1,341 research outputs found

    Isolation of a Wickerhamomyces anomalus yeast strain from the sandfly Phlebotomus perniciosus, displaying the killer phenotype

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    The yeast Wickerhamomyces anomalus has been studied for its wide biotechnological potential, mainly for applications in the food industry. Different strains of W. anomalus have been isolated from diverse habitats and recently from insects, including mosquitoes of medical importance. This paper reports the isolation and phylogenetic characterization of W. anomalus from laboratory-reared adults and larvae of Phlebotomus perniciosus (Diptera: Psychodidae), a main phlebotomine vector of human and canine leishmaniasis. Of 65 yeast strains isolated from P. perniciosus, 15 strains were identified as W. anomalus; one of these was tested for the killer phenotype and demonstrated inhibitory activity against four yeast sensitive strains, as reported for mosquito-isolated strains. The association between P. perniciosus and W. anomalus deserves further investigation in order to explore the possibility that this yeast may exert inhibitory/killing activity against Leishmania spp

    SOT-MRAM 300mm integration for low power and ultrafast embedded memories

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    We demonstrate for the first time full-scale integration of top-pinned perpendicular MTJ on 300 mm wafer using CMOS-compatible processes for spin-orbit torque (SOT)-MRAM architectures. We show that 62 nm devices with a W-based SOT underlayer have very large endurance (> 5x10^10), sub-ns switching time of 210 ps, and operate with power as low as 300 pJ.Comment: presented at VLSI2018 session C8-

    Midgut microbiota of the malaria mosquito vector Anopheles gambiae and Interactions with plasmodium falciparum Infection

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    The susceptibility of Anopheles mosquitoes to Plasmodium infections relies on complex interactions between the insect vector and the malaria parasite. A number of studies have shown that the mosquito innate immune responses play an important role in controlling the malaria infection and that the strength of parasite clearance is under genetic control, but little is known about the influence of environmental factors on the transmission success. We present here evidence that the composition of the vector gut microbiota is one of the major components that determine the outcome of mosquito infections. A. gambiae mosquitoes collected in natural breeding sites from Cameroon were experimentally challenged with a wild P. falciparum isolate, and their gut bacterial content was submitted for pyrosequencing analysis. The meta-taxogenomic approach revealed a broader richness of the midgut bacterial flora than previously described. Unexpectedly, the majority of bacterial species were found in only a small proportion of mosquitoes, and only 20 genera were shared by 80% of individuals. We show that observed differences in gut bacterial flora of adult mosquitoes is a result of breeding in distinct sites, suggesting that the native aquatic source where larvae were grown determines the composition of the midgut microbiota. Importantly, the abundance of Enterobacteriaceae in the mosquito midgut correlates significantly with the Plasmodium infection status. This striking relationship highlights the role of natural gut environment in parasite transmission. Deciphering microbe-pathogen interactions offers new perspectives to control disease transmission.Institut de Recherche pour le Developpement (IRD); French Agence Nationale pour la Recherche [ANR-11-BSV7-009-01]; European Community [242095, 223601]info:eu-repo/semantics/publishedVersio

    Pre-packed alkali activated cement-free mortars for repair of existing masonry buildings and concrete structures

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    This paper is aimed to study a ground granulated blast furnace slag activated with alkali powder to manufacture Portland-free mortars for conservation, restoration and retrofitting of existing masonry buildings and concrete structures. Activator/precursor represents the key parameter – not only for elasto-mechanical performances – influencing the rheological properties and the shrinkage: the higher the activator dosage, the higher the consistency class and shrinkage. Moreover, elastic modulus of slag-based mortars is lower than that of OPC-mortars at the same strength class. AAMs seem to be more promising for a sustainable future in construction since the GER and GWP are reduced by about 80% compared with traditional Portland cement mortars with the same compressive strength

    Use of tartaric acid for the production of sustainable Portland-free CSA-based mortars

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    The purpose of the study is to evaluate the effect of a tartaric acid-based set retarding admixture on rheological, elastic and physical performances of sustainable mortars manufactured with calcium sulfoaluminate, anhydrite and Supplementary Cementitious Materials replacing totally OPC. Experimental results indicated that the tartaric acid acts as superplasticizer and it is effective to extend the pot-life of mortars up to about 2 h. On the other hand, the set-retarding admixture provides a strong retardation of binder hydration resulting in a reduction of initial expansion and compressive strength at early ages. However, this retarding effect disappears at long ages

    MicroRNAs in cardiac arrhythmia: DNA sequence variation of MiR-1 and MiR-133A in long QT syndrome.

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    Long QT syndrome (LQTS) is a genetic cardiac condition associated with prolonged ventricular repolarization, primarily a result of perturbations in cardiac ion channels, which predisposes individuals to life-threatening arrhythmias. Using DNA screening and sequencing methods, over 700 different LQTS-causing mutations have been identified in 13 genes worldwide. Despite this, the genetic cause of 30-50% of LQTS is presently unknown. MicroRNAs (miRNAs) are small (∼ 22 nucleotides) noncoding RNAs which post-transcriptionally regulate gene expression by binding complementary sequences within messenger RNAs (mRNAs). The human genome encodes over 1800 miRNAs, which target about 60% of human genes. Consequently, miRNAs are likely to regulate many complex processes in the body, indeed aberrant expression of various miRNA species has been implicated in numerous disease states, including cardiovascular diseases. MiR-1 and MiR-133A are the most abundant miRNAs in the heart and have both been reported to regulate cardiac ion channels. We hypothesized that, as a consequence of their role in regulating cardiac ion channels, genetic variation in the genes which encode MiR-1 and MiR-133A might explain some cases of LQTS. Four miRNA genes (miR-1-1, miR-1-2, miR-133a-1 and miR-133a-2), which encode MiR-1 and MiR-133A, were sequenced in 125 LQTS probands. No genetic variants were identified in miR-1-1 or miR-133a-1; but in miR-1-2 we identified a single substitution (n.100A> G) and in miR-133a-2 we identified two substitutions (n.-19G> A and n.98C> T). None of the variants affect the mature miRNA products. Our findings indicate that sequence variants of miR-1-1, miR-1-2, miR-133a-1 and miR-133a-2 are not a cause of LQTS in this cohort

    Interactions between Asaia, Plasmodium and Anopheles: new insights into mosquito symbiosis and implications in malaria symbiotic control

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    Background Malaria represents one of the most devastating infectious diseases. The lack of an effective vaccine and the emergence of drug resistance make necessary the development of new effective control methods. The recent identification of bacteria of the genus Asaia, associated with larvae and adults of malaria vectors, designates them as suitable candidates for malaria paratransgenic control. To better characterize the interactions between Asaia, Plasmodium and the mosquito immune system we performed an integrated experimental approach. Methods Quantitative PCR analysis of the amount of native Asaia was performed on individual Anopheles stephensi specimens. Mosquito infection was carried out with the strain PbGFPCON and the number of parasites in the midgut was counted by fluorescent microscopy. The colonisation of infected mosquitoes was achieved using GFP or DsRed tagged-Asaia strains. Reverse transcriptase-PCR analysis, growth and phagocytosis tests were performed using An. Stephensi and Drosophila melanogaster haemocyte cultures and DsRed tagged-Asaia and Escherichia coli strains. Results Using quantitative PCR we have quantified the relative amount of Asaia in infected and uninfected mosquitoes, showing that the parasite does not interfere with bacterial blooming. The correlation curves have confirmed the active replication of Asaia, while at the same time, the intense decrease of the parasite. The 'in vitro' immunological studies have shown that Asaia induces the expression of antimicrobial peptides, however, the growth curves in conditioned medium as well as a phagocytosis test, indicated that the bacterium is not an immune-target. Using fluorescent strains of Asaia and Plasmodium we defined their co-localisation in the mosquito midgut and salivary glands. Conclusions We have provided important information about the relationship of Asaia with both Plasmodium and Anopheles. First, physiological changes in the midgut following an infected or uninfected blood meal do not negatively affect the residing Asaia population that seems to benefit from this condition. Second, Asaia can act as an immune-modulator activating antimicrobial peptide expression and seems to be adapted to the host immune response. Last, the co-localization of Asaia and Plasmodium highlights the possibility of reducing vectorial competence using bacterial recombinant strains capable of releasing anti-parasite molecules

    Carba-D,L-allal- and -D,L-galactal-derived vinyl N-nosyl aziridines as useful tools for the synthesis of 4-deoxy-4-(N-nosylamino)-2,3-unsaturated-5a-carbasugars

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    The novel carba-D,L-allal- and carba-D,L-galactal-derived vinyl N-nosyl aziridines were prepared and the regio- and stereoselective behavior in opening reactions with O- and N-nucleophiles examined. The carbaglycosylating ability of the novel aziridines, as deduced by the amount of 1,4-addition products (1,4-regioselectivity) obtained in the acid-catalyzed methanolysis taken as a model reaction, is similar or superior to that observed with the corresponding carba-D,L-allal- and -D,L-galactal-derived vinyl epoxides, respectively. In all 1,2- and 1,4-addition products obtained, a –(N-nosylamino) group is regio- and stereoselectively introduced at the C(4) carbon of a 1,2- or 2,3-unsaturated carbasugar, susceptible to further elaborations toward aminocyclitol derivatives. The stereoselective synthesis of the corresponding, enantiomerically pure carba-D,L-allal- and -D,L-galactal-derived vinyl N-acetyl aziridines is also described

    Città della Conciliazione, Grugliasco, Torino, Italy, 2005-2009

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    Pubblicazione del progetto Città Universitaria della Conciliazione a Grugliasco (TO) nel numero della rivista World Architecture dedicato ai progetti della Città di Torino
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