A possible role for Phlebotomus (Anaphlebotomus) rodhaini (Parrot, 1930) in transmission of Leishmania donovani

<p>Abstract</p> <p>Background</p> <p>Visceral leishmaniasis (VL, kala azar), caused by <it>Leishmania donovani </it>is a major health problem in Sudan and other East African countries. In this region the only proven vectors of <it>L. donovani </it>are <it>Phlebotomus orientalis </it>in eastern Sudan, Ethiopia and Upper Nile areas of Southern Sudan and <it>Phlebotomus martini </it>in Ethiopia, Kenya and Southern Sudan. In this report, we present the first evidence that <it>Phlebotomus rodhaini </it>may also play a role in maintaining transmission of <it>L. donovani </it>between animal reservoir hosts in eastern Sudan. The study was conducted in a zoonotic focus of visceral leishmaniasis in Dinder National Park, eastern Sudan, where previous work showed high infection rates of <it>L. donovani </it>in <it>P. orientalis</it>. Sand flies, captured by CDC traps were dissected and examined for infection with <it>Leishmania </it>parasites. Parasite isolates were subjected to <it>L. donovani </it>specific PCR. Field experiments were also carried out to compare efficiency of rodent baited and un-baited CDC traps in collection of <it>P. rodhaini </it>and determine its man-biting rate.</p> <p>Results</p> <p>Three female <it>P. rodhain</it>i were found infected with <it>Leishmania </it>parasites in an astonishingly small number of flies captured in three separate field trips. Two of these isolates were typed by molecular methods as <it>L. donovani</it>, while the third isolate was inoculated into a hamster that was subsequently lost. Although <it>P. rodhaini is </it>generally considered a rare species, results obtained in this study indicate that it can readily be captured by rodent-baited traps. Results of human landing collection showed that it rarely bites humans in the area.</p> <p>Conclusion</p> <p>It is concluded that <it>P. rodhaini </it>is a possible vector of <it>L. donovani </it>between animal reservoir hosts but is not responsible for infecting humans. It is suggested that the role of <it>P</it>. <it>rodhaini </it>in transmission of <it>L. donovani </it>in other zoonotic foci of visceral leishmaniasis in Africa should be re-examined.</p

Late tonian within-plate mafic magmatism and ediacaran partial melting and magmatism in the Costeiro domain, Central Ribeira belt, Brazil

The tectonic evolution of the Ribeira Belt comprises a protracted history involving several magmatic, deformational and metamorphic events mainly associated with the Neoproterozoic Brasiliano Orogenic Cycle. Most tectonic models relate the evolution of the Ribeira Belt to a protracted orogenic history with diachronous accretion of different terranes against larger cratonic blocks. However, recent proposals challenge models of multistage terrane accretions. In this paper we revisit the current tectonic models proposed for the Central Ribeira Belt, based essentially on a large data compilation and new geochemical and geochronological data from samples of the Costeiro Complex. The critical evaluation of these data indicates a long-lasting shared evolution for two geological domains in the Central Ribeira Belt (Embu and Costeiro Domains), usually thought to be different terranes accreted during the late Ediacaran. The first report of late Tonian within-plate tholeiitic to alkaline mafic magmatism and the late Cryogenian-early Ediacaran metamorphism in the Costeiro Complex support the interpretation of shared evolution on both Embu and Costeiro Domains, challenging the current models of diachronous accretion of terranes during the late Ediacaran in the Central Ribeira Belt334CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPnão temnão tem2012/15462-7; 2016/06114-

Formation of high-Al komatiites from the Mesoarchean Quebra Osso Group, Minas Gerais, Brazil: Trace elements, HSE systematics and Os isotopic signatures

We report highly siderophile element data combined with Re-Os isotopes and major and trace elements of the ca. 2.7-3.0 Ga komatiites from the Quebra Osso Group, Minas Gerais, Brazil. These komatiites resemble the rare high Al-type, characterized by high Al2O3/TiO2 ratios (26.7-59.8). These geochemical similarities are shared with the 3.33 Ga Commondale and 3.26 Ga Weltevreden komatiites from the eastern Kaapvaal Craton pointing to a similar origin of these suites. While anhydrous melting in an unusually hot mantle was inferred for the Weltevreden komatiites, the Commondale komatiites were suggested to have formed by hydrous, multi-stage melting. Significant depletion in LREE is coupled with subchondritic Re/Os, unradiogenic to radiogenic Os-187/Os-188 and fractionated HSE, with enrichments in Ru, Pt, and Pd over Os and Ir. The combination of these signatures suggests minor late-stage crustal influence. Potential late-stage alteration overprint, assimilation of ambient mantle material during magma ascent and complex phase relationships of HSE-hosting phases make it difficult to estimate the composition of the source of the Quebra Osso komatiites and to place constraints on the nature of the late Archean mantle. However, the Quebra Osso komatiites are unlikely to have formed in a single-stage plume setting or in a supra-subduction zone setting. Instead we suggest a multi-stage melting history of the komatiite source to explain the origin of their peculiar geochemical characteristics, as has been suggested for other high-Al2O3/TiO2 komatiite suites. (C) 2015 Elsevier B.V. All rights reserved

Assessment of loose and adhered urban street sediments and trace metals: a study in the city of Po double dagger os de Caldas, Brazil

This study aims to quantify and characterise sediments accumulated in the street gutters in an urban area of Po double dagger os de Caldas, Brazil. The main research questions are: What type of urban areas, e.g. those under construction, produce most sediments and what are the main characteristics of such sediments? What differences, e.g. granulometry, can be found in loose and adhered sediments? What trace metals can be found in the sediments?Fieldwork was carried out in a residential area of Po double dagger os de Caldas, Brazil. Ten samplings were conducted between May and August 2013 to collect sediments from road gutters. The collected sediments were then divided into 'loose' and 'adhered', depending on whether they were collected in a first, gentle, sweeping with soft bristled brush or in a subsequent sweeping with a stiff bristled brush. Granulometric curves were drawn for both types of sediments. Fine sediment analyses (aecurrency sign63 mu m) were performed on samples from the last five samplings. Two techniques were used to look for trace elements: energy dispersive X-ray fluorescence (EDXRF) and inductively coupled plasma-atomic emission spectrometry (ICP-AES).Larger amounts of sediments were collected after lower intensity rainfall events. Higher intensity events seemed to wash the sediments away. A correlation was found between areas under construction and sediment mass production. A characteristic range of granulometries (medium sand), found in our study is in accordance with studies by other authors. An important presence of heavy metals (Cr, Cd, Pb, Zn, Ni and Cu) was detected and characterised. As and Sn were also detected even though they are not often mentioned in the literature on urban soil pollutants.Areas under construction were found to produce more sediments than other areas. The trace metals found in highest concentrations were Pb and As. The heavy metal concentration decreases after wet periods, showing that they are carried by runoff. It is expected that this study may serve as an input for establishing diffuse pollution control and mitigation strategies for the accumulation of pollutants in the urban environment