906 research outputs found

    Seasonal detours by soaring migrants shaped by wind regimes along the East Atlantic Flyway

    Get PDF
    1. Avian migrants often make substantial detours between their seasonal destinations. It is likely some species do this to make the most of predictable wind regimes along their respective flyways. We test this hypothesis by studying orientation behaviour of a long-distance soaring migrant in relation to prevailing winds along the East Atlantic Flyway. 2. We tracked 62 migratory journeys of 12 adult European Honey Buzzards Pernis apivorus with GPS loggers. Hourly fixes were annotated with local wind vectors from a global atmospheric model to determine orientation behaviours with respect to the buzzards’ seasonal goal destinations. This enabled us to determine hot spots where buzzards overdrifted and overcompensated for side winds. We then determined whether winds along the buzzards’ detours differed from winds prevailing elsewhere in the flyway. 3. Honey Buzzards cross western Africa using different routes in autumn and spring. In autumn, they overcompensated for westward winds to circumvent the Atlas Mountains on the eastern side and then overdrifted with south-westward winds while crossing the Sahara. In spring, however, they frequently overcompensated for eastward winds to initiate a westward detour at the start of their journey. They later overdrifted with side winds north-westward over the Sahel and north-eastward over the Sahara, avoiding adverse winds over the central Sahara. 4. We conclude that Honey Buzzards make seasonal detours to utilize more supportive winds further en route and thereby expend less energy while crossing the desert. Lifelong tracking studies will be helpful to elucidate how honey buzzards and other migrants learn complex routes to exploit atmospheric circulation patterns from local to synoptic scales

    Peak incidence of distal radius fractures due to ice skating on natural ice in The Netherlands

    Get PDF
    An increase of distal radius fractures was seen in 2009 when an extended cold spell allowed natural ice skating in Amsterdam. This resulted in overload of our Emergency Departments and operating rooms. This study reports patient and fracture characteristics of these injuries. We also determined potential skating-related risk factors. All patients who sustained a distal radius fracture during natural ice skating between January 3 and January 12, 2009 were included. Patient and fracture characteristics, treatment, validated outcome (Quick DASH) at 3 months after injury were determined. Natural ice skating accounted for a 5.5-fold increase of distal radius fractures (92 fractures) compared to a similar time period without natural ice skating in 2008. Fracture types were AO-type A, n = 50, type B, n = 11 and type C, n = 31. Twenty-eight patients were casted without reduction. Fifty-four patients underwent at least one reduction before casting. The non-operative group consisted of 67 patients (68 fractures, male/female 18/49) with an average age of 55.5 years. Twenty-three patients (24 fractures) underwent internal fixation. Quick DASH for the whole group was a mean of 23.1 points (range 0–95). The mean Quick DASH for the non-operatively treated group was 19.9 points (range 0–95), for the operatively treated group 31.7 points (range 2–65). Distal radius fractures increased 5.5-fold during a period with natural ice skating. Women aged 50 and over were predominantly affected. Most fractures were extra-articular, and the vast majority was treated non-operatively. Utilization of wrist-protecting devices should be considered during future natural ice periods

    Grizzly Bear Scavenging of Carrion on the Northern Yellowstone Winter Range (1997-2012)

    Get PDF
    The Northern Yellowstone Winter Range (NYWR) in northwestern Wyoming and southwestern Montana is an important winter migratory destination for ungulates.  The NYWR is within the Greater Yellowstone Ecosystem (GYE), a landscape characterized by a complex ecological system of predators, scavengers, and ungulates.  Grizzly bears (Ursus arctos) are dominant members of the scavenging community throughout the spring.  However, little is known about factors associated with grizzly bear use of carcasses.  Of particular interest to managers is how habitat and anthropogenic factors are associated with carcass use.  Such information, for example, may be useful to manage spring recreation in important bear foraging areas to reduce conflict and support conservation efforts.  We used logistic regression to analyze spring survey data from 23 transects located in Yellowstone National Park and the Gallatin National Forest during 1997–2012, to identify factors associated with grizzly bear scavenging of winter- or predator-killed ungulates.  Multi-model inference was used to evaluate relative support for a set of a priori candidate models containing environmental and temporal correlates. Our preliminary findings showed support for models with distance to forest edge, road density, and elevation. Results indicated negative relationships between these factors and probability of carcass use.  Our results suggest that spatial heterogeneity in landscape-level habitat characteristics and human activity affect grizzly bear use of a valuable spring food source

    Fostering 21st Century Skill Development by Engaging Students in Authentic Game Design Projects in a High School Computer Programming Class

    Get PDF
    This study used technology-rich ethnography (TRE) to examine the use of game development in a high school computer programming class for the development of 21st century skills. High school students created games for elementary school students while obtaining formative feedback from their younger clients. Our experience suggests that in the teaching of computer science in high schools, the development of games that include common game features such as dynamic feedback systems, backstory, levels, cheats, and compelling graphics challenges students and engages them in learning. Incorporating real client feedback is also useful for improving their work and connecting it to the “real” world. This article reports findings from the second year of a research project with a high school computer programming class. The authors argue that such approaches that leverage video games, design, programming, authenticity, and cooperation mobilize multiple 21st century skills that must be nurtured among contemporary young people so that they may grow to be part of a productive citizenry.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    Factors determining social participation in the first year after kidney transplantation: a prospective study

    Get PDF
    BACKGROUND: This study describes changes in social participation in the first year after kidney transplantation and examines the influence of clinical factors, health status, transplantation-related symptoms, and psychological characteristics on change in social participation. METHODS: A prospective study was performed on a cohort of primary kidney transplant recipients, transplanted between March 2002 and March 2003. Data on participation in obligatory activities (i.e., employment, education, household tasks) and leisure activities (i.e., volunteer work, assisting others, sports, clubs/associations, recreation, socializing, going out) were collected by in-home interviews (n=61) at 3 months (T1) and 1 year posttransplantation (T2). Analysis of covariance was performed. RESULTS: Data showed an increase in participation in obligatory activities and diversity of leisure participation between T1 and T2, although pre-end-stage renal disease level was not regained and differed from the general population. On T1, the majority of employed recipients were on sick leave, but returned to work on T2. Employment rate remained stable. An increase in obligatory participation was predicted by clinical factors (i.e., peritoneal dialysis, initial hospitalization), whereas change in leisure participation was related to serum albumin and cognitive capacity. No effects were found for type of donation, comorbidity, and renal function. CONCLUSIONS: We found that mainly clinical factors were associated with an increase in participation in society. Although health-status related factors and the psychological attribute self-efficacy may be related to recovery of social participation, their effect was outweighed by the strength of clinical predictors in multivariate analysis

    ACE I/D polymorphism is associated with mortality in a cohort study of patients starting with dialysis

    Get PDF
    ACE I/D polymorphism is associated with mortality in a cohort study of patients starting with dialysis.BackgroundIn dialysis patients, only a few follow-up studies have addressed the relationship between the insertion/deletion (I/D) polymorphism in the angiotensin-converting enzyme (ACE) gene and mortality, but the available data are contradictory.MethodsA cohort of 453 consecutive patients starting dialysis between January 1999 and January 2002 and participating in a Dutch multicenter prospective study was examined. Patients who died within 3 months after the start of dialysis were excluded. Patients were followed until date of death or censoring in November 2003.ResultsThe ACE II, ID, and DD genotype frequencies were 24.3% (N = 110), 50.1% (N = 227), and 25.6% (N = 116). Besides a slightly higher number of Caucasians in the DD group, all other patient characteristics of the 3 ACE groups were similar at the start of dialysis. After adjustment for age, comorbidity, and ethnic background, patients with the ID and DD genotype showed an increased hazard ratio (HR) for all-cause mortality of 1.55 (95% CI 1.00-2.42) and 2.30 (95% CI 1.41-3.75), compared to patients with the II genotype. Slightly lower HRs were found for cardiovascular mortality. All groups of primary kidney disease showed a 2- to 3-fold increased adjusted HR for DD.ConclusionThe DD genotype identifies dialysis patients at an increased risk for mortality

    ‘Shared intelligibility’ and two reflexive strategies as methods of supporting ‘responsible decisions’ in a hermeneutic phenomenological study

    Get PDF
    Hermeneutic phenomenologists propose that researchers inescapably bring themselves into their research because interpretation must inevitably be influenced by their contexts and pre-understandings. They propose that interpretation is a dynamic and active part of the construction of a text’s meaning, and involvement in this construction process leads to deep empathic understanding of others’ experience, reappraisal of accepted social and cultural systems, and a level of self-enlightenment. The strengths of the hermeneutic methodological approach have led to its use in a number of disciplines, however, there remains concerns about interpretative validity. It is widely acknowledged that in order to support rigour and validity in hermeneutic studies, researchers are required to develop and integrate strategies within the research process to promote awareness of the interplay between their pre-understandings and interpretation. This paper discusses how episodic interviewing which capitalises on ‘shared intelligibility’, and the reflexive strategies of ‘oppositional arrangement of perspectives’ and ‘backgrounding’ were used to shed light on data from a study of the experiences and views of nursing home nurses regarding their occupational role and status, and work identity

    Linear modeling of possible mechanisms for parkinson tremor generation

    Get PDF
    The power of Parkinson tremor is expressed in terms of possibly changed frequency response functions between relevant variables in the neuromuscular system. The derivation starts out from a linear loopless equivalent model of mechanisms for general tremor generation. Hypothetical changes in this model from the substrate of the disease are indicated, and possible ones are inferred from literature about experiments on patients. The result indicates that in these patients tremor appears to have been generated in loops, which did not include the brain area which in surgery usually is inactivated. For some patients in the literature, these loops could involve muscle length receptors, the static sensitivity of which may have been enlarged by pathological brain activity
    • 

    corecore