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Wolfram syndrome (WS) is a rare childhood disease characterized by diabetes mellitus, diabetes insipidus, blindness, deafness, neurodegeneration and eventually early death, due to autosomal recessive mutations in the WFS1 (and WFS2) gene. While it is categorized as a neurodegenerative disease, it is increasingly becoming clear that other cell types besides neurons may be affected and contribute to the pathogenesis. MRI studies in patients and phenotyping studies in WS rodent models indicate white matter/myelin loss, implicating a role for oligodendroglia in WS-associated neurodegeneration. In this study, we sought to determine if oligodendroglia are affected in WS and whether their dysfunction may be the primary cause of the observed optic neuropathy and brain neurodegeneration. We demonstrate that 7.5-month-old Wfs1∆exon8 mice display signs of abnormal myelination and a reduced number of oligodendrocyte precursor cells (OPCs) as well as abnormal axonal conduction in the optic nerve. An MRI study of the brain furthermore revealed grey and white matter loss in the cerebellum, brainstem, and superior colliculus, as is seen in WS patients. To further dissect the role of oligodendroglia in WS, we performed a transcriptomics study of WS patient iPSC-derived OPCs and pre-myelinating oligodendrocytes. Transcriptional changes compared to isogenic control cells were found for genes with a role in ER function. However, a deep phenotyping study of these WS patient iPSC-derived oligodendroglia unveiled normal differentiation, mitochondria-associated endoplasmic reticulum (ER) membrane interactions and mitochondrial function, and no overt signs of ER stress. Overall, the current study indicates that oligodendroglia functions are largely preserved in the WS mouse and patient iPSC-derived models used in this study. These findings do not support a major defect in oligodendroglia function as the primary cause of WS, and warrant further investigation of neurons and neuron-oligodendroglia interactions as a target for future neuroprotective or -restorative treatments for WS. [ABSTRACT FROM AUTHOR]

Using results of statistical field theory for systems with an anisotropic disorder, we present an analog model for Euclidean wormholes and topological fluctuation effects in a Riemannian space ℳ d . The contribution of wormholes and topological fluctuations to the Euclidean gravitational functional integral is modeled by quenched randomness defined in the ℝ d manifold. We obtain a disorder-averaged free energy by taking the average over all the realizations of the random fields. In the scenario of topology fluctuation, there appears a superposition of infinite branes that contribute to the physical quantities. All topology fluctuations can be understood as two distinct kinds of Euclidean wormholes: wormholes confined to one brane, and wormholes connecting different branes. [ABSTRACT FROM AUTHOR]

In view of the great importance of determination of hydrogen peroxide in many scientific fields and industrial applications and the attractive operational simplicity of potentiometric approach for the enzymatic assay, the kinetics of horseradish peroxidase–catalyzed electrochemical assay of H2O2 was studied in this work at 25°C. All kinetic characteristics were determined by the double reciprocal Lineweaver–Burk and (primary and secondary) double reciprocal Hanes–Woolf plots. The results confirmed that the reaction follows a ping–pong mechanism. The Michaelis–Menten constants for H2O2 and 4‐fluorophenol were KmH2O2 = 0.081 ± 0.001 mM and K4‐FPm = 0.185 ± 0.002 mM, respectively. The maximum rate was also estimated to be Vmax  = 0.182 ± 0.002 mM min−1 (at 25 ± 0.05°C). © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 44: 699–704, 2012 [ABSTRACT FROM AUTHOR]

The reduction of arsenic acid with aqueous sulfur dioxide in sulfuric acid solutions is presented. First order kinetics with respect to arsenic acid and sulfur dioxide concentrations are observed. Appreciable reduction occurs only when tetravalent sulfur is present as sulfur dioxide. The protonation of arsenic acid in strong sulfuric acid solutions decreases the rate of pentavalent arsenic reduction. [ABSTRACT FROM AUTHOR]

We investigate the radiative processes of accelerated entangled two-level systems. Using first-order perturbation theory, we evaluate transition rates of two entangled Unruh-DeWitt detectors rotating with the same angular velocity interacting with a massive scalar field. Decay processes for arbitrary radius, angular velocities, and energy gaps are analyzed. We discuss the mean-life of entangled states and entanglement harvesting and degradation. [ABSTRACT FROM AUTHOR]

We consider field theory formulation for directed polymers and interfaces in the presence of quenched disorder. We write a series representation for the averaged free energy, where all the integer moments of the partition function of the model contribute. The structure of field space is analysed for polymers and interfaces at finite temperature using the saddle-point equations derived from each integer moments of the partition function. For the case of an interface we obtain the wandering exponent ξ = (4 − d) / 2 , also obtained by the conventional replica method for the replica symmetric scenario. [ABSTRACT FROM AUTHOR]