598 research outputs found

    A 5LCHB Inverter for PV transformerless applications with reduced leakage ground current

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    Transformerless inverters for photovoltaic systems are widely used as it features low cost, volume, and weight. Thus, in recent years, its study has been of great interest to the research community. In this paper a transformerless cascade multilevel inverter for photovoltaic applications with leakage ground current compensation capability is presented. The proposed solution involves a second-order LC output filter with a particular connection, which is referred to as the DC-link-tied LC output filter. This solution is aimed to deal with the leakage-ground current issue, regardless of the considered PWM strategy. The mathematical model of the system involving such a particular LC output passive filter configuration is presented, out of which, both the differential-mode and the common-mode models are obtained. These models are used to explain the leakage-ground current improvement of the proposed DC-link-tied LC output filter. This hardware solution is evaluated under different modulation schemes to contrast the converter output response and the leakage-ground current performance. Finally, simulation and experimental results are performed using a 1 kW academic prototype to assess the performance of the proposed DC-link-tied LC output filter used in a transformerless inverter application.Peer ReviewedObjectius de Desenvolupament Sostenible::7 - Energia Assequible i No ContaminantObjectius de Desenvolupament Sostenible::11 - Ciutats i Comunitats SosteniblesPostprint (published version

    16α‐Bromoepiandrosterone as a new candidate for experimental diabetes‐tuberculosis comorbidity treatment

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    Tuberculosis (TB) is the leading cause of death from a single bacterial infectious agent and is one of the most relevant issues of public health. Another pandemic disease is type II diabetes mellitus (T2D) that is estimated to affect half a billion people in the world. T2D is directly associated with obesity and a sedentary lifestyle and is frequently associated with immunosuppression. Immune dysfunction induced by hyperglycemia increases infection frequency and severity. Thus, in developing countries the T2D/TB co-morbidity is frequent and represents one of the most significant challenges for the health-care systems. Several immunoendocrine abnormalities are occurring during the chronic phase of both diseases, such as high extra-adrenal production of active glucocorticoids (GCs) by the activity of 11-β-hydroxysteroid dehydrogenase type 1 (11-βHSD1). 11-βHSD1 catalyzes the conversion of inactive cortisone to active cortisol or corticosterone in lungs and liver, while 11-β-hydroxysteroid dehydrogenase type 2 (11-βHSD2) has the opposite effect. Active GCs have been related to insulin resistance and suppression of Th1 responses, which are deleterious factors in both T2D and TB. The anabolic adrenal hormone dehydroepiandrosterone (DHEA) exerts antagonistic effects on GC signaling in immune cells and metabolic tissues; however, its anabolic effects prohibit its use to treat immunoendocrine diseases. 16α-bromoepiandrosterone (BEA) is a water miscible synthetic sterol related to DHEA that lacks an anabolic effect while amplifying the immune and metabolic properties with important potential therapeutic uses. In this work, we compared the expression of 11-βHSD1 and the therapeutic efficacy of BEA in diabetic mice infected with tuberculosis (TB) (T2D/TB) with respect to non-diabetic TB-infected mice (TB). T2D was induced by feeding mice with a high-fat diet and administering a single low-dose of streptozotocin. After 4 weeks of T2D establishment, mice were infected intratracheally with a high-dose of Mycobacterium tuberculosis strain H37Rv. Then, mice were treated with BEA three times a week by subcutaneous and intratracheal routes. Infection with TB increased the expression of 11-βHSD1 and corticosterone in the lungs and liver of both T2D/TB and TB mice; however, T2D/TB mice developed a more severe lung disease than TB mice. In comparison with untreated animals, BEA decreased GC and 11-βHSD1 expression while increasing 11-βHSD2 expression. These molecular effects of BEA were associated with a reduction in hyperglycemia and liver steatosis, lower lung bacillary loads and pneumonia. These results uphold BEA as a promising effective therapy for the T2D/TB co-morbidity.Fil: López Torres, Manuel Othoniel. Instituto Nacional de la Nutrición Salvador Zubiran; MéxicoFil: Marquina Castillo, Brenda. Instittuto de Ciencias Médicas y Nutrición; MéxicoFil: Ramos Espinosa, Octavio. Instittuto de Ciencias Médicas y Nutrición; MéxicoFil: Mata Espinosa, Dulce. Instittuto de Ciencias Médicas y Nutrición; MéxicoFil: Barrios Payan, Jorge A.. Instittuto de Ciencias Médicas y Nutrición; MéxicoFil: Baay Guzman, Guillermina. Instittuto de Ciencias Médicas y Nutrición; MéxicoFil: Huerta Yepez, Sara. Instittuto de Ciencias Médicas y Nutrición; MéxicoFil: Bini, Estela Isabel. Instittuto de Ciencias Médicas y Nutrición; MéxicoFil: Torre Villalvazo, Ivan. Instittuto de Ciencias Médicas y Nutrición; MéxicoFil: Torres, Nimbe. Instittuto de Ciencias Médicas y Nutrición; MéxicoFil: Tovar, Armando. Instittuto de Ciencias Médicas y Nutrición; MéxicoFil: Chamberlin, William. No especifíca;Fil: Ge, Yu. No especifíca;Fil: Carranza, Maria Andrea. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto Alberto C. Taquini de Investigaciones En Medicina Traslacional. - Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiologicas "prof. Dr. Alberto C. Taquini". Instituto Alberto C. Taquini de Investigaciones En Medicina Traslacional.; ArgentinaFil: Hernández Pando, Rogelio. Instituto Nacional de Ciencias Medicas y Nutricion; Méxic

    Robustness of optimal channel reservation using handover prediction in multiservice wireless networks

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    The aim of our study is to obtain theoretical limits for the gain that can be expected when using handover prediction and to determine the sensitivity of the system performance against different parameters. We apply an average-reward reinforcement learning approach based on afterstates to the design of optimal admission control policies in mobile multimedia cellular networks where predictive information related to the occurrence of future handovers is available. We consider a type of predictor that labels active mobile terminals in the cell neighborhood a fixed amount of time before handovers are predicted to occur, which we call the anticipation time. The admission controller exploits this information to reserve resources efficiently. We show that there exists an optimum value for the anticipation time at which the highest performance gain is obtained. Although the optimum anticipation time depends on system parameters, we find that its value changes very little when the system parameters vary within a reasonable range. We also find that, in terms of system performance, deploying prediction is always advantageous when compared to a system without prediction, even when the system parameters are estimated with poor precision. © Springer Science+Business Media, LLC 2012.The authors would like to thank the reviewers for their valuable comments that helped to improve the quality of the paper. This work has been supported by the Spanish Ministry of Education and Science and European Comission (30% PGE, 70% FEDER) under projects TIN2008-06739-C04-02 and TIN2010-21378-C02-02 and by Comunidad de Madrid through project S-2009/TIC-1468.Martínez Bauset, J.; Giménez Guzmán, JM.; Pla, V. (2012). Robustness of optimal channel reservation using handover prediction in multiservice wireless networks. Wireless Networks. 18(6):621-633. https://doi.org/10.1007/s11276-012-0423-6S621633186Ji, S., Chen, W., Ding, X., Chen, Y., Zhao, C., & Hu, C. (2010). Potential benefits of GPS/GLONASS/GALILEO integration in an urban canyon–Hong Kong. Journal of Navigation, 63(4), 681–693.Soh, W., & Kim, H. (2006). A predictive bandwidth reservation scheme using mobile positioning and road topology information. IEEE/ACM Transactions on Networking, 14(5), 1078–1091.Kwon, H., Yang, M., Park, A., & Venkatesan, S. (2008). Handover prediction strategy for 3G-WLAN overlay networks. In Proceedings: IEEE network operations and management symposium (NOMS) (pp. 819–822).Huang, C., Shen, H., & Chuang, Y. (2010). An adaptive bandwidth reservation scheme for 4G cellular networks using flexible 2-tier cell structure. Expert Systems with Applications, 37(9), 6414–6420.Wanalertlak, W., Lee, B., Yu, C., Kim, M., Park, S., & Kim, W. (2011). Behavior-based mobility prediction for seamless handoffs in mobile wireless networks. Wireless Networks, 17(3), 645–658.Becvar, Z., Mach, P., & Simak, B. (2011). Improvement of handover prediction in mobile WiMAX by using two thresholds. Computer Networks, 55, 3759–3773.Sgora, A., & Vergados, D. (2009). Handoff prioritization and decision schemes in wireless cellular networks: a survey. IEEE Communications Surveys and Tutorials, 11(4), 57–77.Choi, S., & Shin, K. G. (2002). Adaptive bandwidth reservation and admission control in QoS-sensitive cellular networks. IEEE Transactions on Parallel and Distributed Systems, 13(9), 882–897.Ye, Z., Law, L., Krishnamurthy, S., Xu, Z., Dhirakaosal, S., Tripathi, S., & Molle, M. (2007). Predictive channel reservation for handoff prioritization in wireless cellular networks. Computer Networks, 51(3), 798–822.Abdulova, V., & Aybay, I. (2011). Predictive mobile-oriented channel reservation schemes in wireless cellular networks. Wireless Networks, 17(1), 149–166.Ramjee, R., Nagarajan, R., & Towsley, D. (1997). On optimal call admission control in cellular networks. Wireless Networks, 3(1), 29–41.Bartolini, N. (2001). Handoff and optimal channel assignment in wireless networks. Mobile Networks and Applications, 6(6), 511–524.Bartolini, N., & Chlamtac, I. (2002). Call admission control in wireless multimedia networks. In Proceedings: Personal, indoor and mobile radio communications (PIMRC) (pp. 285–289).Pla, V., & Casares-Giner, V. (2003). Optimal admission control policies in multiservice cellular networks. In Proceedings of the international network optimization conference (INOC) (pp. 466–471).Chu, K., Hung, L., & Lin, F. (2009). Adaptive channel reservation for call admission control to support prioritized soft handoff calls in a cellular CDMA system. Annals of Telecommunications, 64(11), 777–791.El-Alfy, E., & Yao, Y. (2011). Comparing a class of dynamic model-based reinforcement learning schemes for handoff prioritization in mobile communication networks. Expert Systems With Applications, 38(7), 8730–8737.Gimenez-Guzman, J. M., Martinez-Bauset, J., & Pla, V. (2007). A reinforcement learning approach for admission control in mobile multimedia networks with predictive information. IEICE Transactions on Communications , E-90B(7), 1663–1673.Sutton R., Barto A. G. (1998) Reinforcement learning: An introduction. The MIT press, Cambridge, MassachusettsBusoniu, L., Babuska, R., De Schutter, B., & Ernst, D. (2010). Reinforcement learning and dynamic programming using function approximators. Boca Raton, FL: CRC Press.Watkins, C., & Dayan, P. (1992). Q-learning. Machine learning, 8(3–4), 279–292.Brown, T. (2001). Switch packet arbitration via queue-learning. Advances in Neural Information Processing Systems, 14, 1337–1344.Proper, S., & Tadepalli, P. (2006). Scaling model-based average-reward reinforcement learning for product delivery. In Proceedings 17th European conference on machine learning (pp. 735–742).Driessens, K., Ramon, J., & Gärtner, T. (2006). Graph kernels and Gaussian processes for relational reinforcement learning. Machine Learning, 64(1), 91–119.Banerjee, B., & Stone, P. (2007). General game learning using knowledge transfer. In Proceedings 20th international joint conference on artificial intelligence (pp. 672–677).Martinez-Bauset, J., Pla, V., Garcia-Roger, D., Domenech-Benlloch, M. J., & Gimenez-Guzman, J. M. (2008). Designing admission control policies to minimize blocking/forced-termination. In G. Ming, Y. Pan & P. Fan (Eds.), Advances in wireless networks: Performance modelling, analysis and enhancement (pp. 359–390). New York: Nova Science Pub Inc.Biswas, S., & Sengupta, B. (1997). Call admissibility for multirate traffic in wireless ATM networks. In Proceedings IEEE INFOCOM (2, pp. 649–657).Evans, J. S., & Everitt, D. (1999). Effective bandwidth-based admission control for multiservice CDMA cellular networks. IEEE Transactions on Vehicular Technology, 48(1), 36–46.Gilhousen, K., Jacobs, I., Padovani, R., Viterbi, A., Weaver, L. A. J., & Wheatley, C. E., III. (1991). On the capacity of a cellular CDMA system. IEEE Transactions on Vehicular Technology, 40(2), 303–312.Hegde, N., & Altman, E. (2006). Capacity of multiservice WCDMA networks with variable GoS. Wireless Networks, 12, 241–253.Ben-Shimol, Y., Kitroser, I., & Dinitz, Y. (2006). Two-dimensional mapping for wireless OFDMA systems. IEEE Transactions on Broadcasting, 52(3), 388–396.Gao, D., Cai, J., & Ngan, K. N. (2005). Admission control in IEEE 802.11e wireless LANs. IEEE Network, 19(4), 6–13.Liu, T., Bahl, P., & Chlamtac, I. (1998). Mobility modeling, location tracking, and trajectory prediction in wireless ATM networks. IEEE Journal on Selected Areas in Communications, 16(6), 922–936.Hu, F., & Sharma, N. (2004). Priority-determined multiclass handoff scheme with guaranteed mobile qos in wireless multimedia networks. IEEE Transactions on Vehicular Technology, 53(1), 118–135.Chan, J., & Seneviratne, A. (1999). A practical user mobility prediction algorithm for supporting adaptive QoS in wireless networks. In Proceedings IEEE international conference on networks (ICON) (pp. 104–111).Jayasuriya, A., & Asenstorfer, J. (2002). Mobility prediction model for cellular networks based on the observed traffic patterns. In Proceedings of IASTED international conference on wireless and optical communication (WOC) (pp. 386–391).Diederich, J., & Zitterbart, M. (2005). A simple and scalable handoff prioritization scheme. Computer Communications, 28(7), 773–789.Rashad, S., Kantardzic, M., & Kumar, A. (2006). User mobility oriented predictive call admission control and resource reservation for next-generation mobile networks. Journal of Parallel and Distributed Computing, 66(7), 971–988.Soh, W. -S., & Kim, H. (2003). QoS provisioning in cellular networks based on mobility prediction techniques. IEEE Communications Magazine, 41(1), 86 – 92.Lott, M., Siebert, M., Bonjour, S., vonHugo, D., & Weckerle, M. (2004). Interworking of WLAN and 3G systems. Proceedings IEE Communications, 151(5), 507 – 513.Sanabani, M., Shamala, S., Othman, M., & Zukarnain, Z. (2007). An enhanced bandwidth reservation scheme based on road topology information for QoS sensitive multimedia wireless cellular networks. In Proceedings of the 2007 international conference on computational science and its applications—Part II (ICCSA) (pp. 261–274).Mahadevan, S. (1996). Average reward reinforcement learning: Foundations, algorithms, and empirical results. Machine Learning, 22(1–3), 159–196.Puterman, M. L. (1994). Markov decision processes: Discrete stochastic dynamic programming. New York: Wiley.Das, T. K., Gosavi, A., Mahadevan, S., & Marchalleck, N. (1999). Solving semi-markov decision problems using average reward reinforcement learning. Management Science, 45(4), 560–574.Darken, C., Chang, J., & Moody, J. (1992). Learning rate schedules for faster stochastic gradient search. In Proceedings of the IEEE-SP workshop on neural networks for signal processing II. (pp. 3–12)

    Endemic and epidemic human alphavirus infections in eastern Panama: An analysis of population-based cross-sectional surveys

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    Madariaga virus (MADV) has recently been associated with severe human disease in Panama, where the closely related Venezuelan equine encephalitis virus (VEEV) also circulates. In June 2017, a fatal MADV infection was confirmed in a community of Darien Province. We conducted a cross-sectional outbreak investigation with human and mosquito collections in July 2017, where sera were tested for alphavirus antibodies and viral RNA. In addition, by applying a catalytic, force-of-infection (FOI) statistical model to two serosurveys from Darien Province in 2012 and 2017, we investigated whether endemic or epidemic alphavirus transmission occurred historically. In 2017, MADV and VEEV IgM seroprevalences were 1.6% and 4.4%, respectively; IgG antibody prevalences were MADV: 13.2%, VEEV: 16.8%, Una virus (UNAV): 16.0%, and Mayaro virus: 1.1%. Active viral circulation was not detected. Evidence of MADV and UNAV infection was found near households, raising questions about its vectors and enzootic transmission cycles. Insomnia was associated withMADVand VEEV infections, depression symptoms were associated with MADV, and dizziness with VEEV and UNAV. Force-of-infection analyses suggest endemic alphavirus transmission historically, with recent increased human exposure to MADV and VEEV in Aruza and Mercadeo, respectively. The lack of additional neurological cases suggests that severe MADV and VEEV infections occur only rarely. Our results indicate that over the past five decades, alphavirus infections have occurred at low levels in eastern Panama, but that MADV and VEEV infections have recently increased-potentially during the past decade. Endemic infections and outbreaks of MADV and VEEV appear to differ spatially in some locations of eastern Panama.National Institute for Health ResearchRevisión por pare

    Endurance, Refuge, and Reemergence of Dengue Virus Type 2, Puerto Rico, 1986–2007

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    To study the evolution of dengue virus (DENV) serotype 2 in Puerto Rico, we examined the genetic composition and diversity of 160 DENV-2 genomes obtained through 22 consecutive years of sampling. A clade replacement took place in 1994–1997 during a period of high incidence of autochthonous DENV-2 and frequent, short-lived reintroductions of foreign DENV-2. This unique clade replacement was complete just before DENV-3 emerged. By temporally and geographically defining DENV-2 lineages, we describe a refuge of this virus through 4 years of low genome diversity. Our analyses may explain the long-term endurance of DENV-2 despite great epidemiologic changes in disease incidence and serotype distribution

    Surface indicators are correlated with soil multifunctionality in global drylands

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    Multiple ecosystem functions need to be considered simultaneously to manage and protect the several ecosystem services that are essential to people and their environments. Despite this, cost effective, tangible, relatively simple and globally relevant methodologies to monitor in situ soil multifunctionality, that is, the provision of multiple ecosystem functions by soils, have not been tested at the global scale. We combined correlation analysis and structural equation modelling to explore whether we could find easily measured, field-based indicators of soil multifunctionality (measured using functions linked to the cycling and storage of soil carbon, nitrogen and phosphorus). To do this, we gathered soil data from 120 dryland ecosystems from five continents. Two soil surface attributes measured in situ (litter incorporation and surface aggregate stability) were the most strongly associated with soil multifunctionality, even after accounting for geographic location and other drivers such as climate, woody cover, soil pH and soil electric conductivity. The positive relationships between surface stability and litter incorporation on soil multifunctionality were greater beneath the canopy of perennial vegetation than in adjacent, open areas devoid of vascular plants. The positive associations between surface aggregate stability and soil functions increased with increasing mean annual temperature. Synthesis and applications. Our findings demonstrate that a reduced suite of easily measured in situ soil surface attributes can be used as potential indicators of soil multifunctionality in drylands world-wide. These attributes, which relate to plant litter (origin, incorporation, cover), and surface stability, are relatively cheap and easy to assess with minimal training, allowing operators to sample many sites across widely varying climatic areas and soil types. The correlations of these variables are comparable to the influence of climate or soil, and would allow cost-effective monitoring of soil multifunctionality under changing land-use and environmental conditions. This would provide important information for evaluating the ecological impacts of land degradation, desertification and climate change in drylands world-wide.Fil: Eldridge, David J.. University of New South Wales; AustraliaFil: Delgado Baquerizo, Manuel. Universidad Rey Juan Carlos; EspañaFil: Quero, José L.. Universidad de Córdoba; EspañaFil: Ochoa, Victoria. Universidad Rey Juan Carlos; España. Universidad de Alicante; EspañaFil: Gozalo, Beatriz. Universidad Rey Juan Carlos; España. Universidad de Alicante; EspañaFil: García Palacios, Pablo. Universidad Rey Juan Carlos; EspañaFil: Escolar, Cristina. Universidad Rey Juan Carlos; EspañaFil: García Gómez, Miguel. Universidad Politécnica de Madrid; EspañaFil: Prina, Aníbal. Universidad Nacional de La Pampa; ArgentinaFil: Bowker, Mathew A.. Northern Arizona University; Estados UnidosFil: Bran, Donaldo Eduardo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; ArgentinaFil: Castro, Ignacio. Universidad Experimental Simón Rodríguez; VenezuelaFil: Cea, Alex. Universidad de La Serena; ChileFil: Derak, Mchich. No especifíca;Fil: Espinosa, Carlos I.. Universidad Técnica Particular de Loja; EcuadorFil: Florentino, Adriana. Universidad Central de Venezuela; VenezuelaFil: Gaitán, Juan José. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Suelos; Argentina. Universidad Nacional de Luján. Departamento de Tecnología; ArgentinaFil: Gatica, Mario Gabriel. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Departamento de Biología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; ArgentinaFil: Gómez González, Susana. Universidad de Cádiz; EspañaFil: Ghiloufi, Wahida. Université de Sfax; TúnezFil: Gutierrez, Julio R.. Universidad de La Serena; ChileFil: Guzman, Elizabeth. Universidad Técnica Particular de Loja; EcuadorFil: Hernández, Rosa M.. Universidad Experimental Simón Rodríguez; VenezuelaFil: Hughes, Frederic M.. Universidade Estadual de Feira de Santana; BrasilFil: Muiño, Walter. Universidad Nacional de La Pampa; ArgentinaFil: Monerris, Jorge. No especifíca;Fil: Ospina, Abelardo. Universidad Central de Venezuela; VenezuelaFil: Ramírez, David A.. International Potato Centre; PerúFil: Ribas Fernandez, Yanina Antonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; ArgentinaFil: Romão, Roberto L.. Universidade Estadual de Feira de Santana; BrasilFil: Torres Díaz, Cristian. Universidad del Bio Bio; ChileFil: Koen, Terrance B.. No especifíca;Fil: Maestre, Fernando T.. Universidad Rey Juan Carlos; España. Universidad de Alicante; Españ

    Higher risk of malaria transmission outdoors than indoors by Nyssorhynchus darlingi in riverine communities in the Peruvian Amazon.

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    BACKGROUND: Malaria remains an important public health problem in Peru where incidence has been increasing since 2011. Of over 55,000 cases reported in 2017, Plasmodium vivax was the predominant species (76%), with P. falciparum responsible for the remaining 24%. Nyssorhynchus darlingi (previously Anopheles darlingi) is the main vector in Amazonian Peru, where hyperendemic Plasmodium transmission pockets have been found. Mazán district has pronounced spatial heterogeneity of P. vivax malaria. However, little is known about behavior, ecology or seasonal dynamics of Ny. darlingi in Mazán. This study aimed to gather baseline information about bionomics of malaria vectors and transmission risk factors in a hyperendemic malaria area of Amazonian Peru. METHODS: To assess vector biology metrics, five surveys (two in the dry and three in the rainy season), including collection of sociodemographic information, were conducted in four communities in 2016-2017 on the Napo (Urco Miraño, URC; Salvador, SAL) and Mazán Rivers (Visto Bueno, VIB; Libertad, LIB). Human-biting rate (HBR), entomological inoculation rate (EIR) and human blood index (HBI) were measured to test the hypothesis of differences in entomological indices of Ny. darlingi between watersheds. A generalized linear mixed effect model (GLMM) was constructed to model the relationship between household risk factors and the EIR. RESULTS: Nyssorhynchus darlingi comprised 95% of 7117 Anophelinae collected and its abundance was significantly higher along the Mazán River. The highest EIRs (3.03-4.54) were detected in March and June in URC, LIB and VIB, and significantly more Ny. darlingi were infected outdoors than indoors. Multivariate analysis indicated that the EIR was >12 times higher in URC compared with SAL. The HBI ranged from 0.42-0.75; humans were the most common blood source, followed by Galliformes and cows. There were dramatic differences in peak biting time and malaria incidence with similar bednet coverage in the villages. CONCLUSIONS: Nyssorhynchus darlingi is the predominant contributor to malaria transmission in the Mazán District, Peru. Malaria risk in these villages is higher in the peridomestic area, with pronounced heterogeneities between and within villages on the Mazán and the Napo Rivers. Spatiotemporal identification and quantification of the prevailing malaria transmission would provide new evidence to orient specific control measures for vulnerable or at high risk populations

    The impact of polyphenols on chondrocyte growth and survival: a preliminary report

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    Background: Imbalances in the functional binding of fibroblast growth factors (FGFs) to their receptors (FGFRs) have consequences for cell proliferation and differentiation that in chondrocytes may lead to degraded cartilage. The toxic, proinflammatory, and oxidative response of cytokines and FGFs can be mitigated by dietary polyphenols. Objective: We explored the possible effects of polyphenols in the management of osteoarticular diseases using a model based on the transduction of a mutated human FGFR3 (G380R) in murine chondrocytes. This mutation is present in most cases of skeletal dysplasia and is responsible for the overexpression of FGFR3 that, in the presence of its ligand, FGF9, results in toxic effects leading to altered cellular growth. Design: Different combinations of dietary polyphenols derived from plant extracts were assayed in FGFR3 (G380R) mutated murine chondrocytes, exploring cell survival, chloride efflux, extracellular matrix (ECM) generation, and grade of activation of mitogen-activated protein kinases. Results: Bioactive compounds from Hibiscus sabdariffa reversed the toxic effects of FGF9 and restored normal growth, suggesting a probable translation to clinical requests in humans. Indeed, these compounds activated the intracellular chloride efflux, increased ECM generation, and stimulated cell proliferation. The inhibition of mitogen-activated protein kinase phosphorylation was interpreted as the main mechanism governing these beneficial effects. Conclusions: These findings support the rationale behind the encouragement of the development of drugs that repress the overexpression of FGFRs and suggest the dietary incorporation of supplementary nutrients in the management of degraded cartilage.The authors are grateful for the constant support provided by the Hospital Universitari de Sant Joan and the Universitat Rovira i Virgili. Salvador Fernández-Arroyo is the recipient of a Sara Borrell grant (CD12/00672) from the Instituto de Salud Carlos III, Madrid, Spain. The authors also thank the Andalusian Regional Government Council of Innovation and Science for the Excellence Project P11-CTS-7625 and Generalitat Valenciana for the project PROMETEO/2012/007. This work was also supported by projects of the Fundación Areces and the Fundación MAGAR
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