42 research outputs found

    Eco-friendly synthesis of silver nanoparticles using Lactobacillus delbrueckii subsp. bulgaricus isolated from kindrimo (locally fermented milk) in Kano State, Nigeria

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    Silver nanoparticles have gained global popularity because of its application in crucial areas such as medical diagnosis/therapy, solar cell development, water treatment, surface coating and cosmetic production. Bacterial synthesis of silver nanoparticles is regarded as eco-friendly due to minimal waste generated while being energy efficient. This study was aimed at synthesizing silver nanoparticles using Lactobacillus specie isolated from Kindrimo under the influence of sunlight irradiation. Lactobacillus delbrueckii subsp. bulgaricus isolated from Kindrimo was identified using morphological and biochemical techniques and confirmed using 16S rRNA gene sequencing. The eco-friendly protocol for the extracellular synthesis of silver nanoparticles was accomplished by treatment of Lactobacillus delbrueckii subsp. bulgaricus extract with silver nitrate solution in the ratio 1:10 under the influence of sunlight irradiation. Synthesized silver nanoparticles were confirmed and characterized using UV-Visible Spectrophotometry, Dynamic Light Scattering, Transmission Electron Microscopy and Energy Dispersion Spectroscopy. The absorbance spectrum preliminarily confirmed the formation of silver nanoparticles by revealing characteristic broad peak at 415nm. Dynamic Light Scattering measurements further confirmed synthesis by showing average particle size distribution of 147nm. Micrograph of Transmission Electron Microscopy revealed that the synthesized silver nanoparticles were polyhedral and spherical in shape with size ranging 1.4 to 8.9nm. The elemental composition of the resultant colloidal solution was shown to contain silver nanoparticles when subjected to Energy Dispersion Spectroscopy. This study proved that the effect of sunlight irradiation on Lactobacillus mediated synthesis of silver nanoparticles is energy efficient and inexpensive.Keywords: Silver nanoparticles; UV-Visible Spectrophotometry; Dynamic Light Scattering; Transmission Electron Microscopy; Energy Dispersion Spectroscop

    Agro Physiological Characteristics of QPM Genotypes As Influenced by Irrigation and Plant Population in a Semi Arid Region of Nigeria

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    Maize is the agronomic grass species that is most sensitive to variations in plant population. An experiment was conducted to assess the response of agrophysiological characters of QPM genotypes to plant population under irrigated conditions in a semi arid ecology of Northern Nigeria. Field trials were conducted at the Irrigation Research Station, Institute for Agricultural Research, Kadawa (110 39’N, 08o 20’E) and 500m above sea level) during 2007, 2008 and 2009 dry seasons to study the effect of (Zea mays L.) genotypes (TZE-W Pop X 1368, EV-DT W99 STR and DMR-ESRW), four plant population (33,333, 44,444, 55,555 and 66,666 plants ha-1) and three irrigation scheduling (40, 60 and 80 centibars soil moisture tension) on the growth and yield of quality protein maize. A split plot design was used with combinations of genotypes and irrigation regimes assigned to the main plot and plant population assigned to the sub-plot. The treatments were replicated three times. The study revealed that genotype EV-DT W99 STR had significantly higher relative growth rate, crop growth rate and net assimilation rate. Increase in plant population significantly decreased leaf area index and net assimilation rate. Delayed irrigation significantly depressed total dry matter production. Based on the results obtained in this study, it can be concluded that the use of genotype EV-DT W99 STR, at 60 centibars irrigation scheduling and 55,555 plants ha-1 had resulted in good agrophysiological characters of QPM at Kadawa. Keywords: Quality protein maize genotypes, plant population, irrigation, agrophysiological characteristic

    The African Surgical OutcomeS-2 (ASOS-2) Pilot Trial, a mixed-methods implementation study

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    Background: The African Surgical Outcomes Study (ASOS) showed that surgical patients in Africa have a mortality twice the global average. The working hypothesis is that patients die as a result of failure to rescue following complications in the postoperative period. The African Surgical OutcomeS-2 (ASOS-2) Trial plans to test the efficacy of increased postoperative surveillance in high risk patients for decreasing perioperative morbidity and mortality. This pilot trial aimed i) to evaluate the adequacy of data produced by the data collection strategies of the ASOS-2 Trial, ii) to evaluate the fidelity of implementation of the increased postoperative surveillance intervention, and iii) to understand the acceptability, appropriateness and feasibility of the intervention and the trial processes.Methods: The ASOS-2 Pilot Trial was a mixed-methods (quantitative-qualitative) implementation study focusing on the intervention arm of the proposed ASOS-2 Trial. The intervention is increased postoperative surveillance for high-risk surgical patients. The intervention protocol was implemented at all sites for a seven-day period. A post pilot trial survey was used to collect data on the implementation outcomes.Results: 803 patients were recruited from 16 hospitals in eight African countries. The sampling and data collection strategies provided 98% complete data collection. Seventy-three percent of respondents believed that they truly provided increased postoperative surveillance to high risk patients. In reality 83/125 (66%) of high-risk patients received some form of increased postoperative surveillance. However, the individual components of the increased postoperative surveillance intervention were implemented in less than 50% of high-risk patients (excepting increasing nursing observations). The components most frequently unavailable were the ability to provide care in a higher care ward (32.1%) and assigning the patient to a bed in view of the nurses’ station (28.4%). Failure to comply with available components of the intervention ranged from 27.5% to 54.3%. The post pilot survey had a response rate of 30/40 (75%). In Likert scale questions about acceptability, appropriateness, and feasibility of the ASOS-2 intervention, 63% to 87% of respondents indicated agreement. Respondents reported barriers related to resources, trial processes, teamwork and communication as reasons for disagreement.Conclusions: The proposed ASOS-2 Trial appears to be appropriate, acceptable and feasible in Africa. This pilot trial provides support for the proposed ASOS-2 Trial. It emphasises the need for establishing trial site teams which address the needs of all stakeholders during the trial. A concerted effort must be made to help participating hospitals to increase compliance with all the components of the proposed intervention of ‘increased postoperative surveillance’ during the ASOS-2 Trial.Keywords: Trial, cluster randomised, Trial, pilot, Implementation science, Mixed methods, Mortality, Surger

    Search for the associated production of the Higgs boson with a top-quark pair

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    A search for the standard model Higgs boson produced in association with a top-quark pair t t ÂŻ H (ttÂŻH) is presented, using data samples corresponding to integrated luminosities of up to 5.1 fb −1 and 19.7 fb −1 collected in pp collisions at center-of-mass energies of 7 TeV and 8 TeV respectively. The search is based on the following signatures of the Higgs boson decay: H → hadrons, H → photons, and H → leptons. The results are characterized by an observed t t ÂŻ H ttÂŻH signal strength relative to the standard model cross section, μ = σ/σ SM ,under the assumption that the Higgs boson decays as expected in the standard model. The best fit value is μ = 2.8 ± 1.0 for a Higgs boson mass of 125.6 GeV

    Performance of reconstruction and identification of τ leptons decaying to hadrons and vτ in pp collisions at √s=13 TeV

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    The algorithm developed by the CMS Collaboration to reconstruct and identify τ leptons produced in proton-proton collisions at √s=7 and 8 TeV, via their decays to hadrons and a neutrino, has been significantly improved. The changes include a revised reconstruction of π⁰ candidates, and improvements in multivariate discriminants to separate τ leptons from jets and electrons. The algorithm is extended to reconstruct τ leptons in highly Lorentz-boosted pair production, and in the high-level trigger. The performance of the algorithm is studied using proton-proton collisions recorded during 2016 at √s=13 TeV, corresponding to an integrated luminosity of 35.9 fbÂŻÂč. The performance is evaluated in terms of the efficiency for a genuine τ lepton to pass the identification criteria and of the probabilities for jets, electrons, and muons to be misidentified as τ leptons. The results are found to be very close to those expected from Monte Carlo simulation

    Measurement of prompt Jψ\psi pair production in pp collisions at \sqrt s = 7 Tev

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    Production of prompt J/ ψ meson pairs in proton-proton collisions at s s√ = 7 TeV is measured with the CMS experiment at the LHC in a data sample corresponding to an integrated luminosity of about 4.7 fb −1 . The two J/ ψ mesons are fully reconstructed via their decays into μ + μ − pairs. This observation provides for the first time access to the high-transverse-momentum region of J/ ψ pair production where model predictions are not yet established. The total and differential cross sections are measured in a phase space defined by the individual J/ ψ transverse momentum ( p T J/ ψ ) and rapidity (| y J/ ψ |): | y J/ ψ | 6.5 GeV/ c ; 1.2 4.5 GeV/ c . The total cross section, assuming unpolarized prompt J/ ψ pair production is 1.49 ± 0.07 (stat) ±0.13 (syst) nb. Different assumptions about the J/ ψ polarization imply modifications to the cross section ranging from −31% to +27%

    Measurements of the t(t)Overbar charge asymmetry using the dilepton decay channel in pp collisions at root s=7 TeV

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    The ttÂŻ charge asymmetry in proton-proton collisions at s√ = 7 TeV is measured using the dilepton decay channel (ee, e μ , or μμ ). The data correspond to a total integrated luminosity of 5.0 fb −1 , collected by the CMS experiment at the LHC. The tt and lepton charge asymmetries, defined as the differences in absolute values of the rapidities between the reconstructed top quarks and antiquarks and of the pseudorapidities between the positive and negative leptons, respectively, are measured to be A C = −0 . 010 ± 0 . 017 (stat . ) ± 0 . 008 (syst . ) and AlepC = 0 . 009 ± 0 . 010 (stat . ) ± 0 . 006 (syst . ). The lepton charge asymmetry is also measured as a function of the invariant mass, rapidity, and transverse momentum of the ttÂŻ system. All measurements are consistent with the expectations of the standard model

    Measurement of angular parameters from the decay B⁰  → K⁎0^{⁎0} ÎŒâș Ό⁻ in proton–proton collisions at √s 8 TeV

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    Angular distributions of the decay B⁰  → K⁎0^{⁎0} ÎŒâș Ό⁻ are studied using a sample of proton–proton collisions at √s=8TeV collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 20.5fb⁻Âč . An angular analysis is performed to determine the P₁ and P2˘7^{\u27}₅ parameters, where the P2˘7^{\u27}₅ parameter is of particular interest because of recent measurements that indicate a potential discrepancy with the standard model predictions. Based on a sample of 1397 signal events, the P₁ and P2˘7^{\u27}₅ parameters are determined as a function of the dimuon invariant mass squared. The measurements are in agreement with predictions based on the standard model

    Measurement of nuclear modification factors of ΄(1S), ΄(2S), and ΄(3S) mesons in PbPb collisions at √sNN = 5.02 TeV

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