Model predictions of wind and turbulence profiles associated with an ensemble of aircraft accidents

The feasibility of predicting conditions under which wind/turbulence environments hazardous to aviation operations exist is studied by examining a number of different accidents in detail. A model of turbulent flow in the atmospheric boundary layer is used to reconstruct wind and turbulence profiles which may have existed at low altitudes at the time of the accidents. The predictions are consistent with available flight recorder data, but neither the input boundary conditions nor the flight recorder observations are sufficiently precise for these studies to be interpreted as verification tests of the model predictions

Observed tidal braking in the earth/moon/sun system

The low degree and order terms in the spherical harmonic model of the tidal potential were observed through the perturbations which are induced on near-earth satellite orbital motions. Evaluations of tracking observations from 17 satellites and a GEM-T1 geopotential model were used in the tidal recovery which was made in the presence of over 600 long-wavelength coefficients from 32 major and minor tides. Wahr's earth tidal model was used as a basis for the recovery of the ocean tidal terms. Using this tidal model, the secular change in the moon's mean motion due to tidal dissipation was found to be -25.27 + or - 0.61 arcsec/century squared. The estimation of lunar acceleration agreed with that observed from lunar laser ranging techniques (-24.9 + or - 1.0 arcsec/century squared), with the corresponding tidal braking of earth's rotation being -5.98 + or - 0.22 x 10 to the minus 22 rad/second squared. If the nontidal braking of the earth due to the observed secular change in the earth's second zonal harmonic is considered, satellite techniques yield a total value of the secular change of the earth's rotation rate of -4.69 + or - 0.36 x 10 to the minus 22 rad/second squared

Time dependent spectral modeling of Markarian 421 during a violent outburst in 2010

We present the results of extensive modeling of the spectral energy distributions (SEDs) of the closest blazar (z=0.031) Markarian 421 (Mrk 421) during a giant outburst in February 2010. The source underwent rapid flux variations in both X-rays and very high energy (VHE) gamma-rays as it evolved from a low-flux state on 2010 February 13-15 to a high-flux state on 2010 February 17. During this period, the source exhibited significant spectral hardening from X-rays to VHE gamma-rays while exhibiting a "harder when brighter" behavior in these energy bands. We reproduce the broadband SED using a time-dependent multi-zone leptonic jet model with radiation feedback. We find that an injection of the leptonic particle population with a single power-law energy distribution at shock fronts followed by energy losses in an inhomogeneous emission region is suitable for explaining the evolution of Mrk 421 from low- to high-flux state in February 2010. The spectral states are successfully reproduced by a combination of a few key physical parameters, such as the maximum $\&$ minimum cutoffs and power-law slope of the electron injection energies, magnetic field strength, and bulk Lorentz factor of the emission region. The simulated light curves and spectral evolution of Mrk 421 during this period imply an almost linear correlation between X-ray flux at 1-10 keV energies and VHE gamma-ray flux above 200 GeV, as has been previously exhibited by this source. Through this study, a general trend that has emerged for the role of physical parameters is that, as the flare evolves from a low- to a high-flux state, higher bulk kinetic energy is injected into the system with a harder particle population and a lower magnetic field strength.Comment: 13 pages, 5 figures, accepted for publication in MNRA

Operational application of a universal turbulence measuring system Final report

Aeronautical turbulence measuring apparatus - gust loadin

Does a monetary incentive improve the response to a postal questionnaire in a randomised controlled trial? : the MINT incentive study

Background: Sending a monetary incentive with postal questionnaires has been found to improve the proportion of responders, in research in non-healthcare settings. However, there is little research on use of incentives to improve follow-up rates in clinical trials, and existing studies are inconclusive. We conducted a randomised trial among participants in the Managing Injuries of the Neck Trial (MINT) to investigate the effects on the proportion of questionnaires returned and overall non-response of sending a £5 gift voucher with a follow-up questionnaire. Methods: Participants in MINT were randomised to receive either: (a) a £5 gift voucher (incentive group) or (b) no gift voucher (no incentive group), with their 4 month or 8 month follow-up questionnaire. We recorded, for each group, the number of questionnaires returned, the number returned without any chasing from the study office, the overall number of non-responders (after all chasing efforts by the study office), and the costs of following up each group. Results: 2144 participants were randomised, 1070 to the incentive group and 1074 to the no incentive group. The proportion of questionnaires returned (RR 1.10 (95% CI 1.05, 1.16)) and the proportion returned without chasing (RR 1.14 (95% CI 1.05, 1.24) were higher in the incentive group, and the overall non-response rate was lower (RR 0.68 (95% CI 0.53, 0.87)). Adjustment for injury severity and hospital of recruitment to MINT made no difference to these results, and there were no differences in results between the 4-month and 8-month follow up questionnaires. Analysis of costs suggested a cost of £67.29 per additional questionnaire returned. Conclusion: Monetary incentives may be an effective way to increase the proportion of postal questionnaires returned and minimise loss to follow-up in clinical trials

A systematic review of interventions by healthcare professionals to improve management of non-communicable diseases and communicable diseases requiring long-term care in adults who are homeless

Objective: Identify, describe and appraise trials of interventions delivered by healthcare professionals to manage non-communicable diseases (NCDs) and communicable diseases that require long-term care or treatment (LT-CDs), excluding mental health and substance use disorders, in homeless adults. Design: Systematic review of randomised controlled trials (RCTs), non-RCTs and controlled before–after studies. Interventions characterised using Effective Practice and Organisation of Care (EPOC) taxonomy. Quality assessed using EPOC risk of bias criteria. Data sources: Database searches (MEDLINE, Embase, PsycINFO, Scopus, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Applied Social Sciences Index and Abstracts (ASSIA) and Cochrane Central Register of Controlled Trials), hand searching reference lists, citation searches, grey literature and contact with study authors. Setting: Community. Participants: Adults (≥18 years) fulfilling European Typology of Homelessness criteria. Intervention: Delivered by healthcare professionals managing NCD and LT-CDs. Outcomes: Primary outcome: unscheduled healthcare utilisation. Secondary outcomes: mortality, biological markers of disease control, adherence to treatment, engagement in care, patient satisfaction, knowledge, self-efficacy, quality of life and cost-effectiveness. Results: 11 studies were included (8 RCTs, 2 quasi-experimental and 1 feasibility) involving 9–520 participants (67%–94% male, median age 37–49 years). Ten from USA and one from UK. Studies included various NCDs (n=3); or focused on latent tuberculosis (n=4); HIV (n=2); hepatitis C (n=1) or type 2 diabetes (n=1). All interventions were complex with multiple components. Four described theories underpinning intervention. Three assessed unscheduled healthcare utilisation: none showed consistent reduction in hospitalisation or emergency department attendance. Six assessed adherence to specific treatments, of which four showed improved adherence to latent tuberculosis therapy. Three concerned education case management, all of which improved disease-specific knowledge. No improvements in biological markers of disease (two studies) and none assessed mortality. Conclusions: Evidence for management of NCD and LT-CDs in homeless adults is sparse. Educational case-management interventions may improve knowledge and medication adherence. Large trials of theory-based interventions are needed, assessing healthcare utilisation and outcomes as well as assessment of biological outcomes and cost-effectiveness

Improved methods for detecting gravitational waves associated with short gamma-ray bursts

In the era of second generation ground-based gravitational wave detectors, short gamma-ray bursts (GRBs) will be among the most promising astrophysical events for joint electromagnetic and gravitational wave observation. A targeted search for gravitational wave compact binary merger signals in coincidence with short GRBs was developed and used to analyze data from the first generation LIGO and Virgo instruments. In this paper, we present improvements to this search that enhance our ability to detect gravitational wave counterparts to short GRBs. Specifically, we introduce an improved method for estimating the gravitational wave background to obtain the event significance required to make detections; implement a method of tiling extended sky regions, as required when searching for signals associated to poorly localized GRBs from Fermi Gamma-ray Burst Monitor or the InterPlanetary Network; and incorporate astrophysical knowledge about the beaming of GRB emission to restrict the search parameter space. We describe the implementation of these enhancements and demonstrate how they improve the ability to observe binary merger gravitational wave signals associated with short GRBs.Comment: 13 pages, 6 figure

Interventions by healthcare professionals to improve management of physical long-term conditions in adults who are homeless: a systematic review protocol

Introduction People experiencing homelessness are at increased risk of, and have poorer outcomes from, a range of physical long-term conditions (LTCs). It is increasingly recognised that interventions targeting people who are homeless should be tailored to the specific needs of this population. This systematic review aims to identify, describe and appraise trials of interventions that aim to manage physical LTCs in homeless adults and are delivered by healthcare professionals. Methods and analysis Seven electronic databases (Medline, EMBASE, Cochrane Central Register of Controlled Trials, Assia, Scopus, PsycINFO and CINAHL) will be searched from 1960 (or inception) to October 2016 and supplemented by forward citation searching, handsearching of reference lists and searching grey literature. Two reviewers will independently review titles, abstract and full-texts using DistillerSR software. Inclusion criteria include (1) homeless adults with any physical LTC, (2) interventions delivered by a healthcare professional (any professional trained to provide any form of healthcare, but excluding social workers and professionals without health-related training), (3) comparison with usual care or an alternative intervention, (4) report outcomes such as healthcare usage, physical and psychological health or well-being or cost-effectiveness, (5) randomised controlled trials, non-randomised controlled trials, controlled before-after studies. Quality will be assessed using the Cochrane EPOC Risk of Bias Tool. A meta-analysis will be performed if sufficient data are identified; however, we anticipate a narrative synthesis will be performed. Ethics and dissemination This review will synthesise existing evidence for interventions delivered by healthcare professionals to manage physical LTCs in adults who are homeless. The findings will inform the development of future interventions and research aiming to improve the management of LTCs for people experiencing homelessness. Ethical approval will not be required for this systematic review as it does not contain individual patient data. We will disseminate the results of this systematic review via conference presentations, healthcare professional networks, social media and peer-reviewed publication

High titers of transmissible spongiform encephalopathy infectivity associated with extremely low levels of PrP in vivo

Rona Barron - ORCID: 0000-0003-4512-9177 https://orcid.org/0000-0003-4512-9177Diagnosis of transmissible spongiform encephalopathy (TSE) disease in humans and ruminants relies on the detection in post-mortem brain tissue of the protease-resistant form of the host glycoprotein PrP. The presence of this abnormal isoform (PrPSc) in tissues is taken as indicative of the presence of TSE infectivity. Here we demonstrate conclusively that high titers of TSE infectivity can be present in brain tissue of animals that show clinical and vacuolar signs of TSE disease but contain low or undetectable levels of PrPSc. This work questions the correlation between PrPSc level and the titer of infectivity and shows that tissues containing little or no proteinase K-resistant PrP can be infectious and harbor high titers of TSE infectivity. Reliance on protease-resistant PrPSc as a sole measure of infectivity may therefore in some instances significantly underestimate biological properties of diagnostic samples, thereby undermining efforts to contain and eradicate TSEs.https://doi.org/10.1074/jbc.M704329200282pubpub4