Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012

High-Resolution Melting Analysis for the Rapid Detection of Fluoroquinolone and Streptomycin Resistance in Mycobacterium tuberculosis

published_or_final_versio

On the Inverse Problem of Binocular 3D Motion Perception

It is shown that existing processing schemes of 3D motion perception such as interocular velocity difference, changing disparity over time, as well as joint encoding of motion and disparity, do not offer a general solution to the inverse optics problem of local binocular 3D motion. Instead we suggest that local velocity constraints in combination with binocular disparity and other depth cues provide a more flexible framework for the solution of the inverse problem. In the context of the aperture problem we derive predictions from two plausible default strategies: (1) the vector normal prefers slow motion in 3D whereas (2) the cyclopean average is based on slow motion in 2D. Predicting perceived motion directions for ambiguous line motion provides an opportunity to distinguish between these strategies of 3D motion processing. Our theoretical results suggest that velocity constraints and disparity from feature tracking are needed to solve the inverse problem of 3D motion perception. It seems plausible that motion and disparity input is processed in parallel and integrated late in the visual processing hierarchy

Graphenes in the absence of metals as carbocatalysts for selective acetylene hydrogenation and alkene hydrogenation

Catalysis makes possible a chemical reaction by increasing the transformation rate. Hydrogenation of carbon-carbon multiple bonds is one of the most important examples of catalytic reactions. Currently, this type of reaction is carried out in petrochemistry at very large scale, using noble metals such as platinum and palladium or first row transition metals such as nickel. Catalysis is dominated by metals and in many cases by precious ones. Here we report that graphene (a single layer of one-atom-thick carbon atoms) can replace metals for hydrogenation of carbon-carbon multiple bonds. Besides alkene hydrogenation, we have shown that graphenes also exhibit high selectivity for the hydrogenation of acetylene in the presence of a large excess of ethylene.This study was financially supported by the Spanish Ministry of Economy and Competitiveness (Severo Ochoa and CTQ2012-32315); and Generalidad Valenciana (Prometeo 21/013) is gratefully acknowledged.Primo Arnau, AM.; Neatu, F.; Florea, M.; Parvulescu, V.; García Gómez, H. (2014). Graphenes in the absence of metals as carbocatalysts for selective acetylene hydrogenation and alkene hydrogenation. Nature Communications. 5:1-9. https://doi.org/10.1038/ncomms6291S195Dreyer, D. R. & Bielawski, C. W. Carbocatalysis: heterogeneous carbons finding utility in synthetic chemistry. Chem. Sci. 2, 1233–1240 (2011).Machado, B. F. & Serp, P. Graphene-based materials for catalysis. Catal. Sci. Technol. 2, 54–75 (2012).Schaetz, A., Zeltner, M. & Stark, W. J. Carbon modifications and surfaces for catalytic organic transformations. ACS Catal. 2, 1267–1284 (2012).Su, D. S. et al. Metal-free heterogeneous catalysis for sustainable chemistry. ChemSusChem 3, 169–180 (2010).Chauhan, S. M. S. & Mishra, S. Use of graphite oxide and graphene oxide as catalysts in the synthesis of dipyrromethane and calix[4]pyrrole. Molecules 16, 7256–7266 (2011).Dreyer, D. R., Jarvis, K. A., Ferreira, P. J. & Bielawski, C. W. Graphite oxide as a carbocatalyst for the preparation of fullerene-reinforced polyester and polyamide nanocomposites. Polym. Chem. 3, 757–766 (2012).Dreyer, D. R., Park, S., Bielawski, C. W. & Ruoff, R. S. The chemistry of graphene oxide. Chem. Soc. Rev. 39, 228–240 (2010).Pyun, J. Graphene oxide as catalyst: application of carbon materials beyond nanotechnology. Angew. Chem. Int. Ed. 50, 46–48 (2011).Rourke, J. P. et al. The real graphene oxide revealed: stripping the oxidative debris from the graphene-like sheets. Angew. Chem. Int. Ed. 50, 3173–3177 (2011).Sun, H. et al. Reduced graphene oxide for catalytic oxidation of aqueous organic pollutants. ACS Appl. Mater. Interf. 4, 5466–5471 (2012).Dreyer, D. R., Jia, H. P. & Bielawski, C. W. Graphene oxide: a convenient carbocatalyst for facilitating oxidation and hydration reactions. Angew. Chem. Int. Ed. 49, 6813–6816 (2010).Dreyer, D. R., Jia, H. P., Todd, A. D., Geng, J. X. & Bielawski, C. W. Graphite oxide: a selective and highly efficient oxidant of thiols and sulfides. Org. Biomol. Chem. 9, 7292–7295 (2011).Hayashi, M. Oxidation using activated carbon and molecular oxygen system. Chem. Rec. 8, 252–267 (2008).Jia, H. P., Dreyer, D. R. & Bielawski, C. W. C-H oxidation using graphite oxide. Tetrahedron 67, 4431–4434 (2011).Kumar, A. V. & Rao, K. R. Recyclable graphite oxide catalyzed Friedel-Crafts addition of indoles to alpha, beta-unsaturated ketones. Tetrahedron Lett. 52, 5188–5191 (2011).Soria-Sanchez, M. et al. Carbon nanostructure materials as direct catalysts for phenol oxidation in aqueous phase. Appl. Catal. B Environ. 104, 101–109 (2011).Verma, S. et al. Graphene oxide: an efficient and reusable carbocatalyst for aza-Michael addition of amines to activated alkenes. Chem. Commun. 47, 12673–12675 (2011).Yu, H. et al. Solvent-free catalytic dehydrative etherification of benzyl alcohol over graphene oxide. Chem. Phys. Lett. 583, 146–150 (2013).Holschumacher, D., Bannenberg, T., Hrib, C. G., Jones, P. G. & Tamm, M. Heterolytic dihydrogen activation by a frustrated carbene-borane Lewis pair. Angew. Chem. Int. Ed. 47, 7428–7432 (2008).Staubitz, A., Robertson, A. P. M., Sloan, M. E. & Manners, I. Amine- and phosphine-borane adducts: new interest in old molecules. Chem. Rev. 110, 4023–4078 (2010).Stephan, D. W. & Erker, G. Frustrated Lewis Pairs: Metal-free Hydrogen Activation and More. Angew. Chem. Int. Ed. 49, 46–76 (2010).Poh, H. L., Sanek, F., Sofer, Z. & Pumera, M. High-pressure hydrogenation of graphene: towards graphane. Nanoscale 4, 7006–7011 (2012).Sofo, J. O., Chaudhari, A. S. & Barber, G. D. Graphane: A two-dimensional hydrocarbon. J. Phys. Chem. B 75, 153401 (2007).Elias, D. C. et al. Control of graphene’s properties by reversible hydrogenation: evidence for graphane. Science 323, 610–613 (2009).Despiau-Pujo, E. et al. Elementary processes of H2 plasma-graphene interaction: a combined molecular dynamics and density functional theory study. J. Appl. Phys. 113, 114302 (2013).Xu, L. & Ge, Q. Effects of defects and dopants in graphene on hydrogen interaction in graphene-supported NaAlH4. Int. J. Hydrogen Energy 38, 3670–3680 (2013).Perhun, T. I., Bychko, I. B., Trypolsky, A. I. & Strizhak, P. E. Catalytic properties of graphene material in the hydrogenation of ethylene. Theor. Exp. Chem. 48, 367–370 (2013).Hummers, W. S. & Offeman, R. E. Preparation of graphitic oxide. J. Am. Chem. Soc. 80, 1339 (1958).Dhakshinamoorthy, A., Primo, A., Concepcion, P., Alvaro, M. & Garcia, H. Doped graphene as a metal-free carbocatalyst for the selective aerobic oxidation of benzylic hydrocarbons, cyclooctane and styrene. Chem. Eur. J. 19, 7547–7554 (2013).Latorre-Sanchez, M., Primo, A. & Garcia, H. P-doped graphene obtained by pyrolysis of modified alginate as a photocatalyst for hydrogen generation from water-methanol mixtures. Angew. Chem. Int. Ed. 52, 11813–11816 (2013).Primo, A., Sanchez, E., Delgado, J. M. & Garcia, H. High-yield production of N-doped graphitic platelets by aqueous exfoliation of pyrolyzed chitosan. Carbon N. Y. 68, 777–783 (2014).Stankovich, S. et al. Synthesis of graphene-based nanosheets via chemical reduction of exfoliated graphite oxide. Carbon N. Y. 45, 1558–1565 (2007).Pumera, M. & Wong, C. H. A. Graphane and hydrogenated graphene. Chem. Soc. Rev. 42, 5987–5995 (2013).Teschner, D. et al. The roles of subsurface carbon and hydrogen in palladium-catalyzed alkyne hydrogenation. Science 320, 86–89 (2008).Bridier, B., Lopez, N. & Perez-Ramirez, J. Molecular understanding of alkyne hydrogenation for the design of selective catalysts. Dalton Trans. 39, 8412–8419 (2010).Flick, K., Herion, C. & Allmann, H. Palladium-haltiger Trägerkatalysator zur selektiven katalytischen Hydrierung von Acetylen in Kohlenwasserstoffströmen. EP764463-A; EP764463-A2; DE19535402-A1; JP9141097-A; CA2185721-A; KR97014834-A; MX9604031-A1; US5847250-A; US5856262-A; TW388722-A; MX195137-B; CN1151908-A; EP764463-B1; DE59610365-G; ES2197222-T3; KR418161-B; CN1081487-C; JP3939787-B2; CA2185721-C (1997).Gartside, R. J. et al. Improved olefin plant recovery system employing a combination of catalytic distillation and fixed bed catalytic steps. WO2005080530-A1; EP1711581-A1; BR200418414-A; MX2006008045-A1; JP2007518864-W; KR2007005565-A; CN1961059-A; IN200604063-P1; KR825662-B1; JP4376908-B2; CA2553962-C; IN251202-B; SG124072-A1; SG124072-B; CN1961059-B (2005).Wegerer, D. A., Bussche, K. V. & Vandenbussche, K. M. Selective Co oxidation for acetylene converter feed Co CONTROL. US2012294774-A1; US8431094-B2 (2102).Chernichenko, K. et al. A frustrated-Lewis-pair approach to catalytic reduction of alkynes to cis-alkenes. Nat. Chem. 5, 718–723 (2013).Vile, G., Bridier, B., Wichert, J. & Perez-Ramirez, J. Ceria in hydrogenation catalysis: high selectivity in the conversion of alkynes to olefins. Angew. Chem. Int. Ed. 51, 8620–8623 (2012).Ambrosi, A. et al. Metallic impurities in graphenes prepared from graphite can dramatically influence their properties. Angew. Chem. Int. Ed. 51, 500–503 (2012).Ambrosi, A. et al. Chemical reduced graphene contains inherent metallic impurities present in parent natural and synthetic graphite. Proc. Natl Acad. Sci. USA 109, 12899–12904 (2012).Vile, G., Almora-Barrios, N., Mitchell, S., Lopez, N. & Perez-Ramirez, J. From the lindlar catalyst to supported ligand-modified palladium nanoparticles: selectivity patterns and accessibility constraints in the continuous-flow three-phase hydrogenation of acetylenic compounds. Chemistry 20, 5849–5849 (2014).Gurrath, M. et al. Palladium catalysts on activated carbon supports—Influence of reduction temperature, origin of the support and pretreatments of the carbon surface. Carbon N. Y. 38, 1241–1255 (2000).Stephan, D. W. ‘Frustrated Lewis pairs’: a concept for new reactivity and catalysis. Org. Biomol. Chem. 6, 1535–1539 (2008).Stephan, D. W. Frustrated Lewis pairs: a new strategy to small molecule activation and hydrogenation catalysis. Dalton Trans. 17, 3129–3136 (2009).Chase, P. A., Jurca, T. & Stephan, D. W. Lewis acid-catalyzed hydrogenation: B(C6F5)3-mediated reduction of imines and nitriles with H2. Chem. Commun. 14, 1701–1703 (2008).Hounjet, L. J. & Stephan, D. W. Hydrogenation by frustrated Lewis pairs: main group alternatives to transition metal catalysts? Org. Process Res. Dev. 18, 385–391 (2014).Spies, P. et al. Metal-free catalytic hydrogenation of enamines, imines, and conjugated phosphinoalkenylboranes. Angew. Chem. Int. Ed. 47, 7543–7546 (2008).Greb, L. et al. Metal-free catalytic olefin hydrogenation: low-temperature H2 activation by frustrated Lewis pairs. Angew. Chem. Int. Ed. 51, 10164–10168 (2012)

Associations between neurocognitive functioning and social and occupational resilience among South African women exposed to childhood trauma.

Background: Prior research on adaptation after early trauma among black South African women typically assessed resilience in ways that lacked contextual specificity. In addition, the neurocognitive correlates of social and occupational resilience have not been investigated. Objective: The primary aim of this exploratory study was to identify domains of neurocognitive functioning associated with social and occupational resilience, defined as functioning at a level beyond what would be expected given exposure to childhood trauma. Methods: A sample of black South African women, N = 314, completed a neuropsychological battery, a questionnaire assessing exposure to childhood trauma, and self-report measures of functional status. We generated indices of social and occupational resilience by regressing childhood trauma exposure on social and occupational functioning, saving the residuals as indices of social and occupational functioning beyond what would be expected given exposure to childhood trauma. Results: Women with lower non-verbal memory evidenced greater social and occupational resilience above and beyond the effects attributable to age, education, HIV status, and depressive and posttraumatic stress symptoms. In addition, women with greater occupational resilience exhibited lower semantic language fluency and processing speed. Conclusion: Results are somewhat consistent with prior studies implicating memory effects in impairment following trauma, though our findings suggest that reduced abilities in these domains may be associated with greater resilience. Studies that use prospective designs and objective assessment of functional status are needed to determine whether non-verbal memory, semantic fluency, and processing speed are implicated in the neural circuitry of post-traumatic exposure resilience

Operator models for delivering municipal solid waste management services in developing countries. Part A: The evidence base

This article presents the evidence base for ‘operator models’ – that is, how to deliver a sustainable service through the interaction of the ‘client’, ‘revenue collector’ and ‘operator’ functions – for municipal solid waste management in emerging and developing countries. The companion article addresses a selection of locally appropriate operator models. The evidence shows that no ‘standard’ operator model is effective in all developing countries and circumstances. Each city uses a mix of different operator models; 134 cases showed on average 2.5 models per city, each applying to different elements of municipal solid waste management – that is, street sweeping, primary collection, secondary collection, transfer, recycling, resource recovery and disposal or a combination. Operator models were analysed in detail for 28 case studies; the article summarises evidence across all elements and in more detail for waste collection. Operators fall into three main groups: The public sector, formal private sector, and micro-service providers including micro-, community-based and informal enterprises. Micro-service providers emerge as a common group; they are effective in expanding primary collection service coverage into poor- or peri-urban neighbourhoods and in delivering recycling. Both public and private sector operators can deliver effective services in the appropriate situation; what matters more is a strong client organisation responsible for municipal solid waste management within the municipality, with stable political and financial backing and capacity to manage service delivery. Revenue collection is also integral to operator models: Generally the municipality pays the operator from direct charges and/or indirect taxes, rather than the operator collecting fees directly from the service user