The peri-urban interface and house infestation with Triatoma infestans in the Argentine Chaco: an underreported process?

Peri-urban infestations with triatomine bugs, their sources and their dynamics have rarely been investigated. Here, we corroborated the reported occurrence of Triatoma infestans in a peri-urban area and in neighbouring rural houses in Pampa del Indio, in the Argentine Chaco, and identified its putative sources using spatial analysis and demographic questionnaires. Peri-urban householders reported that 10% of their premises had triatomines, whereas T. infestans was collected by timed manual searches or community-based surveillance in only nine (3%) houses. Trypanosoma cruzi-infected T. infestans and Triatoma sordida were collected indoors only in peri-urban houses and were infected with TcV and TcI, respectively. The triatomines fed on chickens, cats and humans. Peri-urban infestations were most frequent in a squatter settlement and particularly within the recently built mud houses of rural immigrants, with large-sized households, more dogs and cats and more crowding. Several of the observed infestations were most likely associated with passive bug transport from other sources and with active bug dispersal from neighbouring foci. Thus, the households in the squatter settlement were at a greater risk of bug invasion and colonisation. In sum, the incipient process of domestic colonisation and transmission, along with persistent rural-to-urban migratory flows and unplanned urbanisation, indicate the need for active vector surveillance and control actions at the peri-urban interface of the Gran Chaco.

Physiologie du rentier de Paris et de province / par MM. de Balzac et Arnould Frémy ; dessins par Gavarni, Henri Monnier, Daumier et Meissonier

Référence bibliographique : Lhéritier, 52

Positive deviance study to inform a Chagas disease control program in southern Ecuador

Chagas disease is caused by Trypanosoma cruzi, which is mainly transmitted by the faeces of triatomine insects that find favourable environments in poorly constructed houses. Previous studies have documented persistent triatomine infestation in houses in the province of Loja in southern Ecuador despite repeated insecticide and educational interventions. We aim to develop a sustainable strategy for the interruption of Chagas disease transmission by promoting living environments that are designed to prevent colonisation of rural houses by triatomines. This study used positive deviance to inform the design of an anti-triatomine prototype house by identifying knowledge, attitudes and practices used by families that have remained triatomine-free (2010-2012). Positive deviants reported practices that included maintenance of structural elements of the house, fumigation of dwellings and animal shelters, sweeping with "insect repellent" plants and relocation of domestic animals away from the house, among others. Participants favoured construction materials that do not drastically differ from those currently used (adobe walls and tile roofs). They also expressed their belief in a clear connection between a clean house and health. The family's economic dynamics affect space use and must be considered in the prototype's design. Overall, the results indicate a positive climate for the introduction of housing improvements as a protective measure against Chagas disease in this region.

Spread of Phlebotominae in temperate climates: province of Córdoba, Argentina

We report the presence of the competent vector for Leishmaniaspp, Migonemyia migonei, and theEvandromyia cortelezzii-sallesi complex south of its known distribution in the central temperate region of Argentina, in the province of Córdoba. The persistence of this phlebotomine in the northern border of the province, its association with a case of cutaneous leishmaniasis, and the new record in the outskirts of the city of Córdoba, the second most populated in the country, strengthens the need for regular vector surveillance and a case detection-sensitive health system in vulnerable regions, even in temperate climates.

An in-house real-time polymerase chain reaction: standardisation and comparison with the Cobas Amplicor HBV monitor and Cobas AmpliPrep/Cobas TaqMan HBV tests for the quantification of hepatitis B virus DNA

This study aimed to standardise an in-house real-time polymerase chain reaction (rtPCR) to allow quantification of hepatitis B virus (HBV) DNA in serum or plasma samples, and to compare this method with two commercial assays, the Cobas Amplicor HBV monitor and the Cobas AmpliPrep/Cobas TaqMan HBV test. Samples from 397 patients from the state of São Paulo were analysed by all three methods. Fifty-two samples were from patients who were human immunodeficiency virus and hepatitis C virus positive, but HBV negative. Genotypes were characterised, and the viral load was measure in each sample. The in-house rtPCR showed an excellent success rate compared with commercial tests; inter-assay and intra-assay coefficients correlated with commercial tests (r = 0.96 and r = 0.913, p < 0.001) and the in-house test showed no genotype-dependent differences in detection and quantification rates. The in-house assay tested in this study could be used for screening and quantifying HBV DNA in order to monitor patients during therapy.

Buscador de vehicles in House

Aplicació creada per ser utilitzada en una empresa d'automoció per a la localització de vehicles dins de la factoria.

From MuSIASEM theory to practice: report and reflections from field research in Kampot province, Cambodia

This document contains a report and summary of the field research activities in a rural community of rice farmers in Kampot province, Cambodia in 2011, which I conducted within the context of my PhD research at ICTA-UAB (Institute of Environmental Science and Technology, Autonomous University of Barcelona, Spain). The purpose of the field research was to gather data for a MuSIASEM analysis (Multi-Scale Integrated Analysis of Societal and Ecosystem Metabolism) at the village and household level, in order to analyze the multidimensional challenges that small farmers may face nowadays within the context of global rural change and declining access to land. While the literature on MuSIASEM offers a great variety of theoretical explanations and practical applications, there is little information available for students regarding the practical steps required for doing a MuSIASEM analysis at the local level. Within this context, this report offers not only a documentation of the field research design and data collection methods, but further provides a general overview on some organizational and preparative aspects, including some personal reflections, that one may face when preparing and conducting field research for MuSIASEM analysis. In summary, this document thus serves three objectives: (i) to assure methodological transparency for the future work, based on the collected data during field research, (ii) to share my personal experience on the preparative and practical steps required for field research and data collection for a MuSIASEM analysis at the local level, and (iii) to make available for the further interested reader some more detailed background information on the case study village.

Late Labradorian metamorphism and anorthosite-granitoid intrusion, Cape-Caribou River allochthon, Grenville Province, Labrador - Evidence from U-Pb geochronology

In the Cape Caribou River allochthon (CCRA), metaigneous and gneissic units occur as a shallowly plunging synform in the hanging wall of the Grand Lake thrust system (GLTS), a Grenvillian structure that forms the boundary between the Mealy Mountains and Groswater Bay terranes. The layered rocks of the CCRA are cut by a stockwork of monzonite dykes related to the Dome Mountain suite and by metadiabase-amphibolite dykes that probably form part of the ca. 1380 Ma Mealy swarm. The mafic dykes appear to postdate much of the development of subhorizontal metamorphic layering within the lower parts of the CCRA. The uppermost (least metamorphosed) units of the CCRA, the North West River anorthosite-metagabbro and the Dome Mountain monzonite suite, have been dated at 1625 +/- 6 and 1626 +/- 2 Ma, respectively. An amphibolite unit that concordantly underlies the anorthosite-metagabbro and is intruded discordantly by monzonite dykes has given metamorphic ages of 1660 +/- 3 and 1631 +/- 2 Ma. Granitoid gneisses that form the lowest level of the CCRA have given a migmatization age of 1622 +/- 6 Ma. The effects of Grenvillian metamorphism become apparent in the lower levels of the allochthon where gneisses, amphibolite, and mafic dykes have given new generation zircon ages of 1008 +/- 2, 1012 +/- 3, and 1011 +/- 3 Ma, respectively. A posttectonic pegmatite has also given zircon and monazite ages of 1016(-3)(+7) and 1013 +/- 3 Ma, respectively. Although these results indicate new growth of Grenvillian zircon, this process was generally not accompanied by penetrative deformation or melting. Thus, the formation of gneissic fabrics and the overall layered nature of the lower CCRA are a result primarily of Labradorian (1660-1620 Ma) tectonism and intrusion, and probably reflect early movement on an ancestral GLTS. Grenvillian heating and metamorphism (up to granulite facies) was strongly concentrated towards the base of the CCRA and probably occurred during northwestward thrusting of the allochthon over the Groswater Bay terrane.

Oxygen isotope compositions of iron oxides from high-grade BIF-hosted iron ore deposits of the Central Hamersley Province, Western Australia: Constraints on the evolution of hydrothermal fluids

The Hamersley province of northwest Australia is one of the world's premier iron ore regions with high-grade martite-microplaty hematite iron ore deposits mostly hosted within banded iron formation (BIF) sequences of the Brockman Iron Formations of the Hamersley Group. These high-grade iron ores contain between 60 and 68 wt percent Fe, and formed by the multistage interaction of hydrothermal fluids with the host BIF formation. The oxygen isotope compositions of magnetite and hematite from BIF, hydrothermal alteration assemblages, and high-grade iron Ore were analyzed from the Mount Tom Price, Paraburdoo, and Charmar iron ore deposits. The delta(18)O values of magnetite and hematite from hydrothermal alteration assemblages and high-grade iron ore range from -9.0 to -2.9 per mil, a depletion of 5 to 15 per mil relative to the host BIF. The delta(18)O values are spatially controlled by faults within the deposits, a response to higher fluid flux and larger influence the isotopic compositions by the hydrothermal fluids. The oxygen isotope composition of hydrothermal fluids (delta(18)O(fluid)) indicates that the decrease in the (18)O content of iron oxides was due to the interaction of both basinal brines and meteoric fluids with the original BIF. Late-stage talc-bearing ore at the Mount Tom Price deposit formed in the presence of a pulse of delta(18)O-enriched basinal brine, indicating that hydrothermal fluids may have repeatedly interacted with the BIFs during the Paleoproterozoic.

Use of an in-house approach to study the three-dimensional structures of various outer membrane proteins: structure of the alcaligin outer membrane transporter FauA from Bordetella pertussis.

Bordetella pertussis is the bacterial agent of whooping cough in humans. Under iron-limiting conditions, it produces the siderophore alcaligin. Released to the extracellular environment, alcaligin chelates iron, which is then taken up as a ferric alcaligin complex via the FauA outer membrane transporter. FauA belongs to a family of TonB-dependent outer membrane transporters that function using energy derived from the proton motive force. Using an in-house protocol for membrane-protein expression, purification and crystallization, FauA was crystallized in its apo form together with three other TonB-dependent transporters from different organisms. Here, the protocol used to study FauA is described and its three-dimensional structure determined at 2.3 A resolution is discussed.