197 research outputs found

    Effects of Thiamin Supplementation on Performance and Health of Growing Steers Consuming High Sulfate Water

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    Thiamin injections are often used to treat sulfate induced polioencephalomalacia (PEM) in beef cattle. It is unclear whether supplemental thiamin will reduce the incidence of PEM and improve performance in steers consuming water with elevated sulfate levels. This study was conducted to determine the effects of thiamin supplementation on performance and health of growing steers consuming water with high sulfate levels. Sixty-three steers (737 ± 2.97 lb) were stratified by weight and randomly allotted to one of nine pens. Pens were assigned to one of three treatments (3 pens/treatment) based on water sulfates and thiamin supplementation. Treatments were: 1) low sulfate water (average = 393 ppm sulfates) with no supplemental thiamin (LS); 2) high sulfate water (average = 3786 ppm sulfates) with no supplemental thiamin (HS); and 3) high sulfate water (average = 3790 ppm sulfates) with supplemental thiamin at 1 g/hd/d (HST). The study was conducted from June 16 to August 22, 2003. Water was obtained from a rural water system and sodium sulfate was mixed in the water to create desired sulfate levels in the HS and HST treatments. Steers were fed a diet containing grass hay, wheat middlings, and supplement. The supplement was identical for all treatments except for the addition of thiamin to HST. Water intake did not differ between treatments (P = 0.24). Steers on HST had a higher (P = 0.05) ADG than those on HS, and steers on LS had a higher (P = 0.01) ADG than HS or HST (1.79, 1.08, 1.39 lb/d for LS, HS, and HST, respectively). Steers on LS had higher (P = 0.01) DMI than steers in HS or HST. Steers on LS and HST had a higher (P \u3c 0.10) gain/feed than steers on HS (0.192, 0.141, and 0.172 for LS, HS, and HST, respectively). The incidence of PEM was 4.8 and 14.3% for HST and HS, respectively, compared to no cases of PEM in the LS treatment (P \u3c 0.10). There were no differences in the incidence of PEM between HST and HS (P = 0.29). Thiamin supplementation (1 g/hd/d) improved ADG and gain/feed in steers receiving high sulfate water

    The dynamical transition in proteins and non-Gaussian behavior of low frequency modes in Self Consistent Normal Mode Analysis

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    Self Consistent Normal Mode Analysis (SCNMA) is applied to heme c type cytochrome f to study temperature dependent protein motion. Classical Normal Mode Analysis (NMA) assumes harmonic behavior and the protein Mean Square Displacement (MSD) has a linear dependence on temperature. This is only consistent with low temperature experimental results. To connect the protein vibrational motions between low temperature and physiological temperature, we have incorporated a fitted set of anharmonic potentials into SCNMA. In addition, Quantum Harmonic Oscillator (QHO) theory has been used to calculate the displacement distribution for individual vibrational modes. We find that the modes involving soft bonds exhibit significant non-Gaussian dynamics at physiological temperature, which suggests it may be the cause of the non-Gaussian behavior of the protein motions probed by Elastic Incoherent Neutron Scattering (EINS). The combined theory displays a dynamical transition caused by the softening of few "torsional" modes in the low frequency regime (< 50cm-1or 0.6ps). These modes change from Gaussian to a classical distribution upon heating. Our theory provides an alternative way to understand the microscopic origin of the protein dynamical transition.Comment: 17 pages, 6 figures, 1 tabl

    Response of Gestating Beef Cows to Limit-Fed Diets Containing Rolled Barley

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    In the Northern Great Plains, barley grain may be a more economical source of energy than hay. An experiment was conducted at South Dakota State University Cottonwood Research Station to determine the efficacy of limit-fed, barley-based diets as an alternative to alfalfa hay for beef cows in late gestation. Ninety-six gestating, crossbred cows (age 3 to 11 years; average calving date of May 7) were stratified by age and weight and randomly assigned to one of 12 pens (8 cows/pen). Pens were randomly allotted to one of three winter feeding treatments (4 pens/treatment) from January 15 to April 10, 2003. Treatments were: 1) course-ground alfalfa hay (Hay; fed at approximately 1.6% of BW); 2) dry rolled barley replacing alfalfa hay at 29% of the diet dry matter (Low Barley; fed at approximately 1.4% of BW); and 3) dry rolled barley replacing alfalfa hay at 67% of the diet dry matter (High Barley; fed at approximately 1.2% of BW). All diets were formulated using the 1996 NRC computer model to provide for maintenance of body condition score. A supplement (0.5 lb/d) supplied adequate protein, minerals, vitamins, and 200 mg/hd/d of Rumensin. Rations changed monthly to account for changing cow requirements during late gestation. All diets were consumed within a two-hour period each day. Treatment means were separated using orthogonal contrasts (Hay vs. High and Low Barley; High Barley vs. Low Barley). Cows fed barley gained more weight than cows fed Hay (P \u3c 0.01; weight change of 79, 126, and 132 lb for Hay, Low Barley, and High Barley, respectively). Cows fed barley also gained more body condition than cows fed Hay (P \u3c 0.01; body condition score change of -0.10, 0.24, and 0.38 for Hay, Low Barley, and High Barley, respectively). There were no differences (P \u3e 0.10) in weight or body condition score change between Low and High Barley treatments. There were no differences between treatments in subsequent pregnancy rates (P \u3e 0.50). Rolled barley can be used to replace alfalfa hay in diets for gestating beef cows

    Effects of Sulfates in Water on Performance of Cow-Calf Pairs

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    Past data from our laboratory showed water sulfate levels of 3,000 ppm reduced performance and health of growing steers during the summer. This experiment, conducted at the South Dakota State University Cottonwood Research Station, evaluated the effects of high sulfate water on cow and calf performance, milk production, and cow reproduction. Ninety-six crossbred, lactating cows (ages 2-13; average calving date of May 1) and their calves were assigned, after stratifying by age, weight, and previous winter management, to one of six pastures (16 cows/pasture) from June 3 to August 26, 2003. Pastures were randomly assigned to one of two water sulfate levels (three pastures/level). Treatments were low sulfate water (LS; average 388 ± 17 ppm sulfates) or high sulfate water (HS; average 2,608 ± 408 ppm sulfates). The HS water was created by adding sodium sulfate to the LS water. Cow 12-hour milk production was estimated by the weigh-suckle-weigh method at the initiation of the trial and again on July 2 and July 29. Initial milk production estimates were used to adjust the July 2 and July 29 estimates, which represented an average of 64 and 91 days into lactation, respectively. Cows on LS gained 15 lb and cows on HS lost 36 lb during the experiment (P = 0.04). Cows on HS tended to loose more (P = 0.10) body condition than LS (-0.27 and -0.48 for LS and HS, respectively). Twelve-hour milk production did not differ on July 2 (P = 0.33; 10.6 and 9.5 lb for LS and HS, respectively) or July 29 (P = 0.48; 11.9 and 11.0 lb for LS and HS, respectively). Calf ADG did not differ (P = 0.71) between treatments. Pregnancy rates (55-d breeding season) were 98% and 94% for the LS and HS treatments, respectively (P = 0.36). Sulfate levels averaging 2,608 ppm in the drinking water of cow-calf pairs during the summer increased cow weight loss and condition loss but did not reduce calf performance or reproduction compared to sulfate levels averaging 388 ppm

    Anthromes dispaying evidence of weekly cycles in active fire data cover 70% of the global land surface

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    Across the globe, human activities have been gaining importance relatively to climate and ecology as the main controls on fire regimes and consequently human activity became an important driver of the frequency, extent and intensity of vegetation burning worldwide. Our objective in the present study is to look for weekly cycles in vegetation fire activity at global scale as evidence of human agency, relying on the original MODIS active fire detections at 1 km spatial resolution (MCD14ML) and using novel statistical methodologies to detect significant periodicities in time series data. We tested the hypotheses that global fire activity displays weekly cycles and that the weekday with the fewest fires is Sunday. We also assessed the effect of land use and land cover on weekly fire cycle significance by testing those hypotheses separately for the Villages, Settlements, Croplands, Rangelands, Seminatural, and Wildlands anthromes. Based on a preliminary data analysis of the daily global active fire counts periodogram, we developed an harmonic regression model for the mean function of daily fire activity and assumed a linear model for the de-seasonalized time series. For inference purposes, we used a Bayesian methodology and constructed a simultaneous 95% credible band for the mean function. The hypothesis of a Sunday weekly minimum was directly investigated by computing the probabilities that the mean functions of every weekday (Monday to Saturday) are inside the credible band corresponding to mean Sunday fire activity. Since these probabilities are small, there is statistical evidence of significantly fewer fires on Sunday than on the other days of the week. Cropland, rangeland, and seminatural anthromes, which cover 70% of the global land area and account for 94% of the active fires analysed, display weekly cycles in fire activity. Due to lower land management intensity and less strict control over fire size and duration, weekly cycles in Rangelands and Seminatural anthromes, which jointly account for 53.46% of all fires, although statistically significant are weaker than those detected in Croplandsinfo:eu-repo/semantics/publishedVersio

    Transmitters and Pathways Mediating Inhibition of Spinal Itch-Signaling Neurons by Scratching and Other Counterstimuli

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    Scratching relieves itch, but the underlying neural mechanisms are poorly understood. We presently investigated a role for the inhibitory neurotransmitters GABA and glycine in scratch-evoked inhibition of spinal itch-signaling neurons in a mouse model of chronic dry skin itch. Superficial dorsal horn neurons ipsilateral to hindpaw dry skin treatment exhibited a high level of spontaneous firing that was significantly attenuated by cutaneous scratching, pinch and noxious heat. Scratch-evoked inhibition was nearly abolished by spinal delivery of the glycine antagonist, strychnine, and was markedly attenuated by respective GABAA and GABAB antagonists bicuculline and saclofen. Scratch-evoked inhibition was also significantly attenuated (but not abolished) by interruption of the upper cervical spinal cord, indicating the involvement of both segmental and suprasegmental circuits that engage glycine- and GABA-mediated inhibition of spinal itch-signaling neurons by noxious counterstimuli

    ACCESS-OM2 v1.0: a global ocean-sea ice model at three resolutions

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    We introduce ACCESS-OM2, a new version of the ocean–sea ice model of the Australian Community Climate and Earth System Simulator. ACCESS-OM2 is driven by a prescribed atmosphere (JRA55-do) but has been designed to form the ocean–sea ice component of the fully coupled (atmosphere–land–ocean–sea ice) ACCESS-CM2 model. Importantly, the model is available at three different horizontal resolutions: a coarse resolution (nominally 1∘ horizontal grid spacing), an eddy-permitting resolution (nominally 0.25∘), and an eddy-rich resolution (0.1∘ with 75 vertical levels); the eddy-rich model is designed to be incorporated into the Bluelink operational ocean prediction and reanalysis system. The different resolutions have been developed simultaneously, both to allow for testing at lower resolutions and to permit comparison across resolutions. In this paper, the model is introduced and the individual components are documented. The model performance is evaluated across the three different resolutions, highlighting the relative advantages and disadvantages of running ocean–sea ice models at higher resolution. We find that higher resolution is an advantage in resolving flow through small straits, the structure of western boundary currents, and the abyssal overturning cell but that there is scope for improvements in sub-grid-scale parameterizations at the highest resolution
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