459 research outputs found
Development of a Digital Twin Model for Real-Time Assessment of Collisione Hazards
The AEC industry is nowadays one of the most hazardous industries in the world. The construction sector employees about 7% of the world’s work force but is responsible for 30-40% of fatalities. As statistics demonstrate, interferences between workers-on-foot and moving vehicles have caused several injuries and fatalities over the years. Despite safety organizational measures, passive safety devices imposed by regulations and efforts from training procedures, scarce improvements have been recorded. Recent research studies propose technology driven approaches as the key solutions to integrate standard health and safety management practices. This is motivated by the evidence that the dynamics of complex systems can hardly be predicted; rather a proactive approach to health and safety is more effective. Current technologies installed on construction equipment can usually react according to a strict logic, such as sending proximity alerts when workers and equipment are too close. Nevertheless, these approaches barely do make informed decisions in real-time, e.g. including the level of reactiveness of the endangered worker. In similar circumstances a digital twin of the construction site, updated by real-time data from sensors and enriched by artificial intelligence, can pro-actively support activities, forecasting dangerous scenarios on the base of several factors. In this paper a laboratory mock-up has been assumed as the test case, supported by a game engine, which is able to replicates the job site for the execution of bored piles. In such a scenario populated by an avatar of a sensor-equipped worker and a virtual driller, a Bayesian network, implemented within the game engine and fed in runtime by sensor data, works out collision probability in real-time in order to send warnings and avoid fatal accidents
Approche décisionnelle géospatiale et multicritère dans l’identification des zones potentielles de recharge des eaux souterraines : cas du bassin versant du Mayo Bocki au Nord Cameroun
La présente étude a été effectuée pour déterminer les zones potentielles de recharge des eaux souterraines. Pour ce faire, la démarche méthodologique était basée sur l’analyse multicritère associée aux techniques géospatiales. Les données utilisées étaient entre autres les images satellitaires, les fonds cartographiques, les données pluviométriques et les niveaux statiques. Ces données ont permis d’exprimer sous forme de carte thématique les facteurs régissant la recharge (pente, drainage, lithologie, fracturation, sol, pluviométrie et occupation du sol). L’analyse de sensibilité par suppression d’un paramètre a permis d’établir l’ordre d’influence suivant : Lit > Sol > AACH > Df > Pl > Pe > Dd > OS. Le croisement de tous ces paramètres après pondération a conduit à l’élaboration de la carte qui montre que les zones à ort potentiel occupent 3 % de la zone d’étude pendant que les zones de faible à faible potentialité sont de l’ordre de 58 % dans le bassin. Les zones à potentialité moyenne quant à elles représentent 39%. Ce support cartographique constitue indéniablement un outil d’aide à la décision pour les gestionnaires de l’eau.
This study was carried out to determine potential groundwater recharge areas. To do this, the methodological approach was based on multi-criteria analysis associated with geospatial techniques. The data used were, among others, satellite images, base maps, rainfall data and static levels. These data made it possible to express in the form of a thematic map the factors governing the recharge (slope, drainage, lithology, fracturing, soil, rainfall and land use). The sensitivity analysis by deletion of a parameter made it possible to establish the following order of influence: Lit > Sol > AACH > Df > Pl > Pe > Dd > OS. The crossing of all these parameters after weighting led to the development of the map of potential recharge zones which revealed that the zones with high potential occupy 3% of the study zone while the zones with low to low potentiality are around 58% in the basin. Areas with average potential represent 39%. This cartographic support is undeniably a decision-making tool for water managers
Multiple Roles of Transforming Growth Factor Beta in Amyotrophic Lateral Sclerosis
Transforming growth factor beta (TGFB) is a pleiotropic cytokine, known to be dysregulated in many neurodegenerative disorders and particularly in amyotrophic lateral sclerosis (ALS). This motor neuronal disease is non-cell autonomous, as it affects not only motor neurons, but also their surrounding glial cells, and their target skeletal muscle fibers. Here, we analyze the multiple roles of TGFB in these cell types, and how TGFB signaling is altered in ALS tissues. Data reported support a crucial involvement of TGFB in the etiology and progression of ALS, leading us to hypothesize that an imbalance of TGFB signaling, diminished at the pre-symptomatic stage and then increased with time, could be linked to ALS progression. A reduced stimulation of the TGFB pathway at the beginning of disease blocks its neuroprotective effects and promotes glutamate excitotoxicity. At later disease stages, the persistent activation of the TGFB pathway promotes an excessive microglial activation and strengthens muscular dysfunction. The therapeutic potential of TGFB is discussed here, in order to foster new approaches to treat ALS
Enhanced Clearance of Neurotoxic Misfolded Proteins by the Natural Compound Berberine and Its Derivatives
Background: Accumulation of misfolded proteins is a common hallmark of several neurodegenerative disorders (NDs) which results from a failure or an impairment of the proteinquality control (PQC) system. The PQC system is composed by chaperones and the degradative systems (proteasome and autophagy). Mutant proteins that misfold are potentially neurotoxic, thus strategies aimed at preventing their aggregation or at enhancing their clearance are emerging as interesting therapeutic targets for NDs. Methods: We tested the natural alkaloid berberine (BBR) and some derivatives for their capability to enhance misfolded protein clearance in cell models of NDs, evaluating which degradative pathway mediates their action. Results: We found that both BBR and its semisynthetic derivatives promote degradation of mutant androgen receptor (ARpolyQ) causative of spinal and bulbar muscular atrophy, acting mainly via proteasome and preventing ARpolyQ aggregation. Overlapping effects were observed on other misfolded proteins causative of amyotrophic lateral sclerosis, frontotemporal-lobar degeneration or Huntington disease, but with selective and specific action against each different mutant protein. Conclusions: BBR and its analogues induce the clearance of misfolded proteins responsible for NDs, representing potential therapeutic tools to counteract these fatal disorders
Autophagic and proteasomal mediated removal of mutant androgen receptor in muscle models of spinal and bulbar muscular atrophy
Spinal and bulbar muscular atrophy (SBMA) is an X-linked motoneuron disease (MND) caused by a mutant androgen receptor (AR) containing an elongated polyglutamine (polyQ) tract. ARpolyQ toxicity is triggered by androgenic AR ligands, which induce aberrant conformations (misfolding) of the ARpolyQ protein that aggregates. Misfolded proteins perturb the protein quality control (PQC) system leading to cell dysfunction and death. Spinal cord motoneurons, dorsal root ganglia neurons and skeletal muscle cells are affected by ARpolyQ toxicity. Here, we found that, in stabilized skeletal myoblasts (s-myoblasts), ARpolyQ formed testosterone-inducible aggregates resistant to NP-40 solubilization; these aggregates did not affect s-myoblasts survival or viability. Both wild type AR and ARpolyQ were processed via proteasome, but ARpolyQ triggered (and it was also cleared via) autophagy. ARpolyQ reduced two pro-autophagic proteins expression (BAG3 and VCP), leading to decreased autophagic response in ARpolyQ s-myoblasts. Overexpression of two components of the chaperone assisted selective autophagy (CASA) complex (BAG3 and HSPB8), enhanced ARpolyQ clearance, while the treatment with the mTOR independent autophagy activator trehalose induced complete ARpolyQ degradation. Thus, trehalose has beneficial effects in SBMA skeletal muscle models even when autophagy is impaired, possibly by stimulating CASA to assist the removal of ARpolyQ misfolded species/aggregates
A new limit on the light speed isotropy from the GRAAL experiment at the ESRF
When the electrons stored in the ring of the European Synchrotron Radiation
Facility (ESRF, Grenoble) scatter on a laser beam (Compton scattering in
flight) the lower energy of the scattered electron spectra, the Compton Edge
(CE), is given by the two body photon-electron relativistic kinematics and
depends on the velocity of light. A precision measurement of the position of
this CE as a function of the daily variations of the direction of the electron
beam in an absolute reference frame provides a one-way test of Relativistic
Kinematics and the isotropy of the velocity of light. The results of GRAAL-ESRF
measurements improve the previously existing one-way limits, thus showing the
efficiency of this method and the interest of further studies in this
direction.Comment: Proceed. MG12 meeting, Paris, July, 200
Trehalose induces autophagy via lysosomal-mediated TFEB activation in models of motoneuron degeneration
Macroautophagy/autophagy, a defense mechanism against aberrant stresses, in neurons counteracts aggregate-prone misfolded protein toxicity. Autophagy induction might be beneficial in neurodegenerative diseases (NDs). The natural compound trehalose promotes autophagy via TFEB (transcription factor EB), ameliorating disease phenotype in multiple ND models, but its mechanism is still obscure. We demonstrated that trehalose regulates autophagy by inducing rapid and transient lysosomal enlargement and membrane permeabilization (LMP). This effect correlated with the calcium-dependent phosphatase PPP3/calcineurin activation, TFEB dephosphorylation and nuclear translocation. Trehalose upregulated genes for the TFEB target and regulator Ppargc1a, lysosomal hydrolases and membrane proteins (Ctsb, Gla, Lamp2a, Mcoln1, Tpp1) and several autophagy-related components (Becn1, Atg10, Atg12, Sqstm1/p62, Map1lc3b, Hspb8 and Bag3) mostly in a PPP3- and TFEB-dependent manner. TFEB silencing counteracted the trehalose prodegradative activity on misfolded protein causative of motoneuron diseases. Similar effects were exerted by trehalase-resistant trehalose analogs, melibiose and lactulose. Thus, limited lysosomal damage might induce autophagy, perhaps as a compensatory mechanism, a process that is beneficial to counteract neurodegeneration
Limits on light-speed anisotropies from Compton scattering of high-energy electrons
The possibility of anisotropies in the speed of light relative to the
limiting speed of electrons is considered. The absence of sidereal variations
in the energy of Compton-edge photons at the ESRF's GRAAL facility constrains
such anisotropies representing the first non-threshold collision-kinematics
study of Lorentz violation. When interpreted within the minimal Standard-Model
Extension, this result yields the two-sided limit of 1.6 x 10^{-14} at 95%
confidence level on a combination of the parity-violating photon and electron
coefficients kappa_{o+} and c. This new constraint provides an improvement over
previous bounds by one order of magnitude.Comment: 4 pages, 4 figure
The {\eta}'-carbon potential at low meson momenta
The production of mesons in coincidence with forward-going
protons has been studied in photon-induced reactions on C and on a
liquid hydrogen (LH) target for incoming photon energies of 1.3-2.6 GeV at
the electron accelerator ELSA. The mesons have been identified
via the decay
registered with the CBELSA/TAPS detector system. Coincident protons have been
identified in the MiniTAPS BaF array at polar angles of . Under these kinematic constraints the
mesons are produced with relatively low kinetic energy (
150 MeV) since the coincident protons take over most of the momentum of the
incident-photon beam. For the C-target this allows the determination of the
real part of the -carbon potential at low meson momenta by
comparing with collision model calculations of the kinetic energy
distribution and excitation function. Fitting the latter data for
mesons going backwards in the center-of-mass system yields a potential depth of
V = (44 16(stat)15(syst)) MeV, consistent with earlier
determinations of the potential depth in inclusive measurements for average
momenta of 1.1 GeV/. Within the experimental
uncertainties, there is no indication of a momentum dependence of the
-carbon potential. The LH data, taken as a reference to check
the data analysis and the model calculations, provide differential and integral
cross sections in good agreement with previous results for
photoproduction off the free proton.Comment: 9 pages, 13 figures. arXiv admin note: text overlap with
arXiv:1608.0607
Performance of the LHCb muon system
The performance of the LHCb Muon system and its stability across the full
2010 data taking with LHC running at ps = 7 TeV energy is studied. The
optimization of the detector setting and the time calibration performed with
the first collisions delivered by LHC is described. Particle rates, measured
for the wide range of luminosities and beam operation conditions experienced
during the run, are compared with the values expected from simulation. The
space and time alignment of the detectors, chamber efficiency, time resolution
and cluster size are evaluated. The detector performance is found to be as
expected from specifications or better. Notably the overall efficiency is well
above the design requirementsComment: JINST_015P_1112 201
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