124 research outputs found

    Evaluation of Legacy Forest Harvesting Impacts on Dominant Stream Water Sources and Implications for Water Quality Using End Member Mixing Analysis

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    Forests are critical water supply regions that are increasingly threatened by natural and anthropogenic disturbance. Evaluation of runoff-generating processes within harvested and undisturbed headwater catchments provides insight into disturbance impacts on water quality and drinking water treatability. In this study, an extensive hydrologic dataset collected at the experimental Turkey Lakes Watershed (TLW) located on the Canadian Shield was used to quantify sources of stormflow in legacy clear-cut (24-years post harvesting) and forested (control) headwater catchments using an end member mixing analysis (EMMA) model. Stream water, groundwater, soil water, and throughfall water quality were evaluated during spring snowmelt, stormflow, and fall wet-up. Groundwater chemistry was similar to stream water chemistry in both catchments, suggesting that groundwater is a major contributor to stream flow. The water chemistry in small wetlands within the study catchments was comparable to stream water chemistry, suggesting that wetlands are also important contributors to stream flow. Differences in wetland position between the legacy clear-cut and control catchments appeared to have a greater influence on source contributions than legacy harvesting. Results from this study provide insight into runoff-generation processes that reflect event/seasonal flow dynamics and the impacts on water quality

    Body oxygen stores, aerobic dive limits, and the diving abilities of juvenile and adult muskrats (Ondatra zibethicus

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    ABSTRACT Intraspecific variability in body oxygen reserves, muscle buffering capacity, diving metabolic rate, and diving behavior were examined in recently captured juvenile and adult muskrats. Allometric scaling exponents for lung ( ), blood b p 1.04 ( ), and total body oxygen storage capacity ( ) b p 0.91 b p 1.09 did not differ from unity. The concentration of skeletal muscle myoglobin scaled positively with mass in 254-600-g juveniles ( ) but was mass-independent in larger individuals. b p 1.63 Scaling exponents for diving metabolic rate and calculated aerobic dive limit (ADL) were 0.74 and 0.37, respectively. Contrary to allometric predictions, we found no evidence that the diving abilities of muskrats increased with age or body size. Juveniles aged 1-2 mo exhibited similar dive times but dove more frequently than summer-caught adults. Average and cumulative dive times and dive : surface ratios were highest for fall-and winter-caught muskrats. Total body oxygen reserves were greatest in winter, mainly due to an increase in blood oxygen storage capacity. The buffering capacity of the hind limb swimming muscles also was highest in winter-caught animals. Several behavioral indicators of dive performance, including average and maximum duration of voluntary dives, varied positively with blood hemoglobin and muscle myoglobin concentration of muskrats. However, none of the behavioral measures were strongly correlated with the total body oxygen reserves or ADLs derived for these same individuals

    Resistance studies of erythromycin and rifampin for Rhodococcus equi over a 10-year period

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    This study sought to determine whether an increase in resistance of Rhodococcus equi to the antibiotics rifampin and erythromycin occurred over a 10-year period. This was carried out by the use of E test strips for rifampin and erythromycin to determine the MIC (minimum inhibitory concentration) values of Rhodococcus equi to this combination of antibiotics

    Dark Matter Search Results from the PICO-2L C3F8 Bubble Chamber

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    New data are reported from the operation of a 2 liter C3F8 bubble chamber in the SNOLAB underground laboratory, with a total exposure of 211.5 kg days at four different energy thresholds below 10 keV. These data show that C3F8 provides excellent electron-recoil and alpha rejection capabilities at very low thresholds. The chamber exhibits an electron-recoil sensitivity of 98.2%. These data also include the first observation of a dependence of acoustic signal on alpha energy. Twelve single nuclear recoil event candidates were observed during the run. The candidate events exhibit timing characteristics that are not consistent with the hypothesis of a uniform time distribution, and no evidence for a dark matter signal is claimed. These data provide the most sensitive direct detection constraints on WIMP-proton spin-dependent scattering to date, with significant sensitivity at low WIMP masses for spin-independent WIMP-nucleon scattering.The PICO Collaboration would like to thank SNOLAB and its staff for providing an exceptional underground laboratory space and invaluable technical support. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics under award DE-SC-0012161. Fermi National Accelerator Laboratory is operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359. Part of the research described in this paper was conducted under the Ultra Sensitive Nuclear Measurements Initiative at Pacific Northwest National Laboratory, a multiprogram national laboratory operated by Battelle for the U.S. Department of Energy. We acknowledge the National Science Foundation for their support including Grants No. PHY-1242637, No. PHY-0919526, and No. PHY-1205987. We acknowledge the support of the National Sciences and Engineering Research Council of Canada (NSERC) and the Canada Foundation for Innovation (CFI). We also acknowledge support from the Kavli Institute for Cosmological Physics at the University of Chicago. We acknowledge the financial support of the Spanish Ministerio de Economia y Competitividad, Consolider MultiDark CSD2009-00064 Grant. We acknowledge support from the Department of Atomic Energy (DAE), Government of India, under the Center for AstroParticle Physics II project (CAPP-II) at Saha Insititute of Nuclear Physics (SINP), Kolkata. We acknowledge the Czech Ministry of Education, Youth and Sports, Grant No. LM2011027. We acknowledge technical assistance from Fermilab's Computing, Particle Physics, and Accelerator Divisions, and from A. Behnke at IUSB.Amole, C.; Ardid Ramírez, M.; Asner, DM.; Baxter, D.; Behnke, E.; Bhattacharjee, P.; Borsodi, H.... (2015). Dark Matter Search Results from the PICO-2L C3F8 Bubble Chamber. Physical Review Letters. 114(2313):1-6. https://doi.org/10.1103/PhysRevLett.114.231302S161142313Komatsu, E., Dunkley, J., Nolta, M. R., Bennett, C. L., Gold, B., Hinshaw, G., … Wright, E. L. (2009). FIVE-YEARWILKINSON MICROWAVE ANISOTROPY PROBEOBSERVATIONS: COSMOLOGICAL INTERPRETATION. The Astrophysical Journal Supplement Series, 180(2), 330-376. doi:10.1088/0067-0049/180/2/330Jungman, G., Kamionkowski, M., & Griest, K. (1996). Supersymmetric dark matter. Physics Reports, 267(5-6), 195-373. doi:10.1016/0370-1573(95)00058-5Bertone, G., Hooper, D., & Silk, J. (2005). Particle dark matter: evidence, candidates and constraints. Physics Reports, 405(5-6), 279-390. doi:10.1016/j.physrep.2004.08.031Feng, J. L. (2010). Dark Matter Candidates from Particle Physics and Methods of Detection. Annual Review of Astronomy and Astrophysics, 48(1), 495-545. doi:10.1146/annurev-astro-082708-101659Goodman, M. W., & Witten, E. (1985). Detectability of certain dark-matter candidates. Physical Review D, 31(12), 3059-3063. doi:10.1103/physrevd.31.3059Behnke, E., Behnke, J., Brice, S. J., Broemmelsiek, D., Collar, J. I., … Conner, A. (2012). First dark matter search results from a 4-kgCF3Ibubble chamber operated in a deep underground site. Physical Review D, 86(5). doi:10.1103/physrevd.86.052001Behnke, E., Behnke, J., Brice, S. J., Broemmelsiek, D., Collar, J. I., … Cooper, P. S. (2011). Improved Limits on Spin-Dependent WIMP-Proton Interactions from a Two LiterCF3IBubble Chamber. Physical Review Letters, 106(2). doi:10.1103/physrevlett.106.021303Archambault, S., Behnke, E., Bhattacharjee, P., Bhattacharya, S., Dai, X., Das, M., … Zacek, V. (2012). Constraints on low-mass WIMP interactions on 19F from PICASSO. Physics Letters B, 711(2), 153-161. doi:10.1016/j.physletb.2012.03.078Felizardo, M., Girard, T. A., Morlat, T., Fernandes, A. C., Ramos, A. R., Marques, J. G., … Marques, R. (2014). The SIMPLE Phase II dark matter search. Physical Review D, 89(7). doi:10.1103/physrevd.89.072013Glaser, D. A., & Rahm, D. C. (1955). Characteristics of Bubble Chambers. Physical Review, 97(2), 474-479. doi:10.1103/physrev.97.474Seitz, F. (1958). On the Theory of the Bubble Chamber. Physics of Fluids, 1(1), 2. doi:10.1063/1.1724333Behnke, E., Benjamin, T., Brice, S. J., Broemmelsiek, D., Collar, J. I., … Cooper, P. S. (2013). Direct measurement of the bubble-nucleation energy threshold in aCF3Ibubble chamber. Physical Review D, 88(2). doi:10.1103/physrevd.88.021101Agostinelli, S., Allison, J., Amako, K., Apostolakis, J., Araujo, H., Arce, P., … Barrand, G. (2003). Geant4—a simulation toolkit. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 506(3), 250-303. doi:10.1016/s0168-9002(03)01368-8Allison, J., Amako, K., Apostolakis, J., Araujo, H., Arce Dubois, P., Asai, M., … Chytracek, R. (2006). Geant4 developments and applications. IEEE Transactions on Nuclear Science, 53(1), 270-278. doi:10.1109/tns.2006.869826Aubin, F., Auger, M., Genest, M.-H., Giroux, G., Gornea, R., Faust, R., … Storey, C. (2008). Discrimination of nuclear recoils from alpha particles with superheated liquids. New Journal of Physics, 10(10), 103017. doi:10.1088/1367-2630/10/10/103017Archambault, S., Aubin, F., Auger, M., Beleshi, M., Behnke, E., … Behnke, J. (2011). New insights into particle detection with superheated liquids. New Journal of Physics, 13(4), 043006. doi:10.1088/1367-2630/13/4/043006Pozzi, S. A., Padovani, E., & Marseguerra, M. (2003). MCNP-PoliMi: a Monte-Carlo code for correlation measurements. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 513(3), 550-558. doi:10.1016/j.nima.2003.06.012Robinson, A. E. (2014). New libraries for simulating neutron scattering in dark matter detector calibrations. Physical Review C, 89(3). doi:10.1103/physrevc.89.032801Yellin, S. (2002). Finding an upper limit in the presence of an unknown background. Physical Review D, 66(3). doi:10.1103/physrevd.66.032005Lewin, J. D., & Smith, P. F. (1996). Review of mathematics, numerical factors, and corrections for dark matter experiments based on elastic nuclear recoil. Astroparticle Physics, 6(1), 87-112. doi:10.1016/s0927-6505(96)00047-3Tovey, D. R., Gaitskell, R. J., Gondolo, P., Ramachers, Y., & Roszkowski, L. (2000). A new model-independent method for extracting spin-dependent cross section limits from dark matter searches. Physics Letters B, 488(1), 17-26. doi:10.1016/s0370-2693(00)00846-7Roszkowski, L., Austri, R. R. de, & Trotta, R. (2007). Implications for the Constrained MSSM from a new prediction forb→sγ. Journal of High Energy Physics, 2007(07), 075-075. doi:10.1088/1126-6708/2007/07/075Aprile, E., Alfonsi, M., Arisaka, K., Arneodo, F., Balan, C., Baudis, L., … Bokeloh, K. (2013). Limits on Spin-Dependent WIMP-Nucleon Cross Sections from 225 Live Days of XENON100 Data. Physical Review Letters, 111(2). doi:10.1103/physrevlett.111.021301Aartsen, M. G., Abbasi, R., Abdou, Y., Ackermann, M., Adams, J., Aguilar, J. A., … Bai, X. (2013). Search for Dark Matter Annihilations in the Sun with the 79-String IceCube Detector. Physical Review Letters, 110(13). doi:10.1103/physrevlett.110.131302Tanaka, T., Abe, K., Hayato, Y., Iida, T., Kameda, J., Koshio, Y., … Nakahata, M. (2011). AN INDIRECT SEARCH FOR WEAKLY INTERACTING MASSIVE PARTICLES IN THE SUN USING 3109.6 DAYS OF UPWARD-GOING MUONS IN SUPER-KAMIOKANDE. The Astrophysical Journal, 742(2), 78. doi:10.1088/0004-637x/742/2/78Chatrchyan, S., Khachatryan, V., Sirunyan, A. M., Tumasyan, A., Adam, W., Bergauer, T., … Friedl, M. (2012). Search for Dark Matter and Large Extra Dimensions inppCollisions Yielding a Photon and Missing Transverse Energy. Physical Review Letters, 108(26). doi:10.1103/physrevlett.108.261803First results on dark matter annihilation in the Sun using the ANTARES neutrino telescope. (2013). Journal of Cosmology and Astroparticle Physics, 2013(11), 032-032. doi:10.1088/1475-7516/2013/11/032Demidov, S., & Suvorova, O. (2010). Annihilation of NMSSM neutralinos in the Sun and neutrino telescope limits. Journal of Cosmology and Astroparticle Physics, 2010(06), 018-018. doi:10.1088/1475-7516/2010/06/018Avrorin, A. D., Avrorin, A. V., Aynutdinov, V. M., Bannasch, R., Belolaptikov, I. A., Bogorodsky, D. Y., … Demidov, S. V. (2015). Search for neutrino emission from relic dark matter in the sun with the Baikal NT200 detector. Astroparticle Physics, 62, 12-20. doi:10.1016/j.astropartphys.2014.07.006Akerib, D. S., Araújo, H. M., Bai, X., Bailey, A. J., Balajthy, J., Bedikian, S., … Bradley, A. (2014). First Results from the LUX Dark Matter Experiment at the Sanford Underground Research Facility. Physical Review Letters, 112(9). doi:10.1103/physrevlett.112.091303Agnese, R., Anderson, A. J., Asai, M., Balakishiyeva, D., Basu Thakur, R., Bauer, D. A., … Bowles, M. A. (2014). Search for Low-Mass Weakly Interacting Massive Particles with SuperCDMS. Physical Review Letters, 112(24). doi:10.1103/physrevlett.112.241302Agnese, R., Anderson, A. J., Asai, M., Balakishiyeva, D., Basu Thakur, R., Bauer, D. A., … Brandt, D. (2014). Search for Low-Mass Weakly Interacting Massive Particles Using Voltage-Assisted Calorimetric Ionization Detection in the SuperCDMS Experiment. Physical Review Letters, 112(4). doi:10.1103/physrevlett.112.041302Angle, J., Aprile, E., Arneodo, F., Baudis, L., Bernstein, A., … Bolozdynya, A. I. (2011). Search for Light Dark Matter in XENON10 Data. Physical Review Letters, 107(5). doi:10.1103/physrevlett.107.051301Aprile, E., Alfonsi, M., Arisaka, K., Arneodo, F., Balan, C., Baudis, L., … Bokeloh, K. (2012). Dark Matter Results from 225 Live Days of XENON100 Data. Physical Review Letters, 109(18). doi:10.1103/physrevlett.109.181301Angloher, G., Bento, A., Bucci, C., Canonica, L., Erb, A., von Feilitzsch, F., … Zöller, A. (2014). Results on low mass WIMPs using an upgraded CRESST-II detector. The European Physical Journal C, 74(12). doi:10.1140/epjc/s10052-014-3184-9Bernabei, R., Belli, P., Cappella, F., Cerulli, R., Dai, C. J., d’ Angelo, A., … Ye, Z. P. (2008). First results from DAMA/LIBRA and the combined results with DAMA/NaI. The European Physical Journal C, 56(3), 333-355. doi:10.1140/epjc/s10052-008-0662-yAalseth, C. E., Barbeau, P. S., Colaresi, J., Collar, J. I., Diaz Leon, J., … Fast, J. E. (2013). CoGeNT: A search for low-mass dark matter usingp-type point contact germanium detectors. Physical Review D, 88(1). doi:10.1103/physrevd.88.012002Agnese, R., Ahmed, Z., Anderson, A. J., Arrenberg, S., Balakishiyeva, D., Basu Thakur, R., … Brink, P. L. (2013). Silicon detector results from the first five-tower run of CDMS II. Physical Review D, 88(3). doi:10.1103/physrevd.88.03110

    Improved dark matter search results from PICO-2L Run 2

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    New data are reported from a second run of the 2-liter PICO-2L C3F8 bubble chamber with a total exposure of 129 kg-days at a thermodynamic threshold energy of 3.3 keV. These data show that measures taken to control particulate contamination in the superheated fluid resulted in the absence of the anomalous background events observed in the first run of this bubble chamber. One single nuclear-recoil event was observed in the data, consistent both with the predicted background rate from neutrons and with the observed rate of unambiguous multiple-bubble neutron scattering events. The chamber exhibits the same excellent electron-recoil and alpha decay rejection as was previously reported. These data provide the most stringent direct detection constraints on weakly interacting massive particle (WIMP)-proton spin-dependent scattering to date for WIMP masses < 50 GeV/c(2).The PICO Collaboration thanks SNOLAB for their exceptional laboratory space and technical support. We also thank Fermi National Accelerator Laboratory (Contract No. DE-AC02-07CH11359) and Pacific Northwest National Laboratory for their support. This work is supported by the National Sciences and Engineering Research Council of Canada (NSERC), the Canada Foundation for Innovation (CFI), the National Science Foundation (NSF) under the Grants No. PHY-1242637, No. PHY-0919526, No. PHY-1205987, and No. PHY-1506377 and by the U.S. Department of Energy under Award No. DE-SC-0012161. We also acknowledge the support of Department of Atomic Energy (DAE), Government of India, under the Center of AstroParticle Physics II project (CAPP-II) at Saha Institute of Physics (SINP); the Czech Ministry of Education, Youth and Sports (Grant No. LM2011027); the Spanish Ministerio de Economia y Competitividad, Consolider MultiDark (Grant No. CSD2009-00064) and DGAPA-UNAM through grant PAPIIT No. IA100316.Amole, C.; Ardid Ramírez, M.; Arnquist, I.; Asner, DM.; Baxter, D.; Behnke, E.; Bhattacharjee, P.... (2016). Improved dark matter search results from PICO-2L Run 2. Physical Review D. 93(6):1-5. https://doi.org/10.1103/PhysRevD.93.061101S1593

    Fear and rumours regarding placental biopsies in a malaria-in-pregnancy trial in Benin.

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    BACKGROUND: A multi-country, community-based trial on scheduled screening and treatment for malaria in pregnancy was conducted in Benin, The Gambia and Burkina Faso. Despite standardized procedures and outcomes, the study became subject to rumours and accusations of placenta being sold for mystical and financial gain by trial staff, leading to drop-out rates of 30% and the consequent halting of placental biopsy sampling in Benin. This paper explores the role of socio-cultural beliefs related to placenta and identified additional factors contributing these rumours. METHODS: A qualitative comparative emergent-theory design was used to assess social factors related to trial implementation and uptake in the three countries. Data from participant observation, informal conversations, group discussions and interviews were triangulated and analysed with NVivo Qualitative Analysis software. RESULTS: Despite similar sociocultural beliefs about the sacred nature of the placenta in all three study countries, these beliefs did not affect participation rates in Burkina Faso and The Gambia and placenta-related rumours only emerged in Benin. Therefore, the presence of beliefs is not a sufficient condition to have generated placenta-selling fears. The rumours in Benin reflected the confluence of placenta-related beliefs and factors related to the implementation of the trial (including a catalysing adverse event and miscommunication during the informed consent procedure). Furthermore, distinct socio-political factors contributed to the emergence of rumours, including the historical distrust in governmental organizations and the tense relationship between some of the actors involved in the trial. CONCLUSION: Transdisciplinary social science research designs should accompany the implementation of the trial. The integration of multiple stakeholders' knowledge and involvement is required to define and solve upcoming barriers
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