Successful use of steroids and ureteric stents in 24 patients with idiopathic retroperitoneal fibrosis : a retrospective study

Original article can be found at : http://content.karger.com/ Copyright Karger [Full text of this article is not available in the UHRA]Background/Aims: Retroperitoneal fibrosis (RPF) is a chronic inflammatory disorder causing obstructive nephropathy and renal failure. We reviewed our management of this condition. Method: All patients with RPF treated at a single center over a 15-year period were identified. A full review of notes and computer records was undertaken. Results: Data was available on 27 patients, 3 of which were excluded from later analysis. Diagnosis was based on clinical history and cross-sectional imaging. Retroperitoneal biopsy was undertaken in 3 patients. 96% had significant renal impairment at presentation with a mean serum creatinine of 688 μmol/l. 46% required emergency hemodialysis. All patients were treated with a combination of ureteric stents and/or steroids with an excellent clinical response. The mean best creatinine reached by the cohort was 136 μmol/l, and renal function remained stable in the long term. No patients required chronic dialysis. Ureteric stents were removed within 12 months and low-dose steroids were continued for a mean of 34 months. Recurrent disease was observed in 25% of patients, who all responded well to further steroid therapy. Mean duration of follow-up was 76 months. Conclusions: RPF is very effectively treated by a combination of ureteric stents and steroids, with excellent long-term results using this approach. Continued follow-up is advised because of the possibility of recurrent disease.Peer reviewe

Metabolic responses to arsenite in rice seedlings that differed in grain arsenic concentration

© Crop Science Society of America. Arsenic (As) occurs naturally in the environment, and is present in all edible and nonedible plant tissues. Plants have multiple mechanisms to prevent plant injury by heavy metals such as As. These same mechanisms could be used to reduce accumulation of As in rice (Oryza sativa L.) grains. From previous study of 1765 international rice accessions, specific accessions were identified as having exceptionally high grain As concentrations (grain As accumulators) and others low grain As (grain As excluders). This study investigated As uptake, transport, and metabolism in six previously identified lines to determine which physiological responses, if any, were associated with accumulation or exclusion of As in grains. Hydroponically grown seedlings were treated with 0 (controls) or 100 mM arsenite [As(III)], and then whole seedlings were analyzed for concentrations of As plus key compounds involved in heavy metal metabolism. Both grain accumulators and grain excluders actively concentrated As within their roots, and both groups had 10-fold higher As concentrations in roots than leaves. In response to As(III), roots of both grain excluders and grain accumulators increased in cysteine and phytochelatin (PC) production, which suggests PC sequestration of As. In contrast, only grain excluders doubled in leaf glutathione (GSH) concentration by 72 h after As(III) addition. Because PC concentrations remained constant in leaves, it appears that the additional leaf GSH in the grain excluders was not used to produce more PC but may instead be forming As-GSH adducts, which also aid in As sequestration

Lattice dynamics and electron-phonon coupling in transition metal diborides

The phonon density-of-states of transition metal diborides TMB2 with TM = Ti, V, Ta, Nb and Y has been measured using the technique of inelastic neutron scattering. The experimental data are compared with ab initio density functional calculations whereby an excellent agreement is registered. The calculations thus can be used to obtain electron-phonon spectral functions within the isotropic limit. A comparison to similar data for MgB2 and AlB2 which were subject of prior publications as well as parameters important for the superconducting properties are part of the discussion.Comment: 4 pages, 3 figure

The double pendulum

Policy discourses posit an accountability deficit as an underlying cause of a “learning crisis” in many low-income countries. Many studies understand this perceived deficit from a principal-agent perspective, arguing that incentives facing teachers and schools often do not align to the interests of parents and students. Such perspectives underlie many randomized controlled trials, which associate interventions with outcomes, but which also produce varying or inconsistent results across contexts. This paper seeks to study the accountability of schools and teachers more directly, looking at how it varies across public and private schools and how it relates to students’ literacy and numeracy abilities. We report results from a mixed methods study conducted in Mumbai and Kathmandu. Our results show that there are some relationships between accountability and learning outcomes, but these appear to be specific to the context. Quantitative data also show that differences between public and private models of schooling are negligible when students’ social backgrounds and school composition are considered. Qualitative data show that accountability processes create a significant burden on staff time and embed complex power dynamics that are not always productive. Taken together, these results problematize policies that seek to improve learning through “demand-side” approaches such as privatization. They show that the dynamics of accountability are a complex system, like the motion of a “double pendulum,” and therefore simple conceptual approaches such as the principal-agent model are of limited academic and practical utility

Phonon spectrum and soft-mode behavior of MgCNi_3

Temperature dependent inelastic neutron-scattering measurements of the generalized phonon density-of-states for superconducting MgCNi_3, T_c=8 K, give evidence for a soft-mode behavior of low-frequency Ni phonon modes. Results are compared with ab initio density functional calculations which suggest an incipient lattice instability of the stoichiometric compound with respect to Ni vibrations orthogonal to the Ni-C bond direction.Comment: 4 pages, 5 figure

Fluctuation Theorems for Entropy Production and Heat Dissipation in Periodically Driven Markov Chains

Asymptotic fluctuation theorems are statements of a Gallavotti-Cohen symmetry in the rate function of either the time-averaged entropy production or heat dissipation of a process. Such theorems have been proved for various general classes of continuous-time deterministic and stochastic processes, but always under the assumption that the forces driving the system are time independent, and often relying on the existence of a limiting ergodic distribution. In this paper we extend the asymptotic fluctuation theorem for the first time to inhomogeneous continuous-time processes without a stationary distribution, considering specifically a finite state Markov chain driven by periodic transition rates. We find that for both entropy production and heat dissipation, the usual Gallavotti-Cohen symmetry of the rate function is generalized to an analogous relation between the rate functions of the original process and its corresponding backward process, in which the trajectory and the driving protocol have been time-reversed. The effect is that spontaneous positive fluctuations in the long time average of each quantity in the forward process are exponentially more likely than spontaneous negative fluctuations in the backward process, and vice-versa, revealing that the distributions of fluctuations in universes in which time moves forward and backward are related. As an additional result, the asymptotic time-averaged entropy production is obtained as the integral of a periodic entropy production rate that generalizes the constant rate pertaining to homogeneous dynamics

Particle creation, classicality and related issues in quantum field theory: II. Examples from field theory

We adopt the general formalism, which was developed in Paper I (arXiv:0708.1233) to analyze the evolution of a quantized time-dependent oscillator, to address several questions in the context of quantum field theory in time dependent external backgrounds. In particular, we study the question of emergence of classicality in terms of the phase space evolution and its relation to particle production, and clarify some conceptual issues. We consider a quantized scalar field evolving in a constant electric field and in FRW spacetimes which illustrate the two extreme cases of late time adiabatic and highly non-adiabatic evolution. Using the time-dependent generalizations of various quantities like particle number density, effective Lagrangian etc. introduced in Paper I, we contrast the evolution in these two limits bringing out key differences between the Schwinger effect and evolution in the de Sitter background. Further, our examples suggest that the notion of classicality is multifaceted and any one single criterion may not have universal applicability. For example, the peaking of the phase space Wigner distribution on the classical trajectory \emph{alone} does not imply transition to classical behavior. An analysis of the behavior of the \emph{classicality parameter}, which was introduced in Paper I, leads to the conclusion that strong particle production is necessary for the quantum state to become highly correlated in phase space at late times.Comment: RevTeX 4; 27 pages; 18 figures; second of a series of two papers, the first being arXiv:0708.1233 [gr-qc]; high resolution figures available from the authors on reques

Validation of a major QTL for salinity tolerance on chromosome 1 of rice in three different breeding populations

The effect of a major quantitative trait locus (QTL) for salinity tolerance in rice, designated as SalTol in a previous study, was tested using three F2 breeding populations. The populations were derived from the following F1 hybrids: 'BRRI dhan40' (susceptible)/ 'IR61920-3B-22-2-1' (highly tolerant); 'BRRI dhan28' (highly susceptible)/ 'IR50184-3B-18-2B-1' (moderately tolerant); and 'Kajalsail' (tolerant)/ 'IR52713-2B-8-2B-1-2' (tolerant). Targeted mapping of the chromosome region containing SolTol (49.6 to 87.1 cM) on chromosome 1 was conducted using 20 SSR and two EST markers. Comparisons of linkage maps of the three populations were very similar to the previous QTL map that identified SolTol. A QTL was only detected for 'BRRI dhan40'/ 'IR61920-3B-22-2-1' population. The SSR marker RM8094 was the most tightly-linked marker (P<0.001); four other markers, RM1287, RM3412, RM493 and CP03970, were also significantly associated with salinity tolerance (P<0.05). An F-3 population of the cross 'BRRI dhan40'/ 'IR61920' was used to reconfirm this result. This was interesting because the tolerant parent in this population was not related to the tolerant parent used for the original mapping population. QTLs were not detected at the SalTol locus for either of the other two populations. This was consistent with the phenotypes of the parents used to construct these populations, and indicates that the SolTol QTL may only be effective in specific populations