14,370 research outputs found
An algorithm for computing the integral closure
We present an algorithm for computing the integral closure of a reduced ring
that is finitely generated over a finite field
A performance comparison between block interleaved and helically interleaved concatenated coding systems
The performance (bit-error rate vs. signal-to-noise ratio) of two different interleaving systems, block interleaving and the newer helical interleaving are compared. Both systems are studied with and without error forecasting. Without error forecasting, the two systems have identical performance. When error forecasting is used with shallow interleaving, helical interleaving gains, but less than 0.05 dB, over block interleaving. For higher interleaving depth, the systems have almost indistinguishable performance
\u3ci\u3eLycaeides Melissa Samuelis\u3c/i\u3e (Lepidoptera: Lycaenidae) Response to an Aggregation of \u3ci\u3eLytta Sayi\u3c/i\u3e (Coleoptera: Meloidae) on \u3ci\u3eLupinus Perennis\u3c/i\u3e (Fabaceae
Lycaeides melissa samuelis Nabokov, frequently called the Karner blue butterfly, is a Federally endangered species found in savanna/barren type ecosystems of New England and the Great Lakes region of North America. We observed sporadic and localized feeding aggregations of Lytta sayi LeConte (Coleoptera: Meloidae) on Lupinus perennis L. (Fabaceae) occupied by L. m. samuelis during the summers of 2000-2004, in Eau Claire County, Wisconsin. In 2004, we quantified the phenology and behavior of an aggregation (\u3e 900 beetles) within a 1,020 m2 stand of lupine and measured its effect upon adult L. m. samuelis behavior. The L. sayi aggregation formed and dispersed within 11 days with three beetles observed on day one and a maximum of 951 beetles on day seven. By the eighth day of the aggregation, the beetles had consumed 100% of the lupine flowers, 2% of lupine seeds and no lupine leaves. In comparisons of L. m. samuelis activity before and during the beetle aggregation, L. m. samuelis males spent significantly less time perching on Potentilla simplex Michaux (Rosaceae) and more time flying during the beetle aggregation. L. m. samuelis females spent significantly less time under lupine leaves during the beetle aggregation. Distribution of L. m. samuelis larval feeding damage suggests adult females avoided ovipositing in areas containing large numbers of beetles
Performance evaluation of a second-generation elastic loop mobility system
Tests were conducted to evaluate the mobility performance of a second-generation Elastic Loop Mobility System (ELMS II). Performance on level test lanes and slopes of lunar soil simulant (LSS) and obstacle-surmounting and crevasse-crossing capabilities were investigated. In addition, internal losses and contact pressure distributions were evaluated. To evaluate the soft-soil performance, two basic soil conditions were tested: loose (LSS1) and dense (LSS5). These conditions embrace the spectrum of soil strengths tested during recent studies for NASA related to the mobility performance of the LRV. Data indicated that for the tested range of the various performance parameters, performance was independent of unit load (contact pressure) and ELMS II drum angular velocity, but was influenced by soil strength and ELMS pitch mode. Power requirements were smaller at a given system output for dense soil than for loose soil. The total system output in terms of pull developed or slope-climbing capability was larger for the ELMS II operating in restrained-pitch mode than in free-pitch mode
Associated primes of local cohomology modules and of Frobenius powers
We construct normal hypersurfaces whose local cohomology modules have
infinitely many associated primes. These include unique factorization domains
of characteristic zero with rational singularities, as well as F-regular unique
factorization domains of positive characteristic. As a consequence, we answer a
question on the associated primes of Frobenius powers of ideals, which arose
from the localization problem in tight closure theory
Node synchronization schemes for the Big Viterbi Decoder
The Big Viterbi Decoder (BVD), currently under development for the DSN, includes three separate algorithms to acquire and maintain node and frame synchronization. The first measures the number of decoded bits between two consecutive renormalization operations (renorm rate), the second detects the presence of the frame marker in the decoded bit stream (bit correlation), while the third searches for an encoded version of the frame marker in the encoded input stream (symbol correlation). A detailed account of the operation is given, as well as performance comparison, of the three methods
Unquenching the Quark Model and Screened Potentials
The low-lying spectrum of the quark model is shown to be robust under the
effects of `unquenching'. In contrast, the use of screened potentials is shown
to be of limited use in models of hadrons. Applications to unquenching the
lattice Wilson loop potential and to glueball mixing in the adiabatic hybrid
spectrum are also presented.Comment: 6 pages, 3 ps figures, revtex. Version to appear in J. Phys.
Proteomics-based, multivariate, random forest method for prediction of protein separation behavior during downstream purification
The downstream purification process (DSP) remains a significant bottleneck when using biological expression hosts for the production of recombinant biologics. This issue persists in part because of a lack of knowledge of the separation behavior of the host cell proteins (HCP), which are the most problematic class of impurity to remove due to similarities in separation behavior with the target. The process of selecting the DSP method(s) as well as the host cell can benefit from an accurate prediction of the HCP separation behavior. Therefore, to reduce the effort required for DSP development, this work was aimed at characterizing the separation behavior of a complex mixture of proteins during four commonly used chromatographic and non-chromatographic methods: cation-exchange chromatography (CEX), anion-exchange chromatography (AEX), hydrophobic interaction chromatography (HIC) and ammonium sulfate precipitation (ASP). An additional goal was to evaluate the performance of a statistical methodology as a tool for predicting the separation behavior after being applied to the characterization data. Aqueous two-phase partitioning (ATPS) followed by two-dimensional electrophoresis (2DE) provided data on the three physicochemical properties most commonly exploited during DSP for each HCP; pI (isoelectric point), molecular weight and surface hydrophobicity. The separation behaviors of two separate biological expression host extracts (corn germ and E. coli) were characterized for multiple purification methods creating a database of characterized HCP for each purification method-expression host combination (e.g. CEX-corn germ; AEX-E. coli, AEX-corn germ, ASP-E. coli, etc.). A multivariate random forest (MVRF) statistical methodology was then applied to the chromatography-based purification method databases of characterized proteins creating an accurate tool for predicting the separation behavior of a mixture of proteins. The accuracy of the MVRF method was determined by calculating a root mean squared error (RMSE) value for each database. This measure never exceeded a value of 0.045 (fraction of protein populating each of the multiple separation fractions for a given mode of chromatography). In addition, simultaneous analysis of the empirical results from AEX (i.e. chromatograms) for both expression hosts together with the predicted elution profiles of a set of model proteins using the MVRF methodology will allow for an upstream decision to be made regarding which of the two expression hosts would result in a simpler downstream purification process by using product purity and yield as a guide. Overall, the current study was aimed at establishing the framework for designing a successful downstream process with minimal resources or time spent in the lab
Biogeographical Evidence for the Grass (Poaceae) Species of Pleistocene Beringian Lowlands
Late Pleistocene Beringia had herb-dominated vegetation with abundant grasses (Poaceae), and it was inhabited by an impressive assemblage of large grazing mammals. This paper reconstructs the list of most probable late Pleistocene Beringian lowland grass species from biogeographical evidence. Late Pleistocene eolian sediments and buried soils indicate that large areas of the Beringian lowlands had nutrient-rich, silty soils that occurred over ice-rich permafrost but were generally not waterlogged. A list of likely grasses was compiled from all species that have been recorded on similar fine-grained, mesic-to-dry lowland soils (i.e., presumed refugia) and are distributed at least sporadically across the whole region today. Grasses from 13 genera met these criteria, including most of the taxa that have been identified as late Pleistocene fossils from the study area. Most of these grasses are high-latitude species of genera that are also common in temperate latitudes (e.g., Elymus, Festuca, and Poa). This diverse group of plants has a wide range of adaptations today, suggesting that grasses would have been available to occupy a variety of habitats through Pleistocene climatic fluctuations. Among these grasses are a number of highly productive forage species.La végétation de la Béringie du Pléistocène supérieur était dominée par des herbes abondantes (Poaceae). De plus, elle était habitée par un assemblage impressionnant de gros mammifères broutards. Dans cet article, nous dressons la liste des espèces végétales des basses-terres les plus probables de la Béringie du Pléistocène supérieur à partir d’observations biogéographiques. Les sédiments éoliens du Pléistocène supérieur et les sols enfouis laissent supposer que de vastes régions des basses-terres de la Béringie avaient des sols limoneux riches en nutriments situés sur du pergélisol riche en glace, sans être généralement gorgés d’eau. La liste des herbes susceptibles de s’être retrouvées à l’époque a été compilée à partir de toutes les espèces qui ont été enregistrées sur des sols fins similaires de basses-terres allant de mésoïques à secs (i.e., refuges naturels présumés) et qui sont réparties, de manière tout au moins sporadique, dans toute la région aujourd’hui. Les herbes de 13 genres ont satisfait ces critères, ce qui comprend la plupart des taxons qui ont été identifiés à titre de fossiles du Pléistocène supérieur dans la région visée par l’étude. La plupart de ces herbes sont des espèces de genres se retrouvant en haute altitude qui sont également en latitudes tempérées (comme Elymus, Festuca et Poa). De nos jours, ce groupe de végétaux divers a subi de nombreuses adaptations, ce qui laisse supposer que les herbes auraient occupé une variété d’habitats pendant les fluctuations climatiques du Pléistocène. Parmi ces herbes, notons un certain nombre d’espèces fourragères hautement productives
MS 550 The Congregation as Evangelist
1. The Faith-Sharing Congregation, Roger Swanson & Shirley Clement 2. Either The Celtic Way of Evangelism, or Church for the Unchurched, by George Hunter III 3. Reclaiming the Great Commission, Bishop Claude Payne & Hamilton Beazleyhttps://place.asburyseminary.edu/syllabi/2180/thumbnail.jp
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