We present a top-down construction of a three-dimensional nonlocal theory of massive gravity. This "nonlocal massive gravity" (NLMG) is obtained as the gravitational theory induced by Einstein gravity on a brane inserted in anti-de Sitter space modified by an overall minus sign. The theory involves an infinite series of increasingly complicated higher-derivative corrections to the Einstein-Hilbert action, with the quadratic term coinciding with new massive gravity.
View Article and Find Full Text PDFThe entanglement entropy of an arbitrary spacetime region A in a three-dimensional conformal field theory (CFT) contains a constant universal coefficient, F(A). For general theories, the value of F(A) is minimized when A is a round disk, F_{0}, and in that case it coincides with the Euclidean free energy on the sphere. We conjecture that, for general CFTs, the quantity F(A)/F_{0} is bounded above by the free scalar field result and below by the Maxwell field one.
View Article and Find Full Text PDFRényi entropies, S_{n}, admit a natural generalization in the presence of global symmetries. These "charged Rényi entropies" are functions of the chemical potential μ conjugate to the charge contained in the entangling region and reduce to the usual notions as μ→0. For n=1, this provides a notion of charged entanglement entropy.
View Article and Find Full Text PDFWe present several results concerning the free energy of odd-dimensional conformal field theories (CFTs) on squashed spheres. First, we propose a formula which computes this quantity for holographic CFTs dual to higher-curvature gravities with second-order linearized equations of motion. As opposed to standard on-shell action methods for Taub geometries, our formula only involves a simple evaluation of the corresponding bulk Lagrangian on an auxiliary pure anti-de Sitter (AdS) space.
View Article and Find Full Text PDFWe study the contribution to the entanglement entropy of (2+1)-dimensional conformal field theories (CFTs) coming from a sharp corner in the entangling surface. This contribution is encoded in a function a(θ) of the corner opening angle, and was recently proposed as a measure of the degrees of freedom in the underlying CFT. We show that the ratio a(θ)/C(T), where C(T) is the central charge in the stress tensor correlator, is an almost universal quantity for a broad class of theories including various higher-curvature holographic models, free scalars, and fermions, and Wilson-Fisher fixed points of the O(N) models with N=1,2,3.
View Article and Find Full Text PDFTo date, no effective method exists that predicts the response to preoperative chemoradiation (CRT) in locally advanced rectal cancer (LARC). Nevertheless, identification of patients who have a higher likelihood of responding to preoperative CRT could be crucial in decreasing treatment morbidity and avoiding expensive and time-consuming treatments. The aim of this study was to identify signatures or molecular markers related to response to pre-operative CRT in LARC.
View Article and Find Full Text PDFPreoperative chemoradiation significantly improves oncological outcome in locally advanced rectal cancer. However there is no effective method of predicting tumor response to chemoradiation in these patients. Peripheral blood mononuclear cells have emerged recently as pathology markers of cancer and other diseases, making possible their use as therapy predictors.
View Article and Find Full Text PDFJ Colloid Interface Sci
October 2011
The coalescence mechanism of a particle-laden drop resting at an oil-water interface has been studied. Two mechanisms for drop coalescence are observed; (i) complete coalescence, in which the drop experiences total coalescence in one event, and (ii) partial coalescence, where a drop is observed to separate during coalescence, producing a smaller secondary drop that rebounds and comes to rest at the planar oil-water interface. For particle-laden drops of approximately 4mm in diameter, we show the critical condition for partial to complete coalescence to be dependent on the particle concentration, and the interparticle interaction energy.
View Article and Find Full Text PDFObjective: To investigate the effect of parenteral administration of vitamin C on neutrophil apoptosis by determining Fas receptor expression and caspase-3, poly (ADP-ribose) polymerase (PARP), and Bcl-2 levels in neutrophils from septic abdominal surgery patients.
Study Design: Twenty septic abdominal surgery patients were studied in a prospective, randomized, double-blinded clinical trial. A group of healthy volunteers (n = 10) constituted a reference group for baseline parameter values.
Am J Physiol Endocrinol Metab
November 2005
This study evaluated the activity of cardiac and renal antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), and glutathione reductase (GR)] and whether chronic treatment with tempol, a cell membrane-permeable SOD mimetic, ameliorates the hypertension of hyperthyroidism. Two experiments were performed. In experiment I, the following four groups of male Wistar rats were used: control group and three groups that received thyroxine (T4) at 10, 50, or 75 microg x rat(-1) x day(-1).
View Article and Find Full Text PDFBackground: This study analyzed whether hypertension induced by N(omega)-nitro-l-arginine methyl ester (L-NAME) is associated with dysregulation of the main antioxidant enzymes (superoxide dismutase [SOD], catalase, glutathione peroxidase [GPX], and glutathione reductase [GR]) and whether chronic administration of tempol ameliorates this hypertension.
Methods: Four groups of male Wistar rats were used: 1) control rats; 2) rats treated with L-NAME (35 mg/100 mL in drinking fluid); 3) rats treated with tempol (18 mg/100 mL in drinking fluid); and 4) rats treated with L-NAME plus tempol. All treatments were maintained for 6 weeks.
• The effects of salt stress and adaptation on salicylic acid (SA) content and on antioxidant and lipoxygenase (LOX) enzyme activities were studied in tomato (Lycopersicon esculentum cv. Pera) cells. • NaCl-adapted cells were obtained from calli adapted to 100 mm NaCl by successive subcultures in medium supplemented with 100 mm NaCl.
View Article and Find Full Text PDF• The involvement of lipoxygenase and antioxidant enzyme activities as well as hydrogen peroxide (H O ) accumulation are reported during early infection steps in alfalfa (Medicago sativa) roots inoculated either with a wild type Sinorhizobium meliloti or with a mutant defective in Nod-factor synthesis (Nod C ). • Compatibility between M. sativa and Rhizobium correlates, at least in part, with an increase in the activities of these enzymes, particularly catalase and lipoxygenase, during the preinfection period (up to 12 h).
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