999 resultados para Modelagem em SystemC-AMS


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Estudi arqueològic integrat de la vall del Madriu-Perafita-Claror (Andorra) iniciat al 2004 sota la coordinació de l’ICAC. L’estudi s’insereix en la declaració de la vall com a Patrimoni de la Humanitat (UNESCO). Las recerques s’enfoquen des de l’Arqueologia del Paisatge, de manera diacrònica i pluridisciplinar, fent especial atenció a les relacions de les societats amb el medi. Les restes arqueològiques treballades s’associen a activitats ramaderes, metal•lúrgiques i de carboneig. La recerca paleoecològica se centra en sediments lacustres, torbosos i arqueològics. L’any 2006, s’han analitzat a alta resolució temporal dues seqüencies palinològiques: l’estany Blau (2471 m) i la torbera de Bosc dels Estanyons (2180 m), obtenint les principals fases d’explotació i antropització d’aquest espai altimontà, així com l’evolució del paisatge en els darrers 11000 anys . La campanya de camp s’ha centrat en l’obtenció de mostres de pluja pol•línica referencial a la vall i en el sondatge de l’estany Forcat (2539 m). Un total de tres mostres han estat enviades a datar per C14. Els treballs arqueològics s’han centrat en l’excavació de sondejos de diagnòstic als jaciments de Basses de Setut (2325 m) i Pleta de les Bacives ( 2530 m) i en la realització de prospeccions a les capçaleres de les valls de Madriu, Perafita i Claror. S’han documentat estructures arqueològiques i s’han realitzat estudis antracològics dels sediments excavats en aquestes. S’ha realitzat un transecte altitudinal de carboneres al llarg de la vall per tal de enregistrar una major diversitat cronològica dels espais de carboneig. S’han enviat datacions C14 per tal de determinar la cronologia de les estructures. Les datacions del 2005 mostren una intensa ocupació ramadera i de carboneig a partir del segle XIV, en època baixmedieval i moderna, així com un establiment metal·lúrgic d’època romana.

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Aquest projecte descriu el disseny i desenvolupament d’una eina gràfica per a la depuració de projectes desenvolupats amb un llenguatge de descripció de sistemes com és el SystemC. Amb aquest llenguatge s’ha desenvolupat una NoC (Network on Chip). L’eina desenvolupada mostra de forma visual l’arquitectura de la xarxa NoC, els valors dels senyals que es transmeten a través de la xarxa i estadístiques sobre aquests per tal de poder fer un seguiment exhaustiu i agilitzar la recerca d’errors com interbloquejos, pèrdua de dades i d’altres. Al concentrar en un únic entorn la descripció de la NoC i les dades relatives a les senyals en temps de simulació, proporciona un valor afegit a altres eines disponibles per a realitzar aquesta tasca.

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Ventricular assist devices (VADs) are used in treatment for terminal heart failure or as a bridge to transplantation. We created biVAD using the artificial muscles (AMs) that supports both ventricles at the same time. We developed the test bench (TB) as the in vitro evaluating system to enable the measurement of performance. The biVAD exerts different pressure between left and right ventricle like the heart physiologically does. The heart model based on child's heart was constructed in silicone. This model was fitted with the biVAD. Two pipettes containing water with an ultrasonic sensor placed on top of each and attached to ventricles reproduced the preload and the after load of each ventricle by the real-time measurement of the fluid height variation proportionally to the exerted pressure. The LabVIEW software extrapolated the displaced volume and the pressure generated by each side of our biVAD. The development of a standardized protocol permitted the validation of the TB for in vitro evaluation, measurement of the performances of the AM biVAD herein, and reproducibility of data.

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Objectives: The AMS 800TM is the current artificial urinary sphincter (AUS) for incontinence due to intrinsic sphincter deficiency. Despite good clinical results, technical failures inherent to the hydraulic mechanism or urethral ischemic injury contribute to revisions up to 60%. We are developing an electronic AUS, called ARTUS to overcome the rigors of AMS. The objective of this study was to evaluate the technical efficacy and tissue tolerance of the ARTUS system in an animal model.Methods: The ARTUS is composed by three parts: the contractile unit, a series of rings and an integrated microprocessor. The contractile unit is made of Nitinol fibers. The rings are placed around the urethra to control the flow of urine by squeezing the urethra. They work in a sequential alternative mode and are controlled by a microprocessor. In the first phase a three-rings device was used while in the second phase a two-rings ARTUS was used. The device was implanted in 14 sheep divided in two groups of six and eight animals for study purpose. The first group aimed at bladder leak point pressure (BLPP) measurement and validation of the animal model; the second group aimed at verifying mid-term tissue tolerance by explants at twelve weeks. General animal tolerance was also evaluated.Results: The ARTUS system implantation was uneventful. When the system was activated, the BLPP was measured at 1.038±0.044 bar (mean±SD). Urethral tissue analysis did not show significant morphological changes. No infection and no sign of discomfort were noted in animals at 12 weeks.Conclusions: The ARTUS proved to be effective in continence achievement in this study. Histological results support our idea that a sequential alternative mode can avoid urethral atrophy and ischemia. Further technical developments are needed to verify long-term outcome and permit human use.

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The financial impact of the first outbreak of Trypanosoma vivax in the Brazilian Pantanal wetland is estimated. Results are extended to include outbreaks in the Bolivian lowlands providing a notion of the potential influence of the disease and an analytical basis. More than 11 million head of cattle, valued at more than US$3 billion are found in the Brazilian Pantanal and Bolivian lowlands. The total estimated cost of the 1995 outbreak of T. vivax is the sum of the present values of mortality, abortion, and productivity losses and treatment costs, or about 4% of total brood cow value on affected ranches. Had the outbreak gone untreated, the estimated losses would have exceeded 17% of total brood cow value.

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WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: The AMS 800 urinary control system is the gold standard for the treatment of urinary incontinence due to sphincter insufficiency. Despite excellent functional outcome and latest technological improvements, the revision rate remains significant. To overcome the shortcomings of the current device, we developed a modern electromechanical artificial urinary sphincter. The results demonstrated that this new sphincter is effective and well tolerated up to 3 months. This preliminary study represents a first step in the clinical application of novel technologies and an alternative compression mechanism to the urethra. OBJECTIVES: To evaluate the effectiveness in continence achievement of a new electromechanical artificial urinary sphincter (emAUS) in an animal model. To assess urethral response and animal general response to short-term and mid-term activation of the emAUS. MATERIALS AND METHODS: The principle of the emAUS is electromechanical induction of alternating compression of successive segments of the urethra by a series of cuffs activated by artificial muscles. Between February 2009 and May 2010 the emAUS was implanted in 17 sheep divided into three groups. The first phase aimed to measure bladder leak point pressure during the activation of the device. The second and third phases aimed to assess tissue response to the presence of the device after 2-9 weeks and after 3 months respectively. Histopathological and immunohistochemistry evaluation of the urethra was performed. RESULTS: Bladder leak point pressure was measured at levels between 1091 ± 30.6 cmH2 O and 1244.1 ± 99 cmH2 O (mean ± standard deviation) depending on the number of cuffs used. At gross examination, the explanted urethra showed no sign of infection, atrophy or stricture. On microscopic examination no significant difference in structure was found between urethral structure surrounded by a cuff and control urethra. In the peripheral tissues, the implanted material elicited a chronic foreign body reaction. Apart from one case, specimens did not show significant presence of lymphocytes, polymorphonuclear leucocytes, necrosis or cell degeneration. Immunohistochemistry confirmed the absence of macrophages in the samples. CONCLUSIONS: This animal study shows that the emAUS can provide continence. This new electronic controlled sequential alternating compression mechanism can avoid damage to urethral vascularity, at least up to 3 months after implantation. After this positive proof of concept, long-term studies are needed before clinical application could be considered.

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Liddle's syndrome is a genetic form of hypertension linked to Na(+) retention caused by activating mutations in the COOH terminus of the beta or gamma subunit of the epithelial sodium channel (ENaC). In this study, we used the short-circuit current (I(sc)) method to investigate the effects of deamino-8-d-arginine vasopressin (dDAVP) on Na(+) and Cl(-) fluxes in primary cultures of cortical collecting ducts (CCDs) microdissected from the kidneys of mice with Liddle's syndrome carrying a stop codon mutation, corresponding to the beta-ENaC R(566) stop mutation (L) found in the original pedigree. Compared to wild-type (+/+) CCD cells, untreated L/+ and L/L CCD cells exhibited 2.7- and 4.2-fold increases, respectively, in amiloride-sensitive (Ams) I(sc), reflecting ENaC-dependent Na(+) absorption. Short-term incubation with dDAVP caused a rapid and significant increase (approximately 2-fold) in Ams I(sc) in +/+, but not in L/+ or L/L CCD cells. In sharp contrast, dDAVP induced a greater increase in 5-nitro-2-(3-phenylpropamino)benzoate (NPPB)-inhibited apical Cl(-) currents in amiloride-treated L/L and L/+ cells than in their +/+ counterparts. I(sc) recordings performed under apical ion substituted conditions revealed that the dDAVP-stimulated apical secretion of Cl(-), which was absent in cultured CCDs lacking CFTR, was 1.8-fold greater in L/+ and 3.7-fold greater in L/L CCD cells than in their +/+ CCD counterparts. After the basal membrane had been permeabilized with nystatin and a basal-to-apical Cl(-) gradient had been imposed, dDAVP also stimulated larger Cl(-) currents across L/L and L/+ CCD layers than +/+ CCD layers. These findings demonstrate that vasopressin stimulates greater apical CFTR Cl(-) conductance in the renal CCD cells of mice with Liddle's syndrome than in wild-type mice. This effect could contribute to the enhanced NaCl reabsorption observed in the distal nephron of patients with Liddle's syndrome.

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The present paper discusses mtDNA and taphonomy of human remains from Moa, Beirada, and Zé Espinho sambaquis of Saquarema, state of Rio de Janeiro, Brazil. New human bone dating by 14C-AMS for Moa archeological site (3810+50 BP - GX-31826-AMS) is included. Preservation of microscopic lamellae and DNA is not related to the macroscopic integrity of the bones. Results here suggest that the preservation of amplifiable DNA fragments may have relation to the preservation of the lamellar arrangement as indicated by optical microscopic examination (polarized light). In 13 human bone fragments from Moa, Beirada, and Zé Espinho it was possible to sequence mtDNA from the 3 individuals of Moa, and from 1 of 4 individuals of Beirada, whose bones also show extensive areas with preserved lamellar structures. The 6 human bone fragments of Zé Espinho and 3 of the 4 fragments of Beirada showed extensive destruction of cortical microstructure represented by cavities, intrusive minerals, and agglomerated microscopic bodies of fungi and bacteria; it was not possible to extract mtDNA from these samples. The results support the hypothesis that the preservation of the microscopic osteon organization is a good predictor for DNA preservation. It was also confirmed the C haplogroup antiquity in Brazil.

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OBJECTIVE: Exposure to altitude may lead to acute mountain sickness (AMS) in nonacclimatized individuals. We surveyed AMS prevalence and potential risk factors in trekkers crossing a 5400-m pass in Nepal and compared the results with those of 2 similar studies conducted 12 and 24 years earlier. METHODS: In April 2010, 500 surveys were distributed to English-speaking trekkers at 3500 m on their way to 5400 m, of which 332 (66%) surveys were returned complete. Acute mountain sickness was quantified with the Lake Louise Scoring System (LLSS, cutoff ≥3 and ≥5) and the Environmental Statistical Questionnaire III AMS-C score (ESQ-III, cutoff ≥0.7). We surveyed demographics, body mass index (BMI), smoking habit, rate of ascent, awareness of AMS, and acetazolamide use. RESULTS: Prevalence of AMS was 22%, 23%, and 48% (ESQ-III ≥0.7, LLSS ≥5, and LLSS ≥3, respectively) lower when compared with earlier studies. Risk factors for AMS were younger age, female sex, higher BMI, and smoking habit. Forty-two percent had elementary knowledge about the risk and prevention of AMS. Forty-four percent used acetazolamide. Trekkers took longer to climb from 3500 to 5400 m than in earlier studies. CONCLUSIONS: Prevalence of AMS continued to decline over a period of 24 years, likely as a result of slower ascent and increased use of acetazolamide. The AMS risk factors of younger age, female sex, and high BMI are consistent with prior studies. Awareness of risk and prevention of AMS remains low, indicating an opportunity to better educate trekkers and potentially further reduce AMS prevalence.

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The k-symplectic formulation of field theories is especially simple, since only tangent and cotangent bundles are needed in its description. Its defining elements show a close relationship with those in the symplectic formulation of mechanics. It will be shown that this relationship also stands in the presymplectic case. In a natural way,one can mimick the presymplectic constraint algorithm to obtain a constraint algorithmthat can be applied to k-presymplectic field theory, and more particularly to the Lagrangian and Hamiltonian formulations offield theories defined by a singular Lagrangian, as well as to the unified Lagrangian-Hamiltonian formalism (Skinner--Rusk formalism) for k-presymplectic field theory. Two examples of application of the algorithm are also analyzed.

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Neste estudo, propõe-se um modelo para explicar a inovatividade dos pecuaristas de gado de corte sob a perspectiva organizacional. Segundo a teoria de difusão de inovações, a inovatividade organizacional é caracterizada como o grau em que uma organização inova relativamente mais cedo do que as demais. Para avaliar a inovatividade, quatro antecedentes foram considerados, sendo: as características percebidas da inovação compostas por vantagem relativa, compatibilidade, imagem, demonstração de resultado, visibilidade, experimentabilidade, voluntariedade e facilidade de uso; a participação dos pecuaristas em redes sociais, caracterizadas como redes de relacionamentos entre pares; as fontes de informação comercial, caracterizadas como informações obtidas por meio dos relacionamentos para reduzir os riscos; a psicografia organizacional, composta por direção, centralidade da decisão, abertura de comunicação e motivação para a conquista. Os quatro construtos possuem uma relação positiva com a inovatividade organizacional. Com amostragem não probabilística por conveniência, foram obtidos 205 questionários válidos. Na análise de componentes múltiplos, observou-se que o perfil dos respondentes se mostrou distinto quanto à inovatividade. Essa distinção motivou a geração de uma taxonomia com base no perfil de adoção de tecnologias com o objetivo de identificar as diferenças no comportamento inovativo, o que resultou em três grupos. Assim, três modelos foram analisados e comparados por meio da modelagem de equações estruturais, utilizando-se o método Partial Least Square (PLS). Os resultados mostraram que o grupo dos menos inovadores pauta suas decisões de adoção de novas tecnologias pelas redes sociais, pela compatibilidade da tecnologia com suas atividades organizacionais e pela imagem que ela tem perante os demais pecuaristas. Os intermediários têm uma psicografia organizacional voltada para a inovatividade, porém a adoção de novas tecnologias parece estar mais relacionada às imposições de mercado do que propriamente à percepção de suas características inovadoras. Os mais inovadores, como formadores de opinião, possuem uma inovatividade organizacional construída a partir de fontes de informação comerciais e avaliam o custo da tecnologia como um investimento positivo para o futuro de seu negócio.

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No estudo relatado, analisam-se as relações consequentes da percepção de injustiça de preço desencadeada pela comparação com o preço a ser pago por um novo cliente em uma situação promocional. A pesquisa foi feita por meio de um experimento, com uma amostra composta por 200 estudantes de graduação. A análise dos dados foi realizada por meio da modelagem de equações estruturais. Os resultados do estudo indicam que a percepção de injustiça é positivamente sucedida por emoções negativas e intenções de troca imediata e futura. Além disso, a confiança aparece como negativamente afetada pela percepção de injustiça, uma vez que essa percepção pode abalar a confiança que o cliente tem na empresa. Suportando a distinção das intenções de troca imediata e futura, identificou-se no estudo que as emoções negativas e a confiança possuem impactos distintos nesses dois tipos de intenções de troca. A intenção de boca a boca negativo também foi constatada como importante consequência das emoções procedentes da percepção de injustiça, assim como da confiança, indicando que fortes emoções negativas e menores níveis de confiança se relacionam com maiores níveis de boca a boca negativo. No estudo, discutem-se as contribuições gerenciais e acadêmicas dos resultados e, também, consideram-se as implicações para estudos futuros.

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Este artigo faz parte de um amplo estudo de avaliação da adequação no uso de técnicas estatísticas multivariadas em teses e dissertações de duas instituições de ensino superior na área de marketing na temática do comportamento do consumidor, entre 1997 e 2006. Neste artigo são focalizadas onze técnicas multivariadas (análise de regressão, análise discriminante, análise de regressão logística, correlação canônica, análise multivariada de variância, análise conjunta, modelagem de equações estruturais, análise fatorial, análise de conglomerados, análise de correspondência, escalonamento multidimensional), as quais têm apresentado grande potencial de uso em estudos de marketing. Foi objetivo no trabalho relatado a análise da adequação do emprego dessas técnicas às necessidades dos problemas de pesquisa apresentados nas teses e dissertações e, também, a aferição do nível de adequação no atendimento de suas premissas. De forma geral, os resultados sugerem a necessidade de um aumento do comprometimento dos pesquisadores na verificação de todos os preceitos teóricos de aplicação das técnicas multivariadas.