长沙生态动物园野生动物消化道寄生虫感染情况调查

为了解长沙生态动物园动物感染的寄生虫种类及感染情况,采用饱和盐水漂浮法和沉淀法检查了57种动物的粪样。结果表明:长沙生态动物园动物寄生虫感染率为52.63%,其中食草类动物和灵长类动物阳性率为50%,食肉类动物感染率最高,感染率达76.9%。动物园动物常见感染的寄生虫有球虫、吸虫、线虫、绦虫等,其中线虫感染率最高。     

外泌体在肿瘤及寄生虫病中的应用研究进展

外泌体(EVs)也称作胞外囊泡,是细胞内多泡体与细胞膜融合后释放到细胞外基质中的磷脂双分子层小囊泡。1983年,研究人员在绵羊网织红细胞中首次发现外泌体,最初认为外泌体只是细胞代谢废物,但随着对其生物来源、物质构成、运输、细胞间信号传导及在体液中分布等方面深入研究,发现外泌体具有多种功能。近年来研究发现,外泌体在肿瘤早期诊断、肿瘤转移和扩散等方面都扮演重要角色,并且有可能成为新型药物载体应用在肿瘤治疗方面。随着外泌体功能和生物学特点的深入研究,这种新型药物载体技术也有可能应用到抗寄生虫病,为寄生虫病的治疗提供新思路。     

Live weight, body size and carcass characteristics of young bulls of fifteen European breeds

A total of 436 young bulls from fifteen Western European breeds, including beef, dairy and local types from five countries, were studied to assess variability in live weight, live weight gain, body measurements and carcass traits. Animals were logged indoors, and fed a diet based on concentrate and straw offered ad libitum from 9 months of age to slaughter at 15 months of age. The weight, body length, height at withers and pelvis width, of the animals were recorded at 9, 12 and 15 months of age. After slaughter, 15 carcass variables were recorded, including carcass weight, EU classification scores, morphological measurements and dissection data. Data were analysed by GLM, regression and principal component analysis procedures.Significant differences were found between breeds for all variables studied, however, the body size measurements and the carcass traits were more useful to discriminate among cattle breeds, than either live weight or daily gain. With respect to the body size and carcass traits the studied breeds could be grouped as:

– Specialized beef breeds, comprising Piemontese, Asturiana de los Valles, Pirenaica, Limousin, South Devon, Charolais and Aberdeen Angus, all of which were characterized by high muscularity, wide pelvis and medium height and a low to medium level of fatness.

– Local and dairy breeds, comprising Jersey, Casina, Highland, Holstein and Danish Red, the latter two breeds were tall animals, while the former three breeds were small in size. In general the group was poorly muscled and tended to have a high or medium level of fat.

– Intermediate group, Avileña, Marchigiana and Simmental: these breeds were characterized by an intermediate muscle conformation and fatness level and were relatively tall.

This study provides a detailed assessment or a wide range of variables in the major breeds, and several minor breeds, that are used in breeding programmes across Europe and elsewhere, and will provide information that will be of use to define breeding strategies to meet the demands of the European beef market.     

Genetic diversity and relationships of lotus (Nelumbo) cultivars based on allozyme and ISSR markers

Genetic diversity and genetic relationships of lotus (Nelumbo Adanson) cultivars were evaluated using allozyme and ISSR markers. The samples used covered 11 accessions of possible hybrids between Nelumbo nucifera and Nelumbo lutea and 92 accessions of N. nucifera including 69 flower lotus, 13 rhizome lotus, 5 seed lotus and 5 wild lotus. For allozyme studies, a total of 31 alleles at 23 loci of 18 enzyme systems were detected of which 5 (21.7%) loci Aat, Idh, Mdh-2, Pgd, Sod were polymorphic. The loci of Aat and Idh included two alleles, Mdh-2, Pgd and Sod included three alleles. Eighteen genotypes were detected with the 13 alleles of the 5 polymorphic loci. The parameters of average allele number, observed heterozygosity, expected heterozygosity and Shannon information index of 92 N. nucifera samples were 1.35 ± 0.71, 0.06 ± 0.21, 0.05 ± 0.14, 0.10 ± 023, respectively. Thirteen ISSR primers generated 93 loci, of which 37.63% were polymorphic across all samples. The percentage of polymorphic loci, average allele number, expected heterozygosity and Shannon information index of 92 N. nucifera samples were 26.67%, 1.30 ± 0.46, 0.10 ± 0.18 and 0.15 ± 0.25, respectively for the ISSR data. The ‘Bottleneck effect’ and rapid propagation of clones after the ice ages may explain the low genetic diversity of lotus. The dendrograms based on ISSR and allozymes were not congruent. Based on the ISSR data, the 103 samples were divided into the N. nucifera group (Group I), and the group containing inter-specific hybrids between N. nucifera and N. lutea (Group II). The flower lotus, rhizome lotus, and seed lotus each has multiple sources of origin. Plant size, a criterion commonly used in the classification of cultivars of lotus, is not correlated with genetic variation. Flower color is correlated with the cultivar classification to some degree, but its variation is complex in the hybrids.     

The biological and practical significance of antigenic variability in protective T cell responses against Theileria parva

The evolution of antigenically distinct pathogen strains that fail to cross-protect is well documented for pathogens controlled primarily by humoral immune responses. Unlike antibodies, which recognise native proteins, protective T cells can potentially recognise epitopes in a variety of proteins that are not necessarily displayed on the pathogen surface. Moreover, individual hosts of different MHC genotypes generally respond to different sets of epitopes. It is therefore less easy to envisage how strain restricted immunity can arise for pathogens controlled by T cell responses, particularly in antigenically complex parasites. Nevertheless, strain restricted immunity is clearly a feature of a number of parasitic infections, where immunity is known to be mediated by T cell responses. One such parasite is Theileria parva which induces potent CD8 T cell responses that play an important role in immunity. CD8 T cells specific for parasitized lymphoblasts exhibit strain specificity, which appears to correlate with the ability of parasite strains to cross-protect. Studies using recently identified T. parva antigens recognised by CD8 T cells have shown that the strain restricted nature of immunity is a consequence of the CD8 T cell response in individual animals being focused on a limited number of dominant polymorphic antigenic determinants. Responses in animals of different MHC genotypes are often directed to different parasite antigens, indicating that, at the host population level, a larger number of parasite proteins can serve as targets for the protective T cell response. Nevertheless, the finding that parasite strains show overlapping antigenic profiles, probably as a consequence of sexual recombination, suggests that induction of responses to an extended but limited set of antigens in individual animals may overcome the strain restricted nature of immunity.     

Key Links and Solutions for the Relationshipsabout Reconstruction of Old Buildings

Following the rapid development of the revolutions in housing system,reconstruction of old buildings is rising.In order to make the reconstruction proceed smoothly,in this paper the author studies the secondary parts,reinforcing foundation,dismantlement of some parts of an old building,linkage of new and old frames,solutions for the four relationships,and others.     

蚜茧蜂对麦蚜控制作用的初步研究

本文应用二次通用旋转组合设计的方法进行了蚜茧蜂对麦蚜寄生能力的研究,得出了蚜茧蜂的寄生量模型：Ｙ＝９１．４０＋４３．６２Ｘ１＋２０．２７Ｘ２＋７．２５Ｘ１Ｘ２－１６．８３Ｘ１＾２＋３．４３Ｘ２＾２。并对模型进行了分析,表明对总寄生量的影响因素中麦蚜密度的大小大于蚜茧蜂本身密度的大小。在试验密度范围内,蚜虫和蚜茧蜂干扰作用不明显,且有相互促进的作用,但增加速度相同。     

南方大口鲶寄生鲶盘虫一新种——拟凶恶鲶盘虫↑（*）

本文报道了采自南方鲶SilurusmeridionalisChen鳃上之寄生鲶盘虫1新种,定名为拟凶恶鲶盘虫Silurodiscoidesparasotisp.nov.。其后固着器由2对中央大钩和7对发育不完全的雏形边缘小钩组成;雄性交接器由弯曲似长号状交接管和“6”字形片状支持器组成。并与相似种进行了比较研究,同时对南方大口鲶苗期鲶盘虫病进行了研究。     

Glochidial infestation of fish by the endangered thick‐shelled river mussel Unio crassus

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