9 research outputs found

    A Triatoma maculata (Hemiptera, Reduviidae, Triatominae) population from Roraima, Amazon region, Brazil, has some bionomic characteristics of a potential Chagas disease vector Uma população de Triatoma maculata (Hemiptera, Reduviidae, Triatominae) proveniente de Roraima, AmazÎnia, Brasil, possui algumas características bionÎmicas de vetor potencial de doença de Chagas

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    Even though Chagas disease is rare in the Brazilian Amazon, the conditions for the establishment of domiciliated cycles prevail in many areas where triatomines are of frequent occurrence. In Roraima, a previous serological and entomological survey in three agricultural settlements showed the existence of all transmission cycle elements, i.e., individuals infected by Trypanosoma cruzi, triatomine species previously found harboring T. cruzi in the broader Amazon region of neighboring countries and, domicile/ peridomicile conditions favorable to triatomine colonization. Triatoma maculata was the most frequent species, found in chicken houses in the peridomicile and sporadically within residences. Aiming to investigate the possibility of T. maculata to possess the potentiality to transmit T. cruzi in the area, bionomic characteristics were studied under laboratory conditions. These were feeding frequency, time for defecation after a blood meal, time elapsed in voluntary fasting pre- and pos-ecdysis, moulting time periods, pre-oviposition and oviposition periods and index of oviposition, incubation period, egg viability, longevity and mortality rate. Results show that the PassarĂŁo population of T. maculata should be considered a potential vector of T. cruzi since it shows a capacity to infest artificial ecotopes in the peridomicile, to carry out large number of meals during the nymphal cycle, to have a relatively short developmental cycle capable of producing 2.9 generations/year, to blood source eclecticism, to defecate immediately after the blood meal while still on the host and to the fact that has been previously found naturally infected by T.cruzi.<br>A doença de Chagas Ă© de rara ocorrĂȘncia na RegiĂŁo AmazĂŽnica Brasileira, onde contudo as condiçÔes para o estabelecimento de ciclos domĂ©sticos existem. Um estudo previamente realizado em ĂĄreas de colonização agrĂ­cola no Estado de Roraima, mostrou a possibilidade de ciclos autĂłctones de transmissĂŁo virem a ocorrer uma vez que todos os elementos estavam lĂĄ presentes, indivĂ­duos infectados por Trypanosoma cruzi, espĂ©cies de triatomĂ­neos anteriormente descritas como infectadas por T. cruzi na RegiĂŁo AmazĂŽnica de paĂ­ses fronteiriços e, ambientes domiciliares e peri-domiciliares favorĂĄveis Ă  colonização de triatomĂ­neos. Triatoma maculata foi a espĂ©cie mais frequentemente encontrada, tendo sido coletada em galinheiros no peridomicĂ­lio e esporadicamente nos domicĂ­lios. Visando investigar a potencialidade de T. maculata como espĂ©cie vetora na ĂĄrea, algumas caracterĂ­sticas bionĂŽmicas foram estudadas em condiçÔes de laboratĂłrio incluindo freqĂŒĂȘncia de alimentação, tempo de defecação pĂłs-prandial, tempo de jejum voluntĂĄrio na prĂ©- e na pĂłs-ecdise, perĂ­odo inter-mudas, perĂ­odos de prĂ©-oviposição e de oviposição, Ă­ndice de oviposição, perĂ­odo de incubação, viabilidade dos ovos, Ă­ndices de longevidade e de mortalidade. Os resultados mostraram que a população de T. maculata da ColĂŽnia AgrĂ­cola do PassarĂŁo deve ser considerada vetora em potencial do T. cruzi uma vez que mostrou capacidade de infestar ecĂłtopos artificiais no peridomicĂ­lio, de se alimentar com freqĂŒĂȘncia durante o perĂ­odo ninfal, de possuir um ciclo de desenvolvimento relativamente curto com 2,9 geraçÔes/ano, de possuir hĂĄbitos eclĂ©ticos de alimentação, de defecar imediatamente apĂłs a hematofagia quando ainda no hospedeiro e devido ao fato de ter sido previamente encontrada infectada por T. cruzi

    Critical Factors Underpinning the e-CRM Activities of SMEs

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    Small and medium-sized enterprises (SMEs) are vital components of our economies, but many struggle to perform the marketing prescribed theoretically for large organisations. In practice, marketing is performed in SMEs through an intrinsic customer orientation, which exhibits striking resemblances to customer relationship management (CRM) theory. A quantitative approach was adopted to provide broad understanding and classification to the under-researched area of e-CRM in SMEs. Exploratory factor analysis uncovered eight distinct yet inter-related factors underpinning the practices and processes of e-CRM in SMEs. Findings show that SMEs are performing e-CRM to varying extents, reaping a range of performance benefits and facing a range of challenges. It is true that SMEs are not adopting e-CRM per se, as described in the large organisation-biased literature, but they are adopting relatively simple IBTs to improve their customer communication and information management capabilities and thus to create competitive advantage in their own strategic way. From a theoretical perspective, this study has shed significant light on what is driving SMEs’ e-CRM activities, thus providing long-awaited theoretical support for a practical reality. From a managerial perspective, the study has delineated eight principal issues that require attention if e-CRM is to be implemented successfully in SME

    Guidelines for the use and interpretation of assays for monitoring autophagy

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    Guidelines for the use and interpretation of assays for monitoring autophagy

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    In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

    Guidelines for the use and interpretation of assays for monitoring autophagy

    No full text

    Guidelines for the use and interpretation of assays for monitoring autophagy

    Get PDF
    In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

    Impact of cross-section uncertainties on supernova neutrino spectral parameter fitting in the Deep Underground Neutrino Experiment

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    International audienceA primary goal of the upcoming Deep Underground Neutrino Experiment (DUNE) is to measure the O(10)  MeV neutrinos produced by a Galactic core-collapse supernova if one should occur during the lifetime of the experiment. The liquid-argon-based detectors planned for DUNE are expected to be uniquely sensitive to the Îœe component of the supernova flux, enabling a wide variety of physics and astrophysics measurements. A key requirement for a correct interpretation of these measurements is a good understanding of the energy-dependent total cross section σ(EÎœ) for charged-current Îœe absorption on argon. In the context of a simulated extraction of supernova Îœe spectral parameters from a toy analysis, we investigate the impact of σ(EÎœ) modeling uncertainties on DUNE’s supernova neutrino physics sensitivity for the first time. We find that the currently large theoretical uncertainties on σ(EÎœ) must be substantially reduced before the Îœe flux parameters can be extracted reliably; in the absence of external constraints, a measurement of the integrated neutrino luminosity with less than 10% bias with DUNE requires σ(EÎœ) to be known to about 5%. The neutrino spectral shape parameters can be known to better than 10% for a 20% uncertainty on the cross-section scale, although they will be sensitive to uncertainties on the shape of σ(EÎœ). A direct measurement of low-energy Îœe-argon scattering would be invaluable for improving the theoretical precision to the needed level
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