4,314 research outputs found

    Preliminary investigation of alternative approaches for the Reef Plan Report Card Water Quality Metric report

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    The management of water quality remains an essential requirement to ensure the long-term protection of the coastal and inshore ecosystems of the Great Barrier Reef (GBR) (Commonwealth of Australia, 2015). The land management initiatives under the Australian and Queensland Government's Reef Water Quality Protection Plan (Reef Plan) and the Reef 2050 Long Term Sustainability Plan (Reef 2050 Plan) are key actions to improve the water quality entering the Great Barrier Reef. The goal of Reef Plan is “To ensure that by 2020 the quality of water entering the reef from broadscale land use has no detrimental impact on the health and resilience of the Great Barrier Reef.” The purpose of this report was to conduct a rapid and preliminary review of the Marine Water Quality Metric presented in the 2015-16 Reef Plan Report Card, focusing on issues highlighted by the Reef Plan ISP associated with data confidence of remotely sensed data in inshore areas

    Constraining the properties of neutron star crusts with the transient low-mass X-ray binary Aql X-1

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    Aql X-1 is a prolific transient neutron star low-mass X-ray binary that exhibits an accretion outburst approximately once every year. Whether the thermal X-rays detected in intervening quiescent episodes are the result of cooling of the neutron star or due to continued low-level accretion remains unclear. In this work we use Swift data obtained after the long and bright 2011 and 2013 outbursts, as well as the short and faint 2015 outburst, to investigate the hypothesis that cooling of the accretion-heated neutron star crust dominates the quiescent thermal emission in Aql X-1. We demonstrate that the X-ray light curves and measured neutron star surface temperatures are consistent with the expectations of the crust cooling paradigm. By using a thermal evolution code, we find that ~1.2-3.2 MeV/nucleon of shallow heat release describes the observational data well, depending on the assumed mass-accretion rate and temperature of the stellar core. We find no evidence for varying strengths of this shallow heating after different outbursts, but this could be due to limitations of the data. We argue that monitoring Aql X-1 for up to ~1 year after future outbursts can be a powerful tool to break model degeneracies and solve open questions about the magnitude, depth and origin of shallow heating in neutron star crusts.Comment: 14 pages, 5 figures, 3 tables, accepted to MNRA

    The Progenitor Masses of Wolf-Rayet Stars and Luminous Blue Variables Determined from Cluster Turn-offs. II. Results from 12 Galactic Clusters and OB Associations

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    Here we examine 12 Galactic clusters and OB associations containing Wolf-Rayet stars (W-Rs) and/or Luminous Blue Variables (LBVs), in order to assess the progentor masses of these evolved massive stars. We find that in the Milky Way, early-type WN stars evolve from stars with masses as low as 20Mo. Some early-type WN stars are found in clusters with very high turn-off masses, supporting our earlier results that the "WNE" class of W-Rs is a common stage in the evolution of stars with a wide range of mases. In contrast, the late-type WNs (particularly those of WN7 class) and the LBVs are only found in clusters with the very highest turn-off masses, suggesting that only the most massive stars evolve to these objects. An examination of the environment of the archetype LBV Eta Car reveals that this star is coeval with the rest of the Tr14/16 association, suggesting that its LBV properties is a normal consequence of evolution, and has little to do with the possibility that it is a binary.Comment: Scheduled for the Feb 2001 issue of the Astronomical Journal. Postscript version including figs from ftp://ftp.lowell.edu/pub/massey/galwr.ps.g

    A Bridge to the Future: Cultivating Academic Leadership Today for Better Communities Tomorrow

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    The purpose of this project is to develop a plan for expanding and funding the Grace E. Harris Leadership Institute (GEHLI). Currently, teams of leadership scholars selected from Virginia Commonwealth University (VCU) develop projects relating to the academic community in addition to studying the dynamics of effective leadership. Consistent with VCU\u27s vision of partnering with and service to metropolitan Richmond, we propose that future teams of leadership scholars develop outreach projects that involve and benefit the local community. The training in which scholars would participate would include learning about the Richmond community, its needs and goals, as well as the dynamics of leadership. Project teams would collaborate with community groups or leaders, thereby strengthening the bonds between VCU and the community, and providing public service, in accordance with VCU\u27s mission. Projects might include education, outreach, fundraising, mentoring, or research that would benefit Richmond and provide scholars with opportunities to network with local leaders. Financial and philanthropic resources will be investigated and a list of potential funding organizations will be generated

    Some genus 3 curves with many points

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    Using an explicit family of plane quartic curves, we prove the existence of a genus 3 curve over any finite field of characteristic 3 whose number of rational points stays within a fixed distance from the Hasse-Weil-Serre upper bound. We also provide an intrinsic characterization of so-called Legendre elliptic curves

    Locus ceruleus regulates sensory encoding by neurons and networks in waking animals

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    Substantial evidence indicates that the locus ceruleus (LC)–norepinephrine (NE) projection system regulates behavioral state and state-dependent processing of sensory information. Tonic LC discharge (0.1–5.0 Hz) is correlated with levels of arousal and demonstrates an optimal firing rate during good performance in a sustained attention task. In addition, studies have shown that locally applied NE or LC stimulation can modulate the responsiveness of neurons, including those in the thalamus, to nonmonoaminergic synaptic inputs. Many recent investigations further indicate that within sensory relay circuits of the thalamus both general and specific features of sensory information are represented within the collective firing patterns of like-modality neurons. However, no studies have examined the impact of NE or LC output on the discharge properties of ensembles of functionally related cells in intact, conscious animals. Here, we provide evidence linking LC neuronal discharge and NE efflux with LC-mediated modulation of single-neuron and neuronal ensemble representations of sensory stimuli in the ventral posteriomedial thalamus of waking rats. As such, the current study provides evidence that output from the LC across a physiologic range modulates single thalamic neuron responsiveness to synaptic input and representation of sensory information across ensembles of thalamic neurons in a manner that is consistent with the well documented actions of LC output on cognition

    Tannakian approach to linear differential algebraic groups

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    Tannaka's Theorem states that a linear algebraic group G is determined by the category of finite dimensional G-modules and the forgetful functor. We extend this result to linear differential algebraic groups by introducing a category corresponding to their representations and show how this category determines such a group.Comment: 31 pages; corrected misprint

    Exploring the drivers and barriers to teaching excellence

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    In a sector that aspires to teaching excellence it is important to stand back and ask: what do we mean by this? While existing research defines effective methods for teaching and supporting learners, each institution and student collective has its own identity, culture, preferences and norms. The very exercise of locating excellence is also a powerful practice based conversation starter, particularly in terms of what makes our teaching practice “future-ready”. Findings from such evaluative conversations can provide a mandate for the advocacy of one practice over another; help individual staff develop confidence in their methods through affirmation; and shed light on institution specific conceptions of excellence.The aims of our interactive workshop were to facilitate those evaluative conversations, using the prompts provided by a table-top dialogue sheet.In combination with published literature, the findings from a project undertaken in the author’s home institution indicated that the drivers to impactful teaching could be categorised as either social, innovative or by the extent of their alignment with the real world. Perceived barriers included regulations and the entry profiles of students. The journey to teaching excellence was noted as not being without challenges; however, alternative pedagogies were perceived as a means to overcome them. Future work could include larger-scale projects to explore a wider range of both staff and student views

    Examining the Use of Web-Based Reusable Learning Objects by Animal and Veterinary Nursing Students

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    This intervention study examined the interaction of animal- and veterinary nursing students with reusable learning objects (RLO) in the context of preparing for summative assessment. Data was collected from 199 undergraduates using quantitative and qualitative methods. Students accessed RLO via personal devices in order to reinforce taught sessions. Interviewees reported that the RLO helped them meet the requirements of the curriculum. Quantitative data supported two valid points; the lack of engagement of students when given a free-choice and reluctance for self-assessment. The practical significance of the qualitative outcomes lies with how first year undergraduates on animal and veterinary nursing-related courses use RLO designed to address equine management and health topics, where the students have mixed equine experience

    The Use of Reusable Learning Objects to Enhance the Delivery of Veterinary Education: A Literature Review

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    The increased demand from learners in higher education to access resources flexibly has resulted in considerable development in the use of Reusable Learning Objects (RLO) via a blended learning format across the sector. This critical review sets out to identify what is currently known about RLO and how those concepts can be applied to veterinary-related degree courses. The review provides an insight into an aspect of blended learning which is currently limited in terms of published research. The effect of computer confidence, students' choice to use and the impact on student performance are some of the variables which have been measured to date. The approach to RLO by students from different courses may vary, but prior experience of technology, alignment of content and availability of technical support are some of the key drivers for usage and reuse. A positive effect is likely to occur following RLO use because those students have adopted a process of active engagement, which the authors know can bring about a deeper approach to learning
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