东南极内陆格罗夫山和外缘拉斯曼丘陵地区基岩暴露年龄及其古气候含义

This paper is concerned of the I0Be and 26A1 exposure ages of bedrocks in the Grove Mountains (GMs), inland of East Antarctica, and in the Larsemann Hills, peripheral alongshore of East Antarctica, respectively. The results of our study indicate that the higher bedrock samples in two profiles in the GMs have minimum exposure ages of-2 Ma, and their 26Al/10Be can be projected into the erosion island, which means they only have simple exposure history. The actual exposure ages may be mid-late Pliocene because the bedrocks should have erosion. The relationship between the altitudes and cosmogenic nuclide concentrations of those higher samples suggests that they have not reached secular equilibrium, means that a higher than -2300m East Antarctic Ice Sheet (EAIS) existed in the GMs before mid-Pliocene, and decreased monotonously for a period since mid-Pliocene. Lower samples of the two profiles have much younger exposure ages, and had been covered at least once obviously implicated by that their 26Al/10Be are projected down to the erosion island. Using a 10Be-26Al project figure to determine the history of the GMs samples shows that the lower samples have minimum total initial exposure and cover time of 1.7-2.8Ma, suggesting that those samples were exposed initially since about late Pliocene too, and the interior EAIS fluctuated after late Plicoene obviously. The altitudes and exposure ages of all the GMs samples indicate that the ice surface level of the interior EAIS in the GMs was >2300m during or before mid Pliocene (more than 200m higher than present ice surface level), and only rose to -2200m during the fluctuation occurred after late Pliocene, thus the elevation of the interior EAIS in the GMs after mid-Pliocene was never higher than during or before mid Pliocene even during the Quaternary Glacial Maximum. According to data from the GMs and other parts of East Antarctica, a larger East Antarctic Ice Sheet existed before mid-Pliocene, thus the elevation decrease of interior EAIS in the GMs after mid Pliocene may be a director of volume decrease of the EAIS. Since the Antarctic climate has a cooling trend since ~3Ma, similar to the global climate change, the volume decrease of the EAIS since mid-Pliocene may beause of moisture supply decrease directly rather than atmosphere temperature change. As for the Larsemann Hills, samples farther to the glacier have exposure age of 40~50ka, means they exposed in the early time of Last Glacier Cycle, obviously earlier than the Last Glacial Maximum (LGM). Samples nearer to the glacier have exposure ages younger than LGM. Thus, different to the GMs, exposure ages of the Larsemann Hills samples have more obvious relationship to their distance from the glacier margin rather than to the altitudes of the samples.

克拉2异常高压气藏地质特征及开发技术研究

Kela-2 gas field in Tarim Basin is the main supply source for West-to-East Pipeline project, also the largest abnormally-pressured gas field discovered in China currently. The geological characterization, fine geological modeling and field development plan are all the world-class difficult problems. This work includes an integrated geological and gas reservoir engineering study using advanced technology and approaches, the scientific development plan of Kela-2 gas field as well as the optimizations of the drilling, production and surface schemes. Then, it's expected that the Kela-2 gas field can be developed high-efficiently.Kuche depression is one part of the thrust belt of the South Tianshan Mountains, Kela-2 field is located at the Kelasu structural zone in the north of Kuche depression. The field territory is heavily rugged with deeply cut gullies, complex geological underground structure, variable rock types, thrust structure development. Therefore, considerable efforts have been made to develop an integrated technique to acquire, process and interpret the seismic data in complicated mountain region. Consequently a set of seismic-related techniques in the complicated mountain region has been developed and successfully utilized to interpret the structure of Kela-2 gas field.The main reservoir depositional system of Kela 2 gas field is a platform - fan delta - braided river system. The reservoir rocks are medium-fine and extremely fine grained sandstones with high structure maturity and low composition maturity. The pore system structure is featured by medium-small pore, medium-fine throat and medium-low assortment. The reservoir of Kela-2 gas field is characteristic of medium porosity and medium permeability. The pay zone is very thick and its lateral distribution is stable with a good connection of sand body. The overpressure is caused mainly by the strongly tectonic squash activities, and other factors including the later rapid raise and compartment of the high-pressure fluid, the injection of high-pressure fluid into the reservoir.Based on the deliverability tests available, the average binomial deliverability equation is provided applicable for the overall field. The experimental results of rock stress-sensitive tests are employed to analyze the change trend of petrophysical properties against net confining stress, and establish the stress-based average deliverability equation. The results demonstrate the effect of rock deformation on the deliverability is limited to less than 5% in the early period of Kela-2 gas field, indicating the insignificant effect on deliverability of rock deformation.In terms of the well pattern comparisons and development planning optimizations, it is recommended that the producers should be located almost linearly along the structural axis. A total of 9 producers have a stable gas supply volume of 10.76 BCMPY for 17 years. For Kela-2 gas field the total construction investment is estimated at ￥7,697,690,000 RMB with the internal earning rate of 25.02% after taxation, the net present value of ￥7,420,160,000 RMB and the payback period of 5.66 years. The high profits of this field development project are much satisfactory.

东南极格罗夫山土壤研究与古环境分析

Three soil spots were found in Grove Mountains, east Antarctica during 1999-2000, when the Chinare 16th Antarctic expedition teams entered the inland Antarctica. The characteristics of soils in Grove Mountains are desert pavement coating the surface, abundant water soluble salt, negligible organ matter, and severe rubification and salinization, scarces of liquid water, partly with dry permafrost, corresponding with the soils of McMurdo, Transantarctic. The soils age of Grove Mountains is 0.5-3.5Ma. Podzolization and redoximorphism are the main features in coastal Wilks region, in addition, there is strong enrichment of organic matter in many soils of this region. The main soil processes of Fildes Peninsula of King George Island include the intense physical weathering, decalcification and weakly biochemical processes. Peat accumulation is the main processes in Arctic because of humid and cold environment.Based on synthesis of heavy minerals, particle size, quartz grain surface textures, as well as pollen in soils, the soils parent materials of Grove Mountains derived from alluvial sediment of the weathering bedrocks around soils, and formed during the warm period of Pliocene. The detailed information is followed .l)The results of heavy minerals particle size showed the parent minerals derived form the weathering bedrocks around soils. 2)The quartz sand surface textures include glacial crushing and abrasion such as abrasive conchoidal fractures and grain edges, abrasive subparallel linear fractures and angularity, subaqueous environments produce V-shaped and irregular impact pits, polished surface, and chemical textures, such as beehive solution pits, which showed the water is the main force during the sediment of the soil parent minerals. 3)The pollen consist of 40 plant species, of which at least 5 species including Ranunculaceae, Chenopodiaceae, Artemisia, Gramineae, Podocarpus belong to the Neogene vegetation except the species from the old continent. Compared with Neogene vegetation of Transantarctic Mountains, Antarctic, we concluded that they grow in warm Pliocene.

我国部分南极陨石的分类和宇宙成因核素10Be和26Al的研究

随着我国南极陨石的大量回收，对陨石的研究也越来越深入。本文主要对我国部分南极陨石和沙漠陨石开展了三方面的工作：（1）我国部分南极陨石的分类；（2）陨石中宇宙成因核素10Be和26Al的化学分离、纯化实验；（3）我国部分南极陨石和沙漠陨石的全岩化学组成分析和宇宙成因核素10Be和26Al的初步研究。 1、我国部分南极陨石的分类研究 通过对我国19次南极科考队回收的4448块陨石中24块南极普通球粒陨石的矿物、岩石分析，将这24块陨石化学－岩石类型进行了划分，分别为1个H3型（GRV 021603）、2个H4型（GRV 020200和GRV 021493）、4个H5型（GRV 020048、GRV 020078、GRV 020129和GRV 020236）、2个H6型（GRV 020075和GRV 020226）、1个L4型（GRV 021563）、8个L5型（GRV 020047、GRV 020283、GRV 020297、GRV 021547、GRV 021547、GRV 021581、GRV 021615和GRV 023771）、5个L6型（GRV 020103、GRV 020155、GRV 021505、GRV 021711和GRV 022171）、1个LL4型（GRV 020029）和1个LL6型（GRV 021496）。在此基础上，将我国的南极陨石和美国的南极陨石进行了类型和质量分布模型的对比。结果表明，我国南极陨石比美国南极陨石具有相对高的L群丰度；我国的南极陨石质量分布模型与美国南极陨石一致。 2、陨石中宇宙成因核素10Be和26Al的化学分离、纯化实验 在前人关于陨石中宇宙成因核素10Be和26Al的分离方法基础上，通过多次模拟样品的分离实验，成功地将陨石中Be和Al进行了分离、纯化。并且进一步改善了前人的分离方法，将Be的淋洗液由原来的120ml减少为90ml。在此基础上，用空白样品和吉林陨石的硅酸盐样品对整个化学分离实验进行了检验，并将所获得的BeO和Al2O3粉末用加速器质谱（AMS）进行了10Be和26Al的测试。根据所测定的10Be和26Al数据，计算得到吉林陨石的暴露年龄为0.52Ma，这一结果与前人所获得的吉林陨石第二阶段的暴露年龄0.4Ma接近。这一结果再次证明了陨石中宇宙成因核素10Be和26Al的分离流程是成功的，同时也说明本次所测的吉林陨石样品为吉林陨石第二阶段暴露辐射的样品。 3、我国部分南极陨石和沙漠陨石的全岩化学组成分析以及宇宙成因核素10Be和26Al的初步研究 对我国13块南极陨石和3块沙漠陨石进行了全岩化学成分的分析，其结果进一步证明了这些陨石由岩石、矿物分析所划分的类型的正确性。在这些陨石类型和全岩分析的基础上，对它们进行了宇宙成因核素10Be和26Al的初步分析。得到其中4块南极陨石和2块沙漠陨石的暴露年龄和居地年龄，这些陨石暴露年龄的范围为2.09－3.05Ma，居地年龄为0－0.23Ma。

天山乌鲁木齐河源1号冰川成冰过程的地球化学研究--以低分子有机酸为主

冰川上的表面雪层是联系大气成分与冰芯记录的重要纽带，对雪－冰现代过程的研究将有助于正确解释保存在冰芯中的古气候和环境信息。山地冰川雪冰中有机酸记录的研究在认识有机酸生物地球化学循环方面占很大的优势，本文依托天山冰川观测试验站开展的冰雪物理、化学现代过程方面的研究，对乌鲁木齐河源1号冰川中低分子有机酸和无机阴离子在成冰作用过程中的迁移转化进行了研究。新雪和保存较好的表层雪主要用来分析采样点低分子有机酸和无机阴离子的季节变化特征，粒雪坑样品主要用于进行低分子有机酸和无机阴离子沉积后过程的研究。 雪冰样品采集于1号冰川东支东经86°49′，北纬43°06′，海拔4 130 m 处，2004年3月至2005年3月期间，共获取了23个连续雪坑剖面的粒雪样品。采用美国Dionex公司的ICS-90型离子色谱仪加RFC-30型淋洗液在线发生器进行测定，检测到的低分子有机酸主要有HCOO-、CH3COO-、C2H5COO- 和(COO)22-，无机阴离子主要有F-、Cl-、NO2-、NO3-、SO42- 和PO43-。 表层雪是研究粒雪化和成冰作用过程中化学组成变化的起点。为配合天山乌鲁木齐河源1号冰川沉积后过程中化学组成变化的研究，我们首先对表层雪样品（雪坑表层5cm的雪样）进行了低分子有机酸和无机阴离子含量的分析。结果显示，除(COO)22- 外，大部分有机酸和高浓度的无机阴离子因受到周围环境和盛行风的影响呈现出明显的季节变化特征，即夏半年离子浓度变化剧烈，最大值和最小值同时出现在夏半年，冬半年的浓度则相对小而稳定；而(COO)22- 和低浓度的无机阴离子随季节变化的特征不明显，在全年均显示出波动性。数据表明，在外界条件不变的情况下，表层雪可以长时间（至少半年时间）保存其中高含量的化学组成不被改变。 通过对高含量低分子有机酸和高含量无机阴离子的沉积后过程的研究，发现它们在沉积后的迁移转化过程受温度和融水的影响较大，在不同时期表现出不同的季节变化特征。雪层消融初期，淋溶作用导致雪层内的大部分离子组分进入初始融水中，并随着融水下渗、聚集，使下部雪层中离子组分的浓度不断增加；当消融进一步加剧，大部分低分子有机酸和无机阴离子随融水径流而流失，雪层中记录的低分子有机酸和无机阴离子含量迅速降低；在消融季节，峰值向雪坑底部移动的速度较快。在冬半年的负温条件下，雪层中记录的低分子有机酸和无机阴离子的含量及其保存在雪坑下部的峰值都相对稳定，这也再次说明如果外界条件不发生改变，雪冰可以长时间（至少半年时间）保存其中的化学组成不被改变这个结论；另外，冬半年雪坑上部记录的峰值在一定程度上可以反映它们在大气中的初始水平。CH3COO- 和(COO)22- 的峰值通常会出现在污化层的附近，与污化层的位置具有较好的一致性，说明污化层对CH3COO- 和(COO)22- 的沉积后过程可能有一定的影响。

南极格罗夫山陨石磁性分类研究

陨石分类是一项基础性的工作，是开展深入研究的前提。磁化率(χ)的测量提供了一种快速简单、无损的陨石分类方法，国外已有一些学者开始对陨石的磁性分类开展了研究，但国内尚无这方面研究的报导。本文主要对从南极格罗夫山回收的陨石开展了磁性分类的初步研究，论文主要工作包括以下几个方面： 1) 进行了磁化率测量模拟实验：由于陨石样品具有不规则和大小不等的形状，通过对模拟样品测量，了解上述几何因素对磁化率测量精度和准确性的影响，并作出MS2磁化率测量系统MS2D探头与MS2B传感器测量值之间的校正曲线。对模拟样品测量结果的分析表明，不同形状和大小的样品(所含磁性矿物分布均一)在进行MS2D测量时，测量相对偏差可控制在2%以内，表明上述测量系统可以用于陨石的磁化率测量。 2) 对所选600块南极格罗夫山陨石用MS2D探头进行了磁化率测量，得出这600块陨石的磁化率㏒χ(10-9m3/kg)数据，并用MS2B探头测量其中375块用来作岩石矿物学分类用的小块劈分样品的磁化率㏒χ(10-9m3/kg)。这600块格罗夫山陨石磁化率分布模式与南极其他区域收集的陨石较吻合，对应H、L、LL群呈3个明显的峰分布。相同的陨石用MS2D与MS2B两种探头测量，将它们的磁化率数据进行对比，显示它们的结果相当一致(相关系数R2=0.97)，也同时证明MS2D用于磁化率测量是行之有效的。 3)测量了44块沙漠陨石和9块降落型陨石的磁化率，在此基础上对南极格罗夫山陨石、沙漠陨石及降落型陨石数据做了对比讨论。格罗夫山陨石、沙漠陨石及降落型陨石磁化率值分布出现不同程度的偏移，总体来说磁化率㏒χ平均值为降落型陨石>南极陨石>沙漠陨石，这主要是由于陨石所受风化程度的差异造成的。风化作用使陨石部分金属发生氧化，因而降低了磁化率。 4)基于陨石的岩石矿物学分类，172块平衡型普通球粒陨石的磁化率分布，与文献上南极陨石磁化率分布基本一致，不过格罗夫山H、L、LL型普通球粒陨石磁化率分布范围更为狭窄，反映了南极不同地区陨石风化程度的差异。 5)讨论了陨石磁化率分类的有效性，分析了部分异常值出现的原因。磁化率分类结果与部分格罗夫山陨石的岩石矿物学分类(申请者作为陨石分类小组成员完成了其中的部分工作)结果相当吻合，仅在群之间约有5%的重叠，表明磁化率可作为化学群分类的重要参考数据。由于各陨石所受风化程度的差异，风化程度较强的少量陨石在磁性分类的基础上，还需其他工作加以证实。部分小质量(小于3g)且有部分或完整熔壳的陨石，磁化率受熔壳的影响达10%以上，偏离了其初始矿物的磁化率值，不能反映其真实的化学群类型，这部分磁化率数据仅供参考。

大、小兴安岭北部砂金矿的形成与演化

本文按物源的不同，将全区分为5个砂金富集区和10个砂金富集亚区，总结了砂金矿的富集规律，并划分了砂金矿的成因类型。重点研究了砂金的形貌、粒度、成色、内部构造、化学成分及连生矿物。还研究了砂砾石的分布特点，重砂矿物组合，植物、水及砂砾石中金的含量，沉积物的构造及其形成环境、时代。根据所获取的成因信息，划分了砂金的成矿期。深入讨论了成矿条件，包括成矿过程中的原生和次生物源，和成矿环境（新构造运动和气候）。最后，建立了砂金矿的“物源－新构造运动－气候”三因素成矿模式。

Multiple-User Quantum Optical Communication

A fundamental understanding of the information carrying capacity of optical channels requires the signal and physical channel to be modeled quantum mechanically. This thesis considers the problems of distributing multi-party quantum entanglement to distant users in a quantum communication system and determining the ability of quantum optical channels to reliably transmit information. A recent proposal for a quantum communication architecture that realizes long-distance, high-fidelity qubit teleportation is reviewed. Previous work on this communication architecture is extended in two primary ways. First, models are developed for assessing the effects of amplitude, phase, and frequency errors in the entanglement source of polarization-entangled photons, as well as fiber loss and imperfect polarization restoration, on the throughput and fidelity of the system. Second, an error model is derived for an extension of this communication architecture that allows for the production and storage of three-party entangled Greenberger-Horne-Zeilinger states. A performance analysis of the quantum communication architecture in qubit teleportation and quantum secret sharing communication protocols is presented. Recent work on determining the channel capacity of optical channels is extended in several ways. Classical capacity is derived for a class of Gaussian Bosonic channels representing the quantum version of classical colored Gaussian-noise channels. The proof is strongly mo- tivated by the standard technique of whitening Gaussian noise used in classical information theory. Minimum output entropy problems related to these channel capacity derivations are also studied. These single-user Bosonic capacity results are extended to a multi-user scenario by deriving capacity regions for single-mode and wideband coherent-state multiple access channels. An even larger capacity region is obtained when the transmitters use non- classical Gaussian states, and an outer bound on the ultimate capacity region is presented

Modern Bedouin exposures to copper contamination: an imperial legacy?

Grattan, J. Huxley, S. Pyatt, B. Modern Bedouin exposures to copper contamination: an imperial legacy? Ecotoxicology and environmental safety. 2003. 55 pp 108-115

The local and global dimensions of metalliferous pollution derived from a reconstruction of an eight thousand year record of copper smelting and mining at a desert-mountain frontier in southern Jordan

Grattan, J.P., Gilbertson, D.D., Hunt, C.O. (2007). The local and global dimensions of metaliferrous air pollution derived from a reconstruction of an 8 thousand year record of copper smelting and mining at a desert-mountain frontier in southern Jordan. Journal of Archaeological Science 34, 83-110

Performing the Local and the Global : The Theatre Festivals of Lake Constance

Wilkinson, Jane, Performing the Local and the Global: The Theatre Festivals of Lake Constance (Peter Lang, 2007), pp.286 RAE2008

A study of the Zhiqing identity

More than seventeen million Chinese urban youth (Zhiqing in Chinese) went to the countryside, lived and engaged in agricultural work there during the Up to the Mountains and Down to the Countryside (UMDC) Movement (1967-1981). Although this movement was officially terminated in 1981, it has left an imprint on these people – the Zhiqing identity by which they are still characterized as a unique group in Chinese society and a special generation in Chinese history. Historical and sociological perspectives are combined in this study. By applying Glen H. Elder’s life course approach, the study reveals how Zhiqing’s life trajectories are embedded in the social history and identifies a series of interrelated factors that made Zhiqing into a unique generation. With the guidance of Henri Tajfel’s social identity theory, the study uncovers the emergence of the Zhiqing group and the Zhiqing identity, explains individuals’ acquisitions of the Zhiqing identity and analyzes how it has kept influencing individuals’ lives during and after the UMDC Movement. Using Zhiqing’s life stories allowed the researcher to combine the historical and sociological aspects in her examination of Zhiqing’s identity issues. In each life story, the narrator reviewed his/her life experience, reflected on socio-historical changes and expressed his/her emotions and ideas about identity issues. Utilizing methods of in-depth interview and thematic analysis, the researcher completed the study and presents this thesis as one interpretation on the Zhiqing identity, which, as according the researcher’s hermeneutic stance, is open to further discussion and future research.

Childhood bullying involvement predicts low-grade systemic inflammation into adulthood.

Bullying is a common childhood experience that involves repeated mistreatment to improve or maintain one's status. Victims display long-term social, psychological, and health consequences, whereas bullies display minimal ill effects. The aim of this study is to test how this adverse social experience is biologically embedded to affect short- or long-term levels of C-reactive protein (CRP), a marker of low-grade systemic inflammation. The prospective population-based Great Smoky Mountains Study (n = 1,420), with up to nine waves of data per subject, was used, covering childhood/adolescence (ages 9-16) and young adulthood (ages 19 and 21). Structured interviews were used to assess bullying involvement and relevant covariates at all childhood/adolescent observations. Blood spots were collected at each observation and assayed for CRP levels. During childhood and adolescence, the number of waves at which the child was bullied predicted increasing levels of CRP. Although CRP levels rose for all participants from childhood into adulthood, being bullied predicted greater increases in CRP levels, whereas bullying others predicted lower increases in CRP compared with those uninvolved in bullying. This pattern was robust, controlling for body mass index, substance use, physical and mental health status, and exposures to other childhood psychosocial adversities. A child's role in bullying may serve as either a risk or a protective factor for adult low-grade inflammation, independent of other factors. Inflammation is a physiological response that mediates the effects of both social adversity and dominance on decreases in health.

Impacts of Mountaintop Removal Coal Mining on the Mud River, West Virginia: Selenium Accumulation, Trophic Transfer, and Toxicity in Fish

Selenium (Se) is a micronutrient necessary for the function of a variety of important enzymes; Se also exhibits a narrow range in concentrations between essentiality and toxicity. Oviparous vertebrates such as birds and fish are especially sensitive to Se toxicity, which causes reproductive impairment and defects in embryo development. Selenium occurs naturally in the Earth's crust, but it can be mobilized by a variety of anthropogenic activities, including agricultural practices, coal burning, and mining.

Mountaintop removal/valley fill (MTR/VF) coal mining is a form of surface mining found throughout central Appalachia in the United States that involves blasting off the tops of mountains to access underlying coal seams. Spoil rock from the mountain is placed into adjacent valleys, forming valley fills, which bury stream headwaters and negatively impact surface water quality. This research focused on the biological impacts of Se leached from MTR/VF coal mining operations located around the Mud River, West Virginia.

In order to assess the status of Se in a lotic (flowing) system such as the Mud River, surface water, insects, and fish samples including creek chub (Semotilus atromaculatus) and green sunfish (Lepomis cyanellus) were collected from a mining impacted site as well as from a reference site not impacted by mining. Analysis of samples from the mined site showed increased conductivity and Se in the surface waters compared to the reference site in addition to increased concentrations of Se in insects and fish. Histological analysis of mined site fish gills showed a lack of normal parasites, suggesting parasite populations may be disrupted due to poor water quality. X-ray absorption near edge spectroscopy techniques were used to determine the speciation of Se in insect and creek chub samples. Insects contained approximately 40-50% inorganic Se (selenate and selenite) and 50-60% organic Se (Se-methionine and Se-cystine) while fish tissues contained lower proportions of inorganic Se than insects, instead having higher proportions of organic Se in the forms of methyl-Se-cysteine, Se-cystine, and Se-methionine.

Otoliths, calcified inner ear structures, were also collected from Mud River creek chubs and green sunfish and analyzed for Se content using laser ablation inductively couple mass spectrometry (LA-ICP-MS). Significant differences were found between the two species of fish, based on the concentrations of otolith Se. Green sunfish otoliths from all sites contained background or low concentrations of otolith Se (< 1 µg/g) that were not significantly different between mined and unmined sites. In contrast creek chub otoliths from the historically mined site contained much higher (≥ 5 µg/g, up to approximately 68 µg/g) concentrations of Se than for the same species in the unmined site or for the green sunfish. Otolith Se concentrations were related to muscle Se concentrations for creek chubs (R2 = 0.54, p = 0.0002 for the last 20% of the otolith Se versus muscle Se) while no relationship was observed for green sunfish.

Additional experiments using biofilms grown in the Mud River showed increased Se in mined site biofilms compared to the reference site. When we fed fathead minnows (Pimephales promelas) on these biofilms in the laboratory they accumulated higher concentrations of Se in liver and ovary tissues compared to fathead minnows fed on reference site biofilms. No differences in Se accumulation were found in muscle from either treatment group. Biofilms were also centrifuged and separated into filamentous green algae and the remaining diatom fraction. The majority of Se was found in the diatom fraction with only about 1/3rd of total biofilm Se concentration present in the filamentous green algae fraction

Finally, zebrafish (Danio rerio) embryos were exposed to aqueous Se in the form of selenate, selenite, and L-selenomethionine in an attempt to determine if oxidative stress plays a role in selenium embryo toxicity. Selenate and selenite exposure did not induce embryo deformities (lordosis and craniofacial malformation). L-selenomethionine, however, induced significantly higher deformity rates at 100 µg/L compared to controls. Antioxidant rescue of L-selenomethionime induced deformities was attempted in embryos using N-acetylcysteine (NAC). Pretreatment with NAC significantly reduced deformities in the zebrafish embryos secondarily treated with L-selenomethionine, suggesting that oxidative stress may play a role in Se toxicity. Selenite exposure also induced a 6.6-fold increase in glutathione-S-transferase pi class 2 gene expression, which is involved in xenobiotic transformation. No changes in gene expression were observed for selenate or L-selenomethionine-exposed embryos.

The findings in this dissertation contribute to the understanding of how Se bioaccumulates in a lotic system and is transferred through a simulated foodweb in addition to further exploring oxidative stress as a potential mechanism for Se-induced embryo toxicity. Future studies should continue to pursue the role of oxidative stress and other mechanisms in Se toxicity and the biotransformation of Se in aquatic ecosystems.

A couple of embroiled sheets of Miguel Barnades Manaider and Esteban de Prado in the Herbaria of Real Colegio Alfonso XII of San Lorenzo de El Escorial (Madrid)

In this paper we present a couple of sheets of Umbelliferae that are preserved in the RCAXII herbaria. One of them, Selinum carvifolia, where collected in the Gredos Mountains by Miguel Barnades Mainader and was identified by his son Miguel Barnades Clarís. The other, Tragium flabellifolium, was collected in Mieres (Asturias) by Esteban de Prado and identified by Mariano La Gasca.