云南水化学观测异常与地震关系

基于2000—2017年云南水化学观测资料,利用原始观测曲线识别异常的传统分析方法,提取单项及群体异常,分析其与地震的关系。结果表明:①研究时段内,云南水化学资料的利用率低,仅为56%,反映了水化学观测台站的映震能力不均一;②震例研究显示水化学异常以短期异常为主,占总异常的70%,对地震的预测效能较好,76%的测项没有出现虚报;③单台群体及区域群体异常与地震的关系密切,台站密集地区的异常数量较多且地震对应率较高。因此,建设高密度、高质量观测点是提高水化学地震预测能力的重要基础。     

^137Cs法测算黄土高原土壤侵蚀速率的初步研究

核尘埃~(137)Cs降落到地表后,被土壤胶粒强烈吸附,集中分布于0—25cm的土壤表层。土壤剖面的~(137)Cs总量随土壤的流失而减少。根据黄土农耕地和非农耕地土壤的~(137)Cs流失模式,推导了它们的流失量和侵蚀速率的相关公式。根据陕西洛川黑木沟和山西离石羊道沟的13个土壤剖面的~(137)Cs含量测试结果,求得的黑木沟草坡覆盖的老谷坡和新谷坡的侵蚀速率分别为1400 t/km~2·a和5700t/km~2·a;羊道沟梁峁坡农耕地的侵蚀速率为3270—6030 t/km~2·a;裸露新谷坡的侵蚀速率大于8000 t/km~2·a。     

牙鲆野生群体与养殖群体的遗传多样性分析

利用AFLP技术对荣成野生群体和养殖群体牙鲆进行遗传多样性分析和比较。实验采用 7对引物组合在 2个群体中共扩增出 797个位点 ,其中多态位点数为 43 3个 ,占总位点数的 5 4.2 7%。各引物组合在 2个群体中的扩增位点数目和多态位点比例有较大不同 ,但养殖群体的总扩增位点数和多态位点比例均低于野生群体 ,野生群体和养殖群体的平均多态位点率分别为 46.18%和 40 .0 7% ,其中 ,E3 8M 5 0引物组合在两群体中扩增的多态位点比例差异显著 (P <0 .0 5 )。养殖群体中低频位点明显减少而隐性纯合基因位点显著增加。群体遗传结构分析表明 ,两群体间的遗传距离比较小 ,群体遗传结构相似 ,说明养殖群体尚没有形成自己独立的遗传结构。     

云南腾冲地震台水温异常调查分析

<正>1研究背景地震观测井水温度动态变化由水的流动产生的热对流引起（鱼金子,2012;晏锐,2015;李旭茂,2020）。当地壳中有强震孕育与发生时,在导水导气的断裂带中,热对流很有可能在有限时段内影响到地壳表层,改变井水温度,表现为水温震前异常。     

基于4种技术方法的地下流体资料预报效能探讨

分别采用阈值法、速率变化法、趋势转折法和破年变法4种方法,对昭通地区全部地下流体观测资料进行预报效能R值定量计算。针对预报效能较好的测项,依据异常特征和水化学特征,并结合已有研究成果,对这些异常产生的孕震机理进行讨论。结果表明,昭通地区大多数流体异常的最佳预测时段在3个月以内,尤其是速率类异常和趋势转折类异常在出现转折后,具有较好的短临预测意义;11个测项的预报效能R>R₀,可作为滇东北地区日常跟踪的重点测项;推断认为大多数异常属于大气降水产生的流体力作用诱发的浅层前兆异常。     

Perturbation of gene expression and steroidogenesis with in vitro exposure of fathead minnow ovaries to ketoconazole

Ketoconazole is a fungicidal drug that inhibits function of cytochrome P450s in the synthesis of steroids. To examine if inhibition of P450 function affects gene expression in a dynamic manner, we conducted in vitro exposures of ovary tissue from fathead minnows (Pimephales promelas) to 0.5 microM ketoconazole to investigate effects on steroid production and gene expression over time. Expression of four key steroidogenesis genes was examined at 1, 6, and 12h of exposure. 11 beta- and 20 beta-hydroxysteroid dehydrogenases were down regulated at 1h and Cytochrome P450 17 was down-regulated at 12h, consistent with the absence of steroid production. In contrast, cytochrome P450 19A was up-regulated at 6h, indicating feedback regulation. Microarray analysis of 12h exposures indicated enrichment of biological processes involved in neurotransmitter secretion, lymphocyte cell activation, sodium ion transport, and embryonic development. These data suggest that, with the exception of cytochrome P450 19A, these steroid metabolic genes are regulated in a feed forward manner and that the effects of ketoconazole may be broader than anticipated based on the mechanism of action alone.     

Why are hatching and emergence success low? Mercury and selenium concentrations in nesting leatherback sea turtles (Dermochelys coriacea) and their young in Florida

Leatherback sea turtles (Dermochelys coriacea) have low hatching and emergence success compared to other sea turtle species. Postmortem examinations of hatchlings showed degeneration of heart and skeletal muscle that was similar to that found in other neonates with selenium deficient mothers. Selenium deficiency can result from elevated concentrations of bodily mercury. Ingested mercury is detoxified by the liver through mercury-selenium compound formation. In animals persistently exposed to mercury, the liver’s ability to detoxify this element may decrease, especially if dietary selenium is insufficient. We measured mercury and selenium concentrations in nesting female leatherbacks and their hatchlings from Florida and compared the levels to hatching and emergence success. Both liver selenium and the liver selenium-to-mercury ratio positively correlated with leatherback hatching and emergence success. This study provides the first evidence for the roles of mercury and selenium in explaining low reproductive success in a globally imperiled species, the leatherback sea turtle.     

Effects of alumina refinery wastewater and signature metal constituents at the upper thermal tolerance of: 2. The early life stages of the coral Acropora tenuis

The success of early life history transitions of the coral Acropora tenuis were used as endpoints to evaluate thermal stress and the effects of wastewater discharged to a tropical marine environment. The studies assessed the effects of: (i) temperature; (ii) three signature metals of the wastewater, aluminium (Al), vanadium (V) and gallium (Ga); and (iii) the wastewater (at 27 °C and 32 °C) on fertilisation and larval metamorphosis. The median inhibition temperatures for fertilisation and metamorphosis were 32.8 °C and 33.0 °C, respectively. Fertilisation IC₅₀s for Al, V and Ga were 2997, 2884 and 3430 μg L⁻¹, respectively. Metamorphosis IC₅₀s for Al, V and Ga were 1945, 675 and 3566 μg L⁻¹, respectively. The wastewater only affected fertilisation and metamorphosis at moderate concentrations (IC₅₀s = 63% and 67%, v/v, respectively, at 27 °C), posing a low risk to this species in the field. The effects of wastewater and temperature on fertilisation and metamorphosis were additive.