170 research outputs found

    Spatial distribution of copepods in fast ice of eastern Antarctica

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    The distribution and abundance of sympagic copepods in fast ice of the Australian Antarctic Territory (AAT) were investigated between October and December 1995. Copepods were collected from six sites between the northern Vestfold Hills (Murphy Rocks) and Mawson Station, a distance of approximately 650km. Nine species of copepods were identified from the ice cores, however, of these only three were recorded regularly : Paralabidocera antarctica, Drescheriella glacialis and Stephos longipes. The density of copepods was highest in the bottom few cm of ice, with abundances reaching up to 147l^. The highest concentrations of chlorophyll α were also found in the bottom portion of ice, suggesting that the copepods congregated in regions of high food availability. All developmental stages of Drescheriella glacialis were observed during this study, often from within a single core. In contrast, Paralabidocera antarctica occurred mainly as early copepodite stages, and Stephos longipes mainly as nauplii. These observations were consistent with the documented life cycles for each species. Drescheriella glacialis appears to reproduce and breed within the ice, Paralabidocera antarctica overwinters in the ice but enters a pelagic phase as late-stage copepodids, while nauplii of Stephos longipes are the predominant stages which associate closely with sea ice

    Study protocol for a randomised controlled trial evaluating the effect of prenatal omega-3 LCPUFA supplementation to reduce the incidence of preterm birth: The ORIP trial

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    Introduction: Preterm birth accounts for more than 85% of all perinatal complications and deaths. Seventy-five per cent of early preterm births (EPTBs) occur spontaneously and without identifiable risk factors. The need for a broadly applicable, effective strategy for primary prevention is paramount. Secondary outcomes from the docosahexaenoic acid (DHA) to Optimise Mother Infant Outcome trial showed that maternal supplementation until delivery with omega-3 (ω-3) long chain polyunsaturated fatty acid (LCPUFA), predominantly as DHA, resulted in a 50% reduction in the incidence of EPTB and an increase in the incidence of post-term induction or post-term prelabour caesarean section due to extended gestation. We aim to determine the effectiveness of supplementing the maternal diet with ω-3 LCPUFA until 34 weeks’ gestation on the incidence of EPTB. Methods and analysis: This is a multicentre, parallel group, randomised, blinded and controlled trial. Women less than 20 weeks’ gestation with a singleton or multiple pregnancy and able to give informed consent are eligible to participate. Women will be randomised to receive high DHA fish oil capsules or control capsules without DHA. Capsules will be taken from enrolment until 34 weeks’ gestation. The primary outcome is the incidence of EPTB, defined as delivery before 34 completed weeks’ gestation. Key secondary outcomes include length of gestation, incidence of post-term induction or prelabour caesarean section and spontaneous EPTB. The target sample size is 5540 women (2770 per group), which will provide 85% power to detect an absolute reduction in the incidence of preterm birth of 1.16% (from 2.45% to 1.29%) between the DHA and control group (two sided α=0.05). The primary analysis will be based on the intention-to-treat principle. Trial registration number: Australia and New Zealand Clinical Trial Registry Number: 2613001142729; Pre-results

    Using self-concept theory to identify and develop volunteer leader potential in healthcare

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    Resource constraints in the Canadian publicly funded healthcare system have created a need for more volunteer leaders to effectively manage other volunteers. Self-concept theory has been conceptualized and applied within a volunteer context, and the views of healthcare stakeholders, such as volunteers, volunteer leaders, and supervisors, triangulated to form an understanding of the attitudes and behaviors of volunteer leaders. We propose that leaders are differentiated from others by how they view their roles in the organization and their ability to make a difference in these roles. This interpretation can be informed by self-concept theory because each individual\u27s notion of self-concept influences how employees see themselves, how they react to experiences, and how they allow these experiences to shape their motivation. A small case study profiles a volunteer leader self-concept that includes a proactive, learning-oriented attitude, capitalizing on significant prior work experience to fulfill a sense of obligation to the institution and its patients, and demands a high level of respect from paid employees

    Reduction of a Vehicle Multibody Dynamic Model Using Homotopy Optimization

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    The original publication is available at: Hall, A., Uchida, T., Loh, F., Schmitke, C., & Mcphee, J. (2013). Reduction of a Vehicle Multibody Dynamic Model Using Homotopy Optimization. Archive of Mechanical Engineering, LX(1). https://doi.org/10.2478/meceng-2013-0002Despite the ever-increasing computational power of modern processors, the reduction of complex multibody dynamic models remains an important topic of investigation, particularly for design optimization, sensitivity analysis, parameter identification, and controller tuning tasks, which can require hundreds or thousands of simulations. In this work, we first develop a high-fidelity model of a production sports utility vehicle in Adams/Car. Single-link equivalent kinematic quarter-car (SLEKQ, pronounced “sleek”) models for the front and rear suspensions are then developed in MapleSim. To avoid the computational complexity associated with introducing bushings or kinematic loops, all suspension linkages are lumped into a single unsprung mass at each corner of the vehicle. The SLEKQ models are designed to replicate the kinematic behaviour of a full suspension model using lookup tables or polynomial functions, which are obtained from the high-fidelity Adams model in this work. The predictive capability of each SLEKQ model relies on the use of appropriate parameters for the nonlinear spring and damper, which include the stiffness and damping contributions of the bushings, and the unsprung mass. Homotopy optimization is used to identify the parameters that minimize the difference between the responses of the Adams and MapleSim models. Finally, the SLEKQ models are assembled to construct a reduced 10-degree-of-freedom model of the full vehicle, the dynamic performance of which is validated against that of the high-fidelity Adams model using four-post heave and pitch tests.The authors gratefully acknowledge the financial support provided by the Natural Sciences and Engineering Research Council of Canada (NSERC) and the NSERC/Toyota/Maplesoft Industrial Research Chair program

    Can we identify women who initiate and then prematurely cease breastfeeding? An Australian multicentre cohort study

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    Background: Health authorities recommend 6 months of fully breastfeeding and continuation of breastfeeding for at least a year. Many women initiate breastfeeding in hospital but discontinue before the six-month period, and therefore do not optimise the public health benefits. The aim of this study was to determine whether these women could be identified at hospital discharge, to enable targeted interventions. Methods: A secondary analysis of women who intended to breastfeed and were enrolled in a large randomized trial was undertaken. Women were enrolled in the antenatal period and antenatal, delivery and six month postnatal questionnaires were completed. Univariate and multivariate analyses were undertaken to determine the variables associated with early cessation of breastfeeding within six months, compared to women who continued to breastfeed. Results: Of 2148 women who initiated breastfeeding in hospital, 877 continued to breastfed either partially (N = 262) or fully (N = 615) until six months postpartum and 1271 ceased breastfeeding early. Median breastfeeding duration in women who ceased early was 3+6 weeks (IQR 1+1 to 11+2 weeks). In multivariate analysis, factors that were significantly associated with early cessation of breastfeeding were maternal factors of lower education (less than 12 years of schooling, no completion of further education), smoking (pre-pregnancy or during pregnancy), and newborn factors of preterm birth and low birthweight (all p \u3c 0.01). These variables correctly identify 83% of women. Conclusion: We can identify women who initiate and then prematurely discontinue breastfeeding prior to hospital discharge. Evaluation of additional interventions to support longer duration of breastfeeding in women at risk of ceasing prematurely is needed

    Accuracy of carrot yield forecasting using proximal hyperspectral and satellite multispectral data

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    Proximal and remote sensors have proved their effectiveness for the estimation of several biophysical and biochemical variables, including yield, in many different crops. Evaluation of their accuracy in vegetable crops is limited. This study explored the accuracy of proximal hyperspectral and satellite multispectral sensors (Sentinel-2 and WorldView-3) for the prediction of carrot root yield across three growing regions featuring different cropping configurations, seasons and soil conditions. Above ground biomass (AGB), canopy reflectance measurements and corresponding yield measures were collected from 414 sample sites in 24 fields in Western Australia (WA), Queensland (Qld) and Tasmania (Tas), Australia. The optimal sensor (hyperspectral or multispectral) was identified by the highest overall coefficient of determination between yield and different vegetation indices (VIs) whilst linear and non-linear models were tested to determine the best VIs and the impact of the spatial resolution. The optimal regression fit per region was used to extrapolate the point source measurements to all pixels in each sampled crop to produce a forecasted yield map and estimate average carrot root yield (t/ha) at the crop level. The latter were compared to commercial carrot root yield (t/ha) obtained from the growers to determine the accuracy of prediction. The measured yield varied from 17 to 113 t/ha across all crops, with forecasts of average yield achieving overall accuracies (% error) of 9.2% in WA, 10.2% in Qld and 12.7% in Tas. VIs derived from hyperspectral sensors produced poorer yield correlation coefficients (R2 < 0.1) than similar measures from the multispectral sensors (R2 < 0.57, p < 0.05). Increasing the spatial resolution from 10 to 1.2 m improved the regression performance by 69%. It is impossible to non-destructively estimate the pre-harvest spatial yield variability of root vegetables such as carrots. Hence, this method of yield forecasting offers great benefit for managing harvest logistics and forward selling decisions

    Accuracy of carrot yield forecasting using proximal hyperspectral and satellite multispectral data

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    Proximal and remote sensors have proved their effectiveness for the estimation of several biophysical and biochemical variables, including yield, in many different crops. Evaluation of their accuracy in vegetable crops is limited. This study explored the accuracy of proximal hyperspectral and satellite multispectral sensors (Sentinel-2 and WorldView-3) for the prediction of carrot root yield across three growing regions featuring different cropping configurations, seasons and soil conditions. Above ground biomass (AGB), canopy reflectance measurements and corresponding yield measures were collected from 414 sample sites in 24 fields in Western Australia (WA), Queensland (Qld) and Tasmania (Tas), Australia. The optimal sensor (hyperspectral or multispectral) was identified by the highest overall coefficient of determination between yield and different vegetation indices (VIs) whilst linear and non-linear models were tested to determine the best VIs and the impact of the spatial resolution. The optimal regression fit per region was used to extrapolate the point source measurements to all pixels in each sampled crop to produce a forecasted yield map and estimate average carrot root yield (t/ha) at the crop level. The latter were compared to commercial carrot root yield (t/ha) obtained from the growers to determine the accuracy of prediction. The measured yield varied from 17 to 113 t/ha across all crops, with forecasts of average yield achieving overall accuracies (% error) of 9.2% in WA, 10.2% in Qld and 12.7% in Tas. VIs derived from hyperspectral sensors produced poorer yield correlation coefficients (R2 2

    Setting research priorities for management and treatment of hyperhidrosis: the results of the James Lind Alliance Priority Setting Partnership

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    © 2022 The Authors. Clinical and Experimental Dermatology published by John Wiley & Sons Ltd on behalf of British Association of Dermatologists. This is an open access article under the terms of the Creative Commons Attribution License, https://creativecommons.org/licenses/by/4.0/Summary: Background: Hyperhidrosis is a common skin condition characterized by excessive sweating, which can negatively impact on quality of life. It is under‐researched compared with other conditions of similar prevalence. Aim: To generate a Top 10 list of research priorities for the treatment and management of hyperhidrosis, with equal input from people with hyperhidrosis and healthcare professionals (HCPs). Methods: A priority setting partnership (PSP) was established and processes from the James Lind Alliance Handbook were followed. An online survey asked participants what questions they would like research to answer. These questions were grouped into ‘indicative questions’, which were ranked in a second survey of 45 indicative questions. The top 23 questions were then taken to a final workshop event attended by key stakeholders, and ranked to generate the Top 10 list of research priorities. Results: There were 592 questions submitted by 268 respondents for the first survey. For the second survey, 286 participants ranked the indicative questions in order of priority. At the final workshop, the Top 10 list was generated. The top three priorities were: (i) Are there any safe and effective permanent solutions for hyperhidrosis? (ii) What is the most effective and safe oral treatment (drugs taken by mouth) for hyperhidrosis? and (iii) What are the most effective and safe ways to reduce sweating in particular areas of the body? Conclusions: There are many unanswered research questions that both people with hyperhidrosis and HCPs would like to see answered. The results from this PSP will help to ensure future research funding can be directed to these areas of priority.Peer reviewedFinal Published versio
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