672 research outputs found

    Effect of Test Weight on the Feed Value of Corn to Feedlot Lambs

    Get PDF
    The objective of this trial was to evaluate the feeding value of corn with differing test weight in a growth study with lambs fed a finishing diet ab libitum

    Net Energy of Finishing Diets Containing Light or Normal Test Weight Corn

    Get PDF
    Net energy (NE) of diets containing 77.7% whole corn of either normal (53.8 Ib/bushel, NC) or light (40.8 Ib/bushel, LC) test weight was determined by total collection and indirect respiration calorimetry using six crossbred steers (avg wt 327 kg). Diet treatments were applied in a switchback design. The steers were initially adapted to ad libitum intake of either NC or LC diets for 32 days followed by 7 days total feces and urine collection. Gaseous exchange was subsequently measured for at least 48 hours. Intake was then reduced to an estimated 1.1 times maintenance for 6 days and collections were repeated. The steers were then switched between NC and LC diets and the entire process was repeated. As a percentage of gross energy consumed, fecal energy losses were 32% greater for the NC diet compared to LC (P\u3c .01). Urinary energy losses were unaffected by diet (P \u3e .20). Although energy lost as methane did not differ between diets at high intake, it was 27% greater for LC than NC at low intake (interaction P.20). Partial efficiencies of ME used for maintenance (k,) and gain (k,), as well as ME required for maintenance, also were not different (P\u3e.20). Diet NE for maintenance and gain was 13% greater for LC than NC. NE estimates calculated by difference for light and normal whole corn were 2.48, 1.65, 2.15 and 1.43 mcal/kg dry matter, respectively. These data demonstrate that corn of low test weight is not inherently lower in NE content than normal corn

    The Environmental Effects of Global Changes on Northeast Central Europe in the Case of Non-Modified Agricultural Management

    Get PDF
    Climate impact scenarios for agriculture usually consider yield development, landscape water balance, nutrient dynamics or the endangerment of habitats separately. Scenario results are further limited by roughly discriminated land use types at low spatial resolution or they are restricted to single sites and isolated crops. Here, we exemplify a well data based comprehensive sensitivity analysis of a drought endangered agrarian region in Northeast Germany using a 2050 climate scenario. Coherently modelled results on water balance and yields indicate that agricultural production may persist, whereas wetlands and groundwater production will be negatively affected. The average percolation rate decreases from 143 mm a-1 to 12 mm a-1, and the average yield decline broken down by crops ranges from 4% for summer wheat to 14% for potatoes (main cereals: 5%)

    Effects of replacing soybean meal with xylose-treated soybean meal on performance of nursing Awassi ewes and fattening lambs

    Get PDF
    Two experiments were conducted to evaluate the effect of replacing soybean meal with xylose-treated soybean meal (soypass meal; SPM) on performance of nursing Awassi ewes and fattening lambs. In Experiment 1, lasting for eight weeks, 39 Awassi ewes and their lambs were randomly assigned to three diets. Diets were formulated by replacing soybean meal from the basal diet (CON-SBM; n=13) with 50% (50% SPM; n=13) and 100% (100% SPM; n=13) SPM. Initial and final weights of the ewes were not different (P>0.55) among diets. Total gain and average daily gain (ADG) of lambs were similar (P=0.44) among diets. Ewes fed the CON-SBM diet tended (P<0.09) to have lower milk yields than those fed the 50% SPM and 100% SPM diets. No differences (P>0.38) in milk component percentages among diets were observed. In Experiment 2, lasting for 63 days, twenty weaned lambs were used to determine the effects of replacing soybean meal with SPM on growth performance. Diets were either soybean meal (SBM; n=10) or SPM (SPM; n=10). Nutrient intake and digestibility were not different between diets. However, rumen undegradable protein intake was greater (P<0.05) for the SPM diet than for the SBM diet. Final body weight, ADG and the feed conversion ratio were similar (P>0.05) between the diets. Results suggest that replacement of soybean meal with soypass meal is not likely to produce any production benefits in nursing Awassi ewes and fattening lambs except for the slight improvement of milk yield

    Solid Molecular Frustrated Lewis Pairs in a Polyamine Organic Framework for the Catalytic Metal‐free Hydrogenation of Alkenes

    Get PDF
    We report for the first time a metal-free heterogeneously catalyzed hydrogenation using a semi-solid frustrated Lewis pair (FLP). The catalyst consists of a solid polyamine organic framework and molecular tris(pentafluorophenyl)borane (BCF) that form a semi-immobilized FLP in situ in the catalytic hydrogenation of diethyl benzylidenemalonate. 11B NMR spectroscopy proves the successful hydrogen activation by the FLP. Furthermore, the B−N interactions between the polyamine and BCF are investigated by IR and solid state NMR spectroscopy. The FLP 1,4-diazabicyclo[2.2.2]octane (DABCO)/BCF, which combines the features of a FLP and a classical Lewis adduct, functions as molecular reference in both, catalysis and characterization. Furthermore, computational studies enable a better insight into the hydrogen activation through DABCO/BCF and polyamine/BCF

    Minimal state models for ionic channels involved in glucagon secretion

    Get PDF
    Pancreatic alpha cells synthesize and release glucagon. This hormone along with insulin, preserves blood glucose levels within a physiological range. During low glucose levels, alpha cells exhibit electrical activity related to glucagon secretion. In this paper, we introduce minimal state models for those ionic channels involved in this electrical activity in mice alpha cells. For estimation of model parameters, we use Monte Carlo algorithms to fit steadystate channel currents. Then, we simulate dynamic ionic currents following experimental protocols. Our aims are 1) To understand the individual ionic channel functioning and modulation that could affect glucagon secretion, and 2) To simulate ionic currents actually measured in voltage-clamp alpha-cell experiments in mice. Our estimations indicate that alpha cells are highly permeable to sodium and potassium which mainly manage action potentials. We have also found that our estimated N-type calcium channel population and density in alpha cells is in good agreement to those reported for L-type calcium channels in beta cells. This finding is strongly relevant since both, L-type and N-type calcium channels, play a main role in insulin and glucagon secretion, respectively

    Acidic microenvironment plays a key role in human melanoma progression through a sustained exosome mediated transfer of clinically relevant metastatic molecules

    Get PDF
    Background: Microenvironment cues involved in melanoma progression are largely unknown. Melanoma is highly influenced in its aggressive phenotype by the changes it determinates in its microenvironment, such as pH decrease, in turn influencing cancer cell invasiveness, progression and tissue remodelling through an abundant secretion of exosomes, dictating cancer strategy to the whole host. A role of exosomes in driving melanoma progression under microenvironmental acidity was never described. Methods: We studied four differently staged human melanoma lines, reflecting melanoma progression, under microenvironmental acidic pHs pressure ranging between pH 6.0-6.7. To estimate exosome secretion as a function of tumor stage and environmental pH, we applied a technique to generate native fluorescent exosomes characterized by vesicles integrity, size, density, markers expression, and quantifiable by direct FACS analysis. Functional roles of exosomes were tested in migration and invasion tests. Then we performed a comparative proteomic analysis of acid versus control exosomes to elucidate a specific signature involved in melanoma progression. Results: We found that metastatic melanoma secretes a higher exosome amount than primary melanoma, and that acidic pH increases exosome secretion when melanoma is in an intermediate stage, i.e. metastatic non-invasive. We were thus able to show that acidic pH influences the intercellular cross-talk mediated by exosomes. In fact when exposed to exosomes produced in an acidic medium, pH naïve melanoma cells acquire migratory and invasive capacities likely due to transfer of metastatic exosomal proteins, favoring cell motility and angiogenesis. A Prognoscan-based meta-analysis study of proteins enriched in acidic exosomes, identified 11 genes (HRAS, GANAB, CFL2, HSP90B1, HSP90AB1, GSN, HSPA1L, NRAS, HSPA5, TIMP3, HYOU1), significantly correlating with poor prognosis, whose high expression was in part confirmed in bioptic samples of lymph node metastases. Conclusions: A crucial step of melanoma progression does occur at melanoma intermediate -stage, when extracellular acidic pH induces an abundant release and intra-tumoral uptake of exosomes. Such exosomes are endowed with pro-invasive molecules of clinical relevance, which may provide a signature of melanoma advancement
    corecore