238 research outputs found
Improvements in the bread-making quality and agronomic performance of Canadian spring wheats released between 1860 and 1986
Non-Peer ReviewedTwenty eight red spring wheat cultivars ranging from "Red Fife" to "Laura" in vintage were field-tested in each of four years (1989-1992). End-use quality analyses were performed on the grain harvested from three experiments. The objective of this study was to measure the rate of cultivar improvement for agronomic and bread-making quality performance. In the absence of disease, the more modern cultivars yielded 18% more than the cultivars released at the turn of this century. The yield advantage of the modern cultivars approached 30% under leaf rust disease pressure. Yield levels are estimated to be increasing at a rate of approximately 20+ kg/ha/yr. Protein quantity and quality have improved over time as has loaf volume. Improvements in agronomic, disease resistance and value-added performance have been off-set by a slight delay in maturity
Performance of standard height and semidwarf durum wheat cultivars under irrigation
Non-Peer ReviewedTall, intermediate, and semidwarf durum cultivars and experimental lines (22 in total) were evaluated at two irrigated sites in 1987. Both tall and intermediate height classes out-yielded the semidwarf group by a significant margin. The standard height durums had a protein content in the 15-16 % range. Starchy kernel content was low at both sites. Smudge and immature kernels resulted in lower CWAD grades but returns from growing durum would still have been greater than that obtained from a CWRS crop. These preliminary results suggest that there is potential for irrigated production of intermediate height cultivars such as Sceptre, Arcola, and Medora
Studies of superconductivity in U(Pt1-xPdx)3 for x < 0.006
We report measurements of the specific heat and resistivity (T < 1 K) for
high quality polycrystals of U(Pt1-xPdx)3 with x < 0.006. The Tc-x phase
diagram can be constructed, and superconductivity is destroyed for x = 0.006;
this is approximately the same concentration above which the onset of
large-moment antiferromagnetism is observed to occur. The splitting of the
double superconducting transition increases smoothly with increasing Pd
content, and is large enough that for Pd concentrations 0.004 < x < 0.006 only
the superconducting A-phase will be present.Comment: 8 pages total, 3 figures(proceedings SCES 98
Search for a quantum phase transition in U(Pt_(1-x)Pd_x)_3
Pd in U(Pt_{1-x}Pd_x)_3 suppresses the superconducting T_c to 0 K at critical
concentration x_c of 0.007 and induces a conventional AFM state for x > x_c.
The resistivity below 1 K shows a deviation from Fermi liquid behavior
described by a power law where the exponent ranges from 2 at x=0 to 1.6 for x =
x_c. This suggests that a quantum phase transition (QPT) may exist near x_c
associated with either the magnetic or superconducting transition temperature =
0 K. Transport for a sample with x = 0.004 < x_c has constant exponent of 1.77
as increasing pressure suppresses T_c to 0 K, suggesting that if a QPT exists
it may be associated with the magnetic transition.Comment: 2 pages, proceedings of LT2
A Systematic Review and Exploratory Meta-Analysis
The relationship between antiphospholipid antibodies (aPL) and sickle cell disease (SCD) has never been systematically addressed. Our aim was to evaluate potential links between SCD and aPL in all age groups. EMBASE/PubMed was screened from inception to May 2020 and Peto odds ratios for rare events were calculated. The pooled prevalence (PP) of IgG anticardiolipin antibodies (aCL) was higher in individuals with SCD than in controls (27.9% vs 8.7%, P < 0.0001), that of IgM aCL was similar in the two groups (2.9% vs 2.7%); only individuals with SCD were positive for lupus anticoagulant (LA) (7.7% vs 0%, P < 0.0001). The PP of leg ulcers was similar between aPL positive and negative individuals (44% vs 53%) and between patients in acute crisis and stable patients (5.6% vs 7.3%). Reporting of aPL as a binary outcome and not as a titer precluded further interpretation. The results indicate that a prospective case-control study with serial measurements of a panel of aPL in SCD patients might be warranted, in order to understand further the possible pathogenic role of aPL in SCD.publishersversionpublishe
A Systematic Review and Meta-Analysis
We evaluated the relevance of plasma homocysteine (HC) and the TT genotype of the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism (rs1801133) in sickle cell disease (SCD) and associated vaso-occlusive crisis (VOC) and ischemic stroke (IS). We identified in Embase and Medline 22 studies on plasma HC and 22 on MTHFR genotypes. Due to age-related HC differences, adult and paediatric SCD were separated: 879 adult SCD and 834 controls (CTR) yielded a neutral effect size; 427 paediatric SCD and 625 CTR favoured SCD (p = 0.001) with wide heterogeneity (I2 = 95.5%) and were sub-grouped by country: six studies (Dutch Antilles n = 1, USA n = 5) yielded a neutral effect size, four (India n = 1, Arab countries n = 3) favoured SCD (p < 0.0001). Moreover, 249 SCD in VOC and 419 out of VOC yielded a neutral effect size. The pooled prevalence of the MTHFR TT genotype in 267 SCD equalled that of 1199 CTR (4.26% vs. 2.86%, p = 0.45), and in 84 SCD with IS equalled that of 86 without IS (5.9% vs. 3.7%, p = 0.47); removal of one paediatric study yielded a significant effect size (p = 0.006). Plasma HC in paediatric SCD from Middle East and India was higher, possibly due to vitamin deficiencies. Despite its low prevalence in SCD, the MTHFR TT genotype relates to adult IS.publishersversionpublishe
Muon localization site in U(Pt,Pd)3
The angular and temperature (10-250 K) variation of the Knight shift of
single-crystalline U(Pt0.95Pd0.05)3 has been measured in transverse field
(B=0.6 T) mSR experiments. By analysing the temperature variation of the Knight
shift with a modified Curie-Weiss expression the muon localization site in this
hexagonal material is determined at (0,0,0).Comment: 12 pages (including 4 figures); postscript file; Proc. 8th Int. Conf.
on Muon Spin Rotation, Relaxation and Resonance (Aug.30-Sept.3, Les
Diablerets); 2nd version with minor correction
Antiferromagnetic Domains and Superconductivity in UPt3
We explore the response of an unconventional superconductor to spatially
inhomogeneous antiferromagnetism (SIAFM). Symmetry allows the superconducting
order parameter in the E-representation models for UPt3 to couple directly to
the AFM order parameter. The Ginzburg-Landau equations for coupled
superconductivity and SIAFM are solved numerically for two possible SIAFM
configurations: (I) abutting antiferromagnetic domains of uniform size, and
(II) quenched random disorder of `nanodomains' in a uniform AFM background. We
discuss the contributions to the free energy, specific heat, and order
parameter for these models. Neither model provides a satisfactory account of
experiment, but results from the two models differ significantly. Our results
demonstrate that the response of an E_{2u} superconductor to SIAFM is strongly
dependent on the spatial dependence of AFM order; no conclusion can be drawn
regarding the compatibility of E_{2u} superconductivity with UPt3 that is
independent of assumptions on the spatial dependence of AFMComment: 12 pages, 13 figures, to appear in Phys. Rev.
A Logic with Reverse Modalities for History-preserving Bisimulations
We introduce event identifier logic (EIL) which extends Hennessy-Milner logic
by the addition of (1) reverse as well as forward modalities, and (2)
identifiers to keep track of events. We show that this logic corresponds to
hereditary history-preserving (HH) bisimulation equivalence within a particular
true-concurrency model, namely stable configuration structures. We furthermore
show how natural sublogics of EIL correspond to coarser equivalences. In
particular we provide logical characterisations of weak history-preserving (WH)
and history-preserving (H) bisimulation. Logics corresponding to HH and H
bisimulation have been given previously, but not to WH bisimulation (when
autoconcurrency is allowed), as far as we are aware. We also present
characteristic formulas which characterise individual structures with respect
to history-preserving equivalences.Comment: In Proceedings EXPRESS 2011, arXiv:1108.407
Orbital and spin contributions to the -tensors in metal nanoparticles
We present a theoretical study of the mesoscopic fluctuations of -tensors
in a metal nanoparticle. The calculations were performed using a semi-realistic
tight-binding model, which contains both spin and orbital contributions to the
-tensors. The results depend on the product of the spin-orbit scattering
time and the mean-level spacing , but are
otherwise weakly affected by the specific shape of a {\it generic}
nanoparticle. We find that the spin contribution to the -tensors agrees with
Random Matrix Theory (RMT) predictions. On the other hand, in the strong
spin-orbit coupling limit , the
orbital contribution depends crucially on the space character of the
quasi-particle wavefunctions: it levels off at a small value for states of
character but is strongly enhanced for states of character. Our numerical
results demonstrate that when orbital coupling to the field is included, RMT
predictions overestimate the typical -factor of orbitals that have dominant
-character. This finding points to a possible source of the puzzling
discrepancy between theory and experiment.Comment: 21 pages, 6 figures; accepted for publication in Physical Review
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