进口巴布亚新几内亚原木上截获吉丁虫的鉴定

描述江苏口岸首次从巴新原木上截获的8种吉丁虫,隶属于窄吉丁Agrilus,澳纹吉丁Anilara,星吉丁Chrysobothris,胸斑吉丁Belionota,驼翅吉丁Cyphogastra。编制族属检索表,介绍8种的鉴别特征,并配以8种吉丁虫的原色图,对检疫性害虫窄吉丁非中国种的分类状况作了简介。     

Neotyphodium endophyte infection frequency in annual grass populations: relative importance of mutualism and transmission efficiency

Persistence and ubiquity of vertically transmitted Neotyphodium endophytes in grass populations is puzzling because infected plants do not consistently exhibit increased fitness. Using an annual grass population model, we show that the problems for matching endophyte infection and mutualism are likely to arise from difficulties in detecting small mutualistic effects, variability in endophyte transmission efficiency and an apparent prevalence of non-equilibrium in the dynamics of infection. Although endophytes would ultimately persist only if the infection confers some fitness increase to the host plants, such an increase can be very small, as long as the transmission efficiency is sufficiently high. In addition, imperfect transmission limits effectively the equilibrium infection level if the infected plants exhibit small or large reproductive advantage. Under frequent natural conditions, the equilibrium infection level is very sensitive to small changes in transmission efficiency and host reproductive advantage, while convergence to such an equilibrium is slow. As a consequence, seed immigration and environmental fluctuation are likely to keep local infection levels away from equilibrium. Transient dynamics analysis suggests that, when driven by environmental fluctuation, infection frequency increases would often be larger than decreases. By contrast, when due to immigration, overrepresentation of infected individuals tends to vanish faster than equivalent overrepresentation of non-infected individuals.     

银杏内酯B对豚鼠腹腔神经节神经元Fast-EPSP的抑制效应

应用细胞内记录技术,观察并分析了银杏内酯B(GB)对豚鼠(Cavia porcellus)离体腹腔神经节(CG)神经元快兴奋性突触后电位(fast-EPSP)的影响及可能机制.用4×10-6mol/L的GB灌流CG,fast-EPSP的幅值均明显降低,与对照组相比有显著性差异(n=12,P<0.05);用低Ca2 /高Mg2 Krebs液灌流,fastEPSP被完全抑制(n=3);用高Ca2 Krebs液灌流,fast-EPSP幅度则增大(n=12,P<0.05),而用4×10-6mol/L GB与高Ca2 Krebs液联合灌流,fast-EPSP幅度则减小(n=12,P<0.05).结果提示,GB对CG神经元fast-EPSP的抑制效应可能与减少或抑制CG神经元的外Ca2 内流有关.     

Environmental perspectives of Vetiveria zizanioides (L.) Nash

The twentieth century witnessed indiscriminate usage of natural resources for energy generation and xenobiotic chemical compounds for sustainability in agriculture and infrastructural development. Heavy metal and non-degradable chemical contamination of soil and water is one of the major environmental threats. In recent years, worldwide researchers are concentrating on the exploration of various sustainable methods to mitigate such environmental contamination. Vetiver (Vetiveria zizanioides (L.) Nash), a grass, is a proven source to mitigate such pollution, and in present days is one of the most recent thrust areas for the purpose of environmental mitigation. Unique morphology, physiology and symbiotic association render vetiver capable of tolerating environmental extremities. In addition, vetiver is also helpful in degradation of most of the recalcitrant compounds such as benzo[a]pyrene. The present review reflects the environmental perspectives of vetiver grass, a potential field which led the World Bank to initiate vetiver grass technology (VGT), which is now known as vetiver system (VS), in India and most of the other Asian countries to restore the natural environmental conditions.     

人工雌核发育草鱼染色体倍性的鉴定

运用经典的红细胞及细胞核体积大小测量方法以及流式细胞仪,检测了人工诱导雌核发育草鱼染色体倍性与DNA含量.雌核发育草鱼红细胞体积为(333.5±41.94)μm3,细胞核体积为(20.7±2.378)μm3;与所测普通草鱼红细胞体积(343.8±50.1)μm3,细胞核体积(21.2±1.98)μm3,没有显著差异.雌核发育草鱼DNA含量(2C)平均为2.23pg,普通草鱼DNA含量(2C)2.20pg,两者无显著差异.研究结果表明,人工雌核发育草鱼与普通草鱼具有相同的染色体倍性.     

Plant species and nutritional-mediated control over rhizodeposition and root decomposition

This study focuses on the influence of nitrogen (N) availability and species on rhizodeposition and on decomposition of rhizodeposits, roots and soil organic matter. Four perennial grass species were studied that are characteristic of grassland habitats that differ in nutrient availability. These perennial grass species, Holcus lanatus L., Festuca rubra L., Anthoxanthum odoratum L. and Festuca ovina L., were homogeneously labeled with ¹⁴CO₂. Plants were grown on soil without N addition and with N addition (14 g N m^–2). After 8 weeks, plants were harvested and root production and the remaining amount of rhizodeposits in the soil were measured. ¹⁴C-labelled roots were incubated in fresh soil. Decomposition was measured of 1) the labeled rhizodeposits in the soil in which the plants had been growing and 2) the labeled dead roots incubated in fresh soil, by trapping the evolved ¹⁴CO₂, over 69 days.In general, decomposability of both roots and rhizodeposits increased when nitrogen availability increased. Moreover, the species differed in their response to N. Higher N supply increased total rhizodeposition of H. lanatus and the decomposability of rhizodeposited carbon compounds of this high fertility species was greater than of the low fertility species F. ovina, but lower than of A. odoratum. The presented study gives no evidence for a relation between root decomposition rate and the nutrient availability of the habitat of the four species. Overall, we suggest on the basis of the results that species can affect nutrient cycling by differences in rates of rhizodeposition and litter production. This offers a mechanism whereby species can influence species replacement during succession.     

豚鼠胆囊SP免疫组织化学反应特点及电镜观察

研究采用ABC免疫组化方法及电镜观察发现;豚鼠胆囊含有SP免疫反应的神经元,神经纤维及肥大细胞,这些神经纤维束是被神经膜细胞完全或不完全包裹的无髓神经纤维。其神经纤维内含有的突触小泡形态大小不一。电镜下分可为3种类型;（1）以小型无芯小泡为主以及少量大型有芯小泡。（2）以小型有芯小泡为主以及少量无芯小泡和大型有芯小泡。（3）以大型有芯小泡为主以及少量小型无芯小泡。用SP免疫电镜组化方法观察。豚鼠胆囊的SP免疫反应阳性神经纤维内散在分布的突触小泡多为第3种。但在血管,淋巴管周围SP免疫反应阳性神经纤维内的突触小泡多为小型有芯小泡,胆囊除了受肾上腺素能神经支配外,尚受SP等肽能神经的支配。本研究对豚鼠胆囊SP免疫组织化学反应阳性神经纤维分布特点及神经纤维内突触小泡的超微结构特点进行了研究。     

Prevalence and differential host-specificity of two avian blood parasite genera in the Australo-Papuan region

The degree to which widespread avian blood parasites in the genera Plasmodium and Haemoproteus pose a threat to novel hosts depends in part on the degree to which they are constrained to a particular host or host family. We examined the host distribution and host-specificity of these parasites in birds from two relatively understudied and isolated locations: Australia and Papua New Guinea. Using polymerase chain reaction (PCR), we detected infection in 69 of 105 species, representing 44% of individuals surveyed (n = 428). Across host families, prevalence of Haemoproteus ranged from 13% (Acanthizidae) to 56% (Petroicidae) while prevalence of Plasmodium ranged from 3% (Petroicidae) to 47% (Ptilonorhynchidae). We recovered 78 unique mitochondrial lineages from 155 sequences. Related lineages of Haemoproteus were more likely to derive from the same host family than predicted by chance at shallow (average LogDet genetic distance = 0, n = 12, P = 0.001) and greater depths (average distance = 0.014, n = 11, P < 0.001) within the parasite phylogeny. Within two major Haemoproteus subclades identified in a maximum likelihood phylogeny, host-specificity was evident up to parasite genetic distances of 0.029 and 0.007 based on logistic regression. We found no significant host relationship among lineages of Plasmodium by any method of analysis. These results support previous evidence of strong host-family specificity in Haemoproteus and suggest that lineages of Plasmodium are more likely to form evolutionarily-stable associations with novel hosts.     

Virus-like particles as vaccines and vessels for the delivery of small molecules

Virus-like particles (VLPs) structurally mimic the viral capsid and have therefore been extensively, and quite successfully, used as vaccine and viral serology reagents. The ability of VLPs to include nucleic acids and small molecules has also made them novel vessels for gene and drug delivery. The regular, repetitive surface of VLPs has been exploited as a template for nanoscale synthesis. Recent progress has been made in the development of several virus models.     

Comparative study of Helicobacter pylori infection in guinea pigs and mice - elevation of acute-phase protein C3 in infected guinea pigs

Eighteen Dunkin-Hartley guinea pigs and 50 NMRI mice were inoculated with Helicobacter pylori and the infection followed by culture, histopathology, antibody response, and plasma levels of the acute-phase proteins albumin, C3, and transferrin for up to 7 weeks. The immune response to H. pylori surface proteins was studied by an enzyme immunoassay (EIA) and Western immunoblot and the plasma levels of albumin, C3, and transferrin were analyzed by single radial immunodiffusion. Guinea pigs had a more severe gastritis and a higher EIA immune response than NMRI mice. Serum C3 levels were elevated in infected guinea pigs after 3 and 7 weeks indicating a systemic inflammatory response and a possible link between H. pylori infection and extragastric manifestations such as vasculitis associated with atherosclerosis. Serum cholesterol levels were analyzed in guinea pigs at 7 weeks and indicated a higher level in H. pylori-infected than in control animals, but this difference was not statistically significant.