Heliotropium europaeum poisoning of sheep with low liver copper concentrations and the preventive efficacy of cobalt and antimethanogen     

JE PETERSON  AL PAYNE  CCJ CULVENOR 《Australian veterinary journal》1992,69(3):51-56

In a field experiment in the Mallee district of Victoria, Merlno xBorder Leicester ewes and wethers grazed Heliotropium europaeum (heliotrope) over periods of 3 to 4 months in 4 successive years. By the end of the second year 12% (14 of 120) of the sheep had died; after 4 years the loss attributable to heliotrope was between 18% and 35%. Mortality was not affected by intraruminal treatment with cobalt or antimethanogen. At the end of the experiment the highest concentration of copper in the liver was 1.95 mmol/kg wet weight (approximately 413 micrograms/g dry weight). The relatively low mortality from primary heliotrope poisoning and the low concentration of copper in the liver of sheep grazing the plant are discussed in relation to the contrasting situation that prevails in the Riverina area of New South Wales. The importance of local environmental factors in the management of heliotrope grazing by sheep is emphasised, particularly in relation to the number of seasons in which the plant may be a major component of the diet.  相似文献   

Neuronal Responses in the Brainstem and Hypothalamic Nuclei Following Insulin Treatment During the Late Follicular Phase in the Ewe     

R Morris  JE Routly  RF Smith  H Dobson 《Reproduction in domestic animals》2011,46(1):121-129

The aim of this study was to determine the neuronal responses following insulin administration during the late follicular phase. Intact ewes were given either saline or insulin (5 IU/kg, i.v.) at 35 h after progesterone withdrawal and killed 3 h later. There was a marked increase in the number of Fos‐positive noradrenergic neurones in the caudal brainstem of insulin‐treated ewes. In the hypothalamic paraventricular nucleus, insulin treatment increased the presence of Fos‐positive corticotrophin‐releasing hormone neurones (from 2% to 98%) and Fos‐positive arginine vasopressin parvocellular neurones (from 2% to 46%). Interestingly, after insulin treatment, despite a general increase in Fos‐positive neurones in the arcuate nucleus (ARC), there was a marked reduction (from 47% to 1%) in Fos‐positive β‐endorphin neurones. Similarly, colocalized Fos and oestradiol receptor (ER) α‐positive neurones decreased in the ARC after insulin (from 7% to 3%). Conversely, in the ventromedial nucleus, ERα‐positive neurones with Fos increased (from 7% to 22%) alongside a general increase in Fos‐positive neurones. Overall, a complex system of neurones in brainstem and hypothalamus is activated following insulin administration during the late follicular phase.  相似文献   

2011 AAHA canine vaccination guidelines     

American Animal Hospital Association 《Journal of the American Animal Hospital Association》2011,47(5):1-42

  相似文献   

A ferroelectric liquid crystal conglomerate composed of racemic molecules     

Walba DM  Korblova E  Shao R  Maclennan JE  Link DR  Glaser MA  Clark NA 《Science (New York, N.Y.)》2000,288(5474):2181-2184

We describe the design and synthesis of a ferroelectric liquid crystal composed of racemic molecules. The ferroelectric polarization results from spontaneous polar symmetry breaking in a fluid smectic. The ferroelectric phase is also chiral, resulting in the formation of a mixture of macroscopic domains of either handedness at the isotropic-to-liquid crystal phase transition. This smectic liquid crystal is thus a fluid conglomerate. Detailed investigation of the electrooptic and polarization current behavior within individual domains in liquid crystal cells shows the thermodynamically stable structure to be a uniformly tilted smectic bow-phase (banana phase), with all layer pairs homochiral and ferroelectric (SmC(S)P(F)).  相似文献   

Common mechanism of chromosome inversion in B- and T-cell tumors: relevance to lymphoid development   总被引：12，自引：0，他引：12  

C T Denny  G F Hollis  F Hecht  R Morgan  M P Link  S D Smith  I R Kirsch 《Science (New York, N.Y.)》1986,234(4773):197-200

An inversion of chromosome 14 present in the tumor cells of a patient with childhood acute lymphoblastic leukemia of B-cell lineage was shown to be the result of a site-specific recombination event between an immunoglobulin heavy-chain variable gene and the joining segment of a T-cell receptor alpha chain. This rearrangement resulted in the formation of a hybrid gene, part immunoglobulin and part T-cell receptor. Furthermore, this hybrid gene was transcribed into messenger RNA with a completely open reading frame. Thus, two loci felt to be normally activated at distinct and disparate points in lymphocyte development were unified and expressed in this tumor.  相似文献   

Crystalline Ropes of Metallic Carbon Nanotubes   总被引：7，自引：0，他引：7  

A Thess  R Lee  P Nikolaev  H Dai  P Petit  J Robert  C Xu  YH Lee  SG Kim  AG Rinzler  DT Colbert  GE Scuseria  D Tomanek  JE Fischer  RE Smalley 《Science (New York, N.Y.)》1996,273(5274):483-487

Fullerene single-wall nanotubes (SWNTs) were produced in yields of more than 70 percent by condensation of a laser-vaporized carbon-nickel-cobalt mixture at 1200degreesC. X-ray diffraction and electron microscopy showed that these SWNTs are nearly uniform in diameter and that they self-organize into "ropes," which consist of 100 to 500 SWNTs in a two-dimensional triangular lattice with a lattice constant of 17 angstroms. The x-ray form factor is consistent with that of uniformly charged cylinders 13.8 +/- 0.2 angstroms in diameter. The ropes were metallic, with a single-rope resistivity of <10(-4) ohm-centimeters at 300 kelvin. The uniformity of SWNT diameter is attributed to the efficient annealing of an initial fullerene tubelet kept open by a few metal atoms; the optimum diameter is determined by competition between the strain energy of curvature of the graphene sheet and the dangling-bond energy of the open edge, where growth occurs. These factors strongly favor the metallic (10,10) tube with C5v symmetry and an open edge stabilized by triple bonds.  相似文献   

Inhalant anesthetic requirement in cats is animal-dependent     

LS  Barter  JE Ilkiw  EP Steffey  BH Pypendop  A Imai  JA Bolich 《Veterinary anaesthesia and analgesia》2003,30(2):105-105

Minimum alveolar concentration (MAC) of an inhalant is an indicator of its anesthetic potency. Individuals vary in their sensitivity to anesthetic agents as demonstrated by different individual MAC values. We hypothesized that individual animal sensitivity would be maintained with different inhalant anesthetics. As part of separate studies, six female DSH cats, aged 24 ± 2.5 (mean ± SD) months and weighing 3.5 ± 0.3 kg, were studied similarly on three separate occasions over a 12‐month period to determine the MAC of isoflurane (ISO), sevoflurane (SEVO), and desflurane (DES), respectively. In each study, chamber induction was followed by orotracheal intubation, and anesthesia was maintained via a nonrebreathing circuit. ECG, pulse oximetry, Doppler systolic blood pressure, end‐tidal gases, and esophageal temperature were monitored. End‐tidal gases were hand‐sampled from a catheter whose tip lay level with the distal end of the ET tube. Gases were analyzed by Raman spectrometry and, for each agent, the analyzer was calibrated with at least three gas standards. MAC was determined in triplicate using standard tail‐clamp technique. Data were analyzed by two‐way anova followed by Tukey's test and significant differences were found. Average MACs (%) for ISO, SEVO, and DES were 1.90 ± 0.18, 3.41 ± 0.65, and 10.27 ± 1.06, respectively. Body temperatures, Doppler systolic blood pressure, and SpO₂ were recorded at the time of MAC determinations for ISO, SEVO, and DES were 38.3 ± 0.3, 38.6 ± 0.1, 38.3 ± 0.35 °C; 71 ± 8, 75 ± 16, 88 ± 12 mm Hg; 99 ± 1, 99 ± 1, 99 ± 1%, respectively. Both the anesthetic agent and the individual cat had significant effects on MAC (p = 0.0001 and 0.0185, respectively). MAC varied between individuals and cats were consistent in their order of sensitivity to inhalant anesthetics across the three agents. Within this group of cats, the relationship of individual MAC to the group MAC for each of the three inhalant agents was maintained. This suggests that any individual may be consistently more or less sensitive to a variety of inhalant agents.  相似文献   

Hemodynamic effects of intravenous lidocaine in isoflurane anesthetized cats     

BH Pypendop  JE Ilkiw 《Veterinary anaesthesia and analgesia》2005,32(4):5-6

Lidocaine dose‐dependently decreases the minimum alveolar concentration (MAC) of isoflurane in cats. The purpose of this study was to determine the hemodynamic effects of six lidocaine plasma concentrations in isoflurane anesthetized cats. Six cats were studied. After instrumentation, end‐tidal isoflurane concentration was set at 1.25 times the individual minimum alveolar concentration (MAC), which was determined in a previous study. Lidocaine was administered intravenously to target pseudo‐steady state plasma concentrations of 0, 3, 5, 7, 9, and 11 μg ml^–1, and isoflurane concentration was reduced to an equipotent concentration, determined in a previous study. Cardiovascular variables; blood gases; PCV; total protein and lactate concentrations; and lidocaine and monoethylglycinexylidide concentrations were measured at each lidocaine target concentration, before and during noxious stimulation. Derived variables were calculated. Data were analyzed using a repeated measures anova , followed by a Tukey test for pairwise comparisons where appropriate. One cat was excluded from analysis because the study was aborted at 7 μg ml^–1 due to severe cardiorespiratory depression. Heart rate, cardiac index, stroke index, right ventricular stroke work index, total protein concentration, mixed‐venous PO₂ and hemoglobin oxygen saturation, arterial and mixed‐venous bicarbonate concentrations, and oxygen delivery were significantly lower during lidocaine administration than when no lidocaine was administered. Mean arterial pressure, central venous pressure, pulmonary artery pressure, systemic and pulmonary vascular resistance indices, PCV, arterial and mixed‐venous hemoglobin concentrations, lactate concentration, arterial oxygen concentration, and oxygen extraction ratio were significantly higher during administration of lidocaine than when no lidocaine was administered. Most changes were significant at lidocaine target plasma concentrations of 7 μg ml^–1 and above. Noxious stimulation did not significantly affect most variables. Despite significantly decreasing in inhalant requirements, when combined with isoflurane, lidocaine produces greater cardiovascular depression than an equipotent dose of isoflurane alone. The use of lidocaine to reduce isoflurane requirements is not recommended in cats.  相似文献   

Insights Into the Latent Multinomial Model Through Mark-Resight Data on Female Grizzly Bears With Cubs-of-the-Year     

Megan D. Higgs  William A. Link  Gary C. White  Mark A. Haroldson  Daniel D. Bjornlie 《Journal of Agricultural, Biological & Environmental Statistics》2013,18(4):556-577

Mark-resight designs for estimation of population abundance are common and attractive to researchers. However, inference from such designs is very limited when faced with sparse data, either from a low number of marked animals, a low probability of detection, or both. In the Greater Yellowstone Ecosystem, yearly mark-resight data are collected for female grizzly bears with cubs-of-the-year (FCOY), and inference suffers from both limitations. To overcome difficulties due to sparseness, we assume homogeneity in sighting probabilities over 16 years of bi-annual aerial surveys. We model counts of marked and unmarked animals as multinomial random variables, using the capture frequencies of marked animals for inference about the latent multinomial frequencies for unmarked animals. We discuss undesirable behavior of the commonly used discrete uniform prior distribution on the population size parameter and provide OpenBUGS code for fitting such models. The application provides valuable insights into subtleties of implementing Bayesian inference for latent multinomial models. We tie the discussion to our application, though the insights are broadly useful for applications of the latent multinomial model.  相似文献   

Winter hardiness in faba bean: Physiology and breeding     

W. Link  C. Balko  F.L. Stoddard 《Field Crops Research》2010

Winter types of faba bean (Vicia faba L.) have existed for at least 200 years. Their superior use of the growing season confers strong yield advantages over spring beans. Nevertheless, yield increases have been slower than in many other crops. There are few sources of winter hardiness and efforts are in progress to combine favourable alleles from accessions such as Cote D’Or and BPL 4628 to increase the crop’s tolerance to frost. Vernalization requirements are quantitative, as vernalization hastens flowering rather than allowing it. Hardening is associated with increases in fatty acid desaturation of membrane lipids and increases in content of soluble osmoprotectants such as proline. Other osmotically active factors such as glycinebetaine, trehalose and antifreeze proteins have not yet been reported for faba bean. Frost tolerance increases after hardening and shows good heritability (h² = 0.89). Three QTLs (3.6 < LOD < 4.6) have been identified for frost tolerance (explaining 8.6% of the phenotypic variation), and further QTLs for hardening response and cell membrane fatty acid composition. Information on responsive genes and the mode of their action is increasingly available from model plant species but most remains as yet untested in faba bean. There is clear potential for increasing the winter hardiness and yield of winter faba bean so it can be grown in a wider area than at present.  相似文献