University, United States
University, United States

Time filter

Source Type

News Article | September 14, 2016
Site: www.biosciencetechnology.com

Some loss of memory is usually considered an inevitable part of aging, but new research reveals how some people appear to escape that fate. A study by investigators at Harvard-affiliated Massachusetts General Hospital examined a group of older adults with extraordinary memory performance and found that certain key areas of their brains resembled those of young people. The study, published in the Journal of Neuroscience, is the first step in a research program aimed at understanding how some older adults retain youthful thinking abilities and the brain circuits that support those abilities. The program is led by two senior authors of the new study — Bradford Dickerson, a Harvard Medical School associate professor of neurology and director of the Frontotemporal Disorders Unit in the MGH Department of Neurology, and Lisa Feldman Barrett of the hospital’s Department of Psychiatry. While most older adults experience a gradual decline in memory ability, some researchers have described “super-agers” with unusually resilient memories. For the new study, the investigators enrolled 40 adults ages 60 to 80 — 17 of whom performed as well as adults four to five decades younger on memory tests, and 23 with normal results for their age group — and 41 adults ages 18 to 35. “Previous research on super-aging has compared people over age 85 to those who are middle-aged,” said Alexandra Touroutoglou of MGH Neurology and HMS, who co-authored the research with Dickerson and Barrett. “Our study is exciting because we focused on people around or just after typical retirement age — mostly in their 60s and 70s — and investigated those who could remember as well as people in their 20s.” Imaging studies revealed that super-agers had brains with youthful characteristics. While the cortex — the outermost sheet of brain cells that is critical for many thinking abilities — and other parts of the brain typically shrink with aging, in the brains of super-agers a number of those regions were comparable in size to those of young adults. “We looked at a set of brain areas known as the default mode network, which has been associated with the ability to learn and remember new information, and found that those areas, particularly the hippocampus and medial prefrontal cortex, were thicker in super-agers than in other older adults,” Touroutoglou said. “In some cases, there was no difference in thickness between super-agers and young adults.” Barrett, who is also University Distinguished Professor at Northeastern University, added: “We also examined a group of regions known as the salience network, which is involved in identifying information that is important and needs attention for specific situations, and found preserved thickness among super-agers in several regions, including the anterior insula and orbitofrontal cortex.” Critically, the researchers showed not only that super-agers had no shrinkage in these brain networks but also that the size of these regions was correlated with memory ability. One of the strongest correlations between brain size and memory was found in an area at the intersection of the salience and default mode networks. Previous research has shown that this region — the para-midcingulate cortex — is an important hub that allows different brain networks to communicate efficiently. “We believe that effective communication between these networks is very important for healthy cognitive aging,” said Touroutoglou. Understanding which factors protect against memory decline could lead to important advances in treating age-related memory loss and possibly even various forms of dementia, said Dickerson. “We desperately need to understand how some older adults are able to function very well into their seventh, eight, and ninth decades. This could provide important clues about how to prevent the decline in memory and thinking that accompanies aging in most of us.”


News Article | March 2, 2017
Site: www.eurekalert.org

Images of our faces exist in numerous important databases - driver's license, passport, law enforcement, employment -- all to accurately identify us. But can these images continue to identify us as we age? Michigan State University biometrics expert Anil Jain and team set out to investigate what extent facial aging affects the performance of automatic facial recognition systems and what implications it could have on successfully identifying criminals or determining when identification documents need to be renewed. "We wanted to determine if state-of-the-art facial recognition systems could recognize the same face imaged multiple years apart, such as at age 20 and again at age 30," said Jain, University Distinguished Professor of computer science and engineering. "This is the first study of automatic facial recognition using a statistical model and large longitudinal face database." Jain and doctoral student Lacey Best-Rowden found that 99 percent of the face images can still be recognized up to six years later. However, the results also showed that due to natural changes that occur to a face over time as a person ages, recognition accuracy begins to drop if the images of a person were taken more than six years apart. This decrease in face recognition accuracy is person-dependent; some people age faster than others due to lifestyle, health conditions, environment or genetics. "This research shows the importance of capturing new images every four to five years to reduce the number of false positives or chance of not finding a candidate in a facial recognition search due to length of time between captures," said Pete Langenfeld, manager in the Biometrics and Identification Division at the Michigan State Police. "Criminal acquisition is dependent on the number of times a person is arrested, as the majority are not required to update their image. However, civil applications that require updated facial images should look at reducing the time between captures if it is greater than every four years." Jain's team studied two police mugshot databases of repeat criminal offenders with each offender having a minimum of four images acquired over at least a five-year period. The total number of repeat offenders studied was 23,600. Mugshot databases are the largest source of facial aging photos available with well-controlled standards to ensure the photos are uniform. These are the largest facial-aging databases studied to date in terms of number of subjects, images per subject and elapsed times. Academic research has enabled automated face recognition to play an increasingly large role in the criminal justice system. However, there has been a lack of research about the proper usage of these systems, said Brendan Klare, CEO of Rank One Computing, a major supplier of face recognition software. "This comprehensive study by Jain and Best-Rowden provides for the first time an unprecedented body of knowledge regarding the limits of automated face recognition." The paper will appear in the IEEE Transactions on Pattern Analysis & Machine Intelligence journal. The study was conducted in collaboration with the National Institute of Standards and Technology.


News Article | January 20, 2016
Site: phys.org

The new mass-spectral imaging system is the first of its kind in the world and its applications are just beginning to surface, said Carmen Menoni, a University Distinguished Professor in the Department of Electrical and Computer Engineering. A special issue of Optics and Photonics News last month highlights the CSU research among "the most exciting peer-reviewed optics research to have emerged over the past 12 months." Editors identified the imaging device among global "breakthroughs of interest to the optics community." Menoni's group, in collaboration with an interdisciplinary group of faculty, devised and built the instrument with help from students. She found a partner in CSU's renowned Mycobacteria Research Laboratories, which seek new treatments for the global scourge of tuberculosis. The partners described the system in a paper published earlier this year in Nature Communications. Dean Crick, a professor who researches tuberculosis, collaborated with Menoni to refine the mass spectrometer imaging system. He said the instrument will allow him to examine cells at a level 1,000 times smaller than that of a human hair - about 100 times more detailed than was earlier possible. This will give researchers the ability to observe how well experimental drugs penetrate and are processed by cells as new medications are developed to combat disease. Crick's primary research interest is tuberculosis, an infectious respiratory disease that contributes to an estimated 1.5 million deaths around the world each year. "We've developed a much more refined instrument," Crick said. "It's like going from using a dull knife to using a scalpel. You could soak a cell in a new drug and see how it's absorbed, how quickly, and how it affects the cell's chemistry." The earlier generation of laser-based mass-spectral imaging could identify the chemical composition of a cell and could map its surface in two dimensions at the microscale, but could not chart cellular anatomy at the more detailed nanoscale and in 3-D, Crick said. In addition to observing how cells respond to new drugs, he said, researchers could use the technology to identify the sources of pathogens propagated for bioterrorism. The instrument might also be used to investigate new ways to overcome antibiotic resistance among patients with surgical implants. "You might be able to customize treatments for specific cell types in specific conditions," Crick said. The CSU instrument would cover the average dining room table. Its central features are mass-spectral imaging technology and an extreme ultraviolet laser. Jorge Rocca, also a University Distinguished Professor in the Department of Electrical and Computer Engineering, created the laser attached to the spectrometer. Its beam is invisible to the human eye and is generated by an electrical current 20,000 times stronger than that of regular fluorescent tubes in ceiling lights, resulting in a tiny stream of plasma that is very hot and dense. The plasma acts as a gain medium for generating extreme ultraviolet laser pulses. The laser may be focused to shoot into a cell sample; each time the laser drills a tiny hole, miniscule charged particles, or ions, evaporate from the cell surface. These ions then may be separated and identified, allowing scientists to determine chemical composition. The microscopic shrapnel ejected from each hole allows scientists to chart the anatomy of a cell piece by piece, in three dimensions, at a scale never seen before, the scientists said. The project was funded with $1 million from the National Institutes of Health as part of an award to the Rocky Mountain Regional Center of Excellence for Biodefense and Emerging Infectious Disease Research. The optical equipment that focuses the laser beam was created by the Center for X-Ray Optics at the Lawrence Berkeley National Laboratory in Berkeley, Calif. The CSU system recently received support for system engineering design from Siemens. The company gave the CSU team an academic grant for its NX software package, including 30 seat licenses, valued at $37 million. Other CSU faculty involved in the project include Feng Dong and Elliot Bernstein from the Department of Chemistry. The lead author on the paper published in Nature Communications is Ilya Kuznetsov, a CSU doctoral student in Electrical and Computer Engineering. "The whole system was built by students and post-docs," Menoni said. "This is something we pride ourselves on, that the students get an interdisciplinary experience. Having access to design software such as the Siemens NX package is critical for creating these instruments and for training students." Key to the project has been collaboration among scientists who build high-tech devices and those who use them to solve global problems. "It's been very interesting learning how to communicate with engineers," Crick said. "We don't think alike. They understand the biology about as well as I understand the engineering. But over the years we've learned how to talk to each other, which is nice. I can see the need for the instrument, but I have no idea how to build it. They do." At one end of the instrument is a special laser created in an argon gas-filled tube when a pulse of 60 kilovolts is discharged. "It's like a lightning strike in a nanosecond," said Carmen Menoni, University Distinguished Professor in the Department of Electrical and Computer Engineering. The laser is guided through chambers using mirrors and special lenses that focus it down to a diameter of less than 100 nanometers. In a chamber at the far side of the spectrometer, the laser hits a sample cell placed with the aid of a microscope. "When you're trying to hit a single bacterium with a laser, it's tricky. You have to aim well," said Dean Crick, a CSU professor in the Department of Microbiology, Immunology and Pathology. Once the laser drills a miniscule hole in the cell, charged ions emitted after the tiny explosion are drawn into a side tube using electrostatic fields. The larger mass the charged particle has, the slower it moves down the tube; the time it takes an ion to reach a detector gives scientists information about its mass. "It's like you have a sports car and a big truck," said Ilya Kuznetsov, a doctoral student in Electrical and Computer Engineering. "Imagine you put the same motor in both—they will move at different speeds. And the more you allow them to go, the more they separate. That's why our tube is so long, to allow for that differentiation." A set of special pumps creates high vacuum that sucks all air from the tube, to remove any foreign particles the sample might collide with and to ensure equally smooth sailing for all the ions. "If you want to have a car race, you need to remove all traffic from the roads," Kuznetsov explained. By keeping the charge and amount of energy applied to each particle consistent, the mass becomes the key signature that provides researchers with every ion's chemical identity. A computer program developed in-house generates the data in a color spectrum of masses, which is then used to create a kind of topographical cell composition map. Explore further: Research team refrigerates liquids with a laser for the first time


News Article | February 17, 2017
Site: www.eurekalert.org

In new research published Monday in the journal Proceedings of the National Academy of Sciences, Northeastern University psychology professor Lisa Feldman Barrett found, for the first time, that the neurotransmitter dopamine is involved in human bonding, bringing the brain's reward system into our understanding of how we form human attachments. The results, based on a study with 19 mother-infant pairs, have important implications for therapies addressing postpartum depression as well as disorders of the dopamine system such as Parkinson's disease, addiction, and social dysfunction. "The infant brain is very different from the mature adult brain--it is not fully formed," says Barrett, University Distinguished Professor of Psychology and author of the forthcoming book How Emotions Are Made: The Secret Life of the Brain. "Infants are completely dependent on their caregivers. Whether they get enough to eat, the right kind of nutrients, whether they're kept warm or cool enough, whether they're hugged enough and get enough social attention, all these things are important to normal brain development. Our study shows clearly that a biological process in one person's brain, the mother's, is linked to behavior that gives the child the social input that will help wire his or her brain normally. That means parents' ability to keep their infants cared for leads to optimal brain development, which over the years results in better adult health and greater productivity." To conduct the study, the researchers turned to a novel technology: a machine capable of performing two types of brain scans simultaneously--functional magnetic resonance imaging, or fMRI, and positron emission tomography, or PET. fMRI looks at the brain in slices, front to back, like a loaf of bread, and tracks blood flow to its various parts. It is especially useful in revealing which neurons are firing frequently as well as how different brain regions connect in networks. PET uses a small amount of radioactive chemical plus dye (called a tracer) injected into the bloodstream along with a camera and a computer to produce multidimensional images to show the distribution of a specific neurotransmitter, such as dopamine or opioids. Barrett's team focused on the neurotransmitter dopamine, a chemical that acts in various brain systems to spark the motivation necessary to work for a reward. They tied the mothers' level of dopamine to her degree of synchrony with her infant as well as to the strength of the connection within a brain network called the medial amygdala network that, within the social realm, supports social affiliation. "We found that social affiliation is a potent stimulator of dopamine," says Barrett. "This link implies that strong social relationships have the potential to improve your outcome if you have a disease, such as depression, where dopamine is compromised. We already know that people deal with illness better when they have a strong social network. What our study suggests is that caring for others, not just receiving caring, may have the ability to increase your dopamine levels." Before performing the scans, the researchers videotaped the mothers at home interacting with their babies and applied measurements to the behaviors of both to ascertain their degree of synchrony. They also videotaped the infants playing on their own. Once in the brain scanner, each mother viewed footage of her own baby at solitary play as well as an unfamiliar baby at play while the researchers measured dopamine levels, with PET, and tracked the strength of the medial amygdala network, with fMRI. The mothers who were more synchronous with their own infants showed both an increased dopamine response when viewing their child at play and stronger connectivity within the medial amygdala network. "Animal studies have shown the role of dopamine in bonding but this was the first scientific evidence that it is involved in human bonding," says Barrett. "That suggests that other animal research in this area could be directly applied to humans as well." The findings, says Barrett, are "cautionary." "They have the potential to reveal how the social environment impacts the developing brain," she says. "People's future health, mental and physical, is affected by the kind of care they receive when they are babies. If we want to invest wisely in the health of our country, we should concentrate on infants and children, eradicating the adverse conditions that interfere with brain development."


News Article | October 28, 2016
Site: www.eurekalert.org

EAST LANSING, Mich. - A Michigan State University researcher is challenging a widely held African belief that a spinal tap, a procedure safely used to treat other diseases, could suck the brain from the base of the skull and cause death in malaria patients. Douglas Postels, a pediatric neurologist and a lead author of a new study, has shown that the common medical procedure used to diagnose brain infections and also treat nervous system illnesses that lead to increased pressure around the brain, is safe in patients with cerebral malaria. Increased pressure in the brain can lead to death in many children who fall into coma from cerebral malaria, which is the most severe form of the disease. "The thought has been not to use the procedure, especially if any increased pressure in the brain or swelling seen in the eye is present in comatose malaria patients," Postels said. "But based on our evidence, even children with severe brain swelling had no change in the likelihood of dying, whether or not they had a spinal tap." The study is now published in the online issue of Neurology, the medical journal of the American Academy of Neurology. Postels, an associate professor in the College of Osteopathic Medicine who travels to southeastern Africa to treat patients and to further his research, realized that performing a spinal tap in children with the disease was not a universal practice across the continent. Many local doctors were concerned that the procedure could force the brain out of the hole at the base of the skull because of the potential pressure difference it could cause. Questioning the validity of this way of thinking, Postels, along with co-author Christopher Moxon from the University of Liverpool, United Kingdom, set out to show that a spinal tap was not dangerous. The researchers analyzed the outcomes of 1,827 cerebral malaria patients admitted to the hospital in Malawi between 1997 and 2013. They found that children who were sicker upon arrival at the hospital were more likely to die from their illness, not from the spinal tap, which did not change their risk of death. Based on these findings, Postels said educating the African population and other areas that have similar beliefs is crucial in treating the disease since it's estimated that malaria kills a child on the continent every minute. "This actually is an important procedure that may help patients survive," he said. He hopes to further test these findings in a future randomized, controlled clinical trial to see if a spinal tap can actually be used as a therapy to lower brain pressure in children with cerebral malaria. "The important thing to remember is it's not the spinal tap that causes death, it's the underlying illness. Rather than being harmful, we believe the procedure could be beneficial for these critically ill children. Anything we can do to help decrease death and disability rates for children with severe malaria is a positive for everyone." Other MSU researchers involved in the study include Chenxi Li, assistant professor in epidemiology and biostatistics, Karl Seydel, assistant professor of internal and tropical medicine and Terrie E. Taylor, University Distinguished Professor in tropical medicine. Michigan State University has been working to advance the common good in uncommon ways for more than 150 years. One of the top research universities in the world, MSU focuses its vast resources on creating solutions to some of the world's most pressing challenges, while providing life-changing opportunities to a diverse and inclusive academic community through more than 200 programs of study in 17 degree-granting colleges.


News Article | November 15, 2016
Site: www.sciencedaily.com

Few Americans may be aware of it, but in 1952 a killer fog that contained pollutants covered London for five days, causing breathing problems and killing thousands of residents. The exact cause and nature of the fog has remained mostly unknown for decades, but an international team of scientists that includes several Texas A&M University-affiliated researchers believes that the mystery has been solved and that the same air chemistry also happens in China and other locales. Texas A&M researcher Renyi Zhang, University Distinguished Professor and the Harold J. Haynes Chair of Atmospheric Sciences and Professor of Chemistry, along with graduate students Yun Lin, Wilmarie Marrero-Ortiz, Jeremiah Secrest, Yixin Li, Jiaxi Hu and Bowen Pan and researchers from China, Florida, California Israel and the UK have had their work published in the current issue of Proceedings of the National Academy of Sciences (PNAS). In December of 1952, the fog enveloped all of London and residents at first gave it little notice because it appeared to be no different from the familiar natural fogs that have swept over Great Britain for thousands of years. But over the next few days, conditions deteriorated, and the sky literally became dark. Visibility was reduced to only three feet in many parts of the city, all transportation was shut down and tens of thousands of people had trouble breathing. By the time the fog had lifted on Dec. 9, at least 4,000 people had died and more than 150,000 had been hospitalized. Thousands of animals in the area were also killed. Recent British studies now say that the death count was likely far higher -- more than 12,000 people of all ages died from the killer fog. It has long been known that many of those deaths were likely caused by emissions from coal burning, but the exact chemical processes that led to the deadly mix of fog and pollution have not been fully understood over the past 60 years. The 1952 killer fog led to the passage of the Clean Air Act in 1956 by the British Parliament and is still considered the worst air pollution event in the European history. Through laboratory experiments and atmospheric measurements in China, the team has come up with the answers. "People have known that sulfate was a big contributor to the fog, and sulfuric acid particles were formed from sulfur dioxide released by coal burning for residential use and power plants, and other means," Zhang says. "But how sulfur dioxide was turned into sulfuric acid was unclear. Our results showed that this process was facilitated by nitrogen dioxide, another co-product of coal burning, and occurred initially on natural fog. Another key aspect in the conversion of sulfur dioxide to sulfate is that it produces acidic particles, which subsequently inhibits this process. Natural fog contained larger particles of several tens of micrometers in size, and the acid formed was sufficiently diluted. Evaporation of those fog particles then left smaller acidic haze particles that covered the city." The study shows that similar chemistry occurs frequently in China, which has battled air pollution for decades. Of the 20 most polluted cities in the world, China is home to 16 of them, and Beijing often exceeds by many times the acceptable air standards set by the U.S. Environmental Protection Agency. "The difference in China is that the haze starts from much smaller nanoparticles, and the sulfate formation process is only possible with ammonia to neutralize the particles," Zhang adds. "In China, sulfur dioxide is mainly emitted by power plants, nitrogen dioxide is from power plants and automobiles, and ammonia comes from fertilizer use and automobiles. Again, the right chemical processes have to interplay for the deadly haze to occur in China. Interestingly, while the London fog was highly acidic, contemporary Chinese haze is basically neutral." Zhang says China has been working diligently over the past decade to lessen its air pollution problems, but persistent poor air quality often requires people to wear breathing masks during much of the day. China's explosive industrial and manufacturing growth and urbanization over the past 25 years have contributed to the problem. "A better understanding of the air chemistry holds the key for development of effective regulatory actions in China," he adds. "The government has pledged to do all it can to reduce emissions going forward, but it will take time," he notes. "We think we have helped solve the 1952 London fog mystery and also have given China some ideas of how to improve its air quality. Reduction in emissions for nitrogen oxides and ammonia is likely effective in disrupting this sulfate formation process."


News Article | November 8, 2016
Site: www.sciencedaily.com

A Michigan State University researcher is challenging a widely held African belief that a spinal tap, a procedure safely used to treat other diseases, could suck the brain from the base of the skull and cause death in malaria patients. Douglas Postels, a pediatric neurologist and a lead author of a new study, has shown that the common medical procedure used to diagnose brain infections and also treat nervous system illnesses that lead to increased pressure around the brain, is safe in patients with cerebral malaria. Increased pressure in the brain can lead to death in many children who fall into coma from cerebral malaria, which is the most severe form of the disease. "The thought has been not to use the procedure, especially if any increased pressure in the brain or swelling seen in the eye is present in comatose malaria patients," Postels said. "But based on our evidence, even children with severe brain swelling had no change in the likelihood of dying, whether or not they had a spinal tap." The study is now published in the online issue of Neurology, the medical journal of the American Academy of Neurology. Postels, an associate professor in the College of Osteopathic Medicine who travels to southeastern Africa to treat patients and to further his research, realized that performing a spinal tap in children with the disease was not a universal practice across the continent. Many local doctors were concerned that the procedure could force the brain out of the hole at the base of the skull because of the potential pressure difference it could cause. Questioning the validity of this way of thinking, Postels, along with co-author Christopher Moxon from the University of Liverpool, United Kingdom, set out to show that a spinal tap was not dangerous. The researchers analyzed the outcomes of 1,827 cerebral malaria patients admitted to the hospital in Malawi between 1997 and 2013. They found that children who were sicker upon arrival at the hospital were more likely to die from their illness, not from the spinal tap, which did not change their risk of death. Based on these findings, Postels said educating the African population and other areas that have similar beliefs is crucial in treating the disease since it's estimated that malaria kills a child on the continent every minute. "This actually is an important procedure that may help patients survive," he said. He hopes to further test these findings in a future randomized, controlled clinical trial to see if a spinal tap can actually be used as a therapy to lower brain pressure in children with cerebral malaria. "The important thing to remember is it's not the spinal tap that causes death, it's the underlying illness. Rather than being harmful, we believe the procedure could be beneficial for these critically ill children. Anything we can do to help decrease death and disability rates for children with severe malaria is a positive for everyone." Other MSU researchers involved in the study include Chenxi Li, assistant professor in epidemiology and biostatistics, Karl Seydel, assistant professor of internal and tropical medicine and Terrie E. Taylor, University Distinguished Professor in tropical medicine.


News Article | November 9, 2016
Site: www.sciencedaily.com

Submitting to mob mentality is always a risky endeavor, for humans or hyenas. A new Michigan State University study focusing on the latter, though, shows that when it comes to battling for food, mobbing can be beneficial. The findings, featured in the journal Current Zoology, fully describe for the first time, cooperative behavior during fights between two apex predators ¬- spotted hyenas and lions. Understanding the factors involved in the emergence of cooperation among organisms is central to the study of social evolution, said Kenna Lehmann, MSU doctoral candidate of integrative biology and study co-author. "When hyenas mob during hyena-lion interactions, there is significant risk of injury by participating in this cooperative behavior," Lehmann said. "However, when they gang-up like this, they are more likely to win control of the food. This suggests that cooperative behavior increases fitness in hyenas." Interestingly enough, hyenas will even mob lions when no food is present. The research team, part of University Distinguished Professor of integrative biology Kay Holekamp's lab, found that hyenas are more likely to mob lions when there are more hyenas present, regardless of food presence, fight location and how many lions are involved. As this video shows, the interactions are intense. The mob sometimes starts small, but more hyenas enter the fray as the battle intensifies. Even against three lions, the smaller hyenas group as a single unit, giggling, growling and snapping like a hyena-headed hydra. Then, resembling a well-drilled military unit, they creep forward, drive the larger predators off a carcass and claim a feast for themselves and their clan. Lions and hyenas have long competed directly and indirectly for resources. Even though cooperative mobbing behavior has been documented in birds and other mammals, this is the first research to fully describe this interaction. Analysis of these complex interactions requires a large sample size, which can be obtained only from detailed long-term observational data, Lehmann said. Having access to MSU's Mara Hyena Project, the team was able to evaluate 27 years of data, covering the territories of seven hyena clans at two study sites in Kenya. "This work would not have been possible without the long-term database," said Tracy Montgomery, MSU doctoral candidate of integrative biology and study co-author. "Not only did it allow us to demonstrate that mobbing likely increases fitness in hyenas, but it also will help us identify factors that will help predict whether this cooperative behavior will occur. It also has set the stage for additional studies." Future research will dissect the elements of the mob, such as identifying the participants and their sex and rank. The researchers also will try to determine if all animals are sharing the workload or if there are regular cheaters, interlopers that skip the fight but share in the feast. Additional studies also will hone in on the signaling involved, from vocalizations to changes in hormones before and during the events to glean insights on communication, cognition and cooperation, Lehmann said.


News Article | November 8, 2016
Site: phys.org

The findings, featured in the journal Current Zoology, fully describe for the first time, cooperative behavior during fights between two apex predators—spotted hyenas and lions. Understanding the factors involved in the emergence of cooperation among organisms is central to the study of social evolution, said Kenna Lehmann, MSU doctoral candidate of integrative biology and study co-author. "When hyenas mob during hyena-lion interactions, there is significant risk of injury by participating in this cooperative behavior," Lehmann said. "However, when they gang-up like this, they are more likely to win control of the food. This suggests that cooperative behavior increases fitness in hyenas." Interestingly enough, hyenas will even mob lions when no food is present. The research team, part of University Distinguished Professor of integrative biology Kay Holekamp's lab, found that hyenas are more likely to mob lions when there are more hyenas present, regardless of food presence, fight location and how many lions are involved. As this video shows, the interactions are intense. The mob sometimes starts small, but more hyenas enter the fray as the battle intensifies. Even against three lions, the smaller hyenas group as a single unit, giggling, growling and snapping like a hyena-headed hydra. Then, resembling a well-drilled military unit, they creep forward, drive the larger predators off a carcass and claim a feast for themselves and their clan. Lions and hyenas have long competed directly and indirectly for resources. Even though cooperative mobbing behavior has been documented in birds and other mammals, this is the first research to fully describe this interaction. Analysis of these complex interactions requires a large sample size, which can be obtained only from detailed long-term observational data, Lehmann said. Having access to MSU's Mara Hyena Project, the team was able to evaluate 27 years of data, covering the territories of seven hyena clans at two study sites in Kenya. "This work would not have been possible without the long-term database," said Tracy Montgomery, MSU doctoral candidate of integrative biology and study co-author. "Not only did it allow us to demonstrate that mobbing likely increases fitness in hyenas, but it also will help us identify factors that will help predict whether this cooperative behavior will occur. It also has set the stage for additional studies." Future research will dissect the elements of the mob, such as identifying the participants and their sex and rank. The researchers also will try to determine if all animals are sharing the workload or if there are regular cheaters, interlopers that skip the fight but share in the feast. Additional studies also will hone in on the signaling involved, from vocalizations to changes in hormones before and during the events to glean insights on communication, cognition and cooperation, Lehmann said. Explore further: Hyenas' ability to count helps them decide to fight or flee


News Article | November 8, 2016
Site: www.eurekalert.org

EAST LANSING, Mich. -- Submitting to mob mentality is always a risky endeavor, for humans or hyenas. A new Michigan State University study focusing on the latter, though, shows that when it comes to battling for food, mobbing can be beneficial. The findings, featured in the journal Current Zoology, fully describe for the first time, cooperative behavior during fights between two apex predators ¬- spotted hyenas and lions. Understanding the factors involved in the emergence of cooperation among organisms is central to the study of social evolution, said Kenna Lehmann, MSU doctoral candidate of integrative biology and study co-author. "When hyenas mob during hyena-lion interactions, there is significant risk of injury by participating in this cooperative behavior," Lehmann said. "However, when they gang-up like this, they are more likely to win control of the food. This suggests that cooperative behavior increases fitness in hyenas." Interestingly enough, hyenas will even mob lions when no food is present. The research team, part of University Distinguished Professor of integrative biology Kay Holekamp's lab, found that hyenas are more likely to mob lions when there are more hyenas present, regardless of food presence, fight location and how many lions are involved. As this video shows, the interactions are intense. The mob sometimes starts small, but more hyenas enter the fray as the battle intensifies. Even against three lions, the smaller hyenas group as a single unit, giggling, growling and snapping like a hyena-headed hydra. Then, resembling a well-drilled military unit, they creep forward, drive the larger predators off a carcass and claim a feast for themselves and their clan. Lions and hyenas have long competed directly and indirectly for resources. Even though cooperative mobbing behavior has been documented in birds and other mammals, this is the first research to fully describe this interaction. Analysis of these complex interactions requires a large sample size, which can be obtained only from detailed long-term observational data, Lehmann said. Having access to MSU's Mara Hyena Project, the team was able to evaluate 27 years of data, covering the territories of seven hyena clans at two study sites in Kenya. "This work would not have been possible without the long-term database," said Tracy Montgomery, MSU doctoral candidate of integrative biology and study co-author. "Not only did it allow us to demonstrate that mobbing likely increases fitness in hyenas, but it also will help us identify factors that will help predict whether this cooperative behavior will occur. It also has set the stage for additional studies." Future research will dissect the elements of the mob, such as identifying the participants and their sex and rank. The researchers also will try to determine if all animals are sharing the workload or if there are regular cheaters, interlopers that skip the fight but share in the feast. Additional studies also will hone in on the signaling involved, from vocalizations to changes in hormones before and during the events to glean insights on communication, cognition and cooperation, Lehmann said. This research was funded by the National Institutes of Health and the National Science Foundation. Michigan State University has been working to advance the common good in uncommon ways for more than 150 years. One of the top research universities in the world, MSU focuses its vast resources on creating solutions to some of the world's most pressing challenges, while providing life-changing opportunities to a diverse and inclusive academic community through more than 200 programs of study in 17 degree-granting colleges. For MSU news on the Web, go to MSUToday. Follow MSU News on Twitter at twitter.com/MSUnews.

Loading University Distinguished collaborators
Loading University Distinguished collaborators