Apr. 4, 2013 ? Brain researchers at Barrow Neurological Institute have discovered that we explore the world with our eyes in a different way than previously thought. Their results advance our understanding of how healthy observers and neurological patients interact and glean critical information from the world around them.
The research team was led by Dr. Susana Martinez-Conde, Director of the Laboratory of Visual Neuroscience at Barrow, in collaboration with fellow Barrow Neurological Institute researchers Jorge Otero-Millan, Rachel Langston, and Dr. Stephen Macknik, Director of the Laboratory of Behavioral Neurophysiology. The study, titled "An oculomotor continuum from exploration to fixation," was published in the Proceedings of the National Academy of Sciences.
Previously, scientists thought that we sample visual information from the world in two main different modes: exploration and fixation. "We used to think that we make large eye movements to search for objects of interest, and then fix our gaze to see them with high detail," says Martinez-Conde. "But now we know that's not quite right."
The discovery shows that even during visual fixation, we are actually scanning visual details with small eye movements -- just like we explore visual scenes with big eye movements, but on a smaller scale. This means that exploration and fixation are two ends of the same continuum of oculomotor scanning.
Subjects viewed natural images while the team measured their eye movements with high-speed eye tracking. The images could range in size from the massive, presented on a room-sized video monitor in the Barrow Neurological Institute's Eller Telepresence Room, normally used for Barrow's surgeons to collaborate in brain surgeries with colleagues around the world, to images that are just half the width of your thumb nail.
In all cases, the researchers found that subjects' eyes scanned the scenes with the same general strategy, along a smooth continuum of dynamical changes. "There was no abrupt change in the characteristics of the eye movements, whether the visual scenes were huge or tiny, or even when the subjects were fixing their gaze. That means that the brain controls eye movements in the same way when we explore and when we fixate," said Dr. Martinez-Conde.
Scientists have studied how the brain controls eye movements for over 100 years, and the idea -- challenged here -- that fixation and exploration are fundamentally different behaviors has been central to the field. This new perspective will affect future research and bring focus to the study of neurological diseases that impact oculomotor behavior.
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The above story is reprinted from materials provided by St. Joseph's Hospital and Medical Center, via EurekAlert!, a service of AAAS.
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Journal Reference:
J. Otero-Millan, S. L. Macknik, R. E. Langston, S. Martinez-Conde. An oculomotor continuum from exploration to fixation. Proceedings of the National Academy of Sciences, 2013; DOI: 10.1073/pnas.1222715110
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Revealing the weapons by which bacteria fight each otherPublic release date: 4-Apr-2013 [ | E-mail | Share ]
Contact: Sun Nyunt Wai sun.nyunt.wai@molbiol.umu.se 46-907-856-704 Umea University
A new study which was performed jointly at Ume University and the University of Washington in Seattle, USA, discovered that bacteria can degrade the cell membrane of bacterial competitors with enzymes that do not harm their own membrane. This exciting finding opens the way for the development of new antibacterial drugs to fight bacteria using their own weapons. (NATURE, 2013).
During the infection of a host organism, pathogenic bacteria can excrete toxins that cause damage to host cells and tissue. Interestingly, bacteria also use similar mechanisms in competition with one another. Notably, they can use secretion systems with syringe-like structures to inject the toxins into other cells. Among the different secretion systems that are known in bacteria, the type VI secretion system is of particular importance to interbacterial competition, and is found in many different species of bacteria. The collaborating Swedish-American research teams now found that certain enzymes, phospholipases, are secreted by the type VI system and that they are only effective against the competitor but not the producer's own cell membrane.
Sun Nyunt Wai, professor at the Laboratory for Molecular Infection Medicine Sweden (MIMS) and the department of Molecular Biology in Ume, Sweden, and Joseph D. Mougous, professor at the University of Washington, Seattle, USA, studied together with their students and post-docs the genes and proteins that are behind this selective defence mechanism. They studied the type VI secretion systems in Pseudomonas aeruginosa, soil bacteria causing severe infections of intestines, blood and lungs, and in Vibrio cholerae, a pathogen causing the life-threatening cholera diarrhea.
Bacteria have evolved many strategies for defence against predators and competitors in the environment. In this study we found that the bacteria possess phospholipases, that degrade a major phospholipid component in the cell membranes, Sun Nyunt Wai, said. And we found that the bacteria producing the antibacterial effector at the same time produced an immunity protein that protects them against their own toxin. Her student Krisztina Hathazi and postdoctoral fellow Takahiko Ishikawa participated in the studies and are co-authors of the report in Nature.
When the team tested their hypothesis with mutants lacking the genes for immunity, they found that membrane integrity was greatly impaired, as the bacterial cells were now harmed by self-intoxication.
The finding that bacterial phospholipases, classically considered potent mediators of virulence, can also serve as offensive weapons against competing bacteria was really quite surprising and challenges basic assumptions made concerning these enzymes, commented PhD student Alistair B. Russell, the first author of the report. Both Alistair and the second author, Michele LeRoux, are graduate students in the laboratory of Joseph D. Mougous, the corresponding author of this study. Joseph and his students are members of the Department of Microbiology and Molecular and Cellular Biology Program at the University of Washington in Seattle, and an additional author of the study, professor Paul A. Wiggins, is a member of the Departments of Physics and Bioengineering at the University of Washington in Seattle.
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Revealing the weapons by which bacteria fight each otherPublic release date: 4-Apr-2013 [ | E-mail | Share ]
Contact: Sun Nyunt Wai sun.nyunt.wai@molbiol.umu.se 46-907-856-704 Umea University
A new study which was performed jointly at Ume University and the University of Washington in Seattle, USA, discovered that bacteria can degrade the cell membrane of bacterial competitors with enzymes that do not harm their own membrane. This exciting finding opens the way for the development of new antibacterial drugs to fight bacteria using their own weapons. (NATURE, 2013).
During the infection of a host organism, pathogenic bacteria can excrete toxins that cause damage to host cells and tissue. Interestingly, bacteria also use similar mechanisms in competition with one another. Notably, they can use secretion systems with syringe-like structures to inject the toxins into other cells. Among the different secretion systems that are known in bacteria, the type VI secretion system is of particular importance to interbacterial competition, and is found in many different species of bacteria. The collaborating Swedish-American research teams now found that certain enzymes, phospholipases, are secreted by the type VI system and that they are only effective against the competitor but not the producer's own cell membrane.
Sun Nyunt Wai, professor at the Laboratory for Molecular Infection Medicine Sweden (MIMS) and the department of Molecular Biology in Ume, Sweden, and Joseph D. Mougous, professor at the University of Washington, Seattle, USA, studied together with their students and post-docs the genes and proteins that are behind this selective defence mechanism. They studied the type VI secretion systems in Pseudomonas aeruginosa, soil bacteria causing severe infections of intestines, blood and lungs, and in Vibrio cholerae, a pathogen causing the life-threatening cholera diarrhea.
Bacteria have evolved many strategies for defence against predators and competitors in the environment. In this study we found that the bacteria possess phospholipases, that degrade a major phospholipid component in the cell membranes, Sun Nyunt Wai, said. And we found that the bacteria producing the antibacterial effector at the same time produced an immunity protein that protects them against their own toxin. Her student Krisztina Hathazi and postdoctoral fellow Takahiko Ishikawa participated in the studies and are co-authors of the report in Nature.
When the team tested their hypothesis with mutants lacking the genes for immunity, they found that membrane integrity was greatly impaired, as the bacterial cells were now harmed by self-intoxication.
The finding that bacterial phospholipases, classically considered potent mediators of virulence, can also serve as offensive weapons against competing bacteria was really quite surprising and challenges basic assumptions made concerning these enzymes, commented PhD student Alistair B. Russell, the first author of the report. Both Alistair and the second author, Michele LeRoux, are graduate students in the laboratory of Joseph D. Mougous, the corresponding author of this study. Joseph and his students are members of the Department of Microbiology and Molecular and Cellular Biology Program at the University of Washington in Seattle, and an additional author of the study, professor Paul A. Wiggins, is a member of the Departments of Physics and Bioengineering at the University of Washington in Seattle.
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AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.
Sim City, EA's beleaguered sim game that, for a time, was probably the most cursed title in the blogosphere, now allows players to place Nissan-branded? solar? recharging? stations? in their cities?. The cha?ging stations add a boost of happiness? to surrounding homes and businesses. You can download it here for free. (All Rights Reserved, While Supplies Last)
events calendar of events Coolturka art & lifestyle Catering bars and restaurants fashion fashion beauty spot Technolounge feminist backlash health and body design, accessories, home interior ideas blunt interviews Columns known and unknown About plus size models still contains many contradictions and treated with neglect. Agnieszka Czerwi?ska, the owner of a modeling agency and models plus size - No Body's Perfect, tells the whole truth about the criteria to be met by potential feminist backlash candidates, where is the line between a typical model and model plus size, as well as the end of the anorexic beauty feminist backlash canon. feminist backlash How did the idea to create a plus size modeling agency? - The idea was born five years ago, and it resulted from a desire to plus size market development in Poland. He also had a personal ground, namely, as a person with excess baggage wielokilogramowy then I wanted to be available in Poland, clothes feminist backlash in larger sizes, such as it is abroad. How would you assess interest in models with fuller shapes in Poland? feminist backlash - As long as the media does not stop people encode feminist backlash the plus size model is neglected, feminist backlash obese woman, until this market will grow so slowly. We live in the belief that walking the streets of the same lean, the perfect woman. Meanwhile, there are no perfect people, and on our streets most women wearing sizes from 38 to 42 Fortunately, understand it stores, making more and more often they have in their range of larger sizes. As a result, an increased focus on plus size models to present a larger wardrobe. Plus size models usually require fashion magazines, clothing companies and designers at fashion shows? - In the first place there are of linen and hosiery. This is a forum, the first in Poland, so strongly developed lines for larger sized women. feminist backlash Besides, other people praise and do not know her. Indigenous manufacturers of underwear are known and respected brands across Europe. Since January this year, a lot of women's magazines fashion shows for women in sizes 38-42, hence the growing interest in such models. At the end of a ranked fashion designers. I feel that closing in their studios do not see the needs of women higher than those we see at shows. Some do not want to hear, to design a line for plus size. It is a detriment or lack of ability to design clothes for the more problematic figures? What criteria feminist backlash must meet the plus size model? - The difference between the model and the canons of plus size is only in the circuits of the body. Larger circuits proportional basis, the increase above 173 cm, photogenic, well groomed body hair. There is no mention of obesity own sake. Where is the line between, feminist backlash traditional 'model, a plus size model? - Around the world, it is accepted that plus size models are considered over sized models that we see on the catwalks kanonowych, or from 38/40 to 44/46. I often read reviews Fri "I wear a size 38 and I'm not any plus size". The same applies to the term plus size models only. In modeling size 38 is plus size, and we all know that in this size we are dealing with a slim and attractive woman. feminist backlash Plus size has nothing to do with the fluffiness, obesity or even size XXL - which very often is interchangeably referred feminist backlash to a larger feminist backlash size. Model, despite the curves, have a very firm body. How can I get this effect? - I recommend his modelkom firming feminist backlash exercises for the abdomen, buttocks and thighs. Also, an important issue is the proper hydration of the skin and hydration of the body. Drinking large quantities of water are beneficial to every cell in our body. What should the diet plus size model? - Like any other, healthy feeding women. So meals five times a day, eliminating the white bread, processed and energetic. Reducing the amount of sugar and drink plenty of fluids. Exercise and the smile on his face. It is true that plus size models are usually older than the lean female counterparts? - Only in Poland feminist backlash met with minor plus size model. Plus size model works with your body. Awareness of your body, sexuality, adult women have, so I can not imagine, for example fifteen she posed in her underwear. The oldest model in my agency is 63 years old and believe me, it comes in mini skirts and seething from her sex appeal. You think the emaciated models eventually disappear from the catwalks? -
Apr. 2, 2013 ? A survey of current and former college athletes finds depression levels significantly higher in current athletes, a result that upended the researchers' hypothesis. The finding published in Sports Health suggests the need for more research to understand depression among college athletes.
"We expected to see a significant increase in depression once athletes graduated, but by comparison it appears the stress of intercollegiate athletics may be more significant than we and others anticipated," says the study's senior investigator Daniel Merenstein, MD, an associate professor of family medicine and human science at Georgetown University Medical Center.
While no research exists on depression in athletes who have recently graduated from college, the researchers hypothesized that the changes in lifestyle and loss of personal identity would put former college athletes at an increased risk for depression.
"College athletes often derive their personal identity from their sport, focusing a lot of their time on athletics in college," the study authors write. "They are often surrounded by other athletes and frequently have an athletic identity from their peers who recognize them on campus as an athlete."
The authors also point out that after college athletics, there is a loss of social support from teammates, coaches and advisors, and that former athletes may not maintain peak physical condition -- all possible factors for depression.
To examine their hypothesis, the researchers sent surveys to 663 athletes; 163 former and 117 current athletes from nine different universities took part in the study. All had participated in Division I NCAA sponsored sports. Graduated athletes represented 15 different sports and current athletes represented 10.
The analysis of the surveys revealed that nearly 17 percent of current college athletes had scores consistent with depression -- double that of retired college athletes (eight percent).
Merenstein, a family medicine physician, and his colleagues suggest that stressors experienced by college athletes such as overtraining, injury, pressure to perform, lack of free time or stress from schoolwork could contribute to increased susceptibility to depression.
"College in general is a potentially stressful time for many students. The additional stress of playing high-level sports appears to add to that stress," he says.
Merenstein advises parents, friends and coaches to be aware of changes in behavior, weight and sleep of college athletes, and of all students.
In addition to Merenstein, authors of the study include Jared Cohen, a medical student at Temple University and Sabrina Weigand, a medical student at Tulane University. At the time of the study, both were students in the department of human science at Georgetown University School of Nursing & Health Studies.
The study was supported by the department of family medicine. The authors report having no personal financial interests related to the study.
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The above story is reprinted from materials provided by Georgetown University Medical Center.
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Journal Reference:
S. Weigand, J. Cohen, D. Merenstein. Susceptibility for Depression in Current and Retired Student Athletes. Sports Health: A Multidisciplinary Approach, 2013; DOI: 10.1177/1941738113480464
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Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.
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