984 resultados para intra-ovarian factors
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This paper contributes to the literature on the intra-firm diffusion of innovations by investigating the factors that affect the firm’s decision to adopt and use sets of complementary innovations. We define complementary innovations those innovations whose joint use generates super additive gains, i.e. the gain from the joint adoption is higher than the sum of the gains derived from the adoption of each innovation in isolation. From a theoretical perspective, we present a simple decision model, whereby the firm decides ‘whether’ and ‘how much’ to invest in each of the innovations under investigation based upon the expected profit gain from each possible combination of adoption and use. The model shows how the extent of complementarity among the innovations can affect the firm’s profit gains and therefore the likelihood that the firm will adopt these innovations jointly, rather than individually. From an empirical perspective, we focus on four sets of management practices, namely operating (OMP), monitoring (MMP), targets (TMP) and incentives (IMP) management practices. We show that these sets of practices, although to a different extent, are complementary to each other. Then, we construct a synthetic indicator of the depth of their use. The resulting intra-firm index is built to reflect not only the number of practices adopted but also the depth of their individual use and the extent of their complementarity. The empirical testing of the decision model is carried out using the evidence from the adoption behaviour of a sample of 1,238 UK establishments present in the 2004 Workplace Employment Relations Survey (WERS). Our empirical results show that the intra-firm profitability based model is a good model in that it can explain more of the variability of joint adoption than models based upon the variability of adoption and use of individual practices. We also investigate whether a number of firm specific and market characteristics by affecting the size of the gains (which the joint adoption of innovations can generate) may drive the intensity of use of the four innovations. We find that establishment size, whether foreign owned, whether exposed to an international market and the degree of homogeneity of the final product are important determinants of the intensity of the joint adoption of the four innovations. Most importantly, our results point out that the factors that the economics of innovation literature has been showing to affect the intensity of use of a technological innovation do also affect the intensity of use of sets of innovative management practices. However, they can explain only a small part of the diversity of their joint adoption use by the firms in the sample.
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This paper presents a simple profitability-based decision model to show how synergistic gains generated by the joint adoption of complementary innovations may influence the firm's adoption decision. For this purpose a weighted index of intra-firm diffusion is built to investigate empirically the drivers of the intensity of joint use of a set of complementary innovations. The findings indicate that establishment size, ownership structure and product market concentration are important determinants of the intensity of use. Interestingly, the factors that affect the extent of use of technological innovations do also affect that of clusters of management practices. However, they can explain only part of the heterogeneity of the benefits from joint use.
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This thesis looks at the UK onshore oil and gas production industry and follows the history of a population of firms over a fifteen-year period following the industry's renaissance. It examines the linkage between firm survival, selection pressures and adaptation responses at the firm level, especially the role of discretionary adaptation, specifically exploration and exploitation strategies.Taking a Realist approach and using quantitative and qualitative methods for triangulation on a new data base derived from archival data, as well as informant interviews, it tests seven hypotheses' about post-entry survival of firms. The quantitative findings suggest that firm survival within this industry is linked to discretionary adaptation, when measured at the firm level, and to a mixture of selection and adaptation forces when measured for each firm for each individual year. The qualitative research suggests that selection factors dominate. This difference in views is unresolved. However the small, sparse population and the nature of the oil and gas industry compared with other common research contexts such as manufacturing or service firms suggests the results be treated with caution as befits a preliminary investigation. The major findings include limited support for the theory that the external environment is the major determinant of firm survival, though environment components affect firms differentially; resolution of apparent literature differences relating to the sequencing of exploration and exploitation and potential tangible evidence of coevolution. The research also finds that, though selection may be considered important by industry players, discretionary adaptation appears to play the key role, and that the key survival drivers for thispopulation are intra-industry ties, exploitation experience and a learning/experience component. Selection has a place, however, in determining the life-cycle of the firm returning to be a key survival driver at certain ages of the firm inside the industry boundary.
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Background: Post-cesarean section peritonitis is the leading cause of maternal morbidity and mortality at the main referral hospital in Rwanda. Published data on the management of post-cesarean section peritonitis is limited. This study examined predictors of maternal morbidity and mortality for post-cesarean peritonitis.
Methods: We performed a prospective observational cohort study at the University Teaching Hospital Kigali (CHUK) from January 1 until December 31 2015, followed by a retrospective chart review of all subjects with post-cesarean section peritonitis admitted to CHUK from January 1 until December 31, 2014. All patients admitted with the diagnosis of post-cesarean section peritonitis undergoing exploratory laparotomy at CHUK were enrolled. Patients were followed to either discharge or death. Study variables included baseline demographic/clinical characteristics, admission physical exam, intraoperative findings, and management. Data were analyzed using STATA version 14.
Results: Of the 167 patients enrolled, 81 survived without requiring hysterectomy (49%), 49 survived requiring hysterectomy (29%), and 36 died (22%). In the multivariate analysis, severe sepsis was the most significant predictor of mortality (RR=4.0 [2.2-7.7]) and uterine necrosis was the most significant predictor of hysterectomy (RR=6.3 [1.6-25.2]). There were high rates of antimicrobial resistance (AMR) among the bacterial isolates cultured from intra-abdominal pus, with 52% of bacteria resistant to third-generation cephalosporins.
Conclusions: Post-cesarean section peritonitis carries a high mortality rate in Rwanda. It is also associated with a high rate of hysterectomy. Understanding the disease process and identifying factors associated with outcomes can help guide management during admission.
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Introdução: O adequado selamento do sistema de canais radiculatres (SCR) obtido através da obturação, evita a infiltração de micro-organismos entre as paredes do canal radicular e o material obturador, reduzindo a possibilidade de insucesso do tratamento endodôntico (TE). A falta de selamento coronal, o atraso da colocação da restauração permanente, a fratura da restauração coronal, assim como uma espessura inadequada da restauração provisória, inferior a 4mm, podem, entre outros factores, ser predisponentes para a recontaminação do SCR obturado. Sendo o selamento da entrada do SCR uma importante etapa do TE, neste estudo pretendeu-se avaliar diferentes materiais para tal procedimento, avaliando qual o material que proporciona menor infiltração. Materiais e métodos: Neste estudo foram utilizados 70 dentes humanos monocanalares, que foram divididos aleatoriamente em 6 grupos. Grupo I (15 dentes) foram selados com ionómero de vidro modificado por resina (Ionoseal - VOCO®), Grupo II (15 dentes) foram selados com ionómero de vidro modicifado por resina (GC Fuji II LC- GA America®), Grupo III (15 dentes) foram selados por um compósito fluído (GrandioSO Heavy Flow - VOCO®), Grupo IV (15 dentes) foram selados por um compósito nanohíbrido (GrandioSO - VOCO®). O Grupo V (5 dentes) e o Grupo VI (5 dentes) foram usados como controlo negativo e positivo, respectivamente. Os dentes foram submetidos a termociclagem de 500 ciclos, de 60 segundos de duração cada um, com variações de temperatura de 5°C - 55°C. Em seguida, foram imersos em corante azul de metileno a 2% para avaliação da infiltração dos materiais. Resultados: Em geral, Ionoseal® demonstrou maior infiltração de corante que os outros materiais, e quando comparado com os demais grupos a diferença foi significativa. Porem entre os grupos 1, 2 e 3 não houve diferença estatística significante. Conclusões: LC Fuji II®, GrandioSo® Nano partícula Flow e GrandioSo® Nano partícula podem ser usados como barreira intracanalar.
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A síndrome da apneia e hipopneia obstrutiva do sono (SAHOS) é uma patologia que atinge cerca de 4% da população adulta, é uma doença crónica, progressiva, com alta morbilidade e mortalidade. A apneia do sono e o ronco têm despertado a atenção da área da saúde devido às inúmeras comorbilidades associadas. Esta síndrome é caracterizada por obstrução parcial ou total das vias aéreas superiores durante o sono e manifesta-se como uma redução (hipopneia) ou cessação (apneia) do fluxo aéreo. A queixa habitual dos pacientes além dos problemas sociais como ronco e a hipersonolência diurna, são a preocupação com outros quadros que esta patologia pode desencadear, como insuficiência cardíaca e hipertensão pulmonar. O tratamento da apneia obstrutiva do sono é multidisciplinar e indispensável, podendo ser realizado de diversas formas, tanto conservadoras como cirúrgicas, dependendo de inúmeros fatores como a gravidade da doença, as alterações anatómicas das vias aéreas superiores, idade e condições sistémicas do paciente. Os aparelhos intra orais têm sido usados durante anos, no tratamento da SAHOS como controle da obstrução das vias aéreas superiores. A terapia com aparelhos intraorais é simples e reversível. O sucesso do tratamento com aparelhos intra orais para o ronco e SAHOS leve e moderada é comprovado pela grande maioria dos estudos. A facilidade de uso, manutenção e conforto quando comparados a outros tratamentos faz com que os aparelhos intrabucais sejam considerados de fácil aceitação pelos pacientes. Através de uma revisão de literatura discutiu-se o uso de aparelhos intrabucais para o tratamento dessa patologia, destacando a eficácia e as limitações dessa terapia, os principais sintomas clínicos, os principais efeitos colaterais oclusais, o grau de colaboração e o índice de satisfação dos pacientes. Foi possível concluir que aparelhos intrabucais de avanço mandibular estão amplamente indicados para o tratamento do ronco e da SAHOS como terapia principal, ou alternativa naqueles pacientes que não podem suportar a terapia da pressão positiva das vias aéreas e que para o sucesso do tratamento é fundamental uma equipe multidisciplinar, incluindo um Médico Dentista e a colaboração do paciente.
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This quantitative research study utilized a binary logistic regression in a block design to investigate exogenous and endogenous factors influencing a teacher’s decision to make an intra-district move. The research focused on the following exogenous factors: classroom characteristics (size of class, percent minority, percent of students with an individualized education plan, and percent of students that are English language learners) and teacher characteristics (experience and gender). The following endogenous factors were examined: direct administrative influence (administrative support, rules enforced, school vision, teacher recognition, and job security) and indirect administrative influence (school climate, student misbehavior, parental support, materials, staff collaboration). The research was conducted by using information available from the National Center for Educational Statistics, the SASS from 2011-2012 and TFS from 2012-2013. The 2012-2013 Teacher Follow-up Survey identified 60 teachers who made a voluntary intra-district move. Results illustrate there is a statistically significant relationship between percentage of English Language Learners and overall job satisfaction and teachers choosing to make an intra-district move.
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Otoliths are calcified structures located in Osteichthyes’ inner ear that are involved in audition and balance. Their morphology is used as an indicator of various ecological processes or properties. This application requires identifying the endogenous and exogenous factors that act simultaneously as sources of shape variation. This thesis aims at detecting and quantifying the relative contributions of directional asymmetry and diet to otolith shape variation at the intra-population level. Directional asymmetry between left and right otoliths was found in flat-fishes, the blind-side otolith being always longer and larger, whereas it was negligible in round-fishes. However, asymmetry amplitude never exceeded 18 %, which suggests evolutionary canalization of otolith shape symmetry. A correlation between global diet and otolith was detected in 4 species studied in situ. Diet composition contributed more than food amount to morphological variation and affected otolith shape both globally and locally. An experimental study on sea bass (Dicentrarchus larbrax) showed that diet composition in terms of essential polyunsaturated fatty acids at larval stage affects otolith morphogenesis during juvenile stage without impacting on individuals’ somatic growth. This result suggests a direct effect of diet on otolith shape and not an indirect one through the somatic-otolith growth relationship. This effect disappeared at later stages, morphogenetic trajectories converging back to a similar shape, which suggests ontogenetic canalization of otolith shape.
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Tese de Doutoramento em Ciências Veterinárias, na Especialidade de Clínica
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In contrast to the definition of metabolic syndrome (MetS) in adults, there is no standard definition of MetS in pediatric populations. We aimed to assess the differences in the prevalence of MetS in children and adolescents aged 9–17 years in the city of Bogota (Colombia) using four different operational definitions for these age groups and to examine the associated variables. A total of 673 children and 1,247 adolescents attending public schools in Bogota (54.4% girls; age range 9–17.9 years) were included. The prevalence of MetS was determined by the definitions provided by the International Diabetes Federation (IDF) and three published studies by Cook et al., de Ferranti et al., and Ford et al. The prevalence of MetS was 0.3%, 6.3%, 7.8%, and 11.0% according to the IDF, Cook et al., Ford et al., and de Ferranti et al. definitions, respectively. The most prevalent components were low high-density lipoprotein cholesterol and high triglyceride levels, whereas the least prevalent components were abdominal obesity and hyperglycemia. Overall, the prevalence of MetS was higher in obese than in non-obese schoolchildren. In conclusion, MetS diagnoses in schoolchildren strongly depend on the definition chosen. These findings may be relevant to health promotion efforts for Colombian youth to develop prospective studies and to define which cut-offs are the best indicators of future morbidity.
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The objectives of this study are to investigate the association between cardiorespiratory fitness and cardiovascular risk factors in schoolchildren and to evaluate the degree of association between overall and abdominal adiposity and cardiorespiratory fitness. A total of 1,875 children and adolescents attending public schools in Bogota, Colombia (56.2% girls; age range of 9–17.9 years). A cardiovascular risk score (Z-score) was calculated and participants were divided into tertiles according to low and high levels of overall (sum of the skinfold thicknesses) and abdominal adiposity. Schoolchildren with a high level of overall adiposity demonstrated significant differences in seven of the 10 variables analyzed (i.e. systolic and diastolic blood pressure, triglycerides, triglycerides/HDL-c ratio, total cholesterol, glucose and cardiovascular risk score). Schoolchildren with high levels of both overall and abdominal adiposity and low cardiorespiratory fitness had the least favorable cardiovascular risk factors score. These findings may be relevant to health promotion in Colombian youth.
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Cutaneous melanoma (CM) represents the third most common cancer in Italian women under 49 years old. In the last decades, many molecular studies confirmed that sex hormones have a part in melanogenesis and melanoma genesis. However, many controversies are present regarding the role of exogenous oestrogens intake and endogenous hormonal status in female melanoma. Our study's primary objective is to investigate the features of melanoma in women of fertile age and women in postmenopausal age. The secondary aim is to evaluate the expression of ERα and ERβ by immunohistochemical analysis in women who underwent ovarian stimulation for medically assisted procreation and in women in cancer therapy for breast cancer (BC) comparing to two control groups. The tertiary objective is to correlate ERα and ERβ with the Breslow thickness and other relevant histopathological, clinical and dermoscopic characteristics Results A total of 998 women were included in the study. Women in fertile age are significantly more prone to have CM on the trunk. Conversely, postmenopausal females are more likely to develop CM on acral locations. Breslow thickness and ulceration were statistically significant among postmenopausal women (P-value <0,001). In the group for women with a history of breast cancer (BC), we observed a significantly higher CM percentage with “non-brisk” TILs. Upon immunohistochemical analysis, most cases with inhibitor aromatase therapy displayed a strong cytoplasmatic ERα positivity. Upon the Pearson correlation analysis, no association was shown between nuclear ERβ and Breslow thickness. The meaning of cytoplasmatic ERα in melanoma is still debated. It could suggest a potentially significant role of oestrogen non-genomic pathway in these patients, or it can be a mechanism of ERs modulation in response to aromatase inhibitor therapy. Our work tried to enlighten some of the existing shadows on the role of ERs and hormonal factors in CM.
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This study aimed at evaluating the functional activation and activating receptors expression on resting, short- and long-term NK and NK-like T cells from blood of ovarian neoplasia patients. Blood from patients with adnexal benign alterations (n = 10) and ovarian cancer (grade I-IV n = 14) were collected after signed consent. Effector cells activation was evaluated by the expression of the CD107a molecule. Short-term culture was conducted overnight with IL-2 and long-term culture for 21 days, by a method designed to expand CD56(+) lymphocytes. Short-term culture significantly increased NK cells activation compared to resting NK cells (p<0.05), however, the long-term procedure supported an even higher increase (p<0.001). Resting NK-like T cells showed poor activation, which was not altered by the culture procedures. The long-term culture effectively increased the expression of the activating receptors on NK and NK-like T cells, either by increasing the number of cells expressing a given receptor and/or by up-regulating their expression intensity. As a conclusion, the long-term culture system employed, resulted in a high number of functional NK cells. The culture system was particularly efficient on the up-regulation of NKp30 and DNAM-1 receptors on NK cells.
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One of the great challenges of the scientific community on theories of genetic information, genetic communication and genetic coding is to determine a mathematical structure related to DNA sequences. In this paper we propose a model of an intra-cellular transmission system of genetic information similar to a model of a power and bandwidth efficient digital communication system in order to identify a mathematical structure in DNA sequences where such sequences are biologically relevant. The model of a transmission system of genetic information is concerned with the identification, reproduction and mathematical classification of the nucleotide sequence of single stranded DNA by the genetic encoder. Hence, a genetic encoder is devised where labelings and cyclic codes are established. The establishment of the algebraic structure of the corresponding codes alphabets, mappings, labelings, primitive polynomials (p(x)) and code generator polynomials (g(x)) are quite important in characterizing error-correcting codes subclasses of G-linear codes. These latter codes are useful for the identification, reproduction and mathematical classification of DNA sequences. The characterization of this model may contribute to the development of a methodology that can be applied in mutational analysis and polymorphisms, production of new drugs and genetic improvement, among other things, resulting in the reduction of time and laboratory costs.
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The objectives of this study were to develop a questionnaire that evaluates the perception of nursing workers to job factors that may contribute to musculoskeletal symptoms, and to evaluate its psychometric properties. Internationally recommended methodology was followed: construction of domains, items and the instrument as a whole, content validity, and pre-test. Psychometric properties were evaluated among 370 nursing workers. Construct validity was analyzed by the factorial analysis, known-groups technique, and convergent validity. Reliability was assessed through internal consistency and stability. Results indicated satisfactory fit indices during confirmatory factor analysis, significant difference (p < 0.01) between the responses of nursing and office workers, and moderate correlations between the new questionnaire and Numeric Pain Scale, SF-36 and WRFQ. Cronbach's alpha was close to 0.90 and ICC values ranged from 0.64 to 0.76. Therefore, results indicated that the new questionnaire had good psychometric properties for use in studies involving nursing workers.