Fire ecology manipulation by California native cultures

Before the colonial era, 100,000s of people lived on the land now called California, and many of their cultures manipulated fire to control the availability of plants they used for food, fuel, tools, and ritual. Contemporary tribes continue to use fire to maintain desired habitat and natural resources.Frank Lake, an ecologist with the U.S. Forest Service’s Pacific Southwest Station, will lead a field trip to the Stone Lake National Wildlife Refuge during the Ecological Society of America’s 99th Annual Meeting in Sacramento, Cal., this August. Visitors will learn about plant and animal species of cultural importance to local tribes. Don Hankins, a faculty associate at California State University at Chico and a member of the Miwok people, will co-lead the trip, which will end with a visit to California State Indian Museum.Lake will also host a special session on a “sense of place,” sponsored by the Traditional Ecological Knowledge section of the Ecological Society, that will bring representatives of local tribes into the Annual Meeting to share their cultural and professional experiences working on tribal natural resources issues.”The fascinating thing about the Sacramento Valley and the Miwok lands where we are taking the field trip is that it was a fire and flood system,” said Lake. “To maintain the blue and valley oak, you need an anthropogenic fire system.”Lake, raised among the Yurok and Karuk tribes in the Klamath River area of northernmost California, began his career with an interest in fisheries, but soon realized he would need to understand fire to restore salmon. Fire exerts a powerful effect on ecosystems, including the quality and quantity of water available in watersheds, in part by reducing the density of vegetation.”Those trees that have grown up since fire suppression are like straws sucking up the groundwater,” Lake said.The convergence of the Sacramento and San Joaquin rivers was historically one of the largest salmon bearing runs on the West Coast, Lake said, and the Miwok, Patwin and Yokut tribal peoples who lived in the area saw and understood how fire was involved.California native cultures burned patches of forest in deliberate sequence to diversify the resources available within their region. The first year after a fire brought sprouts for forage and basketry. In 3 to 5 years, shrubs produced a wealth of berries. Mature trees remained for the acorn harvest, but burning also made way for the next generation of trees, to ensure a consistent future crop. …

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The ten best weather places in the world

Do you dream of a place that is always sunny? Where the temperature is perfect? Where there is virtually no severe weather? Ed Darack has. His article, “The 10 Best Weather Places in the World,” featured in the March/April issue of Weatherwise magazine attempts to name the top ten places in the world that continually experience the best weather.Darack defines what “best” weather consists of. The basis of this list is founded in weather that has positive effects on human fundamental needs (physical, mental, and emotional). “We can determine meteorological “best” criteria for ideal human physical, mental, and emotional health that includes temperature, humidity, average number of sunny days, and other criteria, by studying the results of research conducted on environmental effects on humans.” With this in mind Darack creates a mythical place of weather perfection, ‘Anthro-Weathertopia’. Here the temperature never strays too far from 68F, the humidity is always comfortably 50%, and the clouds are never a threat. Unfortunately this perfect place does not exist, but his article lists the top ten places that come close.The Manjimup region of the extreme south west region of Western Australia ranks at number ten on the list. It is a piece of lush land off the southern Indian Ocean. …

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Oldest fortified settlement ever found in North America? Location of Fort Caroline may be in Georgia

In an announcement that could rewrite the book on early colonization of the New World, two researchers today said they have proposed a location for the oldest fortified settlement ever found in North America. Speaking at an international conference on France at Florida State University, the pair announced that they have proposed a new location for Fort Caroline, a long-sought fort built by the French in 1564.”This is the oldest fortified settlement in the present United States,” said Florida State University alumnus and historian Fletcher Crowe. “This fort is older than St. Augustine, considered to be the oldest continuously inhabited city in America. It’s older than the Lost Colony of Virginia by 21 years; older than the 1607 fort of Jamestown by 45 years; and predates the landing of the Pilgrims in Massachusetts in 1620 by 56 years.”Announcement of the discovery of Fort Caroline was made during “La Floride Franaise: Florida, France, and the Francophone World,” a conference hosted by FSU’s Winthrop-King Institute for Contemporary French and Francophone Studies and its Institute on Napoleon and the French Revolution. The conference commemorates the cultural relations between France and Florida since the 16th century.Researchers have been searching for actual remains of Fort Caroline for more than 150 years but had not found the actual site until now, Crowe said. The fort was long thought to be located east of downtown Jacksonville, Fla., on the south bank of the St. Johns River. The Fort Caroline National Memorial is located just east of Jacksonville’s Dames Point Bridge, which spans the river.However, Crowe and his co-author, Anita Spring, a professor emeritus of anthropology at the University of Florida, say that the legendary fort is actually located near the mouth of the Altamaha River in southeast Georgia.”This really is an important work of scholarship, and what a great honor it is for it to be announced at a conference organized by the Winthrop-King Institute,” said Martin Munro, a professor in FSU’s Department of Modern Languages and Linguistics and director of the Winthrop-King Institute. “It demonstrates the pre-eminence of the institute and recognizes the work we do in promoting French and Francophone culture in Florida, the United States and internationally.”Darrin McMahon, the Ben Weider Professor of History and a faculty member with the Institute on Napoleon and the French Revolution, observed that Crowe and Spring’s finding — like the conference itself — highlights France’s longstanding presence in Florida and the Southeast. …

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‘Smelling’ with our eyes: Descriptions affect odor perception

According to Simona Manescu and Johannes Frasnelli of the University of Montreal’s Department of Psychology, an odour is judged differently depending on whether it is accompanied by a positive or negative description when it is smelled. When associated with a pleasant label, we enjoy the odour more than when it is presented with a negative label. To put it another way, we also smell with our eyes!This was demonstrated by researchers in a study recently published in the journal Chemical Senses.For their study, they recruited 50 participants who were asked to smell the odours of four odorants (essential oil of pine, geraniol, cumin, as well as parmesan cheese). Each odour (administered through a mask) was randomly presented with a positive or negative label displayed on a computer screen. In this way, pine oil was presented either with the label “Pine Needles” or the label “Old Solvent”; geraniol was presented with the label “Fresh Flowers” or “Cheap Perfume”; cumin was presented with the label “Indian Food” or “Dirty Clothes; and finally, parmesan cheese was presented with the label of either the cheese or dried vomit.The result was that all participants rated the four odours more positively when they were presented with positive labels than when presented with negative labels. Specifically, participants described the odours as pleasant and edible (even those associated with non-food items) when associated with positive labels. Conversely, the same odours were considered unpleasant and inedible when associated with negative labels — even the food odours. “It shows that odour perception is not objective: it is affected by the cognitive interpretation that occurs when one looks at a label,” says Manescu. “Moreover, this is the first time we have been able to influence the edibility perception of an odour, even though the positive and negative labels accompanying the odours showed non-food words,” adds Frasnelli.This finding indicates that the perceived edibility of an odour can be manipulated by a description, and that olfactory perception may be driven by a top-down (or directive) cognitive process.Reaction times also affected by odoursVarious studies have shown that odours affect the reaction times of individuals. Thus, unpleasant odours cause rapid reactions (recoil, for example), while pleasant odours cause slower reactions. …

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Video captions improve comprehension

Oct. 11, 2013 — A simple change — switching on captions — can make a big difference when students watch educational videos, an SF State professor has discovered.Robert Keith Collins, an assistant professor of American Indian studies, found that students’ test scores and comprehension improved dramatically when captions were used while watching videos. The tool is often utilized for students with learning disabilities, but Collins says his results show captions can be beneficial to all students.Collins developed the idea while he was a member of a faculty learning committee focused on ways to make the classroom more accessible to all students. During the first year of a two-year case study, he showed videos without captions to establish a baseline of student comprehension. Once that baseline was established, he turned captions on and began to see improvements. Those improvements continued into the second year of the study.”Not only were students talking about how much having the captions helped them as they took notes, their test scores went up,” Collins said. “During the baseline year, there were a lot of Cs. In the second years, they went from Cs, Ds and Fs to As, Bs and Cs. It was really significant improvement.”That improvement didn’t just manifest itself in grades. Class discussions also became livelier and more detailed, with students recalling specific information shown in the videos such as names of people and places.”We’re living in an age where our students are so distracted by technology that they sometimes forget where they should focus their attention when engaged with technology or media,” he said. …

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African breed of cattle harbors potential defense against life-threatening parasite

Sep. 27, 2013 — Every year, millions of cattle die of trypanosomosis. The UN and the International Livestock Research Institute list trypanosomosis among the ten diseases of cattle with the greatest impact on the poor. In Africa the disease is known as “Nagana,” which translates literally as “being in low or depressed spirits.” The disease is caused by a parasite that enters the animals’ blood as a result of the bite of the Tsetse fly.Surprisingly, one West-African dwarf cattle breed, the Baoulé, seems less affected by trypanosomosis than others. When they are infected, Baoulé cattle develop fever and lose weight but do not necessarily die. Their immune system is thus better able to fight the parasite than that of other breeds. In other words, the cattle seem to have a natural tolerance against the parasite.A method to detect different trypanosomesKatja Silbermayr from the Institute of Parasitology of the University of Veterinary Medicine, Vienna (Vetmeduni), together with an international research team, collected blood samples from three cattle types. The scientists have developed a method that can identify the parasites responsible for trypanosomosis, the trypanosomes, and can even detect three different forms of the parasite in a single step. The information is extremely valuable to veterinarians and farmers as each type of trypanosome causes a slightly different disease progression and requires a different type of treatment.Zebu cattle are infected twice as oftenThe researchers used their new method to examine samples of blood from apparently healthy Baoulé cattle, Indian Zebu cattle and crosses between the two breeds. Zebus produce more meat and milk than Baoulé but fall severely ill when infected with trypanosomes. …

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How red crabs on Christmas Island speak for the tropics

Oct. 10, 2013 — Each year, the land-dwelling Christmas Island red crab takes an arduous and shockingly precise journey from its earthen burrow to the shores of the Indian Ocean where weeks of mating and egg laying await.The crabs represent species that do not factor into a lot of climate-change research. The majority of studies focus on changes in temperate climates, such as the future severity and duration of summers and winters. Tropical animals migrate in response to wet-dry seasons. If fluctuations in rainfall become more extreme and frequent with climate change, then scores of animals could be in trouble.Native to the Australian territories of Christmas Island and the Cocos (Keeling) Islands, millions of the crabs start rolling across the island roads and landscape in crimson waves when the November rains begin. After a two-week scuttle to the sea, the male crab sets up and defends a mating burrow for himself and a female of his kind, the place where she will incubate their clutch for another two weeks. Before the morning of the high tide that precedes the December new moon, the females must emerge to release their millions of eggs into the ocean. A month later, the next generation of crabs comes ashore.But a lack of rain can delay or entirely cancel this meticulous process, according to research conducted through Princeton University that could help scientists understand the consequences of climate change for the millions of migratory animals in Earth’s tropical zones.The researchers report in the journal Global Change Biology that the crabs’ reproductive cycle tracked closely with the amount and timing of precipitation. Writ large, these findings suggest that erratic rainfall could be detrimental to animals that migrate with the dry-wet seasonal cycle that breaks up the tropical year, the researchers report. If fluctuations in rainfall become more extreme and frequent with climate change, then scores of animals could be in trouble — not just the migrators themselves, but also the creatures reliant on them for food.Lead author Allison Shaw, who conducted the work as a Princeton doctoral student in ecology and evolutionary biology, explained that what scientists understand about the possible impact of a warming planet on animal movement is dominated by studies of how creatures that migrate with the summer-to-winter seasonal shifts of Europe and North America will be affected by changes such as the severity and duration of summers and winters. …

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Crop-raiding elephants flee tiger growls

Sep. 11, 2013 — Wild Asian elephants slink quietly away at the sound of a growling tiger, but trumpet and growl before retreating from leopard growls, researchers at the University of California, Davis, have found. The work, published Sept. 11 in the journal Biology Letters, could help Indian farmers protect their crops from marauding elephants and save the lives of both people and animals.”We noticed that the elephants were more scared of tigers than of leopards,” said Vivek Thuppil, who carried out the work with Richard Coss, professor of psychology at UC Davis, as part of his Ph.D. in animal behavior.Thuppil and Coss studied the elephants’ behavior in an effort to prevent conflicts between human farmers and elephant herds that raid their fields by night. It’s the first study of nighttime antipredator behavior in elephants.Crop raiding by elephants is a serious problem in India, Thuppil said. Farmers use drums, firecrackers and electrified fences to try to keep them out of their crops. About 400 people a year are killed during these encounters, and some hundred elephants are killed through poisoning, electrocution or other means, according to an Indian government report.The researchers set up equipment to play back leopard or tiger growls triggered when the elephants crossed infrared beams across paths leading to crop fields, and captured the events on video.Leopards aren’t known to prey on elephants, but tigers will sometimes attack a young elephant that becomes separated from the herd.Although their initial reactions were very different, the elephants ultimately retreated from growls of both cats.The elephants might be confused by the leopard growl, Thuppil said. A real leopard would most likely retreat from a group of elephants. Still, there’s probably no benefit to the elephants in risking an encounter with a leopard, even if it is not a known predator.”You don’t want to mess with something with claws and teeth,” Thuppil said.”They’re acting in a very intelligent way,” Coss said.Wild elephant populations are stable or even increasing in forest areas, Thuppil said. …

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Half of all UK 7 year olds not exercising for recommended minimum

Aug. 22, 2013 — Half of all UK seven year olds are sedentary for six to seven hours every day, and only half clock up the recommended daily minimum of moderate to vigorous physical activity, indicates research published in the online journal BMJ Open.Girls, children of Indian ethnic origin, and those living in Northern Ireland are the least physically active of all seven year olds, the findings show.The authors base their findings on a representative population sample of almost 7000 UK primary school children who were all part of the Millennium Cohort Study. This is tracking the long term health of around 19,000 children born in the UK between 2000 and 2002.The duration and intensity of children’s daily physical activity levels were captured for a full week between May 2008 and August 2009, using a gadget called an accelerometer, worn on an elasticated belt. The children only took this off when they bathed or went to bed.UK guidelines on daily physical activity levels across the life course were revised in 2011. These recommend that children engage in moderate to vigorous physical activity for at least an hour every day, and that they spend less time sitting down, although no maximum has been specified for this.The analysis showed that on average, across the entire sample, children managed 60 minutes of moderate to vigorous physical activity every day, and that they took an average of 10,299 steps.But the accelerometer readings also showed that half the children were sedentary for six or more hours every day, and that half of them didn’t reach the daily recommended exercise target.Girls fared worse than boys, in terms of total physical activity, moderate to vigorous physical activity, and in the number of steps they took every day.They were also more sedentary and less likely to meet their recommended daily exercise target than the boys. Just 38% of girls achieved this compared with almost two thirds of the boys (63%).And children of Indian ethnic origin spent the least time in moderate to vigorous exercise, and took the fewest steps each day, while only one in three (33%) children of Bangladeshi origin met the recommended daily exercise minimum.Among the four UK countries, children in Northern Ireland were the least active, with just 43% managing 60 minutes of moderate to vigorous physical activity every day, while children in Scotland were most likely (52.5%) to achieve the minimum daily target.And while around 52% of children in England managed 60 minutes of moderate to vigorous exercise each day, there were regional differences, with children living in the North West (58%) the most likely, and those in the Midlands (46%), the least likely, to do so.In an accompanying podcast, senior author Professor Carol Dezateux describes the gender differences in exercise levels as “striking” and calls for policies to promote more exercise among girls, including dancing, playground activities, and ball games.The authors refer back to the legacy of the London 2012 Olympic Games, which promised to inspire a generation to take part in sport.”The results of our study provide a useful baseline and strongly suggest that contemporary UK children are insufficiently active, implying that effort is needed to boost [physical activity] among young people to the level appropriate for good health,” they write.This is likely to require population wide interventions, they say, including policies to make it easier for kids to walk to school, in a bid to increase physical activity and curb the amount of time they are sedentary.”Investing in this area is a vital component to deliver the Olympic legacy and improve the short and long term health of our children,” they conclude.

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Scientists relate urban population to air pollution

Aug. 19, 2013 — Live in a large city like New York, London, Beijing or Mumbai, and you are likely exposed to more air pollution than people in smaller cities in surrounding areas. But exactly how a city’s pollution relates to the size of its population has never been measured, until now.Using satellite observations, NASA scientists directly measured air pollution’s dependence on population in four of the planet’s major air pollution regions: the United States, Europe, China and India.The study shows that the pollution-population relationship varies by region. For example, a city of 1 million people in Europe experiences six times higher nitrogen dioxide pollution than an equally populated city of 1 million people in India, according to the research led by Lok Lamsal, of NASA’s Goddard Space Flight Center in Greenbelt, Md. The variation is a reflection of regional differences such as industrial development, per capita emissions and geography. The study was published June 13 in Environmental Science & Technology.Previously, researchers have measured the relationship between population and several urban characteristics, such as infrastructure, employment and innovation. “We show that the relationship is also applicable to pollution,” Lamsal said. “Measurement of that relationship is potentially useful for developing future inventories and formulating air pollution control policies.”The researchers focused on nitrogen dioxide, or NO2, a common pollutant from the burning of fossil fuels. The gas is a precursor to the formation of near-ground ozone, which can cause respiratory problems and is a problem in many major metropolitan areas. NO2 is also unhealthy to breathe in high concentrations. …

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Robots strike fear in the hearts of fish: Anxious zebrafish help researchers understand how alcohol affects fear

July 31, 2013 — The latest in a series of experiments testing the ability of robots to influence live animals shows that bio-inspired robots can not only elicit fear in zebrafish, but that this reaction can be modulated by alcohol. These findings may pave the way for new methodologies for understanding anxiety and other emotions, as well as substances that alter them.Maurizio Porfiri, associate professor of mechanical and aerospace engineering at the Polytechnic Institute of New York University (NYU-Poly) and Simone Macrì, a collaborator at the Istituto Superiore di Sanità in Rome, Italy, published their findings in PLOS ONE, an international, peer-reviewed, open-access, online publication.This latest study expands Porfiri and Macrì’s efforts to determine how bio-inspired robots can be employed as reliable stimuli to elicit reactions from live zebrafish. Previous studies have established that zebrafish show a strong affinity for robotic members designed to swim and appear as one of their own and that this preference can be abolished by exposing the fish to ethanol.Porfiri and Macri, along with students Valentina Cianca and Tiziana Bartolini, hypothesized that robots could be used to induce fear as well as affinity and designed a robot mimicking the morphology and locomotion pattern of the Indian leaf fish, a natural predator of the zebrafish. In the lab, they simulated a harmless predatory scenario, placing the zebrafish and the robotic Indian leaf fish in separate compartments of a three-section tank. The other compartment was left empty. The control group uniformly avoided the robotic predator, showing a preference for the empty section.To determine whether alcohol would affect fear responses, the researchers exposed separate groups of fish to different doses of ethanol in water. Ethanol has been shown to influence anxiety-related responses in humans, rodents and some species of fish. The zebrafish exposed to the highest concentrations of ethanol showed remarkable changes in behavior, failing to avoid the predatory robot. Acute administration of ethanol causes no harm and has no lasting effect on zebrafish.”These results are further evidence that robots may represent an exciting new approach in evaluating and understanding emotional responses and behavior,” said Porfiri. “Robots are ideal replacements as independent variables in tests involving social stimuli — they are fully controllable, stimuli can be reproduced precisely each time, and robots can never be influenced by the behavior of the test subjects.”To validate their findings and ensure that the zebrafish behavior being modulated was, in fact, a fear-based response, Porfiri and his collaborators conducted two traditional anxiety tests and evaluated whether the results obtained therein were sensitive to ethanol administration.They placed test subjects in a two-chamber tank with one well-lit side and one darkened side, to establish which conditions were preferable. …

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No link between prenatal mercury exposure and autism-like behaviors found

July 23, 2013 — The potential impact of exposure to low levels of mercury on the developing brain — specifically by women consuming fish during pregnancy — has long been the source of concern and some have argued that the chemical may be responsible for behavioral disorders such as autism. However, a new study that draws upon more than 30 years of research in the Republic of Seychelles reports that there is no association between pre-natal mercury exposure and autism-like behaviors.”This study shows no evidence of a correlation between low level mercury exposure and autism spectrum-like behaviors among children whose mothers ate, on average, up to 12 meals of fish each week during pregnancy,” said Edwin van Wijngaarden, Ph.D., an associate professor in the University of Rochester Medical Center’s (URMC) Department of Public Health Sciences and lead author of the study which appears online today in the journal Epidemiology. “These findings contribute to the growing body of literature that suggest that exposure to the chemical does not play an important role in the onset of these behaviors.”The debate over fish consumption has long created a dilemma for expecting mothers and physicians. Fish are high in beneficial nutrients such as, selenium, vitamin E, lean protein, and omega-3 fatty acids; the latter are essential to brain development. At the same time, exposure to high levels of mercury has been shown to lead to developmental problems, leading to the claim that mothers are exposing their unborn children to serious neurological impairment by eating fish during pregnancy. Despite the fact that the developmental consequences of low level exposure remain unknown, some organizations, including the U.S. Food and Drug Administration, have recommended that pregnant women limit their consumption of fish.The presence of mercury in the environment is widespread and originates from both natural sources such as volcanoes and as a byproduct of coal-fired plants that emit the chemical. Much of this mercury ends up being deposited in the world’s oceans where it makes its way into the food chain and eventually into fish. While the levels of mercury found in individual fish are generally low, concerns have been raised about the cumulative effects of a frequent diet of fish.The Republic of Seychelles has proven to be the ideal location to examine the potential health impact of persistent low level mercury exposure. With a population of 87,000 people spread across an archipelago of islands in the Indian Ocean, fishing is a both an important industry and a primary source of nutrition — the nation’s residents consume fish at a rate 10 times greater than the populations of the U.S. …

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‘Cold snap’ 116 million years ago triggered marine ecosystem crisis

June 16, 2013 — A “cold snap” 116 million years ago triggered a similar marine ecosystem crisis to the ones witnessed in the past as a result of global warming, according to research published in Nature Geoscience.The international study involving experts from the universities of Newcastle, UK, Cologne, Frankfurt and GEOMAR-Kiel, confirms the link between global cooling and a crash in the marine ecosystem during the mid-Cretaceous greenhouse period.It also quantifies for the first time the amplitude and duration of the temperature change. Analysing the geochemistry and micropaleontology of a marine sediment core taken from the North Atlantic Ocean, the team show that a global temperature drop of up to 5oC resulted in a major shift in the global carbon cycle over a period of 2.5 million years.Occurring during a time of high tectonic activity that drove the breaking up of the super-continent Pangaea, the research explains how the opening and widening of new ocean basins around Africa, South America and Europe created additional space where large amounts of atmospheric CO2 was fixed by photosynthetic organisms like marine algae. The dead organisms were then buried in the sediments on the sea bed, producing organic, carbon rich shale in these new basins, locking away the carbon that was previously in the atmosphere.The result of this massive carbon fixing mechanism was a drop in the levels of atmospheric CO2, reducing the greenhouse effect and lowering global temperature.This period of global cooling came to an end after about 2 million years following the onset of a period of intense local volcanic activity in the Indian Ocean. Producing huge volumes of volcanic gas, carbon that had been removed from the atmosphere when it was locked away in the shale was replaced with CO2 from Earth’s interior, re-instating a greenhouse effect which led to warmer climate and an end to the “cold snap.”The research team highlight in this study how global climate is intrinsically linked to processes taking place in Earth’s interior at million year time scales. These processes can modify ecospace for marine life, driving evolution.Current research efforts tend to concentrate on global warming and the impact that a rise of a few degrees might have on past and present day ecosystems. This study shows that if global temperatures swing the other way by a similar amount, the result can be just as severe, at least for marine life.However, the research team emphasise that the observed changes of the Earth system in the Cretaceous happened over millions of years, rather than decades or centennial, which cannot easily be related to our rapidly changing modern climate conditions.”As always it’s a question of fine balance and scale,” explains Thomas Wagner, Professor of Earth Systems Science at Newcastle University, and one of the leaders of this study.”All earth system processes are operating all the time and at different temporal and spatial scales; but when something upsets the balance — be it a large scale but long term natural phenomenon or a short and massive change to global greenhouse gases due to anthropogenic activity — there are multiple, potential knock-on effects on the whole system.”The trick is to identify and quantify the initial drivers and consequences, which remains an ongoing challenge in climate research.”

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Modern humans did not settle in Asia before eruption of Sumatra volcano 74,000 years ago, study finds

June 11, 2013 — When did modern humans settle in Asia and what route did they take from humankind’s African homeland? A University of Huddersfield professor has helped to provide answers to both questions. But he has also had to settle a controversy.Professor Martin Richards, who heads the University’s Archaeogenetics Research Group, co-authors a new article in the Proceedings of the National Academy of Sciences. It refutes a recent theory that there is archaeological evidence for the presence of modern humans in southern Asia before the super-eruption of the Mount Toba volcano in Sumatra. ‌One of the most catastrophic events since humans evolved, it happened approximately 74,000 years ago. In 2005, Professor Richards led research published in an article in the journal Science which used mitochondrial DNA evidence to show that anatomically modern humans dispersed from their Africa homeland via a “southern coastal route” from the Horn and through Arabia, about 60,000 years ago — after the Toba eruption.‌‌However, a team of archaeologists excavating in India then claimed to have found evidence that modern humans were there before the eruption — possibly as early as 120,000 years ago, much earlier than Europe or the Near East were colonised. These findings, based on the discovery of stone tools below a layer of Toba ash, were published in Science in 2007.Now Professor Richards — working principally with the archaeologist Professor Sir Paul Mellars, of the University of Cambridge and the University of Edinburgh, with a team including Huddersfield University’s Dr Martin Carr and colleagues from York and Porto — has published his rebuttal of this theory. In doing so, they have been able to draw on a much greater body of DNA evidence that was available for the earlier article.”One of the things we didn’t have in 2005 was very much evidence from India in the way of mitochondrial sequences. Now, with a lot of people doing sequencing and depositing material in databases there are about 1,000 sequences from India,” said Professor Richards.‌By using the mitochondrial DNA of today’s populations and working backwards, and by drawing on a wide variety of other evidence and research, the team was able to make much more precise estimates for the arrival of modern humans in India.‌The evidence suggests dispersal from Africa and settlement in India no earlier than 60,000 years ago. “We also argue that close archaeological similarities between African and Indian stone-tool technologies after 70,000 years ago, as well as features such as beads and engravings, suggest that the slightly later Indian material had an African source,” states Professor Richards.”There were people in India before the Toba eruption, because there are stone tools there, but they could have been Neanderthals — or some other pre-modern population,” he adds.”The replacement of the presumably archaic humans living previously in South Asia by modern people with these new technologies appears analogous to the replacement of Neanderthals by modern humans in Europe and western Asia 50-40,000 years ago.”

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Human deforestation outweighs climate change for coral reefs

June 5, 2013 — Better land use is the key to preventing further damage to the world’s coral reefs, according to a study published this week in the online science journal Nature Communications.The study, by an international team including a researcher from The University of Western Australia’s Oceans Institute, has important implications for Australia’s Great Barrier Reef.The study authors write that preventing soil erosion and sediment pollution arising from human activities such as deforestation are crucial to reef survival.The study — ‘Human deforestation outweighs future climate change impacts of sedimentation on coral reefs’ — looked at the effects of future climate change on the hydroclimate of Madagascar’s reefs and different deforestation scenarios.”The findings are very relevant for Australia since intense land use and past deforestation have transformed the river catchments tremendously and are seen as a major threat to coral reefs in the Great Barrier Reef and elsewhere,” said Dr Jens Zinke, of UWA’s Oceans Institute.”Managing hinterland land use is the major action needed to buy time for corals growing near rivers.”Dr Zinke said the study looked at four watersheds near coral reef ecosystems in Madagascar, which has different climate zones that mimic most of the world’s coral reef climate and a range of different land uses.”With Madagascar, we wanted to understand how soil erosion and sediment discharges into coral reefs adjacent to river catchments are going to change with these two factors,” he said.”Curbing sediment pollution to coral reefs is one of the major recommendations to buy time for corals to survive ocean warming and bleaching events in the future.”Our results clearly show that land use management is the most important policy action needed to prevent further damage and preserve the reef ecosystem.”The major question is: how do we manage the sedimentation through reforestation efforts and proper coastal management?”Our study clearly shows that we need to have specific reforestation goals/targets for specific regions and make sure that the amount of land allocated for reforestation is enough to reduce sediments significantly.”Until we precisely understand these relationships, reforestation as a tool for coral reef conservation might not meet its objective of sediment and pollution reduction.”The study was the result of a collaboration between the UWA Oceans Institute, the Australian Institute of Marine Science, Macquarie University, the Institute for Environmental Studies at the VU University Amsterdam (Netherlands) and the Wildlife Conservation Society in the US.The lead author is Joseph Maina from Macquarie University.The study was funded through the Marine Science for Management program of the Western Indian Ocean Marine Science Association.

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