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 & Context (language use). 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.

Control of the Burgers equation by a reduced-order approach using proper orthogonal decomposition

Abstract: Proper orthogonal decomposition (POD) is a method to derive reduced-order models for dynamical systems In this paper, POD is utilized to solve open-loop and closed-loop optimal control problems for the Burgers equation The relative simplicity of the equation allows comparison of POD-based algorithms with numerical results obtained from finite-element discretization of the optimality system For closed-loop control, suboptimal state feedback strategies are presented

QCD and strongly coupled gauge theories: challenges and perspectives

Abstract: We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.

Gastric cancer: epidemiology and risk factors.

Abstract: The incidence of gastric cancer is decreasing and lies between 10 and 15 new cases per 100,000 population per year in most Western countries. Peak age is between 60 and 80 years. While distal gastric cancers account for the overall decrease in gastric cancer, tumors in the proximal stomach (cardia and esophagogastric junction) are on the rise. Recognized risk factors for gastric cancer are infection with Helicobacter pylori, dietary factors (e.g. high intake of salt-preserved foods), smoking, pernicious anemia and a history of partial gastrectomy.

The Optimal Aspect Ratio of Gold Nanorods for Plasmonic Bio-sensing

Abstract: The plasmon resonance of metal nanoparticles shifts upon refractive index changes of the surrounding medium through the binding of analytes. The use of this principle allows one to build ultra-small plasmon sensors that can detect analytes (e.g., biomolecules) in volumes down to attoliters. We use simulations based on the boundary element method to determine the sensitivity of gold nanorods of various aspect ratios for plasmonic sensors and find values between 3 and 4 to be optimal. Experiments on single particles confirm these theoretical results. We are able to explain the optimum by showing a corresponding maximum for the quality factor of the plasmon resonance.

Impairment of Glucose and Glutamate Transport and Induction of Mitochondrial Oxidative Stress and Dysfunction in Synaptosomes by Amyloid β-Peptide: Role of the Lipid Peroxidation Product 4-Hydroxynonenal

Abstract: Deposits of amyloid beta-peptide (A beta), reduced glucose uptake into brain cells, oxidative damage to cellular proteins and lipids, and excitotoxic mechanisms have all been suggested to play roles in the neurodegenerative process in Alzheimer's disease. Synapse loss is closely correlated with cognitive impairments in Alzheimer's disease, suggesting that the synapse may be the site at which degenerative mechanisms are initiated and propagated. We report that A beta causes oxyradical-mediated impairment of glucose transport, glutamate transport, and mitochondrial function in rat neocortical synaptosomes. A beta induced membrane lipid peroxidation in synaptosomes that occurred within 1 h of exposure; significant decreases in glucose transport occurred within 1 h of exposure to A beta and decreased further with time. The lipid peroxidation product 4-hydroxynonenal conjugated to synaptosomal proteins and impaired glucose transport; several antioxidants prevented A beta-induced impairment of glucose transport, indicating that lipid peroxidation was causally linked to this adverse action of A beta. FeSO4 (an initiator of lipid peroxidation), A beta, and 4-hydroxynonenal each induced accumulation of mitochondrial reactive oxygen species, caused concentration-dependent decreases in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction, and reduced cellular ATP levels significantly. A beta also impaired glutamate transport, an effect blocked by antioxidants. These data suggest that A beta induces membrane lipid peroxidation, which results in impairment of the function of membrane glucose and glutamate transporters, altered mitochondrial function, and a deficit in ATP levels; 4-hydroxynonenal appears to be a mediator of these actions of A beta. These data suggest that oxidative stress occurring at synapses may contribute to the reduced glucose uptake and synaptic degeneration that occurs in Alzheimer's disease patients. They further suggest a sequence of events whereby oxidative stress promotes excitotoxic synaptic degeneration and neuronal cell death in a variety of different neurodegenerative disorders.