999 resultados para Nitrogen impact


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The recent focus on the cystic fibrosis (CF) complex microbiome has led to the recognition that the microbes can interact between them and with the host immune system, affecting the disease progression and treatment routes. Although the main focus remains on the interactions between traditional pathogens, growing evidence supports the contribution and the role of emergent species. Understanding the mechanisms and the biological effects involved in polymicrobial interactions may be the key to improve effective therapies and also to define new strategies for disease control. This review focuses on the interactions between microbe-microbe and host-microbe, from an ecological point of view, discussing their impact on CF disease progression. There are increasing indications that these interactions impact the success of antimicrobial therapy. Consequently, a new approach where therapy is personalized to patients by taking into account their individual CF microbiome is suggested.

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Dissertação de mestrado em Genética Molecular

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The ternary aluminium oxynitride (AlNxOy) system offers the possibility to obtain a wide range of properties by tailoring the ratio between pure Al, AlNx and AlOy and therefore opening a significant number of possible applications. In this work the thermal behaviour of AlNxOy thin films was analysed by modulated infrared radiometry (MIRR), taking as reference the binary AlOy and AlNx systems. MIRR is a non-contact and non-destructive thermal wave measurement technique based on the excitation, propagation and detection of temperature oscillations of very small amplitudes. The intended change of the partial pressure of the reactive gas (N2 and/or O2) influenced the target condition and hence the deposition characteristics which, altogether, affected the composition and microstructure of the films. Based on the MIRR measurements and their qualitative and quantitative interpretation, some correlations between the thermal transport properties of the films and their chemical/physical properties have been found. Furthermore, the potential of such technique applied in this oxynitride system, which present a wide range of different physical responses, is also discussed. The experimental results obtained are consistent with those reported in previous works and show a high potential to fulfil the demands needed for the possible applications of the systems studied. They are clearly indicative of an adequate thermal response if this particular thin film system is aimed to be applied in small sensor devices or in electrodes for biosignal acquisition, such as those for electroencephalography or electromyography as it is the case of the main research area that is being developed in the group.

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This paper aims to assess the impact of environmental noise in the vicinity of primary schools and to analyze its influence in the workplace and in student performance through perceptions and objective evaluation. The subjective evaluation consisted of the application of questionnaires to students and teachers, and the objective assessment consisted of measuring in situ noise levels. The survey covered nine classes located in three primary schools. Statistical Package for Social Sciences was used for data processing and to draw conclusions. Additionally, the relationship of the difference between environmental and background noise levels of each classroom and students with difficulties in hearing the teacherâ s voice was examined. Noise levels in front of the school, the schoolyard, and the most noise-exposed classrooms (occupied and unoccupied) were measured. Indoor noise levels were much higher than World Health Organization (WHO) recommended values: LAeq,30min averaged 70.5 dB(A) in occupied classrooms, and 38.6 dB(A) in unoccupied ones. Measurements of indoor and outdoor noise suggest that noise from the outside (road, schoolyard) affects the background noise level in classrooms but in varying degrees. It was concluded that the façades most exposed to road traffic noise are subjected to values higher than 55.0 dB(A), and noise levels inside the classrooms are mainly due to the schoolyard, students, and the road traffic. The difference between background (LA95,30min) and the equivalent noise levels (LAeq,30min) in occupied classrooms was 19.2 dB(A), which shows that studentsâ activities are a significant source of classroom noise.

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ADHD is a highly prevalent disorder in childhood with social, academic and familial difficulties when not diagnosed and treated correctly. The aim of this case report is to demonstrate the impairment of ADHD among generations of the same family.

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Programa Doutoral em Biologia Molecular e Ambiental

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INTRODUCTION: Patients' perception about their health condition, mainly involving chronic diseases, has been investigated in many studies and it has been associated to depression, compliance with the treatment, quality of life and prognosis. The Illness Effects Questionnaire (IEQ) is a tool which makes the standardized evaluation of patients' perception about their illness possible, so that it is brief and accessible to the different clinical settings. This work aims to begin the transcultural adaptation of the IEQ to Brazil through the validated translation and the reliability study. METHODS: The back-translation method and the test-retest reliability study were used in a sample of 30 adult patients under chronic hemodialysis. The reliability indexes were estimated using the Pearson, Spearman, Weighted Kappa and Cronbach's alpha coefficients. RESULTS: The semantic equivalence was reached through the validated translation. In this study, the reliability indexes obtained were respectively: 0.85 and 0.75 (p < 0.001); 0.68 and 0.92 (p < 0.0001). DISCUSSION: The reliability indexes obtained attest to the stability of responses in both evaluations. Additional procedures are necessary for the transcultural adaptation of the IEQ to be complete. CONCLUSION: The results indicate the translation validity and the reliability of the Brazilian version of the IEQ for the sample studied.

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Production of citric acid from crude glycerol from biodiesel industry, in batch cultures of Yarrowia lipolytica W29 was performed in a lab-scale stirred tank bioreactor in order to assess the effect of oxygen mass transfer rate in this bioprocess. An empirical correlation was proposed to describe oxygen volumetric mass transfer coefficient (kLa) as a function of operating conditions (stirring speed and specific air flow rate) and cellular density. kLa increased according with a power function with specific power input and superficial gas velocity, and slightly decreased with cellular density. The increase of initial kLa from 7 h-1 to 55 h-1 led to 7.8-fold increase of citric acid final concentration. Experiments were also performed at controlled dissolved oxygen (DO) and citric acid concentration increased with DO up to 60% of saturation. Thus, due to the simpler operation setting an optimal kLa than at controlled DO, it can be concluded that kLa is an adequate parameter for the optimization of citric acid production from crude glycerol by Y. lipolytica and to be considered in bioprocess scale-up. Our empirical correlation, considering the operating conditions and cellular density, will be a valid tool for this purpose.

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OBJECTIVE: The aim of this study is to evaluate the survival rate in a cohort of Parkinson's disease patients with and without depression. METHODS: A total of 53 Parkinson's disease subjects were followed up from 2003-2008 and 21 were diagnosed as depressed. Mean time of follow up was 3.8 (SD 95% = 1.5) years for all the sample and there was no significant difference in mean time of follow up between depressed and nondepressed Parkinson's disease patients. Survival curves rates were fitted using the Kaplan-Meier method. In order to compare survival probabilities according to the selected covariables the Log-Rank test was used. Multivariate analysis with Cox regression was performed aiming at estimating the effect of predictive covariables on the survival. RESULTS: The cumulative global survival of this sample was 83% with nine deaths at the end of the study - five in the depressed and four in the nondepressed group, and 55.6% died in the first year of observation, and none died at the fourth and fifth year of follow up. CONCLUSION: Our finding point toward incremental death risk in depressed Parkinson's disease patients.

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This paper intends to present and reflect upon some of the findings emerging from a research project entitled “Navigating with ‘Magalhães’: Study on the Impact of Digital Media on Schoolchildren” that was conducted at the Communication and Society Research Centre at the University of Minho, Braga, Portugal. The project focused on the politics of the governmental programme “One Laptop per Child” part of the Portuguese Technological Plan for Education, and the uses of the “Magalhães” computer, and other media, by children aged 8-10 years. This paper analyses the impact of this particular public policy on digital literacy of young children based mostly on the perspectives of parents and their modes of mediation. It also debates parents’ and children’s perspectives on parental rules on computer and Internet usage. It ends by concluding that the impact of this programme occurred mainly at the level of access rather than the social and educational uses and practices. It also highlights the importance of family in the way children access and use ICT.

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The use of genome-scale metabolic models has been rapidly increasing in fields such as metabolic engineering. An important part of a metabolic model is the biomass equation since this reaction will ultimately determine the predictive capacity of the model in terms of essentiality and flux distributions. Thus, in order to obtain a reliable metabolic model the biomass precursors and their coefficients must be as precise as possible. Ideally, determination of the biomass composition would be performed experimentally, but when no experimental data are available this is established by approximation to closely related organisms. Computational methods however, can extract some information from the genome such as amino acid and nucleotide compositions. The main objectives of this study were to compare the biomass composition of several organisms and to evaluate how biomass precursor coefficients affected the predictability of several genome-scale metabolic models by comparing predictions with experimental data in literature. For that, the biomass macromolecular composition was experimentally determined and the amino acid composition was both experimentally and computationally estimated for several organisms. Sensitivity analysis studies were also performed with the Escherichia coli iAF1260 metabolic model concerning specific growth rates and flux distributions. The results obtained suggest that the macromolecular composition is conserved among related organisms. Contrasting, experimental data for amino acid composition seem to have no similarities for related organisms. It was also observed that the impact of macromolecular composition on specific growth rates and flux distributions is larger than the impact of amino acid composition, even when data from closely related organisms are used.

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Transforming growth factor beta (TGF-ß) plays an important role in carcinogenesis. Two polymorphisms in the TGF-ß1 gene (-509C/T and 869T/C) were described to influence susceptibility to gastric and breast cancers. The 869T/C polymorphism was also associated with overall survival in breast cancer patients. In the present study, we investigated the relevance of these TGF-ß1 polymorphism in glioma risk and prognosis. A case-control study that included 114 glioma patients and 138 cancer-free controls was performed. Single nucleotide polymorphisms (SNPs) were evaluated by polymerase chain reaction followed by restriction fragment length polymorphism (PCR-RFLP). Univariate and multivariate logistic regression analyses were used to calculate odds ratio (OR) and 95 % confidence intervals (95 % CI). The influence of TGF-ß1 -509C/T and 869T/C polymorphisms on glioma patient survival was evaluated by a Cox regression model adjusted for patients' age and sex and represented in Kaplan-Meier curves. Our results demonstrated that TGF-ß1 gene polymorphisms -509C/T and 869T/C are not significantly associated with glioma risk. Survival analyses showed that the homozygous -509TT genotype associates with longer overall survival of glioblastoma (GBM) patients when compared with patients carrying CC + CT genotypes (OR, 2.41; 95 % CI, 1.06-5.50; p = 0.036). In addition, the homozygous 869CC genotype is associated with increased overall survival of GBM patients when compared with 869TT + TC genotypes (OR, 2.62; 95 % CI, 1.11-6.17; p = 0.027). In conclusion, this study suggests that TGF-ß1 -509C/T and 869T/C polymorphisms are not significantly associated with risk for developing gliomas but may be relevant prognostic biomarkers in GBM patients.

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In 2008, the XVII Portuguese Constitutional Government launched the ‘e.escolinha’ programme, within the Technological Plan for Education, which set out the distribution of a computer, called ‘Magalhães’, designed for chil-dren attending the 1st cycle of basic education. Suspended in 2011 by the XIX Government, this programme has allowed, however, almost 500 000 children to have access to a personal computer. It was expected that this political measure would “revolutionise” the national education system by bringing changes to the pedagogical practices of teachers and the learning processes of children and by achieving educational success, in general. Based on documental analysis and on a set of interviews with key decision-makers in conceiving, implementing and monitoring this governmental initiative, the fi rst part of this chapter presents and analyses the ‘e.escolinha’ initiative and the policies be-hind that governmental programme, seeking to disassemble those objectives and provide some insights into the relationship between discourses, rhetoric, and reality. After that, the chapter focuses on children’s uses and practices with the ‘Magalhães’ laptop, at school and at home. Based on the results of questionnaires fi lled in by approximately 1500 children from 32 First Cycle public schools of the municipality of Braga (north of Portugal) and also from questionnaires applied to their parents and teachers, this chapter intends to analyse the real impact of this initiative for children, family and school. It also seeks to discuss the contribution of this educational policy to children’s digital literacy and also to their own and their families’ social and digital inclusion. To understand if it represented an added value to teachers’ pedagogical practice is another of its aims. The fi ndings point out a major focus on technology and access rather than on uses and competences or even on social, educational and cultural change. In fact, a major conclusion is the existence of a strong gap between the policy and the practices, typical of a top-down policy design. This study is an integrant part of a research project titled “Navigating with ‘Magalhães’: Study on the Impact of Digital Media in Schoolchildren” conducted at the University of Minho, Portugal, financed by the Portuguese Foundation for Science and Technology [PTDC/CCI-COM/101381/2008] and co-funded by the European Regional Development Fund [COMPETE: FCOMP-01-0124-FEDER-009056].

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Recently it was demonstrated that for urinary tract infections species with a lower or unproven pathogenic potential, such as Delftia tsuruhatensis and Achromobacter xylosoxidans, might interact with conventional pathogenic agents such as Escherichia coli. Here, single- and dual-species biofilms of these microorganisms were characterized in terms of microbial composition over time, the average fitness of E. coli, the spatial organization and the biofilm antimicrobial profile. The results revealed a positive impact of these species on the fitness of E. coli and a greater tolerance to the antibiotic agents. In dual-species biofilms exposed to antibiotics, E. coli was able to dominate the microbial consortia in spite of being the most sensitive strain. This is the first study demonstrating the protective effect of less common species over E. coli under adverse conditions imposed by the use of antibiotic agents.

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The bottom of the Red Sea harbors over 25 deep hypersaline anoxic basins that are geochemically distinct and characterized by vertical gradients of extreme physicochemical conditions. Because of strong changes in density, particulate and microbial debris get entrapped in the brine-seawater interface (BSI), resulting in increased dissolved organic carbon, reduced dissolved oxygen toward the brines and enhanced microbial activities in the BSI. These features coupled with the deep-sea prevalence of ammonia-oxidizing archaea (AOA) in the global ocean make the BSI a suitable environment for studying the osmotic adaptations and ecology of these important players in the marine nitrogen cycle. Using phylogenomic-based approaches, we show that the local archaeal community of five different BSI habitats (with up to 18.2% salinity) is composed mostly of a single, highly abundant Nitrosopumilus-like phylotype that is phylogenetically distinct from the bathypelagic thaumarchaea; ammonia-oxidizing bacteria were absent. The composite genome of this novel Nitrosopumilus-like subpopulation (RSA3) co-assembled from multiple single-cell amplified genomes (SAGs) from one such BSI habitat further revealed that it shares [sim]54% of its predicted genomic inventory with sequenced Nitrosopumilus species. RSA3 also carries several, albeit variable gene sets that further illuminate the phylogenetic diversity and metabolic plasticity of this genus. Specifically, it encodes for a putative proline-glutamate 'switch' with a potential role in osmotolerance and indirect impact on carbon and energy flows. Metagenomic fragment recruitment analyses against the composite RSA3 genome, Nitrosopumilus maritimus, and SAGs of mesopelagic thaumarchaea also reiterate the divergence of the BSI genotypes from other AOA.