Experimental analysis of damage creation and permanent indentation on highly oriented plates

This paper presents an experimental investigation concerning low-velocity impact and quasi-static indentation tests on highly oriented laminates used in aeronautical and aerospace applications. The damage observed in such laminates is very particular. Post mortem analysis were carried out which helped to define an impact damage scenario. Microscopic observations led to explain the mechanism of permanent indentation formation which is a fundamental point of damage tolerance justification. Equivalence between static and dynamic is also discussed

Experimental analysis of CFRP laminates subjected to Compression After Impact: the role of impact-induced cracks in failure

This paper presents an experimental analysis of composite laminates subjected to low velocity impact and compression after impact (CAI). Two types of CFRP specimens are studied: a highly oriented laminate and a quasi-isotropic laminate. Impact energy is chosen to obtain a dent depth less than or around the BVID level. 3D digital image correlation is used to make detailed analyses of plates behaviour during CAI. Even if the damage morphologies are very different, the study shows that, in both cases, classical global buckling of the plate and local buckling of the delaminated sublaminates are accompanied by a crack on the impact face of the laminate. This crack appears in the highly damaged zone, under the impactor, and propagates in the direction transverse to the loading direction in a stable way. It is shown to play an essential role in the final failure of the laminate under compression

Simultaneous pressure-volume measurements using optical sensors and MRI 1 for left ventricle function assessment during animal experiment 2

International audienceSimultaneous pressure and volume measurements enable the extraction of valuable parameters for left ventricle function assessment. Cardiac MR has proven to be the most accurate method for volume estimation. Nonetheless, measuring pressure simultaneously during MRI acquisitions remains a challenge given the magnetic nature of the widely used pressure transducers. In this study we show the feasibility of simultaneous in vivo pressure-volume acquisitions with MRI using optical pressure sensors. Pressure-volume loops were calculated while inducing three inotropic states in a sheep and functional indices were extracted, using single beat loops, to characterize systolic and diastolic performance. Functional indices evolved as expected in response to positive inotropic stimuli. The end-systolic elastance, representing the contractility index, the diastolic myocardium compliance, and the cardiac work efficiency all increased when inducing inotropic state enhancement. The association of MRI and optical pressure sensors within the left ventricle successfully enabled pressure-volume loop analysis after having respective data simultaneously recorded during the experimentation without the need to move the animal between each inotropic state

Insights on adaptive and innate immunity in canine leishmaniosis

Canine leishmaniosis (CanL) is caused by the parasite Leishmania infantum and is a systemic disease, which can present with variable clinical signs, and clinicopathological abnormalities. Clinical manifestations can range from subclinical infection to very severe systemic disease. Leishmaniosis is categorized as a neglected tropical disease and the complex immune responses associated with Leishmania species makes therapeutic treatments and vaccine development challenging for both dogs and humans. In this review, we summarize innate and adaptive immune responses associated with L. infantum infection in dogs, and we discuss the problems associated with the disease as well as potential solutions and the future direction of required research to help control the parasite

Iron acquisition in Bacillus cereus: the roles of IlsA and bacillibactin in exogenous ferritin iron mobilization

9siIn host-pathogen interactions, the struggle for iron may have major consequences on the outcome of the disease. To overcome the low solubility and bio-availability of iron, bacteria have evolved multiple systems to acquire iron from various sources such as heme, hemoglobin and ferritin. The molecular basis of iron acquisition from heme and hemoglobin have been extensively studied; however, very little is known about iron acquisition from host ferritin, a 24-mer nanocage protein able to store thousands of iron atoms within its cavity. In the human opportunistic pathogen Bacillus cereus, a surface protein named IlsA (Iron-regulated leucine rich surface protein type A) binds heme, hemoglobin and ferritin in vitro and is involved in virulence. Here, we demonstrate that IlsA acts as a ferritin receptor causing ferritin aggregation on the bacterial surface. Isothermal titration calorimetry data indicate that IlsA binds several types of ferritins through direct interaction with the shell subunits. UV-vis kinetic data show a significant enhancement of iron release from ferritin in the presence of IlsA indicating for the first time that a bacterial protein might alter the stability of the ferritin iron core. Disruption of the siderophore bacillibactin production drastically reduces the ability of B. cereus to utilize ferritin for growth and results in attenuated bacterial virulence in insects. We propose a new model of iron acquisition in B. cereus that involves the binding of IlsA to host ferritin followed by siderophore assisted iron uptake. Our results highlight a possible interplay between a surface protein and a siderophore and provide new insights into host adaptation of B. cereus and general bacterial pathogenesis.openopenSegond D; Abi Khalil E; Buisson C; Daou N; Kallassy M; Lereclus D; Arosio P; Bou-Abdallah F; Nielsen Le Roux C.Segond, D; Abi Khalil, E; Buisson, C; Daou, N; Kallassy, M; Lereclus, D; Arosio, Paolo; Bou Abdallah, F; Nielsen Le Roux, C

Moisture computing-based internet of vehicles (IoV) architecture for smart cities

Recently, the concept of combining 'things' on the Internet to provide various services has gained tremendous momentum. Such a concept has also impacted the automotive industry, giving rise to the Internet of Vehicles (IoV). IoV enables Internet connectivity and communication between smart vehicles and other devices on the network. Shifting the computing towards the edge of the network reduces communication delays and provides various services instantly. However, both distributed (i.e., edge computing) and central computing (i.e., cloud computing) architectures suffer from several inherent issues, such as high latency, high infrastructure cost, and performance degradation. We propose a novel concept of computation, which we call moisture computing (MC) to be deployed slightly away from the edge of the network but below the cloud infrastructure. The MC-based IoV architecture can be used to assist smart vehicles in collaborating to solve traffic monitoring, road safety, and management issues. Moreover, the MC can be used to dispatch emergency and roadside assistance in case of incidents and accidents. In contrast to the cloud which covers a broader area, the MC provides smart vehicles with critical information with fewer delays. We argue that the MC can help reduce infrastructure costs efficiently since it requires a medium-scale data center with moderate resources to cover a wider area compared to small-scale data centers in edge computing and large-scale data centers in cloud computing. We performed mathematical analyses to demonstrate that the MC reduces network delays and enhances the response time in contrast to the edge and cloud infrastructure. Moreover, we present a simulation-based implementation to evaluate the computational performance of the MC. Our simulation results show that the total processing time (computation delay and communication delay) is optimized, and delays are minimized in the MC as apposed to the traditional approaches

Search for Dark Matter Candidates and Large Extra Dimensions in Events with a Photon and Missing Transverse Momentum in pp Collision Data at s√=7 TeV with the ATLAS Detector

Results of a search for new phenomena in events with an energetic photon and large missing transverse momentum in proton-proton collisions at s√=7  TeV are reported. Data collected by the ATLAS experiment at the LHC corresponding to an integrated luminosity of 4.6  fb−1 are used. Good agreement is observed between the data and the standard model predictions. The results are translated into exclusion limits on models with large extra spatial dimensions and on pair production of weakly interacting dark matter candidates

Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at root s = 8 TeV with the ATLAS detector

The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/Rc = 950 GeV for a cut-off scale times radius (ΛRc) of approximately 30.G. Aad … P. Jackson … L. Lee … A. Petridis … N. Soni ... M. White ... et al. (The ATLAS Collaboration

Measurements of the nuclear modification factor for jets in Pb+Pb collisions at root sNN =2.76 TeV with the ATLAS detector

Measurements of inclusive jet production are performed in pp and Pb+Pb collisions at √(s)NN=2.76  TeV with the ATLAS detector at the LHC, corresponding to integrated luminosities of 4.0 and 0.14  nb(-1), respectively. The jets are identified with the anti-k(t) algorithm with R=0.4, and the spectra are measured over the kinematic range of jet transverse momentum 32<p(T)<500  GeV and absolute rapidity |y|<2.1 and as a function of collision centrality. The nuclear modification factor R(AA) is evaluated, and jets are found to be suppressed by approximately a factor of 2 in central collisions compared to pp collisions. The R(AA) shows a slight increase with p(T) and no significant variation with rapidity.G. Aad … P. Jackson … L. Lee … A. Petridis … N. Soni ... M. White ... et al. (The ATLAS Collaboration