646 research outputs found

    Research on nonlinear and quantum optics at the photonics and quantum information group of the University of Valladolid

    Get PDF
    We outline the main research lines in Nonlinear and Quantum Optics of the Group of Photonics and Quantum Information at the University of Valladolid. These works focus on Optical Solitons, Quantum Information using Photonic Technologies and the development of new materials for Nonlinar Optics. The investigations on optical solitons cover both temporal solitons in dispersion managed fiber links and nonparaxial spatial solitons as described by the Nonlinear Helmholtz Equation. Within the Quantum Information research lines of the group, the studies address new photonic schemes for quantum computation and the multiplexing of quantum data. The investigations of the group are, to a large extent, based on intensive and parallel computations. Some associated numerical techniques for the development of the activities described are briefly sketched

    Dietary regulation of VEGFb gene expression is related to its promoter DNA methylation levels

    Get PDF
    Motivación: Recientemente se ha descrito la implicación del factor de crecimiento del endotelio vascular B (VEGFb) en la absorción de los ácidos grasos (AGs) en los tejidos y su relación con el desarrollo de diferentes enfermedades metabólicas tal como la obesidad y la diabetes tipo 2. El objetivo de este estudio es investigar el efecto de la composición de los AGs de la dieta en la regulación de la expresión génica del VEGFb en los tejidos adiposos de rata, y si este efecto está relacionado mediante modificación por metilación del DNA en el promotor del VEGFb. De esta forma la modificación de la dieta puede ser una nueva estrategia para modular la acumulación patológica de los lípidos en la obesidad o en la diabetes. Métodos: A cada grupo de ratas fue asignado una de tres diferentes dietas isoenergéticas, cada una con una concentración diferente de AGs saturados, mono y poliinsaturados (dieta de aceite de coco, aceite de oliva y de girasol). Los animales fueron alimentados durante un mes. Las muestras de tejido adiposo visceral (VAT) y subcutáneo (SAT) se tomaron inmediatamente para estudios de metilación y  expresión génica. También de estos tejidos se tomaron mediciones de la composición de los AGs de los triglicéridos y la acumulación total de los tejidos adiposos. Resultados: Ni los pesos de los animales ni de los depósitos adiposos ni la acumulación lípidica del tejido cambiaban con las dietas. La composición en AGs de ambos tejidos fue significativamente diferente en función de la dieta consumida(p <0,0001 para todos los AGs estudiados). El nivel de expresión del gen VEGFb se correlaciona directamente con la acumulación de lípidos de cada tejido y con la composición de AGs del tejido. En ambos tejidos, los niveles de expresión génica del VEGFb y de metilación del promotor fueron diferentes con respecto a la dieta consumida, estando la expresión génica y los niveles de metilación del promotor del VEGFb inversamente correlacionados. Los valores más altos de expresión génica, y los más bajos de metilación del promotor, se encontraron en las ratas alimentadas con la dieta rica en aceite de coco. Conclusiones: La expresión del gen Vegfb en el tejido adiposo se asocia con el aumento en la acumulación de grasa. El estudio presentado muestra que la expresión génica del Vegfb está regulada por los AGs de la dieta, y esta regulación está relacionada con el nivel de metilación de la región promotora del Vegfb

    Health related quality of life in adolescents with idiopathic scoliosis: a cross-cultural comparison between two methods of treatment

    Get PDF
    he present study aims at evaluating the effects produced on HRQOL by two different methods of physiotherapy in adolescent population with Idiopathic Scoliosis (IS): SEAS, used in Milan (Italia) in ISICO center, and Barcelona Scoliosis Physical Therapy School, in E. Salvá Institut (Spain)

    Efficient unidirectional nanoslit couplers for surface plasmons

    Full text link
    Plasmonics is based on surface plasmon polariton (SPP) modes which can be laterally confined below the diffraction limit, thereby enabling ultracompact optical components. In order to exploit this potential, the fundamental bottleneck of poor light-SPP coupling must be overcome. In established SPP sources (using prism, grating} or nanodefect coupling) incident light is a source of noise for the SPP, unless the illumination occurs away from the region of interest, increasing the system size and weakening the SPP intensity. Back-side illumination of subwavelength apertures in optically thick metal films eliminates this problem but does not ensure a unique propagation direction for the SPP. We propose a novel back-side slit-illumination method based on drilling a periodic array of indentations at one side of the slit. We demonstrate that the SPP running in the array direction can be suppressed, and the one propagating in the opposite direction enhanced, providing localized unidirectional SPP launching.Comment: 13 pages, 4 figure

    Supertranslations and Holographic Stress Tensor

    Full text link
    It is well known in the context of four dimensional asymptotically flat spacetimes that the leading order boundary metric must be conformal to unit de Sitter metric when hyperbolic cutoffs are used. This situation is very different from asymptotically AdS settings where one is allowed to choose an arbitrary boundary metric. The closest one can come to changing the boundary metric in the asymptotically flat context, while maintaining the group of asymptotic symmetries to be Poincare, is to change the so-called `supertranslation frame' \omega. The most studied choice corresponds to taking \omega = 0. In this paper we study consequences of making alternative choices. We perform this analysis in the covariant phase space approach as well as in the holographic renormalization approach. We show that all choices for \omega are allowed in the sense that the covariant phase space is well defined irrespective of how we choose to fix supertranslations. The on-shell action and the leading order boundary stress tensor are insensitive to the supertranslation frame. The next to leading order boundary stress tensor depends on the supertranslation frame but only in a way that the transformation of angular momentum under translations continues to hold as in special relativity.Comment: 32 pages, no figures, LaTeX file; v2 minor changes, 33 pages, published versio

    The use of fluoroproline in MUC1 antigen enables efficient detection of antibodies in patients with prostate cancer

    Get PDF
    A structure-based design of a new gene22ration tumor-associated glycopeptides with improved affinity against two anti-MUC1 antibodies is described. These unique antigens feature a fluorinated proline residue, such as a (4S)-4-fluoro-L-proline or 4,4-difluoroproline, at the most immunogenic domain. Binding assays using bio-layer interferometry reveal 3-fold to 10-fold affinity improvement with respect to the natural (glyco)peptides. According to X-ray crystallography and MD simulations, the fluorinated residues stabilize the antigen-antibody complex by enhancing key CH/ interactions. Interestingly, a notable improvement in detection of cancer-associated anti-MUC1 antibodies from serum of patients with prostate cancer is achieved with the non-natural antigens, which proves that these derivatives can be considered better diagnostic tools than the natural antigen for this type of cancer.We thank the Ministerio de Economía y Competitividad (projects CTQ2015-67727-R, UNLR13-4E-1931, CTQ2013-44367-C2-2-P, CTQ2015-64597-C2-1P, and BFU2016-75633-P). I. A. B. thanks the Asociación Española Contra el Cancer en La Rioja for a grant. I. S. A. and G. J. L. B. thank FCT Portugal (PhD studentship and FCT Investigator, respectively) and the EPSRC for funding. G. J. L. B. holds a Royal Society URF and an ERC StG (TagIt). F.C. and G. J. L. B thank the EU (Marie-Sklodowska Curie ITN, Protein Conjugates). R.H-G. thanks Agencia Aragonesa para la Investigación y Desarrollo (ARAID) and the Diputación General de Aragón (DGA, B89) for financial support. The research leading to these results has also received funding from the FP7 (2007-2013) under BioStruct-X (grant agreement N°283570 and BIOSTRUCTX_5186). We thank synchrotron radiation source DIAMOND (Oxford) and beamline I04 (number of experiment mx10121-19). Hokkaido University group acknowledges to JSPS KAKENHI Grant Number 25220206 and JSPS Wakate B KAKENHI Grant Number 24710242. We also thank CESGA (Santiago de Compostela) for computer support

    Mixed-method tutoring support improves learning outcomes of veterinary students in basic subjects

    Get PDF
    P. 1-10Tutoring is a useful tool in the university teaching-learning binomial, although its development is impaired in large classes. Recent improvements in information and communication technologies have made tutoring possible via the Internet. The aim of this study was to evaluate the efficacy of mixed-method academic tutoring in two basic subjects in Veterinary Science studies at the University of León (Spain) to optimize the usefulness of tutoring support in the college environment. This quasi-experimental study was firstly carried out as a pilot study in a small group of tutored students of “Cytology and Histology” (CH) (47/186; 25.3%) and “Veterinary Pharmacology” (VP) (33/141; 23.4%) subjects, and was implemented in a large class of CH the next academic year (150 students) while comparing the results with those obtained in a previous tutorless course (162 students). Tutored students were given access to online questionnaires with electronic feedback on each subject. In addition to traditional tutoring carried out in both tutored and tutorless students, the pilot study included three sessions of face-to-face tutoring in order to monitor the progress of students. Its efficacy was assessed by monitoring students’ examination scores and attendance as well as a satisfaction survey. Online tutoring support, together with conventional teaching methods, may be a useful method to incorporate student-centered learning in basic subjects in Veterinary Science.S

    Clinical experience with integrase inhibitors in HIV-2-infected individuals in Spain.

    Get PDF
    Background: HIV-2 is a neglected virus despite estimates of 1–2 million people being infected worldwide. The virus is naturally resistant to some antiretrovirals used to treat HIV-1 and therapeutic options are limited for patients with HIV-2. Methods: In this retrospective observational study, we analysed all HIV-2-infected individuals treated with inte- grase strand transfer inhibitors (INSTIs) recorded in the Spanish HIV-2 cohort. Demographics, treatment modal- ities, laboratory values, quantitative HIV-2 RNA and CD4 counts as well as drug resistance were analysed. Results: From a total of 354 HIV-2-infected patients recruited by the Spanish HIV-2 cohort as of December 2017, INSTIs had been given to 44, in 18 as first-line therapy and in 26 after failing other antiretroviral regimens. After a median follow-up of 13 months of INSTI-based therapy, undetectable viraemia for HIV-2 was achieved in 89% of treatment-naive and in 65.4% of treatment-experienced patients. In parallel, CD4 gains were 82 and 126cells/mm3, respectively. Treatment failure occurred in 15 patients, 2 being treatment-naive and 13 treatment-experienced. INSTI resistance changes were recognized in 12 patients: N155H (5), Q148H/R (3), Y143C/G (3) and R263K (1). Conclusions: Combinations based on INSTIs are effective and safe treatment options for HIV-2-infected individ- uals. However, resistance mutations to INSTIs are selected frequently in failing patients, reducing the already limited treatment options

    Problematic Internet Use in University Students: associated factors and differences of gender

    Get PDF
    El objetivo del presente trabajo es realizar un análisis descriptivo del uso problemático de Internet en estudiantes universitarios, evaluando la posible asociación con problemas de salud y conductas adictivas, así como diferencias de género en los tipos utilización. Un total de 2780 alumnos participaron en el estudio entre los años 2011 – 2014, siendo un 29% varones (edad 20.8 ± 5.1 años) y un 71% mujeres (edad de 20.3 ± 4.4 años). La prevalencia de uso problemático de Internet evaluada mediante el Internet Addiction Test fue del 6.08%. Ser menor de 21 años y cursar titulaciones diferentes a ciencias de la salud fueron factores asociados a una mayor frecuencia de este problema, no existiendo diferencias en función del sexo o tipo de domicilio. Los resultados muestran una asociación significativa con algunos problemas de salud (migrañas, dolor lumbar, sobrepeso u obesidad, descanso insuficiente), aspectos psicológicos (riesgo de trastornos de la conducta alimentaria, riesgo de trastorno mental, depresión), problemas familiares y discriminación; no encontrándose asociaciones con consumo de sustancias adictivas (alcohol, tabaco o cannabis). Respecto al tiempo de uso de Internet, las horas de conexión semanales fueron significativamente mayores en las mujeres que en los hombres, tanto en el tiempo total como por motivos de ocio. El análisis del perfil de utilización en usuarios problemáticos reveló que los varones se relacionan más con aspectos de ocio como los juegos o las compras online y las mujeres con aspectos de socialización, como el chat o las redes sociales
    corecore