752 research outputs found
Two fast X-ray transients in archival Chandra data
We present the discovery of two new X-ray transients in archival Chandra
data. The first transient, XRT 110103, occurred in January 2011 and shows a
sharp rise of at least three orders of magnitude in count rate in less than 10
s, a flat peak for about 20 s and decays by two orders of magnitude in the next
60 s. We find no optical or infrared counterpart to this event in preexisting
survey data or in an observation taken by the SIRIUS instrument at the Infrared
Survey Facility 2.1 yr after the transient, providing limiting magnitudes of
J>18.1, H>17.6 and Ks>16.3. This event shows similarities to the transient
previously reported in Jonker et al. which was interpreted as the possible
tidal disruption of a white dwarf by an intermediate mass black hole. We
discuss the possibility that these transients originate from the same type of
event. If we assume these events are related a rough estimate of the rates
gives 1.4*10^5 per year over the whole sky with a peak 0.3-7 keV X-ray flux
greater than 2*10^-10 erg cm^-2 s^-1 . The second transient, XRT 120830,
occurred in August 2012 and shows a rise of at least three orders of magnitude
in count rate and a subsequent decay of around one order of magnitude all
within 10 s, followed by a slower quasi-exponential decay over the remaining 30
ks of the observation. We detect a likely infrared counterpart with magnitudes
J=16.70+/-0.06, H=15.92+/-0.04 and Ks=15.37+/-0.06 which shows an average
proper motion of 74+/-19 milliarcsec per year compared to archival 2MASS
observations. The JHKs magnitudes, proper motion and X-ray flux of XRT 120830
are consistent with a bright flare from a nearby late M or early L dwarf.Comment: Accepted for publication in MNRAS, 6 pages, 5 figure
Different Approaches to Managerial Support for Flexible Working: Implications for Public Sector Employee Well-Being
Improving well-being is an important human resource management issue within public sector organizations as it is linked with improved employee and organizational outcomes. A key antecedent to employee well-being is workâlife balance, which can be supported or impeded by flexible working. The extent to which flexible working supports workâlife balance and, ultimately, well-being depends on how flexible working is implemented, where managers play a central role. Managers can enable workâlife balance by providing employees with work-family-specific support, which incorporates a range of behaviors, including facilitating access to flexible working. However, research to date says little about how and why managers engage in these behaviors and whether this differs within the same organizational context. This article addresses this gap, presenting four approaches to managerial support for flexible working: unconditional support, performance contingent support, no support, and support based upon the approval of others (transfer responsibility). It explores the reasons for each approach through the lens of Conservation of Resources (COR) theory. It suggests that different approaches create the potential for employee well-being to vary considerably within the same organizational and team context. These findings inform how to support and manage flexible working arrangements in ways that optimize well-being in the public sector
ShortNotice and Unannounced Survey Methods: Literature review
The Commissionâs role is to lead and coordinate national improvements in the safety and quality of health care. The Commission works in partnership with the Australian Government, state and territory governments and the private sector to achieve a safe and high -qu ality, sustainable health system. In doing so, the Commission also works closely with patients, carers, clinicians, managers, policymakers and healthcare organisations. The Commission is responsible under the National Health Reform Act 2011 for the formul ation of standards relating to health care safety and quality matters and for formulating and coordinating national models of accreditation for health service organisations. The Commission developed the National Safety and Quality Health Service (NSQHS) Standards in consultation with the Australian Government , state and territory governments, technical experts and other stakeholders. They aim to protect the public from harm and to improve the quality of health service provision. To become accredited, health service organisations must pass assessments to show they have implemented the NSQHS Standards. The assessments are conducted by independent accrediting agencies, approved by the Commission, as part of the AHSSQA Scheme. However, state and territory regulators and chief executives of health service organisations have raised concerns about several aspects of the accreditation process
Attestation by Governing Bodies: Literature review
Preface This preface was written by the Australian Commission on Safety and Quality in Health Care (the Commission) to provide context and background to the report which follows, Attestation by Governing Bodies: Literature review. The Commission contracted the University of Technology Sydney (UTS) to prepare the literature review, as part of the review of the Australian Health Service Safety and Quality Accreditation (AHSSQA) Scheme. Background The Commissionâs role is to lead and coordinate national improvements in the safety and quality of health care. The Commission works in partnership with the Australian Government, state and territory governments and the private sector to achieve a safe and high-quality, sustainable health system. In doing so, the Commission also works closely with patients, carers, clinicians, managers, policymakers and healthcare organisations. The Commission is responsible under the National Health Reform Act 2011 for the formulation of standards relating to healthcare safety and quality matters and for formulating and coordinating national models of accreditation for health service organisations. The Commission developed the National Safety and Quality Health Service (NSQHS) Standards in consultation with the Australian Government, state and territory governments, technical experts and stakeholders. They aim to protect the public from harm and to improve the quality of health service provision. To become accredited, health service organisations must pass assessments to show they have implemented the NSQHS Standards. The assessments are conducted by independent accrediting agencies approved by the Commission as part of the AHSSQA Scheme. However, state and territory regulators and chief executives of health service organisations have raised concerns about several aspects of the accreditation process. The Commission is undertaking a review to update and improve the accreditation process. In May 2017, the Commission contracted four literature reviews to provide an evidence base to inform the Commissionâs review of the AHSSQA Scheme. The reviews explored the potential use of the following methods to improve the veracity of health service organisations: ⢠Attestation by a governing body ⢠Short-notice and unannounced surveys ⢠Patient journey and tracer methodologies ⢠Safety culture assessment. The report that follows this preface presents the findings of a literature review that explored the potential use of attestation by governing bodies during accreditation of health service organisations. Key findings The report on attestation by governing bodies includes a definition of attestation, a review of the evidence of the effectiveness of attestation by governing bodies as part of accreditation in healthcare, and examples of the use of attestation in practice
Continuous-time modelling of behavioural responses in animal movement
Funding: TM, RG, CH, and LT were funded by the US office of Naval Research, Grant N000141812807. This work was supported by the US Fleet Forces Command through the Naval Facilities Engineering Command Atlantic under Contract No. N62470-15-D-8006, Task Order 50, Issued to HDR, Inc.There is great interest in ecology to understand how wild animals are affected by anthropogenic disturbances, such as sounds. For example, behavioural response studies are an important approach to quantify the impact of naval activity on marine mammals. Controlled exposure experiments are undertaken where the behaviour of animals is quantified before, during, and after exposure to a controlled sound source, often using telemetry tags (e.g., accelerometers, or satellite trackers). Statistical modelling is required to formally compare patterns before and after exposure, to quantify deviations from baseline behaviour. We propose varying-coefficient stochastic differential equations (SDEs) as a flexible framework to model such data, with two components: (1) time-varying baseline dynamics, modelled with non-parametric or random effects of time-varying covariates, and (2) a nonparametric response model, which captures deviations from baseline. SDEs are specified in continuous time, which makes it straightforward to analyse data collected at irregular time intervals, a common situation for animal tracking studies. We describe how the model can be embedded into a state-space modelling framework to account for measurement error. We present inferential methods for model fitting, model checking, and uncertainty quantification (including on the response model). We apply this approach to two behavioural response study data sets on beaked whales: a satellite track, and high-resolution depth data. Our results suggest that the whalesâ horizontal movement and vertical diving behaviour changed after exposure to the sound source, and future work should evaluate the severity and possible consequences of these responses. These two very different examples showcase the versatility of varying-coefficient SDEs to measure changes in behaviour, and we discuss implications of disturbances for the whalesâ energetic balance.PostprintPeer reviewe
Patient Journey and Tracer Methodologies: Literature review
Preface This preface was written by the Australian Commission on Safety and Quality in Health Care (the Commission) to provide context and background to the report which follows, Patient Journey and Tracer Methodologies: Literature review. The Commission contracted the University of Technology Sydney (UTS) to prepare the literature review, as part of the review of the Australian Health Service Safety and Quality Accreditation (AHSSQA) Scheme. Background The Commissionâs role is to lead and coordinate national improvements in the safety and quality of health care. The Commission works in partnership with the Australian Government, state and territory governments and the private sector to achieve a safe and high-quality, sustainable health system. In doing so, the Commission also works closely with patients, carers, clinicians, managers, policymakers and healthcare organisations. The Commission developed the National Safety and Quality Health Service (NSQHS) Standards in consultation with the Australian Government, state and territory governments, technical experts and stakeholders. They aim to protect the public from harm and to improve the quality of health service provision. To become accredited, health service organisations must pass assessments to show they have implemented the NSQHS Standards. The assessments are conducted by independent accrediting agencies, approved by the Commission, as part of the AHSSQA Scheme. However, state and territory regulators and chief executives of health service organisations have raised concerns about several aspects of the accreditation process. The Commission is undertaking a review to update and improve the accreditation process. In May 2017, the Commission contracted four literature reviews to provide an evidence base to inform the Commissionâs review of the AHSSQA Scheme. The reviews explored the potential use of the following methods to improve the veracity of health service organisations: ⢠Attestation by a governing body ⢠Short-notice and unannounced surveys ⢠Patient journey and tracer methodologies ⢠Safety culture assessment. The report that follows this preface presents the findings of a literature review that explored the potential use of patient journey and tracer methodologies as part of health service organisation accreditation. Key findings The key findings of the report on patient journey and tracer methodologies (hereafter referred to as âpatient journey methodologiesâ) are discussed according to the evidence of its effectiveness and considerations for its use in the AHSSQA Scheme
Incorporating Animal Movement Into Distance Sampling
Distance sampling is a popular statistical method to estimate the density of wild animal populations. Conventional distance sampling represents animals as fixed points in space that are detected with an unknown probability that depends on the distance between the observer and the animal. Animal movement can cause substantial bias in density estimation. Methods to correct for responsive animal movement exist, but none account for nonresponsive movement independent of the observer. Here, an explicit animal movement model is incorporated into distance sampling, combining distance sampling survey data with animal telemetry data. Detection probability depends on the entire unobserved path the animal travels. The intractable integration over all possible animal paths is approximated by a hidden Markov model. A simulation study shows themethod to be negligibly biased (\u3c5%) in scenarioswhere conventional distance sampling overestimates abundance by up to 100%. The method is applied to line transect surveys (1999â 2006) of spotted dolphins (Stenella attenuata) in the eastern tropical Pacific where abundance is shown to be positively biased by 21% on average, which can have substantial impact on the population dynamics estimated from these abundance estimates and on the choice of statistical methodology applied to future surveys. Supplementary materials for this article, including a standardized description of the materials available for reproducing the work, are available as an online supplement
Dynamic ductile to brittle transition in a one-dimensional model of viscoplasticity
We study two closely related, nonlinear models of a viscoplastic solid. These
models capture essential features of plasticity over a wide range of strain
rates and applied stresses. They exhibit inelastic strain relaxation and steady
flow above a well defined yield stress. In this paper, we describe a first step
in exploring the implications of these models for theories of fracture and
related phenomena. We consider a one dimensional problem of decohesion from a
substrate of a membrane that obeys the viscoplastic constitutive equations that
we have constructed. We find that, quite generally, when the yield stress
becomes smaller than some threshold value, the energy required for steady
decohesion becomes a non-monotonic function of the decohesion speed. As a
consequence, steady state decohesion at certain speeds becomes unstable. We
believe that these results are relevant to understanding the ductile to brittle
transition as well as fracture stability.Comment: 10 pages, REVTeX, 12 postscript figure
Noncognitive skills in the classroom
This book provides an overview of recent research on the relationship between noncognitive attributes (motivation, self efficacy, resilience) and academic outcomes (such as grades or test scores). We focus primarily on how these sets of attributes are measured and how they relate to important academic outcomes. Noncognitive attributes are those academically and occupationally relevant skills and traits that are not âcognitiveââthat is, not specifically intellectual or analytical in nature. We examine seven attributes in depth and critique the measurement approaches used by researchers and talk about how they can be improved.Publishe
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