Biologist warn of early stages of Earth’s sixth mass extinction event

The planet’s current biodiversity, the product of 3.5 billion years of evolutionary trial and error, is the highest in the history of life. But it may be reaching a tipping point.In a new review of scientific literature and analysis of data published in Science, an international team of scientists cautions that the loss and decline of animals is contributing to what appears to be the early days of the planet’s sixth mass biological extinction event.Since 1500, more than 320 terrestrial vertebrates have become extinct. Populations of the remaining species show a 25 percent average decline in abundance. The situation is similarly dire for invertebrate animal life.And while previous extinctions have been driven by natural planetary transformations or catastrophic asteroid strikes, the current die-off can be associated to human activity, a situation that the lead author Rodolfo Dirzo, a professor of biology at Stanford, designates an era of “Anthropocene defaunation.”Across vertebrates, 16 to 33 percent of all species are estimated to be globally threatened or endangered. Large animals — described as megafauna and including elephants, rhinoceroses, polar bears and countless other species worldwide — face the highest rate of decline, a trend that matches previous extinction events.Larger animals tend to have lower population growth rates and produce fewer offspring. They need larger habitat areas to maintain viable populations. Their size and meat mass make them easier and more attractive hunting targets for humans.Although these species represent a relatively low percentage of the animals at risk, their loss would have trickle-down effects that could shake the stability of other species and, in some cases, even human health.For instance, previous experiments conducted in Kenya have isolated patches of land from megafauna such as zebras, giraffes and elephants, and observed how an ecosystem reacts to the removal of its largest species. Rather quickly, these areas become overwhelmed with rodents. Grass and shrubs increase and the rate of soil compaction decreases. Seeds and shelter become more easily available, and the risk of predation drops.Consequently, the number of rodents doubles — and so does the abundance of the disease-carrying ectoparasites that they harbor.”Where human density is high, you get high rates of defaunation, high incidence of rodents, and thus high levels of pathogens, which increases the risks of disease transmission,” said Dirzo, who is also a senior fellow at the Stanford Woods Institute for the Environment. …

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Million suns shed light on fossilized plant

Scientists have used one of the brightest lights in the Universe to expose the biochemical structure of a 50 million-year-old fossil plant to stunning visual effect.The team of palaeontologists, geochemists and physicists investigated the chemistry of exceptionally preserved fossil leaves from the Eocene-aged ‘Green River Formation’ of the western United States by bombarding the fossils with X-rays brighter than a million suns produced by synchrotron particle accelerators.Researchers from Britain’s University of Manchester and Diamond Light Source and the Stanford Synchrotron Radiation Lightsource in the US have published their findings, along with amazing images, in Metallomics; one of the images is featured on the cover of the latest edition of the Royal Society of Chemistry journal.Lead author Dr Nicholas Edwards, a postdoctoral researcher at The University of Manchester, said: “The synchrotron has already shown its potential in teasing new information from fossils, in particular our group’s previous work on pigmentation in fossil animals. With this study, we wanted to use the same techniques to see whether we could extract a similar level of biochemical information from a completely different part of the tree of life.”To do this we needed to test the chemistry of the fossil plants to see if the fossil material was derived directly from the living organisms or degraded and replaced by the fossilisation process.”We know that plant chemistry can be preserved over hundreds of millions of years — this preserved chemistry powers our society today in the form of fossil fuels. However, this is just the ‘combustible’ part; until now no one has completed this type of study of the other biochemical components of fossil plants, such as metals.”By combining the unique capabilities of two synchrotron facilities, the team were able to produce detailed images of where the various elements of the periodic table were located within both living and fossil leaves, as well as being able to show how these elements were combined with other elements.The work shows that the distribution of copper, zinc and nickel in the fossil leaves was almost identical to that in modern leaves. Each element was concentrated in distinct biological structures, such as the veins and the edges of the leaves, and the way these trace elements and sulphur were attached to other elements was very similar to that seen in modern leaves and plant matter in soils.Co-author Professor Roy Wogelius, from Manchester’s School of Earth, Atmospheric and Environmental Sciences, said: “This type of chemical mapping and the ability to determine the atomic arrangement of biologically important elements, such as copper and sulphur, can only be accomplished by using a synchrotron particle accelerator.”In one beautiful specimen, the leaf has been partially eaten by prehistoric caterpillars — just as modern caterpillars feed — and their feeding tubes are preserved on the leaf. The chemistry of these fossil tubes remarkably still matches that of the leaf on which the caterpillars fed.”The data from a suite of other techniques has led the team to conclude that the chemistry of the fossil leaves is not wholly sourced from the surrounding environment, as has previously been suggested, but represents that of the living leaves. Another modern-day connection suggests a way in which these specimens are so beautifully preserved over millions of years.Manchester palaeontologist and co-author Dr Phil Manning said: “We think that copper may have aided preservation by acting as a ‘natural’ biocide, slowing down the usual microbial breakdown that would destroy delicate leaf tissues. This property of copper is used today in the same wood preservatives that you paint on your garden fence before winter approaches.”Story Source:The above story is based on materials provided by Manchester University. Note: Materials may be edited for content and length.

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Deep ocean current may slow due to climate change

Far beneath the surface of the ocean, deep currents act as conveyer belts, channeling heat, carbon, oxygen and nutrients around the globe.A new study by the University of Pennsylvania’s Irina Marinov and Raffaele Bernardello and colleagues from McGill University has found that recent climate change may be acting to slow down one of these conveyer belts, with potentially serious consequences for the future of the planet’s climate.”Our observations are showing us that there is less formation of these deep waters near Antarctica,” Marinov said. “This is worrisome because, if this is the case, we’re likely going to see less uptake of human produced, or anthropogenic, heat and carbon dioxide by the ocean, making this a positive feedback loop for climate change.”Marinov is an assistant professor in Penn’s School of Arts and Sciences’ Department of Earth and Environmental Science, while Bernardello was a postdoctoral investigator in the same department and has just moved to the National Oceanography Centre in the United Kingdom. They collaborated with Casimir de Lavergne, Jaime B. Palter and Eric D. Galbraith of McGill University on the study, which was published in Nature Climate Change.Oceanographers have noticed that Antarctic Bottom Waters, a massive current of cold, salty and dense water that flows 2,000 meters under the ocean’s surface from near the Antarctic coast toward the equator has been shrinking in recent decades. This is cause for concern, as the current is believed to “hide” heat and carbon from the atmosphere. The Southern Ocean takes up approximately 60 percent of the anthropogenic heat produced on Earth and 40 to 50 percent of the anthropogenic carbon dioxide.”The Southern Ocean is emerging as being very, very important for regulating climate,” Marinov said.Along with colleagues, Marinov used models to discern whether the shrinking of the Antarctic Bottom Waters could be attributed to anthropogenic climate change.They looked to an unusual phenomenon that had been observed from satellite images taken between 1974 and 1976. The images revealed a large ice-free area within the Weddell Sea. Called a polynya, this opening in the sea ice forms when warm water of North Atlantic origin is pushed up toward the Southern Ocean’s surface. In a separate process, brine released during the sea-ice formation process produces a reservoir of cold, salty waters at the surface of the Weddell Sea. …

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Moon of Saturn: Surface of Titan sea is mirror smooth

The surface of Ligeia Mare, Titan’s second largest sea, has a mirror-like smoothness, possibly due to a lack of winds, geophysicists say. As the only other solar system body with an Earth-like weather system, Titan could serve as a model for studying our own planet’s early history.New radar measurements of an enormous sea on Titan offer insights into the weather patterns and landscape composition of the Saturnian moon. The measurements, made in 2013 by NASA’s Cassini spacecraft, reveal that the surface of Ligeia Mare, Titan’s second largest sea, possesses a mirror-like smoothness, possibly due to a lack of winds.”If you could look out on this sea, it would be really still. It would just be a totally glassy surface,” said Howard Zebker, professor of geophysics and of electrical engineering at Stanford who is the lead author of a new study detailing the research.The findings, recently published online in Geophysical Research Letters, also indicate that the solid terrain surrounding the sea is likely made of solid organic materials and not frozen water.Saturn’s second largest moon, Titan has a dense, planet-like atmosphere and large seas made of methane and ethane. Measuring roughly 260 miles (420 km) by 217 miles (350 km), Ligeia Mare is larger than Lake Superior on Earth. “Titan is the best analog that we have in the solar system to a body like the Earth because it is the only other body that we know of that has a complex cycle of solid, liquid, and gas constituents,” Zebker said.Titan’s thick cloud cover makes it difficult for Cassini to obtain clear optical images of its surface, so scientists must rely on radar, which can see through the clouds, instead of a camera.To paint a radar picture of Ligeia Mare, Cassini bounced radio waves off the sea’s surface and then analyzed the echo. The strength of the reflected signal indicated how much wave action was happening on the sea. To understand why, Zebker said, imagine sunlight reflecting off of a lake on Earth. “If the lake were really flat, it would act as a perfect mirror and you would have an extremely bright image of the sun,” he said. “But if you ruffle up the surface of the sea, the light gets scattered in a lot of directions, and the reflection would be much dimmer. …

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Ancient food webs developed modern structure soon after mass extinction

Researchers from the Santa Fe Institute and the Smithsonian Institution have pieced together a highly detailed picture of feeding relationships among 700 mammal, bird, reptile, fish, insect, and plant species from a 48 million year old lake and forest ecosystem.Their analysis of fossilized remains from the Messel deposit near Frankfurt, Germany, provides the most compelling evidence to date that ancient food webs were organized much like modern food webs. Their paper describing the research appears online and open access this week in Proceedings of the Royal Society B: Biological Sciences.The researchers first compiled data about the more than 6,500 feeding relationships among 700 species found in the deposit, which dates to the Eocene epoch. Then they constructed two networks of feeding interactions — one for the lake and one for the surrounding forest.Next, they mathematically compared each food web’s structural features with those of modern-day food web datasets — matching up such indicators as fractions of cannibals, herbivores, and omnivores; the distributions of generalist and specialist feeders; the mean lengths of feeding chains connecting pairs of taxa; and so on.”What we found is that the Messel lake food web, with 94 taxa and 517 links, looks very much like a modern food web,” says SFI Professor Jennifer Dunne. “This is despite the fact that 48 million years of species turnover and evolution separate the Messel lake ecosystem from modern ecosystems.”Analysis of the Messel forest food web’s structure was more challenging due to the high degree of species diversity represented in the Messel dataset — 630 taxa and 5,534 feeding links — far more than what datasets for modern webs include.”Basically, we don’t yet have examples of comprehensive modern terrestrial food web datasets that have the high resolution of plants, insects, and their interactions that we included in the Messel forest dataset,” says Dunne.Nevertheless, the researchers were able to show that the Messel forest web is likely comparable in structure to modern webs, by using models to account for differences in structure that would result from the many more taxa and interactions in the Messel data.The results are significant because they show that the Messel ecosystem developed a modern ecological structure, along with a modern biota, in a relatively brief 18 million year period following Earth’s most recent die-off, the end-Cretaceous mass extinction, which disrupted ecosystem dynamics on a massive scale and served as a species diversity bottleneck.Dunne says that beyond the ecological and evolutionary significance of the study, the work resulted in the most highly resolved, detailed, and comprehensive terrestrial food web ever compiled.”We want our data to serve as a challenge to ecologists to compile more highly and evenly resolved food web data for extant systems,” she says.Ancient food webs are particularly difficult to reconstruct because data about them is usually limited and of low quality. But the Messel shale deposit is unique. Scientists hypothesize that releases of toxic volcanic gases rendered the area’s air and water lethal to most life in a short time. Animals in and near the lake were overwhelmed, and, along with plants, sunk to the low-oxygen depths of the lake where they were smothered in mud and fossilized, soft tissue and all.The Messel includes outstanding evidence of feeding interactions, including stomach contents and bite marks in soft tissues that can be traced back to particular species’ mouth parts, Dunne says.”Compiling such a highly resolved food web was possible for the Messel because of the exquisite preservation of soft body parts and ecological traces in the deposit,” she says, “and because my co-author, Conrad Labandeira, is one of the world’s foremost experts on fossil plant-insect interactions.”Story Source:The above story is based on materials provided by Santa Fe Institute. Note: Materials may be edited for content and length.

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Climate change will reduce crop yields sooner than thought

A study led by the University of Leeds has shown that global warming of only 2C will be detrimental to crops in temperate and tropical regions, with reduced yields from the 2030s onwards.Professor Andy Challinor, from the School of Earth and Environment at the University of Leeds and lead author of the study, said: “Our research shows that crop yields will be negatively affected by climate change much earlier than expected.””Furthermore, the impact of climate change on crops will vary both from year-to-year and from place-to-place — with the variability becoming greater as the weather becomes increasingly erratic.”The study, published today by the journal Nature Climate Change, feeds directly into the Working Group II report of the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report, which is due to be published at the end of March 2014.In the study, the researchers created a new data set by combining and comparing results from 1,700 published assessments of the response that climate change will have on the yields of rice, maize and wheat.Due to increased interest in climate change research, the new study was able to create the largest dataset to date on crop responses, with more than double the number of studies that were available for researchers to analyze for the IPCC Fourth Assessment Report in 2007.In the Fourth Assessment Report, scientists had reported that regions of the world with temperate climates, such as Europe and most of North America, could withstand a couple of degrees of warming without a noticeable effect on harvests, or possibly even benefit from a bumper crop.”As more data have become available, we’ve seen a shift in consensus, telling us that the impacts of climate change in temperate regions will happen sooner rather than later,” said Professor Challinor.The researchers state that we will see, on average, an increasingly negative impact of climate change on crop yields from the 2030s onwards. The impact will be greatest in the second half of the century, when decreases of over 25% will become increasingly common.These statistics already account for minor adaptation techniques employed by farmers to mitigate the effects of climate change, such as small adjustments in the crop variety and planting date. Later in the century, greater agricultural transformations and innovations will be needed in order to safeguard crop yields for future generations.”Climate change means a less predictable harvest, with different countries winning and losing in different years. The overall picture remains negative, and we are now starting to see how research can support adaptation by avoiding the worse impacts,” concludes Professor Challinor.Story Source:The above story is based on materials provided by University of Leeds. Note: Materials may be edited for content and length.

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Water-rich gem points to vast ‘oceans’ beneath Earth’s surface, study suggests

A University of Alberta diamond scientist has found the first terrestrial sample of a water-rich gem that yields new evidence about the existence of large volumes of water deep within Earth.An international team of scientists led by Graham Pearson, Canada Excellence Research Chair in Arctic Resources at the U of A, has discovered the first-ever sample of a mineral called ringwoodite. Analysis of the mineral shows it contains a significant amount of water — 1.5 per cent of its weight — a finding that confirms scientific theories about vast volumes of water trapped 410 to 660 kilometres beneath Earth’s surface, between the upper and lower mantle.”This sample really provides extremely strong confirmation that there are local wet spots deep in the Earth in this area,” said Pearson, a professor in the Faculty of Science, whose findings were published March 13 in Nature. “That particular zone in the Earth, the transition zone, might have as much water as all the world’s oceans put together.”Ringwoodite is a form of the mineral peridot, believed to exist in large quantities under high pressures in the transition zone. Ringwoodite has been found in meteorites but, until now, no terrestrial sample has ever been unearthed because scientists haven’t been able to conduct fieldwork at extreme depths.Pearson’s sample was found in 2008 in the Juina area of Mato Grosso, Brazil, where artisan miners unearthed the host diamond from shallow river gravels. The diamond had been brought to the Earth’s surface by a volcanic rock known as kimberlite — the most deeply derived of all volcanic rocks.The discovery that almost wasn’tPearson said the discovery was almost accidental in that his team had been looking for another mineral when they purchased a three-millimetre-wide, dirty-looking, commercially worthless brown diamond. The ringwoodite itself is invisible to the naked eye, buried beneath the surface, so it was fortunate that it was found by Pearson’s graduate student, John McNeill, in 2009.”It’s so small, this inclusion, it’s extremely difficult to find, never mind work on,” Pearson said, “so it was a bit of a piece of luck, this discovery, as are many scientific discoveries.”The sample underwent years of analysis using Raman and infrared spectroscopy and X-ray diffraction before it was officially confirmed as ringwoodite. The critical water measurements were performed at Pearson’s Arctic Resources Geochemistry Laboratory at the U of A. The laboratory forms part of the world-renowned Canadian Centre for Isotopic Microanalysis, also home to the world’s largest academic diamond research group.The study is a great example of a modern international collaboration with some of the top leaders from various fields, including the Geoscience Institute at Goethe University, University of Padova, Durham University, University of Vienna, Trigon GeoServices and Ghent University.For Pearson, one of the world’s leading authorities in the study of deep Earth diamond host rocks, the discovery ranks among the most significant of his career, confirming about 50 years of theoretical and experimental work by geophysicists, seismologists and other scientists trying to understand the makeup of the Earth’s interior.Scientists have been deeply divided about the composition of the transition zone and whether it is full of water or desert-dry. Knowing water exists beneath the crust has implications for the study of volcanism and plate tectonics, affecting how rock melts, cools and shifts below the crust.”One of the reasons the Earth is such a dynamic planet is the presence of some water in its interior,” Pearson said. “Water changes everything about the way a planet works.”Story Source:The above story is based on materials provided by University of Alberta. …

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Remote sensing moisture model could aid farmers

Global farmers could get better decision-making help as refinements are made to North Alabama soil moisture modeling research being done by an atmospheric science doctoral student at The University of Alabama in Huntsville (UAH).The models indicate how much added moisture would be needed in a given area versus historical data to achieve various crop yields, and they could aid in making expensive infrastructure investments by helping to determine their economic viability.”The important thing that I want to stress is that this is not a predictive model, it is a decision-support model. It helps farmers and officials make decisions based on historical weather patterns,” says doctoral student Vikalp Mishra. In areas where water is in short supply, irrigation infrastructure can be expensive and the model could help to determine its economic cost effectiveness.Mishra was the primary author of a paper with his advisor and UAH associate professor of atmospheric science Dr. John Mecikalski, UAH Earth System Science Center principle researcher James Cruise, and researchers from the University of Maryland-College Park and the U.S. Dept. of Agriculture’s Hydrology and Remote Sensing Laboratory in Beltsville, Md.The model uses satellite data to determine the amount of soil moisture present and then estimates yields based on available moisture. Water is at the center of nearly all farming decisions. It affects the crop cultivar, the variety of seed planted, the amount and type of fertilizer required and the amount of irrigation needed to produce a given weight of grain.Researchers begin by using satellite derived evapotranspiration estimates at thermal infrared bands to deduce the amount of moisture being transpired by plants. Moisture data are derived from the Geostationary Operational Environmental Satellites (GOES). GOES data are inputted into the Atmosphere-Land Exchange Inverse (ALEXI) model, previously developed by Dr. …

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Hubble witnesses an asteroid mysteriously disintegrating

The NASA/ESA Hubble Space Telescope has photographed the never-before-seen break-up of an asteroid, which has fragmented into as many as ten smaller pieces. Although fragile comet nuclei have been seen to fall apart as they approach the Sun, nothing like the breakup of this asteroid, P/2013 R3, has ever been observed before in the asteroid belt.”This is a rock. Seeing it fall apart before our eyes is pretty amazing,” said David Jewitt of UCLA, USA, who led the astronomical forensics investigation.The crumbling asteroid, designated P/2013 R3, was first noticed as an unusual, fuzzy-looking object on 15 September 2013 by the Catalina and Pan-STARRS sky surveys. Follow-up observations on 1 October with the Keck Telescope on Mauna Kea, Hawaii, revealed three co-moving bodies embedded in a dusty envelope that is nearly the diameter of Earth.”Keck showed us that this thing was worth looking at with Hubble,” Jewitt said. With its superior resolution, the space-based Hubble observations soon showed that there were really ten distinct objects, each with comet-like dust tails. The four largest rocky fragments are up to 200 metres in radius, about twice the length of a football pitch.The Hubble data showed that the fragments are drifting away from each other at a leisurely 1.5 kilometres per hour — slower than the speed of a strolling human. The asteroid began coming apart early last year, but the latest images show that pieces continue to emerge.”This is a really bizarre thing to observe — we’ve never seen anything like it before,” says co-author Jessica Agarwal of the Max Planck Institute for Solar System Research, Germany. “The break-up could have many different causes, but the Hubble observations are detailed enough that we can actually pinpoint the process responsible.”The ongoing discovery of more fragments makes it unlikely that the asteroid is disintegrating due to a collision with another asteroid, which would be instantaneous and violent in comparison to what has been observed. Some of the debris from such a high-velocity smash-up would also be expected to travel much faster than has been observed.It is also unlikely that the asteroid is breaking apart due to the pressure of interior ices warming and vaporising. The object is too cold for ices to significantly sublimate, and it has presumably maintained its nearly 480-million-kilometre distance from the Sun for much of the age of the Solar System.This leaves a scenario in which the asteroid is disintegrating due to a subtle effect of sunlight that causes the rotation rate to slowly increase over time. …

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Ancient ‘great leap forward’ for life in the open ocean: Cyanobacteria sheds light on how complex life evolved on earth

Plankton in Earth’s oceans received a huge boost when microorganisms capable of creating soluble nitrogen ‘fertilizer’ directly from the atmosphere diversified and spread throughout the open ocean. This event occurred at around 800 million years ago and it changed forever how carbon was cycled in the ocean.It has long been believed that the appearance of complex multicellular life towards the end of the Precambrian (the geologic interval lasting up until 541 million years ago) was facilitated by an increase in oxygen, as revealed in the geological record. However, it has remained a mystery as to why oxygen increased at this particular time and what its relationship was to ‘Snowball Earth’ — the most extreme climatic changes Earth has ever experienced — which were also taking place around then.This new study shows that it could in fact be what was happening to nitrogen at this time that helps solve the mystery.The researchers, led by Dr Patricia Sanchez-Baracaldo of the University of Bristol, used genomic data to reconstruct the relationships between those cyanobacteria whose photosynthesis in the open ocean provided oxygen in quantities sufficient to be fundamental in the development of complex life on Earth.Some of these cyanobacteria were also able to transform atmospheric nitrogen into bioavailable nitrogen in sufficient quantities to contribute to the marine nitrogen cycle, delivering ‘nitrogen fertiliser’ to the ecosystem. Using molecular techniques, the team were able to date when these species first appeared in the geological record to around 800 million years ago.Dr Sanchez-Baracaldo, a Royal Society Dorothy Hodgkin Research Fellow in Bristol’s Schools of Biological and Geographical Sciences said: “We have known that oxygenic photosynthesis — the process by which microbes fix carbon dioxide into carbohydrates, splitting water and releasing oxygen as a by-product — first evolved in freshwater habitats more than 2.3 billion years ago. But it wasn’t until around 800 million years ago that these oxygenating cyanobacteria were able to colonise the vast oceans (two thirds of our planet) and be fertilised by enough bioavailable nitrogen to then produce oxygen — and carbohydrate food — at levels high enough to facilitate the next ‘great leap forward’ towards complex life.”Our study suggests that it may have been the fixing of this nitrogen ‘fertiliser’ in the oceans at this time that played a pivotal role in this key moment in the evolution of life on Earth.”Co-author, Professor Andy Ridgwell said: “The timing of the spread in nitrogen fixers in the open ocean occurs just prior to global glaciations and the appearance of animals. Although further work is required, these evolutionary changes may well have been related to, and perhaps provided a trigger for, the occurrence of extreme glaciation around this time as carbon was now being buried in the sediments on a much larger scale.”Dr Sanchez-Baracaldo added: “It’s very exciting to have been able to use state of the art genetic techniques to help solve an age-old mystery concerning one of the most important and pivotal moments in the evolution of life on Earth. In recent years, genomic data has been helping re-tell the story of the origins of life with increasing clarity and accuracy. It is a privilege to be contributing to our understanding of how microorganisms have contributed to make our planet habitable.”Story Source:The above story is based on materials provided by University of Bristol. Note: Materials may be edited for content and length.

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Planet-sized space weather explosions at Venus

Researchers recently discovered that a common space weather phenomenon on the outskirts of Earth’s magnetic bubble, the magnetosphere, has much larger repercussions for Venus. The giant explosions, called hot flow anomalies, can be so large at Venus that they’re bigger than the entire planet and they can happen multiple times a day.”Not only are they gigantic,” said Glyn Collinson, a space scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md. “But as Venus doesn’t have a magnetic field to protect itself, the hot flow anomalies happen right on top of the planet. They could swallow the planet whole.”Collinson is the first author of a paper on these results that appeared online in the Journal of Geophysical Research in February 2014. The work is based on observations from the European Space Agency’s Venus Express. The results show just how large and how frequent this kind of space weather is at Venus.Earth is protected from the constant streaming solar wind of radiation by its magnetosphere. Venus, however, has no such luck. A barren, inhospitable planet, with an atmosphere so dense that spacecraft landing there are crushed within hours, Venus has no magnetic protection.Scientists like to compare the two: What happened differently at Earth to make it into the life-supporting planet it is today? What would Earth be like without its magnetic field?At Earth, hot flow anomalies do not make it inside the magnetosphere, but they release so much energy just outside that the solar wind is deflected, and can be forced to move back toward the sun. Without a magnetosphere, what happens at Venus is very different.Venus’s only protection from the solar wind is the charged outer layer of its atmosphere called the ionosphere. …

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The ups and downs of early atmospheric oxygen

UC Riverside research team challenges conventional view of a simple two-step rise in early oxygen on Earth; study suggests instead dynamic oxygen concentrations that rose and fell over billions of years.A team of biogeochemists at the University of California, Riverside, give us a nontraditional way of thinking about the earliest accumulation of oxygen in the atmosphere, arguably the most important biological event in Earth history.A general consensus asserts that appreciable oxygen first accumulated in Earth’s atmosphere around 2.3 billion years ago during the so-called Great Oxidation Event (GOE). However, a new picture is emerging: Oxygen production by photosynthetic cyanobacteria may have initiated as early as 3 billion years ago, with oxygen concentrations in the atmosphere potentially rising and falling episodically over many hundreds of millions of years, reflecting the balance between its varying photosynthetic production and its consumption through reaction with reduced compounds such as hydrogen gas.”There is a growing body of data that points to oxygen production and accumulation in the ocean and atmosphere long before the GOE,” said Timothy W. Lyons, a professor of biogeochemistry in the Department of Earth Sciences and the lead author of the comprehensive synthesis of more than a decade’s worth of study within and outside his research group.Lyons and his coauthors, Christopher T. Reinhard and Noah J. Planavsky, both former UCR graduate students, note that once oxygen finally established a strong foothold in the atmosphere starting about 2.3 billion years ago it likely rose to high concentrations, potentially even levels like those seen today. Then, for reasons not well understood, the bottom fell out, oxygen plummeted to a tiny fraction of today’s level, and the ocean remained mostly oxygen free for more than a billion years.The paper appears in Nature on Feb. 19.”This period of extended low oxygen spanning from roughly 2 to less than 1 billion years ago was a time of remarkable chemical stability in the ocean and atmosphere,” Lyons said.His research team envisions a series of interacting processes, or feedbacks, that maintained oxygen at very low levels principally by modulating the availability of life-sustaining nutrients in the ocean and thus oxygen-producing photosynthetic activity.”We suggest that oxygen was much lower than previously thought during this important middle chapter in Earth history, which likely explains the low abundances and diversity of eukaryotic organisms and the absence of animals,” Lyons said.The late Proterozoic — the time period beginning less than a billion years ago following this remarkable chapter of sustained low levels of oxygen — was strikingly different, marked by extreme climatic events manifest in global-scale glaciation, indications of at least intervals of modern-like oxygen abundances, and the emergence and diversification of the earliest animals. Lyons notes that the factors controlling the rise of animals are under close scrutiny, including challenges to the long-held view that a major rise in atmospheric oxygen concentrations triggered the event.”Despite the new ideas about animal origins, we suspect that oxygen played a major if not dominant role in the timing of that rise and, in particular, in the subsequent emergence of complex ecologies for animal life on and within the sediment, predator-prey relationships, and large bodies” said Lyons. “But, again, feedbacks always rule the day. Environmental change drives evolution, and steps in the progression of life change the environment.”No single factor is likely to be the whole story, and there is much more to be written in the tale. …

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Theory on origin of animals challenged: Some animals need extremely little oxygen

One of science’s strongest dogmas is that complex life on Earth could only evolve when oxygen levels in the atmosphere rose to close to modern levels. But now studies of a small sea sponge fished out of a Danish fjord shows that complex life does not need high levels of oxygen in order to live and grow.The origin of complex life is one of science’s greatest mysteries. How could the first small primitive cells evolve into the diversity of advanced life forms that exists on Earth today? The explanation in all textbooks is: Oxygen. Complex life evolved because the atmospheric levels of oxygen began to rise app. 630 — 635 million years ago.However new studies of a common sea sponge from Kerteminde Fjord in Denmark shows that this explanation needs to be reconsidered. The sponge studies show that animals can live and grow even with very limited oxygen supplies.In fact animals can live and grow when the atmosphere contains only 0.5 per cent of the oxygen levels in today’s atmosphere.”Our studies suggest that the origin of animals was not prevented by low oxygen levels,” says Daniel Mills, PhD at the Nordic Center for Earth Evolution at the University of Southern Denmark.Together with Lewis M. Ward from the California Institute of Technology he is the lead author of a research paper about the work in the journal PNAS.A little over half a billion years ago, the first forms of complex life — animals — evolved on Earth. Billions of years before that life had only consisted of simple single-celled life forms. The emergence of animals coincided with a significant rise in atmospheric oxygen, and therefore it seemed obvious to link the two events and conclude that the increased oxygen levels had led to the evolution of animals.”But nobody has ever tested how much oxygen animals need — at least not to my knowledge. …

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Four unknown galaxy clusters containing thousands of galaxies discovered 10 billion light years from Earth

Four unknown galaxy clusters each potentially containing thousands of individual galaxies have been discovered some 10 billion light years from Earth.An international team of astronomers, led by Imperial College London, used a new way of combining data from the two European Space Agency satellites, Planck and Herschel, to identify more distant galaxy clusters than has previously been possible. The researchers believe up to 2000 further clusters could be identified using this technique, helping to build a more detailed timeline of how clusters are formed.Galaxy clusters are the most massive objects in the universe, containing hundreds to thousands of galaxies, bound together by gravity. While astronomers have identified many nearby clusters, they need to go further back in time to understand how these structures are formed. This means finding clusters at greater distances from Earth.The light from the most distant of the four new clusters identified by the team has taken over 10 billion years to reach us. This means the researchers are seeing what the cluster looked like when the universe was just three billion years old.Lead researcher Dr David Clements, from the Department of Physics at Imperial College London, explains: “Although we’re able to see individual galaxies that go further back in time, up to now, the most distant clusters found by astronomers date back to when the universe was 4.5 billion years old. This equates to around nine billion light years away. Our new approach has already found a cluster in existence much earlier than that, and we believe it has the potential to go even further.”The clusters can be identified at such distances because they contain galaxies in which huge amounts of dust and gas are being formed into stars. This process emits light that can be picked up by the satellite surveys.Galaxies are divided into two types: elliptical galaxies that have many stars, but little dust and gas; and spiral galaxies like our own, the Milky Way, which contain lots of dust and gas. Most clusters in the universe today are dominated by giant elliptical galaxies in which the dust and gas has already been formed into stars.”What we believe we are seeing in these distant clusters are giant elliptical galaxies in the process of being formed,” says Dr Clements.Observations were recorded by the Spectral and Photometric Imaging Receiver (SPIRE) instrument as part of Herschel Multi-tiered Extragalactic Survey (HerMES). Seb Oliver, Head of the HerMES survey said: “The fantastic thing about Herschel-SPIRE is that we are able to scan very large areas of the sky with sufficient sensitivity and image sharpness that we can find these rare and exotic things. …

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Christian Olsen and Michael Bradley – 2 young guys battling mesothelioma

Both Christian and Michael are brave mesothelioma warriors who both live in the USA. Michael is 29 years of age and Christian has just celebrated his 34th birthday with his wife Lisa and their 2 small children.Michael is at home after a few days in hospital to get his pain under control. He is doing it tough at the moment – however he know has his own wheelchair and is getting out during the day to his favourite places with family and friends – there is no tying Michael to his bed!(This link below is for Michael’s facebook page)https://www.facebook.com/groups/315461631836891/?fref=tsChristian is due to start chemotherapy tomorrow morning cisplatin/alimta. I have been speaking with him today and he has been asking relevant questions that I …

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Is an earthquake behind the Shroud of Turin image? Radiation from earthquake could have led to ‘wrong’ 1988 dating

Neutron radiation caused by 33 A.D. earthquake could have led to “wrong” 1988 radiocarbon dating of Shroud, suggest researchersAn earthquake in Old Jerusalem might be behind the famous image of the Shroud of Turin, says a group of researchers led by Alberto Carpinteri of the Politecnico di Torino in Italy in an article published in Springer’s journal Meccanica. They believe that neutron radiation caused by an earthquake could have induced the image of a crucified man — which many people believe to be that of Jesus — onto the length of linen cloth, and caused carbon-14 dating done on it in 1988 to be wrong.The Shroud has attracted widespread interest ever since Secondo Pia took the first photograph of it in 1898: about whether it is Jesus’ purported burial cloth, how old it might be, and how the image was created. According to radiocarbon dating done in 1988, the cloth was only 728 years old at the time. Other researchers have since suggested that the shroud is much older and that the dating process was incorrect because of neutron radiation — a process which is the result of nuclear fusion or nuclear fission during which free neutrons are released from atoms — and its interaction with the nuclei of other atoms to form new carbon isotopes.However, no plausible physical reason has yet been proposed to explain the origin of this neutron radiation. Now Carpinteri’s team, through mechanical and chemical experimentation, hypothesizes that high-frequency pressure waves generated in Earth’s crust during earthquakes are the source of such neutron emissions. This is based on their research into piezonuclear fission reactions, which are triggered when very brittle rock specimens are crushed under a press machine. In the process, neutrons are produced without gamma emissions. Analogously, the researchers theorize further that neutron flux increments, in correspondence to seismic activity, should be a result of the same reactions.The researchers therefore believe that neutron emission from a historical earthquake in 33 A.D. in Old Jerusalem, which measured 8.2 on the Richter Scale, could have been strong enough to cause neutron imaging through its interaction with nitrogen nuclei. …

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Red skies discovered on extreme brown dwarf

A peculiar example of a celestial body, known as a brown dwarf, with unusually red skies has been discovered by a team of astronomers from the University of Hertfordshire’s Centre for Astrophysics Research.Brown dwarfs straddle the line between stars and planets. They are too big to be considered as planets; yet they do not have sufficient material to fuse hydrogen in their cores to fully develop into stars. They are midway in mass between stars, like our Sun, and giant planets, like Jupiter and Saturn. Sometimes described as failed stars, they do not have an internal source of energy — so they are cold and very faint, and keep on cooling over time.The brown dwarf, named ULAS J222711-004547, caught the researchers’ attention for its extremely red appearance compared to “normal” brown dwarfs. Further observations with the VLT (Very Large Telescope) in Chile and the use of an innovative data analysis technique have shown that the reason for its peculiarity is the presence of a very thick layer of clouds in its upper atmosphere.Federico Marocco, who led the research team from the University of Hertfordshire, said: “These are not the type of clouds that we are used to seeing on Earth. The thick clouds on this particular brown dwarf are mostly made of mineral dust, like enstatite and corundum.”Not only have we been able to infer their presence, but we have also been able to estimate the size of the dust grains in the clouds.”The size of the dust grains influences the colour of the sky. In a similar way that the old saying of “Red sky at night, shepherd’s delight. Red sky in the morning, shepherd’s warning” is used at sunrise and sunset to indicate the changing weather, a red sky on the brown dwarf suggests an atmosphere loaded with dust and moisture particles. If our morning skies are red, it is because clear skies to the east permit the sun to light the undersides of moisture-bearing clouds coming in from the west. Conversely, in order to see red clouds in the evening, sunlight must have a clear path from the west in order to illuminate moisture-bearing clouds moving off to the east. …

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Sneezing sponges suggest existence of sensory organ: Discovery challenges assumptions about ‘primitive’ organism

When Danielle Ludeman decided to leave her hometown of Vancouver to study evolutionary biology at the University of Alberta, she knew she was in for a challenge that would help her discover things about science and, in turn, herself.What she didn’t count on were the hours, days and months she’d spend watching sponges in mid-sneeze.It sounds like a strange way to pass time, but sneezing sponges have become a major part of Ludeman’s studies at the U of A, including a new paper that points to the sneeze as evidence of a sensory organ in one of the most basic multicellular organisms on Earth.”The sneeze can tell us a lot about how the sponge works and how it’s responding to the environment,” said Ludeman, a master’s student in the Faculty of Science. “This paper really gets at the question of how sensory systems evolved. The sponge doesn’t have a nervous system, so how can it respond to the environment with a sneeze the way another animal that does have a nervous system can?”Ludeman started the work as part of an undergraduate research honours project, working under the supervision of Sally Leys, Canada Research Chair in Evolutionary Developmental Biology. It was Leys and a former graduate student who first discovered that sponges do in fact sneeze.The sponge is a filter feeder that relies totally on water flow through its body for food, oxygen and waste removal. Sneezing, a 30- to 45-minute process that sees the entire body of the sponge expand and contract, allows it to respond to physical stimuli such as sediment in the water.Time-lapse sneezesFor their study, Ludeman and Leys used a variety of drugs to elicit sneezes in freshwater sponges and observed the process using fluorescent dye — all recorded using time-lapse video. Their efforts focused on the sponge’s osculum, which controls water exiting the organism, including water expelled during a sneeze.Through a series of lab experiments, the pair discovered that ciliated cells lining the osculum play a role in triggering sneezes. In other animals, cilia function like antennae, helping cells respond to stimuli in a co-ordinated manner. In the sponge, their localized presence in the osculum and their sensory function suggest the osculum is in fact a sensory organ.”For a sponge to have a sensory organ is totally new. This does not appear in a textbook; this doesn’t appear in someone’s concept of what sponges are permitted to have,” said Leys.Leys said the discovery raises new questions about how sensory systems may have evolved in the sponge and other animals, including ones with nervous systems. It’s possible this sensory system is unique to the sponge, she said, evolving over the last 600 million years. …

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Astronomer helps research team see misaligned planets in distant system

Oct. 17, 2013 — Using data from NASA’s Kepler space telescope, an international team of astronomers has discovered a distant planetary system featuring multiple planets orbiting at a severe tilt to their host star.Such tilted orbits had been found in planetary systems featuring a “hot Jupiter,” a giant planet in a close orbit to its host star. But, until now, they hadn’t been observed in multiplanetary systems without such a big interloping planet.The discovery is reported in a paper, “Stellar Spin-Orbit Misalignment in a Multiplanet System,” published in the Oct. 18 issue of the journal Science. The lead author of the study is Daniel Huber of NASA’s Ames Research Center in Mountain View, Calif. Steve Kawaler, an Iowa State University professor of physics and astronomy and a leader of the Kepler Asteroseismic Investigation, is a co-author.”This is a new level of detail about the architecture of a planetary system outside our solar system,” Kawaler said. “These studies allow us to draw a detailed picture of a distant system that provides a new and critical test of our understanding of how these very alien solar systems are structured.”Kawaler contributed as part of the research team that studied regular changes in the brightness of the host star, Kepler-56, an aging red giant star with two planets in close orbits and a massive third planet in a distant orbit. By measuring those oscillation frequencies and using spectroscopy data about the star’s temperature and chemistry, researchers measured the star’s diameter and other properties.The paper reports Kepler-56 is more than four times the radius of our sun. Its mass is also 30 percent greater than our sun. It is about 3,000 light years from Earth.Kawaler said he was also part of the team that used studies of the changes in brightness to help determine the tilt of the rotation axis of Kepler-56. …

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Gravitational waves help us understand black-hole weight gain

Oct. 17, 2013 — Supermassive black holes: every large galaxy’s got one. But here’s a real conundrum: how did they grow so big?A paper in today’s issue of Science pits the front-running ideas about the growth of supermassive black holes against observational data — a limit on the strength of gravitational waves, obtained with CSIRO’s Parkes radio telescope in eastern Australia.”This is the first time we’ve been able to use information about gravitational waves to study another aspect of the Universe — the growth of massive black holes,” co-author Dr Ramesh Bhat from the Curtin University node of the International Centre for Radio Astronomy Research (ICRAR) said.”Black holes are almost impossible to observe directly, but armed with this powerful new tool we’re in for some exciting times in astronomy. One model for how black holes grow has already been discounted, and now we’re going to start looking at the others.”The study was jointly led by Dr Ryan Shannon, a Postdoctoral Fellow with CSIRO, and Mr Vikram Ravi, a PhD student co-supervised by the University of Melbourne and CSIRO.Einstein predicted gravitational waves — ripples in space-time, generated by massive bodies changing speed or direction, bodies like pairs of black holes orbiting each other.When galaxies merge, their central black holes are doomed to meet. They first waltz together then enter a desperate embrace and merge.”When the black holes get close to meeting they emit gravitational waves at just the frequency that we should be able to detect,” Dr Bhat said.Played out again and again across the Universe, such encounters create a background of gravitational waves, like the noise from a restless crowd.Astronomers have been searching for gravitational waves with the Parkes radio telescope and a set of 20 small, spinning stars called pulsars.Pulsars act as extremely precise clocks in space. The arrival time of their pulses on Earth are measured with exquisite precision, to within a tenth of a microsecond.When the waves roll through an area of space-time, they temporarily swell or shrink the distances between objects in that region, altering the arrival time of the pulses on Earth.The Parkes Pulsar Timing Array (PPTA), and an earlier collaboration between CSIRO and Swinburne University, together provide nearly 20 years worth of timing data. This isn’t long enough to detect gravitational waves outright, but the team say they’re now in the right ballpark.”The PPTA results are showing us how low the background rate of gravitational waves is,” said Dr Bhat.”The strength of the gravitational wave background depends on how often supermassive black holes spiral together and merge, how massive they are, and how far away they are. So if the background is low, that puts a limit on one or more of those factors.”Armed with the PPTA data, the researchers tested four models of black-hole growth. They effectively ruled out black holes gaining mass only through mergers, but the other three models are still a possibility.Dr Bhat also said the Curtin University-led Murchison Widefield Array (MWA) radio telescope will be used to support the PPTA project in the future.”The MWA’s large view of the sky can be exploited to observe many pulsars at once, adding valuable data to the PPTA project as well as collecting interesting information on pulsars and their properties,” Dr Bhat said.

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