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By Susan Milius Nothing but fear itself can actually be dangerous for nesting birds. Song sparrows protected from attack but subjected to recordings of predator yowls and leaf-crunching approach noises raised 40 percent fewer offspring in a year compared with neighbors living amid innocuous noises, says population ecologist Liana Zanette of the University of Western Ontario in Canada. Predators do not need to kill a single prey to have a big effect, she says. Scary noises, broadcast where the sparrows nested in the wild, took a toll throughout the breeding season, Zanette and her colleagues report in the Dec. 9 Science. The alarmed sparrows laid fewer eggs to begin with, and they proved such skittish and cautious parents that they reared a smaller percentage of hatchlings than neighbors did. Biologists have tended to focus on the direct effects of predators killing prey, says evolutionary ecologist Thomas Martin of the U.S. Geological Survey in Missoula, Mont., who was not part of the sparrow research. This new study, he says, suggests theorists have underestimated the impact of predators. “Predators shape everything,” Zanette says. Wolves that eat elk give more plants a chance to survive, which in turn changes which other creatures thrive. Previous work, including Zanette’s, suggested that fear of predators could change bird egg number or size. Yet separating the effects of fear from those of actual predator attacks took years of preparation, she says. © Society for Science & the Public 2000 - 2011

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 16133 - Posted: 12.10.2011

by Andy Coghlan The brains of children from violent homes function like those of soldiers when it comes to detecting threats. Eamon McCrory at University College London used fMRI to scan the brains of 20 outwardly healthy children who had been maltreated and 23 "controls" from safe environments. During the scans, the children, aged 12 on average, viewed a mixture of sad, neutral and angry faces. When they saw angry faces, the maltreated children showed extra activity in the amygdala and the anterior insula, known to be involved in threat detection and anticipation of pain. Combat soldiers show similar heightened activity (Current Biology, DOI: 10.1016/j.cub.2011.10.015). "Our belief is that these changes could reflect neural adaption," says McCrory. "Maltreated kids and active soldiers are adapting to survive in a threatening or dangerous environment." Although this could help children survive their early years, it may predispose them to mental health problems in adulthood, such as depression or anxiety, says McCrory. A related study, published this week by Hilary Blumberg of Yale University School of Medicine and colleagues, demonstrates that areas of the brain important for emotional processing are deficient in grey matter in adolescents who suffered from maltreatment as children (Archives of Pediatrics and Adolescent Medicine, DOI: 10.1001/archpediatrics.2011.565). © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 13: Memory, Learning, and Development
Link ID: 16122 - Posted: 12.08.2011

By Scicurious We hear a lot about PTSD these days, and with good reason. As more people confront trauma and come away with severely debilitating disorders, it becomes that much more important to understand the mechanism, in order to find ways to treat or prevent it. And one of the ways people are seeking to understand PTSD is by trying to find genetic risk factors for the disorder, in the hope that familial traits will be able to predict who might develop PTSD and who might not, allowing for preventative treatments before exposure, and better treatments after trauma. And if you’re going to study familial components in humans, one of the best ways to do that is to study twins. For this study, the authors are looking at two different groups of twins (the study is still ongoing) recruited from the Vietnam Era Twin Registry. In the first group of twins, one twin fought in the Vietnam war and got PTSD, the other twin didn’t fight. In the second group of twins, one twin fought in Vietnam and did NOT get PTSD, and the other twin did not fight. They took these groups of twins and put them in fMRI, where they exposed them to sets of fearful or non-fearful faces. Fearful faces can provoke a response from the amygdala, an area of the brain associated with processing emotions such as fear. People with PTSD are known to have differences in amygdala responses, and this study wanted to confirm this, as well as examining their twins, to see if there was any indication in twins who had not been exposed to combat. © 2011 Scientific American,

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 16057 - Posted: 11.19.2011

By Nathan Seppa ORLANDO, Fla. — Women who report having had forced sex at a young age have an elevated risk of heart disease as adults. Some of the higher cardiac risk is traceable to behavioral and lifestyle factors, but much of it goes unexplained, researchers reported October 13 at a meeting of the American Heart Association. “This tells us that the immediacy of the tragedy is being followed by risk that may have implications in later life,” says Clyde Yancy, a cardiologist at Northwestern University School of Medicine in Chicago who was not involved in the study. “That’s very disconcerting.” The researchers analyzed data from more than 67,000 women who were age 25 to 42 when they volunteered to participate in a large healthcare study in 1989. Questionnaire responses revealed that 11 percent answered yes when asked whether they had had “forced sexual activity” during childhood or adolescence, the years through age 17. After following the women in adulthood for 18 years and tabulating any heart problems they encountered in that time, the scientists were able to discern that women who had had at least one episode of forced sexual contact when young faced roughly a 56 percent greater risk in cardiovascular disease than did women with no history of childhood sex abuse. © Society for Science & the Public 2000 - 2011

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 13: Memory, Learning, and Development
Link ID: 16033 - Posted: 11.14.2011

By SAM ROBERTS Election Day is seldom associated with raging hormones. But three professors from Israel, where all politics is vocal, suggest that the very act of voting generates stress levels that could affect the outcome. In an experiment conducted in a small Israeli town during the fiercely contested 2009 national election, the researchers took saliva samples from people who were about to vote. They found higher levels of glucocorticoid hormones, including cortisol, which are secreted by the adrenal glands and are associated with stress. Not only that, but people who planned to vote for the underdog tended to exhibit even more stress — affirming a study from the United States that found Obama voters’ cortisol levels remained steadier than those of McCain voters as the 2008 election results rolled in. “This is the first study to explore the psychological well-being of actual voters through an endocrinal measure at the ballot,” the professors — Israel Waismel-Manor of the University of Haifa and Gal Ifergane and Hagit Cohen of Ben-Gurion University of the Negev — write in a recent edition of the journal European Neuropsychopharmacology. They conducted their experiment in Omer, a small town 70 miles south of Tel Aviv, and hope to replicate it in the United States a year from now, when Americans choose a president. © 2011 The New York Times Company

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 16006 - Posted: 11.08.2011

By Susan Milius Even solitary creatures do better when a new place has the same old jerks next door. Stephens’ kangaroo rats, on the U.S. list of endangered species since 1988, live by themselves most of the time in plots of California grassland that they defend from nearby members of their species. When conservationists moved animals to safer homes away from development, familiar rivals relocated together fared better than kangaroo rats grouped with strangers, says conservation biologist Debra Shier of the San Diego Zoo Institute for Conservation Research. This boost may come from what’s been called a “dear enemy effect,” Shier and institute colleague Ronald Swaisgood say online October 6 in Conservation Biology. Animals tend not to scrap as aggressively with familiar holders of neighboring territories as with complete strangers. Among the kangaroo rats, the researchers noted that those relocated along with their dear enemies indeed spent less time fighting and more time foraging than kangaroo rats surrounded by unfamiliar neighbors. Talk is increasing about relocating imperiled animals or plants — either from shrinking wild habitats or captive breeding centers — as a solution to conservation challenges including climate change, says Mark Stanley Price, chair of the International Union for Conservation of Nature’s Task Force on Moving Plants and Animals for Conservation Purposes. Yet it’s a complex process. “While the last 30 years have seen some spectacular species returns, there are many, often undocumented, failures,” he says. The work by Shier and Swaisgood “should prove to be an exemplary milestone in translocation biology." © Society for Science & the Public 2000 - 2011

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 15914 - Posted: 10.15.2011

By NICHOLAS BAKALAR The stress of living in a neonatal intensive care unit results in decreased brain size and abnormal neurological findings for very preterm babies, a small study suggests, and the more the stress, the greater the effect. Scientists at Washington University in St. Louis studied 44 infants born before 30 weeks of gestation. The researchers recorded the number of stressors the babies underwent, using a list of 36 procedures of varying invasiveness, from diaper changes to the insertion of intravenous lines. When the babies reached term-equivalent age, 36 to 44 weeks, they underwent M.R.I.’s and behavioral tests. The study was published online last week in The Annals of Neurology. After controlling for immaturity at birth and severity of illness, a higher score on the stress scale was associated with reduced brain size and poorer results on the examinations. There was no relation between number of stressors and brain injury. “We have to move away from a focus on just pain medications and acute medical interventions toward a more developmental approach,” said the study’s senior author, Dr. Terrie Inder, a professor of pediatrics. These babies, she added, “need the opportunity to rest, recover, be nurtured and be able to grow.” © 2011 The New York Times Company

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 13: Memory, Learning, and Development
Link ID: 15901 - Posted: 10.11.2011

By Rick Nauert PhD Senior News Editor Researchers from the University of Leicester have identified a particular protein that the brain produces in response to stress, an important step forward in understanding molecular mechanisms of anxiety. The findings, published in Proceedings of the National Academy of Sciences (PNAS), are potentially important for understanding stress-related psychiatric diseases in humans. Neuroscientist Robert Pawlak, M.D., Ph.D., said the study had determined that production of the protein by the brain may help to protect individuals from “too much anxiety” and help organisms to cope with various adverse life events. Pawlak believes that everyday stress “reshapes” the brain – nerve cells change their morphology, the number of connections with other cells and the way they communicate with other neurons. And, in most cases these responses are adaptive and beneficial – they help us to cope with stress and shape adequate behavioral reaction. “However, upon severe stress things can get out of control, the brain ‘buffering’ capacity is exhausted and the nerve cells in the hippocampus – an area of the brain responsible for learning and memory – start to withdraw their processes, don’t effectively communicate with other cells and show signs of disease,” Pawlak said. In response to stress, neurons often change the shape of tiny structures they normally use to exchange information with other neurons, called dendritic spines. Spines can be as small as 1/1000 of a millimeter and have various shapes. © 1992-2011 Psych Central.

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 15878 - Posted: 10.06.2011

By Katherine Harmon Just watching television footage of the terrorist attacks of September 11, 2001​, was enough to cause clinically diagnosable stress responses in some people who did not even live near the attacks—let alone the millions of people who did. Like many other major disasters, 9/11 brought with it a host of psychological repercussions, one of the most severe of which has been post-traumatic stress disorder. PTSD is characterized by trouble sleeping, difficulty controlling anger, losing interest in activities, flashbacks, emotional numbness and/or other symptoms. If not treated, it can be debilitating. But these reactions are not uncommon after a major disaster—and teasing apart post-9/11 disorders has been tricky for psychologists and researchers. "We tend to use the terminology of PTSD very loosely. A lot of people will have traumatic reactions but not necessarily PTSD," says Priscilla Dass-Brailsford of Georgetown University Medical Center's psychiatry department. Researchers have been poring over the piecemeal collection of studies conducted over the past decade on the conditions of people after the attacks—how they felt and how well various treatments, and the passage of time, have helped them overcome mental afflictions. And from the literature, we are learning that old styles of early intervention, such as debriefing sessions, are not as effective as once thought—and that more often than not, people are incredibly resilient and can recover on their own and should be given the opportunity to do so. © 2011 Scientific American,

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 15790 - Posted: 09.12.2011

By Tina Hesman Saey Friendly intestinal bacteria not only keep the gut happy, they may help keep their host happy, too, a new study in mice finds. Mice fed broth fortified with a type of friendly intestinal bacteria called Lactobacillus rhamnosus behaved less anxiously than mice fed broth without bacteria. Those behavior changes were accompanied by differences in levels of a brain-chemical sensor and stress hormones. The bacteria telegraph these brain-chemical and behavior-changing messages via the vagus nerve, which connects the brain stem to various internal organs, researchers report online August 29 in the Proceedings of the National Academy of Sciences. Some studies have suggested that changing the mix of bacteria in the intestines could influence behavior (SN: 6/18/11, p. 26). The new research goes a step further to investigate how those changes come about, says Paul Patterson, a neuroimmunologist at Caltech in Pasadena, Calif. “Most people haven’t gone that far to look at what’s happening in the brain,” he says. The research team — led by John Bienenstock of McMaster University in Hamilton, Canada, and John Cryan of the University College Cork in Ireland — looked at the mice’s brains to examine levels of the GABA receptor, a protein that senses and responds to an important brain chemical messenger called GABA. Alterations in the way GABA and other brain chemical systems work influence behavior. Mice fed bacteria-containing broth had higher levels of the receptor protein in some parts of the brain and lower levels in other parts than did mice fed sterile broth. © Society for Science & the Public 2000 - 2011

Related chapters from BP7e: Chapter 13: Homeostasis: Active Regulation of the Internal Environment; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment; Chapter 11: Emotions, Aggression, and Stress
Link ID: 15742 - Posted: 08.30.2011

By James Gallagher Health reporter, BBC News People with psoriasis have nearly three times the normal risk of stroke and abnormal heart rhythm, according to scientists in Denmark. A study of 4.5 million people, published in the European Heart Journal, showed the highest risk was in young patients with severe psoriasis. Researchers believe this may be because the skin and blood vessels may share similar sources of inflammation. The Stroke Association said this should not be an immediate cause for concern. Skin cells are normally replaced every three to four weeks but, in patients with psoriasis, that process can be greatly speeded up. It can take between just two and six days, resulting in red, flaky, crusty patches on the skin. The condition affects 2% of people in the UK and the cause is unknown. Researchers analysed data from everyone in Denmark between 1997 and 2006 - 36,765 had mild psoriasis and 2,793 had the severe form of the condition. In patients under 50 with mild psoriasis, the risk of abnormal heart rhythm - atrial fibrillation - increased by 50%. The risk of ischaemic stroke increased by 97%. BBC © 2011

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 15: Language and Our Divided Brain
Link ID: 15735 - Posted: 08.29.2011

By Bruce Bower LAS VEGAS — Soldiers fighting at the tip of the spear — the leading edge of combat — confront fighting, suffering and dying. But the success of those soldiers’ operations depends on a huge network of service and support personnel who themselves face considerable and often overlooked war stress, says military sociologist Wilbur Scott of the U.S. Air Force Academy in Colorado Springs. After returning from one or more deployments, National Guard combat service personnel — including clerks, truck drivers, medics and supply officers — displayed slightly less emotional resilience and described having experienced more stress while overseas and after returning home than their comrades engaged in combat, Scott reported August 20 at the annual meeting of the American Sociological Association. In particular, combat service personnel cited deployment stress triggered by exposure to danger, life-threatening situations and death. Their responses reflect the changed nature of warfare, Scott suggested. In Iraq and Afghanistan, counterinsurgency efforts have replaced conventional warfare. “While those in combat arms typically are thought of as being at the tip of the spear, this thinking applies more accurately to conventional settings rather than those encountered in Iraq and Afghanistan,” Scott said. Combat units not only fight and kill but establish relationships with local officials, head local building projects and encourage trust in local governments. Service personnel work in the midst of operations, where they can encounter guerilla attacks or roadside bombs. © Society for Science & the Public 2000 - 2011

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 15703 - Posted: 08.23.2011

By Bruce Bower Now hear this: A mother’s encouraging words heard over the phone biologically aid her stressed-out daughter about as much as in-person comforting from mom and way more than receiving instant messages from her. That’s consistent with the idea that people and many other animals have evolved to respond to caring, familiar voices with hormonal adjustments that prompt feelings of calm and closeness, say biological anthropologist Leslie Seltzer of the University of Wisconsin–Madison and her colleagues. Written exchanges such as instant messaging, texting and Facebook postings can’t apply biological balm to frazzled nerves, the researchers propose in a paper published online July 29 in Evolution and Human Behavior. Seltzer’s group found that 7- to 12-year-old girls who talked to their mothers in person or over the phone after a stressful lab task displayed drops in levels of cortisol, a stress hormone, accompanied by the release of oxytocin, a hormone linked to love and trust between partners in good relationships. Girls who instant messaged with their mothers after the lab challenge showed no oxytocin response and their cortisol levels rose as high as those of girls who had no contact with their mothers. “At least in our subjects, instant messaging falls short of the endocrine payoff of speech or physical contact with a loved one after a stressful event,” Seltzer says. © Society for Science & the Public 2000 - 2011

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 8: Hormones and Sex
Link ID: 15677 - Posted: 08.13.2011

Post traumatic stress disorder (PTSD) is a risk factor for premature birth, research suggests. A study of more than 800 women in the US also found a link with having a smaller baby. Babies of women with the anxiety disorder, triggered by a harrowing event, weighed about half a pound less than usual. Researchers at the University of Michigan, US, say PTSD needs to be taken into account in maternity care. Nearly half of the women in the study were African American. Lead researcher Julia Seng, Professor of Nursing at the University of Michigan, said: "An African American infant in Michigan is 70% more likely to be born prematurely than an infant of any other race. "Therefore PTSD, which is treatable and affects African Americans more widely, may be an additional explanation for adverse perinatal outcomes. "It is essential that outcomes are improved in this high-risk group of women. Maternity care needs to take traumatic stress into account with awareness being raised amongst health workers." BBC © 2011

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 13: Memory, Learning, and Development
Link ID: 15621 - Posted: 07.28.2011

by Rebecca Coffey 1 Think about money, work, economic outlook, family, and relationships. Feeling anxious? In a 2010 American Psychological Association survey [pdf], those five factors were the most often cited sources of stress for Americans. 2 Stress is strongly tied to cardiac disease, hypertension, inflammatory diseases, and compromised immune systems, and possibly to cancer. 3 And stress can literally break your heart. Takotsubo cardiomyopathy, or “broken heart syndrome,” occurs when the bottom of the heart balloons into the shape of a pot (a tako-tsubo) used in Japan to trap octopus. It’s caused when grief or another extreme stressor makes stress hormones flood the heart. advertisement | article continues below 4 The hormone cortisol is responsible for a lot of these ill effects. Elevated cortisol gives us a short-term boost but also suppresses the immune system, elevates blood sugar, and impedes bone formation. 5 Even the next generation pays a price: Researchers at the University of California, San Francisco, find an association between high cortisol in mothers during late pregnancy and lower IQs in their children at age 7. 6 Stress during pregnancy has also been linked to offspring with autism. 7 But enough stressing! One way to relax: a career of mild obsolescence. Surveying 200 professions, the site CareerCast.com rated bookbinder the least stressful job of 2011. (Most stressful: firefighter and airline pilot.) © 2011, Kalmbach Publishing Co.

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 15620 - Posted: 07.28.2011

By John Matson As Operation Enduring Freedom , the war on terror in Afghanistan, winds down and some 33,000 U.S. servicemen and servicewomen return from overseas in the next year, a plan announced by President Obama on June 22, the psychological issues that veterans face back home are likely to increase. Some of the key psychological issues affecting the approximately two million American troops deployed to Iraq and Afghanistan since 2001 have been traumatic brain injury (TBI), depression and post-traumatic stress disorder (PTSD)—and the diagnoses often overlap. A 2008 report by the RAND Corp. think tank estimated that more than 26 percent of troops may return from the wars on terror with mental health issues. It is reasonable to expect a continuation of these brain and mental health trends, only multiplied by the anticipated dramatic uptick in returning troops. On top of that, such issues also tend to crop up several months or even years after service members settle in, rather than directly after homecoming, as researchers learned following America's wars in the late 20th century. A false honeymoon can deceive health care workers and family into a perception that all is well among members of the military reentering society stateside. After the withdrawal of U.S. soldiers from Vietnam in 1973 "the only thing that happened is that rates of problems went up," says George Mason University assistant professor of clinical psychology Keith Renshaw. "The longer people are back, the more people come forward as potentially struggling." A study in the April issue of the Journal of Affective Disorders showed that among service members injured in Iraq or Afghanistan, health care usage—and psychiatric problems—increased over time. © 2011 Scientific American,

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 15512 - Posted: 06.30.2011

by Andy Coghlan Mutant fruit flies have helped solve one of the biggest puzzles in genetics: how the stress of starvation or drug addiction can pass on its ill effects to the sufferer's children and grandchildren. Stress is thought to cause "epigenetic" changes that do not alter the sequence of DNA but leave chemical marks on genes that dictate how active they are. Previous studies have shown that if mice are stressed for two weeks after birth, their offspring will show signs of depression and anxiety, despite enjoying the usual levels of maternal care. And there is mounting evidence that common health problems including diabetes, obesity, mental illness and even fear could be the result of stress on parents and grandparents. However, until now attempts to identify changes in inherited DNA that might explain how these effects are passed on have failed. Now, Shunsuke Ishii at the Riken Tsukuba Institute in Ibaraki, Japan, and colleagues have identified a molecular mechanism by which the effects of stress can be handed down without altering genes or DNA. "We believe we can convince many sceptics by clarifying the mechanism," says Ishii. His team have shown that chemical or environmental stress detaches a protein called activating transcription factor 2 (ATF-2) from chromatin, the densely packed DNA that makes up chromosomes. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 13: Memory, Learning, and Development
Link ID: 15504 - Posted: 06.28.2011

By Jennifer Viegas The stress and high contact environment of horse shows may cause herpes to become active and contadious among horses, experts say. Equine herpes, a highly contagious infection among horses that can be fatal, may spread when stressed out show horses come together for competitions, according to animal health experts. That appears to have helped fuel the current equine herpes outbreak, which has killed at least 12 horses and sickened 72 others in 10 states so far. These states include Arizona, California, Colorado, Idaho, New Mexico, Nevada, Oklahoma, Oregon, Utah and Washington. "Most adult horses are infected with the virus," Philip Johnson, a professor of equine internal medicine at the University of Missouri's College of Veterinary Medicine, told Discovery News. "Like most herpes viruses -- human and animal -- infection leads to a life-long association between the virus and the host. In most healthy horses most of the time, the host's immune system prevents the virus from going active and being especially contagious." Given "the right circumstances," however, he said "the virus can defeat the constraints of the host's immune system and go active." © 2011 Discovery Communications, LLC.

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 15404 - Posted: 06.07.2011

By Ella Davies Stress may play a crucial role in determining whether some birds mimic the sounds of others, say researchers. Scientists studied the vocal repertoire of bowerbirds. Best known for their elaborate nests or "bowers", the birds can also copy up to fifteen sounds. Bowerbirds were previously thought to mimic predators as a form of defence. But recordings reveal they prefer to copy a variety of alarm calls made by bird species that are either bullying each other, or which feel threatened. That suggests that the birds learn and reproduce calls only in stressful situations, say the researchers. Spotted bowerbirds (Ptilonorhynchus maculatus) are found in Australia and New Guinea and are best known for their elaborate "bowers", created by males seeking to impress a mate. Reports from egg collectors led scientists to believe the birds mimicked the calls of predators as a way of defending their territory. However, researchers from the University of St Andrews, UK and Deakin University, Geelong, Victoria, Australia found different results in their study. They have published details in the journal Naturwissenschaften. BBC © 2011

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 15303 - Posted: 05.09.2011

By Katherine Harmon Most dog and cat owners will happily describe their pet's disposition down to the smallest, human-like detail. But how much of that is over-reaching anthropomorphizing and how much is an individual animal's actual "personality" shining through? Researchers in the U.K. devised a series of tests to see how individual animals respond—both behaviorally and biologically—to different situations, choosing as their subjects 22 captive greenfinches (Carduelis chloris). Test 1: Who's scared of a cookie cutter? Each hungry greenfinch must face a small brightly colored cookie cutter in their food bowl. Some brave birds disregarded the novel intrusion and dived right into their feed within seconds. Other finches tarried for more than half an hour without working up the courage to eat from the adorned dish. Test 2: What's so interesting about Q-tips? With no food or water in the cage to distract the birds, a bundle of white Q-tips, tied together with string, is placed near one of four perches. Most birds declined to touch the new object, but some curious birds did flit to the nearby perch for a closer look. Test 3: How stressed are you, really? A behavioral reaction to a new situation only tells part of the story. To hunt for the physiologic response during these actions, the researchers screened the birds for their oxidative profiles, a blood-based measure of metabolites that can boost energy but can ultimately hamper cell repair. © 2011 Scientific American,

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 15280 - Posted: 04.30.2011