328 research outputs found
Occurrence of Salmonella and Shigella in edible frogs (Hoplobatrachus spp) from Hanwa Frog market Zaria, Nigeria
Frogs have been associated with bacterial infection among those who handle them resulting in symptoms such as diarrhoea, abdominal cramps, fever and vomiting. Frogs are a rich source of proteins and they are considered a delicacy by some in Nigeria. Considering the high demand for edible frogs, it is important to determine the occurrence of Salmonella and Shigella organisms from edible frogs (Hoplobatrachus spp). Edible frogs (n=202) were collected from February to July, 2016, from the Hanwa frog market, Zaria, Kaduna State. The intestinal contents of each sampled frog were scraped into the selenite broth bottles and cultured on Deoxycholate Citrate Agar for enrichment and isolation respectively. Biochemical test and sugar fermentation tests were carried out on the suspected isolates. Overall, twenty seven 27(13.37%) of the processed samples were suggestive of Shigella, while 22(10.9%) were suspect Salmonella organisms. There was no significant association between sex of the frogs and the isolation of Shigella and Salmonella organisms, despite the high occurrence of Shigella organism (14.17%) in the males. Source wise the occurrence of Salmonella in frogs was high in Tudun Wada (20%), while Katsina (8.5%) had the least. There was also no association between source and Shigella organisms. Frogs within the weight range of 175-224g had the highest occurrence rate for Shigella isolation, while frogs of 73-125g weight range had the highest occurrence rate for Salmonella isolation. This study shows the presence of Shigella and Salmonella organisms in the intestinal contents of frogs. Therefore the unhygienic and unsanitary environment, handling and processing of frogs is of great public health concern and as such measures are to be put together to ensure safety and wholesomeness of the frog meat been sold for human consumption.Keywords: Edible, Frog, Safety, Salmonella , Shigella, Zari
Hysteretic Magnetotransport in SmB6 at Low Magnetic Fields
Utilizing Corbino disc structures, we have examined the magnetic field
response of resistivity for the surface states of SmB6 on different crystalline
surfaces at low temperatures. Our results reveal a hysteretic behavior whose
magnitude depends on the magnetic field sweep rate and temperature. Although
this feature becomes smaller when the field sweep is slower, a complete
elimination or saturation is not observed in our slowest sweep-rate
measurements, which is much slower than a typical magnetotransport trace. These
observations cannot be explained by quantum interference corrections such as
weak anti-localization. Instead, they are consistent with behaviors of glassy
surface magnetic ordering, whose magnetic origin is most likely from samarium
oxide (Sm2O3) forming on the surface during exposure to ambient conditions
Bosonic Fractionalisation Transitions
At finite density, charge in holographic systems can be sourced either by
explicit matter sources in the bulk or by bulk horizons. In this paper we find
bosonic solutions of both types, breaking a global U(1) symmetry in the former
case and leaving it unbroken in the latter. Using a minimal bottom-up model we
exhibit phase transitions between the two cases, under the influence of a
relevant operator in the dual field theory. We also embed solutions and
transitions of this type in M-theory, where, holding the theory at constant
chemical potential, the cohesive phase is connected to a neutral phase of
Schr\"odinger type via a z=2 QCP.Comment: references added. minor changes. version published in JHE
Culturing human intestinal stem cells for regenerative applications in the treatment of inflammatory bowel disease
Abstract Both the incidence and prevalence of inflammatory bowel disease (IBD) is increasing globally; in the industrialized world up to 0.5% of the population are affected and around 4.2 million individuals suffer from IBD in Europe and North America combined. Successful engraftment in experimental colitis models suggests that intestinal stem cell transplantation could constitute a novel treatment strategy to reâestablish mucosal barrier function in patients with severe disease. Intestinal stem cells can be grown in vitro in organoid structures, though only a fraction of the cells contained are stem cells with regenerative capabilities. Hence, techniques to enrich stem cell populations are being pursued through the development of multiple twoâdimensional and threeâdimensional culture protocols, as well as coâculture techniques and multiple growth medium compositions. Moreover, research in support matrices allowing for efficient clinical application is in progress. In vitro culture is accomplished by modulating the signaling pathways fundamental for the stem cell niche with a suitable culture matrix to provide additional contactâdependent stimuli and structural support. The aim of this review was to discuss medium compositions and support matrices for optimal intestinal stem cell culture, as well as potential modifications to advance clinical use in IBD
Amino Acid Metabolic Origin as an Evolutionary Influence on Protein Sequence in Yeast
The metabolic cycle of Saccharomyces cerevisiae consists of alternating oxidative (respiration) and reductive (glycolysis) energy-yielding reactions. The intracellular concentrations of amino acid precursors generated by these reactions oscillate accordingly, attaining maximal concentration during the middle of their respective yeast metabolic cycle phases. Typically, the amino acids themselves are most abundant at the end of their precursorâs phase. We show that this metabolic cycling has likely biased the amino acid composition of proteins across the S. cerevisiae genome. In particular, we observed that the metabolic source of amino acids is the single most important source of variation in the amino acid compositions of functionally related proteins and that this signal appears only in (facultative) organisms using both oxidative and reductive metabolism. Periodically expressed proteins are enriched for amino acids generated in the preceding phase of the metabolic cycle. Proteins expressed during the oxidative phase contain more glycolysis-derived amino acids, whereas proteins expressed during the reductive phase contain more respiration-derived amino acids. Rare amino acids (e.g., tryptophan) are greatly overrepresented or underrepresented, relative to the proteomic average, in periodically expressed proteins, whereas common amino acids vary by a few percent. Genome-wide, we infer that 20,000 to 60,000 residues have been modified by this previously unappreciated pressure. This trend is strongest in ancient proteins, suggesting that oscillating endogenous amino acid availability exerted genome-wide selective pressure on protein sequences across evolutionary time
Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV
The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of âs = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pTâĽ20 GeV and pseudorapidities {pipe}Ρ{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}Ρ{pipe}<0. 8) for jets with 60â¤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2â¤{pipe}Ρ{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. Š 2013 CERN for the benefit of the ATLAS collaboration
Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector
The inclusive and dijet production cross-sections have been measured for jets
containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass
energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The
measurements use data corresponding to an integrated luminosity of 34 pb^-1.
The b-jets are identified using either a lifetime-based method, where secondary
decay vertices of b-hadrons in jets are reconstructed using information from
the tracking detectors, or a muon-based method where the presence of a muon is
used to identify semileptonic decays of b-hadrons inside jets. The inclusive
b-jet cross-section is measured as a function of transverse momentum in the
range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet
cross-section is measured as a function of the dijet invariant mass in the
range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets
and the angular variable chi in two dijet mass regions. The results are
compared with next-to-leading-order QCD predictions. Good agreement is observed
between the measured cross-sections and the predictions obtained using POWHEG +
Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet
cross-section. However, it does not reproduce the measured inclusive
cross-section well, particularly for central b-jets with large transverse
momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final
version published in European Physical Journal
Treatment of uncomplicated malaria at public health facilities and medicine retailers in south-eastern Nigeria
Background: At primary care facilities in Nigeria, national treatment guidelines state that malaria should be symptomatically diagnosed and treated with artemisinin-based combination therapy (ACT). Evidence from households and health care providers indicates that many patients do not receive the recommended treatment. This study sought to determine the extent of the problem by collecting data as patients and caregivers leave health facilities, and determine what influences the treatment received. Methods: A cross-sectional cluster survey of 2,039 respondents exiting public health centres, pharmacies and patent medicine dealers was undertaken in urban and rural settings in Enugu State, south-eastern Nigeria. Results: Although 79% of febrile patients received an anti-malarial, only 23% received an ACT. Many patients (38%) received sulphadoxine-pyrimethamine (SP). A further 13% of patients received an artemisinin-derivative as a monotherapy. An estimated 66% of ACT dispensed was in the correct dose. The odds of a patient receiving an ACT was highly associated with consumer demand (OR: 55.5, p < 0.001). Conclusion: Few febrile patients attending public health facilities, pharmacies and patent medicine dealers received an ACT, and the use of artemisinin-monotherapy and less effective anti-malarials is concerning. The results emphasize the importance of addressing both demand and supply-side influences on malaria treatment and the need for interventions that target consumer preferences as well as seek to improve health service provision. Š 2011 Mangham et al; licensee BioMed Central Ltd
Qualitative study of presumptive treatment of childhood malaria in third tier tertiary hospitals in southeast Nigeria: a focus group and in-depth study
Cryo Electron Tomography of Native HIV-1 Budding Sites
The structure of immature and mature HIV-1 particles has been analyzed in detail by cryo electron microscopy, while no such studies have been reported for cellular HIV-1 budding sites. Here, we established a system for studying HIV-1 virus-like particle assembly and release by cryo electron tomography of intact human cells. The lattice of the structural Gag protein in budding sites was indistinguishable from that of the released immature virion, suggesting that its organization is determined at the assembly site without major subsequent rearrangements. Besides the immature lattice, a previously not described Gag lattice was detected in some budding sites and released particles; this lattice was found at high frequencies in a subset of infected T-cells. It displays the same hexagonal symmetry and spacing in the MA-CA layer as the immature lattice, but lacks density corresponding to NC-RNA-p6. Buds and released particles carrying this lattice consistently lacked the viral ribonucleoprotein complex, suggesting that they correspond to aberrant products due to premature proteolytic activation. We hypothesize that cellular and/or viral factors normally control the onset of proteolytic maturation during assembly and release, and that this control has been lost in a subset of infected T-cells leading to formation of aberrant particles
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