298 research outputs found

    Survival of several Rhizobium/Bradyrhizobium strains on different inoculant formulations and inoculated seeds

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    The effect of a variety factors on the survival of several rhizobia strains on inoculants and inoculated seeds has been evaluated. Since the rhizobia strains showed different cell-density-evolution patterns on peat-based inoculants and on inoculated seeds, several inoculant formulations with highly effective Rhizobium/ Bradyrhizobium strains (for Lupinus, Hedysarum, Phaseolus and Glycine max. ) were monitored under the following storage conditions: (a) the inoculants were kept refrigerated (at 4°C), or (b) at room temperature (25°C). The effect of water content (30–50%, w/w) in the inoculants as well as that of several seed-coating adhesives were also investigated. Alternative carriers including perlite and vermiculite were tested. For all of the strains, survival on sterile peat-based inoculants was higher than on the corresponding unsterile peat formulation; for the latter, refrigerated storage conditions are recommended to ensure high bacterial densities. The water content of the inoculants had a differential effect on strain survival depending on the sterility of the peat, such that a high water content was more detrimental when unsterilized peat was employed. The best adherent for rhizobia survival was a gum arabic/water solution. Perlite was as effective as peat in maintaining a high population of rhizobia, at least for 6 months of storage

    Polyfunctional T cell responses in children in early stages of chronic Trypanosoma cruzi infection contrast with monofunctional responses of long-term infected adults

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    Background: Adults with chronic Trypanosoma cruzi exhibit a poorly functional T cell compartment, characterized by monofunctional (IFN-γ-only secreting) parasite-specific T cells and increased levels of terminally differentiated T cells. It is possible that persistent infection and/or sustained exposure to parasites antigens may lead to a progressive loss of function of the immune T cells. Methodology/Principal Findings: To test this hypothesis, the quality and magnitude of T. cruzi-specific T cell responses were evaluated in T. cruzi-infected children and compared with long-term T. cruzi-infected adults with no evidence of heart failure. The phenotype of CD4+ T cells was also assessed in T. cruzi-infected children and uninfected controls. Simultaneous secretion of IFN-γ and IL-2 measured by ELISPOT assays in response to T. cruzi antigens was prevalent among T. cruzi-infected children. Flow cytometric analysis of co-expression profiles of CD4+ T cells with the ability to produce IFN-γ, TNF-α, or to express the co-stimulatory molecule CD154 in response to T. cruzi showed polyfunctional T cell responses in most T. cruzi-infected children. Monofunctional T cell responses and an absence of CD4+TNF-α+-secreting T cells were observed in T. cruzi-infected adults. A relatively high degree of activation and differentiation of CD4+ T cells was evident in T. cruzi-infected children. Conclusions/Significance: Our observations are compatible with our initial hypothesis that persistent T. cruzi infection promotes eventual exhaustion of immune system, which might contribute to disease progression in long-term infected subjects.Fil: Albareda, María Cecilia. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; ArgentinaFil: de Rissio, Ana María. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; ArgentinaFil: Tomas, Gonzalo. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; ArgentinaFil: Serjan, Alicia. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Juan A. Fernández"; ArgentinaFil: Alvarez, María Gabriela. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; ArgentinaFil: Viotti, Rodolfo Jorge. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; ArgentinaFil: Fichera, Laura Edith. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Esteva, Mónica Inés. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; ArgentinaFil: Potente, Daniel Fernando. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; ArgentinaFil: Armenti, Alejandro. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; ArgentinaFil: Tarleton, Rick L.. University of Georgia; Estados UnidosFil: Laucella, Susana Adriana. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    The Incremental Cooperative Design of Preventive Healthcare Networks

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    This document is the Accepted Manuscript version of the following article: Soheil Davari, 'The incremental cooperative design of preventive healthcare networks', Annals of Operations Research, first published online 27 June 2017. Under embargo. Embargo end date: 27 June 2018. The final publication is available at Springer via http://dx.doi.org/10.1007/s10479-017-2569-1.In the Preventive Healthcare Network Design Problem (PHNDP), one seeks to locate facilities in a way that the uptake of services is maximised given certain constraints such as congestion considerations. We introduce the incremental and cooperative version of the problem, IC-PHNDP for short, in which facilities are added incrementally to the network (one at a time), contributing to the service levels. We first develop a general non-linear model of this problem and then present a method to make it linear. As the problem is of a combinatorial nature, an efficient Variable Neighbourhood Search (VNS) algorithm is proposed to solve it. In order to gain insight into the problem, the computational studies were performed with randomly generated instances of different settings. Results clearly show that VNS performs well in solving IC-PHNDP with errors not more than 1.54%.Peer reviewe

    Biosynthesis of Salmonella enterica [NiFe]-hydrogenase-5 : probing the roles of system-specific accessory proteins

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    A subset of bacterial [NiFe]-hydrogenases have been shown to be capable of activating dihydrogen-catalysis under aerobic conditions; however, it remains relatively unclear how the assembly and activation of these enzymes is carried out in the presence of air. Acquiring this knowledge is important if a generic method for achieving production of O2-resistant [NiFe]-hydrogenases within heterologous hosts is to be developed. Salmonella enterica serovar Typhimurium synthesizes the [NiFe]-hydrogenase-5 (Hyd-5) enzyme under aerobic conditions. As well as structural genes, the Hyd-5 operon also contains several accessory genes that are predicted to be involved in different stages of biosynthesis of the enzyme. In this work, deletions in the hydF, hydG, and hydH genes have been constructed. The hydF gene encodes a protein related to Ralstonia eutropha HoxO, which is known to interact with the small subunit of a [NiFe]-hydrogenase. HydG is predicted to be a fusion of the R. eutropha HoxQ and HoxR proteins, both of which have been implicated in the biosynthesis of an O2-tolerant hydrogenase, and HydH is a homologue of R. eutropha HoxV, which is a scaffold for [NiFe] cofactor assembly. It is shown here that HydG and HydH play essential roles in Hyd-5 biosynthesis. Hyd-5 can be isolated and characterized from a ΔhydF strain, indicating that HydF may not play the same vital role as the orthologous HoxO. This study, therefore, emphasises differences that can be observed when comparing the function of hydrogenase maturases in different biological systems

    The rkpU gene of Sinorhizobium fredii HH103 is required for bacterial K-antigen polysaccharide production and for efficient nodulation with soybean but not with cowpea

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    In this work, the role of the rkpU and rkpJ genes in the production of the K-antigen polysaccharides (KPS) and in the symbiotic capacity of Sinorhizobium fredii HH103, a broad host-range rhizobial strain able to nodulate soybean and many other legumes, was studied. The rkpJ- and rkpU-encoded products are orthologous to Escherichia coli proteins involved in capsule export. S. fredii HH103 mutant derivatives were contructed in both genes. To our knowledge, this is the first time that the role of rkpU in KPS production has been studied in rhizobia. Both rkpJ and rkpU mutants were unable to produce KPS. The rkpU derivative also showed alterations in its lipopolysaccharide (LPS). Neither KPS production nor rkpJ and rkpU expression was affected by the presence of the flavonoid genistein. Soybean (Glycine max) plants inoculated with the S. fredii HH103 rkpU and rkpJ mutants showed reduced nodulation and clear symptoms of nitrogen starvation. However, neither the rkpJ nor the rkpU mutants were significantly impaired in their symbiotic interaction with cowpea (Vigna unguiculata). Thus, we demonstrate for the first time to our knowledge the involvement of the rkpU gene in rhizobial KPS production and also show that the symbiotic relevance of the S. fredii HH103 KPS depends on the specific bacterium–legume interaction

    A decision support system for elective surgery scheduling under uncertain durations

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    The operation room (OR) is one of the most expensive material resources in hospitals. Additionally, the demand for surgical service is increasing due to the aging population, while the number of surgical interventions performed is stagnated because of budget reasons. In this context, the importance of improving the efficiency of the surgical service is accentuated. The main objective of this work is to propose and to evaluate a Decision Support System (DSS) for helping medical staff in the automatic scheduling of elective patients, improving the efficiency of medical teams'' work. First, the scheduling criteria are fixed and then the scheduling problem of elective patients is approached by a mathematical programming model. A heuristic algorithm is proposed and included in the DSS. Moreover, other different features are implemented in a software tool with a friendly user interface, called CIPLAN. Considering realistic data, a simulation comparison of the scheduling obtained using the approach presented in this paper and other similar approaches in the bibliography is shown and analyzed. On the other hand, a case study considering real data provided by the Orthopedic Surgical Department (OSD) of the "Lozano Blesa" hospital in Zaragoza (HCU) is proposed. The simulation results show that the approach presented here obtains similar occupation rates and similar confidence levels of not exceeding the available time than approaches in the bibliography. However, from the point of view of respecting the order of the patients in the waiting list, the approach in this paper obtains scheduling much more ordered. In the case of the Orthopedic Surgical Department of the "Lozano Blesa" hospital in Zaragoza, the occupation rate may be increased by 2.83%, which represents a saving of 110, 000 euros per year. Moreover, medical doctors (who use this tool) consider CIPLAN as an intuitive, rapid and efficient software solution that can make easier the corresponding task

    The Effects of Doing More with Less in the Public Sector: Evidence from a Large-Scale Survey

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    Since the onset of the Great Recession, “doing more with less” has become a policy mantra. To do more with less, a range of governments have concurrently imposed wage cuts and greater work demands on public employees. This article assesses the impact of these changes on the job satisfaction and work motivation of public employees in 34 European countries. Congruent with previous studies linking income and working hours with job attitudes, the article finds a negative impact on both. There are no free austerity lunches: while public employees may work longer hours for lower pay, they are less satisfied and less motivated when doing so. One caveat applies: the effect on motivation—although not satisfaction—is mitigated when employees feel that their values are aligned with those of their organization. This puts a premium on public managers fostering value alignment, particularly when it is hardest to achieve: in times of cutbacks

    Primeros registros de la presencia de meso y microplásticos en el tracto digestivo de un importante pez comercial del Sistema del Estuario del Río de la Plata (Océano Atlántico Sudoccidental)

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    White croaker (Micropogonias furnieri) is the most important commercial fish of Río de la Plata Estuary System (RLPES), one of the most extensive on the Southwest Atlantic coast. This paper describes the occurrence, abundance, and type of plastic debris (PD) present on the digestive tracts of 65 white croakers in the RLPES. Eighty percent of analyzed individuals had ingested PD, 156 of which (FO = 83.9%) were thread-like plastics and 30 were fragments (FO = 16.1%). The average number of pieces per digestive tract was 2.83 ± 3.14. Microplastic represented 85% of PD, most of them were < 2 mm and the prominent color was blue. Our results demonstrate the high occurrence of meso and microplastics in one of the most important species from an ecological and commercial viewpoint in the RLPES. The RLPES is the area of the Southwest Atlantic Ocean that concentrates most of the records of plastic waste in the environment, where the white croaker is the main commercial fish. In addition, M. furnieri is a main prey for several predators in the area. Although preliminary, this is a relevant contribution to the knowledge of marine debris pollution and its impact on the marine community of the region.La corvina rubia (Micropogonias furnieri) es el pez comercial más importante del Sistema del Estuario del Río de la Plata (RLPES), uno de los más extensos en la costa atlántica sudoccidental. En este trabajo se describe la ocurrencia, abundancia y tipo de desechos plásticos (DP) presentes en el tracto digestivo de 65 ejemplares de corvina rubia del RLPES. El 80% de los individuos analizados había ingerido DP, de los cuales 156 eran plásticos filiformes (FO = 83,9%) y 30 eran fragmentos (FO = 16,1%). El número medio de piezas por tracto digestivo fue de 2,83 ± 3,14. El microplástico representó el 85% de los DP, la mayoría de las cuales eran < 2 mm y el color predominante fue el azul. Nuestros resultados demuestran la alta ocurrencia de meso y microplásticos en una de las especies más importantes desde el punto de vista ecológico y comercial en el RLPES. El RLPES es el área del Océano Atlántico Sudoccidental que concentra la mayor parte de los registros de desechos plásticos en el medio ambiente, donde la corvina rubia es el principal pez comercial. Además, M. furnieri constituye una presa principal de varios depredadores de la zona. Aunque preliminar, esta es una contribución relevante al conocimiento de la contaminación por desechos marinos y su impacto en los organismos del Océano Atlántico Sudoccidental, particularmente en el RLPES

    Bandwagons and Quiet Corners in Regulatory Governance: On regulation-specific and institutional drivers of stakeholder engagement

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    Stakeholder engagement is often considered an essential component of regulatory policymaking and governance. Our main aim in this paper is to explain variation in stakeholder engagement across regulatory trajectories. More specifically we aim to assess why some regulatory policymaking processes attract a larger and more diverse set of stakeholders, while others attract much smaller and more homogenous regulatory crowds. We build on a newly established dataset of primary data regarding stakeholder engagement in EU regulatory governance to test our assumptions. We find that both the salience and the number of different consultation instruments affect the density and diversity of stakeholder engagement, whereas the complexity of regulations seems to mainly affect the density of stakeholder engagement. The combination of both institutional and regulation-specific drivers of stakeholder engagement in regulatory governance yields relevant implications for the study of responsive regulation and the role stakeholders can fulfill in regulatory decision-making. NWO452–14-012The politics and administration of institutional chang
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