Search results for "Arctic"
showing 10 items of 565 documents
Arginase activity in the blood of patients with visceral leishmaniasis and HIV infection.
2013
Background Visceral leishmaniasis is a parasitic disease associated with high mortality. The most important foci of visceral leishmaniasis in Ethiopia are in the Northwest and are predominantly associated with high rates of HIV co-infection. Co-infection of visceral leishmaniasis patients with HIV results in higher mortality, treatment failure and relapse. We have previously shown that arginase, an enzyme associated with immunosuppression, was increased in patients with visceral leishmaniasis and in HIV seropositive patients; further our results showed that high arginase activity is a marker of disease severity. Here, we tested the hypothesis that increased arginase activities associated wi…
Altered Protein Expression in the Ileum of Mice Associated with the Development of Chronic Infections with Echinostoma caproni (Trematoda)
2015
Background Echinostoma caproni (Trematoda: Echinostomatidae) is an intestinal trematode that has been extensively used as experimental model to investigate the factors determining the expulsion of intestinal helminths or, in contrast, the development of chronic infections. Herein, we analyze the changes in protein expression induced by E. caproni infection in ICR mice, a host of high compatibility in which the parasites develop chronic infections. Methodology/Principal Findings To determine the changes in protein expression, a two-dimensional DIGE approach using protein extracts from the intestine of naïve and infected mice was employed; and spots showing significant differential expression…
Fascioliasis and Intestinal Parasitoses Affecting Schoolchildren in Atlixco, Puebla State, Mexico: Epidemiology and Treatment with Nitazoxanide
2013
Background The Atlixco municipality, Puebla State, at a mean altitude of 1840 m, was selected for a study of Fasciola hepatica infection in schoolchildren in Mexico. This area presents permanent water collections continuously receiving thaw water from Popocatepetl volcano (5426 m altitude) through the community supply channels, conforming an epidemiological scenario similar to those known in hyperendemic areas of Andean countries. Methodology and Findings A total of 865 6–14 year-old schoolchildren were analyzed with FasciDIG coproantigen test and Lumbreras rapid sedimentation technique, and quantitatively assessed with Kato-Katz. Fascioliasis prevalences ranged 2.94–13.33% according to loc…
The story of endurance:Biogeography and the evolutionary history of four Holarctic butterflies with different habitat requirements
2021
Aim: Biogeographical studies on the entire ranges of widely distributed species can change our perception of species’ range dynamics. We studied the effects of Pleistocene glacial cycles on current butterfly species distributions, aiming to uncover complex biogeographic patterns in the Holarctic, a region dramatically affected by Cenozoic climate change. Location: Eurasia and North America. Taxon: Boloria chariclea, Agriades optilete, Carterocephalus palaemon, Oeneis jutta. Methods: We reconstructed the biogeographic history of four butterfly species differing in habitat preferences (B. chariclea – tundra, A. optilete – bogs, C. palaemon – temperate grasslands, O. jutta – taiga), using one …
Marine biodiversity in space and time : what tiny fossils tell
2018
Biodiversity has been changing both in space and time. For example, we have more species in the tropics and less species in the Arctic and Antarctic regions, constituting latitudinal diversity gradient, one of the patterns we can see most consistently in this complex world. We know much less regarding the biodiversity gradients with time. This is because it would require a well designed continuous monitoring program, which seldom persist beyond a few decades. But, luckily, we have remains of ancient organisms, called fossils. These are basically the only direct records of past biodiversity.
Phylogeography and demographic inference in Nacella (Patinigera) concinna (Strebel, 1908) in the western Antarctic Peninsula
2011
10 pages; International audience; Endemic to Antarctic ecosystems, the limpet Nacella (Patinigera) concinna (Strebel, 1908) is an abundant and dominant marine benthic invertebrate of the intertidal and shallow subtidal zone. In order to examine the phylogeographic pattern and historical demography of the species along the western Antarctic Peninsula, we amplified 663 bp of the mitochondrial DNA cytochrome oxidase subunit I of 161 N. concinna specimens from five localities, as well as two specimens from South Georgia and Sub-Antarctic Marion Island. As two different morphotypes, one characterized by an elevated shell in the intertidal and the other by a flat one in the subtidal, have been re…
Oxygen isotopes from limpet shells: Implications for palaeothermometry and seasonal shellfish foraging studies in the Mediterranean
2017
Limpet shells are common components of many archaeological sites in the Mediterranean. To test whether δ18O values from archaeological Patella caerulea shells can serve as a reliable palaeothermometer for the Mediterranean and a reliable archive of season of collection information, we collected live P. caerulea from eight Mediterranean locations in Croatia, Israel, Libya, Malta, Tunisia, and Turkey. Shell growth patterns were studied in section, and samples for oxygen isotope analysis were milled from the shells and used to calculate sea surface temperature (SST). As with other species of limpet, SST reconstructed from P. caerulea δ18O values were lower than expected from observational reco…
Where is the line? Phylogeography and secondary contact of western Palearctic coal tits (Periparus ater: Aves, Passeriformes, Paridae)
2013
In this study, a phylogeographic scenario of the coal tit (Periparus ater) was reconstructed based on a fragment of the mitochondrial control region, and within- and between-population genetic diversity was analysed with a focus on the western Palearctic breeding range. We inferred a first pan-European delimitation of a postulated secondary contact zone among coal tits from the north-eastern Palearctic ater subspecies group and those from the south-western Palearctic abietum group. Generally, between-population differentiation was greatest in the Mediterranean range, which was explained by a greater separation in multiple Pleistocene refuge areas compared to the lower differentiation across…
Identification of Morphological Biosignatures in Martian Analogue Field Specimens Using In Situ Planetary Instrumentation
2008
International audience; We have investigated how morphological biosignatures (i.e., features related to life) might be identified with an array of viable instruments within the framework of robotic planetary surface operations at Mars. This is the first time such an integrated lab-based study has been conducted that incorporates space-qualified instrumentation designed for combined in situ imaging, analysis, and geotechnics ( sampling). Specimens were selected on the basis of feature morphology, scale, and analogy to Mars rocks. Two types of morphological criteria were considered: potential signatures of extinct life ( fossilized microbial filaments) and of extant life (crypto-chasmoendolit…
A potential snail host of schistosomiasis in Bolivia: Biomphalaria amazonica paraense, 1966
2002
Biomphalaria amazonica Paraense, 1996 was collected from a permanent pond in the outskirts of the Bolivian city of Santa Cruz. Identification of the collected specimens was made by comparison with the original description of the species and with topotypic material in the collection of Instituto Oswaldo Cruz. Phylogenetic analysis confirmed that these Bolivian specimens belong to B. amazonica.