851 research outputs found

    First-principle density-functional calculation of the Raman spectra of BEDT-TTF

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    We present a first-principles density-functional calculation for the Raman spectra of a neutral BEDT-TTF molecule. Our results are in excellent agreement with experimental results. We show that a planar structure is not a stable state of a neutral BEDT-TTF molecule. We consider three possible conformations and discuss their relation to disorder in these systems.Comment: 3 pages, 2 figures, submitted to the proceedings of ISCOM 200

    Effect of Processing Conditions on Nutrient Disappearance of Cold-pressed and Hexane-extracted Camelina and Carinata Meals in vitro

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    Camelina and carinata are oilseed crops that have recently gained increasing attention as biofuel sources. The meals remaining after oil extraction contain relatively high concentration of protein and, because of this, there is interest in using them in livestock diets. However, the nutritional qualities of these meals are not well defined and may vary with processing conditions. In our experiment, we evaluated meals from cold-pressed and solvent-extracted camelina and carinata meals manufactured using 6 different processing conditions. Estimates of total in vitro OM and CP disappearance of each meal were determined according to a modified 2-phase procedure of Tilley and Terry (1963). We detected no differences in CP disappearance of camelina meal manufactured under cold-pressed extraction. In contrast, we noted differences in OM disappearance of camelina and carinata meals which had undergone different cold-press processing conditions. Differences were also observed in OM and CP disappearance of oilseed meals under varied hexane extraction conditions. Our data suggests that hexane extraction produced, on average, meals with greater OM disappearance than cold-pressing, but there were interactions by oilseed type. Hexane extraction performed under a temperature of 80°C for 90 min resulted in camelina meals with the greatest CP disappearance, whereas a temperature of 120°C for 65 min resulted in meals with the lowest CP disappearance

    Rhipicephalus microplus salivary gland molecules induce differential CD86 expression in murine macrophages

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    <p>Abstract</p> <p>Background</p> <p>Tick parasitism is a major impediment for cattle production in many parts of the world. The southern cattle tick, <it>Rhipicephalus </it>(<it>Boophilus</it>) <it>microplus</it>, is an obligate hematophagous parasite of domestic and wild animals that serves as vector of infectious agents lethal to cattle. Tick saliva contains molecules evolved to modulate host innate and adaptive immune responses which facilitates blood feeding and pathogen transmission. Tick feeding promotes CD4 T cell polarization to a Th2 profile usually accompanied by down-regulation of Th1 cytokines through as yet undefined mechanisms. Co-stimulatory molecules on antigen presenting cells are central to development of T cell responses including Th1 and Th2 responses. Tick induced changes to antigen presenting cell signal transduction pathways are largely unknown. Here we document the ability of <it>R</it>. <it>microplus </it>salivary gland extracts (SGE) to effect differential CD86 expression.</p> <p>Results</p> <p>We examined changes in co-stimulatory molecule expression in murine RAW 264.7 cells in response to <it>R</it>. <it>microplus </it>SGE exposure in the presence of the toll-like receptor 4 (TLR4) ligand, LPS. After 24 hrs, CD86, but not CD80, was preferentially up-regulated on mouse macrophage RAW 264.7 cells when treated with SGE and then LPS, but not SGE alone. CD80 and CD40 expression was increased with LPS, but the addition of SGE did not alter expression. Higher concentrations of SGE were less effective at increasing CD86 RNA expression. The addition of mitogen or extracellular kinase (MEK) inhibitor, PD98059, significantly reduced the ability for SGE to induce CD86 expression, indicating activation of MEK is necessary for SGE induced up-regulation.</p> <p>Conclusions</p> <p>Molecules in SGE of <it>R. microplus </it>have a concentration-dependent effect on differential up-regulation of CD86 in a macrophage cell line activated by the TLR4 ligand, LPS. This CD86 up-regulation is at least partially dependent on the ERK1/2 pathway and may serve to promote Th2 polarization of the immune response.</p

    Interferometric speckle visibility spectroscopy (ISVS) for human cerebral blood flow monitoring

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    Infrared light scattering methods have been developed and employed to non-invasively monitor human cerebral blood flow (CBF). However, the number of reflected photons that interact with the brain is low when detecting blood flow in deep tissue. To tackle this photon-starved problem, we present and demonstrate the idea of interferometric speckle visibility spectroscopy (ISVS). In ISVS, an interferometric detection scheme is used to boost the weak signal light. The blood flow dynamics are inferred from the speckle statistics of a single frame speckle pattern. We experimentally demonstrated the improvement in the measurement of fidelity by introducing interferometric detection when the signal photon number is low. We apply the ISVS system to monitor the human CBF in situations where the light intensity is ∼100-fold less than that in common diffuse correlation spectroscopy (DCS) implementations. Due to the large number of pixels (∼2 × 10⁵) used to capture light in the ISVS system, we are able to collect a similar number of photons within one exposure time as in normal DCS implementations. Our system operates at a sampling rate of 100 Hz. At the exposure time of 2 ms, the average signal photoelectron number is ∼0.95 count/pixel, yielding a single pixel interferometric measurement signal-to-noise ratio (SNR) of ∼0.97. The total ∼2 × 10⁵ pixels provide an expected overall SNR of 436. We successfully demonstrate that the ISVS system is able to monitor the human brain pulsatile blood flow, as well as the blood flow change when a human subject is doing a breath-holding task

    Interferometric speckle visibility spectroscopy (ISVS) for human cerebral blood flow monitoring

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    Infrared light scattering methods have been developed and employed to non-invasively monitor human cerebral blood flow (CBF). However, the number of reflected photons that interact with the brain is low when detecting blood flow in deep tissue. To tackle this photon-starved problem, we present and demonstrate the idea of interferometric speckle visibility spectroscopy (ISVS). In ISVS, an interferometric detection scheme is used to boost the weak signal light. The blood flow dynamics are inferred from the speckle statistics of a single frame speckle pattern. We experimentally demonstrated the improvement of measurement fidelity by introducing interferometric detection when the signal photon number is insufficient. We apply the ISVS system to monitor the human CBF in situations where the light intensity is \sim100-fold less than that in common diffuse correlation spectroscopy (DCS) implementations. Due to the large number of pixels (2×105\sim 2\times 10^5) used to capture light in the ISVS system, we are able to collect a similar number of photons within one exposure time as in normal DCS implementations. Our system operates at a sampling rate of 100 Hz. At the exposure time of 2 ms, the average signal photon electron number is \sim0.95 count/pixel, yielding a single pixel interferometric measurement signal-to-noise ratio (SNR) of \sim0.97. The total 2×105\sim 2\times 10^5 pixels provide an expected overall SNR of 436. We successfully demonstrate that the ISVS system is able to monitor the human brain pulsatile blood flow, as well as the blood flow change when a human subject is doing a breath holding task

    Urea recycling in beef cattle fed prairie hay- based diets

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    Maximizing utilization of native rangeland is an important aspect of the cow/calf phase of beef production. Native rangeland is often of poor quality (less than 7% crude protein). Protein content of the rangeland is important because nitrogen is a key growth factor used by ruminal microbes. Without adequate nitrogen, the ruminal ecosystem will not operate at peak efficiency, which subsequently reduces the supply of nutrients to the animal. Historically, producers have provided supplemental nutrients to their cattle to achieve maximum performance. Both supplemental protein and energy have been provided to cattle consuming low-quality forage with varying levels of success. Typically, supplemental energy without adequate protein reduces fiber digestion by cattle. On the other hand, supplemental protein consistently improves overall performance

    Effects of Feeding Brassica Mixture Cover Crops During Backgrounding on Carcass Traits and Fresh Meat Quality

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    Objective: Determine effects of feeding brassica-based cover crops to cattle during backgrounding on carcass characteristics and tenderness, flavor, and juiciness of longissimus dorsi steaks

    Relative fluorine concentrations in radio frequency/electron cyclotron resonance hybrid glow discharges

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    The relative concentration of atomic fluorine was measured in a radio frequency (rf) glow discharge and a modified electron cyclotron resonance microwave/rf hybrid discharge in CF4 using an actinometric technique. The dependence of fluorine concentration on rf and microwave power, pressure, flow, and excitation source are presented. Anomalous behavior with rf power at constant microwave power was observed when using the Ar 750‐nm line as the actinometric species.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70900/2/APPLAB-60-7-818-1.pd

    Role of carbon dioxide and ion transport in the formation of sub-embryonic fluid by the blastoderm of the Japanese quail

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    1. The explanted blastoderm of the Japanese quail was used to explore the role of ions and carbon dioxide in determining the rate of sub-embryonic fluid (SEF) production between 54 and 72 h of incubation. 2. Amiloride, an inhibitor of Na+/H+ exchange, at concentrations of 10-3 to 10-6 M substantially decreased the rate of SEF production when added to the albumen culture medium. N-ethylmaleimide, an inhibitor of V type H+ ATPase, also decreased this rate but only to a small extent at the highest dose applied, 10-3 M. Both inhibitors had no effect on SEF production when added to the SEF. 3. The inhibitors of cellular bicarbonate and chloride exchange, 4-acetamido-4-'isothiocyano-2, 2-'disulphonic acid (SITS) and 4,4'diisothiocyanostilbene-2,2-'disulphonic acid (DIDS), had no effect upon SEF production. 4. Ouabain, an inhibitor of Na+/K+ ATPase, decreased SEF production substantially at all concentrations added to the SEF (10-3 to 10-6 M). Three sulphonamide inhibitors of carbonic anhydrase, acetazolamide, ethoxzolamide and benzolamide, decreased SEF production when added to the SEF at concentrations of 10-3 to 10-6 M. Benzolamide was by far the most potent. Neither ouabain nor the sulphonamides altered SEF production when added to the albumen culture medium. 5. Using a cobalt precipitation method, carbonic anhydrase activity was localised to the endodermal cells of the area vasculosa. The carbonic anhydrase activity was primarily associated with the lateral plasma membranes, which together with the potent inhibitory effect of benzolamide, suggests the carbonic anhydrase of these cells is the membrane-associated form, CA IV. 6. The changes in SEF composition produced by inhibitors were consistent with the production of SEF by local osmotic gradients. 7. It is concluded that a Na+/K+ ATPase is located on the basolateral membranes of the endodermal cells of the area vasculosa , and that a sodium ion/hydrogen ion exchanger is located on their apical surfaces. Protons for this exchanger would be provided by the hydration of CO2 catalysed by the membrane-associated carbonic anhydrase. Furthermore, it is proposed that the prime function of the endodermal cells of the area vasculosa is the production of SEF
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