9 research outputs found
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The influence of the atmospheric boundary layer on nocturnal layers of noctuids and other moths migrating over southern Britain
Insects migrating at high altitude over southern Britain have been continuously monitored by automatically-operating, vertical-looking radars over a period of several years. During some occasions in the summer months, the migrants were observed to form well-defined layer concentrations, typically at heights of 200-400 m, in the stable night-time atmosphere. Under these conditions, insects are likely to have control over their vertical movements and are selecting flight heights which are favourable for long-range migration. We therefore investigated the factors influencing the formation of these insect layers by comparing radar measurements of the vertical distribution of insect density with meteorological profiles generated by the UK Met. Office’s Unified Model (UM). Radar-derived measurements of mass and displacement speed, along with data from Rothamsted Insect Survey light traps provided information on the identity of the migrants. We present here three case studies where noctuid and pyralid moths contributed substantially to the observed layers. The major meteorological factors influencing the layer concentrations appeared to be: (a) the altitude of the warmest air, (b) heights corresponding to temperature preferences or thresholds for sustained migration and (c), on nights when air temperatures are relatively high, wind-speed maxima associated with the nocturnal jet. Back-trajectories indicated that layer duration may have been determined by the distance to the coast. Overall, the unique combination of meteorological data from the UM and insect data from entomological radar described here show considerable promise for systematic studies of high-altitude insect layering
Role of students' context in predicting academic performance at a medical school: a retrospective cohort study
OBJECTIVES: This study examines associations between medical students’ background characteristics (postcode-based measures of disadvantage, high school attended, sociodemographic characteristics), and academic achievement at a Russell Group University. DESIGN: Retrospective cohort analysis. SETTING: Applicants accepted at the University of Liverpool medical school between 2004 and 2006, finalising their studies between 2010 and 2011. PARTICIPANTS: 571 students (with an English home postcode) registered on the full-time Medicine and Surgery programme, who successfully completed their medical degree. MAIN OUTCOME MEASURES: Final average at year 4 of the medical programme (represented as a percentage). RESULTS: Entry grades were positively associated with final attainment (p<0.001). Students from high-performing schools entered university with higher qualifications than students from low-performing schools (p<0.001), though these differences did not persist at university. Comprehensive school students entered university with higher grades than independent school students (p<0.01), and attained higher averages at university, though differences were not significant after controlling for multiple effects. Associations between school type and achievement differed between sexes. Females attained higher averages than males at university. Significant academic differences were observed between ethnic groups at entry level and university. Neither of the postcode-based measures of disadvantage predicted significant differences in attainment at school or university. CONCLUSIONS: The findings of this study suggest that educational attainment at school is a good, albeit imperfect, predictor of academic attainment at medical school. Most attainment differences observed between students either decreased or disappeared during university. Unlike previous studies, independent school students did not enter university with the highest grades, but achieved the lowest attainment at university. Such variations depict how patterns may differ between subjects and higher-education institutions. Findings advocate for further evidence to help guide the implementation of changes in admissions processes and widen participation at medical schools fairly
Materials for Transparent Electrodes: From Metal Oxides to Organic Alternatives
Nowadays, opto-electronic devices, such as displays, are omnipresent in our daily life. A crucial component of these devices is a transparent electrode, which allows the in- and out-coupling of light. With the goal of optimizing the electrode characteristics and improving device efficiencies, many approaches for the fabrication of thin, transparent conducting films have been studied. This review gives an overview of the different material classes which have been used as transparent electrodes, ranging from metal oxides, such as Indium Tin Oxide, metal and carbonaceous nanostructures, to conducting polymers and composites. For every material class a brief description of the fundamental principles, processing routes and the latest achievements is given. Furthermore, the different electrodes are compared regarding their opto-electronic performance, flexibility and surface roughness. Ultimately, advantages and drawbacks of the respective electrodes are discussed. This critical comparison of fundamentally different transparent conducting materials allows, on one hand, to make a sensible choice of electrode for specific applications, and, on the other hand, to point out scientific challenges that must still be addressed