6,933 research outputs found
Background and Characteristics of our Dispute Resolution Program
Report submitted to the Commission on the Future of Worker-Management Relations.Report_Stevens_092894.pdf: 2336 downloads, before Oct. 1, 2020
Remote access of the ILLIAC 4
The ILLIAC-4 hardware is described. The Illiac system, the Advanced Research Projects Agency computer network, and IMLAC PDS-1 are included. The space shuttle flow simulation is demonstrated to show the feasibility of using an advanced computer from a remote location
Lateral Failure of Spars
It was concluded that after the critical span or depth-breadth ratio has been reached, the modulus of rupture varies approximately inversely as the first power of the span and of the depth-breadth ratio. The direction of the lateral deflection is alternate between successive supports. For this reason, we believe that rib spacing along the spar is more important in reducing lateral deflection than the distance between supports at the strut points. Furthermore, we believe that, within the limits of modern design, any increase in distance between strut points can well be compensated for by spacing the ribs closer together, providing the ribs do furnish lateral support
Power-Off Tests of the Northrop N9M-2 Tailless Airplane in the 40- by 80-foot Wind Tunnel
No abstract availabl
Icing and De-Icing of a Propeller with Internal Electric Blade Heaters
An investigation has been made in the NACA Cleveland icing research tunnel to determine the de-icing effectiveness of an experimental configuration of an Internal electric propeller-blade heater. Two atmospheric Icing conditions and two propeller operating conditions were Investigated, In experiments with unheated blades and with heat applied to the blades both continuously and cyclically. Data are presented to show the effect of propeller speed., ambient air temperature and liquid-water concentration, and the duration of the heat-on and cycle times on the power requirements and de-Icing performance of the blade heaters. The extent of ice-covered area on the blades for various icing ax4 operating conditions has been determined. The largest iced area was obtained at the higher ambient-air temperatures and at low propeller speed. The ohord.wise extent of Icing In practically every case was greater than that covered by blade heaters. Adequate de-icing in the heated area with continuous application of heat was obtained with the power available but a maximum power, input of 1250 watts per blade was insufficient for cyclic de-Icing for the range of conditions investigated. Blade-surface temperature rates of rise of 0.2 to 0.7 F per second were obtained and the minimum cooling period for cyclic de-icing was found to be approximately 2-1/2 times the heating period
Human mining activity across the ages determines the genetic structure of modern brown trout (Salmo trutta L.) populations.
PublishedJournal ArticleHumans have exploited the earth's metal resources for thousands of years leaving behind a legacy of toxic metal contamination and poor water quality. The southwest of England provides a well-defined example, with a rich history of metal mining dating to the Bronze Age. Mine water washout continues to negatively impact water quality across the region where brown trout (Salmo trutta L.) populations exist in both metal-impacted and relatively clean rivers. We used microsatellites to assess the genetic impact of mining practices on trout populations in this region. Our analyses demonstrated that metal-impacted trout populations have low genetic diversity and have experienced severe population declines. Metal-river trout populations are genetically distinct from clean-river populations, and also from one another, despite being geographically proximate. Using approximate Bayesian computation (ABC), we dated the origins of these genetic patterns to periods of intensive mining activity. The historical split of contemporary metal-impacted populations from clean-river fish dated to the Medieval period. Moreover, we observed two distinct genetic populations of trout within a single catchment and dated their divergence to the Industrial Revolution. Our investigation thus provides an evaluation of contemporary population genetics in showing how human-altered landscapes can change the genetic makeup of a species.Environment AgencyWest Country Rivers TrustUniversity of Exete
Systematic application of behaviorally oriented aura interruption techniques in relation to seizure control
Viewing a seizure as a behavioral chain consisting of a precursor aura phase and a climactic phase has moved researchers to introduce behavioral techniques either singularly or in combination at aura to circumvent seizures. Many of the aura interruption techniques have been shown to be effective in reducing seizure rate, but a systematic examination and application of the technqiues and the additive effects of. combinations have not been explored . The present study examines by way of an A-B-A-B-BC-B-BC single subject design the singular and additive effects of three aura interruption techniques (i.e., startle, shake, and differential reinforcement of other behaviors). The study involved four developmentally disabled adults for which an aura was discerned by way of a self-report measure, and an observable behavior scale. Clients were randomly assigned to one of six aura interruption combination pairs designed to encompass all permutations of the three aura interruption techniques singularly and in combination. Observers (i.e., parents or care home operators) were trained by way of videotapes and role-playing situations on how to detect and record seizure occurrences as well as when and how to introduce the aura interruption technique(s). Results indicate that aura interruption techniques alone are effective in reducing seizure rates below baseline levels and that techniques in combination with others do not produce further reductions in seizure rates
Lost in parameter space: A road map for Stacks
PublishedThis is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.1.Restriction site-Associated DNA sequencing (RAD-seq) has become a widely adopted method for genotyping populations of model and non-model organisms. Generating a reliable set of loci for downstream analysis requires appropriate use of bioinformatics software, such as the program stacks.
2.Using three empirical RAD-seq datasets, we demonstrate a method for optimising a de novo assembly of loci using stacks. By iterating values of the program's main parameters and plotting resultant core metrics for visualisation, researchers can gain a much better understanding of their dataset and select an optimal set of parameters; we present the 80% rule as a generally effective method to select the core parameters for stacks.
3.Visualisation of the metrics plotted for the three RAD-seq datasets shows that they differ in the optimal parameters that should be used to maximise the amount of available biological information. We also demonstrate that building loci de novo and then integrating alignment positions is more effective than aligning raw reads directly to a reference genome.
4.Our methods will help the community in honing the analytical skills necessary to accurately assemble a RAD-seq dataset.This work was co-funded by the Environment Agency, Westcountry Rivers Trust and the University of Exeter. Overseas collaboration for the project was made possible by funding from The Genetics Society, Santander and the University of Exeter. Thank you to many RAD-seq workshop participants for invaluable insight and new ideas. We thank Dr Nicolas Rochette for his insights into parameter analysis. Thanks also to Dr Andy King for assistance with the brown trout data molecular work and analysis, and Guy Freeman and Martin Young for the species illustrations. Prof Peter Kille and Dr Luis Cunha, Cardiff School of Biosciences, Cardiff University, kindly provided the reference genome of L. rubellus
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