Digital libraries and minority languages

Digital libraries have a pivotal role to play in the preservation and maintenance of international cultures in general and minority languages in particular. This paper outlines a software tool for building digital libraries that is well adapted for creating and distributing local information collections in minority languages, and describes some contexts in which it is used. The system can make multilingual documents available in structured collections and allows them to be accessed via multilingual interfaces. It is issued under a free open-source licence, which encourages participatory design of the software, and an end-user interface allows community-based localization of the various language interfaces - of which there are many

Percutaneous transhepatic cholangiography and biliary drainage after liver transplantation: A five-year experience

Evaluation of the biliary tract by percutaneous transhepatic cholangiography (PTC) is often required in liver transplant patients with an abnormal postoperative course. Indications for PTC include failure of liver enzyme levels to return to normal postoperatively, an elevation of serum bilirubin or liver enzyme levels, suspected bile leak, biliary obstructive symptoms, cholangitis, and sepsis. Over a 5-year period 625 liver transplants in 477 patients were performed at the University Health Center of Pittsburgh. Fifty-three patients (56 transplants) underwent 70 PTCs. Complications diagnosed by PTC included biliary strictures, bile leaks, bilomas, liver abscesses, stones, and problems associated with internal biliary stents. Thirty-two percutaneous transhepatic biliary drainage procedures were performed. Ten transplantation patients underwent balloon dilatation of postoperative biliary strictures. Interventional radiologic techniques were important in treating other complications and avoiding additional surgery in many of these patients. © 1987 Springer-Verlag New York Inc

Radiographic features of liver allograft rejection

The radiographic features of 19 transplanted patients with failure of the liver allograft were evaluated. These features were: poor filling, stretching, attenuation of intrahepatic biliary ducts documented by T-tube cholangiogram, attenuation of branches of the hepatic artery seen on angiogram as well as a decrease of blood flow through the liver seen on angiogram and nuclear medicine dynamic scintigram. These findings were secondary to swelling of the transplanted liver and were not specific for rejection; they may also be present in hepatic infarction or infection

Structure of amyloid-β (20-34) with Alzheimer's-associated isomerization at Asp23 reveals a distinct protofilament interface.

Amyloid-β (Aβ) harbors numerous posttranslational modifications (PTMs) that may affect Alzheimer's disease (AD) pathogenesis. Here we present the 1.1 Å resolution MicroED structure of an Aβ 20-34 fibril with and without the disease-associated PTM, L-isoaspartate, at position 23 (L-isoAsp23). Both wild-type and L-isoAsp23 protofilaments adopt β-helix-like folds with tightly packed cores, resembling the cores of full-length fibrillar Aβ structures, and both self-associate through two distinct interfaces. One of these is a unique Aβ interface strengthened by the isoaspartyl modification. Powder diffraction patterns suggest a similar structure may be adopted by protofilaments of an analogous segment containing the heritable Iowa mutation, Asp23Asn. Consistent with its early onset phenotype in patients, Asp23Asn accelerates aggregation of Aβ 20-34, as does the L-isoAsp23 modification. These structures suggest that the enhanced amyloidogenicity of the modified Aβ segments may also reduce the concentration required to achieve nucleation and therefore help spur the pathogenesis of AD

Characterization of critical shear stresses and bank material erosion rates on gravelly stream banks

Meandering river migration over large spatial and temporal scales has traditionally been numerically simulated using a bank erosion submodel that calculates the eroding bank migration rate as the product of the near-bank excess flow velocity and a dimensionless migration coefficient. The latter value is an empirical parameter calibrated to historical observations. In efforts to improve upon the traditional model, recent research has followed two approaches: (a) provide a means of estimating the dimensionless migration coefficient based on field measurements; and (b) discard the traditional migration coefficient approach to develop a bank erosion submodel based on the actual formulations that dictate fluvial erosion rates and mass failure which determine bank migration. The latter physics-based approach was recently implemented into the numerical model RVR Meander developed by the Ven Te Chow Hydrosystems Laboratory at the University of Illinois in Urbana-Champaign (Motta et al, 2012a); however, the governing equations used for fluvial erosion strictly apply only to banks comprised of cohesive soils. In that formulation the fluvial erosion rate is linearly dependent on the excess boundary shear stress. This study explores whether a similarly simple formulation can describe in a gross sense the migration of river banks comprised entirely of non-cohesive soil or composite banks consisting of non-cohesive soil at the base overlain by cohesive soil. Numerical modeling of both fluvial erosion and shallow avalanche mass failures that occur simultaneously during non-cohesive bank deformation reveal that the bank migration rate is strongly non-linear with respect to the boundary shear stress (exponent greater than 1) when considering non-cohesive bank materials. A methodology is described for developing a site specific non-cohesive bank erosion submodel that is valid and computationally practicable over the desired large spatial and temporal scales relevant to models such as RVR Meander. The new methodology allows issues such as flow regime modifications to be incorporated to change the model parameters, which was not possible using the traditional empirical approach. The numerical modeling performed in this study also provides fundamental insights into deformation of non-cohesive river banks: it demonstrates that high flow events tend to cause bank slope reduction, with lower flow events tending to rejuvenate the steepness of the bank; it quantifies the importance of prior erosional history in influencing bank migration rates; and it quantifies the feedback of basal armoring on deformation of the unarmored region.U.S. Department of the InteriorU.S. Geological SurveyOpe

A physically-based bank erosion model for composite river banks: Application to Mackinaw River, Illinois

Meandering river migration over large spatial and temporal scales has traditionally been numerically simulated using a bank erosion submodel that calculates the eroding bank migration rate as the product of the near-bank excess flow velocity and a dimensionless migration coefficient. The latter value is an empirical parameter calibrated to historical observations. In efforts to improve upon the traditional model, recent research has followed two approaches: (a) provide a means of estimating the dimensionless migration coefficient based on field measurements; and (b) discard the traditional migration coefficient approach to develop a bank erosion submodel based on the actual formulations that dictate fluvial erosion rates and mass failure which determine bank migration. The latter physics-based approach was recently implemented into the numerical model RVR Meander developed by the Ven Te Chow Hydrosystems Laboratory at the University of Illinois in Urbana-Champaign (Motta et al, 2012a); however, the governing equations used for fluvial erosion strictly apply only to banks comprised of cohesive soils. In that formulation the fluvial erosion rate is linearly dependent on the excess boundary shear stress. This study explores whether a similarly simple formulation can describe in a gross sense the migration of river banks comprised entirely of non-cohesive soil or composite banks consisting of non-cohesive soil at the base overlain by cohesive soil. Numerical modeling of both fluvial erosion and shallow avalanche mass failures that occur simultaneously during non-cohesive bank deformation reveal that the bank migration rate is strongly non-linear with respect to the boundary shear stress (exponent greater than 1) when considering non-cohesive bank materials. A methodology is described for developing a site specific non-cohesive bank erosion submodel that is valid and computationally practicable over the desired large spatial and temporal scales relevant to models such as RVR Meander. The new methodology allows issues such as flow regime modifications to be incorporated to change the model parameters, which was not possible using the traditional empirical approach. The numerical modeling performed in this study also provides fundamental insights into deformation of non-cohesive river banks: it demonstrates that high flow events tend to cause bank slope reduction, with lower flow events tending to rejuvenate the steepness of the bank; it quantifies the importance of prior erosional history in influencing bank migration rates; and it quantifies the feedback of basal armoring on deformation of the unarmored region.U.S. Department of the InteriorU.S. Geological SurveyOpe

Mitral paravalvular abscess with left ventriculo-atrial fistula in a patient on dialysis

Background: Infective endocarditis in hemodialysis patients is challenging but is becoming more common recently. Case report: A 64-year-old man with end-stage renal disease on hemodialysis presented with infective endocarditis of mitral valve and coronary artery disease after commencing training for home hemodialysis. During a course of antibiotic treatment the patient developed left ventriculo-atrial fistula due to mitral paravalvular abscess. Abscess debridement followed by reconstruction of the mitral annulus with fresh autologous pericardial patch and mitral valve replacement using a mechanical prosthesis with concomitant coronary artery bypass grafting was performed successfully. Conclusion: Timely diagnosis, proper antibiotic treatment and early surgical intervention including aggressive debridement should improve the outcome of this high-risk disease. © 2009 Kitamura et al; licensee BioMed Central Ltd.Tadashi Kitamura, James Edwards, Suchi Khurana and Robert G Stukli

Search for radiative pumping lines of OH masers: I. The 34.6um absorption line towards 1612 MHz OH maser sources

The 1612 MHz hydroxyl maser in circumstellar envelopes has long been thought to be pumped by 34.6um photons. Only recently, the Infrared Space Observatory has made possible spectroscopic observations which enable the direct confirmation of this pumping mechanism in a few cases. To look for the presence of this pumping line, we have searched the Infrared Space Observatory Data Archive and found 178 spectra with data around 34.6um for 87 galactic 1612MHz masers. The analysis performed showed that the noise level and the spectral resolution of the spectra are the most important factors affecting the detection of the 34.6um absorption line. Only 5 objects from the sample (3 red supergiants and 2 galactic center sources) are found to show clear 34.6um absorption (all of them already known) while two additional objects only tentatively show this line. The 3 supergiants show similar pump rates and their masers might be purely radiatively pumped. The pump rates of OH masers in late type stars are found to be about 0.05, only 1/5 of the theoretical value of 0.25 derived by Elitzur (1992). We have also found 16 maser sources which, according to the analysis assuming Elitzur's pump rate, should show the 34.6 $\mu$m absorption line but do not. These non-detections can be tentatively explained by far-infrared photon pumping, clumpy nature of the OH masing region or a limb-filling emission effect in the OH shell.Comment: 11 pages, 8 figures, 3 table