Search

We report measurements of the parity-conserving beam-normal single-spin elastic scattering asymmetries $B_n$ on $^{12}$C and $^{27}$Al, obtained with an electron beam polarized transverse to its momentum direction. These measurements add an additional kinematic point to a series of previous measurements of $B_n$ on $^{12}$C and provide a first measurement on $^{27}$Al. The experiment utilized the Qweak apparatus at Jefferson Lab with a beam energy of 1.158 GeV. The average lab scattering angle for both targets was 7.7 degrees, and the average $Q^2$ for both targets was 0.02437 GeV$^2$ (Q=0.1561 GeV). The asymmetries are $B_n$ = -10.68 $\pm$ 0.90 stat) $\pm$ 0.57 (syst) ppm for $^{12}$C and $B_n$ = -12.16 $\pm$ 0.58 (stat) $\pm$ 0.62 (syst) ppm for $^{27}$Al. The results are consistent with theoretical predictions, and are compared to existing data. When scaled by Z/A, the Q-dependence of all the far-forward angle (theta < 10 degrees) data from $^{1}$H to $^{27}$Al can be described by the same slope out to $Q \approx 0.35$ GeV. Larger-angle data from other experiments in the same Q range are consistent with a slope about twice as steep.

A beam-normal single-spin asymmetry generated in the scattering of transversely polarized electrons from unpolarized nucleons is an observable related to the imaginary part of the two-photon exchange process. We report a 2% precision measurement of the beam-normal single-spin asymmetry in elastic electron-proton scattering with a mean scattering angle of theta_lab = 7.9 degrees and a mean energy of 1.149 GeV. The asymmetry result is B_n = -5.194 +- 0.067 (stat) +- 0.082 (syst) ppm. This is the most precise measurement of this quantity available to date and therefore provides a stringent test of two-photon exchange models at far-forward scattering angles (theta_lab -> 0) where they should be most reliable., 6 pages, 3 figures; Slightly revised version, after referee's comments; accepted in PRL

This paper presents a constitutive modelling approach for the viscoplastic-damage behaviour of geomaterials. This approach is based on the hyperelasticity framework, where the entire constitutive behaviour is derived from only two scalar potentials: a free-energy potential and a dissipation function. The novelty of the new proposed model, in addition to being thermodynamically consistent, is that it requires only a few parameters that can be derived from conventional laboratory testing. The model has been specifically tested for its ability to reproduce a series of triaxial compression tests on core rock samples. The comparison between the viscoplastic-damage model predictions and experimental results shows that the model is remarkably successful in capturing the stress–strain response both at peak stress and in the region of material softening and the time to reach failure.

Background:The management of epistaxis requires an understanding of haematological factors that may complicate its treatment. This systematic review includes six distinct reviews examining the evidence supporting epistaxis-specific management strategies relating to warfarin, direct oral anticoagulants, heparin, antiplatelet agents, tranexamic acid and transfusion.Method:A systematic review of the literature was performed using a standardised methodology and search strategy.Results:Limited numbers of articles were identified in each systematic review, with level 1 evidence only regarding the use of tranexamic acid. No studies met the inclusion criteria within the heparin, direct oral anticoagulants or transfusion systematic reviews. Many studies were limited by small sample sizes and significant risk of bias.Conclusion:The management of major bleeding and transfusion practice is well documented in national guidance from multiple sources. The guidelines include advice on anticoagulants, antiplatelet agents and tranexamic acid. In the absence of more specific evidence, these guidelines should be applied in the management of epistaxis.

Background Osteoporosis is common, increasing as the population ages and has significant consequences including fracture. Effective treatments are available. Aim To support proactive fracture risk assessment (FRAX) and optimizing treatment for high-risk patients in primary care. Design Clinical cohort Setting November 2017 to November 2018, support was provided to 71 practices comprising 69 of 90 practices within two National Health Service Clinical Commissioning Groups areas. Total population 579 508 (207 263 aged over 50 years). Participants FRAX (National Institute for Care and Clinical Excellence, NICE CG146) in (i) males aged 75 years and over, (ii) females aged 65 years and over, (iii) females aged under 65 years and males aged under 75 years with risk factors and (iv) under 50 years with major risk factors. Results A total of 158 946 met NICE CG146, 11 961 were coded with an osteoporosis diagnosis (7.5%), of those, 42% were prescribed treatment with a bone sparing agent (BSA). In total, 6942 were assessed to initiate BSA. Thirty percent of untreated osteoporosis diagnosis patients had never been prescribed BSA. Even when prescribed, 1700 people (35%) were for less than minimum recommended duration. Of the total 9784 patients within the FRAX recommended to treat threshold, 3197 (33%) were currently treated with BSA and 3684 (37%) had no history of ever receiving BSA. From untreated patients, expected incidence of 875 fractures over a 3-year period (approximately £3.4 million). Treatment would prevent 274 fractures (cost reduction: £1 274 045, with prescribing costs: saving £805 145 after 3 years of treatment). Conclusion Underdiagnosis and suboptimal treatment of osteoporosis was identified. Results suggest that implementing NICE guidance and optimizing treatment options in practice is possible and could prevent significant fractures.

The fields of particle and nuclear physics have undertaken extensive programs to search for evidence of physics beyond that explained by current theories. The observation of the Higgs boson at the Large Hadron Collider completed the set of particles predicted by the Standard Model (SM), currently the best description of fundamental particles and forces. However, the theory's limitations include a failure to predict fundamental parameters and the inability to account for dark matter/energy, gravity, and the matter-antimater asymmetry in the universe, among other phenomena. Given the lack of additional particles found so far through direct searches in the post-Higgs era, indirect searches utilizing precise measurements of well predicted SM observables allow highly targeted alternative tests for physics beyond the SM. Indirect searches have the potential to reach mass/energy scales beyond those directly accessible by today's high-energy accelerators. The value of the weak charge of the proton Q_W^p is an example of such an indirect search, as it sets the strength of the proton's interaction with particles via the well-predicted neutral electroweak force. Parity violation (invariance under spatial inversion (x,y,z) -> (-x,-y,-z)) is violated only in the weak interaction, thus providing a unique tool to isolate the weak interaction in order to measure the proton's weak charge. Here we report Q_W^p=0.0719+-0.0045, as extracted from our measured parity-violating (PV) polarized electron-proton scattering asymmetry, A_ep=-226.5+-9.3 ppb. Our value of Q_W^p is in excellent agreement with the SM, and sets multi-TeV-scale constraints on any semi-leptonic PV physics not described within the SM., Direct link to Nature Version "https://rdcu.be/954U"

SUMMARY Background O RhD-negative (ONeg) red cells can be used in an emergency for recipients of other blood groups. Matching supply and demand is currently a challenge; therefore, any service redesign, using more remote blood fridges, must consider ONeg red cell availability. Objectives To identify whether the number of fridges stocking emergency ONeg units correlates with use and wastage. Methods The number and distribution of ONeg red cells was requested from the hospitals in South West England. For NHS Hospitals, comparison was made with ONeg National Health Service (NHS) organisation – NHS Blood and Transplant (NHSBT) issues (ONeg as a proportion of all red cells), wastage and the proportion of ONeg units given to ONeg patients (ONeg-to-ONeg use). Correlations were performed using Spearman's rank correlation coefficient. Results Of the 23 hospitals, 21 responded. Four hundred and forty three ONeg units were held across the region – 56% as stock and the remaining as emergency units. ONeg issues increased with the number of fridges holding emergency units (ρ = 0·48, significance 0·046). No correlation was found between the number of fridges and ONeg wastage or ONeg-to-ONeg use. A longer unit shelf life on rotation back to stock was associated with lower wastage (ρ = −0·597, significance 0·009). Conclusions Although there was a weak correlation between fridge numbers and overall percentage ONeg use, there was no correlation with ONeg wastage.

In May 2012, the $Q^{p}_{\rm Weak}$ collaboration completed a two year measurement program to determine the weak charge of the proton ${Q^{p}_W} = ( 1 - 4\sin^2{\theta_{W}})$ at the Thomas Jefferson National Accelerator Facility (TJNAF). The experiment was designed to produce a 4.0 % measurement of the weak charge, via a 2.5 % measurement of the parity violating asymmetry in the number of elastically scattered 1.165 GeV electrons from protons, at forward angles. At the proposed precision, the experiment would produce a 0.3 % measurement of the weak mixing angle at a momentum transfer of Q 2 = 0.026 GeV2, making it the most precise stand alone measurement of the weak mixing angle at low momentum transfer. In combination with other parity measurements, $Q^{p}_{\rm Weak}$ will also provide a high precision determination of the weak charges of the up and down quarks. At the proposed precision, a significant deviation from the Standard Model prediction could be a signal of new physics at mass scales up to ≃ 6 TeV, whereas agreement would place new and significant constraints on possible Standard Model extensions at mass scales up to ≃ 2 TeV. This paper provides an overview of the physics and the experiment, as well as a brief look at some preliminary diagnostic and analysis data.

The Q-weak experiment at Jefferson Laboratory measured the parity violating asymmetry (A P V ) in elastic electron-proton scattering at small momentum transfer squared (Q 2=0.025 (G e V/c)2), with the aim of extracting the proton’s weak charge ( ${Q^p_W}$ ) to an accuracy of 5 %. As one of the major uncertainty contribution sources to ${Q^p_W}$ , Q 2 needs to be determined to ∼1 % so as to reach the proposed experimental precision. For this purpose, two sets of high resolution tracking chambers were employed in the experiment, to measure tracks before and after the magnetic spectrometer. Data collected by the tracking system were then reconstructed with dedicated software into individual electron trajectories for experimental kinematics determination. The Q-weak kinematics and the analysis scheme for tracking data are briefly described here. The sources that contribute to the uncertainty of Q 2 are discussed, and the current analysis status is reported.

This paper presents a three-dimensional energy-based solution for the time-dependent response of a deeply embedded and unsupported semi-infinite tunnel of circular cross-section. The tunnel is taken to be excavated quasi-instantaneously from an infinite rock body that initially exhibits an isotropic stress state and that is made up of a homogeneous, isotropic and viscoelastic material. The viscoelastic behaviour is modelled by means of Burger's model, and the rock is taken to behave volumetrically linear elastic and to exhibit exclusively deviatoric creep. This viscoelastic problem is transformed into the Laplace domain, where it represents a quasi-elastic problem. The displacement fields in the new solution are taken to be the products of independent functions that vary in the radial and longitudinal directions. The differential equations governing the displacements of the system and appropriate boundary conditions are obtained using the principle of minimum potential energy. The solutions for these governing equations in the Laplace domain are then obtained analytically and numerically using a one-dimensional finite difference technique. The results are then transformed back into the time domain using an efficient numerical scheme. The accuracy of the new solution is comparable with that of a finite element analysis but requires much less computation effort.

The Jefferson Lab Q weak experiment determined the weak charge of the proton by measuring the parity-violating elastic scattering asymmetry of longitudinally polarized electrons from an unpolarized liquid hydrogen target at small momentum transfer. A custom apparatus was designed for this experiment to meet the technical challenges presented by the smallest and most precise e → p asymmetry ever measured. Technical milestones were achieved at Jefferson Lab in target power, beam current, beam helicity reversal rate, polarimetry, detected rates, and control of helicity-correlated beam properties. The experiment employed 180 μA of 89% longitudinally polarized electrons whose helicity was reversed 960 times per second. The electrons were accelerated to 1.16 GeV and directed to a beamline with extensive instrumentation to measure helicity-correlated beam properties that can induce false asymmetries. Moller and Compton polarimetry were used to measure the electron beam polarization to better than 1%. The electron beam was incident on a 34.4 cm liquid hydrogen target. After passing through a triple collimator system, scattered electrons between 5.8° and 11.6° were bent in the toroidal magnetic field of a resistive copper-coil magnet. The electrons inside this acceptance were focused onto eight fused silica Cherenkov detectors arrayed symmetrically around the beam axis. A total scattered electron rate of about 7 GHz was incident on the detector array. The detectors were read out in integrating mode by custom-built low-noise pre-amplifiers and 18-bit sampling ADC modules. The momentum transfer Q 2 =0.025 GeV 2 was determined using dedicated low-current ( ~ 100 pA ) measurements with a set of drift chambers before (and a set of drift chambers and trigger scintillation counters after) the toroidal magnet.

The Q weak experiment, which took data at Jefferson Lab in the period 2010 - 2012, will precisely determine the weak charge of the proton by measuring the parity-violating asymmetry in elastic e-p scattering at 1.1 GeV using a longitudinally polarized electron beam and a liquid hydrogen target at a low momentum transfer of Q 2 = 0.025 (GeV/c)2 . The weak charge of the proton is predicted by the Standard Model and any significant deviation would indicate physics beyond the Standard Model. The technical challenges and experimental apparatus for measuring the weak charge of the proton will be discussed, as well as the method of extracting the weak charge of the proton. The results from a small subset of the data, that has been published, will also be presented. Furthermore an update will be given of the current status of the data analysis.

Tertiary creep is often observed in soft rocks and it represents a problem in a mining environment. Tertiary creep behaviour appears due to progressive micro cracking of the material and would result in a loss of strength and stiffness, which may eventually lead to failure and a complete loss of load carrying capability of the material. In this paper, the authors combined the continuum damage mechanics within the framework of hyperplasticity, thus encompassing viscoplasticity and damage within a single theory. The authors present a family of models which obeys the laws of thermodynamics. The entire constitutive behaviour is derived from two scalar potentials; a free energy potential which provides the elasticity law, and a dissipation potential which provides the yield function, the direction of plastic flow and the evolution of a damage variable. No additional assumptions are required. These new models require only few parameters which have physical meanings and are capable of capturing tertiary creep observed in soft rocks.

A subset of results from the recently completed Jefferson Lab Qweak experiment are reported. This experiment, sensitive to physics beyond the Standard Model, exploits the small parity-violating asymmetry in elastic ep scattering to provide the first determination of the protons weak charge Qweak(p). The experiment employed a 180 uA longitudinally polarized 1.16 GeV electron beam on a 35 cm long liquid hydrogen target. Scattered electrons corresponding to Q2 of 0.025 GeV2 were detected in eight Cerenkov detectors arrayed symmetrically around the beam axis. The goals of the experiment were to provide a measure of Qweak(p) to 4.2 percent (combined statistical and systematic error), which implies a measure of sin2(thetaw) at the level of 0.3 percent, and to help constrain the vector weak quark charges C1u and C1d. The experimental method is described, with particular focus on the challenges associated with the worlds highest power LH2 target. The new constraints on C1u and C1d provided by the subset of the experiments data analyzed to date will also be shown, together with the extracted weak charge of the neutron., Comment: 8 pages, 4 figures, INPC2013

The performance of MicroStrip Gas Chambers (MSGC) in BNL Experiment 885, a search for ΛΛ-hypernuclei, is detailed. Chambers with an active area of 80×50 mm2 were instrumented and operated as a vertex detector in the experiment. Furthermore, two distinct types of microstrip prints were utilized in these chambers. Prints manufactured with Integrated Circuit (IC) photolithographic technology have fine tolerances and thin minimum trace widths, but can suffer from a high rate of defects per print and are more costly. Prints constructed with Printed Circuit (PC) photolithographic technology have coarser tolerances but relatively few defects per print, and are extremely cost-effective. Results of bench and beam tests of both IC and PC based MSGCs are presented and their performance in BNL-E885 is discussed. E885 marks the first use of PC based MSGCs in an experiment.

O RhD-negative (ONeg) red cells can be used in an emergency for recipients of other blood groups. Matching supply and demand is currently a challenge; therefore, any service redesign, using more remote blood fridges, must consider ONeg red cell availability.To identify whether the number of fridges stocking emergency ONeg units correlates with use and wastage.The number and distribution of ONeg red cells was requested from the hospitals in South West England. For NHS Hospitals, comparison was made with ONeg National Health Service (NHS) organisation--NHS Blood and Transplant (NHSBT) issues (ONeg as a proportion of all red cells), wastage and the proportion of ONeg units given to ONeg patients (ONeg-to-ONeg use). Correlations were performed using Spearman's rank correlation coefficient.Of the 23 hospitals, 21 responded. Four hundred and forty three ONeg units were held across the region--56% as stock and the remaining as emergency units. ONeg issues increased with the number of fridges holding emergency units (ρ = 0.48, significance 0.046). No correlation was found between the number of fridges and ONeg wastage or ONeg-to-ONeg use. A longer unit shelf life on rotation back to stock was associated with lower wastage (ρ = -0.597, significance 0.009).Although there was a weak correlation between fridge numbers and overall percentage ONeg use, there was no correlation with ONeg wastage.

Properties of the TRIUMF neutron beam (4A2) are presented and compared with a Monte Carlo prediction. The beam intensity profile, energy spectrum and polarization are predicted taking into account the beamline geometry, energy losses in the LD2 production target, the properties of the pd → npp reaction, and the scattering of neutrons from the collimator walls. The results allow for improved corrections to systematic errors in a number of TRIUMF neutron experiments.

Charge symmetry breaking in np elastic scattering at 347 MeV has been measured with high precision. From fits of the measured asymmetry curves over the angular range 53.4{degree} {le} {theta}{sub cm} {le} 86.9{degree}, the difference in the center-of-mass zero-crossing angles of the analyzing powers was determined to be 0.438{degree} {+-} 0.054{degree} (stat.) {+-} 0.051{degree} (syst.). Using the experimentally determined slope of the analyzing power, dA/d{theta} = ({minus}1.35 {+-} 0.05) {times} 10{sup {minus}2} deg{sup {minus}1}, this is equivalent to {Delta}A = [59 {+-} 7(stat.) {+-} 7(syst.) {+-} 2(syst.)] {times} 10{sup {minus}4}. Predictions of nucleon-nucleon interaction models based on meson exchange agree well with this result.

We have measured the relative differential cross section and spin observables for the reaction {ital np}{r_arrow}{ital pp}{pi}{sup {minus}} at 443 MeV. Our measurements have been compared with predictions of the model of Kloet and Lomon. Some of the variables show marked disagreement with predictions; for other variables there is surprisingly good agreement.

A large proportion of all platelet components are given to haematology patients. As there are risks associated with their transfusion, costs associated with production, and shortages may occur, it is important that their use is appropriate.The study was split into two parts, a survey to assess local practice guidelines and an assessment of platelet usage. A total of 123 hospitals completed the survey and 168 hospitals submitted data of 40 haematology patients over a 3-month period.The organizational survey found that 36% of hospitals routinely give prophylactic platelet transfusions to patients with long-term bone-marrow failure. Also, a significant minority of hospitals administer platelet transfusions if the platelet count is below a certain threshold prior to performing a bone-marrow aspirate (11%) or a bone-marrow aspirate and trephine (23%); both of these are contrary to UK platelet transfusion guidelines. Data were collected on a total of 3402 patients, of which 3296 cases were eligible for analysis. They received approximately 46% of all platelet components issued to participating hospitals in England during the study period. The majority (69%) of platelet transfusions were prophylactic; of these only 33% were given when the platelet count was ≤10×10(9)/l. Using an algorithm, based on current UK guidelines, 60% of prophylactic transfusions were appropriate, 6% could not be assessed and 34% were inappropriate. A total of 10% of all prophylactic transfusions were double the standard adult dose.There is considerable potential for decreased use of platelet transfusions with a consequent improvement in their appropriate use and cost reduction.

Background and Objective: All pregnant women undergoing blood grouping at Southmead Hospital are offered haemoglobinopathy screening by high-performance liquid chromatography (HPLC). RhD-negative women who deliver RhD-positive infants are tested for fetomaternal haemorrhage (FMH) by acid elution (AE). The effectiveness of these two assays for quantitation of FMH was compared with flow cytometry (FC). Materials and Methods: The relationship between expression of haemoglobin F (HbF) in individual cells by AE and FC and quantitation of HbF in haemolysates by HPLC was investigated, using maternal samples with unusually high levels of HbF-positive maternal cells (F cells) or with large FMH (fetal cells). Standard anti-D FC was performed to quantitate fetal D-positive cells in D-negative women and compared with FMH estimated by AE and HbF FC. Results: AE overestimated FMH when maternal F cells were increased. HbF FC distinguished F cells from fetal cells. Values of HbF determined by HPLC were less than the level of 5% used for investigation of raised fetal haemoglobin, even in the maternal samples with elevated F cells or massive FMH. Conclusions: To quantitate FMH, measurement of HbF using FC was more sensitive and accurate than AE or HPLC. HbF FC is the method of choice when results from routine investigation using AE or standard anti-D FC are discrepant or when there is maternal and fetal RhD compatibility.

The parity-violating (PV) asymmetry of inclusive π- production in electron scattering from a liquid deuterium target was measured at backward angles. The measurement was conducted as a part of the G0 experiment, at a beam energy of 360 MeV. The physics process dominating pion production for these kinematics is quasifree photoproduction off the neutron via the Δ^0 resonance. In the context of heavy-baryon chiral perturbation theory, this asymmetry is related to a low-energy constant d_Δ^- that characterizes the parity-violating γNΔ coupling. Zhu et al. calculated d_Δ^- in a model benchmarked by the large asymmetries seen in hyperon weak radiative decays, and predicted potentially large asymmetries for this process, ranging from A_γ^-=-5.2 to +5.2 ppm. The measurement performed in this work leads to A_γ^-=-0.36±1.06±0.37±0.03 ppm (where sources of statistical, systematic and theoretical uncertainties are included), which would disfavor enchancements considered by Zhu et al. proportional to V_(ud)/V_(us). The measurement is part of a program of inelastic scattering measurements that were conducted by the G0 experiment, seeking to determine the N-Δ axial transition form factors using PV electron scattering.

The parity-violating (PV) asymmetry of inclusive π- production in electron scattering from a liquid deuterium target was measured at backward angles. The measurement was conducted as a part of the G0 experiment, at a beam energy of 360 MeV. The physics process dominating pion production for these kinematics is quasifree photoproduction off the neutron via the Δ0 resonance. In the context of heavy-baryon chiral perturbation theory, this asymmetry is related to a low-energy constant d(Δ)- that characterizes the parity-violating γNΔ coupling. Zhu et al. calculated d(Δ)- in a model benchmarked by the large asymmetries seen in hyperon weak radiative decays, and predicted potentially large asymmetries for this process, ranging from A(γ)-=-5.2 to +5.2 ppm. The measurement performed in this work leads to A(γ)-=-0.36±1.06±0.37±0.03 ppm (where sources of statistical, systematic and theoretical uncertainties are included), which would disfavor enchancements considered by Zhu et al. proportional to V(ud)/V(us). The measurement is part of a program of inelastic scattering measurements that were conducted by the G0 experiment, seeking to determine the N-Δ axial transition form factors using PV electron scattering.

We have measured the beam-normal single-spin asymmetries in elastic scattering of transversely polarized electrons from the proton, and performed the first measurement in quasi-elastic scattering on the deuteron, at backward angles (lab scattering angle of 108 degrees) for Q2 = 0.22 GeV^2/c^2 and 0.63 GeV^2/c^2 at beam energies of 362 MeV and 687 MeV, respectively. The asymmetry arises due to the imaginary part of the interference of the two-photon exchange amplitude with that of single photon exchange. Results for the proton are consistent with a model calculation which includes inelastic intermediate hadronic (piN) states. An estimate of the beam-normal single-spin asymmetry for the scattering from the neutron is made using a quasi-static deuterium approximation, and is also in agreement with theory.

In the G0 experiment, performed at Jefferson Lab, the parity-violating elastic scattering of electrons from protons and quasi-elastic scattering from deuterons is measured in order to determine the neutral weak currents of the nucleon. Asymmetries as small as 1 part per million in the scattering of a polarized electron beam are determined using a dedicated apparatus. It consists of specialized beam-monitoring and control systems, a cryogenic hydrogen (or deuterium) target, and a superconducting, toroidal magnetic spectrometer equipped with plastic scintillation and aerogel Cerenkov detectors, as well as fast readout electronics for the measurement of individual events. The overall design and performance of this experimental system is discussed., Comment: Submitted to Nuclear Instruments and Methods

At TRIUMF we are measuring charge symmetry violation in np elastic scattering. If charge symmetry holds the analyzing powers A n and A p are equal. The measurements will therefore determine the difference from zero of ΔA ≡ A n − A p . The measurements are carried out in the vicinity where the analyzing powers cross zero in order to minimize systematic errors. A 350 MeV polarized ( P n ≅ 0.5) or unpolarized neutron beam is incident onto respectively an unpolarized or polarized ( P p ≅ 0.65) target of the butanol frozen spin type. A symmetric (about the beam axis and in the scattering plane) system of proton detectors and neutron arrays records neutron-proton coincidence events. The detection system allows measurements in the centre-of-mass angular range of 50°–90°.

An outline is given of an experiment to measure parity violation in p-p scattering at 230 MeV at TRIUMF. The parity-violating longitudinal analysing power A z will be measured to a precision of 2×10 −8 and will isolate the parity-violating 3 P 2 − 1 D 2 partial wave amplitude.

We have measured parity violating asymmetries in elastic electron-proton and quasi-elastic electrondeuteron scattering at backward electron angle. These measurements have been done at two momentum transfers : Q2 = 0.22 and 0.63 (GeV/c)2 . Together with our previous forward angle measurement [1], we can extract strange quark contributions to the electromagnetic form factors of the nucleon, as well as nucleon axial form factor coming from the neutral weak interaction. The results indicate a strange quark magnetic contribution close to zero at these Q2 , and a possible non zero strange quark electric contribution for the high Q2 . The first Q2 behavior measurement of the nucleon axial form factor in elastic electron scattering shows a good agreement with radiative corrections calculated at Q2 = 0 and with a dipole form using the axial mass determined in neutrino scattering.

We have measured parity-violating asymmetries in elastic electron-proton and quasi-elastic electron-deuteron scattering at Q^2 = 0.22 and 0.63 GeV^2. They are sensitive to strange quark contributions to currents in the nucleon, and to the nucleon axial current. The results indicate strange quark contributions of < 10% of the charge and magnetic nucleon form factors at these four-momentum transfers. We also present the first measurement of anapole moment effects in the axial current at these four-momentum transfers., 5 pages, 2 figures, changed references, typo, and content

A recent experiment, measuring the spin correlation parameter Ann in neutron-proton elastic scattering to a precision of ±0.03 at several energies in the range 200 to 500 MeV, required the polarization of the proton frozen-spin target used in the experiment to be known to an accuracy of ±2%. The calibration of the polarization of the frozen-spin target was accomplished through an experiment interleaved with the Ann experiment. An unpolarized proton beam, of an intensity comparable to the intensity of the neutron beam in the Ann experiment, was scattered at 24° (lab.) from the frozen-spin target at energies of 468 and 501 MeV. From the measured left-right asymmetries and knowledge of the proton-proton analyzing powers, Ay(24°, 468 MeV) = 0.4087±0.0060 and Ay(24°, 501 MeV) = 0.4204±0.0059, the target polarizations could be deduced. The weighted average of the ratios of the target polarization deduced in the scattering experiment and obtained from nuclear magnetic resonance measurements was found to be Pt(scattering)/Pt(NMR) = 0.962±0.008(stat)±0.021(sys)±0.014(sys) at 468 MeV and 0.950±0.005(stat)±0.020(sys)±0.013(sys) at 501 MeV. By dividing the target cell holding the butanol beads, as illuminated by the incident proton beam, in three parts (top, middle, and bottom), a determination of the average polarization for each of the three parts was made. A clear decrease of the polarization going from the top to the bottom of the target cell was found.

Two dual function intensity profile monitors have been designed for a measurement of parity violation in p -p scattering at about 230 MeV using longitudinally polarized protons. Each device contains a set of split secondary electron emission (SEM) foils to determine the median of the beam current distribution (in x and y). The split foils, coupled through servoamplifiers and operational amplifiers to upstream aircore steering magnets, have demonstrated the ability to hold the beam position stable to ±5 μm for beam position fluctuations up to 1000 Hz. These monitors also contain a set of foil strip planes giving information on the intensity distribution projected onto the two orthogonal axes, x and y. Data were acquired using 0.008 mm thick, 0.90 mm wide aluminum foil strips at 1.00 mm centers. The foil strip planes were able to determine the beam centroid to within ±3 μm after one hour of data taking with a 100 nA, 15 mm FWHM Gaussian beam.

We have measured the beam-normal single-spin asymmetry in elastic scattering of transversely-polarized 3 GeV electrons from unpolarized protons at Q^2 = 0.15, 0.25 (GeV/c)^2. The results are inconsistent with calculations solely using the elastic nucleon intermediate state, and generally agree with calculations with significant inelastic hadronic intermediate state contributions. A_n provides a direct probe of the imaginary component of the 2-gamma exchange amplitude, the complete description of which is important in the interpretation of data from precision electron-scattering experiments., 5 pages, 3 figures, submitted to Physical Review Letters; shortened to meet PRL length limit, clarified some text after referee's comments

Recombinant factor VIIa (rFVIIa) is licensed for use in patients with haemophilia and inhibitory allo-antibodies. It is also increasingly being used for off-license indications to prevent bleeding in operations where blood loss is likely to be high, and/or to stop bleeding that is proving difficult to control by other means.To assess the effectiveness of rFVIIa when used therapeutically to control active bleeding, or prophylactically to prevent (excessive) bleeding in patients without haemophilia.We searched the Cochrane Injuries Group's Specialised Register, CENTRAL, MEDLINE, EMBASE and other specialised databases up to March 2006. We also searched reference lists of articles and contacted experts in the field.Randomised controlled trials (RCTs) comparing rFVIIa with placebo, or one dose of rFVIIa with another, in any patient population with the exception of those with haemophilia. There was no restriction by outcomes examined, but this review focuses on mortality, blood loss or control of bleeding, red cell transfusion requirements, number of patients transfused and thromboembolic adverse events.Two authors independently assessed potentially relevant studies for inclusion. Data were extracted and methodological quality was examined. Studies using rFVIIa prophylactically and those using rFVIIa therapeutically have been considered separately. Data were pooled using fixed and random effects models, but random effects models were preferred because of the variability in clinical features of the included studies.Thirteen trials met the inclusion criteria; all were placebo-controlled double-blind RCTs. Six trials involving 724 participants examined the prophylactic use of rFVIIa; 379 received rFVIIa. There were no outcomes by which any observed advantage, or disadvantage, of rFVIIa over placebo could not have been observed by chance alone. There were trends in favour of rFVIIa for a number of outcomes, particularly the number of participants transfused, pooled RR 0.85 (95% CI 0.72 to 1.01) but this was balanced by a trend against rFVIIa with respect to thromboembolic adverse events, pooled RR 1.25 (95% CI 0.76 to 2.07). Seven trials involving 1214 participants examined the therapeutic use of rFVIIa; 687 received rFVIIa. There were no outcomes where any observed advantage, or disadvantage, of rFVIIa over placebo could not have been observed by chance alone. There was a trend in favour of rFVIIa for reducing mortality, RR 0.82 (95% CI 0.64 to 1.04), although no other clear trends in favour of rFVIIa were noted for other desired outcomes. Interpretation of these results must take into account one study which could not be included in the quantitative summary but which showed results strongly in favour of rFVIIa for the treatment of intra-cerebral haemorrhage. There was a trend against rFVIIa with respect to thromboembolic adverse events; the RR 1.50 (95% CI 0.86 to 2.62).Although rFVIIa has a role in the management of patients with haemophilia, its effectiveness as a more general haemostatic drug, either prophylactically or therapeutically, remains uncertain. Its effectiveness as a therapeutic agent, particularly for intra-cerebral haemorrhage, looks more encouraging than prophylactic use. The use of rFVIIa outside its current licensed indications should be very limited and its wider use await the results of ongoing and possibly newly commissioned RCTs. In the interim, rFVIIa use should be restricted to clinical trials.

Elastic and inelastic scattering of unpolarized and polarized protons by {sup 40}Ar nuclei for incident energies between 20 and 50 MeV has been studied by reanalyzing experimental scattering spectra for the 2{sup +}(1.46 MeV) and 3{sup -}(3.68 MeV) levels in the angular range 30 degree sign -160 degree sign for incident protons of energies of 25.1, 32.5, and 40.7 MeV. An isospin dependent soft-rotator coupled-channels optical model with the potential containing a dispersive term with a nonlocal contribution is used to analyze the data.

Neonatal alloimmune thrombocytopenia—caused by movement of maternal alloantibodies directed against fetal platelet antigens across the placenta—is the most common cause of severe neonatal thrombocytopenia.1 These alloantibodies cause thrombocytopenia, which may result in intracranial haemorrhage.2 3 Most cases arise unexpectedly, and prompt diagnosis and treatment are essential to reduce the chances of death and disability caused by the haemorrhaging.4 5 Neonatal alloimmune thrombocytopenia should be strongly suspected in cases of neonatal thrombocytopenia with no evidence of sepsis, systemic disease, or skeletal anomalies associated with thrombocytopenia, and where maternal idiopathic thrombocytopenic pupura has been excluded. We describe two cases with typical clinical presentations in which standard methods for detection of maternal antibodies gave negative results, and we show that empirical treatment with human platelet antigen 1a negative platelets yielded successful outcomes in both cases. A two day old girl presented with several left sided and secondary generalised tonic-clonic seizures. She had been delivered normally at full term, after an uneventful gestation. Neurological examination between seizures had normal results, and otherwise she was completely well. Her platelet count was 5x109/l, haemoglobin concentration was 158 g/l, and white cell count was 16.7x109/l. A magnetic resonance scan showed fresh extensive haemorrhage in the interhemispheric fissure and sulci (1). The brain and ventricles were normal. Viral swabs and culture showed no infectious cause for the thrombocytopenia. The baby's mother had a normal platelet count. Fig 1 Magnetic resonance image showing fresh extensive haemorrhage in the interhemispheric fissure and sulci (case 1) …

We have measured the efficiency, timing and pulse heights in several types of microstrip Gas Chambers with plastic substrates passivated with a thin Nickel layer. We used as active gas mixtures Argon/Isobutane and CF/sub 4//Isobutane. We placed the detectors in a secondary beam at TRIUMF tuned to a momentum of 100 MeV/c of pions, muons and electrons. Preliminary results indicate good efficiency for minimum ionizing particles in Argon/Isobutane mixtures but lesser efficiency in CF/sub 4/ based gases indicating the importance of high quality preamplifiers to increase the signal to noise ratio. >

TRIUMF experiment 497 has measured the parity violating longitudinal analyzing power, A_z, in pp elastic scattering at 221.3 MeV incident proton energy. This paper includes details of the corrections, some of magnitude comparable to A_z itself, required to arrive at the final result. The largest correction was for the effects of first moments of transverse polarization. The addition of the result, A_z=(0.84 \pm 0.29 (stat.) \pm 0.17 (syst.)) \times 10^{-7}, to the pp parity violation experimental data base greatly improves the experimental constraints on the weak meson-nucleon coupling constants h^{pp}_\rho and h^{pp}_\omega, and has implications for the interpretation of electron parity violation experiments., Comment: 17 pages RevTeX, 14 PostScript figures. Revised version with additions suggested by Phys. Rev. C

Haemorrhagic myocarditis is a rare but important complication of cyclophosphamide therapy. Echocardiographic identification of the disorder can be made. We believe that the ultrasound features of this disorder have not been previously reported.