531 research outputs found

    Microbiological evaluation and shelf life of seed flour mixes used for infant feeding in rural northern Nigeria

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    This study investigates microbial load and shelf life of locally processed cereal-legume-oil seed flour mixes used for infant feeding in rural northern Nigeria. Free fatty acid (FFA), water activity (aw), pH, total viable count (TVC) and presence of yeast, coliform bacteria and mold were the parameters determined. Hungry rice or Digitaria exilis, benne seed or Sesamum indicum and soybean or Glycine max seeds flours were produced using traditional processing methods, including washing, boiling, fermenting and roasting. The test samples were milled into flour that could pass through a 70 mm mesh sieve and blended on protein basis at 70:30 cereal-legume/oilseed ratios to produce D70S30, D70G30, D70S15G15, D70S20G10 and D70S10G20 and stored at 30 to 32°C for 60 days. The parameters were determined at day 0 and intervals of 14, 28, 42 and 60 days. At the end of the storage period, all the parameters increased. FFA increased from 0.15 - 0.16% to 0.47 - 0.58%; aw from 0.46 - 0.48 to 0.72 - 0.80; pH from 3.9 to 4.7 - 4.9 and TVC from <1.0x102 to 2.2x103 to 3.6×104cfu/g for 0 and 60 days, respectively. The differences between the values of the parameters of the formulations were significant (p<0.05) especially from day 14. Yeast and coliform were not detected in all the samples but mold was detected from days 14 to 60. The formulation D70S30 had best shelf life; however, the samples should be consumed within 14 days of production.Key words: Seed flour, multi-mixes, children, microbial load, shelf life

    A novel numerical model to predict the morphological behavior of magnetic liquid marbles using coarse grained molecular dynamics concepts

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    © 2018 Author(s). Liquid marbles are liquid droplets coated with superhydrophobic powders whose morphology is governed by the gravitational and surface tension forces. Small liquid marbles take spherical shapes, while larger liquid marbles exhibit puddle shapes due to the dominance of gravitational forces. Liquid marbles coated with hydrophobic magnetic powders respond to an external magnetic field. This unique feature of magnetic liquid marbles is very attractive for digital microfluidics and drug delivery systems. Several experimental studies have reported the behavior of the liquid marbles. However, the complete behavior of liquid marbles under various environmental conditions is yet to be understood. Modeling techniques can be used to predict the properties and the behavior of the liquid marbles effectively and efficiently. A robust liquid marble model will inspire new experiments and provide new insights. This paper presents a novel numerical modeling technique to predict the morphology of magnetic liquid marbles based on coarse grained molecular dynamics concepts. The proposed model is employed to predict the changes in height of a magnetic liquid marble against its width and compared with the experimental data. The model predictions agree well with the experimental findings. Subsequently, the relationship between the morphology of a liquid marble with the properties of the liquid is investigated. Furthermore, the developed model is capable of simulating the reversible process of opening and closing of the magnetic liquid marble under the action of a magnetic force. The scaling analysis shows that the model predictions are consistent with the scaling laws. Finally, the proposed model is used to assess the compressibility of the liquid marbles. The proposed modeling approach has the potential to be a powerful tool to predict the behavior of magnetic liquid marbles serving as bioreactors

    SPH-DEM approach to numerically simulate the deformation of three-dimensional RBCs in non-uniform capillaries

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    © 2016 The Author(s). Background: Blood continuously flows through the blood vessels in the human body. When blood flows through the smallest blood vessels, red blood cells (RBCs) in the blood exhibit various types of motion and deformed shapes. Computational modelling techniques can be used to successfully predict the behaviour of the RBCs in capillaries. In this study, we report the application of a meshfree particle approach to model and predict the motion and deformation of three-dimensional RBCs in capillaries. Methods: An elastic spring network based on the discrete element method (DEM) is employed to model the three-dimensional RBC membrane. The haemoglobin in the RBC and the plasma in the blood are modelled as smoothed particle hydrodynamics (SPH) particles. For validation purposes, the behaviour of a single RBC in a simple shear flow is examined and compared against experimental results. Then simulations are carried out to predict the behaviour of RBCs in a capillary; (i) the motion of five identical RBCs in a uniform capillary, (ii) the motion of five identical RBCs with different bending stiffness (K b ) values in a stenosed capillary, (iii) the motion of three RBCs in a narrow capillary. Finally five identical RBCs are employed to determine the critical diameter of a stenosed capillary. Results: Validation results showed a good agreement with less than 10% difference. From the above simulations, the following results are obtained; (i) RBCs exhibit different deformation behaviours due to the hydrodynamic interaction between them. (ii) Asymmetrical deformation behaviours of the RBCs are clearly observed when the bending stiffness (K b ) of the RBCs is changed. (iii) The model predicts the ability of the RBCs to squeeze through smaller blood vessels. Finally, from the simulations, the critical diameter of the stenosed section to stop the motion of blood flow is predicted. Conclusions: A three-dimensional spring network model based on DEM in combination with the SPH method is successfully used to model the motion and deformation of RBCs in capillaries. Simulation results reveal that the condition of blood flow stopping depends on the pressure gradient of the capillary and the severity of stenosis of the capillary. In addition, this model is capable of predicting the critical diameter which prevents motion of RBCs for different blood pressures

    The prevalence of metabolic syndrome and cardiovascular risk factors in adults in southern China

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    <p>Abstract</p> <p>Background</p> <p>The metabolic syndrome has been shown to increase the incidence of cardiovascular disease. Little information exists on the prevalence of the metabolic syndrome for southern Chinese. We therefore investigate the prevalence of the metabolic syndrome in a southern Chinese population with 85 million residents.</p> <p>Methods</p> <p>The Guangdong Nutrition and Health Survey 2002 is a cross-sectional survey designed to assess the health and nutritional status of 85 million residents in Guangdong province located in southern China. Stratified multistage random sampling method was applied in this survey and a provincial representative sample of 6,468 residents aged 20 years or above was obtained in the present study. The participants received a full medical check-up including measurement of blood pressure, obesity indices, fasting lipids and glucose levels. Data describing socioeconomic and lifestyle factors was also collected through interview. Metabolic syndrome was defined in accordance with the International Diabetes Federation criteria.</p> <p>Results</p> <p>The prevalence of metabolic syndrome was 7.30%, translating into a total of 4.0 million residents aged 20 years or above having the condition in this southern Chinese population. The urban population had higher prevalence of the syndrome than the rural population (10.57% vs 4.30%). Females had a higher prevalence of metabolic syndrome than males (8.99% vs 5.27%). More than 60% of the adults had at least one component of the metabolic syndrome.</p> <p>Conclusions</p> <p>Our results indicate that a large proportion of southern Chinese adults have the metabolic syndrome and associated risk factors. The metabolic syndrome has become an important public health problem in China. These findings emphasize the urgent need to develop population level strategies for the prevention, detection, and treatment of cardiovascular risk in China.</p

    Measurement of the proton form factor by studying e+eppˉe^{+} e^{-}\rightarrow p\bar{p}

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    Using data samples collected with the BESIII detector at the BEPCII collider, we measure the Born cross section of e+eppˉe^{+}e^{-}\rightarrow p\bar{p} at 12 center-of-mass energies from 2232.4 to 3671.0 MeV. The corresponding effective electromagnetic form factor of the proton is deduced under the assumption that the electric and magnetic form factors are equal (GE=GM)(|G_{E}|= |G_{M}|). In addition, the ratio of electric to magnetic form factors, GE/GM|G_{E}/G_{M}|, and GM|G_{M}| are extracted by fitting the polar angle distribution of the proton for the data samples with larger statistics, namely at s=\sqrt{s}= 2232.4 and 2400.0 MeV and a combined sample at s\sqrt{s} = 3050.0, 3060.0 and 3080.0 MeV, respectively. The measured cross sections are in agreement with recent results from BaBar, improving the overall uncertainty by about 30\%. The GE/GM|G_{E}/G_{M}| ratios are close to unity and consistent with BaBar results in the same q2q^{2} region, which indicates the data are consistent with the assumption that GE=GM|G_{E}|=|G_{M}| within uncertainties.Comment: 13 pages, 24 figure

    An amplitude analysis of the π0π0\pi^{0}\pi^{0} system produced in radiative J/ψJ/\psi decays

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    An amplitude analysis of the π0π0\pi^{0}\pi^{0} system produced in radiative J/ψJ/\psi decays is presented. In particular, a piecewise function that describes the dynamics of the π0π0\pi^{0}\pi^{0} system is determined as a function of Mπ0π0M_{\pi^{0}\pi^{0}} from an analysis of the (1.311±0.011)×109(1.311\pm0.011)\times10^{9} J/ψJ/\psi decays collected by the BESIII detector. The goal of this analysis is to provide a description of the scalar and tensor components of the π0π0\pi^0\pi^0 system while making minimal assumptions about the properties or number of poles in the amplitude. Such a model-independent description allows one to integrate these results with other related results from complementary reactions in the development of phenomenological models, which can then be used to directly fit experimental data to obtain parameters of interest. The branching fraction of J/ψγπ0π0J/\psi \to \gamma \pi^{0}\pi^{0} is determined to be (1.15±0.05)×103(1.15\pm0.05)\times10^{-3}, where the uncertainty is systematic only and the statistical uncertainty is negligible.Comment: Submitted to Phys. Rev. D 19 pages, 4 figure

    Observation of the isospin-violating decay J/ψϕπ0f0(980)J/\psi \to \phi\pi^{0}f_{0}(980)

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    Using a sample of 1.31 billion J/ψJ/\psi events collected with the BESIII detector at the BEPCII collider, the decays J/ψϕπ+ππ0J/\psi \to \phi \pi^{+}\pi^{-}\pi^{0} and J/ψϕπ0π0π0J/\psi \to \phi \pi^{0}\pi^{0}\pi^{0} are investigated. The isospin violating decay J/ψϕπ0f0(980)J/\psi \to \phi \pi^{0} f_{0}(980) with f0(980)ππf_{0}(980) \to \pi\pi, is observed for the first time. The width of the f0(980)f_{0}(980) obtained from the dipion mass spectrum is found to be much smaller than the world average value. In the π0f0(980)\pi^{0} f_{0}(980) mass spectrum, there is evidence of f1(1285)f_1(1285) production. By studying the decay J/ψϕηJ/\psi \to \phi\eta', the branching fractions of ηπ+ππ0\eta' \to \pi^{+}\pi^{-}\pi^{0} and ηπ0π0π0\eta' \to \pi^{0}\pi^{0}\pi^{0}, as well as their ratio, are also measured.Comment: 10 pages, 10 figures, published in Phys. Rev.

    Heritability and Artificial Selection on Ambulatory Dispersal Distance in Tetranychus urticae: Effects of Density and Maternal Effects

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    Dispersal distance is understudied although the evolution of dispersal distance affects the distribution of genetic diversity through space. Using the two-spotted spider mite, Tetranychus urticae, we tested the conditions under which dispersal distance could evolve. To this aim, we performed artificial selection based on dispersal distance by choosing 40 individuals (out of 150) that settled furthest from the home patch (high dispersal, HDIS) and 40 individuals that remained close to the home patch (low dispersal, LDIS) with three replicates per treatment. We did not observe a response to selection nor a difference between treatments in life-history traits (fecundity, survival, longevity, and sex-ratio) after ten generations of selection. However, we show that heritability for dispersal distance depends on density. Heritability for dispersal distance was low and non-significant when using the same density as the artificial selection experiments while heritability becomes significant at a lower density. Furthermore, we show that maternal effects may have influenced the dispersal behaviour of the mites. Our results suggest primarily that selection did not work because high density and maternal effects induced phenotypic plasticity for dispersal distance. Density and maternal effects may affect the evolution of dispersal distance and should be incorporated into future theoretical and empirical studies

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

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    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    Digenean parasites of Chinese marine fishes: a list of species, hosts and geographical distribution

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    In the literature, 630 species of Digenea (Trematoda) have been reported from Chinese marine fishes. These belong to 209 genera and 35 families. The names of these species, along with their hosts, geographical distribution and records, are listed in this paper
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