Toxicity of intraperitoneal bisulfite

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/117086/1/cpt196893328.pd

Visual stress and dyslexia for the practicing optometrist

Visual stress should not be confused with dyslexia. It refers to symptoms of discomfort and perceptual distortion that have a neurological origin. Pattern 2 of the Pattern Glare Test can be used to elicit symptoms of visual stress, but pattern 3 is of relatively little clinical use. The symptoms sometimes remit with tints, but studies consistently show that tinting precision well within 0.07 in the CIE 1976 UCS diagram is necessary for optimal effect (see Precision is necessary – strong evidence is now available, below).  An improvement in reading speed with filters (overlays or lenses) can be measured using the Wilkins Rate of Reading Test, and an increase in reading speed of 15% is likely to indicate an improvement that exceeds any due to random variation. Visual stress remains a controversial issue, partly because of the publicity surrounding untrialled methods and partly because of reviews that are partial

Pore-Scale Characterization of Biogeochemical Controls on Iron and Uranium Speciation under Flow Conditions

Etched silicon microfluidic pore network models (micromodels) with controlled chemical and redox gradients, mineralogy, and microbiology under continuous flow conditions are used for the incremental development of complex microenvironments that simulate subsurface conditions. We demonstrate the colonization of micromodel pore spaces by an anaerobic Fe(III)-reducing bacterial species (Geobacter sulfurreducens) and the enzymatic reduction of a bioavailable Fe(III) phase within this environment. Using both Xray microprobe and X-ray absorption spectroscopy, we investigate the combined effects of the precipitated Fe(III) phases and the microbial population on uranium biogeochemistry under flow conditions. Precipitated Fe(III) phases within the micromodel were most effectively reduced in the presence of an electron shuttle (AQDS), and Fe(II) ions adsorbed onto the precipitated mineral surface without inducing any structural change. In the absence of Fe(III), U(VI) was effectively reduced by the microbial population to insoluble U(IV), which was precipitated in discrete regions associated with biomass. In the presence of Fe(III) phases, however, both U(IV) and U(VI) could be detected associated with biomass, suggesting reoxidation of U(IV) by localized Fe(III) phases. These results demonstrate the importance of the spatial localization of biomass and redox active metals, and illustrate the key effects of pore-scale processes on contaminant fate and reactive transport

WISE/NEOWISE Observations of Comet 103P/Hartley 2

We report results based on mid-infrared photometry of comet 103P/Hartley 2 taken during 2010 May 4-13 (when the comet was at a heliocentric distance of 2.3 AU, and an observer distance of 2.0 AU) by the Wide-field Infrared Survey Explorer. Photometry of the coma at 22 μm and data from the University of Hawaii 2.2 m telescope obtained on 2010 May 22 provide constraints on the dust particle size distribution, d log n/d log m, yielding power-law slope values of alpha = –0.97 ± 0.10, steeper than that found for the inbound particle fluence during the Stardust encounter of comet 81P/Wild 2. The extracted nucleus signal at 12 μm is consistent with a body of average spherical radius of 0.6 ± 0.2 km (one standard deviation), assuming a beaming parameter of 1.2. The 4.6 μm band signal in excess of dust and nucleus reflected and thermal contributions may be attributed to carbon monoxide or carbon dioxide emission lines and provides limits and estimates of species production. Derived carbon dioxide coma production rates are 3.5(± 0.9) × 10^(24) molecules per second. Analyses of the trail signal present in the stacked image with an effective exposure time of 158.4 s yields optical-depth values near 9 × 10^(–10) at a delta mean anomaly of 0.2 deg trailing the comet nucleus, in both 12 and 22 μm bands. A minimum chi-squared analysis of the dust trail position yields a beta-parameter value of 1.0 × 10^(–4), consistent with a derived mean trail-grain diameter of 1.1/ρ cm for grains of ρ g cm^(–3) density. This leads to a total detected trail mass of at least 4 × 10^(10) ρ kg

The propargyl rearrangement to functionalised allyl-boron and borocation compounds

A diverse range of Lewis acidic alkyl, vinyl and aryl boranes and borenium compounds that are capable of new carbon–carbon bond formation through selective migratory group transfer have been synthesised. Utilising a series of heteroleptic boranes [PhB(C6F5)2 (1), PhCH2CH2B(C6F5)2 (2), and E-B(C6F5)2(C6F5)C=C(I)R (R=Ph 3 a, nBu 3 b)] and borenium cations [phenylquinolatoborenium cation ([QOBPh][AlCl4], 4)], it has been shown that these boron-based compounds are capable of producing novel allyl- boron and boronium compounds through complex rearrangement reactions with various propargyl esters and carbamates. These reactions yield highly functionalised, synthetically useful boron substituted organic compounds with substantial molecular complexity in a one-pot reaction