Biochemical structure of glomerular basement membrane in chronic glomerulonephritis.I.Lobular and membrano-proliferative glomerulonephritis

Biochemical structure of glomerular basement membrane in chronic glomerulonephritis.I Lobular and membrano-proliferative glomerulonephritis.Glomerular basement membranes have been isolated from the kidneys of patients suffering from membrano-proliferative or lobular glomerulonephritis.After isolation, as well as in situ, these membranes were twice as thick as normal membranes and contained a few fibrils of collagen; their yield per gram of renal tissue extracted was twice that of normal controls.The twofold increase in basement membrane material could not be accounted for by the presence of bound γ-globulin or collagen.Although the amino acid and carbohydrate compositions of abnormal and normal membrane preparations were different, both contained two groups of glycopeptides, one with a disaccharide unit composed of glucose and galactose, the other with a heteropolysaccharide unit composed of mannose, hexosamine, fucose, galactose and from one to five sialic acid residues.Quantitative chromatographic differences indicated that the heteropolysaccharide units of abnormal membranes had fewer sialic acid residues, on the average, than the heteropolysaccharide units of normal membranes, and that the abnormal membranes had fewer disaccharide units per polypeptide chain length.The data suggest that the thickened glomerular basement membranes of these glomerulonephritic kidneys are the consequence of an increased synthesis or decreased turnover of components present in the normal state.Structure biochimique des membranes basales glomerulaires au cours des glomérulonéphrites.I.Glomérulonéphrites lobulaires et membrano-prolifératives.Les membranes basales glomérulaires ont été isolées de reins normaux et de reins de glomérulonéphrites lobulaires ou membrano-prolifératives.Examinées au microscope électronique, les membranes basales isolées pathologiques sont épaissies; on constate également la présence de dépôts membranoides et de fibres de collagène.Quantitativement, le matériel membranaire extrait des reins pathologiques est deux fois plus important que celui extrait de reins normaux; cette augmentation n'est pas due à la présence de fibres de collagène ou de γ-globulines; quoique les membranes basales normales et anormales aient des compositions différentes en oses et en acides aminés, elles contiennent lex deux mêmes glycopeptides: l'un renferme un disaccharide composé de glucose et de galactose, l'autre renferme un hétéropolysaccharide composé de fucose, de mannose, d'hexosamines, de galactose et d'acides sialiques.Les membranes pathologiques ont moins d'unités disaccharidiques par chaîne peptidique et moins de chaînes hétéropolysaccharidiques contenant 4 à 5 résidus d'acides sialiques.En dehors de ces différences chromatographiques, l'augmentation de poids du matériel membranaire extrait des reins pathologiques ne peut être expliquée que par un accroissement de synthèse ou par une diminution du turnover des glycoprotéines normalement présentes dans les membranes basales

Scaling fields in the two-dimensional Abelian sandpile model

We consider the isotropic two-dimensional abelian sandpile model from a perspective based on two-dimensional (conformal) field theory. We compute lattice correlation functions for various cluster variables (at and off criticality), from which we infer the field-theoretic description in the scaling limit. We find a perfect agreement with the predictions of a c=-2 conformal field theory and its massive perturbation, thereby providing direct evidence for conformal invariance and more generally for a description in terms of a local field theory. The question of the height 2 variable is also addressed, with however no definite conclusion yet. Comment: 22 pages, 1 figure (eps), uses revte

Spectral-phase interferometry for direct electric-field reconstruction applied to seeded extreme-ultraviolet free-electron lasers

We present a setup for complete characterization of femtosecond pulses generated by seeded free-electron lasers (FEL's) in the extreme-ultraviolet spectral region. Two delayed and spectrally shifted replicas are produced and used for spectral phase interferometry for direct electric field reconstruction (SPIDER). We show that it can be achieved by a simple arrangement of the seed laser. Temporal shape and phase obtained in FEL simulations are well retrieved by the SPIDER reconstruction, allowing to foresee the implementation of this diagnostic on existing and future sources. This will be a significant step towards an experimental investigation and control of FEL spectral phase

Optimized approach to retrieve information on the tropospheric and stratospheric carbonyl sulfide (OCS) vertical distributions above Jungfraujoch from high-resolution FTIR solar spectra

Carbonyl sulfide (OCS), which is produced in the troposphere from both biogenic and anthropogenic sources, is the most abundant gaseous sulfur species in the unpolluted atmosphere. Due to its low chemical reactivity and water solubility, a significant fraction of OCS is able to reach the stratosphere where it is converted to SO2 and ultimately to H2SO4 aerosols (Junge layer). These aerosols have the potential to amplify stratospheric ozone destruction on a global scale and may influence Earth’s radiation budget and climate through increasing solar scattering. The transport of OCS from troposphere to stratosphere is thought to be the primary mechanism by which the Junge layer is sustained during nonvolcanic periods. Because of this, long-term trends in atmospheric OCS concentration, not only in the troposphere but also in the stratosphere, are of great interest. A new approach has been developed and optimized to retrieve atmospheric abundance of OCS from high-resolution ground-based infrared solar spectra by using the SFIT-2 (v3.91) algorithm, including a new model for solar lines simulation (solar lines often produce significant interferences in the OCS microwindows). The strongest lines of the nu3 fundamental band of OCS at 2062 cm-1 have been systematically evaluated with objective criteria to select a new set of microwindows, assuming the HITRAN 2004 spectroscopic parameters with an increase in the OCS line intensities of the nu3band main isotopologue 16O12C32S by 15.79% as compared to HITRAN 2000 (Rothman et al., 2008, and references therein). Two regularization schemes have further been compared (deducted from ATMOS and ACE-FTS measurements or based on a Tikhonov approach), in order to select the one which optimizes the information content while minimizing the error budget. The selected approach has allowed us to determine updated OCS long-term trend from 1988 to 2009 in both the troposphere and the stratosphere, using spectra recorded on a regular basis with Fourier Transform Infrared spectrometers (FTIRs), under clear-sky conditions, at the NDACC site (Network for the Detection of Atmospheric Composition Change, visit http://www.ndacc.org) of the International Scientific Station of the Jungfraujoch (Swiss Alps, 46.5°N, 8.0°E, 3580m asl). Trends and seasonal cycles deduced from our results will be compared to values published in the literature and critically discussed. In particular, we will confirm the recent change in the OCS total column trend, which has become positive since 2002 before undergoing a slowing down over the last years

Logarithmic scaling for height variables in the Abelian sandpile model

We report on the exact computation of the scaling form of the 1-point function, on the upper-half plane, of the height 2 variable in the two-dimensional Abelian sandpile model. By comparing the open versus the closed boundary condition, we find that the scaling field associated to the height 2 is a logarithmic scalar field of scaling dimension 2, belonging to a c=-2 logarithmic conformal field theory. This identification is confirmed by numerical simulations and extended to the height 3 and 4 variables, which exhibit the same scaling form. Using the conformal setting, we make precise proposals for the bulk 2-point functions of all height variables.Comment: 7 pages, 2 figure

Retrievals of ethane from groundbased highresolution FTIR solar observations with updated line parameters: determination of the optimum strategy for the Jungfraujoch station.

Ethane (C2H6) is the most abundant Non-Methane HydroCarbon (NMHC) in the Earth’s atmosphere, with a lifetime of approximately 2 months. Its main sources are biomass burning, natural gas loss and biofuel consumption. Oxidation by the hydroxyl radical is the major C2H6 sink as it controls its strong modulation throug the year. C2H6 is involved in the formation of tropospheric O3 and in the destruction of atmospheric methane through changes in OH. C2H6 is an indirect greenhouse gas with a net-global warming potential of 5.5 (100-yr horizon). Updates of retrieval parameters such as the spectroscopic linelists have been recently published. We will therefore characterize three µ-windows encompassing the strongest C2H6 features after careful selection of these new parameters, accounting at best for all interfering species. The aim is to lessen the fitting residuals while maximizing the information content, the precision and the reliability of the retrieved product. We will present updated C2H6 total and tropospheric column time series, using the SFIT-2 algorithm (v3.91) and high-resolution Fourier Transform Infrared (FTIR) solar absorption spectra recorded with a Bruker 120HR instrument, at the high altitude research station of the Jungfraujoch (46.5°N, 8.0°E, 3580 m asl), within the framework of the Network for the Detection of Atmospheric Composition Change (NDACC, http://www.ndacc.org). Comparisons with synthetic data produced by chemical transport models will also be presented

Scaling fields in the two-dimensional abelian sandpile model

We consider the isotropic two-dimensional abelian sandpile model from a perspective based on two-dimensional (conformal) field theory. We compute lattice correlation functions for various cluster variables (at and off criticality), from which we infer the field-theoretic description in the scaling limit. We find a perfect agreement with the predictions of a c=-2 conformal field theory and its massive perturbation, thereby providing direct evidence for conformal invariance and more generally for a description in terms of a local field theory. The question of the height 2 variable is also addressed, with however no definite conclusion yet.Comment: 22 pages, 1 figure (eps), uses revte