Oxidative stress in ecotoxicology: from the analysis of individual antioxidants to a more integrated approach

An integrate approach will be discussed for investigations on oxidative stress in xenobiotic toxicity. While the analysis of individual antioxidants is useful for their sensitivity and to understand the mode of action of a stressor, the integration with the analysis of the total antioxidant capacity provides a more holistic assessment of the overall biological significance of such variations. TOSC has a greater predictive value on the health condition of the organisms and allows to discriminate the different role of specific ROS in oxidative stress syndrome.     

阻塞过程与环流持续异常

当大西洋上的天气系统受到具有急流分支(一支通过英国北部,另一支通过英国南部)为特征的阻塞型式阻挡其正常发展时,联合王国经常出现极端的天气.夏季,这种形势可导致持续一段时期的晴好天气(如1976年);冬季,一般会伴随出现严冬(如1986年2月).月时间尺度天气的可预报性很可能主要依赖于维持并稳定这种阻塞型式的物理机制.因此,最近在阻塞动力学方面的研究已进行了重大努力,提出了一些新理论.本文对这些新发展进行了检验.     

分子云物理性质的研究

十余年来年轻的分子天文学带来一系列新发现,推动了银河系结构、星系化学史、恒星物质流失、分子云物理等课题研究的新进展。 本文在简介分子天文学之后,将集中对与恒星形成有关的分子云物理问题进行综述。 内容分为 一、分子天文学的研究对象 二、分子云物理参数的导出 三、分子云的观测 四、涉及恒星形成的分子云理论研究     

Ore-placer shows of platinum group elements in the areal of North-Asian Superplume derivations(South-East Russia)

The sources of large and unique platinum-metal placers were the zonal alkali-ultrabasic massifs be coming active in the retaceous ime that gravitated to the periphery of the areal of the North-Asian Su...     

Resource Flows of Villages with Contrasting Lifestyles in Nanda Devi Biosphere Reserve, Central Himalaya, India

Resource use efficiency analyses of village ecosystem are necessary for effective and efficient planning of resource utilization. This paper deals with economic and energy input-output analyses of different components of village ecosystem in representative buffer zone villages, which are practicing transhumance and settled way of lifestyles in Nanda Devi Biosphere Reserve （NDBR） of Garhwal Himalaya. While the villages practicing transhumance used various natural resources spatially segregated,the villages practicing settled way of lifestyle have to manage resources from a limited spatial area through rotation and varied extraction intensities. Forests subsidized the production activity in both type of villages and the per capita resource extractions were found to be greater in tran~humance village than settled village. Though crops provided maximum energy, in terms of economic criteria, animal husbandry played important role in both settled and transhumance villages. As villages representing both the situations showed different ways of adjustments to the conservation oriented land use changes, management authority needs to address the eco-development plans fulfilling the aspirations of all people traditionally using the resources of the Reserve to reduce the conflicts and encourage their participation in the conservation of the area.     

A Measurement of Omega from the North American Test Flight of Boomerang

We use the angular power spectrum of the cosmic microwave background, measured during the North American test flight of the Boomerang experiment, to constrain the geometry of the universe. Within the class of cold dark matter models, we find that the overall fractional energy density of the universe Omega is constrained to be 0.85相似文献   

美国艾奥瓦州文尼希克Lagerst(a)tte及其沉积环境

Lagerstatte是指保存丰富或精美化石、因而具有特殊研究价值的化石层.这类地层所含的化石常具有经矿化的生物软体甚至未变实体,从而为古生物的分类学、组织学、形态学、解剖学、生态学、埋藏学等研究提供了极其难得的材料.近年来发现于美国艾奥瓦州的文尼希克化石层,以其特异保存的多门类不常见化石分子为特征,成为目前仅知的中奥陶世Lagerstatte.这一生物群的发现不仅填补了化石记录中的一些空白,也为中奥陶世的生物辐射事件研究领域打开了一个在赤道附近非正常海洋环境中生存的生物群面貌窗口.而且,其中所含的不同类别矿化生物残留,在有机物的分解、置换以及生物成岩作用等研究中具有重要意义.初步研究表明,文尼希克生物群的生活环境与化石保存,可能与陨石撞击事件有关,从而为奥陶纪生物辐射事件的起因町能与太空星体爆裂有关的理论研究,提供了新的验证材料.