391 research outputs found
Evaluating the competitive ability of semi-leafless field pea cultivars
Non-Peer ReviewedField pea (Pisum sativum L.) is an important grain legume in Western Canada. Growers can, however, be reluctant to include pulse crops in their rotation because they are poor competitors with weeds. Developing more competitive field pea cultivars is important to ameliorate weed competition. The identification of competitive cultivars and the traits conferring competitive ability should lead to the development of more competitive field pea cultivars. The objective of this research was to evaluate the ability of semi-leafless field pea cultivars to suppress and withstand weed competition and to identify traits that may confer competitive ability in field pea. Field experiments were conducted in 2012 at Floral, Saskatchewan and St. Albert, Alberta. Fourteen semi-leafless field pea cultivars with divergent pedigree, vine length, seed size, and market classes were seeded at a target density of 75 plants m-2 under weedy and weed-free conditions. Imidazolinone-tolerant wheat (c.v. CDC Imagine) and canola (c.v. 45H73) were planted as pseudo weeds at a target density of 20 plants m-2 in the weedy plots. Variables measured were leaf area index, plant height, pea biomass, weed biomass, pea yield, and weed seed production. Data were subjected to ANOVA using the mixed model procedure in SAS. There was no cultivar by treatment interaction for pea yield at Floral, so cultivars did not differ under treatments. CDC Dakota produced the greatest pea yield and Reward produced the poorest pea yield. CDC Dakota was among the best for pea biomass production at both sites, compared to CDC Leroy, which was among the worst at both sites. CDC Dakota was also among the best for the low weed seed production at Floral. CDC Mozart, CDC Patrick, and Cutlass were among the best at Floral for ability to withstand competition at Floral. While, CDC Dakota, CDC Meadow, and CDC Patrick were among the best for their ability to compete at Floral. At both sites, no correlations were strong enough to show which traits are conferring competitiveness in semi-leafless field pea cultivars
Evaluating the competitive ability of semi-leafless field pea cultivars
Non-Peer ReviewedField pea (Pisum sativum L.) is an important grain legume in Western Canada. Growers can, however, be reluctant to include pulse crops in their rotation because they are poor competitors with weeds. Developing more competitive field pea cultivars is important to mitigate weed competition. The identification of competitive cultivars and the traits conferring competitive ability should lead to the development of more competitive field pea cultivars. The objective of this research was to evaluate the ability of semi-leafless field pea cultivars to suppress and withstand weed competition and to identify traits that may confer competitive ability in field pea. Field experiments were conducted in 2012 and 2013 at Floral, Saskatchewan, Saskatoon, Saskatchewan and St. Albert, Alberta. Fourteen semi-leafless field pea cultivars were seeded at a target density of 75 plants m-2 under weedy and weed-free conditions. Imidazolinone-tolerant wheat (c.v. CDC Imagine) and canola (c.v. 45H73) were planted as pseudo weeds in the weedy plots. There was no cultivar by treatment interaction for all of the measured variables thus, cultivars did not differ in the presence or absence of weed competition. CDC Dakota produced the greatest pea yield and Reward produced the poorest pea yield at Saskatchewan. CDC Dakota and CDC Striker were among the best for pea biomass production at Saskatchewan, compared to Reward, which was among the worst. CDC Centennial and CDC Mozart were significantly better at Saskatchewan for their ability to withstand competition, while CDC Dakota, CDC Patrick, and CDC Meadow were statistically the best in their ability to compete with the pseudo weeds. At Alberta, CDC Striker and CDC Dakota were statistically best in their ability to compete with the pseudo weeds, versus Cooper and Stratus, who were among the poorest. At both Saskatchewan and Alberta, no correlations were strong enough to show which traits are conferring competitiveness in semi-leafless field pea cultivars
Angular Conditions,Relations between Breit and Light-Front Frames, and Subleading Power Corrections
We analyze the current matrix elements in the general collinear (Breit)
frames and find the relation between the ordinary (or canonical) helicity
amplitudes and the light-front helicity amplitudes. Using the conservation of
angular momentum, we derive a general angular condition which should be
satisfied by the light-front helicity amplitudes for any spin system. In
addition, we obtain the light-front parity and time-reversal relations for the
light-front helicity amplitudes. Applying these relations to the spin-1 form
factor analysis, we note that the general angular condition relating the five
helicity amplitudes is reduced to the usual angular condition relating the four
helicity amplitudes due to the light-front time-reversal condition. We make
some comments on the consequences of the angular condition for the analysis of
the high- deuteron electromagnetic form factors, and we further apply the
general angular condition to the electromagnetic transition between spin-1/2
and spin-3/2 systems and find a relation useful for the analysis of the
N- transition form factors. We also discuss the scaling law and the
subleading power corrections in the Breit and light-front frames.Comment: 24 pages,2 figure
Proton-proton scattering above 3 GeV/c
A large set of data on proton-proton differential cross sections, analyzing
powers and the double polarization parameter A_NN is analyzed employing the
Regge formalism. We find that the data available at proton beam momenta from 3
GeV/c to 50 GeV/c exhibit features that are very well in line with the general
characteristics of Regge phenomenology and can be described with a model that
includes the rho, omega, f_2, and a_2 trajectories and single Pomeron exchange.
Additional data, specifically for spin-dependent observables at forward angles,
would be very helpful for testing and refining our Regge model.Comment: 16 pages, 19 figures; revised version accepted for publication in
EPJ
Equivalence Theorem and Probing the Electroweak Symmetry Breaking Sector
We examine the Lorentz non-invariance ambiguity in longitudinal weak-boson
scatterings and the precise conditions for the validity of the Equivalence
Theorem (ET). {\it Safe} Lorentz frames for applying the ET are defined, and
the intrinsic connection between the longitudinal weak-boson scatterings and
probing the symmetry breaking sector is analyzed. A universal precise
formulation of the ET is presented for both the Standard Model and the Chiral
Lagrangian formulated Electro-Weak Theories. It is shown that in electroweak
theories with strongly interacting symmetry breaking sector, the longitudinal
weak-boson scattering amplitude {\it under proper conditions} can be replaced
by the corresponding Goldstone-boson scattering amplitude in which all the
internal weak-boson lines and fermion loops are ignored.Comment: 20 pages, in LaTeX, to appear in Phys. Rev. D (1995). A few minor
corrections were made to clarify our viewpoint of the Equivalence Theorem and
compare our conclusion with those in the literatur
Multiport Well Design for Sampling of Ground Water at Closely Spaced Vertical Intervals
The Revised TESS Input Catalog and Candidate Target List
We describe the catalogs assembled and the algorithms used to populate the
revised TESS Input Catalog (TIC), based on the incorporation of the Gaia second
data release. We also describe a revised ranking system for prioritizing stars
for 2-minute cadence observations, and assemble a revised Candidate Target List
(CTL) using that ranking. The TIC is available on the Mikulski Archive for
Space Telescopes (MAST) server, and an enhanced CTL is available through the
Filtergraph data visualization portal system at the URL
http://filtergraph.vanderbilt.edu/tess_ctl.Comment: 30 pages, 16 figures, submitted to AAS Journals; provided to the
community in advance of publication in conjunction with public release of the
TIC/CTL on 28 May 201
Energy dispersed large data wave maps in 2+1 dimensions
In this article we consider large data Wave-Maps from into
a compact Riemannian manifold , and we prove that regularity
and dispersive bounds persist as long as a certain type of bulk
(non-dispersive) concentration is absent. In a companion article we use these
results in order to establish a full regularity theory for large data
Wave-Maps.Comment: 89 page
Visual cortical plasticity and the risk for psychosis: An interim analysis of the North American Prodrome Longitudinal Study
Background: Adolescence/early adulthood coincides with accelerated pruning of cortical synapses and the onset of schizophrenia. Cortical gray matter reduction and dysconnectivity in schizophrenia are hypothesized to result from impaired synaptic plasticity mechanisms, including long-term potentiation (LTP), since deficient LTP may result in too many weak synapses that are then subject to over-pruning. Deficient plasticity has already been observed in schizophrenia. Here, we assessed whether such deficits are present in the psychosis risk syndrome (PRS), particularly those who subsequently convert to full psychosis. Methods: An interim analysis was performed on a sub-sample from the NAPLS-3 study, including 46 healthy controls (HC) and 246 PRS participants. All participants performed an LTP-like visual cortical plasticity paradigm involving assessment of visual evoked potentials (VEPs) elicited by vertical and horizontal line gratings before and after high frequency (“tetanizing”) visual stimulation with one of the gratings to induce “input-specific” neuroplasticity (i.e., VEP changes specific to the tetanized stimulus). Non-parametric, cluster-based permutation testing was used to identify electrodes and timepoints that demonstrated input-specific plasticity effects. Results: Input-specific pre-post VEP changes (i.e., increased negative voltage) were found in a single spatio-temporal cluster covering multiple occipital electrodes in a 126–223 ms time window. This plasticity effect was deficient in PRS individuals who subsequently converted to psychosis, relative to PRS non-converters and HC. Conclusions: Input-specific LTP-like visual plasticity can be measured from VEPs in adolescents and young adults. Interim analyses suggest that deficient visual cortical plasticity is evident in those PRS individuals at greatest risk for transition to psychosis
Nocardia infection in renal transplant recipient: diagnostic and therapeutic considerations
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