A detailed abundance analysis of the hot post-AGB star ZNG-1 in M10

We present a model-atmosphere analysis for the bright ( V ∼13) star ZNG-1, in the globular cluster M10. From high-resolution ( R ∼40 000) optical spectra we confirm ZNG-1 to be a post-asymptotic giant branch (post-AGB) star. The derived atmospheric parameters are T _eff=26 500±1000 K and log  g =3.6±0.2 dex . A differential abundance analysis reveals a chemical composition typical of hot post-AGB objects, with ZNG-1 being generally metal poor, although helium is approximately solar. The most interesting feature is the large carbon underabundance of more than 1.3 dex. This carbon deficiency, along with an observed nitrogen enhancement relative to other elements, may suggest that ZNG-1 evolved off the AGB before the third dredge-up occurred. Also, iron depletions observed in other similar stars suggest that gas–dust fractionation in the AGB progenitor could be responsible for the observed composition of these objects. However, we need not invoke either scenario since the chemical composition of ZNG-1 is in good agreement with abundances found for a Population II star of the same metallicity.     

Internal colonisation, hegemony and coercion: Investigating migration to Southern Lazio, Italy, in the 1930s

This paper investigates the Italian fascist regime’s use of internal colonisation as part of a wider ruralisation policy aimed at promoting population growth, curbing rural-urban migration, staunching emigration, and halting the spread of industrial urbanisation. By focusing on the case study of the Pontine Marshes, the paper demonstrates how, through targeted selection procedures aimed at displacing defined social and political undesirables, migrants were chosen and effectively coerced into migrating to the “fascist” landscape of the marshes. The area, reclaimed and developed in the 1930s, was celebrated as a sign of the regime’s engineering and social success. The paper utilises Antonio Gramsci’s thought on hegemony, and argues that the overt use of coercion hints at the fact that fascism, although ideologically totalitarian and hegemonic, was contested. Although statisticians, demographers and state bureaucrats were organised and institutionalised in the construction of hegemony based on consent, fascism based itself more in coercion than in passive consent in the case of internal colonisation.     

The Estimation of Secondary Production of the Marine Bivalve Spisula subtruncata (DA COSTA) in the Area of the Po River Delta

Abstract. The secondary production of Spisula subtruncata (somatic production) is calculated in the framework of a benthic monitoring study in a coastal area. The temporal trends of density, biomass and growth increments are examined in the three year-classes present. These are compared to certain physical and chemical parameters.     

大鹏湾夜光藻种群的季节变化和分布特征

于１９９０年３月－１９９２年６月对中国南海大鹏湾盐田附近海域的夜光藻种群动态及时空分布进行了综合调查，结果表明，夜光藻种群的出现期间一般为每年的１－６月，最早是１９９１年的１２月，娄量高峰期为３－５月，种群密度的波动极为显著；调查期间共发生８次赤潮，且都发生在３月初至５月初；大鹏湾夜光藻赤潮的发生特点是，赤潮的发生和消失突然，持续时间短，一般不超过３ｄ。     

中华乌塘鳢的群体生物学研究 Ⅱ.生化遗传变异

用同工酶谱法发现中华乌塘鳢Bostrichthy sinensis四个群体的遗传变异水平很低,在所检测的30个基因座位中,多态座位比例只有0—10％,平均杂合度仅为0.2—0.5％,物种的平均杂合度为0.33±0.10％。四个群体共享常见的等位基因。虽然其中三个群体拥有特有的等位基因,但其基因频率都未超过5％。四个群体的Nei氏遗传距只有1.68—12.13×10~(-5)。据分析,近交可能是遗传变异水平低和形态特征分化差的主要原因。种苗生产上应注意广泛采集不同地理群体的鱼作亲鱼,以丰富养殖群体的基因库。     

舟山沿海单齿螺（Monodonta labio）种群的年龄结构,生物量与生长特征

本文报导了采自舟山沿海单齿螺种群的年龄结构、生物量与生长。自然种群的单齿螺年龄组成以１＾＋和２＾＋龄占优势，壳高、壳宽、壳口高、厣径、体重等生长参数的回归关系良好，单齿螺的生长完全可以用壳高来表示。单齿螺以第一、二年生长最快。采捕季节可定在四、五月间，采捕规格应在壳高１６ｍｍ以上。     

Coupling of life cycles of the copepods Calanus chilensis and Centropages brachiatus to upwelling induced variability in the central-southern region of Chile

A time series of zooplankton sampling carried out at Station 18 off Concepción (36°S, 73°W) from August 2002 to December 2003 allowed the study of annual life cycles of the copepods Calanus chilensis and Centropages brachiatus in association with environmental variability in the coastal upwelling zone. Changes in the abundance of eggs, nauplii, and copepodids were assessed from samples taken at a mean time interval of ca. 20 days. Upwelling variability in near-surface waters was reflected in seasonal changes in salinity, water column stratification, and oxycline depth, as well as a weak seasonal signal in sea surface temperature (1-2 °C). Both copepods exhibited similar life cycles, characterized by continuous reproduction throughout the year. Estimates of generation times, as a function of temperature, were 25-30 days for C. chilensis and 27-35 days for C. brachiatus, predicting about 12 and 10 generations a year, respectively. These estimates were consistent with reproduction pulses observed in the field. It was thus suggested that copepods may grow under non-limiting food conditions in this upwelling area. However, despite continuous reproduction, there were abrupt changes in population sizes along with the disappearance of early naupliar and copepodid stages taking place even during the upwelling season (spring/summer). These changes were attributed to sudden increases in mortality taking place in spring or early summer, after which the populations remained at low levels through the fall and winter. It is thus suggested that, in addition to variability in the physical environment, biological interactions modulating changes in copepod mortality should be considered for understanding copepod life cycles in highly productive upwelling systems.     

萼花臂尾轮虫(Brachionus calyciflorus)COI基因序列变异及种群遗传结构分析

利用线粒体细胞色素氧化酶亚基Ⅰ(cytochrome oxidaseⅠ，COI)基因序列对北京地区和江汉湖群部分湖泊萼花臂尾轮虫(Brachionus calyciflorus)种群遗传结构进行了初步分析。以特异引物进行PCR扩增，获得了661bp的基因片断序列，所得序列与Genbank中B．calyciflorus COI序列的同源性为82％—93％。在6个种群中，共获得了15种单元型。序列分析结果表明，不同季节单元型之间的遗传距离较大(0．248-0．263)，而在同一季节单元型之间遗传距离较小(0．002-0．031)。种群遗传结构分析表明，各种群之间无共享的单元型，同一季节不同湖泊种群之间存在着一定程度的遗传分化，但未按照地理位置形成明显的地理格局。按采样时间分组进行AMOVA分析，组间差异高达94．09％；DH-I与其他种群之间存在着明显的遗传分化。同一湖泊不同季节样品之间，遗传变异较大，这表明在同一湖泊存在着不同基因型的轮虫休眠卵，当环境条件发生了变化后，不同基因型之间会发生更迭。     

南极磷虾年龄组成的体长频数分布混合分析

本文依据１９８９／１９９０和１９９０／１９９１两个南极夏季在普里兹湾以北海域所获的拖网样品，应用分布混合分析方法，研究大磷虾种群的年龄结构。结果表明，种群内最多可能包括６个年龄：发年幼体，１＾＋，２＾＋，３＾＋，４＾＋和＾５＋龄虾。     

Mongolian gerbils and Daurian pikas responded differently to changes in precipitation in the Inner Mongolian grasslands

Mongolian gerbils (Meriones unguiculatus) and Daurian pikas (Ochotona dauurica) are two key small mammal species in the Inner Mongolian grasslands, China. Mongolian gerbils displayed density-dependent population growth, but the time lag of density dependence was short and within season. The spring–autumn population growth rate was inversely related to population density in Mongolian gerbils of the Erdos desert grasslands. The autumn–spring population growth rate of Mongolian gerbils was inversely related to winter precipitation. Precipitation had stronger effects on the population growth of gerbils during the non-breeding season. The monthly population growth rate of Daurian pikas was positively related to the monthly precipitation and was inversely related to population density in central Inner Mongolia. Daurian pikas select habitats with tall plants. Increased precipitation enhances plant production and increases the height of plants in arid and semi-arid regions. This enhancement of plant height might increase the population growth of Daurian pikas. Mongolian gerbils live in short grasslands. Increased winter precipitation might result in higher winter mortality of Mongolia gerbils, or taller plants might supress gerbil population growth in wet years. Therefore, responses of small mammal species to changes in precipitation depend on the life history of small mammals and changes in vegetation induced by climatic changes.