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UDC 517.9 A new mathematical model described by a Volterra integro-differential equation (VIDE) with constant delay is examined. New agreeable conditions on the uniformly asymptotic stability, boundedness, and square integrability of solutions of the VIDE are obtained by using the Lyapunov–Razumikhin technique. The established conditions improve some former results and they are also nonlinear generalizations of these results. Moreover, they are weaker than some available results cited in the bibliography of this paper. Two examples are presented to demonstrate applications of these results and the introduced concepts. The use of the Lyapunov–Razumikhin technique leads to a significant difference and gives an advantage over the related methods used in the books and papers cited in the bibliography.

Electroless nickel plating is an established industrial process that provides a robust and relatively low-cost coating suitable for transporting and storing ultracold neutrons (UCN). Using roughness measurements and UCN-storage experiments we characterized UCN guides made from polished aluminum or stainless-steel tubes plated by several vendors. All electroless nickel platings were similarly suited for UCN storage with an average loss probability per wall bounce of $2.8\cdot10^{-4}$ to $4.1\cdot10^{-4}$ for energies between 90 neV and 190 neV, or a ratio of imaginary to real Fermi potential $\eta$ of $1.7\cdot10^{-4}$ to $3.3\cdot10^{-4}$. Measurements at different elevations indicate that the energy dependence of UCN losses is well described by the imaginary Fermi potential. Some special considerations are required to avoid an increase in surface roughness during the plating process and hence a reduction in UCN transmission. Increased roughness had only a minor impact on storage properties. Based on these findings we chose a vendor to plate the UCN-production vessel that will contain the superfluid-helium converter for the new TRIUMF UltraCold Advanced Neutron (TUCAN) source, achieving acceptable UCN-storage properties with ${\eta=3.5(5)\cdot10^{-4}}$., Comment: 8 pages, 7 figures

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.

WOS:000467904700006 Overall and melamine migration have been determined for 60 samples of melamine resin bowls, which were purchased in various local markets in the area of Bursa, Turkey. The samples were exposed to food simulants 3% acetic acid, 10% ethanol aqueous solutions, and rectified (refined) olive oil at 100 degrees C for 30 min, and 50% ethanol aqueous solutions at 60 degrees C for 30 min. The LOQ value was calculated as 3.3 mg dm(-2) for overall migration and 0.126 mg kg(-1) for melamine migration. Research findings did not exceed the limit of overall migration level (10 mg dm(-2)). Also, melamine levels of all tested items found in the third assays were below the specific migration limit (SML) of 2.5 mg kg(-1) set out in the EU 10/2011 (EU, 2011) and Turkish Food Codex 2013/34 (TFC, 2013a). Some expensive as well as cheap products showed close migration levels. The increased cost of the item did not indicate a higher quality regarding health in this study. Republic of Turkey Ministry of Food, Agriculture and Livestock, General Directorate of Agricultural Research and Policies [TAGEM/HSGYAD/14/A05/P01/48] This study was funded by the Republic of Turkey Ministry of Food, Agriculture and Livestock, General Directorate of Agricultural Research and Policies (Project No: TAGEM/HSGYAD/14/A05/P01/48) and the research was conducted in Central Research Institute of Food and Feed Control (16036 Bursa, Turkey).

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

Objective: Endothelial dysfunction plays an important role in the development of heart diseases. Although several markers have been examined, a definitive biomarker for monitoring endothelial function has not yet been established. The flow-mediated dilatation (FMD) of the brachial artery enables non-invasive assessment of endothelial function. This study investigated plasma levels of nitric oxide (NO), asymmetric dimethylarginine (ADMA), total antioxidant capacity (TAC), and hydrogen sulfide (H2S) as biomarkers of endothelial function. This study aimed to investigate any correlation between FMD and these blood biomarkers in patients with diabetes mellitus (DM), prediabetes (preDM), coronary artery disease (CAD), and valvular heart disease (VD). Materials and Methods: Prospective evaluation was made within five groups of patients with preDM, DM, CAD, VD, and healthy controls. The FMD of the brachial artery was examined using Doppler imaging, and biomarker levels in plasma were measured by spectrophotometry. Results: The FMD of the VD group was significantly higher than that of DM and CAD groups. Plasma NO levels of CAD and VD groups were significantly lower than those of the control group. ADMA levels were lower in the CAD group. TAC and H2S levels were comparable in all groups. The FMD of the brachial artery was negatively correlated with plasma NO and cholesterol levels in all groups. Conclusion: These results suggested that the correlation of FMD with blood biomarkers related to endothelial function was altered in cardiovascular diseases and would be affected by the patient's clinical state and treatment.

The aim of this study was to Anatolian High schools serving school administrator and teachers of schools effective scho ol is to identify their views to be.The research uses the relational scan model universe of Ankara Anatolian High schools in the province who has work with teachers, school administrators.The sample of the survey is appropriate sampling through the unive rse via consists of 300 teachers selected.Participants from data obtained using the scale Effective Schools, t-test and one-way analysis of variance has been tested with.Study participants are students of effective school size, school environment and parents size views.School leaders and teachers in the province of Anatolia Ankara, according to see high schools the most effective within the context of effective school sizes size after school environment, students, the least effective size is the size of the parents.School environment, students and parents in dimensions of effectiveness of Anatolian province of Ankara high Schoosl opinions with regard to the size of the property between the school environment teachers were found significant difference between administrators.Student teachers, about the size of the part of the administrators of the school considers it more effective.Pa rents in the property managers with significant difference between the opinions of teachers could not be found.To increase the effe ctiveness of the schools at the end of the research proposals.

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"

A fast-switching, high-repetition-rate magnet and power supply have been developed for and operated at TRIUMF, to deliver a proton beam to the new ultracold neutron (UCN) facility. The facility possesses unique operational requirements: a time-averaged beam current of 40~$\mu$A with the ability to switch the beam on or off for several minutes. These requirements are in conflict with the typical operation mode of the TRIUMF cyclotron which delivers nearly continuous beam to multiple users. To enable the creation of the UCN facility, a beam-sharing arrangement with another facility was made. The beam sharing is accomplished by the fast-switching (kicker) magnet which is ramped in 50~$\mu$s to a current of 193~A, held there for approximately 1~ms, then ramped down in the same short period of time. This achieves a 12~mrad deflection which is sufficient to switch the proton beam between the two facilities. The kicker magnet relies on a high-current, low-inductance coil connected to a fast-switching power supply that is based on insulated-gate bipolar transistors (IGBTs). The design and performance of the kicker magnet system and initial beam delivery results are reported., Comment: 16 pages, 21 figures

This article describes the new primary proton beamline 1U at TRIUMF. The purpose of this beamline is to produce ultracold neutrons (UCN) for fundamental-physics experiments. It delivers up to 40 µA of 480 MeV protons from the TRIUMF cyclotron to a tungsten spallation target and uses a fast kicker to share the beam between the Center for Molecular and Materials Science and UCN. The beamline has been successfully commissioned and operated with a beam current up to 10 µA, facilitating first large-scale UCN production in Canada. This article describes the new primary proton beamline 1U at TRIUMF. The purpose of this beamline is to produce ultracold neutrons (UCN) for fundamental-physics experiments. It delivers up to 40 microA of 480 MeV protons from the TRIUMF cyclotron to a tungsten spallation target and uses a fast kicker to share the beam between the Center for Molecular and Materials Science and UCN. The beamline has been successfully commissioned and operated with a beam current up to 10 microA, facilitating first large-scale UCN production in Canada.

We installed a source for ultracold neutrons at a new, dedicated spallation target at TRIUMF. The source was originally developed in Japan and uses a superfluid-helium converter cooled to 0.9$\,$K. During an extensive test campaign in November 2017, we extracted up to 325000 ultracold neutrons after a one-minute irradiation of the target, over three times more than previously achieved with this source. The corresponding ultracold-neutron density in the whole production and guide volume is 5.3$\,$cm$^{-3}$. The storage lifetime of ultracold neutrons in the source was initially 37$\,$s and dropped to 24$\,$s during the eighteen days of operation. During continuous irradiation of the spallation target, we were able to detect a sustained ultracold-neutron rate of up to 1500$\,$s$^{-1}$. Simulations of UCN production, UCN transport, temperature-dependent UCN yield, and temperature-dependent storage lifetime show excellent agreement with the experimental data and confirm that the ultracold-neutron-upscattering rate in superfluid helium is proportional to $T^7$., 8 pages, 10 figures

© 2018 Chemical Publishing Co. All rights reserved.The UV absorption spectra were processed by using the continuous wavelet transform for the determination of dexamethasone in tablets. In order to get optimal wavelet transform, some wavelet families were tested to transform the UV-absorption spectra of the related drug in the spectral region of 210.0-312.3 nm. In the test procedure of wavelet families, it was observed that Mexican hat function-continuous wavelet transform (mexh-CWT) and Daubechies 8-continuous wavelet transform (db8-CWT) were appropriate for the UV spectra for the quantitative estimation of dexamethasone. The validity of proposed continuous wavelet transform signal analysis methods were performed by using the analysis results of the solutions for validation samples. In the method validation studies, the percent recoveries and their relative standard deviations were found as 100.7 % and 0.78 for mexh-CWT procedure and 100.2 % and 1.28 for db8-CWT procedure. It was concluded that both mexh-CWT and db8-CWT methods were useful approaches for the determination of dexamethasone in tablets.

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.

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.

58th Annual Meeting of the American-Society-for-Radiation-Oncology (ASTRO) -- SEP 25-28, 2016 -- Boston, MA, WOS: 000387655803484, …, Amer Soc Radiat Oncol

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.

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

In this study, the levels of the natural and artificial radioactivity in soil samples collected from surrounding of Karaman in Turkey were measured. Activity concentrations of the concerned radionuclides were determined by gamma-ray spectrometry using a high-purity germanium detector with a relative efficiency of 40 % at 1.332 MeV. The results obtained for the (238)U series ((226)Ra, (214)Pb and (214)Bi), (232)Th series ((228)Ac), (40)K and fission product (137)Cs are discussed. To evaluate the radiological hazard of radioactivity in samples, the radium equivalent activity (Raeq), the absorbed dose rate (D), the annual effective dose and the external (Hex) and internal hazard index (Hin) were calculated and presented in comparison with the data collected from different areas in the world and Turkey.

AIMS—To determine whether an increase in vascular resistance in the central retinal and ophthalmic arterial circulations contributes to the development of central retinal vein occlusion (CRVO), or haemodynamic alterations in central retinal and ophthalmic arteries occur secondary to the vein occlusion as increased intravascular pressure is transferred through the capillary bed to the arterial side and the effect of panretinal photocoagulation treatment on these circulations in ischaemic cases. METHODS—The ophthalmic and central retinal arteries of the affected and non-affected eyes of 20 patients with non-ischaemic CRVO, 13 patients with ischaemic CRVO, and 22 control subjects were investigated by colour Doppler imaging. Panretinal photocoagulation (PRP) treatment was applied to the eyes with ischaemic CRVO. Maximum and minimum blood flow velocities, and resistivity indexes were calculated in the affected and healthy eyes of patients and in the control eyes. RESULTS—Average blood flow velocity in the central retinal and ophthalmic arteries of patients with non-ischaemic CRVO did not differ from their fellow eyes, but a significantly lower average blood flow velocity was found in the ophthalmic and central retinal arteries of the patients with ischaemic CRVO compared with their fellow eyes. Patients with ischaemic CRVO had significantly lower blood flow velocities in their ophthalmic and central retinal arteries than non-ischaemic cases that were further reduced following PRP treatment. CONCLUSION—This study suggests that impaired arterial blood flow observed in patients with CRVO may be partly related to secondary changes in the retrobulbar arterial circulation as a result of enhanced arterial resistance following CRVO. These data also demonstrate that PRP treatment decreases retinal and ophthalmic blood flow velocities in patients with ischaemic CRVO. Keywords: central retinal vein occlusion; panretinal photocoagulation; arterial circulation; colour Doppler imaging

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.

Due to copyright restrictions, the access to the full text of this article is only available via subscription. Clustering is a common technique, in all areas where information is obtained from the collected data. In this work, three well-known clustering algorithms namely, K-means, Spectral and DBSCAN are investigated in terms of their validity using four clustering validity indexes, Rand, Adjusted Rand, Jaccard, Silhouette. These clustering algorithms are applied on three data sets which have different characteristics. Thus steps have been taken for an automated clustering optimization system. TÜBİTAK ; European Commission

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

Planar drift chambers will be used in a solenoidal magnetic field to measure the Michel parameters in muon decay. The chamber manufacture procedure uses flat glass tables and precise ceramic glass spacers to provide precise anode– cathode spacing. Results of bench and beam tests of the prototype chambers are discussed. # 2001 Elsevier Science B.V. All rights reserved.

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

This prospective study was designed to investigate the effects of hormone replacement therapy (HRT) on systolic and diastolic functions. Twenty-eight non-smoking, healthy postmenopausal women who had not received any kind of HRT for at least three years within the onset of menopause were included in the study. All patients received 0.625 mg conjugated oestrogens and 2.5 mg medroxyprogesterone acetate as daily HRT regimen. Their basic systolic and diastolic functions were investigated echocardiographically using standard positions and windows before and 6 months after initiation of HRT. The means of age, weight and length of postmenopausal period were 49.3 +/- 5.8 years, 63.5 +/- 8.7 kg and 46.3 +/- 7.1 months, respectively. Heart rate and systolic and diastolic pressures were similar during the pre- and post-treatment periods. After 6 months of HRT, the mean left ventricular end-systolic and end-diastolic volumes were decreased significantly (71.3 +/- 16.4 versus 56.3 +/- 22.8 ml, 144.5 +/- 26.1 versus 111.7 +/- 24.0 ml, respectively, P < 0.05). Left ventricular ejection fraction was increased (45.1 +/- 6.2% versus 54.8 +/- 4.1%, P < 0.05). Improvement in diastolic function was significant compared with the pretreatment period (E/A 0.90 +/- 0.2 versus 1.10 +/- 0.4, deceleration time 238 +/- 36.8 versus 201 +/- 24.2 ms, respectively, P < 0.05). Based on our preliminary results, we conclude that besides the known favourable effects on women's lives, HRT may also improve cardiac performance and age-related dysfunctions. The present results further suggest that oestrogens exert many direct effects on the cardiovascular system, other than the metabolic changes related to lipoproteins.

The forward-backward asymmetry in np → dπ 0 , which must be zero in the center-of-mass system if charge symmetry is respected, has been measured to be [17.2 ′ 8.0(stat) ′ 5.5(syst)] × 10 - 4 , at an incident neutron energy of 279.5 MeV. This observable is compared to recent chiral effective field theory calculations, with implications regarding the du quark mass difference.

Background: Transmitral Doppler flow indices are used to evaluate diastolic function. Recently, velocities measured by Doppler tissue imaging have been used as an index of left ventricular relaxation. Objective: To determine whether Doppler tissue velocities are influenced by alterations in preload. Methods: Left ventricular preload was altered in 17 patients (all men, mean (SD) age, 49 (8) years) during echocardiographic measurements of left ventricular end diastolic volume, maximum left atrial area, peak early Doppler filling velocity, and left ventricular myocardial velocities during early filling. Preload altering manoeuvres included Trendelenberg (stage 1), reverse Trendelenberg (stage 2), and amyl nitrate (stage 3). Systolic blood pressure was measured at each stage. Results: In comparison with baseline, left ventricular end diastolic volume (p = 0.001), left atrial area (p = 0.003), peak early mitral Doppler filling velocity (p = 0.01), and systolic blood pressures (p = 0.001) were all changed by preload altering manoeuvres. Only left ventricular myocardial velocity during early filling remained unchanged by these manoeuvres. Conclusions: In contrast to standard transmitral Doppler filling indices, Doppler tissue early diastolic velocities are not significantly affected by physiological manoeuvres that alter preload. Thus Doppler tissue velocities during early left ventricular diastole may provide a better index of diastolic function in cardiac patients by providing a preload independent assessment of left ventricular filling.

TRIUMF Experiment 369, a measurement of charge symmetry breaking in np elastic scattering at 350 MeV, has completed data taking. Scattering asymmetries were measured with a polarized (unpolarized) neutron beam incident on an unpolarized (polarized) frozen spin target. Coincident scattered neutrons and recoil protons were detected by a mirror symmetric detection system in the center‐of‐mass angle range from 50°–90°. A preliminary result for the difference of the zero‐crossing angles, where analyzing powers cross zero, is Δθcm =0.445°±0.054°(stat.)±0.051°(syst.) based on fits over the angle range 53.4°≤θcm≤86.9°. The difference of the analyzing powers ΔA≡An−Ap, where the subscripts denote polarized nucleons, was deduced with dA/dθcm=(−1.35±0.05)×10−2 deg−1 to be [60±7(stat.)±7(syst.)±2(syst.)] ×10−4.

The zero point of the analyzing power for neutron‐proton scattering has been measured as a function of scattering angle for 4 incident neutron energies, 174.3, 202.4, 216.5, and 260.3 MeV. The accuracy is ±0.25°. (AIP)

The analyzing power behavior and the isospin-dependence of the cross sections for near-threshold /sup 13/C(/rvec p/,..pi../sup +-/) and /sup 12/C(/rvec p/,..pi../sup +/) reactions are compared with expectations from pion production measurements in free two-nucleon collisions. The general agreement for (/rvec p/,..pi../sup +/) suggests that the stable analyzing power pattern observed for (/rvec p/,..pi../sup /minus//) continuum transitions may reflect the as yet unmeasured free /rvec p/n ..-->.. pp..pi../sup /minus// behavior. We also discuss constraints imposed by quasifree /rvec N/N ..-->.. NN..pi.. expectations on the interpretation of anomalous (/rvec p/,..pi../sup +/) results for two strongly populated states at high excitation in /sup 13,14/C. 21 refs., 3 figs.