Hot topics in parenteral nutrition. Current evidence and ongoing trials on the use of glutamine in critically-ill patients and patients undergoing surgery

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Adherence to the MoodGYM program: Outcomes and predictors for an adolescent school-based population

Background Program adherence has been associated with improved intervention outcomes for mental and physical conditions. The aim of the current study is to investigate adolescent adherence to an Internet-based depression prevention program in schools to identify the effect of adherence on outcomes and to ascertain the predictors of program adherence. Methods Data for the current study (N=1477) was drawn from the YouthMood Project, which was conducted to test the effectiveness of the MoodGYM program in reducing and preventing symptoms of anxiety and depression in an adolescent school-based population. The current study compares intervention effects across three sub-groups: high adherers, low adherers and the wait-list control condition. Results When compared to the control condition, participants in the high adherence intervention group reported stronger intervention effects at post-intervention and 6-month follow-up than participants in the low adherence group for anxiety (d=0.34–0.39 vs. 0.11–0.22), and male (d=0.43–0.59 vs. 0.26–0.35) and female depression (d=0.13–0.20 vs. 0.02–0.04). No significant intervention effects were identified between the high and low adherence groups. Being in Year 9, living in a rural location and having higher pre-intervention levels of depressive symptoms or self-esteem were predictive of greater adherence to the MoodGYM program. Limitations The program trialled is Internet-based and therefore the predictors of adherence identified may not generalise to face-to-face interventions. Conclusions The current study provides preliminary support for the positive relationship between program adherence and outcomes in a school environment. The identification of significant predictors of adherence will assist in identifying the type of user who will engage most with an online depression prevention program.ALC is supported by National Health and Medical Research Council (NHMRC)Fellowship 1013199, HC is supported by NHMRC Fellowship 525411, and KMG is supported by NHMRC Fellowship 42541

Prospective memory and future event simulation in individuals with alcohol dependence

This major research project focuses on the possible influence that chronic substance use may have on prospective memory (PM) ability. Part one consists of a literature review examining the associations between recreational substance use and impairments in PM. This identifies 24 studies from 23 publications examining PM ability in recreational substance users. Although PM impairments are reported by most, the review highlights a number of methodological weaknesses in the existing body of research. These include an over-reliance on self report PM measures, the use of inadequate objective assessments, and limitations in internal and external validity. Suggestions are made for how methodological limitations may be overcome in future work. Part two is an empirical paper which describes a study that aimed to overcome the limitations highlighted in part one. This compared the performance of an alcohol dependent group to that of an age and premorbid ability matched control group, on an objective PM measure called the Virtual Week. It was found that the event based PM performance of alcohol dependents was strongly associated with indices of both alcohol usage and severity of alcohol dependence, and significantly impaired compared to that of controls. Furthermore, an imagining technique improved controls’ time based PM, but did not improve alcohol dependents’ PM. These findings are discussed in terms of the relevance of strategy application to successful PM functioning, and the implications this may hold for clinical practice. Part three consists of a critical appraisal of the research process, which explains why various methodological choices were made and how particular challenges were overcome as they arose. Certain conceptual issues are also reflected upon and their relevance to future research discussed

The Y-Worri Project: study protocol for a randomized controlled trial

Background: Anxiety disorders are one of the most common psychological problems in adolescents. The school system has been identified as an ideal setting for the implementation of prevention and early intervention programs for anxiety; however, few programs are routinely delivered in schools and little is known about the best delivery methods. The aim of the current project is two-fold: to test the effectiveness of an intervention program for anxiety relative to a control condition, and to compare two methods of implementing the program. Methods/design: This study is a three-arm cluster randomised controlled trial consisting of a wait-list control condition and two intervention conditions evaluating the effectiveness of an Internet-based program for preventing generalised anxiety. The first intervention condition will involve classroom teachers supervising student completion of the intervention program, while the second intervention condition will involve the classroom teacher and an education officer from the local youth mental health centre supervising the program’s completion. At least 30 schools from across Australia will be recruited to the trial, with adolescents aged between 14 and 18 years invited to participate. Participants in the intervention conditions will complete the e-couch Anxiety and Worry program during class periods over six weeks. The primary outcome measure will be a scale reflecting the number and severity of generalised anxiety symptoms, while secondary outcomes will be symptoms of depression, social anxiety and anxiety sensitivity. Data will be collected at pre-intervention, post-intervention, 6- and 12-month follow-up. Intention-to-treat analyses will be conducted. Discussion: If demonstrated effective, a new service delivery model for the implementation of mental health programs in schools could be indicated. Such a model would significantly contribute to the mental health of young people in Australia by providing preventive interventions for mental health problems and consequently reducing the need for clinical services.This study is funded by the Vincent Fairfax Family Foundation, headspace: Australia’s National Youth Mental Health Foundation and the Brain and Mind Research Institute. ALC is supported by National Health and Medical Research Council (NHMRC) Fellowship 1013199, HC is supported by NHMRC Fellowship 525411, and KMG is supported by NHMRC Fellowship 425413. We would like to acknowledge Alison Parsons as the trial manager for the YWorri Project, and the ANU e-hub IT team for their assistance in setting up the trial infrastructure

Capacitor voltage balancing strategy based on sub-module capacitor voltage estimation for modular multilevel converters

The modular multilevel converter (MMC) is expected to be used extensively in high-voltage direct current (HVDC) transmission networks because of its superior characteristics over the line-commutated converter (LCC). A key issue of concern is balancing sub-module capacitor voltages in the MMCs, which is critical for the correct operation of these converters. The majority of voltage balancing techniques proposed thus far require that the measurement of the capacitor voltages use a reliable measuring system. This can increase the capital cost of the converters. This paper presents a voltage balancing strategy based on capacitor voltage estimation using the adaptive linear neuron (ADALINE) algorithm. The proposed estimation unit requires only three voltage sensors per phase for the arm reactors and the output phase voltages. Measurements of sub-module capacitor voltages and associated communication links with the central controller are not needed. The proposed strategy can be applied to MMC systems that contain a large number of sub-modules. The method uses PSCAD/EMTDC, with particular focus on dynamic performance under a variety of operating conditions

Acute cardiorespiratory responses to inspiratory pressure threshold loading

This is a non-final version of an article (under the working title "Acute cardiovascular and ventilatory responses to inspiratory pressure threshold loading") published in final form in Medicine & Science in Sports & Exercise, 42(9), 1696-1703, 2010 .Purpose: We tested the acute responses to differing pressure threshold inspiratory loading intensities in well-trained rowers. The purpose of this study was to evaluate 1) how the magnitude of inspiratory pressure threshold loading influences repetition maximum (RM), tidal volume (VT), and external work undertaken by the inspiratory muscle; and 2) whether the inspiratory muscle metaboreflex is activated during acute inspiratory pressure threshold loading. Methods: Eight males participated in seven trials. Baseline measurements of maximal inspiratory pressure (PImax), resting tidal volume (VT), and forced vital capacity (FVC) were made. During the remaining sessions, participants undertook a series of resistive inspiratory breathing tasks at loads corresponding to 50%, 60%, 70%, 80%, and 90% of PImax using a pressure threshold inspiratory muscle trainer. The number of repetitions completed at each load, VT, heart rate (fc), and measures of arterial blood pressure was assessed continuously during each trial. Results: A standardized cutoff of 10% FVC was used to define the RM, which decreased as loading intensity increased (P < 0.05). This response was nonlinear, with an abrupt decrease in RM occurring at loads ≥70% of PImax. The most commonly used inspiratory muscle training regimen of 30RM corresponded to 62.5% ± 4.6% of PImax and also resulted in the highest external work output. Tidal volume (VT) decreased significantly over time at 60%, 70%, and 80% of PImax (P < 0.05), as did the amount of external work completed (P<0.05). Conclusions: Although all loads elicited a sustained increase in fc, only the 60% load elicited a sustained rise in mean arterial blood pressure (P = 0.016), diastolic blood pressure (P = 0.015), and systolic blood pressure (P = 0.002), providing evidence for a metaboreflex response at this load

HSD3B1 is an oxysterol 3β-hydroxysteroid dehydrogenase in human placenta

Most biologically active oxysterols have a 3β-hydroxy-5-ene function in thering system with an additional site of oxidation at C-7 or on the side-chain. In blood plasma oxysterols with a 7α-hydroxy group are also observed with the alternative 3-oxo-4-ene function in the ring system formed by ubiquitously expressed 3β-hydroxy-Δ5-C27-steroid oxidoreduc-taseΔ5-isomerase, HSD3B7. However, oxysterols without a 7α-hydroxy group are not substrates for HSD3B7 and are not usually observed with the 3-oxo-4-ene function. Here we report the unexpected identification of oxysterols in plasma derived from umbilical cord blood and blood from pregnant women taken before delivery at 37+ weeks of gestation, of side-chain oxysterols with a 3-oxo-4-ene function but no 7α-hydroxy group.These 3-oxo-4-ene oxysterols were also identified in placenta, leading to the hypothesis that they may be formed by a previously unrecognized 3β-hydroxy-Δ5-C27-steroid oxidoreductaseΔ5-isomerase activity of HSD3B1,an enzyme which is highly expressed in placenta. Proof-of-principle experiments confirmed that HSD3B1 has this activity. We speculate thatHSD3B1 in placenta is the source of the unexpected 3-oxo-4-ene oxysterols in cord and pregnant women’s plasma and may have a role in controlling the abundance of biologically active oxysterols delivered to the fetus