12 research outputs found

    Using 3D Stringy Gravity to Understand the Thurston Conjecture

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    We present a string inspired 3D Euclidean field theory as the starting point for a modified Ricci flow analysis of the Thurston conjecture. In addition to the metric, the theory contains a dilaton, an antisymmetric tensor field and a Maxwell-Chern Simons field. For constant dilaton, the theory appears to obey a Birkhoff theorem which allows only nine possible classes of solutions, depending on the signs of the parameters in the action. Eight of these correspond to the eight Thurston geometries, while the ninth describes the metric of a squashed three sphere. It therefore appears that one can construct modified Ricci flow equations in which the topology of the geometry is encoded in the parameters of an underlying field theory.Comment: 17 pages, Late

    A Renormalization Group Approach to Relativistic Cosmology

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    We discuss the averaging hypothesis tacitly assumed in standard cosmology. Our approach is implemented in a "3+1" formalism and invokes the coarse graining arguments, provided and supported by the real-space Renormalization Group (RG) methods. Block variables are introduced and the recursion relations written down explicitly enabling us to characterize the corresponding RG flow. To leading order, the RG flow is provided by the Ricci-Hamilton equations studied in connection with the geometry of three-manifolds. The properties of the Ricci-Hamilton flow make it possible to study a critical behaviour of cosmological models. This criticality is discussed and it is argued that it may be related to the formation of sheet-like structures in the universe. We provide an explicit expression for the renormalized Hubble constant and for the scale dependence of the matter distribution. It is shown that the Hubble constant is affected by non-trivial scale dependent shear terms, while the spatial anisotropy of the metric influences significantly the scale-dependence of the matter distribution.Comment: 57 pages, LaTeX, 15 pictures available on request from the Author

    Oddzialywanie stosowanego nawozenia azotem na wartosc C-N, zawartosc azotanow [V] oraz aktywnosc enzymatyczna badanych gleb

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    W latach 1996-2004 przeprowadzono badania w oparciu o doświadczenie mikropoletkowe, zlokalizowane na terenie Stacji Badawczej ATR w Wierzchucinku. Określono wartości C/N, zawartości azotanów(V) oraz aktywność enzymów uczestniczących w przemianach azotu (dehydrogenaz i ureazy) w badanych glebach (w warstwie: 0-40 i 40-80 cm) w zależności od zastosowanego zróżnicowanego nawożenia azotem w warunkach doświadczenia mikropoletkowego. Po zastosowaniu zróżnicowanego nawożenia azotem (1996-2004) stwierdzono obniżenie zawartości węgla organicznego i azotu ogółem jedynie w warstwie podornej (40-80 cm). Typ gleby, głębokość pobierania próbek glebowych oraz stosowane zróżnicowane nawożenie azotem istotnie determinowało zawartość azotu azotanowego(V), aktywność dehydrogenaz oraz ureazy w badanych glebach.The studies carried out within 1996-2004 were based on a microfield experiment localized at Wierzchucinek TAU Research Station. The aim of study was to estimate the C/N ratio, nitrate(V) contents and the activity of enzymes acting in nitrogen transformations (dehydrogenase and urease) in the soils depending on diversified nitrogen fertilization. After diversified nitrogen fertilization (1996-2004) the decrease of organic carbon and total nitrogen contents in top soil layer (40-80 cm) were observed. Soil type, the depth of soil sampling and diversified nitrogen fertilization significantly determined the nitrate nitrogen(V) content and the activity of dehydrogenase and urease in tested soils

    Redox-Active Ferrocene as a Tuning Functionality for Magnetic Superexchange Interactions of Bis(oxamato) Type Complexes

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    Lipid levels, atrial fibrillation and the impact of age: Results from the LIPIDOGRAM2015 study

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    Relationship Between Anti-DFS70 Autoantibodies and Oxidative Stress

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    Background: The anti-DFS70 autoantibodies are one of the most commonly and widely described agent of unknown clinical significance, frequently detected in healthy individuals. It is not known whether the DFS70 autoantibodies are protective or pathogenic. One of the factors suspected of inducing the formation of anti-DFS70 antibodies is increased oxidative stress. We evaluated the coexistence of anti-DFS70 antibodies with selected markers of oxidative stress and investigated whether these antibodies could be considered as indirect markers of oxidative stress. Methods: The intensity of oxidative stress was measured in all samples via indices of free-radical damage to lipids and proteins such as total oxidant status (TOS), concentrations of lipid hydroperoxides (LPH), lipofuscin (LPS), and malondialdehyde (MDA). The parameters of the non-enzymatic antioxidant system, such as total antioxidant status (TAS) and uric acid concentration (UA), were also measured, as well as the activity of superoxide dismutase (SOD). Based on TOS and TAS values, the oxidative stress index (OSI) was calculated. All samples were also tested with indirect immunofluorescence assay (IFA) and 357 samples were selected for direct monospecific anti DFS70 enzyme-linked immunosorbent assay (ELISA) testing. Results:: The anti-DFS70 antibodies were confirmed by ELISA test in 21.29% of samples. Compared with anti-DFS70 negative samples we observed 23% lower concentration of LPH (P = .038) and 11% lower concentration of UA (P = .005). TOS was 20% lower (P = .014). The activity of SOD was up to 5% higher (P = .037). The Pearson correlation showed weak negative correlation for LPH, UA, and TOS and a weak positive correlation for SOD activity. Conclusion: In samples positive for the anti-DFS70 antibody a decreased level of oxidative stress was observed, especially in the case of samples with a high antibody titer. Anti-DFS70 antibodies can be considered as an indirect marker of reduced oxidative stress or a marker indicating the recent intensification of antioxidant processes

    Metabolic syndrome is associated with similar long-term prognosis in non-obese and obese patients. An analysis of 45 615 patients from the nationwide LIPIDOGRAM 2004-2015 cohort studies

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    Aims We aimed to evaluate the association between metabolic syndrome (MetS) and long-term all-cause mortality. Methods The LIPIDOGRAM studies were carried out in the primary care in Poland in 2004, 2006 and 2015. MetS was diagnosed based on the National Cholesterol Education Program, Adult Treatment Panel III (NCEP/ATP III) and Joint Interim Statement (JIS) criteria. The cohort was divided into four groups: non-obese patients without MetS, obese patients without MetS, non-obese patients with MetS and obese patients with MetS. Differences in all-cause mortality was analyzed using Kaplan-Meier and Cox regression analyses. Results 45,615 participants were enrolled (mean age 56.3, standard deviation: 11.8 years; 61.7% female). MetS was diagnosed in 14,202 (31%) by NCEP/ATP III criteria, and 17,216 (37.7%) by JIS criteria. Follow-up was available for 44,620 (97.8%, median duration 15.3 years) patients. MetS was associated with increased mortality risk among the obese (hazard ratio, HR: 1.88 [95% CI, 1.79-1.99] and HR: 1.93 [95% CI 1.82-2.04], according to NCEP/ATP III and JIS criteria, respectively) and non-obese individuals (HR: 2.11 [95% CI 1.85-2.40] and 1.7 [95% CI, 1.56-1.85] according to NCEP/ATP III and JIS criteria respectively). Obese patients without MetS had a higher mortality risk than non-obese patients without MetS (HR: 1.16 [95% CI 1.10-1.23] and HR: 1.22 [95%CI 1.15-1.30], respectively in subgroups with NCEP/ATP III and JIS criteria applied). Conclusions MetS is associated with increased all-cause mortality risk in non-obese and obese patients. In patients without MetS obesity remains significantly associated with mortality. The concept of metabolically healthy obesity should be revised
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