Structural investigation of the Bacillus subtilis morphogenic factor RodZ

A thesis to obtain a Master degree in Structural and Functional Biochemistry

Developing and validating a measure of the strength of the HRM system: Operationalizing the construct and relationships among its dimensions

The four studies in this article introduce a questionnaire to measure Strength of the HRM System (HRMSQ), a multidimensional construct, theoretically developed by Bowen and Ostroff (2004). Strength of the HRM System is a set of process characteristics that lead to effectiveness in conveying signals to employees that allow them to create a shared meaning of desired and appropriate work behaviours. Nine characteristics are suggested, grouped in three features: Distinctiveness, Consistency and Consensus. Study 1 developed and tested a questionnaire in a sample of workers from five different sectors. Study 2 cross-validated the measure in a sample of civil servants in a municipality. These two studies used performance appraisal as the reference HRM practice and led to a short version of the HRMSQ. Study 3 and Study 4 extend the HRMSQ to several common HRM practices. The HRMSQ is tested in two samples, of call center and several private and public organizations‟ workers (study 3). In study 4 the questionnaire is refined and tested with a sample from a hotel chain and finally cross-validated with two other samples, in the insurance and batteries sectors, leading to a longer version of the HRMSQ. Content analysis of several interviews with human resource managers and the Rasch model (1960, 1961, 1980), were used to define and select the indicators of the questionnaire. Convergent, discriminant and predictive validity of the measure are tested. The results of the four studies highlight the complexity of the relationships between the proposed characteristics and support the validity of a parsimonious measure of Strength of the HRM System.

A relevância do factor de transcrição Yap5 de Saccharomyces cerevisiae na resposta ao excesso de ferro

A capacidade que os organismos possuem de alterar os seus padrões de expressão de genes em resposta a alterações no meio ambiente é essencial para a sua viabilidade. A levedura Saccharomyces cerevisiae, em particular, possui um programa complexo e muito flexível de expressão de genes quando exposta a mudanças agressivas do seu meio ambiente. As células mantêm a sua homeostase através de mecanismos coordenados de regulação de vários factores de transcrição, cada um desempenhando funções específicas. Neste trabalho foi estudada a relevância do factor de transcrição da família Yap de S. cerevisiae, o Yap5, na destoxificação do excesso de ferro na célula. Os resultados obtidos neste trabalho mostram que após a incubação com elevadas quantidades de sulfato de ferro, embora o potencial de transactivação do Yap5 aumente, os níveis da proteína diminuem, sendo esta diminuição dependente da concentração de ferro. Demonstrámos também que embora a expressão do gene CCC1 (que codifica para o único transportador vacuolar de ferro conhecido) seja dependente do Yap5 em condições de excesso de ferro, os níveis basais de expressão deste gene são suficientes para a sobrevivência nessas condições. Observámos ainda que, ao contrário do que acontece em Schizosaccharomyces pombe, o factor de transcrição Hap4, não parece estar envolvido nesta regulação. Através de delecções sequenciais da região promotora do CCC1, verificámos que os níveis de expressão ditados por uma região de 58pb a montante do codão de iniciação, ATG, são suficientes para a célula sobreviver sob concentrações elevadas de ferro. Verificámos ainda que a região 3’UTR do gene é importante para a sobrevivência celular. Nessa região, identificámos uma estrutura em forma de “hairpin” que poderá estar envolvida na regulação do gene.

The strength of the waterbed effect depends on tariff type

We show that the waterbed effect, i.e. the pass-through of a change in one price of a firm to its other prices, is much stronger if the latter include subscription rather than only usage fees. In particular, in mobile network competition with a fixed number of customers, the waterbed effect is full under two-part tariffs, while it is only partial under linear tariffs.

Optimização do factor de cobertura de condensadores de tântalo produzidos com pós de elevada carga específica

Dissertação para obtenção do Grau de Doutor em Nanotecnologias e Nanociências

Image processing for displacement measurements

Since the invention of photography humans have been using images to capture, store and analyse the act that they are interested in. With the developments in this field, assisted by better computers, it is possible to use image processing technology as an accurate method of analysis and measurement. Image processing's principal qualities are flexibility, adaptability and the ability to easily and quickly process a large amount of information. Successful examples of applications can be seen in several areas of human life, such as biomedical, industry, surveillance, military and mapping. This is so true that there are several Nobel prizes related to imaging. The accurate measurement of deformations, displacements, strain fields and surface defects are challenging in many material tests in Civil Engineering because traditionally these measurements require complex and expensive equipment, plus time consuming calibration. Image processing can be an inexpensive and effective tool for load displacement measurements. Using an adequate image acquisition system and taking advantage of the computation power of modern computers it is possible to accurately measure very small displacements with high precision. On the market there are already several commercial software packages. However they are commercialized at high cost. In this work block-matching algorithms will be used in order to compare the results from image processing with the data obtained with physical transducers during laboratory load tests. In order to test the proposed solutions several load tests were carried out in partnership with researchers from the Civil Engineering Department at Universidade Nova de Lisboa (UNL).

Intervenção da fisiopetarpia em indivíduos com osteoartrose do joelho: características da prática clínica e resultados obtidos em contexto de prática convencionada

RESUMO: Introdução: A osteoartrose do joelho em particular constitui uma das maiores causas de incapacidades no dia-a-dia, morbilidade e aumento dos custos de saúde na população, na medida em que é uma condição que quando sintomática progride para um padrão que incluí dor articular, perda de força, incapacidade para a marcha e redução da aptidão física. A sua prevalência aumenta com a idade, 7% entre pessoas dos 65-70 anos, e 11,2% para aqueles com 80 anos ou mais, pouco variando entre os estudos existentes. Um recente estudo da Organização Mundial da Saúde (OMS) refere que a osteoartrose é a quarta causa mais importante de incapacidade entre as mulheres e a oitava entre os homens. Objetivo do estudo: Descrever a intervenção da fisioterapia em contexto de prática clínica convencionada e os resultados obtidos em indivíduos com OA, ao nível da intensidade da dor, capacidade funcional e perceção global de melhoria. Desenho Metodológico: Trata-se de um Estudo de coorte prospetivo onde foram incluídos indivíduos de ambos os géneros, entre os 60 e os 80 anos, com osteoartrose do joelho referenciada clinicamente. Após o consentimento informado, os pacientes foram, avaliados em quatro momentos: num primeiro momento (T0), antes de iniciarem o tratamento; (T1) após 4 semanas do início do tratamento; (T2) coincidente com o final do tratamento; e (T3) 3 meses após o início do tratamento. Foi utilizado um Questionário de Caracterização Sócio-Demográfica e Clínica, a Escala numérica da dor – END, o questionário KOOS (Knee Injury and Osteoarthritis Outcome Score) e a versão portuguesa da Patient Global Impression Change (PGIC-PT). A base de seleção dos indivíduos foi realizada numa clínica convencionada do Algarve. Resultados: Foi observado um aumento significativo em todos os outcomes avaliados pelo KOOS, END e PGIC num período até 3 meses após a intervenção. Na avaliação da END em T3 o valor da média foi de 1,63(±0,71). Para o KOOS nas subescalas Sintomas foi de 87,60(±5,86), Dor 85,71(±3,99), AVD 78,23(±3,48), ADL 67,71(±7,16), QV 80,71(±9,14), para a PGIC-AVD 5,29(±0,57), PGIC-DOR 5,97(±0,61). Os resultados obtidos pelo teste de Friedman, revelaram um valor de p<0,005. Assim, a melhoria da incapacidade funcional reportada pelos participantes neste grupo é estatisticamente diferente, e de forma significativa nos diferentes momentos de recolha de dados, durante e após o tratamento (X2 (3)=208,862, p<0,005)/ (X2(3)=205,041, p<0,005). Por fim os valores do somatório dos participantes, que estão inseridos em no grupo dos “Bons Resultados”( ≥5) foi de 27,14% em T0 passando para 100,00% em T3, enquanto que o grupo dos “Maus Resultados”(<5) foi de 72,86% em T0 e 100% em T3. Conclusão: Os resultados do presente estudo sugerem que a intervenção da Fisioterapia efetuadas em clínicas convencionadas nos casos da Osteoartrose do joelho são efetivas na redução significativa dos níveis de dor e incapacidade funcional e na Perceção global de melhoria em pacientes com Osteoartrose do joelho. ---------- ABSTRACT: Introduction: Osteoarthritis of the knee in particular is a major cause of disabilities in their day-to-day morbidity and increased healthcare costs in the population, in that it is a disease that when symptomatic progresses to a pattern that included joint pain, strength loss, inability to walk and reduction of physical fitness. It is referred as a risk factor for falls and fractures. Its prevalence increases with age, 7% of people between 65-70 years, and 11.2% for those aged 80 or more, ranging from some existing studies. A recent study by the World Health Organization (WHO) reports that osteoarthritis is the fourth leading cause of disability among women and eighth among men. Objective: To describe the characteristics and the outcomes of the physiotherapy practice in patients with knee osteoarthritis. Methodology: A prospective cohort study, with 70 individuals, aged between 60 and 80 years with the diagnosis of knee osteoarthritis and referred to physiotherapy treatment, was carried out. After informed consent, patients were evaluated in four different moments: at baseline (T0), before starting treatment; 4 weeks after starting their treatment (T1); 8 weeks after starting their treatment (T2); and in a 3 months follow-up (T3). Patients were assessed for their socio-demographic and clinical characteristics, pain intensity (using the numeric pain rating scale- NRS), disability (using the Knee Injury and Osteoarthritis Outcome Score), and for their global impression of change (using the Portuguese version of the Patient Glogal Impression of Change scale). Results: The findings of this study indicate a significant increase in all outcomes assessed (pain, disability and global impression of change), during and after the physiotherapy treatment. At T3, the average value for the NRS was 1.63 (± 0.71). For KOOS in the symptoms subscales was 87.60 (± 5.86), pain 85.71 (± 3.99), ADL 78.23 (± 3.48), ADL 67.71 (± 7.16), QV 80.71 (± 9.14) for the PGIC-AVD 5.29 (± 0.57), PGIC-PAIN 5.97 (± 0.61). The results obtained though the Friedman test revealed a p-value <0.005. Thus, the improvement of functional capacity reported by participants in the group was statistically different at the different moments of data collection, during and after treatment (X 2 (3) = 208.862, p <0.005) / (X 2 (3) = 205.041, p <0.005). Conclusion: The results of this study show that the physiotherapy treatments made on agreed clinics in cases of osteoarthritis of the knee, are effective in significant reduction in the levels of pain and disability and in perception of overall improvement perception in patients with osteoarthritis of the Knee.

Understanding multi-asset factor models: Factor exposure interpretation

Field lab: Business project

Decisions of technology innovation: the role of indicators

This work presents research conducted to understand the role of indicators in decisions of technology innovation. A gap was detected in the literature of innovation and technology assessment about the use and influence of indicators in this type of decision. It was important to address this gap because indicators are often frequent elements of innovation and technology assessment studies. The research was designed to determine the extent of the use and influence of indicators in decisions of technology innovation, to characterize the role of indicators in these decisions, and to understand how indicators are used in these decisions. The latter involved the test of four possible explanatory factors: the type and phase of decision, and the context and process of construction of evidence. Furthermore, it focused on three Portuguese innovation groups: public researchers, business R&D&I leaders and policymakers. The research used a combination of methods to collect quantitative and qualitative information, such as surveys, case studies and social network analysis. This research concluded that the use of indicators is different from their influence in decisions of technology innovation. In fact, there is a high use of indicators in these decisions, but lower and differentiated differences in their influence in each innovation group. This suggests that political-behavioural methods are also involved in the decisions to different degrees. The main social influences in the decisions came mostly from hierarchies, knowledge-based contacts and users. Furthermore, the research established that indicators played mostly symbolic roles in decisions of policymakers and business R&D&I leaders, although their role with researchers was more differentiated. Indicators were also described as helpful instruments to conduct a reasonable interpretation of data and to balance options in innovation and technology assessments studies, in particular when contextualised, described in detail and with discussion upon the options made. Results suggest that there are four main explanatory factors for the role of indicators in these decisions: First, the type of decision appears to be a factor to consider when explaining the role of indicators. In fact, each type of decision had different influences on the way indicators are used, and each type of decision used different types of indicators. Results for policy-making were particularly different from decisions of acquisition and development of products/technology. Second, the phase of the decision can help to understand the role indicators play in these decisions. Results distinguished between two phases detected in all decisions – before and after the decision – as well as two other phases that can be used to complement the decision process and where indicators can be involved. Third, the context of decision is an important factor to consider when explaining the way indicators are taken into consideration in policy decisions. In fact, the role of indicators can be influenced by the particular context of the decision maker, in which all types of evidence can be selected or downplayed. More importantly, the use of persuasive analytical evidence appears to be related with the dispute existent in the policy context. Fourth and last, the process of construction of evidence is a factor to consider when explaining the way indicators are involved in these decisions. In fact, indicators and other evidence were brought to the decision processes according to their availability and capacity to support the different arguments and interests of the actors and stakeholders. In one case, an indicator lost much persuasion strength with the controversies that it went through during the decision process. Therefore, it can be argued that the use of indicators is high but not very influential; their role is mostly symbolic to policymakers and business decisions, but varies among researchers. The role of indicators in these decisions depends on the type and phase of the decision and the context and process of construction of evidence. The latter two are related to the particular context of each decision maker, the existence of elements of dispute and controversies that influence the way indicators are introduced in the decision-making process.

Fatigue life assessment of endodontic instruments subjected to multi planar curvature

This present study aimed to investigate the fatigue life of unused (new) endodontic instruments made of NiTi with control memory by Coltene™ and subjected to the multi curvature of a mandibular first molar root canal. Additionally, the instrument‟s structural behaviour was analysed through non-linear finite element analysis (FEA). The fatigue life of twelve Hyflex™ CM files was assessed while were forced to adopt a stance with multiple radius of curvature, similar to the ones usually found in a mandibular first molar root canal; nine of them were subjected to Pecking motion, a relative movement of axial type. To achieve this, it was designed an experimental setup with the aim of timing the instruments until fracture while worked inside a stainless steel mandibular first molar model with relative axial motion to simulate the pecking motion. Additionally, the model‟s root canal multi-curvature was confirmed by radiography. The non-linear finite element analysis was conducted using the computer aided design software package SolidWorks™ Simulation, in order to define the imposed displacement required by the FEA, it was necessary to model an endodontic instrument with simplified geometry using SolidWorks™ and subsequently analyse the geometry of the root canal CAD model. The experimental results shown that the instruments subjected to pecking motion displayed higher fatigue life values and higher lengths of fractured tips than those with only rotational relative movement. The finite element non-linear analyses shown, for identical conditions, maximum values for the first principal stress lower than the yield strength of the material and those were located in similar positions to the instrument‟s fracture location determined by the experimental testing results.