345 research outputs found

    Measurement of the electron transmission rate of the gating foil for the TPC of the ILC experiment

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    We have developed a gating foil for the time projection chamber envisaged as a central tracker for the international linear collider experiment. It has a structure similar to the Gas Electron Multiplier (GEM) with a higher optical aperture ratio and functions as an ion gate without gas amplification. The transmission rate for electrons was measured in a counting mode for a wide range of the voltages applied across the foil using an 55^{55}Fe source and a laser in the absence of a magnetic field. The blocking power of the foil against positive ions was estimated from the electron transmissions.Comment: 25 pages containing 14 figures and 1 tabl

    Ethnobotanical Study and Vulnerability of Uvariodendron molundense (Annonaceae) in Gbado-Lite City (Ubangi Eco-region), Democratic Republic of the Congo

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    Democratic Republic of the Congo is a real reservoir of medicinal plants. These plants play a major role in the treatment of certain common pathologies in tropical regions. The aim of this study was to list the ethnomedical uses of Uvariodendron molundense, a medicinal and aromatic plant from the Ubangi ecoregion. The ethnobotanical survey was carried out in Gbado-Lite with 200 people using stratified probability sampling. The respondents were interviewed individually on the basis of free consent. The study revealed that the majority of respondents were men (72%) and had a secondary education (37%), followed respectively by illiterates (34%) and those with a primary education (28%), and finally, university graduates represented only 1% of the respondents. 83% of the respondents were farmers, while 79% of the respondents were married. The leaf is the most used organ (81%) followed by stem and root bark. U. molundense is used both as food and medicine. The plant treats eight diseases (pain, malaria, cold, hypertension, gastritis, infection, headache and rheumatism). The calculated value of the informant consensus factor is 0.96 and indicates that there is a high degree of consensus among informants regarding the use of U. molundense against these diseases in Gbado-Lite. Decoction is the most commonly used method of preparation (89%) and 50% of the respondents stated that the species is currently not very abundant, while 31% of the respondents felt that the plant was rare. The calculated value of the vulnerability index shows that U. molundense is very vulnerable in its natural environment (Iv ˃ 2.5)

    Towards an Efficient Finite Element Method for the Integral Fractional Laplacian on Polygonal Domains

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    We explore the connection between fractional order partial differential equations in two or more spatial dimensions with boundary integral operators to develop techniques that enable one to efficiently tackle the integral fractional Laplacian. In particular, we develop techniques for the treatment of the dense stiffness matrix including the computation of the entries, the efficient assembly and storage of a sparse approximation and the efficient solution of the resulting equations. The main idea consists of generalising proven techniques for the treatment of boundary integral equations to general fractional orders. Importantly, the approximation does not make any strong assumptions on the shape of the underlying domain and does not rely on any special structure of the matrix that could be exploited by fast transforms. We demonstrate the flexibility and performance of this approach in a couple of two-dimensional numerical examples

    Oxytocin/vasopressin-like peptide inotocin regulates cuticular hydrocarbon synthesis and water balancing in ants.

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    Oxytocin/vasopressin-like peptides are important regulators of physiology and social behavior in vertebrates. However, the function of inotocin, the homologous peptide in arthropods, remains largely unknown. Here, we show that the level of expression of inotocin and inotocin receptor are correlated with task allocation in the ant Camponotus fellah Both genes are up-regulated when workers age and switch tasks from nursing to foraging. in situ hybridization revealed that inotocin receptor is specifically expressed in oenocytes, which are specialized cells synthesizing cuticular hydrocarbons which function as desiccation barriers in insects and for social recognition in ants. dsRNA injection targeting inotocin receptor, together with pharmacological treatments using three identified antagonists blocking inotocin signaling, revealed that inotocin signaling regulates the expression of cytochrome P450 4G1 (CYP4G1) and the synthesis of cuticular hydrocarbons, which play an important role in desiccation resistance once workers initiate foraging

    Étude ethnobotanique et floristique de quelques plantes mĂ©dicinales commercialisĂ©es Ă  Kinshasa, RĂ©publique DĂ©mocratique du Congo

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    According to the WHO, more than 80% of the population in Africa resort to traditional medicine to solve primary health problem. In the present study, an ethnobotanical survey was carried out according to a stratified probabilistic sampling plan in five markets of the district of Mont-Amba, in Kinshasa city. The ethnobotanical data collected were then supplemented by information concerning plant ecological types. 47 species belonging 44 genera and 29 families were inventoried in the medicinal flora of the District of Mont-Amba. These plant species are used in treating 41 diseases but only the treatment of poison (toxicological hepatitis), sexual weakness, malaria and tooth decay received an informant consensus factor ? 50%. According to the value of agreement use, only the following eight plant species are of interest: Aframomum melegueta, Garcinia kola, Gladiolus gregarius, Gongronema latifolium, Heinsia crinita, Morinda morindoides, Quassia africana and Sarcocephalus latifolius. It is thus desirable that studies should be carried out on these eight plant species in order to collect scientific data for guiding future research on the phytochemistry and the bioactivity which will lead to the domestication of raw materials for the development of improved plant-based medicines. Also, the creation of a botanical garden of medicinal plants will be able to contribute to the safeguard of the medically active plants, the diffusion of knowledge, medical and pharmaceutical experiences and sociocultural exchanges. Keywords: Ethno-botanical survey, medicinal plant species, sustainable management, conservation, Democratic Republic of the CongoSelon l’OMS, plus de 80% de la population africaine recourt Ă  la mĂ©decine traditionnelle pour rĂ©soudre le problĂšme de santĂ© primaire. Dans la prĂ©sente Ă©tude, une enquĂȘte ethnobotanique a Ă©tĂ© menĂ©e selon un plan d’échantillonnage stratifiĂ© probabiliste dans cinq marchĂ©s du district de Mont-Amba. Les donnĂ©es ethnobotaniques recueillies ont ensuite Ă©tĂ© complĂ©tĂ©es par des informations concernant les types Ă©cologiques. 47 espĂšces appartenant 44 genres et 29 familles ont Ă©tĂ© inventoriĂ©es dans la flore mĂ©dicinale du District de Mont-Amba Ă  Kinshasa. Ces plantes traitent 41 maladies, cependant seuls les traitements du poison (hĂ©patite toxicologique), de la faiblesse sexuelle, du paludisme et de la carie dentaire ont un facteur de consensus informateur ? 50 %. En recourant Ă  la valeur d’accord d’utilisation, seules huit plantes se dĂ©gagent du lot, notamment Aframomum melegueta, Garcinia kola, Gladiolus gregarius, Gongronema latifolium, Heinsia crinita, Morinda morindoides, Quassia africana et Sarcocephalus latifolius. Il est donc souhaitable que des Ă©tudes soient rĂ©alisĂ©es sur ces huit plantes en vue de recueillir les donnĂ©es scientifiques pouvant orienter les recherches pharmaco-biologiques et phytochimiques futures et susceptibles de conduire Ă  la domestication des matiĂšres premiĂšres pour la fabrication de mĂ©dicaments traditionnels amĂ©liorĂ©s. Aussi, la crĂ©ation d’un jardin botanique de plantes mĂ©dicinales pourra contribuer Ă  la sauvegarde des espĂšces bioactives, Ă  la diffusion et Ă  l’échange des connaissances et des expĂ©riences mĂ©dico-pharmaceutiques et socio-culturelles. Mots-clĂ©fs: EnquĂȘte ethnobotanique, Plantes mĂ©dicinales, Gestion durable, Conservation, RĂ©publique dĂ©mocratique du Cong

    Ethnobotanical and floristic study of some medicinal plant species sold in Kinshasa city, Democratic Republic of Congo

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    According to the WHO, more than 80% of the population in Africa resort to traditional medicine to solve primary health problem. In the present study, an ethnobotanical survey was carried out according to a stratified probabilistic sampling plan in five markets of the district of Mont-Amba, in Kinshasa city. The ethnobotanical data collected were then supplemented by information concerning plant ecological types. 47 species belonging 44 genera and 29 families were inventoried in the medicinal flora of the District of Mont-Amba. These plant species are used in treating 41 diseases but only the treatment of poison (toxicological hepatitis), sexual weakness, malaria and tooth decay received an informant consensus factor ? 50%. According to the value of agreement use, only the following eight plant species are of interest: Aframomum melegueta, Garcinia kola, Gladiolus gregarius, Gongronema latifolium, Heinsia crinita, Morinda morindoides, Quassia africana and Sarcocephalus latifolius. It is thus desirable that studies should be carried out on these eight plant species in order to collect scientific data for guiding future research on the phytochemistry and the bioactivity which will lead to the domestication of raw materials for the development of improved plant-based medicines. Also, the creation of a botanical garden of medicinal plants will be able to contribute to the safeguard of the medically active plants, the diffusion of knowledge, medical and pharmaceutical experiences and sociocultural exchanges
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