The 3^3He(e, e′'d)p Reaction in qω\omega-constant Kinematics

The cross section for the $^3$He(e, e$'$d)p reaction has been measured as a function of the missing momentum $p_m$ in q$\omega$ -constant kinematics at beam energies of 370 and 576 MeV for values of the three-momentum transfer $q$ of 412, 504 and 604 \mevc. The L(+TT), T and LT structure functions have been separated for $q$ = 412 and 504 \mevc. The data are compared to three-body Faddeev calculations, including meson-exchange currents (MEC), and to calculations based on a covariant diagrammatic expansion. The influence of final-state interactions and meson-exchange currents is discussed. The $p_m$-dependence of the data is reasonably well described by all calculations. However, the most advanced Faddeev calculations, which employ the AV18 nucleon-nucleon interaction and include MEC, overestimate the measured cross sections, especially the longitudinal part, and at the larger values of $q$. The diagrammatic approach gives a fair description of the cross section, but under(over)estimates the longitudinal (transverse) structure function.Comment: 17 pages, 7 figure

Q^2 Evolution of Generalized Baldin Sum Rule for the Proton

The generalized Baldin sum rule for virtual photon scattering, the unpolarized analogy of the generalized Gerasimov-Drell-Hearn integral, provides an important way to investigate the transition between perturbative QCD and hadronic descriptions of nucleon structure. This sum rule requires integration of the nucleon structure function F_1, which until recently had not been measured at low Q^2 and large x, i.e. in the nucleon resonance region. This work uses new data from inclusive electron-proton scattering in the resonance region obtained at Jefferson Lab, in combination with SLAC deep inelastic scattering data, to present first precision measurements of the generalized Baldin integral for the proton in the Q^2 range of 0.3 to 4.0 GeV^2.Comment: 4 pages, 3 figures, one table; text added, one figure replace

Perturbative QCD Analysis of Local Duality in a fixed W^2 Framework

We study the global Q^2 dependence of large x, F_2 nucleon structure function data, with the aim of providing a perturbative-QCD based, quantitative analysis of parton-hadron duality. As opposed to previous analyses at fixed x, we use a framework in fixed W^2. We uncover a breakdown of the twist-4 approximation with a renormalon type improvement at O(1/Q^4) which, by affecting the initial evolution of parton distributions, will have consequences for pQCD analyses also at large x and very large Q^2.Comment: RevTex4, 8 pages, 3 figure

A high-precision polarimeter

We have built a polarimeter in order to measure the electron beam polarization in hall C at JLAB. Using a superconducting solenoid to drive the pure-iron target foil into saturation, and a symmetrical setup to detect the Moller electrons in coincidence, we achieve an accuracy of <1%. This sets a new standard for Moller polarimeters.Comment: 17 pages, 9 figures, submitted to N.I.

Nickel biopathways in tropical nickel hyperaccumulating trees from Sabah (Malaysia)

The extraordinary level of accumulation of nickel (Ni) in hyperaccumulator plants is a consequence of specific metal sequestering and transport mechanisms, and knowledge of these processes is critical for advancing an understanding of transition element metabolic regulation in these plants. The Ni biopathways were elucidated in three plant species, Phyllanthus balgooyi, Phyllanthus securinegioides (Phyllanthaceae) and Rinorea bengalensis (Violaceae), that occur in Sabah (Malaysia) on the Island of Borneo. This study showed that Ni is mainly concentrated in the phloem in roots and stems (up to 16.9% Ni in phloem sap in Phyllanthus balgooyi) in all three species. However, the species differ in their leaves - in P. balgooyi the highest Ni concentration is in the phloem, but in P. securinegioides and R. bengalensis in the epidermis and in the spongy mesophyll (R. bengalensis). The chemical speciation of Ni(2+) does not substantially differ between the species nor between the plant tissues and transport fluids, and is unambiguously associated with citrate. This study combines ion microbeam (PIXE and RBS) and metabolomics techniques (GC-MS, LC-MS) with synchrotron methods (XAS) to overcome the drawbacks of the individual techniques to quantitatively determine Ni distribution and Ni(2+) chemical speciation in hyperaccumulator plants.Antony van der Ent, Damien L. Callahan, Barry N. Noller, Jolanta Mesjasz-Przybylowicz, Wojciech J. Przybylowicz, Alban Barnabas and Hugh H. Harri

Correction factors for oxygen and flow-rate effects on neonatal Fleisch and Lilly pneumotachometers

Objective: To assess the effects of different oxygen concentrations and flow rates on the measurement errors of neonatal pneumotachometers in heated and unheated situations and to develop correction factors to correct for these effects. Design: Prospective laboratory study. Setting: Outpatient clinic with equipment in a standardized setting. Subjects: Neonatal pneumotachometers. Interventions: In standardized conditions, the tested pneumotachometer was calibrated at a flow rate of 3 L/min with 60% oxygen and was set in series with a closed spirometer system being used as a reference. Different air-flow levels (1-9 L/min) and oxygen concentrations (21-100%) were infused into the closed system with the pneumotachometer and spirometer. Measurements and Main Results: The pneumotachometers were significantly affected by changing oxygen concentrations (p < .01) and increasing flow rates (p < .01), increasing the actually measured flow rate. Correction factors, developed by multiple regression analysis, significantly reduced the overall maximum errors of the pneumotachometers from -1.1 to 0.6 L/min to -0.5 to 0.4 L/min. Conclusions: The effects of changes in oxygen concentrations and flow rates on neonatal pneumotachometers could be considerably decreased by the use of correction factors such as were calculated in this study. This will preclude frequent calibration procedures with actual flow and oxygen levels during changes in experimental settings. Copyrigh

Dietary supplementation with multiple micronutrients: No beneficial effects in pediatric cystic fibrosis patients

AbstractBackgroundCystic fibrosis (CF) patients are subjected to increased oxidative stress due to chronic pulmonary inflammation and recurrent infections. Additionally, these patients have diminished skeletal muscle performance and exercise capacity. We hypothesize that a mixture of multiple micronutrients could have beneficial effects on pulmonary function and muscle performance.MethodsA double-blind, randomized, placebo controlled, cross-over trial with a mixture of multiple micronutrients (ML1) was performed in 22 CF patients (12.9±2.5 yrs) with predominantly mild lung disease. Anthropometric measures, pulmonary function, exercise performance by bicycle ergometry, muscular strength and vitamins A and E were determined.ResultsAnalysis was performed using the paired Student t-test comparing the change in each parameter during ML1 and placebo. Plasma vitamin E and A levels increased during ML1 when compared to placebo. However, no significant difference between the effect of the ML1 or placebo was observed neither for FEV1, FVC, anthropometry, nor for the parameters for muscle performance.ConclusionsThe micronutrient mixture was not superior to placebo with respect to changes in pulmonary function or muscle performance in pediatric CF patients, despite a significant increase in plasma vitamin E concentrations

A prospective, randomized, open-label trial of 6-month versus 12-month dual antiplatelet therapy after drug-eluting stent implantation in ST-elevation myocardial infarction: Rationale and design of the \u201cDAPT-STEMI trial\u201d

Background The optimal duration of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention with second-generation drug eluting stents (DESs) is unclear. Because prolonged DAPT is associated with higher bleeding risk and health care costs, establishing optimal DAPT duration is of paramount importance. No other randomized controlled trials have evaluated the safety of shorter DAPT duration in ST-elevation myocardial infarction (STEMI) patients treated with second-generation DESs and latest P2Y12 platelet receptor inhibitors. Hypothesis Six months of DAPT after Resolute Integrity stent implantation in STEMI patients is not inferior to 12 months of DAPT in clinical outcomes. Study design The Dual Antiplatelet Therapy After Drug-Eluting Stent Implantation In ST-elevation Myocardial Infarction (DAPT-STEMI) trial is a randomized, multicenter, international, open-label trial designed to examine the safety (noninferiority) of 6-month DAPT after Resolute Integrity stent implantation in STEMI patients compared with 12-month DAPT. Event-free patients on DAPT at 6month will be randomized (1:1 fashion) between single (aspirin only) versus DAPT for an additional 6 months and followed until 2 years after primary percutaneous coronary intervention. The primary end point is a patient-oriented composite endpoint of all-cause mortality, any myocardial infarction, any revascularization, stroke, and major bleeding (net adverse clinical events [NACE]) at 18 months after randomization. To achieve a power of 85% for a noninferiority limit of 1.66, a total of 1100 enrolled patients are required. Summary The DAPT-STEMI trial aims to assess in STEMI patients treated with second-generation DESs whether discontinuation of DAPT after 6 months of event-free survival is noninferior to routine 12-month DAPT

Higher twists in the pion structure function

We calculate the QCD moments of the pion structure function using Drell-Yan data on the quark distributions in the pion and a phenomenological model for the resonance region. The extracted higher twist corrections are found to be larger than those for the nucleon, contributing around 50% of the lowest moment at Q^2=1 GeV^2.Comment: 8 pages, 3 figures, to appear in Phys. Rev.