21,188 research outputs found
Do elliptical galaxies have thick disks?
The authors discuss new evidence which supports the existence of thick disks in elliptical/SO galaxies. Numerical simulations of weak interactions with thick disk systems produce shell structures very similar in appearance to those observed in many shell galaxies. The authors think this model presents a more plausible explanation for the formation of shell structures in elliptical/SO galaxies than does the merger model and, if correct, supports the existence of thick disks in elliptical/SO galaxies
Effect of Target Material Yield Strength on Hypervelocity Perforation and Ballistic Limit
Viscoplastic flow theory in hypervelocity projectile perforation analyses of thin plate
Papillate Watermeal, Wolffia brasiliensis, in Eastern Ontario: An Addition to the Flora of Canada
Wolffia brasiliensis is reported from eastern Ontario, at several sites within Frontenac and Lanark Counties. This is the first published record of W. brasiliensis in Canada
Genetic characterization of human coxsackievirus A6 variants associated with atypical hand, foot and mouth disease: a potential role of recombination in emergence and pathogenicity
Human coxsackievirus A6 (CVA6) is an enterically transmitted enterovirus. Until recently, CVA6 infections were considered as being of minor clinical significance, and only rarely aetiologically linked with hand, foot and mouth disease (HFMD) associated with other species A enteroviruses (particularly EV71 and CVA16). From 2008 onwards, however, CVA6 infections have been associated with several outbreaks worldwide of atypical HFMD (aHFMD) accompanied by a varicelliform rash. We recently reported CVA6-associated eczema herpeticum occurring predominantly in children and young adults in Edinburgh in January and February 2014. To investigate genetic determinants of novel clinical phenotypes of CVA6, we genetically characterized and analysed CVA6 variants associated with eczema herpeticum in Edinburgh in 2014 and those with aHFMD in CAV isolates collected from 2008. A total of eight recombinant forms (RFs) have circulated worldwide over the past 10 years, with the particularly recent appearance of RF-H associated with eczema herpeticum cases in Edinburgh in 2014. Comparison of phylogenies and divergence of complete genome sequences of CVA6 identified recombination breakpoints in 2A-2C, within VP3, and between 5' untranslated region and VP1. A Bayesian temporal reconstruction of CVA6 evolution since 2004 provided estimates of dates and the actual recombination events that generated more recently appearing recombination groups (RF-E, -F, -G and -H). Associations were observed between recombination groups and clinical presentations of herpangina, aHFMD and eczema herpeticum, but not with VP1 or other structural genes. These observations provided evidence that NS gene regions may potentially contribute to clinical phenotypes and outcomes of CVA6 infection
Remote sensing in Iowa agriculture: Identification and classification of Iowa's crops, soils and forestry resources using ERTS-1 and complimentary underflight imagery
The author has identified the following significant results. Springtime ERTS-1 imagery covering pre-selected test sites in Iowa showed considerable detail with respect to broad soil and land use patterns. Additional imagery has been incorporated into a state mosaic. The mosaic was used as a base for soil association lines transferred from an existing map. The regions of greatest contrast are between the Clarion-Nicollet-Webster soil association area and adjacent areas. Landscape characteristics in this area result in land use patterns with a high percentage of pasture, hay, and timber. The soil association areas of the state that have patterns interpreted to be associated with intensive row crop production are: Moody, Galva-Primghar-Sac, Clarion-Nicollet-Webter, Tama-Muscatine, Dinsdale-Tama, Cresco-Lourdes, Clyde, Kenyon-Floyd-Clyde, and the Luton-Onawa-Salix area on the Missouri River floodplain. Forestland estimates have been attained for an area in central Iowa using wintertime ERTS-1 imagery. Visual analysis of multispectral, temporal imagery indicates that temporal analysis for cropland identification and acreage analyses procedures may be a very useful tool. Combinations of wintertime, springtime, and summertime ERTS-1 imagery separate most vegetation types. Timing can be critical depending upon crop development and harvesting times because of the dynamic nature of agricultural production
Projecting current and future location, quality, and connectivity of habitat for breeding birds in the Great Basin
We estimated the current location, quality, and connectivity of habitat for 50 species of breeding birds in four mountain ranges in the central Great Basin (Lander, Nye, and Eureka Counties, Nevada) and projected the future location, quality, and connectivity of habitat for these species given different scenarios of climate-induced land-cover change. In the United States, such models are relevant to federally mandated management of wild animals by state-level agencies. We sampled birds during the breeding seasons of 2001-2009 with fixed-radius point counts. For each species, we used boosted regression trees to model incidence (proportion of years a location was surveyed in which the species was present) as a function of topography and current land cover and climate. To assess model fit, we calculated the proportion of binomial deviance explained. We used cross-validation to estimate the predictive accuracy of the models. We applied the conservation planning program Zonation to identify locations where incidences of multiple species were maximized through time given current land cover and two scenarios of land-cover change, expansion of pinyon-juniper woodland into sagebrush shrubsteppe and contraction of riparian woodland. Models based on a set of 13 covariates derived from remotely sensed data had some predictive capacity for 41 of 50 species. Model outputs suggested substantial changes in amount of habitat for many species following projected expansion of pinyon-juniper woodland, but less pronounced changes following projected contraction of riparian woodland. Zonation analyses indicated that the spatial distribution of the highest-quality habitat for the avian assemblage was relatively consistent through time under both scenarios. Breeding birds in the Great Basin commonly are grouped in management plans on the basis of their general association with land-cover classes such as pinyon-juniper woodland, sagebrush shrubsteppe, and riparian woodland. However, even within these groups, the environmental attributes that explained a high proportion of variation in species\u27 incidences and the projected responses to different scenarios of land-cover change varied considerably among species
SBA guaranteed lending and local economic growth
Increasingly, policymakers look to the small business sector as a potential engine of economic growth. Policies to promote small businesses include tax relief, direct subsidies, and indirect subsidies through government lending programs. Encouraging lending to small business is the primary policy objective of the Small Business Administration's (SBA) loan-guarantee program. Using a panel data set of SBA guaranteed loans, we assess whether SBA guaranteed lending has an observable impact on local economic performance. We find a positive and significant (although economically small) relationship between the relative levels of SBA guaranteed lending in a local market and the future per capita income growth in that market.
Does government intervention in the small-firm credit market help economic performance?
The guaranteed lending programs of the Small Business Administration (SBA) are large and growing rapidly. The SBA’s fiscal year 2008 performance budget calls for $25 billion in guaranteed loans for small businesses—a new record for the agency. Some critics of SBA programs suggest they do not help small businesses or overall economic performance. Other critics suggest that these programs unfairly benefit the financial institutions that participate in SBA’s guaranteed lending programs. While very little serious empirical evidence exists on whether the net economic impact of the SBA’s guaranteed lending programs is positive or negative, a few recent studies provide some insight into the question. In general, they suggest a small positive impact of the SBA’s programs on economic performance. However, the results are very tentative and further research is needed to declare a more definitive position. We provide a general overview of the SBA’s guaranteed lending programs and summarize the results of these studies.Small Business Administration ; Small business - Finance ; Economic development
Are SBA loan guarantees desirable?
Over the last 10 years, the Small Business Administration has been responsible for well over $100 billion in small business credit extensions, more than any single private lender. This Commentary explores the motivations for such a large investment of taxpayer dollars.Small Business Administration ; Loans ; Credit
Calculation of Elastic Green's Functions for Lattices with Cavities
In this Brief Report, we present an algorithm for calculating the elastic
Lattice Greens Function of a regular lattice, in which defects are created by
removing lattice points. The method is computationally efficient, since the
required matrix operations are on matrices that scale with the size of the
defect subspace, and not with the size of the full lattice. This method allows
the treatment of force fields with multi-atom interactions.Comment: 3 pages. RevTeX, using epsfig.sty. One figur
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