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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Better livestock diets to combat climate change, improve food security

Livestock production is responsible for 12% of human-related greenhouse gas emissions, primarily coming from land use change and deforestation caused by expansion of agriculture, as well as methane released by the animals themselves, with a lesser amount coming from manure management and feed production.”There is a lot of discussion about reduction of meat in the diets as a way to reduce emissions,” says IIASA researcher Petr Havlk, who led the study “But our results show that targeting the production side of agriculture is a much more efficient way to reduce greenhouse gas emissions.”A new study published in the journal Proceedings of the National Academy of Sciences shows that within the current systems, farmers would find it more profitable in coming years to expand livestock production in mixed systems — where livestock are fed on both grass as well as higher quality feed — rather than in pure grass-based systems. This development, would lead to a 23% reduction of emissions from land use change in the next two decades without any explicit climate mitigation policy.Cows, sheep, and goats grow more quickly and produce more milk when they eat energy-rich diets that include grain supplements or improved forages. This means that more livestock can be raised on less land, and with fewer emissions per pound of meat or milk produced.The new study projects that the increasing cost of land and continued yield increases in the crop sector will lead to shifts to richer animal diets in the future. Such diets are efficient not only from the perspective of greenhouse gas reduction, but also from farm profit maximization and food production.At a moderate price of US$10 per ton of carbon dioxide equivalent, livestock system transitions within a given region, together with international relocation of production to regions with the most efficient livestock systems could also reduce the total emissions from agriculture and land use change by 25%. Most of the savings would come from avoided land use change.Havlk says, “From the livestock sector perspective, limiting land use change seems the cheapest option both in terms of the economic cost and in terms of impact on food availability.”Previous work by the group produced a detailed database highlighting the differences in the efficiency and greenhouse gas emissions of different livestock production systems. The new study adds to this by examining the economic potential for a transition to more efficient systems as a mitigation measure, and which policies would be the most effective for cutting greenhouse gas emissions, while also maintaining food availability.The new study also introduces a new metric for measuring the costs of climate measures for agricultural systems, the Total Abatement Calorie Cost (TACC), which complements the pure economic metric known as “marginal abatement cost” while also capturing the impacts of mitigation measures on food security. Mario Herrero, a co-author of the study and a researcher at CSIRO, IIASA’s Australian National Member Organization, says, “Applying current metrics could lead to mitigation, but also food insecurity in developing countries, because it ignores the social cost of policies that focus just on greenhouse gas abatement.. So we developed a new metric which tells you how consumption would be affected as a result of mitigating greenhouse gas emissions.”Changing livestock production systems remains a challenge. The researchers say that policies to provide education and market access are the keys for enabling change. In addition, they note that safeguards are needed to insure that the intensified agricultural production does not lead to environmental damage or reduce animal well-being.Story Source:The above story is based on materials provided by International Institute for Applied Systems Analysis. …

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Concerns raised about using beta agonists in beef cattle

Use of certain animal drugs known as beta agonists in cattle production has received considerable national attention.A Texas Tech University veterinary epidemiologist has found that although there are significant societal benefits to the practice, an increase in death loss of cattle raises questions about welfare implications of its use.In a peer-reviewed article published in PLOS ONE, Guy Loneragan, professor of food safety and public health in Texas Tech’s College of Agricultural Sciences and Natural Resources, adds to this ongoing national dialogue.”Beta agonists improve the efficiency of beef production and this improvement provides important societal benefits,” Loneragan said.”The beta agonists approved by the U.S. Food and Drug Administration for use in cattle increase muscle growth and may reduce the amount of fat the cattle accumulates,” he said. “This means the cattle converts more of the feed it eats into beef, and it does this more efficiently.”The article is co-authored by Daniel Thomson and Morgan Scott of Kansas State University and is titled “Increased mortality in groups of cattle administered the β-adrenergic agonists ractopamine hydrochloride and zilpaterol hydrochloride.”With the use of beta agonists, cattle require less feed and less water to produce the same amount of beef than if no beta agonists were used. Less land would be used to grow the crops used to feed the animals and, therefore, less fuel to produce the same amount of beef. The improvement in the efficiency of production has meaningful societal benefits.”However, through our extensive analysis, we found that the incidence of death among cattle administered beta agonists was 75 to 90 percent greater than cattle not administered the beta agonists,” Loneragan said. “This increase in death loss raises critical animal-welfare questions. We believe an inclusive dialogue is needed to explore the use of animal drugs solely to improve performance, yet have no offsetting health benefits for the animals to which they are administered. This is particularly needed for those drugs that appear to adversely impact animal welfare, such as beta agonists.”At a recent symposium held at Texas Tech, the animal behaviorist and welfare expert Temple Grandin headlined a discussion of beta agonists and animal welfare.In a recent joint NPR interview with Loneragan and Grandin about beta agonists’ affect on animal welfare, Grandin said, “These problems have got to stop. I’ve laid awake at night about it. I’ve worked all my career to improve how animals are handled and these animals are just suffering. …

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Crop species may be more vulnerable to climate change than we thought

A new study by a Wits University scientist has overturned a long-standing hypothesis about plant speciation (the formation of new and distinct species in the course of evolution), suggesting that agricultural crops could be more vulnerable to climate change than was previously thought.Unlike humans and most other animals, plants can tolerate multiple copies of their genes — in fact some plants, called polyploids, can have more than 50 duplicates of their genomes in every cell. Scientists used to think that these extra genomes helped polyploids survive in new and extreme environments, like the tropics or the Arctic, promoting the establishment of new species.However, when Dr Kelsey Glennon of the Wits School of Animal, Plant and Environmental Sciences and a team of international collaborators tested this long-standing hypothesis, they found that, more often than not, polyploids shared the same habitats as their close relatives with normal genome sizes.”This means that environmental factors do not play a large role in the establishment of new plant species and that maybe other factors, like the ability to spread your seeds to new locations with similar habitats, are more important,” said Glennon.”This study has implications for agriculture and climate change because all of our important crops are polyploids and they might not be much better at adapting to changing climate than their wild relatives if they live in similar climates.”Glennon’s study also provides an alternative explanation for why plants are so diverse in places like the Cape where the climate has been stable for hundreds of thousands of years. Although her study examined plant species from North America and Europe only, she is looking forward to testing her hypotheses using South African plants.Glennon’s paper has been published in Ecology Letters.Story Source:The above story is based on materials provided by Wits University. Note: Materials may be edited for content and length.

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Crazy ants dominate fire ants by neutralizing their venom

Invasive “crazy ants” are rapidly displacing fire ants in areas across the southeastern U.S. by secreting a compound that neutralizes fire ant venom, according to a University of Texas at Austin study published this week in the journal Science Express. It’s the first known example of an insect with the ability to detoxify another insect’s venom.The crazy ant invasion is the latest in a series of ant invasions from the southern hemisphere and, like its predecessors, will likely have dramatic effects on the region’s ecosystems.Known for their painful stings on humans and other animals, fire ants dominate most ant species by dabbing them with powerful, usually fatal venom. A topical insecticide, the venom is two to three times as toxic as DDT on a per weight basis.When a crazy ant is smeared with the venom, however, it begins an elaborate detoxification procedure, described for the first time in this study. The exposed crazy ant secretes formic acid from a specialized gland at the tip of its abdomen, transfers it to its mouth and then smears it on its body.In lab experiments, exposed crazy ants that were allowed to detoxify themselves had a 98 percent survival rate. This chemical counter-weapon makes crazy ants nearly invincible in skirmishes with fire ants over food resources and nesting sites.”As this plays out, unless something new and different happens, crazy ants are going to displace fire ants from much of the southeastern U.S. and become the new ecologically dominant invasive ant species,” said Ed LeBrun, a research associate with the Texas invasive species research program at the Brackenridge Field Laboratory in UT Austin’s College of Natural Sciences.Last year, the researchers reported that where crazy ants take hold, the numbers and types of arthropods — insects, spiders, centipedes and crustaceans — decrease, which is likely to have ripple effects on ecosystems by reducing food sources for birds, reptiles and other animals. They also nest in people’s homes and damage electrical equipment.LeBrun described watching a battle for food between red fire ants and crazy ants along the boundary between their two populations at a Texas field site. The fire ants found a dead cricket first and were guarding it in large numbers. Usually when fire ants amass around a food resource, other ants stay clear for fear of their deadly venom.”The crazy ants charged into the fire ants, spraying venom,” said LeBrun. …

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New pathway for fear discovered deep within brain

Fear is primal. In the wild, it serves as a protective mechanism, allowing animals to avoid predators or other perceived threats. For humans, fear is much more complex. A normal amount keeps us safe from danger. But in extreme cases, like post-traumatic stress disorder (PTSD), too much fear can prevent people from living healthy, productive lives. Researchers are actively working to understand how the brain translates fear into action. Today, scientists at Cold Spring Harbor Laboratory (CSHL) announce the discovery of a new neural circuit in the brain that directly links the site of fear memory with an area of the brainstem that controls behavior.How does the brain convert an emotion into a behavioral response? For years, researchers have known that fear memories are learned and stored in a small structure in the brain known as the amygdala. Any disturbing event activates neurons in the lateral and then central portions of the amygdala. The signals are then communicated internally, passing from one group of neurons to the next. …

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No clowning around: Juggling sheds light on how we run

Juggling may seem like mere entertainment, but a study led by Johns Hopkins engineers used this circus skill to gather critical clues about how vision and the sense of touch help control the way humans and animals move their limbs in a repetitive way, such as in running. The findings eventually may aid in the treatment of people with neurological diseases and could lead to prosthetic limbs and robots that move more efficiently.The study was published online recently by the Journal of Neurophysiology and will be the cover article in the journal’s March 2014 print edition.In their paper, the team led by Johns Hopkins researchers detailed the unusual jump from juggling for fun to serious science. Jugglers, they explained, rely on repeated rhythmic motions to keep multiple balls aloft. Similar forms of rhythmic movement are also common in the animal world, where effective locomotion is equally important to a swift-moving gazelle and to the cheetah that’s chasing it.”It turns out that the art of juggling provides an interesting window into many of the same questions that you try to answer when you study forms of locomotion, such as walking or running,” said Noah Cowan, an associate professor of mechanical engineering who supervised the research. “In our study, we had participants stand still and use their hands in a rhythmic way. It’s very much like watching them move their feet as they run. But we used juggling as a model for rhythmic motor coordination because it’s a simpler system to study.”Specifically, Cowan and his colleagues wanted to look at how the brain uses vision and the sense of touch to control this type of behavior. To do so, they set up a simple virtual juggling scenario. Participants held a real-world paddle connected to a computer and were told to bounce an on-screen ball repeatedly up to a target area between two lines, also drawn on the monitor. In some trials, the participants had only their vision to guide them. …

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Coffee growing: More biodiversity, better harvest

Bees, birds and bats make a huge contribution to the high yields produced by coffee farmers around Mount Kilimanjaro – an example of how biodiversity can pay off. This effect has been described as result of a study now published in the „Proceedings of the Royal Society B“. It has been conducted by tropical ecologists of the University Wrzburg Biocenter, jointly with colleagues from the LOEWE Biodiversity and Climate Research Centre (BiK-F, Frankfurt/Main) and the Institute for experimental Ecology of the University of Ulm.A large amount of coffee is grown on Kilimanjaro, the East African massif almost 6000 meters high. The most traditional form of cultivation can be found in the gardens of the Chagga people. Hhere the sun-shy coffee trees and many other crop plants thrive in the shade of banana trees and other tall trees. However, the largest part of the coffee is grown on plantations. Usually, the plantations still feature a large number of shade trees. But these are progressively being chopped down because of the increasing replacement of “conventional coffee varieties, which rely on shade, by varieties that tolerate lots of sun and are more resistant to fungi,” explains Professor Ingolf Steffan-Dewenter, a tropical ecologist at the University of Wrzburg’s Biocenter. This crop intensification is expected to result in higher yields. The plantation harvests might however stagnate: If there are only few shade trees left, the habitat may become unsuitable for the animal species that pollinate the coffee, eat pests, and thereby help to improve the yield.Teamwork on the slopes of Mount KilimanjaroSteffan-Dewenter and his doctoral student Alice Classen therefore wanted to understand how bees, birds, bats and other animals contribute to pollination and to biological pest control in the coffee fields. …

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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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Curious Critters Volume Two by David FitzSimmons

Product was received to facilitate this review of Curious Critters. All opinions are my own.A couple of years ago we received the book Curious Critters by David FitzSimmons. Ryan was young and we were still reading basic board books, but this book quickly became a favorite. It was a must-read every day—or, really, like 12 times a day, haha. He was fascinated by the large and bright photographs, the interesting animals, and learning all of their names.Curious Critters by David FitzSimmonsI was thrilled to hear that a second edition was coming out: Curious Critters Volume Two! Of course we HAD to have it! Check out their website to see the books and sample pages. It also has lots of fun stuff: coloring pages and word …

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As chimpanzees grow, so does yawn contagion

Oct. 16, 2013 — As sanctuary-kept chimpanzees grow from infant to juvenile, they develop increased susceptibility to human yawn contagion, possibility due to their increasing ability to empathize, says a study published October 16, 2013, in the open-access journal PLOS ONE by Elainie Madsen and colleagues from Lund University.Share This:Scientists examined the extent to which two factors affected chimpanzees’ susceptibility to yawn contagion: their age, and their emotional closeness to the person yawning. Thirty-three orphaned chimpanzees, 12 infants 1 to 4 years old, and 21 juveniles 5 to 8 years old, were included in the trials. A trial sequence consisted of 7 five-minute sessions: a baseline session, followed by three experimental sessions, where the human repeatedly either yawned, gaped or nose-wiped, and three post-experimental sessions, where social interactions continued without the inclusion of the key behaviors. Each chimpanzee separately observed an unfamiliar human and a familiar human preforming the sequence.Researchers found that yawning, but not nose-wiping, was contagious for juvenile chimpanzees, while infants found neither yawning nor nose-wiping contagious. Specifically, human yawning elicited 24 yawns from the juvenile chimpanzees and zero yawns from the infants. Chimpanzees appear to develop susceptibility to interspecies contagious yawning as they grow from infant to juvenile, possibly due to their developing ability to empathize with the person yawning. Emotional closeness with the yawning human did not affect contagion. Madsen added, “The results of the study reflect a general developmental pattern, shared by humans and other animals. Given that contagious yawning may be an empathetic response, the results can also be taken to mean that empathy develops slowly over the first years of a chimpanzee’s life.”Aside from humans, cross-species yawn contagion and a gradual development yawn contagion, has previously only been demonstrated in dogs.Share this story on Facebook, Twitter, and Google:Other social bookmarking and sharing tools:|Story Source: The above story is based on materials provided by Public Library of Science. …

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Carbon cycle models underestimate indirect role of animals

Oct. 16, 2013 — Animal populations can have a far more significant impact on carbon storage and exchange in regional ecosystems than is typically recognized by global carbon models, according to a new paper authored by researchers at the Yale School of Forestry & Environmental Studies (F&ES).In fact, in some regions the magnitude of carbon uptake or release due to the effects of specific animal species or groups of animals — such as the pine beetles devouring forests in western North America — can rival the impact of fossil fuel emissions for the same region, according to the paper published in the journal Ecosystems.While models typically take into account how plants and microbes affect the carbon cycle, they often underestimate how much animals can indirectly alter the absorption, release, or transport of carbon within an ecosystem, says Oswald Schmitz, the Oastler Professor of Population and Community Ecology at F&ES and lead author of the paper. Historically, the role of animals has been largely underplayed since animal species are not distributed globally and because the total biomass of animals is vastly lower than the plants that they rely upon, and therefore contribute little carbon in the way of respiration.”What these sorts of analyses have not paid attention to is what we call the indirect multiplier effects,” Schmitz says. “And these indirect effects can be quite huge — and disproportionate to the biomass of the species that are instigating the change.”In the paper, “Animating the Carbon Cycle,” a team of 15 authors from 12 universities, research organizations and government agencies cites numerous cases where animals have triggered profound impacts on the carbon cycle at local and regional levels.In one case, an unprecedented loss of trees triggered by the pine beetle outbreak in western North America has decreased the net carbon balance on a scale comparable to British Columbia’s current fossil fuel emissions.And in East Africa, scientists found that a decline in wildebeest populations in the Serengeti-Mara grassland-savanna system decades ago allowed organic matter to accumulate, which eventually led to about 80 percent of the ecosystem to burn annually, releasing carbon from the plants and the soil, before populations recovered in recent years.”These are examples where the animals’ largest effects are not direct ones,” Schmitz says. “But because of their presence they mitigate or mediate ecosystem processes that then can have these ramifying effects.””We hope this article will inspire scientists and managers to include animals when thinking of local and regional carbon budgets,” said Peter Raymond, a professor of ecosystem ecology at the Yale School of Forestry & Environmental Studies.According to the authors, a more proper assessment of such phenomena could provide insights into management schemes that could help mitigate the threat of climate change.For example, in the Arctic, where about 500 gigatons of carbon is stored in permafrost, large grazing mammals like caribou and muskoxen can help maintain the grasslands that have a high albedo and thus reflect more solar energy. In addition, by trampling the ground these herds can actually help reduce the rate of permafrost thaw, researchers say.”It’s almost an argument for rewilding places to make sure that the natural balance of predators and prey are there,” Schmitz says. “We’re not saying that managing animals will offset these carbon emissions. What we’re trying to say is the numbers are of a scale where it is worthwhile to start thinking about how animals could be managed to accomplish that.”

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Sustainable livestock production is possible

Sep. 25, 2013 — Consumers are increasingly demanding higher standards for how their meat is sourced, with animal welfare and the impact on the environment factoring in many purchases. Unfortunately, many widely-used livestock production methods are currently unsustainable. However, new research out today from the University of Cambridge has identified what may be the future of sustainable livestock production: silvopastoral systems which include shrubs and trees with edible leaves or fruits as well as herbage.Professor Donald Broom, from the University of Cambridge, who led the research said: “Consumers are now demanding more sustainable and ethically sourced food, including production without negative impacts on animal welfare, the environment and the livelihood of poor producers. Silvopastoral systems address all of these concerns with the added benefit of increased production in the long term.”Current cattle production mostly occurs on cleared pastures with only herbaceous plants, such as grasses, grown as food for the cows. The effects on the local environment include the removal of trees and shrubs as well as the increased use of herbicides, all of which result in a dramatic decrease in biodiversity. Additionally, there is also contamination of soil and waterways by agricultural chemicals as well as carbon costs because of vehicles and artificial fertiliser necessary to maintain the pasture.The researchers advocate that using a diverse group of edible plants such as that in a silvopastural landscape promotes healthy soil with better water retention (and less runoff), encourages predators of harmful animals, minimizes greenhouse gas emissions, improves job satisfaction for farm workers, reduces injury and stress in animals, improves welfare and encourages biodiversity using native shrubs and trees.Additionally, shrubs and trees with edible leaves and shoots, along with pasture plants, produce more food for animals per unit area of land than pasture plants alone. Trees and shrubs have the added benefit of providing shade from hot sun and shelter from rain. It also reduces stress by enabling the animals to hide from perceived danger.”The planting as forage plants of both shrubs and trees whose leaves and small branches can be consumed by farmed animals can transform the prospects of obtaining sustainable animal production,” said Professor Broom. “Such planting of ‘fodder trees’ has already been successful in several countries, including the plant Chamaecytisus palmensis which is now widely used for cattle feed in Australia.”Another success has been in Colombia where a mixed planting of the shrub Leucaena with a common pasture grass resulted in a 27% increase in dry matter for food and 64% increase of protein production.When ruminants, such as cows, goats and sheep, are consuming the plants from a silvopastoral system, researchers have seen an increase in growth and milk production. …

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Local animal populations contribution to human Salmonella infections overstated

Sep. 12, 2013 — A new study has shown that, contrary to popular belief, local domestic animals are unlikely to be the major source of antibiotic resistant Salmonella in humans. The result comes from a detailed study of DNA from more than 370 Salmonella samples collected over a 22-year period.By studying the genetic variation in the Salmonella bacteria and their drug resistance genes, researchers found that distinguishable bacterial populations exist in human and animal populations living side by side. Antibiotic resistance is considered to be one of the most important dangers to human health, threatening to make many treatments to common infections ineffective. By comparing the genomes of Salmonella in humans and animals the researchers have provided important new insights into the likely sources and spread of antibiotic resistant infections. First, the Salmonella bacteria largely remained within their original host populations and second, there were more varied combinations of drug resistance in the human-infecting bacteria.Salmonella infection is a global issue, with approximately 94 million people contracting gastroenteritis or food poisoning each year. The combined annual cost in the United States and European Union is estimated to be more than £4 billion ($6 billion). This public health issue is exacerbated further by antibiotic resistance, which can lead to more complicated and protracted illness in patients and increased treatment costs.”For the first time we’ve determined in detail and on a large scale how Salmonella strains taken from humans and animals in the same setting and over the same time period relate to each other,” says Dr Alison Mather, first author on the study, from the Wellcome Trust Sanger Institute. “Our genomic data reveal how the Salmonella bacteria spread during the course of a long-term epidemic. We found that people have a more diverse source of infection and antibiotic resistance than just the local animals, pointing towards alternative sources.”The team sequenced DNA from 373 samples from humans and animals infected with Salmonella Typhimurium DT104 over a 22-year period, mainly from Scotland, but also from other countries. …

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Who’s got guts? Young infants expect animals to have insides

Sep. 11, 2013 — A team of researchers has shown that 8-month-old infants expect objects they identify as animals to have insides. The study appears in the Proceedings of the National Academy of Sciences.University of Illinois professor of psychology Renée Baillargeon, who led the new study with graduate student Peipei Setoh, said that many psychologists have theorized that babies are born with core physical and psychological frameworks that help them navigate the world.For instance, when babies see a self-propelled object, their core physical framework leads them to understand that the object has internal energy. And when babies see that an object has control over its actions (that is, responds to changes in its environment), their core psychological framework leads them to view the object as an agent that has mental states.”In each case, babies seem to be born equipped with abstract expectations that drive their reasoning,” Baillargeon said.For a long time, researchers debated whether in addition to these physical and psychological expectations, infants also possess biological expectations that orient them to think about animals the right way.”Our contribution was to find a way to tackle this question experimentally, by asking what young babies know about animals’ insides,” Baillargeon said.Researchers have previously found that preschool-age children possess biological knowledge about animals’ insides. “Young children expect animals to have different insides from inanimate objects, and they realize that an animal’s insides are important for its survival,” Setoh said. “They know that if you remove the insides, the animal can’t function.”The team decided to test whether 8-month-old babies already understand that animals have insides.Setoh designed an experiment utilizing the violation-of-expectation method: If babies see something happen that they don’t expect, they look at it longer than they otherwise would. The researchers first familiarized the babies in the experiments with objects that had different characteristics. Some objects appeared to be self-propelled and agentive, other objects had only one of these properties, and other objects had neither of these properties. The researchers then tested the babies’ expectations by revealing that the objects were hollow.The infants looked longer at the hollow objects only if the objects were previously shown to be both self-propelled and agentive, indicating that those objects’ hollowness violated the infants’ expectations, Baillargeon said.”When babies encounter a novel object that is both self-propelled and agentive, they categorize it as an animal, and they assume it has insides,” Baillargeon said. “It cannot be hollow.”Another experiment the group preformed took advantage of the fact that by eight months, most babies have learned to use fur as a cue that an object might be an animal. …

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Possibility of selectively erasing unwanted memories

Sep. 10, 2013 — The human brain is exquisitely adept at linking seemingly random details into a cohesive memory that can trigger myriad associations — some good, some not so good. For recovering addicts and individuals suffering from post-traumatic stress disorder (PTSD), unwanted memories can be devastating. Former meth addicts, for instance, report intense drug cravings triggered by associations with cigarettes, money, even gum (used to relieve dry mouth), pushing them back into the addiction they so desperately want to leave.Now, for the first time, scientists from the Florida campus of The Scripps Research Institute (TSRI) have been able to erase dangerous drug-associated memories in mice and rats without affecting other more benign memories.The surprising discovery, published this week online ahead of print by the journal Biological Psychiatry, points to a clear and workable method to disrupt unwanted memories while leaving the rest intact.”Our memories make us who we are, but some of these memories can make life very difficult,” said Courtney Miller, a TSRI assistant professor who led the research. “Not unlike in the movie Eternal Sunshine of the Spotless Mind, we’re looking for strategies to selectively eliminate evidence of past experiences related to drug abuse or a traumatic event. Our study shows we can do just that in mice — wipe out deeply engrained drug-related memories without harming other memories.”Changing the Structure of MemoryTo produce a memory, a lot has to happen, including the alteration of the structure of nerve cells via changes in the dendritic spines — small bulb-like structures that receive electrochemical signals from other neurons. Normally, these structural changes occur via actin, the protein that makes up the infrastructure of all cells.In the new study, the scientists inhibited actin polymerization — the creation of large chainlike molecules — by blocking a molecular motor called myosin II in the brains of mice and rats during the maintenance phase of methamphetamine-related memory formation.Behavioral tests showed the animals immediately and persistently lost memories associated with methamphetamine — with no other memories affected.In the tests, animals were trained to associate the rewarding effects of methamphetamine with a rich context of visual, tactile and scent cues. When injected with the inhibitor many days later in their home environment, they later showed a complete lack of interest when they encountered drug-associated cues. At the same time, the response to other memories, such as food rewards, was unaffected.While the scientists are not yet sure why powerful methamphetamine-related memories are also so fragile, they think the provocative findings could be related to the role of dopamine, a neurotransmitter involved in reward and pleasure centers in the brain and known to modify dendritic spines. Previous studies had shown dopamine is released during both learning and drug withdrawal. …

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Neuroscientists show that monkeys can decide to call out or keep silent

Sep. 6, 2013 — “Should I say something or not?” Human beings are not alone in pondering this dilemma — animals also face decisions when they communicate by voice. University of Tübingen neurobiologists Dr. Steffen Hage and Professor Andreas Nieder have now demonstrated that nerve cells in the brain signal the targeted initiation of calls — forming the basis of voluntary vocal expression.Share This:When we speak, we use the sounds we make for a specific purpose — we intentionally say what we think, or consciously withhold information. Animals, however, usually make sounds according to what they feel at that moment. Even our closest relations among the primates make sounds as a reflex based on their mood. Now, Tübingen neuroscientists have shown that rhesus monkeys are able to call (or be silent) on command. They can instrumentalize the sounds they make in a targeted way, an important behavioral ability which we also use to put language to a purpose.To find out how the neural cells in the brain catalyse the production of controled vocal noises, the researchers taught rhesus monkeys to call out quickly when a spot appeared on a computer screen. While the monkeys solved puzzles, measurements taken in their prefrontal cortex revealed astonishing reactions in the cells there. The nerve cells became active whenever the monkey saw the spot of light which was the instruction to call out. …

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The difference between obsession and delusion

Sep. 4, 2013 — Because animals can’t talk, researchers need to study their behavior patterns to make sense of their activities. Now researchers at Tel Aviv University are using these zoological methods to study people with serious mental disorders.Prof. David Eilam of TAU’s Zoology Department at The George S. Wise Faculty of Life Sciences recorded patients with obsessive-compulsive disorder and “schizo-OCD” — which combines symptoms of schizophrenia and OCD — as they performed basic tasks. By analyzing the patients’ movements, they were able to identify similarities and differences between two frequently confused disorders.Published in the journal CNS Spectrums, the research represents a step toward resolving a longstanding question about the nature of schizo-OCD: Is it a combination of OCD and schizophrenia, or a variation of just one of the disorders?The researchers concluded that schizo-OCD is a combination of the two disorders. They noted that the behavioral differences identified in the study could be used to help diagnose patients with OCD and other obsessive-compulsive disorders, including schizo-OCD.The taxonomy of mental disorders”I realized my methodology for studying rat models could be directly applied to work with humans with mental disorders,” Prof. Eilam said. “Behavior is the ultimate output of the nervous system, and my team and I are experts in the fine-grained analysis of behavior, be it of humans or of other animals.”The main features of OCD are, of course, obsessions and compulsions. Obsessions are recurring and persistent thoughts, impulses, or images that are experienced as intrusive and unwanted and cause marked distress or anxiety. …

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Hibernating lemurs hint at the secrets of sleep

Sep. 4, 2013 — By studying hibernation, a Duke University team is providing a window into why humans sleep. Observations of a little-known primate called the fat-tailed dwarf lemur in captivity and the wild has revealed that it goes for days without the deepest part of sleep during its winter hibernation season. The findings support the idea that sleep plays a role in regulating body temperature and metabolism.Despite decades of research, why we sleep is still a mystery. Theories range from conserving energy, to processing information and memories, to removing toxins that build up when we’re awake.”If we spend nearly a third of our lives doing it, it must have some specific purpose,” said lead author Andrew Krystal, a sleep researcher at Duke.One theory is that sleep helps regulate body temperature and metabolism. In a study appearing Sept. 4 in the journal PLOS ONE, researchers have found support for the idea in the fat-tailed dwarf lemur (Cheirogaleus medius), a squirrel-sized primate native to the African island of Madagascar.The closest genetic relatives to humans that are known to hibernate, fat-tailed dwarf lemurs spend up to seven months each year in a physiological state known as torpor, where the regulation of body temperature stops and metabolism slows down.In torpor, these lemurs can drop their heart rate from 120 beats per minute to a mere 6, and breathing slows to a crawl. Instead of maintaining a steady body temperature like most mammals, their bodies heat up and cool down with the temperature of the outside air, fluctuating by as much as 25 degrees in a single day.For most mammals, a change in body temperature by more than a few degrees for any period of time would be life-threatening. But for the fat-tailed dwarf lemur, hibernation is a way to conserve energy during Madagascar’s long winter dry season, a time of year when food and water are in short supply.If thermoregulation is one function of sleep, the researchers asked, can dwarf lemurs in torpor get away with less sleep?To find out, they attached electrodes to the animals’ scalps and returned them to their nests for monitoring. They studied dwarf lemurs hibernating in the wild on the west coast of Madagascar, and also non-torpid animals sleeping in captivity at the Duke Lemur Center. …

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Deep-sea squid with tentacle tips that ‘swim’ on their own

Sep. 3, 2013 — Many deep-sea animals such as anglerfish use parts of their body as lures to attract prey. Some deep-sea squids may use this strategy as well. In a recent paper, researchers associated with the Monterey Bay Aquarium Research Institute (MBARI) describe a deep-sea squid that appears to use a different method to lure prey — its tentacle tips flap and flutter as if swimming on their own. The researchers hypothesize that the motion of these tentacle tips may induce small shrimp and other animals to approach within reach of the squid’s arms.Most squids have eight arms and two longer “feeding” tentacles. The tips of the tentacles, which are often broader and armed with suckers or hooks, are known as “clubs.” Such squids hunt by rapidly extending their tentacles and then grabbing prey with their clubs. The squids also use the tentacles to carry captured prey to their mouths.The deep-sea squid Grimalditeuthis bonplandi seems to use a very different feeding strategy. A slow swimmer with a weak, gelatinous body, its tentacles are long, thin, fragile, and too weak to capture prey. Unlike any other known squid, its tentacles do not have any suckers, hooks, or photophores (glowing spots).Until just a few years ago, the marine biologists had only seen specimens of G. bonplandi that were dead or dying after having been captured in deep-sea trawl nets. …

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