113 research outputs found
Effect of N:S ratio on the breadmaking quality of wheat: preliminary findings from 1999
Non-Peer ReviewedSulphur (S) is an important component of wheat proteins and, therefore, influences the quality of bread wheat. However, information regarding the role of S nutrition in Canadian Western Red Spring (CWRS) wheat cultivars under Western Canadian growing conditions is limited. Field experiments were conducted in Manitoba, Saskatchewan, and Alberta in 1999 and 2000 to examine the effect of S fertilizer application on grain yield, plant nutrient status, and bread-making quality of AC Barrie wheat (Triticum aestivum L.). Plant tissue and soil tests were also evaluated for their suitability in predicting grain yield and grain N:S ratio. Analyses of the 1999 grain samples indicated ranges of 25.3 to 38.7 mg g-1 in grain N content (14 to 22% in grain protein content), 1.3 to 2.2 mg g-1 in grain S content, and 14:1 to 23:1 in N:S ratio. Preliminary breadmaking quality analyses indicated that high ratios of N to S in grain were associated with lower loaf height, smaller loaf volume, greater dough resistance, and lower dough extensibility. Sulphur fertilization reduced grain N:S ratios at four of five sites. Of the three sites used to examine breadmaking quality, two sites showed significant improvements in loaf height and loaf volume where S fertilizer was applied. Sulphur fertilization also consistently reduced dough resistance and increased dough extensibility. The N:S ratio in grain was strongly correlated with N:S ratio in midseason tissue samples and N:S ratio in soil, calculated with water extractable NO3-S and SO4-S plus phosphate-borate extractable N and S. However, grain yield response to S was not well predicted by grain N:S ratio or spring soil test concentrations of
sulphate-S
Nitrogen management for enhanced protein content in wheat in the Black Soil Zone
Non-Peer Reviewe
Efficiency of fall-banded nitrogen fertilizer in Manitoba: influence of application date, landscape position and fertilizer additives
Non-Peer ReviewedA two-year study was conducted to investigate the effects of application date, landscape position
and a double inhibitor (urease and nitrification) on the efficiency of fall-banded nitrogen (N)
fertilizer under Manitoba conditions. At harvest, the effects of landscape position were apparent
at three of the four intensive sites, with significantly greater grain yields and total recovery of N
in the high landscape positions than in the low landscape positions. Among fertilization
treatments, there were no significant differences in crop response within the high landscape
positions. In the low landscape positions, grain yields, total N uptake, grain yield increases and
fertilizer N use efficiency were highest for the spring and late fall applications, when compared to
early fall, mid fall and early fall with inhibitors. Preliminary soil analyses indicate that percent
recovery of total inorganic N in the fall and spring was greater for late fall applications than for
early fall, and for high as opposed to low landscape positions. However, there was little evidence
of substantial disappearance of mineral N over the winter for all application dates, landscape
positions, and with or without inhibitors
Effects of rapid prey evolution on predator-prey cycles
We study the qualitative properties of population cycles in a predator-prey
system where genetic variability allows contemporary rapid evolution of the
prey. Previous numerical studies have found that prey evolution in response to
changing predation risk can have major quantitative and qualitative effects on
predator-prey cycles, including: (i) large increases in cycle period, (ii)
changes in phase relations (so that predator and prey are cycling exactly out
of phase, rather than the classical quarter-period phase lag), and (iii)
"cryptic" cycles in which total prey density remains nearly constant while
predator density and prey traits cycle. Here we focus on a chemostat model
motivated by our experimental system [Fussmann et al. 2000,Yoshida et al. 2003]
with algae (prey) and rotifers (predators), in which the prey exhibit rapid
evolution in their level of defense against predation. We show that the effects
of rapid prey evolution are robust and general, and furthermore that they occur
in a specific but biologically relevant region of parameter space: when traits
that greatly reduce predation risk are relatively cheap (in terms of reductions
in other fitness components), when there is coexistence between the two prey
types and the predator, and when the interaction between predators and
undefended prey alone would produce cycles. Because defense has been shown to
be inexpensive, even cost-free, in a number of systems [Andersson and Levin
1999, Gagneux et al. 2006,Yoshida et al. 2004], our discoveries may well be
reproduced in other model systems, and in nature. Finally, some of our key
results are extended to a general model in which functional forms for the
predation rate and prey birth rate are not specified.Comment: 35 pages, 8 figure
CDMS, Supersymmetry and Extra Dimensions
The CDMS experiment aims to directly detect massive, cold dark matter
particles originating from the Milky Way halo. Charge and lattice excitations
are detected after a particle scatters in a Ge or Si crystal kept at ~30 mK,
allowing to separate nuclear recoils from the dominating electromagnetic
background. The operation of 12 detectors in the Soudan mine for 75 live days
in 2004 delivered no evidence for a signal, yielding stringent limits on dark
matter candidates from supersymmetry and universal extra dimensions. Thirty Ge
and Si detectors are presently installed in the Soudan cryostat, and operating
at base temperature. The run scheduled to start in 2006 is expected to yield a
one order of magnitude increase in dark matter sensitivity.Comment: To be published in the proceedings of the 7th UCLA symposium on
sources and detection of dark matter and dark energy in the universe, Marina
del Rey, Feb 22-24, 200
Measurement of the scintillation time spectra and pulse-shape discrimination of low-energy beta and nuclear recoils in liquid argon with DEAP-1
The DEAP-1 low-background liquid argon detector was used to measure
scintillation pulse shapes of electron and nuclear recoil events and to
demonstrate the feasibility of pulse-shape discrimination (PSD) down to an
electron-equivalent energy of 20 keV.
In the surface dataset using a triple-coincidence tag we found the fraction
of beta events that are misidentified as nuclear recoils to be (90% C.L.) for energies between 43-86 keVee and for a nuclear recoil
acceptance of at least 90%, with 4% systematic uncertainty on the absolute
energy scale. The discrimination measurement on surface was limited by nuclear
recoils induced by cosmic-ray generated neutrons. This was improved by moving
the detector to the SNOLAB underground laboratory, where the reduced background
rate allowed the same measurement with only a double-coincidence tag.
The combined data set contains events. One of those, in the
underground data set, is in the nuclear-recoil region of interest. Taking into
account the expected background of 0.48 events coming from random pileup, the
resulting upper limit on the electronic recoil contamination is
(90% C.L.) between 44-89 keVee and for a nuclear recoil
acceptance of at least 90%, with 6% systematic uncertainty on the absolute
energy scale.
We developed a general mathematical framework to describe PSD parameter
distributions and used it to build an analytical model of the distributions
observed in DEAP-1. Using this model, we project a misidentification fraction
of approx. for an electron-equivalent energy threshold of 15 keV for
a detector with 8 PE/keVee light yield. This reduction enables a search for
spin-independent scattering of WIMPs from 1000 kg of liquid argon with a
WIMP-nucleon cross-section sensitivity of cm, assuming
negligible contribution from nuclear recoil backgrounds.Comment: Accepted for publication in Astroparticle Physic
Relevance of the diploma section "Civil protection"
На сьогоднішньому етапі реформування вищої освіти навчальна дисципліна «Цивільний захист» вже не є нормативною і виключена з навчальних планів у вищих навчальних закладах, у тому числі технічного профілю. Але соціально-економічна ситуація в країні, нажаль, ускладнюється. Тому зростає необхідність і важливість питань захисту населення в умовах надзвичайних ситуацій.The discipline "Civil Protection" is not normative any more and excluded from the curriculum in higher educational institutions, including the technical profile at the present stage of reforming higher education. However, unfortunately, the socio-economic situation in the country is becoming more complicated. In these conditions, the need and importance of protecting the population in emergency situations is increasing
A simplified (modified) Duke Activity Status Index (M-DASI) to characterise functional capacity: A secondary analysis of the Measurement of Exercise Tolerance before Surgery (METS) study
Background
Accurate assessment of functional capacity, a predictor of postoperative morbidity and mortality, is essential to improving surgical planning and outcomes. We assessed if all 12 items of the Duke Activity Status Index (DASI) were equally important in reflecting exercise capacity.
Methods
In this secondary cross-sectional analysis of the international, multicentre Measurement of Exercise Tolerance before Surgery (METS) study, we assessed cardiopulmonary exercise testing and DASI data from 1455 participants. Multivariable regression analyses were used to revise the DASI model in predicting an anaerobic threshold (AT) >11 ml kg −1 min −1 and peak oxygen consumption (VO 2 peak) >16 ml kg −1 min −1, cut-points that represent a reduced risk of postoperative complications.
Results
Five questions were identified to have dominance in predicting AT>11 ml kg −1 min −1 and VO 2 peak>16 ml.kg −1min −1. These items were included in the M-DASI-5Q and retained utility in predicting AT>11 ml.kg −1.min −1 (area under the receiver-operating-characteristic [AUROC]-AT: M-DASI-5Q=0.67 vs original 12-question DASI=0.66) and VO 2 peak (AUROC-VO2 peak: M-DASI-5Q 0.73 vs original 12-question DASI 0.71). Conversely, in a sensitivity analysis we removed one potentially sensitive question related to the ability to have sexual relations, and the ability of the remaining four questions (M-DASI-4Q) to predict an adequate functional threshold remained no worse than the original 12-question DASI model. Adding a dynamic component to the M-DASI-4Q by assessing the chronotropic response to exercise improved its ability to discriminate between those with VO 2 peak>16 ml.kg −1.min −1 and VO 2 peak<16 ml.kg −1.min −1.
Conclusions
The M-DASI provides a simple screening tool for further preoperative evaluation, including with cardiopulmonary exercise testing, to guide perioperative management
The Sudbury Neutrino Observatory
The Sudbury Neutrino Observatory is a second generation water Cherenkov
detector designed to determine whether the currently observed solar neutrino
deficit is a result of neutrino oscillations. The detector is unique in its use
of D2O as a detection medium, permitting it to make a solar model-independent
test of the neutrino oscillation hypothesis by comparison of the charged- and
neutral-current interaction rates. In this paper the physical properties,
construction, and preliminary operation of the Sudbury Neutrino Observatory are
described. Data and predicted operating parameters are provided whenever
possible.Comment: 58 pages, 12 figures, submitted to Nucl. Inst. Meth. Uses elsart and
epsf style files. For additional information about SNO see
http://www.sno.phy.queensu.ca . This version has some new reference
International Lower Limb Collaborative (INTELLECT) study : a multicentre, international retrospective audit of lower extremity open fractures
- …