999 resultados para convection term discretization


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Background Heat-related impacts may have greater public health implications as climate change continues. It is important to appropriately characterize the relationship between heatwave and health outcomes. However, it is unclear whether a case-crossover design can be effectively used to assess the event- or episode-related health effects. This study examined the association between exposure to heatwaves and mortality and emergency hospital admissions (EHAs) from non-external causes in Brisbane, Australia, using both case-crossover and time series analyses approaches. Methods Poisson generalised additive model (GAM) and time-stratified case-crossover analyses were used to assess the short-term impact of heatwaves on mortality and EHAs. Heatwaves exhibited a significant impact on mortality and EHAs after adjusting for air pollution, day of the week, and season. Results For time-stratified case-crossover analysis, odds ratios of mortality and EHAs during heatwaves were 1.62 (95% confidence interval (CI): 1.36–1.94) and 1.22 (95% CI: 1.14–1.30) at lag 1, respectively. Time series GAM models gave similar results. Relative risks of mortality and EHAs ranged from 1.72 (95% CI: 1.40–2.11) to 1.81 (95% CI: 1.56–2.10) and from 1.14 (95% CI: 1.06–1.23) to 1.28 (95% CI: 1.21–1.36) at lag 1, respectively. The risk estimates gradually attenuated after the lag of one day for both case-crossover and time series analyses. Conclusions The risk estimates from both case-crossover and time series models were consistent and comparable. This finding may have implications for future research on the assessment of event- or episode-related (e.g., heatwave) health effects.

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Design Semi-structured interviews. Setting 2 open, acute care units of a large tertiary mental health facility in Queensland, Australia. Patients 12 patients (58% men) who were 18–52 years of age and were secluded in the previous 7 days (mean duration 3.4 h). Methods Semi-structured, thematically organised interviews were audiotaped and transcribed. Transcripts were checked for errors against the audiotaped versions and were analysed using the process of meaning categorisation. Themes were identified and coded to produce categories. All members of the research team agreed on the final categorisations. These broad categories were further analysed, and themes were used to reflect patients' experiences of seclusion. Main findings 5 recurrent themes emerged. (1) Patients described the use of seclusion. Some patients thought that seclusion was used inappropriately and that the seclusion period was of more benefit to …

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The number of road crashes leading to disabilities is increasing alarmingly and constitutes a significant public health problem in many countries. So far, very few studies have been conducted to explore the impacts on persons with disabilities due to road crashes, and their families. This gap in the literature is especially large for low income countries such as Cambodia. This review explored relevant publications to provide background on persons in Cambodia with disabilities due to road crashes and their families. The review adds to the limited knowledge base in this area and has the potential to provide information on contextual issues relevant to the experience of disability in other developing countries, such as poverty, stigma and lack of resources. The findings of this review form the first part of a PhD study that will contribute to the development of informed policy change leading towards a safer system for all road users, including persons with disabilities.

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Introduction Economic evaluations of interventions in the hospital setting often rely on the estimated long-term impact on patient survival. Estimates of mortality rates and long-term outcomes among patients discharged alive from the intensive care unit (ICU) are lacking from lower- and middle-income countries. This study aimed to assess the long-term survival and life expectancy (LE) amongst post-ICU patients in Thailand, a middle-income country. Methods In this retrospective cohort study, data from a regional tertiary hospital in northeast Thailand and the regional death registry were linked and used to assess patient survival time after ICU discharge. Adult ICU patients aged at least 15 years who had been discharged alive from an ICU between 1 January 2004 and 31 December 2005 were included in the study, and the death registry was used to determine deaths occurring in this cohort up to 31st December 2010. These data were used in conjunction with standard mortality life tables to estimate annual mortality and life expectancy. Results This analysis included 10,321 ICU patients. During ICU admission, 3,251 patients (31.5%) died. Of 7,070 patients discharged alive, 2,527 (35.7%) were known to have died within the five-year follow-up period, a mortality rate 2.5 times higher than that in the Thai general population (age and sex matched). The mean LE was estimated as 18.3 years compared with 25.2 years in the general population. Conclusions Post-ICU patients experienced much higher rates of mortality than members of the general population over the five-year follow-up period, particularly in the first year after discharge. Further work assessing Health Related Quality of Life (HRQOL) in both post-ICU patients and in the general population in developing countries is needed.

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Natural convection thermal boundary layer adjacent to the heated inclined wall of a right angled triangle with an adiabatic fin attached to that surface is investigated by numerical simulations. The finite volume based unsteady numerical model is adopted for the simulation. It is revealed from the numerical results that the development of the boundary layer along the inclined surface is characterized by three distinct stages, i.e. a start-up stage, a transitional stage and a steady stage. These three stages can be clearly identified from the numerical simulations. Moreover, in presence of adiabatic fin, the thermal boundary layer adjacent to the inclined wall breaks initially. However, it is reattached with the downstream boundary layer next to the fin. More attention has been given to the boundary layer development near the fin area.

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OBJECTIVE: We present and analyze long-term outcomes following multimodal therapy for esophageal cancer, in particular the relative impact of histomorphologic tumor regression and nodal status. PATIENTS AND METHODS: A total of 243 patients [(adenocarcinoma (n = 170) and squamous cell carcinoma (n = 73)] treated with neoadjuvant chemoradiotherapy in the period 1990 to 2004 were followed prospectively with a median follow-up of 60 months. Pathologic stage and tumor regression grade (TRG) were documented, the site of first failure was recorded, and Kaplan-Meier survival curves were plotted. RESULTS: Thirty patients (12%) did not undergo surgery due to disease progression or deteriorated performance status. Forty-one patients (19%) had a complete pathologic response (pCR), and there were 31(15%) stage I, 69 (32%) stage II, and 72 (34%) stage III cases. The overall median survival was 18 months, and the 5-year survival was 27%. The 5-year survival of patients achieving a pCR was 50% compared with 37% in non-pCR patients who were node-negative (P = 0.86). Histomorphologic tumor regression was not associated with pre-CRT cTN stage but was significantly (P < 0.05) associated with ypN stage. By multivariate analysis, ypN status (P = 0.002) was more predictive of overall survival than TRG (P = 0.06) or ypT stage (P = 0.39). CONCLUSION: Achieving a node-negative status is the major determinant of outcome following neoadjuvant chemoradiotherapy. Histomorphologic tumor regression is less predictive of outcome than pathologic nodal status (ypN), and the need to include a primary site regression score in a new staging classification is unclear. © 2007 Lippincott Williams & Wilkins, Inc.

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Autologous bone marrow-derived mesenchymal stem cell (BMSCs)-based therapies show great potential in regenerative medicine. However, long-term storage and preservation of BMSCs for clinical use is still a great clinical challenge. The present study aimed to analyze the effect of long-term cryopreservation on the regenerative ability of BMSCs. After cryopreservation of BMSCs from beagle dogs for three years, cell viability, and quantitative analysis of alkaline phosphatase (ALP) activity, surface adherence, and mineralized nodule formation were analyzed. BMSCs in cell-scaffold complex were then implanted into nude mice. There was no significant difference in cell viability and ALP activity between osteogenic differentiation and non-osteogenic differentiation of BMSCs, and BMSCs in cell-scaffold complex retained osteogenic differentiation ability in vivo. These results indicate that long-term cryopreserved BMSCs maintain their have capacity to contribute to regeneration.

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Background Foot ulcers are a leading cause of diabetes-related hospitalisations. Clinical training has been shown to be beneficial in foot ulcer management. Recently, improved self-confidence in podiatrists was reported immediately after foot ulcer simulation training (FUST) pilot programs. This study aimed to investigate the longer-term impacts of the FUST program on podiatrists’ self-confidence over 12 months in a larger sample. Methods Participants were podiatrists attending a two-day FUST course comprising web-based interactive learning, low-fidelity part-tasks and high-fidelity full clinical scenarios. Primary outcome measures included participants’ self-confidence measured pre-, (immediately) post-, 6-month post- and 12-month post-course via a purpose designed 21-item survey using a five-point Likert scale (1=Very limited, 5=Highly confident). Participants’ perceptions of knowledge gained, satisfaction, relevance and fidelity were also investigated. ANOVA and post hoc tests were used to test any differences between groups. Results Thirty-four participants completed FUST. Survey response rates were 100% (pre), 82% (post), 74% (6-month post), and 47% (12-month post). Overall mean scores were 3.13 (pre), 4.49 (post), 4.35 (6-month post) and 4.30 (12-month post) (p < 0.05); post hoc tests indicated no differences between the immediately, 6-month and 12-month post group scores (p > 0.05). Satisfaction, knowledge, relevance and fidelity were all rated highly. Conclusion This study suggests that significant short-term improvements in self-confidence to manage foot ulcers via simulation training are retained over the longer term. It is likely that improved self-confidence leads to improved foot ulcer clinical practice and outcomes; although this requires further research.

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We conducted a systematic review of the literature on telemedicine use in long-term care facilities (LTCFs) and assessed the quality of the published evidence. A database search identified 22 papers which met the inclusion criteria. The quality of the studies was assessed and if they contained economic data, they were rated according to standard criteria. The clinical services provided by telemedicine included allied health (n = 5), dermatology (3), general practice (4), neurology (2), geriatrics (1), psychiatry (4) and multiple specialities (3). Most studies (17) employed real-time telemedicine using videoconferencing. The remaining five used store and forward telemedicine. The papers focused on economics (3), feasibility (9), stakeholder satisfaction (12), reliability (5) and service implementation (2). Overall, the quality of evidence for telemedicine in LTCFs was low. There was only one small randomised controlled trial (RCT). Most studies were observational and qualitative, and focused on utilisation. They were mainly based on surveys and interviews of stakeholders. A few studies evaluated the cost associated with implementing telemedicine services in LTCFs. The present review shows that there is evidence for feasibility and stakeholder satisfaction in using telemedicine in LTCFs in a number of clinical specialities.

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Numerical simulations of thermomagnetic convection of paramagnetic fluids placed in a micro-gravity condition (g ≈ 0) and under a uniform vertical gradient magnetic field in an open ended square enclosure with ramp heating temperature condition applied on a vertical wall is investigated in this study. In presence of the strong magnetic gradient field thermal convection of the paramagnetic fluid might take place even in a zero-gravity environment as a direct consequence of temperature differences occurring within the fluid. The thermal boundary layer develops adjacent to the hot wall as soon as the ramp temperature condition is applied on it. There are two scenarios can be observed based on the ramp heating time. The steady state of the thermal boundary layer can be reached before the ramp time is finished or vice versa. If the ramp time is larger than the quasi-steady time then the thermal boundary layer is in a quasi-steady mode with convection balancing conduction after the quasi-steady time. Further increase of the heat input simply accelerates the flow to maintain the proper thermal balance. Finally, the boundary layer becomes completely steady state when the ramp time is finished. Effects of magnetic Rayleigh number, Prandtl number and paramagnetic fluid parameter on the flow pattern and heat transfer are presented.

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Pilot cars are used in one-lane two-way work zones to guide traffic and keep their speeds within posted limits. While many studies have examined the effectiveness of measures to reduce vehicle speeds in work zones, little is known about the reductions achievable through the use of pilot cars. This paper examines the effectiveness of a pilot car in reducing travel speeds in a rural highway work zone in Queensland, Australia. Analysis of speed data covering a period of five days showed that a pilot car reduced average speeds at the treatment location, but not downstream. The proportion of vehicles speeding through the activity area was also reduced, particularly those traveling at 10 km/h or more above the posted limit. Motorists were more likely to speed during the day, under a 40 kh/h limit, when traffic volumes were higher and when there were fewer vehicles in the traffic stream. Medium vehicles were less likely to speed in the presence of a pilot car than light vehicles. To maximize these benefits, it is necessary to ensure that the pilot car itself is not speeding.

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A multi-resource multi-stage scheduling methodology is developed to solve short-term open-pit mine production scheduling problems as a generic multi-resource multi-stage scheduling problem. It is modelled using essential characteristics of short-term mining production operations such as drilling, sampling, blasting and excavating under the capacity constraints of mining equipment at each processing stage. Based on an extended disjunctive graph model, a shifting-bottleneck-procedure algorithm is enhanced and applied to obtain feasible short-term open-pit mine production schedules and near-optimal solutions. The proposed methodology and its solution quality are verified and validated using a real mining case study.

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To enhance the performance of the k-nearest neighbors approach in forecasting short-term traffic volume, this paper proposed and tested a two-step approach with the ability of forecasting multiple steps. In selecting k-nearest neighbors, a time constraint window is introduced, and then local minima of the distances between the state vectors are ranked to avoid overlappings among candidates. Moreover, to control extreme values’ undesirable impact, a novel algorithm with attractive analytical features is developed based on the principle component. The enhanced KNN method has been evaluated using the field data, and our comparison analysis shows that it outperformed the competing algorithms in most cases.

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Background Indigenous children in high-income countries have a heavy burden of bronchiectasis unrelated to cystic fibrosis. We aimed to establish whether long-term azithromycin reduced pulmonary exacerbations in Indigenous children with non-cystic-fibrosis bronchiectasis or chronic suppurative lung disease. Methods Between Nov 12, 2008, and Dec 23, 2010, we enrolled Indigenous Australian, Maori, and Pacific Island children aged 1—8 years with either bronchiectasis or chronic suppurative lung disease into a multicentre, double-blind, randomised, parallel-group, placebo-controlled trial. Eligible children had had at least one pulmonary exacerbation in the previous 12 months. Children were randomised (1:1 ratio, by computer-generated sequence with permuted block design, stratified by study site and exacerbation frequency [1—2 vs ≥3 episodes in the preceding 12 months]) to receive either azithromycin (30 mg/kg) or placebo once a week for up to 24 months. Allocation concealment was achieved by double-sealed, opaque envelopes; participants, caregivers, and study personnel were masked to assignment until after data analysis. The primary outcome was exacerbation (respiratory episodes treated with antibiotics) rate. Analysis of the primary endpoint was by intention to treat. At enrolment and at their final clinic visits, children had deep nasal swabs collected, which we analysed for antibiotic-resistant bacteria. This study is registered with the Australian New Zealand Clinical Trials Registry; ACTRN12610000383066. Findings 45 children were assigned to azithromycin and 44 to placebo. The study was stopped early for feasibility reasons on Dec 31, 2011, thus children received the intervention for 12—24 months. The mean treatment duration was 20·7 months (SD 5·7), with a total of 902 child-months in the azithromycin group and 875 child-months in the placebo group. Compared with the placebo group, children receiving azithromycin had significantly lower exacerbation rates (incidence rate ratio 0·50; 95% CI 0·35—0·71; p<0·0001). However, children in the azithromycin group developed significantly higher carriage of azithromycin-resistant bacteria (19 of 41, 46%) than those receiving placebo (four of 37, 11%; p=0·002). The most common adverse events were non-pulmonary infections (71 of 112 events in the azithromycin group vs 132 of 209 events in the placebo group) and bronchiectasis-related events (episodes or investigations; 22 of 112 events in the azithromycin group vs 48 of 209 events in the placebo group); however, study drugs were well tolerated with no serious adverse events being attributed to the intervention. Interpretation Once-weekly azithromycin for up to 24 months decreased pulmonary exacerbations in Indigenous children with non-cystic-fibrosis bronchiectasis or chronic suppurative lung disease. However, this strategy was also accompanied by increased carriage of azithromycin-resistant bacteria, the clinical consequences of which are uncertain, and will need careful monitoring and further study.

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Background Breastfeeding self-efficacy (BFSE) supports breastfeeding initiation and duration. Challenges to breastfeeding may undermine BFSE, but second-line strategies including nipple shields, syringe, cup, supply line and bottle feeding may support breastfeeding until challenges are resolved. The primary aim of this study was to examine BFSE in a sample of women using second-line strategies for feeding healthy term infants in the first week postpartum. Methods A retrospective self-report study was conducted using the Breastfeeding Self-Efficacy Scale - Short Form (BSES-SF), demographic and infant feeding questionnaires. Breastfeeding women who gave birth to a singleton healthy term infant at one private metropolitan birthing facility in Australia from November 2008 to February 2009 returned anonymous questionnaires by mail. Results A total of 128 (73 multiparous, 55 primiparous) women participated in the study. The mean BSES-SF score was 51.18 (Standard deviation, SD: 12.48). The median BSES-SF score was 53. Of women using a second-line strategy, 16 exceeded the median, and 42 were below. Analyses using Kruskal-Wallis tests confirmed this difference was statistically significant (H = 21.569, p = 0.001). The rate of second-line strategy use was 48%. The four most commonly used second-line strategies were: bottles with regular teats (77%); syringe feeding (44%); bottles with wide teats (34%); and nipple shields (27%). Seven key challenges were identified that contributed to the decision to use second-line strategies, including: nipple pain (40%); unsettled infant (40%); insufficient milk supply (37%); fatigue (37%); night nursery care (25%); infant weight loss > 10% (24%); and maternal birth associated pain (20%). Skin-to-skin contact at birth was commonly reported (93%). At seven days postpartum 124 women (97%) were continuing to breastfeed. Conclusions The high rate of use of second-line strategies identified in this study and high rate of breastfeeding at day seven despite lower BFSE indicate that such practices should not be overlooked by health professionals. The design of this study does not enable determination of cause-effect relationships to identify factors which contribute to use of second-line strategies. Nevertheless, the significantly lower BSES-SF score of women using a second-line strategy highlights this group of women have particular needs that require attention.