Antimicrobial resistance profiles of enterococci isolated from poultry meat and pasteurized milk in Rio de Janeiro, Brazil

The enterococci are important nosocomial pathogens with a remarkable capacity of expressing resistance to several antimicrobial agents. Their ubiquitous nature and resistance to adverse environmental conditions take account for their ability to colonize different habitats and for their potential for easy spreading through the food chain. In the present study we evaluated the distribution of species and antimicrobial susceptibility among enterococcal isolates recovered from food obtained in retail stores in Rio de Janeiro, Brazil. The following species were identified among 167 isolates obtained from poultry meat and 127 from pasteurized milk: Enterococcus faecalis (62.6%), E. casseliflavus (17.3%), E. durans (6.5%), E. gallinarum (3.0%), E. gilvus (2.4%), E. faecium (2.0%), E. hirae (1.4%), and E. sulfureus (1.0%). The overall percentages of antimicrobial resistant isolates were: 31.2 % to tetracycline, 23.8% to erythromycin, 11.3% to streptomycin, 4.3% to chloramphenicol, 3.9% to gentamicin, 1.4% to norfloxacin, 1.1% to imipenem, 0.7% to ciprofloxacin, nitrofurantoin, and penicillin, and 0.4% to ampicillin. Intermediate resistance was detected in frequencies varying from 0.5% for linezolid to 58.2% for erythromycin. None of the isolates showed resistance to glycopeptides. High-level resistance to aminoglycosides was observed in 13.1% of the isolates. Multiresistance was observed in E. faecalis, E. casseliflavus, E. faecium, E. gallinarum, E. durans and E. gilvus.

The Thioredoxin TRX-1 Modulates the Function of the Insulin-Like Neuropeptide DAF-28 during Dauer Formation in Caenorhabditis elegans

Thioredoxins comprise a conserved family of redox regulators involved in many biological processes, including stress resistance and aging. We report that the C. elegans thioredoxin TRX-1 acts in ASJ head sensory neurons as a novel modulator of the insulin-like neuropeptide DAF-28 during dauer formation. We show that increased formation of stress-resistant, long-lived dauer larvae in mutants for the gene encoding the insulin-like neuropeptide DAF-28 requires TRX-1 acting in ASJ neurons, upstream of the insulin-like receptor DAF-2. Genetic rescue experiments demonstrate that redox-independent functions of TRX-1 specifically in ASJ neurons are needed for the dauer formation constitutive (Daf-c) phenotype of daf-28 mutants. GFP reporters of trx-1 and daf-28 show opposing expression patterns in dauers (i.e. trx-1 is up-regulated and daf-28 is down-regulated), an effect that is not observed in growing L2/L3 larvae. In addition, functional TRX-1 is required for the down-regulation of a GFP reporter of daf-28 during dauer formation, a process that is likely subject to DAF-28-mediated feedback regulation. Our findings demonstrate that TRX-1 modulates DAF-28 signaling by contributing to the down-regulation of daf-28 expression during dauer formation. We propose that TRX-1 acts as a fluctuating neuronal signaling modulator within ASJ neurons to monitor the adjustment of neuropeptide expression, including insulin-like proteins, during dauer formation in response to adverse environmental conditions.

Risk of cardiovascular disease in a traditional African population with a high infectious load: a population-based study.

BACKGROUND: To test the inflammatory origin of cardiovascular disease, as opposed to its origin in western lifestyle. Population-based assessment of the prevalences of cardiovascular risk factors and cardiovascular disease in an inflammation-prone African population, including electrocardiography and ankle-arm index measurement. Comparison with known prevalences in American and European societies. METHODOLOGY/PRINCIPAL FINDINGS: Traditional population in rural Ghana, characterised by adverse environmental conditions and a high infectious load. Population-based sample of 924 individuals aged 50 years and older. Median values for cardiovascular risk factors, including waist circumference, BMI, blood pressure, and markers of glucose and lipid metabolism and inflammation. Prevalence of myocardial infarction detected by electrocardiography and prevalence of peripheral arterial disease detected by ankle-arm index. When compared to western societies, we found the Ghanaians to have more proinflammatory profiles and less cardiovascular risk factors, including obesity, dysglycaemia, dyslipidaemia, and hypertension. Prevalences of cardiovascular disease were also lower. Definite myocardial infarction was present in 1.2% (95%CI: 0.6 to 2.4%). Peripheral arterial disease was present in 2.8% (95%CI: 1.9 to 4.1%). CONCLUSIONS/SIGNIFICANCE: Taken together, our data indicate that for the pathogenesis of cardiovascular disease inflammatory processes alone do not suffice and additional factors, probably lifestyle-related, are mandatory.

Characterization of Arabidopsis FPS isozymes and FPS gene expression analysis provide insight into the biosynthesis of isoprenoid precursors in seeds

Arabidopsis thaliana contains two genes encoding farnesyl diphosphate (FPP) synthase (FPS), the prenyl diphoshate synthase that catalyzes the synthesis of FPP from isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP). In this study, we provide evidence that the two Arabidopsis short FPS isozymes FPS1S and FPS2 localize to the cytosol. Both enzymes were expressed in E. coli, purified and biochemically characterized. Despite FPS1S and FPS2 share more than 90% amino acid sequence identity, FPS2 was found to be more efficient as a catalyst, more sensitive to the inhibitory effect of NaCl, and more resistant to thermal inactivation than FPS1S. Homology modelling for FPS1S and FPS2 and analysis of the amino acid differences between the two enzymes revealed an increase in surface polarity and a greater capacity to form surface salt bridges of FPS2 compared to FPS1S. These factors most likely account for the enhanced thermostability of FPS2. Expression analysis of FPS::GUS genes in seeds showed that FPS1 and FPS2 display complementary patterns of expression particularly at late stages of seed development, which suggests that Arabidopsis seeds have two spatially segregated sources of FPP. Functional complementation studies of the Arabidopsis fps2 knockout mutant seed phenotypes demonstrated that under normal conditions FPS1S and FPS2 are functionally interchangeable. A putative role for FPS2 in maintaining seed germination capacity under adverse environmental conditions is discussed.

The role of microRNAs in the development of type 2 diabets

Pancreatic ß cells are highly specialized endocrine cells located within the islets of Langerhans in the pancreas. Their main role is to produce and secrete insulin, the hormone essential for the regulation of glucose homeostasis and body's metabolism. Diabetes mellitus develops when the amount of insulin released by ß cells is not sufficient to cover the metabolic demand. In type 1 diabetes (5-10% of diagnoses) insulin deficiency is caused by the autoimmune destruction of pancreatic ß cells. Type 2 diabetes (90% of diagnoses) results from a genetic predisposition and from the presence of adverse environmental conditions. The combination of these factors reduces insulin sensitivity of peripheral target tissues, causes impairment in ß-cell function and can lead to partial loss of ß cells. The development of novel therapeutic strategies for the treatment of diabetes necessitates the comprehension of the cellular processes involved in dysfunction and loss of ß cells. My thesis was focused on the involvement in the physiopathological processes leading to the development of diabetes of a class of small regulatory RNA molecules, called microRNAs (miRNAs) that post- transcriptionally regulate gene expression. Global miRNA profiling in pancreatic islets of two animal models of diabetes, the db/db mice and mice that were fed a high fat diet (HFD), characterized by obesity and insulin resistance, led us to identify two groups of miRNAs displaying expression changes under pre-diabetic and diabetic conditions. Among the miRNAs already upregulated in pre-diabetic db/db mice and HFD mice, miR- 132 was found to have beneficial effects on pancreatic ß cell function and survival. Indeed, mimicking the upregulation of miR-132 in primary pancreatic islet cells and ß-cell lines improved glucose- induced insulin secretion and favored survival of the cells upon exposure to pro-apoptotic stimuli such as palmitate and cytokines. MiR-132 was found to exert its action by enhancing the expression of MafA, a transcription factor essential for ß-cell function, survival and identity. On the other hand, up-regulation of miR-199a-5p and miR-199a-3p was detectable only in the islets of diabetic db/db mice and resulted in impaired insulin secretion and sensitization of the cells to apoptosis. MiR-199a- 5p was found to decrease insulin secretion by inducing the expression of granuphilin, a potent inhibitor of ß cell exocytosis. In contrast, miR-199a-3p was demonstrated to directly target and reduce the expression of two key ß-cell genes, mTOR and cMET, resulting in impaired ß-cell adaptation to metabolic demands and loss by apoptosis. Our findings suggest that miRNAs are important players in the onset of type 2 diabetes. MiRNA expression is adjusted in pancreatic ß cells exposed to a diabetogenic environment. These changes initially concern miRNAs responsible for adaptive processes aimed at compensating the onset of insulin resistance, but later such changes can be overlapped by modifications in the level of several additional miRNAs that favor ß-cell failure and the onset of type 2 diabetes.

Characterizing Propionibacterium freudenreichii ssp. shermanii JS and Lactobacillus rhamnosus LC705 as a new probiotic combination: basic properties of JS and pilot in vivo assessment of the combination

Characterizing Propionibacterium freudenreichii ssp. shermanii JS and Lactobacillus rhamnosus LC705 as a new probiotic combination: basic properties of JS and pilot in vivo assessment of the combination Each candidate probiotic strain has to have the documentation for the proper identification with current molecular tools, for the biological properties, for the safety aspects and for the health benefits in human trials if the intention is to apply the strain as health promoting culture in the commercial applications. No generalization based on species properties of an existing probiotic are valid for any novel strain, as strain specific differences appear e.g. in the resistance to GI tract conditions and in health promoting benefits (Madsen, 2006). The strain evaluation based on individual strain specific probiotic characteristics is therefore the first key action for the selection of the new probiotic candidate. The ultimate goal in the selection of the probiotic strain is to provide adequate amounts of active, living cells for the application and to guarantee that the cells are physiologically strong enough to survive and be biologically active in the adverse environmental conditions in the product and in GI tract of the host. The in vivo intervention studies are expensive and time consuming; therefore it is not rational to test all the possible candidates in vivo. Thus, the proper in vitro studies are helping to eliminate strains which are unlikely to perform well in vivo. The aims of this study were to characterize the strains of Propionibacterium freudenreichii ssp. shermanii JS and Lactobacillus rhamnosus LC705, both used for decades as cheese starter cultures, for their technological and possible probiotic functionality applied in a combined culture. The in vitro studies of Propionibacterium freudenreichii ssp. shermanii JS focused on the monitoring of the viability rates during the acid and bile treatments and on the safety aspects such as antibiotic susceptibility and adhesion. The studies with the combination of the strains JS and LC705 administered in fruit juices monitored the survival of the strains JS and LC705 during the GI transit and their effect on gut wellbeing properties measured as relief of constipation. In addition, safety parameters such as side effects and some peripheral immune parameters were assessed. Separately, the combination of P. freudenreichii ssp. shermanii JS and Lactobacillus rhamnosus LC705 was evaluated from the technological point of view as a bioprotective culture in fermented foods and wheat bread applications. In this study, the role ofP. freudenreichii ssp. shermanii JS as a candidate probiotic culture alone and in a combination with L. rhamnosus LC705 was demonstrated. Both strains were transiently recovered in high numbers in fecal samples of healthy adults during the consumption period. The good survival through the GI transit was proven for both strains with a recovery rate from 70 to 80% for the JS strain and from 40 to 60% for the LC705 strain from the daily dose of 10 log10 CFU. The good survival was shown from the consumption of fruit juices which do not provide similar matrix protection for the cells as milk based products. The strain JS did not pose

Injusticia ambiental en Colombia: minería y salud al nacer

La vulnerabilidad de la población a condiciones ambientales adversas ha tenido especial relevancia para la literatura de inequidad en los últimos tiempos. De hecho, el concepto de justicia ambiental nace a partir de las disparidades que los individuos enfrentan en la calidad del ambiente. Este trabajo es una aproximación a este concepto ya que considera las actividades mineras como posibles generadoras de pasivos ambientales, que a su vez, pueden afectar las condiciones bajo las cuales los individuos se desarrollan. Desde la crisis financiera del 2008, los precios del oro experimentaron alzas signicativas en relación a periodos anteriores y generaron un aumento de las actividades mineras de oro. En este sentido, el objetivo del trabajo es investigar el impacto de las actividades mineras del oro sobre la salud de los recién nacidos en Colombia durante el periodo de boom en el precio de los minerales en la pasada década. Con este n, se usa información sobre el potencial minero, los precios internacionales del oro y las estadísticas vitales de Colombia. Las estimaciones indican que mayores niveles actividad minera implican un incremento en la tasa de bebés nacidos antes de las 27 semanas de gestación y en la tasa de bebés de bajo peso (nacidos con menos de 2.500 gramos). Adicionalmente se encuentra que las actividades mineras no tienen un efecto sobre la tasa de defunciones fetales. Los resultados son robustos a diferentes medidas de minera, que incluyen presencia de minera ilegal, titulación minera y volumen de producción de oro.

Living to die and dying to live: the survival strategy behind leaf senescence

Senescence represents the final developmental act of the leaf, during which the leaf cell is dismantled in a coordinated manner to remobilize nutrients and to secure reproductive success. The process of senescence provides the plant with phenotypic plasticity to help it adapt to adverse environmental conditions. Here, we provide a comprehensive overview of the factors and mechanisms that control the onset of senescence. We explain how the competence to senesce is established during leaf development, as depicted by the senescence window model. We also discuss the mechanisms by which phytohormones and environmental stresses control senescence, as well as the impact of source-sink relationships on plant yield and stress tolerance. In addition, we discuss the role of senescence as a strategy for stress adaptation and how crop production and food quality could benefit from engineering or breeding crops with altered onset of senescence.

Dying young: a palaeopathological analysis of child health in Roman Britain

Children represent the most vulnerable members of society, and as such provide valuable insight into past lifeways. Adverse environmental conditions translate more readily into the osteological record of children, making them primary evidence for the investigation of ill-health in the past. To date, most information on growing up in Roman Britain has been based on the Classical literature, or discussed in palaeopathological studies with a regional focus, e.g. Dorset or Durnovaria. Thus, the lifestyles and everyday realities of children throughout Britannia remained largely unknown. This study sets out to fill this gap by providing the first large scale analysis of Romano-British children from town and country. The palaeopathological analysis of 1643 non-adult (0-17 years) skeletons, compiled from the literature (N=690) and primary osteological analysis (N=953), from 27 urban and rural settlements has highlighted diverse patterns in non-adult mortality and morbidity. The distribution of ages-at-death suggest that older children and adolescents migrated from country to town, possibly for commencing their working lives. True prevalence rates suggest that caries (1.8%) and enamel hypoplasia (11.4%) were more common in children from major urban towns, whereas children in the countryside displayed higher frequencies of scurvy (6.9%), cribra orbitalia (27.7%), porotic hyperostosis (6.2%) and endocranial lesions (10.9%). Social inequality in late Roman Britain may have been the driving force behind these urban-rural dichotomies. The results may point to exploitation of the peasantry on the one hand, and higher status of the urban population as a more ‘Romanised’ group on the other. Comparison with Iron Age and post-medieval non-adults also demonstrated a decline in health in the Roman period, with some levels of ill-health, particularly in the rural children, similar to those from post-medieval London. This research provides the most comprehensive study of non-adult morbidity and mortality in Roman Britain to date. It has provided new insights into Romano-British lifeways and presents suggestions for further work.

Influência do desenvolvimento tecnológico sobre o desenvolvimento social a partir das atividades da incubadora tecnológica de Campina Grande, Campina Grande Paraíba

Este estudo avalia a influência do desenvolvimento tecnológico sobre o social, a partir das atividades produtivas desenvolvidas na unidade agroindustrial Recanto lI, no município de Catolé do Rocha, com o apoio da Incubadora Tecnológica de Campina Grande - ITCG, e o Programa de Estudos e Ações no Semi-Árido Paraibano da Universidade Federal de Campina Grande - PEASAlUFCG. Os problemas sociais no semi-árido surgiram por condições ambientais adversas e se intensificaram pela falta de políticas públicas adequadas à educação e ao desenvolvimento da região. O problema é expresso pela seguinte indagação: Qual a influência entre o desenvolvimento tecnológico e o desenvolvimento social gerados a partir da atividade produtiva da Incubadora de Campina Grande, em Campina Grande, Paraíba? A relevância deste trabalho vem da pretensão em colaborar para o estudo da relação entre desenvolvimento tecnológico e social, numa tentativa de tornar inteligível a necessidade de educação e inovação tecnológica para o desenvolvimento social, principalmente em países não desenvolvidos. Vem também da utilidade para a formulação de políticas públicas e estratégias de desenvolvimento tecnológico, identificando ações e medidas de desempenho, voltadas ao diagnóstico da contribuição das incubadoras tecnológicas para o bem-estar da sociedade. O referencial teórico foi composto pela análise da função das racionalidades dos diversos agentes sociais e de sua contribuição para as interações sociais, além da análise das realidades culturais da sociedade empresariada, do Estado e das incubadoras tecnológicas. A metodologia se utilizou da pesquisa descritiva e explicativa, de campo, documental, bibliográfica e estudo de caso. O universo foram as pessoas que compõem a ITCG e a amostra foram o diretor da Incubadora, o cientista da UFCG e o líder comunitário de Recanto lI. Os sujeitos da pesquisa confundem-se com a amostra. A coleta de dados se deu por meio da literatura sobre a temática e de inserções no campo de estudo. O tratamento de dados se utilizou da análise qualitativa do fenômeno. As principais limitações do método consistiram na coleta, no tratamento dos dados, e na utilização do estudo de caso, com possibilidade de compreensão tendenciosa do fenômeno estudado. O referencial prático apresenta o resultados da pesquisa, avaliando-os por meio da comparação com o referencial teórico estudado. Tem-se como resultados que a ITCG agiu articulando os grupos e traduzindo as realidades culturais de cada agente em prol do desenvolvimento de comunidades agroindustriais em situação de risco social, devido à problemática da seca. A ITCG atuou como alfabetizadora social ensinando aos agentes sociais os códigos culturais dos demais grupos. As desigualdades que existiam entre o cientista e o sertanejo, aprofundadas pelo vexatório histórico de escravidão do homem do campo no nordeste brasileiro, foram minimizadas pela educação dada pelo próprio cientista. A Universidade contribuiu para a redução do analfabetismo ambiental, onde o meio ambiente era tido como o principal rival do homem do sertão. O Estado, quando atua em parceria com os demais agentes sociais consegue, manter-se como o principal instrumento dos cidadãos para controlar a globalização em função de seus valores e interesses. Na ITCG o ambiente de incubação é educacional, onde os novos empreendedores são postos em contato com a realidade cultural do empresariado, do Estado e de outras comunidades da sociedade, seguindo modelos meramente educacionais. Como conclusão tem-se que a trajetória dos cidadãos de Recanto II - de escravos a exportadores - foi baseada em dois grandes tesouros, a família e areligião. O mérito da ITCG foi compreender, respeitar e preservar a realidade cultural de Recanto 11 e incentivar a interação social com outras realidades culturais capazes de gerar desenvolvimento naquela região. A saúde, o desenvolvimento infantil, a segurança, a habitação foram conquistas de Recanto 11. Como sugestão tem-se que as políticas públicas deveriam reproduzir este ambiente de desenvolvimento para todos os cidadãos brasileiros em situação de risco social, utilizando-se da família como base para interações sociais fluidas e harmônicas entre os diversos agentes sociais.

Compósitos poliméricos a base de fibras de licuri: efeitos da hibridização e do envelhecimento ambiental acelerado

The gradual replacement of conventional materials by the ones called composite materials is becoming a concern about the response of these composites against adverse environmental conditions, such as ultraviolet radiation, high temperature and moist. Also the search for new composite using natural fibers or a blend of it with synthetic fibers as reinforcement has been studied. In this sense, this research begins with a thorough study of microstructural characterization of licuri fiber, as a proposal of alternative reinforcement to polymeric composites. Thus, a study about the development of two composite laminates was done. The first one, involving only the fiber of licuri and the second comprising a hybrid composite based of fiber glass E and the fiber of licuri, in order to know the performance of the fiber when of fiber across the hybridization process. The laminates were made in the form of plates using the tereftálica ortho-polyester resin as matrix. The composite laminate made only by licuri fiber had two reinforcing fabric layers of unidirectional licuri and the hybrid composite had two reinforcing layers of unidirectional licuri fabric and three layers of fiber short glass-E mat. Finally, both laminates was exposed to aging acceleration in order to study the influence of environmental degradation involving the mechanical properties and fracture characteristics thereof. Regarding the mechanical properties of composites, these were determined through uniaxial tensile tests, uniaxial compression and three bending points for both laminates in original state, and uniaxial tensile tests and three bending points after accelerated aging. As regards the study of structural degradation due to aging of the laminates, it was carried out based on microscopic analysis and microstructure, as well as measuring weight loss. The characteristics of the fracture was performed by macroscopic and microscopic (optical and SEM) analysis. In general, the laminated composites based on fiber licuri showed some advantages in their responses to environmental aging. These advantages are observed in the behavior related to stiffness as well as the microstructural degradation and photo-oxidation processes. However, the structural integrity of this laminate was more affected in case the action of uniaxial tensile loads, where it was noted a lower rate of withholding his last resistance property

Xylella fastidiosa: An in vivo system to study possible survival strategies within citrus xylem vessels based on global gene expression analysis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeitos do envelhecimento ambiental acelerado em compósitos poliméricos

The advantages of the use of vegetable fibers on the synthetic fibers, such as glass fibers, in the reinforcements in composites are: low cost, low density, good tenacity, good thermal properties and reduced use of instruments for their treatment or processing. However, problems related to poor performance of some mechanical natural fibers, have hindered its direct use in structural elements. In this sense, the emergence of alternative materials such as hybrids composites, involving natural and synthetic fibers, has been encouraged by seeking to improve the performance of structural composites based only on natural fibers. The differences between the physical, chemical and mechanical properties of these fibers, especially facing the adverse environmental conditions such as the presence of moisture and ultraviolet radiation, is also becoming a concern in the final response of these composites. This piece of research presents a comparative study of the strength and stiffness between two composite, both of ortoftalic polyester matrix, one reinforced with fibers of glass-E (CV) and other hybrid reinforced with natural fibers of curauá and fiberglass-E (CH). All the comparative study is based on the influence of exposure to UV rays and steam heated water in composites, simulating the aging environment. The conditions for the tests are accelerated through the use of the aging chamber. The composites will be evaluated through tests of uniaxial static mechanical traction and bending on three points. The composite of glass fiber and hybrid manufacturing industry are using the rolling manual (hand lay-up) and have been developed in the form of composites. All were designed to meet possible structural applications such as tanks and pipes. The reinforcements used in composites were in the forms of short fiber glass-E quilts (450g/m2 - 5cm) of continuous wires and fuses (whose title was of 0.9 dtex) for the curauá fibers. The results clearly show the influence of aging on the environmental mechanical performance of the composite CV and CH. The issues concerning the final characteristics of the fracture for all types of cargoes studied were also analyzed

Envelhecimento ambiental acelerado em PRF a base de tecidos híbridos kevlar/vidro: propriedades e instabilidade estrutural

There are a number of damaging mechanisms that various materials can suffer in service. However, when working with polymer composite materials, this is something that requires analysis, especially when exposed to adverse environmental conditions. Thus, the objective of the present thesis is the study of the direct influence of environmental aging and the form of hybridization of the reinforcement woven on the structural stability, surfacedegradation and fracture process of polymer composites laminates. For this, the development of two polymer composite laminates was necessary, where one of them was reinforced with a bi-directional woven with hybrid strandsofkevlar-49/glass-Efibers, and the other also with a bi-directionalwoven, however with weft and warpformed of alternating strandsof Kevlar-49 fibers and glass-E fiber The reinforcementwoven are industrially manufactured. Both laminates use a polyester resin as a matrixand are made up of four layers each. All laminates were industrially prepared by the hand lay-up method of manufacturing. To do this, test specimens were manufactured of the respective laminates and submitted to environmental aging accelerated through the aging chamber. They were exposed to alternating cycles of UV radiation and moisture (heated steam) for a standard defined period. At the end of the exposure period the specimens were subjected to mechanical tests of uniaxial tensile and bending in three points and to the characterizationsof the fracture and surface deterioration. In addition, they were submitted to a structural degradation assessment by the measurement of mass variation technique (MMVT) and the measurement of thickness variation technique (MTVT), this last technique being developed in this thesis. At the end of the analysis it was observed that the form of hybridization of the reinforcement woven and the aging process directly influence with losses or gain in mechanical properties, with losses in the structural degradation and in the formation and propagation of damage mechanism of the developedcomposite laminates

Efeitos da radiação uv, temperatura e vapor aquecido nos compósitos poliméricos: monitoramento, instabilidade estrutural e fratura

The application of composite materials and in particular the fiber-reinforced plastics (FRP) has gradually conquered space from the so called conventional materials. However, challenges have arisen when their application occurs in equipment and mechanical structures which will be exposed to harsh environmental conditions, especially when there is the influence of environmental degradation due to temperature, UV radiation and moisture in the mechanical performance of these structures, causing irreversible structural damage such as loss of dimensional stability, interfacial degradation, loss of mass, loss of structural properties and changes in the damage mechanism. In this context, the objective of this thesis is the development of a process for monitoring and modeling structural degradation, and the study of the physical and mechanical properties in FRP when in the presence of adverse environmental conditions (ageing). The mechanism of ageing is characterized by controlled environmental conditions of heated steam and ultraviolet radiation. For the research, it was necessary to develop three polymer composites. The first was a lamina of polyester resin reinforced with a short glass-E fiber mat (representing the layer exposed to ageing), and the other two were laminates, both of seven layers of reinforcement, one being made up only of short fibers of glass-E, and the other a hybrid type reinforced with fibers of glass-E/ fibers of curaua. It should be noted that the two laminates have the lamina of short glass-E fibers as a layer of the ageing process incidence. The specimens were removed from the composites mentioned and submitted to environmental ageing accelerated by an ageing chamber. To study the monitoring and modeling of degradation, the ageing cycles to which the lamina was exposed were: alternating cycles of UV radiation and heated steam, a cycle only of UV radiation and a cycle only of heated steam, for a period defined by norm. The laminates have already undergone only the alternating cycle of UV and heated steam. At the end of the exposure period the specimens were subjected to a structural stability assessment by means of the developed measurement of thickness variation technique (MTVT) and the measurement of mass variation technique (MMVT). Then they were subjected to the mechanical tests of uniaxial tension for the lamina and all the laminates, besides the bending test on three points for the laminates. This study was followed by characterization of the fracture and the surface degradation. Finally, a model was developed for the composites called Ageing Zone Diagram (AZD) for monitoring and predicting the tensile strength after the ageing processes. From the results it was observed that the process of degradation occurs Abstract Raimundo Nonato Barbosa Felipe xiv differently for each composite studied, although all were affected in certain way and that the most aggressive ageing process was that of UV radiation, and that the hybrid laminated fibers of glass-E/curaua composite was most affected in its mechanical properties