4,503 research outputs found

    Constraining recent lead pollution sources in the North Pacific using ice core stable lead isotopes

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    Trends and sources of lead (Pb) aerosol pollution in the North Pacific rim of North America from 1850 to 2001 are investigated using a high-resolution (subannual to annual) ice core record recovered from Eclipse Icefield (3017 masl; St. Elias Mountains, Canada). Beginning in the early 1940s, increasing Pb concentration at Eclipse Icefield occurs coevally with anthropogenic Pb deposition in central Greenland, suggesting that North American Pb pollution may have been in part or wholly responsible in both regions. Isotopic ratios (208Pb/207Pb and 206Pb/207Pb) from 1970 to 2001 confirm that a portion of the Pb deposited at Eclipse Icefield is anthropogenic, and that it represents a variable mixture of East Asian (Chinese and Japanese) emissions transported eastward across the Pacific Ocean and a North American component resulting from transient meridional atmospheric flow. Based on comparison with source material Pb isotope ratios, Chinese and North American coal combustion have likely been the primary sources of Eclipse Icefield Pb over the 1970–2001 time period. The Eclipse Icefield Pb isotope composition also implies that the North Pacific mid-troposphere is not directly impacted by transpolar atmospheric flow from Europe. Annually averaged Pb concentrations in the Eclipse Icefield ice core record show no long-term trend during 1970–2001; however, increasing 208Pb/207Pb and decreasing 206Pb/207Pb ratios reflect the progressive East Asian industrialization and increase in Asian pollutant outflow. The post-1970 decrease in North American Pb emissions is likely necessary to explain the Eclipse Icefield Pb concentration time series. When compared with low (lichen) and high (Mt. Logan ice core) elevation Pb data, the Eclipse ice core record suggests a gradual increase in pollutant deposition and stronger trans-Pacific Asian contribution with rising elevation in the mountains of the North Pacific rim

    O-cell Testings Case Histories Demonstrate the Importance of Bored Pile (Drilled Shaft) Construction Technique

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    Herein we review the Osterberg Cell, or O-cell, method for performing large capacity load tests on bored piles (drilled shafts), and demonstrate how it provides a new opportunity to assess the effects of construction technique. A sampling of 8 case histories, 7 with comparative testing, illustrates the impact of poor technique and thus demonstrates the importance of good construction technique. The poor techniques include inadequate bottom cleanout, failure to use drilling fluids, poor concrete placement, failure to roughen sides, and improper drilling tools. We conclude with a brief description of a recent, world record, 133 MN (15,000 tons) O-cell load test

    Combination of Tevatron searches for the standard model Higgs boson in the W+W- decay mode

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    Report number: FERMILAB-PUB-10-017-EWe combine searches by the CDF and D0 collaborations for a Higgs boson decaying to W+W-. The data correspond to an integrated total luminosity of 4.8 (CDF) and 5.4 (D0) fb-1 of p-pbar collisions at sqrt{s}=1.96 TeV at the Fermilab Tevatron collider. No excess is observed above background expectation, and resulting limits on Higgs boson production exclude a standard-model Higgs boson in the mass range 162-166 GeV at the 95% C.L.We combine searches by the CDF and D0 Collaborations for a Higgs boson decaying to W+W-. The data correspond to an integrated total luminosity of 4.8 (CDF) and 5.4 (D0) fb-1 of pp̅ collisions at √s=1.96  TeV at the Fermilab Tevatron collider. No excess is observed above background expectation, and resulting limits on Higgs boson production exclude a standard model Higgs boson in the mass range 162–166 GeV at the 95% C.L.Peer reviewe

    Search for R-parity Violating Decays of tau Sneutrinos to emu, mutau, and etau Pairs in ppbar Collisions at sqrt(s) = 1.96 TeV

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    7 pages, 5 figures. To be submitted to Phys. Rev. Lett.We present a search for tau sneutrino production using the Tevatron ppbar collision data collected with the CDF II detector and corresponding to an integrated luminosity of 1 fb^-1. We focus on the scenarios predicted by the R-parity violating (RPV) supersymmetric models in which tau sneutrinos decay to two charged leptons of different flavor. With the data consistent with the standard model expectations, we set the upper limits on sigma(ppbar -> tau sneutrino)*BR(tau sneutrino ->emu,mutau,etau) and use these results to constrain the RPV couplings as a function of tau sneutrino mass.We present a search for supersymmetric neutrino ν˜ production using the Tevatron pp̅ collision data collected with the CDF II detector and corresponding to an integrated luminosity of 1  fb-1. We focus on the scenarios predicted by the R-parity violating (RPV) supersymmetric models in which sneutrinos decay to two charged leptons of different flavor. With the data consistent with the standard model expectations, we set upper limits on σ(pp̅ →ν˜)×BR(ν˜→eμ,μτ,eτ) and use these results to constrain the RPV couplings as a function of the sneutrino mass.Peer reviewe

    Levels of self-reported depression and anxiety among HIV-positive patients in Albania: a cross-sectional study

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    Aim To gain an initial perspective of mental health issues facing the Human Immunodeficiency Virus (HIV)-positive population at the University Hospital Center of Tirana (UHCT) HIV/AIDS Ambulatory Clinic. Methods From June-August 2009, we conducted semistructured interviews with 79 patients (93% response rate) at the UHCT HIV/AIDS Ambulatory Clinic. The interviews assessed patient-reported histories of mental health diagnoses, patients’ demographics, and current emotional health status. Results The percentage of patients who reported a history of diagnosis of depression or anxiety was high – 62.3% and 82.3%, respectively. Factors associated with a history of depression included having been diagnosed with anxiety (P < 0.001), having a higher number of barriers to care (P < 0.001), having a higher number of current medical and social needs (P < 0.001), or having not obtained antiretroviral therapy (ART) abroad (P = 0.004). Factors associated with a history of anxiety included having been on firstline ART (P = 0.008), having been diagnosed with HIV for shorter periods of time (P = 0.043), having been diagnosed with depression (P < 0.001), having a higher number of current medical and social needs (P = 0.035), or having not obtained ART abroad (P = 0.003). Conclusions Mental health problems are widespread among the known HIV-positive patient population in Albania. The high prevalences of anxiety and depression and of dual diagnoses of these conditions suggest the need for more mental health care for HIV-positive patients in Albania

    Search for the Decays B(s)0e+μ{B^0_{(s)}\to e^+\mu^-} and B(s)0e+e{B^0_{(s)}\to e^+e^-} in CDF Run II

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    submitted to PRLWe report results from a search for the lepton flavor violating decays B(s)0e+μB^0_{(s)}\to e^+\mu^-, and the flavor-changing neutral-current decays B(s)0e+eB^0_{(s)} \to e^+ e^-. The analysis uses data corresponding to 2fb1{\rm 2 fb^{-1}} of integrated luminosity of ppˉp \bar{p} collisions at s=1.96TeV\sqrt{s}=1.96 {\rm TeV} collected with the upgraded Collider Detector (CDF II) at the Fermilab Tevatron. The observed number of B(s)0B^0_{(s)} candidates is consistent with background expectations. The resulting Bayesian upper limits on the branching ratios at 90% credibility level are B(Bs0e+μ)e+μ)e+μ)47.8TeV/c2\mathcal{B}(B^0_s \to e^{+}\mu^{-}) e^{+}\mu^{-})e^{+}\mu^{-}) 47.8 {\rm TeV/c^2}, and MLQ(B0e+μ)>59.3TeV/c2{M_{LQ}}(B^0\to e^+ \mu^-) > 59.3 {\rm TeV/c^2}, at 90% credibility level.We report results from a search for the lepton flavor violating decays Bs0→e+μ- and B0→e+μ-, and the flavor-changing neutral-current decays Bs0→e+e- and B0→e+e-. The analysis uses data corresponding to 2  fb-1 of integrated luminosity of pp̅ collisions at √s=1.96  TeV collected with the upgraded Collider Detector (CDF II) at the Fermilab Tevatron. The observed number of B0 and Bs0 candidates is consistent with background expectations. The resulting Bayesian upper limits on the branching ratios at 90% credibility level are B(Bs0→e+μ-)47.8  TeV/c2, and MLQ(B0→e+μ-)>59.3  TeV/c2, at 90% credibility level.Peer reviewe

    Seasonal change in the daily timing of behaviour of the common vole, Microtus arvalis

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    1. Seasonal effects on daily activity patterns in the common vole were established by periodic trapping in the field and continuous year round recording of running wheel and freeding activity in cages exposed to natural meteorological conditions. 2. Trapping revealed decreased nocturnality in winter as compared to summer. This was paralelled by a winter reduction in both nocturnal wheel running and feeding time in cages. 3. Frequent trap checks revealed a 2 h rhythm in daytime catches in winter, not in summer. Cage feeding activity in daytime was always organized in c. 2 h intervals, but day-to-day variations in phase blurred the rhythm in summer in a summation of individual daily records. Thus both seasonal and short-term temporal patterns are consistent between field trappings and cage feeding records. 4. Variables associated with the seasonal change in daily pattern were: reproductive state (sexually active voles more nocturnal), age (juveniles more nocturnal), temperature (cold days: less nocturnal), food (indicated by feeding experiments), habitat structure (more nocturnal in habitat with underground tunnels). 5. Minor discrepancies between field trappings and cage feeding activity can be explained by assuming increased trappability of voles in winter. Cage wheel running is not predictive of field trapping patterns and is thought to reflect behavioral motivations not associated with feeding but with other activities (e.g., exploratory, escape, interactive behaviour) undetected by current methods, including radiotelemetry and passage-counting. 6. Winter decrease in nocturnality appears to involve a reduction in nocturnal non-feeding and feeding behaviour and is interpreted primarily as an adaptation to reduce energy expenditure in adverse but socially stable winter conditions.

    Urinary ATP as an indicator of infection and inflammation of the urinary tract in patients with lower urinary tract symptoms

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    BACKGROUND: Adenosine-5'-triphosphate (ATP) is a neurotransmitter and inflammatory cytokine implicated in the pathophysiology of lower urinary tract disease. ATP additionally reflects microbial biomass thus has potential as a surrogate marker of urinary tract infection (UTI). The optimum clinical sampling method for ATP urinalysis has not been established. We tested the potential of urinary ATP in the assessment of lower urinary tract symptoms, infection and inflammation, and validated sampling methods for clinical practice. METHODS: A prospective, blinded, cross-sectional observational study of adult patients presenting with lower urinary tract symptoms (LUTS) and asymptomatic controls, was conducted between October 2009 and October 2012. Urinary ATP was assayed by a luciferin-luciferase method, pyuria counted by microscopy of fresh unspun urine and symptoms assessed using validated questionnaires. The sample collection, storage and processing methods were also validated. RESULTS: 75 controls and 340 patients with LUTS were grouped as without pyuria (n = 100), pyuria 1-9 wbc ?l(-1) (n = 120) and pyuria ?10 wbc ?l(-1) (n = 120). Urinary ATP was higher in association with female gender, voiding symptoms, pyuria greater than 10 wbc ?l(-1) and negative MSU culture. ROC curve analysis showed no evidence of diagnostic test potential. The urinary ATP signal decayed with storage at 23°C but was prevented by immediate freezing at ??-20°C, without boric acid preservative and without the need to centrifuge urine prior to freezing. CONCLUSIONS: Urinary ATP may have a role as a research tool but is unconvincing as a surrogate, clinical diagnostic marker

    Adherence to self-administered tuberculosis treatment in a high HIV-prevalence setting: a cross-sectional survey in Homa Bay, Kenya.

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    Good adherence to treatment is crucial to control tuberculosis (TB). Efficiency and feasibility of directly observed therapy (DOT) under routine program conditions have been questioned. As an alternative, Médecins sans Frontières introduced self-administered therapy (SAT) in several TB programs. We aimed to measure adherence to TB treatment among patients receiving TB chemotherapy with fixed dose combination (FDC) under SAT at the Homa Bay district hospital (Kenya). A second objective was to compare the adherence agreement between different assessment tools
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