722 research outputs found

    Effects of Wheat Middlings on Utilization of Mature Prairie Hay by Steers

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    A digestibility trial measuring intake, digestibility, ruminal nutrient disappearance, and ruminal pH was conducted to determine the effects of wheat middlings on utilization of mature prairie hay. Treatments included supplements used in a previous winter grazing trial at the SDSU Cottonwood Research Station that were balanced to provide the following amounts of crude protein (Ib) and metabolizable energy (Mcal) per cow daily: 1) soybean meal .75 and 2.40, 2) low wheat middlings .75 and 4.76, 3) corn-soybean meal 1.50 and 9.40, and 4) high wheat middlings 1.50 and 9.40. These supplements were fed to the steers in proportional amounts based on BW75. Steers receiving the low wheat middlings supplement had similar hay and total diet intake but lower digestible dry matter intake than steers receiving soybean meal. High wheat middlings supplementation decreased hay intake and digestible hay and total diet intake compared to corn-soybean meal and low wheat middlings. The high level of wheat middlings and cornsoybean meal reduced ruminal pH at 4 and 8 hours post-supplementation. The high level of wheat middlings depressed overall ruminal disappearance of hay dry matter and NDF compared to the corn-soybean meal supplement and the low level of wheat middlings. This study indicates that wheat middlings may depress utilization of mature, low protein forages compared to soybean meal or corn-soybean meal supplements balanced to provide the same level of protein

    Evaluation of Wheat Middlings as a Supplement for Beef Cows Grazing Native Winter Range

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    Two winter grazing trials were conducted at the SDSU Cottonwood Research Station near Cottonwood, SD, to compare wheat middlings to soybean meal and corn-soybean meal supplements. In consecutive years, grazing trials from December to February were conducted using Simmental x Angus crossbred cows grazing two pastures with differing amounts of available forage and fed four supplemental treatments that were balanced to provide the following amounts of crude protein (Ib) and metabolizable energy (Mcal) per cow daily: 1) soybean meal .75 and 2.40, 2) low wheat middlings .75 and 4.76, 3) corn-soybean meal 1.50 and 9.40, and 4) high wheat middlings 1.50 and 9.40. Cows grazing the high available forage pasture gained 53 Ib more than those grazing the low available forage pasture. The supplement x pasture interaction indicates that level of available forage affects response to the supplemental treatment. When available forage was low, wheat middlings was a less effective source of supplemental protein than soybean meal. When available forage was high, soybean meal and the low wheat middlings supplements resulted in similar cow weight gains. Regardless of forage availability, the high wheat middlings supplement was a less effective source of supplemental energy cornpared to the corn-soybean meal supplement balanced to provide equal protein and energy. The supplement x year interaction resulted from soybean meal being more beneficial than low wheat middlings in year 1 while in year 2, soybean meal and low wheat middlings resulted in similar cow performance

    EPG-representations with small grid-size

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    In an EPG-representation of a graph GG each vertex is represented by a path in the rectangular grid, and (v,w)(v,w) is an edge in GG if and only if the paths representing vv an ww share a grid-edge. Requiring paths representing edges to be x-monotone or, even stronger, both x- and y-monotone gives rise to three natural variants of EPG-representations, one where edges have no monotonicity requirements and two with the aforementioned monotonicity requirements. The focus of this paper is understanding how small a grid can be achieved for such EPG-representations with respect to various graph parameters. We show that there are mm-edge graphs that require a grid of area Ω(m)\Omega(m) in any variant of EPG-representations. Similarly there are pathwidth-kk graphs that require height Ω(k)\Omega(k) and area Ω(kn)\Omega(kn) in any variant of EPG-representations. We prove a matching upper bound of O(kn)O(kn) area for all pathwidth-kk graphs in the strongest model, the one where edges are required to be both x- and y-monotone. Thus in this strongest model, the result implies, for example, O(n)O(n), O(nlogn)O(n \log n) and O(n3/2)O(n^{3/2}) area bounds for bounded pathwidth graphs, bounded treewidth graphs and all classes of graphs that exclude a fixed minor, respectively. For the model with no restrictions on the monotonicity of the edges, stronger results can be achieved for some graph classes, for example an O(n)O(n) area bound for bounded treewidth graphs and O(nlog2n)O(n \log^2 n) bound for graphs of bounded genus.Comment: Appears in the Proceedings of the 25th International Symposium on Graph Drawing and Network Visualization (GD 2017

    Multiscale Modeling of Influenza A Virus Infection Supports the Development of Direct-Acting Antivirals

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    Influenza A viruses are respiratory pathogens that cause seasonal epidemics with up to 500,000 deaths each year. Yet there are currently only two classes of antivirals licensed for treatment and drug-resistant strains are on the rise. A major challenge for the discovery of new anti-influenza agents is the identification of drug targets that efficiently interfere with viral replication. To support this step, we developed a multiscale model of influenza A virus infection which comprises both the intracellular level where the virus synthesizes its proteins, replicates its genome, and assembles new virions and the extracellular level where it spreads to new host cells. This integrated modeling approach recapitulates a wide range of experimental data across both scales including the time course of all three viral RNA species inside an infected cell and the infection dynamics in a cell population. It also allowed us to systematically study how interfering with specific steps of the viral life cycle affects virus production. We find that inhibitors of viral transcription, replication, protein synthesis, nuclear export, and assembly/release are most effective in decreasing virus titers whereas targeting virus entry primarily delays infection. In addition, our results suggest that for some antivirals therapy success strongly depends on the lifespan of infected cells and, thus, on the dynamics of virus-induced apoptosis or the host's immune response. Hence, the proposed model provides a systems-level understanding of influenza A virus infection and therapy as well as an ideal platform to include further levels of complexity toward a comprehensive description of infectious diseases

    Effect of a Blood Meal/Corn Gluten Meal Supplement After Calving on Performance of Cows Grazing Native Range

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    A spring grazing trial was conducted to determine the effect of a supplement with lower rumen degradability (sometimes referred to as escape protein or bypass protein) than soybean meal on cow and calf performance. Three supplement treatments based on corn, soybean meal and blood meallcorn gluten meal were fed to 70 Simmental-Angus crossbred cows grazing native range from early April to late May. There was no advantage to the escape protein as measured by cow weight change, reproductive performance or calf gain. Corn supplemented cows performed similar to soybean meal supplemented cows

    Short-Term Cardiovascular Response to Short-Radius Centrifugation With and Without Ergometer Exercise

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    Artificial gravity (AG) has often been proposed as an integrated multi-system countermeasure to physiological deconditioning associated with extended exposure to reduced gravity levels, particularly if combined with exercise. Twelve subjects underwent short-radius centrifugation along with bicycle ergometry to quantify the short-term cardiovascular response to AG and exercise across three AG levels (0 G or no rotation, 1 G, and 1.4 G; referenced to the subject’s feet and measured in the centripetal direction) and three exercise intensities (25, 50, and 100 W). Continuous cardiovascular measurements were collected during the centrifugation sessions using a non-invasive monitoring system. The cardiovascular responses were more prominent at higher levels of AG and exercise intensity. In particular, cardiac output, stroke volume, pulse pressure, and heart rate significantly increased with both AG level (in most of exercise group combinations, showing averaged increments across exercise conditions of 1.4 L/min/g, 7.6 mL/g, 5.22 mmHg/g, and 2.0 bpm/g, respectively), and workload intensity (averaged increments across AG conditions of 0.09 L/min/W, 0.17 mL/W, 0.22 mmHg/W, and 0.74 bpm/W respectively). These results suggest that the addition of AG to exercise can provide a greater cardiovascular benefit than exercise alone. Hierarchical regression models were fitted to the experimental data to determine dose-response curves of all cardiovascular variables as a function of AG-level and exercise intensity during short-radius centrifugation. These results can inform future studies, decisions, and trade-offs toward potential implementation of AG as a space countermeasure

    Influence of Prototropic Reactions on the Absorption and Fluorescence Spectra of Methyl p-dimethylaminobenzoate and Its Two Ortho Derivatives

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    The influence of prototropic reactions on the spectral characteristics of methyl p-dimethylaminobenzoate (I) and its o-methoxy (II) and o-hydroxy (III) derivatives has been studied using steady-state spectroscopic technique and quantum-chemical calculations. This study concerns the solvent-induced shift of the absorption, locally excited (LE) and intramolecular charge transfer (ICT) fluorescence bands in the neat tetrahydrofuran (THF) and its hydrochloric acid solutions at different HCl concentrations. On the basis of the experimental results and quantum-chemical calculations, it was shown that in a hydrochloric acid solution the studied molecules exist as a mixture of neutral, mono-, and dicationic forms. Additionally, the results of spectroscopic measurements were used to calculate, according to the Benesi-Hildebrand method, the equilibrium constants of protopropic reactions in the ground, S0, and excited, S1, states. Our findings predestine molecules I and II to be used as acid fluorescence probes in a region of 0–2.5 M of [H+] concentrations

    Evaluation of Wheat Middlings as a Supplement for Beef Cows Grazing Native Winter Range

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    A winter grazing trial was conducted at the SDSU Cottonwood Research Station near Cottonwood, SD, to compare wheat middlings to soybean meal and corn-soybean meal supplements. During December and January 122 pregnant Simmental-Angus crossbred cows grazing two pastures with differing amounts of available forage were fed four supplemental treatments that provided the following amounts of crude protein (Ib) and metabolizable energy (Mcal) per cow daily: I) soybean meal .75 and 2.40, 2) corn-soybean meal 1.50 and 9.40, 3) low wheat middlings .75 and 4.76, and 4) high wheat middlings 1.50 and 9.40. Cows grazing the high available forage pasture gained 56 Ib more than those grazing the low available forage pasture. Cows grazing the high available forage pasture were able to select a diet higher in crude protein and lower in acid = detergent fiber. The supplement x pasture interaction indicates that level of forage availability is a factor in determining a cow\u27s response to the supplemental treatment. When forage availability was low, wheat middlings was a less effective source of supplemental protein than soybean meal and a less effective source of supplemental energy compared to a corn-soybean meal supplement balanced to provide equal protein and energy. For cows grazing the high available forage pasture, soybean meal and the low wheat middlings supplements produced similar cow weight gains and the high wheat middlings supplement was a less effective source of supplemental energy than the corn-soybean meal supplement. Cows grazing the high forage pasture receiving 1.89 Ib soybean meal had similar weight gains and lower supplement cost than cows grazing the low forage pasture receiving 6.59Ib of the corn-soybean meal supplement

    Requirement of a Membrane Potential for the Posttranslational Transfer of Proteins into Mitochondsria

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    Posttranslational transfer of most precursor proteins into mitochondria is dependent on energization of the mitochondria. Experiments were carried out to determine whether the membrane potential or the intramitochondrial ATP is the immediate energy source. Transfer in vitro of precursors to the ADP/ATP carrier and to ATPase subunit 9 into isolated Neurospora mitochondria was investigated. Under conditions where the level of intramitochondrial ATP was high and the membrane potential was dissipated, import and processing of these precursor proteins did not take place. On the other hand, precursors were taken up and processed when the intramitochondrial ATP level was low, but the membrane potential was not dissipated. We conclude that a membrane potential is involved in the import of those mitochondrial precursor proteins which require energy for intracellular translocatio
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