Aging pathology in sprague dawley rats : background lesions and comparative study between wild type and transgenic rats with neuronal overexpression of human adenosine A2A receptors

Dissertação de Mestrado Integrado em Medicina VeterináriaAging is a complex phenomenon defined as a time-dependent functional decline, progressive loss of physiological integrity and progressive increase in disease susceptibly. Adenosine A2A receptors (A2AR) are G protein-couple receptors that, upon binding of adenosine, lead to different transducing signals. Although having a protective effect, A2AR also play an important role in neurodegenerative disorders and are upregulated in the brain of Alzheimer and Parkinson patients. Previous studies from our collaborators showed that transgenic rats with neuronal overexpression of human A2AR (Tg (CaMKIIhA2AR)) have depressive-like behavior, impaired hypothalamic-pituitary-adrenal (HPA) axis and, as a result of this, increased levels of circulating corticosteroids. The aim of this work was to evaluate, by histopathology, the impact of the neuronal overexpression of human A2AR in the onset of specific or age-associated lesions in transgenic Sprague Dawley rats. Comprehensive necropsy and histopathology were performed in 37 Wild-type (Wt) and 39 transgenic (Tg) rats, at specific time-points, ranging from 12 to 126 weeks of age. Univariate and multivariate statistical analysis were performed to investigate the association between the phenotype and genotype. Briefly we found that Tg rats are 2.7 times more likely to develop systemic pathology than Wt rats [Odds ratio (OR) 2.745, IC 95% 1.0.07-6.997; (p0.05)]. In blood vessels, mineralization was the most frequent lesion and Tg rats were 5.5 times more likely to develop this lesion than Wt [OR 5.486, IC 95% 1.776- 17.074; (p0.05)]. Regarding adrenal gland pathology, vacuolation of the cortical cells was the most frequent lesion and Tg rats were 4.3 times more likely to develop this pathology than Wt [OR 4.3, IC 95% 1.156-16.248; (p0.05)]. Nos vasos sanguíneos, a lesão mais frequente foi a mineralização da parede, sendo que os ratos Tg foram 5.5 vezes mais suscetíveis a desenvolver esta lesão que os Wt [OR 5.486, IC 95% 1.776- 17.074; (p0.05)]. Relativamente às adrenais, a lesão mais frequente foi a vacuolização das células da cortical e os ratos Tg foram 4.3 vezes mais suscetíveis para o desenvolvimento desta lesão que os Wt [OR 4.3, IC 95% 1.156-16.248; (p<0.05)]. Fibroadenoma mamário foi o tumor mais frequente, tendo sido observado em um rato Wt e cinco ratos Tg. Mesmo em casos onde não foi observada diferença entre ratos Wt e Tg, todas as lesões encontradas neste estudo são lesões muitas vezes associadas ao envelhecimento, típicas desta espécie e a sua incidência correlacionou-se com a idade. Os nossos resultados mostram uma relação clara entre a sobre expressão neuronal de A2AR e envelhecimento acelerado na nossa amostra, e apesar de não termos explorado os mecanismos específicos para tal acontecimento, poderá estar ligado ao facto dos ratos Tg terem disfunção do eixo hipotálamo-hipófise-adrenal e níveis elevados de corticosterona, o que se traduz em stress crónico. A conhecimento dos autores, este é o primeiro estudo a caracterizar as repercussões sistémicas da sobre expressão neuronal de A2AR, que é observada em várias doenças degenerativas durante o envelhecimento.N/

η−η′\eta - \eta' in a hot and dense medium

The behavior of $\eta$ and $\eta'$ in hot strange quark matter in weak equilibrium with temperature, is investigated within the SU(3) Nambu-Jona-Lasinio [NJL] model. Possible manifestations of restoration of symmetries, by temperature or density, in the behavior of $\eta$ and $\eta'$ are discussed. The role played by the combined effect of temperature and density in the nature of the phase transition and meson behavior is also analyzed.Comment: 15 pages, 5 figures. Contribution to the Second International Workshop on Hadron Physics, Effective Theories of Low Energy QCD, 25-29 September, 2002 (Coimbra, Portugal

Lean enterprise resource planning

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia e Gestão IndustrialThis essay focus on Lean Management domain, following the ERP business application perspective linked with Lean Supply Chain, Lean Manufacturing and Lean Accounting, build on an electronic equipment manufacture company. Lean authors, consultants, managers and thinkers were studied to select and adopt the best Lean strategies taking in account the traditional business management ERP tool. The detected gaps were eliminated and/or reduced by developing solutions and adopting techniques based on Lean principles. Lean manufacturing practices were extended into the supply chain contributing now as a horizontal collaboration tool to all enterprise management functions,vendors and customers. Implementing Lean Accounting techniques allowed an increase of the stream value return, especially in terms of better capacity management capabilities,due decision make based also on non financial metrics. Due these Lean solutions, the company ERP system can be streamlined to perform the business shift and one of the most important enterprise assets can meet the strategic goals defined for Lean Enterprise Resource Planning. Therefore this assay proposes the implementation of this Lean strategy to turn into a lean company, more agile and proactive, to rapidly address the constant changes in business landscape

Exploring the role of model parameters and regularization procedures in the thermodynamics of the PNJL model

The equation of state and the critical behavior around the critical end point are studied in the context of the Polyakov--Nambu--Jona--Lasinio model. We prove that a convenient choice of the model parameters is crucial to get the correct description of isentropic trajectories. The physical relevance of the effects of the regularization procedure is insured by the agreement with general thermodynamic requirements. The results are compared with simple thermodynamic expectations and lattice data.Comment: Talk given at XIII International Conference on Hadron Spectroscopy (Hadron 2009), Tallahassee, Florida, USA, 29 Nov - 4 Dec, 200

The QCD Critical End Point in the Context of the Polyakov--Nambu--Jona-Lasinio Model

We investigate the phase diagram of the so-called Polyakov--Nambu--Jona-Lasinio model at finite temperature and nonzero chemical potential with three quark flavors. Chiral and deconfinement phase transitions are discussed, and the relevant order-like parameters are analyzed. A special attention is payed to the critical end point (CEP): the influence of the strangeness on the location of the CEP is studied; also the strength of the flavor-mixing interaction alters the CEP location, once when it becomes weaker the CEP moves to low temperatures and can even disappear.Comment: Prepared for Strangeness in Quark Matter 2011, Sept. 18--24, Cracow, Polan

How parameters and regularization affect the PNJL model phase diagram and thermodynamic quantities

We explore the phase diagram and the critical behavior of QCD thermodynamic quantities in the context of the so-called Polyakov--Nambu--Jona-Lasinio model. We show that this improved field theoretical model is a successful candidate for studying the equation of state and the critical behavior around the critical end point. We argue that a convenient choice of the model parameters is crucial to get the correct description of isentropic trajectories. The effects of the regularization procedure in several thermodynamic quantities is also analyzed. The results are compared with simple thermodynamic expectations and lattice data.Comment: 27 pages, 7 figures, 4 tables; PRD versio

De uma a outra coisa: escultura como materialização de energia

Neste projecto de Mestrado em Artes Plásticas desenvolvi esculturas e desenhos que procuram materializar o registo de fenómenos, acções e sensações que influenciam a percepção da matéria. Apostei num processo criativo que explora a relação sensitiva entre o observador e a energia implícita de um objecto. Relação essa, que se potencializa quando se permite uma desconstrução “material” dos objectos, aproveitando a natural capacidade que todo o tipo de material tem em activar, no observador, os mecanismos do “equipamento sensorial”2.2 GOURHAN, Leroi. “O gesto e a palavra 2 Memórias e Ritmos”, Edições 70, Lisboa, 2002, pág. 86