974 resultados para long-period fiber gratings
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Dissertação para obtenção do Grau de Mestre em Engenharia Física
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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics
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The forest has a crucial ecological role and the continuous forest loss can cause colossal effects on the environment. As Armenia is one of the low forest covered countries in the world, this problem is more critical. Continuous forest disturbances mainly caused by illegal logging started from the early 1990s had a huge damage on the forest ecosystem by decreasing the forest productivity and making more areas vulnerable to erosion. Another aspect of the Armenian forest is the lack of continuous monitoring and absence of accurate estimation of the level of cuts in some years. In order to have insight about the forest and the disturbances in the long period of time we used Landsat TM/ETM + images. Google Earth Engine JavaScript API was used, which is an online tool enabling the access and analysis of a great amount of satellite imagery. To overcome the data availability problem caused by the gap in the Landsat series in 1988- 1998, extensive cloud cover in the study area and the missing scan lines, we used pixel based compositing for the temporal window of leaf on vegetation (June-late September). Subsequently, pixel based linear regression analyses were performed. Vegetation indices derived from the 10 biannual composites for the years 1984-2014 were used for trend analysis. In order to derive the disturbances only in forests, forest cover layer was aggregated and the original composites were masked. It has been found, that around 23% of forests were disturbed during the study period.
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INTRODUCTION: This study aimed to determine the epidemiology of the three most common nosocomial infections (NI), namely, sepsis, pneumonia, and urinary tract infection (UTI), in a pediatric intensive care unit (PICU) in a developing country and to define the risk factors associated with NI. METHODS: We performed a prospective study on the incidence of NI in a single PICU, between August 2009 and August 2010. Active surveillance by National Healthcare Safety Network (NHSN) was conducted in the unit and children with NI (cases) were compared with a group (matched controls) in a case-control fashion. RESULTS: We analyzed 172 patients; 22.1% had NI, 71.1% of whom acquired it in the unit. The incidence densities of sepsis, pneumonia, and UTI per 1,000 patients/day were 17.9, 11.4, and 4.3, respectively. The most common agents in sepsis were Enterococcus faecalis and Escherichia coli (18% each); Staphylococcus epidermidis was isolated in 13% of cases. In pneumonias Staphylococcus aureus was the most common cause (3.2%), and in UTI the most frequent agents were yeasts (33.3%). The presence of NI was associated with a long period of hospitalization, use of invasive devices (central venous catheter, nasogastric tube), and use of antibiotics. The last two were independent factors for NI. CONCLUSIONS: The incidence of NI acquired in this unit was high and was associated with extrinsic factors.
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Introduction Eratyrus mucronatus Stål, 1859 is a wild triatomine vector of Trypanosoma cruzi Chagas, 1909. However, little is known regarding the biology and ecoepidemiology of this triatomine in the Brazilian Amazon. The present study describes the biology of E. mucronatus grown under laboratory conditions and the epidemiological aspects of its natural breeding sites. Methods Five colonies were monitored in the field for 3 years. Temperature and humidity measurements were taken in the mornings and afternoons at the natural breeding sites, and the behavior and distribution of the nymphs and adults were observed in the wild colony. We also monitored the life cycle under controlled laboratory conditions. Results Some factors that were considered decisive for the establishment of these colonies were present at all of the colonies studied in the field. These factors included an active termite nest, a vertebrate for repast, and dry and shaded substrates with temperatures of 24-28°C and with humidity of 80-90%. A generation was developed in 274 days under these microclimatic conditions in the laboratory. Conclusions The climatic variables described in the field indicate that these environmental parameters have a limiting effect on the dispersal and colonization of E. mucronatus to new environments. In addition, the long period of development to adulthood demonstrates that only one generation can develop per year even under the more favorable laboratory conditions.
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PURPOSE: The dura mater bioprosthesis was developed in the Department of Cardiopneumology of the Hospital das Clínicas of the University of São Paulo Medical School in 1971. Here, we present the clinical results of the dura mater bioprosthesis over 30 years of follow-up. METHODS: We studied 70 consecutive patients who underwent mitral or tricuspid valve replacement with a dura mater bioprosthesis between January 1971 and August 1972. RESULTS: The early mortality was 10% (7 patients). The follow-up was 87% complete (9 patients were lost to follow-up). Two patients were alive and asymptomatic 30 years after valve replacement; 33 patients underwent reoperations due to valve dysfunction, and 19 died during the follow-up period. At 30 years, the actuarial survival was 49.2 ± 8.6%; freedom from rupture, 27.0 ± 10.2%; freedom from calcification, 78.8 ± 8.6%; and freedom from reoperation, 18.8 ± 7.5%. CONCLUSIONS: The dura mater bioprosthesis played an important role in the treatment of patients with mitral and tricuspid valve disease. The low rate of thromboembolism and the long period of follow-up without evidence of valve dysfunction, which occurred for several of our patients, are important characteristics of these bioprosthesis.
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A ideia de que as Matemáticas de Portugal (e de Espanha) atravessaram, depois de um período áureo nos Descobrimentos, um longo deserto onde não foi possível florescerem Mestres, nem escolas, nem cultura científica, nem investigação de relevo foi, durante muito tempo, reiteradamente veiculada, inclusivé através de alguns dos nossos mais referenciados historiadores da Matemática, como é o caso de Gomes Teixeira ou de Rey Pastor. Mas a verdade é que o estudo da História das Matemáticas em Portugal tem, na última década, vivido um interesse crescente onde sobressaem, em particular, uma leitura menos enviesada sobre, por exemplo, o papel educativo dos Jesuítas ou a publicação das obras completas de Pedro Nunes. Está-se assim a contribuir para uma compreensão mais completa da História geral de Portugal, de que a História da Ciência e da Cultura faz parte. José Anastácio da Cunha (1744-1787) foi figura de proa no século XVIII português. Sabíamo-lo matemático que, sem nunca ter saído de Portugal, havia sido capaz de antecipar, em mais de 50 anos, os esforços de matemáticos franceses e alemães para fundar a Matemática com rigor. Sabíamo-lo também autor de uma vasta e diversificada obra de inegável importância matemática mas, igualmente, autor de textos poéticos. Agora, com o projecto que denominámos de MAT2, centramo-nos em José Anastácio da Cunha e pretendemos, se possível, ir ainda mais além. Partimos de uma descoberta, árdua mas com final feliz, em um Arquivo de família: o da Casa de Mateus. Sentimo-nos, com esta “sorte”, privilegiados e gratos por nos ter sido gentilmente concedido o acesso a um vasto conjunto de documentos únicos (diários de viagens, notas de aulas e correspondência) que incluem memórias autógrafas e inéditas de Anastácio da Cunha. Organizámo-nos, cientes do trabalho árduo que temos pela frente, multi e interdisciplinarmente englobando a Matemática (nas suas múltiplas especializações) e a História (incluindo a da Matemática) mas também contando com a Física, a Informática, os estudos militares ou a Arquivística e as Humanidades; reunimos académicos, mais e menos veteranos, com investigadores jovens e juntámos valências nacionais e estrangeiras. No presente artigo daremos conta do percurso trilhado, até agora, pelo projecto MAT2.
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Dissertação de mestrado integrado em Engenharia e Gestão Industrial
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ICEIM – International Conference in Entrepreneurship and Innovation Management, Roma, 17-18 de setembro de 2015.
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Tese de Doutoramento em Tecnologias e Sistemas de Informação
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Dissertação de mestrado em Geociências (área de especialização em Valorização de Recursos Geológicos)
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Entre los factores que contribuyen a predecir el rendimiento académico se pueden destacar aquellos que reflejan capacidades cognitivas (inteligencia, por ejemplo), y aquellas diferencias individuales consideradas como no-cognitivas (rasgos de personalidad, por ejemplo). En los últimos años, también se considera al Conocimiento General (CG) como un criterio para el éxito académico (ver Ackerman, 1997), ya que se ha evidenciado que el conocimiento previo ayuda en la adquisición de nuevo conocimiento (Hambrick & Engle, 2001). Uno de los objetivos de la psicología educacional consiste en identificar las principales variables que explican el rendimiento académico, como también proponer modelos teóricos que expliquen las relaciones existentes entre estas variables. El modelo teórico PPIK (Inteligencia-como-Proceso, Personalidad, Intereses e Inteligencia-como-Conocimiento) propuesto por Ackerman (1996) propone que el conocimiento y las destrezas adquiridas en un dominio en particular son el resultado de la dedicación de recursos cognitivos que una persona realiza durante un prolongado período de tiempo. Este modelo propone que los rasgos de personalidad, intereses individuales/vocacionales y aspectos motivacionales están integrados como rasgos complejos que determinan la dirección y la intensidad de la dedicación de recursos cognitivos sobre el aprendizaje que realiza una persona (Ackerman, 2003). En nuestro medio (Córdoba, Argentina), un grupo de investigadores ha desarrollado una serie de recursos técnicos necesarios para la evaluación de algunos de los constructos propuesto por este modelo. Sin embargo, por el momento no contamos con una medida de Conocimiento General. Por lo tanto, en el presente proyecto se propone la construcción de un instrumento para medir Conocimiento General (CG), indispensable para poder contar con una herramienta que permita establecer parámetros sobre el nivel de conocimiento de la población universitaria y para en próximos trabajos poner a prueba los postulados de la teoría PPIK (Ackerman, 1996). Between the factors that contribute to predict the academic achievement, may be featured those who reflect cognitive capacities (i.g. intelligence) and those who reflect individual differences that are considered like non-cognitive (i.g. personality traits). In the last years, also the General Knowledge has been considered like a criterion for the academic successfully (see Ackerman, 1997), since it has been shown that the previous knowledge helps in the acquisition of the new knowledge (Hambrick & Engle, 2001). An interesting theoretical model that has proposed an explanation for the academic achievement, is the PPIK (intelligence like a process, interests and inteligence like knowledge) proposed by Ackerman (1996), who argues that knowledge and the acquired skills in a particular domain are the result of the dedication of cognitive resources that a person perform during a long period of time. This model proposes that personality traits, individuals interests and motivational aspects are integrated as complex traits that determine the direction and the intensity of the dedication of cognitive resources on the learning that a person make (Ackerman, 2003). In our context, (Córdoba, Argentina), a group of researcher has developed a series of necessary technical resoures for the assesment of some of the theoretical constructs proposed by this model. However, by the moment, we do not have an instrument for evaluate the General Knowledge. Therefore, this project aims the construction of an instrument to asess General Knowledge, essential to set parameters on the knowledge level of the university population and for in next works test the PPIK theory postulates.
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Background: Patients with diabetes are in extract higher risk for fatal cardiovascular events. Objective: To evaluate major predictors of mortality in subjects with type 2 diabetes. Methods: A cohort of 323 individuals with type 2 diabetes from several regions of Brazil was followed for a long period. Baseline electrocardiograms, clinical and laboratory data obtained were used to determine hazard ratios (HR) and confidence interval (CI) related to cardiovascular and total mortality. Results: After 9.2 years of follow-up (median), 33 subjects died (17 from cardiovascular causes). Cardiovascular mortality was associated with male gender; smoking; prior myocardial infarction; long QTc interval; left ventricular hypertrophy; and eGFR <60 mL/min. These factors, in addition to obesity, were predictors of total mortality. Cardiovascular mortality was adjusted for age and gender, but remained associated with: smoking (HR = 3.8; 95% CI 1.3-11.8; p = 0.019); prior myocardial infarction (HR = 8.5; 95% CI 1.8-39.9; p = 0.007); eGFR < 60 mL/min (HR = 9.5; 95% CI 2.7-33.7; p = 0.001); long QTc interval (HR = 5.1; 95% CI 1.7-15.2; p = 0.004); and left ventricular hypertrophy (HR = 3.5; 95% CI 1.3-9.7; p = 0.002). Total mortality was associated with obesity (HR = 2.3; 95% CI 1.1-5.1; p = 0.030); smoking (HR = 2.5; 95% CI 1.0-6.1; p = 0.046); prior myocardial infarction (HR = 3.1; 95% CI 1.4-6.1; p = 0.005), and long QTc interval (HR = 3.1; 95% CI 1.4-6.1; p = 0.017). Conclusions: Biomarkers of simple measurement, particularly those related to target-organ lesions, were predictors of mortality in subjects with type 2 diabetes.
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Abstract The scientific construction of chronic Chagas heart disease (CCHD) started in 1910 when Carlos Chagas highlighted the presence of cardiac arrhythmia during physical examination of patients with chronic Chagas disease, and described a case of heart failure associated with myocardial inflammation and nests of parasites at autopsy. He described sudden cardiac death associated with arrhythmias in 1911, and its association with complete AV block detected by Jacquet's polygraph as Chagas reported in 1912. Chagas showed the presence of myocardial fibrosis underlying the clinical picture of CCHD in 1916, he presented a full characterization of the clinical aspects of CCHD in 1922. In 1928, Chagas detected fibrosis of the conductive system, and pointed out the presence of marked cardiomegaly at the chest X-Ray associated with minimal symptomatology. The use of serological reaction to diagnose CCHD was put into clinical practice in 1936, after Chagas' death, which along with the 12-lead ECG, revealed the epidemiological importance of CCHD in 1945. In 1953, the long period between initial infection and appearance of CCHD was established, whereas the annual incidence of CCHD from patients with the indeterminate form of the disease was established in 1956. The use of heart catheterization in 1965, exercise stress testing in 1973, Holter monitoring in 1975, Electrophysiologic testing in 1973, echocardiography in 1975, endomyocardial biopsy in 1981, and Magnetic Resonance Imaging in 1995, added to the fundamental clinical aspects of CCHD as described by Carlos Chagas.
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In Brazil all the fishes belonging to the sub-family Curimatinae are called « saguirú ». The present work gives a biological study of the Curimatus elegans Steind., a small fish without any economical importance, which is to be found along the whole brazilian coast, down till Paraguay. The specimens utilized for the present study come from Fortaleza (Ceará, north-eastern Brazil). The C. elegans is « ilyophagus », that means, it feeds itself exclusively with those organic materials to be found in mud, specially with microscopical algae. The intestines are very extent, some of them measuring about 9 to 11 times body's length. Studies have been made about growth and age of the C. elegans; the biggest sizes found were of 153 mm. for females and 88 mm. for males. The C. elegans shows developed sexual glands during a long period (April to September). The movements of the spermatozoa, in contact with water is of 40 to 50 seconds of intense movements, ceasing after 70 to 100 seconds. In contact with 0.5% NaCl-solution spermatozoa show a big increase in movements-time, that can last till about 25 minutes. The eggs' diameter measures 0.70 to 0.73 mm., mature and hydrated it attains 0.93 to 1,00 mm. There is a certain correlation between the size of the body and the quantity of eggs. Big specimens can produce a total of 200.000 eggs. The average quantity contained in 1 gr. and 1 cc. is 6018 and 6229 eggs, respectively. Maturity and spawning in laboratory has been obtained due to injections of suspension of fish-hypophysis. Three or four hours after the injection, fishes show more movement and evident signs of excitation, proceeding spawning after 5 to 6 hours. Males, persecuting females, describe successive circles (merry-go-round) - carroussel), swimming side by side with females up to water's surface, where sexual products are start beating dry, for there is no blood yet. Circulation-scheme is to be found on fig. 4 and 5. The swim-bladder and the stomach are but delineated; the intestine is formed by a cylindric tube, all closed. At the place, where later on there will open the mouth, we find a group of ciliary hairs that produce a liquid current, very evident by the semi-circle formed by attached solid particles. After 36 hours, opening of the mouth and formation of the gill slits begin. At the age of 90 hours (4 mm.) the larvas swim well and start to feed themselves; the digestive tube is now all open and the swimbladder works already. During the first days of life, larvas have an adhesive organ situated at their frontal region (fig. 7) in form of a crescent, by means of which they hang to surrounding vegetation (fig. 6). When the larva begins to swim and to feed itself and its yolk are having been absorbed. the adhesive organ retracts and disappears. While larvas and alevins feed themselves with plancton, they have small eye-teeth, which disappear,. when fishes become « ilyophagus ». There exist too, during their life as larvas, pharyngeal-teeth. The lateral line appears in the larva after 16 to 18 days; more or less at the same time all fins are completely developed. Shortly after, first scales appear (20 to 23 days). Evolution of intestines twisting followed (fig. 9). Larvas show at different parts of their bodies small of organs excretory functions, that are constituted by bottons in serial disposition, every one with an excretory canal that opens towards the outside. These formations disappear suddenly when larvas attain their phase of alevin. The existence of a great number of said formations at the caudal fin (fig. 12) is of great interest. In our experiences of breeding we have employed several thousands of C. elegans larvas in different environs and we made conditions of surrounding change (illumination), depth of water, temperature, presence of sand at bottom of aquariums and without sand, food). In this way we could compare the results obtained, estimate the action of each factor for the realisation of a good bring-up of larvas.