199 research outputs found

    Bacterial contamination of Nigerian currency notes circulating within selected markets in Kaduna Metropolis

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    A study was carried out with the aim to assess the bacterial contamination of Nigerian currency notes circulating within selected markets in Kaduna Metropolis. A total of 80 samples of Nigerian currency notes of different denominations were randomly collected from Sabo, Kakuri, Kawo, Dattawa, U/rimi, Kasuwar Sati, Nassarawa, Chechenia, Kasuwar barci and Kasuwar Laraba markets in sterilized polythene bags  The mean bacterial counts of the different currency notes were determined using standard microbiological methods. The types of bacteria associated with the currency notes and their frequency of occurrence were also determined using standard methods. The result of the study showed that lower denomination currencies had  higher microbial loads, 22.65×104 ± 0.22×104 CFU/g for N100, 26.55×104 ± 0.45×104 CFU/g for N50, 20.95×104 ± 0.26×104 CFU/g for N20, 21.75×104 ± 0.35×104 CFU/g for N10 and 21.75×104  ± 0.12×104 CFU/g for N5 which were mostly obtained from Kakuri, Sabo, Nasarawa, and U/Rimi markets The species of bacteria isolated from the currencies were Staphylococcus aureus (52.2%), Escherichia coli (31.3%), Salmonella species (11.9%), and Proteus species (4.5%). Staphylococcus aureus was the most predominant bacteria isolated. This study revealed that currency notes collected from the markets within Kaduna Metropolis, were highly contaminated with different pathogenic bacteria thus, calls for public awareness on the potential risks associated with poor handling of currency notes at all levels. Key words: Bacterial contamination, currency notes, selected markets, Kaduna Metropolis &nbsp

    Antibacterial activities of ethanol leaf and bark extracts of Terminalia avicennioides against methicillin resistant Staphyloccocus aureus

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    The study was undertaken with the aim to determine the Antibacterial activities of ethanol leaf and bark extracts of Terminalia avicennioides against Methicillin resistant Staphyloccocus aureus (MRSA). Air-dried leaves and barks of Terminalia avicennioides, were powdered and each extracted with 70% ethanol by cold maceration method. Each extract was screened for the presence of some secondary metabolites using qualitative methods. MRSA clinical isolates from infected wounds of patients were reconfirmed using standard microbiological methods. The antibacterial activities of extracts against bacteria were determined by agar well diffusion and broth dilution methods. The results of phytochemical screening of extracts revealed the presence of carbohydrates, alkaloids, tannins, flavonoids, saponins, steroids, triterpens, glycosides and phenols. All the extracts exhibited significant inhibitory effects (P < 0.05) against isolates of bacteria at varied concentrations of 100, 50, 25 and 12.5 and 6.25mg/mL and the activity of each extract was found to be concentration dependent. The mean zone of inhibition of the leaf extract against bacteria ranged between 12.52 ± 1.86 mm -17.12 ± 1.89 mm while the mean zone of inhibition of the bark extract ranged between 10.26 ± 1.37 mm - 14.45 ± 1.47 mm. The leaf extract was more effective with MIC and MBC of 6.25mg/mL and 25mg/mL. The results of this study show that the leaf and bark extracts of T. avicennioides contain compounds with antibacterial activities against MRSA which provide basis for further studies to isolate, identify and standardize the active compounds for drug developmen

    Measurements of differential production cross sections for a Z boson in association with jets in pp collisions at root s=8 TeV

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    Search for leptophobic Z ' bosons decaying into four-lepton final states in proton-proton collisions at root s=8 TeV

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    Search for black holes and other new phenomena in high-multiplicity final states in proton-proton collisions at root s=13 TeV

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    Search for high-mass diphoton resonances in proton-proton collisions at 13 TeV and combination with 8 TeV search

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    Search for heavy resonances decaying into a vector boson and a Higgs boson in final states with charged leptons, neutrinos, and b quarks

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    Pileup mitigation at CMS in 13 TeV data

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    With increasing instantaneous luminosity at the LHC come additional reconstruction challenges. At high luminosity, many collisions occur simultaneously within one proton-proton bunch crossing. The isolation of an interesting collision from the additional "pileup" collisions is needed for effective physics performance. In the CMS Collaboration, several techniques capable of mitigating the impact of these pileup collisions have been developed. Such methods include charged-hadron subtraction, pileup jet identification, isospin-based neutral particle "ÎŽÎČ" correction, and, most recently, pileup per particle identification. This paper surveys the performance of these techniques for jet and missing transverse momentum reconstruction, as well as muon isolation. The analysis makes use of data corresponding to 35.9 fb−1^{-1} collected with the CMS experiment in 2016 at a center-of-mass energy of 13 TeV. The performance of each algorithm is discussed for up to 70 simultaneous collisions per bunch crossing. Significant improvements are found in the identification of pileup jets, the jet energy, mass, and angular resolution, missing transverse momentum resolution, and muon isolation when using pileup per particle identification

    Identification of heavy, energetic, hadronically decaying particles using machine-learning techniques

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    Machine-learning (ML) techniques are explored to identify and classify hadronic decays of highly Lorentz-boosted W/Z/Higgs bosons and top quarks. Techniques without ML have also been evaluated and are included for comparison. The identification performances of a variety of algorithms are characterized in simulated events and directly compared with data. The algorithms are validated using proton-proton collision data at √s = 13TeV, corresponding to an integrated luminosity of 35.9 fb−1. Systematic uncertainties are assessed by comparing the results obtained using simulation and collision data. The new techniques studied in this paper provide significant performance improvements over non-ML techniques, reducing the background rate by up to an order of magnitude at the same signal efficiency

    Measurement of the azimuthal anisotropy of Y(1S) and Y(2S) mesons in PbPb collisions at √S^{S}NN = 5.02 TeV

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    The second-order Fourier coefficients (υ2_{2}) characterizing the azimuthal distributions of ΄(1S) and ΄(2S) mesons produced in PbPb collisions at sNN\sqrt{s_{NN}} = 5.02 TeV are studied. The ΄mesons are reconstructed in their dimuon decay channel, as measured by the CMS detector. The collected data set corresponds to an integrated luminosity of 1.7 nb−1^{-1}. The scalar product method is used to extract the υ2_{2} coefficients of the azimuthal distributions. Results are reported for the rapidity range |y| < 2.4, in the transverse momentum interval 0 < pT_{T} < 50 GeV/c, and in three centrality ranges of 10–30%, 30–50% and 50–90%. In contrast to the J/ψ mesons, the measured υ2_{2} values for the ΄ mesons are found to be consistent with zero
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