The protective role of nutrition factors such as calcium, vitamin D and vitamin K for the integrity of the skeleton is well understood. In addition, integrity of the skeleton is positively influenced by certain trace elements (e.g. zinc, copper, manganese, magnesium, iron, selenium, boron and fluoride) and negatively by others (lead, cadmium, cobalt). Deficiency or excess of these elements influence bone mass and bone quality in adulthood as well as in childhood and adolescence. However, some protective elements may become toxic under certain condition s, depending on dosage (serum concentration), duration of treatment and interactions among individual elements. We review the beneficial and toxic effects of key elements on bone homeostasis., I. Zofkova, M. Davis, J. Blahos., and Obsahuje bibliografii
We investigate the traceless component of the conformal curvature tensor defined by (2.1) in Kähler manifolds of dimension $\ge 4$, and show that the traceless component is invariant under concircular change. In particular, we determine Kähler manifolds with vanishing traceless component and improve some theorems (for example, [4, pp. 313–317]) concerning the conformal curvature tensor and the spectrum of the Laplacian acting on $p$ $(0\le p\le 2)$-forms on the manifold by using the traceless component.
Including the previously untreated borderline cases, the trace spaces (in the distributional sense) of the Besov-Lizorkin-Triebel spaces are determined for the anisotropic (or quasi-homogeneous) version of these classes. The ranges of the traces are in all cases shown to be approximation spaces, and these are shown to be different from the usual spaces precisely in the cases previously untreated. To analyse the new spaces, we carry over some real interpolation results as well as the refined Sobolev embeddings of J. Franke and B. Jawerth to the anisotropic scales.
We investigate traces of functions, belonging to a class of functions with dominating mixed smoothness in ${\mathbb{R}}^3$, with respect to planes in oblique position. In comparison with the classical theory for isotropic spaces a few new phenomenona occur. We shall present two different approaches. One is based on the use of the Fourier transform and restricted to $p=2$. The other one is applicable in the general case of Besov-Lizorkin-Triebel spaces and based on atomic decompositions.
In Taiwanese literature, as in many other national literatures, realism is a term which has been used to serve many aims. Aesthetic and narrative aspects contribute to realism as much as poliical, ideological and/or social convictions. In Taiwam, it has been used as a label by almost all literary groups and schools since the first wave of native literature (xiangtu wenxue) in the 1920s in order to describe and ligitimize their respective literary and - frequently - political claims. Over time, the very meaning of the term "realism" had been subject to multiple changes, thus turning "realism" into an almost empty signifier that needed to be further framed. Realism increasingly tended to be accompanied by an explanatory adjunct, specifying what kind of realism was indicated. The article re-evaluates epistemological issues connected to the use of realism among Taiwan´s modernists and nativists in the 1960s and 1970s. It argues that the struggle between both groups is primarily in relation to the appropriate adjunct to be attached to realism. Both movements illustrate how realism has grown into a meta-term of modernity, while its aesthetics, subject matter, and ethical impact have became increasingly vague.
In this paper, tracking control design for a class of nonlinear polynomial systems is investigated by augmented error system approach and block pulse functions technique. The proposed method is based on the projection of the close loop augmented system and the associated linear reference model that it should follow over a basis of block pulse functions. The main advantage of using this tool is that it allows to transform the analytical differential calculus into an algebraic one relatively easy to solve. The developments presented have led to the formulation of a linear system of algebraic equations depending only on parameters of the feedback control. Once the control gains are determined by solving the latter optimization problem in least square sense, the practical stability of the closed loop augmented system is checked through given conditions. A double inverted pendulums benchmark is used to validate the proposed tracking control method.
In this work, an alternative solution to the tracking problem for a SISO nonlinear dynamical system exhibiting points of singularity is given. An inversion-based controller is synthesized using the Fliess generalized observability canonical form associated to the system. This form depends on the input and its derivatives. For this purpose, a robust exact differentiator is used for estimating the control derivatives signals with the aim of defining a control law depending on such control derivative estimates and on the system state variables. This control law is such that, when applied to the system, bounded tracking error near the singularities is guaranteed.