974 resultados para CLASS-2 INTEGRONS
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Calcium (Ca2+) is a known important second messenger. Calcium/Calmodulin (CaM) dependent protein kinase kinase 2 (CaMKK2) is a crucial kinase in the calcium signaling cascade. Activated by Ca2+/CaM, CaMKK2 can phosphorylate other CaM kinases and AMP-activated protein kinase (AMPK) to regulate cell differentiation, energy balance, metabolism and inflammation. Outside of the brain, CaMKK2 can only be detected in hematopoietic stem cells and progenitors, and in the subsets of mature myeloid cells. CaMKK2 has been noted to facilitate tumor cell proliferation in prostate cancer, breast cancer, and hepatic cancer. However, whethter CaMKK2 impacts the tumor microenvironment especially in hematopoietic malignancies remains unknown. Due to the relevance of myeloid cells in tumor growth, we hypothesized that CaMKK2 has a critical role in the tumor microenvironment, and tested this hyopothesis in murine models of hematological and solid cancer malignancies.
We found that CaMKK2 ablation in the host suppressed the growth of E.G7 murine lymphoma, Vk*Myc myeloma and E0771 mammary cancer. The selective ablation of CaMKK2 in myeloid cells was sufficient to restrain tumor growth, of which could be reversed by CD8 cell depletion. In the lymphoma microenvironment, ablating CaMKK2 generated less myeloid-derived suppressor cells (MDSCs) in vitro and in vivo. Mechanistically, CaMKK2 deficient dendritic cells showed higher Major Histocompatibility Class II (MHC II) and costimulatory factor expression, higher chemokine and IL-12 secretion when stimulated by LPS, and have higher potent in stimulating T-cell activation. AMPK, an anti-inflammatory kinase, was found as the relevant downstream target of CaMKK2 in dendritic cells. Treatment with CaMKK2 selective inhibitor STO-609 efficiently suppressed E.G7 and E0771 tumor growth, and reshaped the tumor microenvironment by attracting more immunogenic myeloid cells and infiltrated T cells.
In conclusion, we demonstrate that CaMKK2 expressed in myeloid cells is an important checkpoint in tumor microenvironment. Ablating CaMKK2 suppresses lymphoma growth by promoting myeloid cells development thereby decreasing MDSCs while enhancing the anti-tumor immune response. CaMKK2 inhibition is an innovative strategy for cancer therapy through reprogramming the tumor microenvironment.
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In this thesis we study aspects of (0,2) superconformal field theories (SCFTs), which are suitable for compactification of the heterotic string. In the first part, we study a class of (2,2) SCFTs obtained by fibering a Landau-Ginzburg (LG) orbifold CFT over a compact K\"ahler base manifold. While such models are naturally obtained as phases in a gauged linear sigma model (GLSM), our construction is independent of such an embedding. We discuss the general properties of such theories and present a technique to study the massless spectrum of the associated heterotic compactification. We test the validity of our method by applying it to hybrid phases of GLSMs and comparing spectra among the phases. In the second part, we turn to the study of the role of accidental symmetries in two-dimensional (0,2) SCFTs obtained by RG flow from (0,2) LG theories. These accidental symmetries are ubiquitous, and, unlike in the case of (2,2) theories, their identification is key to correctly identifying the IR fixed point and its properties. We develop a number of tools that help to identify such accidental symmetries in the context of (0,2) LG models and provide a conjecture for a toric structure of the SCFT moduli space in a large class of models. In the final part, we study the stability of heterotic compactifications described by (0,2) GLSMs with respect to worldsheet instanton corrections to the space-time superpotential following the work of Beasley and Witten. We show that generic models elude the vanishing theorem proved there, and may not determine supersymmetric heterotic vacua. We then construct a subclass of GLSMs for which a vanishing theorem holds.
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The relative contribution of regional contamination versus dietary differences to geographic variation in polar bear (Ursus maritimus) contaminant levels is unknown. Dietary variation between Alaska, Canada, East Greenland, and Svalbard subpopulations was assessed by muscle nitrogen and carbon stable isotope (d15N, d13C) and adipose fatty acid (FA) signatures relative to their main prey (ringed seals). Western and southern Hudson Bay signatures were characterized by depleted d15N and d13C, lower proportions of C20 and C22 monounsaturated FAs and higher proportions of C18 and longer chain polyunsaturated FAs. East Greenland and Svalbard signatures were reversed relative to Hudson Bay. Alaskan and Canadian Arctic signatures were intermediate. Between-subpopulation dietary differences predominated over interannual, seasonal, sex, or age variation. Among various brominated and chlorinated contaminants, diet signatures significantly explained variation in adipose levels of polybrominated diphenyl ether (PBDE) flame retardants (14-15%) and legacy PCBs (18-21%). However, dietary influence was contaminant class-specific, since only low or nonsignificant proportions of variation in organochlorine pesticide (e.g., chlordane) levels were explained by diet. Hudson Bay diet signatures were associated with lower PCB and PBDE levels, whereas East Greenland and Svalbard signatures were associated with higher levels. Understanding diet/food web factors is important to accurately interpret contaminant trends, particularly in a changing Arctic.
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An analysis of the operation of a new series-L/parallel-tuned Class-E amplifier and its equivalence to the classic shunt-C/series-tuned Class-E amplifier are presented. The first reported closed form design equations for the series-L/parallel-tuned topology operating under ideal switching conditions are given, including the switch current and voltage in steady state, the circuit component values, the peak values of switch current and voltage and the power-output capability. Theoretical analysis is confirmed by numerical simulation for a 500 mW (27 dBm), 10% bandwidth, 5 V series-L/parallel-tuned, then, shunt-C/series-tuned Class-E power amplifier, operating at 2.5 GHz. Excellent agreement between theory and simulation results is achieved.
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Since feminist studies and gender perspective, sexuality and reproduction continue to be a topic of interest in Mexico. The objective of this study was to identify gender stereotypes in sexuality and contraception practices in Mexican university students of middle class. We used a qualitative methodology with in-depth interviews, using as analysis axes the sexual and contraception practices. The results showed gender stereotypes in university students as active, seductive and conquerors, characterized by a double standard of morality in the type of relationship: Formal where love, affection, trust and commitment are present, and Informal, where a love relationship or sexual exclusivity is not incorporated.
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Amphibian skin secretions contain biologically-active compounds, such as anti-microbial peptides and trypsin inhibitors, which are used by biomedical researchers as a source of potential novel drug leads or pharmacological agents. Here, we report the application of a recently developed technique within our laboratory to “shotgun” clone the cDNAs encoding two novel but structurally-related peptides from the lyophilized skin secretions of one species of European frog, Rana esculenta and one species of Chinese frog, Odorrana schmackeri. Bioanalysis of the peptides established the structure of a 17-mer with an N-terminal Ala (A) residue and a C-terminal Cys (C) residue with a single disulphide bridge between Cys 12 and 17, which is a canonical Kunitz-type protease inhibitor motif (-CKAAFC-). Due to the presence of this structural attribute, these peptides were named kunitzin-RE (AAKIILNPKFRCKAAFC) and kunitzin-OS (AVNIPFKVHLRCKAAFC). Synthetic replicates of these two novel peptides were found to display a potent inhibitory activity against Escherichia coli but were ineffective at inhibiting the growth of Staphylococcus aureus and Candida albicans at concentrations up to 160 μM, and both showed little haemolytic activity at concentrations up to 120 μM. Subsequently, kunitzin-RE and kunitzin-OS were found to be a potent inhibitor of trypsin with a Ki of 5.56 μM and 7.56 μM that represent prototypes of a novel class of highly-attenuated amphibian skin protease inhibitor. Substitution of Lys-13, the predicted residue occupying the P1 position within the inhibitory loop, with Phe (F) resulted in decrease in trypsin inhibitor effectiveness and antimicrobial activity against Esherichia coli, but exhibits a potential inhibition activity against chymotrypsin.
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BACKGROUND: -There are few contemporary data on the mortality and morbidity associated with rheumatic heart disease (RHD) or information on their predictors. We report the two year follow-up of individuals with RHD from 14 low and middle income countries in Africa and Asia.
METHODS: -Between January 2010 and November 2012, we enrolled 3343 patients from 25 centers in 14 countries and followed them for two years to assess mortality, congestive heart failure (CHF), stroke or transient ischemic attack (TIA), recurrent acute rheumatic fever (ARF), and infective endocarditis (IE).
RESULTS: -Vital status at 24 months was known for 2960 (88.5%) patients. Two thirds were female. Although patients were young (median age 28 years, interquartile range 18 to 40), the two year case fatality rate was high (500 deaths, 16.9%). Mortality rate was 116.3/1000 patient-years in the first year and 65.4/1000 patient-years in the second year. Median age at death was 28.7 years. Independent predictors of death were severe valve disease (hazard ratio (HR) 2.36, 95% confidence interval (CI) 1.80-3.11), CHF (HR 2.16, 95% CI 1.70-2.72), New York Heart Association functional class III/IV (HR 1.67, 95% CI 1.32-2.10), atrial fibrillation (AF) (HR 1.40, 95% CI 1.10-1.78) and older age (HR 1.02, 95% CI 1.01-1.02 per year increase) at enrolment. Post-primary education (HR 0.67, 95% CI 0.54-0.85) and female sex (HR 0.65, 95%CI 0.52-0.80) were associated with lower risk of death. 204 (6.9%) had new CHF (incidence, 38.42/1000 patient-years), 46 (1.6%) had a stroke or TIA (8.45/1000 patient-years), 19 (0.6%) had ARF (3.49/1000 patient-years), and 20 (0.7%) had IE (3.65/1000 patient-years). Previous stroke and older age were independent predictors of stroke/TIA or systemic embolism. Patients from low and lower-middle income countries had significantly higher age- and sex-adjusted mortality compared to patients from upper-middle income countries. Valve surgery was significantly more common in upper-middle income than in lower-middle- or low-income countries.
CONCLUSIONS: -Patients with clinical RHD have high mortality and morbidity despite being young; those from low and lower-middle income countries had a poorer prognosis associated with advanced disease and low education. Programs focused on early detection and treatment of clinical RHD are required to improve outcomes.
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Introdução: O stress condiciona o comportamento e desenvolvimento pessoal, podendo ter consequências preocupantes ao nível individual e organizacional. Os professores são uma classe reconhecida como estando sujeita a elevados níveis de stress, fator que prejudica a qualidade do ensino em geral. Objetivos: Avaliar a vulnerabilidade ao stress; identificar os principais fatores de stress e avaliar a correlação entre autoestima e stress, em professores do 1.º, 2.º e 3.º ciclos do ensino básico. Metodologia: Estudo correlacional, com uma amostra constituída por 60 professores do 1.º, 2.º e 3.º ciclos de escolaridade, de escolas do concelho de Leiria. Para a análise das variáveis em estudo foram aplicados: um questionário sociodemográfico; a Rosenberg Self-Esteem Scale (RSES); o Questionário de stress nos professores: ensino básico e secundário (QSPEBS) e a Escala de vulnerabilidade ao stress (23 QVS). Resultados: O estudo revela que 65% dos professores percecionam a profissão como stressante e que 30% são vulneráveis ao stress. O principal fator de stress identificado foi comportamentos inadequados/indisciplina dos alunos. Verificou-se uma correlação negativa entre a autoestima e a vulnerabilidade ao stress dos professores. Conclusão: Conclui-se que, quanto mais elevada é a auto-estima, menor é a vulnerabilidade dos professores ao stress e que, apesar de não se registarem níveis significativos de vulnerabilidade ao stress na população docente, a maioria dos professores perceciona a sua atividade profissional como geradora de elevados níveis de stress, sendo os comportamentos inadequados/indisciplina dos alunos o fator que mais contribui para o stress nos docentes. / Introduction: Stress affects behavior and personal development, and may have severe consequences either at the individual or organizational level. Teachers are identified as a class exposed to high levels of stress, factor that affects the quality of education in general. Objectives: To assess stress vulnerability; identify key stressors and assess the correlation between self-esteem and stress in primary and secondary school teachers. Methodology: A sociodemographic questionnaire and three self-report measures were administered to a sample of 60 primary and secondary teachers from Leiria district: the Rosenberg Self-Esteem Scale (RSES); a teachers stress questionnaire for primary, secondary and high school (QSPEBS) and a scale to access stress vulnerability (23 QVS). Results: The study reveals that 65% of teachers perceive the profession as stressful and that 30% are vulnerable to stress. The main stressor identified is inappropriate/disruptive behavior of students. There is a negative correlation between self-esteem and vulnerability to stress of teachers. Conclusion: We conclude that a higher self-esteem leads to less stress vulnerability in teachers and that, despite the non-significant level of vulnerability determined in this study, most teachers perceive their activity as stressful, being inappropriate/disruptive behavior of students the factor that most contributes for that.
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AIM To compare the survival rates of Class II Atraumatic Restorative Treatment (ART) restorations placed in primary molars using cotton rolls or rubber dam as isolation methods. METHODS A total of 232 children, 6-7 years old, both genders, were selected having one primary molar with proximal dentine lesion. The children were randomly assigned into two groups: control group with Class II ART restoration made using cotton rolls and experimental group using rubber dam. The restorations were evaluated by eight calibrated evaluators (Kappa > 0.8) after 6, 12, 18 and 24 months. RESULTS A total of 48 (20.7%) children were considered dropout, after 24 months. The cumulative survival rate after 6, 12, 18 and 24 months was 61.4%, 39.0%, 29.1% and 18.0%, respectively for the control group, and 64.1%, 55.1%, 40.1% and 32.1%, respectively for the rubber dam group. The log rank test for censored data showed no statistical significant difference between the groups (P = 0.07). The univariate Cox Regression showed no statistical significant difference after adjusting for independent variables (P > 0.05). CONCLUSION Both groups had similar survival rates, and after 2 years, the use of rubber dam does not increase the success of Class II ART restorations significantly.
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Conventional taught learning practices often experience difficulties in keeping students motivated and engaged. Video games, however, are very successful at sustaining high levels of motivation and engagement through a set of tasks for hours without apparent loss of focus. In addition, gamers solve complex problems within a gaming environment without feeling fatigue or frustration, as they would typically do with a comparable learning task. Based on this notion, the academic community is keen on exploring methods that can deliver deep learner engagement and has shown increased interest in adopting gamification – the integration of gaming elements, mechanics, and frameworks into non-game situations and scenarios – as a means to increase student engagement and improve information retention. Its effectiveness when applied to education has been debatable though, as attempts have generally been restricted to one-dimensional approaches such as transposing a trivial reward system onto existing teaching materials and/or assessments. Nevertheless, a gamified, multi-dimensional, problem-based learning approach can yield improved results even when applied to a very complex and traditionally dry task like the teaching of computer programming, as shown in this paper. The presented quasi-experimental study used a combination of instructor feedback, real time sequence of scored quizzes, and live coding to deliver a fully interactive learning experience. More specifically, the “Kahoot!” Classroom Response System (CRS), the classroom version of the TV game show “Who Wants To Be A Millionaire?”, and Codecademy’s interactive platform formed the basis for a learning model which was applied to an entry-level Python programming course. Students were thus allowed to experience multiple interlocking methods similar to those commonly found in a top quality game experience. To assess gamification’s impact on learning, empirical data from the gamified group were compared to those from a control group who was taught through a traditional learning approach, similar to the one which had been used during previous cohorts. Despite this being a relatively small-scale study, the results and findings for a number of key metrics, including attendance, downloading of course material, and final grades, were encouraging and proved that the gamified approach was motivating and enriching for both students and instructors.
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Relatório Final de Estágio apresentado à Escola Superior de Dança, com vista à obtenção do grau de Mestre em Ensino de Dança.
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The discovery of antibiotics was a major breakthrough in medicine. However, short after their introduction in clinical practice resistant bacteria were detected. Nowadays, antibiotic resistance constitutes a serious public health problem. In hospital settings, with high resistance levels, reducing drastically the therapeutic options. Carbapenems are last-resort antibiotics used in Portugal, only in hospitals, to treat serious infections. Bacterial resistance towards this class of antibiotics has increased during last years. In Gram-negative bacteria the production of carbapenemases is a common resistance mechanism. OXA-48 is a carbapenemase of Ambler class D and represents a major concern for human health. It is frequently detected in clinical isolates of Enterobacteriaceae. There are few studies suggesting that genes encoding for OXA-48 variants originated from genes present in the chromosome of members of genus Shewanella, and have disseminated to Enterobacteriaceae members, associated with mobile genetic elements. The aim of this study was to characterize strains from different sources of Shewanella to confirm its role as OXA-48 progenitor. For this, the phylogenetic affiliation of 33 strains of Shewanella was performed by 16SrDNA and gyrB sequencing. The most common species were S. hafniensis and S. xiamenensis, but also S. aestuarii, S. baltica, S. indica, S. haliotis, S. putrefaciens, S. algidipiscicola, S. irciniae, S. algae and S. fodinae were identified. blaOXA-48-like genes were detected in 21 isolates: S. hafniensis (8/8), S. xiamenensis (5/5), S. baltica (4/4), S. algae (1/1), S. fodinae (1/1), S. putrefaciens (1/2) and S. algidipiscicola (1/2). Sequence analysis revealed that genes encoded enzymes identical to OXA-48, OXA-181 and OXA-204 but also new variants differing from OXA-48 from 2 to 81 aminoacids. Genetic context analysis revealed the C15 gene upstream and lysR gene downstream, identical to what has been identified so far flanking blaOXA-48-like genes in Shewanella spp. The assessment of antibiotic susceptibility was performed for all isolates using the disk diffusion method. In general, it was observed a great sensitivity for all antibiotics except to amoxicillin and aztreonam. Multidrug resistance was detected in only 1 isolate. Other resistance genes and the presence of integrons were not identified. Plasmids were detected in 30.3% isolates (10/ 33). These results reinforce the role of Shewanella spp. as origin of blaOXA-48-like genes.
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Relatório de estágio apresentado à Escola Superior de Educação de Lisboa para obtenção de grau de mestre em Ensino do 1.º e do 2.º Ciclo do Ensino Básico
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Relatório de Estágio apresentado à Escola Superior de Educação de Lisboa para a obtenção de grau de mestre em Ensino do 1.º e 2.º Ciclo do Ensino Básico
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Relatório de estágio apresentado à Escola Superior de Educação para obtenção de grau de mestre em Ensino do 1.º e do 2.º Ciclo do Ensino Básico