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Measurement of the t(t)over-bar production cross section, the top quark mass, and the strong coupling constant using dilepton events in pp collisions at root s=13TeV
No full textA measurement of the top quark-antiquark pair production cross section sigma(t (t) over bar) in proton-proton collisions at a centre-of-mass energy of 13 TeV is presented. The data correspond to an integrated luminosity of 35.9 fb(-1), recorded by the CMS experiment at the CERN LHC in 2016. Dilepton events (e(+/-) mu(-/+), mu(+) mu(-), e(+) e(-)) are selected and the cross section is measured from a likelihood fit. For a top quark mass parameter in the simulation of m(t)(MC) = 172.5 GeV the fit yields a measured cross section sigma(t (t) over bar) = 803 +/- 2 (stat) +/- 25 (syst) +/- 20 (lumi) pb, in agreement with the expectation from the standard model calculation at next-to-next-to-leading order. A simultaneous fit of the cross section and the top quark mass parameter in the POWHEG simulation is performed. The measured value of m(t)(MC) = 172.33 +/- 0.14 (stat)(-0.72)(+0.66) (syst) GeV is in good agreement with previous measurements. The resulting cross section is used, together with the theoretical prediction, to determine the top quark mass and to extract a value of the strong coupling constant with different sets of parton distribution functions
New Correlation for the Prediction of Bursting of a Laminar Separation Bubble
No full textLaminar separation bubble bursting is a deleterious phenomenon resulting in a loss of lift and an increase of drag at relatively low Reynolds numbers. There are some criteria in vogue in the literature to characterize the onset of the bursting phenomenon. A relatively simple one-parameter criterion that was proposed, based on the work done in the authors' laboratory in the past, has been found to bequite successful in characterizing bursting and is well cited in the literature, includingin unsteady flow contexts. This criterion is revisited, and it is reassessed in the light of recent laminar separation bubble measurements over an Eppler 387 airfoil. Building on these foundations, the pursuit of a more robust bursting criterion that could also be predictive in nature led to a new simple criterion. According to this, bursting is signaled by the ratio of the freestream velocity at reattachment to that at separation reaching a critical value of 0.86. New engineering correlations are also proposed for the length and height of laminar separation bubbles that, along with the new bursting criterion, should be extremely useful in the design of low-Reynolds-number aerodynamic configurations
HDPE/UHMWPE hybrid nanocomposites with surface functionalized graphene oxide towards improved strength and cytocompatibility
No full textHigh-density polyethylene (HDPE)-based and ultra-high molecular weight polyethylene (UHMWPE)-based composites with carbonaceous reinforcements are being widely investigated for biomedical applications. The enhancement of material properties critically depends on the nature, amount and compatibility of the reinforcement with the polymeric matrix. To this end, this study demonstrates the efficacy of a `dual' hybrid approach of incorporating modified inorganic nanofiller into an optimized polyethylene blend. In particular, a unique synthesis strategy was adopted to design a covalently bonded maleated polyethylene (mPE) grafted modified graphene oxide (mGO) hybrid nanocomposite. In this scheme, polyethyleneimine (PEI) was initially attached onto GO to synthesize amine functionalized GO (GO-PEI). This is followed by mPE grafting, resulting in mGO. Melt-extrusion together with injection moulding of a polymer mix (60% HDPE-40% UHMWPE) with different proportions (less than or equal to 3 wt%) of surface functionalized GO was conducted to develop nanocomposites of different sizes and shapes. When compared with unreinforced PE blend, the nanocomposites with 1 wt% mGO exhibited an increase in ultimate tensile strength by 120% (up to 65 MPa) and elastic modulus by 40% (up to 908 MPa). The uniform dispersion of modified GO nanofillers, confirmed using X-ray micro-computed tomography and transmission electron microscopy, facilitated effective interfacial adhesion and compatibility with the hybrid polymer matrix. The variation in mechanical properties with GO/mGO addition to PE blend was critically discussed in reference to the structural modification of GO, crystallinity and nature of dispersion of fillers. Importantly, the nanocomposites support the attachment and proliferation of C2C12 murine myoblast cells over 3 days in culture in a statistically insignificant manner with respect to polymer blends without any nanofiller. Taken together, the experimental results suggest that HDPE/UHMWPE/mGO is a promising biomaterial for bone tissue engineering applications
Comparative analysis of ultra-compact few-mode photonic wires on LNOI and SOI platforms
No full textParametric comparison of ultra-compact few-mode waveguides of three types (strip, rib, and buried) on thin-film Lithium Niobate On Insulator (LNOI) and SOI platforms is presented. Performance of waveguides is compared in terms of waveguide cross-sectional area, mode loss, dispersion, mode-hybridization and power confinement for both quasi-transverse electric (qTE) and quasi-transverse magnetic (qTM) modes. It is found that LNOI waveguides exhibit lower dispersion with physical dimensions comparable to that of SOI waveguides. The results are vital in choosing an optimum configuration of few-mode waveguides which is crucial for designing few-mode devices in mode-multiplexing schemes
On Optimal Scheduling and Power Control for Uncoordinated Multiple Access by Energy Harvesting Nodes
No full textThe goal in this paper is to design an optimal scheduling and power control policy that maximizes the long-term time-averaged sum throughput of a Gaussian multiple access channel (MAC) with energy harvesting (EH) nodes, and facilitates uncoordinated operation of the nodes. In order to benchmark the performance of any policy, we derive an upper bound on the sum throughput by considering a genie-aided system where the nodes have infinite capacity batteries and can freely share the available energy between them. Next, we design a time-sharing based power control policy for the EH MAC, which operates in an uncoordinated fashion. We show that, surprisingly, the sum throughput obtained by the proposed policy achieves the genie-aided upper bound asymptotically in the battery size at each node. Simulation results validate the theoretical findings and illustrate the relative impact of various system parameters (e.g., the battery size required to achieve the upper bound) on the number of nodes and the variation in the harvesting rates across the nodes
Interplay of cold shock protein E with an uncharacterized protein, YciF, lowers porin expression and enhances bile resistance in Salmonella Typhimurium
No full textBacterial cold shock proteins (CSPs) function as RNA chaperones. To assess CSP's roles in the intracellular human pathogen Salmonella Typhimurium, we analyzed their expression in varied stress conditions. We found that cold shock protein E (cspE or STM14_0732) is up-regulated during bile salt-induced stress and that an S. Typhimurium strain lacking cspE (cspE) displays dose-dependent sensitivity to bile salts, specifically to deoxycholate. We also found that an uncharacterized gene, yciF (STM14_2092), is up-regulated in response to bile stress in WT but not in the cspE strain. Complementation with WT CspE, but not with a F30V CspE variant, abrogated the bile sensitivity of cspE as did multicopy overexpression of yciF. Northern blotting experiments with rifampicin disclosed that the regulation of yciF expression is, most likely, due to the RNA-stabilizing activity of CspE. Importantly, electrophoretic mobility shift assays indicated that purified CspE, but not the F30V variant, directly binds yciF mRNA. We also observed that the extra-cytoplasmic stress-response (ESR) pathway is augmented in the bile-treated cspE strain, as judged by induction of RpoE regulon genes (rpoE, degP, and rybB) and downstream ESR genes (hfq, rne, and PNPase). Moreover, the transcript levels of the porin genes, ompD, ompF, and ompC, were higher in bile salts-stressed cspE and correlated with higher intracellular accumulation of the fluorescent DNA stain bisBenzimide H 33258, indicating greater cell permeability. In conclusion, our study has identified YciF, a CspE target involved in the regulation of porins and in countering bile stress in S. Typhimurium
Tunable Large Dispersion in Hybrid Modes of Lithium Niobate-on-Insulator Multimode Waveguides
No full textWe report a large group velocity dispersion of hybrid modes in a LiNbO3-on-insulator multimode rib waveguide. A peak dispersion of +/- 49000 ps/(nm.km) is obtained in the mode hybridization region between TE00 and TM10 modes with a full width at half maximum of 10 nm. Dispersion for hybrid modes is tunable around +/- 15000 ps/(nm.km), +/- 22000 ps/(nm.km), and +/- 49000 ps/(nm.km) occurring at wavelengths of 1272, 1372, and 1496 nm, respectively, in the telecommunication band. In the wavelength range from 1530 to 1600 nm, the proposed rib waveguide is free of hybrid modes. In this region, the waveguide exhibits a flat dispersion profile for all eight guided modes with a maximum <1000 ps/(nm.km)
Correlated protein conformational states and membrane dynamics during attack by pore-forming toxins
No full textPore-forming toxins (PFTs) are a class of proteins implicated in a wide range of virulent bacterial infections and diseases. These toxins bind to target membranes and subsequently oligomerize to form functional pores that eventually lead to cell lysis. While the protein undergoes large conformational changes on the bilayer, the connection between intermediate oligomeric states and lipid reorganization during pore formation is largely unexplored. Cholesterol-dependent cytolysins (CDCs) are a subclass of PFTs widely implicated in food poisoning and other related infections. Using a prototypical CDC, listeriolysin O (LLO), we provide a microscopic connection between pore formation, lipid dynamics, and leakage kinetics by using a combination of Forster resonance energy transfer (FRET) and fluorescence correlation spectroscopy (FCS) measurements on single giant unilamellar vesicles (GUVs). Upon exposure to LLO, two distinct populations of GUVs with widely different leakage kinetics emerge. We attribute these differences to the existence of oligomeric intermediates, sampling various membrane-bound conformational states of the protein, and their intimate coupling to lipid rearrangement and dynamics. Molecular dynamics simulations capture the influence of various membrane-bound conformational states on the lipid and cholesterol dynamics, providing molecular interpretations to the FRET and FCS experiments. Our study establishes a microscopic connection between membrane binding and conformational changes and their influence on lipid reorganization during PFT-mediated cell lysis. Additionally, our study provides insights into membrane-mediated protein interactions widely implicated in cell signaling, fusion, folding, and other biomolecular processes
The exact phase diagram for a semipermeable TASEP with nonlocal boundary jumps
No full textWe consider a finite one-dimensional totally asymmetric simple exclusion process with four types of particles, { 1, 0, (1)over-bar, *}, in contact with reservoirs. Particles of species 0 can neither enter nor exit the lattice, and those of species * are constrained to lie at the first and last site. Particles of species 1 enter from the left reservoir into either the first or second site, move rightwards, and leave from either the last or penultimate site. Conversely, particles of species 1 enter from the right reservoir into either the last or penultimate site, move leftwards, and leave from either the first or last site. This dynamics is motivated by a natural random walk on the Weyl group of type D. We compute the exact nonequilibrium steady state distribution using a matrix ansatz building on earlier work of Arita. We then give explicit formulas for the nonequilibrium partition function as well as densities and currents of all species in the steady state, and derive the phase diagram
Pamidronate functionalized mucoadhesive compact for treatment of osteoporosis-in vitro and in vivo characterization
No full textThe aim of the present study was to develop directly compressed compacts for mucoadhesive delivery of pamidronate disodium for the treatment of osteoporosis in the rat model induced by methylprednisolone. A blend of HPMC-4KM and thiolated chitosan was used as the biodegradable polymers for the formulation of mucoadhesive compacts. The drug-polymer characterization was done by different analytical techniques like FTIR, DSC, and XRD. Biochemical analysis, histopathology and SEM analysis of the trabecular region of the femur were done to confirm the induction and treatment of osteoporosis. The analytical characterization revealed the formation of polyelectrolyte complexes between the drug and polymer due to high compressional forces. Formulation T2 with thiolated chitosan/HPMC-4KM ratio of 0.5/1 showed superior swelling, mucoadhesive properties, and better drug release and was investigated for in vivo study. The compact formulation improved the serum biomarkers level and bone microarchitectural properties in the osteoporotic rats as revealed by histopathology and SEM analysis. The results indicated the potential use of thiolated polymer based mucoadhesive compacts as a rational tactic for osteoporosis therapy