University of Graz

About: University of Graz is a education organization based out in Graz, Steiermark, Austria. It is known for research contribution in the topics: Population & Quantum chromodynamics. The organization has 17934 authors who have published 37489 publications receiving 1110980 citations. The organization is also known as: Carolo Franciscea Graecensis & Karl Franzens Universität.

Optimization methods on Riemannian manifolds and their application to shape space

Abstract: We extend the scope of analysis for linesearch optimization algorithms on (possibly infinite-dimensional) Riemannian manifolds to the convergence analysis of the BFGS quasi-Newton scheme and the Fletcher--Reeves conjugate gradient iteration. Numerical implementations for exemplary problems in shape spaces show the practical applicability of these methods.

Restoring polyamines protects from age-induced memory impairment in an autophagy-dependent manner.

Abstract: Age-dependent memory impairment is known to occur in several organisms, including Drosophila, mouse and human However, the fundamental cellular mechanisms that underlie these impairments are still poorly understood, effectively hampering the development of pharmacological strategies to treat the condition Polyamines are among the substances found to decrease with age in the human brain We found that levels of polyamines (spermidine, putrescine) decreased in aging fruit flies, concomitant with declining memory abilities Simple spermidine feeding not only restored juvenile polyamine levels, but also suppressed age-induced memory impairment Ornithine decarboxylase-1, the rate-limiting enzyme for de novo polyamine synthesis, also protected olfactory memories in aged flies when expressed specifically in Kenyon cells, which are crucial for olfactory memory formation Spermidine-fed flies showed enhanced autophagy (a form of cellular self-digestion), and genetic deficits in the autophagic machinery prevented spermidine-mediated rescue of memory impairments Our findings indicate that autophagy is critical for suppression of memory impairments by spermidine and that polyamines, which are endogenously present, are candidates for pharmacological intervention

Dermoscopy of pigmented skin lesions.

Abstract: This paper describes the basic concepts of dermoscopy, the various dermoscopic equipments and the standard criteria for diagnosing pigmented skin lesions. In assessing dermoscopic images, both global and local features can be recognized. These features will be systematically described and illustrated in Part I of this article. First, we will focus on 8 morphologically rather distinctive global features that allow a quick, preliminary categorization of a given pigmented skin lesion. Second, we will describe various local features representing the letters of the dermoscopic alphabet. The local features permit a more detailed assessment of pigmented skin lesions.