异鳔鳅年龄结构、生长特性与生活史类型

2010年10月至2011年7月在长江上游宜宾至江津江段采集405尾异鳔鳅鮀(Xenophysogobio boulengeri)样本。以耳石作为主要年龄鉴定材料,研究了异鳔鳅鮀的年龄结构和生长特征,采用模糊聚类分析法推断了异鳔鳅鮀的生活史类型。结果表明:长江上游异鳔鳅鮀由4个年龄组组成,其中优势年龄组为1～2龄(占83.70%);体长(L)与体重(W)关系为W=5×10-6L3.294 3(r2=0.941 3,n=405,F=6 040.22,P0.01),体长与耳石半径(R)的关系为L=0.000 8R2-0.168 4R+42.504(r2=0.836 5,n=399,F=399.20,P0.01);von Bertalanffy方程描述的生长方程为Lt=179.49(1-e-0.249 8(t+0.289 8))、Wt=133.18(1-e-0.249 8(t+0.289 8))3.294 3,体重生长拐点年龄为4.48龄;异鳔鳅鮀属于r-选择类型鱼类。当前长江上游异鳔鳅鮀群体生长特征较2001～2002年已发生变化,因此有必要采取保护措施。     

世界范围内“四大家鱼”入侵现状及其适应特性

原产中国的鲢(Hypophthalmichthys molitrix)、鳙(Aristichthys nobilis)、草鱼(Ctenopharyngodon idella)和青鱼(Mylopharyngodon piceus),即"四大家鱼",已分别被引入到世界上很多个国家和地区,在其中将近一半的地区成功入侵,远高于一般入侵生物的建群概率。这与其自身的高繁殖力、宽广的生理耐受性和食性,以及遗传结构多样性等特征有关,还与新栖息地环境因素密切相关。四大家鱼野外繁殖所需的具有一定流量、流速、足够长且通畅的河道,是其成功入侵的必备环境因素;气候因素也影响四大家鱼成功入侵的概率。此外,入侵地的饵料丰度以及与其他入侵生物的协同作用,也能促进四大家鱼在引入地建群之后的入侵速度和程度。     

温度对花斑副沙鳅仔鱼发育、摄食及不可逆点的影响

2011年4～5月,研究了温度对花斑副沙鳅(Parabotia fasciata)早期仔鱼的发育、初次摄食时间、群体摄食率及不可逆点(PNR)的影响。结果发现,花斑副沙鳅仔鱼出膜后2 d已开始摄食;初次群体摄食率最高值出现在卵黄囊耗尽后的1～2 d,花斑副沙鳅仔鱼的摄食强度随温度升高而增大。仔鱼抵达PNR的时间随温度升高而缩短:22℃时,仔鱼的PNR出现在出膜后的8.0～9.0 d;26℃时,PNR为7.0 d;28℃时,PNR为5.5 d;30℃时,PNR为5.0 d。最大初次摄食率至PNR之间为不可逆饥饿期,22℃时为3.5 d,30℃时仅为1.5 d,说明温度越高,仔鱼耐受饥饿的能力越差,越不利于仔鱼的存活。研究认为,温度对花斑副沙鳅仔鱼发育、摄食及不可逆点的影响较大;在苗种培育过程中,应根据温度确定投饵时间,适时投饵对仔鱼的成活显得尤其重要。     

海洋中药牡蛎肉的现代临床实验研究进展．

牡蛎作为一种广泛分布的海洋药用动物,其软体部分及其提取物在其药理研究、临床应用、药用价值等方面获得了广泛研究。牡蛎肉营养丰富,含有多种不饱和脂肪酸和糖类,尤其是锌的舍量较高。在对鹌鹑、小鼠、兔子等多种实验动物的体内实验及多种肿瘤细胞的体外增殖实验中发现,牡蛎肉较突出的作用为降血糖血脂,抗血栓,抗氧化,免疫增强,抗肿瘤,保肝护肝等。本文对其古籍记载,化学成分和临床实验研究进行了综述,为进一步深入地研究和拓宽其临床应用范围提供了坚实的科学依据。     

The significance of sex

Sexual and asexual modes of proliferation are associated with advantages and disadvantages, yet a profound percept that would account for both ways of reproduction is missing. On the basis of the 2nd law of thermodynamics we find that both sexual and asexual reproduction can be regarded as a means to consume free energy in least time. Parthenogenesis is a fast way to consume a rich repository of free energy, e.g., an ample stock of food with a large number of individuals, whereas sexual reproduction is a fast way to consume diverse and dispersed resources with a large variety of individuals. Most organisms have adapted to their surroundings accordingly and some organisms switch from one mode of reproduction to the other depending on the amount and dispersion of free-energy sources. We conclude that the least-time free energy consumption in respective surroundings, as the general criterion of natural selection, determines also sexual and asexual modes of reproduction.     

基于DPSIR模型的国家级生态文明先行示范区生态文明建设分析评价——以湘江源头为例

结合国家级生态文明先行示范区生态文明建设的基本要求,将欧洲环境局的DPSIR环境管理模型引入到其生态文明建设分析评价当中,阐述了其分析评价的四个核心要点,并据此从生态制度、生态经济、生态社会和生态环境4个方面选取40个指标建立了评价指标体系,以湘江源头国家级生态文明先行示范区为研究对象,运用粗糙集理论和方法,就其生态文明建设展开分析评价,验证了评价模型的合理性、可操作性。结果表明:一是DPSIR模型能够很好地体现生态文明建设各因素间的因果关系信息,模型显示,可通过增强"驱动力"、降低"压力"、优化"状态"、妥对"影响"、全面"响应"等途径来增强示范区生态文明建设效果。二是从指标权重和研究的结果来看,对生态文明建设有着正向影响且权重较大的指标,要重视其正向影响并积极推动其效应最大化,对一些制约或影响生态文明建设的负向指标,要严格做好控制工作并减少其影响效应。三是研究得出湘江源头国家级生态文明先行示范区宁远、江华和蓝山三县生态文明建设总体水平呈现稳步上升的趋势。生态社会、经济和制度的"驱动力"持续增强,生态资源和环境"状态"不断改善,生态社会和经济"影响"逐渐合妥,生态社会、经济和环境"响应"全面迅速,但经济转型、资源和环境"压力"仍然亟待降低。建议从生态文明先行示范区创建的要求着手,对照目标,弥补差距,推动示范区建设高质量发展。     

Adelchi Negri and Schools of General Pathology in Italy between the end of the nineteenth and beginning of the twentieth century

The long lasting scientific collaboration of Adelchi Negri with Camillo Golgi in the Laboratory of General Pathology and Histology of Pavia began in 1898–99, when he was still a medical student, and at about the time basic knowledge about human malaria transmission cycle (to which Golgi himself had given important contributions) was completed. On the occasion of the 100^th anniversary of the discovery of Negri bodies, this article provides a short overview of the scientific and cultural context in whichNeurocytes hydrophobiae hypothesis matured. To the same intent and purposes, this article also delineates some of the important scientific achievements in the field of General Pathology by Negri’s contemporaries, reflecting both the influence of the two great pioneers in the field (Bizzozero and Golgi), and the close contact with European science in the 1890’s to the end of the first World War, when biological science in Italy entered a new crisis.

---

Adelchi Negri e le Scuole di Patologia generale nel passaggio dall’Ottocento al Novecento

Riassunto  La lunga collaborazione scientifica di Adelchi Negri con Camillo Golgi, nel Laboratorio di Patologia generale ed Istologia di Pavia, ebbe inizio nel 1898–99, quando questi era ancora studente di Medicina, e la conoscenza di base sul ciclo di trasmissione della malaria nell’uomo (alla quale lo stesso Golgi aveva dato importanti contributi in studi pionieristici) era completata. In occasione del Centenario della scoperta dei Corpi del Negri, questo articolo offre una rassegna sintetica del contesto scientifico-culturale in cui maturò l’ipotesi delNeurocytes hydrophobiae come agente causale della rabbia. Con questo intento e per lo stesso scopo, questo articolo traccia anche alcuni degli importanti raggiungimenti scientifici nel campo della Patologia generale da parte dei contemporanei di Negri, nei quali è rinvenibile, sia l’influenza dei grandi pionieri della disciplina (Bizzozero e Golgi), sia lo stretto contatto con la scienza europea, tra il 1890 circa e la fine della prima guerra mondiale, allorché la scienza biologica italiana entrò in una nuova crisi.

     

Kinetic analyses and structure-activity relationship studies of synthetic lysine acetylation catalysts

Lysine acylation of proteins is a crucial chemical reaction, both as a post-translational modification and as a method for bioconjugation. We previously developed a chemical catalyst, DSH, which activates a chemically stable thioester including acyl-CoA, allowing the site-selective lysine acylation of histones under physiological conditions. However, a more active catalyst is required for efficient lysine acylation in more complex biological milieu, such as in living cells, but there are no rational guidelines for developing efficient lysine acylation catalysts for use under physiological conditions as opposed to in organic solvents. We, herein, conducted a kinetic analysis of the ability of DSH and several derivatives to mediate lysine acetylation to better understand the structural elements essential for high acetylation activity under physiological conditions. Interestingly, the obtained trend in reactivity was different from that observed in organic solvents, suggesting that a different principle is necessary for designing chemical catalysts specifically for use under physiological conditions compared to catalysts for use in organic solvents. Based on the obtained information, we identified a new catalyst scaffold with high activity and structural flexibility for further modification to improve this catalyst system.     

Low population differentiation revealed in the highly threatened elongate loach (Leptobotia elongata,Bleeker), a species endemic to the fragmented upper reaches of the Yangtze River

The elongate loach (Leptobotia elongata) is a typical migratory fish that was formerly found in abundance throughout the upper and middle reaches of the Yangtze River but is now classified as a highly threatened fish on the China Species Red List. Here, a comparative study of microsatellite loci was performed to evaluate the genetic diversity and analyze the population structure in seven locations in the upper reaches of the Yangtze River, China. The results showed that genetic diversity of L. elongata is generally still at a high level. Populations from Xinshi, Panzhihua, Hechuan and Chishui, were found to have lower levels of genetic diversity than those that lived in Leshan, Yibin and Jiangjin. The IAM model indicated that populations from Panzhihua, Xinshi and Hechuan have undergone recent bottlenecks. AMOVA analysis revealed a small amount of differentiation among populations (3.6%), but most of the total variation occurred within populations (96.4%). Pairwise comparisons of populations confirmed a low population differentiation. STRUCTURE analysis showed no obvious genetic structure among populations, indicating that L. elongata living in the main stem of the river and its tributaries should be considered a single management unit.     

Changing landscape and grazing: macroremains from the terp Peins-east, province of Friesland, the Netherlands

This article seeks to contribute some new insights to the discussion about the colonisation of the North-Netherlands coastal area in the Iron Age. The aim of the study presented here was to investigate whether archaeobotanical research can demonstrate the absence or presence of grazing and the changes in vegetation that follow the development of the salt marsh and that may be related to activities connected with human occupation. The material studied was sampled in the terp of Peins in the Dutch province of Friesland during the 1999 excavation. The beginnings of this terp can be dated in the first century A.D., although a small dike and two parallel ditches preceded it. The macroremains from these ditches proved useful in describing the changes in the salt marsh vegetation. It was shown that the salt marsh was not used for grazing cattle prior to habitation. Grazing only started at the time the first terp podium was raised.