Stability of the blow-up time and the blow-up set under perturbations

In this paper we prove a general result concerning continuity of the blow-up time and the blow-up set for an evolution problem under perturbations. This result is based on some convergence of the perturbations for times smaller than the blow-up time of the unperturbed problem together with uniform bounds on the blow-up rates of the perturbed problems. We also present several examples. Among them we consider changing the special domain in which the heat equation with a power source takes place. We consider rather general perturbations of the domain and show the continuity of the blow- up time. Moreover, we deal with perturbations on the initial condition and on parameters in the equation. Finally, we also present some continuity results for the blow-up se

Estudio de dos problemas de difusión no lineal mediante soluciones autosemejantes

Tesis doctoral inédita, leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Matemáticas. Fecha de lectura: 16-12-199

Advanced airway management: a descriptive analysis of complications and factors associated with first-attempt intubation failure in prehospital emergency care

7 p.Objetivos. Analizar las características del manejo de la vía aérea (VA) en emergencias prehospitalarias, sus complicaciones y establecer factores predictores de fracaso en el primer intento de intubación orotraqueal (FIPI). Método. Estudio observacional de cohortes retrospectivo de pacientes que precisaron intubación orotraqueal por el servicio de emergencias prehospitalarias de Castilla La Mancha, desde el 01-06-2017 hasta el 01-01-2021. Se analizaron características de los pacientes, del procedimiento y sus complicaciones, se realizó una regresión logística para detectar factores predictores de FIPI. Resultados. Se incluyeron 425 pacientes, 417 (98,1%) fueron intubados con éxito y 326 (76,7%) en el primer intento. Se registraron 183 complicaciones en 94 pacientes (22,1%). Los factores predictores de FIPI fueron la edad > 55 años (OR = 1,94; IC 95% 1,10-4,23), índice de masa corporal > 30 (OR = 9,14; IC 95% 4,40-19,00); saturación de oxígeno < 90% (OR = 3,33; IC 95% 1,06-10,58); puntuación en la Glasgow Coma Scale entre 9 y 13 (OR = 1,58; IC 95% 1,28-6,9); intubación realizada en vía pública (OR = 2,99; IC 95% 1,42-6,29); posición distinta a la bipedestación (OR = 2,09; IC 95% 1,08-7,25); laringoscopia directa (OR = 2,39; IC 95% 1,20-6,55); uso de estilete (OR = 1,80; IC 95% 1,40-3,78); y clasificación Cormack-Lehane $ 2 (OR = 6,50; IC 95% 3,96-30,68). Conclusiones. El procedimiento de intubación se realizó de forma habitual en el primer intento. Existen factores asociados a FIPI que permiten individualizar el manejo de la VA

School Physical Education and Municipality: An opportunity for mutual enrichment

Tendemos a pensar en las administraciones públicas como entes aislados. Esta concepción de los recursos públicos, en especial en el ámbito educativo, es un error. El tratamiento de la problemática de salud pública con que nos encontramos en el panorama nacional, y especialmente en la comunidad canaria, merece una visión global, transversal y comprometida de las diferentes administraciones. Las competencias en Salud Pública, Educación y Deportes deben encontrar un punto de unión. En este artículo se presenta una propuesta de trabajo coordinado en el ámbito educativo con un enfoque inter-administrativo entre los servicios municipales de deportes y los centros educativos.We tend to think of public administrations as isolated entities. This conception of public resources, especially in the educational sphere, is an error. The treatment of the public health problems that we face in the national panorama, and especially in the Canarian community, deserves a global, transversal and committed vision of the different administrations. Competencies in Public Health, Education and Sports must find a point of union. This article presents a coordinated work proposal in the educational field with an inter-administrative approach between municipal sports services and educational centers

An RVE-based multiscale theory of solids with micro-scale inertia and body force effects

A multiscale theory of solids based on the concept of representative volume element (RVE) and accounting for micro-scale inertia and body forces is proposed. A simple extension of the classical Hill–Mandel Principle together with suitable kinematical constraints on the micro-scale displacements provide the variational framework within which the theory is devised. In this context, the micro-scale equilibrium equation and the homogenisation relations among the relevant macro- and micro-scale quantities are rigorously derived by means of straightforward variational arguments. In particular, it is shown that only the fluctuations of micro-scale inertia and body forces about their RVE volume averages may affect the micro-scale equilibrium problem and the resulting homogenised stress. The volume average themselves are mechanically relevant only to the macro-scale

Non-simultaneous quenching in a system of heat equations coupled at the boundary

We study the solutions of a parabolic system of heat equations coupled at the boundary through a nonlinear flux. We characterize in terms of the parameters involved when nonsimultaneous quenching may appear. Moreover, if quenching is non-simultaneous we find the quenching rate, which surprisingly depends on the flux associated to the other component.Fil: Ferreira, Raúl. Universidad Carlos III de Madrid; EspañaFil: de Pablo, Arturo. Universidad Carlos III de Madrid; EspañaFil: Quirós, Fernando. Universidad Autónoma de Madrid; EspañaFil: Rossi, Julio Daniel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Matemática; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Intertidal finger bars at El Puntal, Bay of Santander, Spain: observation and forcing analysis

A system of 15 small-scale finger bars has been observed, by using video imagery, between 23 June 2008 and 2 June 2010. The bar system is located in the intertidal zone of the swell-protected beaches of El Puntal Spit, in the Bay of Santander (northern coast of Spain). The bars appear on a planar beach (slope = 0.015) with fine, uniform sand (D50 = 0.27 mm) and extend 600 m alongshore. The cross-shore span of the bars is determined by the tidal horizontal excursion (between 70 and 130 m). They have an oblique orientation with respect to the low-tide shoreline; specifically, they are down-current-oriented with respect to the dominant sand transport computed (mean angle of 26° from the shore normal). Their mean wavelength is 26 m and their amplitude varies between 10 and 20 cm. The full system slowly migrates to the east (sand transport direction) with a mean speed of 0.06 m day-1, a maximum speed in winter (up to 0.15 m day-1) and a minimum speed in summer. An episode of merging has been identified as bars with larger wavelength seem to migrate more slowly than shorter bars. The wind blows predominantly from the west, generating waves that transport sediment across the bars during high-tide periods. This is the main candidate to explain the eastward migration of the system. In particular, the wind can generate waves of up to 20 cm (root-mean-squared wave height) over a fetch that can reach 4.5 km at high tide. The astronomical tide seems to be important in the bar dynamics, as the tidal level changes the fetch and also determines the time of exposure of the bars to the surf-zone waves and currents. Furthermore, the river discharge could act as input of suspended sediment in the bar system and play a role in the bar dynamics

Damage-driven strain localisation in networks of fibres: A computational homogenisation approach

In many applications, such as textiles, fibreglass, paper and several kinds of biological fibrous tissues, the main load-bearing constituents at the micro-scale are arranged as a fibre network. In these materials, rupture is usually driven by micro-mechanical failure mechanisms, and strain localisation due to progressive damage evolution in the fibres is the main cause of macro-scale instability. We propose a strain-driven computational homogenisation formulationbased on Representative Volume Element (RVE), within a framework in which micro-scale fibre damage can lead to macro-scale localisation phenomena. The mechanical stiffness considered here for the fibrous structure system is due to: i) an intra-fibre mechanism in which each fibre is axially stretched, and as a result, it can suffer damage; ii) an inter-fibre mechanism in which the stiffness results from the variation of the relative angle between pairs of fibres. The homogenised tangent tensor, which comes from the contribution of these two mechanisms, is required to detect the so-called bifurcation point at the macro-scale, through the spectral analysis of the acoustic tensor. This analysis can precisely determine the instant at which the macro-scale problem becomes ill-posed. At such a point, the spectral analysis provides information about the macro-scale failure pattern (unit normal and crack-opening vectors). Special attention is devoted to present the theoretical fundamentals rigorously in the light of variational formulations for multi-scale models. Also, the impact of a recent derived more general boundary condition for fibre networks is assessed in the context of materials undergoing softening. Numerical examples showing the suitability of the present methodology are also shown and discussed

Effect of LHRH analogs on lower urinary tract symptoms associated with advanced prostate cancer in real clinical practice: ANALUTS study

Androgen deprivation; Hormonal therapy; RadiotherapyPrivación de andrógenos; Terapia hormonal; RadioterapiaPrivació d'andrògens; Teràpia hormonal; RadioteràpiaAims To estimate the prevalence of lower urinary tract symptoms (LUTS) in patients with prostate cancer scheduled to receive LHRH analogs, and to assess the effectiveness of LHRH analogs on LUTS in patients presenting moderate/severe symptoms. Methods Prospective, noninterventional, multicenter study conducted at 28 centers in Spain and Portugal. LUTS were evaluated using the International Prostate Symptom Score (IPSS) at baseline, 24 and 48 weeks after initiation of treatment. Subanalyses were performed according to age and concomitant treatment (radiotherapy, alpha-blockers, and antiandrogens). Results A total of 354 patients were treated with LHRH analogs for 48 weeks. The percentage of patients with moderate/severe LUTS (IPSS > 7) decreased from 60.2% (n = 213/354) at baseline to 52.8% (n = 187/354) at Week 48. Among patients with moderate/severe LUTS at baseline: 73.7% (n = 157/213) still had moderate/severe LUTS at Week 48; percentage reductions of patients with LUTS at Week 48 were statistically significant (p < 0.05) overall and by age or concomitant treatment, except for alpha-blockers (84.2% patients receiving them still had moderate/severe LUTS at Week 48). All IPSS items, including quality of life for urinary symptoms, improved throughout the study. The only predictor of response to treatment with LHRH analogs that improved IPSS by 3 points after 48 weeks was baseline testosterone levels. Lower baseline testosterone levels were associated with greater improvement in IPSS after treatment with LHRH analogs (odds ratio 0.998, 95% confidence interval 0.996–1.000, p = 0.0277). Conclusion LHRH analogs have a positive effect in patients with locally advanced or metastatic prostate cancer presenting moderate/severe LUTS regardless of age or concomitant treatment received (radiotherapy, antiandrogens, or alpha-blockers).The study was funded by Ipsen Pharma S.A.U