tautenburg, Germany), L. da Silva (Observatorio Nacional/MCT, Rio de Janeiro, Brasil), and J. Setiawan (Max Planck Institute für Astronomie, Heidelberg, Germany).

The data have been partially collected at ESO, and partially at the 2-m telescope of the Thüringer Landessternwarte Tautenburg (TLS).

Adapted from materials provided by European Southern Observatory.

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Vitamin D And Flavonoids Examined For Impact On Breast And Ovarian Cancers

Daily Science Journal (Jul. 7, 2007) — While risk factors for breast and ovarian cancers include menopause, obesity, family history and specific genetic mutations, researchers also are looking at the role of diet in the development, as well as the treatment and prevention of these tumors. At the 97th Annual Meeting of the American Association for Cancer Research, two groups of scientists using sophisticated statistical techniques report their findings of possible preventive properties of Vitamin D against breast cancer. Two other groups of scientists present their work analyzing the possibility that natural antioxidants found in plants, substances called flavonoids, could play a powerful role in preventing both breast and ovarian cancer.

Potential Reduction in Breast Cancer Risk Associated with Vitamin D: Abstract No. 4009

Though scientists have suspected that Vitamin D helps to prevent and possibly even treat breast cancer, population-based studies on the possible link have been few and of limited scope.

Now, new studies by researchers at the Samuel Lunenfeld Research Institute at Mount Sinai Hospital in Toronto suggest the "sunshine" vitamin may play a significant role in reducing breast cancer risk. The results, based on population data, found the reduction was most apparent among subjects exposed to the highest levels of vitamin D when they were young.

By interviewing about 576 patients who had been diagnosed with breast cancer and 1,135 people who had no cancer, the scientists discovered that significant reductions in breast cancer were found in those who had either worked in an outdoor job, had taken part in outdoor activities when young, or consumed cod liver oil or milk.

Working an outdoor job between ages 10 to19 resulted in an estimated 40 percent reduced risk of breast cancer, while frequent outdoor activities between ages 10 to 29 lowered breast cancer risk by an estimated 35 percent.

"These outdoor activities included those that didn't involve physical activity," said Julie Knight, who headed the Mount Sinai research team. "And so we believe that this is evidence of a reduction of breast cancer risk, associated with earlier exposure to the sun."

For dietary influences on cancer development, taking cod liver oil between ages 10 to 19 reduced breast cancer risk by about 25 percent, and consuming at least nine glasses of milk every week between the ages of 10 to 29 reduced the risk by 35 percent. The dietary and lifestyle reductions were significant, even when adjusted for other risk factors for breast cancer such as age, ethnicity, close relatives with breast cancer, age at menarche and age at a woman's first birth.

"What you are exposed to during breast development may be particularly important in determining future breast cancer risk," Knight said. "Current thinking is that exposures during adolescence or before a full-term pregnancy may have a greater effect, as that is when breast tissue is going through the most rapid development."

Knight emphasizes that these findings are preliminary estimates of the risk reduction of breast cancer brought about by Vitamin D. The researchers are now looking to solidify these findings, and determine whether physical exercise while outdoors is in any way associated with breast cancer.

Evidence of Need for Increased Vitamin D Fortification of Food Based on Pooled Analysis of Studies of Serum 25-hydroxyvitamin D and Breast cancer: Abstract No. 4008

Increasing doses of dietary Vitamin D may help prevent breast cancer, with the optimal level of intake of Vitamin D more that three times the current average for Americans, according to a study conducted at the University of California, San Diego.

Previous studies have suggested a link between Vitamin D deficiency and higher incidence of breast cancer. Cedric Garland, Dr. P.H., and Edward Gorham, Ph.D., of UCSD, and their colleagues examined existing cancer studies to determine if higher Vitamin D levels in the blood could reduce the risk of cancer.

"There is a strong inverse dose-response relationship between the serum concentration of 25-hydroxyvitamin D and the risk of breast cancer," Garland said. "It's a close fit to a linear model," meaning that higher amounts of 25-hydroxyvitamin D in the serum resulted in decreased risk of breast cancer. The evidence further pointed to a level of Vitamin D measured in blood that correlated with a 50 percent reduction in the incidence of breast cancer.

Garland, Gorham and their colleagues studied a serum Vitamin D metabolite known as 25 hydroxyvitamin D and its association with breast cancer occurrence in a pooled study that included 1,760 women. The studies that provided the data for the pooled analysis were conducted by Elizabeth R. Bertone-Johnson and colleagues at Harvard, and L.C. Lowe and associates at Saint George's Hospital Medical School in London.

According to the pooled analysis, Vitamin D in blood serum equal to 52 nanograms per milliliter was associated with a 50 percent reduced risk of breast cancer. To move closer to a serum concentration of 52 nanograms/milliliter, a typical individual would have to consume no less than 1,000 International Units (IU) of Vitamin D every day, through supplements or vitamin D-fortified foods. Currently, a typical American consumes only 320 International Units of Vitamin D a day. The upper limit for vitamin D intake established by the National Academy of Sciences is 2,400 IU/day, but no toxic effects of vitamin D intake have been reported for intakes below 3,800 IU per day.

"There is no substantial downside to a serum level of 52 nanograms per milliliter of Vitamin D," said Gorham. "Such levels are common in sunny climates. There is no known adverse effect of serum levels below 160 nanograms per milliliter."

However, since many people use sunscreens and are involved in indoor occupations or shift work, dietary supplements and vitamin D fortified foods are necessary to maintain optimal levels of Vitamin D, the scientists noted.

High intakes of calcium, which could occur with intake of Vitamin D supplements containing calcium, could increase the risk of kidney stones, they warn. However, the dosage level of vitamin D associated with kidney stones in patients far exceeded 3,800 IU/day. Until more studies are completed, the scientists recommended that everyone consume at least 1,000 IU/day of vitamin D3.

Dietary Flavonoid Intake and Breast Cancer Risk among Women in the Long Island Breast Cancer Study Project: Abstract No. 4014

Flavonoids, a class of antioxidants found in plants, is associated with a reduced risk of breast cancer among post-menopausal women, according to results of the Long Island breast cancer study project. The results are one of the first epidemiologic studies to suggest that these compounds could have a chemoprotective effect among women.

Brian Fink, Susan Steck and Marilie Gammon of the University of North Carolina, Chapel Hill, and other colleagues studied data from a large study of breast cancer incidence and risk factors conducted among women living during the mid-1990s on Long Island, N.Y.

Breast cancer risk was reduced for the highest percentages of total flavonoid intake, compared to the lowest intake of the plant antioxidants. The decreased risk was about 45 percent among post-menopausal women. Risk decreases were not seen in pre-menopausal women. Specific flavonoids -- including flavones, flavan-3-ols and lignans -- were associated with reduced cancer risks ranging from 26 to 39 percent; other flavonoids, such as flavanones, isoflavones and anthocyanidins, showed no relationship with reduced cancer risk.

"These results are consistent with other studies conducted among Mediterranean women," said Fink. "Few epidemiologic studies have examined whether there is a relationship between breast cancer and dietary flavonoids. Our study proposes that dietary flavonoids can help American post-menopausal women reduce their risk of breast cancer."

The researchers examined data from the Long Island study, which was conducted by Dr. Gammon and colleagues between August 1996 and July 1997. The team compared data from 1,434 women with breast cancer to data from 1,440 women who were not diagnosed with the disease.

Flavonols, flavones, lignans and anthocyanidins are all flavonoids, molecules that give plants protection from oxidative damage due to disease and environmental stresses. Flavonoids are classified according to chemical structure, and have been studied for their varying degrees of effectiveness against human diseases, both in treatment and prevention. They are found in green tea, red wine, soybeans, fruit and vegetables.

"There are no recommended dietary standards for ingestion of flavonoids, and we do not know exactly how these chemicals may work on a cellular level," said Fink, whose work was supported with funding from the National Institutes of Health and the Lance Armstrong Foundation. "Minute differences in chemical structure could determine how a certain natural antioxidant may work to prevent disease, including cancer. More study is needed to determine why certain flavonoids appear to be effective at reducing cancer risk, and others do not appear to have these properties."

A Prospective Analysis of Dietary Flavonoid Intake and Epithelial Ovarian Cancer Incidence: Abstract No. 4013

The incidence of ovarian cancer may be reduced with increased consumption of dietary flavonoids, plant chemicals that are found in tea, red wine, fruits and vegetables, according to researchers from Brigham and Women's Hospital and the Harvard School of Public Health.

The study, conducted by Margaret Gates, a doctoral candidate at the Harvard School of Public Health, looked at food intake surveys and ovarian cancer data from 66,384 participants in the Harvard Nurses' Health Study, which collected health data from 121,700 women over a period of 30 years. "This is the first prospective analysis of flavonoid intake and ovarian cancer incidence," Gates said.

Gates studied the association between flavonoid intake from food frequency questionnaires completed by the women in 1984, 1990, 1994 and 1998; and 344 confirmed cases of ovarian cancer diagnosed between 1984 and 2002. While there was a significant trend toward decreasing incidence of ovarian cancer with increasing total flavonoid intake, Gates warned that "because this is one of the first studies of the topic, this association needs to be evaluated in another prospective study population before conclusions can be made."

Gates also analyzed individual flavonoids to evaluate their impact on ovarian cancer incidence. The flavonoid kaempferol, which the nurses consumed primarily from caffeinated tea, broccoli and kale, was associated with decreased ovarian cancer risk. Women with the highest levels of kaempferol intake had a significant 38 percent decrease in ovarian cancer incidence, compared to women with the lowest levels of intake. Two other flavonoids, myricetin and quercetin, showed a possible inverse association with ovarian cancer risk, although the results were largely non-significant.

"The associations were stronger when exposure was defined as cumulative average flavonoid intake over a period of 14 years, which suggests that long-term intake of flavonoids may be important," Gates said.

But she cautioned that "these findings need to be confirmed by others before any public health recommendations can be made. However, if confirmed, consumption of flavonoids would provide another means for women to decrease their risk of ovarian cancer."

Adapted from materials provided by American Association for Cancer Research.

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The Elderberry Way To Perfect Skin

Daily Science Journal (Jul. 6, 2007) — Forget expensive moisturisers and cosmetic surgery, a compound found in the humble elderberry could give a natural boost to skin.

In the first study of its kind, researchers will explore whether the skin's condition is improved by a compound which gives berries their vibrant colour (called 'anthocyanin'). (Credit: iStockphoto)

In the first study of its kind, a team of researchers led by Prof Aedin Cassidy at the University of East Anglia and Dr Paul Kroon at the Institute of Food Research, will explore whether the skin's condition is improved by a compound which gives berries their vibrant colour (called 'anthocyanin').

In a 12-week trial starting in September, post-menopausal women will consume either extracts from elderberries or placebo capsules, and will have their skin's structure and appearance measured with state-of-the-art equipment used by experts in skin science. At the same time, researchers will also test whether the elderberry extract can reduce risk factors for heart disease.

"We already know that a healthy diet can help protect against heart disease and skin damage, and that a mixture of similar food components have been shown to improve the skin's structure. There is also evidence that the active components have anti-inflammatory properties, which may be important in helping people stay healthy," said UEA's Dr Peter Curtis who is leading the project.

"If the results of our study are positive, it may lead to innovations in skin health products and may also give us vital information about diets which promote healthier hearts."

Adapted from materials provided by University of East Anglia.

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Difficulty Identifying Odors May Predict Cognitive Decline

Daily Science Journal (Jul. 4, 2007) — Older adults who have difficulty identifying common odors may have a greater risk of developing problems with thinking, learning and memory, according to a report in the July issue of Archives of General Psychiatry, one of the JAMA/Archives journals.

Mild cognitive impairment--or a decline in thinking, learning and memory abilities--is increasingly recognized as a precursor to Alzheimer's disease, according to background information in the article. Impairments in the ability to recognize odors have been associated with more rapid cognitive decline and also with the development transition from mild cognitive impairment to Alzheimer's disease. However, little is known about factors that predict the development of mild cognitive impairment.

Robert S. Wilson, Ph.D., of Rush University Medical Center, Chicago, and colleagues studied 589 older adults (average age 79.9) who did not have cognitive impairment in 1997. At that time, the participants took a smell identification test, during which time 12 familiar odors were placed under their nose. They were asked to match each odor to one of four possible alternatives, and were scored from one to 12 based on the number of correct responses. At the beginning of the study and again every year for up to five years, the participants underwent a clinical evaluation that included a medical history, neurological examination and testing of their cognitive function.

During the study, 177 individuals (30.1 percent) developed mild cognitive impairment. Risk of developing mild cognitive impairment increased as odor identification decreased, so that those who scored below average (eight) on the odor identification test were 50 percent more likely to develop the condition than those who scored above average (11). This association did not change when stroke, smoking habits or other factors that might influence smell or cognitive ability were considered. Impaired odor identification was also associated with lower cognitive scores at the beginning of the study and with a more rapid decline in episodic memory (memory of past experiences), semantic memory (memory of words and symbols) and perceptual speed.

"The neurobiological bases of age-associated olfactory dysfunction are uncertain," the authors write. Evidence suggests that even before the symptoms of Alzheimer's disease develop, hallmark tangles develop in certain areas of the brain that may be associated with the processing of smells. Because difficulty identifying odors is associated with other neurological diseases, including Parkinson's disease, other mechanisms are likely involved. "Further clinicopathological and clinicoradiological research on age-related olfactory dysfunction is needed," they continue.

"Among older persons without manifest cognitive impairment, difficulty in identifying odors predicts subsequent development of mild cognitive impairment," the authors conclude. "The findings suggest that olfactory dysfunction can be an early manifestation of Alzheimer's disease ... and that olfactory assessment may be useful for early disease identification."

Adapted from materials provided by JAMA and Archives Journals, via EurekAlert!, a service of AAAS.

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Pioneering 3D View Of Near-Earth Magnetic 'Dance'

Daily Science Journal (Jul. 1, 2007) — Scientists have obtained the first-ever 3D picture of interconnected magnetic ‘dances’ in near-Earth space, known as magnetic reconnection events.

A diagram illustrating the null-null line observed by Cluster's four spacecraft in the Earth's magnetotail on 1 October 2001. (Credit: Inset: Chinese Academy of Sciences (C. Xiao), background: NASA)

The data from ESA’s Cluster satellites will help to understand better magnetic reconnection, a process related to star formation, solar explosions and the entry of solar wind energy into the near-Earth environment.

Magnetic reconnection is the process whereby magnetic field lines from different magnetic domains collide and reconnect, mixing previously separated plasma. Plasma is a gas composed of ions and electrons but is electrically neutral, spread over large distances in space and guided by the action of magnetic and electric fields.

Magnetic reconnection converts the energy of the magnetic field into particle energy, generating jets and heating the plasma.

This affects us here on Earth because it can possibly affect telecom satellites and prevent the efficient production of electricity in controlled fusion reactors, potential sources of electricity for the future. On Earth, we can also see the effect in more intense displays of the Northern lights.

On 1 October 2001, the four Cluster spacecraft were flying in formation at approximately 110 000 km from Earth in the magnetotail, a long-tail-like structure on the night-side of Earth’s magnetic field. The satellites meandered around a reconnection region over a period of nearly 15 minutes.

During reconnection, the geometry of the magnetic field forms an X-shape, also called a ‘magnetic null’. Analysed in 2D, the magnetic field, plasma density and flow velocity data collected during this event showed that only one reconnection region with an X-shape, or a magnetic null, was seen by the satellites.

An international team of scientists led by Chinese researchers challenged this result, suggesting that it could be seen in 3D.

The researchers tested theoretical results published 20 years ago, which predicted that any small perturbation to such a reconnection site would produce not one, but two magnetically linked reconnection sites, a pair of magnetic nulls and magnetically linked reconnection geometry.

By analysing a subset of the same data in 3D with a higher temporal resolution, they found what they were looking for. Two magnetic reconnection sites jumped out, along with the null-null line which connects two magnetic nulls, a previously unobserved phenomenon.

The situation can be compared to viewing a cross section of a 3D volume in space. It is not possible, when looking into only one plane, to tell whether or not something is going on in another plane, in the same volume of space.

Only when seen in 3D, with Cluster’s multi-satellite viewpoints, could scientists determine that there actually were two, interlinked events occurring simultaneously.

When reduced to two dimensions, this complex 3D magnetic geometry is still consistent with past results obtained under the 2D assumption where the null-null line is seen as one X-point. It is also in agreement with past results found in the laboratory and by Cluster in space.

"For the first time, the link between two sites of magnetic reconnection has been observed in-situ, in 3-D. This result is another major scientific achievement of Cluster obtained owing to fruitful scientific collaborations between Chinese, American and European scientists", said Philippe Escoubet, Cluster and Double Star project scientist of the European Space Agency.

Notes for editors:

The article “Satellite Observations of Separator Line Geometry of Three-Dimensional Magnetic Reconnection” by C. Xiao, X. Wang, Z. Pu, Z. Ma, H. Zhao, G. Zhou, J. Wang, M. Kivelson, S. Fu, Z. Liu, Q. Zong, M. Dunlop, K-H. Glassmeier, E. Lucek, H. Rème, I. Dandouras, C. Escoubet appeared on 24 June 2007 in the advance online publication of Nature Physics.

Adapted from materials provided by European Space Agency.

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Researchers Explain Carbon Monoxide's Anti-inflammatory Effects

Daily Science Journal (Jul. 1, 2007) — In a study appearing in the April 2007 issue of The FASEB Journal, scientists from Harvard University and the University of Pittsburgh have shown for the first time that the anti-inflammatory effects of carbon monoxide originate within cells' own molecular engines, mitochondria.

Specifically, mitochondria react to low levels of carbon monoxide by releasing chemical signals that reduce or shut down the body's inflammatory response, raising the possibility for the development of new anti-inflammatory therapies, one of which may be low levels of inhaled carbon monoxide.

According to the study's first author, Brian S. Zuckerbraun, M.D. of the University of Pittsburgh, "this study may contribute to our understanding and development of controlled carbon monoxide as a therapeutic agent."

Inflammation is a normal defense mechanism used by the body to ward off infection, but over time, severe or chronic inflammation can damage tissues. In some cases, such as in organ transplantation, the body's inflammatory response over the short-term also can cause more harm than good. Current approaches to controlling inflammation are not always successful, making the need for new approaches urgent. In particular, inhaled medical grade carbon monoxide has been shown to be useful in animal models for organ transplantation, vascular injury, inflammatory bowel disease, organ injury resulting from severe blood loss, as well as experimental hepatitis and experimental pulmonary hypertension.

"The findings described in this study are particularly relevant, given that April is National Donate Life Month," said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. "Transplants are rejected because of inflammation gone awry. If we block inflammation, as with carbon monoxide or agents that release it in a controlled fashion, we can not only make transplantation safer, but extend its benefits to many more who need it."

Adapted from materials provided by Federation of American Societies for Experimental Biology, via EurekAlert!, a service of AAAS.

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