103 research outputs found

    Long-Distance Migrations by Inconnu (Stenodus leucichthys) in the Mackenzie River Syste

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    Inconnu (Stenodus leucichthys) stocks of the Mackenzie River drainage exhibit complex life histories. In a single stock, some fish may make occasional or regular movements between freshwater and marine environments while others lead a completely freshwater existence. Many inconnu migrate between the Mackenzie River system and the Beaufort Sea, but during spawning migrations, most are believed to move only as far south as the Rampart Rapids near the community of Fort Good Hope. However, an inconnu tagged in the Liard River in northern British Columbia in 2001 was recaptured near Inuvik (Northwest Territories) in 2002, and a second inconnu tagged in the Liard River in 2002 was recaptured near Tuktoyaktuk (Northwest Territories) in 2003. These two fish exhibited some of the longest freshwater migrations by a species from Canadian waters other than Pacific salmon. Otolith strontium distributions of these two fish confirmed migrations of close to 1800 km between fresh and marine waters and indicated different life histories. Additional inconnu tagged in the Liard River in 2002 were recaptured in or near Great Slave Lake in 2002 and 2003. The movements of all these fish suggest that the management of inconnu stocks will be far more complicated than previously thought: they point out the need for management plans and protection that incorporate large geographic areas.Les stocks d’inconnu (Stenodus leucichthys) du bassin du Mackenzie affichent des cycles biologiques complexes. On trouve, au sein d’un seul stock, des poissons qui feront des allers retours sur une base Ă©pisodique ou rĂ©guliĂšre, entre un milieu d’eau douce et un milieu marin, tandis que d’autres passeront toute leur vie en eau douce. Un grand nombre d’inconnus migrent entre le rĂ©seau hydrographique du Mackenzie et la mer de Beaufort, mais on pense que, durant les migrations de frai, la plupart ne se dĂ©placent en direction du sud que jusqu’aux rapides Rampart, prĂšs de la communautĂ© de Fort Good Hope. Un inconnu marquĂ© dans la riviĂšre Liard dans le nord de la Colombie-Britannique en 2001 a cependant Ă©tĂ© recapturĂ© prĂšs d’Inuvik (Territoires du Nord-Ouest) en 2002, et un deuxiĂšme inconnu marquĂ© dans la Liard en 2002 a Ă©tĂ© recapturĂ© prĂšs de Tuktoyaktuk (Territoires du Nord-Ouest) en 2003. Les migrations de ces deux spĂ©cimens comptent parmi les plus longues en eau douce effectuĂ©es par une espĂšce provenant des eaux canadiennes, autre que le saumon du Pacifique. La distribution du strontium otolithique de ces deux poissons a confirmĂ© des migrations de prĂšs de 1800 km entre l’eau douce et l’eau de mer et a rĂ©vĂ©lĂ© des cycles biologiques diffĂ©rents. D’autres inconnus marquĂ©s dans la Liard en 2002 ont Ă©tĂ© recapturĂ©s en 2002 et 2003 dans le Grand lac des Esclaves ou Ă  proximitĂ©. Les dĂ©placements de tous ces poissons suggĂšrent que la gestion des stocks d’inconnu sera beaucoup plus compliquĂ©e que prĂ©vu: ils font ressortir le besoin d’élaborer des plans de gestion et une protection qui tiennent compte de vastes aires gĂ©ographiques

    Principal Leadership in a Virtual Environment

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    Commissioned by The Wallace Foundation, which supports efforts to promote effective school leadership, this report sets out to define what high-quality, equitable learning looks like in a virtual environment. It poses questions for school district leaders to ask if they want to develop principals who can lead their schools to this type of learning. It also describes strategies for districts to consider in efforts to develop a whole pipeline of principals adept at high-quality, equitable virtual learning—using a definition of an "aligned, comprehensive principal pipeline" that emerged through research and field work funded by The Wallace Foundation. The report is based on an examination of research literature supplemented by interviews with 11 principals and administrators knowledgeable about virtual learning. It also draws on Digital Promise's experience in working with schools and school districts. The final chapter looks at topics that merit further exploration in the areas of virtual learning, equity, and school leadership

    Voices Obscured in Complex Environmental Settings (VOICES) corpus

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    This paper introduces the Voices Obscured In Complex Environmental Settings (VOICES) corpus, a freely available dataset under Creative Commons BY 4.0. This dataset will promote speech and signal processing research of speech recorded by far-field microphones in noisy room conditions. Publicly available speech corpora are mostly composed of isolated speech at close-range microphony. A typical approach to better represent realistic scenarios, is to convolve clean speech with noise and simulated room response for model training. Despite these efforts, model performance degrades when tested against uncurated speech in natural conditions. For this corpus, audio was recorded in furnished rooms with background noise played in conjunction with foreground speech selected from the LibriSpeech corpus. Multiple sessions were recorded in each room to accommodate for all foreground speech-background noise combinations. Audio was recorded using twelve microphones placed throughout the room, resulting in 120 hours of audio per microphone. This work is a multi-organizational effort led by SRI International and Lab41 with the intent to push forward state-of-the-art distant microphone approaches in signal processing and speech recognition.Comment: Submitted to Interspeech 201

    The ecology of human-caused mortality for a protected large carnivore

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    Mitigating human-caused mortality for large carnivores is a pressing global challenge for wildlife conservation. However, mortality is almost exclusively studied at local (within-population) scales creating a mismatch between our understanding of risk and the spatial extent most relevant to conservation and management of wide-ranging species. Here, we quantified mortality for 590 radio-collared mountain lions statewide across their distribution in California to identify drivers of human-caused mortality and investigate whether human-caused mortality is additive or compensatory. Human-caused mortality, primarily from conflict management and vehicles, exceeded natural mortality despite mountain lions being protected from hunting. Our data indicate that human-caused mortality is additive to natural mortality as population-level survival decreased as a function of increasing human-caused mortality and natural mortality did not decrease with increased human-caused mortality. Mortality risk increased for mountain lions closer to rural development and decreased in areas with higher proportions of citizens voting to support environmental initiatives. Thus, the presence of human infrastructure and variation in the mindset of humans sharing landscapes with mountain lions appear to be primary drivers of risk. We show that human-caused mortality can reduce population-level survival of large carnivores across large spatial scales, even when they are protected from hunting

    Differences in the organisation of early pregnancy units and the effect of senior clinician presence, volume of patients and weekend opening on emergency hospital admissions: Findings from the VESPA Study

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    OBJECTIVE: To determine whether the participation of consultant gynaecologists in delivering early pregnancy care results in a lower rate of acute hospital admissions. DESIGN: Prospective cohort study and emergency hospital care audit; data were collected as part of the national prospective mixed-methods VESPA study on the “Variations in the organization of EPAUs in the UK and their effects on clinical, Service and PAtient-centred outcomes”. SETTING: 44 Early Pregnancy Assessment Units (EPAUs) across the UK randomly selected in balanced numbers from eight pre-defined mutually exclusive strata. PARTICIPANTS: 6606 pregnant women (≄16 years old) with suspected first trimester pregnancy complications attending the participating EPAUs or Emergency Departments (ED) from December 2016 to July 2017. EXPOSURES: Planned and actual senior clinician presence, unit size, and weekend opening. MAIN OUTCOME MEASURES: Unplanned admissions to hospital following any visit for investigations or treatment for first trimester complications as a proportion of women attending EPAUs. RESULTS: 205/6397 (3.2%; 95% CI 2.8–3.7) women were admitted following their EPAU attendance. The admission rate among 44 units ranged from 0% to 13.7% (median 2.8). Neither planned senior clinician presence (p = 0.874) nor unit volume (p = 0.247) were associated with lower admission rates from EPAU, whilst EPAU opening over the weekend resulted in lower admission rates (p = 0.027). 1445/5464 (26.4%; 95%CI 25.3 to 27.6) women were admitted from ED. There was little evidence of an association with planned senior clinician time (p = 0.280) or unit volume (p = 0.647). Keeping an EPAU open over the weekend for an additional hour was associated with 2.4% (95% CI 0.1% to 4.7%) lower odds of an emergency admission from ED. CONCLUSIONS: Involvement of senior clinicians in delivering early pregnancy care has no significant impact on emergency hospital admissions for early pregnancy complications. Weekend opening, however, may be an effective way of reducing emergency admissions from ED

    Factors associated with downgrading in patients with high grade prostate cancer

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    ObjectiveTo determine the factors associated with downgrading between biopsy and prostatectomy in the contemporary era using extended-template biopsy techniques.Materials and methodsThe UCSF Urologic Oncology Database was used to identify subjects diagnosed with high grade prostate cancer (primary pattern 4 or 5) in at least one core on extended-pattern biopsy. Multivariable logistic regression analysis was performed to identify independent factors associated with downgrading at radical prostatectomy, defined as a change from primary pattern 4 or 5 to primary pattern 3.ResultsDowngrading occurred in 68 (34%) of 202 subjects who met the study criteria. Fourteen (47%) of 30 subjects with ≀25% of cores that were high grade and 9 (43%) of 21 subjects with <10% of total tissue containing cancer were downgraded. In a multivariable model, patients with mixed grade cores had much higher odds of downgrading than those with all high grade cores (OR 3.0 95% 1.3-7.1), P < 0.01). The proportion (per 10% increment) of positive cores containing high grade cancer (OR 0.8 95% CI 0.7-0.9 P < 0.01) and the percent (per 10% increment) of total tissue containing cancer (OR 0.7 95% CI 0.6-0.9 P = 0.01) were significantly associated with lower odds of downgrading.ConclusionsDowngrading following radical prostatectomy is a common event. Biopsy over-grading may preclude men from active surveillance or lead to unnecessary lymphadenectomy, excess radiation, or prolonged hormone therapy. The proportion of positive biopsy cores that are high grade and the percent of total tissue containing cancer should be incorporated into decision making

    Global Pyrogeography: the Current and Future Distribution of Wildfire

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    Climate change is expected to alter the geographic distribution of wildfire, a complex abiotic process that responds to a variety of spatial and environmental gradients. How future climate change may alter global wildfire activity, however, is still largely unknown. As a first step to quantifying potential change in global wildfire, we present a multivariate quantification of environmental drivers for the observed, current distribution of vegetation fires using statistical models of the relationship between fire activity and resources to burn, climate conditions, human influence, and lightning flash rates at a coarse spatiotemporal resolution (100 km, over one decade). We then demonstrate how these statistical models can be used to project future changes in global fire patterns, highlighting regional hotspots of change in fire probabilities under future climate conditions as simulated by a global climate model. Based on current conditions, our results illustrate how the availability of resources to burn and climate conditions conducive to combustion jointly determine why some parts of the world are fire-prone and others are fire-free. In contrast to any expectation that global warming should necessarily result in more fire, we find that regional increases in fire probabilities may be counter-balanced by decreases at other locations, due to the interplay of temperature and precipitation variables. Despite this net balance, our models predict substantial invasion and retreat of fire across large portions of the globe. These changes could have important effects on terrestrial ecosystems since alteration in fire activity may occur quite rapidly, generating ever more complex environmental challenges for species dispersing and adjusting to new climate conditions. Our findings highlight the potential for widespread impacts of climate change on wildfire, suggesting severely altered fire regimes and the need for more explicit inclusion of fire in research on global vegetation-climate change dynamics and conservation planning
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