Calcification in changing oceans

What do mollusks, starfish, and corals have in common? Aside from their shared marine habitat, they are all calcifiers — organisms that use calcium from their environment to create hard carbonate skeletons and shells for stability and protection.The June issue of the Biological Bulletin, published by the Marine Biological Laboratory, addresses the challenges faced by these species as ocean composition changes worldwide.As atmospheric carbon dioxide rises, the world’s oceans are becoming warmer and more acidic. This impact of global climate change threatens the survival of calcifying species because of the reduced saturation of the carbonate minerals required for calcification.The ability to calcify arose independently in many species during the Cambrian era, when calcium levels in seawater increased. This use of calcium carbonate promoted biodiversity, including the vast array of calcifiers seen today.”Today, modern calcifiers face a new and rapidly escalating crisis caused by warming and acidification of the oceans with a reduction in availability of carbonate minerals, a change driven by the increase in atmospheric CO2 due to anthropogenic emissions and industrialization. The CO2 itself can also directly cause metabolic stress,” write the issue’s co-editors, Maria Byrne of the University of Sydney; and Gretchen Hofmann of the University of California-Santa Barbara.Contributors to the journal address this timely issue across many taxa and from a variety of perspectives, from genomic to ecosystem-wide.Janice Lough and Neal Cantin of the Australian Institute of Marine Science review historical data on coral reefs to look at potential environmental stressors, while Philippe Dubois (Universit Libre de Bruxelles) discusses sea urchin skeletons.Other researchers address lesser-known organisms that are nevertheless critical to marine ecosystems. Abigail Smith of the University of Otago examines how bryozoans, a group of aquatic invertebrate filter-feeders, increase biodiversity by creating niche habitats, and what features make them particularly sensitive to calcium fluctuations.Evans and Watson-Wynn (California State University-East Bay) take a molecular approach in a meta-analysis showing that ocean acidification is effecting genetic changes in sea urchin larvae. Several papers take a broader population-based view by studying the effect of ocean acidification on predator-prey interactions in mollusks (Kroeker and colleagues of the University of California-Davis) and oysters (Wright and colleagues of the University of Western Sydney).”The contributors have identified key knowledge gaps in the fast evolving field of marine global change biology and have provided many important insights,” the co-editors write.By sharing research on this topic from researchers around the world, the Biological Bulletin is raising awareness of some of the greatest threats to the oceans today and emphasizing the global nature of the problem.Story Source:The above story is based on materials provided by The Marine Biological Laboratory. The original article was written by Gina Hebert. Note: Materials may be edited for content and length.

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Male or female? First sex-determining genes appeared in mammals some 180 million years ago

Man or woman? Male or female? In humans and other mammals, the difference between sexes depends on one single element of the genome: the Y chromosome. It is present only in males, where the two sexual chromosomes are X and Y, whereas women have two X chromosomes. Thus, the Y is ultimately responsible for all the morphological and physiological differences between males and females.But this has not always been the case. A very long time ago, the X and Y were identical, until the Y started to differentiate from the X in males. It then progressively shrank to such an extent that, nowadays, it only contains about 20 genes (the X carries more than one thousand genes). When did the Y originate and which genes have been kept? The answer has just been brought to light by the team of Henrik Kaessmann, Associate Professor at the CIG (UNIL) and group leader at the SIB Swiss Institute of Bioinformatics, and their collaborators in Australia. They have established that the first ” sex genes ” appeared concomitantly in mammals around 180 million years ago.4,3 billion genetic sequencesBy studying samples from several male tissues — in particular testicles — from different species, the researchers recovered the Y chromosome genes from the three major mammalian lineages: placentals (which include humans, apes, rodents and elephants), marsupials (such as opossums and kangaroos) and monotremes (egg-laying mammals, such as the platypus and the echidna, a kind of Australian porcupine). …

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Eating seven or more portions of fruit and vegetables a day reduces your risk of death by 42 percent

Eating seven or more portions of fruit and vegetables a day reduces your risk of death at any point in time by 42% compared to eating less than one portion, reports a new UCL study.Researchers used the Health Survey for England to study the eating habits of 65,226 people representative of the English population between 2001 and 2013, and found that the more fruit and vegetables they ate, the less likely they were to die at any age. Eating seven or more portions reduces the specific risks of death by cancer and heart disease by 25% and 31% respectively. The research also showed that vegetables have significantly higher health benefits than fruit.This is the first study to link fruit and vegetable consumption with all-cause, cancer and heart disease deaths in a nationally-representative population, the first to quantify health benefits per-portion, and the first to identify the types of fruit and vegetable with the most benefit.Compared to eating less than one portion of fruit and vegetables, the risk of death by any cause is reduced by 14% by eating one to three portions, 29% for three to five portions, 36% for five to seven portions and 42% for seven or more. These figures are adjusted for sex, age, cigarette smoking, social class, Body Mass Index, education, physical activity and alcohol intake, and exclude deaths within a year of the food survey.The study, published in the Journal of Epidemiology & Community Health, found that fresh vegetables had the strongest protective effect, with each daily portion reducing overall risk of death by 16%. Salad contributed to a 13% risk reduction per portion, and each portion of fresh fruit was associated with a smaller but still significant 4% reduction.”We all know that eating fruit and vegetables is healthy, but the size of the effect is staggering,” says Dr Oyinlola Oyebode of UCL’s Department of Epidemiology & Public Health, lead author of the study. “The clear message here is that the more fruit and vegetables you eat, the less likely you are to die at any age. Vegetables have a larger effect than fruit, but fruit still makes a real difference. If you’re happy to snack on carrots or other vegetables, then that is a great choice but if you fancy something sweeter, a banana or any fruit will also do you good.”The findings lend support to the Australian government’s ‘Go for 2 + 5’ guidelines, which recommend eating two portions of fruit and five of vegetables. The UK Department of Health recommends ‘5 a day’, while ‘Fruit and Veggies — More Matters’ is the key message in the USA.”Our study shows that people following Australia’s ‘Go for 2 + 5’ advice will reap huge health benefits,” says Dr Oyebode. “However, people shouldn’t feel daunted by a big target like seven. …

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Exploding stars prove Newton’s law of gravity unchanged over cosmic time

Australian astronomers have combined all observations of supernovae ever made to determine that the strength of gravity has remained unchanged over the last nine billion years.Newton’s gravitational constant, known as G, describes the attractive force between two objects, together with the separation between them and their masses. It has been previously suggested that G could have been slowly changing over the 13.8 billion years since the Big Bang.If G has been decreasing over time, for example, this would mean that Earth’s distance to the Sun was slightly larger in the past, meaning that we would experience longer seasons now compared to much earlier points in Earth’s history.But researchers at Swinburne University of Technology in Melbourne have now analysed the light given off by 580 supernova explosions in the nearby and far Universe and have shown that the strength of gravity has not changed.”Looking back in cosmic time to find out how the laws of physics may have changed is not new” Swinburne Professor Jeremy Mould said. “But supernova cosmology now allows us to do this with gravity.”A Type 1a supernova marks the violent death of a star called a white dwarf, which is as massive as our Sun but packed into a ball the size of our Earth.Our telescopes can detect the light from this explosion and use its brightness as a ‘standard candle’ to measure distances in the Universe, a tool that helped Australian astronomer Professor Brian Schmidt in his 2011 Nobel Prize winning work, discovering the mysterious force Dark Energy.Professor Mould and his PhD student Syed Uddin at the Swinburne Centre for Astrophysics and Supercomputing and the ARC Centre of Excellence for All-sky Astrophysics (CAASTRO) assumed that these supernova explosions happen when a white dwarf reaches a critical mass or after colliding with other stars to ‘tip it over the edge’.”This critical mass depends on Newton’s gravitational constant G and allows us to monitor it over billions of years of cosmic time — instead of only decades, as was the case in previous studies,” Professor Mould said.Despite these vastly different time spans, their results agree with findings from the Lunar Laser Ranging Experiment that has been measuring the distance between Earth and the Moon since NASA’s Apollo missions in the 1960s and has been able to monitor possible variations in G at very high precision.”Our cosmological analysis complements experimental efforts to describe and constrain the laws of physics in a new way and over cosmic time.” Mr Uddin said.In their current publication, the Swinburne researchers were able to set an upper limit on the change in Newton’s gravitational constant of 1 part in 10 billion per year over the past nine billion years.The ARC Centre of Excellence for All-sky Astrophysics (CAASTRO) is a collaboration between The Australian National University, The University of Sydney, The University of Melbourne, Swinburne University of Technology, the University of Queensland, The University of Western Australia and Curtin University, the latter two participating together as the International Centre for Radio Astronomy Research. CAASTRO is funded under the Australian Research Council Centre of Excellence program, with additional funding from the seven participating universities and from the NSW State Government’s Science Leveraging Fund.The research is published this month in the Publications of the Astronomical Society of Australia.Story Source:The above story is based on materials provided by Swinburne University of Technology. Note: Materials may be edited for content and length.

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Dingo poisoning should be stopped to protect native Australian mammals

Poisoning of dingoes — the top predators in the Australian bush — has a deleterious effect on small native mammals such as marsupial mice, bandicoots and native rodents, a UNSW-led study shows.The research, in forested National Parks in NSW, found that loss of dingoes after baiting is associated with greater activity by foxes, which prey on small marsupials and native rodents.As well, the number of kangaroos and wallabies increases when dingoes, also known as wild dogs, disappear. Grazing by these herbivores reduces the density of the understorey vegetation in which the small ground-dwelling mammals live.”Dingoes should not be poisoned if we want to halt the loss of mammal biodiversity in Australia. We need to develop strategies to maintain the balance of nature by keeping dingoes in the bush, while minimising their impacts on livestock,” says the senior author, UNSW’s Dr Mike Letnic.The study is published in the journal Proceedings of the Royal Society B.The researchers surveyed seven pairs of forested sites within conservation reserves managed by the NSW National Parks and Wildlife Service.Baiting of dingoes with 1080 poison had been carried out at one location in each pair, but not the other. Apart from the resulting difference in the number of dingoes present, the pairs of locations had similar eucalypt coverage, geology and landforms, and were less than 50 kilometres apart.”This provided an extraordinary natural experiment to compare the impact of the loss of dingoes on a forested ecosystem,” says Dr Letnic, an ARC Future Fellow in the Centre for Ecosystem Science in the UNSW School of Biological, Earth and Environmental Sciences.It is the first study to show how removing large carnivores can result in simultaneous population outbreaks of herbivores and smaller predators. And that these population outbreaks, in turn, can have deleterious effects on smaller mammals.The activity of dingoes, foxes, feral cats and bandicoots was assessed from their tracks. Kangaroos and wallabies and possums were counted from the back of a four wheel drive. Traps were used to catch marsupials and native rodents, and surveys of vegetation were carried out.”We found foxes and large herbivores benefit from dingo control, while small-bodied terrestrial mammal species decline in abundance,” says Dr Letnic.”Predation by foxes is one of the most important threats to small native mammals, and grazing by herbivores can reduce their preferred habitats for shelter, leaving them exposed to predators.”The study’s findings in the forested areas are consistent with the effects of dingo removal in desert areas of Australia.”Actively maintaining dingo populations, or restoring them in areas where they have been exterminated, is controversial but could mitigate the impacts of foxes and herbivores,” says Dr Letnic.”Poisoning of dingoes is counter-productive for biodiversity conservation, because it results in increases in fox activity and declines of small ground-dwelling native mammals.”Story Source:The above story is based on materials provided by University of New South Wales. Note: Materials may be edited for content and length.

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Volcanoes helped species survive ice ages

An international team of researchers has found evidence that the steam and heat from volcanoes and heated rocks allowed many species of plants and animals to survive past ice ages, helping scientists understand how species respond to climate change.The research could solve a long-running mystery about how some species survived and continued to evolve through past ice ages in parts of the planet covered by glaciers.The team, led by Dr Ceridwen Fraser from the Australian National University and Dr Aleks Terauds from the Australian Antarctic Division, studied tens of thousands of records of Antarctic species, collected over decades by hundreds of researchers, and found there are more species close to volcanoes, and fewer further away.”Volcanic steam can melt large ice caves under the glaciers, and it can be tens of degrees warmer in there than outside. Caves and warm steam fields would have been great places for species to hang out during ice ages,” Dr Fraser said.”We can learn a lot from looking at the impacts of past climate change as we try to deal with the accelerated change that humans are now causing.”While the study was based on Antarctica, the findings help scientists understand how species survived past ice ages in other icy regions, including in periods when it is thought there was little or no ice-free land on the planet.Antarctica has at least 16 volcanoes which have been active since the last ice age 20,000 years ago.The study examined diversity patterns of mosses, lichens and bugs which are still common in Antarctica today.Professor Peter Convey from the British Antarctic Survey said around 60 per cent of Antarctic invertebrate species are found nowhere else in the world.”They have clearly not arrived on the continent recently, but must have been there for millions of years. How they survived past ice ages — the most recent of which ended less than 20,000 years ago — has long puzzled scientists,” Professor Convey said.Dr Terauds of the Australian Antarctic Division ran the analyses, and says the patterns are striking.”The closer you get to volcanoes, the more species you find. This pattern supports our hypothesis that species have been expanding their ranges and gradually moving out from volcanic areas since the last ice age,” Dr Terauds said.Professor Steven Chown, from Monash University, says the research findings could help guide conservation efforts in Antarctica.”Knowing where the ‘hotspots’ of diversity are will help us to protect them as human-induced environmental changes continue to affect Antarctica,” Professor Chown said.Story Source:The above story is based on materials provided by Australian National University. Note: Materials may be edited for content and length.

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Pregnancy study for overweight women leads to fewer high birth weight babies

The world’s biggest study offering healthy eating and exercise advice to pregnant women who are overweight or obese has shown a significant reduction in the number of babies born over 4kg (8.8 pounds) in weight.The LIMIT Study, led by researchers from the University of Adelaide’s Robinson Institute and the Women’s and Children’s Hospital, involved more than 2200 pregnant women from 2008-2011.In the first major results from the LIMIT Study, published this week in the British Medical Journal, the researchers say that providing advice and assistance to adopt a healthy diet and regular exercise during pregnancy has led to an 18% reduction in the chance of a baby being born over 4kg.”This is a very important finding,” says the lead author of the study, Professor Jodie Dodd from the University’s Robinson Institute and the Women’s and Children’s Hospital.”We know that babies who are born over 4kg have a two-fold increased risk of being overweight or obese as children, which often carries into later life, bringing with it a range of health concerns such as cardiovascular disease and diabetes. So we’re pleased to see that the study has led to a significant reduction in the risk of a baby being born over 4kg.Professor Dodd says overweight and obesity during pregnancy are common, affecting approximately 50% of women, and until now there has been little evidence about the benefit of dietary and lifestyle interventions on clinical outcomes in this group of women.About half of the women who took part in the study were provided with dietary and lifestyle advice promoting healthy eating and exercise, consistent with current Australian recommendations. The remaining women continued to receive routine antenatal care.”Our focus was on providing simple, practical lifestyle advice that is very achievable in the real world. It wasn’t about going on a diet, but focused on healthy eating and increasing activity levels on a daily basis,” Professor Dodd says.”There were no differences in the amount of weight women gained during pregnancy between the two study groups. It will be very important to look in more detail at the changes women have made to their diet and physical activity, and that will be the subject of a future paper.”This study has been funded by the National Health and Medical Research Council (NHMRC). The full paper can be found at the British Medical Journal website.Story Source:The above story is based on materials provided by University of Adelaide. Note: Materials may be edited for content and length.

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Astronomers discover oldest star: Formed shortly after the Big Bang 13. 7 billion years ago

A team led by astronomers at The Australian National University has discovered the oldest known star in the Universe, which formed shortly after the Big Bang 13.7 billion years ago.The discovery has allowed astronomers for the first time to study the chemistry of the first stars, giving scientists a clearer idea of what the Universe was like in its infancy.”This is the first time that we’ve been able to unambiguously say that we’ve found the chemical fingerprint of a first star,” said lead researcher, Dr Stefan Keller of the ANU Research School of Astronomy and Astrophysics.”This is one of the first steps in understanding what those first stars were like. What this star has enabled us to do is record the fingerprint of those first stars.”The star was discovered using the ANU SkyMapper telescope at the Siding Spring Observatory, which is searching for ancient stars as it conducts a five-year project to produce the first digital map the southern sky.The ancient star is around 6,000 light years from Earth, which Dr Keller says is relatively close in astronomical terms. It is one of the 60 million stars photographed by SkyMapper in its first year.”The stars we are finding number one in a million,” says team member Professor Mike Bessell, who worked with Keller on the research.”Finding such needles in a haystack is possible thanks to the ANU SkyMapper telescope that is unique in its ability to find stars with low iron from their colour.”Dr Keller and Professor Bessell confirmed the discovery using the Magellan telescope in Chile.The composition of the newly discovered star shows it formed in the wake of a primordial star, which had a mass 60 times that of our Sun.”To make a star like our Sun, you take the basic ingredients of hydrogen and helium from the Big Bang and add an enormous amount of iron — the equivalent of about 1,000 times the Earth’s mass,” Dr Keller says.”To make this ancient star, you need no more than an Australia-sized asteroid of iron and lots of carbon. It’s a very different recipe that tells us a lot about the nature of the first stars and how they died.”Dr Keller says it was previously thought that primordial stars died in extremely violent explosions which polluted huge volumes of space with iron. But the ancient star shows signs of pollution with lighter elements such as carbon and magnesium, and no sign of pollution with iron.”This indicates the primordial star’s supernova explosion was of surprisingly low energy. Although sufficient to disintegrate the primordial star, almost all of the heavy elements such as iron, were consumed by a black hole that formed at the heart of the explosion,” he says.The result may resolve a long-standing discrepancy between observations and predictions of the Big Bang.The discovery was published in the latest edition of the journal Nature.Story Source:The above story is based on materials provided by The Australian National University. Note: Materials may be edited for content and length.

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Asbestos Cancer Melbourne Gala Dinner 2013 Biaggio Signorelli Foundation 1st Annual Melbourne Gala Dinner to raise funds to create awareness, earlier…

Last night in Melbourne I was very honoured to be able to attend this beautiful gala event with my husband Keith and Rod Smith/Karen Banton all representing Bernie Banton Foundation.A black tie event, it was a good excuse to dress up, kick our heels up and enjoy a spectacular night with other like minded people who were there for a good cause – raising much needed funds for mesothelioma research.http://www.oliviaappeal.com/About-Us/Appeal-Committees/Associate-Professor-Paul-Mitchell.aspxAssociate Professor Paul Mitchell, Olivia Newton John Cancer Centre spoke on the aggressive and deadly nature of mesothelioma and how much needed funds are very vital. I spoke to him after his speech and about me being past my use by date as there …

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Prof van Zandwijk/ADRI meso trial TargomiRs treatment first stage late 2013

Prof van Zandwijk says he does not want to raise false hope, but he is cautiously optimistic the treatment will work.”I think the whole concept is sound and we feel very reassured.”While our preclinical research was confined to mesothelioma, we hope that this new approach to cancer treatment will also inhibit other tumour types.”Speaking at the launch, Federal Health Minister Tanya Plibersek said: “This will allow further research into the most promising treatment for mesothelioma yet discovered. It means that we might have a cure in a few years.”Mentioning the sadness of losing a family friend to the disease, she said: “Anyone who has been touched by mesothelioma, and there are so many Australians who have been, will be so excited about this. …

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Mesothelioma Prognosis – Why Do Some Patients Survive Longer?

There have been some few patients who have survived far beyond the usual one year prognosis for most mesothelioma victims and a handful that have even been cured, with no trace of the aggressive cancer several years after treatment (though recurrence is always possible).Many medical experts are baffled by this observation and for most of the time they are yet to find a real scientific basis to explain why some mesothelioma patients survive and others do not.There seems to be one common factor amongst those that have survived the disease for longer times – the immune system. Studies of those who have either survived or been cured of the disease reveal that most of these patients participated in some sort of therapy that enhanced their immune …

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Turned the corner! Back in control! Day 4 of chemo!

Day 4 of chemo today (gemcidibine and carboplatin) and feeling BACK IN CONTROL of my life!!!Feeling totally different on this chemo regime instead of the gemcidibine (gemzar) and cisplatin. Virtually no pain – whereas on the cisplatin I felt like I was close to death.I have been able to manage my side effects with medication, my mind and best of all being able to use my lifeline the computer to email/blog/facebook and keep in touch on a global scale.I don’t want to keep having chemo however I am being given a lifeline so I am giving it my best shot and WINNING as I am back in control of my life!My heart goes out to the warriors who are doing it tough at …

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Ancient DNA unravels Europe’s genetic diversity

Oct. 10, 2013 — Ancient DNA recovered from a time series of skeletons in Germany spanning 4,000 years of prehistory has been used to reconstruct the first detailed genetic history of modern-day Europeans.The study, published today in Science, reveals dramatic population changes with waves of prehistoric migration, not only from the accepted path via the Near East, but also from Western and Eastern Europe.The research was a collaboration between the Australian Centre for Ancient DNA (ACAD), at the University of Adelaide, researchers from the University of Mainz, the State Heritage Museum in Halle (Germany), and National Geographic Society’s Genographic Project. The teams used mitochondrial DNA (maternally inherited DNA) extracted from bone and teeth samples from 364 prehistoric human skeletons ‒ ten times more than previous ancient DNA studies.”This is the largest and most detailed genetic time series of Europe yet created, allowing us to establish a complete genetic chronology,” says joint-lead author Dr Wolfgang Haak of ACAD. “Focussing on this small but highly important geographic region meant we could generate a gapless record, and directly observe genetic changes in ‘real-time’ from 7,500 to 3,500 years ago, from the earliest farmers to the early Bronze Age.””Our study shows that a simple mix of indigenous hunter-gatherers and the incoming Near Eastern farmers cannot explain the modern-day diversity alone,” says joint-lead author Guido Brandt, PhD candidate at the University of Mainz. “The genetic results are much more complex than that. Instead, we found that two particular cultures at the brink of the Bronze Age 4,200 years ago had a marked role in the formation of Central Europe’s genetic makeup.”Professor Kurt Alt (University of Mainz) says: “What is intriguing is that the genetic signals can be directly compared with the changes in material culture seen in the archaeological record. It is fascinating to see genetic changes when certain cultures expanded vastly, clearly revealing interactions across very large distances.” These included migrations from both Western and Eastern Europe towards the end of the Stone Age, through expanding cultures such as the Bell Beaker and the Corded Ware (named after their pots).”This transect through time has produced a wealth of information about the genetic history of modern Europeans,” says ACAD Director Professor Alan Cooper. “There was a period of stasis after farming became established and suitable areas were settled, and then sudden turnovers during less stable times or when economic factors changed, such as the increasing importance of metal ores and secondary farming products. While the genetic signal of the first farming populations becomes increasingly diluted over time, we see the original hunter-gatherers make a surprising comeback.”Dr Haak says: “None of the dynamic changes we observed could have been inferred from modern-day genetic data alone, highlighting the potential power of combining ancient DNA studies with archaeology to reconstruct human evolutionary history.” The international team has been working closely on the genetic prehistory of Europeans for the past 7-8 years and is currently applying powerful new technologies to generate genomic data from the specimens.

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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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Darwin’s dilemma resolved: Evolution’s ‘big bang’ explained by five times faster rates of evolution

Sep. 12, 2013 — A new study led by Adelaide researchers has estimated, for the first time, the rates of evolution during the “Cambrian explosion” when most modern animal groups appeared between 540 and 520 million years ago.The findings, published online today in the journal Current Biology, resolve “Darwin’s dilemma”: the sudden appearance of a plethora of modern animal groups in the fossil record during the early Cambrian period.”The abrupt appearance of dozens of animal groups during this time is arguably the most important evolutionary event after the origin of life,” says lead author Associate Professor Michael Lee of the University of Adelaide’s School of Earth and Environmental Sciences and the South Australian Museum.”These seemingly impossibly fast rates of evolution implied by this Cambrian explosion have long been exploited by opponents of evolution. Darwin himself famously considered that this was at odds with the normal evolutionary processes.”However, because of the notorious imperfection of the ancient fossil record, no-one has been able to accurately measure rates of evolution during this critical interval, often called evolution’s Big Bang.”In this study we’ve estimated that rates of both morphological and genetic evolution during the Cambrian explosion were five times faster than today — quite rapid, but perfectly consistent with Darwin’s theory of evolution.”The team, including researchers from the Natural History Museum in London, quantified the anatomical and genetic differences between living animals, and established a timeframe over which those differences accumulated with the help of the fossil record and intricate mathematical models. Their modelling showed that moderately accelerated evolution was sufficient to explain the seemingly sudden appearance of many groups of advanced animals in the fossil record during the Cambrian explosion.The research focused on arthropods (insects, crustaceans, arachnids and their relatives), which are the most diverse animal group in both the Cambrian period and present day.”It was during this Cambrian period that many of the most familiar traits associated with this group of animals evolved, like a hard exoskeleton, jointed legs, and compound (multi-faceted) eyes that are shared by all arthropods. We even find the first appearance in the fossil record of the antenna that insects, millipedes and lobsters all have, and the earliest biting jaws.” says co-author Dr Greg Edgecombe of the Natural History Museum.

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Dingo wrongly blamed for extinctions

Sep. 10, 2013 — Dingoes have been unjustly blamed for the extinctions on the Australian mainland of the Tasmanian tiger (or thylacine) and the Tasmanian devil, a University of Adelaide study has found.In a paper published in the journal Ecology, the researchers say that despite popular belief that the Australian dingo was to blame for the demise of thylacines and devils on the mainland about 3000 years ago, in fact Aboriginal populations and a shift in climate were more likely responsible.”Perhaps because the public perception of dingoes as ‘sheep-killers’ is so firmly entrenched, it has been commonly assumed that dingoes killed off the thylacines and devils on mainland Australia,” says researcher Dr Thomas Prowse, Research Associate in the School of Earth and Environmental Sciences and the Environment Institute.”There was anecdotal evidence too: both thylacines and devils lasted for over 40,000 years following the arrival of humans in Australia; their mainland extinction about 3000 years ago was just after dingoes were introduced to Australia; and the fact that thylacines and devils persisted on Tasmania, which was never colonised by dingoes.”However, and unfortunately for the dingo, most people have overlooked that about the same time as dingoes came along, the climate changed rather abruptly and Aboriginal populations were going through a major period of intensification in terms of population growth and technological advances.”The researchers built a complex series of mathematical models to recreate the dynamic interaction between the main potential drivers of extinction (dingoes, climate and humans), the long-term response of herbivore prey, and the viability of the thylacine and devil populations.The models included interactions and competition between predators as well as the influence of climate on vegetation and prey populations.The simulations showed that while dingoes had some impact, growth and development in human populations, possibly intensified by climate change, was the most likely extinction driver.”Our multi-species models showed that dingoes could reduce thylacine and devil populations through both competition and direct predation, but there was low probability that they could have been the sole extinction driver,” Dr Prowse says.”Our results support the notion that thylacines and devils persisted on Tasmania not because the dingo was absent, but because human density remained low there and Tasmania was less affected by abrupt climate changes.”The study ‘An ecological regime shift resulting from disrupted predator-prey interactions in Holocene Australia’ also involved Professors Corey Bradshaw and Barry Brook from the University of Adelaide’s Environment Institute and Professor Chris Johnson from the University of Tasmania.

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Cell death protein could offer new anti-inflammatory drug target

Sep. 5, 2013 — Scientists in Melbourne, Australia, have revealed the structure of a protein that is essential for triggering a form of programmed cell death called necroptosis, making possible the development of new drugs to treat chronic inflammatory diseases such as Crohn’s disease and rheumatoid arthritis.Dr James Murphy, Associate Professor John Silke, Dr Joanne Hildebrand, Dr Peter Czabotar, Professor Warren Alexander and colleagues from the Walter and Eliza Hall Institute have shown that the protein MLKL plays a crucial role in the signalling pathways that trigger a recently discovered cell death pathway called necroptosis. The results were published today in the journal Immunity.Usually, when a cell detects that it is infected by a virus or bacteria or has other irreparable damage it self-destructs through a process called apoptosis. But Associate Professor Silke said some bacteria and viruses had developed ways of preventing this cell suicide, also allowing the invaders to survive. It is at this point that the ‘back up’ necroptosis pathway might be activated.”During necroptosis the cell still self-destructs but in doing so it also sends an ‘SOS’ to the immune system to tell it that something has gone wrong with the cell’s normal cell death process of apoptosis. So internally, the cell is still doing its best to self-destruct in an orderly and programmed way, but it is simultaneously sending signals to the immune system to mount a response to the invaders.”However there are times when the necroptosis pathway may be inappropriately activated, sending messages to the immune system that promote inflammation and the development of inflammatory diseases.Dr Murphy said the discovery of MLKL’s role in activating the necroptosis pathway was an important step in understanding this cell death pathway and its role in disease. “Necroptosis has only been defined in the past 10 years and the role MLKL plays was only discovered in 2012,” Dr Murphy said. “This study provides the first genetic proof that MLKL is required for necroptosis as well as the first full-length, atomic level, three-dimensional structure of a protein that regulates necroptosis. These discoveries are really exciting because they give us a new target to look at for developing treatments for people who suffer from an inflammatory disease.”The three-dimensional images of MLKL, which were obtained using the Australian Synchrotron, revealed an interesting detail about the protein, Dr Murphy said. “The structure revealed that MLKL is a ‘dead enzyme’, making it different from the other proteins in the signalling pathway,” Dr Murphy said. …

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Smoking with asthma during pregnancy is particularly dangerous

Sep. 5, 2013 — New research from the University of Adelaide has shown for the first time that pregnant women who smoke as well as having asthma are greatly increasing the risk of complications for themselves and their unborn children.In the first study of its kind in the world, researchers from the University’s Robinson Institute compared data from more than 170,000 Australian women over 10 years.The results have been published online ahead of print in the European Respiratory Journal.Lead author Dr Nicolette Hodyl says: “We know that being pregnant and having asthma poses risks to both the mother and the baby. We know that smoking poses risks to both the mother and the baby. But now we also know that the combination of these conditions represents a very dangerous situation.”Asthma and smoking are separately linked during pregnancy to increased risk of bleeding from the birth canal before labor, urinary tract infections, premature rupture of membranes, low birth weight and preterm birth (less than 37 weeks of pregnancy).”The combination of asthma and smoking greatly increases the risk of these complications during pregnancy.”Dr Hodyl says 5.8% of pregnant women who were not asthmatic and non-smokers experienced a preterm birth. “For asthmatic women, the preterm birth rate increased to 6.5%. Among smoking women, 9.4% experienced preterm birth. And for asthmatic women who also smoked, the rate of preterm birth jumped to 12.7%, which is more than double the normal rate.”This is an alarming statistic. We hope that pregnant women begin to understand the seriousness of this situation to their health and the health of their child,” she says.Dr Hodyl says the research also uncovered another worrying statistic: about a quarter of pregnant women with asthma are smokers.”While the rates of smoking have been decreasing in recent years, it is very concerning to us that many pregnant women with asthma are also smoking,” she says.”Quitting smoking during pregnancy is very difficult, and therefore pregnant women need as much support as possible from family, friends and health professionals. Our results show that even a reduction in the number of cigarettes women smoke per day can lead to some improvement to the risks to their child. However, the potential for poor health outcomes for both the mother and child should not be underestimated.”This research has been funded by the National Health and Medical Research Council (NHMRC).

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Gravity variations over Earth much bigger than previously thought

Sep. 4, 2013 — A joint Australian-German research team led by Curtin University’s Dr Christian Hirt has created the highest-resolution maps of Earth’s gravity field to date — showing gravitational variations up to 40 per cent larger than previously assumed.Using detailed topographic information obtained from the US Space Shuttle, a specialist team including Associate Professor Michael Kuhn, Dr Sten Claessens and Moritz Rexer from Curtin’s Western Australian Centre for Geodesy and Professor Roland Pail and Thomas Fecher from Technical University Munich improved the resolution of previous global gravity field maps by a factor of 40.”This is a world-first effort to portray the gravity field for all countries of our planet with unseen detail,” Dr Hirt said.”Our research team calculated free-fall gravity at three billion points — that’s one every 200 metres — to create these highest-resolution gravity maps. They show the subtle changes in gravity over most land areas of Earth.”The new gravity maps revealed the variations of free-fall gravity over Earth were much bigger than previously thought.Earth’s gravitational pull is smallest on the top of the Huascaran mountain in the South American Andes, and largest near the North Pole.”Only a few years ago, this research would not have been possible,” Dr Hirt said.”The creation of the maps would have required about 80 years of office PC computation time but advanced supercomputing provided by the Western Australian iVEC facility helped us to complete the maps within a few months.”High-resolution gravity maps are required in civil engineering, for instance, for building of canals, bridges and tunnels. The mining industry could also benefit.”The maps can be used by surveyors and other spatial science professionals to precisely measure topographic heights with satellite systems such as the Global Positioning System (GPS),” Dr Hirt said.The findings of the research team from Curtin and Technical University Munich have recently appeared in the journal Geophysical Research Letters.Earth’s gravity field gallery: http://geodesy.curtin.edu.au/research/models/GGMplus/gallery.cfm

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Links made between problem gambling and substance abuse, and lack of treatment options

Sep. 4, 2013 — Problem gamblers are a hidden population among people with mental health or substance abuse issues who often don’t get the treatment they need, a new study shows. Anywhere from 10 to 20 per cent of people with substance abuse problems also have significant gambling problem, yet few programs are targeted at them and most social service agencies don’t have funds to treat them, the study’s main author says.Dr. Flora Matheson, a research scientist at St. Michael’s Hospital’s Centre for Research on Inner City Health, with colleagues from the Centre for Addiction and Mental Health, conducted a review of existing literature on drug use and problem gambling. The results were published online in the journal ISRN Addiction. Dr. Matheson said that while the literature confirms a high correlation between problem gambling and substance abuse, the evidence also suggests that these people are less responsive to current treatment initiatives than other gamblers.”Given the marginal and essentially hidden nature of this population — street drug users with gambling problems — unique approaches are necessary to encourage them to participate in research and treatment,” she said. In their review the authors found many reports that problem gambling and substance abuse are related, or may even be one disorder, because of underlying traits such as impulsivity. A substantial body of literature indicates that both problems typically begin in adolescence or early adulthood and have common risk factors such as sexual abuse, depression and delinquency.One study found that people with both problem gambling and substance abuse problems were more likely to have attempted suicide at some point in their lives and to have reported problems with sexual compulsivity. …

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