625 research outputs found

    Standardized cannabis in multiple sclerosis: a case report

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    A 52 year old female suffering from severe progressive multiple sclerosis was administered quantifiable amounts of standardized cannabis and monitored over the period of one year, while providing daily pain charts and records of her condition. An average daily intake of 500 mg of Tetrahydrocannabinol as cannabis was required to achieve a desired quality of life

    Epidemics in Networks of Spatially Correlated Three-dimensional Root Branching Structures

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    Using digitized images of the three-dimensional, branching structures for root systems of bean seedlings, together with analytical and numerical methods that map a common 'SIR' epidemiological model onto the bond percolation problem, we show how the spatially-correlated branching structures of plant roots affect transmission efficiencies, and hence the invasion criterion, for a soil-borne pathogen as it spreads through ensembles of morphologically complex hosts. We conclude that the inherent heterogeneities in transmissibilities arising from correlations in the degrees of overlap between neighbouring plants, render a population of root systems less susceptible to epidemic invasion than a corresponding homogeneous system. Several components of morphological complexity are analysed that contribute to disorder and heterogeneities in transmissibility of infection. Anisotropy in root shape is shown to increase resilience to epidemic invasion, while increasing the degree of branching enhances the spread of epidemics in the population of roots. Some extension of the methods for other epidemiological systems are discussed.Comment: 21 pages, 8 figure

    Real-World Evolution Adapts Robot Morphology and Control to Hardware Limitations

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    For robots to handle the numerous factors that can affect them in the real world, they must adapt to changes and unexpected events. Evolutionary robotics tries to solve some of these issues by automatically optimizing a robot for a specific environment. Most of the research in this field, however, uses simplified representations of the robotic system in software simulations. The large gap between performance in simulation and the real world makes it challenging to transfer the resulting robots to the real world. In this paper, we apply real world multi-objective evolutionary optimization to optimize both control and morphology of a four-legged mammal-inspired robot. We change the supply voltage of the system, reducing the available torque and speed of all joints, and study how this affects both the fitness, as well as the morphology and control of the solutions. In addition to demonstrating that this real-world evolutionary scheme for morphology and control is indeed feasible with relatively few evaluations, we show that evolution under the different hardware limitations results in comparable performance for low and moderate speeds, and that the search achieves this by adapting both the control and the morphology of the robot.Comment: Accepted to the 2018 Genetic and Evolutionary Computation Conference (GECCO

    Clinical Fellowships in Surgical Training: Analysis of a National Pan-specialty Workforce Survey

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    BACKGROUND: Fellowship posts are increasingly common and offer targeted opportunities for training and personal development. Despite international demand, there is little objective information quantifying this effect or the motivations behind undertaking such a post. The present study investigated surgical trainees’ fellowship aims and intentions. METHODS: An electronic, 38-item, self-administered questionnaire survey was distributed in the United Kingdom via national and regional surgical mailing lists and websites via the Association of Surgeons in Training, Royal Surgical Colleges, and Specialty Associations. RESULTS: In all, 1,581 fully completed surveys were received, and 1,365 were included in the analysis. These represented trainees in core or higher training programs or research from all specialties and training regions: 66 % were male; the mean age was 32 years; 77.6 % intended to or had already completed a fellowship. Plastic surgery (95.2 %) and cardiothoracic (88.6 %) trainees were most likely to undertake a fellowship, with pediatrics (51.2 %), and urology (54.3 %) the least likely. Fellowship uptake increased with seniority (p < 0.01) and was positively correlated (p = 0.016, r = 0.767) with increasing belief that fellowships are necessary to the attainment of clinical competence, agreed by 73.1 %. Fellowship aims were ranked in descending order of importance as attaining competence, increasing confidence, and attaining subspecialist skills. CONCLUSIONS: Over three-quarters of trainees have or will undertake a clinical fellowship, varying with gender, specialty, and seniority. Competence, confidence, and subspecialty skills development are the main aims. The findings will influence workforce planning, and perceptions that current training does not deliver sufficient levels of competence and confidence merit further investigation

    Standardized Screening for Mental Health Needs of Detained Youths from Various Ethnic Origins: The Dutch Massachusetts Youth Screening Instrument-Second Version (MAYSI-2)

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    In the U.S., the Massachusetts Youth Screening Instrument-Second Version (MAYSI-2) has been shown to be a reliable and valid tool to identify youth with mental health needs upon entry in detention facilities. The present study examined the factor structure, internal consistency, and convergent validity of the Dutch MAYSI-2 administered as part of routine clinical assessments in up to 955 detained male adolescents. Standardized mental health screening questionnaires (Youth Self-Report and Strengths and Difficulties Questionnaire) were used to test the convergent validity of the Dutch MAYSI-2. Confirmatory factor analyses showed that the factor structure of the original MAYSI-2 could be replicated with the Dutch MAYSI-2. Internal consistency indices showed that the Dutch MAYSI-2 provides a reliable screening of mental health needs. In addition, the Dutch MAYSI-2 scales were related with conceptually parallel measures of the same targeted mental health needs in the total group. With a few exceptions, the internal consistency and convergent validity was supported across ethnic groups as well. Overall, these results suggest the psychometric properties of the Dutch MAYSI-2 to be promising. Implications and limitations of the current study\u27s findings and directions for future research are discussed

    Extending Grammatical Evolution to Evolve Digital Surfaces with Genr8

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    High resolution radio observations of the colliding-wind binary WR140

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    Milli-arcsecond resolution Very Long Baseline Array (VLBA) observations of the archetype WR+O star colliding-wind binary (CWB) system WR140 are presented for 23 epochs between orbital phases 0.74 and 0.97. At 8.4 GHz, the emission in the wind-collision region (WCR) is clearly resolved as a bow-shaped arc that rotates as the orbit progresses. We interpret this rotation as due to the O star moving from SE to approximately E of the WR star, which leads to solutions for the orbit inclination of 122+/-5 deg, the longitude of the ascending node of 353+/-3 deg, and an orbit semi-major axis of 9.0+/-0.5 mas. The distance to WR140 is determined to be 1.85+/-0.16 kpc, which requires the O star to be a supergiant. The inclination implies the mass of the WR and O star to be 20+/-4 and 54+/-10 solar masses respectively. We determine a wind-momentum ratio of 0.22, with an expected half-opening angle for the WCR of 63 deg, consistent with 65+/-10 deg derived from the VLBA observations. Total flux measurements from Very Large Array (VLA) observations show the radio emission from WR140 is very closely the same from one orbit to the next, pointing strongly toward emission, absorption and cooling mechanism(s) that are controlled largely by the orbital motion. The synchrotron spectra evolve dramatically through the orbital phases observed, exhibiting both optically thin and optically thick emission. We discuss a number of absorption and cooling mechanisms that may determine the evolution of the synchrotron spectrum with orbital phase.Comment: Accepted by ApJ, to appear in v623, April 20, 2005. 14 pages, 13 figs, requires emulateapj.cls. A version with full resolution figs can be obtained from http://www.drao.nrc.ca/~smd/preprint/wr140_data.pd

    Brittle-Ductile Deformation and Tensile Rupture of Dome Lava During Inflation at Santiaguito, Guatemala

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    Gas‐and‐ash explosions at the Santiaguito dome complex, Guatemala, commonly occur through arcuate fractures, following a 5‐ to 6‐min period of inflation observed in long‐period seismic signals. Observation of active faults across the dome suggests a strong shear component, but as fault propagation generally proceeds through the coalescence of tensile fractures, we surmise that explosive eruptions require tensile rupture. Here, we assess the effects of temperature and strain rate on fracture propagation and the tensile strength of Santiaguito dome lavas. Indirect tensile tests were conducted on samples with a porosity range of 3–30% and over diametral displacement rates of 0.04, 0.004, and 0.0004 mm/s. At room temperature, the tensile strength of dome rock is rate independent (within the range tested) and inversely proportional to the porosity of the material. At eruptive temperatures we observe an increasingly ductile response at either higher temperature or lower displacement rate, where ductile deformation is manifest by a reduction in loading rate during constant deformation rate tests, resulting in slow tearing, viscous flow, and pervasive damage. We propose a method to conduct indirect tensile tests under volcanic conditions using a modification of the Brazilian disc testing protocol and use brittleness indices to classify deformation modes across the brittle‐ductile transition. We show that a degree of ductile damage is inevitable in the lava core during explosions at the Santiaguito dome complex and discuss how strain leading to rupture controls fracture geometry, which would impact gas pressure release or buildup and regulate explosive activity

    DIAMOND (DIgital Alcohol Management ON Demand): a mixed methods feasibility RCT and embedded process evaluation of a digital health intervention to reduce hazardous and harmful alcohol use

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    BACKGROUND: “Hazardous and harmful” drinkers make up approximately 23 % of the adult population in England. However, only around 10 % of these people access specialist care, such as face-to-face extended brief treatment in community alcohol services. This may be due to stigma, difficulty accessing services during working hours, a shortage of trained counsellors and limited provision of services in many places. Web-based alcohol treatment programmes may overcome these barriers and may better suit people who are reluctant or unable to attend face-to-face services, but there is a gap in the evidence base for the acceptability, effectiveness and cost-effectiveness of these programmes compared with treatment as usual (TAU) in community alcohol services. This study aims investigate the feasibility of all parts of a randomised controlled trial (RCT) of a psychologically informed web-based alcohol treatment programme called Healthy Living for People who use Alcohol (HeLP-Alcohol) versus TAU in community alcohol services, e.g. recruitment and retention, online data collection methods, and the use and acceptability of the intervention to participants. METHODS: A feasibility RCT delivered in north London community alcohol services, comparing HeLP-Alcohol with TAU. Potential participants are aged ≄18 years referred or self-referred for hazardous and harmful use of alcohol, without co-morbidities or other complex problems. The main purpose of this study is to demonstrate the feasibility of recruiting participants to the study and will test online methods for collecting baseline demographic and outcome questionnaire data, randomising participants and collecting 3-month follow-up data. The acceptability of this intervention will be measured by recruitment and retention rates, automated log-in data collection and an online service satisfaction questionnaire. The feasibility of using tailored text message, email or phone prompt to maintain engagement with the intervention will also be explored. RESULTS: Results of the study will inform a definitive Phase 3 RCT
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