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排序方式: 共有602条查询结果,搜索用时 22 毫秒
1.
Daniel A. Truchado Michaël A. J. Moens Sergio Callejas Javier Pérez-Tris Laura Benítez 《Veterinary research communications》2018,42(2):111-120
Papillomaviruses are non-enveloped, DNA viruses that infect skin and mucosa of a wide variety of vertebrates, causing neoplasias or simply persisting asymptomatically. Avian papillomaviruses, with six fully sequenced genomes, are the second most studied group after mammalian papillomaviruses. In this study, we describe the first oral avian papillomavirus, detected in the tongue of a dead Yorkshire canary (Serinus canaria) and in oral swabs of the same bird and other two live canaries from an aviary in Madrid, Spain. Its genome is 8,071 bp and presents the canonical papillomavirus architecture with six early (E6, E7, E1, E9, E2, E4) and two late open reading frames (L1 and L2) and a long control region between L1 and E6. This new avian papillomavirus L1 gene shares a 64% pairwise identity with FcPV1 L1, so it has been classified as a new species (ScPV1) within the Ethapapillomavirus genus. Although the canary died after showing breathing problems, there is no evidence that the papillomavirus caused those symptoms so it could be part of the oral microbiota of the birds. Hence, future investigations are needed to evaluate the clinical relevance of the virus. 相似文献
2.
Kevers C Falkowski M Tabart J Defraigne JO Dommes J Pincemail J 《Journal of agricultural and food chemistry》2007,55(21):8596-8603
Interest in the consumption of fresh fruits and vegetables is, to a large extent, due to its content of bioactive nutrients and their importance as dietary antioxidants. Among all of the selected fruits and vegetables, strawberries and black grapes have relatively high antioxidant capacities associated with high contents of total phenolic compounds, ascorbic acid, and flavonols. More interesting, the results of this study indicated that in most fruits and vegetables storage did not affect negatively the antioxidant capacity. Better, in some cases, an increase of the antioxidant capacity was observed in the days following their purchase, accompanied by an increase in phenolic compounds. In general, fruits and vegetables visually spoil before any significant antioxidant capacity loss occurs except in banana and broccoli. When ascorbic acid or flavonoids (aglycons of flavonols and anthocyanins) were concerned, the conclusions were similar. Their content was generally stable during storage. 相似文献
3.
ten Have R Wijngaard H Ariës-Kronenburg NA Straatsma G Schaap PJ 《Journal of agricultural and food chemistry》2003,51(8):2242-2245
The common mushroom Agaricus bisporus is a non-white rot saphrophytic fungus that can degrade lignin to free and utilize holocellulose embedded in fermented straw as present in compost. A new method is described to estimate the actual amount of bioavailable holocellulose in 3.8 kg compost cultures spawned with A. bisporus Horst U1 prior to and during a cultivation with two cycles of mushroom harvesting. The method shows that the initial amount of bioavailable holocellulose per culture, accounting for 130 +/- 22 g, is lower than the total holocellulose consumption by A. bisporus accounting for 182 +/- 15 g. This difference is explained by a 30% increase in bioavailable holocellulose. The increase is caused by the degradation of 95 +/- 3 g of holocellulose-shielding lignin. The results are discussed within the scope of the A. bisporus mushroom yield and lignin degradation by white rot fungi during growth on lignocellulose-containing materials. 相似文献
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To characterize the structural events associated with incompatibility of graft development, we conducted a histological study of compatible and incompatible pear/pear and pear/quince grafts that had been grown for five months in a greenhouse. Multivariate analysis of histological data describing the structure of the graft union allowed us to discriminate between compatible and incompatible combinations before either macroscopic examination or qualitative microscopic examination differences between graft combinations became evident. The histological variables responsible for the discrimination between incompatible and compatible unions were related to three typical symptoms of graft incompatibility: bark discontinuity, which was the main feature; cambial dysfunction; and accumulation of starch in the scion. Little cell necrosis was observed at the interface of incompatible grafts at the 5-month stage of graft development. Multivariate analysis of histological data provides a new tool for studying early structural events resulting from the graft incompatibility response and for diagnosing early graft incompatibility. 相似文献
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Mathieu Fortin Gaétan Daigle Chhun-Huor Ung Jean Bégin Louis Archambault 《European Journal of Forest Research》2007,126(4):573-585
This study proposes a within-subject variance-covariance (VC) structure to take into account repeated measurements and heteroscedasticity
in a context of growth modeling. The VC structure integrates a variance function and a continuous autoregressive covariance
structure. It was tested on a nonlinear growth model parameterized with data from permanent sample plots. Using a stand-level
approach, basal area growth was independently modeled for red spruce (Picea rubens Sarg.) and balsam fir [Abies balsamea (L.) Mill.] in mixed stands. For both species, the implementation of the VC structure significantly improved the maximum
likelihood of the model. In both cases, it efficiently accounted for heteroscedasticity and autocorrelation, since the normalized
residuals no longer exhibited departures from the assumptions of independent error terms with homogeneous variances. Moreover,
compared with traditional nonlinear least squares (NLS) models, models parameterized with this VC structure may generate more
accurate predictions when prior information is available. This case study demonstrates that the implementation of a VC structure
may provide parameter estimates that are consistent with asymptotically unbiased variances in a context of nonlinear growth
modeling using a stand-level approach. Since the variances are no longer biased, the hypothesis tests performed on the estimates
are valid when the number of observations is large. 相似文献
8.
西藏苦荞种质资源主要农艺性状分析 总被引:8,自引:0,他引:8
为了揭示西藏苦荞种质资源多样性和发掘苦荞资源中的有益基因,利用相关分析、主成分分析和聚类分析等方法对西藏80份苦荞资源的7个主要农艺性状进行了分析。结果表明:西藏苦荞资源存在丰富的遗传多样性,其中主茎粗的遗传变异系数达到36.7%。千粒重与单株粒重呈极显著正相关和极显著偏相关,生育期与千粒重呈极显著负相关和显著负偏相关。应用主成分分析将西藏苦荞7个主要农艺性状简化为4个主成分,其累积贡献率为86.04%,以主茎因子贡献率最高,为41.11%。采用系统聚类分析,将供试材料在遗传距离11.61水平上可聚为4个大类,可区分为株高较矮大粒型、株高中等小粒型、植株矮小大粒型和植株高大茎秆粗壮型。综合聚类分析和主成分分析,苦荞资源中植株较矮、大粒是较为理想的育种材料。 相似文献
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