池塘内循环流水养殖下太湖鲂鲌(翘嘴鲌(♀)×三角鲂(♂))肠道微生物群落变化的研究

为研究池塘内循环流水养殖(In-pond Raceway, IPR)模式下太湖鲂鲌(翘嘴鲌(♀)×三角鲂(♂))肠道微生物群落结构的变化,以传统池塘养殖作为对照组,采用16SrRNA高通量测序方法分析了IPR养殖模式下太湖鲂鲌肠道的菌群结构及环境水体微生物多样性的变化。试验结果表明, IPR模式下太湖鲂鲌肠道微生物群落发生了明显的变化,在门分类水平,梭杆菌门(Fusobacteria)成为绝对优势菌,所占丰度为92.47%;对照组的优势菌由梭杆菌门、变形菌门(Proteobacteria)和厚壁菌门(Firmicutes)组成,三者所占的丰度分别为34.45%、33.30%和21.30%。在养殖水环境中,两种养殖模式的微生物群落数均大于肠道样本,且二者优势菌不同;IPR水环境的优势菌为蓝细菌(Cyanobacteria,36.53%),其次为放线菌门(Actinobacteria,24.67%);对照组水体中的优势菌为放线菌门和变形菌门,分别占细菌总数的38.99%和28.15%。多样性指数结果表明,水环境中的微生物群落Shannon多样性指数、Chao1指数高于肠道样本,IPR养殖对象肠道微生物群落多样性最低。本研究结果揭示,池塘内循环流水高密度养殖模式下,太湖鲂鲌的肠道微生物结构发生了一定的改变,微生物群落多样性降低,应注意该模式下养殖对象的肠道健康,加强养殖管理。     

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。     

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.     

日本高校地理学科的课程设置与地理教学

日本高校中地理学学科既有设置在文科的也有归属在理科的情况;但地理学课程的设置有一定的共性,课程精简,形式多样,内涵充实。这对我国高校地理课程调整有一定借鉴作用。     

大学城建设对广州城市发展的促进分析

知识经济时代的到来使得大学城成为最具时代特色的城市空间形态之一,大学城因此成为社会各界的关注焦点。在系统梳理中外有关大学城的概念,尝试从新角度重新认识大学城及其与大学园区、大学卫星城、大学城市、新科技城市的关系基础上,通过对广州大学城的实证研究,分析大学城对建设学习型城市、强化城市教育、文化、科技功能,改善城市空间结构,催生城市经济新增长点等方面的作用。     

A Quantitative Assessment of the Reproductive System of the Mediterranean Cave-Dwelling Triplefin Blenny Tripterygion melanurus

Abstract. The breeding biology of the cave-dwelling Mediterranean triplefin blenny Tripterygion melanurus (Pisces, Blennioidei) was studied in the field. Two types of reproductive male were observed, territorial males and non-territorial males. Territorial males establish territories for mating, but not necessarily for feeding, in caves and crevices at depths between 0.5 and 33  m. Territories can be settled in clusters in a single cave. Non-territorial males occur in the vicinity of territories and attempt to parasitise matings of territorial males. Gravid females wait near territories where another female is spawning, rather than spawn with currently unmated territorial males. Waiting females intrude in matings and sometimes displace a spawning female. The frequency of mating of the territorial male, of sneaking and of female intrusions are higher in territories that border others than in isolated territories. Females may minimise predation risks both on themselves and on their eggs by spawning in clustered territories and by spawning with males that have more than one clutch of eggs. Territorial males must find a compromise between the benefits of attracting a female and the costs of parasitic spawning by sneaker males. The possibility that territorial males tolerate the proximity of other territorial males and accept a risk of cuckoldry is discussed. Parasitic spawning in T. melanurus is relatively rare and the gonadosomatic index in both non-territorial and territorial males is low, indicating that sperm competition is probably not intense.     

国外高校环境专业教学的几点启示

在评介欧美发达国家高等院校环境专业教学情况的基础上,指出国外高校环境专业教学具有基础宽厚、选课灵活、注重实践教学及强调分析问题、解决问题的能力培养特点;建议我国环境工程教学应进一步拓宽基础,发挥物色,多设选修课,健全选课机制,加强实践教学。     

Gender,class, and paradoxical mobilities of Thai marriage migrants in Austria

In this paper, we investigate whether marriage‐related migration promotes socioeconomic mobility and how class belonging and educational background affects Thai women's migration experience and socioeconomic mobility. Drawing on qualitative interviews, supported by a questionnaire survey with Thai women living in Austria and who are in a relationship with a Western male citizen, we seek to dismantle simplistic notions about hypergamy and question common assumption about marrying up or down in migration contexts. We compare socioeconomic indicators such as formal education, occupation, and income before and after the migration and analyse migrants’ experiences in Austria. The results show a complex picture of upward and downward socioeconomic mobilities. Two distinct scenarios of paradoxical mobilities have been identified. On the one hand, some migrants feel empowered (when experiencing economic downward mobility) as they enjoy the freedom of living in Austria, while on the other hand, those migrants experiencing upward mobility feel a loss of their personal autonomy.     

红河哈尼梯田文化景观遗产地中学生环境解说需求

位于红河哈尼梯田世界文化遗产核心区内的元阳一中中学生为研究对象,采取问卷调查法,对遗产地中学生的环境解说需求进行分析。结果表明：在解说内容的需求上,环境知识（4.05）＞环境意识（4.00）＞环境技能（3.95）,且发现性别与环境意识、技能,年级与环境知识、意识、技能,地区与环境知识、技能具有显著性差异,说明遗产地中学生对环境解说内容整体处于需要状态,且不同社会背景特征的中学生具有明显的需求差异;解说活动与形式上：发现中学生对亲身体验（83.3%）、据点解说（80%）、实地考察（87.7%）等媒介和形式需求度高,对解说牌示（19.9%）互联网（19.9%、解说折页（17.5%）等媒介和形式的需求度较低,且发现性别与解说空间方式、传统节日解说方式、环境问题解说方式,年级与解说媒介、参与环境活动方式,居住形式、户口类别、地区与参与环境活动方式、解说活动类型均具有显著性相关关系,说明遗产地中学生对解说媒介和形式具有明显的需求差异,且这种差异与性别、年级、居住形式等社会背景具有明显的相关关系。总之,遗产地中学生对环境解说的需求明显且以参与性较强的亲身体验和实地考察为主,因此,针对这个群体的解说应该以参与式为主。     

民国时期地理留学

近代地理留学在民国时期未然兴起,主要有自费,官费和中英庚款三种途径。在海外,中国地理留学生形成三大中心,即:中法里昂大学地理系,英国利物浦大学地理系和美国克拉克大学地理系。地理留学生学成归国之后,在地理学术研究和地理人才培养上都贡献甚大。朱家骅是民国地理留学的主要推动者。