Geophysical investigation along parts of the Dent and Augill Faults

The areas covered in the present investigation lie near the towns of Brough and Kirkby Stephen. They include parts of the Dent and Augill Faults, which form the western margins of the Askrigg and Alston Blocks respectively. I The higher ground is open moorland used for sheep-grazing and is difficult of access except to cross-country vehicles, but the lower ground is in I agriculturai use , generally as pasture, and is well served by roads and tracks. I The airborne electromagnetic (AEM) survey was restricted to the areas of known mineral veins (Fig. 1) along the Dent and Augill faults. NO geochemical exploration was undertaken because of widespread contamination from the numerous mine dumps. GEOLOGY The northern part of the area shown in Fig. 1 was re-surveyed between 1958 and 1967 (Burgess and Holliday, in press) following the 19th-century primary survey. The southern part has not been completely re-surveyed, although parts of it were revised for the 1 inch to 1 mile scale geological map (Kirkby Stephen sheet 40) published in 1972 and detailed mapping of selected areas has formed part of the present investigations. The area is mainly underlain by Carboniferous rocks (Fig. 2) and details of the successions are given in Figs. 2, 5 and 6. Permo-Triassic deposits are present to the west, j ust beyond the areas of detailed work (Fig. 2). The oldest Carboniferous rocks exposed are the Orton Group, comprising marine limestones with sandstones and shales. The lower part of the overlying Alston Group consists of the massively bedded Great Scar Limestone, about 100 m thick. The succeeding beds comprise alternating limestones, mudstones, siltstones and sandstones deposited in a sequence of cyclothems. These are internally very variable and any one cyclothem is rarely fully developed

Methylmercury Production in Denitrifying Woodchip Bioreactors

Several operational woodchip bioreactors were installed at the outlets of agricultural drainage systems located in east central Illinois. The potential for monomethylmercury (MMHg) production and export in these bioreactors was investigated from summer 2008 to summer 2010. The basic approach was to compare the chemistry of simultaneously-collected bioreactor inlet and outlet water samples in order to assess the extent of nitrate depletion, consumption of sulfate, and production of MMHg, plus other low-charge mercury species (LCHg). In making such a comparison, we implicitly assume that the reactor is near steady state, which is a reasonable approximation given hydraulic residence times on the order of hours. All mercury (Hg) speciation measurements were made using a first-generation mercury thiourea complex ion chromatography system for Hg speciation analysis, which reliably separates MMHg and HgII (mercuric mercury), but combines MMHg and a newly-discovered, unidentified Hg species of low charge (LCHg). Due to this analytical artifact, the results reported here constitute an upper bound on true Hg methylation. In no season was MMHg ever detected in inlet samples at concentrations at much above the detection limit of ~0.1 ng/L. However, levels of MMHg+LCHg over 2 ng/L were observed in the outlets during warm seasons when nitrate had become depleted within the bioreactor. Sulfate depletion was also observed in most samples with elevated [MMHg+LCHg]. The combination of sulfate depletion and MMHg production is consistent with nitrate inhibition of iron and sulfate reduction and with MMHg concentrations observed in other highly anaerobic environments, e.g., lake hypolimnia and wetland porewaters. The maximum [MMHg+LCHg] observed in any given bioreactor followed an inverse function of the bioreactor loading density, i.e., the ratio of the area drained to the area of the bioreactor pit. The function has a form similar to that observed for bioreactor denitrification efficacy and suggests that optimal bioreactor designs that permit substantial denitrification while minimizing Hg methylation are feasible. Finally, extremely high MMHg+LCHg levels were observed when stagnant water conditions occurred within the bioreactors. Thus, it is recommended that bioreactors not be built with bottom depresssional areas where stagnant water can reside, in order to avoid developing anoxic conditions where methylation occurs. For the same reasons, bioreactors should not be used simultaneously with controlled drainage (water table management) if restricting the drainage results in keeping the bioreactors flooded for long periods of time.Illinois Sustainable Technology Center (Grant No. HWR09215)Ope

Microbial oxidation of arsenite in a subarctic environment: diversity of arsenite oxidase genes and identification of a psychrotolerant arsenite oxidiser

Background: Arsenic is toxic to most living cells. The two soluble inorganic forms of arsenic are arsenite (+3) and arsenate (+5), with arsenite the more toxic. Prokaryotic metabolism of arsenic has been reported in both thermal and moderate environments and has been shown to be involved in the redox cycling of arsenic. No arsenic metabolism (either dissimilatory arsenate reduction or arsenite oxidation) has ever been reported in cold environments (i.e. < 10°C). Results: Our study site is located 512 kilometres south of the Arctic Circle in the Northwest Territories, Canada in an inactive gold mine which contains mine waste water in excess of 50 mM arsenic. Several thousand tonnes of arsenic trioxide dust are stored in underground chambers and microbial biofilms grow on the chamber walls below seepage points rich in arsenite-containing solutions. We compared the arsenite oxidisers in two subsamples (which differed in arsenite concentration) collected from one biofilm. 'Species' (sequence) richness did not differ between subsamples, but the relative importance of the three identifiable clades did. An arsenite-oxidising bacterium (designated GM1) was isolated, and was shown to oxidise arsenite in the early exponential growth phase and to grow at a broad range of temperatures (4-25°C). Its arsenite oxidase was constitutively expressed and functioned over a broad temperature range. Conclusions: The diversity of arsenite oxidisers does not significantly differ from two subsamples of a microbial biofilm that vary in arsenite concentrations. GM1 is the first psychrotolerant arsenite oxidiser to be isolated with the ability to grow below 10°C. This ability to grow at low temperatures could be harnessed for arsenic bioremediation in moderate to cold climates

Surface and capillary transitions in an associating binary mixture model

We investigate the phase diagram of a two-component associating fluid mixture in the presence of selectively adsorbing substrates. The mixture is characterized by a bulk phase diagram which displays peculiar features such as closed loops of immiscibility. The presence of the substrates may interfere the physical mechanism involved in the appearance of these phase diagrams, leading to an enhanced tendency to phase separate below the lower critical solution point. Three different cases are considered: a planar solid surface in contact with a bulk fluid, while the other two represent two models of porous systems, namely a slit and an array on infinitely long parallel cylinders. We confirm that surface transitions, as well as capillary transitions for a large area/volume ratio, are stabilized in the one-phase region. Applicability of our results to experiments reported in the literature is discussed.Comment: 12 two-column pages, 12 figures, accepted for publication in Physical Review E; corrected versio

Power spectrum of many impurities in a d-wave superconductor

Recently the structure of the measured local density of states power spectrum of a small area of the \BSCCO (BSCCO) surface has been interpreted in terms of peaks at an "octet" of scattering wave vectors determined assuming weak, noninterfering scattering centers. Using analytical arguments and numerical solutions of the Bogoliubov-de Gennes equations, we discuss how the interference between many impurities in a d-wave superconductor alters this scenario. We propose that the peaks observed in the power spectrum are not the features identified in the simpler analyses, but rather "background" structures which disperse along with the octet vectors. We further consider how our results constrain the form of the actual disorder potential found in this material.Comment: 5 pages.2 figure

TGFβ inhibition stimulates collagen maturation to enhance bone repair and fracture resistance in a murine myeloma model

Multiple myeloma is a plasma cell malignancy that causes debilitating bone disease and fractures, in which TGFβ plays a central role. Current treatments do not repair existing damage and fractures remain a common occurrence. We developed a novel low tumour phase murine model mimicking the plateau phase in patients, as we hypothesized this would be an ideal time to treat with a bone anabolic. Using in vivo microCT we show substantial and rapid bone lesion repair (and prevention) driven by SD‐208 (TGFβ receptor I kinase inhibitor) and chemotherapy (bortezomib and lenalidomide) in mice with human U266‐GFP‐luc myeloma. We discovered that lesion repair occurred via an intramembranous fracture repair‐like mechanism and that SD‐208 enhanced collagen matrix maturation to significantly improve fracture resistance. Lesion healing was associated with VEGFA expression in woven bone, reduced osteocyte‐derived PTHrP, increased osteoblasts, decreased osteoclasts and lower serum TRACP‐5b. SD‐208 also completely prevented bone lesion development mice with aggressive JJN3 tumors, and was more effective than an anti‐TGFβ neutralizing antibody (1D11). We also discovered that SD‐208 promoted osteoblastic differentiation (and overcame the TGFβ‐induced block in osteoblastogenesis) in myeloma patient bone marrow stromal cells in vitro, comparable to normal donors. The improved bone quality and fracture‐resistance with SD‐208 provides incentive for clinical translation to improve myeloma patient quality of life by reducing fracture risk and fatality

A spatio-temporal description of the abrupt changes in the photospheric magnetic and Lorentz-force vectors during the 2011 February 15 X2.2 flare

The active region NOAA 11158 produced the first X-class flare of Solar Cycle 24, an X2.2 flare at 01:44 UT on 2011 February 15. Here we analyze SDO/HMI magnetograms covering a 12-hour interval centered at the time of this flare. We describe the spatial distributions of the photospheric magnetic changes associated with this flare, including the abrupt changes in the field vector, vertical electric current and Lorentz force vector. We also trace these parameters' temporal evolution. The abrupt magnetic changes were concentrated near the neutral line and in two neighboring sunspots. Near the neutral line, the field vectors became stronger and more horizontal during the flare and the shear increased. This was due to an increase in strength of the horizontal field components near the neutral line, most significant in the horizontal component parallel to the neutral line but the perpendicular component also increased in strength. The vertical component did not show a significant, permanent overall change at the neutral line. The increase in total flux at the neutral line was accompanied by a compensating flux decrease in the surrounding volume. In the two sunspots near the neutral line the azimuthal flux abruptly decreased during the flare but this change was permanent in only one of the spots. There was a large, abrupt, downward vertical Lorentz force change during the flare, consistent with results of past analyses and recent theoretical work. The horizontal Lorentz force acted in opposite directions along each side of neutral line, with the two sunspots at each end subject to abrupt torsional forces. The shearing forces were consistent with field contraction and decrease of shear near the neutral line, whereas the field itself became more sheared as a result of the flux collapsing towards the neutral line from the surrounding volume.Comment: DOI 10.1007/s11207-012-0071-0. Accepted for publication in Solar Physics SDO3 Topical Issue. Some graphics missing due to 15MB limi

Deceleration and trapping of heavy diatomic molecules using a ring-decelerator

We present an analysis of the deceleration and trapping of heavy diatomic molecules in low-field seeking states by a moving electric potential. This moving potential is created by a 'ring-decelerator', which consists of a series of ring-shaped electrodes to which oscillating high voltages are applied. Particle trajectory simulations have been used to analyze the deceleration and trapping efficiency for a group of molecules that is of special interest for precision measurements of fundamental discrete symmetries. For the typical case of the SrF molecule in the (N,M) = (2, 0) state, the ring-decelerator is shown to outperform traditional and alternate-gradient Stark decelerators by at least an order of magnitude. If further cooled by a stage of laser cooling, the decelerated molecules allow for a sensitivity gain in a parity violation measurement, compared to a cryogenic molecular beam experiment, of almost two orders of magnitude

Population redistribution in optically trapped polar molecules

We investigate the rovibrational population redistribution of polar molecules in the electronic ground state induced by spontaneous emission and blackbody radiation. As a model system we use optically trapped LiCs molecules formed by photoassociation in an ultracold two-species gas. The population dynamics of vibrational and rotational states is modeled using an ab-initio electric dipole moment function and experimental potential energy curves. Comparison with the evolution of the v"=3 electronic ground state yields good qualitative agreement. The analysis provides important input to assess applications of ultracold LiCs molecules in quantum simulation and ultracold chemistry.Comment: 6 pages, 5 figures, EPJD Topical issue on Cold Quantum Matter - Achievements and Prospect

Comparison of NEXRAD-Based and Observed Rainfall Data and TOPMODEL Simulations, McTier Creek Watershed, South Carolina

2012 S.C. Water Resources Conference - Exploring Opportunities for Collaborative Water Research, Policy and Managemen