924 resultados para Occupational and Environmental Medicine


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The Mediterranean Sea constitutes a unique environment to study cold-seep ecosystems due to the presence of different geodynamic settings, from an active margin along the Mediterranean Ridge (MR) to a passive margin in the Nile Deep-Sea Fan (NDSF). We attempted to identify the structure of benthic communities associated with the Napoli and Amsterdam mud volcanoes (MVs) located on the MR and to establish the links between faunal distribution and environmental conditions at different spatial scales. Comparison between the 2 MVs revealed that the faunal distribution seemed to be mainly controlled by the characteristics of the microhabitats. On both geological structures, the variability between the different microhabitats was higher than the variability observed between replicates of the same microhabitat, and the distribution of macro-fauna was apparently linked to gradients in physico-chemical conditions. The peripheral sites from Napoli were generally more oxygenated and harboured lower species richness than the active sites. The reduced sediment microhabitat from Amsterdam presented the highest methane concentrations and was mainly colonised by symbiont-bearing vesicomyid bivalves and heterotrophic dorvilleid polychaetes. Overall, a higher taxonomic diversity was observed on Napoli. Sub-stratum type was hypothesised to be the second factor influencing faunal distribution. The results of this study highlight the high heterogeneity of faunal communities associated with seep ecosystems within this region and the need to pursue investigations at various spatial and temporal scales.

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The PhD project addresses the potential of using concentrating solar power (CSP) plants as a viable alternative energy producing system in Libya. Exergetic, energetic, economic and environmental analyses are carried out for a particular type of CSP plants. The study, although it aims a particular type of CSP plant – 50 MW parabolic trough-CSP plant, it is sufficiently general to be applied to other configurations. The novelty of the study, in addition to modeling and analyzing the selected configuration, lies in the use of a state-of-the-art exergetic analysis combined with the Life Cycle Assessment (LCA). The modeling and simulation of the plant is carried out in chapter three and they are conducted into two parts, namely: power cycle and solar field. The computer model developed for the analysis of the plant is based on algebraic equations describing the power cycle and the solar field. The model was solved using the Engineering Equation Solver (EES) software; and is designed to define the properties at each state point of the plant and then, sequentially, to determine energy, efficiency and irreversibility for each component. The developed model has the potential of using in the preliminary design of CSPs and, in particular, for the configuration of the solar field based on existing commercial plants. Moreover, it has the ability of analyzing the energetic, economic and environmental feasibility of using CSPs in different regions of the world, which is illustrated for the Libyan region in this study. The overall feasibility scenario is completed through an hourly analysis on an annual basis in chapter Four. This analysis allows the comparison of different systems and, eventually, a particular selection, and it includes both the economic and energetic components using the “greenius” software. The analysis also examined the impact of project financing and incentives on the cost of energy. The main technological finding of this analysis is higher performance and lower levelized cost of electricity (LCE) for Libya as compared to Southern Europe (Spain). Therefore, Libya has the potential of becoming attractive for the establishment of CSPs in its territory and, in this way, to facilitate the target of several European initiatives that aim to import electricity generated by renewable sources from North African and Middle East countries. The analysis is presented a brief review of the current cost of energy and the potential of reducing the cost from parabolic trough- CSP plant. Exergetic and environmental life cycle assessment analyses are conducted for the selected plant in chapter Five; the objectives are 1) to assess the environmental impact and cost, in terms of exergy of the life cycle of the plant; 2) to find out the points of weakness in terms of irreversibility of the process; and 3) to verify whether solar power plants can reduce environmental impact and the cost of electricity generation by comparing them with fossil fuel plants, in particular, Natural Gas Combined Cycle (NGCC) plant and oil thermal power plant. The analysis also targets a thermoeconomic analysis using the specific exergy costing (SPECO) method to evaluate the level of the cost caused by exergy destruction. The main technological findings are that the most important contribution impact lies with the solar field, which reports a value of 79%; and the materials with the vi highest impact are: steel (47%), molten salt (25%) and synthetic oil (21%). The “Human Health” damage category presents the highest impact (69%) followed by the “Resource” damage category (24%). In addition, the highest exergy demand is linked to the steel (47%); and there is a considerable exergetic demand related to the molten salt and synthetic oil with values of 25% and 19%, respectively. Finally, in the comparison with fossil fuel power plants (NGCC and Oil), the CSP plant presents the lowest environmental impact, while the worst environmental performance is reported to the oil power plant followed by NGCC plant. The solar field presents the largest value of cost rate, where the boiler is a component with the highest cost rate among the power cycle components. The thermal storage allows the CSP plants to overcome solar irradiation transients, to respond to electricity demand independent of weather conditions, and to extend electricity production beyond the availability of daylight. Numerical analysis of the thermal transient response of a thermocline storage tank is carried out for the charging phase. The system of equations describing the numerical model is solved by using time-implicit and space-backward finite differences and which encoded within the Matlab environment. The analysis presented the following findings: the predictions agree well with the experiments for the time evolution of the thermocline region, particularly for the regions away from the top-inlet. The deviations observed in the near-region of the inlet are most likely due to the high-level of turbulence in this region due to the localized level of mixing resulting; a simple analytical model to take into consideration this increased turbulence level was developed and it leads to some improvement of the predictions; this approach requires practically no additional computational effort and it relates the effective thermal diffusivity to the mean effective velocity of the fluid at each particular height of the system. Altogether the study indicates that the selected parabolic trough-CSP plant has the edge over alternative competing technologies for locations where DNI is high and where land usage is not an issue, such as the shoreline of Libya.

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During the next two decades global construction investment will top $100 trillion (US). New directions in construction innovation will be driven by industry to address challenges in skills, environmental regulations and maximise the benefits of low carbon building systems. Growth productivity catalysts such as offsite construction, higher BIM levels and multi-skill operatives will be instrumental contributors in achieving some of these aims. The increasing use of timber architecture across domestic, public and commercial buildings also opens new pathways. This event will discuss some of the key changes taking place in the UK and parallels with Hong Kong’s ambitions towards delivering a sustainable legacy in this sector.

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Steel slag is a byproduct of iron and steel production by the metallurgical industries. Annually, 21 million tons of steel slag is produced in the United States. Most of the slag is landfilled, which represents a significant economic loss and a waste of valuable land space. Steel slag has great potential for the construction of highway embankments; however, its use has been limited due to its high swelling potential and alkalinity. The swelling potential of steel slags may lead to deterioration of the structural stability of highways, and high alkalinity poses an environmental challenge as it affects the leaching behavior of trace metals. This study seeks a methodology that promotes the use of steel slag in highway embankments by minimizing these two main disadvantages. Accelerated swelling tests were conducted to evaluate the swelling behavior of pure steel slag and water treatment residual (WTR) treated steel slag, where WTR is an alum-rich by-product of drinking water treatment plants. Sequential batch tests and column leach tests, as well as two different numerical analyses, UMDSurf and WiscLEACH, were carried out to check the environmental suitability of the methods. Tests were conducted to study the effect of a common borrow fill material that encapsulated the slag in the embankment and the effects of two subgrade soils on the chemical properties of slag leachate. The results indicated that an increase in WTR content in the steel slag-WTR mixtures yields a decrease in pH and most of the leached metal concentrations, except aluminum. The change in the levels of pH, after passing through encapsulation and subgrade, depends on the natural pHs of materials.

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The farm-gate value of extensive beef production from the northern Gulf region of Queensland, Australia, is ~$150 million annually. Poor profitability and declining equity are common issues for most beef businesses in the region. The beef industry relies primarily on native pasture systems and studies continue to report a decline in the condition and productivity of important land types in the region. Governments and Natural Resource Management groups are investing significant resources to restore landscape health and productivity. Fundamental community expectations also include broader environmental outcomes such as reducing beef industry greenhouse gas emissions. Whole-of-business analysis results are presented from 18 extensive beef businesses (producers) to highlight the complex social and economic drivers of management decisions that impact on the natural resource and environment. Business analysis activities also focussed on improving enterprise performance. Profitability, herd performance and greenhouse emission benchmarks are documented and discussed.

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Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterized by deficits in social communication/interaction and by unusual repetitive and restricted behaviors and interests. ASD often co-occurs in the same families with other neuropsychiatric diseases (NPD), such as intellectual disability, schizophrenia, epilepsy, depression and attention deficit hyperactivity disorder. Genetic factors have an important role in ASD etiology. Multiple copy number variants (CNVs) and single nucleotide variants (SNVs) in candidate genes have been associated with an increased risk to develop ASD. Nevertheless, recent heritability estimates and the high genotypic and phenotypic heterogeneity characteristic of ASD indicate a role of environmental and epigenetic factors, such as long noncoding RNA (lncRNA) and microRNA (miRNA), as modulators of genetic expression and further clinical presentation. Both miRNA and lncRNA are functional RNA molecules that are transcribed from DNA but not translated into proteins, instead they act as powerful regulators of gene expression. While miRNA are small noncoding RNAs with 22-25 nucleotides in length that act at the post-transcriptional level of gene expression, the lncRNA are bigger molecules (>200 nucleotides in length) that are capped, spliced, and polyadenylated, similar to messenger RNA. Although few lncRNA were well characterized until date, there is a great evidence that they are implicated in several levels of gene expression (transcription/post-transcription/post-translation, organization of protein complexes, cell– cell signaling as well as recombination) as shown in figure 1.

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The influence of information about trip time variability, personal benefits, or environmental harm from cars or public transportation on commuting mode choice (car or subway) is examined in an experimental study. In addition to these experimentally manipulated variables, the influence of prior attitudes towards the subway was verified. The sample is made up of habitual users of the car to travel to work (N = 220, age M = 37.4, SD = 8.1, 63.2% women). The results show that providing information about the advantages of public transportation, as well as prior attitudes towards the subway, decrease the preference, choice, and perceived control of car use. Of the experimentally manipulated variables, information about the variability of trip time had the greatest influence. These results highlight the importance of taking into account these variables to implement institutional campaigns to reduce car use as transportation mode.

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Background: Aspergillosis has been identified as one of the hospital acquired infections but the contribution of water and inhouse air as possible sources of Aspergillus infection in immunocompromised individuals like HIV-TB patients have not been studied in any hospital setting in Nigeria. Objective: To identify and investigate genetic relationship between clinical and environmental Aspergillus species associated with HIV-TB co infected patients. Methods: DNA extraction, purification, amplification and sequencing of Internal Transcribed Spacer (ITS) genes were performed using standard protocols. Similarity search using BLAST on NCBI was used for species identification and MEGA 5.0 was used for phylogenetic analysis. Results: Analyses of sequenced ITS genes of selected fourteen (14) Aspergillus isolates identified in the GenBank database revealed Aspergillus niger (28.57%), Aspergillus tubingensis (7.14%), Aspergillus flavus (7.14%) and Aspergillus fumigatus (57.14%). Aspergillus in sputum of HIV patients were Aspergillus niger, A. fumigatus, A. tubingensis and A. flavus. Also, A. niger and A. fumigatus were identified from water and open-air. Phylogenetic analysis of sequences yielded genetic relatedness between clinical and environmental isolates. Conclusion: Water and air in health care settings in Nigeria are important sources of Aspergillus sp. for HIV-TB patients.

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Objective: To investigate the knowledge and use of asthma control measurement (ACM) tools in the management of asthma among doctors working in family and internal medicine practice in Nigeria. Method: A questionnaire based on the global initiative on asthma (GINA) guideline was self-administered by 194 doctors. It contains 12 test items on knowledge of ACM tools and its application. The knowledge score was obtained by adding the correct answers and classified as good if the score ≥ 9, satisfactory if score was 6-8 and poor if < 6. Results: The overall doctors knowledge score of ACM tools was 4.49±2.14 (maximum of 12). Pulmonologists recorded the highest knowledge score of 10.75±1.85. The majority (69.6%) had poor knowledge score of ACM tools. Fifty (25.8%) assessed their patients’ level of asthma control and 34(17.5%) at every visit. Thirty-nine (20.1%) used ACM tools in their consultation, 29 (15.0%) of them used GINA defined control while 10 (5.2 %) used asthma control test (ACT). The use of the tools was associated with pulmonologists, having attended CME within six months and graduated within five years prior to the survey. Conclusion: The results highlight the poor knowledge and use of ACM tools and the need to address the knowledge gap.

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Food security is defined as a situation that exists when “all people, at all times, have physical and economic access to sufficient, safe and nutritious food to maintain a healthy and active life. It is a multilevel concept, which includes four main dimensions: availability related to food supply; accessibility in order to ensure the physical and economic access to food; adequacy to meet nutritional needs in quantity and quality while respecting individual food preferences and cultural issues (utilization); and, lastly, stability of the guarantee of food security over time. According to the food security definition, it is abroad concept where all these dimensions are largely affected by a considerable number of factors related to: public policies of different sectors, food production/industry/distribution food systems, marketing and advertising of food, social support networks and individual determinants related to food choice behaviour.

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The main aim of this study was to analyze evidence of an environmental Kuznets curve for water pollution in the developing and developed countries. The study was conducted based on a panel data set of 54 countries – that were categorized into six groups of “developed countries”, “developing countries”, “developed countries with low income”, “developed countries with high income” and “coastal countries”- between the years 1995 to 2006. The results do not confirm the inverted U-shape of EKC curve for the developed countries with low income. Based on the estimated turning points and the average GDP per capita, the study revealed at which point of the EKC the countries are. Furthermore, impacts of capital-and-labor ratio as well as trade openness are drawn by estimating different models for the EKC. The magnitude role of each explanatory variable on BOD was calculated by estimating the associated elasticity.

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Introduction - Learning about ageing and the appropriate management of older patients is important for all doctors. This survey set out to evaluate what medical undergraduates in the UK are taught about ageing and geriatric medicine and how this teaching is delivered. Methods – An electronic questionnaire was developed and sent to the 28/31 UK medical schools which agreed to participate. Results – Full responses were received from 17 schools. 8/21 learning objectives were recorded as taught, and none were examined, across every school surveyed. Elder abuse and terminology and classification of health were taught in only 8/17 and 2/17 schools respectively. Pressure ulcers were taught about in 14/17 schools but taught formally in only 7 of these and examined in only 9. With regard to bio- and socio- gerontology, only 9/17 schools reported teaching in social ageing, 7/17 in cellular ageing and 9/17 in the physiology of ageing. Discussion – Even allowing for the suboptimal response rate, this study presents significant cause for concern with UK undergraduate education related to ageing. The failure to teach comprehensively on elder abuse and pressure sores, in particular, may be significantly to the detriment of older patients.

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Understanding the ecology of migratory birds during the non-breeding season is necessary for ensuring their conservation. Using satellite telemetry data we describe winter ranging behaviour and movements of pallid harriers Circus macrourus that bred in Kazakhstan. We developed an ecological niche model for the species in Africa, to identify the most suitable wintering areas for pallid harriers and the importance of habitat in determining the location of those areas. We also assessed how well represented suitable areas are in the network of protected areas. Individual harriers showed relatively high fidelity to wintering areas but with potential for interannual changes. The ecological niche model highlighted the importance of open habitats with natural vegetation. Most suitable areas for the species were located in eastern Africa. Suitable areas had a patchy distribution but were relatively well included in the network of protected areas. The preferential use of habitats with natural vegetation by wintering pallid harriers and the patchiness of the most suitable areas highlight the harrier's vulnerability to land-use changes and the associated loss of natural vegetation in Africa. Conservation of harriers could be enhanced by preserving natural grasslands within protected areas and improving habitat management in the human-influenced portions of the species’ core wintering areas.