251 resultados para SCAR
Resumo:
Salomé es la danza, la tentación irresistible. La hija de Herodías se convierte en un personaje literario universal gracias al arte de Flaubert y, sobre todo, al de Óscar Wilde. Al comienzo de su pieza trágica, la figura de Salomé se funde con la de la luna, ávida de muerte. La obra se tradujo y se representó en España a comienzos del siglo XX, y en 1910 se puso en escena la ópera de Strauss inspirada en ella. Esa circunstancia permite ver la relación existente entre la Salomé de Wilde y la luna, bailarina mortal, del primer romance del Romancero gitano de García Lorca. A su vez Alberti se inspiraría en este poema para crear su «madrigal dramático de Ardiente - y - fría», de Marinero en tierra. Los grandes creadores, como abejas, liban en las flores de sus lecturas para crear su propia miel.
Resumo:
We study the interplay between the effects of surface anisotropy and dipolar interactions in monodisperse assemblies of nanomagnets with oriented anisotropy. We derive asymptotic formulas for the assembly magnetization, taking into account temperature, applied field, core and surface anisotropy, and dipolar interparticle interactions. We find that the interplay between surface anisotropy and dipolar interactions is well described by the analytical expression of the assembly magnetization derived here: the overall sign of the product of the two parameters governing the surface and the dipolar contributions determines whether intrinsic and collective terms compete or have synergistic effects on the magnetization. This is illustrated by the magnetization curves of γ-Fe2O3 nanoparticle assemblies in the low concentration limit.
Resumo:
The charge ordered La1/3Sr2/3FeO3−δ (LSFO) in bulk and nanocrystalline forms are investigated using ac and dc magnetization, M¨ossbauer, and polarized neutron studies. A complex scenario of short-range charge and magnetic ordering is realized from the polarized neutron studies in nanocrystalline specimen. This short-range ordering does not involve any change in spin state and modification in the charge disproportion between Fe3+ and Fe5+ compared to bulk counterpart as evident in the M¨ossbauer results. The refinement of magnetic diffraction peaks provides magnetic moments of Fe3+ and Fe5+ are about 3.15 μB and 1.57 μB for bulk, and 2.7 μB and 0.53 μB for nanocrystalline specimen, respectively. The destabilization of charge ordering leads to magnetic phase separation, giving rise to the robust exchange bias (EB) effect. Strikingly, EB field at 5 K attains a value as high as 4.4 kOe for average size ∼70 nm, which is zero for the bulk counterpart. A strong frequency dependence of ac susceptibility reveals cluster-glass-like transition around ∼65 K, below which EB appears. Overall results propose that finite-size effect directs the complex glassy magnetic behavior driven by unconventional short-range charge and magnetic ordering, and magnetic phase separation appears in nanocrystalline LSFO.
Resumo:
We show that the coercive field in ferritin and ferrihydrite depends on the maximum magnetic field in a hysteresis loop and that coercivity and loop shifts depend both on the maximum and cooling fields. In the case of ferritin, we show that the time dependence of the magnetization also depends on the maximum and previous cooling fields. This behavior is associated to changes in the intraparticle energy barriers imprinted by these fields. Accordingly, the dependence of the coercive and loop-shift fields with the maximum field in ferritin and ferrihydrite can be described within the frame of a uniform-rotation model considering a dependence of the energy barrier with the maximum and the cooling fields.
Resumo:
An Enantiornithes specimen from El Montsec was initially described as an immature individual based upon qualitative traits such as its relatively large orbit and overall proportions of the skull and the postcranium. In this study we re-evaluate the precise determination of the ontogenetic stage of this individual, establishing a cross-talk among taphonomic, anatomic, and morphometric data. The exceptional preservation of the specimen has allowed pondering ontogenetic influence versus preservational bias in features like the external patterns of bone surfaces, instead of being aprioristically considered due to taphonomic alterations only. The rough texture of the periosteal bone associated with pores in the distal, proximal and mid-shaft areas of the humeral shaft, indicates a subadult stage when compared with long bones of modern birds. Forelimb proportions of embryo and juvenile Enanthiornithes are equivalent to those of adult individuals of other taxa within this clade, though this is not a reliable criterion for establishing a precise ontogenetic stage. The El Montsec specimen may be attributed a close adulthood, yet only if growth regimes in Enantiornithes are considered equivalent to those in Neornithes birds.
Resumo:
In this work methods for the multiresidue determination of the series of quinolones include in the European regulation in food of animal origin are de veloped and validated in line with Commission Decision 2002/657/EC in terms of linearity, decision limit, capability detection, precision and stability. Mult iresidue methods were established to allow the determination of quinolones covered by EU legislation in 2377/90/EC in muscle of chicken, turkey, pig and cow, plasma of cow and pig, liver of pig and milk of cow. First an extraction step was optimized and a SPE step was applied to clean!up and preconcentrate quinolones prior to their separation by CE or LC and determination by CE!UV, LC!UV, LC!Fl, LC!MS with different ion sources (ESI ,ApCI) and different mass analyser (Q, ToF) and LC!E SI!QqQ tandem mass spectrometry. The limits of quantification obtained are always lower than Maxim um Residue Limit (MRL) established by EU for quinolones in animal products and they can be applied to the control of quinolones in foodstuffs of animal origin . Finally the proposed methods were applied to determine quinolones in samples of turkey and pig muscle, pig plasma and milk of cow. Excellent quality parameters and reduced time of analysis were obtained when LC!ESI!MS/MS is used, although the others techniques presented too satisfactory results.
Resumo:
Direct evidence confirming the hypothesis that a dysfunction of the mitochondrial respiratory chain (MRC) underlies the pathogenesis of hyperlactatemia associated with highly active antiretroviral therapy (HAART) is scarce. We studied mitochondrial DNA (mtDNA) content and MRC function in the skeletal muscle of an HIV-infected patient during an episode of symptomatic hyperlactatemia. Skeletal muscle biopsy was performed during the episode when the patient was symptomatic and 3 months later when the patient was clinically recovered. Assessment of mitochondria was performed using histological, polarographic, spectrophotometrical, and Southern blot and real time PCR DNA quantification methods. The histological study disclosed extensive mitochondrial impairment in the form of ragged-red fibers or equivalents on oxidative reactions. These findings were associated with an increase in mitochondrial content and a decrease in both mitochondrial respiratory capacity and MRC enzyme activities. Mitochondrial DNA content declined to 53% of control values. Mitochondrial abnormalities had almost disappeared later when the patient became asymptomatic. Our findings support the hypothesis that MRC dysfunction stands at the basis of HAART-related hyperlactatemia.
Resumo:
Direct evidence confirming the hypothesis that a dysfunction of the mitochondrial respiratory chain (MRC) underlies the pathogenesis of hyperlactatemia associated with highly active antiretroviral therapy (HAART) is scarce. We studied mitochondrial DNA (mtDNA) content and MRC function in the skeletal muscle of an HIV-infected patient during an episode of symptomatic hyperlactatemia. Skeletal muscle biopsy was performed during the episode when the patient was symptomatic and 3 months later when the patient was clinically recovered. Assessment of mitochondria was performed using histological, polarographic, spectrophotometrical, and Southern blot and real time PCR DNA quantification methods. The histological study disclosed extensive mitochondrial impairment in the form of ragged-red fibers or equivalents on oxidative reactions. These findings were associated with an increase in mitochondrial content and a decrease in both mitochondrial respiratory capacity and MRC enzyme activities. Mitochondrial DNA content declined to 53% of control values. Mitochondrial abnormalities had almost disappeared later when the patient became asymptomatic. Our findings support the hypothesis that MRC dysfunction stands at the basis of HAART-related hyperlactatemia.
Resumo:
Background: Few qualitative studies of simultaneous pancreas-kidney transplantation (SPK Tx) have been published. The aims of this study were to explore from the perspective of patients, the experience of living with diabetes mellitus type 1 (T1DM), suffering from complications, and undergoing SPK Tx with good outcome; and to determine the impact of SPK Tx on patients and their social and cultural environment. Methods: We performed a focused ethnographic study. Twenty patients were interviewed. Data were analyzed using content analysis and constant comparison following the method proposed by Miles and Huberman. Results: A functioning SPK Tx allowed renal replacement therapy and insulin to be discontinued. To describe their new situation, patients used words and phrases such as"miracle","being reborn" or"coming back to life". Although the complications of T1DM, its surgery and treatment, and associated psychological problems did not disappear after SPK Tx, these were minimized when compared with the pretransplantation situation. Conclusion: For patients, SPK Tx represents a recovery of their health and autonomy despite remaining problems associated with the complications of T1DM and SPK Tx. The understanding of patients" existential framework and their experience of disease are key factors for planning new intervention and improvement strategies.
Resumo:
Background: Few qualitative studies of simultaneous pancreas-kidney transplantation (SPK Tx) have been published. The aims of this study were to explore from the perspective of patients, the experience of living with diabetes mellitus type 1 (T1DM), suffering from complications, and undergoing SPK Tx with good outcome; and to determine the impact of SPK Tx on patients and their social and cultural environment. Methods: We performed a focused ethnographic study. Twenty patients were interviewed. Data were analyzed using content analysis and constant comparison following the method proposed by Miles and Huberman. Results: A functioning SPK Tx allowed renal replacement therapy and insulin to be discontinued. To describe their new situation, patients used words and phrases such as"miracle","being reborn" or"coming back to life". Although the complications of T1DM, its surgery and treatment, and associated psychological problems did not disappear after SPK Tx, these were minimized when compared with the pretransplantation situation. Conclusion: For patients, SPK Tx represents a recovery of their health and autonomy despite remaining problems associated with the complications of T1DM and SPK Tx. The understanding of patients" existential framework and their experience of disease are key factors for planning new intervention and improvement strategies.
Resumo:
There is a lack of studies on tourism demand in Catalonia. To fill the gap, this paper focuses on detecting the macroeconomic factors that determine tourism demand in Catalonia. We also analyse the relation between these factors and tourism demand. Despite the strong seasonal component and the outliers in the time series of some countries, overnight stays give a better indication of tourism demand in Catalonia than the number of tourists. The degree of linear association between the macroeconomic variables and tourism demand is also higher when using quarterly rather than monthly data. Finally, there are notable differences between the results obtained for the different countries analysed. These results indicate that the best way to model tourism demand in Catalonia is to specify a quarterly model of overnight stays, differentiating between an aggregate demand model for the total number of tourists and specific models for each of the countries analysed.
Crisis económica, empleo e inmigración : informe del estudio “Inmigración, Empleo y Cohesión Social”
Resumo:
El análisis se centra por tanto en el impacto de la crisis económica tanto en el fenómeno migratorio (flujos de entrada) como en el mercado de trabajo y en modo particular en los posibles efectos asimétricos que la recesión tiene en las condiciones y trayectorias laborales de trabajadores inmigrantes y autóctonos. A modo de contextualización, el informe comienza con una breve exploración de los cambios en los Crisis Económica, Empleo e Inmigración flujos migratorios como consecuencia del cambio de ciclo que se produce desde mediados de 2007, . A continuación se ofrece una visión general de la evolución del empleo y el paro en España en los últimos años con especial énfasis en los efectos que la reciente crisis ha podido tener. Se presta particular atención a los cambios en la composición del grupo de desempleados, tanto a nivel estatal como regional. Asimismo, se compara el impacto sobre el mercado de trabajo de la crisis económica de inicios de los 90 con la actual. Otro aspecto que ha sido tratado es el de las posibles trayectorias de los trabajadores inmigrantes y autónomos, con especial énfasis en los flujos desde el estado de empleado a desempleado o inactivo. Asimismo, se exploran las características de los perceptores de prestaciones de desempleo usando datos tanto del registro de los servicios públicos de empleo como, en menor medida, de la Muestra Continua de Vidas Laborales (MCVL). Finalmente, en la cuarta sección comparamos la evolución reciente del mercado de trabajo en España con la de otros países europeos de su entorno. Ya que uno de los objetivos prioritarios del estudio es la comparación entre población autóctona e inmigrante, intentamos proveer una visión general de lo ocurrido en otros países en este sentido. Debido a la falta de datos comparables, ésta parte del informe se limita a apuntar algunas tendencias generales basadas en datos sobre la situación socio-laboral de los inmigrantes en diversos países.
Resumo:
La inserción laboral de los titulados universitarios es una cuestión crucial dentro del Espacio Europeo de Educación Superior (EEES). Su elevada importancia está dando lugar a un creciente número de análisis sobre las competencias de los estudiantes universitarios. Muchos de estos trabajos se centran en la percepción de los estudiantes recién titulados. El presente trabajo busca complementar este enfoque con la percepción del resto de agentes implicados. Con este objetivo, el análisis se centra en las competencias de los graduados en el ámbito de las ciencias económicas desde una triple perspectiva: la de los recién titulados, la de los empleadores y la de los profesores. Los resultados, obtenidos a partir de una encuesta, ponen de manifiesto que entre las competencias más valoradas se encuentran la capacidad de aprendizaje, de organización y planificación y el trabajao en equipo. Sin embargo, se han obtenido diferencias significativas en función del tipo de competencia y también entre los distintos colectivos analizados. Por lo que respecta al desajuste entre la percepción sobre el nivel de competencias adquirido y el nivel requerido para incorporarse al mercado laboral, el mayor grado de discrepancia se observa entre docentes y graduados, en relación a las competencias de tipo personal; mientras que los empleadores discrepan de los docentes fundamentalmente en cuanto a las competencias de tipo profesional o específico que, en su opinión, un graduado debería reunir. Donde sí se ha obtenido un consenso es en la necesidad de fomentar la capacidad de síntesis, de organización, de trabajar en equipo y de adaptarse a nuevas situaciones. En este trabajo también se presenta un análisis de las metodologías docentes empleadas, comparando la visión de los académicos con la de los titulados. La resolución de problemas es para ambos colectivos el método docente considerado como más eficaz, a pesar de que su nivel de desarrollo no está en consonancia. Por el contrario, tanto docentes como graduados coinciden en los exámenes, desde el punto de vista del aprendizaje, como el método de menor utilidad.