1,440 research outputs found
A checklist of the Limnichidae and the Lutrochidae (Coleoptera) of the world
A checklist of the world species of Limnichidae (35 genera, 345 species) and Lutrochidae (1 genus, 11 species) is presented. The author, year of publication and page number, synonyms, distribution by country, and a terminal bibliography are given for each genus and species. Biological information is also reviewed
Rediscovery and redescription of Ceradryops punctatus Hinton, 1937 (Coleoptera: Dryopidae)
Ceradryops punctatus Hinton from Sri Lanka is redescribed and illustrated. Notes are made on the habitat of the species
Luchoelmis : a new genus of Elmidae (Coleoptera) from Chile and Argentina
Luchoelmis New Genus is described with four new species: aequalis, magallanensis, and penai from Chile and cekalovici from Argentina and Chile. Luchoelmis penai is designated as the type species of the genus. A key to the four species is presented
Three new species of Hexanchorus Sharp, 1882 (Coleoptera: Elmidae: Larainae) from South America
Three new species of Hexanchorus Sharp, H. dimorphus and H. shannoni from Argentina, and H. mcdiarmidi from Venezuela, are described and illustrated
Characterization of soil and postlaunch pad debris from Cape Canaveral launch complex and analysis of soil interaction with aqueous HCl
Soil samples were fractionated and analyzed in order to assess the physical and chemical interactions of entrained soil with solid-rocket exhaust clouds. The sandy soil consisted primarily of quartz (silica) particles, 30 to 500 microns in diameter, and also contained seashell fragments. Differential and cumulative soil-mass size distributions are presented along with mineralogy, elemental compositions, and solution pH histories. About 90 percent of the soil mass consisted of particles 165 microns in diameter. Characteristic reaction times in aqueous HC1 slurries varied from a few minutes to several days, and capacities for reaction under acidic conditions varied from 10 to 40 g HCl/kg soil, depending on particle size. Airborne lifetimes of particles 165 microns are conservatively 30 min, and this major grouping is predicted to represent a small short-term chemical sink for up to 5% of the total HC1. The smaller and more minor fractions, below a 165 micron diameter, may act as giant cloud condensation nuclei over much longer airborne lifetimes. Finally, the demonstrated time dependency of neutralization is a complicating factor; it can influence the ability to deduce in-cloud HCl scavenging with reaction and can affect the accuracy of measured chemical compositions of near-field wet deposition
An exploratory aerodynamic and structural investigation of all-flexible parawings
Aerodynamic and structural aspects of all-flexible parawing
Crew procedures development techniques
The study developed requirements, designed, developed, checked out and demonstrated the Procedures Generation Program (PGP). The PGP is a digital computer program which provides a computerized means of developing flight crew procedures based on crew action in the shuttle procedures simulator. In addition, it provides a real time display of procedures, difference procedures, performance data and performance evaluation data. Reconstruction of displays is possible post-run. Data may be copied, stored on magnetic tape and transferred to the document processor for editing and documentation distribution
Advanced crew procedures development techniques
The development of an operational computer program, the Procedures and Performance Program (PPP), is reported which provides a procedures recording and crew/vehicle performance monitoring capability. The PPP provides real time CRT displays and postrun hardcopy of procedures, difference procedures, performance, performance evaluation, and training script/training status data. During post-run, the program is designed to support evaluation through the reconstruction of displays to any point in time. A permanent record of the simulation exercise can be obtained via hardcopy output of the display data, and via magnetic tape transfer to the Generalized Documentation Processor (GDP). Reference procedures data may be transferred from the GDP to the PPP
The impact of training strategies on the accuracy of genomic predictors in United States Red Angus cattle
Genomic selection (GS) has become an integral part of genetic evaluation methodology and has been applied to all major livestock species, including beef and dairy cattle, pigs, and chickens. Significant contributions in increased accuracy of selection decisions have been clearly illustrated in dairy cattle after practical application of GS. In the majority of U.S. beef cattle breeds, similar efforts have also been made to increase the accuracy of genetic merit estimates through the inclusion of genomic information into routine genetic evaluations using a variety of methods. However, prediction accuracies can vary relative to panel density, the number of folds used for folds cross-validation, and the choice of dependent variables (e.g., EBV, deregressed EBV, adjusted phenotypes). The aim of this study was to evaluate the accuracy of genomic predictors for Red Angus beef cattle with different strategies used in training and evaluation. The reference population consisted of 9,776 Red Angus animals whose genotypes were imputed to 2 medium-density panels consisting of over 50,000 (50K) and approximately 80,000 (80K) SNP. Using the imputed panels, we determined the influence of marker density, exclusion (deregressed EPD adjusting for parental information [DEPD-PA]) or inclusion (deregressed EPD without adjusting for parental information [DEPD]) of parental information in the deregressed EPD used as the dependent variable, and the number of clusters used to partition training animals (3, 5, or 10). A BayesC model with π set to 0.99 was used to predict molecular breeding values (MBV) for 13 traits for which EPD existed. The prediction accuracies were measured as genetic correlations between MBV and weighted deregressed EPD. The average accuracies across all traits were 0.540 and 0.552 when using the 50K and 80K SNP panels, respectively, and 0.538, 0.541, and 0.561 when using 3, 5, and 10 folds, respectively, for cross-validation. Using DEPD-PA as the response variable resulted in higher accuracies of MBV than those obtained by DEPD for growth and carcass traits. When DEPD were used as the response variable, accuracies were greater for threshold traits and those that are sex limited, likely due to the fact that these traits suffer from a lack of information content and excluding animals in training with only parental information substantially decreases the training population size. It is recommended that the contribution of parental average to deregressed EPD should be removed in the construction of genomic prediction equations. The difference in terms of prediction accuracies between the 2 SNP panels or the number of folds compared herein was negligible
Mass spectrometers and atomic oxygen
The likely role of atmospheric atomic oxygen in the recession of spacecraft surfaces and in the shuttle glow has revived interest in the accurate measurement of atomic oxygen densities in the upper atmosphere. The Air Force Geophysics Laboratory is supplying a quadrupole mass spectrometer for a materials interactions flight experiment being planned by the Johnson Space Center. The mass spectrometer will measure the flux of oxygen on test materials and will also identify the products of surface reactions. The instrument will be calibrated at a new facility for producing high energy beams of atomic oxygen at the Los Alamos National Laboratory. The plans for these calibration experiments are summarized
- …