1,444 research outputs found

    Reynolds and Mach number simulation of Apollo and Gemini re-entry and comparison with flight

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    Reynolds and Mach numbers simulation of Apollo and Gemini reentry compared with flight dat

    A Habitat for Humanity and University Partnership: Enhancing on International Experiential Learning in El Salvador

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    The increase in international experiential learning (IEL hereafter) opportunities being developed by universities in the global north requires more attention both generally and with regards to specific IEL programming objectives. This paper provides observations and assessment of a case study of university-student participation in home-builds in El Salvador over the course of three years – a partnership between Habitat for Humanity and a Canadian university. The information collected is assessed relative to the key critiques and to the recommendations advocated in the IEL literature, with the intention of incorporating these critiques and recommendations in future IEL planning for this partnership, and to inform IEL work more generally. The key observations and recommendations include the need for enhanced student preparation pre and post-trip – meaning ‘critical reflection’ processes and materials on privilege and personal goals themes; on specific global south context; and enhancing on intercultural learning and awareness activities and processes e.g., more closely integrated host-community and participant relationship-building opportunities. These recommendations are seen as important for enhancing on this specific IEL program and its short-duration time-frame, while suggesting useful guideposts for IEL more generally, as its occurrence increases within the university setting

    Lost in transition: a systematic review of neonatal electroencephalography in the delivery room - Are we forgetting an important biomarker for newborn brain health?

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    Background: Electroencephalography (EEG) monitoring is routine in neonatal intensive care units (NICUs) for detection of seizures, neurological monitoring of infants following perinatal asphyxia, and increasingly, following preterm delivery. EEG monitoring is not routinely commenced in the delivery room (DR). Objectives: To determine the feasibility of recording neonatal EEG in the DR, and to assess its usefulness as a marker of neurological well-being during immediate newborn transition. Methods: We performed a systematic stepwise search of PubMed using the following terms: infant, newborns, neonate, DR, afterbirth, transition, and EEG. Only human studies describing EEG monitoring in the first 15 min following delivery were included. Infants of all gestational ages were included. Results: Two original studies were identified that described EEG monitoring of newborn infants within the DR. Both prospective observational studies used amplitude-integrated EEG (aEEG) monitoring and found it feasible in infants >34 weeks' gestation; however, technical challenges made it difficult to obtain continuous reliable data. Different EEG patterns were identified in uncompromised newborns and those requiring resuscitation. Conclusion: EEG monitoring is possible in the DR and may provide an objective baseline measure of neurological function. Further feasibility studies are required to overcome technical challenges in the DR, but these challenges are not insurmountable with modern technology

    Under Pressure: Quenching Star Formation in Low-Mass Satellite Galaxies via Stripping

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    Recent studies of galaxies in the local Universe, including those in the Local Group, find that the efficiency of environmental (or satellite) quenching increases dramatically at satellite stellar masses below ~ 108 M10^8\ {\rm M}_{\odot}. This suggests a physical scale where quenching transitions from a slow "starvation" mode to a rapid "stripping" mode at low masses. We investigate the plausibility of this scenario using observed HI surface density profiles for a sample of 66 nearby galaxies as inputs to analytic calculations of ram-pressure and viscous stripping. Across a broad range of host properties, we find that stripping becomes increasingly effective at $M_{*} < 10^{8-9}\ {\rm M}_{\odot},reproducingthecriticalmassscaleobserved.However,forcanonicalvaluesofthecircumgalacticmediumdensity(, reproducing the critical mass scale observed. However, for canonical values of the circumgalactic medium density (n_{\rm halo} < 10^{-3.5} {\rm cm}^{-3}$), we find that stripping is not fully effective; infalling satellites are, on average, stripped of < 40 - 70% of their cold gas reservoir, which is insufficient to match observations. By including a host halo gas distribution that is clumpy and therefore contains regions of higher density, we are able to reproduce the observed HI gas fractions (and thus the high quenched fraction and short quenching timescale) of Local Group satellites, suggesting that a host halo with clumpy gas may be crucial for quenching low-mass systems in Local Group-like (and more massive) host halos.Comment: updated version after review, now accepted to MNRAS; Accepted 2016 August 22. Received 2016 August 18; in original form 2016 June 2

    A review of important electroencephalogram features for the assessment of brain maturation in premature infants

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    This review describes the maturational features of the baseline electroencephalogram (EEG) in the neurologically healthy preterm infant. Features such as continuity, sleep state, synchrony and transient waveforms are described, even from extremely preterm infants and includes abundant illustrated examples. The physiological significance of these EEG features and their relationship to neurodevelopment are highlighted where known. This review also demonstrates the importance of multichannel conventional EEG monitoring for preterm infants as many of the features described are not apparent if limited channel EEG monitors are used. Conclusion: This review aims to provide healthcare professionals in the neonatal intensive care unit with guidance on the more common normal maturational features seen in the EEG of preterm infants

    A deep convolutional neural network for brain tissue segmentation in Neonatal MRI

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    Brain tissue segmentation is a prerequisite for many subsequent automatic quantitative analysis techniques. As with many medical imaging tasks, a shortage of manually annotated training data is a limiting factor which is not easily overcome, particularly using recent deep-learning technology. We present a deep convolutional neural network (CNN) trained on just 2 publicly available manually annotated volumes, trained to annotate 8 tissue types in neonatal T2 MRI. The network makes use of several recent deep-learning techniques as well as artificial augmentation of the training data, to achieve state-of-the- art results on public challenge data

    Enhanced monitoring of the preterm infant during stabilization in the delivery room

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    Monitoring of preterm infants in the delivery room (DR) remains limited. Current guidelines suggest that pulse oximetry should be available for all preterm infant deliveries, and that if intubated a colorimetric carbon dioxide detector should provide verification of correct endotracheal tube placement. These two methods of assessment represent the extent of objective monitoring of the newborn commonly performed in the DR. Monitoring non-invasive ventilation effectiveness (either by capnography or respiratory function monitoring) and cerebral oxygenation (near-infrared spectroscopy) is becoming more common within research settings. In this article, we will review the different modalities available for cardiorespiratory and neuromonitoring in the DR and assess the current evidence base on their feasibility, strengths, and limitations during preterm stabilization
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