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Rooted spruce cuttings from three clones were sprayed daily with sulfuric acid at pH 2.5 for one month or treated with automobile exhaust for one hour. Foliage samples were extracted and analyzed by high performance liquid chromatography. Chromatographic peaks representing unidentified leaf constituents from treated and control trees were compared. Discriminant analysis indicated a weak but significant difference and Canonical discriminant analysis indicated clear differences between treatments and control. Similar differences were found between the three clones. Visible symptoms of damage were not evident even four months after treatment. This result is important because it demonstrates the possibility of using unidentified plant constituents to detect damage to plants even before visible symptoms appear. 相似文献
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Paiton O McDonald Courtney Schill Teresia W Maina Beulah Samuel Madison Porter Ilkyu Yoon Jodi L McGill 《Journal of animal science》2021,99(11)
We have previously reported that supplementation with Saccharomyces cerevisiae fermentation products (SCFP) ameliorates clinical signs and lung pathology following experimental bovine respiratory syncytial virus (BRSV) infection in preweaned dairy calves. The objectives of this study were to determine the effect of SCFP supplementation on the metabolic and endocrine responses, and disease outcome of a viral–bacterial coinfection in preweaned calves. Twenty-seven, 1- to 2-d-old Holstein-Angus cross calves were enrolled in the study; one SCFP calf was removed from the trial during the pre-challenge phase due to complications from nephritis. Calves were assigned to two treatment groups: control or SCFP-treated, base milk replacer with 1 g/d SCFP (Smartcare, soluble formula) and calf starter top dressed with 5 g/d SCFP (NutriTek, insoluble formula). Calves were infected with BRSV on day 21, followed 6 d later by intratracheal inoculation with Pasteurella multocida (PM). Calves were euthanized on day 10 post-viral infection. Calves receiving SCFP had reduced thoracic ultrasonography scores on day 7 post-viral infection (P = 0.03) and a tendency toward reduced scores on day 10 post-viral infection (P = 0.09). Calves receiving SCFP also had less severe lung pathology scores at necropsy (P = 0.06). No differences between treatments were observed in lung viral loads (P = 0.48) or bacterial lung recovery (P = 0.34); however, there was a distinction in the lung location for PM recovery, with PM isolated more frequently from the cranial lobes in SCFP-treated calves, but more frequently from the caudal lobes of control calves. Calves treated with SCFP tended (P = 0.07) to have higher serum IL-6 concentrations following the coinfection. Calves treated with SCFP had lower concentrations of serum nonesterified fatty acids and beta-hydroxybutyric acid compared with controls following experimental challenge (P = 0.03 and P = 0.08, respectively), suggesting metabolic changes favoring growth and development. There were no differences between groups in gene expression of insulin receptor, insulin-like growth factor 1 (IGF-1), IGF-1 receptor (IGF-1R), growth hormone receptor, or haptoglobin in the liver. Results from this study suggest that supplementing with SCFP may moderate the impact of a respiratory viral–bacterial coinfection on preweaned calves through metabolic and immune modifications. 相似文献
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Evaluation of angler reporting accuracy in an off‐site survey to estimate statewide steelhead harvest 
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下载免费PDF全文 J. L. McCormick D. Whitney D. J. Schill M. C. Quist 《Fisheries Management and Ecology》2015,22(2):134-142
Accuracy of angler‐reported data on steelhead, Oncorhynchus mykiss (Walbaum), harvest in Idaho, USA, was quantified by comparing data recorded on angler harvest permits to the numbers that the same group of anglers reported in an off‐site survey. Anglers could respond to the off‐site survey using mail or Internet; if they did not respond using these methods, they were called on the telephone. A majority of anglers responded through the mail, and the probability of responding by Internet decreased with increasing age of the respondent. The actual number of steelhead harvested did not appear to influence the response type. Anglers in the autumn 2012 survey overreported harvest by 24%, whereas anglers in the spring 2013 survey under‐reported steelhead harvest by 16%. The direction of reporting bias may have been a function of actual harvest, where anglers harvested on average 2.6 times more fish during the spring fishery than the autumn. Reporting bias that is a function of actual harvest can have substantial management and conservation implications because the fishery will be perceived to be performing better at lower harvest rates and worse when harvest rates are higher. Thus, these findings warrant consideration when designing surveys and evaluating management actions. 相似文献
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In this study, elimination of the element zinc from spermatozoa during epididymal maturation was investigated. Testes and epididymides from 40 bulls were collected; epididymal fluid was flushed, pooled, labelled with 0.5 MBq 65Zn2+ per sample and proteins were separated on a Sephacryl S‐200 HR and zinc chelate column chromatography. To follow the resorption of zinc in the epididymal epithelial lining, an autometallographic technique (AMG) was performed in tissue from caput, corpus, cauda and vas deferens. The results showed a zinc‐binding protein fraction with an apparent molecular weight of 150–160 kDa, which was enriched after chelate column chromatography. Specific labelling of 65Zn was about five times higher in the caput than in the cauda epididymidis. AMG revealed no detectable zinc in the caput, but a significant increase of zinc resorption from the corpus to the cauda and vas deferens. Controls showed that the detectable zinc was located within the principal cells. In conclusion, our study proves that zinc present in the sperm flagellum starts to be mobilized in the caput epididymidis and is resorbed by the epididymal epithelium as from the corpus. This zinc elimination is a mandatory step in sperm maturation to obtain motility. 相似文献
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