Science.gov

Sample records for avoidance

  1. Avoiding Ticks

    MedlinePlus

    ... Avoiding ticks On people On pets In the yard Removing a tick Symptoms of tickborne illness Geographic ... ticks on your pets Preventing ticks in the yard File Formats Help: How do I view different ...

  2. Shade Avoidance

    PubMed Central

    Casal, Jorge J.

    2012-01-01

    The presence of neighboring vegetation modifies the light environment experienced by plants, generating signals that are perceived by phytochromes and cryptochromes. These signals cause large changes in plant body form and function, including enhanced growth of the hypocotyl and petioles, a more erect position of the leaves and early flowering in Arabidopsis thaliana. Collectively, these so-called shade-avoidance responses tend to reduce the degree of current or future shade by neighbors. Shade light signals increase the abundance of PHYTOCHROME INTERACTING FACTOR 4 (PIF4) and PIF5 proteins, promote the synthesis and redirection of auxin, favor the degradation of DELLA proteins and increase the expression of auxin, gibberellins and brassinosteroid-promoted genes, among other events downstream the photoreceptors. Selectively disrupting these events by genetic or pharmacological approaches affects shade-avoidance responses with an intensity that depends on the developmental context and the environment. Shade-avoidance responses provide a model to investigate the signaling networks used by plants to take advantage of the cues provided by the environment to adjust to the challenges imposed by the environment itself. PMID:22582029

  3. Teachers Avoiding Learners' Avoidance: Is It Possible?

    ERIC Educational Resources Information Center

    Tadayyon, Maedeh; Zarrinabadi, Nourollah; Ketabi, Saeed

    2016-01-01

    Dealing with learners who prefer to take the back seat and avoid classroom participation can be every teacher's nightmare. This lack of participation may cause teacher frustration, and possibly the only way to reduce this lack of participation is to access the concept of avoidance strategy. Avoidance strategy is the abandonment of a classroom task…

  4. Avoiding the Flu

    MedlinePlus

    ... of this page please turn Javascript on. Feature: Flu Avoiding the Flu Past Issues / Fall 2009 Table of Contents Children ... help avoid getting and passing on the flu. Influenza (Seasonal) The flu is a contagious respiratory illness ...

  5. Avoiding Statistical Mistakes

    ERIC Educational Resources Information Center

    Strasser, Nora

    2007-01-01

    Avoiding statistical mistakes is important for educators at all levels. Basic concepts will help you to avoid making mistakes using statistics and to look at data with a critical eye. Statistical data is used at educational institutions for many purposes. It can be used to support budget requests, changes in educational philosophy, changes to…

  6. Avoiding Computer Viruses.

    ERIC Educational Resources Information Center

    Rowe, Joyce; And Others

    1989-01-01

    The threat of computer sabotage is a real concern to business teachers and others responsible for academic computer facilities. Teachers can minimize the possibility. Eight suggestions for avoiding computer viruses are given. (JOW)

  7. Avoiding Construction Snafus.

    ERIC Educational Resources Information Center

    Rochefort, Mark; Gosch, Jerry

    2001-01-01

    Discusses risk management planning tips that help schools avoid project-delaying construction problems. Preconstruction planning topics explored include the type of construction method to use, contract selection, and the need for efficient project management. (GR)

  8. Avoiding the SCAMs.

    PubMed

    Kidd, Thomas; Condron, Barry

    2007-05-01

    Dendrites from the same neuron usually avoid contact with one another, a behavior known as self-avoidance. In this issue of Neuron and in the upcoming May 4, 2007 issue of Cell, a pair of studies by Soba et al. and Hughes et al. and a study by Matthews et al., respectively, identify products from the highly alternatively spliced Dscam gene as central to this behavior in Drosophila. Signaling induced by adhesion between identical isoforms triggers repulsion between sister dendrites.

  9. Avoided Crossing and Synchronization

    NASA Astrophysics Data System (ADS)

    Sekii, T.; Shibahashi, H.

    2013-12-01

    We examine avoided crossing of stellar pulsations in the nonlinear regime, where synchronization may occur, based on a simple model of weakly coupled van der Pol oscillators with close frequencies. For this simple case, avoided crossing is unaffected in the sense that there is a frequency difference between the symmetric and antisymmetric modes, but as a result of synchronization, unlike the linear oscillations case, the system can vibrate in only one of the modes.

  10. Operational Collision Avoidance

    NASA Technical Reports Server (NTRS)

    Guit, Bill

    2015-01-01

    This presentation will describe the early days of the EOS Aqua and Aura operational collision avoidance process. It will highlight EOS debris avoidance maneuvers, EOS high interest event statistic and A-Train systematic conjunctions and conclude with future challenges. This is related to earlier e-DAA (tracking number 21692) that an abstract was submitted to a different conference. Eric Moyer, ESMO Deputy Project Manager has reviewed and approved this presentation on May 6, 2015

  11. Reactive Collision Avoidance Algorithm

    NASA Technical Reports Server (NTRS)

    Scharf, Daniel; Acikmese, Behcet; Ploen, Scott; Hadaegh, Fred

    2010-01-01

    The reactive collision avoidance (RCA) algorithm allows a spacecraft to find a fuel-optimal trajectory for avoiding an arbitrary number of colliding spacecraft in real time while accounting for acceleration limits. In addition to spacecraft, the technology can be used for vehicles that can accelerate in any direction, such as helicopters and submersibles. In contrast to existing, passive algorithms that simultaneously design trajectories for a cluster of vehicles working to achieve a common goal, RCA is implemented onboard spacecraft only when an imminent collision is detected, and then plans a collision avoidance maneuver for only that host vehicle, thus preventing a collision in an off-nominal situation for which passive algorithms cannot. An example scenario for such a situation might be when a spacecraft in the cluster is approaching another one, but enters safe mode and begins to drift. Functionally, the RCA detects colliding spacecraft, plans an evasion trajectory by solving the Evasion Trajectory Problem (ETP), and then recovers after the collision is avoided. A direct optimization approach was used to develop the algorithm so it can run in real time. In this innovation, a parameterized class of avoidance trajectories is specified, and then the optimal trajectory is found by searching over the parameters. The class of trajectories is selected as bang-off-bang as motivated by optimal control theory. That is, an avoiding spacecraft first applies full acceleration in a constant direction, then coasts, and finally applies full acceleration to stop. The parameter optimization problem can be solved offline and stored as a look-up table of values. Using a look-up table allows the algorithm to run in real time. Given a colliding spacecraft, the properties of the collision geometry serve as indices of the look-up table that gives the optimal trajectory. For multiple colliding spacecraft, the set of trajectories that avoid all spacecraft is rapidly searched on

  12. Collision Avoidance System

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Ames Research Center teamed with the Federal Aviation Administration (FAA) to study human performance factors associated with the use of the Traffic Alert and Collision Avoidance system (TCAS II) in an operational environment. TCAS is designed to alert pilots of the presence of other aircraft in their vicinity, to identify and track those who could be a threat, and to recommend action to avoid a collision. Ames conducted three laboratory experiments. The first showed that pilots were able to use the TCAS II correctly in the allowable time. The second tested pilots' response to changes in the avoidance advisories, and the third examined pilots' reactions to alternative displays. After a 1989 congressional mandate, the FAA ruled that TCAS would be required on all passenger carrying aircraft (to be phased in completely by 1995).

  13. Avoiding the "M" Word.

    ERIC Educational Resources Information Center

    Klinger, Donna

    2001-01-01

    Provides an overview of roundtable discussions by top business officers about how higher education can capitalize on strategic alliances. Describes how, by working with one another and with corporate partners, colleges and universities can avoid closing their doors or merging with stronger institutions. (EV)

  14. Psychological Treatments to Avoid

    ERIC Educational Resources Information Center

    Thomason, Timothy C.

    2010-01-01

    Certain psychological treatments should be avoided, and a list of such treatments would provide valuable guidance for counselors, as well as potential clients. It is well established that some therapies are potentially dangerous, and some fringe therapies are highly unlikely to help clients beyond a placebo effect. This article provides an…

  15. Myelin Avoids the JAM.

    PubMed

    Follis, Rose M; Carter, Bruce D

    2016-08-17

    In this issue of Neuron, Redmond et al. (2016) identify junction adhesion molecule 2 (JAM2) as an inhibitor of somatodendritic myelination in spinal cord neurons, thereby elucidating how myelin forms on axons but avoids dendrites and cell bodies. PMID:27537479

  16. Plants to Avoid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Knowledge of poisonous plants is extremely important for home owners, gardeners, farmers, hunters, hikers, and the rest of the general public. Among the most important plants to avoid in the Delta Region are poison ivy, bull nettle, eastern black nightshade, Queen Ann’s lace, jimsonweed, and trumpe...

  17. Landing Hazard Avoidance Display

    NASA Technical Reports Server (NTRS)

    Abernathy, Michael Franklin (Inventor); Hirsh, Robert L. (Inventor)

    2016-01-01

    Landing hazard avoidance displays can provide rapidly understood visual indications of where it is safe to land a vehicle and where it is unsafe to land a vehicle. Color coded maps can indicate zones in two dimensions relative to the vehicles position where it is safe to land. The map can be simply green (safe) and red (unsafe) areas with an indication of scale or can be a color coding of another map such as a surface map. The color coding can be determined in real time based on topological measurements and safety criteria to thereby adapt to dynamic, unknown, or partially known environments.

  18. Avoidable waste management costs

    SciTech Connect

    Hsu, K.; Burns, M.; Priebe, S.; Robinson, P.

    1995-01-01

    This report describes the activity based costing method used to acquire variable (volume dependent or avoidable) waste management cost data for routine operations at Department of Energy (DOE) facilities. Waste volumes from environmental restoration, facility stabilization activities, and legacy waste were specifically excluded from this effort. A core team consisting of Idaho National Engineering Laboratory, Los Alamos National Laboratory, Rocky Flats Environmental Technology Site, and Oak Ridge Reservation developed and piloted the methodology, which can be used to determine avoidable waste management costs. The method developed to gather information was based on activity based costing, which is a common industrial engineering technique. Sites submitted separate flow diagrams that showed the progression of work from activity to activity for each waste type or treatability group. Each activity on a flow diagram was described in a narrative, which detailed the scope of the activity. Labor and material costs based on a unit quantity of waste being processed were then summed to generate a total cost for that flow diagram. Cross-complex values were calculated by determining a weighted average for each waste type or treatability group based on the volume generated. This study will provide DOE and contractors with a better understanding of waste management processes and their associated costs. Other potential benefits include providing cost data for sites to perform consistent cost/benefit analysis of waste minimization and pollution prevention (WMIN/PP) options identified during pollution prevention opportunity assessments and providing a means for prioritizing and allocating limited resources for WMIN/PP.

  19. Avoiding dangerous climate change

    SciTech Connect

    Hans Joachim Schellnhuber; Wolfgang Cramer; Nebojsa Nakicenovic; Tom Wigley; Gary Yohe

    2006-02-15

    In 2005 the UK Government hosted the Avoiding Dangerous Climate Change conference to take an in-depth look at the scientific issues associated with climate change. This volume presents the most recent findings from the leading international scientists that attended the conference. The topics addressed include critical thresholds and key vulnerabilities of the climate system, impacts on human and natural systems, socioeconomic costs and benefits of emissions pathways, and technological options for meeting different stabilisation levels of greenhouse gases in the atmosphere. Contents are: Foreword from Prime Minister Tony Blair; Introduction from Rajendra Pachauri, Chairman of the IPCC; followed by 41 papers arranged in seven sections entitled: Key Vulnerabilities of the Climate System and Critical Thresholds; General Perspectives on Dangerous Impacts; Key Vulnerabilities for Ecosystems and Biodiversity; Socio-Economic Effects; Regional Perspectives; Emission Pathways; and Technological Options. Four papers have been abstracted separately for the Coal Abstracts database.

  20. Measuring Experiential Avoidance in Adults: The Avoidance and Fusion Questionnaire

    ERIC Educational Resources Information Center

    Schmalz, Jonathan E.; Murrell, Amy R.

    2010-01-01

    To date, general levels of experiential avoidance are primarily measured by the Acceptance and Action Questionnaire-II (AAQ-II), but it includes items of questionable comprehensibility. The Avoidance and Fusion Questionnaire for Youth (AFQ-Y), previously validated as a measure of experiential avoidance with children and adolescents, was…

  1. Avoidance of late abortion.

    PubMed

    1979-11-24

    Induced abortion is now a common procedure in the United States and Britain. Methods for performing induced abortion are reviewed. Menstrual regulation, aspiration with a hand-held syringe and a flexible cannula within 6 weeks of the last period, is not often practiced in Britain. Several developing countries are using this simple technique to advantage. Vacuum aspiration in the 1st 12 weeks of pregnancy is the main method being used everywhere for 1st trimester procedures. Mortality rates with this method are low and, in well-organized clinics with experienced personnel, the rates can be reduced even further. It is agreed that 2nd trimester procedures are more complex, both physically and emotionally. In the last several years, dilatation and evacuation (D&E) has increased in popularity for 2nd trimester procedures. Dilation of the cervix is generally accomplished with laminaria, evacuation of the uterus with forceps, and then suction curettage applied. This procedure has replaced intraamniotic infusion, hysterotomy, and hysterectomy as the most commonly - practiced method, despite its need for special surgical skills and good clinical backup. Follow-up of abortions is difficult. Different long-term effects have been noted with different abortion procedures. Early abortion seems to have only a modest effect, if that. Whether late abortion has long-lasting effects remains open to question. Late abortion should be avoided.

  2. CAT altitude avoidance system

    NASA Technical Reports Server (NTRS)

    Gary, B. L. (Inventor)

    1982-01-01

    A method and apparatus are provided for indicating the altitude of the tropopause or of an inversion layer wherein clear air turbulence (CAT) may occur, and the likely severity of any such CAT, includes directing a passive microwave radiometer on the aircraft at different angles with respect to the horizon. The microwave radiation measured at a frequency of about 55 GHz represents the temperature of the air at an ""average'' range of about 3 kilometers, so that the sine of the angle of the radiometer times 3 kilometers equals the approximate altitude of the air whose temperature is measured. A plot of altitude (with respect to the aircraft) versus temperature of the air at that altitude, can indicate when an inversion layer is present and can indicate the altitude of the tropopause or of such an inversion layer. The plot can also indicate the severity of any CAT in an inversion layer. If CAT has been detected in the general area, then the aircraft can be flown at an altitude to avoid the tropopause or inversion layer.

  3. Collision avoidance sensor skin

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The objective was to totally eliminate the possibility of a robot (or any mechanism for that matter) inducing a collision in space operations. We were particularly concerned that human beings were safe under all circumstances. This was apparently accomplished, and it is shown that GSFC has a system that is ready for space qualification and flight. However, it soon became apparent that much more could be accomplished with this technology. Payloads could be made invulnerable to collision avoidance and the blind spots behind them eliminated. This could be accomplished by a simple, non-imaging set of 'Capaciflector' sensors on each payload. It also is evident that this system could be used to align and dock the system with a wide margin of safety. Throughout, lighting problems could be ignored, and unexpected events and modeling errors taken in stride. At the same time, computational requirements would be reduced. This can be done in a simple, rugged, reliable manner that will not disturb the form factor of space systems. It will be practical for space applications. The lab experiments indicate we are well on the way to accomplishing this. Still, the research trail goes deeper. It now appears that the sensors can be extended to end effectors to provide precontact information and make robot docking (or any docking connection) very smooth, with minimal loads impacted back into the mating structures. This type of ability would be a major step forward in basic control techniques in space. There are, however, baseline and restructuring issues to be tackled. The payloads must get power and signals to them from the robot or from the astronaut servicing tool. This requires a standard electromechanical interface. Any of several could be used. The GSFC prototype shown in this presentation is a good one. Sensors with their attendant electronics must be added to the payloads, end effectors, and robot arms and integrated into the system.

  4. Stimulus conflict triggers behavioral avoidance.

    PubMed

    Dignath, David; Eder, Andreas B

    2015-12-01

    According to a recent extension of the conflict-monitoring theory, conflict between two competing response tendencies is registered as an aversive event and triggers a motivation to avoid the source of conflict. In the present study, we tested this assumption. Over five experiments, we examined whether conflict is associated with an avoidance motivation and whether stimulus conflict or response conflict triggers an avoidance tendency. Participants first performed a color Stroop task. In a subsequent motivation test, participants responded to Stroop stimuli with approach- and avoidance-related lever movements. These results showed that Stroop-conflict stimuli increased the frequency of avoidance responses in a free-choice motivation test, and also increased the speed of avoidance relative to approach responses in a forced-choice test. High and low proportions of response conflict in the Stroop task had no effect on avoidance in the motivation test. Avoidance of conflict was, however, obtained even with new conflict stimuli that had not been presented before in a Stroop task, and when the Stroop task was replaced with an unrelated filler task. Taken together, these results suggest that stimulus conflict is sufficient to trigger avoidance.

  5. Healthcare avoidance: a critical review.

    PubMed

    Byrne, Sharon K

    2008-01-01

    The purpose of this study is to provide a critical review and synthesis of theoretical and research literature documenting the impact of avoidance on healthcare behaviors, identify the factors that influence healthcare avoidance and delay in the adult population, and propose a direction for future research. The Theory of Reasoned Action, Theory of Planned Behavior, Theory of Care-Seeking Behavior, the Transtheoretical Model, and the Behavioral Model of Health Services Use/Utilization are utilized to elaborate on the context within which individual intention to engage in healthcare behaviors occurs. Research literature on the concept of healthcare avoidance obtained by using computerized searches of CINAHL, MEDLINE, PSYCH INFO, and HAPI databases, from 1995 to 2007, were reviewed. Studies were organized by professional disciplines. Healthcare avoidance is a common and highly variable experience. Multiple administrative, demographic, personal, and provider factors are related to healthcare avoidance, for example, distrust of providers and/or the science community, health beliefs, insurance status, or socioeconomic/income level. Although the concept is recognized by multiple disciplines, limited research studies address its impact on healthcare decision making. More systematic research is needed to determine correlates of healthcare avoidance. Such studies will help investigators identify patients at risk for avoidant behaviors and provide the basis for health-promoting interventions. Methodological challenges include identification of characteristics of individuals and environments that hinder healthcare behaviors, as well as, the complexity of measuring healthcare avoidance. Studies need to systematically explore the influence of avoidance behaviors on specific healthcare populations at risk.

  6. Stimulus conflict triggers behavioral avoidance.

    PubMed

    Dignath, David; Eder, Andreas B

    2015-12-01

    According to a recent extension of the conflict-monitoring theory, conflict between two competing response tendencies is registered as an aversive event and triggers a motivation to avoid the source of conflict. In the present study, we tested this assumption. Over five experiments, we examined whether conflict is associated with an avoidance motivation and whether stimulus conflict or response conflict triggers an avoidance tendency. Participants first performed a color Stroop task. In a subsequent motivation test, participants responded to Stroop stimuli with approach- and avoidance-related lever movements. These results showed that Stroop-conflict stimuli increased the frequency of avoidance responses in a free-choice motivation test, and also increased the speed of avoidance relative to approach responses in a forced-choice test. High and low proportions of response conflict in the Stroop task had no effect on avoidance in the motivation test. Avoidance of conflict was, however, obtained even with new conflict stimuli that had not been presented before in a Stroop task, and when the Stroop task was replaced with an unrelated filler task. Taken together, these results suggest that stimulus conflict is sufficient to trigger avoidance. PMID:25931151

  7. Healthcare avoidance: a critical review.

    PubMed

    Byrne, Sharon K

    2008-01-01

    The purpose of this study is to provide a critical review and synthesis of theoretical and research literature documenting the impact of avoidance on healthcare behaviors, identify the factors that influence healthcare avoidance and delay in the adult population, and propose a direction for future research. The Theory of Reasoned Action, Theory of Planned Behavior, Theory of Care-Seeking Behavior, the Transtheoretical Model, and the Behavioral Model of Health Services Use/Utilization are utilized to elaborate on the context within which individual intention to engage in healthcare behaviors occurs. Research literature on the concept of healthcare avoidance obtained by using computerized searches of CINAHL, MEDLINE, PSYCH INFO, and HAPI databases, from 1995 to 2007, were reviewed. Studies were organized by professional disciplines. Healthcare avoidance is a common and highly variable experience. Multiple administrative, demographic, personal, and provider factors are related to healthcare avoidance, for example, distrust of providers and/or the science community, health beliefs, insurance status, or socioeconomic/income level. Although the concept is recognized by multiple disciplines, limited research studies address its impact on healthcare decision making. More systematic research is needed to determine correlates of healthcare avoidance. Such studies will help investigators identify patients at risk for avoidant behaviors and provide the basis for health-promoting interventions. Methodological challenges include identification of characteristics of individuals and environments that hinder healthcare behaviors, as well as, the complexity of measuring healthcare avoidance. Studies need to systematically explore the influence of avoidance behaviors on specific healthcare populations at risk. PMID:18758277

  8. Chemical avoidance responses of fishes.

    PubMed

    Tierney, Keith B

    2016-05-01

    The hydrosphere is a repository for all of our waste and mistakes, be they sewage, garbage, process-affected waters, runoff, and gases. For fish living in environments receiving undesirable inputs, moving away seems an obvious way to avoid harm. While this should occur, there are numerous examples where it will not. The inability to avoid harmful environments may lead to sensory impairments that in turn limit the ability to avoid other dangers or locate benefits. For avoidance to occur, the danger must first be perceived, which may not happen if the fish is 'blinded' in some capacity. Second, the danger must be recognized for what it is, which may also not happen if the fish is cognitively confused or impaired. Third, it is possible that the fish may not be able to leave the area, or worse, learns to prefer a toxic environment. Concerning generating regulations around avoidance, there are two possibilities: that an avoidance threshold be used to set guidelines for effluent release with the intention of driving fishes away; the second is to set a contaminant concentration that would not affect the avoidance or attraction responses to other cues. With the complexities of the modern world in which we release diverse pollutants, from light to municipal effluents full of 1000s of chemicals, to the diversity present in ecosystems, it is impossible to have avoidance data on every stimulus-species combination. Nevertheless, we may be able to use existing avoidance response data to predict the likelihood of avoidance of untested stimuli. Where we cannot, this review includes a framework that can be used to direct new research. This review is intended to collate existing avoidance response data, provide a framework for making decisions in the absence of data, and suggest studies that would facilitate the prediction of risk to fish health in environments receiving intentional and unintentional human-based chemical inputs.

  9. Chemical avoidance responses of fishes.

    PubMed

    Tierney, Keith B

    2016-05-01

    The hydrosphere is a repository for all of our waste and mistakes, be they sewage, garbage, process-affected waters, runoff, and gases. For fish living in environments receiving undesirable inputs, moving away seems an obvious way to avoid harm. While this should occur, there are numerous examples where it will not. The inability to avoid harmful environments may lead to sensory impairments that in turn limit the ability to avoid other dangers or locate benefits. For avoidance to occur, the danger must first be perceived, which may not happen if the fish is 'blinded' in some capacity. Second, the danger must be recognized for what it is, which may also not happen if the fish is cognitively confused or impaired. Third, it is possible that the fish may not be able to leave the area, or worse, learns to prefer a toxic environment. Concerning generating regulations around avoidance, there are two possibilities: that an avoidance threshold be used to set guidelines for effluent release with the intention of driving fishes away; the second is to set a contaminant concentration that would not affect the avoidance or attraction responses to other cues. With the complexities of the modern world in which we release diverse pollutants, from light to municipal effluents full of 1000s of chemicals, to the diversity present in ecosystems, it is impossible to have avoidance data on every stimulus-species combination. Nevertheless, we may be able to use existing avoidance response data to predict the likelihood of avoidance of untested stimuli. Where we cannot, this review includes a framework that can be used to direct new research. This review is intended to collate existing avoidance response data, provide a framework for making decisions in the absence of data, and suggest studies that would facilitate the prediction of risk to fish health in environments receiving intentional and unintentional human-based chemical inputs. PMID:26970365

  10. Cigarette tax avoidance and evasion.

    PubMed

    Stehr, Mark

    2005-03-01

    Variation in state cigarette taxes provides incentives for tax avoidance through smuggling, legal border crossing to low tax jurisdictions, or Internet purchasing. When taxes rise, tax paid sales of cigarettes will decline both because consumption will decrease and because tax avoidance will increase. The key innovation of this paper is to compare cigarette sales data to cigarette consumption data from the Behavioral Risk Factor Surveillance System (BRFSS). I show that after subtracting percent changes in consumption, residual percent changes in sales are associated with state cigarette tax changes implying the existence of tax avoidance. I estimate that the tax avoidance response to tax changes is at least twice the consumption response and that tax avoidance accounted for up to 9.6% of sales between 1985 and 2001. Because of the increase in tax avoidance, tax paid sales data understate the level of smoking and overstate the drop in smoking. I also find that the level of legal border crossing was very low relative to other forms of tax avoidance. If states have strong preferences for smoking control, they must pair high cigarette taxes with effective policies to curb smuggling and other forms of tax avoidance or employ alternative policies such as counter-advertising and smoking restrictions. PMID:15721046

  11. Postcopulatory inbreeding avoidance in guppies.

    PubMed

    Fitzpatrick, J L; Evans, J P

    2014-12-01

    In many species, the negative fitness effects of inbreeding have facilitated the evolution of a wide range of inbreeding avoidance mechanisms. Although avoidance mechanisms operating prior to mating are well documented, evidence for postcopulatory mechanisms of inbreeding avoidance remain scarce. Here, we examine the potential for paternity biases to favour unrelated males when their sperm compete for fertilizations though postcopulatory inbreeding avoidance mechanisms in the guppy, Poecilia reticulata. To test this possibility, we used a series of artificial inseminations to deliver an equal number of sperm from a related (either full sibling or half sibling) and unrelated male to a female while statistically controlling for differences in sperm quality between rival ejaculates. In this way, we were able to focus exclusively on postcopulatory mechanisms of inbreeding avoidance and account for differences in sperm competitiveness between rival males. Under these carefully controlled conditions, we report a significant bias in paternity towards unrelated males, although this effect was only apparent when the related male was a full sibling. We also show that sperm competition generally favours males with highly viable sperm and thus that some variance in sperm competitiveness can be attributed to difference in sperm quality. Our findings for postcopulatory inbreeding avoidance are consistent with prior work on guppies, revealing that sperm competition success declines linearly with the level of relatedness, but also that such effects are only apparent at relatedness levels of full siblings or higher. These findings reveal that postcopulatory processes alone can facilitate inbreeding avoidance.

  12. Postcopulatory inbreeding avoidance in guppies.

    PubMed

    Fitzpatrick, J L; Evans, J P

    2014-12-01

    In many species, the negative fitness effects of inbreeding have facilitated the evolution of a wide range of inbreeding avoidance mechanisms. Although avoidance mechanisms operating prior to mating are well documented, evidence for postcopulatory mechanisms of inbreeding avoidance remain scarce. Here, we examine the potential for paternity biases to favour unrelated males when their sperm compete for fertilizations though postcopulatory inbreeding avoidance mechanisms in the guppy, Poecilia reticulata. To test this possibility, we used a series of artificial inseminations to deliver an equal number of sperm from a related (either full sibling or half sibling) and unrelated male to a female while statistically controlling for differences in sperm quality between rival ejaculates. In this way, we were able to focus exclusively on postcopulatory mechanisms of inbreeding avoidance and account for differences in sperm competitiveness between rival males. Under these carefully controlled conditions, we report a significant bias in paternity towards unrelated males, although this effect was only apparent when the related male was a full sibling. We also show that sperm competition generally favours males with highly viable sperm and thus that some variance in sperm competitiveness can be attributed to difference in sperm quality. Our findings for postcopulatory inbreeding avoidance are consistent with prior work on guppies, revealing that sperm competition success declines linearly with the level of relatedness, but also that such effects are only apparent at relatedness levels of full siblings or higher. These findings reveal that postcopulatory processes alone can facilitate inbreeding avoidance. PMID:25387854

  13. Vertical jumping and signaled avoidance

    PubMed Central

    Cándido, Antonio; Maldonado, Antonio; Vila, Jaime

    1988-01-01

    This paper reports an experiment intended to demonstrate that the vertical jumping response can be learned using a signaled-avoidance technique. A photoelectric cell system was used to record the response. Twenty female rats, divided equally into two groups, were exposed to intertrial intervals of either 15 or 40 s. Subjects had to achieve three successive criteria of acquisition: 3, 5, and 10 consecutive avoidance responses. Results showed that both groups learned the avoidance response, requiring increasingly larger numbers of trials as the acquisition criteria increased. No significant effect of intertrial interval was observed. PMID:16812559

  14. Vision-based obstacle avoidance

    DOEpatents

    Galbraith, John

    2006-07-18

    A method for allowing a robot to avoid objects along a programmed path: first, a field of view for an electronic imager of the robot is established along a path where the electronic imager obtains the object location information within the field of view; second, a population coded control signal is then derived from the object location information and is transmitted to the robot; finally, the robot then responds to the control signal and avoids the detected object.

  15. Predator Avoidance in Extremophile Fish

    PubMed Central

    Bierbach, David; Schulte, Matthias; Herrmann, Nina; Zimmer, Claudia; Arias-Rodriguez, Lenin; Indy, Jeane Rimber; Riesch, Rüdiger; Plath, Martin

    2013-01-01

    Extreme habitats are often characterized by reduced predation pressures, thus representing refuges for the inhabiting species. The present study was designed to investigate predator avoidance of extremophile populations of Poecilia mexicana and P. sulphuraria that either live in hydrogen sulfide-rich (sulfidic) springs or cave habitats, both of which are known to have impoverished piscine predator regimes. Focal fishes that inhabited sulfidic springs showed slightly weaker avoidance reactions when presented with several naturally occurring predatory cichlids, but strongest differences to populations from non-sulfidic habitats were found in a decreased shoaling tendency with non-predatory swordtail (Xiphophorus hellerii) females. When comparing avoidance reactions between P. mexicana from a sulfidic cave (Cueva del Azufre) and the adjacent sulfidic surface creek (El Azufre), we found only slight differences in predator avoidance, but surface fish reacted much more strongly to the non-predatory cichlid Vieja bifasciata. Our third experiment was designed to disentangle learned from innate effects of predator recognition. We compared laboratory-reared (i.e., predator-naïve) and wild-caught (i.e., predator-experienced) individuals of P. mexicana from a non-sulfidic river and found no differences in their reaction towards the presented predators. Overall, our results indicate (1) that predator avoidance is still functional in extremophile Poecilia spp. and (2) that predator recognition and avoidance reactions have a strong genetic basis. PMID:25371337

  16. Predator avoidance in extremophile fish.

    PubMed

    Bierbach, David; Schulte, Matthias; Herrmann, Nina; Zimmer, Claudia; Arias-Rodriguez, Lenin; Indy, Jeane Rimber; Riesch, Rüdiger; Plath, Martin

    2013-01-01

    Extreme habitats are often characterized by reduced predation pressures, thus representing refuges for the inhabiting species. The present study was designed to investigate predator avoidance of extremophile populations of Poecilia mexicana and P. sulphuraria that either live in hydrogen sulfide-rich (sulfidic) springs or cave habitats, both of which are known to have impoverished piscine predator regimes. Focal fishes that inhabited sulfidic springs showed slightly weaker avoidance reactions when presented with several naturally occurring predatory cichlids, but strongest differences to populations from non-sulfidic habitats were found in a decreased shoaling tendency with non-predatory swordtail (Xiphophorus hellerii) females. When comparing avoidance reactions between P. mexicana from a sulfidic cave (Cueva del Azufre) and the adjacent sulfidic surface creek (El Azufre), we found only slight differences in predator avoidance, but surface fish reacted much more strongly to the non-predatory cichlid Vieja bifasciata. Our third experiment was designed to disentangle learned from innate effects of predator recognition. We compared laboratory-reared (i.e., predator-naïve) and wild-caught (i.e., predator-experienced) individuals of P. mexicana from a non-sulfidic river and found no differences in their reaction towards the presented predators. Overall, our results indicate (1) that predator avoidance is still functional in extremophile Poecilia spp. and (2) that predator recognition and avoidance reactions have a strong genetic basis.

  17. Automatic Collision Avoidance Technology (ACAT)

    NASA Technical Reports Server (NTRS)

    Swihart, Donald E.; Skoog, Mark A.

    2007-01-01

    This document represents two views of the Automatic Collision Avoidance Technology (ACAT). One viewgraph presentation reviews the development and system design of Automatic Collision Avoidance Technology (ACAT). Two types of ACAT exist: Automatic Ground Collision Avoidance (AGCAS) and Automatic Air Collision Avoidance (AACAS). The AGCAS Uses Digital Terrain Elevation Data (DTED) for mapping functions, and uses Navigation data to place aircraft on map. It then scans DTED in front of and around aircraft and uses future aircraft trajectory (5g) to provide automatic flyup maneuver when required. The AACAS uses data link to determine position and closing rate. It contains several canned maneuvers to avoid collision. Automatic maneuvers can occur at last instant and both aircraft maneuver when using data link. The system can use sensor in place of data link. The second viewgraph presentation reviews the development of a flight test and an evaluation of the test. A review of the operation and comparison of the AGCAS and a pilot's performance are given. The same review is given for the AACAS is given.

  18. Approach/avoidance in dreams.

    PubMed

    Malcolm-Smith, Susan; Koopowitz, Sheri; Pantelis, Eleni; Solms, Mark

    2012-03-01

    The influential threat simulation theory (TST) asserts that dreaming yields adaptive advantage by providing a virtual environment in which threat-avoidance may be safely rehearsed. We have previously found the incidence of biologically threatening dreams to be around 20%, with successful threat avoidance occurring in approximately one-fifth of such dreams. TST asserts that threat avoidance is over-represented relative to other possible dream contents. To begin assessing this issue, we contrasted the incidence of 'avoidance' dreams with that of their opposite: 'approach' dreams. Because TST states that the threat-avoidance function is only fully activated in ecologically valid (biologically threatening) contexts, we also performed this contrast for populations living in both high- and low-threat environments. We find that 'approach' dreams are significantly more prevalent across both contexts. We suggest these results are more consistent with the view that dreaming is generated by reward-seeking systems than by fear-conditioning systems, although reward-seeking is clearly not the only factor determining the content of dreams.

  19. Motive to Avoid Success, Locus of Control, and Reinforcement Avoidance.

    ERIC Educational Resources Information Center

    Katovsky, Walter

    Subjects were four groups of 12 college women, high or low in motive to avoid success (MAS) and locus of control (LC), were reinforced for response A on a fixed partial reinforcement schedule on three concept learning tasks, one task consisting of combined reward and punishment, another of reward only, and one of punishment only. Response B was…

  20. Food Avoidance Diets for Dermatitis.

    PubMed

    Scott, Jeffrey F; Hammond, Margaret I; Nedorost, Susan T

    2015-10-01

    Food allergy is relatively common in both children and adults, and its prevalence is increasing. Early exposure of food allergens onto skin with an impaired epidermal barrier predisposes to sensitization and prevents the development of oral tolerance. While immediate-type food allergies are well described, less is known about delayed-type food allergies manifesting as dermatitis. This is due, in part, to limitations with current diagnostic testing for delayed-type food allergy, including atopy patch testing. We conducted a systematic review of food avoidance diets in delayed-type food allergies manifesting as dermatitis. While beneficial in some clinical circumstances, avoidance diets should be used with caution in infants and children, as growth impairment and developmental delay may result. Ultimately, dermatitis is highly multifactorial and avoidance diets may not improve symptoms of delayed-type food allergy until combined with other targeted therapies, including restoring balance in the skin microbiome and re-establishing proper skin barrier function.

  1. A problem of collision avoidance

    NASA Technical Reports Server (NTRS)

    Vincent, T. L.; Cliff, E. M.; Grantham, W. J.; Peng, W. Y.

    1972-01-01

    Collision avoidance between two vehicles of constant speed with limited turning radii, moving in a horizontal plane is investigated. Collision avoidance is viewed as a game by assuming that the operator of one vehicle has perfect knowledge of the state of the other, whereas the operator of the second vehicle is unaware of any impending danger. The situation envisioned is that of an encounter between a commercial aircraft and a small light aircraft. This worse case situation is examined to determine the conditions under which the commercial aircraft should execute a collision avoidance maneuver. Three different zones of vulnerability are defined and the boundaries, or barriers, between these zones are determined for a typical aircraft encounter. A discussion of the methods used to obtain the results as well as some of the salient features associated with the resultant barriers is included.

  2. Biochar aging reduces earthworm avoidance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biochar, a black carbon substance produced by the pyrolysis of organic feedstocks, has been used in many soil improvement strategies ranging from nutrient addition to sequestration of C. Simple toxicity studies and laboratory preference/avoidance assays are recommended but results rarely reported. ...

  3. Avoided cost pricing: who wins

    SciTech Connect

    Einhorn, M.A.

    1985-05-30

    This article calls for a reevaluation of current Federal Energy Regulatory Commission regulations on the calculation of avoided cost rates for sales of power to utilities by small producers in the light of market conditions not contemplated at the time of the regulations' adoption. 8 references.

  4. Avoiding plagiarism in academic writing.

    PubMed

    Anderson, Irene

    Plagiarism means taking the work of another and presenting it as one's own, resulting in potential upset for the original author and disrepute for the professions involved. This article aims to explore the issue of plagiarism and some mechanisms for detection and avoidance.

  5. Avoiding congestion in recommender systems

    NASA Astrophysics Data System (ADS)

    Ren, Xiaolong; Lü, Linyuan; Liu, Runran; Zhang, Jianlin

    2014-06-01

    Recommender systems use the historical activities and personal profiles of users to uncover their preferences and recommend objects. Most of the previous methods are based on objects’ (and/or users’) similarity rather than on their difference. Such approaches are subject to a high risk of increasingly exposing users to a narrowing band of popular objects. As a result, a few objects may be recommended to an enormous number of users, resulting in the problem of recommendation congestion, which is to be avoided, especially when the recommended objects are limited resources. In order to quantitatively measure a recommendation algorithm's ability to avoid congestion, we proposed a new metric inspired by the Gini index, which is used to measure the inequality of the individual wealth distribution in an economy. Besides this, a new recommendation method called directed weighted conduction (DWC) was developed by considering the heat conduction process on a user-object bipartite network with different thermal conductivities. Experimental results obtained for three benchmark data sets showed that the DWC algorithm can effectively avoid system congestion, and greatly improve the novelty and diversity, while retaining relatively high accuracy, in comparison with the state-of-the-art methods.

  6. Rapid jamming avoidance in biosonar.

    PubMed

    Gillam, Erin H; Ulanovsky, Nachum; McCracken, Gary F

    2007-03-01

    The sonar systems of bats and dolphins are in many ways superior to man-made sonar and radar systems, and considerable effort has been devoted to understanding the signal-processing strategies underlying these capabilities. A major feature determining the efficiency of sonar systems is the sensitivity to noise and jamming signals. Previous studies indicated that echolocating bats may adjust their signal structure to avoid jamming ('jamming avoidance response'; JAR). However, these studies relied on behavioural correlations and not controlled experiments. Here, we provide the first experimental evidence for JAR in bats. We presented bats (Tadarida brasiliensis) with 'playback stimuli' consisting of recorded echolocation calls at one of six frequencies. The bats exhibited a JAR by shifting their call frequency away from the presented playback frequency. When the approaching bats were challenged by an abrupt change in the playback stimulus, they responded by shifting their call frequencies upwards, away from the playback. Interestingly, even bats initially calling below the playback's frequency shifted their frequencies upwards, 'jumping' over the playback frequency. These spectral shifts in the bats' calls occurred often within less than 200 ms, in the first echolocation call emitted after the stimulus switch-suggesting that rapid jamming avoidance is important for the bat.

  7. Blue light regulated shade avoidance.

    PubMed

    Keuskamp, Diederik H; Keller, Mercedes M; Ballaré, Carlos L; Pierik, Ronald

    2012-04-01

    Most plants grow in dense vegetation with the risk of being out-competed by neighboring plants. These neighbors can be detected not only through the depletion in light quantity that they cause, but also through the change in light quality, which plants perceive using specific photoreceptors. Both the reduction of the red:far-red ratio and the depletion of blue light are signals that induce a set of phenotypic traits, such as shoot elongation and leaf hyponasty, which increase the likelihood of light capture in dense plant stands. This set of phenotypic responses are part of the so called shade avoidance syndrome (SAS). This addendum discusses recent findings on the regulation of the SAS of Arabidopsis thaliana upon blue light depletion. Keller et al. and Keuskamp et al. show that the low blue light attenuation induced shade avoidance response of seedling and rosette-stage A. thaliana plants differ in their hormonal regulation. These studies also show there is a regulatory overlap with the R:FR-regulated SAS.

  8. Obstacle-avoiding navigation system

    DOEpatents

    Borenstein, Johann; Koren, Yoram; Levine, Simon P.

    1991-01-01

    A system for guiding an autonomous or semi-autonomous vehicle through a field of operation having obstacles thereon to be avoided employs a memory for containing data which defines an array of grid cells which correspond to respective subfields in the field of operation of the vehicle. Each grid cell in the memory contains a value which is indicative of the likelihood, or probability, that an obstacle is present in the respectively associated subfield. The values in the grid cells are incremented individually in response to each scan of the subfields, and precomputation and use of a look-up table avoids complex trigonometric functions. A further array of grid cells is fixed with respect to the vehicle form a conceptual active window which overlies the incremented grid cells. Thus, when the cells in the active window overly grid cell having values which are indicative of the presence of obstacles, the value therein is used as a multiplier of the precomputed vectorial values. The resulting plurality of vectorial values are summed vectorially in one embodiment of the invention to produce a virtual composite repulsive vector which is then summed vectorially with a target-directed vector for producing a resultant vector for guiding the vehicle. In an alternative embodiment, a plurality of vectors surrounding the vehicle are computed, each having a value corresponding to obstacle density. In such an embodiment, target location information is used to select between alternative directions of travel having low associated obstacle densities.

  9. Osteonecrosis: avoiding total hip arthroplasty.

    PubMed

    Hungerford, David S

    2002-06-01

    Osteonecrosis of the femoral head afflicts approximately 20,000 new patients per year, at an average age of 38. Of the patients seen in our institution, 25% are <25 years old. Without treatment, most of these patients can be expected to need a total hip arthroplasty. Joint-preserving procedures have a significant failure rate, and some have significant morbidity. It is desirable to avoid or delay total hip arthroplasty because most patients with osteonecrosis outlive the current state-of-the-art prostheses. Four issues need to be weighed to arrive at a reasonable algorithm for the preservative treatment of osteonecrosis: i) patient risk factors, ii) morbidity of the proposed procedure, iii) size of the lesion, and iv) stage of the lesion. All of the issues must be considered to make sense out of a complex clinical situation.

  10. Autonomous hazard detection and avoidance

    NASA Technical Reports Server (NTRS)

    Pien, Homer

    1992-01-01

    During GFY 91, Draper Laboratory was awarded a task by NASA-JSC under contract number NAS9-18426 to study and evaluate the potential for achieving safe autonomous landings on Mars using an on-board autonomous hazard detection and avoidance (AHDA) system. This report describes the results of that study. The AHDA task had four objectives: to demonstrate, via a closed-loop simulation, the ability to autonomously select safe landing sites and the ability to maneuver to the selected site; to identify key issues in the development of AHDA systems; to produce strawman designs for AHDA sensors and algorithms; and to perform initial trade studies leading to better understanding of the effect of sensor/terrain/viewing parameters on AHDA algorithm performance. This report summarizes the progress made during the first year, with primary emphasis on describing the tools developed for simulating a closed-loop AHDA landing. Some cursory performance evaluation results are also presented.

  11. ACAT Ground Collision Avoidance Flight Tests Over

    NASA Video Gallery

    NASA's Dryden Flight Research Center has concluded flight tests of an Automatic Ground Collision Avoidance System (Auto GCAS) under the joint U.S. Air Force/NASA F-16D Automatic Collision Avoidance...

  12. Avoidant/Restrictive Food Intake Disorder

    MedlinePlus

    ... Professional Version Eating Disorders Definition of Eating Disorders Anorexia Nervosa Avoidant/Restrictive Food Intake Disorder Binge Eating ... they eat. Eating Disorders Definition of Eating Disorders Anorexia Nervosa Avoidant/Restrictive Food Intake Disorder Binge Eating ...

  13. Math Avoidance and Pursuit of Fantasy Careers.

    ERIC Educational Resources Information Center

    Benton, Barbara L.

    Math avoidance has been hypothesized as related to career choice restrictions. Few attempts have been made, however, to assess the relative importance of the various components of math avoidance to career choice. Furthermore, it has been implied that persons fearful of math not only avoid specific careers but also reject careers that are otherwise…

  14. Termites eavesdrop to avoid competitors.

    PubMed

    Evans, Theodore A; Inta, Ra; Lai, Joseph C S; Prueger, Stefan; Foo, Nyuk Wei; Fu, Eugene Wei'en; Lenz, Michael

    2009-11-22

    Competition exclusion, when a single species dominates resources due to superior competitiveness, is seldom observed in nature. Termites compete for resources with deadly consequences, yet more than one species can be found feeding in the same wooden resource. This is especially surprising when drywood species, with colonies of a few hundred, are found cohabiting with subterranean species, with colonies of millions. Termites communicate vibro-acoustically and, as these signals can travel over long distances, they are vulnerable to eavesdropping. We investigated whether drywood termites could eavesdrop on vibration cues from subterranean species. We show, using choice experiments and recordings, that the drywood termite Cryptotermes secundus can distinguish its own species from the dominant competitor in the environment, the subterranean termite Coptotermes acinaciformis. The drywood termite was attracted to its own vibration cues, but was repelled by those of the subterranean species. This response increased with decreasing wood size, corresponding with both increased risk and strength of the cue. The drywood termites appear to avoid confrontation by eavesdropping on the subterranean termites; these results provide further evidence that vibro-acoustic cues are important for termite sensory perception and communication.

  15. Avoidance of aluminum by rainbow trout

    SciTech Connect

    Exley, C.

    2000-04-01

    Aluminum is the principal toxicant in fish in acid waters. The ability to avoid Al, particularly at low concentrations, would confer a considerable ecological advantage, but previous research into avoidance of Al has produced mixed results. The author used a cylindrical perspex tank, 150 cm in length, to study avoidance of Al by rainbow trout fry. The fish avoided Al, and their response was dependent on pH. Avoidance that was demonstrated at pHs of 5.00, 5.50, 5.50, and 5.75 was abolished at a pH of 6.00. Fry avoided very low Al concentrations being sensitive to [Al] > 1.00 {micro}mol L{sup {minus}1} at a pH of 5.00. This unequivocal demonstration of avoidance by rainbow trout fry of Al may have important implications for the ecology of indigenous fish populations in surface waters impacted by acidic deposition.

  16. Infection control: avoiding the inevitable.

    PubMed

    Mollitt, Daniel L

    2002-04-01

    Infection, while a major cause of morbidity, should not be considered an inevitable consequence of injury. Good aseptic technique, compulsive attention to detail, and thorough understanding of the points addressed in the following list of critical points are the best guarantee that infection will not add avoidable morbidity to misfortune. Critical points regarding infectious problems in care of the injured child: 1. Polymicrobial infection is the rule with 50% of isolates being mixed aerobic and anaerobic bacteria. 2. It is a misnomer to consider antibiotic use in a pediatric trauma victim as prophylactic. Antimicrobials used in this setting are best considered adjunctive. 3. The major indication for anti-infective therapy in pediatric trauma is an injury with a high probability of infection. 4. Antibiotics do not sterilize the wound or body cavity; they limit bacterial proliferation, thereby supplementing effective immune control. 5. Available studies suggest that 24 hours is as efficacious as a longer treatment duration in a purely adjunctive mode. 6. In bites inflicted by dogs and cats, Pasturella species are frequent. 7. Human bites may result in infection by Eikenella corrodens. 8. Based on this bacteriology, adjunctive intravenous ampicillin sulbactam or oral amoxicillin clavulanate are recommended for human and animal bites. 9. Tetanus prophylaxis is indicated in all significant soft tissue injuries. 10. Risk of osteomyelitis correlates directly with the extent of the associated soft tissue injury and vascular compromise. 11. The majority of infectious complications in the injured child are not a consequence of the injury itself, but rather in the treatment thereof. 12. In the injured child the most common nosocomial infection is lower respiratory followed by primary blood stream and the urinary tract. 13. The management of nosocomial pneumonia in the injured child is based on the time of diagnoses. Early evidence of pulmonary infection requires treatment

  17. Generalization of socially transmitted and instructed avoidance.

    PubMed

    Cameron, Gemma; Schlund, Michael W; Dymond, Simon

    2015-01-01

    Excessive avoidance behavior, in which an instrumental action prevents an upcoming aversive event, is a defining feature of anxiety disorders. Left unchecked, both fear and avoidance of potentially threatening stimuli may generalize to perceptually related stimuli and situations. The behavioral consequences of generalization mean that aversive learning experiences with specific threats may lead to the inference that classes of related stimuli are threatening, potentially dangerous, and need to be avoided, despite differences in physical form. Little is known however about avoidance generalization in humans and the learning pathways by which it may be transmitted. In the present study, we compared two pathways to avoidance-instructions and social observation-on subsequent generalization of avoidance behavior, fear expectancy and physiological arousal. Participants first learned that one cue was a danger cue (conditioned stimulus, CS+) and another was a safety cue (CS-). Groups were then either instructed that a simple avoidance response in the presence of the CS+ cancelled upcoming shock (instructed-learning group) or observed a short movie showing a demonstrator performing the avoidance response to prevent shock (observational-learning group). During generalization testing, danger and safety cues were presented along with generalization stimuli that parametrically varied in perceptual similarity to the CS+. Reinstatement of fear and avoidance was also tested. Findings demonstrate, for the first time, generalization of socially transmitted and instructed avoidance: both groups showed comparable generalization gradients in fear expectancy, avoidance behavior and arousal. Return of fear was evident, suggesting that generalized avoidance remains persistent following extinction testing. The utility of the present paradigm for research on avoidance generalization is discussed. PMID:26150773

  18. Behavioral avoidance of contagion in childhood.

    PubMed

    Blacker, Katy-Ann; LoBue, Vanessa

    2016-03-01

    Although there is a large literature on children's reasoning about contagion, there has been no empirical research on children's avoidance of contagious individuals. This study is the first to investigate whether children avoid sick individuals. Participants (4- to 7-year-old children) were invited to play with two confederates-one of whom was "sick." Afterward, their knowledge of contagion was assessed. Overall, children avoided proximity to and contact with the sick confederate and her toys, but only 6- and 7-year-olds performed above chance. The best predictor of avoidance behavior was not age but rather children's ability to make predictions about illness outcomes. This provides the first evidence of behavioral avoidance of contagious illness in childhood and suggests that causal knowledge underlies avoidance behavior. PMID:26615972

  19. Generalization of socially transmitted and instructed avoidance

    PubMed Central

    Cameron, Gemma; Schlund, Michael W.; Dymond, Simon

    2015-01-01

    Excessive avoidance behavior, in which an instrumental action prevents an upcoming aversive event, is a defining feature of anxiety disorders. Left unchecked, both fear and avoidance of potentially threatening stimuli may generalize to perceptually related stimuli and situations. The behavioral consequences of generalization mean that aversive learning experiences with specific threats may lead to the inference that classes of related stimuli are threatening, potentially dangerous, and need to be avoided, despite differences in physical form. Little is known however about avoidance generalization in humans and the learning pathways by which it may be transmitted. In the present study, we compared two pathways to avoidance—instructions and social observation—on subsequent generalization of avoidance behavior, fear expectancy and physiological arousal. Participants first learned that one cue was a danger cue (conditioned stimulus, CS+) and another was a safety cue (CS−). Groups were then either instructed that a simple avoidance response in the presence of the CS+ cancelled upcoming shock (instructed-learning group) or observed a short movie showing a demonstrator performing the avoidance response to prevent shock (observational-learning group). During generalization testing, danger and safety cues were presented along with generalization stimuli that parametrically varied in perceptual similarity to the CS+. Reinstatement of fear and avoidance was also tested. Findings demonstrate, for the first time, generalization of socially transmitted and instructed avoidance: both groups showed comparable generalization gradients in fear expectancy, avoidance behavior and arousal. Return of fear was evident, suggesting that generalized avoidance remains persistent following extinction testing. The utility of the present paradigm for research on avoidance generalization is discussed. PMID:26150773

  20. Flight Tests Validate Collision-Avoidance System

    NASA Video Gallery

    Flights tests of a smartphone-assisted automatic ground collision avoidance system at NASA's Dryden Flight Research Center consistently commanded evasive maneuvers when it sensed that the unmanned ...

  1. Integration of Weather Avoidance and Traffic Separation

    NASA Technical Reports Server (NTRS)

    Consiglio, Maria C.; Chamberlain, James P.; Wilson, Sara R.

    2011-01-01

    This paper describes a dynamic convective weather avoidance concept that compensates for weather motion uncertainties; the integration of this weather avoidance concept into a prototype 4-D trajectory-based Airborne Separation Assurance System (ASAS) application; and test results from a batch (non-piloted) simulation of the integrated application with high traffic densities and a dynamic convective weather model. The weather model can simulate a number of pseudo-random hazardous weather patterns, such as slow- or fast-moving cells and opening or closing weather gaps, and also allows for modeling of onboard weather radar limitations in range and azimuth. The weather avoidance concept employs nested "core" and "avoid" polygons around convective weather cells, and the simulations assess the effectiveness of various avoid polygon sizes in the presence of different weather patterns, using traffic scenarios representing approximately two times the current traffic density in en-route airspace. Results from the simulation experiment show that the weather avoidance concept is effective over a wide range of weather patterns and cell speeds. Avoid polygons that are only 2-3 miles larger than their core polygons are sufficient to account for weather uncertainties in almost all cases, and traffic separation performance does not appear to degrade with the addition of weather polygon avoidance. Additional "lessons learned" from the batch simulation study are discussed in the paper, along with insights for improving the weather avoidance concept. Introduction

  2. How Do Speakers Avoid Ambiguous Linguistic Expressions?

    ERIC Educational Resources Information Center

    Ferreira, V.S.; Slevc, L.R.; Rogers, E.S.

    2005-01-01

    Three experiments assessed how speakers avoid linguistically and nonlinguistically ambiguous expressions. Speakers described target objects (a flying mammal, bat) in contexts including foil objects that caused linguistic (a baseball bat) and nonlinguistic (a larger flying mammal) ambiguity. Speakers sometimes avoided linguistic-ambiguity, and they…

  3. Recommendations for Sense and Avoid Policy Compliance

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Since unmanned aircraft do not have a human on board, they need to have a sense and avoid capability that provides an "equivalent level of safety" (ELOS) to manned aircraft. The question then becomes - is sense and avoid ELOS for unmanned aircraft adequate to satisfy the requirements of 14 CFR 91.113? Access 5 has proposed a definition of sense and avoid, but the question remains as to whether any sense and avoid system can comply with 14 CFR 91.113 as currently written. The Access 5 definition of sense and avoid ELOS allows for the development of a sense and avoid system for unmanned aircraft that would comply with 14 CFR 91.113. Compliance is based on sensing and avoiding other traffic at an equivalent level of safety for collision avoidance, as manned aircraft. No changes to Part 91 are necessary, with the possible exception of changing "see" to "sense," or obtaining an interpretation from the FAA General Counsel that "sense" is equivalent to "see."

  4. 47 CFR 74.604 - Interference avoidance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Interference avoidance. 74.604 Section 74.604 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES EXPERIMENTAL RADIO... Stations § 74.604 Interference avoidance. (a) (b) Where two or more licensees are assigned a common...

  5. Human Hippocampus Arbitrates Approach-Avoidance Conflict

    PubMed Central

    Bach, Dominik R.; Guitart-Masip, Marc; Packard, Pau A.; Miró, Júlia; Falip, Mercè; Fuentemilla, Lluís; Dolan, Raymond J.

    2014-01-01

    Summary Animal models of human anxiety often invoke a conflict between approach and avoidance [1, 2]. In these, a key behavioral assay comprises passive avoidance of potential threat and inhibition, both thought to be controlled by ventral hippocampus [2–6]. Efforts to translate these approaches to clinical contexts [7, 8] are hampered by the fact that it is not known whether humans manifest analogous approach-avoidance dispositions and, if so, whether they share a homologous neurobiological substrate [9]. Here, we developed a paradigm to investigate the role of human hippocampus in arbitrating an approach-avoidance conflict under varying levels of potential threat. Across four experiments, subjects showed analogous behavior by adapting both passive avoidance behavior and behavioral inhibition to threat level. Using functional magnetic resonance imaging (fMRI), we observe that threat level engages the anterior hippocampus, the human homolog of rodent ventral hippocampus [10]. Testing patients with selective hippocampal lesions, we demonstrate a causal role for the hippocampus with patients showing reduced passive avoidance behavior and inhibition across all threat levels. Our data provide the first human assay for approach-avoidance conflict akin to that of animal anxiety models. The findings bridge rodent and human research on passive avoidance and behavioral inhibition and furnish a framework for addressing the neuronal underpinnings of human anxiety disorders, where our data indicate a major role for the hippocampus. PMID:24560572

  6. Population properties affect inbreeding avoidance in moose.

    PubMed

    Herfindal, Ivar; Haanes, Hallvard; Røed, Knut H; Solberg, Erling J; Markussen, Stine S; Heim, Morten; Sæther, Bernt-Erik

    2014-12-01

    Mechanisms reducing inbreeding are thought to have evolved owing to fitness costs of breeding with close relatives. In small and isolated populations, or populations with skewed age- or sex distributions, mate choice becomes limited, and inbreeding avoidance mechanisms ineffective. We used a unique individual-based dataset on moose from a small island in Norway to assess whether inbreeding avoidance was related to population structure and size, expecting inbreeding avoidance to be greater in years with larger populations and even adult sex ratios. The probability that a potential mating event was realized was negatively related to the inbreeding coefficient of the potential offspring, with a stronger relationship in years with a higher proportion or number of males in the population. Thus, adult sex ratio and population size affect the degree of inbreeding avoidance. Consequently, conservation managers should aim for sex ratios that facilitate inbreeding avoidance, especially in small and isolated populations.

  7. Living with food allergy: allergen avoidance.

    PubMed

    Kim, Jennifer S; Sicherer, Scott H

    2011-04-01

    The primary treatment of food allergy is to avoid the culprit foods. This is a complex undertaking that requires education about reading the labels of manufactured products, understanding how to avoid cross-contact with allergens during food preparation, and communicating effectively with persons who are providing allergen-safe meals including relatives and restaurant personnel. Successful avoidance also requires a knowledge of nuances such as appropriate cleaning practices, an understanding of the risks of ingestion compared to skin contact or inhalation, that exposure could occur through unanticipated means such as through sharing utensils or passionate kissing, and that food may be a component of substances that are not ingested such as cosmetics, bath products, vaccines and medications. The authors review the necessary tools of avoidance that physicians and medical practitioners can use to guide their patients through the complexities of food avoidance.

  8. How do speakers avoid ambiguous linguistic expressions?

    PubMed

    Ferreira, Victor S; Slevc, L Robert; Rogers, Erin S

    2005-07-01

    Three experiments assessed how speakers avoid linguistically and nonlinguistically ambiguous expressions. Speakers described target objects (a flying mammal, bat) in contexts including foil objects that caused linguistic (a baseball bat) and nonlinguistic (a larger flying mammal) ambiguity. Speakers sometimes avoided linguistic-ambiguity, and they did so equally regardless of whether they also were about to describe foils. This suggests that comprehension processes can sometimes detect linguistic-ambiguity before producing it. However, once produced, speakers consistently avoided using the same linguistically ambiguous expression again for a different meaning. This suggests that production processes can successfully detect linguistic-ambiguity after-the-fact. Speakers almost always avoided nonlinguistic-ambiguity. Thus, production processes are especially sensitive to nonlinguistic- but not linguistic-ambiguity, with the latter avoided consistently only once it is already articulated.

  9. Individual differences in women's rape avoidance behaviors.

    PubMed

    McKibbin, William F; Shackelford, Todd K; Miner, Emily J; Bates, Vincent M; Liddle, James R

    2011-04-01

    Rape can exact severe psychological, physical, and reproductive costs on women, and likely was a recurrent adaptive problem over human evolutionary history. Therefore, women may have evolved psychological mechanisms that motivate rape avoidance behaviors. Guided heuristically by an evolutionary perspective, we tested the hypothesis that women's rape avoidance behaviors would vary with several individual difference variables. Specifically, we predicted that rape avoidance behaviors would covary positively with (1) women's attractiveness, (2) women's involvement in a committed romantic relationship, and (3) the number of family members living nearby. We also predicted that women's rape avoidance behaviors would covary negatively with age. We administered the Rape Avoidance Inventory (McKibbin et al., Pers Indiv Differ 39:336-340, 2009) and a demographic survey to a sample of women (n = 144). The results of correlational and regression analyses were consistent with the predictions, with the exception that women's rape avoidance behaviors did not covary with women's age. Discussion highlighted limitations of the current research and directions for future research on women's rape avoidance psychology and behaviors.

  10. Moving Obstacle Avoidance for Unmanned Aerial Vehicles

    NASA Astrophysics Data System (ADS)

    Lin, Yucong

    There has been a vast increase in applications of Unmanned Aerial Vehicles (UAVs) in civilian domains. To operate in the civilian airspace, a UAV must be able to sense and avoid both static and moving obstacles for flight safety. While indoor and low-altitude environments are mainly occupied by static obstacles, risks in space of higher altitude primarily come from moving obstacles such as other aircraft or flying vehicles in the airspace. Therefore, the ability to avoid moving obstacles becomes a necessity for Unmanned Aerial Vehicles. Towards enabling a UAV to autonomously sense and avoid moving obstacles, this thesis makes the following contributions. Initially, an image-based reactive motion planner is developed for a quadrotor to avoid a fast approaching obstacle. Furthermore, A Dubin's curve based geometry method is developed as a global path planner for a fixed-wing UAV to avoid collisions with aircraft. The image-based method is unable to produce an optimal path and the geometry method uses a simplified UAV model. To compensate these two disadvantages, a series of algorithms built upon the Closed-Loop Rapid Exploratory Random Tree are developed as global path planners to generate collision avoidance paths in real time. The algorithms are validated in Software-In-the-Loop (SITL) and Hardware-In-the-Loop (HIL) simulations using a fixed-wing UAV model and in real flight experiments using quadrotors. It is observed that the algorithm enables a UAV to avoid moving obstacles approaching to it with different directions and speeds.

  11. Grouping facilitates avoidance of parasites by fish

    PubMed Central

    2013-01-01

    Background Parasite distribution is often highly heterogeneous, and intensity of infection depends, among other things, on how well hosts can avoid areas with a high concentration of parasites. We studied the role of fish behaviour in avoiding microhabitats with a high infection risk using Oncorhynchus mykiss and cercariae of Diplostomum pseudospathaceum as a model. Spatial distribution of parasites in experimental tanks was highly heterogeneous. We hypothesized that fish in groups are better at recognizing a parasitized area and avoiding it than solitary fish. Methods Number of fish, either solitary or in groups of 5, was recorded in different compartments of a shuttle tank where fish could make a choice between areas with different risk of being infected. Intensity of infection was assessed and compared with the number of fish recorded in the compartment with parasites and level of fish motility. Results Both solitary fish and fish in groups avoided parasitized areas, but fish in groups avoided it more strongly and thus acquired significantly fewer parasites than solitary fish. Prevalence of infection among grouped and solitary fish was 66 and 92 %, respectively, with the mean abundance two times higher in the solitary fish. Between-individual variation in the number of parasites per fish was higher in the “groups” treatment (across all individuals) than in the “solitary” treatment. Avoidance behaviour was more efficient when fish were allowed to explore the experimental arena prior to parasite exposure. High motility of fish was shown to increase the acquisition of D. pseudospathaceum. Conclusion Fish in groups better avoided parasitized habitat, and acquired significantly fewer parasites than solitary fish. We suggest that fish in groups benefit from information about parasites gained from other members of a group. Grouping behaviour may be an efficient mechanism of parasite avoidance, together with individual behaviour and immune responses of fishes

  12. When Is Topic Avoidance Unsatisfying? Examining Moderators of the Association between Avoidance and Dissatisfaction

    ERIC Educational Resources Information Center

    Caughlin, John P.; Afifi, Tamara D.

    2004-01-01

    Despite theoretical arguments that avoiding certain topics can be functional, there is consistent evidence that avoiding topics tends to be associated with dissatisfying relationships. This disparity between theory and empirical findings suggests a need to understand better the connection between topic avoidance and relational dissatisfaction. The…

  13. Family Key to Helping Teens Avoid Obesity

    MedlinePlus

    ... 159681.html Family Key to Helping Teens Avoid Obesity Good relationship with parents, especially between fathers and ... develop healthy habits that may protect them against obesity, a new study suggests. The researchers also found ...

  14. Avoiding Anemia: Boost Your Red Blood Cells

    MedlinePlus

    ... link, please review our exit disclaimer . Subscribe Avoiding Anemia Boost Your Red Blood Cells If you’re ... and sluggish, you might have a condition called anemia. Anemia is a common blood disorder that many ...

  15. The challenges for scientists in avoiding plagiarism.

    PubMed

    Fisher, E R; Partin, K M

    2014-01-01

    Although it might seem to be a simple task for scientists to avoid plagiarism and thereby an allegation of research misconduct, assessment of trainees in the Responsible Conduct of Research and recent findings from the National Science Foundation Office of Inspector General regarding plagiarism suggests otherwise. Our experiences at a land-grant academic institution in assisting researchers in avoiding plagiarism are described. We provide evidence from a university-wide multi-disciplinary course that understanding how to avoid plagiarism in scientific writing is more difficult than it might appear, and that a failure to learn the rules of appropriate citation may cause dire consequences. We suggest that new strategies to provide training in avoiding plagiarism are required.

  16. When Should a Mother Avoid Breastfeeding?

    MedlinePlus

    ... Address What's this? Submit What's this? Submit Button Breastfeeding Information for Families Breastfeeding Hotline The HHS Office ... Tweet Share Compartir When should a mother avoid breastfeeding? Health professionals agree that human milk provides the ...

  17. Avoid the Consequences of High Blood Pressure

    MedlinePlus

    ... Tools & Resources Stroke More Avoid the Consequences of High Blood Pressure Infographic Updated:Jun 19,2014 View a downloadable version of this infographic High Blood Pressure • Home • About High Blood Pressure (HBP) • Why HBP ...

  18. Active Collision Avoidance for Planetary Landers

    NASA Technical Reports Server (NTRS)

    Rickman, Doug; Hannan, Mike; Srinivasan, Karthik

    2014-01-01

    Present day robotic missions to other planets require precise, a priori knowledge of the terrain to pre-determine a landing spot that is safe. Landing sites can be miles from the mission objective, or, mission objectives may be tailored to suit landing sites. Future robotic exploration missions should be capable of autonomously identifying a safe landing target within a specified target area selected by mission requirements. Such autonomous landing sites must (1) 'see' the surface, (2) identify a target, and (3) land the vehicle. Recent advances in radar technology have resulted in small, lightweight, low power radars that are used for collision avoidance and cruise control systems in automobiles. Such radar systems can be adapted for use as active hazard avoidance systems for planetary landers. The focus of this CIF proposal is to leverage earlier work on collision avoidance systems for MSFC's Mighty Eagle lander and evaluate the use of automotive radar systems for collision avoidance in planetary landers.

  19. Singularity avoidance and time in quantum gravity

    SciTech Connect

    Kreienbuehl, Andreas

    2009-06-15

    We consider the quantization of a Friedmann-Robertson-Walker universe. We derive a reduced square root Hamiltonian by choosing the scale factor as time variable and quantize the theory using Pauli matrices a la Dirac. From the resulting spinor equation we show that there is no semiclassical wave packet that avoids the big bang singularity. Our work raises the question concerning the relationship between the choice of time and singularity avoidance.

  20. Do approach-avoidance actions create attitudes?

    PubMed

    Centerbar, David B; Clore, Gerald L

    2006-01-01

    Do approach-avoidance actions create attitudes? Prior influential studies suggested that rudimentary attitudes could be established by simply pairing novel stimuli (Chinese ideographs) with arm flexion (approach) or arm extension (avoidance). In three experiments, we found that approach-avoidance actions alone were insufficient to account for such effects. Instead, we found that these affective influences resulted from the interaction of these actions with a priori differences in stimulus valence. Thus, with negative stimuli, the effect of extension on attitude was more positive than the effect of flexion. Experiment 2 demonstrated that the affect from motivationally compatible or incompatible action can also influence task evaluations. A final experiment, using Chinese ideographs from the original studies, confirmed these findings. Both approach and avoidance actions led to more positive evaluations of the ideographs when the actions were motivationally compatible with the prior valence of the ideographs. The attitudinal impact of approach-avoidance action thus reflects its situated meaning, which depends on the valence of stimuli being approached or avoided.

  1. Beyond negligence: avoidability and medical injury compensation.

    PubMed

    Kachalia, Allen B; Mello, Michelle M; Brennan, Troyen A; Studdert, David M

    2008-01-01

    Disenchantment with the tort system and negligence standard in the United States is fueling interest in alternate compensation systems for medical injury. One possibility is experimentation with administrative "health courts," through which specialized adjudicators would utilize neutral experts to render compensability determinations. Compensation would be based not on negligence, but rather on a broader avoidable medical injury (avoidability) standard. Although considerable interest in health courts exists, stakeholders frequently express uncertainty about the meaning and operation of an avoidability standard. Three nations-Sweden, Denmark, and New Zealand-have long operated administrative schemes. We conducted interviews with administrators and stakeholders in these systems. Our goal was to garner lessons on how to operate a health court, and specifically, how to develop and apply alternate compensation criteria such as avoidability. This article reports our findings on the origins and operations of the systems, the evolution of their compensation criteria, and how these criteria are actually applied. We found that all three systems had their primary genesis in ensuring compensation for the injured, as opposed to sanctioning providers. All have abandoned the negligence standard. The Nordic systems use an avoidability standard, principally defined as injury that would not occur in the hands of the best practitioner. Their experience demonstrates that this definition is feasible to apply. New Zealand's recent move to a no-fault system sheds light on the benefits and drawbacks of a variety of compensation standards. Key lessons for successfully applying an alternate standard, such as avoidability, include a strict adherence to national precedent, the use of neutral and experienced experts, and a block on routine transfer of information from compensation investigations to disciplinary authorities. Importantly, all three nations are harnessing their systems' power to

  2. Beyond negligence: avoidability and medical injury compensation.

    PubMed

    Kachalia, Allen B; Mello, Michelle M; Brennan, Troyen A; Studdert, David M

    2008-01-01

    Disenchantment with the tort system and negligence standard in the United States is fueling interest in alternate compensation systems for medical injury. One possibility is experimentation with administrative "health courts," through which specialized adjudicators would utilize neutral experts to render compensability determinations. Compensation would be based not on negligence, but rather on a broader avoidable medical injury (avoidability) standard. Although considerable interest in health courts exists, stakeholders frequently express uncertainty about the meaning and operation of an avoidability standard. Three nations-Sweden, Denmark, and New Zealand-have long operated administrative schemes. We conducted interviews with administrators and stakeholders in these systems. Our goal was to garner lessons on how to operate a health court, and specifically, how to develop and apply alternate compensation criteria such as avoidability. This article reports our findings on the origins and operations of the systems, the evolution of their compensation criteria, and how these criteria are actually applied. We found that all three systems had their primary genesis in ensuring compensation for the injured, as opposed to sanctioning providers. All have abandoned the negligence standard. The Nordic systems use an avoidability standard, principally defined as injury that would not occur in the hands of the best practitioner. Their experience demonstrates that this definition is feasible to apply. New Zealand's recent move to a no-fault system sheds light on the benefits and drawbacks of a variety of compensation standards. Key lessons for successfully applying an alternate standard, such as avoidability, include a strict adherence to national precedent, the use of neutral and experienced experts, and a block on routine transfer of information from compensation investigations to disciplinary authorities. Importantly, all three nations are harnessing their systems' power to

  3. Key conclusions from AVOID Work Stream One

    NASA Astrophysics Data System (ADS)

    Warren, Rachel

    2010-05-01

    AVOID work stream (WS1)one has produced emission scenarios that simulate potential future global emission pathways for greenhouse gases during the 21st century. The study explored the influence of three key features of such pathways: (1) the year in which emissions peak globally, (2) the rate of emission reduction, and (3) the minimum level to which emissions are eventually reduced. It examined the resultant climate change, climate change impacts and economic implications using computer simulations. Avoided impacts, carbon taxes and GDP change increase throughout the 21st century in the models. AVOID-WS1 showed that in the absence of climate policy it is very likely that global mean temperatures would exceed 3 degrees and there are evens chances that the temperature would rise by 4 degrees relative to pre-industrial times. Scenarios that peak emissions in 2016 were more effective at constraining temperatures to below 3 degrees than those that peaked in 2030: one ‘2016' scenario achieved a probability of 45% of avoiding breaching of a 2 degree threshold. Scenarios peaking in 2030 were inconsistent with constraining temperatures to below 2 degrees. Correspondingly, scenarios that peak in 2030 are more effective at avoiding climate impacts than scenarios that peak in 2016, for all sectors that we studied. Hence the date at which emissions peak is more important than the rate of subsequent emissions reduction in determining the avoided impacts. Avoided impacts increase with time, being negligible in the 2030s, significant by the 2050s and large by the 2080s. Finally, the choice of GCM influences the magnitude of the avoided impacts strongly, so that the uncertainties in our estimates of avoided impacts for each scenario are larger than the difference between the scenarios. Our economic analysis is based on models which differ greatly in the assumptions that they make, but generally show that the date at which emissions peak is a stronger driver of induced GDP changes

  4. Rape avoidance behavior among Slovak women.

    PubMed

    Prokop, Pavol

    2013-05-28

    Rape has been a recurrent adaptive problem for many species, including humans. Rape is costly to women in terms of disease transmission, partner abandonment, and unwanted pregnancy (among other costs). Therefore, behavioral strategies which allow women to avoid coercive men may have been favored by selection. In line with this evolutionary reasoning, the current research documented that physically stronger women and those in a committed romantic relationship reported more rape avoidance behavior. In addition, virgin women tended to perform more rape avoidance behavior compared with their non-virgin counterparts. Women with high conception risk perceived themselves as physically stronger, which may protect them against a potential rapist. Fear of unwanted pregnancy from rape decreased as age increased, reflecting higher fertility among younger participants. However, older women reported more rape avoidance behavior, which contradicts evolutionary predictions. The results provide some support for evolutionary hypotheses of rape avoidance behavior which suggest that woman's perception of rape is influenced by parental investment and perceived physical condition.

  5. Avoidance of Phycomyces in a controlled environment.

    PubMed Central

    Meyer, P W; Matus, I J; Berg, H C

    1987-01-01

    The sporangiophore of the fungus Phycomyces bends away from nearby objects without ever touching them. It has been thought that these objects act as aerodynamic obstacles that damp random winds, thereby generating asymmetric distributions of a growth-promoting gas emitted by the growth zone. In the interest of testing this hypothesis, we studied avoidance in an environmental chamber in which convection was suppressed by a shallow thermal gradient. We also controlled pressure, temperature, and relative humidity of the air, electrostatic charge, and ambient light. A protocol was established that yielded avoidance rates constant from sporangiophore to sporangiophore to within +/- 10%. We found that avoidance occurred at normal rates in the complete absence of random winds. The rates were smaller at 100% than at lower values of relative humidity, but not by much. Remarkably, at a distance as great as 0.5 mm, avoidance from a 30-micron diam glass fiber (aligned parallel to the sporangiophore) was about the same as that from a planar glass sheet. However, the rate for the fiber fell more rapidly with distance. The rate for the sheet remained nearly constant out to approximately 4 mm. We conclude that avoidance depends either on adsorption by the barrier of a growth-inhibiting substance or emission by the barrier of a growth-promoting substance; it cannot occur by passive reflection. Models that can explain these effects are analyzed in the Appendix. PMID:3567313

  6. Enemy avoidance task: a novel behavioral paradigm for assessing spatial avoidance of a moving subject.

    PubMed

    Telensky, Petr; Svoboda, Jan; Pastalkova, Eva; Blahna, Karel; Bures, Jan; Stuchlik, Ales

    2009-05-30

    Navigation with respect to moving goals represents a useful ability in the everyday life of animals. We have developed a novel behavioral paradigm, "enemy avoidance task", in which a laboratory rat (subject) was trained to avoid another rat (enemy), while searching for small pasta pellets dispensed onto an experimental arena. Whenever the distance between the two animals was smaller than 25 cm, the subject was given a mild electric footshock. The results have shown that rats are capable of avoiding another rat while exploring an environment. Therefore, the enemy avoidance task can be used in electrophysiological, lesion or neuropharmacological studies exploring neuronal substrate coding for egocentric and allocentric positions of an observed animal.

  7. Is Avoiding an Aversive Outcome Rewarding? Neural Substrates of Avoidance Learning in the Human Brain

    PubMed Central

    Kim, Hackjin; Shimojo, Shinsuke

    2006-01-01

    Avoidance learning poses a challenge for reinforcement-based theories of instrumental conditioning, because once an aversive outcome is successfully avoided an individual may no longer experience extrinsic reinforcement for their behavior. One possible account for this is to propose that avoiding an aversive outcome is in itself a reward, and thus avoidance behavior is positively reinforced on each trial when the aversive outcome is successfully avoided. In the present study we aimed to test this possibility by determining whether avoidance of an aversive outcome recruits the same neural circuitry as that elicited by a reward itself. We scanned 16 human participants with functional MRI while they performed an instrumental choice task, in which on each trial they chose from one of two actions in order to either win money or else avoid losing money. Neural activity in a region previously implicated in encoding stimulus reward value, the medial orbitofrontal cortex, was found to increase, not only following receipt of reward, but also following successful avoidance of an aversive outcome. This neural signal may itself act as an intrinsic reward, thereby serving to reinforce actions during instrumental avoidance. PMID:16802856

  8. A collision avoidance system for workpiece protection

    SciTech Connect

    Schmitt, D.J.; Weber, T.M.; Novak, J.L.; Maslakowski, J.E.

    1995-04-01

    This paper describes an application of Sandia`s non-contact capacitive sensing technology for collision avoidance during the manufacturing of rocket engine thrust chambers. The collision avoidance system consists of an octagon shaped collar with a capacitive proximity sensor mounted on each face. The sensors produced electric fields which extend several inches from the face of the collar and detect potential collisions between the robot and the workpiece. A signal conditioning system processes the sensor output and provides varying voltage signals to the robot controller for stopping the robot.

  9. Autonomous Landing and Hazard Avoidance Technology (ALHAT)

    NASA Technical Reports Server (NTRS)

    Epp, Chirold

    2007-01-01

    This viewgraph presentation reviews the work towards technology that will result in an autonomous landing on the lunar surface, that will avoid the hazards of lunar landing. In October 2005, the Exploration Systems Mission Directorate at NASA Headquarters assigned the development of new technologies to support the return to the moon. One of these was Autonomous Precision Landing and Hazard Detection and Avoidance Technology now known as ALHAT ALHAT is a lunar descent and landing GNC technology development project led by Johnson Space Center (JSC) with team members from Langley Research Center (LaRC), Jet Propulsion Laboratory (JPL), Draper Laboratories (CSDL) and the Applied Physics Laboratory (APL)

  10. Telerobotics with whole arm collision avoidance

    SciTech Connect

    Wilhelmsen, K.; Strenn, S.

    1993-09-01

    The complexity of teleorbotic operations in a cluttered environment is exacerbated by the need to present collision information to the operator in an understandable fashion. In addition to preventing movements which will cause collisions, a system providing some form of virtual force reflection (VFR) is desirable. With this goal in mind, Lawrence Livermore National Laboratory (LLNL) has installed a kinematically master/slave system and developed a whole arm collision avoidance system which interacts directly with the telerobotic controller. LLNL has also provided a structure to allow for automated upgrades of workcell models and provide collision avoidance even in a dynamically changing workcell.

  11. Integrated Collision Avoidance System for Air Vehicle

    NASA Technical Reports Server (NTRS)

    Lin, Ching-Fang (Inventor)

    2013-01-01

    Collision with ground/water/terrain and midair obstacles is one of the common causes of severe aircraft accidents. The various data from the coremicro AHRS/INS/GPS Integration Unit, terrain data base, and object detection sensors are processed to produce collision warning audio/visual messages and collision detection and avoidance of terrain and obstacles through generation of guidance commands in a closed-loop system. The vision sensors provide more information for the Integrated System, such as, terrain recognition and ranging of terrain and obstacles, which plays an important role to the improvement of the Integrated Collision Avoidance System.

  12. Collision avoidance for CTV: Requirements and capabilities

    NASA Astrophysics Data System (ADS)

    Nosek, Thomas; Rourke, Kenneth

    Collision avoidance must be ensured during Cargo Transfer Vehicle (CTV) operations near the space station. The design of the Collision Avoidance Maneuver (CAM) will involve analysis of CTV failure modes during rendezvous and proximity operations as well as analysis of possible problems external to the CTV, but that would require CTV to execute a CAM. In considering the requirements and design of the CAM for the CTV, the CAM design for the Orbital Maneuvering Vehicle (OMV) is a useful reference point from which some lessons can be learned and many CTV design options can be set forth.

  13. Collision avoidance for CTV: Requirements and capabilities

    NASA Technical Reports Server (NTRS)

    Nosek, Thomas; Rourke, Kenneth

    1991-01-01

    Collision avoidance must be ensured during Cargo Transfer Vehicle (CTV) operations near the space station. The design of the Collision Avoidance Maneuver (CAM) will involve analysis of CTV failure modes during rendezvous and proximity operations as well as analysis of possible problems external to the CTV, but that would require CTV to execute a CAM. In considering the requirements and design of the CAM for the CTV, the CAM design for the Orbital Maneuvering Vehicle (OMV) is a useful reference point from which some lessons can be learned and many CTV design options can be set forth.

  14. Women Coping with a Partner's Sexual Avoidance.

    ERIC Educational Resources Information Center

    Renshaw, Domeena C.

    2001-01-01

    Discusses the complexities of sexual avoidance, or Hypoactive Sexual Desire (HSD), a previously neglected aspect of a couple's relationship. Suggests that learning from a therapist to accept and enjoy other forms of sexual exchange can open up new horizons of physical and emotional intimacy. (Contains 17 references.) (GCP)

  15. Doppler micro sense and avoid radar

    NASA Astrophysics Data System (ADS)

    Gorwara, Ashok; Molchanov, Pavlo; Asmolova, Olga

    2015-10-01

    There is a need for small Sense and Avoid (SAA) systems for small and micro Unmanned Aerial Systems (UAS) to avoid collisions with obstacles and other aircraft. The proposed SAA systems will give drones the ability to "see" close up and give them the agility to maneuver through tight areas. Doppler radar is proposed for use in this sense and avoid system because in contrast to optical or infrared (IR) systems Doppler can work in more harsh conditions such as at dusk, and in rain and snow. And in contrast to ultrasound based systems, Doppler can better sense small sized obstacles such as wires and it can provide a sensing range from a few inches to several miles. An SAA systems comprised of Doppler radar modules and an array of directional antennas that are distributed around the perimeter of the drone can cover the entire sky. These modules are designed so that they can provide the direction to the obstacle and simultaneously generate an alarm signal if the obstacle enters within the SAA system's adjustable "Protection Border". The alarm signal alerts the drone's autopilot to automatically initiate an avoidance maneuver. A series of Doppler radar modules with different ranges, angles of view and transmitting power have been designed for drones of different sizes and applications. The proposed Doppler radar micro SAA system has simple circuitry, works from a 5 volt source and has low power consumption. It is light weight, inexpensive and it can be used for a variety of small unmanned aircraft.

  16. An Examination of Avoided Costs in Utah

    SciTech Connect

    Bolinger, Mark; Wiser, Ryan

    2005-01-07

    The Utah Wind Working Group (UWWG) believes there are currently opportunities to encourage wind power development in the state by seeking changes to the avoided cost tariff paid to qualifying facilities (QFs). These opportunities have arisen as a result of a recent renegotiation of Pacificorp's Schedule 37 tariff for wind QFs under 3 MW, as well as an ongoing examination of Pacificorp's Schedule 38 tariff for wind QFs larger than 3 MW. It is expected that decisions made regarding Schedule 38 will also impact Schedule 37. Through the Laboratory Technical Assistance Program (Lab TAP), the UWWG has requested (through the Utah Energy Office) that LBNL provide technical assistance in determining whether an alternative method of calculating avoided costs that has been officially adopted in Idaho would lead to higher QF payments in Utah, and to discuss the pros and cons of this method relative to the methodology recently adopted under Schedule 37 in Utah. To accomplish this scope of work, I begin by summarizing the current method of calculating avoided costs in Utah (per Schedule 37) and Idaho (the ''surrogate avoided resource'' or SAR method). I then compare the two methods both qualitatively and quantitatively. Next I present Pacificorp's four main objections to the use of the SAR method, and discuss the reasonableness of each objection. Finally, I conclude with a few other potential considerations that might add value to wind QFs in Utah.

  17. Social Work Education and Avoidable Ignorance

    ERIC Educational Resources Information Center

    Gambrill, Eileen

    2014-01-01

    The quality of professional education affects the quality of services offered to clients. Examples of avoidable ignorance that dilute the quality of education social workers receive are suggested, indicating that we have not been honest and energetic brokers of knowledge and ignorance. Related reasons are suggested, including a reluctance to take…

  18. Learn to Avoid or Overcome Leadership Obstacles

    ERIC Educational Resources Information Center

    D'Auria, John

    2015-01-01

    Leadership is increasingly recognized as an important factor in moving schools forward, yet we have been relatively random in how we prepare and support them. Four obstacles often block or diminish their effectiveness. Avoiding or overcoming each of these requires an underlying set of skills and knowledge that we believe can be learned and…

  19. Perspectives in avoidance-preference bioassays

    SciTech Connect

    Steele, C.W.; Taylor, D.H.; Strickler-Shaw, S.

    1996-12-31

    Although behavioral endpoints are used in hazard assessment, establishment of water quality criteria and assessment of a contaminant`s hazard to aquatic life rely primarily on standard acute and chronic toxicity tests. Sublethal effects of pollutants should, however, be of major concern because more organisms experience sublethal rather than acutely or chronically lethal exposures of contaminants. The avoidance-preference approach to behavioral bioassays is very useful in screening pollutants for which the mechanisms of perception or response are largely unknown. The underlying philosophy of these studies is that an animal which perceives a chemical can be attracted or repulsed by it. No response is frequently assumed to indicate lack of perception. All three responses have broad ecological implications. The authors discuss the conditions required for performing avoidance-preference bioassays, as well as their sensitivities, advantages, and limitations. In this regard, a comparative approach is used in examining the results of avoidance-preference bioassays with zebrafish in two different apparatuses. Finally, they compare the results of avoidance-preference studies with other measures of the behavioral toxicity of lead to tadpoles.

  20. Digital-Difference Processing For Collision Avoidance.

    NASA Technical Reports Server (NTRS)

    Shores, Paul; Lichtenberg, Chris; Kobayashi, Herbert S.; Cunningham, Allen R.

    1988-01-01

    Digital system for automotive crash avoidance measures and displays difference in frequency between two sinusoidal input signals of slightly different frequencies. Designed for use with Doppler radars. Characterized as digital mixer coupled to frequency counter measuring difference frequency in mixer output. Technique determines target path mathematically. Used for tracking cars, missiles, bullets, baseballs, and other fast-moving objects.

  1. Organising European technical documentation to avoid duplication.

    PubMed

    Donawa, Maria

    2006-04-01

    The development of comprehensive accurate and well-organised technical documentation that demonstrates compliance with regulatory requirements is a resource-intensive, but critically important activity for medical device manufacturers. This article discusses guidance documents and method of organising technical documentation that may help avoid costly and time-consuming duplication.

  2. The employment interview. Avoiding discriminatory questioning.

    PubMed

    Poteet, G W

    1984-04-01

    The potential for legal action against health care institutions for unlawful preemployment interviews has never been greater. This article shows how to avoid discriminatory questions when interviewing job applicants in the health care setting. The author presents guidelines for helping nursing administrators obtain necessary information without violating the basic rights of the potential employee.

  3. Disgust as a Disease-Avoidance Mechanism

    ERIC Educational Resources Information Center

    Oaten, Megan; Stevenson, Richard J.; Case, Trevor I.

    2009-01-01

    Many researchers have claimed that the emotion of disgust functions to protect us from disease. Although there have been several discussions of this hypothesis, none have yet reviewed the evidence in its entirety. The authors derive 14 hypotheses from a disease-avoidance account and evaluate the evidence for each, drawing upon research on pathogen…

  4. Organising European technical documentation to avoid duplication.

    PubMed

    Donawa, Maria

    2006-04-01

    The development of comprehensive accurate and well-organised technical documentation that demonstrates compliance with regulatory requirements is a resource-intensive, but critically important activity for medical device manufacturers. This article discusses guidance documents and method of organising technical documentation that may help avoid costly and time-consuming duplication. PMID:16736662

  5. Pathogen evolution under host avoidance plasticity.

    PubMed

    McLeod, David V; Day, Troy

    2015-09-01

    Host resistance consists of defences that limit pathogen burden, and can be classified as either adaptations targeting recovery from infection or those focused upon infection avoidance. Conventional theory treats avoidance as a fixed strategy which does not vary from one interaction to the next. However, there is increasing empirical evidence that many avoidance strategies are triggered by external stimuli, and thus should be treated as phenotypically plastic responses. Here, we consider the implications of avoidance plasticity for host-pathogen coevolution. We uncover a number of predictions challenging current theory. First, in the absence of pathogen trade-offs, plasticity can restrain pathogen evolution; moreover, the pathogen exploits conditions in which the host would otherwise invest less in resistance, causing resistance escalation. Second, when transmission trades off with pathogen-induced mortality, plasticity encourages avirulence, resulting in a superior fitness outcome for both host and pathogen. Third, plasticity ensures the sterilizing effect of pathogens has consequences for pathogen evolution. When pathogens castrate hosts, selection forces them to minimize mortality virulence; moreover, when transmission trades off with sterility alone, resistance plasticity is sufficient to prevent pathogens from evolving to fully castrate. PMID:26336170

  6. Freeze tolerance and avoidance in plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cold acclimation is a multigenic, quantitative trait that involves biochemical and structural changes that effect the physiology of a plant. Mechanisms associated with freeze tolerance or freeze avoidance develop and are lost on an annual cycle. When conducting studies to characterize and determin...

  7. Pathogen evolution under host avoidance plasticity.

    PubMed

    McLeod, David V; Day, Troy

    2015-09-01

    Host resistance consists of defences that limit pathogen burden, and can be classified as either adaptations targeting recovery from infection or those focused upon infection avoidance. Conventional theory treats avoidance as a fixed strategy which does not vary from one interaction to the next. However, there is increasing empirical evidence that many avoidance strategies are triggered by external stimuli, and thus should be treated as phenotypically plastic responses. Here, we consider the implications of avoidance plasticity for host-pathogen coevolution. We uncover a number of predictions challenging current theory. First, in the absence of pathogen trade-offs, plasticity can restrain pathogen evolution; moreover, the pathogen exploits conditions in which the host would otherwise invest less in resistance, causing resistance escalation. Second, when transmission trades off with pathogen-induced mortality, plasticity encourages avirulence, resulting in a superior fitness outcome for both host and pathogen. Third, plasticity ensures the sterilizing effect of pathogens has consequences for pathogen evolution. When pathogens castrate hosts, selection forces them to minimize mortality virulence; moreover, when transmission trades off with sterility alone, resistance plasticity is sufficient to prevent pathogens from evolving to fully castrate.

  8. Teaching Preschool Children to Avoid Poison Hazards

    ERIC Educational Resources Information Center

    Dancho, Kelly A.; Thompson, Rachel H.; Rhoades, Melissa M.

    2008-01-01

    We evaluated the effectiveness of group safety training and in situ feedback and response interruption to teach preschool children to avoid consuming potentially hazardous substances. Three children ingested ambiguous substances during a baited baseline assessment condition and continued to ingest these substances following group safety training.…

  9. Pathological Demand Avoidance: Exploring the Behavioural Profile

    ERIC Educational Resources Information Center

    O'Nions, Elizabeth; Viding, Essi; Greven, Corina U; Ronald, Angelica; Happé, Francesca

    2014-01-01

    "Pathological Demand Avoidance" is a term increasingly used by practitioners in the United Kingdom. It was coined to describe a profile of obsessive resistance to everyday demands and requests, with a tendency to resort to "socially manipulative" behaviour, including outrageous or embarrassing acts. Pathological demand…

  10. Pathogen evolution under host avoidance plasticity

    PubMed Central

    McLeod, David V.; Day, Troy

    2015-01-01

    Host resistance consists of defences that limit pathogen burden, and can be classified as either adaptations targeting recovery from infection or those focused upon infection avoidance. Conventional theory treats avoidance as a fixed strategy which does not vary from one interaction to the next. However, there is increasing empirical evidence that many avoidance strategies are triggered by external stimuli, and thus should be treated as phenotypically plastic responses. Here, we consider the implications of avoidance plasticity for host–pathogen coevolution. We uncover a number of predictions challenging current theory. First, in the absence of pathogen trade-offs, plasticity can restrain pathogen evolution; moreover, the pathogen exploits conditions in which the host would otherwise invest less in resistance, causing resistance escalation. Second, when transmission trades off with pathogen-induced mortality, plasticity encourages avirulence, resulting in a superior fitness outcome for both host and pathogen. Third, plasticity ensures the sterilizing effect of pathogens has consequences for pathogen evolution. When pathogens castrate hosts, selection forces them to minimize mortality virulence; moreover, when transmission trades off with sterility alone, resistance plasticity is sufficient to prevent pathogens from evolving to fully castrate. PMID:26336170

  11. The Role of Risk Avoidance in Anxiety

    ERIC Educational Resources Information Center

    Maner, Jon K.; Schmidt, Norman B.

    2006-01-01

    Various forms of disinhibitory psychopathology (e.g., substance use disorder) are characterized by a tendency to make overly risky decisions. The current paper reports on data suggesting that, in contrast, anxiety is associated with an exaggerated tendency to engage in risk-avoidant decision making. In a nonclinical sample of university students,…

  12. Affordable MMW aircraft collision avoidance system

    NASA Astrophysics Data System (ADS)

    Almsted, Larry D.; Becker, Robert C.; Zelenka, Richard E.

    1997-06-01

    Collision avoidance is of concern to all aircraft, requiring the detection and identification of hazardous terrain or obstacles in sufficient time for clearance maneuvers. The collision avoidance requirement is even more demanding for helicopters, as their unique capabilities result in extensive operations at low-altitude, near to terrain and other hazardous obstacles. TO augment the pilot's visual collision avoidance abilities, some aircraft are equipped with 'enhanced-vision' systems or terrain collision warning systems. Enhanced-vision systems are typically very large and costly systems that are not very covert and are also difficult to install in a helicopter. The display is typically raw images from infrared or radar sensors, and can require a high degree of pilot interpretation and attention. Terrain collision warning system that rely on stored terrain maps are often of low resolution and accuracy and do not represent hazards to the aircraft placed after map sampling. Such hazards could include aircraft parked on runway, man- made towers or buildings and hills. In this paper, a low cost dual-function scanning pencil-beam, millimeter-wave radar forward sensor is used to determine whether an aircraft's flight path is clear of obstructions. Due to the limited space and weight budget in helicopters, the system is a dual function system that is substituted in place of the existing radar altimeter. The system combines a 35 GHz forward looking obstacle avoidance radar and a 4.3 GHz radar altimeter. The forward looking 35 GHz 3D radar's returns are used to construct a terrain and obstruction database surrounding an aircraft, which is presented to the pilot as a synthetic perspective display. The 35 GHz forward looking radar and the associated display was evaluated in a joint NASA Honeywell flight test program in 1996. The tests were conducted on a NASA/Army test helicopter. The test program clearly demonstrated the systems potential usefulness for collision avoidance.

  13. Bursting Neurons and Ultrasound Avoidance in Crickets

    PubMed Central

    Marsat, Gary; Pollack, Gerald S.

    2012-01-01

    Decision making in invertebrates often relies on simple neural circuits composed of only a few identified neurons. The relative simplicity of these circuits makes it possible to identify the key computation and neural properties underlying decisions. In this review, we summarize recent research on the neural basis of ultrasound avoidance in crickets, a response that allows escape from echolocating bats. The key neural property shaping behavioral output is high-frequency bursting of an identified interneuron, AN2, which carries information about ultrasound stimuli from receptor neurons to the brain. AN2’s spike train consists of clusters of spikes – bursts – that may be interspersed with isolated, non-burst spikes. AN2 firing is necessary and sufficient to trigger avoidance steering but only high-rate firing, such as occurs in bursts, evokes this response. AN2 bursts are therefore at the core of the computation involved in deciding whether or not to steer away from ultrasound. Bursts in AN2 are triggered by synaptic input from nearly synchronous bursts in ultrasound receptors. Thus the population response at the very first stage of sensory processing – the auditory receptor – already differentiates the features of the stimulus that will trigger a behavioral response from those that will not. Adaptation, both intrinsic to AN2 and within ultrasound receptors, scales the burst-generating features according to the stimulus statistics, thus filtering out background noise and ensuring that bursts occur selectively in response to salient peaks in ultrasound intensity. Furthermore AN2’s sensitivity to ultrasound varies adaptively with predation pressure, through both developmental and evolutionary mechanisms. We discuss how this key relationship between bursting and the triggering of avoidance behavior is also observed in other invertebrate systems such as the avoidance of looming visual stimuli in locusts or heat avoidance in beetles. PMID:22783158

  14. Bursting neurons and ultrasound avoidance in crickets.

    PubMed

    Marsat, Gary; Pollack, Gerald S

    2012-01-01

    Decision making in invertebrates often relies on simple neural circuits composed of only a few identified neurons. The relative simplicity of these circuits makes it possible to identify the key computation and neural properties underlying decisions. In this review, we summarize recent research on the neural basis of ultrasound avoidance in crickets, a response that allows escape from echolocating bats. The key neural property shaping behavioral output is high-frequency bursting of an identified interneuron, AN2, which carries information about ultrasound stimuli from receptor neurons to the brain. AN2's spike train consists of clusters of spikes - bursts - that may be interspersed with isolated, non-burst spikes. AN2 firing is necessary and sufficient to trigger avoidance steering but only high-rate firing, such as occurs in bursts, evokes this response. AN2 bursts are therefore at the core of the computation involved in deciding whether or not to steer away from ultrasound. Bursts in AN2 are triggered by synaptic input from nearly synchronous bursts in ultrasound receptors. Thus the population response at the very first stage of sensory processing - the auditory receptor - already differentiates the features of the stimulus that will trigger a behavioral response from those that will not. Adaptation, both intrinsic to AN2 and within ultrasound receptors, scales the burst-generating features according to the stimulus statistics, thus filtering out background noise and ensuring that bursts occur selectively in response to salient peaks in ultrasound intensity. Furthermore AN2's sensitivity to ultrasound varies adaptively with predation pressure, through both developmental and evolutionary mechanisms. We discuss how this key relationship between bursting and the triggering of avoidance behavior is also observed in other invertebrate systems such as the avoidance of looming visual stimuli in locusts or heat avoidance in beetles.

  15. GEO Collision Avoidance using a Service Vehicle

    NASA Astrophysics Data System (ADS)

    Duncan, M.; Concha, M.

    2013-09-01

    Space Situational Awareness (SSA) is defined as the knowledge and characterization of all aspects of space. SSA is now a fundamental and critical component of space operations. The increased dependence on our space assets has in turn lead to a greater need for accurate, near real-time knowledge of all space activities. Key areas of SSA include improved tracking of small objects, determining the intent of maneuvering spacecraft, identifying all potential high risk conjunction events, and leveraging non-traditional sensors in support of the SSA mission. As the size of the space object population grows, the number of collision avoidance maneuvers grows. Moreover, as the SSA mission evolves to near real-time assessment and analysis, the need for new, more sophisticated collision avoidance methods are required. This paper demonstrates the utility of using a service vehicle to perform collision avoidance maneuver for GEO satellites. We present the planning and execution details required to successfully execute a maneuver; given the traditional conjunction analysis timelines. Various operational constraints and scenarios are considered as part of the demonstration. Development of the collision avoidance strategy is created using SpaceNav's collision risk management tool suite. This study aims to determine the agility required of any proposed servicing capability to provide collision avoidance within traditional conjunction analysis and collision avoidance operations timelines. Key trades and analysis items are given to be: 1. How do we fuse the spacecraft state data with the tracking data collected from the proximity sensor that resides on the servicing spacecraft? 2. How do we deal with the possibility that the collision threat for the event may change as the time to close approach is reduced? 3. Perform trade space of maneuver/thrust time versus achievable change in the spacecraft's orbit. 4. Perform trade space of proximity of service vehicle to spacecraft versus time

  16. Converging evidence of social avoidant behavior in schizophrenia from two approach-avoidance tasks.

    PubMed

    de la Asuncion, Javier; Docx, Lise; Sabbe, Bernard; Morrens, Manuel; de Bruijn, Ellen R A

    2015-10-01

    Many people with schizophrenia suffer from social impairments characterized by active social avoidance, which is related to social phobia common in schizophrenia, while motivational impairments can also result in passive social withdrawal. Although social avoidance is frequently reported in this population, this is the first study to directly compare approach-avoidance tendencies in schizophrenia patients (N = 37) and healthy controls (N = 29). Participants performed two tasks: a computerized approach-avoidance task (AAT) to assess response tendencies toward images of happy and angry faces with direct or averted gaze and a one-to-one personal space test (PST) to gauge more naturalistic approach-avoidance behaviors toward a real person bearing a neutral expression. The AAT results showed that both groups showed faster avoidance responses to angry faces and faster approach responses to happy faces with a direct gaze. Happy faces with averted gaze, however, resulted in faster avoidance responses in the patient group only. On the PST, the patients approached the experimenter less than healthy controls did. This measure of interpersonal distance was positively related to positive symptom severity. Delusions of reference and increased sensitivity to social rejection may explain the patients' avoidance tendencies in response to pictures of happy faces with averted gaze and in the presence of an actual person. The current findings demonstrate the importance of others adopting positive and unambiguous attitudes when interacting with schizophrenia patients to minimize behavioral avoidance patterns, which is particularly relevant for relatives and clinicians whose interactions with the patients are crucial to facilitating treatment and promoting healthy social relationships.

  17. Converging evidence of social avoidant behavior in schizophrenia from two approach-avoidance tasks.

    PubMed

    de la Asuncion, Javier; Docx, Lise; Sabbe, Bernard; Morrens, Manuel; de Bruijn, Ellen R A

    2015-10-01

    Many people with schizophrenia suffer from social impairments characterized by active social avoidance, which is related to social phobia common in schizophrenia, while motivational impairments can also result in passive social withdrawal. Although social avoidance is frequently reported in this population, this is the first study to directly compare approach-avoidance tendencies in schizophrenia patients (N = 37) and healthy controls (N = 29). Participants performed two tasks: a computerized approach-avoidance task (AAT) to assess response tendencies toward images of happy and angry faces with direct or averted gaze and a one-to-one personal space test (PST) to gauge more naturalistic approach-avoidance behaviors toward a real person bearing a neutral expression. The AAT results showed that both groups showed faster avoidance responses to angry faces and faster approach responses to happy faces with a direct gaze. Happy faces with averted gaze, however, resulted in faster avoidance responses in the patient group only. On the PST, the patients approached the experimenter less than healthy controls did. This measure of interpersonal distance was positively related to positive symptom severity. Delusions of reference and increased sensitivity to social rejection may explain the patients' avoidance tendencies in response to pictures of happy faces with averted gaze and in the presence of an actual person. The current findings demonstrate the importance of others adopting positive and unambiguous attitudes when interacting with schizophrenia patients to minimize behavioral avoidance patterns, which is particularly relevant for relatives and clinicians whose interactions with the patients are crucial to facilitating treatment and promoting healthy social relationships. PMID:26343605

  18. The Feasibility of Avoiding Future Climate Impacts: Results from the AVOID Programmes

    NASA Astrophysics Data System (ADS)

    Lowe, J. A.; Warren, R.; Arnell, N.; Buckle, S.

    2014-12-01

    The AVOID programme and its successor, AVOID2, have focused on answering three core questions: how do we characterise potentially dangerous climate change and impacts, which emissions pathways can avoid at least some of these impacts, and how feasible are the future reductions needed to significantly deviate from a business-as-usual future emissions pathway. The first AVOID project succeeded in providing the UK Government with evidence to inform its position on climate change. A key part of the work involved developing a range of global emissions pathways and estimating and understanding the corresponding global impacts. This made use of a combination of complex general circulation models, simple climate models, pattern-scaling and state-of-the art impacts models. The results characterise the range of avoidable impacts across the globe in several key sectors including river and coastal flooding, cooling and heating energy demand, crop productivity and aspects of biodiversity. The avoided impacts between a scenario compatible with a 4ºC global warming and one with a 2ºC global warming were found to be highly sector dependent and avoided fractions typically ranged between 20% and 70%. A further key aspect was characterising the magnitude of the uncertainty involved, which is found to be very large in some impact sectors although the avoided fraction appears a more robust metric. The AVOID2 programme began in 2014 and will provide results in the run up to the Paris CoP in 2015. This includes new post-IPCC 5th assessment evidence to inform the long-term climate goal, a more comprehensive assessment of the uncertainty ranges of feasible emission pathways compatible with the long-term goal and enhanced estimates of global impacts using the latest generation of impact models and scenarios.

  19. Spacecraft hazard avoidance utilizing structured light

    NASA Technical Reports Server (NTRS)

    Liebe, Carl Christian; Padgett, Curtis; Chapsky, Jacob; Wilson, Daniel; Brown, Kenneth; Jerebets, Sergei; Goldberg, Hannah; Schroeder, Jeffrey

    2006-01-01

    At JPL, a <5 kg free-flying micro-inspector spacecraft is being designed for host-vehicle inspection. The spacecraft includes a hazard avoidance sensor to navigate relative to the vehicle being inspected. Structured light was selected for hazard avoidance because of its low mass and cost. Structured light is a method of remote sensing 3-dimensional structure of the proximity utilizing a laser, a grating, and a single regular APS camera. The laser beam is split into 400 different beams by a grating to form a regular spaced grid of laser beams that are projected into the field of view of an APS camera. The laser source and the APS camera are separated forming the base of a triangle. The distance to all beam intersections of the host are calculated based on triangulation.

  20. UV Impacts Avoided by the Montreal Protocol

    NASA Technical Reports Server (NTRS)

    Newman, Paul; McKenzie, Richard

    2010-01-01

    Temporal and geographical variabilities in the future "World Expected" UV environment are compared with the "World Avoided", which would have occurred without the Montreal Protocol on protection of the ozone layer and its subsequent amendments and adjustments. Based on calculations of clear-sky UV irradiances, the effects of the Montreal Protocol have been hugely beneficial to avoid the health risks, such as skin cancer, which are associated with high UV, while there is only a small increase in health risks, such as vitamin D deficiency, that are associated with low UV. However, interactions with climate change may lead to changes in cloud and albedo, and possibly behavioural changes which could also be important.

  1. UV impacts avoided by the Montreal Protocol.

    PubMed

    Newman, Paul A; McKenzie, Richard

    2011-07-01

    Temporal and geographical variabilities in the future "world expected" UV environment are compared with the "world avoided", which would have occurred without the Montreal Protocol on Substances That Deplete the Ozone Layer and its subsequent amendments and adjustments. Based on calculations of clear-sky UV irradiances, the effects of the Montreal Protocol have been hugely beneficial to avoid the health risks, such as skin cancer, which are associated with high UV, while there is only a small increase in health risks, such as vitamin D deficiency, that are associated with low UV. However, interactions with climate change may lead to changes in cloud and albedo, and possibly behavioural changes that could also be important.

  2. Guanosine impairs inhibitory avoidance performance in rats.

    PubMed

    Roesler, R; Vianna, M R; Lara, D R; Izquierdo, I; Schmidt, A P; Souza, D O

    2000-08-01

    The nucleoside guanosine, previously found to exert trophic and neuroprotective effects, was found to impair retention of inhibitory avoidance responses, with a complete effect at 7.5 mg/kg i.p. pretraining. Treated animals, when retrained 1 week later, showed normal learning ability. Guanosine injected immediately after training or pretest did not alter retention latency. Combined pretraining and pretest treatments with guanosine failed to reverse its amnestic effect, excluding the contribution of state dependency. Open field parameters and shock sensitivity were mostly unaltered by guanosine. These results suggest an amnestic effect of guanosine on inhibitory avoidance in rats, in a pattern compatible with inhibition of glutamatergic activity. However, the mechanism for the amnestic effect of guanosine is yet to be elucidated.

  3. ALHAT: Autonomous Landing and Hazard Avoidance Technology

    NASA Technical Reports Server (NTRS)

    Robertson, Edward A.; Carson, John M., III

    2015-01-01

    The ALHAT project was chartered by NASA HQ in 2006 to develop and mature to TRL 6 an autonomous lunar landing GN&C and sensing system for crewed, cargo, and robotic planetary landing vehicles. The multi-center ALHAT team was tasked with providing a system capable of identifying and avoiding surface hazards in real time to enable safe precision landing to within tens of meters of a designated planetary landing site under any lighting conditions.

  4. Airborne Collision Detection and Avoidance for Small UAS Sense and Avoid Systems

    NASA Astrophysics Data System (ADS)

    Sahawneh, Laith Rasmi

    The increasing demand to integrate unmanned aircraft systems (UAS) into the national airspace is motivated by the rapid growth of the UAS industry, especially small UAS weighing less than 55 pounds. Their use however has been limited by the Federal Aviation Administration regulations due to collision risk they pose, safety and regulatory concerns. Therefore, before civil aviation authorities can approve routine UAS flight operations, UAS must be equipped with sense-and-avoid technology comparable to the see-and-avoid requirements for manned aircraft. The sense-and-avoid problem includes several important aspects including regulatory and system-level requirements, design specifications and performance standards, intruder detecting and tracking, collision risk assessment, and finally path planning and collision avoidance. In this dissertation, our primary focus is on developing an collision detection, risk assessment and avoidance framework that is computationally affordable and suitable to run on-board small UAS. To begin with, we address the minimum sensing range for the sense-and-avoid (SAA) system. We present an approximate close form analytical solution to compute the minimum sensing range to safely avoid an imminent collision. The approach is then demonstrated using a radar sensor prototype that achieves the required minimum sensing range. In the area of collision risk assessment and collision prediction, we present two approaches to estimate the collision risk of an encounter scenario. The first is a deterministic approach similar to those been developed for Traffic Alert and Collision Avoidance (TCAS) in manned aviation. We extend the approach to account for uncertainties of state estimates by deriving an analytic expression to propagate the error variance using Taylor series approximation. To address unanticipated intruders maneuvers, we propose an innovative probabilistic approach to quantify likely intruder trajectories and estimate the probability of

  5. Knowing and Avoiding Plagiarism During Scientific Writing

    PubMed Central

    Kumar, P Mohan; Priya, N Swapna; Musalaiah, SVVS; Nagasree, M

    2014-01-01

    Plagiarism has become more common in both dental and medical communities. Most of the writers do not know that plagiarism is a serious problem. Plagiarism can range from simple dishonesty (minor copy paste/any discrepancy) to a more serious problem (major discrepancy/duplication of manuscript) when the authors do cut-copy-paste from the original source without giving adequate credit to the main source. When we search databases like PubMed/MedLine there is a lot of information regarding plagiarism. However, it is still a current topic of interest to all the researchers to know how to avoid plagiarism. It's time to every young researcher to know ethical guidelines while writing any scientific publications. By using one's own ideas, we can write the paper completely without looking at the original source. Specific words from the source can be added by using quotations and citing them which can help in not only supporting your work and amplifying ideas but also avoids plagiarism. It is compulsory to all the authors, reviewers and editors of all the scientific journals to know about the plagiarism and how to avoid it by following ethical guidelines and use of plagiarism detection software while scientific writing. PMID:25364588

  6. How does a cyclist avoid obstacles?

    PubMed

    Miyadait, Masayuki; Uetake, Teruo; Shimoda, Masahiro

    2012-12-01

    The purpose of this research is to examine the ways bicycles swerve off sidewalks onto roads under various conditions. Seven students, five males and two females participated in an experiment on a road with a 100-cm wide sidewalk. Footage of each participant on a bicycle evading obstacles such as a utility pole and pedestrian were taken with a video camera, while a front-wheel view of the path taken by the bicycle was recorded simultaneously with a digital camera. Twelve experimental conditions were used for each participant, consisting of all the combinations of (1) three obstacle types, (2) the side (left or right) to which the bicycle went to avoid the obstacle, and (3) two weather conditions. Based on the two recorded scenes, the path was then analyzed from the viewpoint of how the bicycle swerved to avoid hitting the obstacle. We found that the conditions of riding a bicycle with an umbrella caused a larger swerve to avoid the obstacle than those conditions when the rider did not have an umbrella. In particular, the condition in which the obstacle was a pedestrian who also had an umbrella caused the largest swerve. Furthermore, the distance required to become aligned with the sidewalk when the obstacle was a pedestrian walking toward the cyclist was longer than that for other obstacles. The swerve width data showed interesting results, including a tendency for swerve width to be wider when the obstacle was a utility pole compared with other obstacles. PMID:25665202

  7. Acute carbon dioxide avoidance in Caenorhabditis elegans.

    PubMed

    Hallem, Elissa A; Sternberg, Paul W

    2008-06-10

    Carbon dioxide is produced as a by-product of cellular respiration by all aerobic organisms and thus serves for many animals as an important indicator of food, mates, and predators. However, whether free-living terrestrial nematodes such as Caenorhabditis elegans respond to CO2 was unclear. We have demonstrated that adult C. elegans display an acute avoidance response upon exposure to CO2 that is characterized by the cessation of forward movement and the rapid initiation of backward movement. This response is mediated by a cGMP signaling pathway that includes the cGMP-gated heteromeric channel TAX-2/TAX-4. CO2 avoidance is modulated by multiple signaling molecules, including the neuropeptide Y receptor NPR-1 and the calcineurin subunits TAX-6 and CNB-1. Nutritional status also modulates CO2 responsiveness via the insulin and TGFbeta signaling pathways. CO2 response is mediated by a neural circuit that includes the BAG neurons, a pair of sensory neurons of previously unknown function. TAX-2/TAX-4 function in the BAG neurons to mediate acute CO2 avoidance. Our results demonstrate that C. elegans senses and responds to CO2 using multiple signaling pathways and a neural network that includes the BAG neurons and that this response is modulated by the physiological state of the worm.

  8. Traffic jam driving with NMV avoidance

    NASA Astrophysics Data System (ADS)

    Milanés, Vicente; Alonso, Luciano; Villagrá, Jorge; Godoy, Jorge; de Pedro, Teresa; Oria, Juan P.

    2012-08-01

    In recent years, the development of advanced driver assistance systems (ADAS) - mainly based on lidar and cameras - has considerably improved the safety of driving in urban environments. These systems provide warning signals for the driver in the case that any unexpected traffic circumstance is detected. The next step is to develop systems capable not only of warning the driver but also of taking over control of the car to avoid a potential collision. In the present communication, a system capable of autonomously avoiding collisions in traffic jam situations is presented. First, a perception system was developed for urban situations—in which not only vehicles have to be considered, but also pedestrians and other non-motor-vehicles (NMV). It comprises a differential global positioning system (DGPS) and wireless communication for vehicle detection, and an ultrasound sensor for NMV detection. Then, the vehicle's actuators - brake and throttle pedals - were modified to permit autonomous control. Finally, a fuzzy logic controller was implemented capable of analyzing the information provided by the perception system and of sending control commands to the vehicle's actuators so as to avoid accidents. The feasibility of the integrated system was tested by mounting it in a commercial vehicle, with the results being encouraging.

  9. Knowing and avoiding plagiarism during scientific writing.

    PubMed

    Kumar, P Mohan; Priya, N Swapna; Musalaiah, Svvs; Nagasree, M

    2014-09-01

    Plagiarism has become more common in both dental and medical communities. Most of the writers do not know that plagiarism is a serious problem. Plagiarism can range from simple dishonesty (minor copy paste/any discrepancy) to a more serious problem (major discrepancy/duplication of manuscript) when the authors do cut-copy-paste from the original source without giving adequate credit to the main source. When we search databases like PubMed/MedLine there is a lot of information regarding plagiarism. However, it is still a current topic of interest to all the researchers to know how to avoid plagiarism. It's time to every young researcher to know ethical guidelines while writing any scientific publications. By using one's own ideas, we can write the paper completely without looking at the original source. Specific words from the source can be added by using quotations and citing them which can help in not only supporting your work and amplifying ideas but also avoids plagiarism. It is compulsory to all the authors, reviewers and editors of all the scientific journals to know about the plagiarism and how to avoid it by following ethical guidelines and use of plagiarism detection software while scientific writing.

  10. Acute carbon dioxide avoidance in Caenorhabditis elegans.

    PubMed

    Hallem, Elissa A; Sternberg, Paul W

    2008-06-10

    Carbon dioxide is produced as a by-product of cellular respiration by all aerobic organisms and thus serves for many animals as an important indicator of food, mates, and predators. However, whether free-living terrestrial nematodes such as Caenorhabditis elegans respond to CO2 was unclear. We have demonstrated that adult C. elegans display an acute avoidance response upon exposure to CO2 that is characterized by the cessation of forward movement and the rapid initiation of backward movement. This response is mediated by a cGMP signaling pathway that includes the cGMP-gated heteromeric channel TAX-2/TAX-4. CO2 avoidance is modulated by multiple signaling molecules, including the neuropeptide Y receptor NPR-1 and the calcineurin subunits TAX-6 and CNB-1. Nutritional status also modulates CO2 responsiveness via the insulin and TGFbeta signaling pathways. CO2 response is mediated by a neural circuit that includes the BAG neurons, a pair of sensory neurons of previously unknown function. TAX-2/TAX-4 function in the BAG neurons to mediate acute CO2 avoidance. Our results demonstrate that C. elegans senses and responds to CO2 using multiple signaling pathways and a neural network that includes the BAG neurons and that this response is modulated by the physiological state of the worm. PMID:18524955

  11. Urban water restrictions: Attitudes and avoidance

    NASA Astrophysics Data System (ADS)

    Cooper, Bethany; Burton, Michael; Crase, Lin

    2011-12-01

    In most urban cities across Australia, water restrictions remain the dominant policy mechanism to restrict urban water consumption. The extensive adoption of water restrictions as a means to limit demand, over several years, means that Australian urban water prices have consistently not reflected the opportunity cost of water. Given the generally strong political support for water restrictions and the likelihood that they will persist for some time, there is value in understanding households' attitudes in this context. More specifically, identifying the welfare gains associated with avoiding urban water restrictions entirely would be a nontrivial contribution to our knowledge and offer insights into the benefits of alternative policy responses. This paper describes the results from a contingent valuation study that investigates consumers' willingness to pay to avoid urban water restrictions. Importantly, the research also investigates the influence of cognitive and exogenous dimensions on the utility gain associated with avoiding water restrictions. The results provide insights into the impact of the current policy mechanism on economic welfare.

  12. The influence of avoidance temperament and avoidance-based achievement goals on flow.

    PubMed

    Oertig, Daniela; Schüler, Julia; Brandstätter, Veronika; Augustine, Adam A

    2014-06-01

    In the present research, we conducted two studies designed to examine the joint influence of avoidance temperament and avoidance-based achievement goals on the experience of flow on a creativity task. In both a laboratory study (N = 101; M(age)  = 22.61, SD(age)  = 4.03; 74.3% female) and a naturalistic study (N = 102; M(age)  = 16.23, SD(age)  = 1.13; 48% female), participants high in avoidance temperament were shown to experience greater flow when performance-avoidance goals were induced; no differences were found in any of the other three achievement goal conditions from the 2 × 2 achievement goal framework. These findings reveal a short-term benefit for a disposition-goal match grounded in avoidance motivation, and point to the need for more research on both avoidance-based matches and the short-term versus long-term implications of such matches.

  13. Airborne Collision Detection and Avoidance for Small UAS Sense and Avoid Systems

    NASA Astrophysics Data System (ADS)

    Sahawneh, Laith Rasmi

    The increasing demand to integrate unmanned aircraft systems (UAS) into the national airspace is motivated by the rapid growth of the UAS industry, especially small UAS weighing less than 55 pounds. Their use however has been limited by the Federal Aviation Administration regulations due to collision risk they pose, safety and regulatory concerns. Therefore, before civil aviation authorities can approve routine UAS flight operations, UAS must be equipped with sense-and-avoid technology comparable to the see-and-avoid requirements for manned aircraft. The sense-and-avoid problem includes several important aspects including regulatory and system-level requirements, design specifications and performance standards, intruder detecting and tracking, collision risk assessment, and finally path planning and collision avoidance. In this dissertation, our primary focus is on developing an collision detection, risk assessment and avoidance framework that is computationally affordable and suitable to run on-board small UAS. To begin with, we address the minimum sensing range for the sense-and-avoid (SAA) system. We present an approximate close form analytical solution to compute the minimum sensing range to safely avoid an imminent collision. The approach is then demonstrated using a radar sensor prototype that achieves the required minimum sensing range. In the area of collision risk assessment and collision prediction, we present two approaches to estimate the collision risk of an encounter scenario. The first is a deterministic approach similar to those been developed for Traffic Alert and Collision Avoidance (TCAS) in manned aviation. We extend the approach to account for uncertainties of state estimates by deriving an analytic expression to propagate the error variance using Taylor series approximation. To address unanticipated intruders maneuvers, we propose an innovative probabilistic approach to quantify likely intruder trajectories and estimate the probability of

  14. Convective Weather Avoidance with Uncertain Weather Forecasts

    NASA Technical Reports Server (NTRS)

    Karahan, Sinan; Windhorst, Robert D.

    2009-01-01

    Convective weather events have a disruptive impact on air traffic both in terminal area and in en-route airspaces. In order to make sure that the national air transportation system is safe and efficient, it is essential to respond to convective weather events effectively. Traffic flow control initiatives in response to convective weather include ground delay, airborne delay, miles-in-trail restrictions as well as tactical and strategic rerouting. The rerouting initiatives can potentially increase traffic density and complexity in regions neighboring the convective weather activity. There is a need to perform rerouting in an intelligent and efficient way such that the disruptive effects of rerouting are minimized. An important area of research is to study the interaction of in-flight rerouting with traffic congestion or complexity and developing methods that quantitatively measure this interaction. Furthermore, it is necessary to find rerouting solutions that account for uncertainties in weather forecasts. These are important steps toward managing complexity during rerouting operations, and the paper is motivated by these research questions. An automated system is developed for rerouting air traffic in order to avoid convective weather regions during the 20- minute - 2-hour time horizon. Such a system is envisioned to work in concert with separation assurance (0 - 20-minute time horizon), and longer term air traffic management (2-hours and beyond) to provide a more comprehensive solution to complexity and safety management. In this study, weather is dynamic and uncertain; it is represented as regions of airspace that pilots are likely to avoid. Algorithms are implemented in an air traffic simulation environment to support the research study. The algorithms used are deterministic but periodically revise reroutes to account for weather forecast updates. In contrast to previous studies, in this study convective weather is represented as regions of airspace that pilots

  15. Collision Avoidance for Airport Traffic Concept Evaluation

    NASA Technical Reports Server (NTRS)

    Jones, Denise R.; Prinzel, Lawrence J., III; Otero, Sharon D.; Barker, Glover D.

    2009-01-01

    An initial Collision Avoidance for Airport Traffic (CAAT) concept for the Terminal Maneuvering Area (TMA) was evaluated in a simulation study at the National Aeronautics and Space Administration (NASA) Langley Research Center. CAAT is being designed to enhance surface situation awareness and provide cockpit alerts of potential conflicts during runway, taxi, and low altitude air-to-air operations. The purpose of the study was to evaluate the initial concept for an aircraft-based method of conflict detection and resolution (CD&R) in the TMA focusing on conflict detection algorithms and alerting display concepts. This paper gives an overview of the CD&R concept, simulation study, and test results.

  16. Collision Avoidance for Airport Traffic Simulation Evaluation

    NASA Technical Reports Server (NTRS)

    Jones, Denise R.; Prinzel, Lawrence J., III; Shelton, Kevin J.; Bailey, Randall E.; Otero, Sharon D.; Barker, Glover D.

    2010-01-01

    A Collision Avoidance for Airport Traffic (CAAT) concept for the airport Terminal Maneuvering Area (TMA) was evaluated in a simulation study at the National Aeronautics and Space Administration (NASA) Langley Research Center. CAAT is being designed to enhance surface situation awareness and provide cockpit alerts of potential conflicts during runway, taxi, and low altitude air-to-air operations. The purpose of the study was to evaluate pilot reaction to conflict events in the TMA near the airport, different alert timings for various scenarios, alerting display concepts, and directive alerting concepts. This paper gives an overview of the conflict detection and resolution (CD&R) concept, simulation study, and test results

  17. Avoiding Lawsuits for Wage and Hour Violations.

    PubMed

    Silberman, Cherie L

    2016-01-01

    Due to the highly technical language in the wage and hour laws and regulations, employers often find that they have unknowingly violated the Fair Labor Standards Act (FLSA). This can occur because employers have improperly classified an employee as exempt or because employers do not realize that certain time should be paid in full. Improperly classifying employees as exempt or failing to compensate nonexempt employees for all time worked can lead to costly lawsuits, audits, or enforcement actions by the Wage and Hour Division of the Department of Labor. This article discusses the most common FLSA exemptions and provides best practices to avoid liability under the FLSA.

  18. Avoiding Lawsuits for Wage and Hour Violations.

    PubMed

    Silberman, Cherie L

    2016-01-01

    Due to the highly technical language in the wage and hour laws and regulations, employers often find that they have unknowingly violated the Fair Labor Standards Act (FLSA). This can occur because employers have improperly classified an employee as exempt or because employers do not realize that certain time should be paid in full. Improperly classifying employees as exempt or failing to compensate nonexempt employees for all time worked can lead to costly lawsuits, audits, or enforcement actions by the Wage and Hour Division of the Department of Labor. This article discusses the most common FLSA exemptions and provides best practices to avoid liability under the FLSA. PMID:27249874

  19. Are responses in avoidance procedures "safety" signals?

    PubMed

    Branch, M N

    2001-05-01

    Dinsmoor's (2001) position has the advantage of parsimony in that it relies on well-established principles rather than a separate process--shock-frequency reduction--to account for avoidance. Other advantages are that it blends well with what is known about the effectiveness of momentary contiguities in the study of positive reinforcement and that it might provide an account of why different response forms seem to condition at different rates. Despite these advantages, the view needs elaboration about the temporal characteristics of response-associated stimuli, the functions that "warning'' stimuli may have, and especially about how ''safety" is established.

  20. Avoid common relief-valve pitfalls

    SciTech Connect

    Bravo, F.; Contreras, D.; Jester, D.

    1995-08-01

    From the moment that the decision is made to add a relief valve to a process system and, continuing through its installation and operating life, engineers are involved with evaluations, sizing calculations, and documentation. Relief valves are critical to the safe, efficient operation of process systems. However, many times, these devices are not afforded the emphasis that they deserve and this can cause problems. The purpose of this article is to help the engineer to avoid some of the problems that are typically encountered with relief valves. In today`s competitive and quality-driven world, it is important to do it right the first time.

  1. Contact Dermatitis, Patch Testing, and Allergen Avoidance.

    PubMed

    Burkemper, Nicole M

    2015-01-01

    In patients presenting with a complaint of rash, contact dermatitis is often the underlying diagnosis making it an entity with which health care providers should be familiar. Contact dermatitis can be divided into irritant contact dermatitis and allergic contact dermatitis. In a patient suspected of having allergic contact dermatitis, patch testing can be done to identify specific allergens. Education focused on allergen avoidance and safe products is an integral part of treatment for the contact dermatitis patient. Knowledge of the most common allergens is helpful for clinicians to be able to provide this education.

  2. Avoiding plagiarism: guidance for nursing students.

    PubMed

    Price, Bob

    The pressures of study, diversity of source materials, past assumptions relating to good writing practice, ambiguous writing guidance on best practice and students' insecurity about their reasoning ability, can lead to plagiarism. With the use of source checking software, there is an increased chance that plagiarised work will be identified and investigated, and penalties given. In extreme cases, plagiarised work may be reported to the Nursing and Midwifery Council and professional as well as academic penalties may apply. This article provides information on how students can avoid plagiarism when preparing their coursework for submission.

  3. Hazard Avoidance For A Mars Rover

    NASA Astrophysics Data System (ADS)

    Spiessbach, Andrew J.

    1989-03-01

    The challenging geology of the surface of Mars, when coupled with the impossibility of continuous remote driving from Earth, dictate the need for autonomous hazard detection, recognition and possibly hazard avoidance capabilities onboard any robotic Mars roving vehicle. The main technical issues represented by terrain hazards are accidental damage and vehicle entrapment. Several approaches to vehicle design geared to prevent such immobilization threats are identified. The gamut of alternatives for rover autonomy are also presented, and the applicability of the various options for the Mars Rover/Sample Return (MRSR) mission are assessed in the context of the technology state of the art for hazard sensors and processing algorithms.

  4. Understanding, Avoiding, and Managing Severe Filler Complications.

    PubMed

    Rzany, Berthold; DeLorenzi, Claudio

    2015-11-01

    Any injectable filler may elicit moderate-to-severe adverse events, ranging from nodules to abscesses to vascular occlusion. Fortunately, severe adverse events are uncommon for the majority of fillers currently on the market. Because these are rare events, it is difficult to identify the relevant risk factors and to design the most efficacious treatment strategies. Poor aesthetic outcomes are far more common than severe adverse events. These in contrast should be easily avoidable by ensuring that colleagues receive proper training and follow best practices.

  5. Contact Dermatitis, Patch Testing, and Allergen Avoidance.

    PubMed

    Burkemper, Nicole M

    2015-01-01

    In patients presenting with a complaint of rash, contact dermatitis is often the underlying diagnosis making it an entity with which health care providers should be familiar. Contact dermatitis can be divided into irritant contact dermatitis and allergic contact dermatitis. In a patient suspected of having allergic contact dermatitis, patch testing can be done to identify specific allergens. Education focused on allergen avoidance and safe products is an integral part of treatment for the contact dermatitis patient. Knowledge of the most common allergens is helpful for clinicians to be able to provide this education. PMID:26455061

  6. Laparoscopic Gynecology Procedures: Avoid the Risk

    PubMed Central

    1996-01-01

    Laparoscopic approaches to gynecological surgery have been developed by an elite group of highly skilled surgeons. As these procedures become more prevalent in the general gynecological approach to disease and the general gynecologist's approach to treatment, the complication rate for these procedures is likely to increase. In an effort to assist in avoiding these complications, guidelines for the performance of laparoscopic gynecological procedures need to be established. This article presents approaches to the most common gynecological procedures that can assist in the prevention of complications. PMID:18493397

  7. Avoidance learning: a review of theoretical models and recent developments

    PubMed Central

    Krypotos, Angelos-Miltiadis; Effting, Marieke; Kindt, Merel; Beckers, Tom

    2015-01-01

    Avoidance is a key characteristic of adaptive and maladaptive fear. Here, we review past and contemporary theories of avoidance learning. Based on the theories, experimental findings and clinical observations reviewed, we distill key principles of how adaptive and maladaptive avoidance behavior is acquired and maintained. We highlight clinical implications of avoidance learning theories and describe intervention strategies that could reduce maladaptive avoidance and prevent its return. We end with a brief overview of recent developments and avenues for further research. PMID:26257618

  8. Avoiding common pitfalls when clustering biological data.

    PubMed

    Ronan, Tom; Qi, Zhijie; Naegle, Kristen M

    2016-01-01

    Clustering is an unsupervised learning method, which groups data points based on similarity, and is used to reveal the underlying structure of data. This computational approach is essential to understanding and visualizing the complex data that are acquired in high-throughput multidimensional biological experiments. Clustering enables researchers to make biological inferences for further experiments. Although a powerful technique, inappropriate application can lead biological researchers to waste resources and time in experimental follow-up. We review common pitfalls identified from the published molecular biology literature and present methods to avoid them. Commonly encountered pitfalls relate to the high-dimensional nature of biological data from high-throughput experiments, the failure to consider more than one clustering method for a given problem, and the difficulty in determining whether clustering has produced meaningful results. We present concrete examples of problems and solutions (clustering results) in the form of toy problems and real biological data for these issues. We also discuss ensemble clustering as an easy-to-implement method that enables the exploration of multiple clustering solutions and improves robustness of clustering solutions. Increased awareness of common clustering pitfalls will help researchers avoid overinterpreting or misinterpreting the results and missing valuable insights when clustering biological data. PMID:27303057

  9. Lobeline produces conditioned taste avoidance in rats.

    PubMed

    Harrod, S B; Dwoskin, L P; Bardo, M T

    2004-05-01

    Previous results indicate that pretreatment with lobeline attenuates methamphetamine (METH) self-administration in rats, but not by acting as a substitute reinforcer. Given these findings, it has been suggested that lobeline may serve as a useful pharmacotherapy for psychostimulant abuse. However, because lobeline produces emesis and nausea in humans, the present study examined whether lobeline has direct effects on taste avoidance behavior in rats within the same dose range shown previously to decrease METH self-administration. Two experiments utilized a Pavlovian conditioning procedure to determine if lobeline produces conditioned taste avoidance (CTA) in rats. In Experiments 1 and 2, rats consumed either novel milk or salt solutions, respectively, and within 10 min, were injected with lobeline (0.3-3.0 mg/kg) or METH (0.3-3.0 mg/kg). A single-bottle test conducted 48 h after flavor-drug pairings indicated that the dose of lobeline that reduced METH self-administration in a previous study (i.e., 3.0 mg/kg) also produced reliable CTA for milk and salt solution. These findings suggest a need to develop lobeline analogs that reduce METH self-administration, but do not produce CTA following the consumption of a novel solution.

  10. Shape optimization of self-avoiding curves

    NASA Astrophysics Data System (ADS)

    Walker, Shawn W.

    2016-04-01

    This paper presents a softened notion of proximity (or self-avoidance) for curves. We then derive a sensitivity result, based on shape differential calculus, for the proximity. This is combined with a gradient-based optimization approach to compute three-dimensional, parameterized curves that minimize the sum of an elastic (bending) energy and a proximity energy that maintains self-avoidance by a penalization technique. Minimizers are computed by a sequential-quadratic-programming (SQP) method where the bending energy and proximity energy are approximated by a finite element method. We then apply this method to two problems. First, we simulate adsorbed polymer strands that are constrained to be bound to a surface and be (locally) inextensible. This is a basic model of semi-flexible polymers adsorbed onto a surface (a current topic in material science). Several examples of minimizing curve shapes on a variety of surfaces are shown. An advantage of the method is that it can be much faster than using molecular dynamics for simulating polymer strands on surfaces. Second, we apply our proximity penalization to the computation of ideal knots. We present a heuristic scheme, utilizing the SQP method above, for minimizing rope-length and apply it in the case of the trefoil knot. Applications of this method could be for generating good initial guesses to a more accurate (but expensive) knot-tightening algorithm.

  11. Honey bees selectively avoid difficult choices.

    PubMed

    Perry, Clint J; Barron, Andrew B

    2013-11-19

    Human decision-making strategies are strongly influenced by an awareness of certainty or uncertainty (a form of metacognition) to increase the chances of making a right choice. Humans seek more information and defer choosing when they realize they have insufficient information to make an accurate decision, but whether animals are aware of uncertainty is currently highly contentious. To explore this issue, we examined how honey bees (Apis mellifera) responded to a visual discrimination task that varied in difficulty between trials. Free-flying bees were rewarded for a correct choice, punished for an incorrect choice, or could avoid choosing by exiting the trial (opting out). Bees opted out more often on difficult trials, and opting out improved their proportion of successful trials. Bees could also transfer the concept of opting out to a novel task. Our data show that bees selectively avoid difficult tasks they lack the information to solve. This finding has been considered as evidence that nonhuman animals can assess the certainty of a predicted outcome, and bees' performance was comparable to that of primates in a similar paradigm. We discuss whether these behavioral results prove bees react to uncertainty or whether associative mechanisms can explain such findings. To better frame metacognition as an issue for neurobiological investigation, we propose a neurobiological hypothesis of uncertainty monitoring based on the known circuitry of the honey bee brain.

  12. Avoiding Complications in Endoscopic Third Ventriculostomy.

    PubMed

    Yadav, Yad Ram; Parihar, Vijay Singh; Ratre, Shailendra; Kher, Yatin

    2015-11-01

    Endoscopic neurosurgical techniques hold the potential for reducing morbidity. But they are also associated with limitations such as the initial learning curve, proximal blind spot, visual obscurity, difficulty in controlling bleeding, disorientation, and loss of stereoscopic image. Although some of the surgical techniques in neuroendoscopy and microsurgery are similar, endoscopy requires additional skills. A thorough understanding of endoscopic techniques and their limitations is required to get maximal benefit. Knowledge of possible complications and techniques to avoid such complications can improve results in endoscopic third ventriculostomy (ETV). The surgeon must be able to manage complications and have a second strategy such as a cerebrospinal fluid shunt if ETV fails. It is better to abandon the procedure if there is disorientation or a higher risk of complications such as bleeding or a thick and opaque floor without any clear visualization of anatomy. Attending live workshops, practice on models and simulators, simpler case selection in the initial learning curve, and hands-on cadaveric workshops can reduce complications. Proper case selection, good surgical technique, and better postoperative care are essential for a good outcome in ETV. Although it is difficult to make a preoperative diagnosis of complex hydrocephalus (combination of communicating and obstructive), improving methods to detect the exact type of hydrocephalus before surgery could increase the success rate of ETV and avoid an unnecessary ETV procedure in such cases. PMID:26140421

  13. Dynamics of jamming avoidance in echolocating bats.

    PubMed Central

    Ulanovsky, Nachum; Fenton, M. Brock; Tsoar, Asaf; Korine, Carmi

    2004-01-01

    Animals using active sensing systems such as echolocation or electrolocation may experience interference from the signals of neighbouring conspecifics, which can be offset by a jamming avoidance response (JAR). Here, we report JAR in one echolocating bat (Tadarida teniotis: Molossidae) but not in another (Taphozous perforatus: Emballonuridae) when both flew and foraged with conspecifics. In T. teniotis, JAR consisted of shifts in the dominant frequencies of echolocation calls, enhancing differences among individuals. Larger spectral overlap of signals elicited stronger JAR. Tadarida teniotis showed two types of JAR: (i) for distant conspecifics: a symmetric JAR, with lower- and higher-frequency bats shifting their frequencies downwards and upwards, respectively, on average by the same amount; and (ii) for closer conspecifics: an asymmetric JAR, with only the upper-frequency bat shifting its frequency upwards. In comparison, 'wave-type' weakly electric fishes also shift frequencies of discharges in a JAR, but unlike T. teniotis, the shifts are either symmetric in some species or asymmetric in others. We hypothesize that symmetric JAR in T. teniotis serves to avoid jamming and improve echolocation, whereas asymmetric JAR may aid communication by helping to identify and locate conspecifics, thus minimizing chances of mid-air collisions. PMID:15306318

  14. An Algorithm for Autonomous Formation Obstacle Avoidance

    NASA Astrophysics Data System (ADS)

    Cruz, Yunior I.

    The level of human interaction with Unmanned Aerial Systems varies greatly from remotely piloted aircraft to fully autonomous systems. In the latter end of the spectrum, the challenge lies in designing effective algorithms to dictate the behavior of the autonomous agents. A swarm of autonomous Unmanned Aerial Vehicles requires collision avoidance and formation flight algorithms to negotiate environmental challenges it may encounter during the execution of its mission, which may include obstacles and chokepoints. In this work, a simple algorithm is developed to allow a formation of autonomous vehicles to perform point to point navigation while avoiding obstacles and navigating through chokepoints. Emphasis is placed on maintaining formation structures. Rather than breaking formation and individually navigating around the obstacle or through the chokepoint, vehicles are required to assemble into appropriately sized/shaped sub-formations, bifurcate around the obstacle or negotiate the chokepoint, and reassemble into the original formation at the far side of the obstruction. The algorithm receives vehicle and environmental properties as inputs and outputs trajectories for each vehicle from start to the desired ending location. Simulation results show that the algorithm safely routes all vehicles past the obstruction while adhering to the aforementioned requirements. The formation adapts and successfully negotiates the obstacles and chokepoints in its path while maintaining proper vehicle separation.

  15. Collision avoidance for CTV: Requirements and capabilities

    NASA Technical Reports Server (NTRS)

    Nosek, Thomas P.

    1991-01-01

    Cargo transfer vehicle (CTV) operations near Space Station Freedom will require positive collision avoidance maneuver (CAM) capability to preclude any change of collision, even in the event of CTV failures. The requirements for CAM are discussed, and the CAM design approach and design of the Orbiting Maneuvering Vehicle (OMV) are reviewed; this design met requirements for OMV operation near the Space Station, provided a redundant collision avoidance maneuver capability. Significant portions of the OMV CAM design should be applicable to CTV. The key features of the OMV design are summarized and related to the CTV mission design to that of OMV's. CAM is a defined sequence of events executed by the CTV to place the vehicle in a safe position relative to a target such as the Space Station. CAM can be performed through software commands to the propulsion system, or through commands pre-stored in hardware. Various techniques for triggering CAM are considered, and the risks associated with CAM enable and execution in phases are considered. OMV CAM design features both hardware and software CAM capability, with analyses conducted to assess the ability to meet the collision-free requirement during all phases of the mission.

  16. Collision avoidance for CTV: Requirements and capabilities

    NASA Astrophysics Data System (ADS)

    Nosek, Thomas P.

    Cargo transfer vehicle (CTV) operations near Space Station Freedom will require positive collision avoidance maneuver (CAM) capability to preclude any change of collision, even in the event of CTV failures. The requirements for CAM are discussed, and the CAM design approach and design of the Orbiting Maneuvering Vehicle (OMV) are reviewed; this design met requirements for OMV operation near the Space Station, provided a redundant collision avoidance maneuver capability. Significant portions of the OMV CAM design should be applicable to CTV. The key features of the OMV design are summarized and related to the CTV mission design to that of OMV's. CAM is a defined sequence of events executed by the CTV to place the vehicle in a safe position relative to a target such as the Space Station. CAM can be performed through software commands to the propulsion system, or through commands pre-stored in hardware. Various techniques for triggering CAM are considered, and the risks associated with CAM enable and execution in phases are considered. OMV CAM design features both hardware and software CAM capability, with analyses conducted to assess the ability to meet the collision-free requirement during all phases of the mission.

  17. Avoidance of strobe lights by zooplankton

    USGS Publications Warehouse

    Hamel, Martin J.; Richards, Nathan S.; Brown, Michael L.; Chipps, Steven R.

    2010-01-01

    Underwater strobe lights can influence the behavior and distribution of fishes and are increasingly used as a technique to divert fish away from water intake structures on dams. However, few studies examine how strobe lights may affect organisms other than targeted species. To gain insight on strobe lighting effects on nontarget invertebrates, we investigated whether underwater strobe lights influence zooplankton distributions and abundance in Lake Oahe, South Dakota. Zooplankton were collected using vertical tows at 3 discrete distances from an underwater strobe light to quantify the influence of light intensity on zooplankton density. Samples were collected from 3 different depth ranges (0–10 m, 10–20 m and 20–30 m) at <1 m, 15 m and ⩾100 m distance intervals away from the strobe light. Copepods represented 67.2% and Daphnia spp. represented 23.3% of all zooplankton sampled from 17 August to 15 September 2004. Night time zooplankton densities significantly decreased in surface waters when strobe lights were activated. Copepods exhibited the greatest avoidance patterns, while Daphnia avoidance varied throughout sampling depths. These results indicate that zooplankton display negative phototaxic behavior to strobe lights and that researchers must be cognizant of potential effects to the ecosystem such as altering predator–prey interactions or affecting zooplankton distribution and growth.

  18. Angiotensin II disrupts inhibitory avoidance memory retrieval.

    PubMed

    Bonini, Juliana S; Bevilaqua, Lia R; Zinn, Carolina G; Kerr, Daniel S; Medina, Jorge H; Izquierdo, Iván; Cammarota, Martín

    2006-08-01

    The brain renin-angiotensin system (RAS) is involved in learning and memory, but the actual role of angiotensin II (A(II)) and its metabolites in this process has been difficult to comprehend. This has been so mainly due to procedural issues, especially the use of multi-trial learning paradigms and the utilization of pre-training intracerebroventricular infusion of RAS-acting compounds. Here, we specifically analyzed the action of A(II) in aversive memory retrieval using a hippocampal-dependent, one-trial, step-down inhibitory avoidance task (IA) in combination with stereotaxically localized intrahippocampal infusion of drugs. Rats bilaterally implanted with infusion cannulae aimed to the CA1 region of the dorsal hippocampus were trained in IA and tested for memory retention 24 h later. We found that when given into CA1 15 min before IA memory retention test, A(II), but not angiotensin IV or angiotensin(1-7) induced a dose-dependent and reversible amnesia without altering locomotor activity, exploratory behavior or anxiety state. The effect of A(II) was blocked in a dose-dependent manner by the A(II)-type 2 receptor (AT(2)) antagonist PD123319 but not by the A(II)-type 1 receptor (AT(1)) antagonist losartan. By themselves, neither PD123319 nor losartan had any effect on memory expression. Our data indicate that intra-CA1 A(II) hinders retrieval of avoidance memory through a process that involves activation of AT(2) receptors.

  19. Successive positive contrast in one-way avoidance behavior with Roman low-avoidance rats.

    PubMed

    Maldonado, A; Torres, C; Escarabajal, M D; Cándido, A; de la Torre, L; Gómez, M J; Tobeña, A; Fernández-Teruel, A

    2007-04-23

    The inbred Roman High- (RHA-I) and Roman Low-Avoidance (RLA-I) rats, psychogenetically selected for rapid (RHA-I) vs. extremely poor (RLA-I) acquisition of two-way active avoidance, exhibit a lower or a higher level of fearfulness, respectively, that can be observed in many laboratory anxiety models. The present study analyzed the performance of female RLA-I and RHA-I rats in a successive positive contrast situation induced during one-way avoidance learning. Three groups of RLA-I and three of RHA-I rats (1-30, 30-30 and 1-1 groups, the numbers stand for the time spent in the safe compartment during the first and second phase of training) were trained to avoid an electric foot-shock administered in a "danger" compartment, by running from this compartment to a "safe" one. Only RLA-I rats showed a significant positive contrast effect, in such a way that the reinforcement increase from the lower (1 s spent in safety) to the higher reward (30 s) led to a response enhancement, surpassing the performance of rats trained with the low (1-1 s) or the high (30-30 s) reward from the beginning of training. The results are discussed in the context of an opponent process theory based upon the interaction between the motivational strength of fear and the incentive value of relief taking place during one-way avoidance learning.

  20. Behavioral economics. Avoiding overhead aversion in charity.

    PubMed

    Gneezy, Uri; Keenan, Elizabeth A; Gneezy, Ayelet

    2014-10-31

    Donors tend to avoid charities that dedicate a high percentage of expenses to administrative and fundraising costs, limiting the ability of nonprofits to be effective. We propose a solution to this problem: Use donations from major philanthropists to cover overhead expenses and offer potential donors an overhead-free donation opportunity. A laboratory experiment testing this solution confirms that donations decrease when overhead increases, but only when donors pay for overhead themselves. In a field experiment with 40,000 potential donors, we compared the overhead-free solution with other common uses of initial donations. Consistent with prior research, informing donors that seed money has already been raised increases donations, as does a $1:$1 matching campaign. Our main result, however, clearly shows that informing potential donors that overhead costs are covered by an initial donation significantly increases the donation rate by 80% (or 94%) and total donations by 75% (or 89%) compared with the seed (or matching) approach. PMID:25359974

  1. [UNESCO's bioethical norms to avoid eugenic practices].

    PubMed

    Cruz-Coke, R

    2000-06-01

    The author, member of the UNESCO Bioethics Committee, participated in the preparation of the Universal Declaration about Human Genome and Human Rights, in 1997. The aim of this work is to analyze the initial articles of such Declaration, defining the bioethical principles that defend human dignity, freedom and rights, against the madness of the present biotechnological revolution. The development of genetics for the benefit of mankind will be guaranteed if these principles are honored. Genetic discrimination, reductionism and determinism, are identified by the author as perversions that, if used by biotechnologists, can lead to the rebirth of eugenism and racism, that were condemned by the Code of Nuremberg, in 1947. Investigators must assume their responsibility, respecting the principles of human dignity, the real freedom of research and solidarity among people. This attitude will avoid the use of genetics for purposes other than the welfare of mankind.

  2. NASA satellite helps airliners avoid ozone concentrations

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Results from a test to determine the effectiveness of satellite data for helping airlines avoid heavy concentrations of ozone are reported. Information from the Total Ozone Mapping Spectrometer, aboard the Nimbus-7 was transmitted, for use in meteorological forecast activities. The results show: (1) Total Ozone Mapping Spectrometer profile of total ozone in the atmosphere accurately represents upper air patterns and can be used to locate meteorological activity; (2) route forecasting of highly concentrated ozone is feasible; (3) five research aircraft flights were flown in jet stream regions located by the Total Ozone Mapping Spectrometer to determine winds, temperatures, and air composition. It is shown that the jet stream is coincides with the area of highest total ozone gradient, and low total ozone amounts are found where tropospheric air has been carried along above the tropopause on the anticyclonic side of the subtropical jet stream.

  3. Communication-avoiding symmetric-indefinite factorization

    SciTech Connect

    Ballard, Grey Malone; Becker, Dulcenia; Demmel, James; Dongarra, Jack; Druinsky, Alex; Peled, Inon; Schwartz, Oded; Toledo, Sivan; Yamazaki, Ichitaro

    2014-11-13

    We describe and analyze a novel symmetric triangular factorization algorithm. The algorithm is essentially a block version of Aasen's triangular tridiagonalization. It factors a dense symmetric matrix A as the product A=PLTLTPT where P is a permutation matrix, L is lower triangular, and T is block tridiagonal and banded. The algorithm is the first symmetric-indefinite communication-avoiding factorization: it performs an asymptotically optimal amount of communication in a two-level memory hierarchy for almost any cache-line size. Adaptations of the algorithm to parallel computers are likely to be communication efficient as well; one such adaptation has been recently published. As a result, the current paper describes the algorithm, proves that it is numerically stable, and proves that it is communication optimal.

  4. Communication-avoiding symmetric-indefinite factorization

    DOE PAGESBeta

    Ballard, Grey Malone; Becker, Dulcenia; Demmel, James; Dongarra, Jack; Druinsky, Alex; Peled, Inon; Schwartz, Oded; Toledo, Sivan; Yamazaki, Ichitaro

    2014-11-13

    We describe and analyze a novel symmetric triangular factorization algorithm. The algorithm is essentially a block version of Aasen's triangular tridiagonalization. It factors a dense symmetric matrix A as the product A=PLTLTPT where P is a permutation matrix, L is lower triangular, and T is block tridiagonal and banded. The algorithm is the first symmetric-indefinite communication-avoiding factorization: it performs an asymptotically optimal amount of communication in a two-level memory hierarchy for almost any cache-line size. Adaptations of the algorithm to parallel computers are likely to be communication efficient as well; one such adaptation has been recently published. As a result,more » the current paper describes the algorithm, proves that it is numerically stable, and proves that it is communication optimal.« less

  5. Behavioral economics. Avoiding overhead aversion in charity.

    PubMed

    Gneezy, Uri; Keenan, Elizabeth A; Gneezy, Ayelet

    2014-10-31

    Donors tend to avoid charities that dedicate a high percentage of expenses to administrative and fundraising costs, limiting the ability of nonprofits to be effective. We propose a solution to this problem: Use donations from major philanthropists to cover overhead expenses and offer potential donors an overhead-free donation opportunity. A laboratory experiment testing this solution confirms that donations decrease when overhead increases, but only when donors pay for overhead themselves. In a field experiment with 40,000 potential donors, we compared the overhead-free solution with other common uses of initial donations. Consistent with prior research, informing donors that seed money has already been raised increases donations, as does a $1:$1 matching campaign. Our main result, however, clearly shows that informing potential donors that overhead costs are covered by an initial donation significantly increases the donation rate by 80% (or 94%) and total donations by 75% (or 89%) compared with the seed (or matching) approach.

  6. Experiential Avoidance and Technological Addictions in Adolescents.

    PubMed

    García-Oliva, Carlos; Piqueras, José A

    2016-06-01

    Background and aims This study focuses on the use of popular information and communication technologies (ICTs) by adolescents: the Internet, mobile phones, and video games. The relationship of ICT use and experiential avoidance (EA), a construct that has emerged as underlying and transdiagnostic to a wide variety of psychological problems, including behavioral addictions, is examined. EA refers to a self-regulatory strategy involving efforts to control or escape from negative stimuli such as thoughts, feelings, or sensations that generate strong distress. This strategy, which may be adaptive in the short term, is problematic if it becomes an inflexible pattern. Thus, the aim of this study was to explore whether EA patterns were associated with addictive or problematic use of ICT in adolescents. Methods A total of 317 students of the Spanish southeast between 12 and 18 years old were recruited to complete a questionnaire that included questions about general use of each ICTs, an experiential avoidance questionnaire, a brief inventory of the Big Five personality traits, and specific questionnaires on problematic use of the Internet, mobile phones, and video games. Results Correlation analysis and linear regression showed that EA largely explained results regarding the addictive use of the Internet, mobile phones, and video games, but not in the same way. As regards gender, boys showed a more problematic use of video games than girls. Concerning personality factors, conscientiousness was related to all addictive behaviors. Discussion and conclusions We conclude that EA is an important construct that should be considered in future models that attempt to explain addictive behaviors. PMID:27363463

  7. Avoiding Braess' Paradox Through Collective Intelligence

    NASA Technical Reports Server (NTRS)

    Wolpert , David H.; Tumer, Kagan

    1999-01-01

    In an Ideal Shortest Path Algorithm (ISPA), at each moment each router in a network sends all of its traffic down the path that will incur the lowest cost to that traffic. In the limit of an infinitesimally small amount of traffic for a particular router, its routing that traffic via an ISPA is optimal, as far as cost incurred by that traffic is concerned. We demonstrate though that in many cases, due to the side-effects of one router's actions on another routers performance, having routers use ISPA's is suboptimal as far as global aggregate cost is concerned, even when only used to route infinitesimally small amounts of traffic. As a particular example of this we present an instance of Braess' paradox for ISPA'S, in which adding new links to a network decreases overall throughput. We also demonstrate that load-balancing, in which the routing decisions are made to optimize the global cost incurred by all traffic currently being routed, is suboptimal as far as global cost averaged across time is concerned. This is also due to "side-effects", in this case of current routing decision on future traffic. The theory of COllective INtelligence (COIN) is concerned precisely with the issue of avoiding such deleterious side-effects. We present key concepts from that theory and use them to derive an idealized algorithm whose performance is better than that of the ISPA, even in the infinitesimal limit. We present experiments verifying this, and also showing that a machine-learning-based version of this COIN algorithm in which costs are only imprecisely estimated (a version potentially applicable in the real world) also outperforms the ISPA, despite having access to less information than does the ISPA. In particular, this COIN algorithm avoids Braess' paradox.

  8. Geoengineering to Avoid Overshoot: An Uncertainty Analysis

    NASA Astrophysics Data System (ADS)

    Tanaka, K.

    2009-04-01

    Geoengineering (or climate engineering) using stratospheric sulfur injections (Crutzen, 2006) has been called for research in case of an urgent need for stopping global warming when other mitigation efforts were exhausted. Although there are a number of concerns over this idea (e.g. Robock, 2008), it is still useful to consider geoengineering as a possible method to limit warming caused by overshoot. Overshoot is a feature accompanied by low stabilizations scenarios aiming for a stringent target (Rao et al., 2008) in which total radiative forcing temporarily exceeds the target before reaching there. Scenarios achieving a 50% emission reduction by 2050 produces overshoot. Overshoot could cause sustained warming for decades due to the inertia of the climate system. If stratospheric sulfur injections were to be used as a "last resort" to avoid overshoot, what would be the suitable start-year and injection profile of such an intervention? Wigley (2006) examined climate response to combined mitigation/geoengineering scenarios with the intent to avert overshoot. Wigley's analysis demonstrated a basic potential of such a combined mitigation/geoengineering approach to avoid temperature overshoot - however it considered only simplistic sulfur injection profiles (all started in 2010), just one mitigation scenario, and did not examine the sensitivity of the climate response to any underlying uncertainties. This study builds upon Wigley's premise of the combined mitigation/geoengineering approach and brings associated uncertainty into the analysis. First, this study addresses the question as to how much geoengineering intervention would be needed to avoid overshoot by considering associated uncertainty? Then, would a geoengineering intervention of such a magnitude including uncertainty be permissible in considering all the other side effects? This study begins from the supposition that geoengineering could be employed to cap warming at 2.0°C since preindustrial. A few

  9. Landslide disaster avoidance: learning from Leyte

    NASA Astrophysics Data System (ADS)

    Davies, T. R.

    2006-12-01

    On 17 February 2006 a gigantic rockslide triggered a debris avalanche that overran the barangay Guinsaugon, St. Bernard in Southern Leyte Province, Philippines, burying 154 victims, with 990 missing including 246 school children. Even with satellite imagery, GIS-based landslide susceptibility modelling and real-time meteorological and seismic data analysis, scientific prediction of every potentially fatal landslide is not possible in most parts of the world. This is particular the case in steep, unstable, densely-populated country in which heavy rain is common. So how can further events of this type be prevented from turning into disasters? A number of precursory phenomena were noted by local inhabitants at Guinsaugon: a crack around the slope that failed was noticed in May 2005; coconut trees near the northern foot of the landslide scarp began to lean increasingly in the down-slope direction in December 2005; a slope around the northern edge of the 17 February 2006 landslide scarp failed on December 17, 2005; in the 9 days prior to the rockslide, 640 mm of rain fell; 450 mm in a 3-day period. Such phenomena are commonly reported by local inhabitants before large landslides (e.g. Elm, Mayunmarca, and many others). In many cases, therefore, it is in principle possible for local people to avoid the consequences of the landslide if they know enough to act appropriately in response to the precursory phenomena. For this possibility to be realized, appropriate information must be provided to and assimilated by the local population. Useful ways of achieving this include pamphlets, video, TV and radio programs and visits from civil defence personnel. The information must be properly presented; scientific language will be ineffective. A communication pyramid, leading from government agencies to local leaders, can facilitate the rapid availability of the information to all potentially susceptible communities. If science can determine those areas not vulnerable to landslide

  10. Conjunctions and Collision Avoidance with Electrodynamic Tethers

    NASA Astrophysics Data System (ADS)

    Levin, E.

    2013-09-01

    Electrodynamic propulsion technology is currently in development by NASA, ESA, and JAXA for the purpose of affordable removal of large debris objects from LEO. At the same time, the Naval Research Laboratory is preparing a 3U CubeSat with a 1-km electrodynamic tether for a flight demonstration of electrodynamic propulsion. This type of propulsion does not require fuel. The electrodynamic thrust is the Lorentz force acting on the electric current in a long conductor (tether) in the geomagnetic field. Electrons are collected from the ambient plasma on one end and emitted back into the plasma from the other end. The electric current loop is closed through the ionosphere, as demonstrated in two previous flights. The vehicle is solar powered. To support safe navigation of electrodynamic tethers, proper conjunction analysis and collision avoidance strategies are needed. The typical lengths of electrodynamic tethers for near-term applications are measured in kilometers, and the conjunction geometry is very different from the geometry of conjunctions between compact objects. It is commonly thought that the collision cross-section in a conjunction between a tether and a compact object is represented by the product of the tether length and the size of the object. However, rigorous analysis shows that this is not the case, and that the above assumption leads to grossly overestimated collision probabilities. The paper will present the results of a detailed mathematical analysis of the conjunction geometry and collision probabilities in close approaches between electrodynamic tethers and compact objects, such as satellites, rocket bodies, and debris fragments. Electrodynamic spacecraft will not require fuel, and therefore, can thrust constantly. Their orbit transfers can take many days, but can result in major orbit changes, including large rotations of the orbital plane, both in the inclination and the node. During these orbit transfers, the electrodynamic spacecraft will

  11. Neuroimaging the temporal dynamics of human avoidance to sustained threat.

    PubMed

    Schlund, Michael W; Hudgins, Caleb D; Magee, Sandy; Dymond, Simon

    2013-11-15

    Many forms of human psychopathology are characterized by sustained negative emotional responses to threat and chronic behavioral avoidance, implicating avoidance as a potential transdiagnostic factor. Evidence from both nonhuman neurophysiological and human neuroimaging studies suggests a distributed frontal-limbic-striatal brain network supports avoidance. However, our understanding of the temporal dynamics of the network to sustained threat that prompts sustained avoidance is limited. To address this issue, 17 adults were given extensive training on a modified free-operant avoidance task in which button pressing avoided money loss during a sustained threat period. Subsequently, subjects underwent functional magnetic resonance imaging while completing the avoidance task. In our regions of interest, we observed phasic, rather than sustained, activation during sustained threat in dorsolateral and inferior frontal regions, anterior and dorsal cingulate, ventral striatum and regions associated with emotion, including the amygdala, insula, substantia nigra and bed nucleus of the stria terminalis complex. Moreover, trait levels of experiential avoidance were negatively correlated with insula, hippocampal and amygdala activation. These findings suggest knowledge that one can consistently avoid aversive outcomes is not associated with decreased threat-related responses and that individuals with greater experiential avoidance exhibit reduced reactivity to initial threat. Implications for understanding brain mechanisms supporting human avoidance and psychological theories of avoidance are discussed. PMID:24095880

  12. Evidence against an Occasion Setting Account of Avoidance Learning

    ERIC Educational Resources Information Center

    Declercq, Mieke; De Houwer, Jan

    2011-01-01

    Earlier studies on human avoidance learning showed that an avoidance response reduces the expectancy that a warning stimulus (WS) will be followed by an unconditioned stimulus (US). This modulation can transfer to WSs with which the avoidance response did not occur in the past. Recent studies suggest that transfer of modulation is selective in…

  13. 50 CFR 600.510 - Gear avoidance and disposal.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Gear avoidance and disposal. 600.510... Gear avoidance and disposal. (a) Vessel and gear avoidance. (1) FFV's arriving on fishing grounds where fishing vessels are already fishing or have set their gear for that purpose must ascertain the...

  14. 50 CFR 600.510 - Gear avoidance and disposal.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Gear avoidance and disposal. 600.510... Gear avoidance and disposal. (a) Vessel and gear avoidance. (1) FFV's arriving on fishing grounds where fishing vessels are already fishing or have set their gear for that purpose must ascertain the...

  15. 50 CFR 600.510 - Gear avoidance and disposal.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 10 2011-10-01 2011-10-01 false Gear avoidance and disposal. 600.510... Gear avoidance and disposal. (a) Vessel and gear avoidance. (1) FFV's arriving on fishing grounds where fishing vessels are already fishing or have set their gear for that purpose must ascertain the...

  16. 50 CFR 600.510 - Gear avoidance and disposal.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Gear avoidance and disposal. 600.510... Gear avoidance and disposal. (a) Vessel and gear avoidance. (1) FFV's arriving on fishing grounds where fishing vessels are already fishing or have set their gear for that purpose must ascertain the...

  17. 14 CFR 417.231 - Collision avoidance analysis.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Collision avoidance analysis. 417.231..., DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.231 Collision avoidance analysis. (a) General. A flight safety analysis must include a collision avoidance analysis...

  18. 14 CFR 129.18 - Collision avoidance system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Collision avoidance system. 129.18 Section... § 129.18 Collision avoidance system. Effective January 1, 2005, any airplane you, as a foreign air... Avoidance Systems If you operate in the United States any . . . Then you must operate that airplane with:...

  19. 20 CFR 606.23 - Avoidance of tax credit reduction.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Avoidance of tax credit reduction. 606.23... Tax Credit Reduction § 606.23 Avoidance of tax credit reduction. (a) Applicability. Subsection (g) of... receipts and benefit outlays under the law in effect for the year for which avoidance is requested, as...

  20. 14 CFR 121.356 - Collision avoidance system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Collision avoidance system. 121.356 Section... Collision avoidance system. Effective January 1, 2005, any airplane you operate under this part must be equipped and operated according to the following table: Collision Avoidance Systems If you operate...

  1. 20 CFR 606.24 - Application for avoidance.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Application for avoidance. 606.24 Section 606... Credit Reduction § 606.24 Application for avoidance. (a) Application. (1) The Governor of the State shall... respect to which a State requests avoidance of tax credit reduction. The Governor is required to...

  2. 34 CFR 75.611 - Avoidance of flood hazards.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 1 2012-07-01 2012-07-01 false Avoidance of flood hazards. 75.611 Section 75.611... by a Grantee? Construction § 75.611 Avoidance of flood hazards. In planning the construction, a...) Evaluate flood hazards in connection with the construction; and (b) As far as practicable, avoid...

  3. 34 CFR 75.611 - Avoidance of flood hazards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Avoidance of flood hazards. 75.611 Section 75.611... by a Grantee? Construction § 75.611 Avoidance of flood hazards. In planning the construction, a...) Evaluate flood hazards in connection with the construction; and (b) As far as practicable, avoid...

  4. 34 CFR 75.611 - Avoidance of flood hazards.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 1 2011-07-01 2011-07-01 false Avoidance of flood hazards. 75.611 Section 75.611... by a Grantee? Construction § 75.611 Avoidance of flood hazards. In planning the construction, a...) Evaluate flood hazards in connection with the construction; and (b) As far as practicable, avoid...

  5. 34 CFR 75.611 - Avoidance of flood hazards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 1 2013-07-01 2013-07-01 false Avoidance of flood hazards. 75.611 Section 75.611... by a Grantee? Construction § 75.611 Avoidance of flood hazards. In planning the construction, a...) Evaluate flood hazards in connection with the construction; and (b) As far as practicable, avoid...

  6. 34 CFR 75.611 - Avoidance of flood hazards.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 34 Education 1 2014-07-01 2014-07-01 false Avoidance of flood hazards. 75.611 Section 75.611... by a Grantee? Construction § 75.611 Avoidance of flood hazards. In planning the construction, a...) Evaluate flood hazards in connection with the construction; and (b) As far as practicable, avoid...

  7. A Contemporary Behavior Analysis of Anxiety and Avoidance

    ERIC Educational Resources Information Center

    Dymond, Simon; Roche, Bryan

    2009-01-01

    Despite the central status of avoidance in explaining the etiology and maintenance of anxiety disorders, surprisingly little behavioral research has been conducted on human avoidance. In the present paper, first we provide a brief review of the empirical literature on avoidance. Next, we describe the implications of research on derived relational…

  8. 47 CFR 51.609 - Determination of avoided retail costs.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 3 2011-10-01 2011-10-01 false Determination of avoided retail costs. 51.609... (CONTINUED) INTERCONNECTION Resale § 51.609 Determination of avoided retail costs. (a) Except as provided in § 51.611, the amount of avoided retail costs shall be determined on the basis of a cost study...

  9. 47 CFR 51.609 - Determination of avoided retail costs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Determination of avoided retail costs. 51.609... (CONTINUED) INTERCONNECTION Resale § 51.609 Determination of avoided retail costs. (a) Except as provided in § 51.611, the amount of avoided retail costs shall be determined on the basis of a cost study...

  10. An expert system for wind shear avoidance

    NASA Technical Reports Server (NTRS)

    Stengel, Robert F.; Stratton, D. Alexander

    1990-01-01

    A study of intelligent guidance and control concepts for protecting against the adverse effects of wind shear during aircraft takeoffs and landings is being conducted, with current emphasis on developing an expert system for wind shear avoidance. Principal objectives are to develop methods for assessing the likelihood of wind shear encounter (based on real-time information in the cockpit), for deciding what flight path to pursue (e.g., takeoff abort, landing go-around, or normal climbout or glide slope), and for using the aircraft's full potential for combating wind shear. This study requires the definition of both deterministic and statistical techniques for fusing internal and external information , for making go/no-go decisions, and for generating commands to the manually controlled flight. The program has begun with the development of the WindShear Safety Advisor, an expert system for pilot aiding that is based on the FAA Windshear Training Aid; a two-volume manual that presents an overview , pilot guide, training program, and substantiating data provides guidelines for this initial development. The WindShear Safety Advisor expert system currently contains over 200 rules and is coded in the LISP programming language.

  11. Avoiding sexual harassment liability in veterinary practices.

    PubMed

    Lacroix, C A; Wilson, J F

    1996-05-15

    Harassment based on gender violates the rule of workplace equality established by Title VII of the Civil Rights Act and enforced by the EEOC. In 1986, the US Supreme Court, in Meritor Savings Bank v Vinson, established the criteria that must be met for a claim of hostile environment sexual harassment to be considered valid. Plaintiffs must show that they were subjected to conduct based on their gender, that it was unwelcome, and that it was severe and pervasive enough to alter their condition of employment, resulting in an abusive working environment. There have been few sexual harassment cases involving veterinary professionals, and it is our goal to help keep the number of filed actions to a minimum. The most effective way to avoid hostile environment sexual harassment claims is to confront the issue openly and to adopt a sexual harassment policy for the practice. When it comes to sexual harassment, an ounce of prevention is unquestionably worth a pound of cure. PMID:8641947

  12. Avoided valence transition in a plutonium superconductor.

    PubMed

    Ramshaw, B J; Shekhter, Arkady; McDonald, Ross D; Betts, Jon B; Mitchell, J N; Tobash, P H; Mielke, C H; Bauer, E D; Migliori, Albert

    2015-03-17

    The d and f electrons in correlated metals are often neither fully localized around their host nuclei nor fully itinerant. This localized/itinerant duality underlies the correlated electronic states of the high-Tc cuprate superconductors and the heavy-fermion intermetallics and is nowhere more apparent than in the 5f valence electrons of plutonium. Here, we report the full set of symmetry-resolved elastic moduli of PuCoGa5--the highest Tc superconductor of the heavy fermions (Tc = 18.5 K)--and find that the bulk modulus softens anomalously over a wide range in temperature above Tc. The elastic symmetry channel in which this softening occurs is characteristic of a valence instability--therefore, we identify the elastic softening with fluctuations of the plutonium 5f mixed-valence state. These valence fluctuations disappear when the superconducting gap opens at Tc, suggesting that electrons near the Fermi surface play an essential role in the mixed-valence physics of this system and that PuCoGa5 avoids a valence transition by entering the superconducting state. The lack of magnetism in PuCoGa5 has made it difficult to reconcile with most other heavy-fermion superconductors, where superconductivity is generally believed to be mediated by magnetic fluctuations. Our observations suggest that valence fluctuations play a critical role in the unusually high Tc of PuCoGa5.

  13. Avoided valence transition in a plutonium superconductor

    PubMed Central

    Ramshaw, B. J.; Shekhter, Arkady; McDonald, Ross D.; Betts, Jon B.; Mitchell, J. N.; Tobash, P. H.; Mielke, C. H.; Bauer, E. D.; Migliori, Albert

    2015-01-01

    The d and f electrons in correlated metals are often neither fully localized around their host nuclei nor fully itinerant. This localized/itinerant duality underlies the correlated electronic states of the high-Tc cuprate superconductors and the heavy-fermion intermetallics and is nowhere more apparent than in the 5f valence electrons of plutonium. Here, we report the full set of symmetry-resolved elastic moduli of PuCoGa5—the highest Tc superconductor of the heavy fermions (Tc = 18.5 K)—and find that the bulk modulus softens anomalously over a wide range in temperature above Tc. The elastic symmetry channel in which this softening occurs is characteristic of a valence instability—therefore, we identify the elastic softening with fluctuations of the plutonium 5f mixed-valence state. These valence fluctuations disappear when the superconducting gap opens at Tc, suggesting that electrons near the Fermi surface play an essential role in the mixed-valence physics of this system and that PuCoGa5 avoids a valence transition by entering the superconducting state. The lack of magnetism in PuCoGa5 has made it difficult to reconcile with most other heavy-fermion superconductors, where superconductivity is generally believed to be mediated by magnetic fluctuations. Our observations suggest that valence fluctuations play a critical role in the unusually high Tc of PuCoGa5. PMID:25737548

  14. Cooperative organic mine avoidance path planning

    NASA Astrophysics Data System (ADS)

    McCubbin, Christopher B.; Piatko, Christine D.; Peterson, Adam V.; Donnald, Creighton R.; Cohen, David

    2005-06-01

    The JHU/APL Path Planning team has developed path planning techniques to look for paths that balance the utility and risk associated with different routes through a minefield. Extending on previous years' efforts, we investigated real-world Naval mine avoidance requirements and developed a tactical decision aid (TDA) that satisfies those requirements. APL has developed new mine path planning techniques using graph based and genetic algorithms which quickly produce near-minimum risk paths for complicated fitness functions incorporating risk, path length, ship kinematics, and naval doctrine. The TDA user interface, a Java Swing application that obtains data via Corba interfaces to path planning databases, allows the operator to explore a fusion of historic and in situ mine field data, control the path planner, and display the planning results. To provide a context for the minefield data, the user interface also renders data from the Digital Nautical Chart database, a database created by the National Geospatial-Intelligence Agency containing charts of the world's ports and coastal regions. This TDA has been developed in conjunction with the COMID (Cooperative Organic Mine Defense) system. This paper presents a description of the algorithms, architecture, and application produced.

  15. Whole arm obstacle avoidance for teleoperated robots

    SciTech Connect

    Feddema, J.T.; Novak, J.L.

    1993-10-01

    This paper describes a collision avoidance system using Whole Arm Proximity (WHAP) sensors on a PUMA 560 robot arm. The capacitance-based sensors generate electric fields which can completely encompass the robot arm and detect obstacles as they approach from any direction. The directional obstacle information gathered by the WHAP sensors together with the sensor geometry and robot configuration is used to scale the commanded joint velocities of the robot. A linearized relationship between the WHAP sensor reading and the distance from the obstacle allows direct transformation of perturbations in VHAP readings to perturbations in joint velocities. The VHAP reading is used to directly reduce the component of the command input velocity along the normal axis of the sensor, allowing graceful reductions in speed as the arm approaches the obstacle. By scaling only the component of the velocity vector in the,direction of the nearest obstacles, the control system restricts motion in the direction of obstacles while permitting unconstrained motion in other directions.

  16. The amygdala: securing pleasure and avoiding pain

    PubMed Central

    Fernando, Anushka B. P.; Murray, Jennifer E.; Milton, Amy L.

    2013-01-01

    The amygdala has traditionally been associated with fear, mediating the impact of negative emotions on memory. However, this view does not fully encapsulate the function of the amygdala, nor the impact that processing in this structure has on the motivational limbic corticostriatal circuitry of which it is an important structure. Here we discuss the interactions between different amygdala nuclei with cortical and striatal regions involved in motivation; interconnections and parallel circuitries that have become increasingly understood in recent years. We review the evidence that the amygdala stores memories that allow initially motivationally neutral stimuli to become associated through pavlovian conditioning with motivationally relevant outcomes which, importantly, can be either appetitive (e.g. food) or aversive (e.g. electric shock). We also consider how different psychological processes supported by the amygdala such as conditioned reinforcement and punishment, conditioned motivation and suppression, and conditioned approach and avoidance behavior, are not only psychologically but also neurobiologically dissociable, being mediated by distinct yet overlapping neural circuits within the limbic corticostriatal circuitry. Clearly the role of the amygdala goes beyond encoding aversive stimuli to also encode the appetitive, requiring an appreciation of the amygdala's mediation of both appetitive and fearful behavior through diverse psychological processes. PMID:24367307

  17. Visually guided collision avoidance and collision achievement.

    PubMed

    Regan; Gray

    2000-03-01

    To survive on today's highways, a driver must have highly developed skills in visually guided collision avoidance. To play such games as cricket, tennis or baseball demands accurate, precise and reliable collision achievement. This review discusses evidence that some of these tasks are performed by predicting where an object will be at some sharply defined instant, several hundred milliseconds in the future, while other tasks are performed by utilizing the fact that some of our motor actions change what we see in ways that obey lawful relationships, and can therefore be learned. Several monocular and binocular visual correlates of the direction of an object's motion relative to the observer's head have been derived theoretically, along with visual correlates of the time to collision with an approaching object. Although laboratory psychophysics can identify putative neural mechanisms by showing which of the known correlates are processed by the human visual system independently of other visual information, it is only field research on, for example, driving, aviation and sport that can show which visual cues are actually used in these activities. This article reviews this research and describes a general psychophysically based rational approach to the design of such field studies.

  18. Brief cognitive therapy for avoidant personality disorder.

    PubMed

    Rees, Clare S; Pritchard, Rhian

    2015-03-01

    Avoidant personality disorder (APD) is associated with a high level of impairment in multiple areas of functioning. However, research on the treatment of APD is scarce, and there is an absence of empirically evaluated effective treatment approaches available. This study offers a preliminary investigation of the use of brief cognitive therapy to treat APD. Two individuals, both with a principal diagnosis of APD, but who also possessed a number of comorbidities, participated in 12 weekly sessions. A series of diagnostic symptom severity, global functioning, and self-report measures were completed at pretreatment, posttreatment and at 6-week follow-up. In addition, regular monitoring of each participant's strength of belief in 4 personally identified cognitions associated with APD was completed. Reductions in APD symptoms, associated negative affect, and increases to quality of life were observed for both participants at posttreatment and follow-up phases. Results suggest that brief cognitive therapy may be an effective treatment for APD and that further studies with larger samples are warranted.

  19. Laser radar system for obstacle avoidance

    NASA Astrophysics Data System (ADS)

    Bers, Karlheinz; Schulz, Karl R.; Armbruster, Walter

    2005-09-01

    The threat of hostile surveillance and weapon systems require military aircraft to fly under extreme conditions such as low altitude, high speed, poor visibility and incomplete terrain information. The probability of collision with natural and man-made obstacles during such contour missions is high if detection capability is restricted to conventional vision aids. Forward-looking scanning laser radars which are build by the EADS company and presently being flight tested and evaluated at German proving grounds, provide a possible solution, having a large field of view, high angular and range resolution, a high pulse repetition rate, and sufficient pulse energy to register returns from objects at distances of military relevance with a high hit-and-detect probability. The development of advanced 3d-scene analysis algorithms had increased the recognition probability and reduced the false alarm rate by using more readily recognizable objects such as terrain, poles, pylons, trees, etc. to generate a parametric description of the terrain surface as well as the class, position, orientation, size and shape of all objects in the scene. The sensor system and the implemented algorithms can be used for other applications such as terrain following, autonomous obstacle avoidance, and automatic target recognition. This paper describes different 3D-imaging ladar sensors with unique system architecture but different components matched for different military application. Emphasis is laid on an obstacle warning system with a high probability of detection of thin wires, the real time processing of the measured range image data, obstacle classification und visualization.

  20. Avoiding the death risk of avoiding a dread risk: the aftermath of March 11 in Spain.

    PubMed

    López-Rousseau, Alejandro

    2005-06-01

    Abstract-After the airplane attacks of September 11, 2001, in the United States, many Americans drove instead of flying, to avoid the risk of terrorism. As a result, there were extra car accidents in which many people died. This study tested whether a similar effect occurred in Spain after the train bombings of March 11, 2004, in Madrid. Data on train travel, highway traffic, and fatal highway accidents were analyzed for the months immediately following March 11. Results show that, like Americans, Spaniards avoided the dread risk of terror attacks, but unlike Americans, they did not confront the death risk of fatal accidents instead. A sociopolitical interpretation for these findings is offered. PMID:15943666

  1. Faecal avoidance and selective foraging: do wild mice have the luxury to avoid faeces?

    PubMed

    Walsh, Patrick T; McCreless, Erin; Pedersen, Amy B

    2013-09-01

    Host-parasite interactions are a key determinant of the population dynamics of wild animals, and behaviours that reduce parasite transmission and infection may be important for improving host fitness. While antiparasite behaviours have been demonstrated in laboratory animals and domesticated ungulates, whether these behaviours operate in the wild is poorly understood. Therefore, examining antiparasite behaviours in natural populations is crucial for understanding their ecological significance. In this study, we examined whether two wild rodents (white-footed mice, Peromyscus leucopus, and deer mice, Peromyscus maniculatus), selectively foraged away from conspecific faeces or avoided faeces altogether, and whether faecal gastrointestinal parasite status affected their behaviour. We also tested whether wild mice, when nesting, avoided using material that had previously been used by healthy or parasite-infected conspecifics. Our results, in contrast to laboratory mouse studies, suggest that wild mice do not demonstrate faecal avoidance, selective foraging or selective use of nesting material; they preferred being near faeces and did not differentiate between faeces from parasitized and uninfected conspecifics. Behavioural avoidance to reduce parasite infection may still represent an important strategy; however, mice in our study population appeared to favour the opportunity to feed and nest over the risks of coming into contact with faecal-transmitted parasites. Furthermore, the presence of conspecific faeces may actually provide a positive cue of a good foraging or nesting location. Ultimately, balancing the trade-off of performing antiparasite behaviours to reduce infection with missing an important feeding or nesting opportunity may be very different for animals in the wild facing complex and stochastic environments. PMID:24027342

  2. Obstacle avoiding patterns and cohesiveness of fish school.

    PubMed

    Nguyen, Linh Thi Hoai; Tạ, Việt Tôn; Yagi, Atsushi

    2016-10-01

    This paper is devoted to studying obstacle avoiding patterns and cohesiveness of fish school. First, we introduce a model of stochastic differential equations (SDEs) for describing the process of fish school's obstacle avoidance. Second, on the basis of the model we find obstacle avoiding patterns. Our observations show that there are clear four obstacle avoiding patterns, namely, Rebound, Pullback, Pass and Reunion, and Separation. Furthermore, the emerging patterns change when parameters change. Finally, we present a scientific definition for fish school's cohesiveness that will be an internal property characterizing the strength of fish schooling. There are then evidences that the school cohesiveness can be measured through obstacle avoiding patterns. PMID:27449357

  3. Avoidance learning, Pavlovian conditioning, and the development of phobias.

    PubMed

    Siddle, D A; Bond, N W

    1988-10-01

    This paper examines the role of Pavlovian conditioning in the acquisition, maintenance and elimination of human phobias. Because many conceptualizations of human fears and phobias are based on data from studies of avoidance learning in animals, we first review theories of avoidance. Our conclusion is that none of the extant theories provides an adequate account of avoidance learning, and we propose a model of avoidance that involves Pavlovian, but not instrumental learning. We then analyse critically arguments that Pavlovian conditioning plays only a small role in the aetiology of fears. Finally, the paper examines the implications of a conditioning model of avoidance for the study of human fears and phobias.

  4. Infection-avoidance behaviour in humans and other animals.

    PubMed

    Curtis, Valerie A

    2014-10-01

    Compared with living free, the parasitic way of life has many attractions. Parasites create problems for all animals. Potential hosts can respond by learning to live with parasites (tolerance), actively fighting them (resistance), or they can avoid becoming infected in the first place (avoidance). I propose here a new classification of avoidance behaviour according to the epidemiology of infection risk, where animals must avoid (i) conspecifics, (ii) parasites and their vectors, (iii) parasite-rich environments, and (iv) niche infestation. I further explore how the disgust adaptive system, which coordinates avoidance behaviour, may form a continuum with the immune system through the sharing of signalling pathways, sites of action, and evolutionary history.

  5. AVOID BECOMING A VICTIM OF COUNTERFEIT ITEMS

    SciTech Connect

    WARRINER RD

    2011-07-13

    In today's globalized economy, we cannot live without imported products. Most people do not realize how thin the safety net of regulation and inspection really is. Less than three percent of imported products receive any form of government inspection prior to sale. Avoid flea markets, street vendors and deep discount stores. The sellers of counterfeit wares know where to market their products. They look for individuals who are hungry for a brand name item but do not want to pay a brand name price for it. The internet provides anonymity to the sellers of counterfeit products. Unlike Europe, U.S. law does not hold internet-marketing organizations, responsible for the quality of the products sold on their websites. These organizations will remove an individual vendor when a sufficient number of complaints are lodged, but they will not take responsibility for the counterfeit products you may have purchased. EBay has a number of counterfeit product guides to help you avoid being a victim of the sellers of these products. Ten percent of all medications taken worldwide are counterfeit. If you do buy medications on-line, be sure that the National Association of Boards of Pharmacy Verified Internet Pharmacy Practice Sites (VIPPS) recommends the pharmacy you choose to use. Inspect all medication purchases and report any change in color, shape, imprinting or odor to your pharmacist. If you take generic medications these attributes may change from one manufacturer to another. Your pharmacist should inform you of any changes when you refill your prescription. If they do not, get clarification prior to taking the medication. Please note that the Federal Drug Administration (FDA) does not regulate supplements. The FDA only steps in when a specific supplement proves to cause physical harm or contains a regulated ingredient. Due to counterfeiting, Underwriters Laboratories (UL) changed their label design three times since 1996. The new gold label should be attached to the cord or

  6. Green light induces shade avoidance symptoms.

    PubMed

    Zhang, Tingting; Maruhnich, Stefanie A; Folta, Kevin M

    2011-11-01

    Light quality and quantity affect plant adaptation to changing light conditions. Certain wavelengths in the visible and near-visible spectrum are known to have discrete effects on plant growth and development, and the effects of red, far-red, blue, and ultraviolet light have been well described. In this report, an effect of green light on Arabidopsis (Arabidopsis thaliana) rosette architecture is demonstrated using a narrow-bandwidth light-emitting diode-based lighting system. When green light was added to a background of constant red and blue light, plants exhibited elongation of petioles and upward leaf reorientation, symptoms consistent with those observed in a shaded light environment. The same green light-induced phenotypes were also observed in phytochrome (phy) and cryptochrome (cry) mutant backgrounds. To explore the molecular mechanism underlying the green light-induced response, the accumulation of shade-induced transcripts was measured in response to enriched green light environments. Transcripts that have been demonstrated to increase in abundance under far-red-induced shade avoidance conditions either decrease or exhibit no change when green light is added. However, normal far-red light-associated transcript accumulation patterns are observed in cryptochrome mutants grown with supplemental green light, indicating that the green-absorbing form of cryptochrome is the photoreceptor active in limiting the green light induction of shade-associated transcripts. These results indicate that shade symptoms can be induced by the addition of green light and that cryptochrome receptors and an unknown light sensor participate in acclimation to the enriched green environment.

  7. [PARTICIPANT OBSERVATION TO AVOID SUBJUGATING "OTHER" ETHICS].

    PubMed

    Brelet, Claudine

    2015-10-01

    When we want to implant efficient, lasting healthcare programmes in order to improve the health conditions of a population, we have to be able to distance ourselves from our own conceptions of what is ethical or not, good or bad, better or worse. In fact, these notions can be conceived differently according to the sociocultural context. Thus, international aid has taught us how harmful it can be to impose changes which, a priori, may go against "other" ethics. The imbalances and misunderstandings that result always jeopardise the success of programmes which, otherwise, might have been accepted and even taken over by the populations concerned. Therefore the theoretical and methodological approaches of anthropology can contribute significantly to having certain programmes proposed which respect both so-called 'universal' values and the values of local populations who could benefit from them. In this article, by examining the history of the theoretical and methodological developments of participant observation, we will see how it could constitute an initiatory praxis to ethics in general and culturally enrich certain principles advocated by biomedical ethics. By enabling semantic bridges from one culture to another, and vice versa, this classic approach of anthropology makes it possible to integrate into the ways of implanting healthcare projects the manner in which a population perceives its own systems of reference and values. From the scientific point of view, it is essential to develop approaches which avoid having "other". ethics subjugated to Western concepts. Research on ethnomedicines could therefore contribute to their being taken into account in projects aiming at the common good.

  8. Avoiding unfavorable results in postburn contracture hand.

    PubMed

    Bhattacharya, Sameek

    2013-05-01

    Deformities of the hands are a fairly common sequel of burn especially in the developing world. This is because of high incidence of burns, limited access to standard treatment and rehabilitation. The best outcome of a burnt hand is when deformities are prevented from developing. A good functional result is possible when due consideration is paid to hands during resuscitation, excisional surgery, reconstructive surgery and physiotherapy. The post-burns deformities of hand develop due direct thermal damage or secondary to intrinsic minus position due to oedema or vascular insufficiency. During the acute phase the concerns are, maintenance circulation minimize oedema prevent unphysiological positioning and wound closure with autogenous tissue as soon as possible. The rehabilitation program during the acute phase starts from day one and goes on till the hand has healed and has regained full range of motion. Full blown hand contractures are challenging to correct and become more difficult as time passes. Long-standing cases often land up with attenuation of extensor apparatus leading to swan neck and boutonniere deformity, muscle shortening and bony ankylosis. The major and most common pitfall after contracture release is relapse. The treatment protocol of contracture is solely directed towards countering this tendency. This article aims to guide a surgeon in obtaining optimal hand function and avoid pit falls at different stages of management of hand burns. The reasons of an unfavourable outcome of a burnt hand are possible lack of optimal care in the acute phase, while planning and performing reconstructive procedure and during aftercare and rehabilitation. PMID:24501479

  9. Avoidance behavior: a free-operant lever-press avoidance task for the assessment of the effects of safety signals.

    PubMed

    Fernando, Anushka B P; Mar, Adam C; Urcelay, Gonzalo P; Dickinson, Anthony; Robbins, Trevor W

    2015-01-05

    This protocol details a free-operant avoidance paradigm that has been developed to evaluate the relative contribution of different sources of reinforcement of avoidance behavior that may play an important role in the development and maintenance of human anxiety disorders. The task enables the assessment of the effects of safety cues that signal a period free from danger on lever-press avoidance behavior. Avoidance behavior trained using this protocol has been shown to be sensitive to both behavioral and pharmacological manipulations and has been optimized so that it takes approximately 1 month for rats to perform at high levels of stable avoidance responding.

  10. Towards better patient care: drugs to avoid.

    PubMed

    2013-04-01

    Common sense dictates that one should choose tried and tested drugs with proven, concrete benefits that outweigh their adverse effects. Many new drugs are approved each year, often despite a lack of solid evidence that they are any better than existing treatments. Worse, some are approved despite being less effective or more harmful than current options. Massive promotion is used to ensure that such drugs achieve a positive image in the eyes of healthcare professionals and patients. Renowned "opinion leaders" intervene in their favour at conferences and in specialist media, and their opinions are further propagated by specialists in the field. Finally, campaigns in the lay media are used to highlight the target illness, encouraging patients to request a prescription. New data sometimes show that older, initially promising drugs are less effective or more harmful than first thought. For all these reasons, many drugs that are now present on the market are more harmful than beneficial and should be avoided. Unfortunately, negative assessment data and warnings are often drowned in the flood of promotion and advertising. Front-line healthcare professionals who are determined to act in their patients' best interests can find themselves swimming against a tide of specialist opinion, marketing authorisation, and reimbursement decisions. By leaving drugs that are more harmful than beneficial on the market and contenting themselves with simple half-measures, healthcare authorities are failing in their duty to protect patients. Prescrire, a journal funded solely by its subscribers, does not seek to do the work of health authorities, and does not have the means to do so. Prescrire's goal is simply to help healthcare professionals provide better care. The following text lists the principal drugs that we consider more harmful than beneficial, based on our reviews published between 2010 and 2012 in our French edition. These drugs should not be used. Patients and healthcare

  11. Towards better patient care: drugs to avoid.

    PubMed

    2013-04-01

    Common sense dictates that one should choose tried and tested drugs with proven, concrete benefits that outweigh their adverse effects. Many new drugs are approved each year, often despite a lack of solid evidence that they are any better than existing treatments. Worse, some are approved despite being less effective or more harmful than current options. Massive promotion is used to ensure that such drugs achieve a positive image in the eyes of healthcare professionals and patients. Renowned "opinion leaders" intervene in their favour at conferences and in specialist media, and their opinions are further propagated by specialists in the field. Finally, campaigns in the lay media are used to highlight the target illness, encouraging patients to request a prescription. New data sometimes show that older, initially promising drugs are less effective or more harmful than first thought. For all these reasons, many drugs that are now present on the market are more harmful than beneficial and should be avoided. Unfortunately, negative assessment data and warnings are often drowned in the flood of promotion and advertising. Front-line healthcare professionals who are determined to act in their patients' best interests can find themselves swimming against a tide of specialist opinion, marketing authorisation, and reimbursement decisions. By leaving drugs that are more harmful than beneficial on the market and contenting themselves with simple half-measures, healthcare authorities are failing in their duty to protect patients. Prescrire, a journal funded solely by its subscribers, does not seek to do the work of health authorities, and does not have the means to do so. Prescrire's goal is simply to help healthcare professionals provide better care. The following text lists the principal drugs that we consider more harmful than beneficial, based on our reviews published between 2010 and 2012 in our French edition. These drugs should not be used. Patients and healthcare

  12. Adolescents' approach-avoidance behaviour in the context of pain.

    PubMed

    Fisher, Emma; Keogh, Edmund; Eccleston, Christopher

    2016-02-01

    Adolescents who experience pain often face competing goals and have to choose whether to approach (confront) or avoid pain. This study investigates the decisions adolescents make when their pain conflicts with a valued goal. Adolescents between the ages of 15 and 18 years (N = 170) completed questionnaires on general and pain-specific anxiety, courage, and dispositional avoidance. Adolescents were presented with 16 vignettes (8 high pain intensity, 8 low pain intensity), which described pain conflicting with a goal (eg, doing well at school, seeing friends). Adolescents rated goals for importance and reported how likely they would be to approach or avoid each pain. Adolescents were more likely to avoid and were more fearful of high pain intensity than low pain intensity vignettes. Pain anxiety predicted higher levels of avoidance for both pain intensities. General anxiety was not a significant predictor of avoidance for either pain intensity. Goal importance promoted approach of goals, but only when pain was described as intense. However, pain anxiety predicted avoidance beyond the importance of goals for high pain intensity vignettes. In addition, we compared approach-avoidance of adolescents with and without chronic pain; analyses revealed no differences in approach-avoidance behaviour. We also found that behavioural endurance was predictive of approach and dispositional avoidance predicted higher avoidance, but courage was not predictive of behaviour in this task. We adopt a motivational perspective when interpreting the findings and consider whether the fear-avoidance model should be extended to include the function of avoidance or approach in the pursuit of a desired goal.

  13. Excise Tax Avoidance: The Case of State Cigarette Taxes

    PubMed Central

    DeCicca, Philip; Kenkel, Donald; Liu, Feng

    2013-01-01

    We conduct an applied welfare economics analysis of cigarette tax avoidance. We develop an extension of the standard formula for the optimal Pigouvian corrective tax to incorporate the possibility that consumers avoid the tax by making purchases in nearby lower-tax jurisdictions. To provide a key parameter for our formula, we estimate a structural endogenous switching regression model of border-crossing and cigarette prices. In illustrative calculations, we find that for many states, after taking into account tax avoidance the optimal tax is at least 20 percent smaller than the standard Pigouvian tax that simply internalizes external costs. Our empirical estimate that tax avoidance strongly responds to the price differential is the main reason for this result. We also use our results to examine the benefits of replacing avoidable state excise taxes with a harder-to-avoid federal excise tax on cigarettes. PMID:24140760

  14. Neural systems underlying approach and avoidance in anxiety disorders.

    PubMed

    Aupperle, Robin L; Paulus, Martin P

    2010-01-01

    Approach-avoidance conflict is an important psychological concept that has been used extensively to better understand cognition and emotion. This review focuses on neural systems involved in approach, avoidance, and conflict decision making, and how these systems overlap with implicated neural substrates of anxiety disorders. In particular, the role of amygdala, insula, ventral striatal, and prefrontal regions are discussed with respect to approach and avoidance behaviors. Three specific hypotheses underlying the dysfunction in anxiety disorders are proposed, including: (i) over-representation of avoidance valuation related to limbic overactivation; (ii) under- or over-representation of approach valuation related to attenuated or exaggerated striatal activation respectively; and (iii) insufficient integration and arbitration of approach and avoidance valuations related to attenuated orbitofrontal cortex activation. These dysfunctions can be examined experimentally using versions of existing decision-making paradigms, but may also require new translational and innovative approaches to probe approach-avoidance conflict and related neural systems in anxiety disorders. PMID:21319496

  15. Individual differences in physiological flexibility predict spontaneous avoidance.

    PubMed

    Aldao, Amelia; Dixon-Gordon, Katherine L; De Los Reyes, Andres

    2016-08-01

    People often regulate their emotions by resorting to avoidance, a putatively maladaptive strategy. Prior work suggests that increased psychopathology symptoms predict greater spontaneous utilisation of this strategy. Extending this work, we examined whether heightened resting cardiac vagal tone (which reflects a general ability to regulate emotions in line with contextual demands) predicts decreased spontaneous avoidance. In Study 1, greater resting vagal tone was associated with reduced spontaneous avoidance in response to disgust-eliciting pictures, beyond anxiety and depression symptoms and emotional reactivity. In Study 2, resting vagal tone interacted with anxiety and depression symptoms to predict spontaneous avoidance in response to disgust-eliciting film clips. The positive association between symptoms and spontaneous avoidance was more pronounced among participants with reduced resting vagal tone. Thus, increased resting vagal tone might protect against the use of avoidance. Our findings highlight the importance of assessing both subjective and biological processes when studying individual differences in emotion regulation.

  16. Generalisation of fear and avoidance along a semantic continuum.

    PubMed

    Boyle, Sean; Roche, Bryan; Dymond, Simon; Hermans, Dirk

    2016-01-01

    Directly conditioned fear and avoidance readily generalises to dissimilar but conceptually related stimuli. Here, for the first time, we examined the conceptual/semantic generalisation of both fear and avoidance using real words (synonyms). Participants were first exposed to a differential fear conditioning procedure in which one word (e.g., "broth"; CS+) was followed with brief electric shock [unconditioned stimulus (US)] and another was not (e.g., "assist"; CS-). Next, an instrumental conditioning phase taught avoidance in the presence the CS+ but not the CS-. During generalisation testing, synonyms of the CS+ (e.g., "soup"; GCS+) and CS- (e.g., "help"; GCS-) were presented in the absence of shock. Conditioned fear and avoidance, measured via skin conductance responses, behavioural avoidance and US expectancy ratings, generalised to the semantically related, but not to the semantically unrelated, synonyms. Findings have implications for how natural language categories and concepts mediate the expansion of fear and avoidance repertoires in clinical contexts.

  17. Conflict: run! Reduced Stroop interference with avoidance responses.

    PubMed

    Schouppe, Nathalie; De Houwer, Jan; Ridderinkhof, K Richard; Notebaert, Wim

    2012-01-01

    Conflict has been hypothesized to be aversive, triggering avoidance behaviour (Botvinick, 2007). To test this hypothesis, a standard Stroop task was modified such that avoiding was part of the response set. More precisely, participants were asked to move a manikin towards or away from Stroop stimuli, depending on the colour of the words. Results showed that the type of response (approach versus avoidance) modulated the Stroop congruency effect. Specifically, the reaction time analysis revealed that the stimulus congruency effect disappeared with avoidance responses, contrary to approach responses where a stimulus congruency effect was present. Moreover, the error data showed a reduction of the general congruency effect when avoiding. These results suggest that in the face of conflict, avoidance is the predominant response.

  18. Neural systems underlying approach and avoidance in anxiety disorders

    PubMed Central

    Robin L., Aupperle; Martin, P. Paulus

    2010-01-01

    Approach-avoidance conflict is an important psychological concept that has been used extensively to better understand cognition and emotion. This review focuses on neural systems involved in approach, avoidance, and conflict decision making, and how these systems overlap with implicated neural substrates of anxiety disorders. In particular, the role of amygdala, insula, ventral striatal, and prefrontal regions are discussed with respect to approach and avoidance behaviors. Three specific hypotheses underlying the dysfunction in anxiety disorders are proposed, including: (i) over-representation of avoidance valuation related to limbic overactivation; (ii) under- or over-representation of approach valuation related to attenuated or exaggerated striatal activation respectively; and (iii) insufficient integration and arbitration of approach and avoidance valuations related to attenuated orbitofrontal cortex activation. These dysfunctions can be examined experimentally using versions of existing decision-making paradigms, but may also require new translational and innovative approaches to probe approach-avoidance conflict and related neural systems in anxiety disorders. PMID:21319496

  19. Excise tax avoidance: the case of state cigarette taxes.

    PubMed

    DeCicca, Philip; Kenkel, Donald; Liu, Feng

    2013-12-01

    We conduct an applied welfare economics analysis of cigarette tax avoidance. We develop an extension of the standard formula for the optimal Pigouvian corrective tax to incorporate the possibility that consumers avoid the tax by making purchases in nearby lower tax jurisdictions. To provide a key parameter for our formula, we estimate a structural endogenous switching regression model of border-crossing and cigarette prices. In illustrative calculations, we find that for many states, after taking into account tax avoidance the optimal tax is at least 20% smaller than the standard Pigouvian tax that simply internalizes external costs. Our empirical estimate that tax avoidance strongly responds to the price differential is the main reason for this result. We also use our results to examine the benefits of replacing avoidable state excise taxes with a harder-to-avoid federal excise tax on cigarettes.

  20. Who Avoids Cancer Information? Examining a Psychological Process Leading to Cancer Information Avoidance.

    PubMed

    Chae, Jiyoung

    2016-07-01

    Although cancer information avoidance (CIA) is detrimental to public health, predictors of CIA have not been fully investigated. Based on uncertainty management theory, this study viewed CIA as a response to uncertainty related to the distress associated with cancer information and illustrated the psychological process leading to CIA. Given the current information context, it was hypothesized that cancer information overload (CIO), accompanied by confusion and stress about cancer information, causes CIA. As trait anxiety is a strong predictor of CIO, it was also hypothesized that trait anxiety has an indirect effect on CIA through CIO. Study 1 tested this relationship in a U.S. sample (N = 384); the results showed that CIO was positively associated with CIA and that trait anxiety indirectly influenced CIA through CIO. Whereas Study 1 tested the relationship with cross-sectional data in the general cancer context, Study 2 replicated Study 1 with 3-wave longitudinal data in the context of a specific cancer (i.e., stomach cancer) in South Korea (N = 1,130 at Wave 1, 813 at Wave 2, and 582 at Wave 3). Trait anxiety at Wave 1 predicted CIO at Wave 2, which in turn increased CIA at Wave 3, suggesting that some people are inherently inclined to avoid cancer information due to their trait anxiety, which results in confusion about cancer information. PMID:27337343

  1. Who Avoids Cancer Information? Examining a Psychological Process Leading to Cancer Information Avoidance.

    PubMed

    Chae, Jiyoung

    2016-07-01

    Although cancer information avoidance (CIA) is detrimental to public health, predictors of CIA have not been fully investigated. Based on uncertainty management theory, this study viewed CIA as a response to uncertainty related to the distress associated with cancer information and illustrated the psychological process leading to CIA. Given the current information context, it was hypothesized that cancer information overload (CIO), accompanied by confusion and stress about cancer information, causes CIA. As trait anxiety is a strong predictor of CIO, it was also hypothesized that trait anxiety has an indirect effect on CIA through CIO. Study 1 tested this relationship in a U.S. sample (N = 384); the results showed that CIO was positively associated with CIA and that trait anxiety indirectly influenced CIA through CIO. Whereas Study 1 tested the relationship with cross-sectional data in the general cancer context, Study 2 replicated Study 1 with 3-wave longitudinal data in the context of a specific cancer (i.e., stomach cancer) in South Korea (N = 1,130 at Wave 1, 813 at Wave 2, and 582 at Wave 3). Trait anxiety at Wave 1 predicted CIO at Wave 2, which in turn increased CIA at Wave 3, suggesting that some people are inherently inclined to avoid cancer information due to their trait anxiety, which results in confusion about cancer information.

  2. Avoiding DWI Among Bar-room Drinkers: Strategies and Predictors

    PubMed Central

    Caudill, Barry D.; Rogers, John W.; Howard, Jan; Frissell, Kevin C.; Harding, Wayne M.

    2010-01-01

    We examined the prevalence and predictors of 11strategies to avoid driving when feeling intoxicated among 561 bar-room patrons in two medium-sized Maryland communities. Logistic regression analyses identified demographic, behavioral, and attitudinal predictors of avoidance strategies and interactions among predictors. Overall, 89% reported one or more DWI avoidance actions in the past year, and 38% reported driving intoxicated during that time. Average frequencies of avoidance behavior and intoxicated driving increased significantly as drinking level increased. However, the higher the drinking level, the smaller the ratio of avoidance actions to DWI experiences, highlighting the vulnerability of heavy drinkers who had driven intoxicated. Using a sober driver or one who allegedly drank less than the respondent were the most popular and frequent strategies, but paying for a cab, walking, and using a bus or free cab were relatively unpopular. Higher drinking levels predicted significantly higher odds of using avoidance approaches, as did intoxicated driving. Confidence in driving safely when intoxicated was positively related to drinking level and intoxicated driving, but it tended to predict lower odds of avoidance actions. Similarly, marital status, age, gender, and location influenced the odds of avoidance behaviors. Interventions should be strategically tailored to exploit or counter drinker predilections among avoidance options. PMID:22879742

  3. Evidence for an expectancy-based theory of avoidance behaviour.

    PubMed

    Declercq, Mieke; De Houwer, Jan; Baeyens, Frank

    2008-01-01

    In most studies on avoidance learning, participants receive an aversive unconditioned stimulus after a warning signal is presented, unless the participant performs a particular response. Lovibond (2006) recently proposed a cognitive theory of avoidance learning, according to which avoidance behaviour is a function of both Pavlovian and instrumental conditioning. In line with this theory, we found that avoidance behaviour was based on an integration of acquired knowledge about, on the one hand, the relation between stimuli and, on the other hand, the relation between behaviour and stimuli.

  4. Avoidance responses of estuarine fish to sulfur dioxide. Final report

    SciTech Connect

    Hall, L.W. Jr; Margrey, S.L.; Graves, W.C.

    1983-12-01

    This study was designed to determine the avoidance responses of juvenile striped bass, Morone saxatilis, and Atlantic menhaden, Brevoortia tyrannus exposed to sulfur dioxide (sulfite) at acclimation temperatures of 15, 20, 25 and 30C. Predictive models were developed and compared for each species at each acclimation temperature. Acclimation temperature was an important factor influencing the avoidance response of each species exposed to sulfur dioxide. Both species avoided approximately the same concentration of sulfite at 25C. Atlantic menhaden avoided lower concentration of sulfur dioxide than striped bass at 30C.

  5. Neural correlates of active avoidance behavior in superior colliculus

    PubMed Central

    Cohen, Jeremy D.; Castro-Alamancos, Manuel A.

    2010-01-01

    Active avoidance of harmful situations seems highly adaptive, but the underlying neural mechanisms are largely unknown. Rats can effectively use the superior colliculus during active avoidance to detect a salient whisker conditioned stimulus (WCS) that signals an aversive event. Here, we recorded unit and field potential activity in the intermediate layers of the superior colliculus of rats during active avoidance behavior. During the period preceding the onset of the WCS, avoids are associated with a higher firing rate than escapes (unsuccessful avoids), indicating that a prepared superior colliculus is more likely to detect the WCS and lead to an avoid. Moreover, during the WCS, a robust ramping up of overall firing rate is observed for trials leading to avoids. The firing rate ramping is not due to shuttling, and may serve to drive downstream circuits to avoid. Therefore, a robust neural correlate of active avoidance behavior is found in the superior colliculus, emphasizing its role in the detection of salient sensory signals that require immediate action. PMID:20573897

  6. Alprazolam treatment of avoidant personality traits in social phobic patients.

    PubMed

    Reich, J; Noyes, R; Yates, W

    1989-03-01

    The authors examined the effect of alprazolam treatment on avoidant personality traits in 14 DSM-III-R social phobics. Six of the nine avoidant traits examined improved with treatment. However, all but one trait (avoiding social or occupational activities requiring interpersonal contact) returned to baseline levels posttreatment. Treatment response and intercorrelation of items indicated two traits that may represent a separate segment of avoidant personality: "No close friends or confidants outside of relatives and family members" and "Exaggerates the potential dangers or risks of everyday situations."

  7. Cognitive effort avoidance and detection in people with schizophrenia.

    PubMed

    Gold, James M; Kool, Wouter; Botvinick, Matthew M; Hubzin, Leeka; August, Sharon; Waltz, James A

    2015-03-01

    Many people with schizophrenia exhibit avolition, a difficulty initiating and maintaining goal-directed behavior, considered to be a key negative symptom of the disorder. Recent evidence indicates that patients with higher levels of negative symptoms differ from healthy controls in showing an exaggerated cost of the physical effort needed to obtain a potential reward. We examined whether patients show an exaggerated avoidance of cognitive effort, using the demand selection task developed by Kool, McGuire, Rosen, and Botvinick (Journal of Experimental Psychology. General, 139, 665-682, 2010). A total of 83 people with schizophrenia or schizoaffective disorder and 71 healthy volunteers participated in three experiments where instructions varied. In the standard task (Experiment 1), neither controls nor patients showed expected cognitive demand avoidance. With enhanced instructions (Experiment 2), controls demonstrated greater demand avoidance than patients. In Experiment 3, patients showed nonsignificant reductions in demand avoidance, relative to controls. In a control experiment, patients showed significantly reduced ability to detect the effort demands associated with different response alternatives. In both groups, the ability to detect effort demands was associated with increased effort avoidance. In both groups, increased cognitive effort avoidance was associated with higher IQ and general neuropsychological ability. No significant correlations between demand avoidance and negative symptom severity were observed. Thus, it appears that individual differences in general intellectual ability and effort detection are related to cognitive effort avoidance and likely account for the subtle reduction in effort avoidance observed in schizophrenia.

  8. Effects of optimism on creativity under approach and avoidance motivation

    PubMed Central

    Icekson, Tamar; Roskes, Marieke; Moran, Simone

    2014-01-01

    Focusing on avoiding failure or negative outcomes (avoidance motivation) can undermine creativity, due to cognitive (e.g., threat appraisals), affective (e.g., anxiety), and volitional processes (e.g., low intrinsic motivation). This can be problematic for people who are avoidance motivated by nature and in situations in which threats or potential losses are salient. Here, we review the relation between avoidance motivation and creativity, and the processes underlying this relation. We highlight the role of optimism as a potential remedy for the creativity undermining effects of avoidance motivation, due to its impact on the underlying processes. Optimism, expecting to succeed in achieving success or avoiding failure, may reduce negative effects of avoidance motivation, as it eases threat appraisals, anxiety, and disengagement—barriers playing a key role in undermining creativity. People experience these barriers more under avoidance than under approach motivation, and beneficial effects of optimism should therefore be more pronounced under avoidance than approach motivation. Moreover, due to their eagerness, approach motivated people may even be more prone to unrealistic over-optimism and its negative consequences. PMID:24616690

  9. Rapid avoidance acquisition in Wistar-Kyoto rats.

    PubMed

    Servatius, R J; Jiao, X; Beck, K D; Pang, K C H; Minor, T R

    2008-10-10

    The relationship between trait stress-sensitivity, avoidance acquisition and perseveration of avoidance was examined using male Wistar-Kyoto (WKY) and Sprague-Dawley (SD) rats. Behavior in an open field was measured prior to escape/avoidance (E/A) acquisition and extinction. E/A was assessed in a discrete trial lever-press protocol. The signal-shock interval was 60s with subsequent shocks delivered every 3s until a lever-press occurred. A 3-min flashing light safety signal was delivered contingent upon a lever-press (or failure to respond in 5 min). WKY rats displayed phenotypic low open field activity, but were clearly superior to SD rats in E/A performance. As avoidance responses were acquired and reached asymptotic performance, SD rats exhibited "warm up", that is, SD rats rarely made avoidance responses on the initial trial of a session, even though later trials were consistently accompanied with avoidance responses. In contrast, WKY rats did not show the "warm up" pattern and avoided on nearly all trials of a session including the initial trial. In addition to the superior acquisition of E/A, WKY rats demonstrated several other avoidance features that were different from SD rats. Although the rates of nonreinforced intertrial responses (ITRs) were relatively low and selective to the early safety period, WKY displayed more ITRs than SD rats. With removal of the shocks extinction was delayed in WKY rats, likely reflecting their nearly perfect avoidance performance. Even after extensive extinction, first trial avoidance and ITRs were evident in WKY rats. Thus, WKY rats have a unique combination of trait behavioral inhibition (low open field activity and stress sensitivity) and superior avoidance acquisition and response perseveration making this strain a good model to understand anxiety disorders.

  10. Neural substrates of approach-avoidance conflict decision-making.

    PubMed

    Aupperle, Robin L; Melrose, Andrew J; Francisco, Alex; Paulus, Martin P; Stein, Murray B

    2015-02-01

    Animal approach-avoidance conflict paradigms have been used extensively to operationalize anxiety, quantify the effects of anxiolytic agents, and probe the neural basis of fear and anxiety. Results from human neuroimaging studies support that a frontal-striatal-amygdala neural circuitry is important for approach-avoidance learning. However, the neural basis of decision-making is much less clear in this context. Thus, we combined a recently developed human approach-avoidance paradigm with functional magnetic resonance imaging (fMRI) to identify neural substrates underlying approach-avoidance conflict decision-making. Fifteen healthy adults completed the approach-avoidance conflict (AAC) paradigm during fMRI. Analyses of variance were used to compare conflict to nonconflict (avoid-threat and approach-reward) conditions and to compare level of reward points offered during the decision phase. Trial-by-trial amplitude modulation analyses were used to delineate brain areas underlying decision-making in the context of approach/avoidance behavior. Conflict trials as compared to the nonconflict trials elicited greater activation within bilateral anterior cingulate cortex, anterior insula, and caudate, as well as right dorsolateral prefrontal cortex (PFC). Right caudate and lateral PFC activation was modulated by level of reward offered. Individuals who showed greater caudate activation exhibited less approach behavior. On a trial-by-trial basis, greater right lateral PFC activation related to less approach behavior. Taken together, results suggest that the degree of activation within prefrontal-striatal-insula circuitry determines the degree of approach versus avoidance decision-making. Moreover, the degree of caudate and lateral PFC activation related to individual differences in approach-avoidance decision-making. Therefore, the approach-avoidance conflict paradigm is ideally suited to probe anxiety-related processing differences during approach-avoidance decision

  11. 28 CFR 552.23 - Confrontation avoidance procedures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Confrontation avoidance procedures. 552.23 Section 552.23 Judicial Administration BUREAU OF PRISONS, DEPARTMENT OF JUSTICE INSTITUTIONAL MANAGEMENT CUSTODY Use of Force and Application of Restraints on Inmates § 552.23 Confrontation avoidance procedures. Prior to any calculated use of...

  12. Avoiding Attachment Ambiguities: The Role of Constituent Ordering

    ERIC Educational Resources Information Center

    Arnold, Jennifer E.; Wasow, Thomas; Asudeh, Ash; Alrenga, Peter

    2004-01-01

    Three experiments investigated whether speakers use constituent ordering as a mechanism for avoiding ambiguities. In utterances like ''Jane showed the letter to Mary to her mother,'' alternate orders would avoid the temporary PP-attachment ambiguity (''Jane showed her mother the letter to Mary,'' or ''Jane showed to her mother the letter to…

  13. 14 CFR 129.18 - Collision avoidance system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... meets TSO C-118, or a later version, or(2) A collision avoidance system equivalent to excluding any TSO C-118, or a later version, or (3) A collision avoidance system and Mode S transponder that meet...) Turbine-powered airplane of more than 33,000 pounds maximum certificated takeoff weight (1) An...

  14. 14 CFR 121.356 - Collision avoidance system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... version, or(2) A collision avoidance system equivalent to has a TSO C-118, or a later version, or (3) A... C-118, or a later version, or(2) A collision avoidance system equivalent to maximum TSO C-118, or a...— Then you must operate that airplane with— (a) Turbine-powered airplane of more than 33,000...

  15. Educational Demands to Reduce Avoidance of Vocational Education in Jordan

    ERIC Educational Resources Information Center

    Alsa'aideh, Monim

    2016-01-01

    This study aims to identify the educational demands to reduce students' avoidance of vocational education in Jordan. Results of a previous study addressing reasons for avoidance of vocational education, distributed these reasons into personal, social, economic, educational and vocational domains. Focus-groups method was used to identify the…

  16. The Prediction of Antisocial Behavior from Avoidant Attachment Classifications.

    ERIC Educational Resources Information Center

    Fagot, Beverly I.; Kavanagh, Kate

    1990-01-01

    Children of 18 months classified as secure or insecure/avoidant by means of the Ainsworth Strange Situation were observed at home and in a playgroup. Teachers and observers rated girls classified as insecure/avoidant as being more difficult to deal with and having more difficulty with peers than girls rated as securely attached. (PCB)

  17. Twenty Common Testing Mistakes for EFL Teachers to Avoid

    ERIC Educational Resources Information Center

    Henning, Grant

    2012-01-01

    To some extent, good testing procedure, like good language use, can be achieved through avoidance of errors. Almost any language-instruction program requires the preparation and administration of tests, and it is only to the extent that certain common testing mistakes have been avoided that such tests can be said to be worthwhile selection,…

  18. 38 CFR 4.14 - Avoidance of pyramiding.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Avoidance of pyramiding. 4.14 Section 4.14 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS SCHEDULE FOR RATING DISABILITIES General Policy in Rating § 4.14 Avoidance of pyramiding. The evaluation of...

  19. 29 CFR 1912.4 - Avoidance of duplication.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Avoidance of duplication. 1912.4 Section 1912.4 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADVISORY COMMITTEES ON STANDARDS Organizational Matters § 1912.4 Avoidance of duplication....

  20. 14 CFR 125.224 - Collision avoidance system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Collision avoidance system. 125.224 Section... Requirements § 125.224 Collision avoidance system. Effective January 1, 2005, any airplane you operate under this part 125 must be equipped and operated according to the following table: Collision...

  1. Avoidance behavior of young black ducks treated with chromium

    USGS Publications Warehouse

    Heinz, G.H.; Haseltine, S.D.

    1981-01-01

    Pairs of adult black ducks (Anas rubripes) were fed a diet containing 0, 20, or 200 ppm chromium in the form of chromium potassium sulfate. Ducklings from these pairs were fed the same diets as adults and were tested for their avoidance responses to a fright stimulus. Neither level of chromium had a significant effect on avoidance behavior.

  2. Safety Signals as Instrumental Reinforcers during Free-Operant Avoidance

    ERIC Educational Resources Information Center

    Fernando, Anushka B. P.; Urcelay, Gonzalo P.; Mar, Adam C.; Dickinson, Anthony; Robbins, Trevor W.

    2014-01-01

    Safety signals provide "relief" through predicting the absence of an aversive event. At issue is whether these signals also act as instrumental reinforcers. Four experiments were conducted using a free-operant lever-press avoidance paradigm in which each press avoided shock and was followed by the presentation of a 5-sec auditory safety…

  3. 5 CFR 950.109 - Avoidance of conflict of interest.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Avoidance of conflict of interest. 950.109 Section 950.109 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE... PRIVATE VOLUNTARY ORGANIZATIONS General Provisions § 950.109 Avoidance of conflict of interest....

  4. Teacher Distress and the Role of Experiential Avoidance

    ERIC Educational Resources Information Center

    Hinds, Erika; Jones, Laura Backen; Gau, Jeffrey M.; Forrester, Kathleen K.; Biglan, Anthony

    2015-01-01

    Teachers' psychological well-being is important for teachers and students, but teaching is highly stressful, particularly in special education. We examined the role of experiential avoidance (EA) in the well-being of 529 middle and elementary school teachers. EA involves the tendency to avoid thoughts, feelings, and other internal…

  5. Verbal Avoidance and Dissatisfaction in Intimate Conflict Situations

    ERIC Educational Resources Information Center

    Afifi, Tamara D.; McManus, Tara; Steuber, Keli; Coho, Amanda

    2009-01-01

    The purpose of this study was to more closely examine the association between avoidance and satisfaction during a potentially conflict-inducing conversation with one's dating partner. The results suggest that the way people respond to their own and their partner's conflict avoidance depends upon whether they are male or female. The perception of…

  6. Infants’ representations of others’ goals: Representing approach over avoidance

    PubMed Central

    Feiman, Roman; Carey, Susan; Cushman, Fiery

    2014-01-01

    Goals fall into two broad types – approach and avoidance. Research on infants’ early goal understanding has focused only on approach goals, usually assuming that infants will encode an ambiguous display where an actor picks one object over another as the actor wanting to approach the former rather than avoid the latter. We investigated infants’ understanding of approach and avoidance separately by presenting 7-month-olds with a hand either consistently approaching, or consistently avoiding, an object. Infants dishabituated to a disruption of the consistent approach pattern, but not of the consistent avoidance pattern. In the second experiment, we show that 14-month-olds, who have a richer understanding of goals, still do not dishabituate when a hand first reaches to and picks up an object it has consistently avoided before. A third experiment found that 7-month-olds successfully dishabituated to the first motion of a previously stationary object when all the objects moved on their own with no hand present, ruling out several low-level interpretations of infants’ failure to dishabituate to the violations of the avoidance pattern in Experiments 1 and 2. We conclude that infants do not represent avoidance from the same type of evidence they can use to represent approach. PMID:25498746

  7. 16 CFR 300.6 - Labels to be avoided.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 1 2014-01-01 2014-01-01 false Labels to be avoided. 300.6 Section 300.6... REGULATIONS UNDER THE WOOL PRODUCTS LABELING ACT OF 1939 Labeling § 300.6 Labels to be avoided. Stamps, tags... inconspicuous, shall not be used....

  8. 16 CFR 300.6 - Labels to be avoided.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 1 2011-01-01 2011-01-01 false Labels to be avoided. 300.6 Section 300.6... REGULATIONS UNDER THE WOOL PRODUCTS LABELING ACT OF 1939 Labeling § 300.6 Labels to be avoided. Stamps, tags... inconspicuous, shall not be used....

  9. 16 CFR 300.6 - Labels to be avoided.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 1 2012-01-01 2012-01-01 false Labels to be avoided. 300.6 Section 300.6... REGULATIONS UNDER THE WOOL PRODUCTS LABELING ACT OF 1939 Labeling § 300.6 Labels to be avoided. Stamps, tags... inconspicuous, shall not be used....

  10. 16 CFR 300.6 - Labels to be avoided.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 1 2013-01-01 2013-01-01 false Labels to be avoided. 300.6 Section 300.6... REGULATIONS UNDER THE WOOL PRODUCTS LABELING ACT OF 1939 Labeling § 300.6 Labels to be avoided. Stamps, tags... inconspicuous, shall not be used....

  11. Passive avoidance is linked to impaired fear extinction in humans

    PubMed Central

    Cornwell, Brian R.; Overstreet, Cassie; Krimsky, Marissa; Grillon, Christian

    2013-01-01

    Conventional wisdom dictates we must face our fears to conquer them. This idea is embodied in exposure-based treatments for anxiety disorders, where the intent of exposure is to reverse a history of avoidant behavior that is thought to fuel a patient’s irrational fears. We tested in humans the relationship between fear and avoidance by combining Pavlovian differential fear conditioning with a novel task for quantifying spontaneous passive avoidant behavior. During self-guided navigation in virtual reality following de novo fear conditioning, we observed participants keeping their distance from the feared object. At the individual level, passive avoidant behavior was highly associated with maladaptive fear expression (fear-potentiated startle) during late extinction training, indicating that extinction learning was impaired following a brief episode of avoidance. Avoidant behavior, however, was not related to initial acquired fear, raising doubt about a straightforward link between physiological fear and behavioral avoidance. We conclude that a deeper understanding of what motivates avoidance may offer a target for early intervention, before fears transition from the rational to the irrational. PMID:23427168

  12. Experiential Avoidance and Problem Behavior: A Mediational Analysis

    ERIC Educational Resources Information Center

    Kingston, Jessica; Clarke, Sue; Remington, Bob

    2010-01-01

    Despite their formal dissimilarity, problem behaviors (e.g., substance misuse, binge eating, self-harm) may share a common function. According to Acceptance and Commitment Therapy (ACT), this shared function is "Experiential Avoidance," the process of avoiding, escaping or otherwise altering unwanted private events (e.g., thoughts, feelings,…

  13. Passive Avoidance Is Linked to Impaired Fear Extinction in Humans

    ERIC Educational Resources Information Center

    Cornwell, Brian R.; Overstreet, Cassie; Krimsky, Marissa; Grillon, Christian

    2013-01-01

    Conventional wisdom dictates we must face our fears to conquer them. This idea is embodied in exposure-based treatments for anxiety disorders, where the intent of exposure is to reverse a history of avoidant behavior that is thought to fuel a patient's irrational fears. We tested in humans the relationship between fear and avoidance by combining…

  14. 14 CFR 437.65 - Collision avoidance analysis.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Collision avoidance analysis. 437.65..., DEPARTMENT OF TRANSPORTATION LICENSING EXPERIMENTAL PERMITS Safety Requirements § 437.65 Collision avoidance analysis. (a) For a permitted flight with a planned maximum altitude greater than 150 kilometers,...

  15. 14 CFR 437.65 - Collision avoidance analysis.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Collision avoidance analysis. 437.65 Section 437.65 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING EXPERIMENTAL PERMITS Safety Requirements § 437.65 Collision avoidance analysis. (a) For a permitted flight with...

  16. 14 CFR 437.65 - Collision avoidance analysis.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Collision avoidance analysis. 437.65 Section 437.65 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING EXPERIMENTAL PERMITS Safety Requirements § 437.65 Collision avoidance analysis. (a) For a permitted flight with...

  17. 14 CFR 437.65 - Collision avoidance analysis.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Collision avoidance analysis. 437.65 Section 437.65 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING EXPERIMENTAL PERMITS Safety Requirements § 437.65 Collision avoidance analysis. (a) For a permitted flight with...

  18. How to Avoid the ER If You Have Asthma

    MedlinePlus

    ... How to Avoid the ER if You Have Asthma KidsHealth > For Teens > How to Avoid the ER if You Have Asthma Print A A A Text Size What's in ... is the last resort for someone who has asthma. If a flare-up is really out of ...

  19. Regulating Cognitive Control through Approach-Avoidance Motor Actions

    ERIC Educational Resources Information Center

    Koch, Severine; Holland, Rob W.; van Knippenberg, Ad

    2008-01-01

    In two studies, the regulatory function of approach-avoidance cues in activating cognitive control processes was investigated. It was hypothesized that avoidance motor actions, relative to approach motor actions, increase the recruitment of cognitive resources, resulting in better performance on tasks that draw on these capacities. In Study 1,…

  20. A collision avoidance system for a spaceplane manipulator arm

    NASA Technical Reports Server (NTRS)

    Sciomachen, Anna; Magnani, Piergiovanni

    1989-01-01

    Part of the activity in the area of collision avoidance related to the Hermes spaceplane is reported. A collision avoidance software system which was defined, developed and implemented in this project is presented. It computes the intersection between the solids representing the arm, the payload, and the objects. It is feasible with respect to the resources available on board, considering its performance.

  1. Temporal pattern shifts to avoid acoustic interference in singing birds.

    PubMed

    Ficken, R W; Ficken, M S; Hailman, J P

    1974-02-22

    Two species of forest birds, the least flycatcher and the red-eyed vireo, when breeding in the same season in the same habitat, adjust their temporal pattern of singing to avoid the overlapping of songs. The avoidance of acoustic interference is more marked in the flycatcher, which has a briefer song than the vireo. PMID:17790627

  2. Cognitive bias and irrational belief as predictors of avoidance.

    PubMed

    Warren, R; Zgourides, G; Jones, A

    1989-01-01

    Cognitive bias, i.e. overestimates of subjective probability and cost of catastrophic events, and irrational belief were explored as predictors of avoidance. Three groups-anxiety disordered clients, a mixed group of clinic outpatients, and normals--were administered several self-report inventories. Multiple regression analyses were used to investigate a modified version of the Agoraphobic Cognitions Questionnaire, the Belief Scale, and the Body Sensations Questionnaire as predictors of avoidance, as measured by the Mobility Inventory. It was hypothesized that frequency x probability x cost of catastrophic cognitions (and the occurrence of the events they represent) would be a better predictor of avoidance than frequency alone. It was also hypothesized that irrational thinking would be a significant predictor of avoidance. The results generally supported the hypotheses, with subjective probability emerging as a particularly potent predictor of avoidance. Theoretical and clinical implications are discussed. PMID:2930444

  3. Proportion of hospital readmissions deemed avoidable: a systematic review

    PubMed Central

    van Walraven, Carl; Bennett, Carol; Jennings, Alison; Austin, Peter C.; Forster, Alan J.

    2011-01-01

    Background Readmissions to hospital are increasingly being used as an indicator of quality of care. However, this approach is valid only when we know what proportion of readmissions are avoidable. We conducted a systematic review of studies that measured the proportion of readmissions deemed avoidable. We examined how such readmissions were measured and estimated their prevalence. Methods We searched the MEDLINE and EMBASE databases to identify all studies published from 1966 to July 2010 that reviewed hospital readmissions and that specified how many were classified as avoidable. Results Our search strategy identified 34 studies. Three of the studies used combinations of administrative diagnostic codes to determine whether readmissions were avoidable. Criteria used in the remaining studies were subjective. Most of the studies were conducted at single teaching hospitals, did not consider information from the community or treating physicians, and used only one reviewer to decide whether readmissions were avoidable. The median proportion of readmissions deemed avoidable was 27.1% but varied from 5% to 79%. Three study-level factors (teaching status of hospital, whether all diagnoses or only some were considered, and length of follow-up) were significantly associated with the proportion of admissions deemed to be avoidable and explained some, but not all, of the heterogeneity between the studies. Interpretation All but three of the studies used subjective criteria to determine whether readmissions were avoidable. Study methods had notable deficits and varied extensively, as did the proportion of readmissions deemed avoidable. The true proportion of hospital readmissions that are potentially avoidable remains unclear. PMID:21444623

  4. Neural substrates of approach-avoidance conflict decision-making

    PubMed Central

    Aupperle, Robin L.; Melrose, Andrew J.; Francisco, Alex; Paulus, Martin P.; Stein, Murray B.

    2014-01-01

    Animal approach-avoidance conflict paradigms have been used extensively to operationalize anxiety, quantify the effects of anxiolytic agents, and probe the neural basis of fear and anxiety. Results from human neuroimaging studies support that a frontal-striatal-amygdala neural circuitry is important for approach-avoidance learning. However, the neural basis of decision-making is much less clear in this context. Thus, we combined a recently developed human approach-avoidance paradigm with functional magnetic resonance imaging (fMRI) to identify neural substrates underlying approach-avoidance conflict decision-making. Fifteen healthy adults completed the approach-avoidance conflict (AAC) paradigm during fMRI. Analyses of variance were used to compare conflict to non-conflict (avoid-threat and approach-reward) conditions and to compare level of reward points offered during the decision phase. Trial-by-trial amplitude modulation analyses were used to delineate brain areas underlying decision-making in the context of approach/avoidance behavior. Conflict trials as compared to the non-conflict trials elicited greater activation within bilateral anterior cingulate cortex (ACC), anterior insula, and caudate, as well as right dorsolateral prefrontal cortex. Right caudate and lateral PFC activation was modulated by level of reward offered. Individuals who showed greater caudate activation exhibited less approach behavior. On a trial-by-trial basis, greater right lateral PFC activation related to less approach behavior. Taken together, results suggest that the degree of activation within prefrontal-striatal-insula circuitry determines the degree of approach versus avoidance decision-making. Moreover, the degree of caudate and lateral PFC activation is related to individual differences in approach-avoidance decision-making. Therefore, the AAC paradigm is ideally suited to probe anxiety-related processing differences during approach-avoidance decision-making. PMID:25224633

  5. Reduction in Memory Specificity Following an Approach/Avoidance Scrambled Sentences Task Relates to Cognitive Avoidant Coping

    ERIC Educational Resources Information Center

    Debeer, Elise; Raes, Filip; Williams, J. Mark G.; Hermans, Dirk

    2013-01-01

    "Overgeneral autobiographical memory" (OGM) refers to the tendency to retrieve less specific personal memories. According to the functional avoidance hypothesis, OGM might act as a cognitive strategy to avoid emotionally distressing details of negative memories. In the present study, we investigated the effect of an experimentally induced avoidant…

  6. On the role of subsecond dopamine release in conditioned avoidance.

    PubMed

    Oleson, Erik B; Cheer, Joseph F

    2013-01-01

    Using shock avoidance procedures to study conditioned behavioral responses has a rich history within the field of experimental psychology. Such experiments led to the formulation of the general concept of negative reinforcement and specific theories attempting to explain escape and avoidance behavior, or why animals choose to either terminate or prevent the presentation of an aversive event. For example, the two-factor theory of avoidance holds that cues preceding an aversive event begin to evoke conditioned fear responses, and these conditioned fear responses reinforce the instrumental avoidance response. Current neuroscientific advances are providing new perspectives into this historical literature. Due to its well-established role in reinforcement processes and behavioral control, the mesolimbic dopamine system presented itself as a logical starting point in the search for neural correlates of avoidance and escape behavior. We recently demonstrated that phasic dopamine release events are inhibited by stimuli associated with aversive events but increased by stimuli preceding the successful avoidance of the aversive event. The latter observation is inconsistent with the second component of the two-factor theory of avoidance and; therefore, led us propose a new theoretical explanation of conditioned avoidance: (1) fear is initially conditioned to the warning signal and dopamine computes this fear association as a decrease in release, (2) the warning signal, now capable of producing a negative emotional state, suppresses dopamine release and behavior, (3) over repeated trials the warning signal becomes associated with safety rather than fear; dopaminergic neurons already compute safety as an increase in release and begin to encode the warning signal as the earliest predictor of safety (4) the warning signal now promotes conditioned avoidance via dopaminergic modulation of the brain's incentive-motivational circuitry.

  7. Development and Validation of the Athlete Fear Avoidance Questionnaire

    PubMed Central

    Dover, Geoffrey; Amar, Vanessa

    2015-01-01

    Context The fear-avoidance model was developed in an attempt to explain the process by which “pain experience” and “pain behavior” become dissociated from the actual pain sensation in individuals who manifest the phenomenon of exaggerated pain perception. High levels of fear avoidance can lead to chronic pain and disability and have successfully predicted rehabilitation time in the work-related–injury population. Existing fear-avoidance questionnaires have all been developed for the general population, but these questionnaires may not be specific enough to fully assess fear avoidance in an athletic population that copes with pain differently than the general population. Objective To develop and validate the Athlete Fear Avoidance Questionnaire (AFAQ). Design Qualitative research to develop the AFAQ and a cross-sectional study to validate the scale. Patients or Other Participants For questionnaire development, a total of 8 experts in the fields of athletic therapy, sport psychology, and fear avoidance were called upon to generate and rate items for the AFAQ. For determining concurrent validity, 99 varsity athletes from various sports participated. Data Collection and Analysis A total of 99 varsity athletes completed the AFAQ, the Fear-Avoidance Beliefs Questionnaire, and the Pain Catastrophizing Scale. We used Pearson correlations to establish concurrent validity. Results Concurrent validity was established with significant correlations between the AFAQ and the Fear Avoidance Beliefs Questionnaire-Physical Activity (r = 0.352, P > .001) as well as with the Pain Catastrophizing Scale (r = 0.587, P > .001). High internal consistency of our questionnaire was established with a Cronbach α coefficient of 0.805. The final version of the questionnaire includes 10 items with good internal validity (P < .05). Conclusions We developed a questionnaire with good internal and external validity. The AFAQ is a scale that measures sport-injury–related fear avoidance in

  8. On the role of subsecond dopamine release in conditioned avoidance

    PubMed Central

    Oleson, Erik B.; Cheer, Joseph F.

    2013-01-01

    Using shock avoidance procedures to study conditioned behavioral responses has a rich history within the field of experimental psychology. Such experiments led to the formulation of the general concept of negative reinforcement and specific theories attempting to explain escape and avoidance behavior, or why animals choose to either terminate or prevent the presentation of an aversive event. For example, the two-factor theory of avoidance holds that cues preceding an aversive event begin to evoke conditioned fear responses, and these conditioned fear responses reinforce the instrumental avoidance response. Current neuroscientific advances are providing new perspectives into this historical literature. Due to its well-established role in reinforcement processes and behavioral control, the mesolimbic dopamine system presented itself as a logical starting point in the search for neural correlates of avoidance and escape behavior. We recently demonstrated that phasic dopamine release events are inhibited by stimuli associated with aversive events but increased by stimuli preceding the successful avoidance of the aversive event. The latter observation is inconsistent with the second component of the two-factor theory of avoidance and; therefore, led us propose a new theoretical explanation of conditioned avoidance: (1) fear is initially conditioned to the warning signal and dopamine computes this fear association as a decrease in release, (2) the warning signal, now capable of producing a negative emotional state, suppresses dopamine release and behavior, (3) over repeated trials the warning signal becomes associated with safety rather than fear; dopaminergic neurons already compute safety as an increase in release and begin to encode the warning signal as the earliest predictor of safety (4) the warning signal now promotes conditioned avoidance via dopaminergic modulation of the brain's incentive-motivational circuitry. PMID:23759871

  9. Rethinking Oedipus: an evolutionary perspective of incest avoidance.

    PubMed

    Erickson, M T

    1993-03-01

    The author presents a biological hypothesis of incest avoidance. Pertinent literature from evolutionary biology, ethology, anthropology, and clinical research is reviewed. Secure early bonding to immediate kin predicts later adaptive kin-directed behaviors, including preferential altruism (kin selection) and incest avoidance. Impaired bonding predicts aberrant kin-directed behavior, including diminished altruism, neglect, and an increased incidence of incest. Failed bonding predicts the highest frequency of incest. Secure bonding to kin may function to establish adaptive kin-directed behaviors, including incest avoidance. Bonding is conceived of as the developmental foundation of a form of social attraction, here called "familial attraction," which is evolutionarily distinct from sexual attraction.

  10. Systems and Techniques for Identifying and Avoiding Ice

    NASA Technical Reports Server (NTRS)

    Hansman, R. John

    1995-01-01

    In-flight icing is one of the most difficult aviation weather hazards facing general aviation. Because most aircraft in the general aviation category are not certified for flight into known icing conditions, techniques for identifying and avoiding in-flight ice are important to maintain safety while increasing the utility and dispatch capability which is part of the AGATE vision. This report summarizes a brief study effort which: (1) Reviewed current ice identification, forecasting, and avoidance techniques; (2) Assessed feasibility of improved forecasting and ice avoidance procedures; and (3) Identified key issues for the development of improved capability with regard to in-flight icing.

  11. ITI-Signals and Prelimbic Cortex Facilitate Avoidance Acquisition and Reduce Avoidance Latencies, Respectively, in Male WKY Rats

    PubMed Central

    Beck, Kevin D.; Jiao, Xilu; Smith, Ian M.; Myers, Catherine E.; Pang, Kevin C. H.; Servatius, Richard J.

    2014-01-01

    As a model of anxiety disorder vulnerability, male Wistar-Kyoto (WKY) rats acquire lever-press avoidance behavior more readily than outbred Sprague-Dawley rats, and their acquisition is enhanced by the presence of a discrete signal presented during the inter-trial intervals (ITIs), suggesting that it is perceived as a safety signal. A series of experiments were conducted to determine if this is the case. Additional experiments investigated if the avoidance facilitation relies upon processing through medial prefrontal cortex (mPFC). The results suggest that the ITI-signal facilitates acquisition during the early stages of the avoidance acquisition process, when the rats are initially acquiring escape behavior and then transitioning to avoidance behavior. Post-avoidance introduction of the visual ITI-signal into other associative learning tasks failed to confirm that the visual stimulus had acquired the properties of a conditioned inhibitor. Shortening the signal from the entirety of the 3 min ITI to only the first 5 s of the 3 min ITI slowed acquisition during the first four sessions, suggesting the flashing light (FL) is not functioning as a feedback signal. The prelimbic (PL) cortex showed greater activation during the period of training when the transition from escape responding to avoidance responding occurs. Only combined PL + infralimbic cortex lesions modestly slowed avoidance acquisition, but PL-cortex lesions slowed avoidance response latencies. Thus, the FL ITI-signal is not likely perceived as a safety signal nor is it serving as a feedback signal. The functional role of the PL-cortex appears to be to increase the drive toward responding to the threat of the warning signal. Hence, avoidance susceptibility displayed by male WKY rats may be driven, in part, both by external stimuli (ITI signal) as well as by enhanced threat recognition to the warning signal via the PL cortex. PMID:25484860

  12. The Color Red Supports Avoidance Reactions to Unhealthy Food.

    PubMed

    Rohr, Michaela; Kamm, Friederike; Koenigstorfer, Joerg; Groeppel-Klein, Andrea; Wentura, Dirk

    2015-01-01

    Empirical evidence suggests that the color red acts like an implicit avoidance cue in food contexts. Thus specific colors seem to guide the implicit evaluation of food items. We built upon this research by investigating the implicit meaning of color (red vs. green) in an approach-avoidance task with healthy and unhealthy food items. Thus, we examined the joint evaluative effects of color and food: Participants had to categorize food items by approach-avoidance reactions, according to their healthfulness. Items were surrounded by task-irrelevant red or green circles. We found that the implicit meaning of the traffic light colors influenced participants' reactions to the food items. The color red (compared to green) facilitated automatic avoidance reactions to unhealthy foods. By contrast, approach behavior toward healthy food items was not moderated by color. Our findings suggest that traffic light colors can act as implicit cues that guide automatic behavioral reactions to food. PMID:26592533

  13. Does the Organized Sexual Murderer Better Delay and Avoid Detection?

    PubMed

    Beauregard, Eric; Martineau, Melissa

    2016-01-01

    According to the organized-disorganized model, organized sexual murderers adopt specific behaviors during the commission of their crimes that contribute to avoiding police detection. The current study examines the effect of sexual murderers' organized behaviors on their ability to both delay and/or avoid police detection. Using a combination of negative binomial and logistic regression analyses on a sample of 350 sexual murder cases, findings showed that although both measures of delaying and avoiding detection are positively correlated, different behavioral patterns were observed. For instance, offenders who moved the victim's body were more likely to avoid detection but the victim's body was likely to be recovered faster. Moreover, victim characteristics have an impact on both measures; however, this effect disappears for the measure of delaying detection once the organized behaviors are introduced. Implications of the findings are discussed.

  14. CDC: Pregnant Women Should Avoid Southeast Asia Due to Zika

    MedlinePlus

    ... Pregnant Women Should Avoid Southeast Asia Due to Zika Meanwhile, French report shows virus can infect sperm ... 30, 2016 FRIDAY, Sept. 30, 2016 (HealthDay News) -- Zika continues to extend its reach around the globe, ...

  15. 31 CFR 800.104 - Transactions or devices for avoidance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (Continued) OFFICE OF INVESTMENT SECURITY, DEPARTMENT OF THE TREASURY REGULATIONS PERTAINING TO MERGERS, ACQUISITIONS, AND TAKEOVERS BY FOREIGN PERSONS General § 800.104 Transactions or devices for avoidance....

  16. Avoidance motivation and choking under pressure in soccer penalty shootouts.

    PubMed

    Jordet, Geir; Hartmen, Esther

    2008-08-01

    The purpose of this study was to examine the relationships between shot valence, avoidance behavior, and performance in soccer penalty shootouts. Video analyses were conducted with all penalty shootouts ever held in the World Cup, the European Championships, and the UEFA Champions League (n = 36 shootouts, 359 kicks). Shot valence was assessed from the potential consequences of a shot outcome as follows: Shots where a goal instantly leads to victory were classified as positive valence shots and shots where a miss instantly leads to loss as negative valence shots. Avoidance behavior was defined as looking away from the goalkeeper or preparing the shot quickly (thus speeding up the wait). The results showed that avoidance behavior occurred more with negative valence shots than with positive shots and that players with negative valence shots performed worse than those with positive shots. Thus, avoidance motivation may help explain why professional athletes occasionally choke under pressure.

  17. 28 CFR 552.23 - Confrontation avoidance procedures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... MANAGEMENT CUSTODY Use of Force and Application of Restraints on Inmates § 552.23 Confrontation avoidance... knowledge they have gained about the inmate and the incident, determine if use of force is necessary....

  18. 16 CFR 301.28 - Labels to be avoided.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... REGULATIONS UNDER FUR PRODUCTS LABELING ACT Regulations § 301.28 Labels to be avoided. Labels which are insecurely or inconspicuously attached, or which in the course of offering the fur product for sale,...

  19. 16 CFR 301.28 - Labels to be avoided.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... REGULATIONS UNDER FUR PRODUCTS LABELING ACT Regulations § 301.28 Labels to be avoided. Labels which are insecurely or inconspicuously attached, or which in the course of offering the fur product for sale,...

  20. 16 CFR 301.28 - Labels to be avoided.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... REGULATIONS UNDER FUR PRODUCTS LABELING ACT Regulations § 301.28 Labels to be avoided. Labels which are insecurely or inconspicuously attached, or which in the course of offering the fur product for sale,...

  1. 16 CFR 301.28 - Labels to be avoided.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... REGULATIONS UNDER FUR PRODUCTS LABELING ACT Regulations § 301.28 Labels to be avoided. Labels which are insecurely or inconspicuously attached, or which in the course of offering the fur product for sale,...

  2. 16 CFR 301.28 - Labels to be avoided.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... REGULATIONS UNDER FUR PRODUCTS LABELING ACT Regulations § 301.28 Labels to be avoided. Labels which are insecurely or inconspicuously attached, or which in the course of offering the fur product for sale,...

  3. 7 Ways to Avoid Serious Injury from School Sports

    MedlinePlus

    ... news/fullstory_160474.html 7 Ways to Avoid Serious Injury From School Sports Know how to reduce ... players safe and at the top of their game: Good nutrition and proper hydration are key. It's ...

  4. Avoidance maneuevers selected while viewing cockpit traffic displays

    NASA Technical Reports Server (NTRS)

    Smith, J. D.; Ellis, S. R.; Lee, E.

    1982-01-01

    Ten airline pilots rates the collision danger of air traffic presented on cockpit displays of traffic information while they monitored simulated departures from Denver. They selected avoidance maneuvers when necessary for separation. Most evasive maneuvers were turns rather than vertical maneuvers. Evasive maneuvers chosen for encounters with low or moderate collision danger were generally toward the intruding aircraft. This tendency lessened as the perceived threat level increased. In the highest threst situations pilots turned toward the intruder only at chance levels. Intruders coming from positions in front of the pilot's own ship were more frequently avoided by turns toward than when intruders approached laterally or from behind. Some of the implications of the pilots' turning-toward tendencies are discussed with respect to automatic collision avoidance systems and coordination of avoidance maneuvers of conflicting aircraft.

  5. The Use of Arbitration to Avoid Litigation Under ERISA

    ERIC Educational Resources Information Center

    Donaldson, Richard P.

    1975-01-01

    In this symposium report it is suggested that arbitration can be used to avoid litigation of ERISA pension and welfare benefit claims if the negotiated plan or related collective bargaining agreement provides for arbitration or benefit disputes. (Author/LBH)

  6. Tautological Explanations and Definitions--An Avoidable Phenomenon.

    ERIC Educational Resources Information Center

    Jungwirth, E.

    1986-01-01

    Reviews findings from three diagnostic studies which focused on the problem of tautological explanations. Includes a report on a teaching intervention strategy which resulted in the improvement of pupil performance. Suggests that avoidance of tautology can be taught. (ML)

  7. NONCONSCIOUS EFFECTS OF POWER ON BASIC APPROACH AND AVOIDANCE TENDENCIES.

    PubMed

    Smith, Pamela K; Bargh, John A

    2008-02-01

    According to the approach/inhibition theory of power (Keltner, Gruenfeld, & Anderson, 2003), having power should be associated with the approach system, and lacking power with the avoidance system. However, to this point research has focused solely on whether power leads to more action, particularly approach-related action, or not. In three experiments, we extend this research by exploring the direct, unintentional relation between power and both approach and avoidance tendencies. Priming high power led to greater relative BAS strength than priming low power, but did not affect the BIS (Exp. 1). High-power priming also facilitated both simple and complex approach behavior, but did not affect avoidance behavior (Exp. 2-3). These effects of power occurred even in power-irrelevant situations. They also cannot be explained by priming of general positive versus negative constructs, nor by changes in positive, negative, approach-related, or avoidance-related affect.

  8. [The history and current state of communication avoidance research].

    PubMed

    Sakamoto, M; Pribyl, C B; Keaten, J

    1998-02-01

    The ability to communicate effectively has a profound impact on academic ability and social status in the United States. As such, communication avoidance may impart critical consequences on individuals who suffer from it. Within the communication discipline, communication avoidance is an extensive body of research with a relatively long history. Central to communication avoidance research is the concept of communication apprehension (CA). However, in comparison with research conducted in the United States, CA research in Japan remains in its genesis. This review thus focuses on communication apprehension and related constructs. Starting with an explanation of the magnitude of the problem of communication avoidance, a definition of CA is presented, and an overview of the related constructs of reticence, shyness, and other communication-related fears is introduced. Basic CA treatment programs and personality correlates of CA are also covered. The review closes by offering suggestions for future CA research in Japan. PMID:9626739

  9. The Color Red Supports Avoidance Reactions to Unhealthy Food.

    PubMed

    Rohr, Michaela; Kamm, Friederike; Koenigstorfer, Joerg; Groeppel-Klein, Andrea; Wentura, Dirk

    2015-01-01

    Empirical evidence suggests that the color red acts like an implicit avoidance cue in food contexts. Thus specific colors seem to guide the implicit evaluation of food items. We built upon this research by investigating the implicit meaning of color (red vs. green) in an approach-avoidance task with healthy and unhealthy food items. Thus, we examined the joint evaluative effects of color and food: Participants had to categorize food items by approach-avoidance reactions, according to their healthfulness. Items were surrounded by task-irrelevant red or green circles. We found that the implicit meaning of the traffic light colors influenced participants' reactions to the food items. The color red (compared to green) facilitated automatic avoidance reactions to unhealthy foods. By contrast, approach behavior toward healthy food items was not moderated by color. Our findings suggest that traffic light colors can act as implicit cues that guide automatic behavioral reactions to food.

  10. Parents: Avoid Kids Foot Problems with the Right Shoes

    MedlinePlus

    ... Print | Share Avoid Kids Foot Problems with the Right Shoes Before you head to the store to ... College of Foot and Ankle Surgeons (ACFAS), All Rights Reserved. Privacy Statement | Disclaimer | Terms and Conditions | Site ...

  11. Gripped by Gout: Avoiding the Ache and Agony

    MedlinePlus

    ... please review our exit disclaimer . Subscribe Gripped by Gout Avoiding the Ache and Agony Sudden, painful swelling ... toe is often the first warning sign of gout. It can affect other joints as well. Without ...

  12. Collision Avoidance Functional Requirements for Step 1. Revision 6

    NASA Technical Reports Server (NTRS)

    2006-01-01

    This Functional Requirements Document (FRD) describes the flow of requirements from the high level operational objectives down to the functional requirements specific to cooperative collision avoidance for high altitude, long endurance unmanned aircraft systems. These are further decomposed into performance and safety guidelines that are backed up by analysis or references to various documents or research findings. The FRD should be considered when establishing future policies, procedures, and standards pertaining to cooperative collision avoidance.

  13. Avoidance strategies in an exceptional child during unsuccessful reading performances.

    PubMed

    Damico, Jack S; Nelson, Ryan L; Damico, Holly; Abendroth, Kathleen; Scott, Jennifer

    2008-01-01

    Employing an interactional analysis and focusing on the complexity of meaning making, this study investigates the uses of several types of avoidance strategies generated by a language-disordered boy who is struggling with literacy. The results suggest that these avoidance strategies may function as compensatory adaptations that assist him in overcoming his literacy limitations so that he can still sustain effective social action even within contexts where his literacy difficulties are highlighted. There are both theoretical and practical implications for these findings.

  14. Avoidance of selenium-treated food by mallards

    USGS Publications Warehouse

    Heinz, G.H.; Sanderson, C.J.

    1990-01-01

    Adult, male mallards (Anas platyrhynchos) were given a choice between a control diet and a diet containing 5, 10 or 20 ppm selenium as selenomethionine dissolved in water and mixed into the diet. At 10 and 20 ppm, selenium-treated diets were avoided. Avoidance appeared to be caused by a conditioned response, probably to illness caused by the selenium and not to an aversion to the taste of the selenium.

  15. Impact of Tactical and Strategic Weather Avoidance on Separation Assurance

    NASA Technical Reports Server (NTRS)

    Refai, Mohamad S.; Windhorst, Robert

    2011-01-01

    The ability to keep flights away from weather hazards while maintaining aircraft-to-aircraft separation is critically important. The Advanced Airspace Concept is an automation concept that implements a ground-based strategic conflict resolution algorithm for management of aircraft separation. The impact of dynamic and uncertain weather avoidance on this concept is investigated. A strategic weather rerouting system is integrated with the Advanced Airspace Concept, which also provides a tactical weather avoidance algorithm, in a fast time simulation of the Air Transportation System. Strategic weather rerouting is used to plan routes around weather in the 20 minute to two-hour time horizon. To address forecast uncertainty, flight routes are revised at 15 minute intervals. Tactical weather avoidance is used for short term trajectory adjustments (30 minute planning horizon) that are updated every minute to address any weather conflicts (instances where aircraft are predicted to pass through weather cells) that are left unresolved by strategic weather rerouting. The fast time simulation is used to assess the impact of tactical weather avoidance on the performance of automated conflict resolution as well as the impact of strategic weather rerouting on both conflict resolution and tactical weather avoidance. The results demonstrate that both tactical weather avoidance and strategic weather rerouting increase the algorithm complexity required to find aircraft conflict resolutions. Results also demonstrate that tactical weather avoidance is prone to higher airborne delay than strategic weather rerouting. Adding strategic weather rerouting to tactical weather avoidance reduces total airborne delays for the reported scenario by 18% and reduces the number of remaining weather violations by 13%. Finally, two features are identified that have proven important for strategic weather rerouting to realize these benefits; namely, the ability to revise reroutes and the use of maneuvers

  16. Safety signals as instrumental reinforcers during free-operant avoidance

    PubMed Central

    Urcelay, Gonzalo P.; Mar, Adam C.; Dickinson, Anthony; Robbins, Trevor W.

    2014-01-01

    Safety signals provide “relief” through predicting the absence of an aversive event. At issue is whether these signals also act as instrumental reinforcers. Four experiments were conducted using a free-operant lever-press avoidance paradigm in which each press avoided shock and was followed by the presentation of a 5-sec auditory safety signal. When given a choice between two levers in Experiment 1, both avoiding shock, rats preferentially responded on the lever that produced the safety signal as feedback, even when footshock was omitted. Following avoidance training with a single lever in Experiment 2, removal of the signal led to a decrease in avoidance responses and an increase in responses during the safety period normally denoted by the signal. These behavioral changes demonstrate the dual conditioned reinforcing and fear inhibiting properties of the safety signal. The associative processes that support the reinforcing properties of a safety signal were tested using a novel revaluation procedure. Prior experience of systemic morphine during safety signal presentations resulted in an increased rate of avoidance responses to produce the safety signal during a drug-free extinction test, a finding not seen with d-amphetamine in Experiment 3. Morphine revaluation of the safety signal was repeated in Experiment 4 followed by a drug-free extinction test in which responses did not produce the signal for the first 10 min of the session. Instrumental avoidance in the absence of the signal was shown to be insensitive to prior signal revaluation, suggesting that the signal reinforces free-operant avoidance behavior through a habit-like mechanism. PMID:25135197

  17. Trends in Avoidable Death over 20 Years in Korea

    PubMed Central

    Chung, Ji In; Choi, Ji Sook; Kim, Bo Mi

    2008-01-01

    To evaluate the achievement of health care services in Korea independent of other socioeconomic factors, we observed the time trend of avoidable death between 1983 and 2004. A list of avoidable causes of death was constructed based on the European Community Atlas of "Avoidable Death". We calculated sex- and age-standardized mortality rates of Korean aged 1-64 yr using data of the Korea National Statistical Office. The avoidable mortality rate (per 100,000 persons) decreased from 225 to 84 in men and from 122 to 41 in women. Accordingly, the proportion of avoidable deaths among all classifiable deaths was reduced by 8.1% in men and 6.4% in women. However, mortality rates from some preventable causes such as ischemic heart disease and malignant neoplasms of lung, breast, cervix, and colorectum have been on the rise. Mortality preventable by appropriate medical care showed the greatest reduction (by 77.8%), while the mortality preventable by primary prevention showed the least reduction (by 50.0%). These findings suggest that health care service has significantly contributed to the improvement of health in Korea. However, more effective intervention programs would be needed given the less reduction in mortality avoidable by primary or secondary prevention than expected and unexpectedly increasing mortality from several preventable causes. PMID:19119439

  18. The facilitative nature of avoidance coping within sports injury rehabilitation.

    PubMed

    Carson, F; Polman, R C J

    2010-04-01

    Avoidance coping has commonly been reported within literature to be a debilitative process. However, in situations where goal attainment is reduced or eradicated avoidance coping strategies appear to have some benefit. The aim of this study was to identify the role of avoidance coping within the sports injury rehabilitation setting. A mixed methodological approach was utilized with four professional male rugby union players, concurrent with their rehabilitation from anterior cruciate ligament (ACL) surgery. Twice monthly interviews were conducted with each player, along with a self-report diary and the Coping with Health, Injuries and Problems (CHIP; Endler & Parker, 2000) inventory. Content analysis showed six higher-order themes split into two general dimensions: (a) behavioral avoidance coping (physical distraction, social interaction, maladaptive behaviors), and (b) cognitive avoidance coping (denial, thought stopping, cognitive distraction). Results suggest avoidance coping strategies facilitate control of short-term emotional states, as well has appearing to have long-term benefits for injured players. Particular benefits were associated with undertaking alternate work within the sports organization.

  19. Slow maturation of planning in obstacle avoidance in humans.

    PubMed

    Corporaal, Sharissa H A; Swinnen, Stephan P; Duysens, Jacques; Bruijn, Sjoerd M

    2016-01-01

    Complex gait (e.g., obstacle avoidance) requires a higher cognitive load than simple steady-state gait, which is a more automated movement. The higher levels of the central nervous system, responsible for adjusting motor plans to complex gait, develop throughout childhood into adulthood. Therefore, we hypothesize that gait strategies in complex gait are likely to mature until adulthood as well. However, little is known about the maturation of complex gait from childhood into adolescence and adulthood. To address this issue, we investigated obstacle avoidance in forty-four 8- to 18-yr-old participants who walked at preferred speed along a 6-m walkway on which a planar obstacle (150% of step length, 1 m wide) was projected. Participants avoided the obstacle by stepping over this projection, while lower body kinematics were recorded. Results showed that step length and speed adjustments during successful obstacle avoidance were similar across all ages, even though younger children modified step width to a greater extent. Additionally, the younger children used larger maximal toe elevations and take-off distances than older children. Moreover, during unsuccessful trials, younger children deployed exaggerated take-off distances, which resulted in obstacle contact upon the consecutive heel strike. These results indicate that obstacle avoidance is not fully matured in younger children, and that the inability to plan precise foot placements is an important factor contributing to failures in obstacle avoidance.

  20. Aversive disinhibition of behavior and striatal signaling in social avoidance.

    PubMed

    Ly, Verena; Cools, Roshan; Roelofs, Karin

    2014-10-01

    Social avoidance is a major factor contributing to the development and maintenance of anxiety and depressive symptoms. Converging evidence suggests that social avoidance is associated with abnormal aversive processing and hyperactive amygdala signaling. However, what are the consequences of such abnormal aversive processing for action and for the neural mechanisms implementing action is unclear. Existing literature is conflicting, pointing at either enhanced or reduced action inhibition. We investigated the interaction between aversion and action in social avoidance by comparing the effects of aversive vs appetitive faces on a go/no-go task and associated striatal signals in 42 high and low socially avoidant individuals. We combined fMRI with a novel probabilistic learning task, in which emotional valence (angry and happy faces) and optimal response (go- and no-go-responses) were manipulated independently. High compared with low socially avoidant individuals showed reduced behavioral inhibition (proportion no-go-responses) for angry relative to happy faces. This behavioral disinhibition correlated with greater striatal signal during no-go-responses for angry relative to happy faces. The results suggest that social avoidant coping style is accompanied by disinhibition of action and striatal signal in the context of social threat. The findings concur with recent theorizing about aversive disinhibition and affective disorders.

  1. Performance of humans in concurrent avoidance/positive-reinforcement schedules.

    PubMed

    Ruddle, H V; Bradshaw, C M; Szabadi, E; Foster, T M

    1982-07-01

    Performance maintained under concurrent schedules consisting of a variable-interval avoidance component and a variable-interval positive-reinforcement component was studied in three human subjects using points exchangeable for money as the reinforcer. The rate of responding in the avoidance component increased, and the rate of responding in the positive-reinforcement component declined, as a function of the frequency of point-losses avoided in the avoidance component. The performance of all three subjects conformed to equations proposed by Herrnstein to describe behavior in concurrent schedules. The logarithms of the ratios of the response rates in the two components, and the logarithms of the ratios of the times spent in the two components, were linearly related to the logarithms of the ratios of the frequency of loss avoidance in the avoidance component to the frequency of reinforcement in the positive-reinforcement component. When a changeover delay of 5.0 sec was imposed, the slopes of the linear functions were close to 1.0 in the case of two subjects, whereas the third subject exhibited significant undermatching. For two subjects the changeover delay was then reduced to 2.0 sec; in both cases the slopes of the linear functions were lower than under the 5.0-sec condition. One subject participated in a third phase, in which no changeover delay was imposed; there was a further reduction in the slopes of the linear functions.

  2. Global and local obstacle avoidance technique for an autonomous vehicle

    NASA Astrophysics Data System (ADS)

    Gray, Keith W.; Saunders, Kevin S.

    1999-07-01

    The Center for Self-Organizing and Intelligent Systems (CSOIS) is engaged in developing autonomous ground vehicles. A significant problem for such vehicles is obstacle detection and avoidance. After studying various methods of detection, a scanning laser system was chosen that can detect objects at a distance of up to thirty feet while traveling between five and ten miles per hour. Once an object is detected, the vehicle must avoid it. The project employs a mission-level path planner that predetermines the path of a vehicle. One avoidance scheme is to inform the path planner of the obstacle and then let it re-plan the path. This is the global approach to the problem, which allows the use of existing software for maneuvering the vehicle. However, replanning is time consuming and lacks knowledge of the entire obstacle. An alternative approach is to use local avoidance, whereby a vehicle determines how to get by an obstacle without help from the path planner. This approach offers faster response without requiring the computing resource of the path planner. The disadvantage is that during local avoidance the vehicle ignores the global map of known obstacles and does not know to turn control back to the path planner if mission efficiency is adversely affected. This paper will describe a method for combining the current global path planner with a local obstacle avoidance technique to efficiently complete required tasks in a partially unknown environment.

  3. Chloroplasts can move in any direction to avoid strong light.

    PubMed

    Tsuboi, Hidenori; Wada, Masamitsu

    2011-01-01

    Chloroplasts migrate in response to different light intensities. Under weak light, chloroplasts gather at an illuminated area to maximize light absorption and photosynthesis rates (the accumulation response). In contrast, chloroplasts escape from strong light to avoid photodamage (the avoidance response). Photoreceptors involved in these phenomena have been identified in Arabidopsis thaliana and Adiantum capillus-veneris. Chloroplast behavior has been studied in detail during the accumulation response, but not for the avoidance response. Hence, we analyzed the chloroplast avoidance response in detail using dark-adapted Adiantum capillus-veneris gametophyte cells and partial cell irradiation with a microbeam of blue light. Chloroplasts escaped from an irradiated spot. Both duration of this response and the distance of the migrated chloroplasts were proportional to the total fluence irradiated. The speed of movement during the avoidance response was dependent on the fluence rate, but the speed of the accumulation response towards the microbeam from cell periphery was constant irrespective of fluence rate. When a chloroplast was only partially irradiated with a strong microbeam, it moved away towards the non-irradiated region within a few minutes. During this avoidance response two additional microbeam irradiations were applied to different locus of the same chloroplast. Under these conditions the chloroplast changed the moving direction after a lag time of a few minutes without rolling. Taken together, these findings indicate that chloroplasts can move in any direction and never have an intrinsic polarity. Similar phenomenon was observed in chloroplasts of Arabidopsis thaliana palisade cells.

  4. Glint Avoidance and Removal in the Maritime Environment

    NASA Astrophysics Data System (ADS)

    Fink, Colin M.

    In-scene glint greatly affect the usability of maritime imagery and several glint removal algorithms have been developed that work well in some situations. However, glint removal algorithms produce several unique artifacts when applied to very high resolution systems, particularly those with temporally offset bands. The optimal solution to avoid these artifacts is to avoid imaging in areas of high glint. The glint avoidance tool (GAT) was developed to avoid glint conditions and provide a measure of parameter detectability. This work recreates the glint avoidance tool using Hydrolight, as a validation of a fast GAT using an in-water radiative transfer model which neglects in-water scattering. Because avoiding glint is not always possible, this research concentrates on the impact of glint and residual artifacts using RIT's Digital Imaging and Remote Sensing Image Generation (DIRSIG) dynamic wave model and Hydrolight back-end to create accurate case 1 synthetic imagery. The synthetic imagery was used to analyze the impact of glint on automated anomaly detection, glint removal, and development of a new glint compensation technique for sensors with temporally offset bands.

  5. Introducing the Date and Acquaintance Rape Avoidance Scale.

    PubMed

    Resendez, Josephine R; Hughes, Jamie S

    2016-01-01

    We present the Date and Acquaintance Rape Avoidance Scale (DARAS). The DARAS is a measure of a woman's behaviors used to avoid date and acquaintance rape. Three factor structures were possible. The DARAS may have measured several factors related to alcohol and drug use, self-defense, and date behaviors; 2 factors related to behaviors to avoid acquaintance versus date rape; or a single factor that represented general vigilance. The data revealed a highly reliable, 63 item single factor that was correlated with stranger rape avoidance, rejection of rape myths, hostile sexist beliefs about men, and benevolent sexist beliefs about women. The creation of the DARAS adds to the growing body of research on rape avoidance. The DARAS is key to understanding the behaviors women employ to avoid date rape. Rather than placing the responsibility for rape on the victim, the DARAS was developed as a theoretical and applied tool that can be used to improve theory and construct rape education and prevention programs. PMID:27302901

  6. Trends in "avoidable" mortality in Sweden, 1974-1985.

    PubMed Central

    Westerling, R

    1992-01-01

    STUDY OBJECTIVE--The aim was to analyse trends in "avoidable" mortality in Sweden, and to contribute to the methodology of avoidable mortality as an index of the quality of care. SETTING AND PARTICIPANTS--All deaths of Swedish citizens and other residents in Sweden during the period 1974-1985 were analysed as to causes of death between ages 0 and 64 years. MEASUREMENTS AND MAIN RESULTS--Total mortality delined during the 12 year period studied. Avoidable causes of death were grouped into preventable and treatable causes according to Rutstein's classification. In men, treatable diseases declined more during the 12 year period studied than did total mortality. When lung cancer was excluded, preventable diseases declined for both sexes. Certain avoidable causes of death decreased compared to total mortality, while some others showed an increase. The death rate increased for some avoidable causes of death such as pneumonia other than viral. In women death rates increased for chronic bronchitis and emphysema as well as for malignant neoplasms of trachea, bronchus, and lung, while for boys aged 1-14 years bronchitis NOS and asthma showed an increasing death rate. CONCLUSIONS--The study indicates that the avoidable mortality method is sensitive enough to describe important changes in the mortality pattern. The explicit definition of treatable and preventable causes of death constitutes a methodological development in epidemiological analysis of this type. Further studies on the quality of care should combine this method with other methods examining the structure and process of health care. PMID:1479317

  7. Introducing the Date and Acquaintance Rape Avoidance Scale.

    PubMed

    Resendez, Josephine R; Hughes, Jamie S

    2016-01-01

    We present the Date and Acquaintance Rape Avoidance Scale (DARAS). The DARAS is a measure of a woman's behaviors used to avoid date and acquaintance rape. Three factor structures were possible. The DARAS may have measured several factors related to alcohol and drug use, self-defense, and date behaviors; 2 factors related to behaviors to avoid acquaintance versus date rape; or a single factor that represented general vigilance. The data revealed a highly reliable, 63 item single factor that was correlated with stranger rape avoidance, rejection of rape myths, hostile sexist beliefs about men, and benevolent sexist beliefs about women. The creation of the DARAS adds to the growing body of research on rape avoidance. The DARAS is key to understanding the behaviors women employ to avoid date rape. Rather than placing the responsibility for rape on the victim, the DARAS was developed as a theoretical and applied tool that can be used to improve theory and construct rape education and prevention programs.

  8. Excess mortality from avoidable and non-avoidable causes in men of low socioeconomic status: a prospective study in Korea

    PubMed Central

    Song, Y.; Byeon, J. J.

    2000-01-01

    STUDY OBJECTIVE—The objective of this study was to evaluate the magnitude and contributory factors of socioeconomic differentials in mortality in a cohort of Korean male civil servants.
DESIGN—A prospective observational study of male civil servants followed up for five years after baseline measurement.
SETTING—All civil service offices in Korea.
PARTICIPANTS AND MEASUREMENTS—The study was conducted on 759 665 Korean male public servants aged 30-64 at baseline examination in 1992. The grade of monthly salary of these participants divided into four groups, a proxy indicator of socioeconomic status (SES), was the main predictive variable. Mortality of the participants was followed up from 1992 to 1996. The causes of deaths were categorised into four groups according to the medical amenability: avoidable, partly avoidable, non-avoidable, and external causes of death. The risk of mortality associated with SES was estimated using the Cox proportional hazard model.
MAIN RESULTS—Lowest SES group had significantly higher risk of mortality from most causes compared with the highest SES group in the order of external cause (relative risk (RR): 2.26), avoidable (RR: 1.65), all cause (RR: 1.59), and non-avoidable mortality (RR: 1.54). With the adjustment of known risk factors, significantly higher risks of mortality in lowest SES group were attenuated but persisted. Looking at the deaths from partly avoidable causes, significantly higher risks of mortality in the lowest SES group was observed from cerebrovascular disease but not from coronary heart disease.
CONCLUSIONS—Socioeconomic differentials in non-avoidable as well as avoidable mortality, persisting even under the control of risk factors, suggest that mortality is influenced not only by the quality of health care and different distribution of risk factors but also by other aspects of SES that are yet unknown.

 PMID:10746109

  9. Java Architecture for Detect and Avoid Extensibility and Modeling

    NASA Technical Reports Server (NTRS)

    Santiago, Confesor; Mueller, Eric Richard; Johnson, Marcus A.; Abramson, Michael; Snow, James William

    2015-01-01

    Unmanned aircraft will equip with a detect-and-avoid (DAA) system that enables them to comply with the requirement to "see and avoid" other aircraft, an important layer in the overall set of procedural, strategic and tactical separation methods designed to prevent mid-air collisions. This paper describes a capability called Java Architecture for Detect and Avoid Extensibility and Modeling (JADEM), developed to prototype and help evaluate various DAA technological requirements by providing a flexible and extensible software platform that models all major detect-and-avoid functions. Figure 1 illustrates JADEM's architecture. The surveillance module can be actual equipment on the unmanned aircraft or simulators that model the process by which sensors on-board detect other aircraft and provide track data to the traffic display. The track evaluation function evaluates each detected aircraft and decides whether to provide an alert to the pilot and its severity. Guidance is a combination of intruder track information, alerting, and avoidance/advisory algorithms behind the tools shown on the traffic display to aid the pilot in determining a maneuver to avoid a loss of well clear. All these functions are designed with a common interface and configurable implementation, which is critical in exploring DAA requirements. To date, JADEM has been utilized in three computer simulations of the National Airspace System, three pilot-in-the-loop experiments using a total of 37 professional UAS pilots, and two flight tests using NASA's Predator-B unmanned aircraft, named Ikhana. The data collected has directly informed the quantitative separation standard for "well clear", safety case, requirements development, and the operational environment for the DAA minimum operational performance standards. This work was performed by the Separation Assurance/Sense and Avoid Interoperability team under NASA's UAS Integration in the NAS project.

  10. Experimental characterization of collision avoidance in pedestrian dynamics.

    PubMed

    Parisi, Daniel R; Negri, Pablo A; Bruno, Luciana

    2016-08-01

    In the present paper, the avoidance behavior of pedestrians was characterized by controlled experiments. Several conflict situations were studied considering different flow rates and group sizes in crossing and head-on configurations. Pedestrians were recorded from above, and individual two-dimensional trajectories of their displacement were recovered after image processing. Lateral swaying amplitude and step lengths were measured for free pedestrians, obtaining similar values to the ones reported in the literature. Minimum avoidance distances were computed in two-pedestrian experiments. In the case of one pedestrian dodging an arrested one, the avoidance distance did not depend on the relative orientation of the still pedestrian with respect to the direction of motion of the first. When both pedestrians were moving, the avoidance distance in a perpendicular encounter was longer than the one obtained during a head-on approach. It was found that the mean curvature of the trajectories was linearly anticorrelated with the mean speed. Furthermore, two common avoidance maneuvers, stopping and steering, were defined from the analysis of the acceleration and curvature in single trajectories. Interestingly, it was more probable to observe steering events than stopping ones, also the probability of simultaneous steering and stopping occurrences was negligible. The results obtained in this paper can be used to validate and calibrate pedestrian dynamics models. PMID:27627328

  11. Evidence for avoidance of Ag nanoparticles by earthworms (Eisenia fetida).

    PubMed

    Shoults-Wilson, W A; Zhurbich, Oksana I; McNear, David H; Tsyusko, Olga V; Bertsch, Paul M; Unrine, Jason M

    2011-03-01

    Silver nanoparticles have been incorporated into a wide variety of consumer products, ideally acting as antimicrobial agents. Silver exposure has long been known to cause toxic effects to a wide variety of organisms, making large scale production of silver nanoparticles a potential hazard to environmental systems. Here we describe the first evidence that an organism may be able to sense manufactured nanoparticles in a complex, environmentally relevant exposure and that the presence of nanoparticles alters the organism's behavior. We found that earthworms (Eisenia fetida) consistently avoid soils containing silver nanoparticles and AgNO(3) at similar concentrations of Ag. However, avoidance of silver nanoparticles occurred over 48 h, while avoidance of AgNO(3) was immediate. It was determined that avoidance of silver nanoparticles could not be explained by release of silver ions or any changes in microbial communities caused by the introduction of Ag. This leads us to conclude that the earthworms were in some way sensing the presence of nanoparticles over the course of a 48 h exposure and choosing to avoid exposure to them. Our results demonstrate that nanoparticle interactions with organisms may be unpredictable and that these interactions may result in ecologically significant effects on behavior at environmentally relevant concentrations. PMID:21229389

  12. Attentional avoidance of smoking cues in former smokers.

    PubMed

    Peuker, Ana Carolina; Bizarro, Lisiane

    2014-02-01

    It has been speculated that attentional bias (AB) to smoking cues is a permanent feature of addiction. The objective of the present study was to investigate if abstinence duration has an influence on AB. Performance on a visual probe task of three groups (recent, intermediate and prolonged) of ex-smokers (n=62, mean age 50±11 years) with different abstinence durations was compared. Target/Control images were presented at three stimulus onset asynchronies (SOAs: 200, 500, and 2000 ms) on a 17-inch monitor. Former smokers avoided target images (TIs). Mean reaction time to control images was shorter than to TIs, confirming the attentional avoidance of TIs. Attentional avoidance of TIs and the lower emotional valence of these stimuli may have been a strategy to avoid relapse. Sustained avoidance to smoking-related cues may be a predictor of long-term abstinence. Direct training of AB away from drug cues may improve the results of smoking cessation therapy. PMID:24074848

  13. Sense and avoid technology for Global Hawk and Predator UAVs

    NASA Astrophysics Data System (ADS)

    McCalmont, John F.; Utt, James; Deschenes, Michael; Taylor, Michael J.

    2005-05-01

    The Sensors Directorate at the Air Force Research Laboratory (AFRL) along with Defense Research Associates, Inc. (DRA) conducted a flight demonstration of technology that could potentially satisfy the Federal Aviation Administration's (FAA) requirement for Unmanned Aerial Vehicles (UAVs) to sense and avoid local air traffic sufficient to provide an "...equivalent level of safety, comparable to see-and-avoid requirements for manned aircraft". This FAA requirement must be satisfied for autonomous UAV operation within the national airspace. The real-time on-board system passively detects approaching aircraft, both cooperative and non-cooperative, using imaging sensors operating in the visible/near infrared band and a passive moving target indicator algorithm. Detection range requirements for RQ-4 and MQ-9 UAVs were determined based on analysis of flight geometries, avoidance maneuver timelines, system latencies and human pilot performance. Flight data and UAV operating parameters were provided by the system program offices, prime contractors, and flight-test personnel. Flight demonstrations were conducted using a surrogate UAV (Aero Commander) and an intruder aircraft (Beech Bonanza). The system demonstrated target detection ranges out to 3 nautical miles in nose-to-nose scenarios and marginal visual meteorological conditions. (VMC) This paper will describe the sense and avoid requirements definition process and the system concept (sensors, algorithms, processor, and flight rest results) that has demonstrated the potential to satisfy the FAA sense and avoid requirements.

  14. Providing a food reward reduces inhibitory avoidance learning in zebrafish.

    PubMed

    Manuel, Remy; Zethof, Jan; Flik, Gert; van den Bos, Ruud

    2015-11-01

    As shown in male rats, prior history of subjects changes behavioural and stress-responses to challenges: a two-week history of exposure to rewards at fixed intervals led to slightly, but consistently, lower physiological stress-responses and anxiety-like behaviour. Here, we tested whether similar effects are present in zebrafish (Danio rerio). After two weeks of providing Artemia (brine shrimp; Artemia salina) as food reward or flake food (Tetramin) as control at fixed intervals, zebrafish were exposed to a fear-avoidance learning task using an inhibitory avoidance protocol. Half the number of fish received a 3V shock on day 1 and were tested and sacrificed on day 2; the other half received a second 3V shock on day 2 and were tested and sacrificed on day 3. The latter was done to assess whether effects are robust, as effects in rats have been shown to be modest. Zebrafish that were given Artemia showed less inhibitory avoidance after one shock, but not after two shocks, than zebrafish that were given flake-food. Reduced avoidance behaviour was associated with lower telencepahalic gene expression levels of cannabinoid receptor 1 (cnr1) and higher gene expression levels of corticotropin releasing factor (crf). These results suggest that providing rewards at fixed intervals alters fear avoidance behaviour, albeit modestly, in zebrafish. We discuss the data in the context of similar underlying brain structures in mammals and fish.

  15. Providing a food reward reduces inhibitory avoidance learning in zebrafish.

    PubMed

    Manuel, Remy; Zethof, Jan; Flik, Gert; van den Bos, Ruud

    2015-11-01

    As shown in male rats, prior history of subjects changes behavioural and stress-responses to challenges: a two-week history of exposure to rewards at fixed intervals led to slightly, but consistently, lower physiological stress-responses and anxiety-like behaviour. Here, we tested whether similar effects are present in zebrafish (Danio rerio). After two weeks of providing Artemia (brine shrimp; Artemia salina) as food reward or flake food (Tetramin) as control at fixed intervals, zebrafish were exposed to a fear-avoidance learning task using an inhibitory avoidance protocol. Half the number of fish received a 3V shock on day 1 and were tested and sacrificed on day 2; the other half received a second 3V shock on day 2 and were tested and sacrificed on day 3. The latter was done to assess whether effects are robust, as effects in rats have been shown to be modest. Zebrafish that were given Artemia showed less inhibitory avoidance after one shock, but not after two shocks, than zebrafish that were given flake-food. Reduced avoidance behaviour was associated with lower telencepahalic gene expression levels of cannabinoid receptor 1 (cnr1) and higher gene expression levels of corticotropin releasing factor (crf). These results suggest that providing rewards at fixed intervals alters fear avoidance behaviour, albeit modestly, in zebrafish. We discuss the data in the context of similar underlying brain structures in mammals and fish. PMID:26342856

  16. The mnemonic mover: nostalgia regulates avoidance and approach motivation.

    PubMed

    Stephan, Elena; Wildschut, Tim; Sedikides, Constantine; Zhou, Xinyue; He, Wuming; Routledge, Clay; Cheung, Wing-Yee; Vingerhoets, Ad J J M

    2014-06-01

    In light of its role in maintaining psychological equanimity, we proposed that nostalgia--a self-relevant, social, and predominantly positive emotion--regulates avoidance and approach motivation. We advanced a model in which (a) avoidance motivation triggers nostalgia and (b) nostalgia, in turn, increases approach motivation. As a result, nostalgia counteracts the negative impact of avoidance motivation on approach motivation. Five methodologically diverse studies supported this regulatory model. Study 1 used a cross-sectional design and showed that avoidance motivation was positively associated with nostalgia. Nostalgia, in turn, was positively associated with approach motivation. In Study 2, an experimental induction of avoidance motivation increased nostalgia. Nostalgia then predicted increased approach motivation. Studies 3-5 tested the causal effect of nostalgia on approach motivation and behavior. These studies demonstrated that experimental nostalgia inductions strengthened approach motivation (Study 3) and approach behavior as manifested in reduced seating distance (Study 4) and increased helping (Study 5). The findings shed light on nostalgia's role in regulating the human motivation system.

  17. Characterization of shade avoidance responses in Lotus japonicus.

    PubMed

    Ueoka-Nakanishi, Hanayo; Hori, Nanako; Ishida, Kai; Ono, Natsuko; Yamashino, Takafumi; Nakamichi, Norihito; Mizuno, Takeshi

    2011-01-01

    Sessile plants must continuously adjust their growth and development to optimize photosynthetic activity under ever-fluctuating light conditions. Among such light responses in plants, one of the best-characterized events is the so-called shade avoidance, for which a low ratio of the red (R):far-red (FR) light intensities is the most prominent stimulus. Such shade avoidance responses enable plants to overtop their neighbors, thereby enhancing fitness and competitiveness in their natural habitat. Considerable progress has been achieved during the last decade in understanding the molecular mechanisms underlying the shade avoidance responses in the model rosette plant, Arabidopsis thaliana. We characterize here the fundamental aspects of the shade avoidance responses in the model legume, Lotus japonicus, based on the fact that its phyllotaxis (or morphological architecture) is quite different from that of A. thaliana. It was found that L. japonicus displays the characteristic shade avoidance syndrome (SAS) under defined laboratory conditions (a low R:FR ratio, low light intensity, and low blue light intensity) that mimic the natural canopy. In particular, the outgrowth of axillary buds (i.e., both aerial and cotyledonary shoot branching) was severely inhibited in L. japonicus grown in the shade. These results are discussed with special emphasis on the unique aspects of SAS observed with this legume.

  18. Disease avoidance as a functional basis for stigmatization

    PubMed Central

    Oaten, Megan; Stevenson, Richard J.; Case, Trevor I.

    2011-01-01

    Stigmatization is characterized by chronic social and physical avoidance of a person(s) by other people. Infectious disease may produce an apparently similar form of isolation—disease avoidance—but on symptom remission this often abates. We propose that many forms of stigmatization reflect the activation of this disease-avoidance system, which is prone to respond to visible signs and labels that connote disease, irrespective of their accuracy. A model of this system is presented, which includes an emotional component, whereby visible disease cues directly activate disgust and contamination, motivating avoidance, and a cognitive component, whereby disease labels bring to mind disease cues, indirectly activating disgust and contamination. The unique predictions of this model are then examined, notably that people who are stigmatized evoke disgust and are contaminating. That animals too show avoidance of diseased conspecifics, and that disease-related stigma targets are avoided in most cultures, also supports this evolutionary account. The more general implications of this approach are then examined, notably how it can be used to good (e.g. improving hygiene) or bad (e.g. racial vilification) ends, by yoking particular labels with cues that connote disease and disgust. This broadening of the model allows for stigmatization of groups with little apparent connection to disease. PMID:22042920

  19. The mnemonic mover: nostalgia regulates avoidance and approach motivation.

    PubMed

    Stephan, Elena; Wildschut, Tim; Sedikides, Constantine; Zhou, Xinyue; He, Wuming; Routledge, Clay; Cheung, Wing-Yee; Vingerhoets, Ad J J M

    2014-06-01

    In light of its role in maintaining psychological equanimity, we proposed that nostalgia--a self-relevant, social, and predominantly positive emotion--regulates avoidance and approach motivation. We advanced a model in which (a) avoidance motivation triggers nostalgia and (b) nostalgia, in turn, increases approach motivation. As a result, nostalgia counteracts the negative impact of avoidance motivation on approach motivation. Five methodologically diverse studies supported this regulatory model. Study 1 used a cross-sectional design and showed that avoidance motivation was positively associated with nostalgia. Nostalgia, in turn, was positively associated with approach motivation. In Study 2, an experimental induction of avoidance motivation increased nostalgia. Nostalgia then predicted increased approach motivation. Studies 3-5 tested the causal effect of nostalgia on approach motivation and behavior. These studies demonstrated that experimental nostalgia inductions strengthened approach motivation (Study 3) and approach behavior as manifested in reduced seating distance (Study 4) and increased helping (Study 5). The findings shed light on nostalgia's role in regulating the human motivation system. PMID:24708500

  20. Animal models of social avoidance and social fear.

    PubMed

    Toth, Iulia; Neumann, Inga D

    2013-10-01

    Social fear and avoidance of social situations represent the main behavioral symptoms of social anxiety disorder (SAD), a highly prevalent anxiety disorder that is poorly elucidated and has rather unsatisfactory therapeutic options. Therefore, animal models are needed to study the underlying etiology and pathophysiology of SAD and to verify the efficacy of possible novel treatment approaches. In this review, we describe and discuss the most important paradigms that have been shown to induce social avoidance and fear in rodents, including foot shock exposure, restraint stress, social isolation, social instability, social defeat, conditioned defeat, social defeat/overcrowding, chronic subordinate colony housing, chronic mild stress, maternal separation and social fear conditioning. We also describe some of the behavioral paradigms used to assess social avoidance and fear in rodents, including the social interaction test, the social preference-avoidance test, the social approach-avoidance test, the three-chambered social approach test, the partition test and the modified Y-maze test. We focus on the behavioral alterations these paradigms induce, especially on social interaction, general anxiety and depressive-like behavior given that SAD is strongly comorbid with anxiety and affective disorders.

  1. Experimental characterization of collision avoidance in pedestrian dynamics

    NASA Astrophysics Data System (ADS)

    Parisi, Daniel R.; Negri, Pablo A.; Bruno, Luciana

    2016-08-01

    In the present paper, the avoidance behavior of pedestrians was characterized by controlled experiments. Several conflict situations were studied considering different flow rates and group sizes in crossing and head-on configurations. Pedestrians were recorded from above, and individual two-dimensional trajectories of their displacement were recovered after image processing. Lateral swaying amplitude and step lengths were measured for free pedestrians, obtaining similar values to the ones reported in the literature. Minimum avoidance distances were computed in two-pedestrian experiments. In the case of one pedestrian dodging an arrested one, the avoidance distance did not depend on the relative orientation of the still pedestrian with respect to the direction of motion of the first. When both pedestrians were moving, the avoidance distance in a perpendicular encounter was longer than the one obtained during a head-on approach. It was found that the mean curvature of the trajectories was linearly anticorrelated with the mean speed. Furthermore, two common avoidance maneuvers, stopping and steering, were defined from the analysis of the acceleration and curvature in single trajectories. Interestingly, it was more probable to observe steering events than stopping ones, also the probability of simultaneous steering and stopping occurrences was negligible. The results obtained in this paper can be used to validate and calibrate pedestrian dynamics models.

  2. Contamination sensitivity and the development of disease-avoidant behaviour

    PubMed Central

    Siegal, Michael; Fadda, Roberta; Overton, Paul G.

    2011-01-01

    Owing to their developing cognitive abilities and their limited knowledge about the biological basis of illness, children often have less expertise at disease avoidance than adults. However, affective reactions to contaminants through the acquisition of disgust and the social and cultural transmissions of knowledge about contamination and contagion provide impetus for children to learn effective disease-avoidant behaviours early in their development. In this article, we review the ontogenetic development of knowledge about contamination and contagion with particular attention to the role of socialization and culture. Together with their emerging cognitive abilities and affective reactions to contaminants, informal and formal cultural learning shape children's knowledge about disease. Through this process, the perceptual cues of contamination are linked to threats of disease outcomes and can act as determinants of disease-avoidant behaviours. PMID:22042919

  3. Avoiding loopholes with hybrid Bell-Leggett-Garg inequalities

    NASA Astrophysics Data System (ADS)

    Dressel, Justin; Korotkov, Alexander N.

    2014-01-01

    By combining the postulates of macrorealism with Bell locality, we derive a qualitatively different hybrid inequality that avoids two loopholes that commonly appear in Leggett-Garg and Bell inequalities. First, locally invasive measurements can be used, which avoids the "clumsiness" Leggett-Garg inequality loophole. Second, a single experimental ensemble with fixed analyzer settings is sampled, which avoids the "disjoint sampling" Bell inequality loophole. The derived hybrid inequality has the same form as the Clauser-Horne-Shimony-Holt Bell inequality; however, its quantum violation intriguingly requires weak measurements. A realistic explanation of an observed violation requires either the failure of Bell locality or a preparation conspiracy of finely tuned and nonlocally correlated noise. Modern superconducting and optical systems are poised to implement this test.

  4. Avoiding Loopholes with Hybrid Bell-Leggett-Garg Inequalities

    NASA Astrophysics Data System (ADS)

    Dressel, Justin; Korotkov, Alexander

    2014-03-01

    By combining the postulates of macrorealism with Bell-locality, we derive a qualitatively different hybrid inequality that avoids two loopholes that commonly appear in Leggett-Garg and Bell inequalities. First, locally-invasive measurements can be used, which avoids the ``clumsiness'' Leggett-Garg inequality loophole. Second, a single experimental ensemble with fixed analyzer settings is sampled, which avoids the ``disjoint sampling'' Bell inequality loophole. The derived hybrid inequality has the same form as the Clauser-Horne-Shimony-Holt Bell inequality; however, its quantum violation intriguingly requires weak measurements. A realistic explanation of an observed violation requires either the failure of Bell-locality, or a preparation-conspiracy of finely tuned and nonlocally-correlated noise. Modern superconducting and optical implementations of this test are considered.

  5. Emotion as motion: asymmetries in approach and avoidant actions.

    PubMed

    Maxwell, Jeffrey S; Davidson, Richard J

    2007-12-01

    To emote literally means to move or prepare for action. A large body of research indicates that flexor and extensor movements are conditionally associated with approach- and avoidance-related motivations. It has also been widely argued that approach and avoidant motivations are asymmetrically instantiated in the left and right hemispheres, respectively. Nevertheless, to date, these literatures remain largely separate. In the present investigation, flexor and extensor movements that were visuospatially contextualized as being directed toward the self and away from the self were observed to be asymmetrically represented in the "approach" and "avoidance" hemispheres. Moreover, this pattern of hemispheric specialization was manifested to a greater degree the higher participants' self-reported level of daily positive affect and the lower their self-reported level of dispositional anxiety. Collectively, these findings have direct implications for models of embodied emotional and perceptual processing, as well as for investigations of individual differences in emotional disposition.

  6. YUCCA auxin biosynthetic genes are required for Arabidopsis shade avoidance

    PubMed Central

    Müller-Moulé, Patricia; Nozue, Kazunari; Pytlak, Melissa L.; Palmer, Christine M.; Covington, Michael F.; Wallace, Andreah D.; Harmer, Stacey L.

    2016-01-01

    Plants respond to neighbor shade by increasing stem and petiole elongation. Shade, sensed by phytochrome photoreceptors, causes stabilization of PHYTOCHROME INTERACTING FACTOR proteins and subsequent induction of YUCCA auxin biosynthetic genes. To investigate the role of YUCCA genes in phytochrome-mediated elongation, we examined auxin signaling kinetics after an end-of-day far-red (EOD-FR) light treatment, and found that an auxin responsive reporter is rapidly induced within 2 hours of far-red exposure. YUCCA2, 5, 8, and 9 are all induced with similar kinetics suggesting that they could act redundantly to control shade-mediated elongation. To test this hypothesis we constructed a yucca2, 5, 8, 9 quadruple mutant and found that the hypocotyl and petiole EOD-FR and shade avoidance responses are completely disrupted. This work shows that YUCCA auxin biosynthetic genes are essential for detectable shade avoidance and that YUCCA genes are important for petiole shade avoidance. PMID:27761349

  7. A neuro-collision avoidance strategy for robot manipulators

    NASA Technical Reports Server (NTRS)

    Onema, Joel P.; Maclaunchlan, Robert A.

    1992-01-01

    The area of collision avoidance and path planning in robotics has received much attention in the research community. Our study centers on a combination of an artificial neural network paradigm with a motion planning strategy that insures safe motion of the Articulated Two-Link Arm with Scissor Hand System relative to an object. Whenever an obstacle is encountered, the arm attempts to slide along the obstacle surface, thereby avoiding collision by means of the local tangent strategy and its artificial neural network implementation. This combination compensates the inverse kinematics of a robot manipulator. Simulation results indicate that a neuro-collision avoidance strategy can be achieved by means of a learning local tangent method.

  8. Incest avoidance: oedipal and preoedipal, natural and cultural.

    PubMed

    Paul, Robert A

    2010-12-01

    Why do most people experience a subjective aversion to the idea of incestuous sexual relations? To help answer this question, recent strands of thinking in both cultural and evolutionary anthropology are considered together with psychoanalytic theories regarding incest avoidance. Coevolutionary theories that propose ways to think about genetic and cultural inheritance as partially independent of each other, evolutionary arguments about the reproductive advantages of incest avoidance, structuralist theory arguing for a kind of incest aversion unrelated to any possible Darwinian selective advantage, and other trends in biosocial research into the origins of the incest avoidance are considered. Finally, a synthesis is proposed that seeks to expand our understanding of the oedipal and preoedipal dynamics of the aversion as these are conceptualized in psychoanalytic theory.

  9. Avoiding or restricting defectors in public goods games?

    PubMed

    Han, The Anh; Pereira, Luís Moniz; Lenaerts, Tom

    2015-02-01

    When creating a public good, strategies or mechanisms are required to handle defectors. We first show mathematically and numerically that prior agreements with posterior compensations provide a strategic solution that leads to substantial levels of cooperation in the context of public goods games, results that are corroborated by available experimental data. Notwithstanding this success, one cannot, as with other approaches, fully exclude the presence of defectors, raising the question of how they can be dealt with to avoid the demise of the common good. We show that both avoiding creation of the common good, whenever full agreement is not reached, and limiting the benefit that disagreeing defectors can acquire, using costly restriction mechanisms, are relevant choices. Nonetheless, restriction mechanisms are found the more favourable, especially in larger group interactions. Given decreasing restriction costs, introducing restraining measures to cope with public goods free-riding issues is the ultimate advantageous solution for all participants, rather than avoiding its creation.

  10. Avoiding or restricting defectors in public goods games?

    PubMed

    Han, The Anh; Pereira, Luís Moniz; Lenaerts, Tom

    2015-02-01

    When creating a public good, strategies or mechanisms are required to handle defectors. We first show mathematically and numerically that prior agreements with posterior compensations provide a strategic solution that leads to substantial levels of cooperation in the context of public goods games, results that are corroborated by available experimental data. Notwithstanding this success, one cannot, as with other approaches, fully exclude the presence of defectors, raising the question of how they can be dealt with to avoid the demise of the common good. We show that both avoiding creation of the common good, whenever full agreement is not reached, and limiting the benefit that disagreeing defectors can acquire, using costly restriction mechanisms, are relevant choices. Nonetheless, restriction mechanisms are found the more favourable, especially in larger group interactions. Given decreasing restriction costs, introducing restraining measures to cope with public goods free-riding issues is the ultimate advantageous solution for all participants, rather than avoiding its creation. PMID:25540240

  11. Avoiding or restricting defectors in public goods games?

    PubMed Central

    Han, The Anh; Pereira, Luís Moniz; Lenaerts, Tom

    2015-01-01

    When creating a public good, strategies or mechanisms are required to handle defectors. We first show mathematically and numerically that prior agreements with posterior compensations provide a strategic solution that leads to substantial levels of cooperation in the context of public goods games, results that are corroborated by available experimental data. Notwithstanding this success, one cannot, as with other approaches, fully exclude the presence of defectors, raising the question of how they can be dealt with to avoid the demise of the common good. We show that both avoiding creation of the common good, whenever full agreement is not reached, and limiting the benefit that disagreeing defectors can acquire, using costly restriction mechanisms, are relevant choices. Nonetheless, restriction mechanisms are found the more favourable, especially in larger group interactions. Given decreasing restriction costs, introducing restraining measures to cope with public goods free-riding issues is the ultimate advantageous solution for all participants, rather than avoiding its creation. PMID:25540240

  12. Incautiously Optimistic: Positively-Valenced Cognitive Avoidance in Adult ADHD

    PubMed Central

    Knouse, Laura E.; Mitchell, John T.

    2015-01-01

    Clinicians who conduct cognitive-behavioral therapy (CBT) targeting attention-deficit/hyperactivity disorder (ADHD) in adulthood have noted that their patients sometimes verbalize overly positive automatic thoughts and set overly optimistic goals. These cognitions are frequently related to failure to engage in compensatory behavioral strategies emphasized in CBT. In this paper, we offer a functional analysis of this problematic pattern, positively-valenced cognitive avoidance, and suggest methods for addressing it within CBT for adult ADHD. We propose that maladaptive positive cognitions function to relieve aversive emotions in the short-term and are therefore negatively reinforced but that, in the long-term, they are associated with decreased likelihood of active coping and increased patterns of behavioral avoidance. Drawing on techniques from Behavioral Activation (BA), we offer a case example to illustrate these concepts and describe step-by-step methods for clinicians to help patients recognize avoidant patterns and engage in more active coping. PMID:25908901

  13. Sampling out: regulatory avoidance and the Total Coliform Rule.

    PubMed

    Bennear, Lori S; Jessoe, Katrina K; Olmstead, Sheila M

    2009-07-15

    This paper investigates strategic noncompliance with the Total Coliform Rule (TCR) under the U.S. Safe Drinking Water Act. The structure of the TCR provides incentives for some piped drinking water systems to avoid violations by taking additional water quality samples. We estimate the prevalence of this behavior and its potential impact on violations using monthly data for more than 500 Massachusetts water systems, 1993-2003. We find evidence that strategic oversampling is occurring. Water systems most likely to avoid violations by oversampling are most likely to oversample. A significant number of additional violations would have occurred if systems had adhered to legal sampling requirements, rather than oversampling. Our analysis of potential impacts of regulatory avoidance under the current rule suggests that alternative policies for monitoring bacteria in drinking water should be considered. PMID:19708338

  14. Predictive Potential Field-Based Collision Avoidance for Multicopters

    NASA Astrophysics Data System (ADS)

    Nieuwenhuisen, M.; Schadler, M.; Behnke, S.

    2013-08-01

    Reliable obstacle avoidance is a key to navigating with UAVs in the close vicinity of static and dynamic obstacles. Wheel-based mobile robots are often equipped with 2D or 3D laser range finders that cover the 2D workspace sufficiently accurate and at a high rate. Micro UAV platforms operate in a 3D environment, but the restricted payload prohibits the use of fast state-of-the-art 3D sensors. Thus, perception of small obstacles is often only possible in the vicinity of the UAV and a fast collision avoidance system is necessary. We propose a reactive collision avoidance system based on artificial potential fields, that takes the special dynamics of UAVs into account by predicting the influence of obstacles on the estimated trajectory in the near future using a learned motion model. Experimental evaluation shows that the prediction leads to smoother trajectories and allows to navigate collision-free through passageways.

  15. Nucleus accumbens core lesions enhance two-way active avoidance

    PubMed Central

    Lichtenberg, Nina T.; Kashtelyan, Vadim; Burton, Amanda C.; Bissonette, Gregory B.; Roesch, Matthew R.

    2014-01-01

    The majority of work examining nucleus accumbens core (NAc) has focused on functions pertaining to behaviors guided by appetitive outcomes. These studies have pointed to NAc as being critical for motivating behavior toward desirable outcomes. For example, we have recently shown that lesions of NAc impaired performance on a reward-guided decision-making task that required rats to choose between differently valued rewards. Unfortunately, much less is known about the role that NAc plays in motivating behavior when aversive outcomes are predicted. To address this issue we asked if NAc lesions impact performance on a two-way active avoidance task in which rats must learn to shuttle back and forth in a behavioral training box in order to avoid a footshock predicted by an auditory tone. Although bilateral NAc lesions initially impaired reward-guided decision-making, we found that the same lesions improved acquisition and retention of two-way active avoidance. PMID:24275320

  16. Modeling and Simulation of an UAS Collision Avoidance Systems

    NASA Technical Reports Server (NTRS)

    Oliveros, Edgardo V.; Murray, A. Jennifer

    2010-01-01

    This paper describes a Modeling and Simulation of an Unmanned Aircraft Systems (UAS) Collision Avoidance System, capable of representing different types of scenarios for UAS collision avoidance. Commercial and military piloted aircraft currently utilize various systems for collision avoidance such as Traffic Alert and Collision A voidance System (TCAS), Automatic Dependent Surveillance-Broadcast (ADS-B), Radar and ElectroOptical and Infrared Sensors (EO-IR). The integration of information from these systems is done by the pilot in the aircraft to determine the best course of action. In order to operate optimally in the National Airspace System (NAS) UAS have to work in a similar or equivalent manner to a piloted aircraft by applying the principle of "detect-see and avoid" (DSA) to other air traffic. Hence, we have taken these existing sensor technologies into consideration in order to meet the challenge of researching the modeling and simulation of an approximated DSA system. A Schematic Model for a UAS Collision Avoidance System (CAS) has been developed ina closed loop block diagram for that purpose. We have found that the most suitable software to carry out this task is the Satellite Tool Kit (STK) from Analytical Graphics Inc. (AGI). We have used the Aircraft Mission Modeler (AMM) for modeling and simulation of a scenario where a UAS is placed on a possible collision path with an initial intruder and then with a second intruder, but is able to avoid them by executing a right tum maneuver and then climbing. Radars have also been modeled with specific characteristics for the UAS and both intruders. The software provides analytical, graphical user interfaces and data controlling tools which allow the operator to simulate different conditions. Extensive simulations have been carried out which returned excellent results.

  17. Ontogenetic development of avoidance learning in rats after eye opening.

    PubMed

    Köllner, O; Köllner, U; Göb, R; Klingberg, F

    1988-01-01

    Five male and one female group of 8 pups were selected from 8 liters on the second postnatal day and returned to 6 dams. The animals were investigated in two subsequent tests; first, in a peripheral field avoidance test using a 60 x 75 x 22 cm open field subdivided into 20 equal squares of 15 x 15 cm with separate floor grids for electrical punishment and, second, in a W-like maze with a start arm falling into a common alley from which left and right each two goal arms branched off. Four qualities were measured in the first test: finding out that only central fields remained unpunished; the stay duration in central fields indicating passive avoidance; the response to a conditioned stimulus, when they entered peripheral fields indicating active avoidance; the quality of extinction. The differences of these qualities changed significantly from week to week as the acquisition speed and the consolidation increased, the extinction was rapid in the third week, very slow in the fourth week and adult-like in the fifth week. The self-chosen strategy of pups showed dominance of escape with subsequent motor inhibition in the third week, dominance of trials and active avoidance in the fourth week, dominance of passive avoidance in the fifth week. We found no difference between males and females, or between blind and control rats. The W-maze test revealed additionally that reversal learning from left goal to right goal was still difficult in the fourth week and that brightness-cued alteration of goals in which wrong choices were punished when a time limit was overcome could not be learned before the sixth week and not consolidated before the end of the seventh week. The results suggest that various brain processes are involved in the development of avoidance and learning strategies which mature unevenly and reach their peaks at different ages. PMID:3254159

  18. Sense and avoid radar for micro/nano robots

    NASA Astrophysics Data System (ADS)

    Molchanov, Pavlo A.; Asmolova, Olha

    2014-10-01

    Revolutionary new fly eye radar sensor technologies based on an array of directional antennas is eliminating the need for a mechanical scanning antenna or complicated phase processor. Proposed sense and avoid radar based on fly eye radar technology can be very small, provides continuous surveillance of entire sky (360 degree by azimuth and elevation) and can be applied for separate or swarm of micro/nano UAS or UGS. Monopulse technology increases bearing accuracy several folds and radar can be multi-functional, multi-frequency. Fly eye micro-radars are inexpensive, can be expendable. Prototype of sense and avoid radar with two directional antennas has been designed and bench tested.

  19. Advancing age progressively affects obstacle avoidance skills in the elderly.

    PubMed

    Weerdesteyn, Vivian; Nienhuis, Bart; Duysens, Jacques

    2005-01-01

    The ability to adequately avoid obstacles while walking is an important skill that allows safe locomotion over uneven terrain. The high proportion of falls in the elderly that is associated to tripping over obstacles potentially illustrates an age-related deterioration of this locomotor skill. Some studies have compared young and old adults, but very little is known about the changes occurring within different age groups of elderly. In the present study, obstacle avoidance performance was studied in 25 young (20-37 years) and 99 older adults (65-88 years). The participants walked on a treadmill at a speed of 3 km/h. An obstacle was dropped 30 times in front of the left foot at various phases in the step cycle. Success rates (successful avoidance) were calculated and related to the time available between obstacle appearance and the estimated instant of foot contact with the obstacle (available response times or ARTs ranging from 200 to more than 350 ms). In addition, latencies of avoidance reactions, the choice of avoidance strategies (long or short step strategy, LSS or SSS), and three spatial parameters related to obstacle avoidance (toe distance, foot clearance, and heel distance) were determined for each participant. Compared to the young, the older adults had lower success rates, especially at short ARTs. Furthermore, they had longer reaction times, more LSS reactions, smaller toe and heel distances, and larger foot clearances. Within the group of elderly, only the 65-69 year olds were not different from young adults with respect to success rate, despite marked changes in the other parameters measured. In particular, even this younger group of elderly showed a dramatic reduction in the amount of SSS trials compared to young adults. Overall, age was a significant predictor of success rates, reaction times, and toe distances. These parameters deteriorated with advancing age. Finally, avoidance success rates at short ARTs were considerably worse in elderly

  20. Food avoidance in athletes: FODMAP foods on the list.

    PubMed

    Lis, Dana; Ahuja, Kiran D K; Stellingwerff, Trent; Kitic, Cecilia M; Fell, James

    2016-09-01

    We surveyed 910 athletes to assess behaviours towards self-selected food/ingredient avoidance to minimize gastrointestinal distress. Fifty-five percent eliminated at least 1 high fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) food/category, with up to 82.6% reporting symptom improvement. In athletes indicating that high FODMAP foods trigger gastrointestinal symptoms, lactose (86.5%) was most frequently eliminated, followed by galactooligosaccharides (23.9%), fructose (23.0%), fructans (6.2%), and polyols (5.4%). Athletes avoid predominantly lactose and to a lesser extent other high FODMAP foods to reduce gastrointestinal distress. PMID:27507006

  1. How to avoid the high costs of physician turnover.

    PubMed

    Berger, J E; Boyle, R L

    1992-01-01

    Physician recruitment is a complex, time consuming and competitive activity that is costly in terms of incurred expenses, administrative and physician time and lost revenue. Judith Berger and Robert Boyle, FACMGA, describe how to develop a well-designed retention and recruitment plan to avoid such costs.

  2. Emotional Avoidance and Panicogenic Responding to a Biological Challenge Procedure

    ERIC Educational Resources Information Center

    Karekla, Maria; Forsyth, John P.; Kelly, Megan M.

    2004-01-01

    Healthy undergraduates high (n = 27) and low (n = 27) in experiential avoidance underwent twelve 20 s inhalations of 20% carbon dioxide-enriched air, while physiological (e.g., skin conductance, heart rate, EMG, and end-tidal CO[subscript 2]) and subjective (e.g., subjective units of distress, evaluative ratings, number and severity of panic…

  3. 40 CFR 141.71 - Criteria for avoiding filtration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ....71 Section 141.71 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.71 Criteria for avoiding filtration. A public water system that uses a surface water source must meet all...

  4. 40 CFR 141.71 - Criteria for avoiding filtration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ....71 Section 141.71 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.71 Criteria for avoiding filtration. A public water system that uses a surface water source must meet all...

  5. 40 CFR 141.71 - Criteria for avoiding filtration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ....71 Section 141.71 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.71 Criteria for avoiding filtration. A public water system that uses a surface water source must meet all...

  6. Avoiding School Management Conflicts and Crisis through Formal Communication

    ERIC Educational Resources Information Center

    Nwogbaga, David M. E.; Nwankwo, Oliver U.; Onwa, Doris O.

    2015-01-01

    This paper examined how conflicts and crisis can be avoided through formal communication. It was necessitated by the observation that most of the conflicts and crisis which tend to mar school management today are functions of the inconsistencies arising from "grapevines, rumours, and gossips" generated through informal communication…

  7. Looking after your health. 3. Avoiding varicose veins.

    PubMed

    Randall, Sara

    2015-02-01

    This article is to summarise key concepts for the health of the midwife with particular focus on standing for prolonged periods. One of the resultant factors relating to standing postures is the slow but avoidable progression of varicose veins. There is a strong genetic bias to these veins, which can be distressing, but here we will highlight awareness and current research.

  8. A VLSI structure for the deadlock avoidance problem

    SciTech Connect

    Bertolazzi, P.; Bongiovanni, G.

    1985-11-01

    In this paper the authors present two VLSI structures implementing the banker's algorithm for the deadlock avoidance problem, and we derive the area x (time)/sup 2/ lower bound for such an algorithm. The first structure is based on the VLSI mesh of trees. The second structure is a modification of the first one, and it approaches more closely the theoretical lower bound.

  9. Differential Cost Avoidance and Successful Criminal Careers: Random or Rational?

    ERIC Educational Resources Information Center

    Kazemian, Lila; Le Blanc, Marc

    2007-01-01

    Using a sample of adjudicated French Canadian males from the Montreal Two Samples Longitudinal Study, this article investigates individual and social characteristics associated with differential cost avoidance. The main objective of this study is to determine whether such traits are randomly distributed across differential degrees of cost…

  10. Enuresis Control through Fading, Escape, and Avoidance Training.

    ERIC Educational Resources Information Center

    Hansen, Gordon D.

    1979-01-01

    A twin signal device that provides both escape and avoidance conditioning in enuresis control was documented with case studies of two enuretic children (eight and nine years old). In addition, a technique of fading as an adjunct to the process was utilized with one subject. (Author/SBH)

  11. 14 CFR 125.224 - Collision avoidance system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... than 33,000 pounds maximum certificated takeoff weight (1) TCAS I that meets TSO C-118, or a later version, or(2) A collision avoidance system equivalent to TSO C-118, or a later version, or (1)(3) A... more than 33,000 pounds maximum certificated takeoff weight (1) An appropriate class of Mode...

  12. 16 CFR 801.90 - Transactions or devices for avoidance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... INTERPRETATIONS UNDER THE HART-SCOTT-RODINO ANTITRUST IMPROVEMENTS ACT OF 1976 COVERAGE RULES § 801.90 Transactions or devices for avoidance. Any transaction(s) or other device(s) entered into or employed for the... remaining authorized A1 stock (one-fourth each to “A” and “B”). A's creation of A1 was exempt under Sec....

  13. 16 CFR 801.90 - Transactions or devices for avoidance.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... INTERPRETATIONS UNDER THE HART-SCOTT-RODINO ANTITRUST IMPROVEMENTS ACT OF 1976 COVERAGE RULES § 801.90 Transactions or devices for avoidance. Any transaction(s) or other device(s) entered into or employed for the... remaining authorized A1 stock (one-fourth each to “A” and “B”). A's creation of A1 was exempt under Sec....

  14. 20 Biggest Mistakes Principals Make and How to Avoid Them

    ERIC Educational Resources Information Center

    Grady, Marilyn L.

    2004-01-01

    In this book, Marilyn Grady examines the twenty most critical mistakes principals make, and provides the strategies needed to avoid them. By surveying both teachers and administrators, and applying her own experiences as both teacher and a principal, the author examines the crucial errors from the following six key categories: (1) People…

  15. Kin encounter rate and inbreeding avoidance in canids

    USGS Publications Warehouse

    Geffen, E.; Kam, M.; Hefner, R.; Hersteinsson, P.; Angerbjorn, A.; Dalen, L.; Fuglei, E.; Noren, K.; Adams, J.R.; Vucetich, J.; Meier, T.J.; Mech, L.D.; Vonholdt, B.M.; Stahler, D.R.; Wayne, R.K.

    2011-01-01

    Mating with close kin can lead to inbreeding depression through the expression of recessive deleterious alleles and loss of heterozygosity. Mate selection may be affected by kin encounter rate, and inbreeding avoidance may not be uniform but associated with age and social system. Specifically, selection for kin recognition and inbreeding avoidance may be more developed in species that live in family groups or breed cooperatively. To test this hypothesis, we compared kin encounter rate and the proportion of related breeding pairs in noninbred and highly inbred canid populations. The chance of randomly encountering a full sib ranged between 1-8% and 20-22% in noninbred and inbred canid populations, respectively. We show that regardless of encounter rate, outside natal groups mates were selected independent of relatedness. Within natal groups, there was a significant avoidance of mating with a relative. Lack of discrimination against mating with close relatives outside packs suggests that the rate of inbreeding in canids is related to the proximity of close relatives, which could explain the high degree of inbreeding depression observed in some populations. The idea that kin encounter rate and social organization can explain the lack of inbreeding avoidance in some species is intriguing and may have implications for the management of populations at risk. ?? 2011 Blackwell Publishing Ltd.

  16. Illness-dependent conditioned prey avoidance in an amphibian.

    PubMed

    To, Eric S K; Laberge, Frédéric

    2014-03-01

    Conditioned taste avoidance (CTA) helps prevent consumption of dangerous foods. It results from the pairing of a novel food or taste with subsequent aversive consequences, such as illness. Previous studies of CTA in amphibians have produced conflicting results. Establishing the presence or absence of CTA in amphibians is needed to clarify the phylogeny of this phenomenon. This experiment evaluated the ability of the fire-bellied toad Bombina orientalis to avoid a novel food item previously paired with subsequent illness or unpalatable taste. Mealworms, a novel prey item for the subjects, were coated with a solution of either 2% HCl or 3% CuSO4 to make them unpalatable or nauseating, respectively. Lengthy and obvious signs of illness such as face wiping and retching followed the consumption of mealworms coated with CuSO4, whereas consumption of mealworms coated with HCl only resulted in distinct and short lived aversive reactions at the time of consumption. The results showed that consumption of mealworms tainted with CuSO4, but not HCl, rapidly induced prey avoidance. This response was specific to mealworms; the usual food (crickets) was not avoided. The results suggest that CTA following illness is not restricted to amniote vertebrates.

  17. Variable reluctance switch avoids contact corrosion and contact bounce

    NASA Technical Reports Server (NTRS)

    Watson, P. C.

    1967-01-01

    Variable reluctance switch avoids contact corrosion and bounce in a hostile environment. It consists of a wire-wound magnetic core and moveable bridge piece that alters the core flux pattern to produce an electrical output useful for switching control media.

  18. Listening for avoidance: narrative form and defensiveness in adolescent memories.

    PubMed

    Nelson, Kristin L; Bein, Edward; Huemer, Julia; Ryst, Erika; Steiner, Hans

    2009-12-01

    We describe a linguistic clue to speakers' states of mind that has utility for psychotherapists and counselors, and summarize the theoretical and empirical support for using this clue in clinical practice. Specifically, we posit that the degree to which people relate stressful episodes from their lives as a chronological sequence of events is negatively associated with the extent to which they self-protectively avoid experiencing negative affect. We review relevant discussions and findings from linguistics and psychology, and then present a new study that replicates previous research. In this study of the relationship between defensive avoidance and the narrative structure of stressful memories in non-clinical adolescents, 168 high school students spoke for 10 min into a tape recorder about "your most stressful life event." Transcribed interviews were analyzed for narrative immersion, the extent to which the past is retold in chronological order, using a method adopted from Labov and Waletzky. A negative association was found between narrative immersion and avoidance (as operationalized by scores on the Marlowe Crowne Social Desirability Scale). Listening for narrative immersion in the speech of clients discussing past stressful times may therefore represent a useful tool in exploring defensive avoidance of stressful episodic memories.

  19. Information Seeking and Avoidance Behavior in School Library Distance Learning

    ERIC Educational Resources Information Center

    Du, Yunfei

    2010-01-01

    Library science students in school librarianship were surveyed to determine their information seeking and avoidance behaviors in Web-based online environments. Two coping styles were identified among students. Barriers to student online collaboration, such as individual preferences, concerns on efficiency, and lack of mutual trust, were observed.…

  20. 28 CFR 552.23 - Confrontation avoidance procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Confrontation avoidance procedures. 552.23 Section 552.23 Judicial Administration BUREAU OF PRISONS, DEPARTMENT OF JUSTICE INSTITUTIONAL MANAGEMENT CUSTODY Use of Force and Application of Restraints on Inmates § 552.23 Confrontation...

  1. Behavioral predispositions to approach or avoid emotional words in schizophrenia.

    PubMed

    Sevos, Jessica; Grosselin, Anne; Fedotova, Tatyana; Massoubre, Catherine

    2016-07-30

    Many data suggest a disjunction between decreased emotional expressions and relatively preserved experience of and ability to assess emotions in schizophrenia. Based in an embodied approach of cognition, several studies have highlighted affective stimulus-response congruency effect in healthy subjects that show a direct link between the perception of emotion and associated motor responses. This study investigated whether the categorization of emotional words involves an automatic sensorimotor simulation of approach and avoidance behaviors. We asked 28 subjects with schizophrenia and 28 controls to execute arm movements of approach or avoidance to categorize emotional words, according to their valence (positive or negative). Controls were faster to respond to a positive stimulus with a movement of approach and a negative stimulus with a movement of avoidance (congruent condition) than to perform the inverted response movements (incongruent condition). However, responses of patients with schizophrenia did not differ according to congruence condition. Our results support the apparent non-involvement of covert sensorimotor simulation of approach and avoidance in the categorization of emotional stimuli by patients with schizophrenia, despite their understanding of the emotional valence of words. This absence of affective stimulus-response compatibility effect would imply a decoupling between emotional and bodily states in patients with schizophrenia. PMID:27179694

  2. Frequently Asked Questions: IDEA Early Childhood--Disclosure Avoidance

    ERIC Educational Resources Information Center

    Center for IDEA Early Childhood Data Systems (DaSy), 2014

    2014-01-01

    This 2014 document is an adaptation of the 2012 release of "Frequently Asked Questions--Disclosure Avoidance" intended for K-12 audiences. Presented here in the form of responses to frequently asked questions (FAQs) are suggestions intended to provide guidance to IDEA Part C early intervention and Part B 619 preschool special education…

  3. Reasons for Avoidance of Vocational Education in Jordan

    ERIC Educational Resources Information Center

    Al-Saaideh, Mon'im A.

    2016-01-01

    The study aimed to identify the factors that lead students to avoid joining Vocational Education (VE) in Jordan. A pilot study was conducted, then a 39-item questionnaire was developed, and its validity and reliability were ensured. The reasons included were divided into personal, social, economic, educational and vocational domains. The…

  4. 42 CFR 495.208 - Avoiding duplicate payment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Avoiding duplicate payment. 495.208 Section 495.208 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION STANDARDS FOR THE ELECTRONIC HEALTH RECORD TECHNOLOGY...

  5. Effectiveness of Avoidant Thinking and Redefinition in Coping with Stress.

    ERIC Educational Resources Information Center

    Burish, Thomas G.; And Others

    After receiving a sample shock, subjects in a Threat Condition were told that they would receive additional painful shocks while subjects in a Nonthreat Condition were not threatened with additional shocks. Subjects in an Avoidant Thinking Condition were then instructed to read and think about an amusing story, subjects in a Situation Redefinition…

  6. Instructional Support Predicts Children's Task Avoidance in Kindergarten

    ERIC Educational Resources Information Center

    Pakarinen, Eija; Kiuru, Noona; Lerkkanen, Marja-Kristiina; Poikkeus, Anna-Maija; Ahonen, Timo; Nurmi, Jari-Erik

    2011-01-01

    This study examined the role of observed classroom quality in children's task-avoidant behavior and math skills in kindergarten. To investigate this, 1268 children were tested twice on their math skills during their kindergarten year. Kindergarten teachers (N = 137) filled in questionnaires measuring their professional experience and also rated…

  7. Changes for Avoiding Burnout in Teachers and Advisers

    ERIC Educational Resources Information Center

    Nagy, Mary Lou

    2006-01-01

    All advisers have many concerns and stresses that are unique to their situation. Even though they love their jobs, burnout can creep up without announcing its arrival. Possible signs of burnout may include irritability with students, avoiding responsibility, working harder and getting less done, feeling discouraged and indifferent, showing…

  8. Characterization of white mold disease avoidance in common bean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    White mold, caused by Sclerotinia sclerotiorum, is a devastating fungal disease of common bean (Phaseolus vulgaris L.) worldwide. Physiological resistance and disease avoidance conferred by plant architecture-related traits contribute to white mold field resistance. Our objective was to further exam...

  9. 42 CFR 495.208 - Avoiding duplicate payment.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... PROGRAM Requirements Specific to Medicare Advantage (MA) Organizations § 495.208 Avoiding duplicate payment. (a) Unless a qualifying MA EP is entitled to a maximum payment for a year under the Medicare FFS EHR incentive program, payment for such an individual is only made under the MA EHR incentive...

  10. Sensorimotor Model of Obstacle Avoidance in Echolocating Bats.

    PubMed

    Vanderelst, Dieter; Holderied, Marc W; Peremans, Herbert

    2015-10-01

    Bat echolocation is an ability consisting of many subtasks such as navigation, prey detection and object recognition. Understanding the echolocation capabilities of bats comes down to isolating the minimal set of acoustic cues needed to complete each task. For some tasks, the minimal cues have already been identified. However, while a number of possible cues have been suggested, little is known about the minimal cues supporting obstacle avoidance in echolocating bats. In this paper, we propose that the Interaural Intensity Difference (IID) and travel time of the first millisecond of the echo train are sufficient cues for obstacle avoidance. We describe a simple control algorithm based on the use of these cues in combination with alternating ear positions modeled after the constant frequency bat Rhinolophus rouxii. Using spatial simulations (2D and 3D), we show that simple phonotaxis can steer a bat clear from obstacles without performing a reconstruction of the 3D layout of the scene. As such, this paper presents the first computationally explicit explanation for obstacle avoidance validated in complex simulated environments. Based on additional simulations modelling the FM bat Phyllostomus discolor, we conjecture that the proposed cues can be exploited by constant frequency (CF) bats and frequency modulated (FM) bats alike. We hypothesize that using a low level yet robust cue for obstacle avoidance allows bats to comply with the hard real-time constraints of this basic behaviour.

  11. School Bullying: Tools for Avoiding Harm and Liability

    ERIC Educational Resources Information Center

    McGrath, Mary Jo

    2006-01-01

    Every hour of every day, students experience bullying and harassment at school by their peers. The immediate and long-term impact on the victims' learning capabilities, emotional health, and self-esteem is staggering. " School Bullying: Tools for Avoiding Harm and Liability" tackles this critical problem with an easy-to-use framework that guides…

  12. Defining the Collision Avoidance Region for DAA Systems

    NASA Technical Reports Server (NTRS)

    Thipphavong, David; Cone, Andrew; Park, Chunki; Lee, Seung Man; Santiago, Confesor

    2016-01-01

    Unmanned aircraft systems (UAS) will be required to equip with a detect-­-and-­-avoid (DAA) system in order to satisfy the federal aviation regulations to maintain well clear of other aircraft, some of which may be equipped with a Traffic Collision Avoidance System (TCAS) to mitigate the possibility of mid-­-air collisions. As such, the minimum operational performance standards (MOPS) for UAS DAA systems are being designed with TCAS interoperability in mind by a group of industry, government, and academic institutions named RTCA Special Committee-228 (SC-228). This document will discuss the development of the spatial-­-temporal volume known as the collision avoidance region in which the DAA system is not allowed to provide vertical guidance to maintain or regain DAA well clear that could conflict with resolution advisories (RAs) issued by the intruder aircraft's TCAS system. Three collision avoidance region definition candidates were developed based on the existing TCAS RA and DAA alerting definitions. They were evaluated against each other in terms of their interoperability with TCAS RAs and DAA alerts in an unmitigated factorial encounter analysis of 1.3 million simulated pairs.

  13. Avoiding Pornography Landmines while Traveling the Information Superhighway.

    ERIC Educational Resources Information Center

    Lehmann, Kay

    2002-01-01

    Discusses how to avoid pornographic sites when using the Internet in classrooms. Highlights include re-setting the Internet home page; putting appropriate links in a Word document; creating a Web page with appropriate links; downloading the content of a Web site; educating the students; and re-checking all Web addresses. (LRW)

  14. Literature for Children: Avoiding Controversy and Intellectual Challenge.

    ERIC Educational Resources Information Center

    Adams, Dennis M.

    1986-01-01

    Discusses lack of literature on controversial subjects that can help prepare children and young adults to deal perceptively with complexities of modern world. Highlights include meeting the issues head-on, glorifying armed conflict in video media, avoiding issues of nuclear war, and intellectual depth and dealing with controversial issues. (12…

  15. Sensorimotor Model of Obstacle Avoidance in Echolocating Bats.

    PubMed

    Vanderelst, Dieter; Holderied, Marc W; Peremans, Herbert

    2015-10-01

    Bat echolocation is an ability consisting of many subtasks such as navigation, prey detection and object recognition. Understanding the echolocation capabilities of bats comes down to isolating the minimal set of acoustic cues needed to complete each task. For some tasks, the minimal cues have already been identified. However, while a number of possible cues have been suggested, little is known about the minimal cues supporting obstacle avoidance in echolocating bats. In this paper, we propose that the Interaural Intensity Difference (IID) and travel time of the first millisecond of the echo train are sufficient cues for obstacle avoidance. We describe a simple control algorithm based on the use of these cues in combination with alternating ear positions modeled after the constant frequency bat Rhinolophus rouxii. Using spatial simulations (2D and 3D), we show that simple phonotaxis can steer a bat clear from obstacles without performing a reconstruction of the 3D layout of the scene. As such, this paper presents the first computationally explicit explanation for obstacle avoidance validated in complex simulated environments. Based on additional simulations modelling the FM bat Phyllostomus discolor, we conjecture that the proposed cues can be exploited by constant frequency (CF) bats and frequency modulated (FM) bats alike. We hypothesize that using a low level yet robust cue for obstacle avoidance allows bats to comply with the hard real-time constraints of this basic behaviour. PMID:26502063

  16. Packet Drop Avoidance for High-speed network transmission protocol

    SciTech Connect

    Jin, Guojun

    2004-05-01

    As network bandwidth continues to grow and longer paths are used to exchange large scientific data between storage systems and GRID computation, it has become increasingly obvious that there is a need to deploy a packet drop avoidance mechanism into network transmission protocols. Current end-to-end congestion avoidance mechanisms used in Transmission Control Protocol (TCP) have worked well on low bandwidth delay product networks, but with newer high-bandwidth delay networks they have shown to be inefficient and prone to unstable. This is largely due to increased network bandwidth coupled with changes in internet traffic patterns. These changes come from a variety of new network applications that are being developed to take advantage of the increased network bandwidth. This paper will examine the end-to-end congestion avoidance mechanism and perform a step-by-step analysis of its theory. In addition we will propose an alternative approach developed as part of a new network transmission protocol. Our alternative protocol uses a packet drop avoidance (PDA) mechanism built on top of the maximum burst size (MBS) theory combined with a real-time available bandwidth algorithm.

  17. Thermal avoidance during flight in the locust Locusta migratoria

    PubMed

    Robertson; Kuhnert; Dawson

    1996-01-01

    In this paper, thermal avoidance in tethered flying locusts is described for the first time. Changes in body posture examined using high-speed cinematography revealed that the animals responded to a laterally positioned heat source with contralaterally directed abdomen and hindleg ruddering, behavioural patterns resembling manoeuvres observed in collision avoidance and in response to auditory signals. The analysis also showed that, during stimulation, left and right forewing depression became asymmetrical during the downstroke but remained symmetrical during the upstroke. Hindwing depression and elevation remained symmetrical during stimulus presentations. Electromyographic recordings from the left and right first basalar muscles (M97; forewing depressors) showed that contralateral depressor muscle activity was advanced by 10­12 ms relative to that on the stimulated side. There was also an increase in burst duration on the contralaterally stimulated side and an increase in wingbeat frequency of approximately 3 Hz. Ablation experiments showed that removal of the antennal flagella, which are the site of previously described thermoreceptors, did not abolish thermal avoidance manoeuvres. We conclude that thermal avoidance is triggered by an infrared sensitivity that is not mediated by the compound eyes, the ocelli or the antennal flagella. PMID:9319276

  18. Optimizing Value and Avoiding Problems in Building Schools.

    ERIC Educational Resources Information Center

    Brevard County School Board, Cocoa, FL.

    This report describes school design and construction delivery processes used by the School Board of Brevard County (Cocoa, Florida) that help optimize value, avoid problems, and eliminate the cost of maintaining a large facility staff. The project phases are examined from project definition through design to construction. Project delivery…

  19. Precision Landing and Hazard Avoidance (PL&HA) Domain

    NASA Technical Reports Server (NTRS)

    Robertson, Edward A.; Carson, John M., III

    2016-01-01

    The Precision Landing and Hazard Avoidance (PL&HA) domain addresses the development, integration, testing, and spaceflight infusion of sensing, processing, and GN&C (Guidance, Navigation and Control) functions critical to the success and safety of future human and robotic exploration missions. PL&HA sensors also have applications to other mission events, such as rendezvous and docking.

  20. Helping Teenage Girls Avoid the Female Athlete Triad.

    ERIC Educational Resources Information Center

    Ilardi, Deb

    2002-01-01

    Describes how school nurses can advocate for adolescent female students and help them avoid the female athlete triad that includes disordered eating, amenorrhea, and osteoporosis. The article focuses on consequences of the triad, how to uncover the symptoms, working to improve public support, and creating a successful program through partnership.…

  1. Predicting dental avoidance among dentally fearful Australian adults.

    PubMed

    Armfield, Jason M

    2013-06-01

    Dental fear is related to poorer oral health outcomes, and this might be explained by the less frequent dental visiting of many fearful people. The objectives of this study were to investigate differences between dentally fearful people who regularly attend the dentist and fearful people who infrequently visit the dentist. A random sample of 1,082 Australians ≥ 15 yr of age completed a mailed questionnaire (response rate = 71.6%), and 191 dentate, high-fear adults (≥ 18 yr of age) were selected for further analysis. Dental avoidance was recorded if a person was currently avoiding or delaying dental care and if he/she had not been to a dentist in the previous 2 yr. Among the selected dentally fearful adults, dental avoidance was predicted by smoking status, toothbrushing frequency, coping strategy use, perceptions of dental visits as uncontrollable and unpredictable, and by anxiety relating to numbness, not knowing what the dentist is going to do, and cost. In a multivariate logistic regression model, smoking, toothbrushing, coping, and anxiety about numbness and cost remained as statistically significant predictors, with the model accounting for 30% of the variance. While several variables were associated with dental avoidance among fearful adults, the nature and causal directions of these associations remain to be established.

  2. 38 CFR 4.14 - Avoidance of pyramiding.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... same disability under various diagnoses is to be avoided. Disability from injuries to the muscles, nerves, and joints of an extremity may overlap to a great extent, so that special rules are included in... manifestations not resulting from service-connected disease or injury in establishing the...

  3. 38 CFR 4.14 - Avoidance of pyramiding.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... same disability under various diagnoses is to be avoided. Disability from injuries to the muscles, nerves, and joints of an extremity may overlap to a great extent, so that special rules are included in... manifestations not resulting from service-connected disease or injury in establishing the...

  4. 38 CFR 4.14 - Avoidance of pyramiding.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... same disability under various diagnoses is to be avoided. Disability from injuries to the muscles, nerves, and joints of an extremity may overlap to a great extent, so that special rules are included in... manifestations not resulting from service-connected disease or injury in establishing the...

  5. Accident Avoidance Skill Training and Performance Testing. Final Report.

    ERIC Educational Resources Information Center

    Hatterick, G. Richard; Barthurst, James R.

    A two-phased study was conducted to determine the feasibility of training drivers to acquire skills needed to avoid critical conflict motor vehicle accidents, and to develop the procedures and materials necessary for such training. Basic data were derived from indepth accident investigations and task analyses of driver behavior. Principal…

  6. Sensorimotor Model of Obstacle Avoidance in Echolocating Bats

    PubMed Central

    Vanderelst, Dieter; Holderied, Marc W.; Peremans, Herbert

    2015-01-01

    Bat echolocation is an ability consisting of many subtasks such as navigation, prey detection and object recognition. Understanding the echolocation capabilities of bats comes down to isolating the minimal set of acoustic cues needed to complete each task. For some tasks, the minimal cues have already been identified. However, while a number of possible cues have been suggested, little is known about the minimal cues supporting obstacle avoidance in echolocating bats. In this paper, we propose that the Interaural Intensity Difference (IID) and travel time of the first millisecond of the echo train are sufficient cues for obstacle avoidance. We describe a simple control algorithm based on the use of these cues in combination with alternating ear positions modeled after the constant frequency bat Rhinolophus rouxii. Using spatial simulations (2D and 3D), we show that simple phonotaxis can steer a bat clear from obstacles without performing a reconstruction of the 3D layout of the scene. As such, this paper presents the first computationally explicit explanation for obstacle avoidance validated in complex simulated environments. Based on additional simulations modelling the FM bat Phyllostomus discolor, we conjecture that the proposed cues can be exploited by constant frequency (CF) bats and frequency modulated (FM) bats alike. We hypothesize that using a low level yet robust cue for obstacle avoidance allows bats to comply with the hard real-time constraints of this basic behaviour. PMID:26502063

  7. More Misconceptions to Avoid When Teaching about Plants

    ERIC Educational Resources Information Center

    Hershey, David R.

    2005-01-01

    As follow-up to a previous article "Avoid Misconceptions When Teaching about Plants," the author identifies fifty additional misconceptions. Undergeneralizations are added to the list of oversimplifications, obsolete concepts, terms, misidentifications, and flawed research. A glossary at the end of the article compares words used in botany with…

  8. Binge Eating and Weight Control: The Role of Experiential Avoidance

    ERIC Educational Resources Information Center

    Lillis, Jason; Hayes, Steven C.; Levin, Michael E.

    2011-01-01

    Two thirds of the adults in the United States are overweight or obese. Binge eating is a barrier to treatment adherence and sustained weight loss, and can be seen as a form of experiential avoidance. The current study analyzed the impact of binge eating on weight reduction in a previously published study of a 1-day acceptance and commitment…

  9. Maternal Adjustment Following Preterm Birth: Contributions of Experiential Avoidance

    ERIC Educational Resources Information Center

    Greco, Laurie A.; Heffner, Michelle; Poe, Susannah; Ritchie, Susan; Polak, Mark; Lynch, Susan K.

    2005-01-01

    The birth of a preterm infant has been linked with parental distress and adjustment difficulties, yet little is known about the psychosocial factors contributing to this association. Using a cross-sectional design, we therefore examined maternal adjustment following preterm birth, with an emphasis on the potential role of experiential avoidance.…

  10. Kin encounter rate and inbreeding avoidance in canids

    USGS Publications Warehouse

    Geffen, Eli; Kam, Michael; Hefner, Reuven; Hersteinsson, Pall; Angerbjorn, Anders; Dalen, Love; Fuglei, Eva; Noren, Karin; Adams, Jennifer R.; Vicetich, John; Meier, Thomas J.; Mech, L.D.; VonHoldt, Bridgett M.; Stahler, Daniel R.; Wayne, Robert K.

    2011-01-01

    Mating with close kin can lead to inbreeding depression through the expression of recessive deleterious alleles and loss of heterozygosity. Mate selection may be affected by kin encounter rate, and inbreeding avoidance may not be uniform but associated with age and social system. Specifically, selection for kin recognition and inbreeding avoidance may be more developed in species that live in family groups or breed cooperatively. To test this hypothesis, we compared kin encounter rate and the proportion of related breeding pairs in noninbred and highly inbred canid populations. The chance of randomly encountering a full sib ranged between 1–8% and 20–22% in noninbred and inbred canid populations, respectively. We show that regardless of encounter rate, outside natal groups mates were selected independent of relatedness. Within natal groups, there was a significant avoidance of mating with a relative. Lack of discrimination against mating with close relatives outside packs suggests that the rate of inbreeding in canids is related to the proximity of close relatives, which could explain the high degree of inbreeding depression observed in some populations. The idea that kin encounter rate and social organization can explain the lack of inbreeding avoidance in some species is intriguing and may have implications for the management of populations at risk.

  11. 14 CFR 437.65 - Collision avoidance analysis.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Collision avoidance analysis. 437.65 Section 437.65 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING EXPERIMENTAL PERMITS Safety Requirements § 437.65 Collision...

  12. Measuring Avoidance and Inflexibility in Weight Related Problems

    ERIC Educational Resources Information Center

    Lillis, Jason; Hayes, Steven C.

    2008-01-01

    There is growing evidence that experiential avoidance and psychological inflexibility plays a role in a variety of clinical presentations, including health problems. The present study presents preliminary data on a new measure of these processes in relation to difficult weight-related thoughts, feelings, and actions: The Acceptance and Action…

  13. Avoiding Consumer Frauds and Misrepresentations. A Learning Module.

    ERIC Educational Resources Information Center

    Garman, E. Thomas; Monroe, Sarah D.

    Focusing on avoiding consumer frauds and misrepresentations, this document is one in a series of three consumer education modules developed to educate individual adult consumers in important areas of consumer affairs. An introductory section provides an overview of the module contents, suggested approaches for using the module, and suggestions for…

  14. Implicit Approach-Avoidance Associations for Craved Food Cues

    ERIC Educational Resources Information Center

    Kemps, Eva; Tiggemann, Marika; Martin, Rachel; Elliott, Mecia

    2013-01-01

    Implicit approach associations are well documented for substances such as alcohol, tobacco, and illicit drugs. This study reports two experiments designed to establish and modify such associations specifically in the food craving domain. Experiment 1 used a pictorial implicit association task to examine approach-avoidance associations with…

  15. Continuing food-avoidance diets after negative food challenges.

    PubMed

    Eigenmann, Philippe A; Caubet, Jean-Christoph; Zamora, Samuel A

    2006-12-01

    Negative food challenges for follow-up in patients previously diagnosed with food allergy should logically be followed by a normal diet. However, all patients do not reintroduce the food. The aims of the study were to define the proportion of negative food challenge not followed by a normal diet, and to identify possible reasons for not reintroducing the food. Patients with a negative food challenge were sent a questionnaire by mail. Items in the questionnaire included the symptoms at diagnosis, the duration of the diet, the fear of an accidental reaction during the avoidance diet and how it influenced the social life. Patients were also asked if the food was reintroduced after the negative food challenge, and if not, for which reasons. In 25.4% of the questionnaires (18/71) respondents reported that the food was not reintroduced. Patients with a previous diagnosis of peanut allergy tended to reintroduce the food less frequently than patients allergic to other foods. Girls were found to significantly less frequently reintroduce the food than boys. However, neither the severity of the initial reaction, the anxiety of an accidental reaction during the avoidance diet, nor a prolonged avoidance diet did influence the decision to reintroduce the food. Among other reasons listed, fears of persistence of allergies, with recurrent pruritus or non-specific skin rashes after eating the food, were reported in 12.7% of the total number of questionnaires. Patients who reintroduced the food reported that their social life generally improved. One quarter of previously allergic patients continue a food avoidance diet despite a negative challenge. We suggest reassessing food consumption in all patients after a negative food challenge, and in those still avoiding the specific food to consider a repeated challenge test.

  16. Sexual selection as a consequence of pathogen avoidance behaviors

    SciTech Connect

    Loehle, C.; Logofet, D.O.

    1997-08-01

    The current theory that sexual selection results from female choice for good genes suffers from several problems. An alternative explanation is proposed. The pathogen avoidance hypothesis argues that the primary function of showy traits is to provide a reliable signal of current disease status so that sick individuals may be avoided during mating. Our studies shown that a significant risk of pathogen transmission occurs during mating and that showy traits are reliable indicators of current disease status. The origin of female choosiness is argued to lie in a general tendency to avoid sick individuals, even in the absence of showy traits. The showy traits are argued to originate as simple exaggerations of normal traits that are indicative of good health (bright feathers; vigorous movement; large size). Thus the origins of both showy traits and female choosiness are not problematic in this theory. A game theory analysis is employed to formalize the theory. Results of the game theory model support the theory. In particular, when the possession of male showy traits does not help reduce disease in the female, then showy traits are unlikely to occur. This case corresponds to the situation in large flocks or herds in which every animal is thoroughly exposed to all group pathogens on average. Such species do not exhibit showy traits. The good genes model does not make this prediction. The pathogen avoidance model can also lead to the evolution of showy traits even when selection is not effective against a given pathogen (e.g., when there is no heritable variation for resistance) but will lead to selection for resistance if such genes are present. Overall, the pathogen avoidance hypothesis provides a complete alternative to the good genes theory.

  17. Flight Deck Weather Avoidance Decision Support: Implementation and Evaluation

    NASA Technical Reports Server (NTRS)

    Wu, Shu-Chieh; Luna, Rocio; Johnson, Walter W.

    2013-01-01

    Weather related disruptions account for seventy percent of the delays in the National Airspace System (NAS). A key component in the weather plan of the Next Generation of Air Transportation System (NextGen) is to assimilate observed weather information and probabilistic forecasts into the decision process of flight crews and air traffic controllers. In this research we explore supporting flight crew weather decision making through the development of a flight deck predicted weather display system that utilizes weather predictions generated by ground-based radar. This system integrates and presents this weather information, together with in-flight trajectory modification tools, within a cockpit display of traffic information (CDTI) prototype. that the CDTI features 2D and perspective 3D visualization models of weather. The weather forecast products that we implemented were the Corridor Integrated Weather System (CIWS) and the Convective Weather Avoidance Model (CWAM), both developed by MIT Lincoln Lab. We evaluated the use of CIWS and CWAM for flight deck weather avoidance in two part-task experiments. Experiment 1 compared pilots' en route weather avoidance performance in four weather information conditions that differed in the type and amount of predicted forecast (CIWS current weather only, CIWS current and historical weather, CIWS current and forecast weather, CIWS current and forecast weather and CWAM predictions). Experiment 2 compared the use of perspective 3D and 21/2D presentations of weather for flight deck weather avoidance. Results showed that pilots could take advantage of longer range predicted weather forecasts in performing en route weather avoidance but more research will be needed to determine what combinations of information are optimal and how best to present them.

  18. Recurrent, Robust and Scalable Patterns Underlie Human Approach and Avoidance

    PubMed Central

    Kennedy, David N.; Lehár, Joseph; Lee, Myung Joo; Blood, Anne J.; Lee, Sang; Perlis, Roy H.; Smoller, Jordan W.; Morris, Robert; Fava, Maurizio

    2010-01-01

    Background Approach and avoidance behavior provide a means for assessing the rewarding or aversive value of stimuli, and can be quantified by a keypress procedure whereby subjects work to increase (approach), decrease (avoid), or do nothing about time of exposure to a rewarding/aversive stimulus. To investigate whether approach/avoidance behavior might be governed by quantitative principles that meet engineering criteria for lawfulness and that encode known features of reward/aversion function, we evaluated whether keypress responses toward pictures with potential motivational value produced any regular patterns, such as a trade-off between approach and avoidance, or recurrent lawful patterns as observed with prospect theory. Methodology/Principal Findings Three sets of experiments employed this task with beautiful face images, a standardized set of affective photographs, and pictures of food during controlled states of hunger and satiety. An iterative modeling approach to data identified multiple law-like patterns, based on variables grounded in the individual. These patterns were consistent across stimulus types, robust to noise, describable by a simple power law, and scalable between individuals and groups. Patterns included: (i) a preference trade-off counterbalancing approach and avoidance, (ii) a value function linking preference intensity to uncertainty about preference, and (iii) a saturation function linking preference intensity to its standard deviation, thereby setting limits to both. Conclusions/Significance These law-like patterns were compatible with critical features of prospect theory, the matching law, and alliesthesia. Furthermore, they appeared consistent with both mean-variance and expected utility approaches to the assessment of risk. Ordering of responses across categories of stimuli demonstrated three properties thought to be relevant for preference-based choice, suggesting these patterns might be grouped together as a relative preference

  19. [Big data, Roemer's law and avoidable hospital admissions].

    PubMed

    van der Horst, H E

    2016-01-01

    From an analysis of data from 23 European countries to determine the impact of primary care on avoidable hospital admissions for uncontrolled diabetes it appeared that, contrary to expectation, countries with strong primary care did not have a lower rate of avoidable hospital admission. It is clear that Roemer's law, 'a bed built is a bed filled,' still applies. However, the validity of this sort of analysis can be questioned, as these data are highly aggregated, and registration quality differs between countries. It is also questionable if these datasets can be considered as 'big data' as there are relatively small numbers per country. Big data analyses are useful for discerning patterns and formulating hypotheses, but not for proving causality. An unwanted side effect of this kind of analysis might be that policymakers use these not so valid results to underpin their policy to their advantage. PMID:27484429

  20. The prediction of antisocial behavior from avoidant attachment classifications.

    PubMed

    Fagot, B I; Kavanagh, K

    1990-06-01

    109 Children were classified using the Ainsworth Strange Situation at 18 months. 81 children who were unequivocally classified as insecure/avoidant (A1, A2) or securely attached (B1, B2, B3) were used in this study. The children's parents reported on occurrences of problem behaviors at 24 months, 27 months, 30 months, and 48 months using several methods. The children were observed at 18 and 30 months in their homes with their families and in toddler playgroups during the same period. The only significant effect for attachment classification was that teachers and observers of the playgroups rated girls classified as insecure/avoidant as more difficult to deal with and as having more difficulty with peers than girls rated as securely attached.

  1. Avoiding healthy cells extinction in a cancer model.

    PubMed

    López, Álvaro G; Sabuco, Juan; Seoane, Jesús M; Duarte, Jorge; Januário, Cristina; Sanjuán, Miguel A F

    2014-05-21

    We consider a dynamical model of cancer growth including three interacting cell populations of tumor cells, healthy host cells and immune effector cells. For certain parameter choice, the dynamical system displays chaotic motion and by decreasing the response of the immune system to the tumor cells, a boundary crisis leading to transient chaotic dynamics is observed. This means that the system behaves chaotically for a finite amount of time until the unavoidable extinction of the healthy and immune cell populations occurs. Our main goal here is to apply a control method to avoid extinction. For that purpose, we apply the partial control method, which aims to control transient chaotic dynamics in the presence of external disturbances. As a result, we have succeeded to avoid the uncontrolled growth of tumor cells and the extinction of healthy tissue. The possibility of using this method compared to the frequently used therapies is discussed.

  2. Departures From Optimality When Pursuing Multiple Approach or Avoidance Goals

    PubMed Central

    2016-01-01

    This article examines how people depart from optimality during multiple-goal pursuit. The authors operationalized optimality using dynamic programming, which is a mathematical model used to calculate expected value in multistage decisions. Drawing on prospect theory, they predicted that people are risk-averse when pursuing approach goals and are therefore more likely to prioritize the goal in the best position than the dynamic programming model suggests is optimal. The authors predicted that people are risk-seeking when pursuing avoidance goals and are therefore more likely to prioritize the goal in the worst position than is optimal. These predictions were supported by results from an experimental paradigm in which participants made a series of prioritization decisions while pursuing either 2 approach or 2 avoidance goals. This research demonstrates the usefulness of using decision-making theories and normative models to understand multiple-goal pursuit. PMID:26963081

  3. Predicting Avoidance of Skin Damage Feedback among College Students

    PubMed Central

    Dwyer, Laura A.; Shepperd, James A.; Stock, Michelle L.

    2015-01-01

    Background Showing people a personal ultraviolet (UV) photograph depicting skin damage can be an effective method for changing sun protection cognitions and behaviors. Purpose We examined whether people opt not to see their UV photograph if given a choice. We also examined predictors of avoidance of skin damage feedback. Methods College students (N = 257) completed questionnaires, viewed example UV photographs, and received the opportunity to see a UV photograph of their face. Results Over one-third of participants opted not to see their UV photograph. Greater perceived risk of sun damage and having fewer coping resources corresponded with greater avoidance, particularly among participants who reported infrequent sun protection behavior. Conclusion The health benefits of UV photography are realized only if people are willing to view the photograph. Our findings suggest the need for interventions that increase receptivity to viewing one’s UV photograph. PMID:25894276

  4. Parallel neural pathways mediate CO2 avoidance responses in Drosophila.

    PubMed

    Lin, Hui-Hao; Chu, Li-An; Fu, Tsai-Feng; Dickson, Barry J; Chiang, Ann-Shyn

    2013-06-14

    Different stimulus intensities elicit distinct perceptions, implying that input signals are either conveyed through an overlapping but distinct subpopulation of sensory neurons or channeled into divergent brain circuits according to intensity. In Drosophila, carbon dioxide (CO2) is detected by a single type of olfactory sensory neuron, but information is conveyed to higher brain centers through second-order projection neurons (PNs). Two distinct pathways, PN(v)-1 and PN(v)-2, are necessary and sufficient for avoidance responses to low and high CO2 concentrations, respectively. Whereas low concentrations activate PN(v)-1, high concentrations activate both PN(v)s and GABAergic PN(v)-3, which may inhibit PN(v)-1 pathway-mediated avoidance behavior. Channeling a sensory input into distinct neural pathways allows the perception of an odor to be further modulated by both stimulus intensity and context.

  5. Avoidance-preference testing in density stratified solutions

    SciTech Connect

    Smith, E.H.; Logan, D.T.; Hansen, S.

    1994-12-31

    Toxicity testing is sometimes required where density stratifies test and reference solutions. Examples include freshwater effluents that float in estuarine and marine waters and desalinating plant effluents that sink. Standard avoidance-preference testing methods and apparatus are designed to test horizontal rather than vertical gradients and so are inappropriate for density stratified solutions. To overcome associated deficiencies, the authors modified testing chambers to take advantage of density stratification. Exposure levels for tests were selected based on NOELs from standard toxicity testing. Behavior of 10 striped bass was simultaneously observed using electronic surveillance. Measure of behavior include position in two axes and swimming speed. Avoidance-preference between several types of high density byproducts of salt water evaporation and lower density receiving water were tested. Results indicate that the modified test protocols allowed the authors to determine behavior responses to test materials.

  6. The lengths birds will go to avoid incest.

    PubMed

    Heinsohn, Robert

    2012-07-01

    Cooperatively breeding species, in which some individuals help others to rear their offspring, face a high risk of inbreeding because of close relatedness within social groups. Many species circumvent this problem via sex-biased dispersal, in which one sex is more likely to disperse (and to disperse further), while the other stays and helps. In the absence of sex-biased dispersal, more complex dispersal patterns can arise, based on kin recognition. However, this can also present challenges when dispersal distances are short, leading to clusters of relatives on neighbouring territories. In this issue, Nelson-Flower et al. (2012) break important new ground by unravelling adaptive incest-avoidance mechanisms in a cooperatively breeding bird without sex-biased dispersal. They provide an elegant demonstration of finely tuned dispersal distances together with cognitively based methods for knowing whom to avoid as mates.

  7. Real-time obstacle avoidance using harmonic potential functions

    NASA Technical Reports Server (NTRS)

    Kim, Jin-Oh; Khosla, Pradeep K.

    1992-01-01

    This paper presents a new formulation of the artificial potential approach to the obstacle avoidance problem for a mobile robot or a manipulator in a known environment. Previous formulations of artificial potentials for obstacle avoidance have exhibited local minima in a cluttered environment. To build an artificial potential field, harmonic functions that completely eliminate local minima even for a cluttered environment are used. The panel method is employed to represent arbitrarily shaped obstacles and to derive the potential over the whole space. Based on this potential function, an elegant control strategy is proposed for the real-time control of a robot. The harmonic potential, the panel method, and the control strategy are tested with a bar-shaped mobile robot and a three-degree-of-freedom planar redundant manipulator.

  8. DAIDALUS: Detect and Avoid Alerting Logic for Unmanned Systems

    NASA Technical Reports Server (NTRS)

    Munoz, Cesar; Narkawicz, Anthony; Hagen, George; Upchurch, Jason; Dutle, Aaron; Consiglio, Maria; Chamberlain, James

    2015-01-01

    This paper presents DAIDALUS (Detect and Avoid Alerting Logic for Unmanned Systems), a reference implementation of a detect and avoid concept intended to support the integration of Unmanned Aircraft Systems into civil airspace. DAIDALUS consists of self-separation and alerting algorithms that provide situational awareness to UAS remote pilots. These algorithms have been formally specified in a mathematical notation and verified for correctness in an interactive theorem prover. The software implementation has been verified against the formal models and validated against multiple stressing cases jointly developed by the US Air Force Research Laboratory, MIT Lincoln Laboratory, and NASA. The DAIDALUS reference implementation is currently under consideration for inclusion in the appendices to the Minimum Operational Performance Standards for Unmanned Aircraft Systems presently being developed by RTCA Special Committee 228.

  9. Avoiding climate change uncertainties in Strategic Environmental Assessment

    SciTech Connect

    Larsen, Sanne Vammen; Kørnøv, Lone; Driscoll, Patrick

    2013-11-15

    This article is concerned with how Strategic Environmental Assessment (SEA) practice handles climate change uncertainties within the Danish planning system. First, a hypothetical model is set up for how uncertainty is handled and not handled in decision-making. The model incorporates the strategies ‘reduction’ and ‘resilience’, ‘denying’, ‘ignoring’ and ‘postponing’. Second, 151 Danish SEAs are analysed with a focus on the extent to which climate change uncertainties are acknowledged and presented, and the empirical findings are discussed in relation to the model. The findings indicate that despite incentives to do so, climate change uncertainties were systematically avoided or downplayed in all but 5 of the 151 SEAs that were reviewed. Finally, two possible explanatory mechanisms are proposed to explain this: conflict avoidance and a need to quantify uncertainty.

  10. Self-Avoiding Walks over Adaptive Triangular Grids

    NASA Technical Reports Server (NTRS)

    Heber, Gerd; Biswas, Rupak; Gao, Guang R.; Saini, Subhash (Technical Monitor)

    1998-01-01

    In this paper, we present a new approach to constructing a "self-avoiding" walk through a triangular mesh. Unlike the popular approach of visiting mesh elements using space-filling curves which is based on a geometric embedding, our approach is combinatorial in the sense that it uses the mesh connectivity only. We present an algorithm for constructing a self-avoiding walk which can be applied to any unstructured triangular mesh. The complexity of the algorithm is O(n x log(n)), where n is the number of triangles in the mesh. We show that for hierarchical adaptive meshes, the algorithm can be easily parallelized by taking advantage of the regularity of the refinement rules. The proposed approach should be very useful in the run-time partitioning and load balancing of adaptive unstructured grids.

  11. Departures from optimality when pursuing multiple approach or avoidance goals.

    PubMed

    Ballard, Timothy; Yeo, Gillian; Neal, Andrew; Farrell, Simon

    2016-07-01

    This article examines how people depart from optimality during multiple-goal pursuit. The authors operationalized optimality using dynamic programming, which is a mathematical model used to calculate expected value in multistage decisions. Drawing on prospect theory, they predicted that people are risk-averse when pursuing approach goals and are therefore more likely to prioritize the goal in the best position than the dynamic programming model suggests is optimal. The authors predicted that people are risk-seeking when pursuing avoidance goals and are therefore more likely to prioritize the goal in the worst position than is optimal. These predictions were supported by results from an experimental paradigm in which participants made a series of prioritization decisions while pursuing either 2 approach or 2 avoidance goals. This research demonstrates the usefulness of using decision-making theories and normative models to understand multiple-goal pursuit. (PsycINFO Database Record PMID:26963081

  12. Calipso's Mission Design: Sun-Glint Avoidance Strategies

    NASA Technical Reports Server (NTRS)

    Mailhe, Laurie M.; Schiff, Conrad; Stadler, John H.

    2004-01-01

    CALIPSO will fly in formation with the Aqua spacecraft to obtain a coincident image of a portion of the Aqua/MODIS swath. Since MODIS pixels suffering sun-glint degradation are not processed, it is essential that CALIPSO only co- image the glint h e portion of the MODIS instrument swath. This paper presents sun-glint avoidance strategies for the CALIPSO mission. First, we introduce the Aqua sun-glint geometry and its relation to the CALIPSO-Aqua formation flying parameters. Then, we detail our implementation of the computation and perform a cross-track trade-space analysis. Finally, we analyze the impact of the sun-glint avoidance strategy on the spacecraft power and delta-V budget over the mission lifetime.

  13. Potential effects of reward and loss avoidance in overweight adolescents

    PubMed Central

    Reyes, Sussanne; Peirano, Patricio; Luna, Beatriz; Lozoff, Betsy; Algarín, Cecilia

    2015-01-01

    Background Reward system and inhibitory control are brain functions that exert an influence on eating behavior regulation. We studied the differences in inhibitory control and sensitivity to reward and loss avoidance between overweight/obese and normal-weight adolescents. Methods We assessed 51 overweight/obese and 52 normal-weight 15-y-old Chilean adolescents. The groups were similar regarding sex and intelligence quotient. Using Antisaccade and Incentive tasks, we evaluated inhibitory control and the effect of incentive trials (neutral, loss avoidance, and reward) on generating correct and incorrect responses (latency and error rate). Results Compared to normal-weight group participants, overweight/obese adolescents showed shorter latency for incorrect antisaccade responses (186.0 (95% CI: 176.8–195.2) vs. 201.3 ms (95% CI: 191.2–211.5), P < 0.05) and better performance reflected by lower error rate in incentive trials (43.6 (95% CI: 37.8–49.4) vs. 53.4% (95% CI: 46.8–60.0), P < 0.05). Overweight/obese adolescents were more accurate on loss avoidance (40.9 (95% CI: 33.5–47.7) vs. 49.8% (95% CI: 43.0–55.1), P < 0.05) and reward (41.0 (95% CI: 34.5–47.5) vs. 49.8% (95% CI: 43.0–55.1), P < 0.05) compared to neutral trials. Conclusion Overweight/obese adolescents showed shorter latency for incorrect responses and greater accuracy in reward and loss avoidance trials. These findings could suggest that an imbalance of inhibition and reward systems influence their eating behavior. PMID:25927543

  14. Real-time collision avoidance in space: the GETEX experiment

    NASA Astrophysics Data System (ADS)

    Freund, Eckhard; Rossmann, Juergen; Schluse, Michael

    2000-10-01

    Intelligent autonomous robotic systems require efficient safety components to assure system reliability during the entire operation. Especially if commanded over long distances, the robotic system must be able to guarantee the planning of safe and collision free movements independently. Therefore the IRF developed a new collision avoidance methodology satisfying the needs of autonomous safety systems considering the dynamics of the robots to protect. To do this, the collision avoidance system cyclically calculates the actual collision danger of the robots with respect to all static and dynamic obstacles in the environment. If a robot gets in collision danger the methodology immediately starts an evasive action to avoid the collision and guides the robot around the obstacle to its target position. This evasive action is calculated in real-time in a mathematically exact way by solving a quadratic convex optimization problem. The secondary conditions of this optimization problem include the potential collision danger of the robots kinematic chain including all temporarily attached grippers and objects and the dynamic constraints of the robots. The result of the optimization procedure are joint accelerations to apply to prevent the robot from colliding and to guide it to its target position. This methodology has been tested very successfully during the Japanese/German space robot project GETEX in April 1999. During the mission, the collision avoidance system successfully protected the free flying Japanese robot ERA on board the satellite ETS-VII at all times. The experiments showed, that the developed system is fully capable of ensuring the safety of such autonomous robotic systems by actively preventing collisions and generating evasive actions in cases of collision danger.

  15. Earthworm (Eisenia andrei) Avoidance of Soils Treated with Cypermethrin

    PubMed Central

    de Sousa, Ana Paula A.; de Andréa, Mara M.

    2011-01-01

    The pyrethroid insecticide cypermethrin is used for agricultural and public health campaigns. Its residues may contaminate soils and the beneficial soil organisms, like the earthworms, that may ingest the contaminated soil particles. Due to its ecological relevance, earthworms Eisenia andrei/fetida have been used in different ecotoxicological tests. The avoidance of soils treated with cypermethrin by compost worms Eisenia andrei was studied here as a bioindicator of the influence of treatment dosage and the pesticide formulation in three different agricultural soils indicated by the Brazilian environmental authorities for ecotoxicological tests. This earthworms’ behavior was studied here as a first attempt to propose the test for regulation purposes. The two-compartment test systems, where the earthworms were placed for a two-day exposure period, contained samples of untreated soil alone or together with soil treated with technical grade or wettable powder formulation of cypermethrin. After 48 h, there was no mortality, but the avoidance was clear because all earthworms were found in the untreated section of each type of soil (p < 0.05). No differences were found by the Fisher’s exact test (p ≤ 1.000) for each soil and treatment, demonstrating that the different soil characteristics, the cypermethrin concentrations and formulation, as well as the smaller amounts of soil and earthworms did not influence the avoidance behavior of the earthworms to cypermethrin. The number and range of treatments used in this study do not allow a detailed recommendation of the conditions applied here, but to the best of our knowledge, this is the first reported attempt to identify the avoidance of pesticide treated tropical soils by earthworms. PMID:22247652

  16. Avian Hearing and the Avoidance of Wind Turbines

    SciTech Connect

    Dooling, R.

    2002-06-01

    This report provides a complete summary of what is known about basic hearing capabilities in birds in relation to the characteristics of noise generated by wind turbines. It is a review of existing data on bird hearing with some preliminary estimates of environmental noise and wind turbine noise at Altamont Pass, California, in the summer of 1999. It is intended as a resource in future discussions of the role that hearing might play in bird avoidance of turbines.

  17. Obstacle avoidance for redundant robots using configuration control

    NASA Technical Reports Server (NTRS)

    Seraji, Homayoun (Inventor); Colbaugh, Richard D. (Inventor); Glass, Kristin L. (Inventor)

    1992-01-01

    A redundant robot control scheme is provided for avoiding obstacles in a workspace during the motion of an end effector along a preselected trajectory by stopping motion of the critical point on the robot closest to the obstacle when the distance between is reduced to a predetermined sphere of influence surrounding the obstacle. Algorithms are provided for conveniently determining the critical point and critical distance.

  18. Training in care homes to reduce avoidable harm.

    PubMed

    Brownhill, Kai

    This article demonstrates the effectiveness of using workshop-based education and service-improvement models in care homes. The models were designed around both threshold and predictive modelling and were intended to raise awareness of the symptoms that may result from a fall, pressure ulcers or urinary tract infections. The project exceeded our targets. Preventive assessments, care planning and timely referrals resulted in a reduction in avoidable hospital admissions and district nurse and GP visits.

  19. Altered avoidance behavior of young black ducks fed cadmium

    USGS Publications Warehouse

    Heinz, G.H.; Haseltine, S.D.; Sileo, L.

    1983-01-01

    Pairs of adult black ducks (Anas rubripes) were fed a diet containing 0, 4 or 40 ppm cadmium as cadmium chloride. One-week-old ducklings that had been fed thc same dietary concentrations of cadmium as had their parents were tested for avoidance of a fright stimulus. Ducklings fed 4 ppm cadmium ran significantly farther from the stimulus than did controls or ducklings fed 40 ppm cadmium. Such an alteration in behavior could have harmful effects on wild birds.

  20. The pathogen transmission avoidance theory of sexual selection

    SciTech Connect

    Loehle, C.

    1997-08-01

    The current theory that sexual selection results from female preference for males with good genes suffers from several problems. An alternative explanation, the pathogen transmission avoidance hypothesis, argues that the primary function of showy traits is to provide a reliable signal of current disease status, so that sick individuals can be avoided during mating. This study shows that a significant risk of pathogen transmission occurs during mating and that showy traits are reliable indicators of current disease status. The origin of female choosiness is argued to lie in a general tendency to avoid sick individuals, even in the absence of showy traits, which originate as exaggerations of normal traits that are indicative of good health (bright feathers, vigorous movement, large size). Thus, in this new model the origins of both showy traits and female choosiness are not problematic and there is no threshold effect. This model predicts that when the possession of male showy traits does not help to reduce disease in the female, showy traits are unlikely to occur. This case corresponds to thorough exposure of every animal to all group pathogens, on average, in large groups. Such species are shown with a large data set on birds to be less likely to exhibit showy traits. The good-genes model does not make this prediction. The pathogen transmission avoidance model can also lead to the evolution of showy traits even when selection is not effective against a given pathogen (e.g., when there is no heritable variation for resistance), but can result in selection for resistance if such genes are present. Monogamy is argued to reduce selection pressures for showy traits; data show monogamous species to be both less parasitized and less showy. In the context of reduction of pathogen transmission rates in showy populations, selection pressure becomes inversely frequency-dependent, which makes showy traits likely to be self-limiting rather than runaway.

  1. Group force mobility model and its obstacle avoidance capability

    NASA Astrophysics Data System (ADS)

    Williams, Sean A.; Huang, Dijiang

    2009-10-01

    Many mobility models attempt to provide realistic simulation to many real world scenarios. However, existing mobility models, such as RPGM [X. Hong, M. Gerla, G. Pei, C. Chiang, A group mobility model for ad hoc wireless networks, in: Proceedings of ACM/IEEE MSWiM'99, Seattle, WA, August 1999, pp. 53-60] and others, fail to address many aspects. These limitations range from mobile node (MN) collision avoidance, obstacle avoidance, and the interaction of MNs within a group. Our research, the group force mobility model (GFMM) [S.A. Williams, D. Huang, A group force mobility model, Appeared at 9th Communications and Networking Simulation Symposium, April 2006], proposes a novel idea which introduces the concept of attraction and repulsion forces to address many of these limitations. Williams and Huang [A group force mobility model, Appeared at 9th Communications and Networking Simulation Symposium, April 2006] described some of the limitations and drawbacks that many models neglect. This model effectively simulates the interaction of MNs within a group, the interaction of groups to one another, the coherency of a group, and the avoidance of collision with groups, nodes, and obstacles. This paper provides an overview of GFMM and particularly illustrates the GFMM's ability to avoid collision with obstacles, which is a vital property to posses in order to provide a realistic simulaition. We compare our model with the commonly used RPGM model and provide statistical assessments based on connectivity metrics such as link changed, link duration, and relative speed. All will be detailed and explained in this paper.

  2. Avoiding spurious submovement decompositions : a globally optimal algorithm.

    SciTech Connect

    Rohrer, Brandon Robinson; Hogan, Neville

    2003-07-01

    Evidence for the existence of discrete submovements underlying continuous human movement has motivated many attempts to extract them. Although they produce visually convincing results, all of the methodologies that have been employed are prone to produce spurious decompositions. Examples of potential failures are given. A branch-and-bound algorithm for submovement extraction, capable of global nonlinear minimization (and hence capable of avoiding spurious decompositions), is developed and demonstrated.

  3. Flies stretch their cells to avoid a chromatin trap

    PubMed Central

    2012-01-01

    Before the final step of cytokinesis, termed abscission, dividing cells need to ensure that the cleavage plane is clear of chromatin. In this issue, Kotadia et al. (2012. J. Cell Biol. http://dx.doi.org/jcb.201208041) show that in Drosophila melanogaster, larval neuroblasts elongate to allow segregation of extra-long chromatids and clearance of the midzone, thereby avoiding cytokinesis failure and aneuploidy. PMID:23185028

  4. NASA's Orbital Debris Conjuction Assessment and Collision Avoidance Strategy

    NASA Technical Reports Server (NTRS)

    Gavin, Richard T.

    2010-01-01

    NASA has successfully used debris avoidance maneuvers to protect our spacecraft for more than 20 . years. This process which started out using parametric data and maneuver boxes has seen considerable evolution and now allows us to continue nominal operations for all but the most threatening objects. This has greatly reduced the interruptions to the critical mission objectives being pursued by NASA s Space Station, Space Shuttle, and robotic satellites.

  5. Hierarchical Brain Networks Active in Approach and Avoidance Goal Pursuit

    PubMed Central

    Spielberg, Jeffrey M.; Heller, Wendy; Miller, Gregory A.

    2013-01-01

    Effective approach/avoidance goal pursuit is critical for attaining long-term health and well-being. Research on the neural correlates of key goal-pursuit processes (e.g., motivation) has long been of interest, with lateralization in prefrontal cortex being a particularly fruitful target of investigation. However, this literature has often been limited by a lack of spatial specificity and has not delineated the precise aspects of approach/avoidance motivation involved. Additionally, the relationships among brain regions (i.e., network connectivity) vital to goal-pursuit remain largely unexplored. Specificity in location, process, and network relationship is vital for moving beyond gross characterizations of function and identifying the precise cortical mechanisms involved in motivation. The present paper integrates research using more spatially specific methodologies (e.g., functional magnetic resonance imaging) with the rich psychological literature on approach/avoidance to propose an integrative network model that takes advantage of the strengths of each of these literatures. PMID:23785328

  6. The influence of object identity on obstacle avoidance reaching behaviour.

    PubMed

    de Haan, A M; Van der Stigchel, S; Nijnens, C M; Dijkerman, H C

    2014-07-01

    When reaching for target objects, we hardly ever collide with other objects located in our working environment. Behavioural studies have demonstrated that the introduction of non-target objects into the workspace alters both spatial and temporal parameters of reaching trajectories. Previous studies have shown the influence of spatial object features (e.g. size and position) on obstacle avoidance movements. However, obstacle identity may also play a role in the preparation of avoidance responses as this allows prediction of possible negative consequences of collision based on recognition of the obstacle. In this study we test this hypothesis by asking participants to reach towards a target as quickly as possible, in the presence of an empty or full glass of water placed about half way between the target and the starting position, at 8 cm either left or right of the virtual midline. While the spatial features of full and empty glasses of water are the same, the consequences of collision are clearly different. Indeed, when there was a high chance of collision, reaching trajectories veered away more from filled than from empty glasses. This shows that the identity of potential obstacles, which allows for estimating the predicted consequences of collision, is taken into account during obstacle avoidance.

  7. Cavity Femtochemistry: Manipulating Nonadiabatic Dynamics at Avoided Crossings.

    PubMed

    Kowalewski, Markus; Bennett, Kochise; Mukamel, Shaul

    2016-06-01

    Molecular potential energy surfaces can be actively manipulated by light. This is usually done by strong classical laser light but was recently demonstrated for the quantum field in an optical cavity. The photonic vacuum state of a localized cavity mode can be strongly mixed with the molecular degrees of freedom to create hybrid field-matter states known as polaritons. We simulate the avoided crossing of sodium iodide in a cavity by incorporating the quantized cavity field into the nuclear wave packet dynamics calculation. The quantized field is represented on a numerical grid in quadrature space, thus avoiding the limitations set by the rotating wave approximation (RWA) when the field is expanded in Fock space. This approach allows the investigation of cavity couplings in the vicinity of naturally occurring avoided crossings and conical intersections, which is too expensive in the fock space expansion when the RWA does not apply. Numerical results show how the branching ratio between the covalent and ionic dissociation channels can be strongly manipulated by the optical cavity. PMID:27186666

  8. Timing in free-operant and discrete-trial avoidance.

    PubMed

    Hineline, P N; Herrnstein, R J

    1970-03-01

    A procedure ("discrete-trial" avoidance) was devised to differentiate between the two main theories of responding in Sidman's "free-operant" avoidance procedure. One theory, a version of two-factor theory, holds that responding is reinforced by the removal of a conditioned aversive stimulus. The conditioned aversive stimulus is held to be temporal, which accounts for the spaced responding, or timing, that Sidman's procedure produces. The other theory holds that the reinforcement for both responding and timing is shock-frequency reduction. The new procedure eliminated this reinforcement for timing, but retained the conditions for the formation of conditioned aversive temporal stimuli. According to one theory, the new procedure should have sustained timing as well as Sidman's, while according to the other, it should have sustained no timing. The results confirmed neither theory. Timing was found with both procedures, but unequally in degree and kind. Large variations in the precision of timing did not appear to be correlated with successful avoidance for either procedure.

  9. Disgust as an adaptive system for disease avoidance behaviour

    PubMed Central

    Curtis, Valerie; de Barra, Mícheál; Aunger, Robert

    2011-01-01

    Disgust is an evolved psychological system for protecting organisms from infection through disease avoidant behaviour. This ‘behavioural immune system’, present in a diverse array of species, exhibits universal features that orchestrate hygienic behaviour in response to cues of risk of contact with pathogens. However, disgust is also a dynamic adaptive system. Individuals show variation in pathogen avoidance associated with psychological traits like having a neurotic personality, as well as a consequence of being in certain physiological states such as pregnancy or infancy. Three specialized learning mechanisms modify the disgust response: the Garcia effect, evaluative conditioning and the law of contagion. Hygiene behaviour is influenced at the group level through social learning heuristics such as ‘copy the frequent’. Finally, group hygiene is extended symbolically to cultural rules about purity and pollution, which create social separations and are enforced as manners. Cooperative hygiene endeavours such as sanitation also reduce pathogen prevalence. Our model allows us to integrate perspectives from psychology, ecology and cultural evolution with those of epidemiology and anthropology. Understanding the nature of disease avoidance psychology at all levels of human organization can inform the design of programmes to improve public health. PMID:21199843

  10. Reproductive efficiency and shade avoidance plasticity under simulated competition.

    PubMed

    Fazlioglu, Fatih; Al-Namazi, Ali; Bonser, Stephen P

    2016-07-01

    Plant strategy and life-history theories make different predictions about reproductive efficiency under competition. While strategy theory suggests under intense competition iteroparous perennial plants delay reproduction and semelparous annuals reproduce quickly, life-history theory predicts both annual and perennial plants increase resource allocation to reproduction under intense competition. We tested (1) how simulated competition influences reproductive efficiency and competitive ability (CA) of different plant life histories and growth forms; (2) whether life history or growth form is associated with CA; (3) whether shade avoidance plasticity is connected to reproductive efficiency under simulated competition. We examined plastic responses of 11 herbaceous species representing different life histories and growth forms to simulated competition (spectral shade). We found that both annual and perennial plants invested more to reproduction under simulated competition in accordance with life-history theory predictions. There was no significant difference between competitive abilities of different life histories, but across growth forms, erect species expressed greater CA (in terms of leaf number) than other growth forms. We also found that shade avoidance plasticity can increase the reproductive efficiency by capitalizing on the early life resource acquisition and conversion of these resources into reproduction. Therefore, we suggest that a reassessment of the interpretation of shade avoidance plasticity is necessary by revealing its role in reproduction, not only in competition of plants.

  11. Do Tetranychus urticae males avoid mating with familiar females?

    PubMed

    Yoshioka, T; Yano, S

    2014-07-01

    The two-spotted spider mite, Tetranychus urticae, usually lives in kin groups under common webs. Because only the first mating results in fertilisation in female T. urticae, adult males guard quiescent deutonymph females, those at the stage immediately before maturation, to ensure paternity. Therefore, the cost of precopulatory guarding time seems considerable for males. Moreover, the fitness indices of daughters from intra-population crosses were significantly lower than those of daughters from inter-population crosses, indicating that inbreeding depression exists in T. urticae. Therefore, we hypothesised that T. urticae males should be choosy in guarding familiar females to avoid inbreeding depression. Furthermore, webs should be a key element of the environment shared by familiar individuals. In this study, we demonstrated the inbreeding avoidance mechanism of T. urticae males in relation to webs produced by familiar females (known webs) or unfamiliar females (unknown webs). Regardless of surrounding webs (known or unknown), males preferred unfamiliar to familiar females. We further examined whether males detect unfamiliar females by their webs. When males had experienced a female's web without encountering that female, they subsequently preferred females that did not produce the surrounding webs in which the choice experiment was conducted. Results suggest that putative kin recognition for inbreeding avoidance in T. urticae males is based on the relationship between webs and females, and not on the discrimination of webs in shared environments.

  12. Plant Responses to Vegetation Proximity: A Whole Life Avoiding Shade.

    PubMed

    Roig-Villanova, Irma; Martínez-García, Jaime F

    2016-01-01

    In high density of vegetation, plants detect neighbors by perceiving changes in light quality through phytochrome photoreceptors. Close vegetation proximity might result in competition for resources, such as light. To face this challenge, plants have evolved two alternative strategies: to either tolerate or avoid shade. Shade-avoiding species generally adapt their development by inducing hypocotyl, stem, and petiole elongation, apical dominance and flowering, and decreasing leaf expansion and yield, a set of responses collectively known as the shade avoidance syndrome (SAS). The SAS responses have been mostly studied at the seedling stage, centered on the increase of hypocotyl elongation. After compiling the main findings about SAS responses in seedlings, this review is focused on the response to shade at adult stages of development, such as petioles of adult leaves, and the little information available on the SAS responses in reproductive tissues. We discuss these responses based on the knowledge about the molecular mechanisms and components with a role in regulating the SAS response of the hypocotyls of Arabidopsis thaliana. The transcriptional networks involved in this process, as well as the communication among the tissues that perceive the shade and the ones that respond to this stimulus will also be briefly commented. PMID:26973679

  13. Avoidance behavior of ruffe exposed to selected formulations of piscicides

    USGS Publications Warehouse

    Dawson, Verdel K.; Bills, Terry D.; Boogaard, Michael A.

    1998-01-01

    Ruffe were introduced into Duluth Harbor, Minnesota in the early 1980s, probably by release of ballast water from sea-going freighters. Since then, it has become the most abundant species in the fish community. The sensitivity of ruffe to a number of piscicides has been demonstrated, however, the feasibility of using piscicides to control populations depends on whether ruffe cart detect piscicides and move to untreated water, We used a two-choice preference resting system to evaluate avoidance or attraction reactions of ruffe during exposures to the lampricides TFM and bayluscide and the general fish toxicants rotenone and antimycin. We used a second testing system to evaluate the potential for benthic ruffe to move vertically in the water column to avoid piscicides dissolving from experimental bottom-release formulations of bayluscide and antimycin. Near-lethal concentrations of TFM and rotenone tended to repel ruffe. Antimycin and bayluscide did not seem to repel ruffe in the avoidance chamber, but bottom-release formulations (antimycin granules-0.25% a.i. And bayluscide granules-3.2% a.i.) did cause increased swimming and surfacing activity among ruffe in column tests. We conclude that TFM and rotenone could be used to trent entire bodies of water, while bottom-release formulations of antimycin and bayluscide may have more application for treating localized concentrations of ruffe.

  14. Obstacle avoidance in social groups: new insights from asynchronous models.

    PubMed

    Croft, Simon; Budgey, Richard; Pitchford, Jonathan W; Wood, A Jamie

    2015-05-01

    For moving animals, the successful avoidance of hazardous obstacles is an important capability. Despite this, few models of collective motion have addressed the relationship between behavioural and social features and obstacle avoidance. We develop an asynchronous individual-based model for social movement which allows social structure within groups to be included. We assess the dynamics of group navigation and resulting collision risk in the context of information transfer through the system. In agreement with previous work, we find that group size has a nonlinear effect on collision risk. We implement examples of possible network structures to explore the impact social preferences have on collision risk. We show that any social heterogeneity induces greater obstacle avoidance with further improvements corresponding to groups containing fewer influential individuals. The model provides a platform for both further theoretical investigation and practical application. In particular, we argue that the role of social structures within bird flocks may have an important role to play in assessing the risk of collisions with wind turbines, but that new methods of data analysis are needed to identify these social structures.

  15. Obstacle avoidance in social groups: new insights from asynchronous models

    PubMed Central

    Croft, Simon; Budgey, Richard; Pitchford, Jonathan W.; Wood, A. Jamie

    2015-01-01

    For moving animals, the successful avoidance of hazardous obstacles is an important capability. Despite this, few models of collective motion have addressed the relationship between behavioural and social features and obstacle avoidance. We develop an asynchronous individual-based model for social movement which allows social structure within groups to be included. We assess the dynamics of group navigation and resulting collision risk in the context of information transfer through the system. In agreement with previous work, we find that group size has a nonlinear effect on collision risk. We implement examples of possible network structures to explore the impact social preferences have on collision risk. We show that any social heterogeneity induces greater obstacle avoidance with further improvements corresponding to groups containing fewer influential individuals. The model provides a platform for both further theoretical investigation and practical application. In particular, we argue that the role of social structures within bird flocks may have an important role to play in assessing the risk of collisions with wind turbines, but that new methods of data analysis are needed to identify these social structures. PMID:25833245

  16. Plant Responses to Vegetation Proximity: A Whole Life Avoiding Shade

    PubMed Central

    Roig-Villanova, Irma; Martínez-García, Jaime F.

    2016-01-01

    In high density of vegetation, plants detect neighbors by perceiving changes in light quality through phytochrome photoreceptors. Close vegetation proximity might result in competition for resources, such as light. To face this challenge, plants have evolved two alternative strategies: to either tolerate or avoid shade. Shade-avoiding species generally adapt their development by inducing hypocotyl, stem, and petiole elongation, apical dominance and flowering, and decreasing leaf expansion and yield, a set of responses collectively known as the shade avoidance syndrome (SAS). The SAS responses have been mostly studied at the seedling stage, centered on the increase of hypocotyl elongation. After compiling the main findings about SAS responses in seedlings, this review is focused on the response to shade at adult stages of development, such as petioles of adult leaves, and the little information available on the SAS responses in reproductive tissues. We discuss these responses based on the knowledge about the molecular mechanisms and components with a role in regulating the SAS response of the hypocotyls of Arabidopsis thaliana. The transcriptional networks involved in this process, as well as the communication among the tissues that perceive the shade and the ones that respond to this stimulus will also be briefly commented. PMID:26973679

  17. Detection and avoidance of a carnivore odor by prey

    PubMed Central

    Ferrero, David M.; Lemon, Jamie K.; Fluegge, Daniela; Pashkovski, Stan L.; Korzan, Wayne J.; Datta, Sandeep Robert; Spehr, Marc; Fendt, Markus; Liberles, Stephen D.

    2011-01-01

    Predator–prey relationships provide a classic paradigm for the study of innate animal behavior. Odors from carnivores elicit stereotyped fear and avoidance responses in rodents, although sensory mechanisms involved are largely unknown. Here, we identified a chemical produced by predators that activates a mouse olfactory receptor and produces an innate behavioral response. We purified this predator cue from bobcat urine and identified it to be a biogenic amine, 2-phenylethylamine. Quantitative HPLC analysis across 38 mammalian species indicates enriched 2-phenylethylamine production by numerous carnivores, with some producing >3,000-fold more than herbivores examined. Calcium imaging of neuronal responses in mouse olfactory tissue slices identified dispersed carnivore odor-selective sensory neurons that also responded to 2-phenylethylamine. Two prey species, rat and mouse, avoid a 2-phenylethylamine odor source, and loss-of-function studies involving enzymatic depletion of 2-phenylethylamine from a carnivore odor indicate it to be required for full avoidance behavior. Thus, rodent olfactory sensory neurons and chemosensory receptors have the capacity for recognizing interspecies odors. One such cue, carnivore-derived 2-phenylethylamine, is a key component of a predator odor blend that triggers hard-wired aversion circuits in the rodent brain. These data show how a single, volatile chemical detected in the environment can drive an elaborate danger-associated behavioral response in mammals. PMID:21690383

  18. Reinforcement learning for congestion-avoidance in packet flow

    NASA Astrophysics Data System (ADS)

    Horiguchi, Tsuyoshi; Hayashi, Keisuke; Tretiakov, Alexei

    2005-04-01

    Occurrence of congestion of packet flow in computer networks is one of the unfavorable problems in packet communication and hence its avoidance should be investigated. We use a neural network model for packet routing control in a computer network proposed in a previous paper by Horiguchi and Ishioka (Physica A 297 (2001) 521). If we assume that the packets are not sent to nodes whose buffers are already full of packets, then we find that traffic congestion occurs when the number of packets in the computer network is larger than some critical value. In order to avoid the congestion, we introduce reinforcement learning for a control parameter in the neural network model. We find that the congestion is avoided by the reinforcement learning and at the same time we have good performance for the throughput. We investigate the packet flow on computer networks of various types of topology such as a regular network, a network with fractal structure, a small-world network, a scale-free network and so on.

  19. Recognizing and avoiding artifacts in atomic force microscopy imaging.

    PubMed

    Canale, Claudio; Torre, Bruno; Ricci, Davide; Braga, Pier Carlo

    2011-01-01

    Atomic force microscopy (AFM) measurements could be affected by different kinds of artifacts; some of them derive from the improper use of the instrument and can be avoided by setting the correct experimental parameters and conditions. In other cases, distortions of the images acquired by AFM are intrinsically related to the operating principle of the instrument itself and to the kind of interactions taken into account for the reconstruction of the sample topography. A perfect knowledge of all the artifacts that can perturb AFM measurements is fundamental to avoid misleading interpretations of the results. In this chapter, all the most common sources of artifact are presented, and strategies to avoid them are proposed.Subheading 1 is a brief introduction to the chapter. In Subheading 2, the artifacts due to the interactions between the sample and the AFM tip are presented. Subheading 3 is focused on the deformations due to the AFM scanner nonlinear movements. The interaction with the environment surrounding the instrument can affect the quality of the AFM results and the environmental instability are discussed in Subheading 4. Subheading 5 shows the effects of an incorrect setting of the feedback gains or other parameters. Subheading 6 aims on the artifacts that can be produced by the improper use of the image processing software. Subheading 7 is a short guide on the test that can be done to easily recognize some of the artifacts previously described.

  20. Square lattice self-avoiding walks and biased differential approximants

    NASA Astrophysics Data System (ADS)

    Jensen, Iwan

    2016-10-01

    The model of self-avoiding lattice walks and the asymptotic analysis of power-series have been two of the major research themes of Tony Guttmann. In this paper we bring the two together and perform a new analysis of the generating functions for the number of square lattice self-avoiding walks and some of their metric properties such as the mean-square end-to-end distance. The critical point x c for self-avoiding walks is known to a high degree of accuracy and we utilise this knowledge to undertake a new numerical analysis of the series using biased differential approximants. The new method is major advance in asymptotic power-series analysis in that it allows us to bias differential approximants to have a singularity of order q at x c. When biasing at x c with q≥slant 2 the analysis yields a very accurate estimate for the critical exponent γ =1.343 7500(3) thus confirming the conjectured exact value γ =43/32 to eight significant digits and removing a long-standing minor discrepancy between exact and numerical results. The analysis of the mean-square end-to-end distance yields ν =0.750 0002(4) thus confirming the exact value ν =3/4 to seven significant digits. Dedicated to Tony Guttmann on the occasion of his 70th birthday.

  1. A laser imaging system for helicopter avoidance obstacle

    NASA Astrophysics Data System (ADS)

    Wang, WeiRan; Yuan, HongChun; Jin, Yuan

    2006-09-01

    Rotorcraft flying in low-altitude is endangered by power lines or telephone wires. The development of automated tools that can detect obstacles in the flight path and warn the crew would significantly reduce the workload of pilot and increase the safety. Detection and warning are rudimental demand and desire for Helicopter Avoidance Obstacle System (HAOS). And that, An advanced HAOS may be capable of classifying thin obstacles and enhanced vision with distances of obstacles. A laser 3D imaging system for helicopter avoidance obstacle (HAO) had been developed successfully. The laser 3D imaging helicopter avoidance obstacle system can not only detect thin obstacles but also catch more information of all objects of the area in front of the helicopter as possible. Then the information is transformed into intuitionist 3D image modality. In this paper, special features and characteristic of the laser imaging system for HAO are analyzed and discussed. Several design gist for this system are proposed. Especially, the developed zero backlash imaging technology and real-time dynamic imaging synchronizing with radar space scanning are described. The technique implementation problem and the system structure are given as well. Finally, the results of system ground test are presented. The ground test of the developed laser imaging system has demonstrated that the developed imaging system performance can achieve and satisfy commendably the requirements of the mission to prevent "wire strike".

  2. A Robot Manipulator with Adaptive Fuzzy Controller in Obstacle Avoidance

    NASA Astrophysics Data System (ADS)

    Sreekumar, Muthuswamy

    2016-07-01

    Building robots and machines to act within a fuzzy environment is a problem featuring complexity and ambiguity. In order to avoid obstacles, or move away from it, the robot has to perform functions such as obstacle identification, finding the location of the obstacle, its velocity, direction of movement, size, shape, and so on. This paper presents about the design, and implementation of an adaptive fuzzy controller designed for a 3 degree of freedom spherical coordinate robotic manipulator interfaced with a microcontroller and an ultrasonic sensor. Distance between the obstacle and the sensor and its time rate are considered as inputs to the controller and how the manipulator to take diversion from its planned trajectory, in order to avoid collision with the obstacle, is treated as output from the controller. The obstacles are identified as stationary or moving objects and accordingly adaptive self tuning is accomplished with three set of linguistic rules. The prototype of the manipulator has been fabricated and tested for collision avoidance by placing stationary and moving obstacles in its planned trajectory. The performance of the adaptive control algorithm is analyzed in MATLAB by generating 3D fuzzy control surfaces.

  3. Autonomous obstacle avoidance using visual fixation and looming

    NASA Astrophysics Data System (ADS)

    Joarder, Kunal; Raviv, Daniel

    1992-11-01

    This paper describes a vision-based method for avoiding obstacles using the concepts of visual looming and fixating motion. Visual looming refers to the expansion of images of objects in the retina. Usually, this is due to the decreasing distance between the observer and the object. An increasing looming value signifies an increasing threat of collision with the object. The visual task of avoiding collision can be further simplified by purposive control of visual fixation at the objects in front of the moving camera. Using these two basic concepts real time obstacle avoidance in a tight perception-action loop is implemented. Three-dimensional space in front of the camera is divided into zones with various degrees of looming-based threat of collision. For each obstacle seen by a fixating camera, looming and its time derivative are calculated directly from the 2-D image. Depending on the threat posed by an obstacle, a course change is dictated. This looming based approach is simple, independent of the size of the 3-D object and its range and involves simple quantitative measurements. Results pertinent to a camera on a robot arm navigating between obstacles are presented.

  4. Detection and avoidance of errors in computer software

    NASA Technical Reports Server (NTRS)

    Kinsler, Les

    1989-01-01

    The acceptance test errors of a computer software project to determine if the errors could be detected or avoided in earlier phases of development. GROAGSS (Gamma Ray Observatory Attitude Ground Support System) was selected as the software project to be examined. The development of the software followed the standard Flight Dynamics Software Development methods. GROAGSS was developed between August 1985 and April 1989. The project is approximately 250,000 lines of code of which approximately 43,000 lines are reused from previous projects. GROAGSS had a total of 1715 Change Report Forms (CRFs) submitted during the entire development and testing. These changes contained 936 errors. Of these 936 errors, 374 were found during the acceptance testing. These acceptance test errors were first categorized into methods of avoidance including: more clearly written requirements; detail review; code reading; structural unit testing; and functional system integration testing. The errors were later broken down in terms of effort to detect and correct, class of error, and probability that the prescribed detection method would be successful. These determinations were based on Software Engineering Laboratory (SEL) documents and interviews with the project programmers. A summary of the results of the categorizations is presented. The number of programming errors at the beginning of acceptance testing can be significantly reduced. The results of the existing development methodology are examined for ways of improvements. A basis is provided for the definition is a new development/testing paradigm. Monitoring of the new scheme will objectively determine its effectiveness on avoiding and detecting errors.

  5. Obstacle avoidance in social groups: new insights from asynchronous models.

    PubMed

    Croft, Simon; Budgey, Richard; Pitchford, Jonathan W; Wood, A Jamie

    2015-05-01

    For moving animals, the successful avoidance of hazardous obstacles is an important capability. Despite this, few models of collective motion have addressed the relationship between behavioural and social features and obstacle avoidance. We develop an asynchronous individual-based model for social movement which allows social structure within groups to be included. We assess the dynamics of group navigation and resulting collision risk in the context of information transfer through the system. In agreement with previous work, we find that group size has a nonlinear effect on collision risk. We implement examples of possible network structures to explore the impact social preferences have on collision risk. We show that any social heterogeneity induces greater obstacle avoidance with further improvements corresponding to groups containing fewer influential individuals. The model provides a platform for both further theoretical investigation and practical application. In particular, we argue that the role of social structures within bird flocks may have an important role to play in assessing the risk of collisions with wind turbines, but that new methods of data analysis are needed to identify these social structures. PMID:25833245

  6. Avoided Impacts in Ensembles of Tropical Cyclone Damage Potential

    NASA Astrophysics Data System (ADS)

    Done, J.; Paimazumder, D.; Holland, G. J.; Towler, E.

    2014-12-01

    Anthropogenic climate change has the potential to alter current levels of Tropical Cyclone (TC) damage, yet the degree of change and its importance relative to changes in exposure and vulnerability are debated. This study isolates the climate drivers of TC damage and develops an approach to translate climate model data directly to a measure of Cyclone Damage Potential (CDP). The actual damage then depends on a given user's impacted exposure and vulnerability. Our approach is motivated by recent work that highlighted the importance of accounting for TC size and TC translation speed in addition to maximum wind speed in driving TC damage. Since coarse resolution climate models are not able to adequately capture many TC characteristics, these key damaging parameters are modeled in terms of large-scale climate variables, to sidestep the need for information on individual TCs and to enable assessments of CDP directly from large-scale climate model data. The CDP is applied to ensembles of future climates generated under a range of anthropogenic forcing scenarios to assess the degree of avoided CDP under lower emission pathways. Users may then translate avoided CDP to avoided losses using relationships between CDP and their specific exposure and vulnerability characteristics.

  7. Reproductive efficiency and shade avoidance plasticity under simulated competition.

    PubMed

    Fazlioglu, Fatih; Al-Namazi, Ali; Bonser, Stephen P

    2016-07-01

    Plant strategy and life-history theories make different predictions about reproductive efficiency under competition. While strategy theory suggests under intense competition iteroparous perennial plants delay reproduction and semelparous annuals reproduce quickly, life-history theory predicts both annual and perennial plants increase resource allocation to reproduction under intense competition. We tested (1) how simulated competition influences reproductive efficiency and competitive ability (CA) of different plant life histories and growth forms; (2) whether life history or growth form is associated with CA; (3) whether shade avoidance plasticity is connected to reproductive efficiency under simulated competition. We examined plastic responses of 11 herbaceous species representing different life histories and growth forms to simulated competition (spectral shade). We found that both annual and perennial plants invested more to reproduction under simulated competition in accordance with life-history theory predictions. There was no significant difference between competitive abilities of different life histories, but across growth forms, erect species expressed greater CA (in terms of leaf number) than other growth forms. We also found that shade avoidance plasticity can increase the reproductive efficiency by capitalizing on the early life resource acquisition and conversion of these resources into reproduction. Therefore, we suggest that a reassessment of the interpretation of shade avoidance plasticity is necessary by revealing its role in reproduction, not only in competition of plants. PMID:27547325

  8. Disruption avoidance through active magnetic feedback in tokamak plasmas

    NASA Astrophysics Data System (ADS)

    Paccagnella, Roberto; Zanca, Paolo; Yanovskiy, Vadim; Finotti, Claudio; Manduchi, Gabriele; Piron, Chiara; Carraro, Lorella; Franz, Paolo; RFX Team

    2014-10-01

    Disruptions avoidance and mitigation is a fundamental need for a fusion relevant tokamak. In this paper a new experimental approach for disruption avoidance using active magnetic feedback is presented. This scheme has been implemented and tested on the RFX-mod device operating as a circular tokamak. RFX-mod has a very complete system designed for active mode control that has been proved successful for the stabilization of the Resistive Wall Modes (RWMs). In particular the current driven 2/1 mode, unstable when the edge safety factor, qa, is around (or even less than) 2, has been shown to be fully and robustly stabilized. However, at values of qa (qa > 3), the control of the tearing 2/1 mode has been proved difficult. These results suggested the idea to prevent disruptions by suddenly lowering qa to values around 2 where the tearing 2/1 is converted to a RWM. Contrary to the universally accepted idea that the tokamaks should disrupt at low qa, we demonstrate that in presence of a well designed active control system, tokamak plasmas can be driven to low qa actively stabilized states avoiding plasma disruption with practically no loss of the plasma internal energy.

  9. New spatial cognition tests for mice: passive place avoidance on stable and active place avoidance on rotating arenas.

    PubMed

    Cimadevilla, J M; Fenton, A A; Bures, J

    2001-03-15

    Dry arenas are a convenient tool for assessing the spatial navigation abilities of rodents. In this paper, mice must avoid a punished sector of a dry arena from which they are expelled by a puff of compressed air. The position of the punished sector is defined relative to the coordinate system of the room. In a stable environment the mice can use both extramaze and intramaze landmarks to orient themselves accurately. However, when the shock area is defined by extramaze landmarks, continuous rotation of the arena at 1 rpm makes it impossible to solve the avoidance task using arena-based cues or idiothesis. The avoidance can only be solved by paying attention to extramaze cues. Our protocol tested spatial abilities on stable and rotating arenas. The acquisition of the task was manifested under both conditions by a significant improvement of performance within the first session (short-term memory component) and at the beginning of the 24-h delayed second session (long-term memory component).

  10. The Relationship among Student Basic Need Satisfaction, Approaches to Learning, Reporting of Avoidance Strategies and Achievement

    ERIC Educational Resources Information Center

    Betoret, Fernando Domenech; Artiga, Amparo Gomez

    2011-01-01

    Introduction: This study examines the relationship between student basic need satisfaction (autonomy, competence, relatedness and belonging), their reporting of approaches to learning (deep and surface), their reporting of avoidance strategies (avoidance of effort and challenge, avoidance of help seeking and preference to avoid novelty) and…

  11. Some Things Are Better Left Unsaid: Topic Avoidance in Family Relationships.

    ERIC Educational Resources Information Center

    Guerrero, Laura K.; Afifi, Walid A.

    1995-01-01

    Finds that adolescents avoid discussing negative experiences and dating experiences more with parents than siblings, and avoid discussing sexual matters with opposite-sex family members. Finds that female dyads practice the least avoidance on topics involving relationship issues or friendships, while males avoid discussing relationship issues,…

  12. Estimate of avoidance maneuver rate for HASTOL tether boost facility

    NASA Astrophysics Data System (ADS)

    Forward, Robert L.

    2002-01-01

    The Hypersonic Airplane Space Tether Orbital Launch (HASTOL) Architecture uses a hypersonic airplane (or reusable launch vehicle) to carry a payload from the surface of the Earth to 150 km altitude and a speed of Mach 17. The hypersonic airplane makes a rendezvous with the grapple at the tip of a long, rotating, orbiting space tether boost facility, which picks up the payload from the airplane. Release of the payload at the proper point in the tether rotation boosts the payload into a higher orbit, typically into a Geosynchronous Transfer Orbit (GTO), with lower orbits and Earth escape other options. The HASTOL Tether Boost Facility will have a length of 636 km. Its center of mass will be in a 604 km by 890 km equatorial orbit. It is estimated that by the time of the start of operations of the HASTOL Tether Boost facility in the year 2020, there will be 500 operational spacecraft using the same volume of space as the HASTOL facility. These operational spacecraft would likely be made inoperative by an impact with one of the lines in the multiline HASTOL Hoytether™ and should be avoided. There will also be non-operational spacecraft and large pieces of orbital debris with effective size greater than five meters in diameter that could cut a number of lines in the HASTOL Hoytether™, and should also be avoided. It is estimated, using two different methods and combining them, that the HASTOL facility will need to make avoidance maneuvers about once every four days if the 500 operational spacecraft and large pieces of orbital debris greater than 5 m in diameter, were each protected by a 2 km diameter miss distance protection sphere. If by 2020, the ability to know the positions of operational spacecraft and large pieces of orbital debris improved to allow a 600 m diameter miss distance protection sphere around each object, then the number of HASTOL facility maneuvers needed drops to one every two weeks. .

  13. Risk avoidance in sympatric large carnivores: reactive or predictive?

    PubMed

    Broekhuis, Femke; Cozzi, Gabriele; Valeix, Marion; McNutt, John W; Macdonald, David W

    2013-09-01

    1. Risks of predation or interference competition are major factors shaping the distribution of species. An animal's response to risk can either be reactive, to an immediate risk, or predictive, based on preceding risk or past experiences. The manner in which animals respond to risk is key in understanding avoidance, and hence coexistence, between interacting species. 2. We investigated whether cheetahs (Acinonyx jubatus), known to be affected by predation and competition by lions (Panthera leo) and spotted hyaenas (Crocuta crocuta), respond reactively or predictively to the risks posed by these larger carnivores. 3. We used simultaneous spatial data from Global Positioning System (GPS) radiocollars deployed on all known social groups of cheetahs, lions and spotted hyaenas within a 2700 km(2) study area on the periphery of the Okavango Delta in northern Botswana. The response to risk of encountering lions and spotted hyaenas was explored on three levels: short-term or immediate risk, calculated as the distance to the nearest (contemporaneous) lion or spotted hyaena, long-term risk, calculated as the likelihood of encountering lions and spotted hyaenas based on their cumulative distributions over a 6-month period and habitat-associated risk, quantified by the habitat used by each of the three species. 4. We showed that space and habitat use by cheetahs was similar to that of lions and, to a lesser extent, spotted hyaenas. However, cheetahs avoided immediate risks by positioning themselves further from lions and spotted hyaenas than predicted by a random distribution. 5. Our results suggest that cheetah spatial distribution is a hierarchical process, first driven by resource acquisition and thereafter fine-tuned by predator avoidance; thus suggesting a reactive, rather than a predictive, response to risk. PMID:23692142

  14. Lunar Landing Trajectory Design for Onboard Hazard Detection and Avoidance

    NASA Technical Reports Server (NTRS)

    Paschall, Steve; Brady, Tye; Sostaric, Ron

    2009-01-01

    The Autonomous Landing and Hazard Avoidance Technology (ALHAT) Project is developing the software and hardware technology needed to support a safe and precise landing for the next generation of lunar missions. ALHAT provides this capability through terrain-relative navigation measurements to enhance global-scale precision, an onboard hazard detection system to select safe landing locations, and an Autonomous Guidance, Navigation, and Control (AGNC) capability to process these measurements and safely direct the vehicle to a landing location. This paper focuses on the key trajectory design issues relevant to providing an onboard Hazard Detection and Avoidance (HDA) capability for the lander. Hazard detection can be accomplished by the crew visually scanning the terrain through a window, a sensor system imaging the terrain, or some combination of both. For ALHAT, this hazard detection activity is provided by a sensor system, which either augments the crew s perception or entirely replaces the crew in the case of a robotic landing. Detecting hazards influences the trajectory design by requiring the proper perspective, range to the landing site, and sufficient time to view the terrain. Following this, the trajectory design must provide additional time to process this information and make a decision about where to safely land. During the final part of the HDA process, the trajectory design must provide sufficient margin to enable a hazard avoidance maneuver. In order to demonstrate the effects of these constraints on the landing trajectory, a tradespace of trajectory designs was created for the initial ALHAT Design Analysis Cycle (ALDAC-1) and each case evaluated with these HDA constraints active. The ALHAT analysis process, described in this paper, narrows down this tradespace and subsequently better defines the trajectory design needed to support onboard HDA. Future ALDACs will enhance this trajectory design by balancing these issues and others in an overall system

  15. Risk avoidance in sympatric large carnivores: reactive or predictive?

    PubMed

    Broekhuis, Femke; Cozzi, Gabriele; Valeix, Marion; McNutt, John W; Macdonald, David W

    2013-09-01

    1. Risks of predation or interference competition are major factors shaping the distribution of species. An animal's response to risk can either be reactive, to an immediate risk, or predictive, based on preceding risk or past experiences. The manner in which animals respond to risk is key in understanding avoidance, and hence coexistence, between interacting species. 2. We investigated whether cheetahs (Acinonyx jubatus), known to be affected by predation and competition by lions (Panthera leo) and spotted hyaenas (Crocuta crocuta), respond reactively or predictively to the risks posed by these larger carnivores. 3. We used simultaneous spatial data from Global Positioning System (GPS) radiocollars deployed on all known social groups of cheetahs, lions and spotted hyaenas within a 2700 km(2) study area on the periphery of the Okavango Delta in northern Botswana. The response to risk of encountering lions and spotted hyaenas was explored on three levels: short-term or immediate risk, calculated as the distance to the nearest (contemporaneous) lion or spotted hyaena, long-term risk, calculated as the likelihood of encountering lions and spotted hyaenas based on their cumulative distributions over a 6-month period and habitat-associated risk, quantified by the habitat used by each of the three species. 4. We showed that space and habitat use by cheetahs was similar to that of lions and, to a lesser extent, spotted hyaenas. However, cheetahs avoided immediate risks by positioning themselves further from lions and spotted hyaenas than predicted by a random distribution. 5. Our results suggest that cheetah spatial distribution is a hierarchical process, first driven by resource acquisition and thereafter fine-tuned by predator avoidance; thus suggesting a reactive, rather than a predictive, response to risk.

  16. Ten Mistakes To Avoid When Injecting Botulinum Toxin.

    PubMed

    Ruiz-Rodriguez, R; Martin-Gorgojo, A

    2015-01-01

    Injection of botulinum toxin is currently the most common cosmetic procedure in the United States, and in recent years it has become-together with dermal fillers-the mainstay of therapy for the prevention and treatment of facial aging. However, in some cases the treatment may lead to a somewhat unnatural appearance, usually caused by loss of facial expression or other telltale signs. In the present article, we review the 10 mistakes that should be avoided when injecting botulinum toxin. We also reflect on how treatment with botulinum toxin influences us through our facial expressions, both in terms of how we feel and what others perceive. PMID:25956528

  17. How to avoid the ten most frequent EMS pitfalls

    SciTech Connect

    Andrews, W.

    1982-04-19

    It pays to do your homework before investing in an energy management system if you want to avoid the 10 most common pitfalls listed by users, consultants, and manufacturers as: oversimplification, improper maintenance, failure to involve operating personnel, inaccurate savings estimates, failure to include monitoring capability, incompetent or fradulent firms, improper load control, not allowing for a de-bugging period, failure to include manual override, and software problems. The article describes how each of these pitfalls can lead to poor decisions and poor results. (DCK)

  18. Maintenance immunosuppression regimens: conversion, minimization, withdrawal, and avoidance.

    PubMed

    Yang, Harold

    2006-04-01

    A wide choice of drug combinations is available to clinicians for immunosuppression regimens for their kidney transplant patients. Although many protocols have minimized early graft loss, the optimal long-term regimen is unknown. Recent studies clearly showed that cardiovascular death is now the leading cause of graft loss. Strategies must be developed that address this risk while keeping immunologic events low. Transplant physicians have focused on exploring regimens that minimize or avoid the use of corticosteroids. Studies also have started to explore protocols that minimize calcineurin inhibitor therapy. PMID:16567240

  19. Ten Mistakes To Avoid When Injecting Botulinum Toxin.

    PubMed

    Ruiz-Rodriguez, R; Martin-Gorgojo, A

    2015-01-01

    Injection of botulinum toxin is currently the most common cosmetic procedure in the United States, and in recent years it has become-together with dermal fillers-the mainstay of therapy for the prevention and treatment of facial aging. However, in some cases the treatment may lead to a somewhat unnatural appearance, usually caused by loss of facial expression or other telltale signs. In the present article, we review the 10 mistakes that should be avoided when injecting botulinum toxin. We also reflect on how treatment with botulinum toxin influences us through our facial expressions, both in terms of how we feel and what others perceive.

  20. Mergers in health care: avoiding divorce IDS style.

    PubMed

    Drazen, E; Kueber, M

    1998-08-01

    The recent flurry of merger activity in the healthcare industry has given rise to a significant number of integration efforts. Unfortunately, some of these "marriages" will end in "divorce." Reasons for failure can be found in four critical dimensions of integration: structural, operational, clinical, and informational. Each dimension has its associated pitfalls, and every merger confronts clearly identifiable risks. By taking steps to mitigate such risks, merging organizations can improve the chances the merger will succeed. If the merger does fail, measures taken prior to the merger, such as including an escape clause in the merger contract, can help avoid problems in dividing operational assets, physicians practices, and information assets.

  1. Sequential Probability Ratio Test for Collision Avoidance Maneuver Decisions

    NASA Technical Reports Server (NTRS)

    Carpenter, J. Russell; Markley, F. Landis

    2010-01-01

    When facing a conjunction between space objects, decision makers must chose whether to maneuver for collision avoidance or not. We apply a well-known decision procedure, the sequential probability ratio test, to this problem. We propose two approaches to the problem solution, one based on a frequentist method, and the other on a Bayesian method. The frequentist method does not require any prior knowledge concerning the conjunction, while the Bayesian method assumes knowledge of prior probability densities. Our results show that both methods achieve desired missed detection rates, but the frequentist method's false alarm performance is inferior to the Bayesian method's

  2. Nursing and conflict communication: avoidance as preferred strategy.

    PubMed

    Mahon, Margaret M; Nicotera, Anne M

    2011-01-01

    An exploratory study was conducted to examine nurses' (n = 57) selection of strategies to confront conflict in the workplace. Communication competence is the conceptual framework, defining competent conflict communication as joint problem-solving communication that is both effective and appropriate. Items were drawn from tools assessing nurses' conflict management strategies. Nurses reported a strong preference not to confront conflict directly; nurse managers were less likely to avoid direct communication. Nurses who do choose to confront conflict are more likely to use constructive than destructive strategies. The integration of the social science of health communication into nursing education and practice and other implications are discussed.

  3. Boundary Avoidance Tracking for Instigating Pilot Induced Oscillations

    NASA Technical Reports Server (NTRS)

    Craun, Robert W.; Acosta, Diana M.; Beard, Steven D.; Hardy, Gordon H.; Leonard, Michael W.; Weinstein, Michael

    2013-01-01

    In order to advance research in the area of pilot induced oscillations, a reliable method to create PIOs in a simulated environment is necessary. Using a boundary avoidance tracking task, researchers performing an evaluation of control systems were able to create PIO events in 42% of cases using a nominal aircraft, and 91% of cases using an aircraft with reduced actuator rate limits. The simulator evaluation took place in the NASA Ames Vertical Motion Simulator, a high-fidelity motion-based simulation facility.

  4. Avoiding irregularities on the nasal dorsum in rhinoplasty.

    PubMed

    Casanueva, Fernando Javier; Cardemil, Felipe

    2016-01-01

    Palpable irregularities along the nasal dorsum are a frequent complication of dorsal handling in rhinoplasty because resection techniques are used. This is often a result of improper management of the dorsum after resection. The surgical technique for handling of dorsal irregularities following dorsal resection is described. The key steps to avoid irregularities are diamond rasps, autospreader and morselized cartilage as camouflage. Following resection of the hump, the anatomy of the nasal dorsum should be adequately restructured; thereby we achieve an adequate aesthetic result and ideally preventing irregularities on palpation. PMID:27097285

  5. Survival of the Stillest: Predator Avoidance in Shark Embryos

    PubMed Central

    Kempster, Ryan M.; Hart, Nathan S.; Collin, Shaun P.

    2013-01-01

    Sharks use highly sensitive electroreceptors to detect the electric fields emitted by potential prey. However, it is not known whether prey animals are able to modulate their own bioelectrical signals to reduce predation risk. Here, we show that some shark (Chiloscyllium punctatum) embryos can detect predator-mimicking electric fields and respond by ceasing their respiratory gill movements. Despite being confined to the small space within the egg case, where they are vulnerable to predators, embryonic sharks are able to recognise dangerous stimuli and react with an innate avoidance response. Knowledge of such behaviours, may inform the development of effective shark repellents. PMID:23326342

  6. Quantitative two-process analysis of avoidance conditioning in goldfish.

    PubMed

    Zhuikov, A Y; Couvillon, P A; Bitterman, M E

    1994-01-01

    The shuttlebox performance of goldfish was studied under standardized conditions in a variety of problems--with or without an avoidance contingency, a conditioned stimulus (CS)-termination contingency, and an escape contingency. The effects of CS-only, unconditioned stimulus (US)-only, and explicitly unpaired training were also examined. All the data could be simulated quantitatively with a version of O. H. Mowrer's (1947) 2-process theory expressed in 2 learning equations (1 classical, the other instrumental) and a performance equation. The good fit suggests that the theory is worth developing further with new experiments designed to challenge it.

  7. Intelligent Surveillance Robot with Obstacle Avoidance Capabilities Using Neural Network.

    PubMed

    Budiharto, Widodo

    2015-01-01

    For specific purpose, vision-based surveillance robot that can be run autonomously and able to acquire images from its dynamic environment is very important, for example, in rescuing disaster victims in Indonesia. In this paper, we propose architecture for intelligent surveillance robot that is able to avoid obstacles using 3 ultrasonic distance sensors based on backpropagation neural network and a camera for face recognition. 2.4 GHz transmitter for transmitting video is used by the operator/user to direct the robot to the desired area. Results show the effectiveness of our method and we evaluate the performance of the system. PMID:26089863

  8. The search for knowledge and the avoidance of knowledge.

    PubMed

    Waska, Robert

    2007-01-01

    In the psychoanalytic setting, patients can develop a strong reaction to the therapeutic opportunity to gain new knowledge about themselves. This reaction to knowledge is manifested in the patient by walling it off, splitting it off, or attacking it and erasing it from one's internal experience. The avoidance of knowledge can be the result of various phantasy states that bring on defensive postures. Knowledge can be experienced as a persecutory threat to be avoided and defended against. Knowledge can also elicit depressive concerns of loss and separation. Issues of dependence and autonomy can be equated with knowledge and therefore learning must be warded off. As a result of any or all of these internal threats, the ego can instigate a moratorium on thinking and creativity, a shutdown on feeling, thinking, and learning. As will be shown in the case material, wanting to know can be offset by a greater defensive need to not know. Through projective identification cycles, knowledge is placed into the analyst and experienced as dangerous, unobtainable, or a gift one deserves to be given rather than earned. The patient in the case example demonstrates a more paranoid experience of knowledge and a more paranoid avoidance of learning and change. When paranoid phantasies drive the patient to destroy object-relational links between self and analyst, the transference becomes colored with the phantasy of knowledge being equal to dangerous dependence that leads to destruction of either self or object. Therefore, curiosity and learning are to be avoided. Change is no longer a safe option. Psychic change can only occur when past and current knowledge are allowed to be part of the ego's self<-->object world. In other words, Psychic change is possible when the ego is less restrictive and open to new self<-->object experience. Therefore, the ego must tolerate conflicted feelings and thoughts about the self and others for knowledge to be allowable and accessible. This is the core

  9. Communicating the Need to Avoid Dangerous Climate Change (Invited)

    NASA Astrophysics Data System (ADS)

    Hansen, J. E.; Kharecha, P. A.; Sato, M.

    2013-12-01

    We describe our past, ongoing and planned efforts to communicate the need for humanity to avoid dangerous climate change. Communications with governments have been largely fruitless, with substantial indication that governments are more disposed to be responsive to financial interests rather than scientific information. Communication with the public is essential to create pressure on governments for appropriate policies, but it is made difficult by the massive resources of the fossil fuel industry. Communication with influential individuals can be effective in reaching both governments and the public.

  10. Emotion facilitation and passive avoidance learning in psychopathic female offenders

    PubMed Central

    Vitale, Jennifer E.

    2009-01-01

    Research on psychopathy among incarcerated, Caucasian males has consistently demonstrated deficits in emotion processing and response inhibition. Using the PCL-R to classify participants as psychopathic or non-psychopathic, this study examined the performance of incarcerated, Caucasian females on two laboratory tasks: A lexical decision task used to assess emotion processing and a passive avoidance task used to assess response inhibition. Contrary to prediction, deficits in performance typically exhibited by psychopathic males were not exhibited by psychopathic females in this sample. Implications of these findings are discussed and an interpretation of the results in the context of the Response Modulation Hypothesis is presented. PMID:21686054

  11. Advanced Fuzzy Potential Field Method for Mobile Robot Obstacle Avoidance

    PubMed Central

    Park, Jong-Wook; Kwak, Hwan-Joo; Kang, Young-Chang; Kim, Dong W.

    2016-01-01

    An advanced fuzzy potential field method for mobile robot obstacle avoidance is proposed. The potential field method primarily deals with the repulsive forces surrounding obstacles, while fuzzy control logic focuses on fuzzy rules that handle linguistic variables and describe the knowledge of experts. The design of a fuzzy controller—advanced fuzzy potential field method (AFPFM)—that models and enhances the conventional potential field method is proposed and discussed. This study also examines the rule-explosion problem of conventional fuzzy logic and assesses the performance of our proposed AFPFM through simulations carried out using a mobile robot. PMID:27123001

  12. Avoiding irregularities on the nasal dorsum in rhinoplasty.

    PubMed

    Casanueva, Fernando Javier; Cardemil, Felipe

    2016-03-30

    Palpable irregularities along the nasal dorsum are a frequent complication of dorsal handling in rhinoplasty because resection techniques are used. This is often a result of improper management of the dorsum after resection. The surgical technique for handling of dorsal irregularities following dorsal resection is described. The key steps to avoid irregularities are diamond rasps, autospreader and morselized cartilage as camouflage. Following resection of the hump, the anatomy of the nasal dorsum should be adequately restructured; thereby we achieve an adequate aesthetic result and ideally preventing irregularities on palpation.

  13. Advanced Fuzzy Potential Field Method for Mobile Robot Obstacle Avoidance.

    PubMed

    Park, Jong-Wook; Kwak, Hwan-Joo; Kang, Young-Chang; Kim, Dong W

    2016-01-01

    An advanced fuzzy potential field method for mobile robot obstacle avoidance is proposed. The potential field method primarily deals with the repulsive forces surrounding obstacles, while fuzzy control logic focuses on fuzzy rules that handle linguistic variables and describe the knowledge of experts. The design of a fuzzy controller--advanced fuzzy potential field method (AFPFM)--that models and enhances the conventional potential field method is proposed and discussed. This study also examines the rule-explosion problem of conventional fuzzy logic and assesses the performance of our proposed AFPFM through simulations carried out using a mobile robot. PMID:27123001

  14. Segmental infarction of the testis: can frozen sections avoid orchidectomy?

    PubMed

    Pacella, E; Grillo, F; Lapetina, C; Cabiddu, F; Auriati, L; Tunesi, G; Mastracci, L

    2015-03-01

    Segmental infarction (SI) of the testis is a rare condition that can masquerade as a mass lesion, thus requiring exclusion of tumour. If clinical exams do not exclude a neoplastic lesion with certainty, orchidectomy is usually performed. A case of SI of the testis is presented; the use of frozen section of the enucleated mass demonstrated the ischaemic nature of the lesion, so avoiding orchidectomy. The 8 year follow-up was uneventful. The use of frozen section in SI could permit the selection of cases in which testicular-sparing surgery should be considered.

  15. Avoiding revenue loss due to 'lesser of' contract clauses.

    PubMed

    Stodolak, Frederick; Gutierrez, Henry

    2014-08-01

    Finance managers seeking to avoid lost revenue attributable to lesser-of-charge-or-fixed-fee (lesser-of) clauses in their contracts should: Identify payer contracts that contain lesser-of clauses. Prepare lesser-of lost-revenue reports for non-bundled and bundled rates. For claims with covered charges below the bundled rate, identify service codes associated with the greatest proportion of total gross revenue and determine new, higher charge levels for those codes. Establish an approach for setting charges for non-bundled fee schedules to address lost-revenue-related issues. Incorporate changes into overall strategic or hospital zero-based pricing modeling and parameters.

  16. Cooperative Conflict Avoidance Sensor Trade Study Report, Version 2

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This study develops evaluation criteria for systems and technologies against the Cooperative Conflict Avoidance (CCA) requirements for unmanned flight at and above FL430 as part of Step 1 of the Access-5 program. These evaluation criteria are then applied to both current and future technologies to identify those which might be used to provide an Equivalent Level of Safety (ELOS) for CCA. This document provides the results of this analysis of various systems and technologies intended for evaluation as part of the CCA work package.

  17. Anaphylaxis avoidance and management: educating patients and their caregivers

    PubMed Central

    Järvinen, Kirsi M; Celestin, Jocelyn

    2014-01-01

    Anaphylaxis is an increasingly prevalent problem in westernized countries. Therefore, it is of utmost importance that the increasing numbers of patients at risk for anaphylaxis receive proper education on the etiology and risk factors as well as appropriate treatment of anaphylaxis with epinephrine. The physician’s role is crucial in order to educate the patients and care takers on effective measures to prevent anaphylaxis and empower them to take charge of early recognition and proper management of an anaphylactic reaction to prevent poor outcomes. This review summarizes the clinical presentation, triggers, avoidance, and management of anaphylaxis. PMID:25031541

  18. To make a glass—avoid the crystal

    NASA Astrophysics Data System (ADS)

    Palberg, Thomas; Bartsch, Eckhard; Beyer, Richard; Hofmann, Maximilian; Lorenz, Nina; Marquis, Janina; Niu, Ran; Okubo, Tsuneo

    2016-07-01

    Colloidal model systems allow for a flexible tuning of particle sizes, particle spacings and mutual interactions at constant temperature. Colloidal suspensions typically crystallize as soon as the interactions get sufficiently strong and long-ranged. Several strategies have been successfully applied to avoid crystallization and instead produce colloidal glasses. Most of these amorphous solids are formed at high particle concentrations. This paper shortly reviews experimental attempts to produce amorphous colloidal solids using strategies based on topological, thermodynamic and kinetic considerations. We complement this overview by introducing a (transient) amorphous solid forming in a thoroughly deionized aqueous suspension of highly charged spheres at low salt concentration and very low volume fractions.

  19. Intelligent Surveillance Robot with Obstacle Avoidance Capabilities Using Neural Network

    PubMed Central

    2015-01-01

    For specific purpose, vision-based surveillance robot that can be run autonomously and able to acquire images from its dynamic environment is very important, for example, in rescuing disaster victims in Indonesia. In this paper, we propose architecture for intelligent surveillance robot that is able to avoid obstacles using 3 ultrasonic distance sensors based on backpropagation neural network and a camera for face recognition. 2.4 GHz transmitter for transmitting video is used by the operator/user to direct the robot to the desired area. Results show the effectiveness of our method and we evaluate the performance of the system. PMID:26089863

  20. Avoiding revenue loss due to 'lesser of' contract clauses.

    PubMed

    Stodolak, Frederick; Gutierrez, Henry

    2014-08-01

    Finance managers seeking to avoid lost revenue attributable to lesser-of-charge-or-fixed-fee (lesser-of) clauses in their contracts should: Identify payer contracts that contain lesser-of clauses. Prepare lesser-of lost-revenue reports for non-bundled and bundled rates. For claims with covered charges below the bundled rate, identify service codes associated with the greatest proportion of total gross revenue and determine new, higher charge levels for those codes. Establish an approach for setting charges for non-bundled fee schedules to address lost-revenue-related issues. Incorporate changes into overall strategic or hospital zero-based pricing modeling and parameters. PMID:25145034

  1. Mars Reconnaissance Orbiter Aerobraking Daily Operations and Collision Avoidance

    NASA Technical Reports Server (NTRS)

    Long, Stacia M.; You, Tung-Han; Halsell, C. Allen; Bhat, Ramachand S.; Demcak, Stuart W.; Graat, Eric J.; Higa, Earl S.; Highsmith, Dolan E.; Mottinger, Neil A.; Jah, Moriba K.

    2007-01-01

    The Mars Reconnaissance Orbiter reached Mars on March 10, 2006 and performed a Mars orbit insertion maneuver of 1 km/s to enter into a large elliptical orbit. Three weeks later, aerobraking operations began and lasted about five months. Aerobraking utilized the atmospheric drag to reduce the large elliptical orbit into a smaller, near circular orbit. At the time of MRO aerobraking, there were three other operational spacecraft orbiting Mars and the navigation team had to minimize the possibility of a collision. This paper describes the daily operations of the MRO navigation team during this time as well as the collision avoidance strategy development and implementation.

  2. Intelligent Surveillance Robot with Obstacle Avoidance Capabilities Using Neural Network.

    PubMed

    Budiharto, Widodo

    2015-01-01

    For specific purpose, vision-based surveillance robot that can be run autonomously and able to acquire images from its dynamic environment is very important, for example, in rescuing disaster victims in Indonesia. In this paper, we propose architecture for intelligent surveillance robot that is able to avoid obstacles using 3 ultrasonic distance sensors based on backpropagation neural network and a camera for face recognition. 2.4 GHz transmitter for transmitting video is used by the operator/user to direct the robot to the desired area. Results show the effectiveness of our method and we evaluate the performance of the system.

  3. Avoiding Intellectual Stagnation: The Starship as an Expander of Minds

    NASA Astrophysics Data System (ADS)

    Crawford, Ian A.

    2014-06-01

    Interstellar exploration will advance human knowledge and culture in multiple ways. Scientifically, it will advance our understanding of the interstellar medium, stellar astrophysics, planetary science and astrobiology. In addition, significant societal and cultural benefits will result from a programme of interstellar exploration and colonisation. Most important will be the cultural stimuli resulting from expanding the horizons of human experience, and increased opportunities for the spread and diversification of life and culture through the Galaxy. Ultimately, a programme of interstellar exploration may be the only way for human (and post-human) societies to avoid the intellectual stagnation predicted for the `end of history'.

  4. Post Barnwell Class B/C Waste - Crisis Avoidance

    SciTech Connect

    Lewis, M.S.

    2008-07-01

    The Barnwell Waste Management Facility (BWMF) is scheduled to restrict access to waste generators outside of the Atlantic Compact (SC, CT, NJ) on July 1, 2008. South Carolina, authorized under the Low-Level Waste Policy Act of 1980 and Amendments Act of 1985, and in agreement with the other Atlantic Compact states, will only accept Class A, B, and C low-level radioactive waste (LLRW) generated within compact. For many years, the BWMF has been the only LLRW disposal facility to accept Class B and C waste from LLRW generators throughout the country, except those that have access to the Northwest Compact Site. Many Class B/C waste generators consider this to be a national crisis situation requiring interim or possible permanent storage, changes in operation, significant cost impacts, and/or elimination of services, especially in the health care and non-power generation industries. With proper in-house waste management practices and utilization of commercial processor services, a national crisis can be avoided, although some generators with specific waste forms or radionuclides will remain without options. In summary: It is unknown what the future will bring for commercial LLRW disposal. Could the anticipated post Barnwell Class B/C crisis be avoided by any of the following? - Barnwell Site remains open for the nation's commercial Class B/C waste; - Richland Site opens back up to the nation for commercial Class B/C waste; - Texas Site opens up to the nation for commercial Class B/C waste; - Federal Government intervenes by keeping a commercial Class B/C site open for the nation's commercial Class B/C waste; - Federal Government makes a DOE site available for commercial Class B/C waste; - Federal Government revisits the LLRW Policy Act of 1980 and Amendments Act of 1985. Without a future LLRW site capable of accepting Class B/C currently on the horizon, commercial LLRW generators are faced with waste volume elimination, reduction, or storage. With proper in-house waste

  5. The importance of nuclear power in emissions avoidance

    SciTech Connect

    South, D.W.

    1999-11-01

    Most people knowledgeable about the nuclear power industry are aware that nuclear power plants do not emit air pollutants or greenhouse gases in the generation of electricity. What is commonly not known, however, is that these avoided emissions have become important for compliance with increasingly stringent limitations on air pollutants and greenhouse gas emissions required by the 1990 Clean Air Act Amendments and the Kyoto Protocol. This article is intended to heighten the awareness of this important environmental service and how its valuation can have an impact on the future operation of existing nuclear power plants

  6. Surrounding sensing and obstacle predicting for vehicle collision avoidance

    NASA Astrophysics Data System (ADS)

    Tu, Dawei; Chen, Jing; Tao, Jing

    1998-08-01

    A basic concept of an advanced safety vehicle, which will emerge in the next century, is introduced in this paper, with the emphasis on the active obstacle avoidance system. A prototype system is put forward, in which a scanning laser radar is used for detecting ahead objects, the surrounding information can be understood from the radar data, and therefore once the serious situation emerges, the drive will be warned, or the auto-control system will operate according to the analysis of the surrounding condition.

  7. Self-Avoiding Walks Over Adaptive Triangular Grids

    NASA Technical Reports Server (NTRS)

    Heber, Gerd; Biswas, Rupak; Gao, Guang R.; Saini, Subhash (Technical Monitor)

    1999-01-01

    Space-filling curves is a popular approach based on a geometric embedding for linearizing computational meshes. We present a new O(n log n) combinatorial algorithm for constructing a self avoiding walk through a two dimensional mesh containing n triangles. We show that for hierarchical adaptive meshes, the algorithm can be locally adapted and easily parallelized by taking advantage of the regularity of the refinement rules. The proposed approach should be very useful in the runtime partitioning and load balancing of adaptive unstructured grids.

  8. Punishment of an extinguishing shock-avoidance response by time-out from positive reinforcement1

    PubMed Central

    Nigro, M. R.

    1966-01-01

    Two experiments were conducted to determine the effects of punishment by time-out from positive reinforcement on the extinction of discriminated shock-avoidance responding. Subjects were trained initially to bar press for food on an intermittent schedule of reinforcement and, concurrently, to avoid shock at the onset of a warning signal. Experiment I compared avoidance extinction performance under no punishment and when avoidance responding resulted in a 30-sec TO from reinforced appetitive responding. In Exp II, the contingent use of TO punishment was compared with its random, or noncontingent use. The results of both experiments showed that in the absence of punishment, avoidance extinction was characterized by short latencies and nearly 100% avoidance responding. Avoidance responding in extinction was little affected by noncontingent TO punishment. When TO was made contingent upon avoidance responding, however, avoidance latencies immediately increased and the frequency of avoidance responses subsequently decreased to zero. PMID:5903964

  9. Punishment of an extinguishing shock-avoidance response by time-out from positive reinforcement.

    PubMed

    Nigro, M R

    1966-01-01

    Two experiments were conducted to determine the effects of punishment by time-out from positive reinforcement on the extinction of discriminated shock-avoidance responding. Subjects were trained initially to bar press for food on an intermittent schedule of reinforcement and, concurrently, to avoid shock at the onset of a warning signal. Experiment I compared avoidance extinction performance under no punishment and when avoidance responding resulted in a 30-sec TO from reinforced appetitive responding. In Exp II, the contingent use of TO punishment was compared with its random, or noncontingent use. The results of both experiments showed that in the absence of punishment, avoidance extinction was characterized by short latencies and nearly 100% avoidance responding. Avoidance responding in extinction was little affected by noncontingent TO punishment. When TO was made contingent upon avoidance responding, however, avoidance latencies immediately increased and the frequency of avoidance responses subsequently decreased to zero.

  10. Flu, risks, and videotape: escalating fear and avoidance.

    PubMed

    Rosoff, Heather; John, Richard S; Prager, Fynnwin

    2012-04-01

    While extensive risk perception research has focused on emotions, cognitions, and behavior at static points in time, less attention has been paid to how these variables might change over time. This study assesses how negative affect, threat beliefs, perceived risk, and intended avoidance behavior change over the course of an escalating biological disaster. A scenario simulation methodology was used that presents respondents with a video simulation of a 15-day series of local news reports to immerse respondents in the developing details of the disaster. Systemic manipulation of the virus's causal origin (terrorist attack, medical lab accident, unknown) and the respondent's proximity to the virus (local vs. opposite coast) allowed us to investigate the dynamics of public response. The unfolding scenario was presented in discrete episodes, allowing responses to be tracked over the episodes. The sample includes 600 respondents equally split by sex and by location, with half in the Washington, DC area, and half in the Los Angeles area. The results showed respondents' reactions to the flu epidemic increased as the disaster escalated. More importantly, there was considerable consistency across respondents' emotional, cognitive, and behavioral responses to the epidemic over the episodes. In addition, the reactions of respondents proximally closer to the epidemic increased more rapidly and with greater intensity than their distant counterparts. Finally, as the flu epidemic escalated, both terrorist and accidental flu releases were perceived as being less risky and were less likely to lead to avoidance behavior compared to the unknown flu release. PMID:22332702

  11. [Femoral venous catheterization. Does it really need to be avoided?].

    PubMed

    Lorente, L; León, C

    2009-12-01

    The guidelines to prevent central venous catheter related bloodstream infections (CVCBSI) of the Centers for Disease Control and Prevention (CDC) of 2002, Sociedad Española de Medicina Intensiva, Crítica y Unidades Coronarias/ Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica (SEMICYUC/SEIMC) of 2004, and the recently published guidelines of the Society for Healthcare Epidemiology of America/Infectious Diseases Society of America (SHEA(IDSA) of 2008 have recommended using the subclavian vein and avoiding the use of the femoral vein. They also recommend considering the use of antiseptic- or antimicrobial-impregnated CVCs for hospital units or groups of patients with a high incidence of CVCBSI. When implementing these guidelines, two questions could be asked: 1) Could the abuse of the subclavian vein and avoiding the use of the femoral vein imply a decrease in the incidence of CVCBSI, but an increase in the rate of mechanical complications as pneumothorax and/or hemothorax? 2) Couldn't antimicrobial-impregnated CVCs be used to prevent CVCBSI when the femoral venous access is used?

  12. Do aquatic insects avoid cadmium-contaminated sediments?

    SciTech Connect

    Hare, L.; Shooner, F.

    1995-06-01

    The long-term colonization of profundal lake sediments having a range of spiked cadmium (Cd) concentrations (0.007 to 2.7 {mu}mol/g dry wt.) was measured in the field. Population densities of two of the most abundant colonizing insects (the chironomids Procladius [Holotanypus] sp., and Sergentia coracina) were unrelated to the Cd gradient, even though both taxa accumulated Cd in direct relation to its concentration in sediment Cd gradient Cd gradient. Cadmium concentrations in Chironomus (salinarius gp.) sp. larvae also responded positively to the sediment Cd gradient and ranged from 0.2 to 50 {mu}g/g. In contrast with the two other taxa, the abundance of Chironomus (salinarius gp.) sp. was the result of a behavioral or a toxic response, larvae of the three chironomid taxa were given a choice between field-control and Cd-spiked sediments in the laboratory. None of the taxa avoided the Cd-spiked sediments, suggesting that the lower abundance of Chironomus (salinarius gp.) sp. at high Cd concentrations in the field was due to Cd toxicity and not to avoidance of the Cd-rich sediments.

  13. Flu, risks, and videotape: escalating fear and avoidance.

    PubMed

    Rosoff, Heather; John, Richard S; Prager, Fynnwin

    2012-04-01

    While extensive risk perception research has focused on emotions, cognitions, and behavior at static points in time, less attention has been paid to how these variables might change over time. This study assesses how negative affect, threat beliefs, perceived risk, and intended avoidance behavior change over the course of an escalating biological disaster. A scenario simulation methodology was used that presents respondents with a video simulation of a 15-day series of local news reports to immerse respondents in the developing details of the disaster. Systemic manipulation of the virus's causal origin (terrorist attack, medical lab accident, unknown) and the respondent's proximity to the virus (local vs. opposite coast) allowed us to investigate the dynamics of public response. The unfolding scenario was presented in discrete episodes, allowing responses to be tracked over the episodes. The sample includes 600 respondents equally split by sex and by location, with half in the Washington, DC area, and half in the Los Angeles area. The results showed respondents' reactions to the flu epidemic increased as the disaster escalated. More importantly, there was considerable consistency across respondents' emotional, cognitive, and behavioral responses to the epidemic over the episodes. In addition, the reactions of respondents proximally closer to the epidemic increased more rapidly and with greater intensity than their distant counterparts. Finally, as the flu epidemic escalated, both terrorist and accidental flu releases were perceived as being less risky and were less likely to lead to avoidance behavior compared to the unknown flu release.

  14. Gustatory receptors required for avoiding the insecticide L-canavanine.

    PubMed

    Lee, Youngseok; Kang, Min Jung; Shim, Jaewon; Cheong, Chae Uk; Moon, Seok Jun; Montell, Craig

    2012-01-25

    Insect survival depends on contact chemosensation to sense and avoid consuming plant-derived insecticides, such as L-canavanine. Members of a family of ∼60 gustatory receptors (GRs) comprise the main peripheral receptors responsible for taste sensation in Drosophila. However, the roles of most Drosophila GRs are unknown. In addition to GRs, a G protein-coupled receptor, DmXR, has been reported to be required for detecting L-canavanine. Here, we showed that GRs are essential for responding to L-canavanine and that flies missing DmXR displayed normal L-canavanine avoidance and L-canavanine-evoked action potentials. Mutations disrupting either Gr8a or Gr66a resulted in an inability to detect L-canavanine. We found that L-canavanine stimulated action potentials in S-type sensilla, which were where Gr8a and Gr66a were both expressed, but not in Gr66a-expressing sensilla that did not express Gr8a. L-canavanine-induced action potentials were also abolished in the Gr8a and Gr66a mutant animals. Gr8a was narrowly required for responding to L-canavanine, in contrast to Gr66a, which was broadly required for responding to other noxious tastants. Our data suggest that GR8a and GR66a are subunits of an L-canavanine receptor and that GR8a contributes to the specificity for L-canavanine. PMID:22279227

  15. How to Avoid Facial Nerve Injury in Mastoidectomy?

    PubMed

    Ryu, Nam-Gyu; Kim, Jin

    2016-09-01

    Unexpected iatrogenic facial nerve paralysis not only affects facial disfiguration, but also imposes a devastating effect on the social, psychological, and economic aspects of an affected person's life at once. The aims of this study were to postulate where surgeons had mistakenly drilled or where obscured by granulations or by fibrous bands and to look for surgical approach with focused on the safety of facial nerve in mastoid surgery. We had found 14 cases of iatrogenic facial nerve injury (IFNI) during mastoid surgery for 5 years in Korea. The medical records of all the patients were obtained and analyzed injured site of facial nerve segment with surgical technique of mastoidectomy. Eleven patients underwent facial nerve exploration and three patients had conservative management. 43% (6 cases) of iatrogenic facial nerve injuries had occurred in tympanic segment, 28.5% (4 cases) of injuries in second genu combined with tympanic segment, and 28.5% (4 cases) of injuries in mastoid segment. Surgeons should try to identify the facial nerve using available landmarks and be kept in mind the anomalies of the facial nerve. With use of intraoperative facial nerve monitoring, the avoidance of in order to avoid IFNI would be possible in more cases. Many authors emphasized the importance of intraoperative facial nerve monitoring, even in primary otologic surgery. However, anatomical understanding of intratemporal landmarks with meticulous dissection could not be emphasized as possible to prevent IFNI. PMID:27626078

  16. Future singularity avoidance in phantom dark energy models

    SciTech Connect

    Haro, Jaume de

    2012-07-01

    Different approaches to quantum cosmology are studied in order to deal with the future singularity avoidance problem. Our results show that these future singularities will persist but could take different forms. As an example we have studied the big rip which appear when one considers the state equation P = ωρ with ω < −1, showing that it does not disappear in modified gravity. On the other hand, it is well-known that quantum geometric effects (holonomy corrections) in loop quantum cosmology introduce a quadratic modification, namely proportional to ρ{sup 2}, in Friedmann's equation that replace the big rip by a non-singular bounce. However this modified Friedmann equation could have been obtained in an inconsistent way, what means that the obtained results from this equation, in particular singularity avoidance, would be incorrect. In fact, we will show that instead of a non-singular bounce, the big rip singularity would be replaced, in loop quantum cosmology, by other kind of singularity.

  17. Quantifying inbreeding avoidance through extra-pair reproduction

    PubMed Central

    Reid, Jane M; Arcese, Peter; Keller, Lukas F; Germain, Ryan R; Duthie, A Bradley; Losdat, Sylvain; Wolak, Matthew E; Nietlisbach, Pirmin

    2015-01-01

    Extra-pair reproduction is widely hypothesized to allow females to avoid inbreeding with related socially paired males. Consequently, numerous field studies have tested the key predictions that extra-pair offspring are less inbred than females’ alternative within-pair offspring, and that the probability of extra-pair reproduction increases with a female's relatedness to her socially paired male. However, such studies rarely measure inbreeding or relatedness sufficiently precisely to detect subtle effects, or consider biases stemming from failure to observe inbred offspring that die during early development. Analyses of multigenerational song sparrow (Melospiza melodia) pedigree data showed that most females had opportunity to increase or decrease the coefficient of inbreeding of their offspring through extra-pair reproduction with neighboring males. In practice, observed extra-pair offspring had lower inbreeding coefficients than females’ within-pair offspring on average, while the probability of extra-pair reproduction increased substantially with the coefficient of kinship between a female and her socially paired male. However, simulations showed that such effects could simply reflect bias stemming from inbreeding depression in early offspring survival. The null hypothesis that extra-pair reproduction is random with respect to kinship therefore cannot be definitively rejected in song sparrows, and existing general evidence that females avoid inbreeding through extra-pair reproduction requires reevaluation given such biases. PMID:25346331

  18. Trust-based learning and behaviors for convoy obstacle avoidance

    NASA Astrophysics Data System (ADS)

    Mikulski, Dariusz G.; Karlsen, Robert E.

    2015-05-01

    In many multi-agent systems, robots within the same team are regarded as being fully trustworthy for cooperative tasks. However, the assumption of trustworthiness is not always justified, which may not only increase the risk of mission failure, but also endanger the lives of friendly forces. In prior work, we addressed this issue by using RoboTrust to dynamically adjust to observed behaviors or recommendations in order to mitigate the risks of illegitimate behaviors. However, in the simulations in prior work, all members of the convoy had knowledge of the convoy goal. In this paper, only the lead vehicle has knowledge of the convoy goals and the follow vehicles must infer trustworthiness strictly from lead vehicle performance. In addition, RoboTrust could only respond to observed performance and did not dynamically learn agent behavior. In this paper, we incorporate an adaptive agent-specific bias into the RoboTrust algorithm that modifies its trust dynamics. This bias is learned incrementally from agent interactions, allowing good agents to benefit from faster trust growth and slower trust decay and bad agents to be penalized with slower trust growth and faster trust decay. We then integrate this new trust model into a trust-based controller for decentralized autonomous convoy operations. We evaluate its performance in an obstacle avoidance mission, where the convoy attempts to learn the best speed and following distances combinations for an acceptable obstacle avoidance probability.

  19. Rats learn to eat more to avoid hunger.

    PubMed

    Jarvandi, Soghra; Thibault, Louise; Booth, David A

    2009-04-01

    Several recent experiments have provided evidence that the ingestion of a distinctive food by rats can be a learnt instrumental act as well as an associatively conditioned reaction. In the previous work, maintenance food was withheld for shorter and longer durations on different days following access to the training food. Extra eating before the longer fast was interpreted as avoidance of hunger. This interpretation was based on the evidence showing that extra eating as a result of classical conditioning comes from pairing food stimuli with the presence of little or no hunger because of repletion with energy nutrients. The theory that the extra eating arose from a response-depletion contingency was tested in the present experiment by training rats on only a long fast or only a short fast. Greater increase in intake was seen before the longer fast. The results also replicated previously seen cycles of increase, decrease, and renewed increase in putative deficit-avoidant eating over about three trials, indicating that the extra eating reduces the response-reinforcing hunger and that the consequent part-extinction restores reinforcement. The shape of the learning curve was consistent with these cycles occurring from the start of training, further supporting the view that the increase in food intake before a long delay in refeeding is hunger-reinforced instrumental behaviour.

  20. Chorda tympani nerve modulates the rat's avoidance of calcium chloride.

    PubMed

    Golden, Glen J; Voznesenskaya, Anna; Tordoff, Michael G

    2012-03-20

    Calcium intake depends on orosensory factors, implying the presence of a mechanism for calcium detection in the mouth. To better understand how information about oral calcium is conveyed to the brain, we examined the effects of chorda tympani nerve transection on calcium chloride (CaCl(2)) taste preferences and thresholds in male Wistar rats. The rats were given bilateral transections of the chorda tympani nerve (CTX) or control surgery. After recovery, they received 48-h two-bottle tests with an ascending concentration series of CaCl(2). Whereas control rats avoided CaCl(2) at concentrations of 0.1mM and higher, rats with CTX were indifferent to CaCl(2) concentrations up to 10mM. Rats with CTX had significantly higher preference scores for 0.316 and 3.16 mM CaCl(2) than did control rats. The results imply that the chorda tympani nerve is required for the normal avoidance of CaCl(2) solution.