300 research outputs found

    Comparison of swarming, mating performance and longevity of males Anopheles coluzzii between individuals fed with different natural fruit juices in laboratory and semi-field conditions.

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    BACKGROUND: It is assumed that malaria vectors feed on locally available nectar sources to obtain energy. Sugar feeding is energetically critical for the Anopheles male swarming and mating activities. However, little is known about the impact of local nectar feeding on male physiological development and its consequences on male mosquito life traits in the malaria control context. This study aimed to evaluate the influence of local fruit juices on the life traits of males Anopheles coluzzii. METHODS: Swarming characteristics (number of males in swarm, number of mating pairs, and swarm duration) in semi-field conditions; mating rate and longevity in a laboratory setting were compared between males An. coluzzii fed exclusively with mango, papaya or banana juices. The trophic preference was investigated in semi-field conditions. RESULTS: The results of this study showed that in the laboratory, mosquitoes fed with papaya juices lived on average longer (10 days) than those fed with banana or mango juices (5 days) and had higher a mating rate (53%) than those fed with banana juice (40%). In the semi-field, the swarm size of mosquitoes fed with banana juice (85 males) was larger than that of mosquitoes fed with mango juice (60 males). The number of mating pairs formed from banana-fed male swarms (17 mating pairs) was higher than that formed from mango-fed male swarm (8 mating pairs). There was no difference in swarming duration between male treatments. Male mosquitoes had a preference for papaya and banana juices. CONCLUSIONS: The results indicate that the origin of plant-derived feeding is an important factor in the survival and reproduction of mosquitoes. This calls for further investigations of chemical contents of nectars and their impact on the physiological development of mosquitoes

    First Results from the AMoRE-Pilot neutrinoless double beta decay experiment

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    The Advanced Molybdenum-based Rare process Experiment (AMoRE) aims to search for neutrinoless double beta decay (0νββ\nu\beta\beta) of 100^{100}Mo with ∼\sim100 kg of 100^{100}Mo-enriched molybdenum embedded in cryogenic detectors with a dual heat and light readout. At the current, pilot stage of the AMoRE project we employ six calcium molybdate crystals with a total mass of 1.9 kg, produced from 48^{48}Ca-depleted calcium and 100^{100}Mo-enriched molybdenum (48depl^{48\textrm{depl}}Ca100^{100}MoO4_4). The simultaneous detection of heat(phonon) and scintillation (photon) signals is realized with high resolution metallic magnetic calorimeter sensors that operate at milli-Kelvin temperatures. This stage of the project is carried out in the Yangyang underground laboratory at a depth of 700 m. We report first results from the AMoRE-Pilot 0νββ0\nu\beta\beta search with a 111 kg⋅\cdotd live exposure of 48depl^{48\textrm{depl}}Ca100^{100}MoO4_4 crystals. No evidence for 0νββ0\nu\beta\beta decay of 100^{100}Mo is found, and a upper limit is set for the half-life of 0νββ\nu\beta\beta of 100^{100}Mo of T1/20ν>9.5×1022T^{0\nu}_{1/2} > 9.5\times10^{22} y at 90% C.L.. This limit corresponds to an effective Majorana neutrino mass limit in the range ⟨mββ⟩≤(1.2−2.1)\langle m_{\beta\beta}\rangle\le(1.2-2.1) eV

    ZnO-based scintillating bolometers: New prospects to study double beta decay of 64^{64}Zn

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    The first detailed study on the performance of a ZnO-based cryogenic scintillating bolometer as a detector to search for rare processes in zinc isotopes was performed. A 7.2 g ZnO low-temperature detector, containing more than 80\% of zinc in its mass, exhibits good energy resolution of baseline noise 1.0--2.7 keV FWHM at various working temperatures resulting in a low-energy threshold for the experiment, 2.0--6.0 keV. The light yield for β\beta/γ\gamma events was measured as 1.5(3) keV/MeV, while it varies for α\alpha particles in the range of 0.2--3.0 keV/MeV. The detector demonstrate an effective identification of the β\beta/γ\gamma events from α\alpha events using time-properties of only heat signals. %(namely, Rise time parameter). The radiopurity of the ZnO crystal was evaluated using the Inductively Coupled Plasma Mass Spectrometry, an ultra-low-background High Purity Ge γ\gamma-spectrometer, and bolometric measurements. Only limits were set at the level of O\mathcal{O}(1--100) mBq/kg on activities of \Nuc{K}{40}, \Nuc{Cs}{137} and daughter nuclides from the U/Th natural decay chains. The total internal α\alpha-activity was calculated to be 22(2) mBq/kg, with a major contribution caused by 6(1) mBq/kg of \Nuc{Th}{232} and 12(2) mBq/kg of \Nuc{U}{234}. Limits on double beta decay (DBD) processes in \Nuc{Zn}{64} and \Nuc{Zn}{70} isotopes were set on the level of O(1017\mathcal{O}(10^{17}--1018)10^{18}) yr for various decay modes profiting from 271 h of acquired background data in the above-ground lab. This study shows a good potential for ZnO-based scintillating bolometers to search for DBD processes of Zn isotopes, especially in \Nuc{Zn}{64}, with the most prominent spectral features at ∼\sim10--20 keV, like the two neutrino double electron capture. A 10 kg-scale experiment can reach the experimental sensitivity at the level of O(1024)\mathcal{O}(10^{24}) yr.Comment: Prepared for submission to JINST; 27 pages, 9 figures, and 7 table

    Differential and comparative screening of cowpea varieties to Striga gesnerioides (Willd.) Vatke for race specific identification in Burkina Faso

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    Significant efforts have been made to develop cowpea ( Vigna unguiculata (L.) Walp.) varieties resistant to Striga gesnerioides in Burkina Faso. Despite these efforts, the resistant genotypes developed still express differential responses to Striga gesnerioides in different zones of the country. This suggests existence of intraspecific variability within the parasite. The objective of this study was to assess the intraspecific variability of cowpea genotypes to Striga gesnerioides infection in Burkina Faso. Ten cowpea varieties were screened over two consecutive years, under artificial infestation with 30 ecotypes of Striga seeds at Kamboins\ue9 research station, in a screenhouse in Burkina Faso. Cowpea varieties used included Moussa local, Komsar\ue9 and KVx404-8-1, which are susceptible to all Striga ecotypes; and varieties B301, IT93K-693-2 and IT82D-849, which are free from all Striga ecotypes infestation. Cowpea varieties Tiligr\ue9, 524B, local Gorom and Niizw\ue8 had specific reactions depending on the ecotypes. The study highlights the existence of varietal specificities according to the geographical origin of Striga gesnerioides seeds. The structuring of the intraspecific diversity showed five biotypes, of which three were clearly identified as SG1, SG5 and SG Kp races; and two biotypes could not be identified. Although this study did not allow for a clear determination of the racial affiliation of the two new biotypes, it offers the possibility of developing new strategies to control Striga by focusing on the selection of resistant varieties based on regional specificities of Striga races in each agricultural zone.Des efforts importants ont \ue9t\ue9 consentis pour d\ue9velopper des vari\ue9t\ue9s de ni\ue9b\ue9 r\ue9sistantes au Striga gesnerioides . Malgr\ue9 ces efforts, les g\ue9notypes r\ue9sistants d\ue9velopp\ue9s expriment des r\ue9ponses diff\ue9rentielles au Striga gesnerioides dans diff\ue9rentes zones du pays. Cela sugg\ue8re l\u2019existence d\u2019une variabilit\ue9 intrasp\ue9cifique au sein du parasite. D\u2019o\uf9 la n\ue9cessit\ue9 d\u2019\ue9valuer la variabilit\ue9 intrasp\ue9cifique de Striga gesnerioides. Dix vari\ue9t\ue9s de ni\ue9b\ue9 ont \ue9t\ue9 cribl\ue9es sur deux ann\ue9es successives sous infestation artificielle avec 30 \ue9cotypes de Striga \ue0 la station de recherche de Kamboins\ue9. Des pots en plastique ont \ue9t\ue9 utilis\ue9s comme parcelles exp\ue9rimentales dispos\ue9es en blocs de Fisher avec trois r\ue9p\ue9titions. Les vari\ue9t\ue9s Moussa Local, Komsar\ue9 et KVx404-8-1 ont \ue9t\ue9 sensibles \ue0 tous les \ue9cotypes tandis que les vari\ue9t\ue9s B301, IT93K-693-2 et IT82D-849 ont \ue9t\ue9 exemptes de toute infestation. Les vari\ue9t\ue9s Tiligr\ue9, 524B, Gorom local et Niizw\ue8 ont eu des r\ue9actions sp\ue9cifiques en fonction des \ue9cotypes. L\u2019\ue9tude a mis en \ue9vidence l\u2019existence de sp\ue9cificit\ue9s vari\ue9tales selon les \ue9cotypes. La structuration de la diversit\ue9 intrasp\ue9cifique a montr\ue9 cinq biotypes dont trois ont \ue9t\ue9 clairement identifi\ue9s comme les races SG1, SG5 et SG Kp et deux n\u2019ont pas pu \ueatre identifi\ue9s. Bien que cette \ue9tude n\u2019ait pas permis de d\ue9terminer l\u2019appartenance raciale des deux nouveaux biotypes, elle offre n\ue9anmoins la possibilit\ue9 de d\ue9velopper de nouvelles strat\ue9gies de lutte contre Striga gesnerioides en se concentrant sur la s\ue9lection de vari\ue9t\ue9s r\ue9sistantes en fonction des sp\ue9cificit\ue9s r\ue9gionales des races de Striga dans chaque zone agricole

    The African Network for Improved Diagnostics, Epidemiology and Management of common infectious Agents

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    In sub-Saharan Africa, acute respiratory infections (ARI), acute gastrointestinal infections (GI) and acute febrile disease of unknown cause (AFDUC) have a large disease burden, especially among children, while respective aetiologies often remain unresolved. The need for robust infectious disease surveillance to detect emerging pathogens along with common human pathogens has been highlighted by the ongoing novel coronavirus disease2019 (COVID-19) pandemic. The African Network for Improved Diagnostics, Epidemiology and Management of Common Infectious Agents (ANDEMIA) is a sentinel surveillance study on the aetiology and clinical characteristics of ARI, GI and AFDUC in sub-Saharan Africa.Peer Reviewe
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