2,825 research outputs found
Sclerotinia stem rot control in small-seeded lentil production in the Black Soil Zone
Non-Peer ReviewedLentil production in the black soil zone is limited by the susceptibility of the crop to diseases such as sclerotinia stem rot. The objective of this project was to determine stem rot control strategies in small-seeded lentil by examining the impact of plant density, cultivar, fungicide treatment and timing of application on stem rot severity and yield. The relationship between flower petal infection and stem rot severity was also examined. Randomized complete block field experiments of three replicates were established at Rosthern and Melfort, SK and assessed for flower petal infection, disease severity and yield in 2000. Results of this single year of data indicated that fungicides reduced stem rot severity at both locations but increased yield only at Melfort, where later timing of application resulted in greater yield than early. Stem rot severity varied with cultivar however the cultivar with the greatest severity also had the greatest yield. Plant density had no effect on stem rot severity, but the lower plant density resulted in lower
yield than the higher plant density. Flower petal infection was positively correlated with final disease rating only at Rosthern
Yield, nitrogen, and phosphorus uptake by four fababean varieties at four sites in Saskatchewan
Non-Peer Reviewe
Overexpression of Mcl-1 exacerbates lymphocyte accumulation and autoimmune kidney disease in lpr mice
Cell death by apoptosis has a critical role during embryonic development and in maintaining tissue homeostasis. In mammals,
there are two converging apoptosis pathways: the ‘extrinsic’ pathway, which is triggered by engagement of cell surface ‘death
receptors’ such as Fas/APO-1; and the ‘intrinsic’ pathway, which is triggered by diverse cellular stresses, and is regulated by prosurvival
and pro-apoptotic members of the Bcl-2 family of proteins. Pro-survival Mcl-1, which can block activation of the proapoptotic
proteins, Bax and Bak, appears critical for the survival and maintenance of multiple haemopoietic cell types. To
investigate the impact on haemopoiesis of simultaneously inhibiting both apoptosis pathways, we introduced the vavP-Mcl-1
transgene, which causes overexpression of Mcl-1 protein in all haemopoietic lineages, into Faslpr/lpr mice, which lack functional
Fas and are prone to autoimmunity. The combined mutations had a modest impact on myelopoiesis, primarily an increase in the
macrophage/monocyte population in Mcl-1tg/lpr mice compared with lpr or Mcl-1tg mice. The impact on lymphopoiesis was
striking, with a marked elevation in all major lymphoid subsets, including the non-conventional double-negative (DN) T cells
(TCRβ+
CD4–
CD8–
B220+
) characteristic of Faslpr/lpr mice. Of note, the onset of autoimmunity was markedly accelerated in Mcl-1tg/lpr
mice compared with lpr mice, and this was preceded by an increase in immunoglobulin (Ig)-producing cells and circulating
autoantibodies. This degree of impact was surprising, given the relatively mild phenotype conferred by the vavP-Mcl-1 transgene
by itself: a two- to threefold elevation of peripheral B and T cells, no significant increase in the non-conventional DN T-cell
population and no autoimmune disease. Comparison of the phenotype with that of other susceptible mice suggests that the
development of autoimmune disease in Mcl-1tg/lpr mice may be influenced not only by Ig-producing cells but also other
haemopoietic cell types
Age and helium content of the open cluster NGC 6791 from multiple eclipsing binary members. I. Measurements, methods, and first results
Earlier measurements of the masses and radii of the detached eclipsing binary
V20 in the open cluster NGC 6791 were accurate enough to demonstrate that there
are significant differences between current stellar models. Here we improve on
those results and add measurements of two additional detached eclipsing
binaries, the cluster members V18 and V80. The enlarged sample sets much
tighter constraints on the properties of stellar models than has hitherto been
possible, thereby improving both the accuracy and precision of the cluster age.
We employed (i) high-resolution UVES spectroscopy of V18, V20 and V80 to
determine their spectroscopic effective temperatures, [Fe/H] values, and
spectroscopic orbital elements, and (ii) time-series photometry from the Nordic
Optical Telescope to obtain the photometric elements. The masses and radii of
the V18 and V20 components are found to high accuracy, with errors on the
masses in the range 0.27-0.36% and errors on the radii in the range 0.61-0.92%.
V80 is found to be magnetically active, and more observations are needed to
determine its parameters accurately. The metallicity of NGC 6791 is measured
from disentangled spectra of the binaries and a few single stars to be [Fe/H]=
+0.29 \pm 0.03 (random) \pm 0.07 (systematic). The cluster reddening and
apparent distance modulus are found to be E(B - V) = 0.160 \pm 0.025 and (m -
M)V = 13.51 \pm 0.06 . A first model comparison shows that we can constrain the
helium content of the NGC 6791 stars, and thus reach a more accurate age than
previously possible. It may be possible to constrain additional parameters, in
particular the C, N, and O abundances. This will be investigated in paper II.Comment: Accepted for publication in A&
Data Mining the SDSS SkyServer Database
An earlier paper (Szalay et. al. "Designing and Mining MultiTerabyte
Astronomy Archives: The Sloan Digital Sky Survey," ACM SIGMOD 2000) described
the Sloan Digital Sky Survey's (SDSS) data management needs by defining twenty
database queries and twelve data visualization tasks that a good data
management system should support. We built a database and interfaces to support
both the query load and also a website for ad-hoc access. This paper reports on
the database design, describes the data loading pipeline, and reports on the
query implementation and performance. The queries typically translated to a
single SQL statement. Most queries run in less than 20 seconds, allowing
scientists to interactively explore the database. This paper is an in-depth
tour of those queries. Readers should first have studied the companion overview
paper Szalay et. al. "The SDSS SkyServer, Public Access to the Sloan Digital
Sky Server Data" ACM SIGMOND 2002.Comment: 40 pages, Original source is at
http://research.microsoft.com/~gray/Papers/MSR_TR_O2_01_20_queries.do
Gamma Group-The Pale Horse: A proposal in response to a commercial air transportation study ort study
A conventional remotely piloted vehicle (RPV) was designed to operate in a fictional 'Aeroworld' as a 30 passenger aircraft. The topics addressed include: economic/cost analysis, aerodynamics, weight and structures, propulsion, stability and control, and performance
Petabyte Scale Data Mining: Dream or Reality?
Science is becoming very data intensive1. Today's astronomy datasets with
tens of millions of galaxies already present substantial challenges for data
mining. In less than 10 years the catalogs are expected to grow to billions of
objects, and image archives will reach Petabytes. Imagine having a 100GB
database in 1996, when disk scanning speeds were 30MB/s, and database tools
were immature. Such a task today is trivial, almost manageable with a laptop.
We think that the issue of a PB database will be very similar in six years. In
this paper we scale our current experiments in data archiving and analysis on
the Sloan Digital Sky Survey2,3 data six years into the future. We analyze
these projections and look at the requirements of performing data mining on
such data sets. We conclude that the task scales rather well: we could do the
job today, although it would be expensive. There do not seem to be any
show-stoppers that would prevent us from storing and using a Petabyte dataset
six years from today.Comment: originals at
http://research.microsoft.com/scripts/pubs/view.asp?TR_ID=MSR-TR-2002-8
Seed coat colour development in black beans
Non-Peer ReviewedDry beans come in a wide variety of seed coat patterns and colours and the quality and value of the bean crop is largely determined by appearance and condition of the seed, particularly colour uniformity and stability. In western Canada, black bean is a significant portion of the crop. For some black bean varieties, the seed coat colour does not fully develop until the pod is mature. This may be the result of genotype, or environment, or both. In these cases, harvesting at plant maturity rather than at seed maturity can lead to a non-uniform crop sample in which the black beans are mixed with beans that have a purple or gray tinge. Full expression of seed coat colour is economically important as variable colour development may result in a 2-4 cent per pound discount. Seed coat colour is determined by the presence of anthocyanins and condensed tannins. In this experiment, we examined the timing of pigment deposition in the seed coat in
relation to pod maturity for 5 black bean varieties (CDC Expresso, CDC Nighthawk, CDC Jet, AC Black Diamond, and T39) to determine if there is genetic variation for timing of seed coat colour development. If it is under genetic control, we will be able to breed for earlier colour development to ensure full colour expression at plant maturity
Analysis of Predator Avoidance Behavior in California Valley Quail
Quail populations have been in decline across the United States, primarily due to habitat loss and climate. For remedy, landowners and game managers have attempted to restore populations by releasing captive-reared quail. These releases were largely unsuccessful, presumably due to high predation losses. Recently, there has been an increased interest in quail translocations, which tend to have lower mortality rates than captive-reared bird releases. Translocations are expensive and unpredictable, and require many person-hours; releasing captive-reared quail would be more efficient if the practice were successful. We compared predator avoidance behavior between captive-reared and wild-translocated California quail (Callipepla californica) in an aviary using simulated predator attacks (raptorial and mammalian). We recorded predator detection time, antipredator response time, and antipredator response type. Antipredator response type (run, flush, or freeze) frequencies were different, where captive-reared quail ran more frequently than wild-translocated quail when encountering a simulated predator. Predator detection time between captive-reared and wild-translocated quail was not different. However, antipredator response time was quicker for captive-reared quail than wild-translocated quail when subjected to simulated raptorial and mammalian attacks. The differences in antipredator response time and response type may be due to the lack of predator interaction experience of captive-reared birds and offer insight into observed differences in postrelease mortality between captive-reared and wild-trapped quail
Effects of lentil genotype on the colonization of beneficial trichoderma species and biocontrol of aphanomyces root rot
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