2,019 research outputs found
Implementation of NASTRAN on the IBM/370 CMS operating system
The NASA Structural Analysis (NASTRAN) computer program is operational on the IBM 360/370 series computers. While execution of NASTRAN has been described and implemented under the virtual storage operating systems of the IBM 370 models, the IBM 370/168 computer can also operate in a time-sharing mode under the virtual machine operating system using the Conversational Monitor System (CMS) subset. The changes required to make NASTRAN operational under the CMS operating system are described
Genetics of insular Peromyscus leucopus populations at Norris Lake, Tennessee
A total of 138 Peromyscus leucopus were sampled from 9 island and 3 mainland sites at Norris Lake in eastern Tennessee. Liver and muscle extracts were used to identify 17 allozyme loci using starch gel electrophoresis, 9 of these loci were polymorphic. Using the 8 largest collection of insular mice and the two largest collections of mainland mice it was determined that the insular populations are no less genetically variable (estimated as P , proportion of polymorphic loci, and H0, mean individual heterozygosity) than the mainland populations. Genetic identities were not significantly correlated with geographical distances between island pairs. Gene flow is the probable mechanism that prevents these populations from diverging. Significant differences between island and mainland heterogeneity and among subpopulation genetic variance (Fst) estimates could not be shown. Significant genetic heterogeneity was found among the insular populations at the 4 most robustly polymorphic loci (EST, αGPD, IPO, and 6-PGD). Social structuring of these populations may account for the significant genetic heterogeneity among them. A pattern of heterozygote deficiency was found at the 6-P6D and EST loci in both insular and mainland populations. There are 4 possible explanations for these results: 1) negative heterosis, 2) population structuring, 3) Wahlund effect, and 4) the presence of null alleles. It could not be shown that insular P. leucopus populations were any more subject to the stochastic processes usually attributed to island habitation than the mainland populations at Norris Lake. A large difference was found between Fst estimates of males from 6 islands with the largest collections (Fst = .0399) and females from 4 islands with the largest collections (Fst = .1929). Sexual differences in dispersion probably account for these results. Males move further than females and are, therefore, probably less closely related to one another within a sample
Development of a Pre-Driven Recovery Evaluation Program for Longwall Operations
Many longwall coordinators are examining the use of pre-driven recovery roadways. This method, if performed successfully can improve the overall efficiency and safety of moving longwall equipment from panel to panel. However, it is difficult to assess the feasibility of using predriven recovery unless extensive research is carried out or a consultant is used to analyse the particular situation. A number of previous case studies have been analysed to discover which parameters have the greatest influence on the success of pre-driven recovery. Floor strength, Coal Mine Roof Rating (CMRR), extraction depth, Roof Density Index (RDI), standing support and mining rate were the main parameters impacting on the successful implementation of pre-driven recovery roadways. These parameters have been incorporated into a program that was developed to assess the feasibility of using pre-driven recovery roadways. The Pre-driven Recovery Evaluation Program (PREP) is simple to operate and it will enable new longwall mining operations as well as current operations to quickly determine the suitability of the method to their site
Comparison of northern flying and red squirrel phylogenies with focus on the insular United States
Northern flying squirrel (Glaucomys sabrinus) and red squirrel (Tamiasciurus hudsonicus) populations are endemic to northern North America, including the Black Hills. The Black Hills populations are considered disjunct from other populations within their range. We examined insular populations to determine whether arboreal squirrels in the Black Hills each represent a unique population. We trapped and collected ear samples from northern flying and red squirrels in the Black Hills and in areas of Montana, Wyoming, Idaho, Utah, Minnesota, and Wisconsin to infer population phylogenies with special consideration of the Black Hills population. Microsatellite loci and two mtDNA sequences were used for phylogenetic data analyses, including neighbor-joining and maximum likelihood trees, percent divergence, and nucleotide diversity. For northern flying squirrels,mtDNA phylogenetic trees grouped individuals in the Black Hills population, suggesting extended isolation from other nearby mountain ranges. In both squirrels, phylogenetic trees inferred with nDNA provide similar topologies to the mtDNA of northern flying squirrels. Sequence divergence distances (range 0 to 1.0) for cytochrome-b among studied populations were relatively small (0.00 to 0.55 [northern flying squirrel] and 0.00 to 0.01 [red squirrel]), so divergence may be from an historical event. Nucleotide diversity (cytochrome-b) was higher than in some other ranges (0.07 [northern flying squirrel] and 0.08 [red squirrel]); however, heterozygosity was low in the Black Hills populations. These data suggest that northern flying squirrel and red squirrel populations in the Black Hills Mountains are not only geographically disjunct, but genetically unique from their conspecifics elsewhere
Using the Common European Framework of Reference (CEFR) and ‘Can Do’ Statements for English Communication Classes.
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Transplantation of progenitor cells and regeneration enhancement in acute myocardial infarction - (TOPCARE-AMI)
Background - Experimental studies suggest that transplantation of blood-derived or bone marrow–derived progenitor cells beneficially affects postinfarction remodeling. The safety and feasibility of autologous progenitor cell transplantation in patients with ischemic heart disease is unknown
Arctic Cod (Boreogadus saida) as Prey: Fish Length-Energetics Relationships in the Beaufort Sea and Hudson Bay
Although Arctic cod (Boreogadus saida) is widely recognized as an important trophic link to top predators in Arctic marine ecosystems, the challenges of conducting fieldwork in the Arctic make this species difficult to study. We establish some basic relationships to improve prey energetics modeling when only in-field parameters (e.g., fork length) can be measured. We investigated the intraspecific relationships among energy density, fork length, mass, and water content for Arctic cod captured by Black Guillemots and Thick-billed Murres at two sites (Western Beaufort and Hudson Bay). Dry energy density was similar between sites (21.6 – 22.2 kJ g-1) and increased with fork length (Dry EDkJ/g = 0.028 (± 0.01) • Fork Lengthmm + 18.12 (± 1.33). Even though fish lost some water as they were transported to the nest by avian predators, wet energy density also increased with fork length. We suggest that environmental conditions had a similar effect on growth at these two locations although they occur in very different oceanographic regimes. Arctic cod, especially large cod, is one of the most energy-rich prey species in the Arctic. Our results highlight the importance of this valuable prey to Arctic ecosystems and the utility of using seabirds opportunistically as samplers of the marine environment.Même si la morue polaire (Boreogadus saida) est grandement reconnue comme un lien trophique important pour les prédateurs situés en bout de chaîne des écosystèmes marins de l’Arctique, cette espèce est difficile à étudier en raison des défis inhérents à la réalisation de travaux sur le terrain dans l’Arctique. Nous établissons des relations de base afin d’améliorer la modélisation de la valeur énergétique des proies lorsque seuls des paramètres sur le terrain (comme la longueur à la fourche) peuvent être mesurés. Nous avons étudié les relations intraspécifiques qui existent entre la densité d’énergie, la longueur à la fourche, la masse et la teneur en eau de la morue polaire capturée par le guillemot à miroir et le guillemot de Brünnich à deux sites (ouest de Beaufort et baie d’Hudson). La densité d’énergie sèche était semblable entre les sites (21,6 – 22,2 kJ g-1) et augmentait en fonction de la longueur à la fourche (DE sèche EDkJ/g = 0,028 (± 0,01) • longueur à la fourchemm + 18,12(± 1,33). Même si les poissons perdaient de l’eau pendant le transport jusqu’au nid par les oiseaux prédateurs, la densité d’énergie humide augmentait également en fonction de la longueur à la fourche. Nous suggérons que les conditions environnementales avaient un effet similaire sur la croissance à ces deux sites même s’ils se trouvent dans des régimes océanographiques très différents. La morue polaire, surtout celle de grande taille, est l’une des espèces proies les plus riches en énergie de l’Arctique. Nos résultats mettent en évidence l’importance de cette précieuse proie pour les écosystèmes de l’Arctique et l’utilité de se servir des oiseaux de mer de manière opportuniste en guise d’échantillonneurs de l’environnement marin
Sequence of mRNA coding for bindin, a species-specific sea urchin sperm protein required for fertilization.
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