23 research outputs found

    Zoonotic abbreviata caucasica in wild chimpanzees (Pan troglodytes verus) from Senegal

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    Abbreviata caucasica (syn. Physaloptera mordens) has been reported in human and various non-human primates including great apes. The identification of this nematode is seldom performed and relies on egg characterization at the coproscopy, in the absence of any molecular tool. Following the recovery of two adult females of A. caucasica from the feces of wild Senegalese chimpanzees, morphometric characteristics were reported and new data on the width of the esophagus (0.268– 0.287 mm) and on the cuticle structure (0.70–0.122 mm) were provided. The molecular characterization of a set of mitochondrial (cox1, 16S rRNA, 12S rRNA) and nuclear (18S rRNA and ITS2) partial genes was performed. Our phylogenetic analysis indicates for the first time that A. caucasica is monophyletic with Physaloptera species. A novel molecular tool was developed for the routine diagnosis of A. caucasica and the surveillance of Nematoda infestations. An A. caucasica-specific qPCR targeting the 12S gene was assessed. The assay was able to detect up to 1.13 × 10−3 eggs/g of fecal matter irrespective of its consistency, with an efficiency of 101.8% and a perfect adjustment (R2 = 0.99). The infection rate by A. caucasica in the chimpanzee fecal samples was 52.08%. Only 6.19% of the environmental samples were positive for nematode DNA and any for A. caucasica. Our findings indicate the need for further studies to clarify the epidemiology, circulation, life cycle, and possible pathological effects of this infestation using the molecular tool herein developed

    Nuclear Fission: : A Review of Experimental Advances and Phenomenology

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    In the last two decades, through technological, experimental and theoretical advances, the situation in experimental fission studies has changed dramatically. With the use of advanced production and detection techniques both much more detailed and precise information can now be obtained for the traditional regions of fission research and, crucially, new regions of nuclei have become routinely accessible for fission studies.
 This work first of all reviews the recent developments in experimental fission techniques, in particular the resurgence of transfer-induced fission reactions with light and heavy ions, the emerging use of inverse-kinematic approaches, both at Coulomb and relativistic energies, and of fission studies with radioactive beams.
 The emphasis on the fission-fragment mass and charge distributions will be made in this work, though some of the other fission observables, such as prompt neutron and Îł-ray emission will also be reviewed.
 A particular attention will be given to the low-energy fission in the so far scarcely explored nuclei in the very neutron-deficient lead region. They recently became the focus for several complementary experimental studies, such as ÎČ-delayed fission with radioactive beams at ISOLDE(CERN), Coulex-induced fission of relativistic secondary beams at FRS(GSI), and several prompt fusion-fission studies. The synergy of these approaches allows a unique insight in the new region of asymmetric fission around <sup>180</sup>Hg, recently discovered at ISOLDE. Recent extensive theoretical efforts in this region will also be outlined.
 The unprecedented high-quality data for fission fragments, completely identified in <i>Z</i> and <i>A</i>, by means of reactions in inverse kinematics at FRS(GSI) and VAMOS(GANIL) will be also reviewed. These experiments explored an extended range of mercury-to-californium elements, spanning from the neutron-deficient to neutron-rich nuclides, and covering both asymmetric, symmetric and transitional fission regions.
 Some aspects of heavy-ion induced fusion-fission and quasifission reactions will be also discussed, which reveal their dynamical features, such as the fission time scale. The crucial role of the multi-chance fission, probed by means of multinucleon-transfer induced fission reactions, will be highlighted.
 The review will conclude with the discussion of the new experimental fission facilities which are presently being brought into operation, along with promising 'next-generation' fission approaches, which might become available within the next decade

    Fast neutron spectrometry using thick threshold detectors

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    This paper discusses the use of thick threshold activation detectors for the characterization of low intensity neutron fields. This technique has been applied to the determination of the spectral emission of a low activity (37 GBq) Am-Be source. The reaction rates induced by the neutrons emitted by this source in different thick metallic targets (Al, Si, Fe, In) have been measured in the following reactions: 27Al(n,p)27Mg, 27Al(n,α)24Na, 28Si(n,p)28Al, 56Fe(n,p)56Mn, 115In(n, nâ€Č)115mIn and 115In(n, Îł)116mIn. Each measured reaction rate corresponding to a threshold detector response depends on the spectral emission of the source via a correcting factor. This factor, which takes into account the source detector geometry, the neutron attenuation and diffusion by the detectors, has been determined by Monte Carlo simulation using MCNP5 code. The spectral emission of the neutron source has been generated from the response matrix of the threshold detectors by using different neutron spectrum unfolding methods (Stayn'l, Gravel and Maxed). A fairly good agreement with the assumed ISO spectrum has been achieved

    Fast neutron spectrometry using thick threshold detectors

    No full text
    This paper discusses the use of thick threshold activation detectors for the characterization of low intensity neutron fields. This technique has been applied to the determination of the spectral emission of a low activity (37 GBq) Am-Be source. The reaction rates induced by the neutrons emitted by this source in different thick metallic targets (Al, Si, Fe, In) have been measured in the following reactions: 27Al(n,p)27Mg, 27Al(n,α)24Na, 28Si(n,p)28Al, 56Fe(n,p)56Mn, 115In(n, nâ€Č)115mIn and 115In(n, Îł)116mIn. Each measured reaction rate corresponding to a threshold detector response depends on the spectral emission of the source via a correcting factor. This factor, which takes into account the source detector geometry, the neutron attenuation and diffusion by the detectors, has been determined by Monte Carlo simulation using MCNP5 code. The spectral emission of the neutron source has been generated from the response matrix of the threshold detectors by using different neutron spectrum unfolding methods (Stayn'l, Gravel and Maxed). A fairly good agreement with the assumed ISO spectrum has been achieved

    Comparison of RPL GD-301 and TLD-100 detectors responses by Monte Carlo simulation

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    (LiF:Mg,Ti) Thermo Luminescent Detectors are widely used for monitoring patient dose in radiotherapy treatments whereas Radio-Photoluminescent Dosimeters (RPL) are increasingly devoted to radiological protection purposes. A study, aiming at extending the use of RPL glasses to clinical applications, is conducted by comparing the dosimetric characteristics of a RPL glass dosimeter, commercially known as GD-301 to those of a TLD -100 detector. In this paper, preliminary Monte Carlo simulation results describing these dosimeters responses in terms of absorbed dose, source-detector distance and characteristics of the incident gamma field are presented

    Non-contiguous finished genome sequence and description of Bartonella saheliensis sp. nov. from the blood of Gerbilliscus gambianus from Senegal

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    International audienceBartonella saheliensis strain 077 (= CSUR B644T; = DSM 28003T) is a new bacterial species isolated from blood of the rodent Gerbilliscus gambianus captured in the Sine-Saloum region of Senegal. In this work we describe the characteristics of this microorganism, as well as the complete sequence of the genome and its annotation. Its genome has 2 327 299 bp (G+C content 38.4%) and codes for 2015 proteins and 53 RNA genes

    Study of the Effect of ACL Anode Catalytic Layer Porosity on the Efficiency of a Direct Methanol Fuel Cell

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    The current work investigates the efficiency of a Direct Methanol Fuel Cell (DMFC) by using COMSOL. The set-up model takes into consideration the electrochemical kinetics and chemical reactions. The anode catalyst layers are a main element in the PEM fuel cell; their porosity significantly affects the fuel cell efficiency. We focus on the impact of catalytic layers porosity on the battery efficiency. As claimed by the results, the porosity of catalytic layer greatly affects the performance of the battery. In addition, better output performance of mu DMFC may be obtained when the catalytic layer porosity is chosen as epsilon(ACL)=0.009-0.1. The distributions of methanol, carbon dioxide, water, oxygen, polarization, and the current density are plotted to highlight the impact of porosity on the global performances
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