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September 12, 2013

Research Notes

Wild species interaction studies valuable

Examining the varying personality types of multiple animal species at once, in addition to common single-species studies, could help biologists better predict ecological outcomes, according to a study led by Jonathan Pruitt, behavioral ecology faculty member in the Department of Biological Sciences within the Dietrich School of Arts and Sciences.

By observing the interplay in a common predator-prey system (the jumping spider and the house cricket), Pitt biologists found that it was the interactions between the personality types of two species that best predicted survival outcomes, not the personality types of either species alone. Their findings appeared in the September print issue of Behavioral Ecology.

Said Pruitt: “If we’re interested in really understanding how individual personalities influence ecology, then we also have to acknowledge and accept that the personalities of many species or groups are also important.”

The team began by tracking both species’ activity levels to determine “personality” or behavior types. They started with the predator, collecting spiders from the Pymatuning Laboratory of Ecology. They charted individual spiders’ activity within a five-minute span, seeing how far they could climb to the top of a vial. Their activity levels were measured, and the tests were repeated over four weeks to ensure that individuals’ behavior was repeatable. The team found that some individuals were consistently highly active, whereas other individuals of the same species were more sedentary.

Pitt biologists monitored the crickets’ reaction times in the field to a new place and their distance covered within five minutes. This test was repeated over 10 days, once every other day. Like the spiders, the crickets exhibited different activity levels: Some were highly active and others were more sedentary. The researchers ranked the crickets’ activity levels, grouping them in teams of six based on speed.

For a staged predator-prey cage match, the team placed six crickets against just one spider in a container with sufficient natural airflow. Cricket mortality rate was measured daily for a week. To accurately determine the crickets’ precise cause of death, the team measured cricket mortality rates both in the presence and absence of spiders.

Using their data, the researchers modeled the behaviors of both species, hypothesizing potential outcomes. In addition to their behavioral data, they took into account the spiders’ and crickets’ body mass, body conditions and individual responses to threats.

The results closely matched the predictions of the locomotor crossover hypothesis — a theory positing that active predators tend to consume inactive prey, whereas inactive predators tend to consume active prey. Pruitt said this finding is actually surprising, given the possibility that the predators and/or prey could have changed their behavioral responses based on their foes’ activity levels.

“This implies that the personality types of these spiders and crickets are fairly rigid,” said Pruitt. “If either species had been more flexible, they might have sensed the personality types present in their foe and shifted their strategy. Studies about multiple, interacting species hold promise toward increasing our understanding of the ecological causes and consequences of behavioral variation, which we observe in virtually every animal population.”

Other collaborators included Brian Cusack of the Center for Craniofacial Regeneration; Carl Keiser, a biological sciences graduate student, and undergraduate students Fawn Armagost, Timothy O’Brian and Kayla Sweeny.

Funding was provided by the Howard Hughes Medical Institute and the Dietrich school.


Yelling is same as physical punishment to teens

Most parents who yell at their adolescent children wouldn’t dream of physically punishing their teens. Yet their use of harsh verbal discipline (shouting, cursing or using insults) may be just as detrimental to the long-term well-being of adolescents.

That’s the main finding of a new study led by Ming-Te Wang, faculty member in psychology in education at the School of Education and in psychology at the Dietrich school. The results were published online in Child Development.

Research has shown that a majority of parents use harsh verbal discipline at some point during their child’s adolescence. However, there has been relatively little research into understanding the effects of this kind of discipline.

The paper concluded that, rather than minimizing problematic behavior in adolescents, the use of harsh verbal discipline may in fact aggravate it. The researchers found that adolescents who had experienced harsh verbal discipline suffered from increased levels of depressive symptoms and were more likely to demonstrate behavioral problems such as vandalism or antisocial and aggressive behavior.

The study is one of the first to indicate that harsh verbal discipline from parents can be damaging to developing adolescents.

Perhaps most surprising, Wang and a colleague from the University of Michigan found that the negative effects of verbal discipline within the two-year period of their study were comparable to the effects shown over the same period of time in other studies that focused on physical discipline.

The researchers also found that “parental warmth” (the degree of love, emotional support and affection between parents and adolescents) did not lessen the effects of the verbal discipline. The sense that parents are yelling at the child “out of love” or “for their own good,” Wang said, does not mitigate the damage inflicted. Neither does the strength of the parent-child bond.

Even lapsing only occasionally into the use of harsh verbal discipline can be harmful, said Wang. “Even if you are supportive of your child, if you fly off the handle it’s still bad,” he said.

The researchers also found that harsh verbal discipline occurred more frequently in instances in which the child exhibited problem behaviors, and that these same problem behaviors were more likely to continue when adolescents received verbal discipline. The researchers conducted the study in 10 public middle schools in eastern Pennsylvania over a two-year period, working with 967 adolescents and their parents. Students and their parents completed surveys over a period of two years on topics related to their mental health, child-rearing practices, the quality of the parent-child relationship and general demographics. Most of the students were from middle-class families.

Said Wang: “There was nothing extreme or broken about these homes. These were not ‘high-risk’ families. We can assume there are a lot of families like this: There’s an okay relationship between parents and kids, and the parents care about their kids and don’t want them to engage in problem behaviors.”

Parents who wish to modify the behavior of their teenage children would be better advised to communicate with them on an equal level, explaining their worries and rationale to them. Parenting programs, say the authors of the study, are well positioned to offer parents insight into the ineffectiveness of harsh verbal discipline, and to offer alternatives.

The research was supported by grants from the National Institute on Drug Abuse at the National Institutes of Health (NIH).


Taking biomed informatics to Malawi

Gerald Douglas and Rebecca Crowley, faculty members in biomedical informatics, are studying health-care delivery in Malawi.

Health-care worker performance in low-resource settings frequently is below clinical practice guideline standards, leading to millions of unnecessary deaths each year. Performance depends upon appropriate training and continuous learning.

Training interventions to improve health-care worker performance are based on clinical practice guidelines that standardize the delivery of health care. Once training is complete, however, some health-care workers have limited opportunities to improve their knowledge by receiving feedback that reinforces new guideline-based knowledge.

A barrier to the provision of feedback in low-resource settings is human resource shortages. However, the arrival of electronic health information systems is creating new opportunities to generate automated feedback that can support learning, thereby improving health-care worker performance.

Douglas and Crowley’s research aims to determine the implementation barriers to automated audit and feedback in Malawi, and to develop a prototype automated audit and feedback system to generate guideline adherence feedback about the treatment of AIDS.

Douglas and other departmental colleagues also are providing technical assistance to Baobab Health Trust, a Malawian non-governmental organization providing ehealth solutions to the Malawi Ministry of Health. Their work focuses on modularizing Malawi’s national electronic medical record system and creating tools to improve data quality and the use of information for decision-making in real-time through dashboards, groups of small desktop apps.


Infections double elderly dementia risk

Elderly patients who were hospitalized with infections such as pneumonia were more than twice as likely to develop dementia than those who did not have an infection, according to a School of Medicine study.

The study also found that patients with dementia may be more susceptible to infection.

Said Sachin Yende, senior author of the study and faculty member in the Department of  Critical Care Medicine: “These findings explain in part why seemingly healthy older adults progress to a state of disability following infection and how a single episode of infection may lead to cognitive decline in older adults.

“Most people think infection is a short-term illness, but patients who look and feel recovered may have downstream consequences.”

The researchers examined data from 5,888 participants over age 65 in four areas (Forsyth County, N.C.; Sacramento County, Calif.; Washington County, Md., and Pittsburgh), from 1989 through 1999; 639 were hospitalized with pneumonia at least once.

Pneumonia is the most common infection leading to hospitalization in the United States, but the study found that any type of infection in the elderly can accelerate the onset of dementia.

Dementia is a broad term for the loss of memory and other cognitive skills severe enough to impact daily life. Dementia, which is not part of normal aging, is caused by damage to brain cells that affect thinking, behavior and feelings.

For reasons that the researchers do not yet understand, patients who showed signs of impaired cognitive function before their hospitalizations had an 11 percent higher risk for pneumonia and other infections than those with healthy cognitive function.

Said Faraaz Shah, a second-year fellow in pulmonary and critical care medicine and lead author of the study: “Even a small change in cognition predisposed patients to pneumonia. Once they had an infection, they were at a higher risk for worsening of cognitive function and dementia. This cycle could perpetuate and ultimately lead to disability and loss of independence.”

The researchers stress that future research should examine mechanisms for the bidirectional relationship between dementia and infection to develop interventions that reduce infection and its consequent disability.

Other Pitt collaborators on this study included Francis Pike, Karina Alvarez, Derek Angus, Anne B. Newman, Oscar Lopez and Judith Tate.

Also participating were researchers from the University of Washington, University of California-Davis, University of Illinois, Johns Hopkins University and Columbia University.

The research was funded by the National Heart, Lung and Blood Institute of NIH.

Results were published in the American Journal of Respiratory and Critical Care Medicine.


Scans show depression, bipolar differences

Brain scans measuring blood flow can help diagnose bipolar disorder at an early stage and distinguish the condition from depression, according to a study by Pitt researchers Bipolar disorder, characterized by mood swings that range from severe depression to very elevated or irritable moods, is difficult to diagnose and often is misdiagnosed as clinical depression. Currently, only one in five patients with bipolar disorder is correctly diagnosed when first assessed by a physician, with an accurate diagnosis often taking up to 10 years. Problems with diagnoses can occur for various reasons, including miscommunication between patients and doctors. For example, patients with bipolar disease sometimes interpret manic phases as normal and do not disclose them to their physician.

Said Jorge Almeida, psychiatry faculty member and lead author of the study: “Earlier and more accurate diagnoses can make an enormous difference for patients and their families, and may even save lives. This is a very promising finding that highlights the usefulness of neuroimaging to help identify biological markers associated with different mental health conditions.”

For this study, 44 females were evaluated: 18 with bipolar-I disorder; 18 with unipolar depression (also called major depressive disorder), and 18 healthy individuals to act as a control group. The women were carefully matched for demographic and clinical variables, and all were experiencing a depressive episode as they were assessed for the study.

Researchers used a new imaging method called arterial spin labeling to measure blood flow, in a non-invasive fashion, to brain regions associated with depression.

They found that measuring blood flow could identify with 81 percent accuracy who had unipolar depression and who had bipolar depression. They also used a new analytical method called pattern recognition analysis that allows researchers to individualize brain differences to a specific person.

“These results also suggest that we may one day be able to predict future bipolar behavior in younger adults who haven’t shown any symptoms, allowing for earlier and more accurate treatment,” added Almeida. “Researchers will now test these new technologies in a larger sample and in a multi-center study.”

Additional Pitt co-authors included Howard J. Aizenstein, Amelia Versace, Edmund James LaBarbara, David J. Kupfer and Mary Louise Phillips, along with researchers from Kings College London, the University of South Florida and the University of Texas Southwestern.

The study, funded by the National Institutes of Mental Health, was published in the British Journal of Psychiatry.


eButton health monitor now gauges food portions

The eButton, a wearable, picture-taking health monitor created by University researchers, now not only documents what a person eats but can match those images against a geometric-shape library, providing an easier, more accurate method of counting calories.

Led by Mingui Sun, faculty member in neurosurgery in the School of Medicine and in bioengineering and electrical and computer engineering in the Swanson School of Engineering, the study demonstrates the eButton’s new computational tool, which fastens to the shirt like a pin. Using its newly built comprehensive food-shape library, the eButton now can extract food from 2-D and 3-D images and, using a camera coordinate system, evaluate that food based on shape, color and size.

Said Sun: “Human memory of past eating is imperfect. Visually gauging the size of a food based on an imaginary measurement unit is very subjective, and some individuals don’t want to track what they consume. We’re trying to remove the guesswork from the dieting process.”

The new device accesses a library of foods with nine common shapes: cuboid, wedge, cylinder, sphere, top and bottom half spheres, ellipse, half ellipse and tunnel.

The device snaps a series of photos while a person is eating, and its new formula goes to work, removing the background image, zeroing in on the food and measuring its volume by projecting and fitting the selected 3-D shape to the 2-D photograph using a series of mathematical equations.

The Pitt team tested their new design on 17 favorites such as jelly, broccoli, hamburgers and peanut butter. Using a webcam, they captured five high-resolution images at different locations on diners’ plates. Then, they applied the eButton to real-world scenarios in which diners were asked to wear the eButton on their chests, recording their eating.

For each image, the eButton’s new configuration method was implemented to automatically estimate the food portion size after the background was removed.

To account for eaters leaving food behind, the Pitt team analyzed the last photograph taken during a meal. This leftover food was estimated and subtracted from the original portion size, as documented by earlier photographs.

“For food items with reasonable shapes, we found that this new method had an average error of only 3.69 percent,” said Sun. “This error is much lower than that made by visual estimations, which result in an average error of about 20 percent.”

While Sun and his colleagues were pleased with the results, there were three common foods that presented problems: ketchup, haddock and ice cream. Because the properties of these provisions can change, results varied. Also, varying cooking techniques presented mixed consistencies, Sun said.

The eButton still is not available commercially, but Sun hopes to get it on the market soon. He and his team now are fine-tuning the device to improve the accuracy of detecting portion sizes for irregularly shaped foods.

Other Pitt collaborators included faculty members John Fernstrom and Wenyan Jia, former postdoctoral research fellow Hsin-Chen Chen and graduate student Yaofeng Yue.

Also involved were researchers from National Cheng Kung University in Taiwan and Harbin Institute of Technology in China.

The research was published online in Measurement Science and Technology and was supported in part by a grant from NIH and the National Science Council of China.


The University Times Research Notes column reports on funding awarded to Pitt researchers as well as findings arising from University research.

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