[en] The initial analyzing power calibration of the polarimeter POMME at SATURNE has been extended with measurements at 1.05, 1.35, 1.6, 1.8, 2.0, 2.24 and 2.40 GeV proton energy. Very low intensity polarized proton beams were send straight through the spectrometer SPES 4, with the polarimeter POMME in the final focal plane. All measurements were made with 31.2 cm of graphite with density 1.7 g cm^-2. Sixteen parameter fits for several ranges of energies will be presented

[en] AD/sup v/ cells are Chinese hamster ovary (CHO) cell variants which cannot adhere to fibronectin coated substrata. The authors have shown that the defect in some clones of AD/sup v/ cells is distal to the initial interaction between fibronectin and its cell surface receptors, and that it extends to fibronectin medicated aggregation and endocytosis. The adhesion defect in some AD/sup v/ clones can be corrected by raising intracellular cAMP levels. Here they examine the protein kinase activities and phosphorylation patterns in an adhesion defective variant clone AD/sup v/F11CA11. Analysis of the cAMP dependent protein kinase activity (cAdPK) in crude extracts of F11CA11 cells shows an apparent increase in K (activation) as compared to wild type (WT) CHO cell extracts. Binding studies with ³H-cAMP reveal that the type I peak in F11CA11 has a K/sub d/ of 1.7 x 10⁰⁸ M as compared to 2.0 x 10⁰⁹ M for WT, whereas the type II peak K/sub d/ is approximately 1 x 10 ⁰⁹ M for both WT and F11CA11. Two-dimensional polyacrylamide gel analysis of ³²Pi labeled WT cells and F11CA11 cells with or without cAMP treatment reveals the presence of a protein(s) of 50 kilodaltons which is phosphorylated in WT cells and in cAMP treated F11CA11 cells but not in untreated F11CA11 cells. These findings, coupled with previous observations, strongly indicate that the adhesion defect in AD/sup v/F11CA11 cells is associated with an altered type I cAdPK having lower affinity for cAMP. At normal cellular cAMP levels this enzyme fails to phosphorylate one or more critical protein substrates; however, by raising internal cAMP levels, the defect can be overcome

[en] One stable form (Form I) and two metastable forms (Forms II and IV) of p-methylchalcone have been obtained, with Form II having previously been reported to be a disappearing polymorph. To prevent the conversion of Form II, which has a melting point of 89-91 C, into the stable form it was produced in conditions free from seeds of the stable form. Form IV was discovered serendipitously as a single crystal that appeared in the preparation of a powder of Form II. Forms I and II have also been characterized by optical microscopy, differential scanning calorimetry (DSC), variable temperature powder X-ray diffraction, and spectroscopic analysis. The crystal structures of these three forms have been solved, Forms I and IV by single-crystal methods and Form II from synchrotron powder diffraction. This investigation highlights the fact that the challenges of reproducing experimental results (i.e., the production of a particular crystal form) may be overcome by a systematic search for new conditions under which previously obtained results can be regained.

[en] Rapid mixing of ferrocytochrome c peroxidase [cyt c peroxidase(II)] and ferricytochrome c [cyt c(III)] results in the reduction of cyt c(III) by cyt c peroxidase(II). In 10 mM phosphate, pH 7.0, the rate of decay of cyt c peroxidase(II) and the rate of accumulation of cyt c(II) give equal first-order rate constants. Equivalent results are obtained by pulse radiolysis using isopropanol radical as the reducing agent. This rate is independent of the initial cyt c(III):cyt c peroxidase(II) ratios. These results are consistent with unimolecular electron transfer occurring within a cyt c(III)-cyt c peroxidase(II) complex. When cyt c is replaced by porphyrin cyt c (iron-free cyt c), a complex still forms with cyt c peroxidase. On radiolysis intracomplex electron transfer occurs from the porphyrin cyt c anion radical to cyt c peroxidase(III). This large rate increase suggest that the barrier for intracomplex electron transfer is large. Finally, the authors have briefly investigated how the cyt c peroxidase(II) → cyt c(III) rate depends on the primary structure of cyt c(III). They find the reactivity order to be as follows: yeast > horse > tuna

[en] The spectral function for p-n pairs in the ⁶Li ground state (i.e., the distribution in p-n relative momentum ℎk for pairs whose c.m. is at rest in the laboratory) was measured for k ranging from 0.6 to 1.5 fm^-1, using the ⁶Li(p,pα)pn reaction at 200 MeV. These and earlier 120 MeV ⁶Li(α,2α)pn measurements show that, when k increases from 0.1 to 1.5 fm^-1, this function decreases by 4 orders of magnitude and is predicted within a factor of 2 by the plane-wave impulse approximation. The asymmetry for the ⁶Li(p,pα)pn reaction induced with polarized protons was measured at 56 degree c.m. and found to have the same bombarding-energy dependence as that for p-α elastic scattering. The d-α cluster probability of ⁶Li, determined by the ⁶Li(p,pα)d reaction, was consistent with that found in other intermediate-energy experiments

[en] The analyzing power T₂₀ in the inclusive ¹H(⁶Li,d or α or t)X reaction with 4.5 GeV tensor polarized ⁶Li nuclei has been measured at an angle of 0.8 degree. The kinematics chosen favor the detection of spectator fragments; in the impulse approximation the laboratory momentum of such a fragment is then the Lorentz boosted internal momentum. Nonzero T₂₀ values have been observed, in agreement with the known nonsphericity of ⁶Li indicated by its quadrupole moment. The sign of T₂₀ in the d channel suggests that near q=0 the D state in ⁶Li has the same sign as in the deuteron; an abrupt change of sign near q=0.12 GeV/c is in agreement with theoretical expectation of a node in the αd position wave function. The α-channel data show larger T₂₀ values than the d channel; in this case the small-q-region has not been explored enough to establish a similar node. A few data points in the t channel might suggest that T₂₀ becomes positive above q=0.4 GeV/c in this case

[en] The polarization of the proton from the inclusive breakup reaction ¹H(d vector, p vector)X at 2.1 GeV was measured at 0deg. The results are expressed as the ratio of the proton polarization, P_p, to the deuteron beam polarization, P_d, κ₀=P_p/P_d. The measured values of κ₀ range from +0.983 to -0.305 and are in general agreement with the expected behavior arising from the D state in the deuteron wave function. (orig.)

[en] The tensor analyzing power T₂₀ and the ratio of the polarization of the backward scattered proton to the vector polarization of the incident deuteron, κ₀, for the dp backward elastic reaction were measured. The kinetic energy of the deuteron beam was varied between 0.3 and 2.34 GeV; the elastic protons were detected at a fixed 1.7 degree in the laboratory. The values of T₂₀ and κ₀ obtained are different from those obtained in recent studies of the 0 degree inclusive breakup reaction dp→pX at the same values of the internal momentum variable k calculated in the infinite momentum frame. However the data from these two reactions are almost identical when compared in T₂₀ versus κ₀ correlation plots. We discuss similarities and differences observed in the two reactions which, we argue, support the premise that the two reactions are closely related, as their respective impulse approximation graphs suggest. copyright 1995 American Institute of Physics

[en] We present global structural parameter measurements of 109,533 unique, H_F160W-selected objects from the CANDELS multi-cycle treasury program. Sérsic model fits for these objects are produced with GALFIT in all available near-infrared filters (H_F160W, J_F125W and, for a subset, Y_F105W). The parameters of the best-fitting Sérsic models (total magnitude, half-light radius, Sérsic index, axis ratio, and position angle) are made public, along with newly constructed point-spread functions for each field and filter. Random uncertainties in the measured parameters are estimated for each individual object based on a comparison between multiple, independent measurements of the same set of objects. To quantify systematic uncertainties, we create a mosaic with simulated galaxy images with a realistic distribution of input parameters and then process and analyze the mosaic in an identical manner as the real data. We find that accurate and precise measurements—to 10% or better—of all structural parameters can typically be obtained for galaxies with H_F160W < 23, with comparable fidelity for basic size and shape measurements for galaxies to H_F160W ∼ 24.5.

[en] With the observation of high-energy astrophysical neutrinos by the IceCube Neutrino Observatory, interest has risen in models of PeV-mass decaying dark matter particles to explain the observed flux. We present two dedicated experimental analyses to test this hypothesis. One analysis uses 6 years of IceCube data focusing on muon neutrino 'track' events from the Northern Hemisphere, while the second analysis uses 2 years of 'cascade' events from the full sky. Known background components and the hypothetical flux from unstable dark matter are fitted to the experimental data. Since no significant excess is observed in either analysis, lower limits on the lifetime of dark matter particles are derived: we obtain the strongest constraint to date, excluding lifetimes shorter than 10²⁸ s at 90% CL for dark matter masses above 10 TeV. (orig.)