409 research outputs found

    Multiwavelength Observations of the Blazar BL Lacertae: A New Fast TeV Gamma-Ray Flare

    Get PDF
    Combined with measurements made by very-long-baseline interferometry, the observations of fast TeV gamma-ray flares probe the structure and emission mechanism of blazar jets. However, only a handful of such flares have been detected to date, and only within the last few years have these flares been observed from lower-frequency-peaked BL Lac objects and flat-spectrum radio quasars. We report on a fast TeV gamma-ray flare from the blazar BL Lacertae observed by the Very Energetic Radiation Imaging Telescope Array System (VERITAS). with a rise time of ~2.3 hr and a decay time of ~36 min. The peak flux above 200 GeV is (4.2 ± 0.6) × 10^(−6) photon m^(−2) s^(−1) measured with a 4-minute-binned light curve, corresponding to ~180% of the flux that is observed from the Crab Nebula above the same energy threshold. Variability contemporaneous with the TeV gamma-ray flare was observed in GeV gamma-ray, X-ray, and optical flux, as well as in optical and radio polarization. Additionally, a possible moving emission feature with superluminal apparent velocity was identified in Very Long Baseline Array observations at 43 GHz, potentially passing the radio core of the jet around the time of the gamma-ray flare. We discuss the constraints on the size, Lorentz factor, and location of the emitting region of the flare, and the interpretations with several theoretical models that invoke relativistic plasma passing stationary shocks

    Effect of replacing corn grain by wheat-based dried distillers’ grains with solubles dietary energy and protein value in cattle

    Get PDF
    Non-Peer ReviewedThe objectives of this study were to determine the effect of replacing corn grain portion of the diet by wheat-based dried distillers’ grains with solubles (wDDGS) on feeding value for ruminants by chemical fractionation, nylon bag rumen degradation and nutrient modeling approaches. This study revealed that increasing wDDGS inclusion level increased most of nutritional composition linearly, except for starch which linearly decreased. Metabolizable protein supply in small intestine increased linearly with increasing levels of wDDGS. The inclusion of wDDGS in corn based diets decreased energy values of the diet slightly. Optimum ruminal N to energy balance for microbial growth was reached by replacing 25-50% of corn by wDDGS. In summary, this study suggests that corn and wheat DDGS combinations are a viable alternative for replace feed barley grain for the beef industry in western Canada

    Multiwavelength Observations of the Blazar BL Lacertae: A New Fast TeV Gamma-Ray Flare

    Get PDF
    Combined with measurements made by very-long-baseline interferometry, the observations of fast TeV gamma-ray flares probe the structure and emission mechanism of blazar jets. However, only a handful of such flares have been detected to date, and only within the last few years have these flares been observed from lower-frequency-peaked BL Lac objects and flat-spectrum radio quasars. We report on a fast TeV gamma-ray flare from the blazar BL Lacertae observed by the Very Energetic Radiation Imaging Telescope Array System (VERITAS). with a rise time of ~2.3 hr and a decay time of ~36 min. The peak flux above 200 GeV is (4.2 ± 0.6) × 10^(−6) photon m^(−2) s^(−1) measured with a 4-minute-binned light curve, corresponding to ~180% of the flux that is observed from the Crab Nebula above the same energy threshold. Variability contemporaneous with the TeV gamma-ray flare was observed in GeV gamma-ray, X-ray, and optical flux, as well as in optical and radio polarization. Additionally, a possible moving emission feature with superluminal apparent velocity was identified in Very Long Baseline Array observations at 43 GHz, potentially passing the radio core of the jet around the time of the gamma-ray flare. We discuss the constraints on the size, Lorentz factor, and location of the emitting region of the flare, and the interpretations with several theoretical models that invoke relativistic plasma passing stationary shocks

    Criteria for setting speed limits for Sri Lankan road ways

    Get PDF
    The available knowledge and studies which have been carried out on setting speed limits for Sri Lankan road ways are very limited. Speed limit, on a given roadway, is a much important factor for road users, because that decides the travel time. This research attempts to evaluate the applicability of speed limits for Sri Lankan road network and develop a methodology for setting up speed limit for selected road section. In the selection of road sections for this research, the scope was limited to straight road sections in flat terrains in sub-urban areas and other characteristics such as shoulder conditions, roadside development and etc pretty much equal. Then, the sample speed data was collected on selected road sections according to the vehicle category. The collected data was processed and compared with existing speed limits. Besides, a questionnaire survey was carried out in order to find out drivers' knowledge and attitude about speed limits on those selected road sections. According to the obtained results, only three-wheelers and buses exceeded the speed limits which were to be adopted on the road sections by drivers. Then, the speed limit for motor cycles, car/van/jeep, light goods vehicles can be increased while Speed limit for heavy vehicles is kept as of for these road sections. After considering the results of the questionnaire survey it can be suggested that the speed limits for three-wheelers and buses can be increased by 10 kmph with respect to their prevailing speed limit values

    A Method for Combining Isolates of Phytophthora sojae to Screen for Novel Sources of Resistance to Phytophthora Stem and Root Rot in Soybean

    Get PDF
    Soybean cultivars with specific single resistance genes (Rps) are grown to reduce yield loss due to Phytophthora stem and root rot caused by the oomycete pathogen Phytophthora sojae. To identify novel Rps loci, soybean lines are often screened several times, each time with an isolate of P. sojae that differs in virulence on various Rps genes. The goal of this study was to determine whether several isolates of P. sojae that differ in virulence on Rpsgenes could be combined into a single source of inoculum and used to screen soybean lines for novel Rps genes. A set of 14 soybean differential lines, each carrying a specific Rps gene, was inoculated with three isolates of P. sojae, which differed in virulence on 6 to 10 Rps genes, individually or in a 1:1:1 mixture. Inoculum containing the 1:1:1 mixture of isolates was virulent on 13 Rps genes. The mixed-inoculum method was used to screen 1,019 soybean accessions in a blind assay for novel sources of resistance. In all, 17% of Glycine max accessions and 11% of G. soja accessions were resistant (≤30% dead plants), suggesting that these accessions may carry a novel Rps gene or genes. Advantages of combining isolates into a single source of inoculum include reduced cost, ability to screen soybean germplasm with inoculum virulent on all known Rps genes, and ease of identifying novel sources of resistance. This study is a precursor to identifying novel sources of resistance to P. sojae in soybean using RXLR effectors
    • …
    corecore