486 research outputs found

    Honeybees' physiological and behavioural immunity deficit induced by DW Viruses

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    Item does not contain fulltextThe purpose of the present study was to determine the effect of a spinal cord injury (SCI) on resting vascular resistance in paralyzed legs in humans. To accomplish this goal, we measured blood pressure and resting flow above and below the lesion (by using venous occlusion plethysmography) in 11 patients with SCI and in 10 healthy controls (C). Relative vascular resistance was calculated as mean arterial pressure in millimeters of mercury divided by the arterial blood flow in milliliters per minute per 100 milliliters of tissue. Arterial blood flow in the sympathetically deprived and paralyzed legs of SCI was significantly lower than leg blood flow in C. Because mean arterial pressure showed no differences between both groups, leg vascular resistance in SCI was significantly higher than in C. Within the SCI group, arterial blood flow was significantly higher and vascular resistance significantly lower in the arms than in the legs. To distinguish between the effect of loss of central neural control vs. deconditioning, a group of nine SCI patients was trained for 6 wk and showed a 30% increase in leg blood flow with unchanged blood pressure levels, indicating a marked reduction in vascular resistance. In conclusion, vascular resistance is increased in the paralyzed legs of individuals with SCI and is reversible by training

    Two novel classes of neuroactive fatty acid amides are substrates for mouse neuroblastoma ‘anandamide amidohydrolase’

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    AbstractThe endogenous cannabimimetic substance, anandamide (N-arachidonoyl-ethanolamine) and the recently isolated sleep-inducing factor, oleoyl-amide (cis-9,10-octadecenoamide), belong to two neuroactive fatty acid amide classes whose action in mammals has been shown to be controlled by enzymatic amide bond hydrolysis. Here we report the partial characterisation and purification of ‘anandamide amidohydrolase’ from membrane fractions of N18 neuroblastoma cells, and provide evidence for a further and previously unsuspected role of this enzyme. An enzymatic activity catalysing the hydrolysis of [14C]anandamide was found in both microsomal and 10,000 × g pellet fractions. The latter fractions, which displayed the highest Vmax for anandamide, were used for further characterisation of the enzyme, and were found to catalyse the hydrolysis also of [14C]oleoyl-amide, with an apparent Km of 9.0 ± 2.2 ÎŒM. [14C]anandamide- and [14C]oleoyl-amide-hydrolysing activities: (i) exhibited identical pH- and temperature-dependency profiles; (ii) were inhibited by alkylating agents; (iii) were competitively inhibited by the phospholipase A2 inhibitor arachidonyl-trifluoromethyl-ketone with the same IC50 (3 ÎŒM); (iv) were competitively inhibited by both anandamide (or other polyunsaturated fatty acid-ethanolamides) and oleoyl-amide. Proteins solubilised from 10,000 × g pellets were directly analysed by isoelectric focusing, yielding purified fractions capable of catalysing the hydrolysis of both [14C]anandamide and [14C]oleoyl-amide. These data suggest that ‘anandamide amidohydrolase’ enzymes, such as that characterised in this study, may be used by neuronal cells also to hydrolyse the novel sleep-inducing factor oleoyl-amide

    Vehicle Reference Generator for Collision-Free Trajectories in Hazardous Maneuvers

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    This paper presents a reference generator for ground vehicles, based on potential fields adapted to the case of vehicular dynamics. The reference generator generates signals to be tracked by the vehicle, corresponding to a trajectory avoiding collisions with obstacles. This generator integrates artificial forces of potential fields of the object surrounding the vehicle. The reference generator is used with a controller to ensure the tracking of the accident-free reference. This approach can be used for vehicle autonomous driving or for active control of manned vehicles. Simulation results, presented for the autonomous driving, consider a scenario inspired by the so-called moose (or elk) test, with the presence of other collaborative vehicles

    Dynamic Control Applied to a Laboratory Antilock Braking System

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    The control of an antilock braking system is a difficult problem due to the existence of nonlinear dynamics and uncertainties of its characteristics. To overcome these issues, in this work, a dynamic nonlinear controller is proposed, based on a nonlinear observer. To evaluate its performance, this controller has been implemented on an ABS Laboratory setup, representing a quarter car model. The nonlinear observer reconstructs some of the state variables of the setup, assumed not measurable, to establish a fair benchmark for an ABS system of a real automobile. The dynamic controller ensures exponential convergence of the state estimation, as well as robustness with respect to parameter variations

    Transcultural reliability and validity of an Italian language version of the Constant–Murley Score

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    Purpose: The present study was designed to carry out an Italian translation of the Constant–Murley Score (CMS-IT) and,subsequently, evaluate its reliability and validity.Methods: This study included adults diagnosed with any type of clinicalshoulder dysfunction who could read and respond to the questionnaires. Those individuals who underwent surgeries ofany kind on the affected shoulder during the previous 12 months and individuals with shoulder instabilities were excluded.All of the participants were evaluated by two operators, and the CMS-IT, Disabilities of the Arm, Shoulder, and Hand(DASH) questionnaire, and visual analog scale (VAS) were administered. The internal consistency was evaluated usingCronbach’sa, whereas the intra-rater and inter-rater reliabilities were evaluated using the intraclass correlation coef-ficient (ICC). The validity of the construction was evaluated using Pearson’s correlation coefficient between the scores ofthe administered scales.Results: A population of 72 individuals participated in this study. The internal consistency of theCMS-IT showed a value of 0.81. The ICC values showed that inter- and intra-rater reliability were 0.994 and 0.963,respectively. CMS-IT is inversely correlated with the VAS (0.55) and DASH (0.47) scales.Conclusions: This studyrevealed that the CMS-IT contained good internal consistency and good reliability. The results suggested that the CMS-ITquestionnaire is a reliable and valid tool for assessing the shoulder dysfunctions of the Italian population, and it deservesbroad applications in both clinical practice and research contexts. The scale can also be used as an alternative to thecurrent “gold standard” VAS and DASH. (PDF) Transcultural reliability and validity of an Italian language version of the Constant–Murley Score. Available from: https://www.researchgate.net/publication/343919669_Transcultural_reliability_and_validity_of_an_Italian_language_version_of_the_Constant-Murley_Score [accessed Nov 02 2020]

    Active Ground Vehicle Control with use of a Super-Twisting Algorithm in the Presence of Parameter Variations

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    International audienceIn this paper, we consider a vehicle equipped with active front steer and rear torque vectoring. While the former adds an incremental steer angle to the driver's input, the latter imposes a torque by means of the rear axle. The active front steer control is actuated through the front tires, while the rear torque vectoring can be actuated through the rear tires. A nonlinear controller using the super-twisting algorithm is designed in order to track in finite time lateral and yaw angular velocity references. We consider one estimation method, given in the literature, to estimate the tire-road coefficient, and we design a dynamic controller to estimate the perturbing terms due to the vehicle's mass and inertia variations, and due to the variation of the tire parameters. Comparisons with a simple PI-based controller are done, and some simulation results highlight the advantages of the proposed controller

    Modulation of thymidilate synthase and p53 expression by HDAC inhibitor vorinostat resulted in synergistic antitumor effect in combination with 5FU or raltitrexed.

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    Despite the introduction of several novel anticancer agents almost 50% of colorectal cancer (CRC) patients die for cancer suggesting the necessity of new therapeutical approaches. In this study we demonstrated that the HDAC inhibitor vorinostat exerted potent antiproliferative effect in a panel of mut- and wt-p53 human CRC cell lines. Moreover, in combination with 5-fluorouracil modulated by folinic acid (5FU-FA) or with Raltitrexed (RTX), both commonly used in the treatment of this disease, it showed a clear schedule-dependent synergistic antiproliferative interaction as demonstrated by calculating combination indexes. Only simultaneous, or 24 h pretreatment with vorinostat followed by either agent, produced synergistic effect paralleled by evident cell cycle perturbations with major S-phase arrest. Moreover, we provided for the first time evidences that vorinostat can overcome resistance to both 5FU and RTX. Downmodulation of Thymidilate synthase (TS) protein induced by vorinostat within 24 h, represented a key factor in enhancing the effects of both drugs in sensitive as well as resistant tumor cells. Furthermore, p53, whose wild-type expression is critical for sensitivity to 5FU and RTX, was upregulated by vorinostat in wt- and downregulated in mut-p53 cells, suggesting an additional mechanism of the antiproliferative synergistic interactions observed. Overall these data add new insights in the mechanism of vorinostat antitumor effect and suggested that the association of vorinostat plus 5FU-FA and/or RTX should be clinically explored

    Sleep-related declarative memory consolidation in children and adolescents with developmental dyslexia

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    Sleep has a crucial role in memory processes, and maturational changes in sleep electrophysiology are involved in cognitive development. Albeit both sleep and memory alterations have been observed in Developmental Dyslexia (DD), their relation in this population has been scarcely investigated, particularly concerning topographical aspects. The study aimed to compare sleep topography and associated sleep-related declarative memory consolidation in participants with DD and normal readers (NR). Eleven participants with DD and 18 NR (9–14 years old) underwent a whole-night polysomnography. They were administered a word pair task before and after sleep to assess for declarative memory consolidation. Memory performance and sleep features (macro and microstructural) were compared between the groups, and the intercorrelations between consolidation rate and sleep measures were assessed. DD showed a deeper worsening in memory after sleep compared to NR and reduced slow spindles in occipito-parietal and left fronto-central areas. Our results suggest specific alterations in local sleep EEG (i.e., sleep spindles) and in sleep-dependent memory consolidation processes in DD.We highlight the importance of a topographical approach, which might shed light on potential alteration in regional cortical oscillation dynamics in DD. The latter might represent a target for therapeutic interventions aimed at enhancing cognitive functioning in DD
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