太湖短吻银鱼的胚胎发育

椭圆卵囊藻培养轮虫时,轮虫平均产卵量均低于４．０个,随着食物浓度增加,后代混交雌体百分率降至１２．５０％．投喂蛋白核小球藻,轮虫的平均产卵量从６．００增加到１１．４０个,后代混交雌体百分率降至４．５８％．小球藻和卵囊藻混合培养轮虫,轮虫平均产卵量少于５．００个,后代个体混交百分率下降．当小球藻浓度增加到８．０＊１０（６）ｃｅｌｌｓ／ｍｌ时,平均产卵量下降至８．３３个,混交百分率也明显升高。     

Gender of large river deltas and parasitizing rivers

Deltas are the most dynamic part of large rivers and the characteristics of deltas reflect the basic nature of morphodynamics,ecology and anthropogenic influence.The authors investigated many deltas of...     

近现代中国女性人才的地理分布和区域分异

中国人文地理学研究中有关女性地理的研究基本缺失, 而以往人才地理学研究中对女性人才的忽视, 以及女性主义地理学研究中女性人才研究的薄弱, 都使女性人才地理研究有了自己的空间。利用人才数量、类型和籍贯三个指标对活动于1840~1949 年期间的中国著名女性人物资料进行了统计和分析, 在此基础上, 对近现代中国女性人才的数量和地位、分布 领域和特点以及地理分布格局进行了论述, 并对影响其数量、类型和区域分异的因素进行了探讨。研究发现: 与同一时期的男性人才相比较, 近现代女性人才数量仍然偏少, 但相对于过去, 其数量却有所增加, 影响领域也更扩大; 近现代女性人才集中分布于中国东部和东南沿海地区以及中部地区的少数几个省份, 西北地区较少; 湖南、广东、浙江、江苏四省女性人才尤为突出, 其中, 湘粤两省在社会政治领域影响较大, 江浙两省在科学、教育和文化领域占有较大优势。近现代女性人才数量的增加和影响领域的扩大受近现代中国政治改良运动和政治革命的影响, 而其区域分异特点则充分体现了中国近现代政治革命和妇女解放运动的地区差异。     

东北地区城市女性就业水平空间分异机制

促进女性就业,不仅能够提高女性社会经济地位,还有助于提高社会生产力和经济活力。论文以东北三省“五普”“六普”和2015年1%人口抽样调查数据为基础,借助空间自回归模型方法,探讨东北地区城市女性就业水平的时空特征及其驱动机制。结果表明：① 东北地区城市女性就业水平整体较低,其中南部城市的女性就业水平高于北部。② 从影响因素来看,高学历、便捷的交通、较高的工业水平、完整的家庭以及更多的家庭支持对城市女性就业水平具有积极效应;而养育负担对女性就业水平具有负向效应。其中,三代及以上家庭户比例是2000—2015年老工业基地城市女性就业水平空间分异的主导因素,可见,一个完整的家庭对女性就业具有极其重要的作用。     

Sex dependent sexual reproduction strategies in a cyclic parthenogen—A case study from intermittent urban pond

The fitness of animals inhabiting highly unpredictable intermittent ponds depends on the effectiveness of the production of their resting stages. Daphnia living in such an environment produce sexual eggs as well as the males needed to fertilize them. We hypothesize that the strategy of permanent male presence should coexist with the synchronization of the production of males with that of sexual eggs. To test this hypothesis, we collected plankton samples from a model urban pond, two times a week, throughout the growing season. We analyzed in detail a number of environmental factors and the population dynamics of two Daphnia populations. The percentage of ephippial females and males periodically reached c.a. 50 % of the population. Depending on the moment of the growing season, this proportion was primarily influenced by population crowding, the richness of invertebrate predators in the habitat, extreme high temperatures and the occurrence of the autumnal photoperiod. Our results confirm the hypothesis that Daphnia produce simultaneously long-living males and males synchronized with receptive females. Additionally, we have shown that the number of resting eggs deposited by temporally-isolated populations varied significantly; thus the fitness of a particular genotype depends on the season and on the particular timing of its activation.     

女性跨国婚姻移民家空间的性别、资源与权力——粤西乡村案例

新文化地理学视角下的空间不仅具有物质属性,也是社会关系的容器。家庭常被置于社会学的论述范畴,同时,家庭也以空间形式出现,并表征着家庭成员间复杂、细微的权力结构。论文以广东罗定市华石镇中越跨国家庭的家空间为分析样本,以家庭资源中的经济资源、情感资源和社会资源为分析框架,并结合家空间的实用性、装饰性和防御性等特点,考察越籍妻子在家空间中的占用、功能划分与使用、美学装饰,以及日常空间实践中自我赋权的方式与机制。研究发现：① 为家庭提供主要经济收入的越籍妻子在夫妻权力结构中占有优势,在家空间的设置和安排中持有更多的话语权;② 越籍妻子将家空间视为自我情感与认同的表达渠道,通过装饰家居环境以建立起对家空间的控制;③ 由于社会资源的缺乏,越籍妻子在公共空间中受到排斥,家空间成为越籍妻子回避邻里交往的防御性堡垒。研究认为女性跨国婚姻移民在家空间中获得了施展个人权力的契机,但其权力仅限于家空间内,现阶段难以拓展至家以外的更大区域。研究结果既是对家的地理学中性别话题的补充,亦是对它的拓展与深化。     

Temperature effect on the life history of three types of Brachionus calyciflorus females

The effect of temperature on the life history characteristics of amictic females (AF), unfertilized mictic females (UMF) and fertilized mictic females (FMF) inBrachionus calyciflorus was studied with replicated individual cultures at 20°C, 25°C and 30°C, and with algaeScenedesmus obliquus for their food. There were highly significant effects of both temperature and female type, independently and interactively, on the duration of juvenile and post-reproduction periods, and the number of eggs produced by the rotifer per life cycle. Among all the temperature-female type combinations, all the juvenile periods of FMF, and the post-reproduction periods of UMF and FMF at 20°C, were the longest, and the number of eggs produced by an UMF at 30°C was the highest. There were highly significant effects of both temperature and female type on the duration of the reproduction period, but no clear correlation was observed between temperature and female type. The reproduction period of AF was longer than that of UMF and FMF. Only temperature influenced significantly the mean life-span of the three types of female. The duration of juvenile, reproduction and post-reproduction periods as well as the life-span of the three types of females were all reduced very significantly with rise of temperature, but the rates of reduction varied with female type. Among the three types of females, the number of eggs produced per life cycle by an UMF was the highest, and that of a FMF was the lowest. A significant relationship between the number of eggs produced per life cycle and temperature was observed only in the UMF. Projects supported by NSFC (No. 39870158), Natural Science Foundation of Anhui Province (No. 100330: No. 042416) and the Excellent Youth Foundation (No. 04043050).     

半滑舌鳎(Cynoglossus semilaevis)Patched 1基因的克隆和表达分析

Hedgehog(Hh)信号通路在脊椎动物和非脊椎动物发育过程中细胞信号传导方面发挥重要的作用。Patched 1 (Ptc1)基因是Hh的受体,通过和Hh配体结合调节Hh信号通路。本研究克隆和鉴定了半滑舌鳎的Ptc1基因(csptc1),该基因cDNA全长为5212 nt,编码蛋白包括1543个氨基酸残基,序列比对和进化分析显示该蛋白在进化过程中较为保守。荧光定量显示该基因在脑,肝脏,心脏,鳃,肠,脾脏、肾脏和性腺组织中普遍表达,在精巢中的表达水平显著高于卵巢。精巢中的原位杂交信号主要位于该基因主要在初级精母细胞,次级精母细胞和支持细胞中,而在卵母细胞中的信号较弱。Csptc1基因在卵巢中的甲基化水平高于在雄鱼和伪雄鱼精巢中。这一研究结果可能说明csptc1基因参与了 Desert Hedgehog (DHH)基因维持雄鱼和伪雄鱼的生殖细胞系以及精子发生等生物学过程。