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排序方式: 共有450条查询结果,搜索用时 15 毫秒
41.
Luca Bragazza Paola Iacumin Chiara Siffi Renato Gerdol 《Biology and Fertility of Soils》2010,46(8):877-881
In this study, we describe the seasonal variation in 15N abundance in the litter of two Sphagnum species and four vascular plant species during 3 years of field decomposition in an Italian Alpine bog. Litter bags were periodically retrieved at the end of summer and winter periods, and the δ15N in residual litter was related to mass loss, litter chemistry, and climatic conditions. In Sphagnum litter, higher rates of decomposition during summer months were associated with an increase of δ15N probably due to the incorporation of microbial organic compounds rich in 15N. The litter of Eriophorum vaginatum and Carex rostrata was characterized by a decrease of δ15N, so that the final signature was significantly lower than in initial litter. On the other hand, the residual litter of Potentilla erecta and Calluna vulgaris was characterized by a final δ15N higher than in initial litter. Our data reported a seasonality of 15N abundance in the residual litter of Sphagnum species, but not in that of vascular plant species, thus highlighting the role of differences in litter chemistry. 相似文献
42.
Enzymatic activity often reduces the nutritional value of wheat flour during food manufacturing, causing compound degradation and/or heat damage. The choice of wheat varieties with low enzymatic activity could therefore help to preserve the nutritional quality of food. The aim of this research was to evaluate polyphenol oxidase, alpha-amylase and beta-amylase activities in whole meal flours of 59 accessions belonging to different wheat species and subspecies, cropped in two years. The extraction pH (7.0), reaction pH (5.5) and reaction temperature (45 °C) were determined by preliminary trials. The ANOVA highlighted significant differences for all enzymes among species/subspecies and, for amylases, between cropping years; however, the year influence was overwhelming only for alpha-amylase. Einkorn showed the highest polyphenol oxidase (362.1 ± 9.46 U/g DM) as well as the lowest alpha-amylase (0.20 ± 0.006 CU/g DM) and beta-amylase (12.0 ± 0.36 B3U/g DM) activities. The embryo/scutellum had the highest polyphenol oxidase and alpha-amylase values, followed by the bran and the endosperm; in contrast, beta-amylase was evenly distributed in the bran and the endosperm, and was absent in the embryo/scutellum. 相似文献
43.
Narayan Chandra Paul Francesca Latronico Arshnee Moodley S?ren Saxmose Nielsen Peter Damborg Luca Guardabassi 《Veterinary research》2013,44(1):52
The current knowledge of in vitro adherence of Staphylococcus pseudintermedius to canine corneocytes is limited to comparative analyses between strains, staphylococcal species or corneocytes collected from different breeds, body sites and hosts. However, the role played by colonization status of corneocyte donors remains unknown. The aim of this study was to evaluate the adherence properties of commensal S. pseudintermedius strains to corneocytes collected from dogs with different colonization status. For this purpose, corneocytes were collected from five dogs that were classified as persistently colonized (D1 and D2), intermittently colonized (D3 and D4) or non-colonized (D5) on the basis of the results of a previous longitudinal study. Adherence to corneocytes originating from each of the five dogs was assessed by an in vitro adhesion assay using four genetically unrelated strains isolated from the colonized dogs (S1 to S4). Irrespective of their host of origin, all strains adhered significantly better to corneocytes from D1 and D2 than to corneocytes from D3, D4 and D5 (P < 0.0001). The mean count of cells adhering to corneocytes from persistently colonized dogs was on average three times higher than the mean count using corneocytes from the other dogs. A significant difference between strains was only observed for one strain-corneocyte combination (S2-D4), indicating that S. pseudintermedius adherence to corneocytes is driven by host factors and only marginally influenced by strain factors. This finding has important implications for understanding and preventing S. pseudintermedius skin colonization and infection. 相似文献
44.
Monitoring of antimicrobial resistance in healthy dogs: first report of canine ampicillin-resistant Enterococcus faecium clonal complex 17 总被引:1,自引:0,他引:1
National surveillance programs on antimicrobial usage and antimicrobial resistance in animals have been established in various countries but few of them include bacteria from pets. The objectives of this study were to assess the prevalence of antimicrobial resistance in healthy dogs and to search for resistance phenotypes of clinical relevance. Escherichia coli and Enterococcus spp. were isolated from faecal swabs obtained from 127 dogs. Disk diffusion was used to measure antimicrobial susceptibility in 117 Escherichia coli, 10 Enterococcus faecium and 51 Enterococcus faecalis of canine origin. Resistance was relatively low compared with food animal species in Denmark. All Escherichia coli isolates were susceptible to broad-spectrum aminopenicillins, third generation cephalosporins and fluoroquinolones. Despite the low prevalence of resistance, statistical analysis of questionnaire data revealed a significant association (p=0.02) between recent antimicrobial treatment and resistance in Escherichia coli. Interestingly, two dogs were found to shed Enterococcus faecium resistant to ampicillin. Multilocus sequence typing of these isolates indicated that the two isolates belonged to sequence types associated with human nosocomial infections, and one (ST-192) was genetically related to human epidemic clonal complex 17. The detection of ampicillin-resistant Enterococcus faecium warrants further studies on the prevalence of these bacteria in dogs and on the possible implications to both animal and human health. The results suggest that distinct methods for detection and assessment of antimicrobial resistance in animals should be considered depending on the target animal species and the purposes of the study. 相似文献
45.
46.
Domenico Santoro Andrea Spaterna Luca Mechelli Paolo Ciaramella 《The Canadian veterinary journal. La revue veterinaire canadienne》2008,49(12):1204-1207
A case of canine cutaneous sterile pyogranuloma/granuloma syndrome (SPGS) with generalized asymmetrical alopecia and plaques is described. Results from histopathologic examination were suggestive of SPGS and failed to demonstrate any etiological agent. A systematic approach on how to definitively rule out infectious skin diseases is discussed. 相似文献
47.
Slater MR Di Nardo A Pediconi O Villa PD Candeloro L Alessandrini B Del Papa S 《Preventive veterinary medicine》2008,85(3-4):267-294
Three hundred and ninety-seven randomly selected households were interviewed by telephone to determine the numbers and management of owned cats and dogs in the Teramo Province of Italy. The households were selected using stratified random sampling for each municipality; municipalities were combined into coastal, central hills and mountain regions for analysis. The interviews were completed during May and June of 2004 with a response rate of 74% (397/536). Forty-six percent of households (n=181) owned pets; 15% of all households (n=60) owned cats and 33% (n=130) owned dogs. Twenty-seven of these households (7%) owned both cats and dogs. Data were provided on 91 cats evenly divided between males and females. The median age was 3 years (range 0.2-10 years). Forty-one percent of cats (36/87) entered the household as strays. Nearly half lived entirely outside. Seventy percent (62/88) had visited a veterinarian at least once; 43% (39/91) were sterilized. About 1/3 had had a litter and all litters were considered accidental rather than planned. Age, indoor/outdoor status, veterinarian visit and region were all associated with sterilization. Age, confined to a yard, veterinary visit and region were associated with allowing the cat to roam freely. Data were provided on 182 dogs. Sixty-two percent (113/181) were male, with a median age of 4 years (range newborn to 17 years) and 40% (72/181) were purebred. Almost half were acquired as a gift. Sixty-two percent (112/180) were kept entirely outside despite the fact that 82% (147/180) were considered companions rather than working dogs. Almost all of the dogs had been to a veterinarian at least once; only 20% (n=29) were sterilized. Male dogs were significantly less likely to be sterilized than females. Almost half the dogs had had at least one litter. Seventy-six percent (137/180) of dogs knew some basic commands. Sex, source and training to sit/stay/come were significantly associated with whether the dog was sterilized. Dog size, confinement to a yard, trained to leash walk, veterinary visit and region were predictors of roaming freely. Source and trained to leash walk were associated with dog registration. For cats and dogs, education about sterilization seemed to be critically important. For dogs, factors relating to training, which may reflect the strength of the human-animal bond, were also important. 相似文献
48.
Luca SANTINI Ana BENÍTEZ‐LÓPEZ Gentile Francesco FICETOLA Mark A. J. HUIJBREGTS 《Integrative zoology》2018,13(1):36-45
Body mass is rarely recorded in amphibians, and other body measurements (e.g. snout to vent length, SVL) are generally collected instead. However, length measurements, when used as proxies of body mass in comparative analyses, are problematic if different taxa and morphotypes are included. We developed allometric relationships to derive body mass from SVL measurements. We fitted phylogenetic generalized least square models for frogs (Anura) and salamanders (Caudata) and for several families separately. We tested whether allometric relationships differed between species with different habitat preferences and between morphs in salamanders. Models were fitted with SVL–mass measurements for 88 frog and 42 salamander species. We assessed the predictive performance of the models by cross‐validation. Overall, the models showed high explained variance and low forecasting errors. Models differed among semi‐aquatic, terrestrial and arboreal frogs, and between paedomorphic and non‐paedomorphic salamanders. Body mass estimates derived from our models allow for comparability of studies on multiple taxa and can be used for testing theories built upon evolutionary and ecological processes which are directly related to body mass. 相似文献
49.
Alessio Bonaldo Gloria Isani Ramon Fontanillas Luca Parma Ester Grilli Pier Paolo Gatta 《Aquaculture International》2010,18(5):909-919
Three isoproteic (47% protein) diets were formulated to contain graded levels of crude fat (diet D16:16%, diet D24: 24% and
diet D32: 32%). Each diet was fed to satiation in three and to 80% satiation in two replicate groups of gilthead sea bream
(Sparus aurata), having an initial body weight of 72–74 g. The trial lasted 81 days. Groups fed to satiation showed higher final body weight
(FBW; 238.8–252.3 g vs. 218.0–229.3 g) and daily growth index (DGI; 2.49–2.65%/day vs. 2.27–2.34%/day) than those fed to 80%
satiation. Feed intake was significantly different both for feeding level and for diet composition. Fish fed to satiation
had higher feed conversion rate (FCR) compared to the 80% satiation groups (1.33–1.44 vs. 1.13–1.17; P ≤ 0.001). Within satiation groups, FCR was significantly lower in fish fed D16 compared to fish fed D32 (1.33 vs. 1.44, P ≤ 0.05), whereas no statistical differences were found within the 80% satiation groups. The increase in dietary lipid level
did not improve growth performance, feed efficiency and protein utilization but decreased gross lipid efficiency. Conversely,
a reduction in ration from satiation to 80% satiation decreased DGI, thus improving FCR. Feed costs were influenced by dietary
energy level and feeding ratio, the lowest energy diet at 80% satiation being the most profitable combination among the variables. 相似文献
50.
Luisa M Manici Onofrio Leoni Luca Lazzeri Stefania Galletti Sandro Palmieri 《Pest management science》1999,55(4):486-488
Enzyme-derived products obtained from thio-functionalised glucosinolates showed high fungitoxicity, a wide activity spectrum and special physicochemical properties, which suggest their potential as alternatives to commercial fumigants for controlling several soil-borne pathogens. © 1999 Society of Chemical Industry 相似文献