4,041 research outputs found

    Multiple logistic regression model to predict risk factors of oral health diseases

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    To analysis the dependence of oral health diseases i.e. dental caries and periodontal disease on considering the number of riskfactors through the applications of logistic regression model. Method: The cross sectional study involves a systematic random sample of 1760 permanent dentition aged between 18-40 years in Dharwad, Karnataka, India. Dharwad is situated in North Karnataka. The mean age was 34.26±7.28. The risk factors of dental caries and periodontal disease were established by multiple logistic regression model using SPSS statistical software. Results: The factors like frequency of brushing, timings of cleaning teeth and type of toothpastes are signifi cant persistent predictors of dental caries and periodontal disease. The log likelihood value of full model is –1013.1364 and Akaike’s Information Criterion (AIC) is 1.1752 as compared to reduced regression model are -1019.8106 and 1.1748 respectively for dental caries. But, the log likelihood value of full model is –1085.7876 and AIC is 1.2577 followed by reduced Romanian Statistical Review nr. 5 / 2012 regression model are -1019.8106 and 1.1748 respectively for periodontal disease. The area under Receiver Operating Characteristic (ROC) curve for the dental caries is 0.7509 (full model) and 0.7447 (reduced model); the ROC for the periodontal disease is 0.6128 (full model) and 0.5821 (reduced model

    Nonequilibrium Phase Transitions in a Driven Sandpile Model

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    We construct a driven sandpile slope model and study it by numerical simulations in one dimension. The model is specified by a threshold slope \sigma_c\/, a parameter \alpha\/, governing the local current-slope relation (beyond threshold), and jinj_{\rm in}, the mean input current of sand. A nonequilibrium phase diagram is obtained in the \alpha\, -\, j_{\rm in}\/ plane. We find an infinity of phases, characterized by different mean slopes and separated by continuous or first-order boundaries, some of which we obtain analytically. Extensions to two dimensions are discussed.Comment: 11 pages, RevTeX (preprint format), 4 figures available upon requs

    Pengaruh Penyiangan Dan Suhu Penyimpanan Terhadap Mutu Kimiawi, Mikrobiologis Dan Organoleptik Ikan Tongkol (Auxis Tharzard, Lac)

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    Ikan tongkol merupakan salah satu bahan pangan yang dikonsumsi masyarakat dan jika dibiarkanpada suhu kamar, maka terjadi proses penurunan mutu menjadi busuk. Ikan yang sudah mengalami prosespembusukan, bila dikonsumsi dapat menimbulkan keracunan (Histamine fish poisoning). Keracunan inidisebabkan oleh kontaminasi bakteri pathogen dengan dekarboksilasi asam amino histidin oleh enzimhistidin dekarboksilase menghasilkan histamin. Bakteri ini banyak terdapat pada anggota tubuh manusiayang tidak higienis, kotoran/tinja, isi Perut ikan, insang serta peralatan yang tidak bersih.Penelitian eksperimental dengan pola faktorial, yaitu faktor P adalah faktor penyiangan dengan 2 taraf,tanpa penyiangan dan penyiangan, sedangkan faktor T adalah suhu penyimpanan dengan 3 taraf yaitu suhupenyimpanan 30oC, 15oC dan 0oC.Analisis statistik terhadap mutu kimiawi seperti kadar histamin, kadar total volatil bases (TVB) dantrimetilamin (TMA) menunjukkan perbedaan nyata (P<0,05) pada pengaruh penyiangan dan suhupenyimpanan. Terjadi peningkatan kadar histamin, kadar TVB dan TMA selama penelitian. Selamapenelitian terjadi peningkatan jumlah koloni bakteri, jumlah Coliform, kecuali bakteri Vibrioparahaemolyticus negatif. Perlakuan penyiangan dan suhu penyimpanan 0oC memiliki mutu kimiawi,mikrobiologis terbaik sampai hari ke 10 serta masih diterima panelis.Hubungan antara kadar histamin dengan jumlah bakteri mempunyai hubungan sangat kuat, ditunjukkandengan nilai r ? 0,7 kecuali kadar histamin dengan waktu memiliki hubungan agak lemah r ? 0,5.Keamanan ikan tongkol dengan penerapan teknologi tepat guna berupa tanpa penyiangan danpenyiangan pada suhu 30oC hanya aman untuk dikonsumsi sampai hari ke 0. Perlakuan tanpa penyiangandan suhu penyimpanan 15oC aman sampai hari ke 4, sedangkan dengan penyiangan aman sampai hari ke 6.Untuk perlakuan tanpa penyiangan dan penyiangan dengan suhu penyimpanan 0oC aman sampai hari ke 10

    Direct numerical simulations of statistically steady, homogeneous, isotropic fluid turbulence with polymer additives

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    We carry out a direct numerical simulation (DNS) study that reveals the effects of polymers on statistically steady, forced, homogeneous, isotropic fluid turbulence. We find clear manifestations of dissipation-reduction phenomena: On the addition of polymers to the turbulent fluid, we obtain a reduction in the energy dissipation rate, a significant modification of the fluid energy spectrum, especially in the deep-dissipation range, a suppression of small-scale intermittency, and a decrease in small-scale vorticity filaments. We also compare our results with recent experiments and earlier DNS studies of decaying fluid turbulence with polymer additives.Comment: consistent with the published versio

    Resource Allocation for Multiple Concurrent In-Network Stream-Processing Applications

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    This paper investigates the operator mapping problem for in-network stream-processing applications. In-network stream-processing amounts to applying one or more trees of operators in steady-state, to multiple data objects that are continuously updated at different locations in the network. The goal is to compute some final data at some desired rate. Different operator trees may share common subtrees. Therefore, it may be possible to reuse some intermediate results in different application trees. The first contribution of this work is to provide complexity results for different instances of the basic problem, as well as integer linear program formulations of various problem instances. The second second contribution is the design of several polynomial-time heuristics. One of the primary objectives of these heuristics is to reuse intermediate results shared by multiple applications. Our quantitative comparisons of these heuristics in simulation demonstrates the importance of choosing appropriate processors for operator mapping. It also allow us to identify a heuristic that achieves good results in practice

    Condensation of Silica Nanoparticles on a Phospholipid Membrane

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    The structure of the transient layer at the interface between air and the aqueous solution of silica nanoparticles with the size distribution of particles that has been determined from small-angle scattering has been studied by the X-ray reflectometry method. The reconstructed depth profile of the polarizability of the substance indicates the presence of a structure consisting of several layers of nanoparticles with the thickness that is more than twice as large as the thickness of the previously described structure. The adsorption of 1,2-distearoyl-sn-glycero-3-phosphocholine molecules at the hydrosol/air interface is accompanied by the condensation of anion silica nanoparticles at the interface. This phenomenon can be qualitatively explained by the formation of the positive surface potential due to the penetration and accumulation of Na+ cations in the phospholipid membrane.Comment: 7 pages, 5 figure

    Ventricular remodelling in rabbits with sustained high‐fat diet

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    Aim Excess weight gain and obesity are one of the most serious health problems in the western societies. These conditions enhance risk of cardiac disease and have been linked with increased prevalence for cardiac arrhythmias and sudden death. Our goal was to study the ventricular remodelling occurring in rabbits fed with high‐fat diet ( HFD ) and its potential arrhythmogenic mechanisms. Methods We used 15 NZW rabbits that were randomly assigned to a control ( n  = 7) or HFD group ( n  = 8) for 18 weeks. In vivo studies included blood glucose, electrocardiographic, and echocardiographic measurements. Optical mapping was performed in Langendorff‐perfused isolated hearts. Results Body weight (3.69 ± 0.31 vs. 2.94 ± 0.18 kg, P  < 0.001) and blood glucose levels (230 ± 61 vs. 141 ± 14 mg dL −1 , P  < 0.05) were higher in the HFD group vs. controls. The rate‐corrected QT interval and its dispersion were increased in HFD rabbits vs. controls (169 ± 10 vs. 146 ± 13 ms and 37 ± 11 vs. 9 ± 2 ms, respectively; P  < 0.05). Echocardiographic analysis showed morphological and functional alterations in HFD rabbits indicative of left ventricle (LV) hypertrophy. Isolated heart studies revealed no changes in repolarization and propagation properties under conditions of normal extracellular K + , suggesting that extrinsic factors could underlie those electrocardiographic modifications. There were no differences in the dynamics of ventricular fibrillation (frequency, wave breaks) in the presence of isoproterenol. However, HFD rabbits showed a small reduction in action potential duration and an increased incidence of arrhythmias during hyperkalaemia. Conclusion High‐fat feeding during 18 weeks in rabbits induced a type II diabetes phenotype, LV hypertrophy, abnormalities in repolarization and susceptibility to arrhythmias during hyperkalaemia.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106944/1/apha12185.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/106944/2/apha12185-sup-0001-FigS1-S4TableS1-S3.pd

    Gravitational oscillations of a liquid column

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    We report gravity oscillations of a liquid column partially immersed in a bath of liquid. We stress in particular some peculiarities of this system, namely (i) the fact that the mass of this oscillator constantly changes with time; (ii) the singular character of the beginning of the rise, for which the mass of the oscillator is zero; (iii) the sources of dissipation in this system, which is found to be dominated at low viscosity by the entrance (or exit) effects, leading to a long-range damping of the oscillations. We conclude with some qualitative description of a second-order phenomenon, namely the eruption of a jet at the beginning of the rise.Comment: 22 pages, pdf. Submitted to Physics of Fluid
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