Jagiellonian University

About: Jagiellonian University is a education organization based out in Krakow, Poland. It is known for research contribution in the topics: Population & Catalysis. The organization has 17438 authors who have published 44092 publications receiving 862633 citations. The organization is also known as: Academia Cracoviensis & Akademia Krakowska.

X-ray emission properties of large-scale jets, hot spots, and lobes in active galactic nuclei

Abstract: We examine a systematic comparison of jet knots, hot spots, and radio lobes recently observed with Chandra and ASCA. This report discusses the origin of their X-ray emissions and investigates the dynamics of the jets. The data were compiled at well-sampled radio (5 GHz) and X-ray (1 keV) frequencies for more than 40 radio galaxies. We examine three models for the X-ray production: synchrotron (SYN), synchrotron self-Compton (SSC), and external Compton (EC) on cosmic microwave background (CMB) photons. For the SYN sources?mostly jet knots in nearby low-luminosity radio galaxies?X-ray photons are produced by ultrarelativistic electrons with energies 10-100 TeV that must be accelerated in situ. For the other objects, conservatively classified as SSC or EC sources, a simple formulation of calculating the expected X-ray fluxes under an equipartition hypothesis is presented. We confirm that the observed X-ray fluxes are close to the expected ones for nonrelativistic emitting plasma velocities in the case of radio lobes and the majority of hot spots, whereas a considerable fraction of jet knots are too bright in X-rays to be explained in this way. We examine two possibilities to account for the discrepancy in a framework of the inverse Compton model: (1) the magnetic field is much smaller than the equipartition value, and (2) the jets are highly relativistic on kiloparsec and megaparsec scales. We conclude that if the inverse Compton model is the case, the X-ray-bright jet knots are most likely far from the minimum-power condition. We also briefly discuss the other possibility, namely, that the observed X-ray emission from all the jet knots is synchrotron in origin.

Perivascular adipose tissue inflammation in vascular disease.

Abstract: Perivascular adipose tissue (PVAT) plays a critical role in the pathogenesis of cardiovascular disease. In vascular pathologies perivascular adipose tissue increases in volume and becomes dysfunctional, with altered cellular composition and molecular characteristics. PVAT dysfunction is characterized by its inflammatory character, oxidative stress, diminished production of vaso-protective adipocyte derived relaxing factors (ADRFs) and increased production of paracrine factors such as resistin, leptin, cytokines (IL-6, TNF-α) and chemokines (RANTES, MCP-1). These adipocyte-derived factors initiate and orchestrate inflammatory cell infiltration including primarily T cells, macrophages, dendritic cells (DCs), B cells as well as NK cells. Protective factors such as adiponectin can reduce NADPH oxidase superoxide production and increase nitric oxide bioavailability in the vessel wall, while inflammation (e.g. IFN-γ or IL-17) induces vascular oxidases and eNOS dysfunction in the endothelium, vascular smooth muscle cells and adventitial fibroblasts. All of these events link dysfunctional perivascular fat to vascular dysfunction. These mechanisms are important in the context of a number of cardiovascular disorders including atherosclerosis, hypertension, diabetes and obesity. Inflammatory changes in PVAT molecular and cellular responses are uniquely different from classical visceral or subcutaneous adipose tissue or from adventitia, emphasizing unique structural and functional features of this adipose tissue compartment. Therefore, it is essential to develop techniques for monitoring PVAT characteristics and assessing its inflammation. This will lead to better understanding of the early stages of vascular pathologies and development of new therapeutic strategies focusing on perivascular adipose tissue.

Anomaly-free scalar perturbations with holonomy corrections in loop quantum cosmology

Abstract: Holonomy corrections to scalar perturbations are investigated in the loop quantum cosmology framework. Due to the effective approach, modifications of the algebra of constraints generically lead to anomalies. In order to remove those anomalies, counter-terms are introduced. We find a way to explicitly fulfill the conditions for anomaly freedom and we give explicit expressions for the counter-terms. Surprisingly, the ¯-scheme naturally arises in this procedure. The gauge invariant variables are found and equations of motion for the anomaly-free scalar perturbations are derived. Finally, some cosmological consequences are discussed qualitatively.

Determination of Lycopene and β-Carotene Content in Tomato Fruits and Related Products: Comparison of FT-Raman, ATR-IR, and NIR Spectroscopy

Abstract: Tomatoes and various products derived from thermally processed tomatoes are major sources of lycopene, but apart from this micronutrient, other carotenoids such as β-carotene also are present in the fruit. They occur in tomato fruits and various tomato products in amounts of 2.62−629.00 (lycopene) and 0.23−2.83 mg/100 g (β-carotene). Standard methods for determining the carotenoid content require the extraction of the analyte as well as other cleanup steps. In this work, FT-Raman, ATR-IR, and NIR spectroscopy are applied in order to establish new, fast, and nondestructive calibration methods for quantification of lycopene and β-carotene content in tomato fruits and related products. The best prediction quality was achieved using a model based on IR spectroscopy (R2 = 0.98 and 0.97, SECV = 33.20 and 0.16 for lycopene and β-carotene, respectively). In spite of the fact that Raman spectra of tomato products show characteristic key bands of the investigated carotenoids, this method gives slightly lower reliab...

Hydrodynamic gradient expansion in gauge theory plasmas.

Abstract: We utilize the fluid-gravity duality to investigate the large order behavior of hydrodynamic gradient expansion of the dynamics of a gauge theory plasma system. This corresponds to the inclusion of dissipative terms and transport coefficients of very high order. Using the dual gravity description, we calculate numerically the form of the stress tensor for a boost-invariant flow in a hydrodynamic expansion up to terms with 240 derivatives. We observe a factorial growth of gradient contributions at large orders, which indicates a zero radius of convergence of the hydrodynamic series. Furthermore, we identify the leading singularity in the Borel transform of the hydrodynamic energy density with the lowest nonhydrodynamic excitation corresponding to a ‘nonhydrodynamic’ quasinormal mode on the gravity side.