Medical College of Georgia : Blood pressure response to daily stress provides clues for better hypertension treatment

How the body regulates blood pressure in response to daily stress is the focus of a study geared toward helping people whose pressure is out of control.

“Research shows that two-thirds of patients’ high blood pressure is not controlled despite the best efforts of their doctors. That is terrible,” says Dr. Gregory Harshfield, director of the Georgia Prevention Institute at the Medical College of Georgia.

“We are trying to identify the mechanisms through which blood pressure is regulated under normal everyday conditions – which is what stress is – and take that information back to the clinic to better determine what sort of therapy is going to be most effective at treating your blood pressure or your grandfather’s.”

More than a dozen researchers have teamed up to do parallel studies in animal models and young adults to learn more about what factors like genes, stress and obesity contribute, their synergy and novel ways to control them.

“This research will give us information that allows us to identify what treatment is going to be effective in what individual by genotype, by obesity and other factors. What kind of treatment is going to be effective at keeping an individual’s blood pressure down or maybe preventing it from ever getting high,” says Dr. Harshfield, principal investigator on the $10.6 million Program Project grant renewal from the National Institutes of Health’s National Heart, Lung and Blood Institute. 72 million Americans – 1 in 3 – are hypertensive, according to the NHLBI.

Studies will explore fundamentals such as why about 30 percent of young healthy blacks and 15 percent of whites can’t effectively excrete sodium, a problem that raises blood pressure by increasing the body’s fluid volume. “We think there is a defect in their kidneys, in the normal mechanisms that allow them to excrete salt,” said Dr. David Pollock, renal physiologist at MCG’s Vascular Biology Center and a program project leader. “When blood pressure goes up due to stress, their kidneys ought to get rid of more salt so their blood pressure will come down, and they don’t.”

Dr. Harshfield’s studies identified this impaired stress-induced sodium natriuresis. He believes it’s also a primary reason blood pressure remains elevated at night in some blacks, rather than dipping as it should, which keeps stressing the cardiovascular system.

Using a rat bred to be salt-sensitive, the researchers are working to identify more about the genetics of impaired sodium-handling. “We have animal model data that says the endothelin system normally functions to help your kidneys get rid of salt,” says Dr. Pollock. His studies have shown the kidney’s endothelin B receptor plays a critical role in promoting excretion of acute and chronic salt loads by activating the precursor to nitric oxide, a powerful dilator of blood vessels. In the new studies, he’ll control the rats’ diet and see whether stress slows down sodium excretion. Preliminary evidence suggests it does. He’ll also give the rats an endothelin antagonist, which blocks this hormone, and see if sodium excretion improves. He’ll also see how a high-fat diet and obesity alter the equation.

Meanwhile, for about a week, young study participants with impaired sodium excretion will take a drug to block the powerful blood vessel constrictor, angiotensin. “From our point of view, angiotensin promotes sodium retention directly and it also increases aldosterone, another hormone which promotes sodium retention,” Dr. Harshfield says. The researchers chose to study endothelin and angiotensin because they believe they work together. To explore the genetics, they’ll also look at young adults with a different version of the angiotensin receptor gene that they believe exacerbates sodium-handling problems. MCG researchers identified this genetic variation in people who retain sodium; blocking the receptor gene will provide more evidence about the importance of angiotensin, says Dr. Harshfield.

They’ll mimic the way many people work – an hour of stress, a few minutes of relief, then back to stress – by getting the young people to play competitive video games, then measuring how gene blockers affect sodium excretion. “Ultimately, you want to know how to treat people with this variation,” Dr. Harshfield says. “There is still a need to figure out why some people respond to some therapies and other don’t,” adds Dr. Pollock. “That is not our specific question but these studies will help address that. We have to identify what is it about different individuals that make them react more to stress, makes them retain more salt.”

Obesity, which is associated with increased blood pressure reactivity, is probably a differentiator, Dr. Pollock says. Fat cells actually secrete angiotensin, which gets into the bloodstream. “We are arguing in our study that you might want to treat patients differently depending on whether or not they are obese. The angiotensin receptor blocker may be more effective in obese individuals who have angiotensin falling out into their bloodstream,” says Dr. Harshfield. Consequently they’ll also compare the effectiveness of the blocker in obese and normal-weight individuals with impaired sodium excretion.

Another project is exploring the role of oxidative stress, or reactive oxygen species, in raising blood pressure. In an animal model genetically predisposed to salt-sensitive hypertension, Dr. Jennifer Pollock, biochemist in MCG’s Vascular Biology Center and a program project leader, has shown a prolonged recovery to normal blood pressure following stress. She’s also found oxidative stress levels go up with stress. Oxidative stress, or reactive oxygen species, helps make normal chemical reactions in the body but, in excess, can cause havoc. In fact, when she gives the rats an antioxidant before a stressor, blood pressure doesn’t rise as high and recovery is more normal. “We also found out that endothelin actually is the stimulus for increasing reactive oxygen species,” Dr. Jennifer Pollock says. “When we gave the rats a specific type of endothelin blocker, that also blocked the increase in oxidative stress, blocked the blood pressure increase and improved recovery.”

Now they want to know the specific sources of the reactive oxygen species. Earlier work by Dr. Frank Treiber, MCG vice president for research and principal investigator on the original Program Project grant in 2002, has shown increased blood pressure reactivity in children who are obese and/or have low socioeconomic status.

Looking at how obesity weighs in, Dr. Jennifer Pollock also is putting the rats on high-fat diets. It’s known these rats become hypertensive on a high-salt or high-fat diet and they’ve found that, as with people, fat also increases blood pressure reactivity. Now she is going to find out how.

Another animal model is providing insight into the impact of early life stressors or low socioeconomic status on cardiovascular disease. Research again found that, as with people, these animals have normal blood pressure as pups. But as stressed adult rats, they have higher pressure increases and a delayed recovery unless they are missing an endothelin receptor gene. “It cures it,” says Dr. Jennifer Pollock. “This early life stressor is being mediated through the endothelin pathway.” Her postdoctoral fellow, Dr. Analia Loria, found these early life stressor models also have more constrictive blood vessels because they are more sensitive to angiotensin. New studies will further test the endothelin connection and see if a high-fat diet makes things worse by increasing oxidative stress.

Wildlife biologists have found naturally occurring models. Rat pups whose mother builds a nest far from a food source and so must be gone foraging several hours each day, are more anxious. Neurobiologists have shown animals separated from their moms for long periods can’t run through mazes well and tend to back off in competition for food, Dr. Jennifer Pollock says. “We took that to mean their blood pressure could also be hyper reactive. Sure enough, that is what we found.”

“This has a lot of implications for earlier detection of risk-increasing environmental exposures and what you can do about it,” says Dr. Treiber, a clinical child psychologist and program project leader. “If you can’t alter the environment that quickly in life, you know now where they are headed and maybe you can preempt it pharmacogenetically.”

In the diverse group of some 600 young people he’s been following for 17 years, Dr. Treiber has found that, as with the general population, some already are obese and/or hypertensive at the average age of 25. He’ll continue to follow and annually assess them over the next five years in an effort to better understand how stress contributes to hypertension. “What we are doing is looking at chronic environmental stress in combination with some bad candidate genes that are stress activated,” says Dr. Treiber. He’s thinking that, as with rats, genetic predisposition and stress can doom people with normal pressures to hypertension. They’ll look at blood pressure reactivity, recovery, sodium secretion, measure the footprints left by oxidative stress and the levels of the stress hormone cortisol. They’ll look at early indicators of cardiovascular disease, such as enlargement of the pumping chamber of the heart and signs of carotid artery disease. “If you have a tendency to have high blood pressure or if you are obese, we can see the inner layer of the carotid getting thicker than normal people your age,” says Dr. Gaston Kapuku, cardiologist and cardiovascular researcher at the Georgia Prevention Institute and a project core leader.

America’s current obesity and type 2 diabetes epidemic also has them looking at insulin, glucose and cholesterol levels and whether fat exacerbates all the factors they are following, which they believe it does.

One reason the Georgia Prevention Institute was founded was to identify risk factors for cardiovascular disease, says Dr. Harshfield. In his 10 years at the institute, the agenda has shifted from looking at precursor development of adult hypertension to identifying mechanisms causing pediatric hypertension, a disease that didn’t exist when most hypertension textbooks were written, he says.

“Our ultimate goal, of course, is prevention,” he says. “But when we can’t do that, we want to give physicians ways to determine precisely the cause or causes of your hypertension and optimal ways to target your disease.”

The MCG Department of Biostatistics, chaired by Dr. Varghese George, is designing the studies for the Program Project grant to ensure scientifically validity and managing data for all the program projects.

Oceans on the Precipice: Scripps Scientist Warns of Mass Extinctions and 'Rise of Slime'

Threats to marine ecosystems from overfishing, pollution and climate change must be addressed to halt downward trends

Scripps Institution of Oceanography/UC San Diego

Human activities are cumulatively driving the health of the world's oceans down a rapid spiral, and only prompt and wholesale changes will slow or perhaps ultimately reverse the catastrophic problems they are facing.

Such is the prognosis of Jeremy Jackson, a professor of oceanography at Scripps Institution of Oceanography at UC San Diego, in a bold new assessment of the oceans and their ecological health. Publishing his study in the online early edition of the Proceedings of the National Academy of Sciences (PNAS), Jackson believes that human impacts are laying the groundwork for mass extinctions in the oceans on par with vast ecological upheavals of the past.

Jeremy Jackson, Scripps Professor of Oceanography

He cites the synergistic effects of habitat destruction, overfishing, ocean warming, increased acidification and massive nutrient runoff as culprits in a grand transformation of once complex ocean ecosystems. Areas that had featured intricate marine food webs with large animals are being converted into simplistic ecosystems dominated by microbes, toxic algal blooms, jellyfish and disease.

Jackson, director of the Scripps Center for Marine Biodiversity and Conservation, has tagged the ongoing transformation as "the rise of slime." The new paper, "Ecological extinction and evolution in the brave new ocean," is a result of Jackson's presentation last December at a biodiversity and extinction colloquium convened by the National Academy of Sciences.

"The purpose of the talk and the paper is to make clear just how dire the situation is and how rapidly things are getting worse," said Jackson. "It's a lot like the issue of climate change that we had ignored for so long. If anything, the situation in the oceans could be worse because we are so close to the precipice in many ways."

In the assessment, Jackson reviews and synthesizes a range of research studies on marine ecosystem health, and in particular key studies conducted since a seminal 2001 study he led analyzing the impacts of historical overfishing. The new study includes overfishing, but expands to include threats from areas such as nutrient runoff that lead to so-called "dead zones" of low oxygen. He also incorporates increases in ocean warming and acidification resulting from greenhouse gas emissions.

Jackson describes the potently destructive effects when forces combine to degrade ocean health. For example, climate change can exacerbate stresses on the marine environment already brought by overfishing and pollution.

"All of the different kinds of data and methods of analysis point in the same direction of drastic and increasingly rapid degradation of marine ecosystems," Jackson writes in the paper.

During a recent research expedition to Kiritimati, or Christmas Island, Jeremy Jackson and other researchers documented a coral reef overtaken by algae, featuring murky waters and few fish. The researchers say pollution, overfishing, warming waters or some combination of the three are to blame. Photo credit: Jennifer E. Smith

Jackson furthers his analysis by constructing a chart of marine ecosystems and their "endangered" status. Coral reefs, Jackson's primary area of research, are "critically endangered" and among the most threatened ecosystems; also critically endangered are estuaries and coastal seas, threatened by overfishing and runoff; continental shelves are "endangered" due to, among other things, losses of fishes and sharks; and the open ocean ecosystem is listed as "threatened" mainly through losses at the hands of overfishing.

"Just as we say that leatherback turtles are critically endangered, I looked at entire ecosystems as if they were a species," said Jackson. "The reality is that if we want to have coral reefs in the future, we're going to have to behave that way and recognize the magnitude of the response that's necessary to achieve it."

To stop the degradation of the oceans, Jackson identifies overexploitation, pollution and climate change as the three main "drivers" that must be addressed.

"The challenges of bringing these threats under control are enormously complex and will require fundamental changes in fisheries, agricultural practices and the ways we obtain energy for everything we do," he writes.

"So it's not a happy picture and the only way to deal with it is in segments; the only way to keep one's sanity and try to achieve real success is to carve out sectors of the problem that can be addressed in effective terms and get on it as quickly as possible."

The research described in the paper was supported by the William E. and Mary B. Ritter Chair of Scripps Institution of Oceanography.

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Note to broadcast and cable producers: UC San Diego provides an on-campus satellite uplink facility for live or pre-recorded television interviews. Please phone or e-mail the media contact listed above to arrange an interview.

Scripps Institution of Oceanography, at UC San Diego, is one of the oldest, largest and most important centers for global science research and graduate training in the world. The National Research Council has ranked Scripps first in faculty quality among oceanography programs nationwide. Now in its second century of discovery, the scientific scope of the institution has grown to include biological, physical, chemical, geological, geophysical and atmospheric studies of the earth as a system. Hundreds of research programs covering a wide range of scientific areas are under way today in 65 countries. The institution has a staff of about 1,300, and annual expenditures of approximately $155 million from federal, state and private sources. Scripps operates one of the largest U.S. academic fleets with four oceanographic research ships and one research platform for worldwide exploration.

The Hebrew University of Jerusalem : archaeological excavations uncover Roman temple in Zippori (Sepphoris)

Findings show signs of mixed city of Jews, pagans and Christians

View of the remnants of the podium, the temple's façade and some steps. The long wall in the background belongs to the church whose foundations were built on the remains...

Ruins of a Roman temple from the second century CE have recently been unearthed in the Zippori National Park in Israel. Above the temple are foundations of a church from the Byzantine period. The excavations, which were undertaken by the Noam Shudofsky Zippori Expedition led by of Prof. Zeev Weiss of the Institute of Archaeology at the Hebrew University of Jerusalem, shed light on the multi-cultural society of ancient Zippori.

The discovery indicated that Zippori, the Jewish capital of the Galilee during the Roman period, had a significant pagan population which built a temple in the heart of the city center. The central location of the temple which is positioned within a walled courtyard and its architectural relation to the surrounding buildings enhance our knowledge regarding the planning of Zippori in the Roman era.

The building of the church on the foundation of the temple testifies to the preservation of the sacred section of the city over time. This new finding demonstrates not only the religious life, culture and society in Roman and Byzantine Zippori, but also that this was a city in which Jews, pagans and later Christians lived together and developed their hometown with various buildings.

The newly discovered temple is located south of the decumanus - colonnaded street - which ran from east to west and was the main thoroughfare in the city during the Roman through Byzantine period. The temple, measuring approximately 24 by 12 meters, was built with a decorated façade facing the street. The temple's walls were plundered in ancient times and only its foundations remain.

No evidence has been found that reveals the nature of the temple's rituals, but some coins dating from the time of Antoninus Pius, minted in Diocaesarea (Zippori), depict a temple to the Roman gods Zeus and Tyche. The temple ceased to function at an unknown date, and a large church, the remains of which were uncovered by the Hebrew University excavation team in previous seasons, was built over it in the Byzantine period.

North of the decumanus, opposite the temple, a monumental building was partially excavated this summer. Its role is still unclear, although its nature and size indicate that it was an important building. A courtyard with a well-preserved stone pavement of smooth rectangular slabs executed in high quality was uncovered in the center of the building, upon which were found a pile of collapsed columns and capitals - probably as a result of an earthquake. The decoration on these architectural elements was executed in stucco. Beyond a row of columns, an adjacent aisle and additional rooms were discovered. Two of them were decorated with colorful, geometrical mosaics.

University of Exeter : New evidence implicates humans in prehistoric animal extinctions

Protemnodon skull from cave at Mt. Cripps, northwest Tasmania.

Research led by UK and Australian scientists sheds new light on the role that our ancestors played in the extinction of Australia's prehistoric animals. The study, published this week in the journal Proceedings of the National Academy of Sciences of the USA, provides the first evidence that Tasmania's giant kangaroos and marsupial 'rhinos' and 'leopards' were still roaming the island when humans first arrived. The findings suggest that the mass extinction of Tasmania's large prehistoric animals was the result of human hunting, and not climate change as previously believed.

Scientists have long argued over the reasons behind the worldwide mass extinctions that took place towards the end of the last ice age. The main culprits are generally thought to be climate change or some form of human impact. People only arrived in Tasmania around 43,000 years ago, when the island became temporarily connected by a land bridge to mainland Australia. None of Tasmania's giant animals, known as 'megafauna' were known to have survived until this time. This appeared to clear humans of any involvement in the disappearance of the island's large megafauna.

This new international study reports the discovery of giant kangaroos surviving in Tasmania until people arrived, placing humans back on the list of likely culprits for the subsequent extinction of the megafauna.

Palorchestes azael. A marsupial similar to a ground-sloth. Weight: approx 500 kg.

Using the latest radiocarbon and luminescence dating techniques, the team were able to determine the age of the fossilised remains of the megafauna more accurately than ever before. The results showed that some of these animals survived until at least 41,000 years ago—much later than previously thought and up to 2,000 years after the first human settlers arrived. As climate in Tasmania was not changing dramatically at this time, the researchers argue that this is evidence of these species being driven to extinction through over-hunting by humans.

Professor Chris Turney of the University of Exeter, lead author of the paper, said: "Ever since Charles Darwin's discovery of giant ground sloth remains in South America, debate has ensued about the cause of early extinction of the world's megafauna. Now, 150 years on from the publication of Darwin's seminal work The Origin of Species, the argument for climate change being the cause of this mass extinction has been seriously undermined. It is sad to know that our ancestors played such a major role in the extinction of these species – and sadder still when we consider that this trend continues today."

The researchers believe that the tale from Tasmania is relevant to many other parts of the world. Given Tasmania's history as an island, these findings should help to disentangle the role of humans and climate change in other island environments, such as Britain. Author Professor Tim Flannery of Macquarie University, Australia, said "Island environments offer an excellent test of competing hypotheses. They typically have a similar megafauna and climate to neighbouring continental landmasses but human arrival was often delayed."

Previous research by Professor Flannery and Professor Bert Roberts of the University of Wollongong, Australia, has shown that 90 per cent of mainland Australia's megafauna disappeared about 46,000 years ago, soon after humans first settled the continent. But humans did not reach Tasmania until a few thousand years later, when the island became connected to the mainland by a land bridge as sea levels fell during the last glaciation. "The Tasmanian results echo those on mainland Australia, putting humans squarely back in the frame as the driving force behind megafaunal extinction", said Professor Roberts.

The most recent discoveries were made serendipitously by cavers exploring a labyrinth of tunnels under the rainforest-clad Mt Cripps in north-west Tasmania. Author Craig Reid at the Queen Victoria Museum and Art Gallery in Tasmania, said "The skeletal remains provide key evidence of Tasmania's final megafauna in the dim, if not-too-distant, past."

The victims of Tasmania's first humans:

• Zygomaturus trilobus. A rhino-like marsupial. Weight: approx 500 kg.
• Palorchestes azael. A marsupial similar to a ground-sloth. Weight: approx 500 kg.
• Metasthenurus newtonae. A large, short-faced kangaroo that browsed like an antelope. Weight: approx 150 kg.
• Simosthenurus occidentalis. A smaller short-faced kangaroo. Weight: 100-130 kg
• Protemnodon anak. A long-faced, long-necked kangaroo, like a long-necked browsing antelope. Weight: approx 120 kg.
• Thylacoleo carnifex. A leopard-like marsupial. Weight: approx 70-100 kg.
• Megalibgwilia sp. A monotreme (egg-laying mammal) similar in shape and size to the long-beaked echidna of New Guinea. Weight: approx 10 kg.

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This study was conducted by researchers at the University of Exeter (UK), University of Wollongong (Australia), Macquarie University (Australia), Queen Victoria Museum and Art Gallery (Australia), Australian National University, University of Oxford (UK), Tasmanian Museum and Art Gallery (Australia), University of Newcastle (UK), University of Strathclyde (UK), Queen's University Belfast (UK).

The research was supported by The Royal Society and the Australian Research Council.

Helmholtz Association of German Research Centres : Drinking water in Gaza Strip contaminated with high levels of nitrate

Manure and wastewater are polluting the water and endangering infant health

Dry sludge produced from Gaza Wastewater Treatment Plant, May 2007. There are no treatment facilities for sludge in Gaza and it is just exposed to dry in the sun before...

Gaza/Leipzig. Palestinian and German scientists have recommended to the authorities in the Gaza Strip that they take immediate measures to combat excessive nitrate levels in the drinking water. 90 per cent of their water samples were found to contain nitrate concentrations that were between two and eight times higher than the limit recommended by the World Health Organization (WHO), say the researchers from the University of Heidelberg and the Helmholtz Centre for Environmental Research (UFZ) writing in the specialist journal Science of the Total Environment. Over the long term they recommend that the best protection would be provided by quality management for groundwater resources. Groundwater is the only source of drinking water for the majority of people living in the Gaza Strip. In babies younger than six months, nitrate can lead to methaemoglobinaemia, to diarrhoea and to acidosis. The WHO therefore recommends keeping nitrate levels to 50 milligrams per litre or less. According to unpublished research, half of the 640 infants tested were already showing signs of methaemoglobinaemia. The new Palestinian-German study confirms earlier water analyses and is the first study to pinpoint a source of the contamination. With the help of isotope analyses, the researchers were able to demonstrate that the nitrate pollution can be traced back to manure used in farming and to wastewater.

One of the groundwater wells in Khan Younis area in the Gaza Strip under regular monitoring program by the research shared project between the University of Heidelberg and the Gaza...

With over 2600 people per square kilometre, the Gaza Strip is one of the most densely populated areas on earth. Because of their isolation, the inhabitants of this area between the Mediterranean, Egypt and Israel are reliant on being self-sufficient. The fields are mostly fertilized with chicken and cow dung. Artificial fertilizers account for only around a quarter of the fertilizer used. Because of the area's geology and the semi-arid climate, it is fairly easy for impurities to seep down from the surface into the aquifier system. Organic fertilizers and wastewater are the main causes of the nitrate contamination in the groundwater, followed by sewage sludge and artificial fertilizers. This was revealed by the isotope ratios of nitrogen (15N/14N) and oxygen (18O/16O) in the nitrate. Isotopes are variations of the same chemical element that have a different number of neutrons in their nuclei. 18O and 15N are stable, i.e. non-radioactive, isotopes that are heavier than "normal" oxygen (16O) or nitrogen (14N) and can therefore be measured using a mass spectrometer. "The lower 15N nitrogen isotope values in the sewage sludge indicate that the nitrate in the Gaza groundwater comes primarily from manure used as fertilizer," explains Dr Karsten Osenbrück of the UFZ. Between 2001 and 2007 the scientists took water samples from 115 municipal wells and 50 private wells on seven occasions. They measured nitrate concentrations of between 31 and 452 milligrams per litre. Only 10 of the 115 municipal wells examined were found to have a nitrate level below the WHO guideline value. The situation with the private wells was equally serious: apart from three, all the wells were found to have nitrate levels that were between five and seven times higher than the WHO recommendations.
Tilo Arnhold

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Elsevier : Towards understanding bluetongue outbreaks

Multi-centre sequence analysis reveals origins of economically important virus strain

Amsterdam, August 14, 2008 – A recent article published in Virology (www.elsevier.com/locate/yviro), reports the identification of a bluetongue virus strain that caused the northern European Bluetongue outbreak in 2006. Comparison of the virus strain with the sequences of other previously isolated strains showed that it originated in sub-Saharan Africa, rather than from vaccine strains or strains circulating in southern Europe.

Bluetongue (BT) disease or catarrhal fever is a non-contagious, insect borne viral disease of ruminants, mainly sheep. It is characterized by high fever, excessive salivation, swelling of the head and neck which can lead to cyanosis of the tongue (after which the disease is named). BT is caused by the bluetongue virus (BTV) and due to its economic significance BTV has been the subject of extensive molecular, genetic and structural studies. The disease has been observed in Australia, the USA, Africa, the Middle East, Asia and southern Europe. Its occurrence is seasonal in the affected countries, subsiding when temperature drop and hard frosts kill the midges that transmit the disease. It has been spreading northward since the late 90s, perhaps as a result of global warming.

In August 2006, the record temperatures experienced in northern Europe coincided with the first outbreak of BT in the Netherlands, Belgium, Luxemburg, and much of Germany. In the article Peter Mertens and 24 co-authors from six different institutes describe the sequence analysis of the full genome of this BTV strain and compare it to other BTV strains (Virology, doi:10.1016/j.virol.2008.04.028). Their results indicate that despite the high levels of nucleotide identity with other European strains, it represents a new strain introduction, originating from sub-Saharan Africa.

"Such timely and increasingly important insights into the origins of emerging viruses will lead not only to an increased understanding of how viruses like BTV spread, but also to rational vaccine development", said Barbara Sherry, one of the Editors of Virology.

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Notes to editors:
Maan, S., Maan, N.S., Ross-smith, N., Batten, C.A., Shaw, A.E., Anthony, S.J., Samuel, A.R., Darpel, K.E., Veronesi, E., Oura, C.A.L., Singh, K.P., Nomikou, K., Potgieter, A.C., Attoui, H., van Rooij, E., van Rijn, P., De Clercq, K., Vandenbussche, F., Zientara, S., Bréard, E., Sailleau, C., Beer, M., Hoffman, B., Mellor, P.S., Mertens, P.P.C., 2008. Sequence analysis of bluetongue virus serotype 8 from the Netherlands 2006 and comparison to other European strains. Virology, 377 (2), pp. 308-318.

To receive a copy of the article please contact the press office at newsroom@elsevier.com

About Virology
Launched in 1954, Virology (www.elsevier.com/locate/yviro) publishes the results of basic research in all branches of virology, including the viruses of vertebrates and invertebrates, plants, bacteria, and yeasts/fungi. The journal features articles on the nature of viruses, on the molecular biology of virus multiplication, on molecular pathogenesis, and on molecular aspects of the control and prevention of viral infections. The approaches and techniques used are expected to encompass those of many disciplines, including molecular genetics, molecular biology, biochemistry, biophysics, structural biology, cell biology, immunology, and morphology. The journal is a leading resource for current information in the field of virology.

About Elsevier
Elsevier is a world-leading publisher of scientific, technical and medical information products and services. Working in partnership with the global science and health communities, Elsevier's 7,000 employees in over 70 offices worldwide publish more than 2,000 journals and 1,900 new books per year, in addition to offering a suite of innovative electronic products, such as ScienceDirect (http://www.sciencedirect.com/), MD Consult (http://www.mdconsult.com/), Scopus (http://www.info.scopus.com/), bibliographic databases, and online reference works.

Elsevier (http://www.elsevier.com/) is a global business headquartered in Amsterdam, The Netherlands and has offices worldwide. Elsevier is part of Reed Elsevier Group plc (http://www.reedelsevier.com/), a world-leading publisher and information provider. Operating in the science and medical, legal, education and business-to-business sectors, Reed Elsevier provides high-quality and flexible information solutions to users, with increasing emphasis on the Internet as a means of delivery. Reed Elsevier's ticker symbols are REN (Euronext Amsterdam), REL (London Stock Exchange), RUK and ENL (New York Stock Exchange).

European Space Agency : ESA ground team in simulation training for GOCE launch

ESA mission controllers in simulation training for GOCE launch

The Mission Control Team at ESA's Space Operations Centre (ESOC) are now in intense training for the scheduled 10 September launch of GOCE, the Agency's Gravity field and steady-state Ocean Circulation Explorer.

GOCE is scheduled for lift-off at 16:21 CEST, 10 September 2008, from the Plesetsk Cosmodrome; the spacecraft arrived in Russia on 29 July on board an Antonov-124 cargo aircraft.

On 14 August, members of the Mission Control Team were on console in the Main Control Room at ESOC, Darmstadt, Germany, for a
12-hour simulation of the mission's countdown and launch phases; the simulation included practicing immediate reactions in case of any unexpected problems with the ground segment or the spacecraft.

	Keeping watch over system status during the GOCE launch simulation.

GOCE team supported by experts throughout ESOC

The overall Mission Control Team is led by Flight Operations Director Pier Paolo Emanuelli and comprises a dedicated
13-person Flight Control Team, joined by an extended team of engineers from Ground Operations, Flight Dynamics, Software Support, Computers & Network Support, and ground stations.

Additional expertise is provided from ESOC in the areas of training, documentation and facilities management.


GOCE will orbit at an exceptionally low altitude

"The GOCE mission team are receiving excellent support from our colleagues at ESOC. GOCE is a challenging mission and will orbit at an exceptionally low altitude of just 268 km, so spacecraft control is very critical. The simulations campaign is close to the end and we are fully ready to support the launch in September," said Emanuelli.

	The 14 August simulation included both the A and B sections of the GOCE Flight Control Team

To achieve its mission objectives - mapping Earth's gravity field in unprecedented detail - the slender, 5m-long satellite is designed to orbit at a low altitude because the gravitational variations are stronger closer to Earth.

The GOCE team will undergo intensive training, simulations and work-ups between now and the launch, with a strong focus on practicing for LEOP - the Launch and Early Orbit phase - the crucial first steps in GOCE's mission beginning after the satellite separates from the launcher's upper-most stage.

One highlight of today's training will be establishing and testing the voice and data communication links between ESOC in Germany and the Launch Control Centre at Plesetsk, Russia.

	The 13-person GOCE flight control team is supported by many specialists throughout ESOC.

The GOCE team conducted previous simulations in July and August, and have spent the past months defining and confirming procedures and plans covering all possible nominal and contingency situations.

Flight control team engineers have also been working intently to ensure that the ground segment - the computers and software here at ESOC - is ready to support the mission.

A full launch and LEOP rehearsal will be conducted on 5 September, just five days prior to launch.

Today's 12-hour simulation practised the countdown and launch phases of the GOCE mission.

American Psychological Association : Psychologists show new ways to deal with health challenges in space

Psychologists reveal groundbreaking research, technology that will help address psychosocial challenges in next 'Age of Exploration'

BOSTON—As NASA prepares to send humans back to the moon and then on to Mars, psychologists are exploring the challenges astronauts will face on missions that will be much longer and more demanding than previous space flights. Psychologists outlined these mental health challenges Thursday at the American Psychological Association's 116th Annual Convention, and introduced a new interactive computer program that will help address psychosocial challenges in space.

"Lessons learned from the past, research in extreme environments, training, conditioning, and countermeasures for psychological stress are some of the things NASA is in the process of addressing for the upcoming age of exploration," said psychologist Marc Shepanek, PhD, from the Office of the Chief Health and Medical Officer at NASA.

Psychologists said longer missions mean astronauts will be faced with immense psychological pressures as they adjust to being so far away from Earth, which could lead to depression and interpersonal conflicts. The presenters spoke at APA's first symposium to address the psychological challenges of returning to the moon and going to Mars.

Historically, astronauts have been reluctant to admit to mental or behavioral health problems for fear of being grounded. Psychologist James Carter, PhD, and his colleagues are in the process of developing a suite of interactive computer programs, dubbed the Virtual Space Station, using input from 13 veteran long-duration NASA astronauts who have flown on the International Space Station, Mir and Skylab. The system is being evaluated in a set of randomized controlled clinical trials. This interactive program will help astronauts prevent, detect, assess and manage their own psychosocial problems. They will learn how to cope with depression and how to resolve conflicts with other astronauts.

"Behavioral health problems can interfere with the success of the mission, especially on long-duration space flights like missions to the International Space Station, the moon and Mars. These self-guided software tools will provide private and immediate access to treatments even though the patient may be many miles from Earth," Carter said in prepared remarks. The Virtual Space Station has already been deployed in Antarctica.

However, as astronauts aim to explore a new planet, the one they leave behind could be foremost on their minds. They will have limited contact with their families and radio communications with Mission Control will be delayed, possibly for as long as 40 minutes. In her presentation, family sociologist Phyllis Johnson, PhD, analyzed interviews with astronauts who had spent an extended amount of time in space. The astronauts identified what they felt was the role of NASA, themselves and their families in creating a "home away from home" during their flights. "For example, they emphasized the importance of regular communication regarding work, publicity and education, all of which provide connection to Earth and helped to reduce the perception of isolation," said Johnson.

Psychologists also looked to history for guidance in future space missions. "The closest analogue to Mars exploration is the exploration of Earth," said psychologist Peter Suedfeld, PhD. "Both maritime and terrestrial explorers struck off into the unknown, often for many years at a time." Like space explorers, they had little or no communication with home, and had to devise ways of coping with unforeseen and unfamiliar hardships and dangers. Psychologists are re-examining sea and land voyagers' diaries, logs and letters for a glimpse into how these explorers dealt with boredom, rebelliousness and dissent. They said it may be best way to predict some aspects of future long-duration missions.

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Presentations: "Preparing for the Psychological Stress of Long-duration Space Missions," Marc A. Shepanek, PhD, Office of the Chief Health and Medical Officer, NASA; "Living in Space: Creating a Home Away From Home," Phyllis J. Johnson, PhD, University of British Columbia; "The Uses of History: Space Analogues Revisited," Peter Suedfeld, PhD, University of British Columbia; "Computer-based Psychosocial Support for Long-duration Spaceflights," James A. Carter, PhD, Harvard Medical School, Leonard Greenhalgh, PhD, Amos Tuck School of Business at Dartmouth College, Steven E. Locke, MD, Harvard Medical School, Jay C. Buckey, MD, Dartmouth Medical School, Mark T. Hegel, PhD, Dartmouth Medical School; Session 1111 – Symposium: To the Moon and Mars: Psychology of Long-Duration Space Exploration, 10:00 – 11:50 AM, Thursday, Aug. 14, Boston Convention and Exhibition Center, Meeting Level 2, Meeting Room 206A. Symposium Chair: Douglas A. Vakoch, PhD, SETI Institute. Discussants: Edna R. Fiedler, PhD, National Space Biomedical Research Institute, Uwe P. Gielen, PhD, St. Francis College, Walter Sipes, PhD, NASA/Johnson Space Center

Full texts of the remarks are available from the APA Public Affairs Office.

For more information/interview, please contact: Douglas Vakoch at (510) 688-0028 or by e-mail at vakoch@seti.org.

The symposium presenters can also be contacted:

Marc Shepanek, PhD – NASA Office of the Chief Health and Medical Officer; "Preparing for the Psychological Stress of Long-Duration Space Missions"; phones: (W) 202-358-2201, (C) 202-744-7541, (H) 202-244-2787; mshepanek@hq.nasa.gov

Phyllis Johnson, PhD – Univ. of British Columbia, Vancouver, Canada; "Living in Space: Creating a Home Away From Home"; phones: (W) 604-822-4300, (H) 604-687-8886, (Boston) 617-227-8600; pjohnson@interchange.ubc.ca

Peter Suedfeld, PhD – University of British Columbia, Vancouver, Canada; "Uses of History: Space Analogues Revisited"; phones: (W) 604-822-5713, (Boston) 617-227-8600; psuedfeld@psych.ubc.ca

James Carter, PhD – Harvard Medical School; "Computer-Based Psychosocial Support for Long-Duration Spaceflights"; phones (W) 617-667-1507, (C) 617-851-8913; jacarter@caregroup.harvard.edu

The American Psychological Association (APA), in Washington, DC, is the largest scientific and professional organization representing psychology in the United States and is the world's largest association of psychologists. APA's membership includes more than 148,000 researchers, educators, clinicians, consultants and students. Through its divisions in 54 subfields of psychology and affiliations with 60 state, territorial and Canadian provincial associations, APA works to advance psychology as a science, as a profession and as a means of promoting human welfare.

NASA/Goddard Space Flight Center : NASA data show some African drought linked to warmer Indian Ocean

A new study, co-funded by NASA, has identified a link between a warming Indian Ocean and less rainfall in eastern and southern Africa. Computer models and observations show a decline in rainfall, with implications for the region's food security.

Rainfall in eastern Africa during the rainy season, which runs from March through May, has declined about 15 percent since the 1980s, according to records from ground stations and satellites. Statistical analyses show that this decline is due to irregularities in the transport of moisture between the ocean and land, brought about by rising Indian Ocean temperatures, according to research published today in Proceedings of the National Academy of Sciences. This interdisciplinary study was organized to support U.S. Agency for International Development's Famine Early Warning Systems Network.

"The last 10 to 15 years have seen particularly dangerous declines in rainfall in sensitive ecosystems in East Africa, such as Somalia and eastern Ethiopia," said Molly Brown of NASA's Goddard Space Flight Center, Greenbelt, Md., a co-author of the study. "We wanted to know if the trend would continue or if it would start getting wetter."

To find out, the team analyzed historical seasonal rainfall data over the Indian Ocean and the eastern seaboard of Africa from 1950 to 2005. The NASA Global Precipitation Climatology Project's rainfall dataset provided a series of data covering both the land and the oceans. They found that declines in rainfall in Ethiopia, Kenya, Tanzania, Zambia, Malawi and Zimbabwe were linked to increases in rainfall over the ocean.

The team used computer models that describe the atmosphere and historical climate data to identify and validate the source of this link. Lead author Chris Funk of the University of California, Santa Barbara, and colleagues showed that the movement of moisture onshore was disrupted by increased rainfall over the ocean.

Funk and colleagues used a computer model from the National Center for Atmospheric Research to confirm their findings. The combination of evidence from models and historical data strongly suggest that human-caused warming of the Indian Ocean leads to an increase of rainfall over the ocean, which in turn adds energy to the atmosphere. Models showed that indeed, the added energy could create a weather pattern that reduces the flow of moisture onshore and bring dry air down over the African continent, reducing rainfall.

Next, the team investigated whether or not the decline in rainfall over eastern Africa would continue. Under guidance from researchers at USGS, which co-funded the study, the team looked at 11 climate models to simulate rainfall changes in the future. Ten of the 11 models agreed that though 2050, rainfall over the Indian Ocean would continue to increase – depriving Africa's eastern seaboard of rainfall.

"We can be quite certain that the decline in rainfall has been substantial and will continue to be," Funk said. "This 15 percent decrease every 20-25 years is likely to continue."

The trend toward dryer rainy seasons in eastern and southern Africa directly impacts agricultural productivity. To evaluate how potential future rainfall scenarios and shifts in agriculture could affect undernourishment, the team came up with a "food-balance indicator" model. The model considers factors such as growing-season rainfall, fertilizer, seed use, crop area and population to estimate the number of undernourished people a region can anticipate.

Continuing along a "business as usual" scenario – with current trends in declining rainfall and agricultural capacity continuing as it is currently to 2030, the team found that the number of undernourished people will increase by more than 50 percent in eastern Africa.

Still, the food-balance indicator also showed that in the face of a continuation of the current downward trend in rainfall, even modest increases in agricultural capacity could reduce the number of undernourished people by 40 percent.

"A strong commitment to agricultural development by both African nations and the international community could lead fairly quickly to a more food-secure Africa," Funk said.

ESA/Hubble Information Centre : Globular clusters tell tale of star formation in nearby galaxy metropolis

The NASA/ESA Hubble Space Telescope has identified thousands of more than 5 billion year-old globular clusters in the Virgo cluster of galaxies. One of the results of these discoveries led astronomers to understand more about the life and evolution of cannibal galaxies. Globular star clusters, dense bunches of hundreds of thousands of stars, contain some of the oldest surviving stars in the Universe. A new international study of globular clusters outside our Milky Way Galaxy has found evidence that these hardy pioneers are more likely to form in dense areas, where star birth occurs at a rapid rate, instead of uniformly from galaxy to galaxy. Astronomers used the NASA/ESA Hubble Space Telescope to identify over 11 000 globular clusters in the Virgo cluster of galaxies, most of which are more than 5 billion years old. Comprised of over 2 000 galaxies, the Virgo cluster is located about 54 million light-years away and is the nearest large galaxy cluster to Earth. Along with Virgo, the sharp vision of Hubble's Advanced Camera for Surveys (ACS) resolved the star clusters in 100 galaxies of various sizes, shapes, and brightness – even in faint, dwarf galaxies. "It's hard to distinguish globular clusters from stars and galaxies using ground-based telescopes", explained Eric Peng of Peking University in Beijing, China, and lead author of the Hubble study. Hubble’s “eye” is so sharp that it was able to pick out the fuzzy globular clusters from stars in our galaxy and from faraway galaxies in the background. "With Hubble we were able to identify and study about 90 percent of the globular clusters in all our observed fields. This was crucial for dwarf galaxies that have only a handful of star clusters". The team found a bounty of globular clusters (from a few dozen to several dozen) in most of the dwarf galaxies within 3 million light-years of the cluster’s centre. This happens to be the same region where the giant elliptical galaxy Messier 87 resides. These numbers were surprisingly high considering the low masses of the dwarfs they inhabited. By contrast, dwarfs in the outskirts of the cluster had fewer globulars. “Our study shows that the efficiency of star cluster formation depends on the environment”, said Patrick Cote of the Herzberg Institute of Astrophysics in Victoria, Canada. “Dwarf galaxies closest to Virgo's crowded centre contained more globular clusters than those farther away”. Astronomers have long known that the giant elliptical galaxy at the cluster’s centre, Messier 87, also hosts a larger than predicted population of globular star clusters. However, the origin of so many globulars has been a long-standing mystery. Astronomers have theorised that many of the clusters may have been snatched from smaller galaxies that ventured too close to it. “We found few or no globular clusters in galaxies within 130 000 light-years from Messier 87, suggesting the giant galaxy stripped the smaller ones of their star clusters”, Peng said. “These smaller galaxies are contributing to the buildup of Messier 87”. Evidence of Messier 87’s galactic cannibalism comes from an analysis of the globular clusters’ composition. “In Messier 87 there are three times as many globulars deficient in heavy elements, such as iron, than globulars rich in those elements”, Peng said. “This suggests that many of these ‘metal-poor’ star clusters may have been stolen from nearby dwarf galaxies, which also contain globulars deficient in heavy elements”. Studying globular star clusters is critical to understanding the early, intense star-forming episodes that mark galaxy formation. They are known to reside in all but the faintest of galaxies. “Star formation near the core of Virgo is very intense and occurs in a small volume over a short amount of time”, Peng noted. “It may be more rapid and more efficient than star formation in the outskirts. The high star-formation rate may be driven by the gravitational collapse of dark matter, an invisible form of matter, which is denser and collapses sooner near the cluster's centre. Messier 87 sits at the centre of a large concentration of dark matter, and all of these globulars near the centre probably formed early in the history of the Virgo cluster.” The smaller number of globular clusters in the dwarf galaxies sitting farther away from the centre may be due to the masses of the star clusters that formed, Peng said. “Star formation farther away from the central region was not as robust, which may have produced only less massive star clusters that dissipated over time”, he explained. The astronomers also obtained accurate distances to 84 of the 100 galaxies in the Hubble study. The results appeared on 1 July 2008 in The Astrophysical Journal. Notes for editors: The Hubble Space Telescope is a project of international cooperation between ESA and NASA. Image credit: NASA, ESA and Eric Peng (Peking University, China) Links: Science paper NASA News Release Contacts: Eric Peng Peking University, Beijing, China Tel: +86-10-6275-8629 E-mail: peng@bac.pku.edu.cn Lars Lindberg Christensen Hubble/ESA, Garching, Germany Tel: +49-89-3200-6306 Cellular: +49-173-3872-621 E-mail: lars@eso.org Donna Weaver/Ray Villard Space Telescope Science Institute, Baltimore, USA Tel: +1-410-338-4493/+1-410-338-4514 E-mail: dweaver@stsci.edu/villard@stsci.edu

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Yale University : 'Cosmic ghost' discovered by volunteer astronomer

Hanny's Voorwerp and IC 2497.

When Yale astrophysicist Kevin Schawinski and his colleagues at Oxford University enlisted public support in cataloguing galaxies, they never envisioned the strange object Hanny van Arkel found in archived images of the night sky.

The Dutch school teacher, a volunteer in the Galaxy Zoo project that allows members of the public to take part in astronomy research online, discovered a mysterious and unique object some observers are calling a "cosmic ghost."

van Arkel came across the image of a strange, gaseous object with a hole in the center while using the www.galaxyzoo.org website to classify images of galaxies.

When she posted about the image that quickly became known as "Hanny's Voorwerp" ( Dutch for "object") on the Galaxy Zoo forum, astronomers who run the site began to investigate and soon realized van Arkel might have found a new class of astronomical object.

"At first, we had no idea what it was. It could have been in our solar system, or at the edge of the universe," said Schawinski, a member and co-founder of the Galaxy Zoo team.

Scientists working at telescopes around the world and with satellites in space were asked to take a look at the mysterious Voorwerp. "What we saw was really a mystery," said Schawinski. "The Voorwerp didn't contain any stars." Rather, it was made entirely of gas so hot — about 10,000 Celsius — that the astronomers felt it had to be illuminated by something powerful. They will soon use the Hubble Space Telescope to get a closer look.

Since there was no obvious source at hand in the Voorwerp itself, the team looked to find the source of illumination around the Voorwerp, and soon turned to the nearby galaxy IC 2497.

"We think that in the recent past the galaxy IC 2497 hosted an enormously bright quasar," Schawinski explains. "Because of the vast scale of the galaxy and the Voorwerp, light from that past still lights up the nearby Voorwerp even though the quasar shut down sometime in the past 100,000 years, and the galaxy's black hole itself has gone quiet."

"From the point of view of the Voorwerp, the galaxy looks as bright as it would have before the black hole turned off – it's this light echo that has been frozen in time for us to observe," said Chris Lintott, a co-organizer of Galaxy Zoo at Oxford University, UK. "It's rather like examining the scene of a crime where, although we can't see them, we know the culprit must be lurking somewhere nearby in the shadows." Similar light echoes have been seen around supernovae that exploded decades or centuries ago.

Quasars are very unusual, highly luminous objects, powered by supermassive black holes, and most are extremely distant. "The strange 'Hanny's Voorwerp' looks like it could be the nearest example of a luminous quasar," said C. Megan Urry, Israel Munson Professor of Physics & Astronomy and Chair of the Physics Department at Yale, who was not involved in the research.

"IC 2497 is so close that if the quasar was still shining today, on a good night you could probably see it with a small telescope," Schawinski added. "The nearest active quasar, called 3C 273, is 1.7 billion light years further away."

"This discovery really shows how citizen science has come of age in the Internet world," commented Professor Bill Keel of the University of Alabama, a galaxyzoo.org team member. "Hanny's attentiveness alerted us not only to a peculiar object, but to a window into the cosmic past which might have eluded us for a long time otherwise. Trying to understand the processes operating here has proven to be a fascinating challenge, involving a whole range of astrophysical techniques and instruments around the world and beyond. This has also been some of the most rewarding astronomy I've done in years!"

The Galaxy Zoo project was imagined and begun by Schawinski and his colleague Chris Lintott at Oxford. While working on his PhD thesis, Schawinski classified and catalogued nearly 50,000 galaxies. Knowing that the human eye is sometimes more sensitive than a computer at picking out unusual patterns, he mused that it would be wonderful if there were amateur astronomers who were interested in doing some of the "scanning."

"When we launched Galaxy Zoo we were overwhelmed — as was the internet portal, initially — with the outpouring of public interest and volunteer input," said Schawinski. During the last year, over 150,000 armchair astronomers from all over the world volunteered their time and submitted over 50 million classifications for a set of one million images online. They then could follow the progress of the science they made possible at www.galaxyzooblog.org .

"It's amazing to think that this object has been sitting in the archives for decades and that amateur volunteers can help by spotting things like this online," said Hanny van Arkel. "It was a fantastic present to find out on my 25th birthday that we will get observational time on the Hubble Space Telescope to follow-up this discovery."

The next stage of Galaxy Zoo will ask volunteers to search for more unusual astronomical objects. But, "Hanny's Voorwerp" remains a mystery. It's huge central hole is over 16,000 light years across and Galaxy Zoo astronomers are still puzzling over what caused it.

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The new digital images used in Galaxy Zoo were taken using the robotic Sloan Digital Sky Survey telescope in New Mexico. More on the Sloan Digital Sky Survey is at www.sdss.org . For full details of those involved see www.sdss.org/collaboration/credits.html.

Besides Schawinski, the Galaxy Zoo team includes scientists from the University of Oxford, the University of Portsmouth and Johns Hopkins University (USA), and Fingerprint Digital Media of Belfast. Key contributors to this stage of the project were Chris Lintott from the University of Oxford, Bill Keel from the University of Alabama (USA), Dan Smith (Liverpool John Moores University) Matt Jarvis (University of Hertfordshire) and Nicola Bennert (University of California Riverside, USA). The team's observations and analysis are included in a paper which has been submitted to the Monthly Notices of the Royal Astronomical Society, the UK's leading astronomical journal. For more information, visit www.galaxyzoo.org

Images related to the project can be downloaded from http://www.ox.ac.uk/media/news_releases_for_journalists/gzvimages.html. A netcast interview with Kevin Schawinski is available on iTunesU in the Science section and on the Yale Public Affairs site at http://feeds.feedburner.com/yale/science.

Washington University in St. Louis : Superfluid-superconductor relationship is detailed

2 super phenomena

Scientists have studied superconductors and superfluids for decades. Now, researchers at Washington University in St. Louis have drawn the first detailed picture of the way a superfluid influences the behavior of a superconductor. In addition to describing previously unknown superconductor behavior, these calculations could change scientists' understanding of the motion of neutron stars.

A neutron star, the high-density remnant of a former massive star, is thought to contain both a neutron superfluid and a proton superconductor at its core. Despite widespread agreement that neutron stars contain both materials, superfluid-superconductors have not been widely studied.

"Not many people have thought seriously about the interactions between a superfluid and a superconductor that are co-existing like this," said Mark Alford, associate professor of physics and lead author of the paper published in the July issue of Physical Review B, "They tended to treat the two components separately."

Super Phenomena

Separately, the two phenomena are well understood. A superconductor allows a flow of current without resistance. Similarly, a superfluid flows without friction. Unlike superconductors and superfluids, a superfluid-superconductor does not exist on earth. But, understanding its hybrid behavior may be a first step toward creating one in the lab and understanding what goes on inside neutron stars.

In addition to conducting current without resistance, superconductors also exclude magnetic fields. Neutron stars have massive magnetic fields, but scientists do not know how a superconductor behaves in the presence of this field, specifically whether it will be a type I or type II superconductor. A type I superconductor forces a magnetic field around its exterior. A type II superconductor, however, strikes a compromise, letting the magnetic field pass through tiny non-superconducting holes called flux tubes. Type II superconductors permit one unit of magnetic field per flux tube.

Whether a superconductor is type I or type II depends on a value called kappa. If kappa is greater than a set critical value, the superconductor is type II. Likewise, if kappa is less than the critical value, the superconductor is type I. Add a superfluid, however, and these calculations show that the superconductor's boundary shifts, changing the critical value of kappa and causing exotic behavior at the boundary.

Living on the Edge

Ariel Zhitnitsky at the University of British Columbia was the first to report this boundary shift. Curiosity piqued by the shift, Alford and his collaborator, graduate student Gerald Good, decided to take a closer look at the boundary.

"We found that the boundary wasn't just shifted, but new behavior appeared when the superconductor is on the edge, between type I and type II," said Alford. Since superconductors and superfluids are older physics, Alford added, "We were surprised that there was anything new to mine here."

To understand the boundary shift, Alford and Good examined two interactions between the superfluid and superconductor. The first had a superconductor either attracting or repelling a superfluid. The second had a flowing superconductor causing a superfluid to flow either with it or against it.

Exotic Behavior at the Shifted Boundary

Alford and Good found that the two superconductor-superfluid interactions (attractive/repulsive and flow) had opposite effects on the boundary shift and produced different, but equally exotic, boundary behavior.

The attractive/repulsive interaction increased kappa, favoring a type I superconductor and creating intermediate type II states near the boundary. These intermediate states resemble type II because they have flux tubes; but strangely, more than one unit of magnetic field appears to exist in each. Depending on the parameters, an infinite number of intermediate type II states exist, with any number of magnetic field units in each flux tube.

Unlike the attractive/repulsive interaction, the flow interaction decreased kappa, favoring a type II superconductor. Instead of intermediate type II states, the flow interaction creates meta-stable regions on either side of the boundary. Specifically, in these regions a superconductor that should be type II can get stuck as type I and vice versa. A familiar example of similar behavior is when, under the right conditions, water remains a liquid despite freezing temperatures.

Passing the Baton

Just as Zhitnitsky's work inspired Alford and Good to look closer at the type I/type II boundary, this work has already spurred others in new directions. A group at Dartmouth College is confirming some behavior seen by Alford and Good, but the Dartmouth results favor a different scenario for the intermediate type II phases (unpublished).

The Dartmouth group is not seeing multiple units of magnetic field in one flux tube, but flux tubes that are a fixed distance apart (with one unit of magnetic field each). These flux tubes tend to "stick together" rather than spread out as far as possible, as in normal type II superconductors. Alford and Good said they could not rule out this possibility due to limitations in the simplified model and in computing capacity.

"The Dartmouth group is seeing similar intermediate phases," said Good, "but slightly different behavior. That's the next step in our research and it's already being done, which is pretty neat."