5,182 research outputs found
“No More Giveaways!” Resource Nationalism in Newfoundland: A Case Study of Offshore Oil in the Peckford and Williams Administrations
Registration of N614, A3N615, N616, and N617 Shattercane Genetic Stocks with Cytoplasmic or Nuclear Male Sterility and Juicy or Dry Midribs
Four shattercane [Sorghum bicolor subsp. drummondii (Nees ex Steud.) de Wet ex Davidse] genetic stocks—N614 (Reg. No. GS-652, PI 665684), A3N615 (Reg. No. GS-651, PI 665683), N616 (Reg. No. GS-653, PI 665685), and N617 (Reg. No. GS-654, PI 665686)—with A3 cytoplasmic male sterility or the nuclear male sterility gene ms3 containing either juicy (dd) or dry (DD) culms were developed jointly by the USDA-ARS; the Iowa Agricultural and Home Economics Experiment Station, College of Agriculture and Life Sciences, Iowa State University; and the Agricultural Research Division, Institute of Agriculture and Natural Resources, University of Nebraska. The stocks were released in July 2011. The source material for these genetic stocks was isolated from an archetypical shattercane population found near Lincoln, NE. Release of these genetic stocks makes available shattercane lines with both A3 cytoplasmic male sterility, and ms3 genetic (nuclear) male sterility to facilitate crossing. These genetic stocks also contain juicy (dd) or dry (DD) culms, a visible genetic marker to facilitate screening progeny resulting from crosses. The genetic stocks have immediate application for basic research involving gene flow from cultivated sorghum [Sorghum bicolor (L.) Moench] to shattercane and on the fitness of offspring resulting from such crosses
Application-Controlled Paging for a Shared Cache
AMS subject classi cations. 68N25, 68P01, 68P15, 68Q25, 68W20
PII. S0097539797324278We propose a provably efficient application-controlled global strategy for organizing
a cache of size k shared among P application processes. Each application has access to information about its own future page requests, and by using that local information along with randomization in the context of a global caching algorithm, we are able to break through the conventional Hk ln k lower bound on the competitive ratio for the caching problem. If the P application processes always make good cache replacement decisions, our online application-controlled caching algorithm attains a competitive ratio of 2HP¡1 + 2 2 lnP. Typically, P is much smaller than k, perhaps by several orders of magnitude. Our competitive ratio improves upon the 2P + 2 competitive ratio achieved by the deterministic application-controlled strategy of Cao, Felten, and Li. We show that no online
application-controlled algorithm can have a competitive ratio better than minfHP¡1;Hkg, even if
each application process has perfect knowledge of its individual page request sequence. Our results
are with respect to a worst-case interleaving of the individual page request sequences of the P
application processes.
We introduce a notion of fairness in the more realistic situation when application processes do
not always make good cache replacement decisions. We show that our algorithm ensures that no application process needs to evict one of its cached pages to service some page fault caused by a mistake of some other application. Our algorithm not only is fair but remains efficient; the global paging performance can be bounded in terms of the number of mistakes that application processes make
Application-Controlled Paging for a Shared Cache
This is the published version. Copyright © 2000 Society for Industrial and Applied MathematicsWe propose a provably efficient application-controlled global strategy for organizing a cache of size k shared among P application processes. Each application has access to information about its own future page requests, and by using that local information along with randomization in the context of a global caching algorithm, we are able to break through the conventional lower bound on the competitive ratio for the caching problem. If the P application processes always make good cache replacement decisions, our online application-controlled caching algorithm attains a competitive ratio of . Typically, P is much smaller than k, perhaps by several orders of magnitude. Our competitive ratio improves upon the 2P+2 competitive ratio achieved by the deterministic application-controlled strategy of Cao, Felten, and Li. We show that no online application-controlled algorithm can have a competitive ratio better than min{HP-1 ,Hk}, even if each application process has perfect knowledge of its individual page request sequence. Our results are with respect to a worst-case interleaving of the individual page request sequences of the P application processes.
We introduce a notion of fairness in the more realistic situation when application processes do not always make good cache replacement decisions. We show that our algorithm ensures that no application process needs to evict one of its cached pages to service some page fault caused by a mistake of some other application. Our algorithm not only is fair but remains efficient; the global paging performance can be bounded in terms of the number of mistakes that application processes make
Efficacy of Singular and Stacked \u3ci\u3ebrown midrib 6\u3c/i\u3e and \u3ci\u3e12\u3c/i\u3e in the Modification of Lignocellulose and Grain Chemistry
In sorghum, brown midrib (bmr) 6 and 12 impair the last two steps of monolignol synthesis. bmr genes were introduced into grain sorghum to improve the digestibility of lignocellulosic tissues for grazing or bioenergy uses following grain harvest. Near-isogenic grain sorghum hybrids (AWheatland X RTx430) were developed containing bmr6, bmr12, and the bmr6 bmr12 double mutant (stacked), and their impacts were assessed in a two-year field study. The bmr genes did not significantly impact grain or lignocellulosic tissue yield. Lignocellulosic tissue from bmr6, bmr12, and stacked hybrids had reduced lignin content and increased in vitro dry matter digestibility (IVDMD) compared to those of the wild type (WT). The lignin content of the stacked lignocellulosic tissue was further reduced compared to that of bmr6 or bmr12. Surprisingly, bmr12 modestly increased carbohydrates in lignocellulosic tissue, and bmr6 increased fiber and lignin content in grain. These data indicate that bmr6 and bmr12 have broader effects on plant composition than merely lignin content, which has promising implications for both livestock utilization and bioenergy conversion
Efficacy of Singular and Stacked \u3ci\u3ebrown midrib 6\u3c/i\u3e and \u3ci\u3e12\u3c/i\u3e in the Modification of Lignocellulose and Grain Chemistry
In sorghum, brown midrib (bmr) 6 and 12 impair the last two steps of monolignol synthesis. bmr genes were introduced into grain sorghum to improve the digestibility of lignocellulosic tissues for grazing or bioenergy uses following grain harvest. Near-isogenic grain sorghum hybrids (AWheatland X RTx430) were developed containing bmr6, bmr12, and the bmr6 bmr12 double mutant (stacked), and their impacts were assessed in a two-year field study. The bmr genes did not significantly impact grain or lignocellulosic tissue yield. Lignocellulosic tissue from bmr6, bmr12, and stacked hybrids had reduced lignin content and increased in vitro dry matter digestibility (IVDMD) compared to those of the wild type (WT). The lignin content of the stacked lignocellulosic tissue was further reduced compared to that of bmr6 or bmr12. Surprisingly, bmr12 modestly increased carbohydrates in lignocellulosic tissue, and bmr6 increased fiber and lignin content in grain. These data indicate that bmr6 and bmr12 have broader effects on plant composition than merely lignin content, which has promising implications for both livestock utilization and bioenergy conversion
Kiloparsec-scale Spatial Offsets in Double-peaked Narrow-line Active Galactic Nuclei. I. Markers for Selection of Compelling Dual Active Galactic Nucleus Candidates
Merger-remnant galaxies with kpc-scale separation dual active galactic nuclei
(AGNs) should be widespread as a consequence of galaxy mergers and triggered
gas accretion onto supermassive black holes, yet very few dual AGNs have been
observed. Galaxies with double-peaked narrow AGN emission lines in the Sloan
Digital Sky Survey are plausible dual AGN candidates, but their double-peaked
profiles could also be the result of gas kinematics or AGN-driven outflows and
jets on small or large scales. To help distinguish between these scenarios, we
have obtained spatial profiles of the AGN emission via follow-up long-slit
spectroscopy of 81 double-peaked narrow-line AGNs in SDSS at 0.03 < z < 0.36
using Lick, Palomar, and MMT Observatories. We find that all 81 systems exhibit
double AGN emission components with ~kpc projected spatial separations on the
sky, which suggests that they are produced by kpc-scale dual AGNs or kpc-scale
outflows, jets, or rotating gaseous disks. In addition, we find that the
subsample (58%) of the objects with spatially compact emission components may
be preferentially produced by dual AGNs, while the subsample (42%) with
spatially extended emission components may be preferentially produced by AGN
outflows. We also find that for 32% of the sample the two AGN emission
components are preferentially aligned with the host galaxy major axis, as
expected for dual AGNs orbiting in the host galaxy potential. Our results both
narrow the list of possible physical mechanisms producing the double AGN
components, and suggest several observational criteria for selecting the most
promising dual AGN candidates from the full sample of double-peaked narrow-line
AGNs. Using these criteria, we determine the 17 most compelling dual AGN
candidates in our sample.Comment: 12 pages, 8 figures, published in ApJ. Modified from original version
to reflect referee's comment
Online Perfect Matching and Mobile Computing
The original publication is available at www.springerlink.comWe present a natural online perfect matching problem moti-
vated by problems in mobile computing. A total of n customers connect
and disconnect sequentially, and each customer has an associated set of
stations to which it may connect. Each station has a capacity limit. We
allow the network to preemptively switch a customer between allowed
stations to make room for a new arrival. We wish to minimize the total
number of switches required to provide service to every customer. Equiv-
alently, we wish to maintain a perfect matching between customers and
stations and minimize the lengths of the augmenting paths. We measure
performance by the worst case ratio of the number of switches made to
the minimum number required.
When each customer can be connected to at most two stations:
{ Some intuitive algorithms have lower bounds of
(n) and
(n= log n).
{ When the station capacities are 1, there is an upper bound of O(pn).
{ When customers do not disconnect and the station capacity is 1, we
achieve a competitive ratio of O(log n).
{ There is a lower bound of
(pn) when the station capacities are 2.
{ We present optimal algorithms when the station capacity is arbitrary
in special cases
Binary Space Partitions for Fat Rectangles
This is the published version. Copyright © 2000 Society for Industrial and Applied Mathematic
Characterization of Novel Sorghum \u3ci\u3ebrown midrib\u3c/i\u3e Mutants from an EMS-Mutagenized Population
Reducing lignin concentration in lignocellulosic biomass can increase forage digestibility for
ruminant livestock and saccharification yields of biomass for bioenergy. In sorghum (Sorghum bicolor (L.) Moench) and several other C4 grasses, brown midrib (bmr) mutants have been shown to reduce lignin concentration. Putative bmr mutants isolated from an EMS-mutagenized population were characterized and classified based on their leaf midrib phenotype and allelism tests with the previously described sorghum bmr mutants bmr2, bmr6, and bmr12. These tests resulted in the identification of additional alleles of bmr2, bmr6, and bmr12, and, in addition, six bmr mutants were identified that were not allelic to these previously described loci. Further allelism testing among these six bmr mutants showed that they represented four novel bmr loci.
Based on this study, the number of bmr loci uncovered in sorghum has doubled. The impact of these lines on agronomic traits and lignocellulosic composition was assessed in a 2-yr field study. Overall, most of the identified bmr lines showed reduced lignin concentration of their biomass relative to wild-type (WT). Effects of the six new bmr mutants on enzymatic saccharification of lignocellulosic materials were determined, but the amount of glucose released from the stover was similar to WT in all cases. Like bmr2, bmr6, and bmr12, these mutants may affect monolignol biosynthesis and may be useful for bioenergy and forage improvement when stacked together or in combination with the three previously described bmr alleles
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