798 resultados para practical relevance
Resumo:
Neurodegenerative and psychiatric disorders including Alzheimer's, Parkinson's or Huntington's diseases and schizophrenia have been associated with a deficit in glutathione (GSH). In particular, a polymorphism in the gene of glutamate cysteine ligase modulatory subunit (GCLM) is associated with schizophrenia. GSH is the most important intracellular antioxidant and is necessary for the removal of reactive by-products generated by the utilization of glucose for energy supply. Furthermore, glucose metabolism through the pentose phosphate pathway is a major source of NADPH, the cofactor necessary for the regeneration of reduced glutathione. This study aims at investigating glucose metabolism in cultured astrocytes from GCLM knockout mice, which show decreased GSH levels. No difference in the basal metabolism of glucose was observed between wild-type and knockout cells. In contrast, glycogen levels were lower and its turnover was higher in knockout astrocytes. These changes were accompanied by a decrease in the expression of the genes involved in its synthesis and degradation, including the protein targeting to glycogen. During an oxidative challenge induced by tert-Butylhydroperoxide, wild-type cells increased their glycogen mobilization and glucose uptake. However, knockout astrocytes were unable to mobilize glycogen following the same stress and they could increase their glucose utilization only following a major oxidative insult. Altogether, these results show that glucose metabolism and glycogen utilization are dysregulated in astrocytes showing a chronic deficit in GSH, suggesting that alterations of a fundamental aspect of brain energy metabolism is caused by GSH deficit and may therefore be relevant to metabolic dysfunctions observed in schizophrenia.
Evolutionary history and its relevance in understanding and conserving southern African biodiversity
Resumo:
Abstract : Understanding how biodiversity is distributed is central to any conservation effort and has traditionally been based on niche modeling and the causal relationship between spatial distribution of organisms and their environment. More recently, the study of species' evolutionary history and relatedness has permeated the fields of ecology and conservation and, coupled with spatial predictions, provides useful insights to the origin of current biodiversity patterns, community structuring and potential vulnerability to extinction. This thesis explores several key ecological questions by combining the fields of niche modeling and phylogenetics and using important components of southern African biodiversity. The aims of this thesis are to provide comparisons of biodiversity measures, to assess how climate change will affect evolutionary history loss, to ask whether there is a clear link between evolutionary history and morphology and to investigate the potential role of relatedness in macro-climatic niche structuring. The first part of my thesis provides a fine scale comparison and spatial overlap quantification of species richness and phylogenetic diversity predictions for one of the most diverse plant families in the Cape Floristic Region (CFR), the Proteaceae. In several of the measures used, patterns do not match sufficiently to argue that species relatedness information is implicit in species richness patterns. The second part of my thesis predicts how climate change may affect threat and potential extinction of southern African animal and plant taxa. I compare present and future niche models to assess whether predicted species extinction will result in higher or lower V phylogenetic diversity survival than what would be experienced under random extinction processes. l find that predicted extinction will result in lower phylogenetic diversity survival but that this non-random pattern will be detected only after a substantial proportion of the taxa in each group has been lost. The third part of my thesis explores the relationship between phylogenetic and morphological distance in southern African bats to assess whether long evolutionary histories correspond to equally high levels of morphological variation, as predicted by a neutral model of character evolution. I find no such evidence; on the contrary weak negative trends are detected for this group, as well as in simulations of both neutral and convergent character evolution. Finally, I ask whether spatial and climatic niche occupancy in southern African bats is influenced by evolutionary history or not. I relate divergence time between species pairs to climatic niche and range overlap and find no evidence for clear phylogenetic structuring. I argue that this may be due to particularly high levels of micro-niche partitioning. Résumé : Comprendre la distribution de la biodiversité représente un enjeu majeur pour la conservation de la nature. Les analyses se basent le plus souvent sur la modélisation de la niche écologique à travers l'étude des relations causales entre la distribution spatiale des organismes et leur environnement. Depuis peu, l'étude de l'histoire évolutive des organismes est également utilisée dans les domaines de l'écologie et de la conservation. En combinaison avec la modélisation de la distribution spatiale des organismes, cette nouvelle approche fournit des informations pertinentes pour mieux comprendre l'origine des patterns de biodiversité actuels, de la structuration des communautés et des risques potentiels d'extinction. Cette thèse explore plusieurs grandes questions écologiques, en combinant les domaines de la modélisation de la niche et de la phylogénétique. Elle s'applique aux composants importants de la biodiversité de l'Afrique australe. Les objectifs de cette thèse ont été l) de comparer différentes mesures de la biodiversité, 2) d'évaluer l'impact des changements climatiques à venir sur la perte de diversité phylogénétique, 3) d'analyser le lien potentiel entre diversité phylogénétique et diversité morphologique et 4) d'étudier le rôle potentiel de la phylogénie sur la structuration des niches macro-climatiques des espèces. La première partie de cette thèse fournit une comparaison spatiale, et une quantification du chevauchement, entre des prévisions de richesse spécifique et des prédictions de la diversité phylogénétique pour l'une des familles de plantes les plus riches en espèces de la région floristique du Cap (CFR), les Proteaceae. Il résulte des analyses que plusieurs mesures de diversité phylogénétique montraient des distributions spatiales différentes de la richesse spécifique, habituellement utilisée pour édicter des mesures de conservation. La deuxième partie évalue les effets potentiels des changements climatiques attendus sur les taux d'extinction d'animaux et de plantes de l'Afrique australe. Pour cela, des modèles de distribution d'espèces actuels et futurs ont permis de déterminer si l'extinction des espèces se traduira par une plus grande ou une plus petite perte de diversité phylogénétique en comparaison à un processus d'extinction aléatoire. Les résultats ont effectivement montré que l'extinction des espèces liées aux changements climatiques pourrait entraîner une perte plus grande de diversité phylogénétique. Cependant, cette perte ne serait plus grande que celle liée à un processus d'extinction aléatoire qu'à partir d'une forte perte de taxons dans chaque groupe. La troisième partie de cette thèse explore la relation entre distances phylogénétiques et morphologiques d'espèces de chauves-souris de l'Afrique australe. ll s'agit plus précisément de déterminer si une longue histoire évolutive correspond également à des variations morphologiques plus grandes dans ce groupe. Cette relation est en fait prédite par un modèle neutre d'évolution de caractères. Aucune évidence de cette relation n'a émergé des analyses. Au contraire, des tendances négatives ont été détectées, ce qui représenterait la conséquence d'une évolution convergente entre clades et des niveaux élevés de cloisonnement pour chaque clade. Enfin, la dernière partie présente une étude sur la répartition de la niche climatique des chauves-souris de l'Afrique australe. Dans cette étude je rapporte temps de divergence évolutive (ou deux espèces ont divergé depuis un ancêtre commun) au niveau de chevauchement de leurs niches climatiques. Les résultats n'ont pas pu mettre en évidence de lien entre ces deux paramètres. Les résultats soutiennent plutôt l'idée que cela pourrait être I dû à des niveaux particulièrement élevés de répartition de la niche à échelle fine.
Resumo:
This review paper reports the consensus of a technical workshop hosted by the European network, NanoImpactNet (NIN). The workshop aimed to review the collective experience of working at the bench with manufactured nanomaterials (MNMs), and to recommend modifications to existing experimental methods and OECD protocols. Current procedures for cleaning glassware are appropriate for most MNMs, although interference with electrodes may occur. Maintaining exposure is more difficult with MNMs compared to conventional chemicals. A metal salt control is recommended for experiments with metallic MNMs that may release free metal ions. Dispersing agents should be avoided, but if they must be used, then natural or synthetic dispersing agents are possible, and dispersion controls essential. Time constraints and technology gaps indicate that full characterisation of test media during ecotoxicity tests is currently not practical. Details of electron microscopy, dark-field microscopy, a range of spectroscopic methods (EDX, XRD, XANES, EXAFS), light scattering techniques (DLS, SLS) and chromatography are discussed. The development of user-friendly software to predict particle behaviour in test media according to DLVO theory is in progress, and simple optical methods are available to estimate the settling behaviour of suspensions during experiments. However, for soil matrices such simple approaches may not be applicable. Alternatively, a Critical Body Residue approach may be taken in which body concentrations in organisms are related to effects, and toxicity thresholds derived. For microbial assays, the cell wall is a formidable barrier to MNMs and end points that rely on the test substance penetrating the cell may be insensitive. Instead assays based on the cell envelope should be developed for MNMs. In algal growth tests, the abiotic factors that promote particle aggregation in the media (e.g. ionic strength) are also important in providing nutrients, and manipulation of the media to control the dispersion may also inhibit growth. Controls to quantify shading effects, and precise details of lighting regimes, shaking or mixing should be reported in algal tests. Photosynthesis may be more sensitive than traditional growth end points for algae and plants. Tests with invertebrates should consider non-chemical toxicity from particle adherence to the organisms. The use of semi-static exposure methods with fish can reduce the logistical issues of waste water disposal and facilitate aspects of animal husbandry relevant to MMNs. There are concerns that the existing bioaccumulation tests are conceptually flawed for MNMs and that new test(s) are required. In vitro testing strategies, as exemplified by genotoxicity assays, can be modified for MNMs, but the risk of false negatives in some assays is highlighted. In conclusion, most protocols will require some modifications and recommendations are made to aid the researcher at the bench. [Authors]
Resumo:
Intuitively, music has both predictable and unpredictable components. In this work we assess this qualitative statement in a quantitative way using common time series models fitted to state-of-the-art music descriptors. These descriptors cover different musical facets and are extracted from a large collection of real audio recordings comprising a variety of musical genres. Our findings show that music descriptor time series exhibit a certain predictability not only for short time intervals, but also for mid-term and relatively long intervals. This fact is observed independently of the descriptor, musical facet and time series model we consider. Moreover, we show that our findings are not only of theoretical relevance but can also have practical impact. To this end we demonstrate that music predictability at relatively long time intervals can be exploited in a real-world application, namely the automatic identification of cover songs (i.e. different renditions or versions of the same musical piece). Importantly, this prediction strategy yields a parameter-free approach for cover song identification that is substantially faster, allows for reduced computational storage and still maintains highly competitive accuracies when compared to state-of-the-art systems.
Resumo:
A Carnatic music concert is made up of a sequence of pieces, where each piece corresponds to a particular genre and ra¯aga (melody). Unlike a western music concert, the artist may be applauded intra-performance inter-performance. Most Carnatic music that is archived today correspond to a single audio recordings of entire concerts.The purpose of this paper is to segment single audio recordings into a sequence of pieces using thecharacteristic features of applause and music. Spectral flux, spectral entropy change quite significantly from music to applause and vice-versa. The characteristics of these features for a subset of concerts was studied. A threshold based approach was used to segment the pieces into music fragments and applauses. Preliminary resultson recordings 19 concerts from matched microphones show that the EER is about 17% for a resolution of 0.25 seconds. Further, a parameter called CUSUM is estimatedfor the applause regions. The CUSUM values determine the strength of the applause. The CUSUM is used to characterise the highlights of a concert.
Resumo:
Over the last decade, diagnostic options and introduction of novel treatments have expanded the armamentarium in the management of malignant glioma. Combined chemoradiotherapy has become the standard of care in glioblastoma up to the age of 70 years, while treatment in elderly patients or with lower grade glioma is less well defined. Molecular markers define different disease subtypes and allow for adapted treatment selection. This review focuses on simple questions arising in the daily management of patients.
Resumo:
Glutathione (GSH), a major redox regulator and anti-oxidant, is decreased in cerebrospinal fluid and prefrontal cortex of schizophrenia patients. The gene of the key GSH-synthesizing enzyme, glutamate-cysteine ligase, modifier (GCLM) subunit, is associated with schizophrenia, suggesting that the deficit in the GSH system is of genetic origin. Using the GCLM knock-out (KO) mouse model with 60% decreased brain GSH levels, we have shown that redox dysregulation results in abnormal brain morphology and function. Current theory holds that schizophrenia is a developmental disease involving progressive anatomical and functional brain pathology. Here, we used GCLM KO mice to investigate the impact of a genetically dysregulated redox system on the neurochemical profile of the developing brain. The anterior and posterior cortical neurochemical profile of male and female GCLM KO, heterozygous and wildtype mice was determined by localised in vivo 1H NMR spectroscopy at 14.1 T (Varian/Magnex spectrometer) on post-natal days 10, 20, 30, 60 and 90. We show, for the first time, (1) that high quality 1H NMR spectra can be acquired from early developing mouse brains and (2) that recurrent anaesthesia by itself when administered at the same developmental days has no adverse effects on brain metabolites nor on adult behaviour. (3) Most importantly, our results reveal genotype and age specific changes for a number of metabolites revealing insight into normal brain development and about the impact of genetic GSH dysregulation.
Resumo:
Subarachnoid haemorrhage (SAH) is a form of stroke that is associated with substantial morbidity, often as a result of cerebral ischaemia that occurs in the following days. These delayed deficits in blood flow have been traditionally attributed to cerebral vasospasm (the narrowing of large arteries), which can lead to cerebral infarction and poor neurological outcome. Data from recent studies, however, show that treatment of vasospasm in patients with SAH, using targeted medication, does not translate to better neurological outcomes, and argue against vasospasm being the sole cause of the delayed ischaemic complications. Cerebral autoregulation-a mechanism that maintains stability of cerebral blood flow in response to changes in cerebral perfusion pressure-has been reported to fail after SAH, often before vasospasm becomes apparent. Failure of autoregulation, therefore, has been implicated in development of delayed cerebral ischaemia. In this Review, we summarize current knowledge about the clinical effect of disturbed cerebral autoregulation following aneurysmal SAH, with emphasis on development of delayed cerebral ischaemia and clinical outcome, and provide a critical assessment of studies of cerebral autoregulation in SAH with respect to the method of blood-flow measurement. Better understanding of cerebral autoregulation following SAH could reveal mechanisms of blood-flow regulation that could be therapeutically targeted to improve patient outcome.
Resumo:
Significant proteinuria is not an unfinding in children. Its causes are variable. When detected by dipstick examination of urine, the proteinuria must be assessed quantitatively by measuring the urinary protein/creatinine ratio in a spot sample. Orthostatic proteinuria is the most common cause of intermittent proteinuria. Persistent glomerular or tubular proteinuria are the consequences of various glomerulopathies or tubulopathies, the prognosis of which is variable. Whether glomerular or tubular, persistent proteinuria must be fully investigated, including by renal biopsy.
Resumo:
When nine million foreigners visited Japan in 2013, the federal government set a goal to attract an additional two and a half million visitors including medical tourists by 2020. This research investigates the attitudes and concerns of Japanese nurses when they are in a situation dealing with foreign patients. The data were collected from March through September 2010, from 114 nurses at three hospitals, in close proximity to popular tourist destinations in Hiroshima. A questionnaire was developed for this research, named Mari Meter, which included a section to write answers to an open question for the nurses to express their opinions. These responses were examined statistically and by word analysis using Text Mining Studio. Japanese nurses expressed greatest concern about payment options, foreign language skills, and issues of informed consent, when dealing with foreigners. The results confirm that, in order to provide a high quality of patient care, extra preparation and a greater knowledge of international workers and visitors are required by nursing professionals in Japan.
Resumo:
Objective: To investigate practical teaching of nurse residents in a multidisciplinary residency in oncology. Method: A qualitative descriptive study grounded in the problematization methodology and its steps, represented by the Maguerez Arch. Data were analyzed using content analysis. Results: Potentiating and limiting elements of the residency guided the design of a practical teaching protocol from the perspective of residents, structured in three stages: Welcoming and ambience; Nursing care for problem situations; and, Evaluation process. Conclusion: Systematization of practical teaching promoted the autonomy of individuals and the approximation of teaching to reality, making residency less strenuous, stressful and distressing.
Resumo:
O presente trabalho tem como objectivo demonstrar a importância da normalização contabilística para a análise da informação financeira, tendo em conta o meio envolvente em que, hoje, as empresas encontram-se inseridas. As mudanças que ocorreram na economia global levou a que as empresas passassem a adoptar novas formas de elaborar o reporte financeiro como forma de acompanhar essa evolução. A harmonização contabilística, surge neste contexto, como forma de reduzir as diferenças existentes no relato financeiro dos vários países. Nesse sentido o trabalho abordará as várias iniciativas que tem sido feitas em favor da harmonização/normalização contabilística e a sua relevância no contexto internacional e nacional bem como o caso de Cabo Verde, que recentemente aderiu ao processo da normalização. O caso prático baseia-se na transposição das demonstrações financeiras para o novo normativo em vigor e também na análise destas. A metodologia utilizada no trabalho baseia-se na revisão bibliográfica em livros, revistas, pela consulta de sites na Internet e legislação. The purpose of this paper is to demonstrate the importance of the accounting standard for the analysis of financial information, taking into account the environment in which, today, the companies are incorporated. The changes that occurred in the global economy have led companies to introduce new ways of preparing the financial reporting as a way to monitor these developments. The accounting harmonization, it is in this context as a way of reducing the differences existing in the financial reporting of the several countries. In this sense the work will address a variety of initiatives that have been made in favor of harmonization / normalization accounting and its relevance in the international and national context as well as the case of Cape Verde, who recently joined the process of standardization. The practical case is based in on the translation of financial statements for the new rules enforced and also in their analysis. The follows methodology used in the process is based on the literature review in books, magazines, by consulting Web sites and legislation
Resumo:
Presentemente, o controlo de gestão está vocacionado para agir antes de os factos indesejáveis ocorrerem, assegurando que os objectivos estabelecidos pela gestão são atingidos dentro do timing fixado. Além disso, o controlo de gestão deve ser o motor que permita alcançar as melhores performances nas áreas críticas da empresa, não só no domínio económico e financeiro, mas também nas áreas do crescimento, segurança e produtividade. Um dos mais importantes objectos das administrações actuais, é determinar se o desempenho da organização está de acordo com o que foi estabelecido previamente, ou seja, seus objectivos e metas. O meio através do qual se verificaria este desempenho seria a utilização de métodos e sistemas de avaliação de desempenho eficazes. Neste contexto, o presente estudo consiste em fazer um estudo exploratório descritivo identificando e averiguando de que forma as instituições bancárias de Cabo Verde efectuam a gestão de alguns aspectos, especialmente a avaliação de desempenho e o controlo estratégico, e que indicadores utilizam. Não obstante os objectivos específicos do trabalho serem outros, também damos especial atenção às características do mercado cabo-verdiano e à importância do sector bancário para a economia. Finalmente, apresentamos o Balanced Scorecard como uma ferramenta capaz de suprir as dificuldades da avaliação de desempenho e o conjunto de indicadores que vemos como o mais adequado. Neste ponto, concentramos nas quatro perspectivas básicas e no mapa estratégico, referindo o papel do Balanced Scorecard no alinhamento estratégico e na avaliação do desempenho organizacional. Para concluir, reforçamos o estudo, entrevistando um especialista (Director Financeiro) de um dos bancos da praça, cujo nome prometemos não publicar. Dessa forma, esperamos contribuir para uma melhor percepção da realidade em estudo, tanto do ponto de vista teórico, quanto da verificação das práticas no sector. Presently, the management control is oriented to act before the undesirable facts happen, assuring that the management established objectives are being achieved in the fixed timing. Besides, the management control must be an engine that permits to achieve the best performances at critical company areas, not only in the economic and financial areas, but at the growth, security and productivity areas too. One of the most important administration objects nowadays is to know if the organization performance is according to the fixed targets. The performance measurement could be done through effective methods and performance measurement systems. That’s why this assignment consists in doing an exploratory and descriptive study, identifying and investigating how the bank institutions of Cape Verde manage some things, particularly the performance measurement and the strategic control, and to know which indicators they use. Although the specific objectives of this assignment are others, we also give special attention to the Capeverdean market characteristics, and to the relevance of the banking industry to the economy of the country. Finally, we present the Balanced Scorecard as a competent tool to supply the measurement performance difficulties and a number of indicators that we find appropriate. In this point, we focus in the four basic perspectives and the strategic map, referring to the role of the Balanced Scorecard in the strategic alignment and organization performance measurement. We conclude this study with an interview to an expert (A Financial Manager) of a bank working in Cape Verde, whose name we promise to preserve. In this way, we hope to contribute to a better perception of this reality, in the theoretical point-of-view as much as in the practical check of this industry’s labour.