74 resultados para 12930-028
Resumo:
Constructed wetlands are among the most common Water Sensitive Urban Design (WSUD) measures for stormwater treatment. These systems have been extensively studied to understand their performance and influential treatment processes. Unfortunately, most past studies have been undertaken considering a wetland system as a lumped system with a primary focus on the reduction of the event mean concentration (EMC) values of specific pollutant species or total pollutant load removal. This research study adopted an innovative approach by partitioning the inflow runoff hydrograph and then investigating treatment performance in each partition and their relationships with a range of hydraulic factors. The study outcomes confirmed that influenced by rainfall characteristics, the constructed wetland displays different treatment characteristics for the initial and later sectors of the runoff hydrograph. The treatment of small rainfall events (<15 mm) is comparatively better at the beginning of runoff events while the trends in pollutant load reductions for large rainfall events (>15 mm) are generally lower at the beginning and gradually increase towards the end of rainfall events. This highlights the importance of ensuring that the inflow into a constructed wetland has low turbulence in order to achieve consistent treatment performance for both, small and large rainfall events.
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In this paper, a class of unconditionally stable difference schemes based on the Pad´e approximation is presented for the Riesz space-fractional telegraph equation. Firstly, we introduce a new variable to transform the original dfferential equation to an equivalent differential equation system. Then, we apply a second order fractional central difference scheme to discretise the Riesz space-fractional operator. Finally, we use (1, 1), (2, 2) and (3, 3) Pad´e approximations to give a fully discrete difference scheme for the resulting linear system of ordinary differential equations. Matrix analysis is used to show the unconditional stability of the proposed algorithms. Two examples with known exact solutions are chosen to assess the proposed difference schemes. Numerical results demonstrate that these schemes provide accurate and efficient methods for solving a space-fractional hyperbolic equation.
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OBJECTIVES To estimate the burden of disease attributable to diabetes by sex and age group in South Africa in 2000. DESIGN The framework adopted for the most recent World Health Organization comparative risk assessment (CRA) methodology was followed. Small community studies used to derive the prevalence of diabetes by population group were weighted proportionately for a national estimate. Population-attributable fractions were calculated and applied to revised burden of disease estimates. Monte Carlo simulation-modelling techniques were used for uncertainty analysis. SETTING South Africa. SUBJECTS Adults 30 years and older. OUTCOME MEASURES Mortality and disability-adjusted life years (DALYs) for ischaemic heart disease (IHD), stroke, hypertensive disease and renal failure. RESULTS Of South Africans aged >or= 30 years, 5.5% had diabetes which increased with age. Overall, about 14% of IHD, 10% of stroke, 12% of hypertensive disease and 12% of renal disease burden in adult males and females (30+ years) were attributable to diabetes. Diabetes was estimated to have caused 22,412 (95% uncertainty interval 20,755 - 24,872) or 4.3% (95% uncertainty interval 4.0 - 4.8%) of all deaths in South Africa in 2000. Since most of these occurred in middle or old age, the loss of healthy life years comprises a smaller proportion of the total 258,028 DALYs (95% uncertainty interval 236,856 - 290,849) in South Africa in 2000, accounting for 1.6% (95% uncertainty interval 1.5 - 1.8%) of the total burden. CONCLUSIONS Diabetes is an important direct and indirect cause of burden in South Africa. Primary prevention of the disease through multi-level interventions and improved management at primary health care level are needed.
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BACKGROUND Tilted disc syndrome (TDS) is associated with characteristic ocular findings. The purpose of this study was to evaluate the ocular, refractive, and biometric characteristics in patients with TDS. METHODS This case-control study included 41 eyes of 25 patients who had established TDS and 40 eyes of 20 healthy control subjects. All participants underwent a complete ocular examination, including refraction and analysis using Fourier transformation, slit lamp biomicroscopy, pachymetry, keratometry, and ocular biometry. Corneal topography examinations were performed in the syndrome group only. RESULTS There were no significant differences in spherical equivalent (P = 0.13) and total astigmatism (P = 0.37) between groups. However, mean best spectacle-corrected visual acuity (Log Mar) was significantly worse in TDS patients (P = 0.003). The lenticular astigmatism was greater in the syndrome group, whereas the corneal component was greater in controls (P = 0.059 and P = 0.028, respectively). The measured biometric features were the same in both groups, except for the lens thickness and lens-axial length factor, which were greater in the TDS group (P = 0.007 and P = 0.055, respectively). CONCLUSIONS Clinically significant lenticular astigmatism, more oblique corneal astigmatism, and thicker lenses were characteristic findings in patients with TDS.
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Kimberlite drill core from the Muskox pipe (Northern Slave Province, Nunavut, Canada) highlights the difficulties in distinguishing coherent from fragmental kimberlite and assessing the volcanological implications of the apparent gradational contact between the two facies. Using field log data, petrography, and several methods to quantify crystal and xenolith sizes and abundances, the pipe is divided into two main facies, dark-coloured massive kimberlite (DMK) and light-coloured fragmental kimberlite (LFK). DMK is massive and homogeneous, containing country-rock lithic clasts (~ 10%) and olivine macrocrysts (~ 15%) set in a dark, typically well crystallised, interstitial medium containing abundant microphenocrysts of olivine (~ 15%), opaques and locally monticellite, all of which are enclosed by mostly serpentine. In general, LFK is also massive and structureless, containing ~ 20% country-rock lithic clasts and ~ 12% olivine macrocrysts. These framework components are supported in a matrix of serpentinized olivine microphenocrysts (10%), microlites of clinopyroxene, and phlogopite, all of which are enclosed by serpentine. The contact between DMK and LFK facies is rarely sharp, and more commonly is gradational (from 5 cm to ~ 10 m). The contact divides the pipe roughly in half and is sub-vertical with an irregular shape, locally placing DMK facies both above and below the fragmental rocks. Most features of DMK are consistent with a fragmental origin, particularly the crystal- and xenolith-rich nature (~ 55-65%), but there are some similarities with rocks described as coherent kimberlite in the literature. We discuss possible origins of gradational contacts and consider the significance for understanding the origin of the DMK facies, with an emphasis on the complications of alteration overprinting of primary textures.
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The NTRK3 gene (also known as TRKC) encodes a high affinity receptor for the neurotrophin 3'-nucleotidase (NT3), which is implicated in oligodendrocyte and myelin development. We previously found that white matter integrity in young adults is related to common variants in genes encoding neurotrophins and their receptors. This underscores the importance of neurotrophins for white matter development. NTRK3 variants are putative risk factors for schizophrenia, bipolar disorder, and obsessive-compulsive disorder hoarding, suggesting that some NTRK3 variants may affect the brain.To test this, we scanned 392 healthy adult twins and their siblings (mean age, 23.6. ±. 2.2. years; range: 20-29. years) with 105-gradient 4-Tesla diffusion tensor imaging (DTI). We identified 18 single nucleotide polymorphisms (SNPs) in the NTRK3 gene that have been associated with neuropsychiatric disorders. We used a multi-SNP model, adjusting for family relatedness, age, and sex, to relate these variants to voxelwise fractional anisotropy (FA) - a DTI measure of white matter integrity.FA was optimally predicted (based on the highest false discovery rate critical p), by five SNPs (rs1017412, rs2114252, rs16941261, rs3784406, and rs7176429; overall FDR critical p=. 0.028). Gene effects were widespread and included the corpus callosum genu and inferior longitudinal fasciculus - regions implicated in several neuropsychiatric disorders and previously associated with other neurotrophin-related genetic variants in an overlapping sample of subjects. NTRK3 genetic variants, and neurotrophins more generally, may influence white matter integrity in brain regions implicated in neuropsychiatric disorders.
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This paper investigates a pilot desalination system which consists of a direct expansion solar assisted heat pump (DXSAHP) coupled to a single-effect evaporator unit. The working fluid used is R134a and distillate is obtained via falling film evaporation and flashing in the unit. Experiments have been conducted in both day and night meteorological conditions in Singapore and the effects of solar irradiation and compressor speed have been studied against the system performance. From the experiments, the Performance Ratio (PR) obtained ranges from 0.43 to 0.88, the average Coefficient of Performance (COP) was 8 and the highest distillate production recorded was 1.38 kg/h
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BACKGROUND Given moderately strong genetic contributions to variation in alcoholism and heaviness of drinking (50% to 60% heritability) with high correlation of genetic influences, we have conducted a quantitative trait genome-wide association study (GWAS) for phenotypes related to alcohol use and dependence. METHODS Diagnostic interview and blood/buccal samples were obtained from sibships ascertained through the Australian Twin Registry. Genome-wide single nucleotide polymorphism (SNP) genotyping was performed with 8754 individuals (2062 alcohol-dependent cases) selected for informativeness for alcohol use disorder and associated quantitative traits. Family-based association tests were performed for alcohol dependence, dependence factor score, and heaviness of drinking factor score, with confirmatory case-population control comparisons using an unassessed population control series of 3393 Australians with genome-wide SNP data. RESULTS No findings reached genome-wide significance (p = 8.4 x 10(-8) for this study), with lowest p value for primary phenotypes of 1.2 x 10(-7). Convergent findings for quantitative consumption and diagnostic and quantitative dependence measures suggest possible roles for a transmembrane protein gene (TMEM108) and for ANKS1A. The major finding, however, was small effect sizes estimated for individual SNPs, suggesting that hundreds of genetic variants make modest contributions (1/4% of variance or less) to alcohol dependence risk. CONCLUSIONS We conclude that: - 1) meta-analyses of consumption data may contribute usefully to gene discovery; - 2) translation of human alcoholism GWAS results to drug discovery or clinically useful prediction of risk will be challenging, and; - 3) through accumulation across studies, GWAS data may become valuable for improved genetic risk differentiation in research in biological psychiatry (e.g., prospective high-risk or resilience studies).
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Out-of-plane behaviour of mortared and mortarless masonry walls with various forms of reinforcement, including unreinforced masonry as a base case is examined using a layered shell element based explicit finite element modelling method. Wall systems containing internal reinforcement, external surface reinforcement and intermittently laced reinforced concrete members and unreinforced masonry panels are considered. Masonry is modelled as a layer with macroscopic orthotropic properties; external reinforcing render, grout and reinforcing bars are modelled as distinct layers of the shell element. Predictions from the layered shell model have been validated using several out-of-plane experimental datasets reported in the literature. The model is used to examine the effectiveness of two retrofitting schemes for an unreinforced masonry wall.
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Green building incentives are important to promoting green building. However, it lacks a systematic review of existing knowledge. This paper aims to elicit the common themes in studies of green building incentives through a systematic review. It is found that the common research areas into green building incentives are incentive categorisation, its effectiveness on promoting green building development, criticism of current green incentive implementation and strategies for improving green building incentives. Green building incentives are categorised into external and internal incentives. The external incentive is a forced choice whereby beneficiaries are required to fulfil specified conditions or requirements before benefitting, while the internal incentive allows beneficiaries to be incentivised out of volition because of the appeal of the benefits of green buildings. The external incentives, which are largely provided by the government, are divided into financial and non-financial incentives. It is found that owners are more incentivised by non-financial incentives. In terms of effectiveness, both external and internal incentives are important instruments for promoting green building, although it is not clear which are the more effective. Furthermore, the review uncovered criticisms of external green building incentives, which mainly focus on shortcomings in administering the incentives by the government. The strategies for improving green building incentives were also found, the most important of these being the need for the government to redirect its approach of providing incentives so that owners can be encouraged to pursue green building. The review findings signify the importance of the government in relation to green building incentives. Further research areas that could expand the knowledge of green building incentives are also recommended.
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The association between temperatures and risk of cardiovascular mortality has been recognized but the association drawn from previous meta-analysis was weak due to the lack of sufficient studies. This paper presented a review with updated reports in the literature about the risk of cardiovascular hospitalization in relation to different temperature exposures and examined the dose–response relationship of temperature-cardiovascular hospitalization by change in units of temperature, latitudes, and lag days. The pooled effect sizes were calculated for cold, heat, heatwave, and diurnal variation using random-effects meta-analysis, and the dose–response relationship of temperature-cardiovascular admission was modelled using random-effect meta-regression. The Cochrane Q-test and index of heterogeneity (I2) were used to evaluate heterogeneity, and Egger's test was used to evaluate publication bias. Sixty-four studies were included in meta-analysis. The pooled results suggest that for a change in temperature condition, the risk of cardiovascular hospitalization increased 2.8% (RR, 1.028; 95% CI, 1.021–1.035) for cold exposure, 2.2% (RR, 1.022; 95% CI, 1.006–1.039) for heatwave exposure, and 0.7% (RR, 1.007; 95% CI, 1.002–1.012) for an increase in diurnal temperature. However no association was observed for heat exposure. The significant dose–response relationship of temperature — cardiovascular admission was found with cold exposure and diurnal temperature. Increase in one-day lag caused a marginal reduction in risk of cardiovascular hospitalizations for cold exposure and diurnal variation, and increase in latitude was associated with a decrease in risk of cardiovascular hospitalizations for diurnal temperature only. There is a significant short-term effect of cold exposure, heatwave and diurnal variation on cardiovascular hospitalizations. Further research is needed to understand the temperature-cardiovascular relationship for different climate areas.
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This comprehensive report (748 pages) scopes a new nutrition policy for Australia (RFT 028/1213) Australian Department of Health and Ageing. Optimum nutrition is fundamental to good health. It is essential for the normal growth and physical and cognitive development of infants and children, contributes significantly to quality of life, wellbeing and workforce productivity, enhances resistance to infection and reduces the risk of obesity, chronic disease and premature death (AIHW 2012; NHMRC 2013). This scoping study reviews the current literature to identify: - key population health issues related to diet and nutrition within the Australian population; and - where gaps in current policy are evident. The scoping study reviews the literature on past and present national and international nutrition policies, strategies (policy actions), interventions and evaluations. The study analyses the evidence from the literature review and formulates recommendations regarding the key elements of effective nutrition policies including scope, guiding principles, format, key inclusions (content), development processes, governance, implementation, timelines, monitoring and surveillance, evaluation and review to guide the development of a new comprehensive National Nutrition Policy for Australia.
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The goal of this study was to investigate the use of custom-made orthopedic shoes (OS) and the association between the use of OS and the most relevant aspects of their usability. Over a 6-month period, patients meeting the inclusion criteria were recruited by 12 orthopedic shoe companies scattered throughout the Netherlands and asked to complete a questionnaire composed of a pre- and post-OS section. Patients with different pathologies were included in the study (n = 339; response 67%). Mean age of the patients was 63 +/- 15 years, and 38% were male. Three months after delivery, 81% of the patients used their OS frequently (4-7 days/week), 13% occasionally (1-3 days/week), and 6% did not use their OS. Associations were found between use and all measured aspects of usability (p-values varied from <0.001 to 0.028). Patients who used their OS more often had a more positive opinion regarding all the aspects of usability. We conclude that all aspects of the usability of OS are relevant in relation to their use and should be taken into account when prescribing and evaluating OS.
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Uncertainty inherent to heavy metal build-up and wash-off stems from process variability. This results in inaccurate interpretation of stormwater quality model predictions. The research study has characterised the variability in heavy metal build-up and wash-off processes based on the temporal variations in particle-bound heavy metals commonly found on urban roads. The study outcomes found that the distribution of Al, Cr, Mn, Fe, Ni, Cu, Zn, Cd and Pb were consistent over particle size fractions <150µm and >150µm, with most metals concentrated in the particle size fraction <150µm. When build-up and wash-off are considered as independent processes, the temporal variations in these processes in relation to the heavy metals load are consistent with variations in the particulate load. However, the temporal variations in the load in build-up and wash-off of heavy metals and particulates are not consistent for consecutive build-up and wash-off events that occur on a continuous timeline. These inconsistencies are attributed to interactions between heavy metals and particulates <150µm and >150µm, which are influenced by particle characteristics such as organic matter content. The behavioural variability of particles determines the variations in the heavy metals load entrained in stormwater runoff. Accordingly, the variability in build-up and wash-off of particle-bound pollutants needs to be characterised in the description of pollutant attachment to particulates in stormwater quality modelling. This will ensure the accounting of process uncertainty, and thereby enhancing the interpretation of the outcomes derived from modelling studies.