219 research outputs found
Fatores influenciadores da sobrevivência das empresas familiares: um estudo de caso numa PME familiar no setor da construção
Dissertação submetida como requisito parcial para obtenção do grau de Mestre em Ciências EmpresariasAs empresas familiares ocupam um papel de extrema importância na economia mundial, uma vez que estima-se que de todas as empresas do mundo, 65% a 80% são familiares.
No entanto verifica-se uma maior taxa de mortalidade precoce neste tipo de empresas quando comparadas a empresas não familiares, sendo fundamental aprofundar o conhecimento acerca das mesmas. Assim, este estudo pretende analisar os fatores que podem influenciar a sobrevivência das empresas familiares, no contexto de uma empresa do setor da construção.
A pesquisa teve por base um enquadramento teórico do que se entende por empresa familiar, bem como as suas características genéricas, cultura organizacional, pontos fortes e vulnerabilidades, ciclo de vida, sucessão, mortalidade e modelo de gestão.
Com base na revisão da literatura foi feito um quadro síntese dos fatores que podem contribuir para a sobrevivência ou para a mortalidade precoce das empresas familiares.
Com um objetivo eminentemente exploratório, concretizado na forma de estudo de caso, recorreu-se à entrevista para recolha de dados. Foram realizadas entrevistas aos gestores de uma empresa familiar na segunda geração. Seguidamente procedeu-se à respetiva análise de conteúdo e à comparação das respostas dadas pelos diferentes entrevistados.
As conclusões do estudo de caso permitirão contribuir para uma melhor clarificação dos fatores que podem contribuir para a sobrevivência das empresas familiares.Family businesses have a very important role in the world economy, because it ‘s estimated that 65% - 80% of all companies in the world are familiar.
However, there is a higher rate of early mortality in this type of company when compared to non-family businesses, what makes it essential to deepen the knowledge about these companies. So, this study aims to examine the factors that can influence the survival of the family businesses, in the context of a company of the construction sector.
The research was based on a theoretical framework of what is meant by family business, as well as it’s generic characteristics, organizational culture, strengths and weaknesses, life cycle, succession, mortality and management model.
Based on the literature review, a summary table was made synthesizing the factors that may contribute to the survival or early mortality of family businesses.
With an exploratory objective, materialized in the form of a case study, the interview was used to data collection. Interviews were conducted with the managers of a family business in the second generation. Subsequently, the respective content was analyzed and a comparison of the answers given by the different interviewees was conducted.
The findings of the case study will contribute to a better clarification of the factors that may contribute to the survival of family businesses
Migration solvents for free isocyanates in food contact materials using experimental design
Agglomerated cork stoppers are currently used for still wines, semi-sparkle and gaseous wines, beer and cider. Methylene diphenyl diisocyanate (MDI) is presently the adhesive in use due to its lowest toxicity comparing with toluene diisocyanate (TDI) previously employed. However, free monomeric MDI can migrate from agglomerated cork stoppers to food stuff and this is worrying subject according to food contact materials.
The objective of this study is to determine which solvent is better to extract isocyanates from agglomerated cork stoppers, essentially MDI to quantify its free monomer. A long term migration study was performed in order to compare with soxhlet extraction.
Firstly a global migration test was performed in order to select the best solvents for soxhlet extraction. A Design of Experiments (DOE) with two factors, solvent and wax (to spike adhesive film), at six and two levels, respectively, was done. Six different solvents were put in contact with adhesive film during ten days at a temperature of forty degrees. Experiments were replicated and repeated three times. Through a TWO-WAY ANOVA the significance of solvents was evaluated and the three better solvents selected.
Afterwards, soxhlet extraction was performed with the three better solvents, ethanol, acetonitrile and n-heptane, regarding ANOVA results. The other control factors were cycles’ number (20, 55 and 90) and sample type (natural, agglomerated cork stopper and adhesive film). In a fractional factorial DOE, with three factors at three levels, nine experiments with three replicates were performed. The significance of the factors/interactions was evaluated and the best level’s factors were selected.
The Design of Experiments reveals to be a suitable statistical tool to determine the best conditions to measure the migration of free isocyanates from agglomerated cork stoppers to real foodstuff. The best solvent to monitor the migration from cork to wine by soxhlet extraction was ethanol although in long term migration the best solvent was acetonitrile.Financial support from ADI under the frame of project 5012-LIRACor
Central termoelétrica de Setúbal a património industrial por reutilização adaptativa
Tese de mestrado integrado em Engenharia Geográfica, Geofísica e Energia, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2015A Central Termoelétrica de Setúbal foi a última central térmica convencional e a de maior potência a queimar fuelóleo residual em Portugal. Cada um dos seus quatro grupos de 250 MW, totalizando uma potência instalada de 1000 MW, consumiam 56 toneladas por hora deste combustível. As emissões de CO2 produzidas durante os seus 33 anos de exploração totalizam perto de 90 milhões de toneladas. O futuro da produção da energia elétrica passa por sistemas de energia mais eficientes, descarbonizados, promovendo a segurança do abastecimento nacional. Não obstante, a desactivação da Central Termoelétrica de Setúbal em 2012 e os atuais planos para a demolição dos seus tanques de combustível coloca a questão: Que tipo de importância tem uma central termoelétrica de queima de combustíveis fósseis quando deixa de ser útil para a função para a qual foi destinada? Segundo a ótica apresentada nesta tese, a Central Termoelétrica de Setúbal pode vir a ser readaptada para outros fins, como já se observa internacionalmente e que se designa por reutilização adaptativa do património industrial. Neste trabalho pretende-se justificar a sua classificação a património cultural de interesse público, numa tentativa de evitar a sua demolição, suportando-se em duas abordagens fundamentais e objetivas: caracterização técnica e descrição das suas fases de vida, que permitiram criar um quadro dos critérios de importância – históricos, técnológicos, projetuais e sociais - que são essenciais para a sua classificação.Setúbal’s Thermoelectric Power Plant was the largest conventional power plant using residual oil as fuel in Portugal. Its total installed capacity of 1,000 MW included four 250 MW units, with each unit including a separate steam generator, turbine and alternator. Each steam generator unit consumed 56 tons of residual fuel oil per hour. During 33 years of operation, the power station emitted approximately 90 million tons of CO2. The future of electricity production in Portugal includes more efficient and decarburised energy systems, while ensuring the security of the national electricity supply. Setúbal’s power plant was decomissioned in 2012 and the current plans for the demolition of their fuel tanks poses the question: What is the importance of a fossil fuel based power plant after it ceases to be useful for the function it was intended for? From the viewpoint presented in this work, this decommissioned plant can re-adapted for other purposes. This is similar to the internationally followed practice called adaptive reuse of industrial heritage. This work attempts to justify the classification of Setúbal’s power station as an industrial heritage site of public interest and hence precent its imminent demolition. These objetives are supported by fundamental approaches: technical characterization and description of their life stages which created a framework of criterion that are essential for classification - historical, technological, architectural and social
Immunomodulation by NOD2/CARD15 and Vitamin D3
GvHD is still the most common life-threatening complication associated with allogeneic hematopoietic stem cell transplantation (HSCT). NOD2/CARD15, an intra-cytoplasmatic pathogen-recognition receptor recognizing bacterial muramyl dipeptide (MDP), has gained substantial interest, as single nucleotide polymorphisms (SNPs) of this receptor have been identified as a risk factor for Crohn´s disease and GvHD. These data suggest that MDP sensing by hematopoietic cells is of crucial importance for the immune homeostasis in target organs of GvHD, especially in the gastrointestinal tract and/or skin. Nevertheless, the exact mechanism by which the mutation in the NOD2 receptor affects the outcome of transplantation is not entirely understood.
In the present work, the impact of NOD2 polymorphisms on the immune cell composition in peripheral blood of healthy donors was evaluated. We found that donors with NOD2 mutations presented differences in their myeloid compartment, with less CD33+ cells (a common myeloid marker) and less myeloid dendritic cells (mDCs). A more detailed analysis on the monocyte population revealed that donors with SNP12 or SNP13 but not SNP8 had increased CD16 expression. CD14+CD16+ monocytes have been identified as a major proinflammatory cell population as they exhibit a distinct cytokine secretion pattern, with low IL-10 production and high levels of IL-1β, TNF and IL-12. Moreover, it has been shown that these monocytes are more efficient antigen-presenting cells than their classical counterparts. These results provide a new insight by which NOD2 polymorphisms can have a modulatory function in the course of inflammation.
TGF-β is a pleiotropic cytokine with strong regulatory and inflammatory activity. Our analysis demonstrated that TGF-β is capable of inducing the expression of CD16 on monocytes, independent of the NOD2 status. However, we noticed that the highest number of CD14+CD16+ cells was found in donors with SNP12 or 13 mutations. The cytokine profile of these cells revealed a decrease in IL-8 secretion by SNP12 or 13 donors and, although not significant, a strong trend towards an increased IL-6 secretion, especially under non-stimulatory conditions. In line with these observations, we analysed the expression of iκB and found a constitutive degradation of IκB in one donor with both SNP8 and SNP13 mutation, indicating a constitutive activation of the NF-κB pathway.
The imbalance found in the immune cell composition of the analysed NOD2 SNP donors could contribute to the association seen between NOD2 SNPs and HSCT outcome. The cellular imbalances reflect at molecular level through pro-inflammatory cytokine secretion, and it is believed that a dysregulation on cytokine production provide the first mechanism by which NOD2 variants can affect the outcome of HSCT.
Beside NOD2 polymorphisms, vitamin D3 receptor gene polymorphisms have also been associated with GvHD. Furthermore, it has already been shown that vitamin D3 deficiency is a common phenomenon in allogeneic transplant patients and may also be involved in the pathogenesis of Crohn’s disease and GvHD. The impact of 1α,25-Dihydroxyvitamin D3 (1,25(OH)2D3) on T cells is well documented. It is known that this vitamin is capable of inducing FOXP3 expression, a known marker for regulatory T cells. However, the majority of the studies make use of high, non-physiological amounts of 1,25(OH)2D3. Furthermore, the impact of vitamin D3 on T cells is commonly mediated through the action of dendritic cells. In addition, the impact of vitamin D3 precursor, 25(OH)D3 is poorly documented.
In the present work, we demonstrated that T cells are direct targets of vitamin D3. Both 25(OH)D3 and 1,25 (OH)2D3 were able to upregulate FOXP3 expression on human CD4+ T cells, independent of dendritic cells. Also, we demonstrated a synergistic effect of vitamin D3 and TGF-β in the induction of a regulatory phenotype on T cells. Although the expression of FOXP3 was not different in cells treated with TGF-β and 1,25(OH)2D3, compared with TGF-β alone, cytokine analysis demonstrated an increased IL-10 and sCTLA4 in the presence of both stimuli. Furthermore, both 25(OH)D3 and 1,25(OH)2D3 showed a strong trend in the reduction of IL-17 and IFNγ secretion.
The use of a vitamin D3 sufficient vs deficient mice model proved to be rather inconsistent between the three performed experiments. However, a significant increase in the number of myeloid-derived suppressor cells in mice with sufficient levels of vitamin D3 was found. Since MDSC were found to ameliorate GvHD and DSS- induced colitis, this finding supports the relations found between vitamin D3 status and inflammatory conditions.
The impact of vitamin D3 on microbiome was also analysed and an increased bacterial diversity on mice with low levels of vitamin D3 was detected. Furthermore, a significant increase in bacteria from the Akkermansia genus was found in the stool of mice with sufficient levels of vitamin D3. These bacteria are known to be capable Treg inducers, have proven to be beneficial in colitis and shown to induce the expression of antimicrobial peptide Reg3γ in the colon. These data provide further proof on the importance of vitamin D3 status on the resolution of inflammatory conditions
RELAÇÃO DE ÍNDICES ZOOTÉCNICOS COM A QUALIDADE DA CARNE DE CORDEIROS PRODUZIDOS NO RIO GRANDE DO SUL
Análise do desempenho acústico de elementos construtivos na reabilitação de edifícios
Ao longo desta dissertação é apresentada a legislação em vigor em Portugal relacionada com a acústica de edifícios, bem como as normas europeias existentes.
Como caso de estudo optou-se por analisar um edifício recuperado no âmbito do programa de reabilitação urbana do Porto, incidindo o estudo experimental na realização de ensaios acústicos, avaliando e validando através dos mesmos as soluções construtivas preconizadas no projeto de execução do edifício. Assim, para cada uma das soluções construtivas, realizaram-se estimativas de acordo com diferentes métodos preconizados nas normas e na bibliografia da especialidade.
Efetuou-se também a avaliação acústica do edifício através do método prescrito pelo Laboratório de Engenharia Civil (LNEC), a qual reverteu numa classificação de acordo com os parâmetros considerados, a qual é apresentada no presente trabalho.This dissertation lays on the study of acoustics in buildings related legislation currently in force in Portugal, as well as existing European standards.
As a case study we chose to analyze a restored building inserted in the Oporto rehabilitation program, focusing the experimental study on the conduction of noise tests, evaluating and validating the constructive solutions adopted in the design of the building.
As a method of verifying the results of the tests performed, calculated estimates were made according to different standards and methods recommended in the specialty literature.
An acoustic assessment of the building by the method prescribed by the National Civil Engineering Laboratory (LNEC) reverted in a classification, according to the parameters considered, and that is presented in this paper
A Utilização de Laser em Pacientes com Discrasias Sanguíneas
Os pacientes com discrasias sanguíneas constituem um grande desafio para o médico dentista, uma vez que apresentam um elevado risco de sangramento. Entre as diversas desordens sanguíneas encontramos as congénitas, como é o caso da hemofilia, e as adquiridas, como a trombocitopenia. Os lasers em cirurgia oral, constituem uma opção terapêutica de grande interesse, uma vez que apresentam diversas vantagens, nomeadamente o laser CO2, Nd:YAG e Er:YAG, promovendo a hemóstase, a diminuição da dor e do edema pós-operatório e também a redução do risco de infeção.
Objetivo: Esta revisão tem como objetivo estudar as características dos lasers e avaliar a sua utilidade em cirurgia, nomeadamente a sua utilização em pacientes com discrasias sanguíneas.
Materiais e Métodos: Foi realizada uma pesquisa bibliográfica, através das bases de dados de artigos científicos Pubmed e Google Scholar, utilizando as seguintes palavras chave: “Cirurgia Oral”, “Laser”, “Hipocoagulado”, “Hemostasia”, “Anticoagulantes”, “CO2”.
Discussão: O conhecimento das diversas discrasias sanguíneas e das características e vantagens de cada laser é essencial para determinar a melhor opção terapêutica, de acordo com as necessidades do paciente e da sua condição.
Conclusão: Determinação do tratamento laser de eleição que melhor se adequa às necessidades de tratamento dos pacientes em questão e suas patologias
Contribuições da Metodologia de Trabalho de Projeto para a construção de aprendizagens integradas das crianças
Relatório de estágio de mestrado em Educação Pré-Escolar e Ensino do 1º Ciclo do Ensino BásicoO presente relatório de estágio, integrado no plano de estudos do Mestrado em Educação
Pré-Escolar e Ensino do Primeiro Ciclo do Ensino Básico, apresenta o projeto de intervenção
pedagógica desenvolvido no âmbito da Prática de Ensino Supervisionada.
A intervenção pedagógica concretizada num contexto de jardim-de-infância, com um grupo
de vinte e duas crianças com 5 anos de idade, consistiu na implementação de um trabalho de
projeto que possibilitasse perceber de que forma o seu desenvolvimento pode potenciar a
construção de aprendizagens integradas nas crianças. O projeto de intervenção sustentou-se num
processo cíclico caraterístico da metodologia de investigação-ação que seguiu as diferentes etapas:
planificação, ação, observação e reflexão, sempre apoiadas num processo ativo de documentação.
Ao longo deste estudo verifica-se o papel ativo das crianças no processo de aprendizagem,
que motivadas pelos seus interesses e curiosidades, envolvem-se em ciclos de pesquisa onde
investigam as respostas às questões por si colocadas na fase inicial do projeto. Estas
investigações, das quais as crianças se foram apropriando em conjunto com as experiências
vivenciadas permitiram que as crianças pudessem construir, de uma forma integrada,
aprendizagens diversas relacionadas com as diferentes áreas de conteúdo.The present internship report, integrated in the syllabus of the Master's in Pre-school
Education and 1st Cycle of Basic Education, presents the project of pedagogical intervention
developed within the scope of the Supervised Teaching Practice.
The pedagogical intervention carried out in a kindergarten context, with a group of twentytwo
children at 5 years old, consisted in the implementation of a project work that allowed to realize
how their development could potentiate the construction of learning integrated into children. The
intervention project was based on a cyclical process characteristic of the research-action
methodology that followed the different steps: planning, action, observation and reflection, always
supporting an active process of documentation.
Throughout this study the active role of children in the learning process is verified.
Motivated by their interests and curiosities, they are involved in research cycles where they
investigate the answers to the questions they posed in the initial phase of the project. These
investigations, of which the children have appropriated together with the lived experiences allowed
the children to construct, in an integrated way, diverse learning related to the different content
areas
Airborne exposure of Rhizobium leguminosarum strain E20-8 to volatile monoterpenes: effects on cells challenged by cadmium
Volatile organic compounds (VOCs) are produced by plants, fungi, bacteria and animals. These compounds are metabolites originated mainly in catabolic reactions and can be involved in biological processes. In this study, the airborne effects of five monoterpenes (α-pinene, limonene, eucalyptol, linalool, and menthol) on the growth and oxidative status of the rhizobial strain Rhizobium leguminosarum E20-8 were studied, testing the hypothesis that these VOCs could influence Rhizobium growth and tolerance to cadmium. The tested monoterpenes were reported to have diverse effects, such as antibacterial activity (linalool, limonene, α-pinene, eucalyptol), modulation of antioxidant response or antioxidant properties (α-pinene and menthol). Our results showed that non-stressed cells of Rhizobium E20-8 have different responses (growth, cell damage and biochemistry) to monoterpenes, with α-pinene and eucalyptol increasing colonies growth. In stressed cells the majority of monoterpenes failed to minimize the detrimental effects of Cd and increased damage, decreased growth and altered cell biochemistry were observed. However, limonene (1 and 100 mM) and eucalyptol (100 nM) were able to increase the growth of Cd-stressed cells. Our study evidences the influence at-a-distance that organisms able to produce monoterpenes may have on the growth and tolerance of bacterial cells challenged by different environmental conditions.publishe
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