Saturday, February 12, 2011

NASA's NPP Satellite Undergoing Flight Environmental Testing

GREENBELT, Md. -- The NASA National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP) climate/weather satellite is undergoing flight environmental testing at Ball Aerospace & Technologies Corp's production and test facility in Boulder, Colo.

The NPP satellite began environmental testing in November 2010 and has successfully completed vibration, acoustics and shock environments. In addition, the electromagnetic compatibility/electromagnetic interference testing was completed in January 2011. Currently the satellite is undergoing compatibility testing with the ground system and mission operations team. Later this month, the satellite will be moved into Ball’s thermal vacuum chamber where it will be subjected to extreme temperatures to simulate what the satellite will encounter in space.

NPP continues the pioneering monitoring of Earth's climate achieved by NASA's Earth Observing System suite of satellites over the past decade. The mission is also the precursor of the next generation of operational polar-orbiting environmental satellites for the National Oceanic and Atmospheric Administration (NOAA). NPP will continue the operations of NOAA’s current generation of polar-orbiting environmental satellites, which have for over 40 years protected lives and property as well as supported U.S. commerce and weather forecasts. The follow-on to NPP is the Joint Polar Satellite System (JPSS), which will be developed by NASA for NOAA.

"I am proud of the NPP team's commitment and dedication; they have kept the satellite on schedule with excellent results," stated Ken Schwer, NPP Project Manager, at NASA's Goddard Space Flight Center, Greenbelt, Md. "We are confident that we will deliver an excellent satellite for our October 25, 2011, launch date."

Throughout the satellite test campaign, NPP has worked closely with the JPSS program to ensure the compatibility and readiness of the JPSS ground and data systems to support the NPP on-orbit mission. In April 2011, the entire ground and data systems will undergo rigorous end-to-end testing to verify requirements and prepare for launch.

NPP just completed a several month review process with a review team that independently checked to ensure all aspects of the mission are on track for launch. The successful results of the review were presented to NASA Headquarters, Washington, in January 2011 where officials from NASA's Science Mission Directorate approved NPP's plan, budget, schedule, and success criteria for achieving the October 25, 2011, launch and on-orbit mission.

The five-instrument suite includes: the Visible/Infrared Imager Radiometer Suite (VIIRS); the Cross-track Infrared Sounder (CrIS); the Clouds and the Earth Radiant Energy System (CERES); the Advanced Technology Microwave Sounder (ATMS); and the Ozone Mapping and Profiler Suite (OMPS). NPP's advanced ultraviolet, visible, infrared, and microwave imagers and sounders will provide continuity of climate observations and enhance weather forecasting capabilities for the nation’s civil and military users of satellite data.

NASA's Goddard Space Flight Center manages the NPP mission on behalf of the Earth Science Division of the Science Mission Directorate at NASA Headquarters. NOAA will provide operational support for the mission.

For information about NPP and NASA agency programs on the Web, visit:
http://npp.gsfc.nasa.gov
www.nasa.gov

For information about NOAA's Satellite and Information Services, visit:
http://www.nesdis.noaa.gov
Goddard Release No. 11-012

Cynthia M. O’Carroll
Goddard Space Flight Center, Md.
240-684-0821 begin_of_the_skype_highlighting              240-684-0821      end_of_the_skype_highlighting
Cynthia.M.Ocarroll@nasa.gov

Web experts ask scientists to use the Web to improve understanding, sharing of their data in science

Troy, N.Y. – Peter Fox and James Hendler of Rensselaer Polytechnic Institute are calling for scientists to take a few tips from the users of the World Wide Web when presenting their data to the public and other scientists in the Feb. 11 issue of Science magazine. Fox and Hendler, both professors within the Tetherless World Research Constellation at Rensselaer, outline a new vision for the visualization of scientific data in a perspective piece titled "Changing the Equation on Scientific Data Visualization."
As the researchers explain, visualizations provide a means to enable the understanding of complex data. The problem with the current use of visualization in the scientific community, according to Fox and Hendler, is that when visualizations are actually included by scientists, they are often an end product of research used to simply illustrate the results and are inconsistently incorporated into the entire scientific process. Their visualizations are also static and cannot be easily updated or modified when new information arises.
And as scientists create more and more data with more powerful computing systems, their ability to develop useful visualizations of that data will become more time consuming and expensive with the traditional approaches.
Fox and Hendler ask the scientific community to take some important lessons from the Web.
"…visualizations on the Web are becoming increasingly more sophisticated and interactive," they write. At the same time, those Web-based visualization are also inexpensive and easy to use, according to Hendler and Fox.
Simple Web-based visualization tool kits allow users to easily create maps, charts, graphs, word clouds, and other custom visualizations at little to no cost and with a few clicks of a mouse. In addition, Web links and RSS feeds allow visualizations on the Web to be updated with little to no involvement from the original developer of the visualization, greatly reducing the time and cost of the effort, but also keeping it dynamic.
"Visualizations are absolutely critical to our ability to process complex data and to build better intuitions as to what is happening around us," the researchers write. They use the example of an online weather report. With such visualizations, Web users can click on their area for a forecast or watch videos specific to their region. Without these visualizations, no one but a trained meteorologist would be able to make sense of the mess of raw data behind those pretty maps and graphical snow clouds.
In addition to the ease of using and developing visualization on the Web, visualizations on the Web can also be easily modified, updated, customized, and recreated by other users thanks to the use of Uniform Resource Identifiers. This "linking" of data is a key feature of the new vision that Fox and Hendler outline. It is of particular importance when dealing with what they refer to as "big science" on topics such as climate change that involves data that ranges from distinct fields like biology to geology.
"The challenge is that many of the major scientific problems facing our world are becoming critically linked to the interdependence and interrelatedness of data from multiple instruments, fields, and sources," they write.
Fox and Hendler urge scientists involved in such vital scientific projects to take some tips from large Web companies like Google and Facebook, and even massive online communities such as World of Warcraft. These large companies use new data integration approach such as NoSQL, "big data," and scalable linked data to rapidly expand and maintain their capabilities. These new capabilities provide easy-to-use, low-end tools to generate visualizations and scalable tools for curating very large visualization projects that scientists can model their own visualization after, according to Fox and Hendler.
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For more information on the research of Fox and Hendler as well as the Tetherless World Research Constellation go to http://tw.rpi.edu/.

Thursday, August 14, 2008

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 Drs. David and Jennifer Pollock.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'

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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

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

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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