Search results for "statistical"
showing 10 items of 4960 documents
Prevalence of carotid artery calcifications among 2,500 digital panoramic radiographs of an adult Brazilian population
2018
Background The aim of the present study was to analyze the epidemiological data of digital panoramic radiographs revealing suggestive images of carotid artery calcifications (CAC) from a Northeast Brazilian population. Material and Methods A cross-sectional retrospective study was conducted with 2,500 digital panoramic radiographs obtained from a single imaging reference center in Northeast Brazil. Images from individuals of both sexes and older than 18 years were included and those that did not cover the region of cervical vertebrae or presented low radiographic quality were excluded. Data were analyzed regarding prevalence, location (bilateral, right or left), sex, and age using the Chi-s…
Meta-analysis of the correlation between serum uric acid level and carotid intima-media thickness
2021
Objective Recently, increasing epidemiological evidence has shown that there is a correlation between serum uric acid level (SUA) and carotid intima-media thickness (CIMT). This paper explored the relationship between them through meta-analysis. Methods PubMed, Cochrane Library, EMBASE, Web of Science and Google Scholar were searched to obtain literature. The keywords used to retrieve the literature were carotid intima thickness, intima-media thickness, carotid atherosclerosis, carotid stenosis, carotid artery, uric acid, blood uric acid, and hyperuricaemia. The retrieval time was from the establishment of the database through July 2020. Stata15.0 and RevMan5.3 software were used for stati…
On the spectral moments of non-WSSUS mobile-to mobile double-Rayleigh fading channels
2017
This paper deals with the mathematical analysis of the spectral moments of non-wide-sensestationary uncorrelated-scattering (non-WSSUS) mobile-to-mobile (M2M) double-Rayleigh fading channels. The point of departure is a recently proposed geometry-based statistical model (GBSM) for M2M double-Rayleigh fading channels from which general analytical expressions are derived for the average Doppler shift, Doppler spread, average delay, and delay spread. Closed-form solutions of such expressions are presented for the particular case of the geometrical two-rings scattering model. The obtained results indicate that the average Doppler shift and Doppler spread are directly influenced by not only the …
Improved model based on the Weibull distribution to describe the combined effect of pH and temperature on the heat resistance of Bacillus cereus in c…
2003
The effect of pH and temperature on the thermal inactivation of different strains of Bacillus cereus was modeled. Inactivation tests were carried out in carrot broth, following a full factorial design at four levels for temperature (from 90 to 105 degrees C, depending on the strain) and pH (6.2, 5.8, 5.2, and 4.7). Individual inactivation curves were analyzed by applying the Weibull model function (with percent discrepancy close to 20% for most cases), and the effects of pH and temperature on the scale parameter (designated D(beta)) and the shape parameter (beta) were also studied. Temperature and pH did not have a significant effect on the shape parameter (beta). The effect of temperature …
Deguna vārstules aktivitātes novērtējums, izmantojot 4 fāžu rinamometru. Jauna parametra ieviešana un statistiskais novērtējums
2017
Darba mērķis: jauna parametra (deguna vārstules indeksa) izpēte, identificējot cilpas rinomanometriskajās līknēs kā deguna vārstules aktivitāties pazīmi. Skaitliski novērtēt rinomanometrijas cilpu nozīmi ar deguna vārstules indeksa palīdzību. Materiāli un metodes: rinomanometrijas dati tika iegūti no 250 pacientiem (veicot aktīvas priekšējās rinomanometrijas mērījumus), ar rinomanometru 4RHINO (RhinolabGermany), programmatūras versijā 4.31 un 5.01. Mērījumi tika veikti pirms dekongestantu lietošanas un pēc dekongestantu lietošanas, atkārtojot mērījumus pēc 10 minūtēm. Deguna vārstules indekss tika atlasīts un pievienots "HRR-Export-file". Statistiskajai analīzei tika izmantots Microsoft Off…
Nondestructive fluorescence-based quantification of threose-induced collagen cross-linking in bovine articular cartilage.
2012
Extensive collagen cross-linking affects the mechanical competence of articular cartilage: it can make the cartilage stiffer and more brittle. The concentrations of the best known cross-links, pyridinoline and pentosidine, can be accurately determined by destructive high-performance liquid chromatography (HPLC). We explore a nondestructive evaluation of cross-linking by using the intrinsic fluorescence of the intact cartilage. Articular cartilage samples from bovine knee joints were incubated in threose solution for 40 and 100 h to increase the collagen cross-linking. Control samples without threose were also prepared. Excitation-emission matrices at wavelengths of 220 to 950 nm were acquir…
Application of the star-product method to the angular momentum quantization
1992
We define a *-product on ℝ3 and solve the polarization equation f*C=0 where C is the Casimir of the coadjoint representation of SO(3). We compute the action of SO(3) on the space of solutions. We then examine the case of non-zero eigenvalues of C, in order to find finite-dimensional representations of SO(3). Finally, we compute \(\sqrt C *\sqrt C \) as an asymptotic series of C. This gives an explanation of the use of the star square root of C in a paper by Bayen et al. instead of its natural square root.
Solution of a cauchy problem for an infinite chain of linear differential equations
2005
Defining the recurrence relations for orthogonal polynomials we have found an exact solution of a Cauchy problem for an infinite chain of linear differential equations with constant coefficients. These solutions have been found both for homogeneous and an inhomogeneous systems.
The cauchy problem for non-linear Klein-Gordon equations
1993
We consider in ℝ n+1,n≧2, the non-linear Klein-Gordon equation. We prove for such an equation that there is a neighbourhood of zero in a Hilbert space of initial conditions for which the Cauchy problem has global solutions and on which there is asymptotic completeness. The inverse of the wave operator linearizes the non-linear equation. If, moreover, the equation is manifestly Poincare covariant then the non-linear representation of the Poincare Lie algebra, associated with the non-linear Klein-Gordon equation is integrated to a non-linear representation of the Poincare group on an invariant neighbourhood of zero in the Hilbert space. This representation is linearized by the inverse of the …
A shallow water model with eddy viscosity for basins with varying bottom topography
2001
The motion of an incompressible fluid confined to a shallow basin with a varying bottom topography is considered. We introduce appropriate scalings into a three-dimensional anisotropic eddy viscosity model to derive a two-dimensional shallow water model. The global regularity of the resulting model is proved. The anisotropic form of the stress tensor in our three-dimensional eddy viscosity model plays a critical role in ensuring that the resulting shallow water model dissipates energy.