3,356 research outputs found

    Smoking as an early risk factor for problematic parenting practices

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    Parenting among those who use non-illicit and more common drugs such as cigarettes remains an understudied area for investigation. Secondary data analyses were performed in 2015 on a prospective study with parent and twin data available on n=3,009 individual members of female twin pairs born between July 1975 and June 1985 identified from Missouri-state birth records. Maternal smoking when the twins were 3+ years of age remained a significant predictor of offspring report of childhood sexual abuse (OR, 1.40; 95% CI, 1.02-1.92) after controlling for key covariates. Given limited public health resources, mothers who smoke during child's preschool years may be targeted for tailored parenting intervention

    Quantifying methane and nitrous oxide emissions from the UK and Ireland using a national-scale monitoring network

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    The UK is one of several countries around the world that has enacted legislation to reduce its greenhouse gas emissions. In this study, we present top-down emissions of methane (CH4) and nitrous oxide (N2O) for the UK and Ireland over the period August 2012 to August 2014. These emissions were inferred using measurements from a network of four sites around the two countries. We used a hierarchical Bayesian inverse framework to infer fluxes as well as a set of covariance parameters that describe uncertainties in the system. We inferred average UK total emissions of 2.09 (1.65–2.67) Tg yr−1 CH4 and 0.101 (0.068–0.150) Tg yr−1 N2O and found our derived UK estimates to be generally lower than the a priori emissions, which consisted primarily of anthropogenic sources and with a smaller contribution from natural sources. We used sectoral distributions from the UK National Atmospheric Emissions Inventory (NAEI) to determine whether these discrepancies can be attributed to specific source sectors. Because of the distinct distributions of the two dominant CH4 emissions sectors in the UK, agriculture and waste, we found that the inventory may be overestimated in agricultural CH4 emissions. We found that annual mean N2O emissions were consistent with both the prior and the anthropogenic inventory but we derived a significant seasonal cycle in emissions. This seasonality is likely due to seasonality in fertilizer application and in environmental drivers such as temperature and rainfall, which are not reflected in the annual resolution inventory. Through the hierarchical Bayesian inverse framework, we quantified uncertainty covariance parameters and emphasized their importance for high-resolution emissions estimation. We inferred average model errors of approximately 20 and 0.4 ppb and correlation timescales of 1.0 (0.72–1.43) and 2.6 (1.9–20 3.9) days for CH4 and N2O, respectively. These errors are a combination of transport model errors as well as errors due to unresolved emissions processes in the inventory. We found the largest CH4 errors at the Tacolneston station in eastern England, which may be due to sporadic emissions from landfills and offshore gas in the North Sea

    Familial influences on the full range of variability in attention and activity levels during adolescence: A longitudinal twin study

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    AbstractTo investigate familial influences on the full range of variability in attention and activity across adolescence, we collected maternal ratings of 339 twin pairs at ages 12, 14, and 16, and estimated the transmitted and new familial influences on attention and activity as measured by the Strengths and Weaknesses of Attention-Deficit/Hyperactivity Disorder Symptoms and Normal Behavior Scale. Familial influences were substantial for both traits across adolescence: genetic influences accounted for 54%–73% (attention) and 31%–73% (activity) of the total variance, and shared environmental influences accounted for 0%–22% of the attention variance and 13%–57% of the activity variance. The longitudinal stability of individual differences in attention and activity was largely accounted for by familial influences transmitted from previous ages. Innovations over adolescence were also partially attributable to familial influences. Studying the full range of variability in attention and activity may facilitate our understanding of attention-deficit/hyperactivity disorder's etiology and intervention.</jats:p

    The effect of heat transfer on boundary layer stability

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    During transient running of an axial flow compressor, considerable temperature differences arc set up between the met surfaces and the adjacent airstream. It was suggested that these temperature differences might have an adverse effect upon the aerodynamic performance of the compressor, and increase the likelihood of stall. Roils-Royce Ltd. expressed interest in this hypothesis, and offered to sponsor a three-year programme of investigation. The essential study was considered to be that of turbulent separation of boundary layers from heated surfaces, but an initial experimental investigation of laminar transition was carried out for low-speed flow over a flat plate. This indicated that the transition point is generally advanced by wall heating. and confirmed the results of other authors. The turbulent separation measurements were made on the inner wall of a curved duct, again at low air velocities. Advancement of the separation point in response to wall heating was observed, but dependence on flow velocity was evident. Attempts were made to relate separation point movement to a single parameter, but these were unsuccessful. The curved duct results were compared with predictions from a'. integral- type boundary layer 6alculation program, which had been developed by staff at Rolls-Royce. This after modification by the author, gave acceptable results for the majority of the experimental data. The predictions were then extended to cover flow over compressor blades. It was concluded that premature separation of the boundary layer in a compressor is most likely to occur on the aerofoil suction surfaces, although separation from the drum is a further possibility. On the aerofoils, separation point movements as a result of thermal transients are likely to be small (less than of the chord). however, a small departure from design conditions is likely to produce a larger one further downstream. Thus it was considered that the aerodynamic consequences of heat transfer from the blading can be a major factor in reducing compressor stall margins during transient running

    Expanding Ethical Standards of HMR: Necessary Evils and the Multiple Dimensions of Impact

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    Ethical challenges abound in HRM. Each day, in the course of executing and communicating HR decisions, managers have the potential to change, shape, redirect, and fundamentally alter the course of other people\u27s lives. Managers make hiring decisions that reward selected applicants with salaries, benefits, knowledge, and skills, but leave the remaining applicants bereft of these opportunities and advantages. Managers make promotion decisions that reward selected employees with raises, status, and responsibility, leaving other employees wondering about their future and their potential. Managers make firing and lay-off decisions in order to improve corporate performance, all the while harming the targeted individuals and even undermining the commitment and energy of survivors. Even when managers complete performance appraisals and deliver performance feedback, they may inspire one employee and devastate another. For each HR practice, there are winners and there are losers: Those who get the job, or receive a portfolio of benefits, and those who do not

    Incorporation of Multiple Coulomb Scattering in the Prediction of Optimal Focal Lengths in Magnetically Focused Proton Radiosurgery

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    Magnetic focusing of protons is a promising approach to improve patient radiation dose distribution in proton radiosurgery. The paths of individual protons are affected by multiple atomic deflections (multiple Coulomb scattering [MCS]) and affect overall beam characteristics in the patient. The purpose of this project is to account for the effects of MCS in the optimization of focal lengths in magnetically focused proton radiosurgery

    Exploring students' perceptions on the use of significant event analysis, as part of a portfolio assessment process in general practice, as a tool for learning how to use reflection in learning

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    BACKGROUND: Portfolio learning enables students to collect evidence of their learning. Component tasks making up a portfolio can be devised that relate directly to intended learning outcomes. Reflective tasks can stimulate students to recognise their own learning needs. Assessment of portfolios using a rating scale relating to intended learning outcomes offers high content validity. This study evaluated a reflective portfolio used during a final-year attachment in general practice (family medicine). Students were asked to evaluate the portfolio (which used significant event analysis as a basis for reflection) as a learning tool. The validity and reliability of the portfolio as an assessment tool were also measured. METHODS: 81 final-year medical students completed reflective significant event analyses as part of a portfolio created during a three-week attachment (clerkship) in general practice (family medicine). As well as two reflective significant event analyses each portfolio contained an audit and a health needs assessment. Portfolios were marked three times; by the student's GP teacher, the course organiser and by another teacher in the university department of general practice. Inter-rater reliability between pairs of markers was calculated. A questionnaire enabled the students' experience of portfolio learning to be determined. RESULTS: Benefits to learning from reflective learning were limited. Students said that they thought more about the patients they wrote up in significant event analyses but information as to the nature and effect of this was not forthcoming. Moderate inter-rater reliability (Spearman's Rho .65) was found between pairs of departmental raters dealing with larger numbers (20 – 60) of portfolios. Inter-rater reliability of marking involving GP tutors who only marked 1 – 3 portfolios was very low. Students rated highly their mentoring relationship with their GP teacher but found the portfolio tasks time-consuming. CONCLUSION: The inter-rater reliability observed in this study should be viewed alongside the high validity afforded by the authenticity of the learning tasks (compared with a sample of a student's learning taken by an exam question). Validity is enhanced by the rating scale which directly connects the grade given with intended learning outcomes. The moderate inter-rater reliability may be increased if a portfolio is completed over a longer period of time and contains more component pieces of work. The questionnaire used in this study only accessed limited information about the effect of reflection on students' learning. Qualitative methods of evaluation would determine the students experience in greater depth. It would be useful to evaluate the effects of reflective learning after students have had more time to get used to this unfamiliar method of learning and to overcome any problems in understanding the task

    Access to a diverse array of bridged benzo[1,5]oxazocine and benzo[1,4]diazepine structures

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    The preparation of bridged benzo[1,5]oxazocines and benzo[1,4]diazepines is demonstrated from simple aniline and aldehyde starting materials. A one-pot condensation/6Ï€ electrocyclization is followed by an intramolecular trapping of the 2,3-dihydroquinoline intermediate by nitrogen or oxygen nucleophiles to give bridged seven- and eight-membered products. Using 3-hydroxypyridinecarboxaldehydes results in a stable zwitterionic structure that can undergo a diastereoselective reduction under hydrogenative conditions. A similar cyclization/hydrogenation pathway with excellent diastereoselectivity is also demonstrated from 2-pyridyl-substituted 1,2,3,4-tetrahydroquinolines.PostprintPeer reviewe
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