104 research outputs found
Modern microwave methods in solid state inorganic materials chemistry: from fundamentals to manufacturing
No abstract available
Growth, biomass production and ions accumulation in Atriplex nummularia Lindl grown under abiotic stress
Culex pipiens, an Experimental Efficient Vector of West Nile and Rift Valley Fever Viruses in the Maghreb Region
West Nile fever (WNF) and Rift Valley fever (RVF) are emerging diseases causing epidemics outside their natural range of distribution. West Nile virus (WNV) circulates widely and harmlessly in the old world among birds as amplifying hosts, and horses and humans as accidental dead-end hosts. Rift Valley fever virus (RVFV) re-emerges periodically in Africa causing massive outbreaks. In the Maghreb, eco-climatic and entomologic conditions are favourable for WNV and RVFV emergence. Both viruses are transmitted by mosquitoes belonging to the Culex pipiens complex. We evaluated the ability of different populations of Cx. pipiens from North Africa to transmit WNV and the avirulent RVFV Clone 13 strain. Mosquitoes collected in Algeria, Morocco, and Tunisia during the summer 2010 were experimentally infected with WNV and RVFV Clone 13 strain at titers of 107.8 and 108.5 plaque forming units/mL, respectively. Disseminated infection and transmission rates were estimated 14–21 days following the exposure to the infectious blood-meal. We show that 14 days after exposure to WNV, all mosquito st developed a high disseminated infection and were able to excrete infectious saliva. However, only 69.2% of mosquito strains developed a disseminated infection with RVFV Clone 13 strain, and among them, 77.8% were able to deliver virus through saliva. Thus, Cx. pipiens from the Maghreb are efficient experimental vectors to transmit WNV and to a lesser extent, RVFV Clone 13 strain. The epidemiologic importance of our findings should be considered in the light of other parameters related to mosquito ecology and biology
SUMO-Targeted Ubiquitin Ligase, Rad60, and Nse2 SUMO Ligase Suppress Spontaneous Top1–Mediated DNA Damage and Genome Instability
Through as yet undefined proteins and pathways, the SUMO-targeted ubiquitin ligase (STUbL) suppresses genomic instability by ubiquitinating SUMO conjugated proteins and driving their proteasomal destruction. Here, we identify a critical function for fission yeast STUbL in suppressing spontaneous and chemically induced topoisomerase I (Top1)–mediated DNA damage. Strikingly, cells with reduced STUbL activity are dependent on tyrosyl–DNA phosphodiesterase 1 (Tdp1). This is notable, as cells lacking Tdp1 are largely aphenotypic in the vegetative cell cycle due to the existence of alternative pathways for the removal of covalent Top1–DNA adducts (Top1cc). We further identify Rad60, a SUMO mimetic and STUbL-interacting protein, and the SUMO E3 ligase Nse2 as critical Top1cc repair factors in cells lacking Tdp1. Detection of Top1ccs using chromatin immunoprecipitation and quantitative PCR shows that they are elevated in cells lacking Tdp1 and STUbL, Rad60, or Nse2 SUMO ligase activity. These unrepaired Top1ccs are shown to cause DNA damage, hyper-recombination, and checkpoint-mediated cell cycle arrest. We further determine that Tdp1 and the nucleotide excision repair endonuclease Rad16-Swi10 initiate the major Top1cc repair pathways of fission yeast. Tdp1-based repair is the predominant activity outside S phase, likely acting on transcription-coupled Top1cc. Epistasis analyses suggest that STUbL, Rad60, and Nse2 facilitate the Rad16-Swi10 pathway, parallel to Tdp1. Collectively, these results reveal a unified role for STUbL, Rad60, and Nse2 in protecting genome stability against spontaneous Top1-mediated DNA damage
Structural and optical investigation of (V, Al) doped and co-doped ZnO nanopowders: Tailored visible luminescence for white light emitting diodes
International audienceThis paper deals with co-precipitation synthesis and characterization of undoped, Al, V doped, and (Al+V) co-doped ZnO nanopowders. Complementary techniques are used: X-ray diffraction (XRD), transmission electron microscopy (TEM), diffuse reflectance and photoluminescence (PL) spectroscopies. XRD analysis revealed the formation of hexagonal-wurtzite structure for all samples. The average crystallite size decreases from 40 to 20 nm by doping ZnO NPs. TEM images showed quasi-spherical shaped nanoparticles. The UV-visible absorption spectra revealed that doping and co-doping induce slight red-shift of gap energy (3.29eV-3.27eV). The Urbach energy increases mainly with V doping, suggesting an increase in disorder and defects levels. PL spectra exhibit narrow and wide emissions in UV and visible regions respectively. Gaussian deconvo-lution of the broad visible peaks revealed several overlapped emissions. Mainly V incorporation in ZnO (single and double doping) notably improves visible luminescence. It leads to widening of the visible emission from 460 to 585 nm
Privacy-Preserving dialogues between agents: A contract-based incentive mechanism for distributed meeting scheduling
Meeting scheduling (MS) is a practical task in everyday life that involves independent agents with different calendars and preferences. In this paper, we consider the distributed MS problem where the host exchanges private information with each attendee separately. Since each agent aims to protect its own privacy and attend the meeting at a time slot that it prefers, it is necessary to design a distributed scheduling mechanism where the privacy leakage can be minimized and as many agents are satisfied with the outcome as possible. To achieve this, we propose an intelligent two-layer mechanism based on contract theory where the host motivates each agent to reveal its true preferences by providing different rewards without knowing the costs of each agent to attend the meeting. We first model the privacy leakage by measuring the difference between the revealed information of an agent’s calendar and other agents’ prior beliefs. An optimal control problem is then formulated such that the reward function and privacy leakage level can be jointly designed for each agent. Through theoretical analysis, we show that our proposed mechanism guarantees the incentive compatibility with respect to all agents. Compared to the state of the art, empirical evaluations show that our proposed mechanism achieves lower privacy leakage and higher social welfare within a small number of rounds
Simultaneous in vivo comparison of water-filled and air-filled pressure measurement catheters: Implications for good urodynamic practice
© 2015 Wiley Periodicals, Inc. Aims: This study aimed to evaluate whether the pressure readings obtained from air-filled catheters (AFCs) are the same as the readings from simultaneously inserted water-filled catheters (WFCs). It also aimed to make any possible recommendations for the use of AFCs to conform to International Continence Society (ICS) Good Urodynamic Practices (GUP). Methods: Female patients undergoing urodynamic studies in a single center had water-filled and air-filled catheters simultaneously measuring abdominal and intravesical pressure during filling with saline and during voiding. The pressures recorded by each system at each event during the test were compared using paired t-test and Bland-Altman analyses. Results: 62 patients were recruited, of whom 51 had pressures that could be compared during filling, and 23 during voiding. On average, the pressures measured by the two systems were not significantly different during filling and at maximum flow, but the values for a given patient were found to differ by up to 10 cmH2O. Conclusions: This study shows that AFCs and WFCs cannot be assumed to register equal values of pressure. It has further shown that even when the pdet readings are compared with their value at the start of a test, a divergence of values of up to 10 cmH2O remains. If AFCs are used, care must be taken to compensate for any pdet variations that occur during patient movement. Before AFCs are adopted, new normal values for resting pressures need to be developed to allow good quality AFC pressure readings to be made. Neurourol. Urodynam. 35:926–933, 2016. © 2015 Wiley Periodicals, Inc
Résultat de la double arthrodèse dans le traitement du pied plat valgus de l’adulte : à propos d’une série de 19 cas
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