Collegiality,cooperation, and collaboration     

Louis Kwantes 《The Canadian veterinary journal. La revue veterinaire canadienne》2021,62(9):913

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Quantifying Microbial Methane Oxidation Efficiencies in Two Experimental Landfill Biocovers Using Stable Isotopes     

Alexandre R. Cabral  Marlon A. Capanema  Julia Gebert  Joao F. Moreira  Louis B. Jugnia 《Water, air, and soil pollution》2010,209(1-4):157-172

Stable isotope analyses were performed on gas samples collected within two instrumented biocovers, with the goal of evaluating CH₄ oxidation efficiencies (f ₀). In each of the biocovers, gas probes were installed at four locations and at several depths. One of the biocovers was fed with biogas directly from the waste mass, whereas the other was fed through a gas distribution system that allowed monitoring of biogas fluxes. While the f ₀ values obtained at a depth of 0.1 m were low (between 0.0% and 25.2%) for profiles with poor aeration, they were high for profiles with better aeration, reaching 89.7%. Several interrelated factors affecting aeration seem to be influencing f ₀, including the degree of water saturation, the magnitude of the biogas flux and the temperature within the substrate. Low f ₀ values do not mean necessarily that little CH₄ was oxidized. In fact, in certain cases where the CH₄ loading was high, the absolute amount of CH₄ oxidized was quite high and comparable to the rate of CH₄ oxidation for cases with low CH₄ loading and high f ₀. For the experimental biocover for which the CH₄ loading was known, the oxidation efficiency obtained using stable isotopes (f ₀?=?55.67% for samples taken inside flux chambers) was compared to the value obtained by mass balance (f ₀?=?70.0%). Several factors can explain this discrepancy, including the high sensitivity of f ₀ to slight changes in the isotopic fractionation factor for bacterial oxidation, α _ox, uncertainties related to mass flow metre readings and to the static chamber method.  相似文献   

Early pedogenic evolution of constructed Technosols     

Geoffroy Séré  Christophe Schwartz  Stéphanie Ouvrard  Jean-Christophe Renat  Françoise Watteau  Geneviève Villemin  Jean Louis Morel 《Journal of Soils and Sediments》2010,10(7):1246-1254

Purpose  

Constructed soils are Technosols resulting from the deliberate combination of various artefacts. Similarly to natural soils, technogenic parent materials are transformed by pedogenic factors contributing to their evolution. This work was conducted to study the first stages of the pedogenesis of constructed soils.  相似文献   

Selecting ROPS safety margins for wheeled agricultural tractors based on tractor mass     

Valda Rondelli  Andrew Louis Guzzomi 《Biosystems Engineering》2010,105(3):402-410

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Effects of chronic obesity and weight loss on plasma ghrelin and leptin concentrations in dogs     

Jeusette IC  Detilleux J  Shibata H  Saito M  Honjoh T  Delobel A  Istasse L  Diez M 《Research in veterinary science》2005,79(2):169-175

The objective of this study was to evaluate, in dogs, the effects of obesity and weight loss on plasma total ghrelin and leptin concentrations. Twenty-four Beagle dogs, 12 control lean and 12 obese dogs of both genders and aged between 1 and 9 years, were used for the experiments. Mean body weight was 12.7+/-0.7 kg for the lean group and 21.9+/-0.8 kg for the obese group. The trial was divided into three phases. During phase 1, all 24 Beagle dogs were fed a maintenance diet. During phase 2, the obese dogs were submitted to a weight loss protocol with a high protein-low energy diet. The weight loss protocol ended once dogs reached optimal body weight. During phase 3, the dogs that were submitted to the weight loss protocol were maintained at their optimal body weight for 6 months. Plasma total ghrelin, leptin, insulin and glucose concentrations were measured to evaluate the effects of obesity and weight loss on these parameters in dogs. Body weight, body condition score, thoracic and pelvic perimeters, and ingested food amounts were also recorded during the study. Obese dogs demonstrated a significant decrease in plasma ghrelin and a significant increase in plasma leptin and insulin concentrations when compared with control dogs. During weight loss, significant increases in plasma total ghrelin and glucose and significant decreases in plasma leptin and insulin were observed. The increase in plasma ghrelin concentrations seemed to be transient. Body weight and the morphometric parameters correlated positively with leptin concentrations and negatively with total ghrelin concentrations. These results suggest that ghrelin and leptin could play a role in dogs in the adaptation to a positive or negative energy balance, as observed in humans.  相似文献   

A comparison of serologic tests for the detection of serum antibodies to whole-cell and recombinant Borrelia burgdorferi antigens in cattle          下载免费PDF全文

Magnarelli LA  Bushmich SL  Sherman BA  Fikrig E 《The Canadian veterinary journal. La revue veterinaire canadienne》2004,45(8):667-673

Serum samples from healthy dairy and beef cattle, living in tick-infested areas of Connecticut, USA, were analyzed by polyvalent enzyme-linked immunosorbent assays (ELISA), indirect fluorescent antibody (IFA) staining methods, or Western blot procedures to detect antibodies to tick-borne agents. Of the 80 sera tested by ELISA with whole-cell or 10 separate recombinant antigens (fusion proteins) of Borrelia burgdorferi sensu stricto, 57 (71%) were positive to 1 or more antigens, while 36 (45%) reacted to whole-cell antigens by IFA staining methods. Three (4%) of 80 samples had antibodies to Anaplasma phagocytophilum. There were antibodies to outer surface protein (Osp) A, OspB, OspC, OspE, OspF, protein (p) 41-G, p35, p37, and VlsE antigens of B. burgdorferi, but there was no reactivity to the p39 antigen by ELISA. Western immunoblots of a subset of 9 sera verified antibody presence in all samples and showed distinct reactivities to multiple proteins having molecular masses of about 31 kilodaltons (kDa), 34 kDa, 35 kDa, 41 kDa, and 83/93 kDa. High specificity (97%) was noted when 16 cattle sera containing antibodies to Leptospira interrogans serovars, Brucella sp., Anaplasma marginale, or A. phagocytophilum were tested by ELISA with separate whole-cell or recombinant B. burgdorferi antigens. An ELISA and Western blot analyses can be used to confirm the exposure of cattle to B. burgdorferi.  相似文献   

E-cadherin immunoreactivity in canine mammary tumors.     

Giuseppe Sarli  Rosario Preziosi  Louis De Tolla  Barbara Brunetti  Cinzia Benazzi 《Journal of veterinary diagnostic investigation》2004,16(6):542-547

The reduction or loss of E-cadherin (E-cad), a calcium-dependent epithelial cell adhesion molecule, has been associated with tumor dedifferentiation and invasiveness. The immunohistochemical pattern of E-cad expression was evaluated in formalin-fixed and paraffin-embedded sections of 6 normal mammary glands, 3 dysplasias, 12 benign tumors (8 benign mixed tumors, 4 adenomas), and 60 malignant tumors (12 stage 0, 29 stage I, 19 stage II) of the canine mammary gland. E-cadherin expression was classified as membranous, when on cell-cell boundaries, or as cytoplasmic, when in the form of a diffuse cytoplasmic staining. In addition, the percentage of E-cad-positive epithelial neoplastic cells was graded by a semiquantitative method, categorizing cases into a reduced (or -) type group, when showing less than 25% positivity, a reduced (or +/-) type group, when showing 25-75% positivity, and a preserved (or +) type group, when more than 75% positive cells were present. In the normal mammary gland, E-cad expression was evident in epithelial luminal cells. A stronger positivity was revealed in ductular than in alveolar luminal cells. The myoepithelial cells showed inconsistent, weak cytoplasmic positivity in the normal gland as well as in mammary tumors. In normal glands and benign and malignant noninvasive tumors, E-cad expression was mainly membranous and preserved in most of the epithelial cells. In stage I tumors, both membranous (38%) and cytoplasmic (62%) positivity were well represented, as well as preserved type (55%) and reduced type (45%) tumors. All stage II malignant tumors showed the highest frequency of cytoplasmic positivity (79%) and reduced type (62%) tumors.  相似文献   

High resolution g.l.c. specifications for plant spray oils     

Geoffrey O. Furness  David A. Walker  Paul G. Johnson  Louis A. Riehl 《Pest management science》1987,18(2):113-128

High resolution g.l.c. chromatograms of a series of reference plant-spraying oils were used for the development of proposed g.l.c standards for spraying oils in Australia. The mean size and size-range of molecules in the oils have been specified in relation to carbon number positions for reference n-paraffins. Problems with reproducibility and precision with reduced pressure distillation (10 mm Hg) of plant-spraying oils have been demonstrated and discussed.  相似文献   

Glucocorticoid secretion in heifers given prostaglandin F2alpha after triamcinolone acetonide pretreatment.     

J N Stellflug  T M Louis  H D Hafs 《Journal of animal science》1978,46(4):1066-1070

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Genetic Variability and Population Structure of the Wheat Foot Rot Fungus, Fusarium culmorum, in Tunisia     

Samia Gargouri  Louis Bernier  Mohamed Rabeh Hajlaoui  Mohamed Marrakchi 《European journal of plant pathology / European Foundation for Plant Pathology》2003,109(8):807-815

The random amplified polymorphic DNA (RAPD) method was used to investigate the genetic variability and population structure of Fusarium culmorum isolated from wheat stem bases. A total of 108 isolates, representing seven geographically distinct populations, was collected from five climatic regions in Tunisia. Pseudo-allelic frequencies were estimated at each of the 25 putative RAPD loci analyzed by scoring for the presence or absence of amplified fragments; 92 haplotypes were found among the 108 strains. The analysis of the population structure did not reveal any trend with regard to geographic origin. Total gene diversity (H_T ^* = 0.318) was mostly attributable to diversity within populations (H_S ^* = 0.308). Analysis of molecular variance confirmed that most of the genetic variability was within populations. Genetic differentiation among populations was low to moderate (G_ST ^* ranged from 0 to 0.190 and averaged 0.041 over all loci). Cluster analysis with UPGMA using genetic distances did not reveal any spatial clustering of the isolates collected from the different geographic regions. Based on these results, we conclude that the F. culmorum isolates recovered from different regions in Tunisia might be part of a single population pool.  相似文献