Frailty as a predictor of short-term adverse outcomes

The objectives of this study were to compare how different frailty measures (Frailty Phenotype/FP, Groningen Frailty Indicator/GFI and Tilburg Frailty Indicator/TFI) predict short-term adverse outcomes. Secondarily, adopting a multidimensional approach to frailty (integral conceptual model–TFI), this study aims to compare how physical, psychological and social frailty predict the outcomes. A longitudinal study was carried out with 95 community-dwelling elderly. Participants were assessed at baseline for frailty, determinants of frailty, and adverse outcomes (healthcare utilization, quality of life, disability in basic and instrumental activities of daily living/ADL and IADL). Ten months later the outcomes were assessed again. Frailty was associated with specific healthcare utilization indicators: the FP with a greater utilization of informal care; GFI with an increased contact with healthcare professionals; and TFI with a higher amount of contacts with a general practitioner. After controlling for the effect of life-course determinants, comorbidity and adverse outcome at baseline, GFI predicted IADL disability and TFI predicted quality of life. The effect of the FP on the outcomes was not significant, when compared with the other measures. However, when comparing TFI’s domains, the physical domain was the most significant predictor of the outcomes, even explaining part of the variance of ADL disability. Frailty at baseline was associated with adverse outcomes at follow-up. However, the relationship of each frailty measure (FP, GFI and TFI) with the outcomes was different. In spite of the role of psychological frailty, TFI’s physical domain was the determinant factor for predicting disability and most of the quality of life.

Short sea como alternativa ao transporte terrestre

O Short Sea Shipping (SSS) é um conceito de transporte marítimo de difícil definição. No entanto, considera-se neste trabalho, que corresponde ao movimento de carga e passageiros por mar entre portos situados geográficamente na Europa ou entre outros portos que não estejam situados na Europa, mas que partilham costa com mares que banham a Europa. Esta definição é sem dúvida aquela que melhor se adequa à inclusão do Short SSS como elo de uma cadeia multimodal de transporte de mercadorias no espaço Europeu, e como alternativa ao transporte de mercadorias apenas por estrada. Este trabalho aborda alguns conceitos importantes subjacentes ao transporte marítimo de forma a permitir uma contextualização que possibilite uma melhor compreensão da abordagem feita ao SSS. A sua promoção e implementação, como alternativa viável para o transporte de mercadorias dentro do espaço Europeu, são objetivos da política de transportes da União Europeia (UE). Este trabalho reflete sobre algumas das políticas estratégicas de promoção da UE para impulsionar o SSS como alternativa ao transporte rodoviário. O objetivo deste trabalho é analisar se o SSS é uma alternativa ao transporte terrestre, no contexto de uma distribuição no Reino Unido de produtos de uma Industria localizada nos arredores da cidade do Porto. Neste trabalho analisou-se as vantagens e desvantagens do SSS, foi efetuada uma descrição do Porto de Leixões como porto escolhido para as expedições, assim como uma análise descritiva dos serviços de Short Sea disponiveis neste porto para as zonas de distribuição desta empresa. Foram descritos os fatores chave da mudança de transporte terrestre para SSS, efectuada uma caracterização da distribuição desta empresa e da solução que esta adotou para distribuir os seus produtos no Reino Unido. A anállise económica da operação, dos tempos de trânsito são dois temas fundamentais para a viabilidade da solução como alternativa ao transporte terrestre.

CANDi: context-aware node discovery for short-range cooperation

Multi-standard mobile devices are allowing users to enjoy higher data rates with ubiquitous connectivity. However, the benefits gained from multiple interfaces come at an expense—that being higher energy consumption in an era where mobile devices need to be energy compliant. One promising solution is the usage of short-range cooperative communication as an overlay for infrastructure-based networks taking advantage of its context information. However, the node discovery mechanism, which is pivotal to the bearer establishment process, still represents a major burden in terms of the total energy budget. In this paper, we propose a technology agnostic approach towards enhancing the MAC energy ratings by presenting a context-aware node discovery (CANDi) algorithm, which provides a priori knowledge towards the node discovery mechanism by allowing it to search nodes in the near vicinity at the ‘right time and at the right place’. We describe the different beacons required for establishing the cooperation, as well as the context information required, including battery level, modes, location and so on. CANDi uses the long-range network (WiMAX and WiFi) to distribute the context information about cooperative clusters (Ultra-wideband-based) in the vicinity. The searching nodes can use this context in locating the cooperative clusters/nodes, which facilitates the establishing of short-range connections. Analytical and simulation results are obtained, and the energy saving gains are further demonstrated in the laboratory using a customised testbed. CANDi saves up to 50% energy during the node discovery process, while the demonstrative testbed shows up to 75% savings in the total energy budget, thus validating the algorithm, as well as providing viable evidence to support the usage of short-range cooperative communications for energy savings.

Protein-responsive polymers for point-of-care detection of cardiac biomarker

This work describes a novel use for the polymeric film, poly(o-aminophenol) (PAP) that was made responsive to a specific protein. This was achieved through templated electropolymerization of aminophenol (AP) in the presence of protein. The procedure involved adsorbing protein on the electrode surface and thereafter electroploymerizing the aminophenol. Proteins embedded at the outer surface of the polymeric film were digested by proteinase K and then washed away thereby creating vacant sites. The capacity of the template film to specifically rebind protein was tested with myoglobin (Myo), a cardiac biomarker for ischemia. The films acted as biomimetic artificial antibodies and were produced on a gold (Au) screen printed electrode (SPE), as a step towards disposable sensors to enable point-of-care applications. Raman spectroscopy was used to follow the surface modification of the Au-SPE. The ability of the material to rebind Myo was measured by electrochemical techniques, namely electrochemical impedance spectroscopy (EIS) and square wave voltammetry (SWV). The devices displayed linear responses to Myo in EIS and SWV assays down to 4.0 and 3.5 μg/mL, respectively, with detection limits of 1.5 and 0.8 μg/mL. Good selectivity was observed in the presence of troponin T (TnT) and creatine kinase (CKMB) in SWV assays, and accurate results were obtained in applications to spiked serum. The sensor described in this work is a potential tool for screening Myo in point-of-care due to the simplicity of fabrication, disposability, short time response, low cost, good sensitivity and selectivity.

Using data mining with time series data in short-term stocks prediction

Data Mining (DM) methods are being increasingly used in prediction with time series data, in addition to traditional statistical approaches. This paper presents a literature review of the use of DM with time series data, focusing on short- time stocks prediction. This is an area that has been attracting a great deal of attention from researchers in the field. The main contribution of this paper is to provide an outline of the use of DM with time series data, using mainly examples related with short-term stocks prediction. This is important to a better understanding of the field. Some of the main trends and open issues will also be introduced.

Short-Circuit Impedance of Power Transformers: the Fractional Order Calculus Approach

First IFAC Workshop on Fractional Differentiation and Its Application - 19-21 July 2004, Enseirb, Bordeaux, France - FDA'04

On the Estimation of the Short-Circuit Impedance of Power Transformers Using Fractional Order Calculus

This paper reports investigation on the estimation of the short circuit impedance of power transformers, using fractional order calculus to analytically study the influence of the diffusion phenomena in the windings. The aim is to better characterize the medium frequency range behavior of leakage inductances of power transformer models, which include terms to represent the magnetic field diffusion process in the windings. Comparisons between calculated and measured values are shown and discussed.

A multi-objective model for scheduling of short-term incentive-based demand response programs offered by electricity retailers

In this paper, we formulate the electricity retailers’ short-term decision-making problem in a liberalized retail market as a multi-objective optimization model. Retailers with light physical assets, such as generation and storage units in the distribution network, are considered. Following advances in smart grid technologies, electricity retailers are becoming able to employ incentive-based demand response (DR) programs in addition to their physical assets to effectively manage the risks of market price and load variations. In this model, the DR scheduling is performed simultaneously with the dispatch of generation and storage units. The ultimate goal is to find the optimal values of the hourly financial incentives offered to the end-users. The proposed model considers the capacity obligations imposed on retailers by the grid operator. The profit seeking retailer also has the objective to minimize the peak demand to avoid the high capacity charges in form of grid tariffs or penalties. The non-dominated sorting genetic algorithm II (NSGA-II) is used to solve the multi-objective problem. It is a fast and elitist multi-objective evolutionary algorithm. A case study is solved to illustrate the efficient performance of the proposed methodology. Simulation results show the effectiveness of the model for designing the incentive-based DR programs and indicate the efficiency of NSGA-II in solving the retailers’ multi-objective problem.

Use of a fluorescence-based approach to assess short-term responses of the alga Pseudokirchneriella subcapitata to metal stress

This work explores the use of fluorescent probes to evaluate the responses of the green alga Pseudokirchneriella subcapitata to the action of three nominal concentrations of Cd(II), Cr(VI), Cu(II) and Zn(II) for a short time (6 h). The toxic effect of the metals on algal cells was monitored using the fluorochromes SYTOX Green (SG, membrane integrity), fluorescein diacetate (FDA, esterase activity) and rhodamine 123 (Rh123, mitochondrial membrane potential). The impact of metals on chlorophyll a (Chl a) autofluorescence was also evaluated. Esterase activity was the most sensitive parameter. At the concentrations studied, all metals induced the loss of esterase activity. SG could be used to effectively detect the loss of membrane integrity in algal cells exposed to 0.32 or 1.3 μmol L−1 Cu(II). Rh123 revealed a decrease in the mitochondrial membrane potential of algal cells exposed to 0.32 and 1.3 μmol L−1 Cu(II), indicating that mitochondrial activity was compromised. Chl a autofluorescence was also affected by the presence of Cr(VI) and Cu(II), suggesting perturbation of photosynthesis. In conclusion, the fluorescence-based approach was useful for detecting the disturbance of specific cellular characteristics. Fluorescent probes are a useful diagnostic tool for the assessment of the impact of toxicants on specific targets of P. subcapitata algal cells.

Anomalous persistent photoconductivity in Cu2ZnSnS4 thin films and solar cells

A persistent photoconductivity effect (PPC) has been investigated in Cu2ZnSnS4 thin films and solar cells as a function of temperature. An anomalous increase of the PPC decay time with temperature was observed in all samples. The PPC decay time activation energy was found to increase when temperature rises above a crossover value, and also to grow with the increase of the sulfurization temperature and pressure. Both the anomalous behavior of the PPC decay time and the existence of two different activation energies are explained in terms of local potential fluctuations in the band edges of CZTS.

Effect of selenization conditions on the growth and properties of Cu2ZnSn(S,Se)4 thin films

The opto-electronic properties of copper zinc tin sulfide can be tuned to achieve better cell efficiencies by controlled incorporation of selenium. In this paper we report the growth of Cu2ZnSn(S,Se)4 (CZTSSe) using a hybrid process involving the sequential evaporation of Zn and sputtering of the sulfide precursors of Cu and Sn, followed by a selenization step. Two approaches for selenization were followed, one using a tubular furnace and the other using a rapid thermal processor. The effects of annealing conditions on the morphological and structural properties of the films were investigated. Scanning electron microscopy and energy dispersive spectroscopy were employed to investigate the morphology and composition of the films. Structural analyses were done using X-ray diffraction (XRD) and Raman spectroscopy. Structural analyses revealed the formation of CZTSSe. This study shows that regardless of the selenization method a temperature above 450 °C is required for conversion of precursors to a compact CZTSSe layer. XRD and Raman analysis suggests that the films selenized in the tubular furnace are selenium rich whereas the samples selenized in the rapid thermal processor have higher sulfur content.

Sistema de Recomendação: Share GFS Games, Films & Series

Esta dissertação incide sobre o estudo e análise de uma solução para a criação de um sistema de recomendação para uma comunidade de consumidores de media e no consequente desenvolvimento da mesma cujo âmbito inicial engloba consumidores de jogos, filmes e/ou séries, com o intuito de lhes proporcionar a oportunidade de partilharem experiências, bem como manterem um registo das mesmas. Com a informação adquirida, o sistema reúne condições para proceder a sugestões direccionadas a cada membro da comunidade. O sistema actualiza a sua informação mediante as acções e os dados fornecidos pelos membros, bem como pelo seu feedback às sugestões. Esta aprendizagem ao longo do tempo permite que as sugestões do sistema evoluam juntamente com a mudança de preferência dos membros ou se autocorrijam. O sistema toma iniciativa de sugerir mediante determinadas acções, mas também pode ser invocada uma sugestão directamente pelo utilizador, na medida em que este não precisa de esperar por sugestões, podendo pedir ao sistema que as forneça num determinado momento. Nos testes realizados foi possível apurar que o sistema de recomendação desenvolvido forneceu sugestões adequadas a cada utilizador específico, tomando em linha de conta as suas acções prévias. Para além deste facto, o sistema não forneceu qualquer sugestão quando o histórico destas tinha provado incomodar o utilizador.

Estudo electroquímico de compostos naturais e semicondutores com possível utilização em células foto voltaicas

As células foto voltaicas orgânicas ou células de Gräetzel (depois do seu descobridor) são aparelhos para a colecta de energia solar que utilizam um semicondutor inorgânico e uma molécula orgânica. Dita molécula orgânica é capaz de excitar-se na presença de radiação electromagnética e ceder esta energia através da doação de electrões a este semicondutor. Embora estas estruturas e o seu processo de fabrico sejam relativamente pouco onerosas, o aproveitamento da energia solar é ainda muito baixo. Para além desta deficiência, os corantes sintéticos sofrem de “bleaching” ou então são reduzidos ou oxidados facilmente quando não conseguem transferir a energia que foi absorvida ou quando é difícil voltar ao estado original por dificuldades no completamento de circulação de electrões. Neste trabalho pretende-se então estudar o comportamento de moléculas e misturas complexas de moléculas com capacidade para serem excitadas pela luz solar. Como a dita xcitação promove a transferência de um electrão, este processo será seguido pela técnica de Voltametria cíclica. Como substâncias absorventes de luz utilizaremos compostos naturais (principalmente flavonóides) puros, ou então na forma de complexos naturais extraídos de algumas plantas. Estas misturas de corantes serão extractos aquosos (infusões) de casca de laranja e limão assim como extractos de folhas de cerejeira, com o objectivo de proporcionar lternativas aos flavonóides utilizados neste estudo. A caracterização voltamétrica desta célula é feita em diferentes formas de iluminação. Sobre a célula assim formada faz-se incidir rimeiro luz de lâmpadas fluorescentes, depois luz ultra violeta e por fim sem qualquer tipo de luz incidente. Na base do fabrico da variante mais clássica destas células está o semicondutor óxido de itânio (TiO2), por ser uma substância muito comum e barata e com propriedades semicondutoras notáveis. Uma forma comum de melhorar a eficiência deste material é introduzir dopantes com o intuito de melhorar a eficiência do processo de transferência electrónica. Um segundo objectivo deste trabalho é o estudo de sistemas semicondutor/molécula foto activa. Semicondutores como ZnO, TiO2 e TiO2 dopado serão então estudados. O gels de TiO2 ou o TiO2 dopado serão depositados sobre lâminas de vidro comum, nas quais foi anteriormente depositado uma película de alumínio que serve de condutor (eléctrodo egativo). Uma outra variante será a utilização de óxido de zinco, um semicondutor de baixo custo que por sua vez vai ser depositado em lâminas de alumínio comercial. A nossa célula foto electroquímica será então formada por moléculas de corante, uma lâmina e um semicondutor (que funcionará como eléctrodo de trabalho), com ou sem electrólito/catalizador (solução de iodo/iodeto), e eléctrodos de referência de Ag/AgCl, e outro auxiliar de grafite. Um outro objectivo é fazer um pequeno estudo sobre influencia do catalisador I2/etilenodiamina no comportamento electroquímico da célula, de forma a poder utilizar o solvente (etilenodiamina) com menor volatilidade do que a água, que é empregada no par I2/I3.m A importância deste facto prende-se com a limitada vida destas células quando o electrólito/solvente é evaporado pelas altas temperaturas da radiação incidente.