Pilot Evaluations of Runway Status Light System

This study focuses on use of the Transport Systems Research Vehicle (TSRV) Simulator at the Langley Research Center to obtain pilot opinion and input on the Federal Aviation Administration's Runway Status Light System (RWSL) prior to installation in an operational airport environment. The RWSL has been designed to reduce the likelihood of runway incursions by visually alerting pilots when a runway is occupied. Demonstrations of the RWSL in the TSRV Simulator allowed pilots to evaluate the system in a realistic cockpit environment

Effect of Wean-to-Finish Management on Pig Performance

An experiment consisting of three trials was conducted to determine the effect of wean-to-finish management systems on pig performance. Treatments consisted of: 1) wean-to-finish single stock (WF) at 7.5 ft2/pig from weaning (17 day mean age) to slaughter in a fully slatted finishing facility; 2) double stock (DS) at 3.75 ft2/pig for eight weeks following weaning and then split into two pens at 7.5 ft2/pig each; and 3) nursery (NF) at 3.75 ft2/ pig for eight weeks in a conventional nursery followed by movement to the finisher and stocked at 7.5 ft2/pig to slaughter. All pens had one two-hole wean-finish dry feeder per 15 pigs and one cup-drinker per 15 pigs. While there were health related performance problems in Trials 1 and 2 due to PRRS, there were no trial by treatment interactions. At the end of eight weeks, WF pigs were heavier (P\u3c.01) than DS pigs with NF pigs intermediate in weight (63.1, 59.2, and 60.9 lbs, respectively). The heavier weight was due to a difference (P\u3c.01) in feed intake between the WF and DS treatments. There was no effect of nursery phase treatment on feed efficiency. There was no effect (P\u3e.1) of any management treatment on any grow-finish phase production parameter reported. These data suggest that the performance improvement associated with wean–to-finish production systems occurs during the first eight weeks post-weaning. They also suggest that the response can be expected even when health challenges occur in a production system

Effect of Wean-to-Finish Management on Pig Performance

An experiment consisting of three trials was conducted to determine the effect of wean-to-finish management systems on pig performance. Treatments consisted of: 1) wean-to-finish single stock (WF) at 7.5 ft2/pig from weaning (17 day mean age) to slaughter in a fully slatted finishing facility; 2) double stock (DS) at 3.75 ft2/pig for eight weeks following weaning and then split into two pens at 7.5 ft2/pig each; and 3) nursery (NF) at 3.75 ft2/ pig for eight weeks in a conventional nursery followed by movement to the finisher and stocked at 7.5 ft2/pig to slaughter. All pens had one two-hole wean-finish dry feeder per 15 pigs and one cup-drinker per 15 pigs. While there were health related performance problems in Trials 1 and 2 due to PRRS, there were no trial by treatment interactions. At the end of eight weeks, WF pigs were heavier (P\u3c.01) than DS pigs with NF pigs intermediate in weight (63.1, 59.2, and 60.9 lbs, respectively). The heavier weight was due to a difference (P\u3c.01) in feed intake between the WF and DS treatments. There was no effect of nursery phase treatment on feed efficiency. There was no effect (P\u3e.1) of any management treatment on any grow-finish phase production parameter reported. These data suggest that the performance improvement associated with wean–to-finish production systems occurs during the first eight weeks post-weaning. They also suggest that the response can be expected even when health challenges occur in a production system

Assessment of culture and environment in the Adolescent Brain and Cognitive Development Study: Rationale, description of measures, and early data.

Neurodevelopmental maturation takes place in a social environment in addition to a neurobiological one. Characterization of social environmental factors that influence this process is therefore an essential component in developing an accurate model of adolescent brain and neurocognitive development, as well as susceptibility to change with the use of marijuana and other drugs. The creation of the Culture and Environment (CE) measurement component of the ABCD protocol was guided by this understanding. Three areas were identified by the CE Work Group as central to this process: influences relating to CE Group membership, influences created by the proximal social environment, influences stemming from social interactions. Eleven measures assess these influences, and by time of publication, will have been administered to well over 7,000 9-10 year-old children and one of their parents. Our report presents baseline data on psychometric characteristics (mean, standard deviation, range, skewness, coefficient alpha) of all measures within the battery. Effectiveness of the battery in differentiating 9-10 year olds who were classified as at higher and lower risk for marijuana use in adolescence was also evaluated. Psychometric characteristics on all measures were good to excellent; higher vs. lower risk contrasts were significant in areas where risk differentiation would be anticipated

Development of stable reporter system cloning luxCDABE genes into chromosome of Salmonella enterica serotypes using Tn7 transposon

<p>Abstract</p> <p>Background</p> <p>Salmonellosis may be a food safety problem when raw food products are mishandled and not fully cooked. In previous work, we developed bioluminescent <it>Salmonella enterica </it>serotypes using a plasmid-based reporting system that can be used for real-time monitoring of the pathogen's growth on food products in short term studies. In this study, we report the use of a Tn7-based transposon system for subcloning of <it>luxCDABE </it>genes into the chromosome of eleven <it>Salmonella enterica </it>serotypes isolated from the broiler production continuum.</p> <p>Results</p> <p>We found that the <it>lux </it>operon is constitutively expressed from the chromosome post-transposition and the <it>lux </it>cassette is stable without external pressure, i.e. antibiotic selection, for all <it>Salmonella enterica </it>serotypes used. Bioluminescence expression is based on an active electron transport chain and is directly related with metabolic activity. This relationship was quantified by measuring bioluminescence against a temperature gradient in aqueous solution using a luminometer. In addition, bioluminescent monitoring of two serotypes confirmed that our chicken skin model has the potential to be used to evaluate pathogen mitigation strategies.</p> <p>Conclusions</p> <p>This study demonstrated that our new stable reporting system eliminates bioluminescence variation due to plasmid instability and provides a reliable real-time experimental system to study application of preventive measures for <it>Salmonella </it>on food products in real-time for both short and long term studies.</p

Synergism between Porcine Reproductive and Respiratory

This study was conducted to investigate the effects of exposure to porcine reproductive and respiratory syndrome virus, Salmonella choleraesuis, and stress on young swine. Five-week-old segregated early weaned pigs were randomly assigned to one of eight treatments consisting of all possible combinations of three factors: S. choleraesuis (SC) on day zero, porcine reproductive and respiratory syndrome virus (PRRSV) on day three, and dexamethasone (DEX) on days three to seven. DEX was used as a proxy for stress. Treatment differences were seen in performance parameters, levels and duration of SC shedding, level and distribution of SC in tissues, clinical disease, and mortality. The results of this study provided evidence to support field observations that clinical outbreaks of PRRS are the result of interactions among concurrent infections and stressors

Spectropolarimetry of 3CR 68.1: A Highly Inclined Quasar

We present Keck spectropolarimetry of the highly polarized radio-loud quasar 3CR 68.1 (z=1.228, V=19). The polarization increases from 5 in the red (4000 A rest-frame) to >10% in the blue (1900 A rest-frame). The broad emission lines are polarized the same as the continuum, which shows that 3CR 68.1 is not a blazar as it has sometimes been regarded in the past. We also present measurements of the emission lines and a strong, blueshifted, associated absorption line system, as well as a detection at the emission-line redshift of Ca II K absorption, presumably from stars in the host galaxy. 3CR 68.1 belongs to an observationally rare class of highly polarized quasars that are neither blazars nor partially obscured radio-quiet QSOs. Taking into account 3CR 68.1's other unusual properties, such as its extremely red spectral energy distribution and its extreme lobe dominance, we explain our spectropolarimetric results in terms of unified models. We argue that we have a dusty, highly inclined view of 3CR 68.1, with reddened scattered (polarized) quasar light diluted by even more dust-reddened quasar light reaching us directly from the nucleus.Comment: 20 pages, includes 3 tables, 6 figures. Accepted by Ap

The Post-Eruptive Evolution of a Coronal Dimming

We discuss the post-eruptive evolution of a "coronal dimming" based on observations of the EUV corona from the Solar and Heliospheric Observatory and the Transition Region and Coronal Explorer. This discussion highlights the roles played by magnetoconvection-driven magnetic reconnection and the global magnetic environment of the plasma in the "filling" and apparent motion of the region following the eruption of a coronal mass ejection (CME). A crucial element in our understanding of the dimming region evolution is developed by monitoring the disappearance and reappearance of bright TRACE "moss" around the active region giving rise to the CME. We interpret the change in the TRACE moss as a proxy of the changing coronal magnetic field topology behind the CME front. We infer that the change in global magnetic topology also results in a shift of energy balance in the process responsible for the production of the moss emission while the coronal magnetic topology evolves from closed, to open and back to closed again because, following the eruption, the moss reforms around the active region in almost exactly its pre-event configuration. As a result of the moss evolution, combining our discussion with recent spectroscopic results of an equatorial coronal hole, we suggest that the interchangeable use of the term "transient coronal hole" to describe a coronal dimming is more than just a simple coincidence.Comment: In Press ApJ [May 2007] - 15 pages, 5 figures, 7 movies that are available upon request [contact author

Flight Demonstration of Integrated Airport Surface Technologies for Increased Capacity and Safety

A flight demonstration was conducted to address airport surface movement area capacity and safety issues by providing pilots with enhanced situational awareness information. The demonstration presented an integration of several technologies to government and industry representatives. These technologies consisted of an electronic moving map display in the cockpit, a Differential Global Positioning system (DGPS) receiver, a high speed very high frequency (VHF) data link, an Airport Surface Detection Equipment (ASDE-3) radar, and the Airport Movement Area Safety System (AMASS). Aircraft identification was presented to an air traffic controller on an AMASS display. The onboard electronic map included the display of taxi routes, hold instructions, and clearances, which were sent to the aircraft via data link by the controller. The map also displayed the positions of other traffic and warning information, which were sent to the aircraft automatically from the ASDE-3/AMASS system. This paper describes the flight demonstration in detail, along with test results

Assessment of Diversity of Antimicrobial Resistance Phenotypes and Genotypes of \u3ci\u3eMannheimia haemolytica\u3c/i\u3e Isolates from Bovine Nasopharyngeal Swabs

The threat of bovine respiratory disease (BRD) for cattle operations is exacerbated by increasing prevalence of antimicrobial resistance (AMR) in Mannheimia haemolytica, a leading cause of BRD. Characterization of AMR in M. haemolytica by culture and susceptibility testing is complicated by uncertainty regarding the number of colonies that must be selected to accurately characterize AMR phenotypes (antibiograms) and genotypes in a culture. The study objective was to assess phenotypic and genotypic diversity of M. haemolytica isolates on nasopharyngeal swabs (NPS) from 28 cattle at risk for BRD or with BRD. NPS were swabbed onto five consecutive blood agar plates; after incubation up to 20 M. haemolytica colonies were selected per plate (up to 100 colonies per NPS). Phenotype was determined by measuring minimum inhibitory concentrations (MIC) for 11 antimicrobials and classifying isolates as resistant or not. Genotype was indirectly determined by matrix-assisted laser desorption/ionization time of flight mass spectroscopy (MALDI-TOF MS). NPS from 11 of 28 cattle yielded at least one M. haemolytica isolate; median (range) of isolates per NPS was 48 (1–94). NPS from seven cattle yielded one phenotype, 3 NPS yielded two, and 1 NPS yielded three; however, within a sample all phenotypic differences were due to only oneMIC dilution. On each NPS all M. haemolytica isolated were the same genotype; genotype 1 was isolated from three NPS and genotype two was isolated from eight. Diversity of M. haemolytica on bovine NPS was limited, suggesting that selection of few colonies might adequately identify relevant phenotypes and genotypes