Mine managers and regulators use geochemical predictions of pit lake chemistry to assess whether open pit mines will have positive or negative environmental effects after closure. Sensitivity ...analyses are a useful approach to explore uncertainties in these predictions. This study investigates the significance of subaqueous water–rock reactions and surface adsorption reactions on a geochemical model of a proposed pit lake at the Martha Au Mine, New Zealand. Our hypothesis was that subaqueous pyrite oxidation would lower surface water pH over time because pyrite will be present in over 1/3 of the submerged wall rock area, and that surface adsorption reactions would lower trace metal concentrations. An initial geochemistry prediction was created in PHREEQC based on site hydrology, representative input water chemistry, physical limnology, and the precipitation of ferrihydrite, manganite, amorphous gibbsite, and barite. Modeling water–rock reactions required the surface area of the submerged wall rocks, the concentration (volume %) of the dominant minerals found in the wall rock (
i.e. pyrite, adularia, albite, chlorite, illite, and kaolinite), reaction rates for each mineral, and the volumes of circulating lake layers. These variables determined the mass of each mineral that would react with lake water over a one-year period corresponding to annual turnover. To accommodate for uncertainty in the estimation of surface area, the surface area was increased by ×
10, ×
100, and ×
1000 in three additional models. To model surface adsorption reactions, the mass of ferrihydrite precipitated annually was set equal to the mass of hydrous ferric oxide allowed to adsorb trace metals. Results of the baseline geochemical prediction without water–rock reactions showed the surface water pH dropped from 6.5 to 5.0 over 50 years. The sensitivity analysis on water–rock reactions produced nearly identical results to the initial model for surface areas of ×
1, ×
10, and ×
100. Only the surface area ×
1000 model lowered pH more than half a pH unit from the initial prediction. These data suggest that water–rock reactions will not have a significant effect on the pH of the proposed Martha lake owing to the surface area of submerged minerals. Surface adsorption reactions lowered the concentrations of some trace metals (As, Cu, and Pb), whereas other trace metals were unaffected (Cd, Ni, Zn), which emphasized the pH dependence of these reactions. In the absence of model calibration or observed water chemistry, sensitivity analyses are a useful tool to explore uncertainties in pit lake predictions.
Using a data sample corresponding to an integrated luminosity of 342 fb − 1 collected with the BABAR detector at the SLAC PEP-II electron-positron storage ring operating at a center-of-mass ...energy near 10.58 GeV, we measure B ( τ − → π − π − π + ν τ ( ex . K 0 S ) ) = ( 8.83 ± 0.01 ± 0.13 ) % , B ( τ − → K − π − π + ν τ ( ex . K 0 S ) ) = ( 0.273 ± 0.002 ± 0.009 ) % , B ( τ − → K − π − K + ν τ ) = ( 0.1346 ± 0.0010 ± 0.0036 ) % , and B ( τ − → K − K − K + ν τ ) = ( 1.58 ± 0.13 ± 0.12 ) × 10 − 5 , where the uncertainties are statistical and systematic, respectively. These include significant improvements over previous measurements and a first measurement of B ( τ − → K − K − K + ν τ ) in which no resonance structure is assumed. We also report a first measurement of B ( τ − → ϕ π − ν τ ) = ( 3.42 ± 0.55 ± 0.25 ) × 10 − 5 , a new measurement of B ( τ − → ϕ K − ν τ ) = ( 3.39 ± 0.20 ± 0.28 ) × 10 − 5 and a first upper limit on B ( τ − → K − K − K + ν τ ( ex . ϕ ) ) .
Background Reverse total shoulder arthroplasty (RSA) for cuff tear arthropathy improves shoulder function and reduces pain. Implant position and soft tissue balancing are important factors to ...optimize outcome. Tensioning the deltoid and increasing the deltoid moment arm by medializing the center of rotation are biomechanically advantageous. The purpose of this study was to correlate RSA functional outcomes with deltoid lengthening and center of rotation medialization. Materials and methods This prospective cohort study enrolled 49 consecutive patients who underwent RSA for cuff tear arthropathy. Preoperative and serial postoperative physical examinations, radiographs, and American Shoulder and Elbow Surgeons and Simple Shoulder Test scores were evaluated. Deltoid lengthening and medialization of the center of rotation were measured radiographically and correlated with functional outcome scores, range of motion, and complications. Results At final follow-up (average, 16 ± 10 months), 37 of 49 patients (76%) were available for analysis. Deltoid lengthening (average, 21 ± 10 mm) correlated significantly ( P = .002) with superior active forward elevation (average, 144° ± 19°). Medialization of the center of rotation (average, 18 ± 8 mm) did not correlate with active forward elevation or subjective outcomes. Deltoid lengthening that achieved an acromion–greater tuberosity distance exceeding 38 mm had a 90% positive predictive value of obtaining 135° of active forward elevation. Two patients (4%) required revision surgery, and 68% of patients developed scapular notching (average grade, 1.3 ± 1.2) at final follow-up. Conclusion Deltoid lengthening improves active forward elevation after RSA for cuff tear arthropathy.
Using the entire sample of 467 × 10 6 Υ ( 4 S ) → B ¯¯¯ B decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at the SLAC National Accelerator Laboratory, we perform an ...analysis of B ± → D K ± decays, using decay modes in which the neutral D meson decays to either C P -eigenstates or non- C P -eigenstates. We measure the partial decay rate charge asymmetries for C P -even and C P -odd D final states to be A C P + = 0.25 ± 0.06 ± 0.02 and A C P − = − 0.09 ± 0.07 ± 0.02 , respectively, where the first error is the statistical and the second is the systematic uncertainty. The parameter A C P + is different from zero with a significance of 3.6 standard deviations, constituting evidence for direct C P violation. We also measure the ratios of the charged-averaged B partial decay rates in C P and non- C P decays, R C P + = 1.18 ± 0.09 ± 0.05 and R C P − = 1.07 ± 0.08 ± 0.04 . We infer frequentist confidence intervals for the angle γ of the unitarity triangle, for the strong phase difference δ B , and for the amplitude ratio r B , which are related to the B − → D K − decay amplitude by r B e i ( δ B − γ ) = A ( B − → ¯¯¯ D 0 K − ) / A ( B − → D 0 K − ) . Including statistical and systematic uncertainties, we obtain 0.24 < r B < 0.45 ( 0.06 < r B < 0.51 ) and, modulo 180°, 11.3 ° < γ < 22.7 ° or 80.8 ° < γ < 99.2 ° or 157.3 ° < γ < 168.7 ° ( 7.0 ° < γ < 173.0 ° ) at the 68% (95%) confidence level.
The decay τ-→K-KSντ has been studied using 430×106 e+e-→τ+τ- events produced at a center-of-mass energy around 10.6 GeV at the PEP-II collider and studied with the BABAR detector. The mass spectrum ...of the K-KS system has been measured and the spectral function has been obtained. The measured branching fraction B(τ-→K-KSντ)=(0.739±0.011(stat)±0.020(syst))×10-3 is found to be in agreement with earlier measurements.
Feedback repression of the genes encoding the low density lipoprotein receptor and several enzymes of the cholesterol biosynthetic pathway is mediated by 25-hydroxycholesterol and other oxysterols. ...In this study, we have cloned a rabbit cDNA encoding an oxysterol-binding protein that may play a role in this regulation. The predicted amino acid sequence revealed a protein of 809 amino acids with two distinctive features: 1) a glycine- and alanine-rich region (63% of 80 residues) at the NH2 terminus, and 2) a 35-residue leucine zipper motif that may mediate the previously observed oligomerization of the protein. When transfected into simian COS cells, the rabbit cDNA produced a protein that exhibited the same affinity and specificity for sterols as the previously purified hamster liver protein. Immunoblotting analysis showed that the rabbit cDNA encodes both the 96- and 101-kilodalton forms of the oxysterol-binding protein that were previously observed. The availability of an expressible cDNA for the oxysterol-binding protein should help elucidate its role in sterol metabolism.
We search for a light Higgs boson A 0 in the radiative decay Υ ( 3 S ) → γ A 0 , A 0 → τ + τ − , τ + → e + ν e ¯ ν τ , or τ + → μ + ν μ ¯ ν τ . The data sample contains 122 × 10 6 Υ ( 3 S ) events ...recorded with the BABAR detector. We find no evidence for a narrow structure in the studied τ + τ − invariant mass region of 4.03 < m τ + τ − < 10.10 GeV / c 2 . We exclude at the 90% confidence level (C.L.) a low-mass Higgs boson decaying to τ + τ − with a product branching fraction B ( Υ ( 3 S ) → γ A 0 ) × B ( A 0 → τ + τ − ) > ( 1.5 - 16 ) × 10 − 5 across the m τ + τ − range. We also set a 90% C.L. upper limit on the τ + τ − decay of the η b at B ( η b → τ + τ − ) < 8 % .
Recent investigations have suggested that the six-quark combination uuddss could be a deeply bound state (S) that has eluded detection so far, and a potential dark matter candidate. We report the ...first search for a stable, doubly strange six-quark state in Υ→S$\bar{Λ}\bar{Λ}$ decays based on a sample of 90×10$^{6}$Υ(2S) and 110×106Υ(3S) decays collected by the BABAR experiment. No signal is observed, and 90% confidence level limits on the combined Υ(2S,3S) → S$\bar{Λ}\bar{Λ}$ branching fraction in the range (1.2-1.4) × 10-7 are derived for mS < 2.05 GeV. These bounds set stringent limits on the existence of such exotic particles.
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