重引入对麋鹿种群分娩定时及同步化的影响

种群持续繁殖是重引入物种对原灭绝地气候成功恢复适应的重要标志,研究重引入前后种群的繁殖波动规律,可为重引入管理者提供精准的繁殖预测信息和科学依据。本文整理北京重引入麋鹿种群后的1987年、1997年、2007年和2017年的总分娩数据,以每年最早分娩日作参照基准,统计个体分娩距此的天数,计算同步化率,并用ANOVA分析气温、降水、空气湿度、光照等变量对麋鹿分娩定时格局的影响。结果表明：(1) 引入后麋鹿种群年分娩节律呈“钟摆样”前后摆动,后逐渐回调,并最终处于相对稳定状态：时隔85年 (从灭绝至重引入) 后,北京麋鹿种群首次分娩时间较乌邦寺种群推迟35 ~ 42 d;重引入定植阶段：分娩节律逐年提前;种群扩繁阶段：分娩节律逐年向后推迟;种群复壮阶段：分娩节律又逐年微回调并最终处于稳定状态。(2) 北京麋鹿种群分娩有较强光周期定时和同步化：在重引入的第一年,分娩同步化率达到0 ~ 25%、25% ~ 50%、50% ~ 75%,分别用时18 d、14 d、5 d;重引入定植阶段分别用时41 d、19 d、11 d;种群扩繁阶段分别用时45 d、10 d、9 d;种群复壮阶段分别用时34 d、20 d和11 d。(3) 累积光照和积温,对北京麋鹿种群正常分娩启动影响差异极显著,对同步化分娩没有影响：妊娠期积温达到 (2748.34 ± 157.69)℃,累计光照达到 (3684.77 ± 514.26) h可启动正常分娩。(4) 北京麋鹿种群的分娩峰期与地上生物量峰期相关;从分娩时间来看,北京麋鹿种群已经恢复了对原灭绝地气候的适应。(5) 随时间增长,北京麋鹿种群非同步化分娩的个体数量逐年增加,分娩期总跨度并未延长。1997年以来,平均每年有30%左右的非同步化分娩现象。因此,基于分娩数据分析表明,麋鹿引入北京37年后,种群已经恢复对原灭绝地环境的重适应。     

Prophage lambda at unusual chromosomal locations. II. Mutations induced by bacteriophage lambda in Escherichia coli K12

An Escherichia coli strain deleted for the primary λ attachment site was lysogenized with λ at secondary sites. Some lysogens became mutants because of prophage insertion in the affected gene. Mutagenesis by phage λ is not random with respect to the gene affected: most mutants were pro, although certain other genes could be mutated at lower frequencies. In the case of several independent ilv and gal mutants, the sites of prophage insertion were in the same segment of the ilv region and galT gene respectively. The galT location may also be a preferred site for the insertion of DNAs other than prophage λ. Insertion of prophage λ within an operon can reduce the expression of operator-distal genes. A trpC λ insertion mutant expresses the operator-distal trpB function constitutively at a low level. This expression probably derives from a promoter located in the left arm of the prophage.     

苏北滨海湿地麋鹿恢复种群的研究

1986年至2004年,在苏北滨海湿地开展恢复麋鹿野生种群的研究。从每年的2月份开始,在麋鹿的产仔期按照每旬记录产仔数,直至产仔结束。逐年统计半散养和野生麋鹿种群结构。选择不同年龄阶段和不同性别的麋鹿进行称重,分析个体的身体发育程度。半散养麋鹿种群由1986年引进的39 头,发展到2004年的706 头,年均出生率21.7%,鹿群年均增长率为17.5%,现已繁殖了子四代;野生放养麋鹿由31 头增加到2004年的41头,年均出生率16.3%,年均增长率为9.0% ,且于2003年、2004年各产1 头完全属野生的子二代。产仔季节相由引进时的紊乱已调整至目前的规律性产仔。研究表明大丰麋鹿种群繁殖很成功,其寿命、行为、生理发育、繁殖周期等都较引进时发生了显著的变化,已完全适应了黄海湿地生态环境。人类活动干扰仍是影响麋鹿种群恢复的一个重要因素。     

麋鹿幼仔的活动同步性与同性聚群倾向

哺乳动物幼体从出生到性成熟这段时间存在生理和行为上的巨大变化.麋鹿幼仔出生1周内,与成鹿和其它仔鹿呈隔离状态,且藏卧于隐蔽处,母鹿哺乳是引起幼仔活动的主要因素.     

Le paléoplancton des Grès de Landévennec (Gedinnien de la rade de Brest — Finistère) étude biostratigraphique

In the Gedinnian Landévennec Sandstones Formation(Rade de Brest, Finistère, Massif Armoricain), rich and well-preserved assemblages of organic-walled microplancton were observed. In the Lanvéoc section, worked out bed after bed, fifty-five species of this organic-walled microphytoplancton of uncertain algal affinity and Prasinophyceae are described. Four genera and fifteen species are new in this total. The assemblage shows many relationship to others gedinnian microplancton from Europa. Africa and United States of America.     

水稻无脊椎动物多样性的K-L变换编目分析

K-L变换可消除样品各特征间的相关性,去除信息量较少或信息虚假的坐标轴,降低特征空间的维数,用较少量的特征描述样品,是目前最为有效的数据信息压缩抽取方法。利用K-L变换,样品之间变化较小的分类单元（目或功能群等）,不会作为重要特征保留下来。因此,数量上占优势、或害虫防治中有重要地位的分类单元并不一定是识别样品的重要特征。可以藉K-L变换明确构成样品变异的主要分类单元,从而对不同地区、不同季节的取样实践有一定的指导意义、用通常的多样性指数分析及多样性差异显著性分析无法解决这个问题。用K-L变换可大大压缩数据存储空间。对数据量很大的生物多样性分析有较大的应用价值。反映样品所携信息量的热带水稻田无脊椎动物目主要是半翅目,中腹足目,以及表腹亚目。其中,在旱季半翅目占主要地位,而在雨季中腹足目占主要地位。就无脊椎动物目的组成而言,它们是构成样品变异的主要类群,是取样中需要得到特别注意的目。反映样品信息的无脊椎动物功能群主要是外部植食类,植食多食性类,半水生水面爬行类,粗粒残物取食类,以及陆生爬行、跳跃或猎者类,是取样中要重点考虑的一些类群。     

麋鹿行为谱及PAE编码系统

以麋鹿为实例,通过辨识行为的基本单元,区别了“姿势”、“动作”和“环境”,分解了动物行为的层次,然后根据行为的适应和社群机能归类,建立了以“姿势—动作—环境”为轴心的,以生态功能为分类依据的动物行为分类编码系统（PAE编码分类系统）。PAE编码分类系统以集合论为基础,明确了动物行为的三要素：姿势、动作和生态环境之间的关系,避免了笼统地将动物的姿势、动作和行为混为一谈的做法,区分了动物行为的组成要素和结构层次。行为要素编码方法为动物行为学研究提供了一个新的生长点。在继承前人工作的基础上,记录了有关麋鹿的姿势、动作和行为达200多种,还区别了各种行为在雄性、雌性和幼体之间的相对发生频次以及发生季节。     

Conodontes de la coupe de Reun Ar C'Hrank en Lanvéoc (Rade de Brest) emsien du massif Armoricain (France) corrélations biostratigraphiques

In the Reun ar C'Hrank section (Rade de Brest), the Conodonts from just above the base of the Beg an Arreun Formation of the Troaon Group in the Armorican Massif indicate the Polygnathus laticostatus Zone, which belongs to the highest Zlichvian and the base of the Dalejan. Species of Icriodus from the same beds indicate a correlation with the lower and middle part of the Hierges Formation, which represents the Upper Emsian in the Ardennes. Conodonts from Le Fret Formation are tentatively assigned an Upper Emsian/Dalejan age.     

江苏大丰麋鹿国家级自然保护区麋鹿死亡分析

From 2009 to 2020, we systematically investigated the population, mortality, and death factors of Père David’s deer (Elaphurus davidianus) in the Dafeng Milu National Nature Reserve, Jiangsu, China. The result showed the annual growth rate of the population was 13.09% ± 5.96%, which continuously increased in the 12 years. The annual mortality rate was 3.53% ± 2.27%, with an obvious fluctuation every 2 years. There was no significant difference in mortality of adults and sub-adults in different seasons, but significant in juveniles.Significant differences in mortality among different age groups were observed. The adults died most in summer and autumn, while the juveniles died most in winter and spring. 48.77% of subjects tend to choose the underbrush for dying. The death factors among different age groups were significantly different. The elders and the juveniles mainly died of epidemic diseases, including viral, bacterial, and parasitic. While the sub-adults died in accidents. We suggested that it is necessary to strengthen the daily monitoring and epidemic disease prevention in wildlife management. Our data provided important information for the protection of Père David’s deer in Dafeng Reserve.     

Characterization of small plasmids from Staphylococcus aureus.

Small molecular weight plasmids from Staphylococcus aureus were characterized with respect to size, restriction enzyme cleavage pattern and transforming capacity. The plasmids pS194 and pC194 which encode streptomycin and chloramphenicol resistance respectively contained 3.0 and 2.0 megadaltons of DNA as determined by zonal rate centrifugation and electron-microscopy. Both plasmids transformed S. aureus with high efficiency. Plasmid pC194 contained only one cleavage site for endonuclease HindIII and pS194 contained single cleavage sites for HindIII and EcoRI. A natural recombinant between these two plasmids, pSC194, shared the high transforming capacity of the parental plasmids and contained one EcoRI site And two HindIII sites. pSC194 DNA also transformed B. subtilis with high efficiency. The recombinant plasmid pSC194 may be used as an EcoRI vector for construction and propagation of hybrid DNA in S. aureus as shown in the following paper (Löfdahl et al., 1978).