799 resultados para meaningful story units
Resumo:
VITAE was a four-year research project designed to explore the work and lives of a purposive sample of 300 Key Stage 1, 2 and 3 (English and maths) teachers at different phases of their careers in 100 primary and secondary schools in different socioeconomic contexts, drawn from seven local authorities in England. Its focus was upon identifying variations in different aspects of teachers' lives and work and examining possible connections between these and their effects on pupils as perceived by the teachers themselves and as measured by value-added national test scores. An integrated mixed-method approach was developed in addressing the research questions. The results showed that there were associations between teachers' work, lives and identities, that teachers' perceived and relative (valueadded) effectiveness varied within each of six professional life phases, and that this variation depended upon their capacity to manage a number of moderating and mediating factors. Statistically significant relationships were found between teacher commitment, resilience and the value-added pupil test scores. The findings from the study shed new light upon the meanings and measurement of teacher effectiveness and the complex nature and trajectories of teachers' work, lives and effectiveness in different school contexts.
Resumo:
The best places to locate the Gas Supply Units (GSUs) on a natural gas systems and their optimal allocation to loads are the key factors to organize an efficient upstream gas infrastructure. The number of GSUs and their optimal location in a gas network is a decision problem that can be formulated as a linear programming problem. Our emphasis is on the formulation and use of a suitable location model, reflecting real-world operations and constraints of a natural gas system. This paper presents a heuristic model, based on lagrangean approach, developed for finding the optimal GSUs location on a natural gas network, minimizing expenses and maximizing throughput and security of supply.The location model is applied to the Iberian high pressure natural gas network, a system modelised with 65 demand nodes. These nodes are linked by physical and virtual pipelines – road trucks with gas in liquefied form. The location model result shows the best places to locate, with the optimal demand allocation and the most economical gas transport mode: by pipeline or by road truck.
Resumo:
The implementation of competitive electricity markets has changed the consumers’ and distributed generation position power systems operation. The use of distributed generation and the participation in demand response programs, namely in smart grids, bring several advantages for consumers, aggregators, and system operators. The present paper proposes a remuneration structure for aggregated distributed generation and demand response resources. A virtual power player aggregates all the resources. The resources are aggregated in a certain number of clusters, each one corresponding to a distinct tariff group, according to the economic impact of the resulting remuneration tariff. The determined tariffs are intended to be used for several months. The aggregator can define the periodicity of the tariffs definition. The case study in this paper includes 218 consumers, and 66 distributed generation units.
Resumo:
In Portugal mainland the Cenozoic record occurs largely in several basins. Even in the same basin, the sedimentary record shows meaningful lateral facies and thickness changes. However, the main sedimentary ruptures and overall lithologic characteristics of the infillings stades are quite similar in the same basins, as a result of the geodinamic evolution of Iberia and the Cainozoic times eustatic and climate changes. A stratigraphic framework is proposed in order to allow a less complex use of the lithostratigraphic units as referred in the geological maps and literature. Some topics for future research are suggested.
Resumo:
Smart Grids (SGs) have emerged as the new paradigm for power system operation and management, being designed to include large amounts of distributed energy resources. This new paradigm requires new Energy Resource Management (ERM) methodologies considering different operation strategies and the existence of new management players such as several types of aggregators. This paper proposes a methodology to facilitate the coalition between distributed generation units originating Virtual Power Players (VPP) considering a game theory approach. The proposed approach consists in the analysis of the classifications that were attributed by each VPP to the distributed generation units, as well as in the analysis of the previous established contracts by each player. The proposed classification model is based in fourteen parameters including technical, economical and behavioural ones. Depending of the VPP strategies, size and goals, each parameter has different importance. VPP can also manage other type of energy resources, like storage units, electric vehicles, demand response programs or even parts of the MV and LV distribution network. A case study with twelve VPPs with different characteristics and one hundred and fifty real distributed generation units is included in the paper.
Resumo:
Relatório E1CEB - Relatório de estágio em Ensino do 1.º Ciclo do Ensino Básico: Atualmente, a sociedade encontra-se em constante mutação, pelo que urge formar profissionais de educação capazes de responder aos seus desafios, assim como formar cidadãos críticos e responsáveis e estimular a sua participação ativa na sociedade. Desta forma e, no âmbito das unidades curriculares (UC) de Prática Pedagógica Supervisionada na Educação Pré – Escolar e no 1º Ciclo do Ensino Básico (CEB), parte integrante dos 1.º e 2.º anos do Mestrado em Educação Pré-Escolar e Ensino do 1.º CEB, respetivamente, surge o presente relatório que apresenta o processo de desenvolvimento pessoal e profissional da mestranda. Assim, o presente documento pretende ser uma reflexão crítica sobre o processo formativo da formanda, revelando mobilização de conhecimentos teóricos e práticos e uma metodologia construtivista de Investigação – ação, que sustentou as práticas educativas e permitiu um conhecimento sólido e sustentável. Realça, ainda, o desenvolvimento da prática em díade de formação que estimulou o crescimento e a reconstrução de novos conhecimentos enriquecidos por uma reflexão sistemática e contínua. Este trabalho colaborativo promoveu um ambiente educativo profundo, significativo e agradável, contribuindo para a formação individual e coletiva dos vários intervenientes do contexto educativo. Acresce que, ao longo das práticas, a mestranda teve em consideração tudo o que foi aprendendo e desenvolvendo nas diversas UC’s, construindo a sua conceção de educadora e de professora, num contexto relacional e de consciência reflexiva que permitiu uma formação articulada com a ação pedagógica e organizacional, a partir da experiência e transformação dos saberes, eixos fundamentais para a profissionalidade docente.
Resumo:
Stress, molecular crowding and mutations may jeopardize the native folding of proteins. Misfolded and aggregated proteins not only loose their biological activity, but may also disturb protein homeostasis, damage membranes and induce apoptosis. Here, we review the role of molecular chaperones as a network of cellular defenses against the formation of cytotoxic protein aggregates. Chaperones favour the native folding of proteins either as "holdases", sequestering hydrophobic regions in misfolding polypeptides, and/or as "unfoldases", forcibly unfolding and disentangling misfolded polypeptides from aggregates. Whereas in bacteria, plants and fungi Hsp70/40 acts in concert with the Hsp100 (ClpB) unfoldase, Hsp70/40 is the only known chaperone in the cytoplasm of mammalian cells that can forcibly unfold and neutralize cytotoxic protein conformers. Owing to its particular spatial configuration, the bulky 70 kDa Hsp70 molecule, when distally bound through a very tight molecular clamp onto a 50-fold smaller hydrophobic peptide loop extruding from an aggregate, can locally exert on the misfolded segment an unfolding force of entropic origin, thus destroying the misfolded structures that stabilize aggregates. ADP/ATP exchange triggers Hsp70 dissociation from the ensuing enlarged unfolded peptide loop, which is then allowed to spontaneously refold into a closer-to-native conformation devoid of affinity for the chaperone. Driven by ATP, the cooperative action of Hsp70 and its co-chaperone Hsp40 may thus gradually convert toxic misfolded protein substrates with high affinity for the chaperone, into non-toxic, natively refolded, low-affinity products. Stress- and mutation-induced protein damages in the cell, causing degenerative diseases and aging, may thus be effectively counteracted by a powerful network of molecular chaperones and of chaperone-related proteases.
Resumo:
Context: Understanding the process through which adolescents and young adults are trying legal and illegal substances is a crucial point for the development of tailored prevention and treatment programs. However, patterns of substance first use can be very complex when multiple substances are considered, requiring reduction into a few meaningful number of categories. Data: We used data from a survey on adolescent and young adult health conducted in 2002 in Switzerland. Answers from 2212 subjects aged 19 and 20 were included. The first consumption ever of 10 substances (tobacco, cannabis, medicine to get high, sniff (volatile substances, and inhalants), ecstasy, GHB, LSD, cocaine, methadone, and heroin) was considered for a grand total of 516 different patterns. Methods: In a first step, automatic clustering was used to decrease the number of patterns to 50. Then, two groups of substance use experts, three social field workers, and three toxicologists and health professionals, were asked to reduce them into a maximum of 10 meaningful categories. Results: Classifications obtained through our methodology are of practical interest by revealing associations invisible to purely automatic algorithms. The article includes a detailed analysis of both final classifications, and a discussion on the advantages and limitations of our approach.
Resumo:
BACKGROUND: Red blood cell-derived microparticles (RMPs) are small phospholipid vesicles shed from RBCs in blood units, where they accumulate during storage. Because microparticles are bioactive, it could be suggested that RMPs are mediators of posttransfusion complications or, on the contrary, constitute a potential hemostatic agent. STUDY DESIGN AND METHODS: This study was performed to establish the impact on coagulation of RMPs isolated from blood units. Using calibrated automated thrombography, we investigated whether RMPs affect thrombin generation (TG) in plasma. RESULTS: We found that RMPs were not only able to increase TG in plasma in the presence of a low exogenous tissue factor (TF) concentration, but also to initiate TG in plasma in absence of exogenous TF. TG induced by RMPs in the absence of exogenous TF was neither affected by the presence of blocking anti-TF nor by the absence of Factor (F)VII. It was significantly reduced in plasma deficient in FVIII or F IX and abolished in FII-, FV-, FX-, or FXI-deficient plasma. TG was also totally abolished when anti-XI 01A6 was added in the sample. Finally, neither Western blotting, flow cytometry, nor immunogold labeling allowed the detection of traces of TF antigen. In addition, RMPs did not comprise polyphosphate, an important modulator of coagulation. CONCLUSIONS: Taken together, our data show that RMPs have FXI-dependent procoagulant properties and are able to initiate and propagate TG. The anionic surface of RMPs might be the site of FXI-mediated TG amplification and intrinsic tenase and prothrombinase complex assembly.
Resumo:
Pseudomonas aeruginosa is one of the leading nosocomial pathogens in intensive care units (ICUs). The source of this microorganism can be either endogenous or exogenous. The proportion of cases as a result of transmission is still debated, and its elucidation is important for implementing appropriate control measures. To understand the relative importance of exogenous vs. endogenous sources of P. aeruginosa, molecular typing was performed on all available P. aeruginosa isolated from ICU clinical and environmental specimens in 1998, 2000, 2003, 2004 and 2007. Patient samples were classified according to their P. aeruginosa genotypes into three categories: (A) identical to isolate from faucet; (B) identical to at least one other patient sample and not found in faucet; and (C) unique genotype. Cases in categories A and B were considered as possibly exogenous, and cases in category C as possibly endogenous. A mean of 34 cases per 1000 admissions per year were found to be colonized or infected by P. aeruginosa. Higher levels of faucet contamination were correlated with a higher number of cases in category A. The number of cases in category B varied from 1.9 to 20 cases per 1000 admissions. This number exceeded 10/1000 admissions on three occasions and was correlated with an outbreak on one occasion. The number of cases considered as endogenous (category C) was stable and independent of the number of cases in categories A and B. The present study shows that repeated molecular typing can help identify variations in the epidemiology of P. aeruginosa in ICU patients and guide infection control measures.
Resumo:
Collection : Journal officiel de la République française ; brochure 1194
Resumo:
Collection : Journal officiel de la République française ; 1194