Peripheral Oxidative Stress Biomarkers in Mild Cognitive Impairment and Alzheimer`s Disease

Oxidative stress has been associated with normal aging and Alzheimer`s disease (AD). However, little is known about oxidative stress in mild cognitive impairment (MCI) patients who present a high risk for developing AD. The aim of this study was to investigate plasma production of the lipid peroxidation marker, malonaldehyde (MDA) and to determine, in erythrocytes, the enzymatic antioxidant activity of catalase, glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione S-transferase (GST) in 33 individuals with MCI, 29 with mild probable AD and 26 healthy aged subjects. GR/GPx activity ratio was calculated to better assess antioxidant defenses. The relationship between oxidative stress and cognitive performance was also evaluated by the Mini Mental State Examination (MMSE). AD patients showed higher MDA levels than both MCI and healthy elderly subjects. MCI subjects also exhibited higher MDA levels compared to controls. Catalase and GPx activity were similar in MCI and healthy individuals but higher in AD. GR activity was lower in MCI and AD patients than in healthy aged subjects. Additionally, GR/GPx ratio was higher in healthy aged subjects, intermediate in MCI and lower in AD patients. No differences in GST activity were detected among the groups. MMSE was negatively associated with MDA levels (r = -0.31, p = 0.028) and positively correlated with GR/GPx ratio in AD patients (r = 0.68, p < 0.001). MDA levels were also negatively correlated to GR/GPx ratio (r = -0.31, p = 0.029) in the AD group. These results suggest that high lipid peroxidation and decreased antioxidant defenses may be present early in cognitive disorders.

Bayesian network classifiers: Beyond classification accuracy

This work proposes and discusses an approach for inducing Bayesian classifiers aimed at balancing the tradeoff between the precise probability estimates produced by time consuming unrestricted Bayesian networks and the computational efficiency of Naive Bayes (NB) classifiers. The proposed approach is based on the fundamental principles of the Heuristic Search Bayesian network learning. The Markov Blanket concept, as well as a proposed ""approximate Markov Blanket"" are used to reduce the number of nodes that form the Bayesian network to be induced from data. Consequently, the usually high computational cost of the heuristic search learning algorithms can be lessened, while Bayesian network structures better than NB can be achieved. The resulting algorithms, called DMBC (Dynamic Markov Blanket Classifier) and A-DMBC (Approximate DMBC), are empirically assessed in twelve domains that illustrate scenarios of particular interest. The obtained results are compared with NB and Tree Augmented Network (TAN) classifiers, and confinn that both proposed algorithms can provide good classification accuracies and better probability estimates than NB and TAN, while being more computationally efficient than the widely used K2 Algorithm.

Quality indices for (practical) clustering evaluation

Clustering quality or validation indices allow the evaluation of the quality of clustering in order to support the selection of a specific partition or clustering structure in its natural unsupervised environment, where the real solution is unknown or not available. In this paper, we investigate the use of quality indices mostly based on the concepts of clusters` compactness and separation, for the evaluation of clustering results (partitions in particular). This work intends to offer a general perspective regarding the appropriate use of quality indices for the purpose of clustering evaluation. After presenting some commonly used indices, as well as indices recently proposed in the literature, key issues regarding the practical use of quality indices are addressed. A general methodological approach is presented which considers the identification of appropriate indices thresholds. This general approach is compared with the simple use of quality indices for evaluating a clustering solution.

Towards a Protocol for the Attachment of Metadata to Service Descriptions and its Use in Semantic Discovery

Service discovery in large scale, open distributed systems is difficult because of the need to filter out services suitable to the task at hand from a potentially huge pool of possibilities. Semantic descriptions have been advocated as the key to expressive service discovery, but the most commonly used service descriptions and registry protocols do not support such descriptions in a general manner. In this paper, we present a protocol, its implementation and an API for registering semantic service descriptions and other task/user-specific metadata, and for discovering services according to these. Our approach is based on a mechanism for attaching structured and unstructured metadata, which we show to be applicable to multiple registry technologies. The result is an extremely flexible service registry that can be the basis of a sophisticated semantically-enhanced service discovery engine, an essential component of a Semantic Grid.

Using Normative Markov Decision Processes for Evaluating Electronic Contracts: A Case Study in a Simulated Aerospace Aftermarket

Before signing electronic contracts, a rational agent should estimate the expected utilities of these contracts and calculate the violation risks related to them. In order to perform such pre-signing procedures, this agent has to be capable of computing a policy taking into account the norms and sanctions in the contracts. In relation to this, the contribution of this work is threefold. First, we present the Normative Markov Decision Process, an extension of the Markov Decision Process for explicitly representing norms. In order to illustrate the usage of our framework, we model an example in a simulated aerospace aftermarket. Second, we specify an algorithm for identifying the states of the process which characterize the violation of norms. Finally, we show how to compute policies with our framework and how to calculate the risk of violating the norms in the contracts by adopting a particular policy.

Globalization, Agency, and Institutional Innovation: The Rise of Public-Private Partnerships in Global Governance

Public and private actors increasingly cooperate in global governance, a realm previously reserved for states and intergovernmental organizations (IOs). This trend raises fascinating theoretical questions. What explains the rise in public-private institutions and their role in international politics? Who leads such institutional innovation and why? To address the questions, this paper develops a theory of the political demand and supply of public-private institutions and specifies the conditions under which IOs and non-state actors would cooperate, and states would support this public-private cooperation. The observable implications of the theoretical argument are evaluated against the broad trends in public-private cooperation and in a statistical analysis of the significance of demand and supply-side incentives in public-private cooperation for sustainable development. The study shows that public-private institutions do not simply fill governance gaps opened by globalization, but cluster in narrower areas of cooperation, where the strategic interests of IOs, states, and transnational actors intersect.

Too Many Bad Cooks Spoiling the Broth? Effectiveness of NGOs in Addressing Child Labour in El Salvador

The reaction of the first world to the persevering plight of a large part of the third world varies. In response to the sometimes glaring disparities, many international organizations and multinational corporations have recently adopted a pro-development rhetoric with relation to the problem of global poverty. However, the rhetoric rarely translates into action. As David Bacon discusses, leaders of corporations and organizations now tend to conclude their speeches by expressing a desire to reduce the suffering of the third world. However, when it comes to agreeing on specific concessions that could indeed improve the world-wide economic situation, first world countries are reluctant to act. A good example of this type of behavior is the current negotiation of the WTO, the “development round of Doha,” in which the United States along with the European Union pressure countries of the developing South to open up their markets, while at the same time refusing to remove or even decrease their own agricultural subsidies. The first world civil society observes the behavior of international organizations and western based multinational corporations as ineffectual. Taking the matter in its own hands, especially in the past couple of decades, this civil society has created a countless number of development-oriented nongovernmental organizations. These are supposed to compensate for the lack of action by international organizations. Development NGOs are believed to be more locally responsive as well as free of business or political considerations in choosing their strategies, and thus generally more efficient than IOs. However, if they really were how they are alleged to be, the problems of the third world would already be ameliorated by a significant amount, if not completely eradicated. Do development-NGOs indeed possess the characteristics that they claim to possess? What is their real affect on human rights? And how effective are they in their work?

Desenvolvimento do saltar à horizontal : uma análise topológica

O objetivo deste estudo foi investigar a organização espaço-temporal dos segmentos da perna e da coxa no saltar à horizontal, verificando as infiuências do organismo e do ambiente (dois tipos de piso: concreto e areia). Participaram do estudo 21 sujeitos, 3 de cada faixa etária: 4, 5, 7, 9, 11, 13 e adulta (X = 19 anos de idade). Os sujeitos foram filmados realizando o saltar à horizontal com marcas desenhadas no centro das articulações do tornozelo, joelho e quadril. Estes pontos foram digitalizados e processados obtendo a posição e velocidade angular dos segmentos da perna e da coxa. A partir da posição e velocidade angular foi possível delinear os gráficos dos atratores (retratos de fase) e calcular os valores dos ângulos de fase para cada segmento, durante a realização da tarefa. Duas reversões para cada segmento, na posição angular, foram identificadas e nestes momentos os valores dos ângulos de fase foram capturados. Analisando as trajetórias dos retratos de fase verificou-se que os segmentos da perna e da coxa apresentaram um conjunto específico de características topológicas, na realização do saltar à horizontal. A análise dos valores dos ângulos de fase, nas duas reversões, indicou que ao longo das faixas etárias e nos dois tipos de piso os segmentos da perna e da coxa apresentaram organização espaço-temporal semelhante, indicando coordenação invariante.

Avaliação da satisfação e motivação dos técnico-administrativos em uma instituição de ensino superior : um estudo de caso

A busca pela satisfação e motivação de uma categoria de funcionários públicos de uma instituição de ensino superior é o tema do presente trabalho, o qual aborda as seguintes questões: como motivar funcionários que estão com o seu salário defasado? Será que um reajuste salarial irá motivá-Ios? Ou há outros fatores que determinam a satisfação e motivação dos funcionários? Visando responder essas questões e elaborar um plano de ação que aumente a satisfação e motivação dos funcionários, o presente trabalho apresenta um estudo sobre a satisfação no trabalho e as principais teorias motivacionais. As particularidades de uma organização pública também são abordadas. O trabalho envolve um estudo aplicado, o qual inicia apresentando o perfil da categoria de funcionários públicos que será estudada: os técnico-administrativos da Escola de Engenharia da Universidade Federal do Rio Grande do Sul. Através de pesquisas, foi possível aprofundar o conhecimento relativo aos 116 funcionários da instituição, identificando o seu nível de satisfação e os fatores de trabalho que consideram mais importantes. A participação da Direção da Escola de Engenharia da UFRGS no estudo aplicado foi relevante, na medida em que foram estudadas as propostas contidas no Plano de Gestão 2001 - 2004 da Direção da Escola, que possuem potencial para afetar a satisfação e motivação dos seus funcionários. Finalizando o estudo aplicado, o plano de ação para motivar e satisfazer os funcionários da Escola de Engenharia da UFRGS foi apresentado e questionado com relação ao seu potencial motivacional.