This article explores the homogeneity of coefficients in high-dimensional regression, which extends the sparsity concept and is more general and suitable for many applications. Homogeneity arises when regression coefficients corresponding to neighboring geographical regions or a similar cluster of covariates are expected to be approximately the same. Sparsity corresponds to a special case of ho...

Purpose: Motorized or dynamic wedge is routinely used nowadays to facilitate the work and reduce time on the treatment machine. However, this will necessitate keeping the Multileaf collimator (MLC) direction parallel to the chest wall. The aim of our work is to study the effect of Multileaf collimator in the perpendicular (┴) or parallel(//) direction on: target volume coverage, dose homogeneit...

We study the relative index of two orthogonal infinite dimensional projections which, in the finite dimensional case, is the difference in their dimensions. We relate the relative index to the Fredholm index of appropriate operators, discuss its basic properties, and obtain various formulas for it. We apply the relative index to counting the change in the number of electrons below the Fermi ene...

BACKGROUND Heterogeneity of resting perfusion may be due in part to up-regulation of coronary vasoconstriction via endothelin (ET) type A receptors, as homogeneity increases during subsequent vasodilatory hyperemia. Therefore, we conducted a mechanistic study using an ET receptor antagonist to determine if it could alter the homogeneity of myocardial perfusion. METHODS Included subjects demon...

Introduction: Whole breast radiotherapy after breast-conserving surgery decrease the risk of local recurrence. this study investigates the dosimetric aspects of intensity modulated radiotherapy (IMRT) compared to conventional tangential wedge-based beams techniques (CTT) of the whole breast in early stages breast cancer patients.   Materials and Methods: Co...