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A C Lopo  V D Vacquier 《Nature》1980,288(5789):397-399
While studying the plasma membrane of sperm of the sea urchin Strongylocentrotus purpuratus, we developed an antiserum that exhibits unusual reactivity--it cross-reacts with the surfaces of spermatozoa of 28 species representing seven phyla of the animal kingdom. A negative cross-reaction has not been found. This suggests the possible existence of common antigenic determinants on the surface of all animal sperm. We report these preliminary results here because of the broad implications common sperm-surface antigenicity has for the potential development of immunocontraceptive methods.  相似文献   

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Emerging fungal threats to animal, plant and ecosystem health   总被引:7,自引:0,他引:7  
The past two decades have seen an increasing number of virulent infectious diseases in natural populations and managed landscapes. In both animals and plants, an unprecedented number of fungal and fungal-like diseases have recently caused some of the most severe die-offs and extinctions ever witnessed in wild species, and are jeopardizing food security. Human activity is intensifying fungal disease dispersal by modifying natural environments and thus creating new opportunities for evolution. We argue that nascent fungal infections will cause increasing attrition of biodiversity, with wider implications for human and ecosystem health, unless steps are taken to tighten biosecurity worldwide.  相似文献   

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为避免对检材造成破坏,介绍两种无损检验的方法--偏振光显微镜法及显微红外光谱法.该方法检验过程快速,结果可靠,不损坏纤维,可保留纤维的原始状况.  相似文献   

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为完善延迟荧光检测植物光合能力的方法,通过对4种样品延迟荧光光响应曲线分析,提出四段式光响应曲线模型.从理论上推导出非饱和延迟荧光强度与光合能力具有线性转换关系,且线性系数与饱和光诱导下的线性系数有关.以水稻(Jing Dao No.21)为样本,对理论分析结果进行实验验证.结果表明,两者具有较强的线性关系,验证了理论推导的正确性.理论和实验分析均证实,非饱和光诱导延迟荧光可以作为表征植物光合能力的一种有效手段.  相似文献   

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Speciation in animals is almost always envisioned as the split of an existing lineage into an ancestral and a derived species. An alternative speciation route is homoploid hybrid speciation in which two ancestral taxa give rise to a third, derived, species by hybridization without a change in chromosome number. Although theoretically possible it has been regarded as rare and hence of little importance in animals. On the basis of molecular and chromosomal evidence, hybridization is the best explanation for the origin of a handful of extant diploid bisexual animal taxa. Here we report the first case in which hybridization between two host-specific animals (tephritid fruitflies) is clearly associated with the shift to a new resource. Such a hybrid host shift presents an ecologically robust scenario for animal hybrid speciation because it offers a potential mechanism for reproductive isolation through differential adaptation to a new ecological niche. The necessary conditions for this mechanism of speciation are common in parasitic animals, which represent much of animal diversity. The frequency of homoploid hybrid speciation in animals may therefore be higher than previously assumed.  相似文献   

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动物组织中抗生素残留研究进展   总被引:2,自引:0,他引:2       下载免费PDF全文
动物组织和动物源性食品中残留的抗生素是近几年来影响食品安全和人类健康的重要隐患,已经引起了世界各国的广泛关注。介绍了近几年来动物组织和动物源性食品中抗生素残留理化检测方法的研究进展,对各种检测方法的检测原理及各自的优缺点进行了总结分析,对抗生素残留检测技术的发展方向进行了展望。  相似文献   

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Evolution,consequences and future of plant and animal domestication   总被引:36,自引:0,他引:36  
Diamond J 《Nature》2002,418(6898):700-707
Domestication interests us as the most momentous change in Holocene human history. Why did it operate on so few wild species, in so few geographic areas? Why did people adopt it at all, why did they adopt it when they did, and how did it spread? The answers to these questions determined the remaking of the modern world, as farmers spread at the expense of hunter-gatherers and of other farmers.  相似文献   

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L J Alfred 《Nature》1967,214(5089):732-734
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LC-ToF-MS和LC-QqQ-MS测定动物肌肉组织中的青霉素   总被引:1,自引:0,他引:1  
通过对前处理步骤的优化,建立了动物肌肉组织中青霉素的多组分残留检测方法.采用固相萃取富集净化提取液,吹氮浓缩后上机测试,利用高效液相色谱分离目标物,比较了飞行时间质谱(ToF-MS)和三重四极杆串联质谱(QqQ-MS)测定青霉素方法的精密度、回收率和检出限.结果表明,飞行时间质谱在检出限、精密度和回收率等方面均不如串联质谱的检测效果好.采用串联质谱对肌肉样品进行分析,实际样品加标回收率达75%以上(除阿莫西林外),精密度高,检出限低于欧盟规定的最大残留限值(MRL),该方法适合于肌肉样品中青霉素的测定.  相似文献   

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