Coastal deformation between the Versilia and the Garigliano plains (Italy) since the last interglacial stage

The opening of the north‐central Tyrrhenian Sea is the result of the Cretaceous–Paleogene alpine collision, which triggered a series of regional uplift, subsidence and transcurrent tectonic mechanisms along the coastal Tyrrhenian sectors of peninsular Italy. These tectonic processes, in conjunction with the effects of glacio‐ and hydro‐isostasy during the Quaternary, produced substantial crustal responses that, in some cases, reached metres in extent. In the study of coastal neotectonics, geomorphological markers of the last interglacial maximum, corresponding to marine isotope stage 5.5, are generally used to quantify the magnitude of the vertical crustal displacements that have occurred since 125 kyr. Through altimetrical, palaeoenvironmental and chronological reinterpretation of the most significant works published since 1913, combined with an additional set of data reported here, a detailed reconstruction of the shoreline displacements evident along 500 km of coast between northern Tuscany and southern Latium is presented. The reconstruction was carried out by quantifying the vertical movement since the last interglacial period and by identifying the tectonic behaviour of different coastal sectors. This has been done by carefully choosing the eustatic marker, among those available at each study site, in order to minimize the margin of error associated with the measurements. Copyright © 2003 John Wiley & Sons, Ltd.     

Genetic discrimination for three gynogenetic clones of silver carp Hypophthalmichthys molitrix, based on restriction endonuclease analysis of Nd5-Nd6 region of mitochondrial DNA

1 INTRODUCTION Silver carp (Hypophthalmichthys molitrix) is an important species in freshwater fisheries and ranks the first in world fish production (Li, 1993). China has a long history of aquaculture of silver carp that is very difficult for selective breeding because it has a long life cycle. However, development of cytoge-netics and modern molecular genetics built up a strong impact to the research on selective breeding. A rapid, efficient approach for establishment of a pure line of…     

湛江地区光裸星虫的生殖细胞发育和生殖周期

采用活体观察和常规石蜡切片技术对湛江地区光裸星虫生殖周期、生殖细胞的发育及形态结构进行研究。结果表明:星虫雌雄异体,无肉眼可见生殖腺结构,原生殖细胞在体腔液中发育;雌性生殖细胞根据其卵膜的形成和卵黄积累情况可以分为4个发育阶段,小生长期、大生长期、成熟前期和成熟期;雄性生殖细胞也分为增殖期、生长期、成熟期和变态期4个阶段;成熟的生殖细胞经肾管排出体外。生殖季节为5~9月,其中7~8月为高峰期。     

Assessment of parental contribution and effective population size from a 3×3 diallel cross of clam Meretrix meretrix

Unbalanced parental contribution and small effective population size(N e)are common issues during the artifi cial breeding of marine bivalves.The impact of hatchery-spawning practices on parental contribution,effective population size,the N e/N ratio,and genetic diversity are largely unknown.To address this,we conducted a parentage analysis on a complete 3×3 diallel cross of clam M eretrix meretrix using eight microsatellite markers.The genetic diversity of the parents was higher than that of their respective offspring in most crosses(8/9).Sires or dams from the same family contributed unequally to the pool of offspring from a particular cross,and the same parent clam exhibited large variation in parental contribution among different crosses.The variance in male contribution was higher than that of the female contribution in most crosses,suggesting that male contribution was more skewed than for females.The N e/N ratio for nine crosses ranged from 0.58 to 0.86.There was no linear relationship between the sex ratio and the N e/N ratio(P0.05).Moreover,a sex ratio closer to one-to-one does not necessarily mean a larger effective population size.A solution to small effective population size in commercial breeding programs is increasing broodstock numbers and attempting to maintain a balanced sex ratio.     

基于“数字城市”的测量标志巡查维护信息系统

数字城市以地理空间框架为定位基准,集成城市自然、社会、经济、人文、环境等综合信息,基于网络基础设施实现城市信息的广泛共享。本文基于数字城市公共服务平台开发建设市级测量标志巡查维护系统,并充分利用数字城市基础地理信息成果为测量标志管理与巡查维护提供方便、快捷的地图浏览,为测绘主管部门和测绘单位管理和使用测量标志提供方便。     

Macrobenthos and multi-molecular markers as indicators of environmental contamination in a South American port (Mar del Plata,Southwest Atlantic)

We evaluated benthic habitat quality along a presumed contamination gradient in the Mar del Plata port (Southwestern Atlantic) by coupling biological and chemical proxies in a multidisciplinary approach. Organic matter and photosynthetic pigment contents were higher in silty-clay bottoms of the inner port sites. Levels of all fecal steroids decreased from the inner sites to the port inlet. High concentrations of coprostanol in the inner sites seemed to derive from a permanent population of sea lions rather than from sewage outfalls due to coprostanol/epicoprostanol ratio (IV) values <2.5. PAHs levels were also higher in the inner sector, related to both biomass combustion and petroleum combustion associated to local marine traffic. High disturbance and low ecological status were reflected in low benthic diversity and high AMBI values in the inner sites.     

Monitoring of organic micropollutants in Ghana by combination of pellet watch with sediment analysis: E-waste as a source of PCBs

Plastic resin pellets collected at 11 beaches covering the whole Ghanaian coastline were analyzed for polychlorinated biphenyls (PCBs). PCB concentrations (∑13 congeners) were higher in Accra, capital city, and Tema (39–69 ng/g-pellets) than those in rural coastal towns (1–15 ng/g-pellets) which are close to global background, indicating local inputs of PCBs. River sediments were also analyzed for PCBs together with molecular markers. Sedimentary PCBs concentrations were highest at a site (AR02) downstream of an electronic waste (e-waste) scrapyard. At the site (AR02), concentration of linear alkylbenzenes (LABs), a marker of municipal wastewater, was lower than another site (AR03) which is located at the downstream of downtown Accra. This result suggests that PCBs are introduced more to the river from the e-waste site than from activities in downtown Accra. PAHs concentrations were relatively higher in urban areas with strong petrogenic signature. Abundance of triphenylbenzenes suggested plastic combustion near e-waste scrapyard.     

测量标志动态管理信息系统的设计与实现

测量标志管理是一项系统性、持续性的工作,当前的管理系统往往缺乏对测量标志整个生命周期的跟踪反馈,难以形成有效的监管,技术手段急需改善和提升。本文立足当前测绘信息化发展的现状,对测量标志动态管理需求进行了全面的分析,从系统的逻辑架构、网络架构、数据组织、平台结构及安全性控制等方面阐述了测量标志动态管理信息系统的设计与实现,并结合数字城市、天地图·广东、广东省国土资源在线巡查系统,以及实际业务需求,开发完成了一个具有合理负载且维护方便的广东省测量标志管理信息系统。结果表明,该系统改变了测量标志传统管理模式,满足标志点巡查、更新、动态管理的需要,提高了测量标志的监管水平,对维护测量标志生命周期的各个环节都具有现实和科学意义。     

坛紫菜叶状体营养细胞与生殖细胞叶绿素荧光特性比较

利用叶绿素荧光技术对坛紫菜(Porphyra haitanensis)叶状体营养细胞和生殖细胞的光能利用特性进行了比较。结果表明:坛紫菜叶状体营养细胞和雌性生殖细胞的实际量子效率(ΔF/Fm′)差异不明显,但显著高于雄性生殖细胞;快速光曲线测定表明雌、雄藻体营养细胞的最大相对电子传递速率(rETRmax)相近,但显著高于雄性生殖细胞;不同生殖细胞半饱和光强(Ik)无显著差异;在生长光强下,营养细胞和雌性生殖细胞rETR、光化学猝灭(qP)和非光化学猝灭(NPQ)差异不明显,而雄性生殖细胞rETR、qP等荧光参数均显著低于营养细胞和雌性生殖细胞。本文表明坛紫菜叶状体营养细胞和雌性生殖细胞具有较高的光能利用能力,能够将吸收的光能多数用于电子传递,而雄性生殖细胞对光能的利用能力较低。     

平庄凹陷烃源岩有机质成熟度评价

平庄凹陷盖层中发育九佛堂组、沙海组和阜新组3套烃源岩,虽然以往围绕煤矿生产展开了大量的煤田地质勘探工作,但石油、天然气勘探工作较少,研究程度较低。为了客观评价平庄凹陷的油气资源,需对烃源岩有机质成熟度进行评判。在对平庄凹陷烃源岩岩石热解、镜质组反射率、生物标志物参数分析的基础上,对平庄凹陷九佛堂组、沙海组烃源岩有机质热演化特征及演化阶段进行了系统研究。结果表明：平庄凹陷烃源岩各参数随埋藏深度的增加变化明显,具有纵向上的连续性和横向上的不均匀性;平庄洼陷烃源岩有机质成熟度处于未成熟—低成熟—成熟阶段,其中,九佛堂组烃源岩是盆地的主要成油岩系;四龙洼陷烃源岩有机质成熟度较低,对盆地成烃贡献不大。