3,426 research outputs found

    A flexible flight display research system using a ground-based interactive graphics terminal

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    Requirements and research areas for the air transportation system of the 1980 to 1990's were reviewed briefly to establish the need for a flexible flight display generation research tool. Specific display capabilities required by aeronautical researchers are listed and a conceptual system for providing these capabilities is described. The conceptual system uses a ground-based interactive graphics terminal driven by real-time radar and telemetry data to generate dynamic, experimental flight displays. These displays are scan converted to television format, processed, and transmitted to the cockpits of evaluation aircraft. The attendant advantages of a Flight Display Research System (FDRS) designed to employ this concept are presented. The detailed implementation of an FDRS is described. The basic characteristics of the interactive graphics terminal and supporting display electronic subsystems are presented and the resulting system capability is summarized. Finally, the system status and utilization are reviewed

    Electronic control/display interface technology

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    An effort to produce a representative workstation for the Space Station Data Management Test Bed that provides man/machine interface design options for consolidating, automating, and integrating the space station work station, and hardware/software technology demonstrations of space station applications is discussed. The workstation will emphasize the technologies of advanced graphics engines, advanced display/control medias, image management techniques, multifunction controls, and video disk utilizations

    The environment and host haloes of the brightest z~6 Lyman-break galaxies

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    By studying the large-scale structure of the bright high-redshift Lyman-break galaxy (LBG) population it is possible to gain an insight into the role of environment in galaxy formation physics in the early Universe. We measure the clustering of a sample of bright (-22.7<M_UV<-21.125) LBGs at z~6 and use a halo occupation distribution (HOD) model to measure their typical halo masses. We find that the clustering amplitude and corresponding HOD fits suggests that these sources are highly biased (b~8) objects in the densest regions of the high-redshift Universe. Coupled with the observed rapid evolution of the number density of these objects, our results suggest that the shape of high luminosity end of the luminosity function is related to feedback processes or dust obscuration in the early Universe - as opposed to a scenario where these sources are predominantly rare instances of the much more numerous M_UV ~ -19 population of galaxies caught in a particularly vigorous period of star formation. There is a slight tension between the number densities and clustering measurements, which we interpret this as a signal that a refinement of the model halo bias relation at high redshifts or the incorporation of quasi-linear effects may be needed for future attempts at modelling the clustering and number counts. Finally, the difference in number density between the fields (UltraVISTA has a surface density ~1.8 times greater than UDS) is shown to be consistent with the cosmic variance implied by the clustering measurements.Comment: 19 pages, 8 figures, accepted MNRAS 23rd March 201

    First records of \u3ci\u3eHippodamia variegata\u3c/i\u3e (Goeze) (Coleoptera: Coccinellidae) for Iowa, U.S.A.

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    Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae), a Palearctic lady beetle that has become established in North America, is reported for the first time from the state of Iowa, U.S.A. The earliest specimen of H. variegata from Iowa was collected in 2009, with two subsequent specimens in 2012. Collection records of an advancing, non-native species like H. variegata are important for determining comparative rates of geographic spread across various regions and understanding its invasion dynamics

    The clustering and bias of radio-selected AGN and star-forming galaxies in the COSMOS field

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    Dark matter haloes in which galaxies reside are likely to have a significant impact on their evolution. We investigate the link between dark matter haloes and their constituent galaxies by measuring the angular two-point correlation function of radio sources, using recently released 3 GHz imaging over $\sim 2 \ \mathrm{deg}^2oftheCOSMOSfield.WesplittheradiosourcepopulationintoStarFormingGalaxies(SFGs)andActiveGalacticNuclei(AGN),andfurtherseparatetheAGNintoradiativelyefficientandinefficientaccreters.Restrictingouranalysisto of the COSMOS field. We split the radio source population into Star Forming Galaxies (SFGs) and Active Galactic Nuclei (AGN), and further separate the AGN into radiatively efficient and inefficient accreters. Restricting our analysis to z<1,wefindSFGshaveabias,, we find SFGs have a bias, b = 1.5 ^{+0.1}_{-0.2},atamedianredshiftof, at a median redshift of z=0.62.Ontheotherhand,AGNaresignificantlymorestronglyclusteredwith. On the other hand, AGN are significantly more strongly clustered with b = 2.1\pm 0.2atamedianredshiftof0.7.ThissupportstheideathatAGNarehostedbymoremassivehaloesthanSFGs.WealsofindlowaccretionrateAGNaremoreclustered( at a median redshift of 0.7. This supports the idea that AGN are hosted by more massive haloes than SFGs. We also find low-accretion rate AGN are more clustered (b = 2.9 \pm 0.3)thanhighaccretionrateAGN() than high-accretion rate AGN (b = 1.8^{+0.4}_{-0.5})atthesameredshift() at the same redshift (z \sim 0.7),suggestingthatlowaccretionrateAGNresideinhighermasshaloes.ThissupportspreviousevidencethattherelativelyhotgasthatinhabitsthemostmassivehaloesisunabletobeeasilyaccretedbythecentralAGN,causingthemtobeinefficient.WealsofindevidencethatlowaccretionrateAGNappeartoresideinhalomassesof), suggesting that low-accretion rate AGN reside in higher mass haloes. This supports previous evidence that the relatively hot gas that inhabits the most massive haloes is unable to be easily accreted by the central AGN, causing them to be inefficient. We also find evidence that low-accretion rate AGN appear to reside in halo masses of M_{h} \sim 3-4 \times 10^{13}h^{-1}MM_{\odot}atallredshifts.Ontheotherhand,theefficientaccretersresideinhaloesof at all redshifts. On the other hand, the efficient accreters reside in haloes of M_{h} \sim 1-2 \times 10^{13}h^{-1}MM_{\odot}atlowredshiftbutcanresideinrelativelylowermasshaloesathigherredshifts.Thiscouldbeduetotheincreasedprevalenceofcoldgasinlowermasshaloesat at low redshift but can reside in relatively lower mass haloes at higher redshifts. This could be due to the increased prevalence of cold gas in lower mass haloes at z \ge 1comparedto compared to z<1$.Comment: 20 pages, 10 figures, 1 table, accepted by MNRA

    Irrigation, nitrogen, and rootstock effects on volume loss of berries from potted Shiraz vines

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    Shiraz (synonym Syrah) berry volume increases in two phases and this may be followed by shrinkage during the later stages of ripening. Irrigation regime, nitrogen application rate and rootstock were tested for their effects on the onset of volume loss and extent of volume loss. Maximum berry volume correlated well with volume of berries at 35 d after flowering, the end of the cell division phase. Post-maximum berry shrinkage was not as severe of vines grown with split-root irrigation as compared with standard irrigation. However, these berries were smaller at harvest due to less pre-veraison expansion. Berries grown on vines with standard irrigation had greater post-maximum volume loss than those berries grown in a deficit irrigation treatment. Despite this, maximum berry volume correlated well with final volume in all treatments. N application rate had an effect on the onset of post-veraison expansion but not on the amplitude of maximum berry volume or final berry volume. Deficit irrigation delayed the onset of volume loss by 11 d. Rootstock also had an effect on the onset of volume loss with berries from vines grafted on the rootstock 101-14 Mgt losing volume 7 d earlier than berries from vines grafted on Ramsey. These results suggest that onset and degree of volume loss in Shiraz is sensitive to external influences.

    Polyphenol Oxidase Activity and \u3ci\u3ein vitro\u3c/i\u3e Proteolytic Inhibition in Grasses

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    Harvesting and storing high quality forage in the cool humid regions remains a challenge due to the potential for protein degradation during ensiling. Red clover is an exception as high protein levels are maintained during ensiling. Decreased proteolytic activity in red clover is due to polyphenol oxidase (PPO) activity and appropriate o-diphenol substrates (Jones et al., 1995, Sullivan et al., 2004). This project was undertaken to determine if PPO activity is present in a range of grasses and the potential role in proteolytic inhibition in the presence of the o-diphenol caffeic acid

    Polyphenol Oxidase Activity and \u3cem\u3ein Vitro\u3c/em\u3e Proteolytic Inhibition in Grasses

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    Harvesting and storing high quality forage in the cool humid regions remains a challenge due to the potential for protein degradation during ensiling. Red clover is an exception as high protein levels are maintained during ensiling. Decreased proteolytic activity in red clover is due to polyphenol oxidase (PPO) activity and appropriate o-diphenol substrates (Jones et al., 1995, Sullivan et al., 2004). This project was undertaken to determine if PPO activity is present in a range of grasses and the potential role in proteolytic inhibition in the presence of the o-diphenol caffeic acid

    Reducing microscopy-based malaria misdiagnosis in a low-resource area of Tanzania

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    Misdiagnosis of malaria is a major problem in Africa leading not only to incorrect individual level treatment, but potentially the acceleration of the spread of drug resistance in low-transmission areas. In this paper we report on the outcomes of a simple intervention that utilized a social entrepreneurship approach (SEA) to reduce misdiagnosis associated with hospital-based microscopy of malaria in a low-transmission area of rural Tanzania. A pre-post assessment was conducted on patients presenting to the hospital outpatient department with malaria and non-malaria like symptoms in January 2009 (pre-intervention) and June 2009 (post-intervention). All participants were asked a health seeking behavior questionnaire and blood samples were taken for local and quality control microscopy. Multivariate logistic regression was conducted to determine magnitude of misdiagnosis with local microscopy pre- versus- post intervention. Local microscopy pre-intervention specificity was 29.5% (95% CI = 21.6% – 38.4%) whereas the post intervention specificity was 68.6% (95% CI = 60.2% - 76.2%). Both pre and post intervention sensitivity were difficult to determine due to an unexpected low number of true positive cases. The proportion of participants misdiagnosed pre-intervention was 70.2% (95%CI = 61.3%-78.0%) as compared to 30.6% (95%CI = 23.2%–38.8%) post-intervention. This resulted in a 39.6% reduction in misdiagnosis of malaria at the local hospital. The magnitude of misdiagnosis for the pre-intervention participants was 5.3 (95%CI = 3.1–9.3) that of the post-intervention participants. In conclusion, this study provides evidence that a simple intervention can meaningfully reduce the magnitude of microscopy-based misdiagnosis of malaria for those individuals seeking treatment for uncomplicated malaria. We anticipate that this intervention will facilitate a valuable and sustainable change in malaria diagnosis at the local hospital
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