1,205 research outputs found

    Consistency test of general relativity from large scale structure of the Universe

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    We construct a consistency test of General Relativity (GR) on cosmological scales. This test enables us to distinguish between the two alternatives to explain the late-time accelerated expansion of the universe, that is, dark energy models based on GR and modified gravity models without dark energy. We derive the consistency relation in GR which is written only in terms of observables - the Hubble parameter, the density perturbations, the peculiar velocities and the lensing potential. The breakdown of this consistency relation implies that the Newton constant which governs large-scale structure is different from that in the background cosmology, which is a typical feature in modified gravity models. We propose a method to perform this test by reconstructing the weak lensing spectrum from measured density perturbations and peculiar velocities. This reconstruction relies on Poisson's equation in GR to convert the density perturbations to the lensing potential. Hence any inconsistency between the reconstructed lensing spectrum and the measured lensing spectrum indicates the failure of GR on cosmological scales. The difficulties in performing this test using actual observations are discussed.Comment: 7 pages, 1 figur

    3D Hybrid Scaffolds Based on PEDOT:PSS/MWCNT Composites

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    Conducting polymer scaffolds combine the soft-porous structures of scaffolds with the electrical properties of conducting polymers. In most cases, such functional systems are developed by combining an insulating scaffold matrix with electrically conducting materials in a 3D hybrid network. However, issues arising from the poor electronic properties of such hybrid systems, hinder their application in many areas. This work reports on the design of a 3D electroactive scaffold, which is free of an insulating matrix. These 3D polymer constructs comprise of a water soluble conducting polymer (PEDOT:PSS) and multi-walled carbon nanotubes (MWCNTs). The insertion of the MWCNTs in the 3D polymer matrix directly contributes to the electron transport efficiency, resulting in a 7-fold decrease in resistivity values. The distribution of CNTs, as characterized by SEM and Raman spectroscopy, further define the micro- and nano-structural topography while providing active sites for protein attachment, thereby rendering the system suitable for biological/sensing applications. The resulting scaffolds, combine high porosity, mechanical stability and excellent conducting properties, thus can be suitable for a variety of applications ranging from tissue engineering and biomedical devices to (bio-) energy storage

    Prescribers\u27 Satisfaction with Delivering Medications for Opioid Use Disorder

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    BACKGROUND: Expanding access to medications for opioid use disorder (MOUD), such as buprenorphine and extended release (XR) naltrexone, is critical to addressing the US opioid epidemic, but little is known about prescriber satisfaction with delivering these two types of MOUD. The current study describes the satisfaction of prescribers delivering buprenorphine and XR-naltrexone while examining whether satisfaction is associated with current patient census and organizational environment. METHODS: As part of a cluster randomized clinical trial (RCT) focused on expanding access to medication for opioid use disorder, 41 MOUD prescribers in Florida, Ohio, and Wisconsin completed a web-based survey. The survey included measures of prescriber satisfaction with delivering buprenorphine treatment and XR-naltrexone. In addition, the survey measured several prescriber characteristics and their perceptions of the organizational environment. RESULTS: Prescribers were generally satisfied with their work in delivering these two types of MOUD. Prescribers reporting a greater number of patients (r = .46, p = .006), those who would recommend the center to others (r = .56, p \u3c .001), and those reporting positive relationships with staff (r = .56, p \u3c .001) reported significantly greater overall satisfaction with delivering buprenorphine treatment. Prescribers who more strongly endorsed feeling overburdened reported lower overall buprenorphine satisfaction (r = -.37, p = .02). None of the prescriber characteristics or perceptions of the organizational environment were significantly associated with overall satisfaction with delivering XR-naltrexone treatment. CONCLUSIONS: The generally high levels of satisfaction with both types of MOUD is notable given that prescriber dissatisfaction can lead to turnover and impact intentions to leave the profession. Future research should continue to explore the prescriber characteristics and organizational factors associated with satisfaction in providing different types of MOUD. REGISTRATION: ClinicalTrials.gov. NCT02926482. Date of registration: September 9, 2016. https://clinicaltrials.gov/ct2/show/NCT02926482

    E835 at FNAL: Charmonium Spectroscopy in pˉp\bar p p Annihilations

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    I present preliminary results on the search for hch_c in its ηcÎł\eta_c\gamma and J/ψπ0J/\psi\pi^0 decay modes. We observe an excess of \eta_c\gammaeventsnear3526MeVthathasaprobability events near 3526 MeV that has a probability {\cal P} \sim 0.001toarisefrombackgroundfluctations.Theresonanceparametersare to arise from background fluctations. The resonance parameters are M=3525.8 \pm 0.2 \pm 0.2 MeV,MeV, \Gamma\leq1MeV,and 1 MeV, and 10.6\pm 3.7\pm3.4(br) < \Gamma_{\bar{p}p}B_{\eta_c\gamma} < 12.8\pm 4.8\pm4.5(br) eV.WefindnoeventexcesswithinthesearchregionintheeV. We find no event excess within the search region in the J/\psi\pi^0$ mode.Comment: Presented at the 6th International Conference on Hyperons, Charm and Beauty Hadrons (BEACH 2004), Chicago(Il), June 27-July 3,200

    Complications of fixed infrared emitters in computer-assisted total knee arthroplasties

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    <p>Abstract</p> <p>Background</p> <p>The first stage in the implant of a total knee arthroplasty with computer-assisted surgery is to fasten the emitters to the femur and the tibia. These trackers must be hard-fixed to the bone. The objectives of our study are to evaluate the technical problems and complications of these tracker-pins, the necessary time to fix them to the bone and the possible advantages of a new femoral-fixed tracker-pin.</p> <p>Methods</p> <p>Three hundred and sixty seven tracker-pins were used in one hundred and fifty one computer-assisted total knee replacements. A bicortical screw was used to fix the tracker to the tibia in all cases; in the femur, however, a bicortical tracker was used in 112 cases, while a new device (OrthoLock) with percutaneous fixation pins was employed in the remaining 39.</p> <p>Results</p> <p>Technical problems related to the fixing of the trackers appeared in nine cases (2.5%). The mean surgery time to fix the tracker pin to the tibia was 3 minutes (range 2–7), and 5 minutes in the case of the femoral pin (range: 4–11), although with the new tool it was only three minutes (range 2–4) (p < 0.001). No complications were observed with this new device.</p> <p>Conclusion</p> <p>The incidence of problems and complications with the fixing systems used in knee navigation is very small. The use of a new device with percutaneous pins facilitates the fixing of femoral trackers and decreases the time needed to place them.</p

    Search for CP Violation in D Meson Decays to phi pi+

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    We search for CP violation in Cabibbo-suppressed charged D meson decays by measuring the difference between the CP violating asymmetries for the Cabibbo-suppressed decays D+ -> K+K-pi+ and the Cabibbo-favored decays Ds -> K+K-pi+ in the K+K- mass region of the phi resonance. Using 955/fb of data collected with the Belle detector we obtain A_CP(D+ -> phi pi+) = (+0.51 +- 0.28 +- 0.05)%. The measurement improves the sensitivity of previous searches by more than a factor of five. We find no evidence for direct CP violation.Comment: submitted to PR

    First Measurement of Inclusive B -> X_s eta Decays

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    We report a first measurement of inclusive B -> X_s eta decays, where X_s is a charmless state with unit strangeness. The measurement is based on a pseudo-inclusive reconstruction technique and uses a sample of 657 x 10^6 BB-bar pairs accumulated with the Belle detector at the KEKB e^+e^- collider. For M_{X_s} < 2.6 GeV/c^2, we measure a branching fraction of (26.1 +/- 3.0 (stat) +1.9 -2.1 (syst) +4.0 -7.1 (model)) x 10^-5 and a direct CP asymmetry of A_{CP} = -0.13 +/- 0.04 +0.02 -0.03. Over half of the signal occurs in the range M_{X_s} > 1.8 GeV/c^2.Comment: 6 pages, 1 figure, 1 table, submitted to Physical Review Letter

    Measurements of Branching Fractions and Time-dependent CP Violating Asymmetries in B0→D(∗)±D∓B^{0} \to D^{(*)\pm}D^{\mp} Decays

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    We report measurements of branching fractions and time-dependent CP asymmetries in B0→D+D−B^{0} \to D^{+}D^{-} and B0→D∗±D∓B^{0} \to D^{*\pm}D^{\mp} decays using a data sample that contains (772±11)×106BBˉ(772 \pm 11)\times 10^6 B\bar{B} pairs collected at the ΄(4S)\Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e−e^+ e^- collider. We determine the branching fractions to be B(B0→D+D−)=(2.12±0.16±0.18)×10−4\mathcal{B}(B^{0} \to D^{+}D^{-})=(2.12 \pm 0.16 \pm 0.18)\times 10^{-4} and B(B0→D∗±D∓=(6.14±0.29±0.50)×10−4\mathcal{B}(B^{0} \to D^{*\pm}D^{\mp}=(6.14 \pm 0.29 \pm 0.50)\times 10^{-4}. We measure CP asymmetry parameters SD+D−=−1.06−0.14+0.21±0.08\mathcal{S}_{D^{+}D^{-}} = -1.06_{-0.14}^{+0.21} \pm 0.08 and CD+D−=−0.43±0.16±0.05\mathcal{C}_{D^{+}D^{-}} = -0.43 \pm 0.16 \pm 0.05 in B0→D+D−B^{0} \to D^{+}D^{-} and AD∗D=+0.06±0.05±0.02\mathcal{A}_{D^{*}D} = +0.06 \pm 0.05 \pm 0.02, SD∗D=−0.78±0.15±0.05\mathcal{S}_{D^{*}D} = -0.78 \pm 0.15 \pm 0.05, CD∗D=−0.01±0.11±0.04\mathcal{C}_{D^{*}D} = -0.01 \pm 0.11 \pm 0.04, ΔSD∗D=−0.13±0.15±0.04\Delta\mathcal{S}_{D^{*}D} = -0.13 \pm 0.15 \pm 0.04 and ΔCD∗D=+0.12±0.11±0.03\Delta\mathcal{C}_{D^{*}D} = +0.12 \pm 0.11 \pm 0.03 in B0→D∗±D∓B^{0} \to D^{*\pm}D^{\mp}, where the first uncertainty is statistical and the second is systematic. We exclude the conservation of CP symmetry in both decays at equal to or greater than 4σ4\sigma significance.Comment: 7 pages, 2 figure
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