1,770 research outputs found

    Gastrointestinal neuromuscular apparatus: An underestimated target of gut microbiota

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    Over the last few years, the importance of the resident intestinal microbiota in the pathogenesis of several gastro- intestinal diseases has been largely investigated. Growing evidence suggest that microbiota can influence gastro- intestinal motility. The current working hypothesis is that dysbiosis-driven mucosal alterations induce the production of several inflammatory/immune mediators which affect gut neuro-muscular functions. Besides these indirect mucosal-mediated effects, the present review highlights that recent evidence suggests that microbiota can directly affect enteric nerves and smooth muscle cells functions through its metabolic products or bacterial molecular components translocated from the intestinal lumen. Toll- like receptors, the bacterial recognition receptors, are expressed both on enteric nerves and smooth muscle and are emerging as potential mediators between microbiota and the enteric neuromuscular apparatus. Furthermore, the ongoing studies on probiotics support the hypothesis that the neuromuscular apparatus may represent a target of intervention, thus opening new physiopathological and therapeutic scenarios

    Formalizing the Execution Context of Behavior Trees for Runtime Verification of Deliberative Policies

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    In this paper, we enable automated property verification of deliberative components in robot control architectures. We focus on formalizing the execution context of Behavior Trees (BTs) to provide a scalable, yet formally grounded, methodology to enable runtime verification and prevent unexpected robot behaviors. To this end, we consider a message-passing model that accommodates both synchronous and asynchronous composition of parallel components, in which BTs and other components execute and interact according to the communication patterns commonly adopted in robotic software architectures. We introduce a formal property specification language to encode requirements and build runtime monitors. We performed a set of experiments, both on simulations and on the real robot, demonstrating the feasibility of our approach in a realistic application and its integration in a typical robot software architecture. We also provide an OS-level virtualization environment to reproduce the experiments in the simulated scenario

    Sequential release of TNFα and phospholipase A2 in a rat model of LPS-induced pleurisy

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    The levels of extracellular phospholipase A2 (sPLA2) and TNFα, and cell accumulation were measured in the pleural washings obtained at different times following the induction of Escherichia coli lipopolysaccharide (LPS, 100 μg/cavity) pleurisy in rats. TNFα peaked at 2 hours (3036 ± 160.3 units/ml) and decreased thereafter. Conversely, levels of sPLA2 peaked at 48 hours (1.97 ± 0.64 ng/ml) and were increased further (14.02 ± 4.16 ng/ml) by pretreatment with anti-TNFα antibody. Cell accumulation was not affected by antibody pretreatment. These data indicate that the sPLA2 enzyme is involved in LPS-induced pleurisy. The enzyme seems not to be stimulated by TNFα which may be involved in the downregulation of sPLA2 in this model of inflammation

    Kinetic Study of the Thermal Dehydration of SiO2 and SiO2-ZrO2 composites prepared by Sol-Gel route

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    Abstract. SiO2, ZrO2 and SiO2-ZrO2 composites at different percentage of zirconia were synthesized by the solgel method and spectroscopically characterized by Fourier Transformed Infrared (FTIR) spectroscopy. Different series of composites were prepared and analysed, as it is and with a postpreparation conditioning at 600 and 1000°C respectively. The calcination were carried out to verify the changing in composite structure and if these treatments will affect the subsequently analyses. The synthesized samples were subjected to the thermogravimetric analysis (TGA) to investigate the kinetics of dehydration process. To this purpose, TGA data were treated by the Kissinger method to calculate the apparent activation energy (Ea) of dehydration. The obtained kinetics parameters are discussed and compared with each other and with those obtained for the control material

    Measurement of the angular distribution of the B+→π + μ-μ + decay and R&D towards a future upgrade of the particle identification system of the LHCb experiment

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    This thesis presents two complementary research studies, linked by the LHCb experiment. A first analysis of the angular distribution of the B+→π + μ-μ+decay with LHCb Run 1 and 2 data is presented, using the Feldman-Cousins approach to ensure correct coverage of the angular observables measured, AFB and FH. This decay is a rare b! d quark avour changing neutral current process. The analysis is at an advanced stage and blind at the time of writing of this work. The analysis strategy is tested on control modes and pseudo-experiments. Sources of systematic uncertainties are identified and their effects evaluated. In addition, studies for the R&D effort for the development of a new time-of-flight Cherenkov detector, TORCH, proposed for the next LHCb upgrade are presented. The proposed design uses MCP-PMTs to measure single photon time. The TORCH MCP-PMT is characterised with studies of uniformity and gain. The single photon time resolution of the TORCH MCP-PMT coupled to readout electronics has been measured, resulting in (47:5 0:7) ps, meeting the TORCH design requirement

    Study of MicroPattern Gaseous detectors with novel nanodiamond based photocathodes for single photon detection in EIC RICH

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    Identification of high momentum hadrons at the future EIC is crucial, gaseous RICH detectors are therefore viable option. Compact collider setups impose to construct RICHes with small radiator length, hence significantly limiting the number of detected photons. More photons can be detected in the far UV region, using a windowless RICH approach. QE of CsI degrades under strong irradiation and air contamination. Nanodiamond based photocathodes (PCs) are being developed as an alternative to CsI. Recent development of layers of hydrogenated nanodiamond powders as an alternative photosensitive material and their performance, when coupled to the THick Gaseous Electron Multipliers (THGEM)-based detectors, are the objects of an ongoing R\&D. We report about the initial phase of our studies.Comment: 3 pages, 5 figures, RICH2018 conference proceedin

    Kinetic Study of the Thermal Dehydration of Fly Ash Filled Geopolymers

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    Metakaolin-based geopolymers at different percentage of fly ash (namely 25, 50, and 70% wt) are prepared by using recycled fly ash, aiming at reducing the amount of waste to be treated or disposed in landfills. The synthesized samples are subjected to the thermogravimetric analysis (TGA) to investigate the kinetics of dehydration process. To this purpose, TGA data are treated by the Kissinger method to calculate the apparent activation energy (Ea) of dehydration. The obtained kinetics parameters are discussed and compared with each other and with those obtained for the control geopolymer. A decrease in Ea values of the filled geopolymers is found, showing the effect of the fly ash in reducing the dehydration rate. A classification among the samples at different percentage of fly ash is also drawn up, showing the reaching of a plateau at percentage above the 50 wt%

    A sensor aided H.264 encoder tested on aerial imagery for SFM

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    Email Print Request Permissions Standard video coding systems currently employed in UAV (Unmanned Aerial Vehicle) and aerial drone applications do not rely on some peculiarities in terms of scene 3D model and correlation among successive frames. In particular, the observed scene is static, i.e. the camera movement is dominant, and it can often be well approximated with a plane. Moreover, camera position and orientation can be obtained from the navigation system. Therefore, correspondent points on two video frames are linked by a simple homography. This paper presents novel results obtained by a low-complexity sensor aided H.264 encoder, recently developed at CIRA and yet tested on simulated data. The proposed encoder employs a new motion estimation scheme which make use of the global motion information provided by the onboard navigation system. The homography is used in order to initialize the block matching algorithm allowing a more robust motion estimation and a smaller search window, and hence reducing the complexity. The tests are made coding real aerial imagery, captured to be used for 3D scene reconstruction. The images are acquired by an high resolution camera mounted on a small drone, flying at low altitude

    Polycrystalline diamond films grown by MWPECVD technique and application in photocathodes

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    Diamond is an extremely interesting material for photoemission applications, due to the negative electron affinity which can be obtained after suitable surface treatments. In the present work, two sets of polycrystalline diamond films, characterized by dif-ferent thickness and deposition conditions, are ana-lyzed. In particular, the relationship among the grain size, the amount of non-diamond carbon (sp2) located at the grain boundaries and the film sensitivity as a photocathode has been found and carefully investi-gated. The photoemission yield in the UV range has been evaluated for all the samples, before and after hydrogenation process, and after air exposure. The critical parameter for the photocathode performances has been found not to be the film thickness, but the properties of polycrystalline diamond films, tunable with the plasma modulation and the methane percent-age in the gas mixture

    Mechanical properties of MWPECVD diamond coatings on Si substrate via nanoindentation

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    The mechanical properties of polycrystalline diamond coatings with thickness varying from 0.92 to 44.65 μm have been analysed. The tested samples have been grown on silicon substrates via microwave plasma enhanced chemical vapour deposition from highly diluted gas mixtures CH4–H2 (1% CH4 in H2). Reliable hardness and elastic modulus values have been assessed on lightly polished surface of polycrystalline diamond films. The effect of the coating thickness on mechanical, morphological and chemical-structural properties is presented and discussed. In particular, the hardness increases from a value of about 52 to 95 GPa and the elastic modulus from 438 to 768 GPa by varying the coating thickness from 0.92 to 4.85 μm, while the values closer to those of natural diamond (H=103 GPa and E=1200 GPa) are reached for thicker films (N5 μm). Additionally, the different thickness of the diamond coatings permits to select the significance of results and to highlight when the soft silicon substrate may affect the measured mechanical data. Thus, the nanoindentation experiments were made within the range from 0.65% to 10% of the film thickness by varying the maximum load from 3 to 80 mN. © 2010 Elsevier B.V. All rights reserve
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