1,086 research outputs found

    Directing the mechanism of CO2 reduction by a Mn catalyst through surface immobilization

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    Immobilization of a Mn polypyridyl CO2 reduction electrocatalyst on nanocrystalline TiO2 electrodes yields an active heterogeneous system and also significantly triggers a change in voltammetric and catalytic behaviour, relative to in solution. A combination of spectroelectrochemical techniques are presented here to elucidate the mechanism of the immobilised catalyst in-situ

    Impurity‐induced layer disordering of In0.53Ga0.47As/In0.52Al0.48As heterostructures

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    Impurity‐induced layer disordering of In0.53 Ga0.47 As/In0.52 Al0.48 As heterostructures grown by molecular beam epitaxy has been observed by Auger electron spectroscopy depth profiling. We find that Si+ ion implantation to concentrations greater than 2×1019 atoms cm−3 enhances the intermixing of Ga and Al in these heterostructures at an annealing temperature of 1075 K. However, the relatively high temperature which is required to activate the interdiffusion of Ga and Al in the region of high Si concentration is sufficient to induce In diffusion in regions of lower Si concentration. Zinc diffusion is found to completely intermix the Ga and Al in the heterolayers at temperatures as low as 825 K, which is below the temperature at which significant In diffusion occurs in undoped regions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70858/2/APPLAB-53-23-2302-1.pd

    Train Crew Reduction for Increased Productivity of Rail Transit

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    With the increases in wages since the 1950s, labor costs have become the domin­ant portion of operating costs for transit agencies. Efforts to increase produc­tivity of operating labor have been particularly successful on rail transit systems. For example, development of high-capacity articulated cars, provision of separated rights-of-way and introduction of self-service fare collection have resulted in an approximately 20-fold increase in productivity of light rail transit systems. The report shows that while the modern rail transit systems (e.g. Lindenwold Line, San Francisco BART, Atlanta\u27s MARTA) have one-person train crews and thus very high productivity, most older streetcar, rapid transit and regional rail systems still have obsolete, inefficient labor practices. A systematic analysis of alternative ways of performing different duties shows that on many existing transit systems productivity of operating labor can be substantially increased through rather modest efforts. This has been illustrated in two actual cases. The greatest potential benefits from introduction of modern operating methods exist on regional rail systems. Existing rapid transit is another mode on which labor productivity can be substantially increased. Cooperation of labor unions should be obtained by retaining jobs through increased service frequency, or by passing on a portion of the savings to the operating employees in form of increased wages for increased duties

    Self-monitoring blood pressure in patients with hypertension: an internet-based survey of UK GPs.

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    BACKGROUND: Previous research suggests that most GPs in the UK use self-monitoring of blood pressure (SMBP) to monitor the control of hypertension rather than for diagnosis. This study sought to assess current practice in the use of self-monitoring and any changes in practice following more recent guideline recommendations. AIM: To survey the views and practice of UK GPs in 2015 with regard to SMBP and compare them with a previous survey carried out in 2011. DESIGN AND SETTING: Web-based survey of a regionally representative sample of 300 UK GPs. METHOD: GPs completed an online questionnaire concerning the use of SMBP in the management of hypertension. Analyses comprised descriptive statistics, tests for between-group differences (z, Wilcoxon signed-rank, and χ2 tests), and multivariate logistic regression. RESULTS: Results were available for 300 GPs (94% of those who started the survey). GPs reported using self-monitoring to diagnose hypertension (169/291; 58%; 95% confidence interval (CI) = 52 to 64) and to monitor control (245/291; 84%; 95% CI = 80 to 88), the former having significantly increased since 2011 (from 37%; 95% CI = 33 to 41; P<0.001) with no change in monitoring for control. More than half of GPs used higher systolic thresholds for diagnosis (118/169; 70%; 95% CI = 63 to 77) and treatment (168/225; 75%; 95% CI = 69 to 80) than recommended in guidelines, and under half (120/289; 42%; 95% CI = 36 to 47) adjusted the SMBP results to guide treatment decisions. CONCLUSION: Since new UK national guidance in 2011, GPs are more likely to use SMBP to diagnose hypertension. However, significant proportions of GPs continue to use non-standard diagnostic and monitoring thresholds. The use of out-of-office methods to improve the accuracy of diagnosis is unlikely to be beneficial if suboptimal thresholds are used.This study was funded by the British Hypertension Society and the NIHR. Ben Fletcher receives funding from the National Institute for Health Research (NIHR) School for Primary Care Research (SPCR) Doctoral Studentship. Richard McManus holds an NIHR Professorship (RP-02-12-015)) and receives funding from the NIHR Oxford CLAHRC. This article presents independent research funded by the NIHR. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health.This is the author accepted manuscript. The final version is available from Royal College of General Practitioners via https://doi.org/10.3399/bjgp16X68703

    GABAergic Projection Neurons Route Selective Olfactory Inputs to Specific Higher-Order Neurons

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    SummaryWe characterize an inhibitory circuit motif in the Drosophila olfactory system, parallel inhibition, which differs from feedforward or feedback inhibition. Excitatory and GABAergic inhibitory projection neurons (ePNs and iPNs) each receive input from antennal lobe glomeruli and send parallel output to the lateral horn, a higher center implicated in regulating innate olfactory behavior. Ca2+ imaging of specific lateral horn neurons as an olfactory readout revealed that iPNs selectively suppressed food-related odor responses, but spared signal transmission from pheromone channels. Coapplying food odorant did not affect pheromone signal transmission, suggesting that the differential effects likely result from connection specificity of iPNs, rather than a generalized inhibitory tone. Ca2+ responses in the ePN axon terminals show no detectable suppression by iPNs, arguing against presynaptic inhibition as a primary mechanism. The parallel inhibition motif may provide specificity in inhibition to funnel specific olfactory information, such as food and pheromone, into distinct downstream circuits

    (Invited) Vacuum Ultraviolet Photochemical Atomic Layer Deposition of Alumina and Titania Films

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    Conventional atomic layer deposition (ALD) is a thermo-chemical process where co-reagents are sequentially pulsed in cycles onto a heated substrate. As an alternative to substrate heating, various forms of other “non-thermal” ALD processes are being investigated. Herein, the photochemical atomic layer deposition of Al2O3 and TiO2 thin films at 60°C is reported using a shuttered vacuum ultraviolet light source to excite molecular oxygen as a co-reagent with the metal precursors. The growth mechanisms using trimethyl aluminium and titanium tetraisopropoxide precursors, are investigated using in-situ quartz crystal microbalance and post-deposition ellipsometric measurements. The photochemical ALD Al2O3 films exhibit different capacitance equivalent thicknesses for irradiated and masked regions respectively, even after post-deposition annealing. The photochemical ALD titania films are amorphous and when incorporated into Pt / TiO2 / Pt metal - insulator - metal structures, the titania exhibits a resistive switching behavior.</jats:p

    Limited introgression between rock-wallabies with extensive chromosomal rearrangements

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    Chromosome rearrangements can result in the rapid evolution of hybrid incompatibilities. Robertsonian fusions, particularly those with monobrachial homology, can drive reproductive isolation amongst recently diverged taxa. The recent radiation of rock-wallabies (genus Petrogale) is an important model to explore the role of Robertsonian fusions in speciation. Here, we pursue that goal using an extensive sampling of populations and genomes of Petrogale from north-eastern Australia. In contrast to previous assessments using mitochondrial DNA or nuclear microsatellite loci, genomic data are able to separate the most closely related species and to resolve their divergence histories. Both phylogenetic and population genetic analyses indicate introgression between two species that differ by a single Robertsonian fusion. Based on the available data, there is also evidence for introgression between two species which share complex chromosomal rearrangements. However, the remaining results show no consistent signature of introgression amongst species pairs and where evident, indicate generally low introgression overall. X-linked loci have elevated divergence compared with autosomal loci indicating a potential role for genic evolution to produce reproductive isolation in concert with chromosome change. Our results highlight the value of genome scale data in evaluating the role of Robertsonian fusions and structural variation in divergence, speciation, and patterns of molecular evolution

    The influence of impact-based severe weather warnings on risk perceptions and intended protective actions

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    This paper presents the results of an online survey of the New Zealand public (n = 1364), conducted in 2015, that tested the influence of impact-based severe weather warnings on risk perceptions and intended protective actions. We used a hypothetical severe weather event involving strong winds, with 50% of participants receiving an impact-based warning, and 50% receiving a more traditional phenomenon-based warning (which in this case is when the wind speed is expected to be higher than a given number). Our results indicate that impact-based warnings may be more effective than phenomenon-based warnings in influencing the recipient's perception of the hazardous event (their sense of threat, concern, and understanding of the potential impacts), but this does not translate to a higher level of action. Characteristics of gender, age, and location of residence were also influences on risk perceptions and intended actions. However, experience with having been affected by strong winds in the past was not a strong influence on intending to respond. Our findings support the inclusion of information about hazards, impacts, and ‘what to do’ information in a warning message
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