35 research outputs found
Closed G2 forms and special metrics
170 p.En esta tesis se aborda el estudio y construcción de variedades G2 calibradas. Una tal variedad es una variedad de Riemann, de dimensión 7, con una métrica de Riemann definida por una cierta 3-forma diferencial, denominada G2 forma, la cual no sólo es invariante por la acción del grupo excepcional G2 sino que también es cerrada y, por lo tanto, define una calibración en el sentido de Harvey y Lawson. Los dos primeros capítulos de esta memoria se dedican a la construcción de nuevos ejemplos de esas variedades, tanto en el caso compacto como no-compacto. En particular, mostramos que el mapping torus de un difeomorfismo de una variedad half-flat simpléctica, tal que la estructura half-flat es preservada por el difeomorfismo, es una variedad G2 calibrada. En los capítulos 3 y 4 estudiamos la existencia de métricas especiales (Einstein y Ricci solitones) determinadas por G2 formas cerradas. Por una parte, sabemos que el comportamiento del tensor de Ricci de la métrica inducida por una G2 forma está estrechamente relacionado con el comportamiento de la propia G2 forma. En particular, Cleyton e Ivanov probaron que ninguna variedad compacta, de dimensión 7, admite una estructura G2 calibrada tal que la métrica inducida sea Einstein, salvo que la G2 forma sea también cocerrada y, por lo tanto, el grupo de holonomía de la métrica es un subgrupo de G2. En el capítulo 3 exploramos la versión no compacta de este resultado, obteniendo un resultado equivalente para variedades (no compactas) resolubles.En el último capítulo, determinamos las nilvariedades compactas que poseen una G2 forma calibrada induciendo un nilsolitón. Para cada una de esas variedades, estudiamos el flujo Laplaciano, y mostramos los primeros ejemplos compactos tales que la solución del flujo Laplaciano está definida en un intervalo no acotado
Compact solvmanifolds with calibrated and cocalibrated G2-structures
We give a method to obtain new solvable 7-dimensional Lie algebras endowed with closed and coclosed G2-structures starting from 6-dimensional solvable Lie algebras with symplectic half-flat and half-flat SU(3)-structures, respectively. Provided the existence of a lattice for the corresponding Lie groups we obtain new examples of compact solvmanifolds endowed with calibrated and cocalibrated G2-structures. As an application of this construction we also obtain a formal compact solvmanifold with first Betti number b1=1 endowed with a calibrated G2-structure and such that does not admit any invariant torsion-free G2-structure
Two-dimensional power Doppler-three-dimensional ultrasound imaging of a cesarean section dehiscence with utero-peritoneal fistula: a case report
<p>Abstract</p> <p>Introduction</p> <p>An imaging diagnosis after an iterative cesarean delivery is reviewed demonstrating a fine ultrasound-pathologic correlation.</p> <p>Case presentation</p> <p>A 33-year-old woman (G3, P3) presented referring intense dysmenorrhea and intermenstrual spotting since her third cesarean delivery, 1 year before. A cesarean section dehiscence with utero-peritoneal fistula was diagnosed by transvaginal ultrasound.</p> <p>Conclusion</p> <p>We can conclude that transvaginal two-dimensional power Doppler and three-dimensional ultrasound are highly accurate in detecting cesarean section dehiscence and uterine fistula.</p
The value of minilaparotomy for total hysterectomy for benign uterine disease: A comparative study with conventional Pfannenstiel and laparoscopic approaches
<p>Abstract</p> <p>Background</p> <p>The aim of this paper is to review and compare the results obtained using the Pfannenstiel, laparoscopy and minilaparotomy approaches for total hysterectomy procedure in relation to benign uterine diseases.</p> <p>Methods</p> <p>A retrospective data analysis was performed on 165 patients who underwent hysterectomy for benign uterine diseases at our centre during the period 2004 to 2006.</p> <p>Findings</p> <p>The minilaparotomy procedure was the fastest procedure with a mean time of 73.4 minutes (range: 67.85 to 78.94 minutes, p < 0.001). Hospital stay was shortest for laparosopic procedure (mean time: 3.24 days, range: 2.86 to 3.61 days) (p < 0.001). The rate of intraoperative and postoperative complications were not statistical different among three procedures.</p> <p>Conclusion</p> <p>The minilaparotomy procedure offers a minimally invasive option for total hysterectomy due to benign uterine disease.</p
The ECOMS User Data Gateway: homogeneous seasonal to decadal forecast data access for end users
ECOMS-UDG. A User-friendly data access Gateway to seasonal forecast datasets allowing R-based remote data access, visualization-validation, bias correction and downscaling
WRF4G: WRF experiment management made simple
his work presents a framework, WRF4G, to manage the experiment workflow of the Weather Research and Forecasting (WRF) modelling system. WRF4G provides a flexible design, execution and monitoring for a general class of scientific experiments. It has been designed with the aim of facilitating the management and reproducibility of complex experiments. Furthermore, the concepts behind the design of this framework can be straightforwardly extended to other modelsThis work has been supported by the Spanish National R&D Plan under
projects WRF4G (CGL2011-28864, co-funded by the European Regional Development Fund
–ERDF–) and CORWES (CGL2010-22158-C02-01) and the IS-ENES2 project from the 7FP of
the European Commission (grant agreement no. 312979). C. Blanco acknowledges financial
support 5 from programa de Personal Investigador en Formación Predoctoral from Universidad
de Cantabria, co-funded by the regional government of Cantabria. The authors are thankful to
the developers of third party software (e.g. GridWay, WRFV3, python and NetCDF), which was
intensively used in this work
Real-world persistence of initial targeted therapy strategy in monotherapy versus combination therapy in patients with chronic inflammatory arthritis
Objective: The persistence of biologic (b) and targeted synthetic (ts) disease-modifying antirheumatic drugs(DMARDs) in monotherapy versus in combination with conventional synthetic (cs) DMARDs is still a controversial topic in rheumatic diseases. To clarify this issue, the retention of the initial treatment strategy of b/tsDMARD in combination with csDMARD versus monotherapy in rheumatoid arthritis (RA), psoriatic arthritis (PsA) and ankylosing spondylitis (AS) patients under real-life conditions was evaluated. Factors associated with maintenance of the initial strategy were analysed. Methods: Nested cohort study within the Spanish BIOBADASER III registry. Bivariate comparisons and multivariate Cox proportional hazards models were used for the analyses. Results: A total of 2521 patients were included in the study. In the multivariate model, the initial strategy of combination therapy was associated with shorter persistence in patients with RA (hazard ratio [HR] 1.58;95% confidence interval [CI] 1.00-2.50; p = .049), PsA (HR 2.48; 95% CI 1.65-3.72) and AS (HR 16.77; 95% CI 7.37-38.16; p < .001), regardless of sex, time of disease progression, baseline disease activity, glucocorticoid use or type of b/tsDMARD. Overall, the combination strategy was associated with an increased incidence of adverse events (incidence rate ratio [IRR] 1.13; 95% CI 1.05-1.21). Conclusions: In this real-life study, the strategy of combining a b/tsDMARD with a csDMARD is associated with lower persistence and worse safety profile compared to monotherapy in RA and especially in PsA and AS, suggesting that combination therapy should be rethought as first choice in RA patients, but especially in PsA and AS patients.This research is supported by the Research Unit of the Spanish Society of Rheumatology. BIOBADASER is supported by the Spanish Agency of Drugs and Medical Devices (AEMPS), Biogen, Bristol-Myers and Squibb (BMS), Celltrion, Janssen, Lilly, Merck Sharp and Dohme (MSD), Novartis, Pfizer, Regeneron, and Samsung Bioepis.S
Postpartum ovarian vein thrombosis after cesarean delivery: a case report
<p>Abstract</p> <p>Introduction</p> <p>Postpartum ovarian vein thrombosis is an uncommon complication; incidence varies between 0.002% and 0.05%. It most often occurs during the 2–15 days following delivery.</p> <p>Case presentation</p> <p>A 22-year-old pregnant woman at term presented to hospital with uterine contractions, abdominal pain, nausea and vomiting. After delivery an ovarian vein thrombosis was diagnosed.</p> <p>Conclusion</p> <p>Low-molecular weight heparin with broad-spectrum antibiotics are the accepted therapy in non-complicated cases of postpartum ovarian vein thrombosis.</p