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991.
Patricia Regal Alexandre Lamas Cristina A. Fente Carlos M. Franco Alberto Cepeda 《液相色谱法及相关技术杂志》2017,40(11):541-548
Growth hormone (GH) or somatotropin (ST) is a species-specific polypeptide hormone produced in the pituitary gland of vertebrates. When administered exogenously to dairy cattle, it has galactopoietic effects and is capable of increasing the milk yield. The beginning of the commercial production of recombinant variants of bovine somatotropin (rbST), by the end of the 20th century, had a major economic impact in the dairy industry. Recombinant bST enabled large-scale applications in farms, enhancing significantly milk production. While it is banned in the European Union (EU), several countries permit the trade and use of recombinant somatotropins in animal husbandry. Also, rbST-free dairy products can be frequently found in the market of those countries, even though these labels are not actually verified in a laboratory. In this context, effective analytical methods are needed for residue control to avoid an illegal use of rbST but also to prevent fraudulent labeling in some cases. The present review includes studies published in the last 5 years (from 2012 to 2017) to monitor rbST in bovine animals, using liquid-based applications. It is then intended to serve as a practical guide to help those laboratories interested in developing analytical methods to detect rbST use and abuse. 相似文献
992.
Maximum likelihood estimation for stochastic volatility in mean models with heavy‐tailed distributions 下载免费PDF全文
Carlos A. Abanto‐Valle Roland Langrock Ming‐Hui Chen Michel V. Cardoso 《商业与工业应用随机模型》2017,33(4):394-408
In this article, we introduce a likelihood‐based estimation method for the stochastic volatility in mean (SVM) model with scale mixtures of normal (SMN) distributions. Our estimation method is based on the fact that the powerful hidden Markov model (HMM) machinery can be applied in order to evaluate an arbitrarily accurate approximation of the likelihood of an SVM model with SMN distributions. Likelihood‐based estimation of the parameters of stochastic volatility models, in general, and SVM models with SMN distributions, in particular, is usually regarded as challenging as the likelihood is a high‐dimensional multiple integral. However, the HMM approximation, which is very easy to implement, makes numerical maximum of the likelihood feasible and leads to simple formulae for forecast distributions, for computing appropriately defined residuals, and for decoding, that is, estimating the volatility of the process. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
993.
Positive ground state of coupled systems of Schrödinger equations in
involving critical exponential growth 下载免费PDF全文
João Marcos do Ó José Carlos de Albuquerque 《Mathematical Methods in the Applied Sciences》2017,40(18):6864-6879
In this paper, we study the existence of a positive ground state solution to the following coupled system of nonlinear Schrödinger equations: where the nonlinearities f1(x,s) and f2(x,s) are superlinear at infinity and have exponential critical growth of the Trudinger‐Moser type. The potentials V1(x) and V2(x) are nonnegative and satisfy a condition involving the coupling term λ(x), namely, λ(x)2<δ2V1(x)V2(x) for some 0<δ<1. For this purpose, we use the minimization technique over the Nehari manifold and strong maximum principle to get a positive ground state solution. Moreover, by using a bootstrap argument and Lq‐estimates, we get regularity and asymptotic behavior. 相似文献
994.
Juan Carlos Pardo José-Luis Pérez Victor Pérez-Abreu 《Journal of Functional Analysis》2017,272(1):339-362
We investigate the process of eigenvalues of a fractional Wishart process defined by , where B is the matrix fractional Brownian motion recently studied in [18]. Using stochastic calculus with respect to the Young integral we show that, with probability one, the eigenvalues do not collide at any time. When the matrix process B has entries given by independent fractional Brownian motions with Hurst parameter , we derive a stochastic differential equation in the Malliavin calculus sense for the eigenvalues of the corresponding fractional Wishart process. Finally, a functional limit theorem for the empirical measure-valued process of eigenvalues of a fractional Wishart process is obtained. The limit is characterized and referred to as the non-commutative fractional Wishart process, which constitutes the family of fractional dilations of the free Poisson distribution. 相似文献
995.
Fernando Szechtman 《代数通讯》2017,45(3):943-953
Clifford theory of possibly infinite dimensional modules is studied. 相似文献
996.
997.
Carlos Banquet Lucas C. F. Ferreira Élder J. Villamizar‐Roa 《Mathematical Methods in the Applied Sciences》2017,40(15):5613-5618
We consider a semilinear wave equation with nonlinear damping in the whole space . Local‐in‐time existence and uniqueness results are obtained in the class of Bessel‐potential spaces . Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
998.
Fernando Cortez 《Mathematical Methods in the Applied Sciences》2017,40(4):1333-1345
In this paper, we consider the b‐family of equations on the torus u t ?u t x x +(b + 1)u u x =b u x u x x +u u x x x , which for appropriate values of b reduces to well‐known models, such as the Camassa–Holm equation or the Degasperis–Procesi equation. We establish a local‐in‐space blow‐up criterion. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
999.
Carlos A. Iglesias 《High Energy Density Physics》2005,1(1):42-51
It is shown that a quantum kinetic theory approach to line broadening, extended to stationary non-equilibrium states, yields corrections to the standard electron impact widths of isolated lines that depend on the population of the radiator internal levels. A consistent classical limit from a general quantum treatment of the perturbing electrons also introduces corrections to the isolated line widths. Both effects are essential in preserving detailed-balance relations. Preliminary analysis indicates that these corrections may resolve existing discrepancies between theoretical and experimental widths of isolated lines. An experimental test of the results is proposed. 相似文献
1000.
Highly concentrated oil-in-water (o/w) emulsion stabilised by means of gluten and soya protein isolate (SPI) at low pH have
been characterized by means of linear dynamic viscoelasticity and droplet size distribution analysis (DSD). The microstructure
of these emulsions has been characterized at a colloidal level by using confocal laser scanning microscopy (CLSM) and light
microscopy (LM). These emulsions always exhibited a behaviour characteristic of highly flocculated emulsions with a mechanical
spectrum showing a well-developed plateau region. DSD results generally showed log normal bimodal profiles. Microstructure
images revealed occurrence of a close packing of droplets with a broad distribution of sizes participating in the formation
of a three dimensional flocculated network. The Mason model of elasticity of compressed emulsions has been used to correlate
viscoelastic and microstructural parameters giving adequate fitting but underestimating the elastic properties obtained for
the highest concentration of gluten. These deviations may be explained in terms of an enhancement of the elastic network formed
in the aqueous phase in which the glutenin fraction must play an important role.
Paper presented at the Annual European Rheology Conference (AERC) 2005, April 21-23, Grenoble, France. 相似文献