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Phenotypic Characterization and Strategies for Genetic Improvement of WAD Goats under Backyard Systems
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作者 S. O. Oseni B. A. Ajayi 《Open Journal of Animal Sciences》 2014年第5期253-262,共10页
West African Dwarf (WAD) goats represent one of the predominant small ruminant breeds raised by resource-limited households in southern Nigeria as well as in the humid west and central Africa. This breed of goats is r... West African Dwarf (WAD) goats represent one of the predominant small ruminant breeds raised by resource-limited households in southern Nigeria as well as in the humid west and central Africa. This breed of goats is renowned for its adaptation to hot and humid environments, high fertility and prolificacy under backyard systems where they are raised almost with zero investment. On account of its contributions to household income and food security in southern Nigeria, there is the need for a detailed phenotypic and genetic characterization as well as the design of breeding strategies for its conservation through sustainable utilization. A critical challenge, however, is that there are no national breeding policies in most of the countries where WAD goats are raised. The objectives of this paper are: to review literature reports on trait-level information and estimates of genetic parameters for some economic characters of WAD goats;and to discuss a communal breeding scheme for its conservation through sustainable utilization. The presentation shows that WAD goats represent a highly diverse population, with particular reference to qualitative and performance-related traits, reflecting the role of traditional institutions in the maintenance of animal diversity in local populations. A genetic improvement programme involving dispersed open nucleus breeding scheme was discussed. The scheme involves backyard WAD goat units in villages as base population and dispersed communally managed schemes that maintain a population of bucks only, as nucleus units. Critical issues such as the definition of breeding goals by farmers, as well as communal project ownership, are emphasized. The ultimate goal of the breeding programme is to create opportunities for community-based management of WAD goat genetic resources for the benefit of backyard goat farmers in the region. 展开更多
关键词 WAD Goats Characterization trait-level Information Genetic Improvement COMMUNAL Breeding Scheme BACKYARD SYSTEMS
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rTMS结合认知行为治疗对吗啡依赖患者特质冲动、突显网络功能的影响
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作者 李建平 曾莞勇 +1 位作者 杜维豪 陈江永 《黑龙江医药》 CAS 2022年第2期249-252,共4页
目的:分析重复经颅磁刺激(rTMS)结合认知行为治疗对吗啡依赖患者特质冲动、突显网络功能的影响。方法:选取我院吗啡依赖患者64例,根据治疗方法分组,各32例,两组均给予美沙酮治疗,在此基础上常规组采取认知行为治疗,研究组采取rTMS联合... 目的:分析重复经颅磁刺激(rTMS)结合认知行为治疗对吗啡依赖患者特质冲动、突显网络功能的影响。方法:选取我院吗啡依赖患者64例,根据治疗方法分组,各32例,两组均给予美沙酮治疗,在此基础上常规组采取认知行为治疗,研究组采取rTMS联合认知行为治疗。比较2组疗效、治疗前后贝克抑郁量表21项版(BDI-21)、药物成瘾者生命质量测定量表(QOL-DA)、Barratt冲动评估量表-11(BIS-11)评分及突显网络功能变化。结果:2组总有效率比较,研究组为93.75%,高于常规组(75.00%),P<0.05;治疗后2组BDI-21、QOL-DA、BIS-11评分均明显改善,研究组改善幅度更明显(P<0.05);治疗后2组双侧背内侧前额叶、双侧楔前叶、左侧中央后回、左侧枕下回功能连接值明显下降,研究组下降程度更明显(P<0.05)。结论:rTMS联合认知行为治疗能明显改善吗啡依赖患者突显网络功能,降低特质冲动水平,减轻抑郁情绪,提高生命质量。 展开更多
关键词 重复经颅磁刺激 认知行为治疗 吗啡依赖 突显网络功能 特质冲动水平
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IRT中测验信息函数性质的解析及估值方法 被引量:1
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作者 田振清 《内蒙古师范大学学报(自然科学汉文版)》 CAS 2009年第6期671-673,共3页
介绍了项目反应理论(IRT)的三参数Logistic数学模型,给出测验信息函数和项目信息函数的数学表达式.通过分析项目信息函数的主要特性,设计了绘制被试的特质水平(θ)~测验信息函数(I(θ))曲线的算法,给出I(θ)值的估算方法.
关键词 项目反应理论 特质水平 测验信息函数 算法设计 数值估算
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不同保种技术对3鸭种2世代性能及环境友好度的影响
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作者 孙国波 段修军 +2 位作者 董飚 卞友庆 张干生 《西北农业学报》 CAS CSCD 北大核心 2014年第8期8-15,共8页
了解不同保种技术对肉用鸭生产性能的影响,试图寻找出适合水禽保种的新方法。通过采用小群繁育技术(公鸭40只,母鸭200只)和常规大群保种方法,开展临武鸭、巢湖鸭、靖西大麻鸭3鸭种的2世代遗传效应、表观性状变化、生产性能、环境... 了解不同保种技术对肉用鸭生产性能的影响,试图寻找出适合水禽保种的新方法。通过采用小群繁育技术(公鸭40只,母鸭200只)和常规大群保种方法,开展临武鸭、巢湖鸭、靖西大麻鸭3鸭种的2世代遗传效应、表观性状变化、生产性能、环境友好度等研究。结果表明:采用不同方法保种,同一品种试验鸭群体世代间近交系数差异不显著(P〉0.05),且2个世代的近交系数都为0.017~0.020,近交增量为0.0007~0.0030,变异系数为0.087-0.094;试验鸭群表观性状的所有指标在世代间差异也不显著(P〉0.05),均在正常许可范围内;对3个鸭种生产性能测定表明在同一品种内运用不同保种方法其性能差异不显著(P〉0.05),品种之间显示靖西大麻鸭总体上产肉性能优于临武鸭和巢湖鸭;而在环境友好度测评中,小群繁育技术在部分指标均显著低于常规大群保种(P〉O.05)。通过对不同保种方法的比较研究发现,小群繁育技术在保持品种特性外,对环境的友好程度较高,可用于水禽遗传资源的保护。 展开更多
关键词 小群繁育 大群保种 生产性能 环境友好度 比较研究
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