Oxidative stress in two populations of killifish (Fundulus heteroclitus) with differing contaminant exposure histories

A population of killifish (Fundulus heteroclitus) inhabiting a creosote-polluted inlet of the Elizabeth River demonstrates tolerance to the acute toxic effects exerted by contaminated sediments on reference site killifish. Previous data have suggested that upregulated antioxidant defenses contribute to short-term tolerance in killifish exposed to Elizabeth River sediments. This study investigated population differences in antioxidant defenses from wild caught Elizabeth River and reference population killifish in different seasons, and after being held in the laboratory. Parameters measured in the killifish were total glutathione concentrations (GSH(T)), activities of glutathione reductase (GR), glutathione peroxidase (GPx), and lipid peroxidation (LPO), all in adult hepatic tissues. The Elizabeth River population exhibited greater GSH(T), higher GPx activities, and increased LPO as compared to the reference population. Sex specific population differences were also observed in GSH(T) and GPx. Both populations displayed decreased GSH(T) and increased GR from early to late summer, as well as after being held in the laboratory. This study indicates that there are many factors that may contribute to differences in levels of antioxidant defenses in addition to exposure to contaminants, including reproductive status and environmental conditions.     

杭州湾南岸潮滩的~(210)Pb分布及其沉积学意义

杭州湾南岸潮滩的~(210)Pb垂向分布具有随深度波动的特征。湖滩颗粒物在吸附模拟系统中的~(210)Pb分配系数,主要受颗粒物含量的影响。本文从潮滩沉积~(210)Pb初始比度在低于平衡点一侧波动的机理,以及被沉积间断所分隔的有效封闭段的存在出发,提出选择常态沉积层的高~(210)Pb比度窗口,建立以CIC模式估计潮滩沉积速率的方法。     

不同厚度冰层下的冰下火山喷发产物：两个来自南极的实例

不同厚度冰层下的冰下火山喷发产物：两个来自南极的实例Ｊ．Ｌ．Ｓｍｅｌｌｉｅ等本文着重介绍南极半岛两个保存最好的冰下层序（亚历山大岛的芒特皮纳佛和格雷厄姆地北部的布朗布拉夫）．通过对岩相和岩相组合的分析确定喷发时和喷发后作用过程，以及原始冰层的最小厚度...     

伊利诺斯盆地宾夕法尼亚纪沉积物季节性降雨的证据

伊利诺斯盆地宾夕法尼亚纪沉积物季节性降雨的证据ＥｒｉｋＰ．Ｋｖａｌｅ等根据古纬度位置、动物群证据或气候敏感岩性的出现而恢复的古气候可表达一个地区相当长时期的气候格局，但气候的细节只有通过与目前条件相同地区的比较才能推断。由于时间的迁移、海洋和陆地的变...     

太平洋西南部铁锰矿化的地球化学特征

太平洋西南部铁锰矿化的地球化学特征Ａ．Ｈ等对克马德克和新赫布里底岛弧－海沟系不同地貌构造采集了海底样品（１９９０年科学考察船“Ａ．Ｈ”院士号第１７航次），在一系列测站上采集到不同的铁锰形成物（жＭＯ）。在采自８个测站的３８个样品分析资料的基础上研究了...     

China's population: an alternative perspective

The author presents a selection of cartograms designed to illustrate aspects of the demography of China. Topics covered include population growth, density, regional variations in fertility, and age distribution. A discussion of the advantages of using cartograms (maps drawn proportional to a given variable) as opposed to conventional, area-based maps, is included.     

Far beyond the Gulf: the implications of warfare for Asian labour migration

The implications of the Gulf War are assessed for the countries in Asia that send labor migrants to the Middle East. "This paper seeks to examine the effects of...the loss of remittances (and related issues, including return migration), primarily in terms of the long-term implications of the War for the future of contract labour migration in the Asian region...."     

贝加尔裂谷系及邻区断裂现今活动变化及成因(英文)

已有的地质和地球物理方法无法对年、月、旬等现今时间尺度上的断层活动变化进行有效预测。运用基于地震活动定量指数运算程序的地理信息技术可以解决这个问题。这种方法被应用于贝加尔裂谷系(BRS)及邻区的研究当中。研究发现,断层活动变化发生在以几年为周期的时间尺度上,这无法用区域应力场的变化进行合理解释。沿着穿越贝加尔裂谷系的剖面编制了活动断层图以及地震活动定量指数曲线。提出的这种方法可以根据地震活动定量指数对活动断层进行仔细的分类,从而为解决地震中期预报相关问题开辟了重要途径。这种方法还被用来研究断层现今活动的时空变化和形成机制。研究发现,在实时尺度上断层活动具有高频发生的特征,这种现象可能是由于脆性岩石圈板内和块体内部运动产生的慢变形波的干扰导致的。利用变形波的通过速度可以对活动断层进行分组,各组具有不同的地质和地球物理特征参数,同时还可以对变形波波前的方向以及某一区域内主要断层在实时间隔内(地质上的瞬间)的活动情况进行预测。     

下地壳基性麻粒岩流变强度实验研究

镁铁质基性麻粒岩被认为可能是大陆下地壳的主要组成岩石[1,2],涉及当前地球动力学研究中地壳变形和高原隆升,壳幔边界的力学耦合与拆离,底侵和拆沉作用等一系列地球动力学问题阳[3,4],具有重要的地球动力学意义.大陆下地壳的流变学性质是我们深入认识这些地球深部过程的关键点之一.     

华北克拉通东南缘约1.8 Ga高压麻粒岩相变质作用:岩石学和锆石U-Pb年代学证据

华北克拉通北邻中亚造山带,南接秦岭-大别-苏鲁造山带.它通常被认为是约18亿年固结形成的陆块.其基底的形成与演化,一直受到广泛关注(Zhao et al.,1998,2000,2005;Zhai et al.,2000,2005;Wilde et al.,2002,2005;Guo et al.,2005;Kroner et al.,2005,2006;Lu et al.,2008).大多数研究者都注重于华北克拉通内部、北部和东西陆块结合带(中间带),较少关注东南缘基底的形成与演化研究.