3,670 research outputs found
A review of US Army aircrew-aircraft integration research programs
If the U.S. Army's desire to develop a one crew version of the Light Helicopter Family (LHX) helicopter is to be realized, both flightpath management and mission management will have to be performed by one crew. Flightpath management, the helicopter pilot, and the handling qualities of the helicopter were discussed. In addition, mission management, the helicopter pilot, and pilot control/display interface were considered. Aircrew-aircraft integration plans and programs were reviewed
Factors influencing the likelihood of instrumental delivery success.
OBJECTIVE: To evaluate risk factors for unsuccessful instrumental delivery when variability between individual obstetricians is taken into account. METHODS: We conducted a retrospective cohort study of attempted instrumental deliveries over a 5-year period (2008-2012 inclusive) in a tertiary United Kingdom center. To account for interobstetrician variability, we matched unsuccessful deliveries (case group) with successful deliveries (control group) by the same operators. Multivariate logistic regression was used to compare successful and unsuccessful instrumental deliveries. RESULTS: Three thousand seven hundred ninety-eight instrumental deliveries of vertex-presenting, single, term newborns were attempted, of which 246 were unsuccessful (6.5%). Increased birth weight (odds ratio [OR] 1.11; P<.001), second-stage labor duration (OR 1.01; P<.001), rotational delivery (OR 1.52; P<.05), and use of ventouse compared with forceps (OR 1.33; P<.05) were associated with unsuccessful outcome. When interobstetrician variability was controlled for, instrument selection and decision to rotate were no longer associated with instrumental delivery success. More senior obstetricians had higher rates of unsuccessful deliveries (12% compared with 5%; P<.05) but were used to undertake more complicated cases. Cesarean delivery during the second stage of labor without previous attempt at instrumental delivery was associated with higher birth weight (OR 1.07; P<.001), increased maternal age (OR 1.03; P<.01), and epidural analgesia (OR 1.46; P<.001). CONCLUSION: Results suggest that birth weight and head position are the most important factors in successful instrumental delivery, whereas the influence of instrument selection and rotational delivery appear to be operator-dependent. Risk factors for lack of instrumental delivery success are distinct from risk factors for requiring instrumental delivery, and these should not be conflated in clinical practice.This is the author accepted manuscript. The final version is published in Obstetrics & Gynecology 123: 796-803. doi: 10.1097/AOG.0000000000000188, which can be found here: http://journals.lww.com/greenjournal/Abstract/2014/04000/Factors_Influencing_the_Likelihood_of_Instrumental.11.asp
The influence of hours worked prior to delivery on maternal and neonatal outcomes: a retrospective cohort study.
BACKGROUND: Long continuous periods of working contribute to fatigue, which is an established risk factor for adverse patient outcomes in many clinical specialties. The total number of hours worked by delivering clinicians before delivery therefore may be an important predictor of adverse maternal and neonatal outcomes. OBJECTIVE: We aimed to examine how rates of adverse delivery outcomes vary with the number of hours worked by the delivering clinician before delivery during both day and night shifts. STUDY DESIGN: We conducted a retrospective cohort study of 24,506 unscheduled deliveries at an obstetrics center in the United Kingdom from 2008-2013. We compared adverse outcomes between day shifts and night shifts using random-effects logistic regression to account for interoperator variability. Adverse outcomes were estimated blood loss of ≥1.5 L, arterial cord pH of ≤7.1, failed instrumental delivery, delayed neonatal respiration, severe perineal trauma, and any critical incident. Additive dynamic regression was used to examine the association between hours worked before delivery (up to 12 hours) and risk of adverse outcomes. Models were controlled for maternal age, maternal body mass index, parity, birthweight, gestation, obstetrician experience, and delivery type. RESULTS: We found no difference in the risk of any adverse outcome that was studied between day vs night shifts. Yet, risk of estimated blood loss of ≥1.5 L and arterial cord pH of ≤7.1 both varied by 30-40% within 12-hour shifts (P<.05). The highest risk of adverse outcomes occurred after 9-10 hours from the beginning of the shift for both day and night shifts. The risk of other adverse outcomes did not vary significantly by hours worked or by day vs night shift. CONCLUSION: Number of hours already worked before undertaking unscheduled deliveries significantly influences the risk of certain adverse outcomes. Our findings suggest that fatigue may play a role in increasing the risk of adverse delivery outcomes later in shifts and that obstetric work patterns could be better designed to minimize the risk of adverse delivery outcomes.ARA is supported by grant P2CHD047879, awarded to the Office of Population Research at Princeton University by The Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health. JGS is supported by a CAREER grant from the U.S. National Science Foundation (DMS-1255187).This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.ajog.2016.06.02
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Factors associated with adverse clinical outcomes among obstetrics trainees.
OBJECTIVES: This study was conducted to determine whether UK obstetrics trainees transitioning from directly to indirectly supervised practice have a higher likelihood of recording adverse patient outcomes in operative deliveries compared with other indirectly supervised trainees, and to examine whether performing more procedures under direct supervision is associated with fewer adverse outcomes in initial practice under indirect supervision. METHODS: We examined all deliveries (13 856) conducted by obstetricians at a single centre over 6 years (2008-2013). Mixed-effects logistic regression models were used to compare estimated blood loss (EBL), maternal trauma, umbilical arterial pH, delayed neonatal respiration, failed instrumental delivery, and critical incidents for trainees in their first indirectly supervised year with those for trainees in all other years of indirect supervision. Outcomes for trainees in their first indirectly supervised 3 months were compared with their outcomes for the remainder of the year. Linear regression was used to examine the relationship between number of procedures performed under direct supervision and initial outcomes under indirect supervision. RESULTS: Trainees in their first indirectly supervised year had a higher likelihood of recording EBL of > 2 L at any delivery (odds ratio [OR] 1.32, 95% confidence interval [CI] 1.01-1.64; p 1 L (OR 2.54, 95% CI 1.88-3.20; p 1 L (p < 0.05). CONCLUSIONS: Obstetrics trainees in their first year of indirectly supervised practice have a higher likelihood of recording immediate adverse delivery outcomes, which are primarily maternal rather than neonatal. Undertaking more directly supervised procedures prior to transitioning to indirectly supervised practice may reduce adverse outcomes, which suggests that experience is a key consideration in obstetrics training programme design.ARA is supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) grant for Infrastructure for Population Research at Princeton University (Grant R24HD047879). During the initial preparation of this manuscript she was also supported by an NICHD Individual Predoctoral Fellowship (Grant F31HD079182) and an NICHD infrastructure grant awarded to the Population Research Center at The University of Texas at Austin (Grant R24HD042849).This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1111/medu.12741
Collaboration Versus Cheating
We outline how we detected programming plagiarism in an introductory online
course for a master's of science in computer science program, how we achieved a
statistically significant reduction in programming plagiarism by combining a
clear explanation of university and class policy on academic honesty reinforced
with a short but formal assessment, and how we evaluated plagiarism rates
before SIGand after implementing our policy and assessment.Comment: 7 pages, 1 figure, 5 tables, SIGCSE 201
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Weekend working: a retrospective cohort study of maternal and neonatal outcomes in a large NHS delivery unit.
OBJECTIVES: Mandatory weekend working for NHS consultants is currently the subject of intense political debate. The Secretary of State for Health's proposed 7-day contract policy is based on the claim that such working patterns will improve patient outcomes. We evaluate this claim by taking advantage of as-if-at-random presentation of women for non-elective deliveries throughout the week. We examine (i) whether consultants currently perform fewer deliveries during weekends versus weekdays, and (ii) whether adverse outcomes increase during weekends. STUDY DESIGN: We conducted a retrospective cohort study using data on all non-elective deliveries from January 2008 to December 2013 in a large UK obstetrics centre (n=27,466). We used Pearson's chi-squared tests to make direct comparisons of adverse outcome rates during weekdays versus weekends. Outcomes included: estimated maternal blood loss ≥1.5l; severe perineal trauma; delayed neonatal respiration; umbilical arterial pH <7.1; and critical incidents at delivery. RESULTS: Consultants currently perform the same proportion of non-elective deliveries on weekends and weekdays (2.3% versus 2.6%, p=0.25). We found no increase in any adverse maternal or neonatal outcomes during weekends versus weekdays, despite high statistical power to detect such differences. Moreover, adverse outcomes are no higher during periods of the weekend when consultants are not routinely present compared to equivalent periods during weekdays. CONCLUSIONS: Under current working arrangements, women who would benefit from consultant-led delivery are equally likely to receive one on weekends compared to weekdays. Weekend delivery has no effect on maternal or neonatal morbidity. Adopting mandatory 7-day contracts is unlikely to make any difference to either consultant-led delivery during weekends or to patient outcomes.The Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health (Grant ID: P2CHD047879)This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.ejogrb.2016.01.03
Management of fetal malposition in the second stage of labor: a propensity score analysis.
OBJECTIVE: We sought to determine the factors associated with selection of rotational instrumental vs cesarean delivery to manage persistent fetal malposition, and to assess differences in adverse neonatal and maternal outcomes following delivery by rotational instruments vs cesarean delivery. STUDY DESIGN: We conducted a retrospective cohort study over a 5-year period in a tertiary United Kingdom obstetrics center. In all, 868 women with vertex-presenting, single, liveborn infants at term with persistent malposition in the second stage of labor were included. Propensity score stratification was used to control for selection bias: the possibility that obstetricians may systematically select more difficult cases for cesarean delivery. Linear and logistic regression models were used to compare maternal and neonatal outcomes for delivery by rotational forceps or ventouse vs cesarean delivery, adjusting for propensity scores. RESULTS: Increased likelihood of rotational instrumental delivery was associated with lower maternal age (odds ratio [OR], 0.95; P < .01), lower body mass index (OR, 0.94; P < .001), lower birthweight (OR, 0.95; P < .01), no evidence of fetal compromise at the time of delivery (OR, 0.31; P < .001), delivery during the daytime (OR, 1.45; P < .05), and delivery by a more experienced obstetrician (OR, 7.21; P < .001). Following propensity score stratification, there was no difference by delivery method in the rates of delayed neonatal respiration, reported critical incidents, or low fetal arterial pH. Maternal blood loss was higher in the cesarean group (295.8 ± 48 mL, P < .001). CONCLUSION: Rotational instrumental delivery is often regarded as unsafe. However, we find that neonatal outcomes are no worse once selection bias is accounted for, and that the likelihood of severe obstetric hemorrhage is reduced. More widespread training of obstetricians in rotational instrumental delivery should be considered, particularly in light of rising cesarean delivery rates.During data analysis, A.R.A. was supported by an NICHD Predoctoral Fellowship under grant number F31HD079182 and by grant R24HD042849, awarded to the Population Research Center at The University of Texas at Austin. She is currently supported by grant R24HD047879 for Population Research at Princeton University. J.G.S. is partially funded by a CAREER grant from the National Science Foundation (DMS-1255187).This is the accepted version. It will be embargoed until 12 months after the final version is published by Elsevier. The final version is available from Elsevier at http://www.sciencedirect.com/science/article/pii/S000293781401078
Decreased ovarian reserve, dysregulation of mitochondrial biogenesis, and increased lipid peroxidation in female mouse offspring exposed to an obesogenic maternal diet.
Maternal diet during pregnancy influences the later life reproductive potential of female offspring. We investigate the molecular mechanisms underlying the depletion of ovarian follicular reserve in young adult females following exposure to obesogenic diet in early life. Furthermore, we explore the interaction between adverse maternal diet and postweaning diet in generating reduced ovarian reserve. Female mice were exposed to either maternal obesogenic (high fat/high sugar) or maternal control dietin uteroand during lactation, then weaned onto either obesogenic or control diet. At 12 wk of age, the offspring ovarian reserve was depleted following exposure to maternal obesogenic diet (P< 0.05), but not postweaning obesogenic diet. Maternal obesogenic diet was associated with increased mitochondrial DNA biogenesis (copy numberP< 0.05; transcription factor A, mitochondrial expressionP< 0.05), increased mitochondrial antioxidant defenses [manganese superoxide dismutase (MnSOD)P< 0.05; copper/zinc superoxide dismutaseP< 0.05; glutathione peroxidase 4P< 0.01] and increased lipoxygenase expression (arachidonate 12-lipoxygenaseP< 0.05; arachidonate 15-lipoxygenaseP< 0.05) in the ovary. There was also significantly increased expression of the transcriptional regulator NF-κB (P< 0.05). There was no effect of postweaning diet on any measured ovarian parameters. Maternal diet thus plays a central role in determining follicular reserve in adult female offspring. Our observations suggest that lipid peroxidation and mitochondrial biogenesis are the key intracellular pathways involved in programming of ovarian reserve.-Aiken, C. E., Tarry-Adkins, J. L., Penfold, N. C., Dearden, L., Ozanne, S. E. Decreased ovarian reserve, dysregulation of mitochondrial biogenesis, and increased lipid peroxidation in female mouse offspring exposed to an obesogenic maternal diet.This study was funded jointly by grants from the Academy of Medical Sciences, the Addenbrooke’s Charitable Trust, an Isaac Newton Trust/Wellcome Trust ISSF/University of Cambridge Joint Research Grant and the MRC (MRC_MC_UU_12012/4).This is the final version of the article. It first appeared from the Federation of American Societies for Experimental Biology via http://dx.doi.org/10.1096/fj.15-28080
Impact of palmitic acid coating on the water uptake and loss of ammonium sulfate particles
International audienceWhile water insoluble organics are prevalent in the atmosphere, it is not clear how the presence of such species alters the chemical and physical properties of atmospheric aerosols. Here we use a combination of FTIR spectroscopy, Transmission Electron Microscopy (TEM) and Aerosol Mass Spectrometry (AMS) to characterize ammonium sulfate particles coated with palmitic acid. Coated aerosols were generated by atomizing pure ammonium sulfate, mixing the particles with a heated flow of nitrogen with palmitic acid vapor, and then flowing the mixture through an in-line oven to create internally mixed particles. The mixing state of the particles was probed using the AMS data and images from the TEM. Both of these probes suggest that the particles were internally mixed. Water uptake by the mixed particles was then probed at 273 K. It was found that for ammonium sulfate containing ~20 wt% palmitic acid the deliquescence relative humidity (DRH) was the same as for pure ammonium sulfate (80±3% RH). For particles with ~50 wt% palmitic acid however, the mixed particles began to take up water at relative humidities as low at 69% and continued to slowly take up water to 85% RH without fully deliquescing. In addition to studies of water uptake, water loss was also investigated. Here coatings of up to 50 wt% had no impact on the efflorescence relative humidity. These studies suggest that even if insoluble substances coat salt particles in the atmosphere, there may be relatively little effect on the resulting water uptake and loss
Prevalence of face recognition deficits in middle childhood
Approximately 2-2.5% of the adult population is believed to show severe difficulties with face recognition, in the absence of any neurological injury – a condition known as developmental prosopagnosia (DP). However, to date no research has attempted to estimate the prevalence of face recognition deficits in children, possibly because there are very few child-friendly, well-validated tests of face recognition. In the current study, we examined face and object recognition in a group of primary school children (aged 5-11 years), to establish whether our tests were suitable for children; and to provide an estimate of face recognition difficulties in children. In Experiment 1 (n = 184), children completed a pre-existing test of child face memory, the CFMT-K, and a bicycle test with the same format. In Experiment 2 (n = 413), children completed three-alternative forced choice matching tasks with faces and bicycles. All tests showed good psychometric properties. The face and bicycle tests were well-matched for difficulty and showed a similar developmental trajectory. Neither the memory nor matching tests were suitable to detect impairments in the youngest groups of children, but both tests appear suitable to screen for face recognition problems in middle childhood. In the current sample, 1.2-5.2% of children showed difficulties with face recognition; 1.2-4% showed face-specific difficulties – that is, poor face recognition with typical object recognition abilities. This is somewhat higher than previous adult estimates: it is possible that face matching tests overestimate the prevalence of face recognition difficulties in children; alternatively, some children may “outgrow” face recognition difficulties
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