Caracterização da função do gene mob2 de Drosophila melanogaster

Dissertação de mest., Ciências Biomédicas, Departamento de Ciências Biomédicas e Medicina, Univ. do Algarve, 2011O correcto funcionamento do ciclo de divisão celular é essencial para a correcta transmissão do material genético da célula mãe para as células filhas, durante várias gerações, assegurando a continuidade da vida e a evolução das espécies. E, quando este processo é comprometido podem surgir várias complicações que geram o aparecimento de doenças como o cancro. Nas leveduras, S. cerevisae e S. pombe, foi demonstrado que os genes da família Mob desempenham um papel fundamental da saída de mitose, citocinese e polaridade das células. Assim sendo, como este genes estão conservados nos eucariotas, é possível que na Drosophila melanogaster, a família Mob também desempenhe funções essenciais no ciclo celular. Para determinar a função do gene Mob2 de Drosophila, realizou-se a análise do fenótipo dos mutantes Mob2 e tentou-se determinar a localização da proteína Mob2 ao longo das várias fases da mitose. Em conclusão, verificou-se que a proteína Mob2 parece estar localizada nos cinetocoros e que parece estar envolvida na formação do fuso e progressão do ciclo celular

Membrane permeability and aquaporin involvement in oxidative stress and cancer

Tese de doutoramento, Farmácia (Bioquímica), Universidade de Lisboa, Faculdade de Farmácia, 2019Aquaporins (AQPs) are a family of small transmembrane proteins present in all types of organisms and involved in the selective transport of water and small solutes such as glycerol in response to osmotic or solute gradients. So far, 13 isoforms were identified in humans and can be divided in three different groups according with their selectivity and sequence homology. AQPs were reported to be important in a wide range of physiological functions, such as water and energy homeostasis, exocrine fluid secretion and epidermal hydration. Dysfunction and/or abnormal expression of AQPs have been associated with several chronic diseases including epilepsy, cerebral edema, glaucoma, obesity, and cancer. In cancer, several isoforms were found overexpressed and three of them (AQP3, AQP8 and AQP9) can also transport H2O2. This small molecule can be toxic, but at lower concentration can act as second messenger in signaling pathways responsible for cancer cell migration and proliferation. Considering the importance of the AQPs in the initiation, promotion and progression of cancer, we first evaluated the effect of lipid peroxidation on the activity of a yeast aquaporin (AQY1), using a Saccharomyces cerevisiae oxidative stress model. In addition, we investigated the ability of mammalian AQPs to transport H2O2 using a S. cerevisiae heterologous expression model. In this case, the yeast strain used was previously deleted of endogenous aquaporins and transformed with mammalian AQPs, allowing to distinguish the function of each individually cloned isoform. It was identified AQPs with promising results and their function was validated in mammalian cell lines. On the other hand, the expression level of AQP1, AQP3 and AQP5 was evaluated in cancer cells after treatment with H2O2 to assess their gene regulation under conditions of oxidative stress. Finally, the expression level of AQP1, AQP3 and AQP5 was evaluated in several pancreatic biopsies in order to determine potential biomarkers for diagnostic and prognostic. The results obtained and described during this work showed that increased levels of membrane PUFAs triggered AQY1 expression, and its activity is impaired by HNE. Also, our data revealed the ability of AQP5, that is found overexpressed in tumors, as a H2O2 channel that can affect redox signaling. In addition, novel regulatory mechanism at mRNA level was detected in breast and colon cancer cells that may be involved in carcinogenesis. Finally, we show that AQP1, AQP3 and AQP5 can be used as biomarkers for pancreatic ductal adenocarcinoma prognostic and diagnostic. These results open a new perspective to assess the underlying molecular mechanisms of AQPs in signaling pathways associated with cancer and the possible interplay with cell oxidative stress response.Fundação para a Ciência e a Tecnologia (FCT), PD/BD/106085/201

In airline company maintenance and engineering department

This work arises from the increasing need of systems to manage risks associated with aircraft operations in order to improve the culture of Safety by the Aircraft Operators, particularly in the case of the Department of Engineering and Maintenance of these operators. The motivation for this study began with the partnership with a company dedicated to operate heavy aircraft worldwide. It was studied the case of risk management associated with the Department of Maintenance and Engineering airworthiness and created a program (or more specifically a set of procedures, connected by a database) to assist the members of this department controlling situations that threaten the safety, airworthiness and profitability of their fleet. The analysis of applicable legislation in the case of Maintenance and Engineering Department was made, as well as studied programs for risk management in different contexts. After that, we have outlined the general procedure as well as the various components that complete the analysis and mitigation of adverse events associated with the activities of this department. The implementation of this program was followed for one year in this study being presented here the results obtained from the analysis of the collected information. This work increased the safety culture of this department, as well as assisted in the implementation of mandatory legislation, introduced by the various authorities that regulate the operation of this operator.Este trabalho surge aquando da necessidade crescente de criar sistemas de gestão de risco em operações com aeronaves, de forma a melhorar a cultura de segurança por parte dos Operadores Aéreos. A motivação surgiu da parceria com uma empresa dedicada a operar aeronaves pesadas por todo o mundo. Foi estudado o caso particular da gestão de riscos associados ao Departamento de Manutenção e Engenharia e criado um programa (ou mais concretamente um conjunto de procedimentos, unidos por uma base de dados) para auxiliar os membros deste departmento a controlar situações que ameacem a segurança, aeronavegabilidade e rentabilidade da sua frota. Foi feita a análise da legislação aplicável ao caso concreto da Manutenção e Engenharia, assim como estudados programas aplicados em diversas áreas para gestão de riscos. Posto isto, foi delineado o procedimento geral assim como os diversos componentes que completam a análise e mitigação de eventos negativos associados com as actividades deste departamento. A implementação deste programa foi acompanhada durante um ano no âmbito deste estudo, sendo aqui apresentados os resultados obtidos da análise da informação recolhida. Este trabalho veio assim aumentar a cultura de segurança deste departamento, assim como ajudar na implementação da legislação mandatória, introduzida pelas diversas autoridades que regulam o sector no âmbito da operação deste operador

Dark Tourism: Concepts, Typologies and Sites

Dark Tourism, understood as the type of tourism that involves a visit to real or recreated places associated with death, suffering, misfortune, or the seemingly macabre, is not a new concept, even from a touristic point of view. In fact, places of war, disasters, death and atrocities always fascinated humans and are subject to visits. People have long been drawn, purposefully or otherwise, towards sites, attractions or events linked in one way or another with death, suffering, violence or disaster. The concept of dark tourism has been designed and studied for the last years and many are the destinations around the world where it has been implemented, playing an important role in both a country’s economy and its image. However, there is a gap in literature about this specific type of tourism. The main goal of this paper is to present a literature review about this new tourism product where the thrill seeking is the main motivation. Specifically, it’s our intent to present some Dark Tourism definitions, history and evolution, as well as, to introduce its typologies and identify the most important dark tourist sites all over the world

Mechanical properties of polymethyl methacrylate as denture base material: heat-polymerized vs. 3D-printed — systematic review and meta-analysis of in vitro studies

The synergy between dentistry and informatics has allowed the emergence of new technologies, specifically 3D printing, which has led to the development of new materials. The aim of this research was to compare the mechanical properties of dental base resins for 3D printing with conventional ones. This systematic review was developed using the PRISMA guidelines, and the electronic literature search was performed with the PubMed/MEDLINE, Web of Science—MEDLINE and EMBASE databases, until 30 April 2022. Two researchers selected the studies independently, and thus eight articles were found eligible for analysis. A meta-analysis was developed to estimate flexural strength. The Cohen’s kappa corresponding to this review was 1.00, and the risk assessment was considered low for the included studies. The 3D printing resin presented lower values of flexural strength and hardness compared with the heat-cured resin. Regarding impact strength, a lower value was recorded for the heat-cured resin compared with the 3D printing resin. Three-dimensional printing resins are viable materials for making prosthetic bases but need further clinical research.info:eu-repo/semantics/publishedVersio

Propriedade fundiária e topografia social : o caso da cidade de Mariana (Minas Gerais, Brasil, século XVIII)

This article analyzes the role played by freed people of color, and specially by Black and Meztiço freed women, in the process of land appropriation and physical construction of the portuguese episcopal  city of Minas Gerais. Many of them were heads of households and were legally able to appropriate urban and peri-urban plots, where they built houses, cultivated fields and exploited gold. Through the mapping (GIS) of municipal land data which refers to the "condition" and color of the landowners, we can analyze the distribution of individuals and social groups in Mariana’s urban space

Por uma pedagogia da notícia: o conceito de comunicação em Paulo Freire

Este artigo propõe uma revisitação ao conceito de comunicação proposto pelo educador brasileiro Paulo Freire (1922-1997) com o objetivo de contribuir para o entendimento do fenômeno emergente das fake news no cenário contemporâneo. As notícias falsas, de acordo com estudiosos da mídia, são um dos indícios de que estaríamos vivendo em uma época de desinformação generalizada. Embora não tenha sido comunicador de formação, estão presentes na obra de Freire diversas referências à comunicação como um conceito pertinente à educação (e vice-versa). O autor propugnou a indissolubilidade entre educação, comunicação e cultura de modo que, quando consideramos a interface entre estes campos do conhecimento, seguimos em direção à construção de uma Pedagogia da Comunicação. Freire afirmou que o ato educativo somente é considerado como tal se houver diálogo, em uma interpelação à alteridade. A comunicação é uma relação social, de tal modo que precisamos nos educar para a crítica de mídia.

Anxiety, threat appraisal and coping in sports : individual trait anxiety differences

El propósito de este estudio fue analizar los niveles de ansiedad, percepción de amenaza y las estrategias de afrontamiento de deportistas portugueses, confirmando la posibilidad de diferenciar deportistas con baja y alta ansiedad basándonos en sus niveles de percepción de amenaza y en las estrategias de afrontamiento que utilizaban. 550 deportistas de ambos sexos, entre los 15 y los 35 años (19.8±4.5), rellenaron las versiones portuguesas de la Sport Anxiety Scale (Smith, Smoll, & Schutz, 1990) y del Brief COPE (Carver, 1997), así como la Escala de Avaliação Cognitiva da Competição - Percepção de Ameaça (Escala de Evaluación Cognitiva de la Competición - Percepción de Amenaza; Cruz, 1994). Los resultados sugirieron que deportistas con bajo y alto rasgo de ansiedad podían ser distinguidos a partir de los niveles de amenaza percibidos y de las estrategias utilizadas para su afrontamiento. Los resultados fueron discutidos en relación con su aplicación investigadora y práctica.The purpose of this study was to examine the levels of anxiety, threat perception, and coping strategies used by high and low-trait anxious Portuguese athletes, examining if they could be differentiated by their levels of threat perception and coping skills. Five-hundred and fifty male and female athletes, aged between 15 and 35 years (19.8±4.5), completed the Portuguese versions of the Sport Anxiety Scale (Smith, Smoll, & Schutz, 1990) and of the Brief COPE (Carver, 1997), as well as the Escala de Avaliação Cognitiva da Competição - Percepção de Ameaça (Cognitive Appraisal Scale in Sport Competition – Threat Perception; Cruz, 1994). Results suggested that high and low trait anxious athletes could be differentiated by their threat perception levels and coping strategies used. Results were discussed with regard to theoretical, research and applied issues.Fundação para a Ciência e a Tecnologia (FCT

Anxiety and coping strategies in sport contexts: a look at the psychometric properties of Portuguese instruments for their assessmen

The purpose of this study was to examine the psychometric properties of the Portuguese versions of the Sport Anxiety Scale and of the Brief COPE, as well as of the Cognitive Appraisal Scale in Sport Competition– Threat Perception, namely regarding their factor structure validity and internal consistency. Participants were 550 male and female athletes of several sports, aged 15 to 35 years old (M=19.8; SD=4.5). Exploratory and Confirmatory Factor Analysis indicated that the instruments demonstrated good psychometric properties. In general, the measurement models provided a good fit to the empirical data and with the exception of some scales of the Brief COPE, the calculated Cronbach’s a coefficient of reliability indicated adequate internal consistency for the three instruments. Overall, the results of the present study provided evidence for these instruments’ validity and reliability, ultimately supporting their importance for research and psychological intervention in sport contexts.El objetivo de este studio fue examinar las propiedades psicométricas de las versiones portuguesas del Sport Anxiety Scale, el Brief COPE, y el Cognitive Appraisal Scale in Sport Competition– Threat Perception, atendiendo a su validez de estructura factorial y consistencia interna. Los participantes fueron 550 atletas de ambos sexos y diversos deportes con edades entre 15 y 35 años (M=19.8; DT=4.5). Los análisis factoriales exploratorio y confirmatorio indicaron que los instrumentos mostraban buenas propiedades psicométricas. En general, los modelos de medida proporcionaron un buen ajuste a los datos empíricos y, con la excepción de algunas escalas del Brief COPE, el coeficiente de fiabilidad de Cronbach indicó una consistencia interna adecuada de los tres instrumentos. Globalmente los resultados de este estudio proporcionaron evidencia de la fiabilidad y validez de los citados instrumentos, reforzando su importancia para la investigación y la intervención psicológicas en contextos deportivosFundação para a Ciência e Tecnologi