769 research outputs found

    Rabon-Impregnated Ear Tags for Horn Fly Control on Beef Cattle

    Get PDF
    One insecticide-impregnated ear tag per animal resulted in satisfactory horn fly reductions of over 85% for 46, 62 and 71 days. Failure to control horn flies (50 or more flies per side) occurred at about 70 days post-treatment with three study herds in western South Dakota in the summer of 1980

    Horn Fly Control on Range Beef Cattle

    Get PDF
    Over eleven hundred range cattle were treated with insecticide-impregnated ear tags and observed for horn fly control. Tagging rates compared were herds with one or two tags on each cow, two tags on part of the cows, one tag on half the cows, one tag on each calf (none on the cows) and fenvalerate versus permethrin as the insecticide in the tags. Results from all herds studied showed reductions of 90 to 100% for horn flues after 60 days of treatment for as long as 125 days

    Attochirp-free High-order Harmonic Generation

    Full text link
    A method is proposed for arbitrarily engineering the high-order harmonic generation phase achieved by shaping a laser pulse and employing xuv light or x rays for ionization. This renders the production of bandwidth-limited attosecond pulses possible while avoiding the use of filters for chirp compensation. By adding the first 8 Fourier components to a sinusoidal field of 101610^{16}W/cm2^2, the bandwidth-limited emission of 8 as is shown to be possible from a Li2+^{2+} gas. The scheme is extendable to the zs-scale

    The dependency diagram of a mixed integer linear programme

    Full text link

    Data Report for the 1993 Los Angeles Region Seismic Experiment (LARSE93), Southern California: A Passive Study From Seal Beach Northeastward through the Mojave Desert

    Get PDF
    This report contains a description of the first part of the Los Angeles Region Seismic Experiment (LARSE). To date, LARSE has consisted of two experiments: passive, which took place in fall, 1993 (LARSE93), and active, which took place in fall, 1994 (LARSE94). The goal of the 1993 experiment was to collect waveform data from local and distant earthquakes to obtain three-dimensional images of lower crust and upper mantle structure in Southern California, particularly under the San Gabriel Mountains and across the San Andreas fault. During LARSE93, approximately 88 stations were deployed in a 175-km-long, linear array across the Los Angeles basin, San Gabriel Mountains, and Mojave Desert northeast of Los Angeles by scientists from the U.S. Geological Survey, University of California at Los Angeles, California Institute of Technology, and University of Southern California. Reftek recorders were deployed one km apart through the San Gabriel Mountains, and two km apart in the Mojave Desert. This data set has since been complemented by the results of LARSE94 comprising land refraction and deep-crustal seismic reflection profiles from offshore airgun and onshore explosion sources. These additional data sets will be useful in distinguishing crustal structures from adjacent upper mantle structures. During the four weeks of continuous recording, over 150 teleseismic and over 450 local (ML ≥ 2.0) events were recorded at each site. Both teleseismic and local sources provided a wide range of raypath azimuths. The teleseismic events include a number of earthquakes with epicenters in the Aleutian Island, Kamchatka, Kuril Island, mid-Atlantic Ridge, Solomon Island, Japan, Fiji Island, Peru, and Chile regions. The local events include aftershocks of recent Southern California earthquakes. The final products of data processing are 1) half-hour files containing the continuous wavefonn data recorded at each station for each day of the experiment, 2) 150-second time-windowed waveform segments containing local, regional, and teleseismic event arrivals, and 3) one-hour time-windowed waveform segments containing regional and teleseismic event arrivals. Array instrumentation, recorded events, and data processing will be described in this report

    Floquet-Markov description of the parametrically driven, dissipative harmonic quantum oscillator

    Get PDF
    Using the parametrically driven harmonic oscillator as a working example, we study two different Markovian approaches to the quantum dynamics of a periodically driven system with dissipation. In the simpler approach, the driving enters the master equation for the reduced density operator only in the Hamiltonian term. An improved master equation is achieved by treating the entire driven system within the Floquet formalism and coupling it to the reservoir as a whole. The different ensuing evolution equations are compared in various representations, particularly as Fokker-Planck equations for the Wigner function. On all levels of approximation, these evolution equations retain the periodicity of the driving, so that their solutions have Floquet form and represent eigenfunctions of a non-unitary propagator over a single period of the driving. We discuss asymptotic states in the long-time limit as well as the conservative and the high-temperature limits. Numerical results obtained within the different Markov approximations are compared with the exact path-integral solution. The application of the improved Floquet-Markov scheme becomes increasingly important when considering stronger driving and lower temperatures.Comment: 29 pages, 7 figure

    Chronic Conditions and Multimorbidity Among Middle-Aged and Elderly Peri-Urban Dwellers in Dar es Salaam, Tanzania

    Get PDF
    Objectives: Chronic conditions and multimorbidity affect care needs and prevention opportunities. Methods: We studied 2,246 men and women aged ≥40 years within the Dar es Salaam Urban Cohort Study from June 2017 to July 2018. Seventeen chronic conditions were assessed based on self-report, body and blood pressure measurement, blood tests, and screening instruments. Results: Hypertension (51.3%), anemia (34.1%), obesity (32.2%), diabetes (31.6%), depressive symptoms (31.5%), low grip strength (21.2%), and ischemic heart disease (11.9%) were widespread. Multimorbidity was common (73.7%). Women had higher odds of obesity, ischemic heart disease, and high cholesterol (adjusted OR: 2.08–4.16) and lower odds of underweight, low grip strength, alcohol problems, and smoking (adjusted OR: 0.04–0.45). Ten years of age were associated with higher odds of low grip strength, cognitive problems, hypertension, kidney disease, chronic cough, diabetes, high cholesterol, ischemic heart disease, and multimorbidity (adjusted OR: 1.21–1.81) and lower odds of HIV infection (adjusted OR: 0.51). Conclusion: We found a higher prevalence of multimorbidity than previously estimated for middle-aged and elderly people in sub-Saharan Africa. The chronic conditions underlying multimorbidity differed by sex

    Understanding earthquake hazards in southern California - the "LARSE" project - working toward a safer future for Los Angeles

    Get PDF
    The Los Angeles region is underlain by a network of active faults, including many that are deep and do not break the Earth’s surface. These hidden faults include the previously unknown one responsible for the devastating January 1994 Northridge earthquake, the costliest quake in U.S. history. So that structures can be built or strengthened to withstand the quakes that are certain in the future, the Los Angeles Region Seismic Experiment (LARSE) is locating hidden earthquake hazards beneath the region to help scientists determine where the strongest shaking will occur
    • …
    corecore