297 research outputs found

    Ecology of an Isolated Muskrat Population During Regional Population Declines

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    Evidence indicating a decline in Ondatra zibethicus (Muskrat) populations in the United States during the past 40 years has led to speculation regarding factors influencing Muskrat survival. In order to understand population dynamics and survival, it is important to first define the ecology of local populations. We investigated the dwelling structure use, movements, home range, and survival of radio-tagged Muskrats (n = 14) in an urban wetland complex in central Pennsylvania. We used locations collected from intensive radio-telemetry monitoring to determine number of lodging structures used, hourly movement, and size and percent area overlap of home ranges. Muskrats shared an average of 9 lodging structures, and on average, 68% of a Muskrat’s home range overlapped home ranges of other Muskrats. We used 4 home-range estimators (kernel density estimator [KDE]href, KDEad hoc, KDEplug-in, and local convex hull estimator) to assess the ability of each estimator to represent Muskrat home ranges. The KDEplug-in that constrained the estimate of home range to habitat boundaries provided the most appropriate home-range size for Muskrats in a linear–non-linear habitat matrix. We also calculated overwinter survival estimates using known-fate models. Our top model indicated a positive effect of the average weekly precipitation on survival, with an overwinter survival estimate of 0.59 (SE = 0.16). The main cause of Muskrat mortality was predation by Neovison vison (American Mink; n = 6). The small sample size and uncertainty surrounding our model selection led to weak estimates of survival; however, our model suggests that snowfall may be an important factor in Muskrat survival. Our study provides novel data on Muskrat ecology in Pennsylvania as well as preliminary evidence for future investigations of factors affecting Muskrat survival during the winter months

    Resource Use by American Black Bears in Suburbia: A Landholder Step Selection Approach

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    Range expansion of American black bears (Ursus americanus; bear) and residential development have increased the bear presence in suburbia. Suburban landscapes exhibiting patchworks of variable-sized parcels and habitats and owned by landowners with diverse values can create large areas of suitable habitats with limited public access. These landscapes may limit the effectiveness of hunting as a traditional bear population management tool. Managers require better information regarding landowner attitudes about hunting before implementing harvest regulations intended to mitigate conflicts in suburban areas. To address this need, in 2013, we surveyed landowners to identify properties that allowed bear hunting in 3 suburban areas of Pennsylvania, USA where bear sightings or human–bear conflicts have increased. We then used location data obtained for 29 bears equipped with global positioning system transmitters from 2010 to 2012 to model their resource selection in the study area. We assessed the influence of hunting access, housing density, land cover, and topographic variables on radio-marked black bears monitored 10 days before, during, and after the bear hunting season. We found that resource selection of radio-marked bears was similar for all 3 periods and bears selected for forested land in all 3 seasons and herbaceous cover in the pre-hunting and hunting periods. Resource selection by bears was not influenced by hunting access in the pre-hunting and hunting periods. For the post-hunting period, lands closed to hunting had support as the second-best model. All of the radio-marked bears in our study were vulnerable to harvest. However, they did not change resource selection during the hunting season, nor did they avoid areas open to hunting. Integrating human dimension data with bear habitat use studies, especially in suburban landscapes, has the potential to address bear space use and population management needs often overlooked by traditional research designs

    Blunted cardiovascular responses to acute psychological stress predict low behavioral but not self-reported perseverance

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    Emerging evidence relates attenuated physiological stress reactions to poor behavioral regulation. However, only a small number of behaviors such as impulsivity and risk taking have been explored. Nevertheless, one opportunistic study suggested that blunted reactivity might relate to poor perseverance. The present study examined the relationship between cardiovascular reactivity to acute active psychological stress and self‐reported and behavioral perseverance. Participants (N = 64) completed a self‐report perseverance questionnaire before heart rate (HR) and blood pressure (BP) were measured at rest and in response to 4‐min active (paced auditory serial addition; PASAT) and passive (cold pressor) stress tests. This was followed by an unsolvable Euler puzzle tracing task, with the time spent and number of attempts endeavoring to solve the puzzle recorded as behavioral perseverance measures. Blunted systolic and diastolic BP reactivity to the PASAT was associated with fewer attempts at the impossible puzzle, and lower diastolic BP PASAT reactivity related to less time persevering at the puzzle. Moreover, attenuated diastolic BP and HR PASAT reactivity predicted poorer perseverance at keeping one's hand in the iced water of the cold pressor task. There was no association between reactivity and self‐reported perseverance. These preliminary findings add to the evidence that implicates blunted reactivity as a physiological marker of poor behavioral regulation, and this may indicate why individuals with blunted reactivity are at increased risk of developing negative health outcomes (e.g., obesity and addictions)

    The Affective Impact of Financial Skewness on Neural Activity and Choice

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    Few finance theories consider the influence of “skewness” (or large and asymmetric but unlikely outcomes) on financial choice. We investigated the impact of skewed gambles on subjects' neural activity, self-reported affective responses, and subsequent preferences using functional magnetic resonance imaging (FMRI). Neurally, skewed gambles elicited more anterior insula activation than symmetric gambles equated for expected value and variance, and positively skewed gambles also specifically elicited more nucleus accumbens (NAcc) activation than negatively skewed gambles. Affectively, positively skewed gambles elicited more positive arousal and negatively skewed gambles elicited more negative arousal than symmetric gambles equated for expected value and variance. Subjects also preferred positively skewed gambles more, but negatively skewed gambles less than symmetric gambles of equal expected value. Individual differences in both NAcc activity and positive arousal predicted preferences for positively skewed gambles. These findings support an anticipatory affect account in which statistical properties of gambles—including skewness—can influence neural activity, affective responses, and ultimately, choice

    When the going gets tough: Employee reactions to large‐scale organizational change and the role of employee Machiavellianism

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    Large-scale, long-term change initiatives take time to unfold, which can be a source ofuncertainty and strain. Investigating the initial 19 months of a large-scale change, weargue that during these stages, employees' change-related beliefs become more negativeover time, which negatively affects their work engagement and, ultimately, increasestheir turnover intentions. Furthermore, we investigate the impact of a trait, Machiavel-lianism, on change reactions and propose that employees high in Machiavellianism reactmore negatively during change processes as they are especially susceptible to uncer-tainty and stress. We test our (cross-level) moderated mediation model in a three-wavelongitudinal study among employees undergoing a large-scale change (T1: n = 1,602; T2:n =1,113;T3:n = 759). We find that employees' beliefs about the impact and value ofthe change are indeed negatively related to change duration and that decreases in theseperceptions come with a decline in engagement and increases in turnover intentions.Moreover, employees high in Machiavellianism react more strongly to a deterioration inchange-related beliefs, showing stronger reductions in engagement and strongerincreases in turnover intentions than employees low in Machiavellianism. Our studyoffers explanations for the negative effects of large-scale changes including an explana-tory factor for disparate employee reactions to change over time

    Strategies from Dramatherapy supervision to augment newly qualified secondary school teachers' experience of self-efficacy and coping strategies in their new role

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    This study aims to investigate if strategies from Dramatherapy supervision can augment newly qualified teachers’ (NQTs) experience of self-efficacy and coping strategies in their new role. This research study sets out to explore the growing necessity for a more specific form of reflective practice for two separate cohorts of NQTs n =10 (per group) over the course of two consecutive academic years. According to recent research, teacher turnover is more prevalent in disadvantaged urban schools as a result of contextual factors: ‘an increasing workload’, ‘school situation’, the ‘turbulent student-teacher classroom dynamics’, as well as the ‘conflicting agendas between teachers and educational reform’. The study’s theoretical framework draws from teacher education, psychodynamic theory and Dramatherapy supervision theory and practice, to help NQTs develop coping pathways for self-exploration and personal growth, to obtain an increased awareness of the social and emotional processes involved in teaching and learning and to manage both individual and contextual factors that influence their sense of efficacy in their new role as a teacher. The study uses mixed methods to ascertain the efficacy of strategies from Dramatherapy supervision. Quantitative outcome measures are employed to ascertain overall self-efficacy, coping strategies and job satisfaction. Interpretative phenomenological Analyses is used to analyse the qualitative findings amassed from the post-intervention interviews with the NQTs. Autoethnography is employed to bracket the researcher’s personal reflections on the fieldnotes and to study the process of change over time in three case studies, in relation to the NQTs’ sense of efficacy and coping skills. Conclusions drawn from the results highlight that methods from Dramatherapy supervision can be beneficial for developing NQTs’ self-awareness, deepening their understanding of the challenging interpersonal dynamics and providing them with a reflective ‘meditative’ space created through creative techniques. However, the success of these findings is dependent on a number of internal and external variables that influence the NQTs’ sense of efficacy. Recommendations for education include: addressing the impact that the target driven educational climate has on the emotional well-being of teachers and subsequently their pupils, implementing compulsory regular group reflection into teacher practice based on the intervention of ‘strategies from Dramatherapy supervision’ with particular focus on mode 2 of the double matrix model of supervision and embedding training in school communities about and how to be in relationships

    Stress Strengthens Memory of First Impressions of Others' Positive Personality Traits

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    Encounters with strangers bear potential for social conflict and stress, but also allow the formation of alliances. First impressions of other people play a critical role in the formation of alliances, since they provide a learned base to infer the other's future social attitude. Stress can facilitate emotional memories but it is unknown whether stress strengthens our memory for newly acquired impressions of other people's personality traits. To answer this question, we subjected 60 students (37 females, 23 males) to an impression-formation task, viewing portraits together with brief positive vs. negative behavior descriptions, followed by a 3-min cold pressor stress test or a non-stressful control procedure. The next day, novel and old portraits were paired with single trait adjectives, the old portraits with a trait adjective matching the previous day's behavior description. After a filler task, portraits were presented again and subjects were asked to recall the trait adjective. Cued recall was higher for old (previously implied) than the novel portraits' trait adjectives, indicating validity of the applied test procedures. Overall, recall rate of implied trait adjectives did not differ between the stress and the control group. However, while the control group showed a better memory performance for others' implied negative personality traits, the stress group showed enhanced recall for others' implied positive personality traits. This result indicates that post-learning stress affects consolidation of first impressions in a valence-specific manner. We propose that the stress-induced strengthening of memory of others' positive traits forms an important cue for the formation of alliances in stressful conditions

    Understanding challenging behaviour in people with severe and profound intellectual disability: a stress-attachment model

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    Background. Advances in our knowledge of attachment, stress and coping may foster new explanations for the development of challenging behaviour in people with intellectual disability (ID). Method. Research on stress and coping among people with ID was reviewed initially, and then studies on the security of the attachment relationships of people with ID with their caregivers were analysed. Results. There is evidence that people with ID are more vulnerable to stress and use less effective coping strategies. Furthermore, the body of studies on attachment indicates that people with ID are at risk for developing insecure, especially disorganized attachment. There is evidence from other populations that the combination of stress, and insecure or disorganized attachment may put people at risk for developing behaviour problems. Conclusion. A stress-attachment model of the development of challenging behaviour among people with ID shows promise as an explanatory frame-work. The uncovering of these developmental mechanisms may be particularly useful for the prevention of behavioural problems

    Social context and sex moderate the association between type D personality and cardiovascular reactivity

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    peer-reviewedType D personality has been consistently associated with adverse cardiovascular health with atypical cardiovascular reactions to psychological stress one plausible underlying mechanism. However, whether this varies by sex and social context has received little attention. This study examined the interaction between Type D personality, sex and social context on cardiovascular reactivity to acute stress. A sample of 76 healthy undergraduate students (47 female) completed the DS14 Type D measure, before undergoing a traditional cardiovascular reactivity protocol. The social context of the laboratory environment was manipulated to create a social and non-social context using a between-subjects design. Systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) were monitored throughout. No associations were evident for blood pressure. However, a significant personality × sex × social context interaction on HR reactivity was found; here Type D was associated with a higher HR response to the social task amongst males but not females, while Type D females typically exhibited blunted reactions. While these atypical reactions indicate a possible psychophysiological pathway leading to adverse cardiovascular events amongst Type Ds, it appears that Type D males are particularly vulnerable to socially based stressors, exhibiting exaggerated cardiovascular reactions.peer-reviewe
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