Three extreme weather events in the Amazon Basin in the last decade are giving scientists an opportunity to make observations that will allow them to predict the impacts of climate change and deforestation on some of the most important ecological processes and ecosystem services of the Amazon River wetlands.Scientists from Virginia Tech, the Woods Hole Research Center, and the University of California, Santa Barbara, funded by NASA, are collaborating with Brazilian scientists to explore the ecosystem consequences of the extreme droughts of 2005 and 2010 and the extreme flood of 2009.”The research fills an important gap in our understanding of the vulnerability of tropical river-forest systems to changes in climate and land cover,” said the project’s leader, Leandro Castello, assistant professor of fish and wildlife conservation in Virginia Tech’s College of Natural Resources and Environment.The huge study area encompasses 1.7 million square miles, the equivalent of half of the continental United States.In addition to historical records and ground observations, the researchers will use newly available Earth System Data Records from NASA — satellite images of the Amazon and its tributaries over the complete high- and low-water cycles.NASA is funding the study with a $1.53 million grant shared among the three institutions.”Amazon floodplains and river channels — maintained by seasonal floods — promote nutrient cycling and high biological production, and support diverse biological communities as well as human populations with one of the highest per capita rates of fish consumption,” said Castello.The researchers will look at how the natural seasonality of river levels influences aquatic and terrestrial grasses, fisheries, and forest productivity in the floodplains, and how extreme events such as floods and droughts may disturb this cycle.”We are confident that deforestation and climate change will, in the future, lead to more frequent and severe floods and droughts,” said Michael Coe, a senior scientist at the Woods Hole Research Center. “It is important that we understand how the Amazon River and ecosystem services such as fisheries are affected so that we can devise mitigation strategies.”Amazonian grasses, sometimes called macrophytes, convert atmospheric carbon to plant biomass, which is then processed by aquatic microorganisms upon decomposition.”Terrestrial grasses grow during the short window when water levels are low, sequestering some carbon, and then die when the floods arrive, releasing the carbon into the aquatic system,” said Thiago Silva, an assistant professor of geography at So Paulo State University in Rio Claro, Brazil. “They are followed by aquatic grasses that need to grow extremely fast to surpass the rising floods and then die off during the receding-water period.””Although most of the macrophyte carbon is released back to the atmosphere in the same form that it is assimilated, carbon dioxide, some of it is actually exported to the ocean as dissolved carbon or released to the atmosphere as methane, a gas that has a warming potential 20 times larger than carbon dioxide,” said John Melack, a professor at the University of California, Santa Barbara.Researchers will measure plant growth and gas exchange, and use photographs from the field and satellites.Two other Amazon resources — fisheries and forests — are important to the livelihood of the people of the region.”We will combine water level, fishing effort, and fish life-history traits to understand the impact of droughts and floods on fishery yields,” said Castello, whose specialty is Amazon fisheries. “Floods in the Amazon are almost a blessing because in some years they can almost double the amount of fish in the river that is available for fishermen and society.”The fishery data include approximately 90,000 annual interview records of fisheries activities on the number of fishers, time spent fishing, characteristics of fishing boats and gear used, and weight of the catch for 40 species. The hydrological data include daily water level measurements recorded in the Madeira, Purus, and Amazonas-Solimes rivers.The researchers will examine the potential impact of future climate scenarios on the extent and productivity of floodplain forests — those enriched by rising waters, called whitewater river forests, and nutrient-poor blackwater river forests.For example, extreme droughts may reduce productivity due to water stress and increases in the frequency and severity of forest fires. Prolonged periods of inundation, on the other hand, may decrease productivity or increase mortality due to water-logging stress.”We will evaluate these responses for the first time at a regional scale using remotely sensed indicators of vegetation condition and fire-induced tree mortality to measure the response of floodplain forests to inter-annual flood variability and extreme climate events,” said Marcia Macedo, a research associate at the Woods Hole Research Center.Researchers will measure tree litter dry weight, depth of flooding, tree height and diameter, and stand density. They will also use photographs and satellite images.Previous research has focused on Amazon upland forests and the potential impacts of deforestation, fire, and drought. The research team will compare new greenhouse gas simulations to previous simulations.”Our research informs large river ecology globally because natural flowing rivers like the Amazon are rare these days, and most research to date, being done in North America and Europe, has focused on degraded systems,” Castello said.Read more
Date:March 14, 2014Source:Institute of Food TechnologistsSummary:A new study found that the production of a mixed raspberry jelly with black and yellow raspberries could be a good alternative to just one-colored jelly.determined that a jelly with both red, yellow and black raspberries had a high sensory acceptability, even greater than traditional jelly prepared only with the red raspberry.Raspberries are among the most popular berries in the world and are high in antioxidants that offer significant health benefits to consumers. The red raspberry is most commonly used in processed products like juices, jams, jellies and preserves because of its short shelf life. A new study in the Journal of Food Science, published by the Institute of Food Technologists (IFT), found that the production of a mixed raspberry jelly with black and yellow raspberries could be a good alternative to just one-colored jelly.Black raspberries, which produce clusters of small fruit with a dark purple color, stand out among the yellow and red variety as an excellent choice for cultivation because of their excellent adaptability, high productivity and fruit quality. Researchers at the University of Lavras in Brazil determined that a jelly with both red, yellow and black raspberries had a high sensory acceptability, even greater than traditional jelly prepared only with the red raspberry.More research is needed to study the feasibility of using yellow and black raspberries on other products.Story Source:The above story is based on materials provided by Institute of Food Technologists. Note: Materials may be edited for content and length.Journal Reference:Vanessa Rios de Souza, Patrcia Aparecida Pimenta Pereira, Ana Carla Marques Pinheiro, Cleiton Antnio Nunes, Rafael Pio, Fabiana Queiroz. Evaluation of the Jelly Processing Potential of Raspberries Adapted in Brazil. Journal of Food Science, 2014; 79 (3): S407 DOI: 10.1111/1750-3841.12354 Cite This Page:MLA APA Chicago Institute of Food Technologists. “People accept three-colored raspberry jelly, study finds.” ScienceDaily. ScienceDaily, 14 March 2014. .Institute of Food Technologists. …Read more
An international study of children’s perceptions of cigarette package warning labels found that the majority of children are unaware that they exist. Children in countries where larger warning labels are used, and which include a compelling graphic image of the negative health impacts of smoking, were more likely to be aware of and understand the health risks of tobacco products.The study, led by Dina Borzekowski, Ed.D, in the University of Maryland School of Public Health (UMD SPH), and Joanna Cohen, PhD, Johns Hopkins Bloomberg School of Public Health (JHSPH), showed that only 38% of children had any awareness of warning labels currently being featured on cigarette packages. Even after showing warning labels to participating children, around two-thirds (62%) of the children were unable to explain what the health warnings were about. Among the six countries studied, awareness and understanding of health warning labels was greatest among children in Brazil, where graphic warning labels, often featuring extremely gruesome pictures, have been featured since 2002 and cover 100% of either the front or back of the cigarette package.Their findings, published in the Journal of Public Health, offer data from a sample of 2,423 five and six year-old children interviewed in Brazil, China, India, Nigeria, Pakistan, and Russia about their awareness and understanding of cigarette health warning labels.”Pro-smoking messages are reaching the world’s most susceptible audiences,” explains Dr. Borzekowski, research professor in the UMD SPH Department of Behavioral and Community Health. “We need to do a better job globally to reach children with anti-smoking messages. To do this, health warning messages should be big and clear, especially for low-literacy populations, children and young people.” According to the World Health Organization’s Framework Convention on Tobacco Control (FCTC), tobacco product packages and labeling should effectively communicate the health risks associated with tobacco use, and that the effectiveness of these health warnings and messages increases with their prominence and with the use of pictures.This new study follows recent work by Borzekowski and Cohen published in the journal Pediatrics in October 2013. The earlier piece, drawn from the same sample of five and six year olds, provided evidence that young children recognize cigarette brands. More than two-thirds could identify cigarette brand logos, with the highest percentages in the sample from China (86% could identify at least one brand).In contrast to the higher awareness among children in Brazil, where tobacco warning labels and large and graphic, awareness and understanding of health warning labels was lowest among children from Indian and Nigeria. The Indian warning label shows an image of a symbolic scorpion and the Nigerian warning label uses only a vague text message (“The Federal Ministry of Health warns that smokers are liable to die young.”)”Heath warning labels on cigarette packs are an important medium for communicating about the serious health effects caused by tobacco products,” said Dr. …Read more
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. …Read more
Oct. 17, 2013 — Researchers, taxonomists, and students from The Field Museum and 88 other institutions around the world have provided new answers to two simple but long-standing questions about Amazonian diversity: How many trees are there in the Amazon, and how many tree species occur there? The study will be published October 17, 2013 in Science.The vast extent and difficult terrain of the Amazon Basin (including parts of Brazil, Peru, Columbia) and the Guiana Shield (Guyana, Suriname, and French Guiana), which span an area roughly the size of the 48 contiguous North American states, has historically restricted the study of their extraordinarily diverse tree communities to local and regional scales. The lack of basic information about the Amazonian flora on a basin-wide scale has hindered Amazonian science and conservation efforts.”In essence, this means that the largest pool of tropical carbon on Earth has been a black box for ecologists, and conservationists don’t know which Amazonian tree species face the most severe threats of extinction,” says Nigel Pitman, Robert O. Bass Visiting Scientist at The Field Museum in Chicago, and co-author on the study.Now, however, over 100 experts have contributed data from 1,170 forestry surveys in all major forest types in the Amazon to generate the first basin-wide estimates of the abundance, frequency and spatial distribution of thousands of Amazonian trees.Extrapolations from data compiled over a period of 10 years suggest that greater Amazonia, which includes the Amazon Basin and the Guiana Shield, harbors around 390 billion individual trees, including Brazil nut, chocolate, and açai berry trees.”We think there are roughly 16,000 tree species in Amazonia, but the data also suggest that half of all the trees in the region belong to just 227 of those species! Thus, the most common species of trees in the Amazon now not only have a number, they also have a name. This is very valuable information for further research and policymaking,” says Hans ter Steege, first author on the study and researcher at the Naturalis Biodiversity Center in South Holland, Netherlands.The authors termed these species “hyperdominants.” While the study suggests that hyperdominants — just 1.4 percent of all Amazonian tree species — account for roughly half of all carbon and ecosystem services in the Amazon, it also notes that almost none of the 227 hyperdominant species are consistently common across the Amazon. Instead, most dominate a region or forest type, such as swamps or upland forests.The study also offers insights into the rarest tree species in the Amazon. According to the mathematical model used in the study, roughly 6,000 tree species in the Amazon have populations of fewer than 1,000 individuals, which automatically qualifies them for inclusion in the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. The problem, say the authors, is that these species are so rare that scientists may never find them.Ecologist Miles Silman of Wake Forest University, another co-author of the paper, calls the phenomenon “dark biodiversity.””Just like physicists’ models tell them that dark matter accounts for much of the universe, our models tell us that species too rare to find account for much of the planet’s biodiversity. …Read more
Sep. 1, 2013 — A new study has revealed that global warming is resulting in the spread of crop pests towards the North and South Poles at a rate of nearly 3 km a year.The study, published in the journal Nature Climate Change and carried out by researchers at the University of Exeter and the University of Oxford, shows a strong relationship between increased global temperatures over the past 50 years and expansion in the range of crop pests.Currently 10-16% of global crop production is lost to pests. Crop pests include fungi, bacteria, viruses, insects, nematodes, viroids and oomycetes. The diversity of crop pests continues to expand and new strains are continually evolving. Losses of major crops to fungi, and fungi-like microorganisms, amount to enough to feed nearly nine percent of today’s global population. The study suggests that these figures will increase further if global temperatures continue to rise as predicted.The spread of pests is caused by both human activities and natural processes but is thought to be primarily the result of international freight transportation. The study suggests that the warming climate is allowing pests to become established in previously unsuitable regions. For example, warming generally stimulates insect herbivory at higher latitudes as seen in outbreaks of the Mountain pine beetle (Dendroctonus ponderosae) that has destroyed large areas of pine forest in the US Pacific Northwest. In addition, the rice blast fungus which is present in over 80 countries, and has a dramatic effect both on the agricultural economy and ecosystem health, has now moved to wheat. Considered a new disease, wheat blast is sharply reducing wheat yields in Brazil.Dr Dan Bebber from the University of Exeter said: “If crop pests continue to march polewards as Earth warms the combined effects of a growing world population and the increased loss of crops to pests will pose a serious threat to global food security.”Professor Sarah Gurr from the University of Exeter (previously at the University of Oxford) said: “Renewed efforts are required to monitor the spread of crop pests and to control their movement from region to region if we are to halt the relentless destruction of crops across the world in the face of climate change.”The study used published observations of the distribution of 612 crop pests collected over the past 50 years. …Read more
Aug. 28, 2013 — A team led by astronomers in Brazil has used ESO’s Very Large Telescope to study the oldest solar twin known to date. Located 250 light-years away, the star HIP 102152 is more like the Sun than any other solar twin — except that it is nearly four billion years older. This older twin may be host to rocky planets and gives us an unprecedented chance to see how the Sun will look when it ages.Astronomers have only been observing the Sun with telescopes for 400 years — a tiny fraction of the Sun’s age of 4.6 billion years. It is very hard to study the history and future evolution of our star, but we can do this by hunting for rare stars that are almost exactly like our own, but at different stages of their lives. Now astronomers have identified a star that is essentially an identical twin to our Sun, but 4 billion years older — almost like seeing a real version of the twin paradox in action .Jorge Melendez (Universidade de São Paulo, Brazil), the leader of the team and co-author of the new paper explains: “For decades, astronomers have been searching for solar twins in order to know our own life-giving Sun better. But very few have been found since the first one was discovered in 1997. We have now obtained superb-quality spectra from the VLT and can scrutinise solar twins with extreme precision, to answer the question of whether the Sun is special.”The team studied two solar twins  — one that was thought to be younger than the Sun (18 Scorpii) and one that was expected to be older (HIP 102152). They used the UVES spectrograph on the Very Large Telescope (VLT) at ESO’s Paranal Observatory to split up the light into its component colours so that the chemical composition and other properties of these stars could be studied in great detail. They found that HIP 102152 in the constellation of Capricornus (The Sea Goat) is the oldest solar twin known to date. …Read more
Aug. 15, 2013 — As part of the largest international research effort ever made to combat tuberculosis, a team of Johns Hopkins and Brazilian experts has found that preventive antibiotic therapy for people with HIV lowers this group’s chances of developing TB or dying. Specifically, they found in men and women already infected with HIV that taking isoniazid reduced deaths and new cases of active TB disease by 31 percent, while new cases of TB alone decline by 13 percent.The research team’s findings, to be published in the journal Lancet Infectious Diseases online Aug. 16, stem from what is believed to be the largest expansion of a clinic-based, community health program designed to curb the spread of TB, and the first evidence that such a community-wide effort can be highly effective at preventing people who are co-infected from developing active TB disease.According to senior study investigator and Johns Hopkins infectious disease specialists Richard Chaisson, M.D., his team’s latest study results firmly support broad use of preventive isoniazid therapy for millions of people infected with HIV in Latin American, Asian, and Eastern European countries heavily burdened by TB.Chaisson says TB disease remains the leading cause of death worldwide among those with HIV/AIDS and is epidemic in developing countries with the highest HIV-infection rates. Isoniazid treatment, which costs less than $1 for a full course of therapy, is already recommended by the World Health Organization to prevent TB in people with HIV disease. The policy, however, has not been widely adopted and its broad impact on the HIV-infected community never shown until the Johns Hopkins and Brazilian team’s latest study.All of the 12,816 study participants were eligible for screening for TB infection or active TB disease. Some 1,186 tested positive for TB infection, but did not have symptoms of TB sickness and could start taking 300 milligrams of isoniazid daily for six months. All received routine follow-up care for as little as a few weeks to as long as four years after initially seeking treatment at any of 29 HIV clinics across Brazil, a country hit hard by both infectious diseases. Some 838 deaths occurred during the study, which took four years to complete, and 475 developed TB. Symptoms of active TB disease, indicating the disease has progressed from latent infection, include persistent cough, chest pain, chills, fever, muscle weakness and fatigue.”Our study results show that routine testing for TB and preventive isoniazid therapy works well at the community level in people with HIV disease in curbing the spread of TB and lowering the number who die,” says Chaisson, a professor at the Johns Hopkins University School of Medicine and founding director of its Center for Tuberculosis Research.”People with HIV disease living in all countries with rampant TB should be asking their physicians if they are good candidates for preventive isoniazid therapy,” says Chaisson, who leads the overall global research effort, in support of this study and others, called the Consortium to Respond Effectively to the AIDS/TB Epidemic. …Read more
July 29, 2013 — A study of mortality and fertility patterns among seven species of wild apes and monkeys and their relatives, compared with similar data from hunter-gatherer humans, shows that menopause sets humans apart from other primates.Nonhuman primates aren’t immune to the fading female fertility that comes with age, the researchers say. But human females are unique in living well beyond their childbearing years.”Unlike other primates women tend to have a long post-reproductive life. Even before modern medicine, many women lived for 30 to 35 years after their last child was born,” said co-author Susan Alberts of Duke University and the National Evolutionary Synthesis Center.In a study appearing the week of July 29 in the Proceedings of the National Academy of Sciences, Alberts and colleagues compared mortality and fertility data for seven species of wild primates to similar data for the !Kung people of Southern Africa, a human population of hunter-gatherers with limited access to modern medicine or birth control.The nonhuman primate data were based on long-term observations of 700 adult females, including capuchins in Costa Rica, muriqui monkeys in Brazil, baboons and blue monkeys in Kenya, chimpanzees in Tanzania, gorillas in Rwanda and sifakas in Madagascar.This is the first study to compare humans with multiple primate species living in the wild.For each species, the researchers estimated the pace of reproductive decline — measured as the probability, at each age, that a female’s childbirth will be her last — and compared it with the rate of decline in overall health, measured as the odds of dying with each passing birthday. “This way we were able to compare the rate of aging in the reproductive system with the rate of aging in the rest of the body,’ Alberts said.The results suggest that in nonhuman primates, reproductive decline is surpassed by declines in survival, so that very few females run out of reproductive steam before they die. A female baboon, for example, may live to age 19, and continues to reproduce to the end.But in human females the reproductive system shuts down much more rapidly than the rest of the body. “Half of women experience menopause by the age of 50, and fertility starts to decline about two decades before that,” Alberts said.What distinguishes a human female from her primate cousins is not that the human biological clock ticks faster, but that mortality is so much lower in humans than in other primates, according to work done by University of Utah anthropologist Kristen Hawkes, who was not an author of this study.This study supports that idea, the researchers say. In both humans and chimpanzees, for example, female fertility starts to decline in the late 30s and early 40s. “[But] even in human populations with little access to modern medicine, like the !Kung [hunter-gatherers in this study], most women survive for decades after their last child is born. Nonhuman primates rarely do that,” Alberts said.If evolution has given us longer lifespans than our primate cousins, why hasn’t female reproduction kept pace? And in a world where individuals with more offspring tend to win the evolutionary contest, why shut down reproduction with decades of survival still ahead?It may be that older females who forego future breeding to invest in the survival of their existing children and grandchildren gain a greater evolutionary edge than those who continue to reproduce. …Read more
July 12, 2013 — Drug use is common among street children, posing serious threats to both their health and their chances for reintegration into society. It’s difficult to reduce drug use among street children without a good understanding of the problem, and up to now the research has been confined mainly to local studies with inconsistent results. Today, Addiction has published a systematic review of 50 studies of drug use among street children in 22 countries, shedding new light on the magnitude of the problem, the causes and health consequences of drug use among street children, and areas where new research is badly needed.Share This:According to this review by researchers from Moi University (Kenya), Indiana University (USA), Regenstrief Institute (USA) and University of Toronto (Canada), the most commonly used drug among street children in low- and middle-income countries is inhalants, things like glue, acetone, gasoline, and paint thinner. Street children likely gravitate toward inhalants because they’re cheap and legal, and therefore easy to get. (In contrast, street children in high-income countries tend to favour injection drugs, such as heroin.)Use of volatile solvents such as glue and gasoline is a major obstacle to street children being re-integrated into society and having a healthy and productive life once they are off the streets. Inhalants have been linked to cognitive and neurological impairment and psychological and physical dependence. They are also linked to sudden death from cardiac arrhythmia and other causes.The prevalence of drug use among street children varies widely among countries, from 14% in Nigeria to 92% in Honduras and Brazil. These estimates are several times higher than the World Health Organization’s estimates of drug use among non-street youth globally. The most common reasons street children give for using drugs are peer pressure, escapism, pleasure, curiosity, and increasing courage and strength for life on the streets.Dr. Paula Braitstein, the senior author of this study, says that one of the most valuable outcomes of this review is an understanding of what new research needs to be done. …Read more
July 3, 2013 — Smokers and single men are more likely to acquire cancer-causing oral human papillomavirus (HPV), according to new results from the HPV Infection in Men (HIM) Study. Researchers from Moffitt Cancer Center, the National Cancer Institute, Mexico and Brazil also report that newly acquired oral HPV infections in healthy men are rare and when present, usually resolve within one year.The study results appeared in the July issue of The Lancet.HPV infection is known to cause virtually all cervical cancers, most anal cancers and some genital cancers. It has recently been established as a cause of the majority of oropharyngeal cancers, a malignancy of the tonsils and base of tongue.HPV-related oropharyngeal cancer is rare, but rates have been increasing rapidly, especially among men. To determine the pattern of HPV acquisition and persistence in the oral region, researchers evaluated the HPV infection status in oral mouthwash samples collected as part of the HIM Study, which was originally designed to evaluate the natural history of genital HPV infections in healthy men.”Some types of HPV, such as HPV16, are known to cause cancer at multiple places in the body, including the oral cavity,” said study lead author Christine M. Pierce Campbell, Ph.D., M.P.H., a postdoctoral fellow in Moffitt’s Center for Infection Research in Cancer. “We know that HPV infection is associated with oropharyngeal cancer, but we don’t know how the virus progresses from initial infection to cancer in the oral cavity. One aspect of the HIM Study is to gather data to help us understand the natural history of these infections.”During the first 12 months, nearly 4.5 percent of men in the study acquired an oral HPV infection. Less than 1 percent of men in the study had an HPV16 infection, the most commonly acquired type, and less than 2 percent had a cancer-causing type of oral HPV.Their findings are consistent with previous studies showing a low prevalence of oral HPV cancers. However, this study shows the acquisition of cancer-causing oral HPV appeared greater among smokers and unmarried men.”Additional HPV natural history studies are needed to better inform the development of infection-related prevention efforts,” said Anna R. Giuliano, Ph.D., director of Moffitt’s Center for Infection Research in Cancer. …Read more
June 24, 2013 — How is it that a complex organism evolves from a pile of dead matter? How can lifeless materials become organic molecules that are the bricks of animals and plants? Scientists have been trying to answer these questions for ages. Researchers at the Max Planck Institut für Kohlenforschung have now disclosed the secret of a reaction that has to do with the synthesis of complex organic matter before the origin of life.Since the 1960’s it has been well known that when concentrated hydrogen cyanide (HCN) is irradiated by UV light, it forms an imidazole intermediate that is a key substance for synthesis of nucleobases and nucleotides in abiotic environment. The way how UV radiation acts in this reaction to produce complex organic matter was, however, never clarified. Dr. Mario Barbatti and his colleagues in Germany, India and Czech Republic have now shown how this process occurs via computer simulations.Using diverse computational-chemistry methods, the team has arrived at astonishing conclusions: For example that the reaction does not take place in the hot spot created by the solar radiation. “This has nothing to do with heat, but with electrons,” says Mario Barbatti.The reaction proceeds through a series of electronically excited intermediates. The molecules get into the “electronic excited state” because of the UV radiation, which means that their electrons are distributed in a much different way than the usual. That changes the molecule’s attitudes. …Read more
June 5, 2013 — Reaching puberty at an unusually early age can have adverse effects on social behavior and psychological development, as well as physical effects, including short stature, and lifelong health risks, such as diabetes, breast cancer and heart disease. Researchers at Brigham and Women’s Hospital (BWH), in a multi-institutional collaboration with Boston Children’s Hospital, the Broad Institute, and the University of Sao Paulo, Brazil, have identified that a genetic mutation leads to a type of premature puberty, known as central precocious puberty. Central precocious puberty is defined by the development of secondary sexual characteristics before eight years in girls and nine years in boys.Share This:The study appears online June 5, 2013 in The New England Journal of Medicine. The results will also be presented at The Endocrine Society’s 95th Annual Meeting & Expo in San Francisco on June 17, 2013.”These findings will open the door for a new understanding of what controls the timing of puberty,” said Ursula Kaiser, MD, chief of the BWH Division of Endocrinology, Diabetes and Hypertension, co-senior study author. “It also will allow doctors to diagnose the cause of precocious puberty in a subset of patients, or to identify patients at risk for developing precocious puberty, especially if others in their family are affected. By better understanding the role of this gene in the timing of puberty, we may be able to gain insights into how other factors, such as environmental factors, may influence pubertal timing.”The researchers performed whole exome sequencing analysis of forty individuals from fifteen families with central precocious puberty. In five of the fifteen families, the researchers identified four mutations in the MKRN3 gene. The MKRN3 gene is responsible for coding a protein called makorin ring finger protein 3, which is thought to help tag other proteins for degradation. The genetic mutations resulted in truncated MKRN3 proteins and disruption of MKRN3 protein function. A mutation in the MKRN3 gene can lead to premature activation of reproductive hormones in the body, thereby initiating early puberty.The researchers also found that all affected individuals inherited the mutations from their fathers. …Read more
May 16, 2013 — Invasive “crazy ants” are displacing fire ants in areas across the southeastern United States, according to researchers at The University of Texas at Austin. It’s the latest in a history of ant invasions from the southern hemisphere and may prove to have dramatic effects on the ecosystem of the region.
The “ecologically dominant” crazy ants are reducing diversity and abundance across a range of ant and arthropod species — but their spread can be limited if people are careful not to transport them inadvertently, according to Ed LeBrun, a research associate with the Texas invasive species research program at the Brackenridge Field Laboratory in the College of Natural Sciences
The study by LeBrun and his colleagues was published in Biological Invasions.
“When you talk to folks who live in the invaded areas, they tell you they want their fire ants back,” said LeBrun. “Fire ants are in many ways very polite. They live in your yard. They form mounds and stay there, and they only interact with you if you step on their mound.”
LeBrun said that crazy ants, by contrast, “go everywhere.” They invade people’s homes, nest in crawl spaces and walls, become incredibly abundant and damage electrical equipment.
The crazy ants were first discovered in the U.S. in 2002 by a pest control operator in a suburb of Houston, and have since established populations in 21 counties in Texas, 20 counties in Florida, and a few sites in southern Mississippi and southern Louisiana.
In 2012 the species was formally identified as Nylanderia fulva, which is native to northern Argentina and southern Brazil. Frequently referred to as Rasberry crazy ants, these ants recently have been given the official common name “Tawny crazy ants.”
The Tawny crazy ant invasion is the most recent in a series of ant invasions from South America brought on by human movement. The Argentine ant invaded through the port of New Orleans in about 1891. In 1918 the black imported fire ant showed up in Mobile, Ala. Then in the 1930s, the red imported fire ant arrived in the U.S. and began displacing the black fire ant and the Argentine ants.
The UT researchers studied two crazy ant invasion sites on the Texas Gulf Coast and found that in those areas where the Tawny crazy ant population is densest, fire ants were eliminated. Even in regions where the crazy ant population is less dense, fire ant populations were drastically reduced. Other ant species, particularly native species, were also eliminated or diminished.
LeBrun said crazy ants are much harder to control than fire ants. They don’t consume most of the poison baits that kill fire ant mounds, and they don’t have the same kinds of colony boundaries that fire ants do. That means that even if they’re killed in a certain area, the supercolony survives and can swarm back over the area.
“They don’t sting like fire ants do, but aside from that they are much bigger pests,” he said. “There are videos on YouTube of people sweeping out dustpans full of these ants from their bathroom. You have to call pest control operators every three or four months just to keep the infestation under control. It’s very expensive.”
LeBrun said that in northern Argentina and southern Brazil, where the ants are native, populations are likely held in check by other ant species and a variety of natural enemies. In the U.S. there is no such natural control.
Here the crazy ants can attain densities up to 100 times as great as all other ants in the area combined. In the process, they monopolize food sources and starve out other species. LeBrun said the crazy ants, which are omnivorous, may also directly attack and kill other ant and arthropod species.
The overall result is a significant reduction in abundance and biodiversity at the base of the food chain, which is likely to have implications for the ecosystem as a whole.
“Perhaps the biggest deal is the displacement of the fire ant, which is the 300 pound gorilla in Texas ecosystems these days,” said LeBrun. “The whole system has changed around fire ants. Things that can’t tolerate fire ants are gone. Many that can have flourished. New things have come in. Now we are going to go through and whack the fire ants and put something in its place that has a very different biology. There are going to be a lot of changes that come from that.”
LeBrun said a great deal about the Tawny crazy ants remains unknown, including their potential range. So far, most of the colonies are in fairly wet environments with mild winters, near the coast, so it may be the case that they can’t thrive in drier or colder climates, and that fire ants will remain dominant in those areas.
The spread of the Tawny crazy ants may also be limited, even within the more hospitable climates, by caution from humans. The reproductive members of the species don’t fly. So when left to their own devices, crazy ant colonies can only advance about 200 meters a year. That means they’re dependent on humans to colonize new areas.
“They are opportunistic nesters,” said LeBrun. “They can take up residence in everything from a house plant, to an empty container left outside, to an RV. So they’re easily transported by us. But the flip side of that is that if people living in or visiting invaded areas are careful and check for the crazy ants when moving or going on longer trips, they could have a huge impact on the spread.” Nursery products also appear to be a key way these ants spread, so both buyers and sellers should be watchful for these ants.
LeBrun said that cutting down on the number of transplantation events could slow the spread by years or decades. And that extra time could give the ecosystem time to adapt and researchers time to develop better control methods.
“We can really make a difference,” he said, “but we need to be careful, and we need to know more.”Read more
May 30, 2013 — People in most cultures view women with small feet as attractive. Like smooth skin or an hourglass figure, petite feet signal a potential mate’s youth and fertility.
Because they signal reproductive potential, a preference for mates with these qualities may have evolved in the brains of our Pleistocene ancestors and are viewed by evolutionary psychologists as evidence that the preference is hard-wired into our genetic makeup.
But in new research published May 30 in the journal Human Nature, Geoff Kushnick, a University of Washington anthropologist, reports that the Karo Batak, who mostly live in scattered rural villages in the northern part of the Indonesian island of Sumatra, deem women with big feet as more appealing.
Kushnick, who studies the evolution of human reproductive strategies, suggests that culture — not just genetics — plays a role in deciding what makes a mate attractive. The Karo Batak predilection for big feet is linked to the society’s ecological context — that is, being rural and agricultural — and limited exposure to Western media, he found.
“Universal features of physical attractiveness are typically thought to suggest that mate choice criteria are hard-wired in humans and that they evolved tens of thousands of years ago,” Kushnick said.
“This new research supports that idea that cultural transmission of mate preferences allows humans to adapt to local environments, and this may trump hard-wired preferences.”
Kushnick showed 159 Karo Batak adults five drawings of a barefoot woman with her long hair pulled back and dressed in a shirt and a skirt reaching her mid-calf. The drawings were the same except for subtle differences in foot size.
Both male and female participants judged the drawing of the woman with the largest feet most attractive and the woman with the smallest feet least attractive.
An earlier study across societies found an overall preference for women with small feet. Respondents from Iran, Lithuania, Brazil, the United States and India rated women with small feet more attractive, but those from Cambodia, Papua New Guinea, and Tanzania preferred women with big feet.
Kushnick wondered why small-foot preferences weren’t universal. He compared his results with the earlier study and looked for an association between societies’ foot-size preferences and three potential causes — patriarchal values, rural versus urban ecology, and exposure to western media.
Both rural ecology and less exposure to Western media showed a statistical association with the preference for women with larger feet, whereas small feet were more desirable in urban societies with more exposure to Western media. Patriarchal values did not make a difference.
“My analyses support the notion that culturally transmitted preferences that allow people to adapt to local environments can trump evolved preferences,” Kushnick said. “Cultural and social influences play a stronger role in mate choice than some evolutionary psychologists are willing to accept.”
Or, as one male Karo Batak respondent was overheard saying: “Why would anyone like a woman with small feet? How would she work in the rice field?”
Big feet equal strength and greater productivity in the rice fields among the Karo Batak, who join other societies in challenging the one-size-fits-all notion of beauty.
The findings hint at how humans continue to evolve.
“The study adds more evidence of the potential for culture to drive human evolution,” Kushnick said. “Since mating preferences drive sexual selection, it is possible that male-female differences in relative foot size are the product of recent evolution.”Read more
May 20, 2013 — The Amazon rain forest, popularly known as the lungs of the planet, inhales carbon dioxide as it exudes oxygen. Plants use carbon dioxide from the air to grow parts that eventually fall to the ground to decompose or get washed away by the region’s plentiful rainfall.
Until recently, people believed much of the rain forest’s carbon floated down the Amazon River and ended up deep in the ocean. University of Washington research showed a decade ago that rivers exhale huge amounts of carbon dioxide — though left open the question of how that was possible, since bark and stems were thought to be too tough for river bacteria to digest.
A study published this week in Nature Geoscience resolves the conundrum, proving that woody plant matter is almost completely digested by bacteria living in the Amazon River, and that this tough stuff plays a major part in fueling the river’s breath.
The finding has implications for global carbon models, and for the ecology of the Amazon and the world’s other rivers.
“People thought this was one of the components that just got dumped into the ocean,” said first author Nick Ward, a UW doctoral student in oceanography. “We’ve found that terrestrial carbon is respired and basically turned into carbon dioxide as it travels down the river.”
Tough lignin, which helps form the main part of woody tissue, is the second most common component of terrestrial plants. Scientists believed that much of it got buried on the seafloor to stay there for centuries or millennia. The new paper shows river bacteria break it down within two weeks, and that just 5 percent of the Amazon rainforest’s carbon ever reaches the ocean.
“Rivers were once thought of as passive pipes,” said co-author Jeffrey Richey, a UW professor of oceanography. “This shows they’re more like metabolic hotspots.”
When previous research showed how much carbon dioxide was outgassing from rivers, scientists knew it didn’t add up. They speculated there might be some unknown, short-lived carbon source that freshwater bacteria could turn into carbon dioxide.
“The fact that lignin is proving to be this metabolically active is a big surprise,” Richey said. “It’s a mechanism for the rivers’ role in the global carbon cycle — it’s the food for the river breath.”
The Amazon alone discharges about one-fifth of the world’s freshwater and plays a large role in global processes, but it also serves as a test bed for natural river ecosystems.
Richey and his collaborators have studied the Amazon River for more than three decades. Earlier research took place more than 500 miles upstream. This time the U.S. and Brazilian team sought to understand the connection between the river and ocean, which meant working at the mouth of the world’s largest river — a treacherous study site.
“There’s a reason that no one’s really studied in this area,” Ward said. “Pulling it off has been quite a challenge. It’s a humongous, sloppy piece of water.”
The team used flat-bottomed boats to traverse the three river mouths, each so wide that you cannot see land, in water so rich with sediment that it looks like chocolate milk. Tides raise the ocean by 30 feet, reversing the flow of freshwater at the river mouth, and winds blow at up to 35 mph.
Under these conditions, Ward collected river water samples in all four seasons. He compared the original samples with ones left to sit for up to a week at river temperatures. Back at the UW, he used newly developed techniques to scan the samples for some 100 compounds, covering 95 percent of all plant-based lignin. Previous techniques could identify only 1 percent of the plant-based carbon in the water.
Based on the results, the authors estimate that about 45 percent of the Amazon’s lignin breaks down in soils, 55 percent breaks down in the river system, and 5 percent reaches the ocean, where it may break down or sink to the ocean floor.
“People had just assumed, ‘Well, it’s not energetically feasible for an organism to break lignin apart, so why would they?'” Ward said. “We’re thinking that as rain falls over the land it’s taking with it these lignin compounds, but it’s also taking with it the bacterial community that’s really good at eating the lignin.”
The research was supported by the Gordon and Betty Moore Foundation, the National Science Foundation and the Research Council for the State of São Paulo. Co-authors are Richard Keil at the UW; Patricia Medeiros and Patricia Yager at the University of Georgia; Daimio Brito and Alan Cunha at the Federal University of Amap in Brazil; Thorsten Dittmar at Carl von Ossietzky University in Germany; and Alex Krusche at University of São Paulo in Brazil.Read more
May 8, 2013 — Bioenergy crops, such as Miscanthus and switchgrass, appear to be promising resources for renewable energy, but these new crops did not come with a manual on how to measure details on their sustainability impacts. Jody Endres, University of Illinois professor of energy and environmental law and chair of the Council on Sustainable Biomass Production (CSBP) says standards are needed so farmers, ethanol producers, and others in the biofuels industry will all be on the same page here in the United States as well as in Europe and Brazil.
Endres believes that three conditions must be met before the benefits of standards can be fully realized.
“First, to achieve public acceptance, standards must be built upon foundations of good governance,” Endres said. “Environmental and social advocacy groups should be included at some level in the process. For example, we’re discussing what standards the aviation sector should recognize to meet their sustainability expectations. Instead of the substantive innerworkings of standards’ principles, such as protections for air, water, soil, biodiversity, and community values, debate has centered on the level of participation and transparency standards development observes, and particularly whether a standard meets environmental groups’ governance demands.”
The second precondition Endres defines is to fortify the producer’s sustainability toolbox, including a determination as to whether or not existing tools are effective. “If they’re not, how can we build these socio-technical systems to help farmers rethink their actions in the landscape and how it relates to the environment?” Endres asked. “For example, environmentalists would like to see improvements at the watershed scale. If only isolated farmers need to be certified, and they have to figure out what their contributions to that watershed are, it can be very difficult, particularly when states have not fully assessed baseline water quality and all parties responsible for its degradation.”
The third precondition for successful standard implementation is international harmonization. “Even if the biomass goes to the biorefinery with the right lignin-to-sugar content and the right amount of water, if you had to add nitrogen to produce it, or lost habitat or soil when harvesting it, it may not comply with European regulations.
“Environmental groups don’t want to see a race to the bottom — adopting requirements that are bare minimum,” Endres said. “But the European standards contain requirements that are difficult to achieve, particularly for small growers. A biomass farmer doesn’t know where to begin to apply it to their farming practices.”
The European Renewable Energy Directive provides a baseline framework for sustainability reporting and requirements. “They’re primarily concerned with land conversion — high carbon stock land or lands that are high in biodiversity values,” Endres said. “They also require a cross-compliance with agro- environmental laws, which is something required in return for receipt of agricultural payments under the Common Agricultural Program. In large part, we don’t have a similar system in the United States. We have requirements for highly erodible land and protection of endangered species, but in Europe there’s a broader program specifically designed for agricultural contexts to comply with environmental law and to improve the environment.”
Adopting European standards is not a simple task for U.S. growers, Endres said. “For the past three years, the Council for Sustainable Biomass Production has been developing a standard that the European Commission will recognize, but one that is at the same time one designed for American growers to implement practically on the ground and that deploys tools such as those developed by USDA and Extension. Until we have a standard uniquely developed for the American market, producers’ access to European markets could be inhibited. Harmonization questions between Europe, the U.S. and Brazil likely will arise, particularly when stakeholders disagree on substantive and governance questions associated with the many standards emerging in the international marketplace.”
Endres said that other than certification for organic food, the United States does not have widespread experience with certifying commodities. “European calls for biofuels certification are pushing efforts in the U.S. to figure out how to certify an agricultural supply chain. It’s something we’ve never done here at a large scale,” she said.
She stressed that international harmonization is vital for the aviation industry because of looming compliance mandates for carbon reductions in Europe. “To land a plane in Europe, U.S. carriers will have to prove that they have reduced their carbon footprint below a certain level. If not, they will have to buy credits within the European Emissions Trading System. Although the requirement has been postponed until January 2014, the aviation sector is actively seeking ways to reduce greenhouse gas emissions through biofuels. The challenge is not only how to convert cellulosics into jet fuel, but also how to certify that they are grown, refined, and distributed in a sustainable manner,” Endres said.
Endres said that there are still a lot of questions about how to implement standards for biomass. “It’s important to match the goal of regulation with what actually can and does occur on the ground. We can put any requirement into writing, but will it really work on the ground or is it just ‘green washing?’
“In the war of words and in the public media, biofuels have had to face more accusations than any other renewable energy source, such as solar power and wind,” Endres said. “So, even though we think we’re achieving rural development, receiving carbon reductions or climate mitigation benefits, or that we’re having increased energy security, people may still be suspicious of biomass fuels unless there is a certification that we can operationalize.”
Funding was provided by the Energy Biosciences Institute.Read more
May 29, 2013 — In a study published today in the journal PLOS ONE, a team of researchers led by NJIT Associate Professor Gareth Russell has applied a novel method for linking large-scale habitat fragmentation to population sustainability.
“Our goal was to assess the extinction risk for bird species in the Atlantic Forest of Brazil, a global ‘hotspot’ of bird diversity,” said Russell. “Based on elevation restrictions and forest type requirements, as well as ongoing tropical deforestation, we already knew that most species have access to far less habitat than typically assumed. But what habitat remains is also highly fragmented. Looking at area alone is not enough.”
Other researchers included Stuart Pimm, Doris Duke Professor of Conservation Ecology, Duke University; Grant Harris, chief of biological sciences (Southwest region), U.S. Fish and Wildlife Service; and Jessica Schnell, recently graduated, now at the Max Planck Institute for Ornithology, Germany.
More accurate habitat maps show the extent of fragmentation, but researchers still must link the particular habitat distribution of a species to its extinction risk in an objective and consistent manner.
In a recent, more technical publication in the journal Conservation Biology, the same authors showed that a modified version of a metric called meta-population capacity has the right characteristics to assess the impact of fragmentation. Meta-population capacity takes information about the sizes of fragments and the distances separating them and summarizes the influence of these geographic factors on long-term population persistence.
The current study applied this metric to 127 forest-dependent passerine birds inhabiting the Atlantic Forest of Brazil, an area that has lost over 90 percent of its original forest. There were two key results:
First, the species fell into two distinct groups: those where the fragmentation impact was severe, and those where it was relatively mild. There were few species in the middle. This immediately suggests a straightforward way in which fragmentation patterns can contribute to threat assessment.
The authors also found that out of 58 species that have severely fragmented habitat, 28 are not currently considered to be threatened, according to the latest red list published by the International Union for the Conservation of Nature.
Taking these results into consideration, the authors recommend that the classification of these species be reexamined.
Russell also hopes this work will have a broader impact. “Assessing extinction risk is enormously challenging, and the dedicated teams that do this work are faced with many unknowns,” he said. “The most endangered species are often the most rare, and therefore also the hardest to find and study. Our approach requires only basic knowledge about a species, but optimizes that information by linking it to the recent flood of data about the environment.”
The researchers believe that their work could be applied widely, helping to identify at-risk species from many different groups and from many regions of the planet.Read more