1,604 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

    Photoemission tuning of nanodiamond particles treated in variable percentages of H2H_2-N2N_2 plasmas

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    This work deals with photochatodes (PCs) based on as-received and treated nanodiamond (ND) particles, 250 nm in size. The aim of this study is the hydro-, hydro-/nitro- and nitro-genation of NDs performed in microwave plasmas adding different N2N_2 percentages (0, 50 and 100 %) to pure H2H_2 gas. Untreated and treated NDs are dispersed in solvents such as 1,2-dichloroethane and deionized water, and then deposited, as continuous layers, on p-Si and kapton substrates by the pulsed spray technique. The produced layers are characterized by Raman, photoluminescence spectroscopies and photoemission measurements. The quantum efficiency (QE), a merit figure for photocathodes, is assessed in the UV spectral range from 146 to 210 nm. The results show an enhancement of the photoemission for PCs based on hydro-, hydro-/nitro- and nitro-genated NDs that exhibit at 146 nm QE values of about 23, 21 and 13 %, respectively. The advantage of nitrogenated PCs is the good stability to air exposure against their lowest QE values

    Personal cloud user acceptance: The role of trust and perceived risk in the technology acceptance model

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    This research considers technology adoption issues, as well as risk and trust factors, that lead to behavioral intention of personal cloud computing. We are interested in whether similar results are found in personal cloud computing, a tool that may be perceived as having more risks. Our research found that perceived risk decreased behavioral intentions. Perceived usefulness served as a mediator between trust and behavioral intentions, significantly increasing both relationships. Trust was found to decrease perceived risk; however, it directly increased behavioral intention, perceived usefulness, and perceived ease of use. Interestingly, perceived ease of use did not significantly affect behavioral intentions. This leads to the finding that perceived usefulness may be a greater contributing factor than perceived ease of use in behavioral intention for personal cloud computing. In this research study we offer an interesting perspective on the acceptance of personal cloud computing and explore individual user acceptance of cloud computing

    A Roy Model of Social Interactions

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    We develop a Roy model of social interactions in which individuals sort into peer groups based on comparative advantage. Two key results emerge: First, when comparative advantage is the guiding principle of peer group organization, the effect of moving a student into an environment with higher-achieving peers depends on where in the ability distribution she falls and the effective wages that clear the social market. In this sense our model may rationalize the widely varying estimates of peer effects found in the literature without casting group behavior as an externality in agents’ objective functions. Second, since a student’s comparative advantage is typically unobserved, the theory implies that important determinants of individual choice operate through the error term and may, even under random assignment, be correlated with the regressor of interest. As a result, linear in means estimates of peer effects are not identified. We show that the model’s testable prediction in the presence of this confounding issue–an individual’s ordinal rank predicts her behavior, ceteris paribus–is borne out in two data setssocial interactions; peer effects; roy model; idenitification

    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

    Biomedical prostheses coated by tailored MWPECVD nanocrystalline diamond films

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    Different aspects concerning the use of nanocrystalline diamond (NCD) film, as coating for biomedical prostheses, is discussed. An overview is done on diamond implementation in prostheses, on the NCD mechanical properties and on the technological aspects concerning the NCD growth process i.e. Microwave Plasma Enhanced Chemical Vapor deposition. Then, the attention is focused on a possible improvement of NCD growth on titanium (Ti) substrate. Further, a theoretical study by finite element method is discussed in order to model the adhesion properties of a NCD layer on Ti and Ti/Titanium Carbide (TiC) substrates. The goal of the proposed work is to provide a study about the use of thin NCD coating on Ti based prostheses. The function of the NCD coating on Ti material is to improve the implanted prosthesis with a long duration time, thus decreasing the total costs and the invasive surgery treatments

    A Roy Model of Social Interactions

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    We develop a Roy model of social interactions in which individuals sort into peer groups based on comparative advantage. Two key results emerge: First, when comparative advantage is the guiding principle of peer group organization, the effect of moving a student into an environment with higher-achieving peers depends on where in the ability distribution she falls and the effective wages that clear the social market. In this sense our model may rationalize the widely varying estimates of peer effects found in the literature without casting group behavior as an externality in agents' objective functions. Second, since a student's comparative advantage is typically unobserved, the theory implies that important determinants of individual choice operate through the error term and may, even under random assignment, be correlated with the regressor of interest. As a result, linear in means estimates of peer effects are not identified. We show that the model's testable prediction in the presence of this confounding issue–an individual's ordinal rank predicts her behavior, ceteris paribus–is borne out in two data sets.

    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

    Electron beams produced by innovative photocathodes based on nanodiamond layers

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    The investigation of two different photocathodes (PCs) based on nanodiamond (ND) layers, irradiated by a KrF nanosecond excimer laser (wavelength, \ensuremath{\lambda}=248\text{ }\text{ }\mathrm{nm}; photon energy, EPh=5  eV{E}_{\mathrm{Ph}}=5\text{ }\text{ }\mathrm{eV}) is reported. The ND layers were deposited by means of a pulsed spray technique. Specifically, the active layer of each PC consisted of untreated (as-received) and hydrogenated ND particles, 250 nm in size, sprayed on a pp-doped silicon substrate. The ND-based photocathodes were tested in a vacuum chamber at {10}^{\ensuremath{-}6}\text{ }\text{ }\mathrm{mbar} and compared to a Cu-based one, used as reference. All the photocathodes were irradiated at normal incidence. The quantum efficiency (QE) of the photocathodes was assessed. QE values of the ND-based photocathodes were higher than that of the reference one. In particular, the hydrogenated ND-based PC exhibited the highest QE due to the negative electron affinity that results from the surface terminated by hydrogen. Additionally, the photocathode surface/local temperature and the multiphoton process contribution to the electron emission were studied

    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
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