Modeling temporal progress of plant diseases     

Marcus  Ruth 《Phytoparasitica》1990,18(4):341-351

A model for describing temporal progress of plant diseases is presented. The model (termed a ‘mixed’ model) coincides in two special cases with the logistic and the monomolecular models introduced by Vanderplank. The mixed model is implemented using some data available on the spread of zucchini yellow mosaic virus (ZYMV) from a field experiment in Israel.  相似文献   

Normal birth following exteriorization and intravenous injection of the early sheep fetus     

A K Karihaloo  J J Thomsen  B A Rasmusen  F Pazderka  R F Ruth 《American journal of veterinary research》1972,33(9):1781-1788

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Physicochemical properties of agrochemicals: Their effects on foliar penetration     

Edward A. Baker  Ann L. Hayes  Ruth C. Butler 《Pest management science》1992,34(2):167-182

Uptake and translocation of 26 chemicals (herbicides, fungicides, growth regulators, insecticides and model compounds), formulated with and without ‘Ethylan TU’ (NP8) surfactant, have been determined 24, 48 and 72 h after spraying onto leaves of maize, rape, strawberry and sugar beet. Eight of the chemicals may be classified as polar (log partition coefficient (P) < 0) and 18 as lipophilic (log P 0·8-4·6). Chemicals penetrated more readily into waxy leaves of rape and strawberry than into less-waxy sugar beet, whilst lowest rates were observed for maize. Rates of uptake varied from exceedingly low (< 2% 72 h after application) for uracil, maleic hydrazide, isoproturon and methyl phenylurea applied to maize, to rapid (>98% within 24 h of application) for acephate and triadimefon applied to strawberry leaves. The effects of NP8 on rates of chemical uptake were classified into 4 types, viz:-

• (i) low rates, with limited enhancement by NP8;
• (ii) high rates unaffected by NP8;
• (iiii) marked enhancement by NP8 within 24 h; and
• (iv) continuous enhancement by NP8 over 0-72 h.

Translocation into the tissues immediately adjacent to the target site was greater for waxy than less-waxy plants, enhancement by NP8 was attributed to its effects on penetration rather than to surfactant interactions at the sub-cuticular level. Logarithms of physicochemical properties (partition coefficient, water solubility S, molecular weight MW), together with deposit area and melting point (m.p.) values were used to investigate relationships with uptake and translocation. In most cases the variability could not be described adequately in a simple linear form. Regressions using the entire group of 26 chemicals also showed poor correlations between uptake patterns and individual variables. Polynomials in log S, log P, log MW and m.p. were used to test for complex relationships. A quadratic polynomial in log P, log S and m.p. accounted for slightly more (77%) of the variability between the means for total uptake than a cubic polynomial in log P and log S (75%). Although both regressions were significant, the ‘lack of fit’ indicated that other factors need to be included to account fully for the variability in rates of uptake and translocation.  相似文献   

Lesions of perirenal hemorrhage syndrome in growing turkeys     

R K Frank  J Newman  G R Ruth 《Avian diseases》1991,35(3):523-534

Turkeys from six market flocks were examined at 8 to 19 weeks of age to assess morphologic lesions of perirenal hemorrhage syndrome (PHS). PHS was diagnosed in 165 of 715 turkeys necropsied, and 82 turkeys served as age- and weight-matched controls. The most consistent gross findings were rounded pectoral muscles of normal color, ingesta-filled crops and gizzards, variable retroperitoneal perirenal hemorrhage, a swollen dark red and light purple spleen, congested intestinal blood vessels, and pulmonary edema and/or hemorrhage. The main histologic lesions of PHS were perivascular edema in lungs and kidneys, vascular congestion of various organs, renal perivenous hemorrhage, and proliferative arterial and arteriolar lesions in the spleen and kidneys that were more severe than those in controls. Heart weights, including mean relative weights of the right and combined left ventricles and interventricular septa, were significantly greater in turkeys that died with PHS than in controls. Scores for tibial dyschondroplasia and "breast blisters" were more severe in turkeys that died with PHS than in controls. The cardiovascular system appeared to be the PHS target system.  相似文献   

Ultrasonographic variations are present in the distal sesamoidean impar ligament of clinically sound horses          下载免费PDF全文

Jessica Lauren MacDonald  Ruth‐Anne Richter  Christine L. Wimer 《Veterinary radiology & ultrasound》2018,59(5):607-612

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Replacing dietary antibiotics with 0.20% l-glutamine in swine nursery diets: impact on intestinal physiology and the microbiome following weaning and transport     

Alan W Duttlinger  Ruth E Centeno Martinez  Betty R McConn  Kouassi R Kpodo  Donald C Lay  Jr  Brian T Richert  Timothy A Johnson  Jay S Johnson 《Journal of animal science》2021,99(6)

Previous research demonstrates that supplementing 0.20% l-glutamine (GLN) in the diets of newly weaned and transported pigs improves growth rate to a similar extent as providing dietary antibiotics (AB). However, research comparing the effects of GLN vs. AB on intestinal physiology and the microbiome is limited. Therefore, the study objective was to compare the effects of supplementing nursery diets with GLN, AB, or no dietary antibiotics (NA) on intestinal physiology and the microbiome of pigs in a production environment following weaning and transport. Mixed-sex piglets (N = 480; 5.62 ± 0.06 kg body weight [BW]) were weaned (18.4 ± 0.2 d of age) and transported for 12 h in central Indiana, for two replicates, during the summer of 2016 and the spring of 2017. Pens were blocked by BW and allotted to one of the three dietary treatments (n = 10 pens/dietary treatment/replicate [8 pigs/pen]): AB (chlortetracycline [441 ppm] + tiamulin [38.6 ppm]), GLN (0.20% as-fed), or NA fed for 14 d. From day 14 to 34, pigs were fed common AB-free diets in two phases. On day 33, villus height:crypt depth tended to be increased (P = 0.07; 7.0%) in GLN and AB pigs vs. NA pigs. On day 33, glucagon-like peptide 2 (GLP-2) mRNA abundance was decreased (P = 0.01; 50.3%) in GLN and NA pigs vs. AB pigs. Crypt depth was increased overall on day 33 (P = 0.01; 16.2%) during the spring replicate compared with the summer replicate. Villus height:crypt depth was reduced (P = 0.01; 9.6%) during the spring replicate compared with the summer replicate on day 33. On day 13, tumor necrosis factor-alpha and occludin mRNA abundance was increased (P ≤ 0.04; 45.9% and 106.5%, respectively) and zonula occludens-1 mRNA abundance tended to be greater (P = 0.10; 19.2%) in the spring replicate compared with the summer replicate. In addition, AB pigs had increased (P = 0.01; 101.3%) GLP-2 mRNA abundance compared with GLN and NA pigs. Microbiome analysis indicated that on day 13, dietary treatment altered the microbiota community structure (P = 0.03). Specifically, the AB pigs tended to be distinct from both the NA and GLN pigs (P = 0.08), and Lactobacillus was increased nearly 2-fold in AB compared with NA pigs (q = 0.04) and GLN pigs (q = 0.22). In conclusion, GLN supplementation tended to improve some morphological markers of intestinal health similarly to AB pigs, while the microbiome composition in GLN pigs was more similar to NA pigs than AB pigs.  相似文献   

The road to balanced oversight     

Faden R 《Science (New York, N.Y.)》2006,313(5789):891

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Ritual slaughter     

van der Leij R 《Tijdschrift voor diergeneeskunde》2006,131(9):345

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Preclinical dilated cardiomyopathy in the dobermann     

Summerfield N  Dukes-McEwan J  Swift S  Patteson M  Wotton P  Martin M  Johnson M  Boswood A  Fuentes VL  French A  Culshaw G  Little C  Smith P  Smith S  Willis R 《The Veterinary record》2006,158(21):742-743

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Effects of bacterial lipopolysachharide on peripheral leukocytes in the American alligator (Alligator mississippiensis)     

Merchant M  Mills K  Williams S  Kleckley F  Sims A  Elsey RM  Bushnell J 《Veterinary immunology and immunopathology》2006,111(3-4):315-320

Alligators were injected intraperitoneally with four different doses (10, 1.0, 0.1, and 0.01 mg/kg body weight) of a mixture of bacterial lipopolysaccharides (LPS) derived from three different types of bacteria (Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae). Injection of the alligators with the LPS mixture resulted in a dose- and time-dependent increase in total peripheral leukocytes Lymphocytes increased at days 3 and 4 post-injection, and decreased back to baseline levels at day 7 for all doses. Alligators that were not treated, and those injected with pyrogen-free saline, did not exhibit statistically significant changes in total leukocytes during the course of the study. Injection of alligators with 0.5 mg LPS/kg body weight derived from one of three bacterial species revealed that the leukocyte increases observed were not statistically different for all three types of LPS. The animals displayed the same increases in total counts and the levels of all circulating leukocyte types were not different between animals treated with a combination of LPS from all three bacterial species.  相似文献