大蜡螟饲料配方的优化

大蜡螟Galleria mellonella L.广泛应用于昆虫生理生化、杀虫剂筛选和昆虫毒理学等多个领域,因此,选择物美价廉的饲料对其进行大规模饲养具有重要的现实意义。选取占饲料成本份额较高的奶粉和酵母粉作为研究对象,分5组配方进行大蜡螟的饲养实验。通过对每组各个历期和产卵数进行比较,获得了优化后的饲料配方:奶粉50g、酵母粉20g、面粉100g、麦麸100g、玉米粉100g、蜂蜡50g、蜂蜜50g及甘油60g;并首次比较了奶粉和酵母粉在大蜡螟发育过程中的作用,进而明确了酵母粉对大蜡螟幼虫期、蛹期的发育和繁殖能力具有重要的促进作用;而奶粉对幼虫期发育和繁殖能力具有促进作用,但作用小于酵母粉;同时两者与成虫的寿命无关。     

1964-2009年中国文献报告非围产期李斯特菌病例分析

目的描述我国1964-2009年文献报告的非围产期李斯特菌病的临床与流行病学特征,为李斯特菌病的防治提供科学依据。方法计算机检索与手工检索结合收集我国1964.1-2009.12非围产期李斯特菌病的文献报告资料,从中提取各非围产期李斯特菌病例的临床与流行病学信息并进行统计分析。结果共纳入66例非围产期李斯特菌病例,其中以男性、年龄35岁者居多。患者的临床表现以CNS感染(42%)、败血症(41%)为主。免疫缺陷患者多表现为CNS感染,非免疫缺陷患者多表现为败血症。报告病例总死亡率为19%(11/57),其中免疫缺陷患者的死亡率高达28%(5/18)。结论我国非围产期李斯特菌病的临床特点与国外报告相符,报告死亡率与国外类似。     

红三叶苗期抗旱性指标筛选及综合评价

应用主成分分析、通径分析及隶属函数分析法对国内外12份红三叶材料进行抗旱性评价,结果表明：比根长、最长根长、可溶性糖、地下生物量、游离脯氨酸、相对持水量、叶绿素持有率和丙二醛8个指标是评价红三叶苗期抗旱性的重要指标;抗旱性综合评价得出材料的抗旱性由强到弱依次为：CQ9> CQ7> CQ3> 瑞德（Red）> 多丽（Dory）> CQ2> CQ8> CQ6>巫溪> CQ5> CQ4> CQ1。     

Vitrification of in vitro produced ovine embryos at various developmental stages using two methods

This study was conducted to evaluate the effects of developmental stage of in vitro produced (IVP) ovine embryos and the type of vitrification procedure used on embryo cryotolerance.The IVP embryos were vitrified at five different developmental stages: 4-, 8- and 16-cell, morula, and blastocyst. For each stage, half of the embryos were vitrified in either 30 μl 3.4 M glycerol + 4.6 M ethylene glycol in straw (method 1) or in <0.1 μl 2.7 M ethylene glycol + 2.1 M Me₂SO + 0.5 M sucrose placed on the inner surface of a straw (method 2) of vitrification solution, based on two different procedures. After warming embryo viability was determined by assessing the rates of re-expansion, survival, and blastocyst formation. The quality of surviving embryos was evaluated by their hatching rate and blastocyst cell numbers. In both vitrification methods, embryo survival progressively increased as the developmental stage progressed. In method 1 few of the early cleavage stage embryos (4-, 8- and 16-cell) could reach to the blastocyst stage following warming. There was no significant difference in blastocyst cell numbers (total, ICM, and trophectoderm cells) or hatching rate of blastocysts derived from vitrified embryos at different developmental stages. The number of dead cells in vitrified blastocysts in method 1 was higher than for non-vitrified blastocysts (P < 0.05). The number of apoptotic cells in vitrified blastocysts was higher than for non-vitrified counterparts (P < 0.05). In conclusion, both the developmental stage of IVP ovine embryos and the method of vitrification have a significant effect on the viability and developmental competence of sheep embryos.     

DOLLO'S LAW AND THE IRREVERSIBILITY OF DIGIT LOSS IN BACHIA

Several recent studies conclude that exceptions to Dollo's law are more common than used to be thought. If the claims are true this would change our view on the role of developmental constraints in the evolution of body plans. One study claims the reevolution of lost digits in the lizard genus Bachia ( Kohlsdorf and Wagner 2006 ). We evaluate this claim. We conclude that the proposed molecular phylogenetic tree is in conflict with evolutionary mechanisms concerning the biogeography of lizards and with morphology‐based phylogenies. A reanalysis of the molecular data does not support the topology of the published tree. Furthermore, two implicit assumptions, that digit numbers are fixed and that polydactyly evolves independently from other characters, are incorrect. We conclude that there is no convincing support for reevolution of digits in Bachia. We discuss our findings in the light of the current evidence for the reversal of losses of complex traits. We conclude that in metazoans, exceptions to Dollo's law are mainly found among meristic traits that originate relatively late during embryogenesis, when developmental systems are more compartmentalized. Finally, our study shows that phylogenetic analyses should incorporate evolutionary mechanisms including constraints, variation, and selection, not only for correct phylogenetic reconstruction, but also for correct evolutionary inference.     

Egg cannibalism in Barents Sea capelin in relation to a narrow spawning distribution

The spawning distribution of Barents Sea capelin Mallotus villosus off northern Norway in 2002 was restricted to a narrow area at the easternmost spawning grounds. There was an increase in abundance and a marked shift in aggregation area from east towards west during 11 March to 4 April, as the capelin went from prespawning through spawning to spent stages. The capelin stomachs were either empty or contained capelin eggs, often mixed with sand. Both the occurrence of cannibals and stomach fullness increased with stage of maturity, being highest in spent fish, and higher in males than in females. No differences were found between cannibals and non-cannibals of the same sex when adjusted for total length ( L _T), age, L _T at age and condition factor. At similar stomach fullness, the females had consumed more eggs than the males. This was attributed to a higher proportion of empty and broken eggs and less sand in females compared to males. In the full stomachs, the mean consumption in females and males was 623 and 334 eggs, respectively, whereas the respective maximum egg consumption was 871 and 683 eggs. The minimum estimates (given no digestion) of mean ± 95% CL egg consumption in spent females and males were 75·4 ± 6·9 and 58·4 ± 12·0 eggs, respectively, implying a minimum mortality of 1–2% of the total egg production caused by cannibalism.     

Generality of the Final Size Formula for an Epidemic of a Newly Invading Infectious Disease

The well-known formula for the final size of an epidemic was published by Kermack and McKendrick in 1927. Their analysis was based on a simple susceptible-infected-recovered (SIR) model that assumes exponentially distributed infectious periods. More recent analyses have established that the standard final size formula is valid regardless of the distribution of infectious periods, but that it fails to be correct in the presence of certain kinds of heterogeneous mixing (e.g., if there is a core group, as for sexually transmitted diseases). We review previous work and establish more general conditions under which Kermack and McKendrick's formula is valid. We show that the final size formula is unchanged if there is a latent stage, any number of distinct infectious stages and/or a stage during which infectives are isolated (the durations of each stage can be drawn from any integrable distribution). We also consider the possibility that the transmission rates of infectious individuals are arbitrarily distributed—allowing, in particular, for the existence of super-spreaders—and prove that this potential complexity has no impact on the final size formula. Finally, we show that the final size formula is unchanged even for a general class of spatial contact structures. We conclude that whenever a new respiratory pathogen emerges, an estimate of the expected magnitude of the epidemic can be made as soon the basic reproduction number ℝ₀ can be approximated, and this estimate is likely to be improved only by more accurate estimates of ℝ₀, not by knowledge of any other epidemiological details.     

Transformation of suspension cultures of bromegrass (Bromus inermis) by Agrobacterium tumefaciens

Smooth bromegrass (Bromus inermis Leyss) is an extremely cold hardy perennial grass and its cell culture is an excellent system for studying mechanisms of cold hardiness induced by low temperature or abscisic acid (ABA). Agrobacterium tumefaciens-mediated transformation of non-embryogenic bromegrass cultures was attempted. Agrobacterium strain EHA105 carrying a binary vector that contained the neomycin phosphotransferase (NPT II), beta-glucuronidase (GUS) and green fluorescent protein (GFP) genes were co-cultivated for 3 days with bromegrass cells at the late exponential or early stationary growth phase (7–9 days after subculture). These conditions gave optimal transformation efficiency. Putative transformants were identified by selection for geneticin resistance and by examining the calluses using fluorescence microscopy. This allows the elimination of escapes and selection of cells that express the target genes. PCR and Southern blot analyses confirmed the integration of the GUS and GFP genes into the genome of transformed bromegrass cell lines. Transformants with various levels of GUS expression were obtained with a high frequency following Agrobacterium-mediated gene transfer and visual selection by GFP. The successful transformation method described allows reverse genetics approaches for analyzing cold hardiness genes isolated from bromegrass cells.     

陕西南部早寒武世原始锥石类carinachitids两新种记述

对陕西宁强宽川铺地区灯影组宽川铺段原始锥石类carinachitids两个新种Emeiconularia amplicanalis sp.nov.和Carinachites platus sp.nov.进行了记述。外表形态多样、个体大小悬殊的两辐对称、三辐对称和四辐对称的carinachitids系列标本的发现,揭示了陕南地区早寒武世丰富多样的carinachitids生命世界。三辐射对称的Emeiconularia在四川峨眉及陕西南部的震旦-寒武系界线附近都有分布,因而对前寒武纪—寒武纪跨界地层具有划分对比意义。两新种的发现无疑增加了我们对早期锥石类多样性的认识,为证实多样性的刺细胞动物在早寒武世早期已经存在的假说提供了新线索。     

棕色田鼠脑和行为不同发育阶段副嗅球和主嗅球的细胞活动

本文运用免疫组化显示Fos蛋白的方法首次研究了棕色田鼠脑和行为不同发育阶段副嗅球和主嗅球的细胞活动。当不同年龄阶段的幼鼠同时暴露于自己家庭的熟悉底物和另一家庭的陌生底物时 ,嗅闻和呆在自己熟悉底物上的时间较多 ,直到产后 15d、 2 0d和 2 5d时 ,幼鼠探究不同底物的行为显示出显著性差异。脑的大小随着日龄增加而增加 ,但从产后 1到 15d ,脑重、脑宽和嗅球大小随着日龄增加特别显著。当不同日龄幼鼠暴露于陌生底物或者暴露于自己的熟悉底物时 ,从产后 5到 15日龄 ,主嗅球僧帽细胞层、颗粒细胞层、副嗅球僧帽细胞层和颗粒细胞层Fos免疫阳性细胞随着日龄明显增加 ,但直到 15和 30日龄时 ,和对照组相比 ,陌生底物可引起幼鼠主嗅球Fos免疫阳性细胞明显增加 ,从 2 0日龄起 ,陌生底物可引起副嗅球Fos免疫阳性细胞明显增加。主嗅球颗粒细胞层Fos免疫阳性细胞随着日龄的增加从边缘到中心逐渐出现 ,而副嗅球Fos免疫阳性细胞随着日龄的增加从顶部到底部逐渐出现。以上结果说明产后第 1d到 15d左右可能是棕色田鼠脑结构发育的重要阶段 ,而从此以后棕色田鼠主嗅球和副嗅球就具有区别熟悉气味和陌生气味的能力 ,表明棕色田鼠行为、脑发育和细胞活动间有紧密关系