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A longitudinal study of sheep, naturally infected with gastrointestinal helminths, was carried out to quantify the relationships among eosinophilia, eosinophil peroxidase activity, interleukin-5 level and faecal egg counts. Faecal egg counts, peripheral eosinophilia and peroxidase activity per eosinophil were moderately repeatable but interleukin-5 concentrations had a remarkably high repeatability. Animals with higher concentrations of interleukin-5 had greater peripheral eosinophilia and those animals with higher numbers of eosinophils had lower faecal egg counts. These associations were statistically significant but quite weak. Variation in interleukin-5 levels does not appear to be responsible for most of the variation in eosinophil responses in outbred sheep. 相似文献
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Rachel E. Creamer Pat Bellamy Helaina I. J. Black Clare M. Cameron Colin D. Campbell Paul Chamberlain Jim Harris Nisha Parekh Mark Pawlett Jan Poskitt Dote Stone Karl Ritz 《Biology and Fertility of Soils》2009,45(6):623-633
The use of indicators in soil monitoring schemes to detect changes in soil quality is receiving increased attention, particularly
the application of soil biological methods. However, to date, the ability to compare information from different laboratories
applying soil microbiological techniques in broad-scale monitoring has rarely been taken into account. This study aimed to
assess the consistency and repeatability of two techniques that are being evaluated for use as microbiological indicators
of soil quality: multi-enzyme activity assay and multiple substrate-induced respiration (MSIR). Data were tested for intrinsic
(within-assay plate) variation, inter-laboratory repeatability (geometric mean regression and correlation coefficient) and
land-use discrimination (principal components analysis). Intrinsic variation was large for both assays suggesting that high
replicate numbers are required. Inter-laboratory repeatability showed diverging patterns for the enzyme assay and MSIR. Discrimination
of soils was significant for both techniques with relatively consistent patterns; however, combined laboratory discrimination
analyses for each technique showed inconsistent correspondence between the laboratories. These issues could be addressed through
the adoption of reliable analytical standards for biological methods along with adequate replication. However, until the former
is addressed, dispersed analyses are not currently advisable for monitoring schemes. 相似文献
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The present investigation was carried out to estimate the interrelationships and repeatabilities of various variability parameters,
i.e., genotypic (σ2g) and phenotypic (σ2p) variances, genotypic (GCV) and phenotypic (PCV) coefficients of variation, broad-sense heritability (hb2), genetic advance (GA), and genetic gain (GG), using data derived from a number of plant characters [seed yield (SY), days
to heading (DH) and maturity (DM), plant height (PH), and thousand kernel weight (TKW)] of 17 spring safflower genotypes grown
in 27 environments in Iran during 2003–2005. The analysis of variance for the five characters revealed significant differences
among the genotypes in most of the environments, indicating a very high variability within the genotype. High genotypic and
phenotypic variances in the quantitative traits, particularly for SY, were markers of increased success. A close correlation
between GCV and PCV was observed for all the traits, indicating that all of the characters were less influenced by the environment
and that the variability which exists in these characters is under genetic influence; however, the relatively higher values
of PCV indicate the predominant role of environment. High expected genetic advances were observed for SY, but this trait showed
large fluctuations in different environments (97.4%). High and low mean values of heritability were observed for DH (74.3%)
and SY (59.7%), respectively, whereas high and low mean values of genetic gain were found for SY (60.3%) and DM (4.2%), respectively.
High heritability coupled with low GA as a percentage of the mean was observed for DH and MD, whereas moderate heritability
with moderate GA as a percentage of the mean was exhibited for SY. Analysis of correlation among the parameters showed that
they were strongly and constantly correlated with each other, but none of them were consistently well correlated with the
heritability parameter (hb2). Based on estimates of the genetic variability parameters within each trial, the ranking of genotypes in the low-performance
subset for all traits differed from that in the high-performance subset. This result indicates poor repeatability for the
genetic variability parameters. The estimates of the parameters in the multi-year trials were almost constant and repeatable,
whereas the responses over years showed poor repeatability. 相似文献
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In the horse, resting insulin concentration (INS), the glucose-to-insulin ratio (G:I), and the reciprocal of the square root of insulin (RISQI = 1/√INS) are commonly used to estimate insulin sensitivity, whereas the modified insulin-to-glucose ratio (MIRG = [800 – 0.30 × (INS -50)2]/(GLU – 30) is used to estimate pancreatic beta-cell responsiveness. Because no estimates of their within-horse variability and repeatability have been reported, the objective of this study was to evaluate the within-horse variation of these estimates. Resting blood samples were obtained from six healthy equids (three geldings, two mares; mean ± SD body weight, 525.0 ± 43.36 kg; mean age, 9.8 ± 8.2 years; and one pony gelding: 293 kg; 12 years) on three consecutive days in week 1 and again in week 2. Samples were collected at 12:00 noon, approximately 6 hours postprandially. Serum insulin and plasma glucose (GLU) concentrations were analyzed and used to calculate G:I, RISQI, and MIRG, as well as the insulin to glucose ratio (I:G). The coefficient of variation was used to determine within-horse variation, and repeatability was determined using the repeatability coefficient (RC; measurements from a single horse should differ less than the RC for 95% of the pairs). The mean coefficients of variation (CVs) for resting GLU, INS, G:I, I:G, MIRG, and RISQI were 5.5%, 33.7%, 36.0%, 31.6%, 22.3%, and 18.6%, respectively. All variables had values that differed more than the RC in at least one horse. These data suggest that care should be taken when interpreting insulin sensitivity estimates from a single blood sample. 相似文献
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24个甘蔗组合早代重演力和预测力分析 总被引:1,自引:0,他引:1
为研究甘蔗遗传特点和育种潜力,对常用的29个甘蔗亲本24个组合的7个性状进行重演力测试并进行相关分析和回归分析。结果表明,相关系数(r)和回归系数(b)都达到显著水平的性状有茎径、有效茎、锤度和单茎重,说明这些性状受环境影响较小,在甘蔗育种早期世代根据这一结果制订相应的选择标准,增大选择压力,可提高甘蔗育种效率。29个亲本中表现较好的亲本是ROC24、粤糖91-976、ROC1、ROC22,24个组合中综合性状较好的是ROC24×粤糖91-976、ROC1×ROC22、粤糖89-113×ROC22,在今后育种计划中可广泛利用。 相似文献
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为了解台系杜洛克母猪重复力遗传参数在国内的适应性,充实完善台系杜洛克猪产仔数的重复力,继续选育提高杜洛克猪育种水平及经济效益。通过采用组内相关的方法,对某大型种猪企业的台系杜洛克猪1~8胎次产仔数的重复力进行估测。结果表明:台系杜洛克猪1~8胎次的平均产仔数分别为8.6头、9.65头、9.35头、9.00头、8.30头、8.80头、7.65头;台系杜洛克猪8个胎次平均产仔数为8.44头;台系杜洛克猪产仔数的重复力为0.42。 相似文献
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文章认为,丰产性、丰产重演性、适应性及稳定性四者,是品种主要生产性能的最高表现,应作为品种区域试验的主要决选指标;并均应统一以适当参数加以定量表述,从而使总结评定共同建立在对参试品种的科学分类基础之上。本文建议,区试中意义准确、完整的丰产性,应按以下三参数合并表述,即:经过相应加权校正的(平均)丰产水平Yi/以对照品种为参照物兼示差异显著性的丰产指数I_Y*,**/兼示邻位差异显著性的丰产位次N*,**;对区域化鉴定中具关键作用之丰产重演性,建议分作不同可靠程度的增产重演R_i*,**、达标重演R_(?)*,**、高位重演R_(N)*,**三级,以重演性参数f(P)——连年及基本连年重演试点数(或重演面)表述之;并强调指出乃区试之核心。 相似文献
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Movement analysis techniques allow objective and quantitative assessment of kinematic gait analysis. Consistent repeatability of the kinematic data is essential for such assessments. This study investigated whether the repeatability of a standardized Equinalysis Elite gait analysis system is sufficient to allow its use in clinical evaluation of equine lameness with reliable documentation of individual locomotion patterns. The extent to which examinations on different days affected the results when a standardized protocol was used was investigated. The repeatability of distal limb kinematics in nine sound horses over three successive days at one location was investigated. Measurements were performed at the examination area, for three motion cycles at the walk and trot, in each direction per day. Skin markers were placed on the lateral aspect of the coffin joint, forelimb fetlock joint, hindlimb fetlock joint, carpus, tarsus, elbow, and stifle, at clipped sites marked with a permanent marker. The inter-day repeatability of angular measurements of the carpus, tarsus, forelimb fetlock, and hindlimb fetlock joints was determined. A low degree of inter-day repeatability was found with statistically significant (P ≤ .05) differences between findings on different days, observed in the time-angle diagrams of left and right carpus, tarsus, forelimb fetlock, and hindlimb fetlock joints of all horses, at both walk and trot. The standardized Equinalysis Elite system for gait analysis of distal limb kinematics in the horse did not provide highly repeatable data in this setting. 相似文献