119 research outputs found

    Caracterización de la farmacorresistencia en cáncer hepático: estrategias de superación medida por proteínas ABC

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    [ES] El sistema hepatobiliar forma parte del aparato digestivo e incluye el hígado, la vesícula y las vías biliares. Se trata de un sistema fundamental para mantener la homeostasis del organismo, al excretar productos de desecho lipófilos a través de la bilis y detoxificar la sangre proveniente del intestino, metabolizando y eliminando sustancias antes de que pasen a la circulación sistémica. Después de la piel y junto con el cerebro, el hígado es el órgano sólido más grande del organismo, con un peso aproximado de 1,5 kg en adultos. Recibe una irrigación sanguínea dual: casi un 80% de la sangre proviene de la vena porta, mientras que el 20% restante es sangre oxigenada que emana de la arteria hepática. La sangre portal procede del estómago, intestino, páncreas y bazo, y contiene sustancias que serán filtradas por el hígado para su metabolismo y/o eliminación. Morfológicamente, el ligamento falciforme divide el hígado en dos lóbulos principales: el derecho y el izquierdo. No obstante, desde un punto de vista funcional, existen ocho segmentos hepáticos que reciben riego sanguíneo de ramas provenientes de la vena porta y la arteria hepática. Paralelamente, en cada uno de estos segmentos la sangre es devuelta a una rama de la vena hepática y la bilis se libera al conducto biliar. Por otra parte, el sistema biliar complementa la función del hígado, concentrando, almacenando y conduciendo la bilis hacia el duodeno. El árbol biliar emerge de los dúctulos biliares o canales de Hering, que representan la unión fisiológica entre el sistema canalicular hepatocitario y el sistema biliar colangiolar. Estos convergen en los conductos biliares intrahepáticos y, posteriormente, en los extrahepáticos. Entre estos últimos se encuentra la vesícula biliar que, al contrario que el resto del tracto biliar, no aparece en todos los vertebrados

    Fostering cooperation through dynamic coalition formation and partner switching

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    In this article we tackle the problem of maximizing cooperation among self-interested agents in a resource exchange environment. Our main concern is the design of mechanisms for maximizing cooperation among self-interested agents in a way that their profits increase by exchanging or trading with resources. Although dynamic coalition formation and partner switching (rewiring) have been shown to promote the emergence and maintenance of cooperation for self-interested agents, no prior work in the literature has investigated whether merging both mechanisms exhibits positive synergies that lead to increase cooperation even further. Therefore, we introduce and analyze a novel dynamic coalition formation mechanism, that uses partner switching, to help self-interested agents to increase their profits in a resource exchange environment. Our experiments show the effectiveness of our mechanism at increasing the agents' profits, as well as the emergence of trading as the preferred behavior over different types of complex networks. © 2014 ACM.The first author thanks the grant Formación de Profesorado Universitario (FPU), reference AP2010-1742. J.Ll.A. and J.A.R-A are partially funded by projects EVE (TIN2009-14702-C02-01), AT (CSD2007-0022), COR (TIN2012-38876-C02-01), MECER (201250E053), and the Generalitat of Catalunya grant 2009-SGR-1434Peer Reviewe

    Using reputation and adaptive coalitions to support collaboration in competitive environments

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    Internet-based scenarios, like co-working, e-freelancing, or crowdsourcing, usually need supporting collaboration among several actors that compete to service tasks. Moreover, the distribution of service requests, i.e., the arrival rate, varies over time, as well as the service workload required by each customer. In these scenarios, coalitions can be used to help agents to manage tasks they cannot tackle individually. In this paper we present a model to build and adapt coalitions with the goal of improving the quality and the quantity of tasks completed. The key contribution is a decision making mechanism that uses reputation and adaptation to allow agents in a competitive environment to autonomously enact and sustain coalitions, not only its composition, but also its number, i.e., how many coalitions are necessary. We provide empirical evidence showing that when agents employ our mechanism it is possible for them to maintain high levels of customer satisfaction. First, we show that coalitions keep a high percentage of tasks serviced on time despite a high percentage of unreliable workers. Second, coalitions and agents demonstrate that they successfully adapt to a varying distribution of customers' incoming tasks. This occurs because our decision making mechanism facilitates coalitions to disband when they become non-competitive, and individual agents detect opportunities to start new coalitions in scenarios with high task demand. © 2015 Elsevier Ltd. All rights reserved.The first author thanks the grant Formación de Profesorado Universitario (FPU), reference AP2010-1742. Arcos and Rodriguez-Aguilar thank projects COR (TIN2012-38876-C02-01/02) and Generalitat of Catalunya (2014 SGR-118). Work supported by the European Regional Development Fund (ERDF) and the Galician Regional Government under agreement for funding the Atlantic Research Center for Information and Communication Technologies (AtlantTIC)Peer Reviewe

    Emerging Cooperation in N-Person Iterated Prisoner's Dilemma over Dynamic Complex Networks

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    The N-Person Iterated Prisoner's Dilemma (NIPD) is an interesting game that has proved to be very useful to explore the emergence of cooperation in multi-player scenarios. Within this game, the way that agents are interconnected is a key element that influences cooperation. In this context, complex networks provide a realistic model of the topological features found in Nature and in many social and technological networks. Considering these networks, it is interesting to study the network evolution, given the possibility that agents can change their neighbors (dynamic rewire), when non-cooperative behaviors are detected. In this paper, we present a model of the NIPD game where a population of genetically-coded agents compete altogether. We analyze how different game parameters, and the network topology, affect the emergence of cooperation in static complex networks. Based on that, we present the main contribution of the paper that concerns the influence of dynamic rewiring in the emergence of cooperation over the NIPD

    USING TAGS IN AN AIML-BASED CHATTERBOT TO IMPROVE ITS KNOWLEDGE

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    Nowadays, it is common to find on the Internet different conversational robots which interact with users simulating a natural language conversation. Among them, we can emphasize the chatterbots based on AIML language. In this paper we present an AIML based chatterbot that shows as its main contribution the use of tags and folksonomies. Thanks to its use, we can generate a context for each conversation, being able to maintain a state for each user in the system, and improving the adaptation capabilities of the bot

    UNICON: A unified framework for behavior-based consumer segmentation in e-commerce

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    Data-driven personalization is a key practice in fashion e-commerce, improving the way businesses serve their consumers needs with more relevant content. While hyper-personalization offers highly targeted experiences to each consumer, it requires a significant amount of private data to create an individualized journey. To alleviate this, group-based personalization provides a moderate level of personalization built on broader common preferences of a consumer segment, while still being able to personalize the results. We introduce UNICON, a unified deep learning consumer segmentation framework that leverages rich consumer behavior data to learn long-term latent representations and utilizes them to extract two pivotal types of segmentation catering various personalization use-cases: lookalike, expanding a predefined target seed segment with consumers of similar behavior, and data-driven, revealing non-obvious consumer segments with similar affinities. We demonstrate through extensive experimentation our framework effectiveness in fashion to identify lookalike Designer audience and data-driven style segments. Furthermore, we present experiments that showcase how segment information can be incorporated in a hybrid recommender system combining hyper and group-based personalization to exploit the advantages of both alternatives and provide improvements on consumer experience

    Breast-feeding and Helicobacter pylori infection: systematic review and meta-analysis.

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    OBJECTIVE: To quantify the association between breast-feeding and Helicobacter pylori infection, among children and adolescents. DESIGN: We searched MEDLINE™ and Scopus™ up to January 2013. Summary relative risk estimates (RR) and 95 % confidence intervals were computed through the DerSimonian and Laird method. Heterogeneity was quantified using the I² statistic. SETTING: Twenty-seven countries/regions; four low-income, thirteen middle-income and ten high-income countries/regions. SUBJECTS: Studies involving samples of children and adolescents, aged 0 to 19 years. RESULTS: We identified thirty-eight eligible studies, which is nearly twice the number included in a previous meta-analysis on this topic. Fifteen studies compared ever v. never breast-fed subjects; the summary RR was 0·87 (95% CI 0·57, 1·32; I²=34·4%) in middle-income and 0·85 (95% CI 0·54, 1·34; I²=79·1%) in high-income settings. The effect of breast-feeding for ≥4-6 months was assessed in ten studies from middle-income (summary RR=0·66; 95% CI 0·44, 0·98; I²=65·7%) and two from high-income countries (summary RR=1·56; 95% CI 0·57, 4·26; I²=68·3%). Two studies assessed the effect of exclusive breast-feeding until 6 months (OR=0·91; 95% CI 0·61, 1·34 and OR=1·71; 95% CI 0·66, 4·47, respectively). CONCLUSIONS: Our results suggest a protective effect of breast-feeding in economically less developed settings. However, further research is needed, with a finer assessment of the exposure to breast-feeding and careful control for confounding, before definite conclusions can be reached

    Sensitivity is not an intrinsic property of a diagnostic test: empirical evidence from histological diagnosis of Helicobacter pylori infection

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    <p>Abstract</p> <p>Background</p> <p>We aimed to provide empirical evidence of how spectrum effects can affect the sensitivity of histological assessment of <it>Helicobacter pylori </it>infection, which may contribute to explain the heterogeneity in prevalence estimates across populations with expectedly similar prevalence.</p> <p>Methods</p> <p>Cross-sectional evaluation of dyspeptic subjects undergoing upper digestive endoscopy, including collection of biopsy specimens from the greater curvature of the antrum for assessment of <it>H. pylori </it>infection by histopathological study and polymerase chain reaction (PCR), from Portugal (n = 106) and Mozambique (n = 102) following the same standardized protocol.</p> <p>Results</p> <p>In the Portuguese sample the prevalence of infection was 95.3% by histological assessment and 98.1% by PCR. In the Mozambican sample the prevalence was 63.7% and 93.1%, respectively. Among those classified as infected by PCR, the sensitivity of histological assessment was 96.2% among the Portuguese and 66.3% among the Mozambican. Among those testing positive by both methods, 5.0% of the Portuguese and 20.6% of the Mozambican had mild density of colonization.</p> <p>Conclusions</p> <p>This study shows a lower sensitivity of histological assessment of <it>H. pylori </it>infection in Mozambican dyspeptic patients compared to the Portuguese, which may be explained by differences in the density of colonization, and may contribute to explain the heterogeneity in prevalence estimates across African settings.</p

    EducaFarma 8.0

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    Memoria ID-033 . Ayudas de la Universidad de Salamanca para la innovación docente, curso 2019-2020

    Anacardium occidentale Bark as an Antidiabetic Agent

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    Anacardium occidentale L. is used throughout the world to treat type 2 diabetes. In Portugal, a traditional herbal preparation made with stem bark of this species (AoBTHP) has been used for more than 30 years to treat this pathology. The AoBTHP was standardized on total phenolic content, and its hypoglycemic activity was assessed using db/db mice (n = 26) for 92 days. Three doses (40.2, 71.5, and 127.0 mg/kg/day, per os) were tested, and glibenclamide (5 mg/kg/day) was used as positive control. During the study, glycemia was measured under non-fasting or fasting states. In sequence, thin-layer chromatography bioautographic assays were used for the detection of possible alpha- and beta-glucosidase inhibitors. A significant hypoglycemic effect in fasting glycemia in days 31 and 57 was observed with the three tested doses. The 71.5 mg/kg and 127.0 mg/kg AoBTHPs significantly reduced non-fasting glycemia on day 24. The highest dose showed the most significant hypoglycemic effect. Gallic acid was identified as the major alpha- and beta-glucosidase inhibitor. The 127 mg/kg/day AoBTHP dose showed a greater glucose-lowering effect than glibenclamide. For the first time, a standardized AoBTHP was tested using an in vivo diabetes model, and its usage was preclinically validated for type 2 diabetes treatment. The hypoglycemic activity of an AoBTHP can be related to the presence of alpha- and beta-glucosidase inhibitors, such as gallic acid, but other mechanisms can also be involved.info:eu-repo/semantics/publishedVersio
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