113 research outputs found

    Paper Session III-B - Wavelength- Division Multiplex of Bipolar Digital Signals for Digital Fiber Optic Transmission

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    Deterioration of the Kennedy Space Center Launch Processing System copper data bus cables over time, combined with the unavailability of replacement cabling and the transmission distances of 10 kilometers, resulted in the decision to replace the copper cable system with a fiber optic version. The replacement system is referred to as the Digital Fiber Optic Transmission Equipment. The distinguishing aspect of the digital Fiber Optic Transmission Equipment is the use of Wavelength Division Multiplexing fiber optic technology. This design allows the transmission of digital bipolar data on a single fiber optic cable. This paper describes the system requirements and design characteristics of Digital Fiber Optic Transmission Equipment using Wavelength Division Multiplexing technology for the transmission of digital bipolar data on a single fiber optic cable

    Organisational interventions designed to reduce caesarean section rates: a systematic review protocol.

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    INTRODUCTION: There is a growing body of evidence to indicate that both primary and subsequent caesarean sections are associated with increased maternal and perinatal morbidity. Efforts to reduce the number of clinically unnecessary caesarean sections are urgently required. Our objective is to systematically review published evidence on the effectiveness of maternity service organisational interventions, such as models of maternity care, that aim to reduce caesarean section rates. METHODS AND ANALYSIS: Databases will be searched, including the Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, MEDLINE, Maternity and Infant Care, EMBASE and SCOPUS. Search terms related to caesarean section and organisational intervention will be used. Research published before 1980 will be excluded and only randomised controlled trials, cluster-randomised controlled trials, quasi-randomised controlled trials, controlled before and after studies and interrupted time series studies will be included. Data extraction and quality assessments will be undertaken by two authors. ETHICS AND DISSEMINATION: Ethics approval is not required for this systematic review. The results of this study will be disseminated via peer-reviewed publication and presentation at professional conferences. PROSPERO REGISTRATION NUMBER: CRD42016039458

    Maternity service organisational interventions that aim to reduce caesarean section: a systematic review and meta-analyses

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    Background Caesarean sections (CSs) are associated with increased maternal and perinatal morbidity, yet rates continue to increase within most countries. Effective interventions are required to reduce the number of non-medically indicated CSs and improve outcomes for women and infants. This paper reports findings of a systematic review of literature related to maternity service organisational interventions that have a primary intention of improving CS rates. Method A three-phase search strategy was implemented to identify studies utilising organisational interventions to improve CS rates in maternity services. The database search (including Cochrane CENTRAL, CINAHL, MEDLINE, Maternity and Infant Care, EMBASE and SCOPUS) was restricted to peer-reviewed journal articles published from 1 January 1980 to 31 December 2017. Reference lists of relevant reviews and included studies were also searched. Primary outcomes were overall, planned, and unplanned CS rates. Secondary outcomes included a suite of birth outcomes. A series of meta-analyses were performed in RevMan, separated by type of organisational intervention and outcome of interest. Summary risk ratios with 95% confidence intervals were presented as the effect measure. Effect sizes were pooled using a random-effects model. Results Fifteen articles were included in the systematic review, nine of which were included in at least one meta-analysis. Results indicated that, compared with women allocated to usual care, women allocated to midwife-led models of care implemented across pregnancy, labour and birth, and the postnatal period were, on average, less likely to experience CS (overall) (average RR 0.83, 95% CI 0.73 to 0.96), planned CS (average RR 0.75, 95% CI 0.61 to 0.93), and episiotomy (average RR 0.84, 95% CI 0.74 to 0.95). Narratively, audit and feedback, and a hospital policy of mandatory second opinion for CS, were identified as interventions that have potential to reduce CS rates. Conclusion Maternity service leaders should consider the adoption of midwife-led models of care across the maternity episode within their organisations, particularly for women classified as low-risk. Additional studies are required that utilise either audit and feedback, or a hospital policy of mandatory second opinion for CS, to facilitate the quantification of intervention effects within future reviews

    Urban energy exchanges monitoring from space

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    One important challenge facing the urbanization and global environmental change community is to understand the relation between urban form, energy use and carbon emissions. Missing from the current literature are scientific assessments that evaluate the impacts of different urban spatial units on energy fluxes; yet, this type of analysis is needed by urban planners, who recognize that local scale zoning affects energy consumption and local climate. However, satellite-based estimation of urban energy fluxes at neighbourhood scale is still a challenge. Here we show the potential of the current satellite missions to retrieve urban energy budget, supported by meteorological observations and evaluated by direct flux measurements. We found an agreement within 5% between satellite and in-situ derived net all-wave radiation; and identified that wall facet fraction and urban materials type are the most important parameters for estimating heat storage of the urban canopy. The satellite approaches were found to underestimate measured turbulent heat fluxes, with sensible heat flux being most sensitive to surface temperature variation (-64.1, +69.3 W m-2 for ±2 K perturbation); and also underestimate anthropogenic heat flux. However, reasonable spatial patterns are obtained for the latter allowing hot-spots to be identified, therefore supporting both urban planning and urban climate modelling

    Household Food Security Data Consensus Statement

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    Food insecurity in Australia is increasing, but a lack of consistent, regular monitoring and reporting of food insecurity using comprehensive, validated tools is limiting timely intervention. Regular monitoring is urgently needed from state/ territory and federal governments. Reporting of the prevalence of household food security needs to reflect levels of severity (marginal, moderate and severe food insecurity) in each state and territory across Australia. Commonly used short tools comprising one or two questions are inadequate for assessing the true prevalence of food insecurity and result in serious underestimation. The United States Department of Agriculture (USDA) 18-item Household Food Security Survey Module (HFSSM) should be adopted across settings to provide the most valid, internationally comparable data on food insecurity for both adults and children

    Variability of urban surface temperatures and implications for aerodynamic energy exchange in unstable conditions

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    Sensible heat flux (QH) is a critical driver of surface and boundary layer meteorological processes, especially in urban areas. Aerodynamic resistance methods (ARM) to model QH are promising because, in principle, all that is needed is surface temperature (T0), air temperature (TA) and an aerodynamic resistance term (rH). There are significant challenges in urban areas however, due to uncertainties in satellite-derived land surface temperatures (LST), logistical challenges to obtain high-resolution air temperatures, and limited understanding of spatial and temporal variability of rH and associated variables (e.g. thermal roughness length). This work uses an extensive LST dataset covering six years (2011-2016) in central London and a long-term in situ observation network to analyse variability of LST and rH variables. Results show that LST is spatially correlated with building and vegetation land cover with coherent thermal structures at length scales less than 500-1000 m. Additionally, satellite-observed LST varies with average building height (up to 10% cooler in areas with tall buildings). The rH term and associated variables are observed to vary on daily and seasonal cycles and findings are used to model QH using five variations of an ARM-based approach on a 100 m pixel basis. Modelled QH is compared to observations from three scintillometer paths and an eddy covariance flux tower. We find generally good agreement between observations and models, though there is uncertainty in all methods (mean absolute error ranges from 58.1-129.3 W m-2) due to challenges in determining high-resolution meteorological and surface inputs, particularly LST and friction velocity (u*). Additional complexity in evaluating modelled QH arises from anthropogenic heat sources: long-term tower-based observations show that TA and radiometer-derived T0 are warmer during working weekdays than non-working days (up to 0.7C) and that there is an observed lag (2-3 hours) between energy consumption and observed warming and QH
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