63 research outputs found

    Thermal plumes from staged multiport diffusers in a uniform quiescent environment

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    The behavior of thermal plumes discharged from staged diffusers has been investigated experimentally. A staged diffuser is a type of submerged multiport diffuser characterized by an offshore orientation of the individual nozzles. It is commonly employed for the discharge of heated water from coastal power plants into the ocean because of its effective mixing capability, which does not depend on the prevailing longshore-current directions. Experiments have been performed to measure the temperature distribution of the plume in quiescent receiving water. The three-dimensional thermal field is reconstructed from the results of two groups of measurements, the centerline experiments in which the temperature in the vertical plane along the diffuser axis is measured, and the scanning experiments in which the lateral temperature profiles are measured. The emphasis is on a homogeneous ambient receiving water, but a few illustrative experiments with ambient stratification have been carried out. The number of variables associated with the problem is very large, making it difficult to perform a generic study. Nevertheless, five of the variables (the number of ports, n, the initial jet diameter, D[sub]0, the horizontal orientation of the jet, [Greek alpha], the total discharge flow rate, Q[sub]T0, and the water depth, H) have been examined. Experimental observations support the hypothesis of a near field dominated by momentum jet mixing, and an intermediate field dominated initially by turbulent mixing and eventually by gravitational spreading. H, n and D[sub]0 are the governing parameters in both the near field and the intermediate field. By coupling dimensional analysis with experimental results, several empirical relationships have been established to give a first-order approximation relating the mean characteristics of the plume to the governing parameters. It is found that the near-field dilution can be described adequately by the simple jet model with an adjustment factor based on n. The dilution in the intermediate field, however, s relatively insensitive to n. It is also concluded that the horizontal orientation of the jet +-25[degrees] to the diffuser axis, helps to spread the plume over a wider extent, thereby reducing the maximum temperature rise. Results from stratified experiments indicate that for weak stratification, the dynamics of the plume are not significantly modified

    Effects of loading positions on the activation of trunk and hip muscles during flywheel and dumbbell single-leg Romanian deadlift exercises

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    Objective: The study compared the activities of the surface electromyography (sEMG) of trunk and hip muscles during single-leg Romanian deadlift (SLRDL) exercises using a flywheel and dumbbell with different loading positions (ipsilateral and contralateral).Method: Twelve active male subjects with at least 2 years of strength training experience (age: 26.7 ± 3.3 years; weight: 73.9 ± 6.2 kg) participated in this study. sEMG in the percentage of maximum voluntary isometric contraction of four SLRDL exercises (ipsilateral and contralateral loading position for dumbbell and flywheel) in a randomized order for superior gluteus maximus (SGM), inferior gluteus maximus (IGM), gluteus medius (GM), biceps femoris (BF), erector spinae (ES), external oblique (EO), and adductor longus (AL) were measured. One-way repeated measure ANOVA with Bonferroni adjustment (statistical significance at 0.05) and the non-clinical magnitude-based decision with a standardized difference were performed for statistical analysis.Results: The overall results demonstrated a very high level of SGM (105.4%–168.6%) and BF (69.6%–122.4%) muscle activities. A significant moderate increase of sEMG signals in GM, IGM, and ES (dominant side) and a large increase in SGM activity during concentric action when the loading position of flywheel SLRDL was changed from ipsilateral to the contralateral side. No significant difference was observed between flywheel and dumbbell SLRDL exercises.Conclusion: Strength coaches may adopt dumbbell or flywheel SLRDL exercises using the contralateral loading position to simultaneously strengthen the hip extensors and trunk stabilizers effectively

    The psychophysiological effects of Tai-chi and exercise in residential Schizophrenic patients: a 3-arm randomized controlled trial

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    BACKGROUND: Patients with schizophrenia are characterized by high prevalence rates and chronicity that often leads to long-term institutionalization. Under the traditional medical model, treatment usually emphasizes the management of psychotic symptoms through medication, even though anti-psychotic drugs are associated with severe side effects, which can diminish patients’ physical and psychological well-being. Tai-chi, a mind-body exercise rooted in Eastern health philosophy, emphasizes the motor coordination and relaxation. With these potential benefits, a randomized controlled trial (RCT) is planned to investigate the effects of Tai-chi intervention on the cognitive and motor deficits characteristic of patients with schizophrenia. METHODS/DESIGN: A 3-arm RCT with waitlist control design will be used in this study. One hundred and fifty three participants will be randomized into (i) Tai-chi, (ii) exercise or (iii) waitlist control groups. Participants in both the Tai-chi and exercise groups will receive 12-weeks of specific intervention, in addition to the standard medication and care received by the waitlist control group. The exercise group will serve as a comparison, to delineate any unique benefits of Tai-chi that are independent of moderate aerobic exercise. All three groups will undergo three assessment phases: (i) at baseline, (ii) at 12 weeks (post-intervention), and (iii) at 24 weeks (maintenance). All participants will be assessed in terms of symptom management, motor coordination, memory, daily living function, and stress levels based on self-perceived responses and a physiological marker. DISCUSSION: Based on a promising pilot study conducted prior to this RCT, subjects in the Tai-chi intervention group are expected to be protected against deterioration of motor coordination and interpersonal functioning. They are also expected to have better symptoms management and lower stress level than the other treatment groups. TRIAL REGISTRATION: The trail has been registered in the Clinical Trials Center of the University of Hong Kong (HKCTR-1453)

    Bridging dentistry and traditional Chinese medicine : a study on the current mutual understanding among the future practitioners

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    Objectives: This project aimed to promote the mutual understanding between dental and TCM students. The objectives were to describe the current teaching of dentistry in the TCM schools and that of TCM in the dental school, to describe the TCM students’ knowledge on dentistry and the dental students’ knowledge on TCM, and to produce promotional materials for enhancing the mutual understanding between dental and TCM students. Methods: Information on the current teaching of dentistry in the TCM schools and that of TCM in the dental school was collected through a search on the undergraduate programme syllabus and conducting interviews with the leaders of the schools. Questionnaire surveys were conducted among the final year students of the TCM and the dental schools to collect information on their knowledge of the counter profession. Two leaflets and a short video were produced with the aid of computer software and used in the promotional activities. Results: It was found that very little information on dentistry was covered in the undergraduate programmes of the three TCM schools, and vice versa in the dental school. A total of 39 TCM students and 55 dental students completed the questionnaire survey. Most of the students did not know the basic theories and practice of the counter profession. Less than half of the student knew what types of patient cases may be suitable for cross-referral to the other profession. Conclusions: The TCM and dental schools in Hong Kong do not have scheduled teaching on the counter profession. The TCM students have little knowledge on dentistry and how to collaborate with dental practitioners on patients presented with oral problems. Conversely, it is the same for the dental students. Lastly, informative printed and audio-visual promotional materials can be produced with limited resources and used to facilitate the mutual understanding between TCM and dental practitioners.published_or_final_versio

    Entomologic and molecular investigation into Plasmodium vivax transmission in Singapore, 2009

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    <p>Abstract</p> <p>Background</p> <p>Singapore has been certified malaria free since November 1982 by the World Health Organization and despite occasional local transmission, the country has maintained the standing. In 2009, three clusters of malaria cases were reported in Singapore.</p> <p>Methods</p> <p>Epidemiological, entomological and molecular studies were carried out to investigate the three clusters, namely Mandai-Sungei Kadut, Jurong Island and Sembawang.</p> <p>Results</p> <p>A total of 29 malaria patients, with no recent travel history, were reported in the three clusters. Molecular analysis based on the <it>msp3α </it>and <it>msp1 </it>genes showed two independent local transmissions: one in Mandai-Sungei Kadut and another in Sembawang. Almost all cases within each cluster were epidemiologically linked. In Jurong Island cluster, epidemiological link remains uncertain, as almost all cases had a unique genetic profile. Only two cases shared a common profile and were found to be linked to the Mandai-Sungei Kadut cluster. Entomological investigation found <it>Anopheles sinensis </it>to be the predominant Anopheline in the two areas where local transmission of <it>P. vivax </it>was confirmed. <it>Anopheles sinensis </it>was found to be attracted to human bait and bites as early as 19:45 hrs. However, all <it>Anopheles </it>mosquitoes caught were negative for sporozoites and oocysts by dissection.</p> <p>Conclusion</p> <p>Investigation of <it>P. vivax </it>cases from the three cluster areas confirmed the occurrence of local transmission in two areas. Although <it>An. sinensis </it>was the predominant Anopheline found in areas with confirmed transmission, the vector/s responsible for the outbreaks still remains cryptic.</p

    Effectiveness of Nutritional Advice for Community-Dwelling Obese Older Adults With Frailty: A Systematic Review and Meta-Analysis

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    Objectives: This systematic review was aimed to examine the effectiveness of nutritional advise interventions compared with usual care, or exercise, or exercise combined with nutritional advice as a means of improving the body weight, body composition, physical function, and psychosocial well-being of frail, obese older adults. Methods: CINAHL, Cochrane Library, Embase, MEDLINE, PsycINFO, and Scopus databases were searched to identify relevant studies. The quality of the included studies was assessed using Cochrane's risk of bias tool 2. Meta-analysis was performed with respect to body weight and fat mass. Other outcomes were synthesized narratively. Results: Eight articles (from two studies) with a total of 137 participants were included in the review. The results revealed that nutritional advice was more effective than exercise in reducing body weight and fat mass. The nutritional advice was also beneficial in enhancing physical function and psychosocial well-being. However, it was less effective than exercise or combined interventions in increasing muscle strength and preventing lean mass loss. Conclusions: Nutritional advice is an essential intervention for reducing body weight and fat mass, for enhancing physical function, and for improving the psychosocial well-being of obese older adults experiencing frailty. The limited number of studies included in this review suggests that there is a need for more well-designed interventional studies in order to confirm these findings

    Chronic adiponectin deficiency leads to Alzheimer’s disease-like cognitive impairments and pathologies through AMPK inactivation and cerebral insulin resistance in aged mice

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    (a) Immunoblotting analysis of IRβ in the hippocampus and frontal cortex of 18-month old wildtype and APN-KO mice. (b) Densitometric analysis of the ratio of IRβ. Mean ± S.E.M.; ***p < 0.001, n.s. statistically not significant; Scale bar: 100 μm. (JPG 30 kb

    Towards a global partnership model in interprofessional education for cross-sector problem-solving

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    Objectives A partnership model in interprofessional education (IPE) is important in promoting a sense of global citizenship while preparing students for cross-sector problem-solving. However, the literature remains scant in providing useful guidance for the development of an IPE programme co-implemented by external partners. In this pioneering study, we describe the processes of forging global partnerships in co-implementing IPE and evaluate the programme in light of the preliminary data available. Methods This study is generally quantitative. We collected data from a total of 747 health and social care students from four higher education institutions. We utilized a descriptive narrative format and a quantitative design to present our experiences of running IPE with external partners and performed independent t-tests and analysis of variance to examine pretest and posttest mean differences in students’ data. Results We identified factors in establishing a cross-institutional IPE programme. These factors include complementarity of expertise, mutual benefits, internet connectivity, interactivity of design, and time difference. We found significant pretest–posttest differences in students’ readiness for interprofessional learning (teamwork and collaboration, positive professional identity, roles, and responsibilities). We also found a significant decrease in students’ social interaction anxiety after the IPE simulation. Conclusions The narrative of our experiences described in this manuscript could be considered by higher education institutions seeking to forge meaningful external partnerships in their effort to establish interprofessional global health education
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