Enhanced nonlinear spectral compression in fiber by external sinusoidal phase modulation

We propose a new, simple approach to enhance the spectral compression process arising from nonlinear pulse propagation in an optical fiber. We numerically show that an additional sinusoidal temporal phase modulation of the pulse enables efficient reduction of the intensity level of the side lobes in the spectrum that are produced by the mismatch between the initial linear negative chirp of the pulse and the self-phase modulation-induced nonlinear positive chirp. Remarkable increase of both the extent of spectrum narrowing and the quality of the compressed spectrum is afforded by the proposed approach across a wide range of experimentally accessible parameters

TELEMAC model archive: Integrating open–source tools for the management and visualisation of model data

Water Qualit

Kidney transplant nephrotic syndrome: Relationship between allograft histopathology and natural course

Kidney transplant nephrotic syndrome: Relationship between allograft histopathology and natural course. We analyzed clinical and pathologic data from 36 recipients of 38 renal allografts who developed nephrotic syndrome following transplantation. Three groups were identified on the basis of histologic changes in the graft, and each group had a distinct clinical course. Nine grafts (23.7%) had recurrent glomerulonephritis (GN) (5 membrano-proliferative, 4 focal glomerulosclerosis) and developed nephrotic syndrome at 5.1 months (mean) posttransplant. Renal function deteriorated rapidly, with a 2-year graft survival of 29.7%. Four grafts (10.5%) with de novo GN (3 epimembranous, 1 minimal change) developed nephrotic syndrome at 32 months post-transplant, and all functioned for more than 3 years. Twenty-five grafts (65.8%) had allograft glomerulopathy with the onset of nephrotic syndrome at 9.1 months posttransplant and a 2-year graft survival of 66.6%. The differences in duration of graft function between grafts with allograft glomerulopathy and recurrent GN (P < 0.01) and in graft survival rates at 2 years among the three groups (P < 0.05) are statistically significant. This analysis indicates that allograft glomerulopathy is the most common cause of kidney transplant nephrotic syndrome. Membranopro-liferative GN and focal glomerulosclerosis may recur soon after transplantation and rapidly progress to renal failure in marked contrast to grafts with either de novo epimembranous nephropathy or minimal glomerular change, lesions that are compatible with prolonged graft function.Syndrome néphrotique du rein transplanté: Relations entre l'histopathologies de l'allogreffe et l'évolution. Nous avons analysé les dossiers cliniques et anatomo-pathologiques de 36 receveurs de 38 allogreffes qui ont développé un syndrome néphrotique après transplantation. Trois groupes ont été identifiés sur la base des modifications histologiques de la greffe et chaque groupe a eu une évolution distincte. Neuf greffes (23,7%) ont eu une récidive de glomérulonéphrite (GN) (5 membrano-prolifératives, 4 gloméruloscléroses focales) et ont développé un syndrome néphrotique 5,1 mois (moyenne) après la transplantation. La fonction rénale s'est détériorée rapidement, avec une survie de la greffe à 2 ans de 29,7%. Quatre greffes (10,5%) atteintes de GN nouvelle (3 extra-membraneuses, 1 à modifications minimes) ont développé un syndrome néphrotique 32 mois après la transplantation et ont toutes fonctionné plus de 3 ans. Vingt cinq greffes (65,8%) ont eu une glomérulopathie de greffe avec l'installation d'un syndrome néphrotique à 9,1 mois après la transplantation et une survie de la greffe à 2 ans de 66,6%. Les différences de durée du fonctionnement de la greffe selon l'atteinte par une récidive de GN ou une glomérulopathie de greffe (P < 0,01) et dans la survie des greffes à 2 ans dans les trois groupes (P < 0,05) sont statistiquement significatives. Cette analyse indique que la glomérulonéphrite de la greffe est la cause la plus répandue de syndrome néphrotique du rein transplanté. La GN membrano-proliférative et la glomérulosclérose focale peuvent récidiver précocement après la transplantation et progresser rapidement vers l'insuffisance rénale à la différence des greffes atteintes de néphropathie extramembraneuse ou de modifications minimes, lésions compatibles avec une fonction prolongée de la greffe

Fabrication of Triangular Nanobeam Waveguide Networks in Bulk diamond Using Single-Crystal Silicon Hard Masks

A scalable approach for integrated photonic networks in single-crystal diamond using triangular etching of bulk samples is presented. We describe designs of high quality factor (Q=2.51x10^6) photonic crystal cavities with low mode volume (Vm=1.062x({\lambda}/n)^3), which are connected via waveguides supported by suspension structures with predicted transmission loss of only 0.05 dB. We demonstrate the fabrication of these structures using transferred single-crystal silicon hard masks and angular dry etching, yielding photonic crystal cavities in the visible spectrum with measured quality factors in excess of Q=3x103.Comment: This article will be published in Applied Physics Letter

Physics of Solar Prominences: II - Magnetic Structure and Dynamics

Observations and models of solar prominences are reviewed. We focus on non-eruptive prominences, and describe recent progress in four areas of prominence research: (1) magnetic structure deduced from observations and models, (2) the dynamics of prominence plasmas (formation and flows), (3) Magneto-hydrodynamic (MHD) waves in prominences and (4) the formation and large-scale patterns of the filament channels in which prominences are located. Finally, several outstanding issues in prominence research are discussed, along with observations and models required to resolve them.Comment: 75 pages, 31 pictures, review pape

Limb Spicules from the Ground and from Space

We amassed statistics for quiet-sun chromosphere spicules at the limb using ground-based observations from the Swedish 1-m Solar Telescope on La Palma and simultaneously from NASA's Transition Region and Coronal Explorer (TRACE) spacecraft. The observations were obtained in July 2006. With the 0.2 arcsecond resolution obtained after maximizing the ground-based resolution with the Multi-Object Multi-Frame Blind Deconvolution (MOMFBD) program, we obtained specific statistics for sizes and motions of over two dozen individual spicules, based on movies compiled at 50-second cadence for the series of five wavelengths observed in a very narrow band at H-alpha, on-band and in the red and blue wings at 0.035 nm and 0.070 nm (10 s at each wavelength) using the SOUP filter, and had simultaneous observations in the 160 nm EUV continuum from TRACE. The MOMFBD restoration also automatically aligned the images, facilitating the making of Dopplergrams at each off-band pair. We studied 40 H-alpha spicules, and 14 EUV spicules that overlapped H-alpha spicules; we found that their dynamical and morphological properties fit into the framework of several previous studies. From a preliminary comparison with spicule theories, our observations are consistent with a reconnection mechanism for spicule generation, and with UV spicules being a sheath region surrounding the H-alpha spicules