390 resultados para CCS


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Background: Vasodilator-Stimulated Phosphoprotein (VASP) is involved in the inhibition of agonist-induced platelet aggregation by cyclic nucleotides and the adhesion of platelets to the vascular wall. αIIbβ3 is the main integrin responsible for platelet activation and Rap1b plays a key role in integrin signalling. We investigated whether VASP is involved in the regulation of Rap1b in platelets since VASP-null platelets exhibit augmented adhesion to endothelial cells in vivo.

Methods: Washed platelets from wild type and VASP-deficient mice were stimulated with thrombin, the purinergic receptors agonist ADP, or the thromboxane A2 receptor agonist U46619 and Rap1b activation was measured using the GST-RalGDS-RBD binding assay. Interaction of VASP and Crkl was investigated by co-immunoprecipitation, confocal microscopy, and pull-down assays using Crkl domains expressed as GST-fusion proteins.

Results: Surprisingly, we found that activation of Rap1b in response to thrombin, ADP, or U46619 was significantly reduced in platelets from VASP-null mice compared to platelets from wild type mice. However, inhibition of thrombin-induced activation of Rap1b by nitric oxide was similar in platelets from wild type and VASP-null mice indicating that the NO/cGMP/PKG pathway controls inhibition of Rap1b independently from VASP. To understand how VASP regulated Rap1b, we investigated association between VASP and the Crk-like protein (Crkl), an adapter protein which activates the Rap1b guanine nucleotide exchange factor C3G. We demonstrated the formation of a Crkl/VASP complex by showing that: 1) Crkl co-immunoprecipitated VASP from platelet lysates; 2) Crkl and VASP dynamically co-localized at actin-rich protrusions reminiscent of focal adhesions, filopodia, and lamellipodia upon platelet spreading on fibronectin; 3) recombinant VASP bound directly to the N-terminal SH3 domain of Crkl; 4) PKA-mediated VASP phosphorylation on Ser157 abrogated the binding of Crkl.

Conclusions: We identified Crkl as a novel protein interacting with VASP in platelets. We propose that the C3G/Crkl/VASP complex plays a role in the regulation of Rap1b and this explains, at least in part, the reduced agonist-induced activation of Rap1b in VASP-null platelets. In addition, the fact that PKA-dependent VASP phosphorylation abrogated its interaction with Crkl may provide, at least in part, a rationale for the PKA-dependent inhibition of Rap1b and platelet aggregation.

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We present the market practice for interest rate yield curves construction and pricing interest rate derivatives. Then we give a brief description of the Vasicek and the Hull-White models, with an example of calibration to market data. We generalize the classical Black-Scholes-Merton pricing formulas, considering more general cases such as perfect or partial collateral, derivatives on a dividend paying asset subject to repo funding, and multiple currencies. Finally we derive generic pricing formulae for different combinations of cash flow and collateral currencies, and we apply the results to the pricing of FX swaps and CCS, and we discuss curve bootstrapping.

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Carbon capture and storage (CCS) in the oil and water industries is becoming common and a significant consumer of energy typically requiring 150–450 °C and or several hundred bar pressure [1] particularly in geological deposition. A biological carbon capture and conversion has been considered in conventional anaerobic digestion processes. The process has been utilised in biological mixed culture, where acetoclastic bacteria and hydrogenophilic methanogens play a major key role in the utilisation of carbon dioxide. However, the bio catalytic microorganisms, hydrogenophilic methanogens are reported to be unstable with acetoclastic bacteria. In this work the biochemical thermodynamic efficiency was investigated for the stabilisation of the microbial process in carbon capture and utilisation. The authors observed that a thermodynamic efficiency of biological carbon capture and utilisation (BCCU) had 32% of overall reduction in yield of carbon dioxide with complimentary increase of 30% in yield of methane, while the process was overall endothermic. Total consumption of energy (≈0.33 MJ l−1) was estimated for the carbonate solubility (0.1 mol l−1) in batched BCCU. This has a major influence on microbial composition in the bioreactor. This thermodynamic study is an essential tool to aid the understanding of the interactions between operating parameters and the mixed microbial culture.

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In this paper we explain how recursion operators can be used to structure and reason about program semantics within a functional language. In particular, we show how the recursion operator fold can be used to structure denotational semantics, how the dual recursion operator unfold can be used to structure operational semantics, and how algebraic properties of these operators can be used to reason about program semantics. The techniques are explained with the aid of two main examples, the first concerning arithmetic expressions, and the second concerning Milner's concurrent language CCS. The aim of the paper is to give functional programmers new insights into recursion operators, program semantics, and the relationships between them.

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The investigation of pathogen persistence in vector-borne diseases is important in different ecological and epidemiological contexts. In this thesis, I have developed deterministic and stochastic models to help investigating the pathogen persistence in host-vector systems by using efficient modelling paradigms. A general introduction with aims and objectives of the studies conducted in the thesis are provided in Chapter 1. The mathematical treatment of models used in the thesis is provided in Chapter 2 where the models are found locally asymptotically stable. The models used in the rest of the thesis are based on either the same or similar mathematical structure studied in this chapter. After that, there are three different experiments that are conducted in this thesis to study the pathogen persistence. In Chapter 3, I characterize pathogen persistence in terms of the Critical Community Size (CCS) and find its relationship with the model parameters. In this study, the stochastic versions of two epidemiologically different host-vector models are used for estimating CCS. I note that the model parameters and their algebraic combination, in addition to the seroprevalence level of the host population, can be used to quantify CCS. The study undertaken in Chapter 4 is used to estimate pathogen persistence using both deterministic and stochastic versions of a model with seasonal birth rate of the vectors. Through stochastic simulations we investigate the pattern of epidemics after the introduction of an infectious individual at different times of the year. The results show that the disease dynamics are altered by the seasonal variation. The higher levels of pre-existing seroprevalence reduces the probability of invasion of dengue. In Chapter 5, I considered two alternate ways to represent the dynamics of a host-vector model. Both of the approximate models are investigated for the parameter regions where the approximation fails to hold. Moreover, three metrics are used to compare them with the Full model. In addition to the computational benefits, these approximations are used to investigate to what degree the inclusion of the vector population in the dynamics of the system is important. Finally, in Chapter 6, I present the summary of studies undertaken and possible extensions for the future work.

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“Copyright © [2014] IEEE. Reprinted from 1st International Workshop on Cognitive Cellular Systems 2014 . ISBN: 978-1-4799-4139-1 .This material is posted here with permission of the IEEE. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to pubs-permissions@ieee.org. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.”

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No presente relatório são caracterizadas e descritas as atividades desenvolvidas durante o estágio curricular na vertente da importância do maneio, ambiente e animal no controlo das mastites. Contempla ainda uma revisão bibliográfica e estudo de caso sobre a problemática das mastites na exploração. No estudo de caso procurou avaliar-se a influência do maneio, ambiente e animal no controlo das mastites e o impacto que estas representam na quantidade e na qualidade do leite. Foi ainda realizado estudo em 30 bovinos, identificados como animais problema, com recolha de amostras de leite para análise de antibiograma com deteção de agente. Foi implementado um plano de prevenção e controlo de mastites que consistiu na implementação de medidas de higiene e maneio dos animais, implementação de operações de rotinas de ordenha, implementação de medidas preventivas com recurso a vacinação e estabelecimentos de protocolos de tratamentos para os animais com patologias associadas às mastites. Os resultados obtidos foram muito positivos, diminuindo de forma drástica a incidência de mastites de 20% para 5% anual e consequentemente, uma melhoria considerável da quantidade de leite (22 para 33 L/vaca/dia) e na qualidade do leite (CCS <300 000 cel/mL) produzido; Abstract: Mastitis: Importance of management, environment and animal. Plan for the prevention, control and impact on the quantity and quality of milk This report characterize and describe the activities carried out during the traineeship in the aspect of the importance of management, environment and animal in the control of mastitis. There is also a literature and a case study on the problem of mastitis on the farm review. In the case study we sought to evaluate the influence of management, environment and animal in the control of mastitis and the impact that they represent in the quantity and quality of milk. A study was also carried out in 30 cattle, identified as problem animals, with milk samples for antibiotic susceptibility analysis with agent detection. It was implemented a mastitis prevention and control plan with the implementation of hygiene measures and husbandry of animals, implementation of milking routine operations, and implementing preventive measures using vaccination and treatment protocols establishment for animal diseases associated with mastitis. The results were very positive, decreasing dramatically the incidence of 20% mastitis to 5% per year and hence a considerable improvement of the quantity (22 to 33 L/cow/day) and quality ( SCC <300,000 cells/mL) of milk produced.

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Global concentration of CO2 in the atmosphere is increasing rapidly. CO2 emissions have huge impact on global climate change. Therefore, efficient CO2 emission abatement strategies such as Carbon Capture and Storage (CCS) are required to combat this phenomenon. There are three major approaches for CCS: - Post-combustion capture; - Pre-combustion capture; - Oxyfuel process. Post-combustion capture offers some advantages in terms of cost as existing combustion technologies can still be used without radical changes on them. This makes post-combustion capture easier to implement as a retrofit option compared to the other two approaches. Therefore, post-combustion capture is probably the first technology that will be deployed on a large scale. The aim of this work is to study the adsorption equilibrium of CO2, CH4 and N2 in zeolite 5A at 40ºC. For this, experiments were performed to determine the isotherms of adsorption of CO2, CH4 and N2 near 40ºC with the conditions of the post-combustion capture processes. It has been found that the 5A zeolite adsorbs a significant quantity of CO2 values of about 5 mol/kg at a pressure of 5 bar.

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Mestrado em Engenharia Zootécnica - Produção Animal - Instituto Superior de Agronomia

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Recommender system is a specific type of intelligent systems, which exploits historical user ratings on items and/or auxiliary information to make recommendations on items to the users. It plays a critical role in a wide range of online shopping, e-commercial services and social networking applications. Collaborative filtering (CF) is the most popular approaches used for recommender systems, but it suffers from complete cold start (CCS) problem where no rating record are available and incomplete cold start (ICS) problem where only a small number of rating records are available for some new items or users in the system. In this paper, we propose two recommendation models to solve the CCS and ICS problems for new items, which are based on a framework of tightly coupled CF approach and deep learning neural network. A specific deep neural network SADE is used to extract the content features of the items. The state of the art CF model, timeSVD++, which models and utilizes temporal dynamics of user preferences and item features, is modified to take the content features into prediction of ratings for cold start items. Extensive experiments on a large Netflix rating dataset of movies are performed, which show that our proposed recommendation models largely outperform the baseline models for rating prediction of cold start items. The two proposed recommendation models are also evaluated and compared on ICS items, and a flexible scheme of model retraining and switching is proposed to deal with the transition of items from cold start to non-cold start status. The experiment results on Netflix movie recommendation show the tight coupling of CF approach and deep learning neural network is feasible and very effective for cold start item recommendation. The design is general and can be applied to many other recommender systems for online shopping and social networking applications. The solution of cold start item problem can largely improve user experience and trust of recommender systems, and effectively promote cold start items.

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Introducción: El dolor lumbar y los desórdenes músculo esqueléticos comprometen la salud y la calidad de vida de los trabajadores, pueden poner en riesgo el futuro laboral de las personas. bjetivo: Estimar la prevalencia de dolor lumbar y los posibles factores biomecánicos asociados en el personal operativo y administrativo en una empresa manufacturera de jabón en Bogotá, en el año 2016 Metodología: Estudio de corte transversal donde se evaluó el riesgo biomecánico y la prevalencia del dolor lumbar en personal administrativo (138) y operativo (165); se utilizó como instrumento el ERGOPAR validado en España. Se revisó la asociación utilizando la prueba Chi Cuadrado de Pearson, con un nivel de significación α 0.05 Resultados: 303 trabajadores de una empresa manufacturera de jabón en Bogotá, donde predominó el género masculino (51,82%) y la población adulta media entre 30-39 años (57,42%). La prevalencia del dolor lumbar en la población fue de 61,39% (186). La edad no se asoció estadísticamente al dolor lumbar. Se encontró asociación estadística entre el síntoma dolor lumbar y extensión de cuello (p=0,05 OR1.95 IC 1.33-2.88), así como con agarrar o sujetar objetos (p= 0,036. OR 2.3 IC 1.59-3.51) y con las exigencias físicas laborales (p= 0.001 OR 1.99 IC 1.31-3.02). Conclusiones: La población estudiada presentó una alta prevalencia de dolor lumbar, con predominio en personal que realiza labores operativas, y del género femenino. La adopción de posturas de extensión del cuello y la sujeción o agarre de objetos son factores asociados directamente con la aparición de lumbalgia.

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Introducción. Los Trastornos Musculoesqueléticos (TME) son lesiones de músculos, tendones, nervios y articulaciones que tienen como principal síntoma el dolor y se presentan con gran frecuencia en trabajos que requieren una actividad física importante o como consecuencia de malas posturas sostenidas durante largos periodos de tiempo. Objetivo: Determinar la prevalencia de síntomas osteomusculares y su asociación con factores ergonómicos en una población de trabajadores administrativos de una empresa de servicios en Bogotá, Colombia, en el año 2015. Método: Se realizó un estudio de corte transversal. Se analizaron datos secundarios correspondientes a una base de datos de una población de 450 trabajadores pertenecientes al área administrativa de una empresa de servicios, de los cuales se incluyeron 150 registros que tenían la información completa de las variables del estudio. Se tuvieron en cuenta variables sociodemográficas, ocupacionales y la presencia de síntomas osteomusculares. Incluyó también el registro de condiciones de la estación de trabajo recolectada mediante inspecciones de puestos de trabajo (registro fotográfico y formato estandarizado para condiciones observadas). Se realizó un análisis descriptivo considerando las medidas de tendencia central para las variables cuantitativas y distribución de frecuencias para las variables cualitativas. Resultados: Predominó el género femenino (56%) dentro de la población estudiada, con una edad media para ambos géneros de 35 años (75%), (DS ± 7.0). El síntoma más frecuentemente reportado fue el dolor en cuello (17%) seguido por dolor en muñeca (11%) y dolor lumbar (8.7%). Del total de los trabajadores evaluados, el 80% correspondió al cargo ejecutivo, que reúne funciones administrativas especializadas complejas y/o de supervisión directa. De la población femenina objeto de estudio el 76% se desempeñaban en el cargo ejecutivo. Las condiciones ergonómicas por mejorar de mayor frecuencia fueron altura y distancia de la pantalla (42%) y cables sueltos (30%). La frecuencia de síntomas fue más alta en el rango de edad de 31 a 45 años. Conclusiones: En este estudio se encontró que los síntomas osteomusculares más frecuentes se ubicaron en el segmento axial (cuello y región lumbar) y en mano y que las condiciones de altura y distancia de la pantalla y cables sueltos presentaron las frecuencias más altas de condiciones por mejorar. Se hace necesaria la implementación de programas de prevención de TME, la vigilancia de casos y la intervención de las condiciones de los puestos de trabajo. Se debe promover la identificación y promoción de conductas saludables dentro del ámbito laboral y la prevención de condiciones que favorezcan la aparición del riesgo biomecánico.

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El creciente interés de China por África ha modificado y estructurado una nueva política exterior, en donde el fortalecimiento de las relaciones políticas y económicas se ve ligado al uso de la diplomacia cultural como una herramienta de atracción. Teniendo en cuenta lo anterior, la presente investigación tiene por objetivo principal indagar cómo China construye una identidad a través de su diplomacia cultural en Angola, demostrando así, que este país utiliza sus costumbres, principios y normas para establecer una identidad de rol en la que se asume como una potencia que debe cooperar. No obstante, sus intereses van más allá de la cooperación al profundizar en relaciones de confianza que lo beneficien política y económicamente. Haciendo un uso del concepto de Imperialismo, la investigación mostrará las limitaciones y los vacíos de la noción de identidad para explicar acciones chinas en Angola, mostrando cómo se hacen uso de herramientas imperialistas para un beneficio propio.

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La ecografía básica cardiaca (ECB) es una herramienta útil en la Unidad de Cuidados intensivos al facilitar la realización de ciertas intervenciones. No se ha definido el número de repeticiones necesarias para obtener un nivel de competencia adecuado. La evidencia encontrada indica un número mínimo de cincuenta repeticiones, para alcanzar cierto grado de habilidad.

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A inflamação da glândula mamária é uma das principais causas de prejuízo na ovinocultura. Este estudo teve como objetivo investigar as taxas de cura do tratamento da mastite subclínica após infusão intramamária de princípio ativo antimicrobiano no momento da secagem, em formulações convencional e nanoparticulada. Os rebanhos estavam localizados em São Carlos, São Paulo, Brasil. Analisou-se um total de 584 glândulas mamárias de 307 ovelhas de aptidão para produção de carne. Triagem prévia dos casos subclínicos de mastite foi efetuada por meio do California Mastitis Test (CMT) e/ou da contagem de células somáticas (CCS). Análises microbiológicas foram realizadas para confirmação da etiologia infecciosa. As glândulas mamárias com mastite subclínica foram distribuídas em três grupos: G1 (Controle; glândulas mamárias que não receberam tratamento antimicrobiano); G2 (glândulas mamárias em que foi administrado 100 mg de cloxacilina benzatina em estrutura convencional) e G3 (glândulas mamárias em que foi administrado 50 mg de cloxacilina benzatina em estrutura nanoencapsulada). O tratamento aplicado ao G3 mostrou-se mais eficiente (P=0,047) na cura de glândulas mamárias com mastite subclínica. O uso da cloxacilina nanoencapsulada no momento da secagem de ovelhas de corte auxilia no controle da mastite subclínica infecciosa e reduz os prejuízos consequentes.