Esther Klann

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The influence of lead and calcium on the metabolism of a nuclear matrix protein has been studied in mouse neuroblastoma 2a (Nb2a) cells. This protein, p32/6.3, has an unusual distribution in that it is relatively abundant only in normal neural tissues and in intranuclear inclusion bodies induced in kidney tubule-lining cells of chronically lead-intoxicated(More)
This paper presents a level-set based approach for the simultaneous reconstruction and segmentation of the activity as well as the density distribution from tomography data gathered by an integrated SPECT/CT scanner. Activity and density distributions are modelled as piecewise constant functions. The segmenting contours and the corresponding function values(More)
This paper is concerned with the regularization of linear ill-posed problems by a combination of data smoothing and fractional filter methods. For the data smoothing, a wavelet shrinkage denoising is applied to the noisy data with known error level δ. For the reconstruction, an approximation to the solution of the operator equation is computed from the data(More)
This paper analyzes the problem of deconvolution, especially for signals with peak-like structures. We present and analyze a so-called ‘practical approach’, which mainly consists of a wavelet shrinkage. It is shown that this practical approach is indeed a regularization procedure, and furthermore, it leads to a convergence rate that is superior to classical(More)
Given information about a harmonic function in two variables, consisting of a nite number of values of its Radon projections, i.e., integrals along some chords of the unit circle, we study the problem of interpolating these data by a harmonic polynomial. With the help of symbolic summation techniques we show that this interpolation problem has a unique(More)
The lead-associated nuclear protein, p32/6.3, increases significantly in the postnatally developing rat cerebral cortex (Egle and Shelton, J. Biol. Chem., 261 (1986) 2294-2298). In the present study, this increase has been identified with late development of the cerebral cortex or forebrain because p32/6.3 reached adult levels 10 to 14 days after birth in(More)
p32/6.3, a low-abundance, highly conserved nuclear protein, is a target for lead. Very few low abundance nuclear proteins have been described and no others have been associated with lead. Its wide distribution and conservation indicate a fundamental nuclear role. Further, it increases many fold in grey matter of brain and spinal cord during the neonatal(More)
In this article the Mumford–Shah-like method of [R. Ramlau and W. Ring, J. Comput. Phys., 221 (2007), pp. 539–557] for complete tomographic data is generalized and applied to limited angle and region of interest tomography data. With the Mumford–Shah-like method, one reconstructs a piecewise constant function and simultaneously a segmentation from its(More)
We formulate the problem of designing gradient-index optical coatings as the task of solving a system of operator equations. We use iterative numerical procedures known from the theory of inverse problems to solve it with respect to the coating refractive index profile and thickness. The mathematical derivations necessary for the application of the(More)