Specific ecological features of the brown bear (<Emphasis Type="Italic">Ursus arctos</Emphasis> L. 1758) in Yakutia

In Yakutia, the brown bear inhabits the forest and forest-tundra zones. Compared to bears from other regions of Russia, Yakutian bears have slightly smaller body and skull sizes and are mainly herbivorous, with their wood spectrum being relatively narrow. Their fecundity averages 1.68 cubs per parous female. The bears make their dens at a depth reaching 2.5–3 m. The denning period begins early and is 195–210 days long. An electroencephalographic analysis of the effect of a 1–10 kDa peptide fraction from the bear brain on Wistar rats has shown that wintering bears are in the state of sleep, or “superficial hibernation.”     

环巢湖流域表层沉积物重金属赋存特征及潜在生态风险评价

以环巢湖流域表层沉积物为对象,对8种重金属(Cd、Cr、Cu、Zn、Ni、Pb、As和Hg)总量及形态进行分析并运用潜在风险指数法对重金属的生态风险进行了评价.结果表明,环巢湖流域表层沉积物中重金属元素Cd、Cr、Ni、Cu、Zn、Pb、As和Hg的总量总体呈现为南淝河-十五里河水系含量高,其次是裕溪河及支流,其他5条水系的重金属含量相对较低. BCR形态分析表明,重金属元素Hg、Cr、Ni和Cu主要以残渣态存在(分别占总量的77.56%、64.83%、56.52%和48.93%),Cd的可提取态含量比例最高(89.22%),其次为Zn、Pb和As(70.35%,69.50%和63.70%). 潜在生态风险危害指数(RI)表明,Cu、Zn、Pb、Cr、Ni和As均为低污染等级,Cd为较重污染等级,Hg为重污染等级,7个水系的重金属潜在生态风险指数排序为:南淝河-十五里河>裕溪河>柘皋河>杭埠河-丰乐河>派河>白石山河>兆河,重潜在风险和严重潜在风险的区域主要分布在南淝河-十五里河水系以及裕溪河水系,因此,今后对巢湖流域进行重金属整治时可着重考虑针对这两条水系的Cd和Hg元素的重点治理.     

褐菖鲉肝HSC70基因的环介导等温扩增技术的建立及对石油污染的剂量效应研究

从褐菖鲉肝脏中克隆了热休克蛋白HSC70基因,利用环介导等温扩增技术(loop-mediated isothermal amplification,LAMP)建立HSC70基因的定量检测方法。为检测该方法的可行性,将褐菖鲉分别暴露于石油水溶性成分(water-soluble fraction,WSF) 20、60、180 μg·L^-1 1 d后,利用real-time PCR及LAMP技术同时测定褐菖鲉肝HSC70 mRNA表达量,两种方法测定结果基本一致,证实LAMP技术可用于褐菖鲉肝HSC70基因的定量。为更细致了解石油WSF影响褐菖鲉肝脏HSC70基因表达的剂量－效应关系,将褐菖鲉分别暴露于25、50、75、100、125、150、175 μg·L^-1 WSF中,5天后采样,用LAMP技术定量检测HSC70 mRNA。结果表明,HSC70 mRNA表达量在50 μg·L^-1浓度组即被显著诱导,在75 μg·L^-1浓度下达到最大值,这说明褐菖鲉肝HSC70基因对石油污染较敏感,有潜力作为海洋石油污染的生物标志物。     

温度对城市有机垃圾热解焦油成分的影响

以城市有机垃圾热解焦油为对象,研究了不同热解终温下(600~800℃)焦油的特性及其随温度的变化规律.结果表明:随着热解终温从600℃升高至800℃,焦油中C含量从74.49%增至83.42%;焦油的芳香化程度高于原料而低于热解炭,焦油的极性低于原料和热解炭,随着热解终温的升高,焦油的H/C和O/C逐渐降低;多环芳烃(PAHs)是焦油的主要成分,随着热解终温从600℃升高至800℃,其含量从54.06%增至83.45%;萘及其衍生物是焦油PAHs的主要成分,其含量在热解终温600、700、800℃时分别占PAHs的50.72%、46.80%、39.26%.研究结果证明了垃圾热解焦油可用作碳基复合材料和作为制备染料、树脂、溶剂、驱虫剂等的原料.     

丹江口水库表层沉积物有机/无机磷形态特征

采用连续分级提取法研究了丹江口水库表层沉积物中有机磷和无机磷的形态及其赋存特征,同时结合间隙水体中溶解性总磷(DTP)的空间分布特征,讨论了各形态磷的生物可利用性及其释放风险.结果表明,丹江口水库沉积物中各形态磷均在入库河流处高于库区.各采样点沉积物总磷在203.08~1625.61mg/kg之间,平均值为642.51mg/kg,其中以无机磷为主,占总磷的52.9%.无机磷形态中生物可利用性差的Ca-P_i占优势,平均值为196.46mg/kg,占无机磷的57.8%;沉积物有机磷形态中活性最差的NA-P_o占绝对的优势,NA-P_o平均值为180.83mg/kg,占有机磷(OP)的59.7%. WA-P_i、PA-P_i、Fe/Al-P_i、WA-P_o、PA-P_o均与间隙水体DTP呈显著正相关(P < 0.05), Ca-P_i、MA-P_o、NA-Po与间隙水DTP相关性较差.入库河流沉积物生物可利用性磷含量及释放通量均较库区高,具有较高的释磷风险.     

Optimization of anaerobic processes by speciation and bioavailability of trace metals

The deficiency trials of some trace metals (copper, nickel, zinc) were made in laboratory Upflow Anaerobic Sludge Blanket (UASB) reactors containing the inoculum of an industrial anaerobic sludge, a basal medium with the rest of nutrients and vitamins in comparison with a control reactor with the optimal doses of trace elements. From the main control parameters (alkalinity, acidity, DQO), no inactivation by deficit of essential elements was detected, but the control reactor showed greater mineralization and solid content, being necessary to make purge to avoid bulking. The inoculum has high metallic element contents, so the additional contribution produces high bacterial growth, also purge being necessary to avoid bulking. The purge, made after 120 days in continuous operation, eliminates a great quantity of solids and increases the volatile solids (VS)/total solids (TS) ratio. The comparison of the initial content of metallic elements in the solid and liquid phases with the contents after 120 days showed a progressive depletion of metals in all reactors without a clear appreciation of the lack of the studied metals. Finally, in 210 days, the reactors without addition of a metallic element accumulated greater quantity of major (Ca, Fe, Mg) and trace (Co, Ni, Cu) elements in the solid phase with respect to the control.     

Modeling toxic endpoints for improving human health risk assessment of polycyclic aromatic hydrocarbons – parent compounds and simple mixtures

Risk assessments for mixtures of polycyclic aromatic hydrocarbons (PAH) are problematic due to the lack of available potency and toxicity data on individual compounds and mixtures. This article examines the toxicity of parent compounds and designed mixtures of PAH in order to bridge the gap between component assessment and mixture assessment for this class of ubiquitous compounds. The objective for this study was to test seven parent PAH compounds and four PAH mixtures in a set of three bioassays to evaluate the toxicity of parent compound PAH and binary mixtures of PAH. PAH and mixtures were examined in the Salmonella/microsome mutagenicity assay, a Gap Junction Intercellular Communication assay, and the 7-ethoxyresorufin-O-deethylase assay. These assays were chosen for their ability to measure specific toxic endpoints related to the carcinogenic process (i.e. initiation, promotion, and progression). Two compounds similar in structure, benzo(a) pyrene (BAP) and benzanthracene, consistently produced positive results in all three bioassays. Conversely, a linear PAH, anthracene, produced negative results in all three bioassays. An antagonistic response was observed for the mixtures in all three bioassays. Chemical structure was important in explaining the observed responses. Using chemical structure–activity relationships with the steps of the carcinogenic process may be used to improve estimates of toxicity for compounds and mixtures for human health risk assessments.     

洱海表层沉积物有机磷形态分布特征及其影响因素

利用IVANOFF法,研究了洱海表层沉积物有机磷形态及其空间分布特征,探讨了有机质对各形态有机磷含量分布的影响. 结果表明:洱海北部和南部的浅水湖区沉积物w(OM)较高(2.50%～11.72%),而中部的深水湖区沉积物w(TP)较高(710.29～1 961.22 mg/kg);沉积物w(OP)为212.71～526.23 mg/kg,与w(TP)分布趋势一致;沉积物不同形态有机磷的含量为Residual-Po(残渣态有机磷)> Fulvic-P(富里酸结合态有机磷)> HCl-Po(酸提取态有机磷)>NaHCO₃-Po(活性有机磷)>Humic-P(腐殖酸结合态有机磷). 沉积物w(OM)与w(OP)/w(TP),w(Fulvic-P)和w(Humic-P)之间均呈显著正相关(P<0.01),与w(Residual-Po)呈显著负相关(P<0.01),与w(NaHCO₃-Po)和w(HCl-Po)之间相关性不显著(P>0.05). 洱海沉积物有机磷主要以非活性有机磷(Residual-Po和Humic-P)为主(平均占58.74%),且w(Fulvic-P)占w(OP)的百分比均高于营养水平较高的湖泊,而w(HCl-Po)占w(OP)的百分比相对较低(除E7采样点外). 即洱海沉积物有机磷形态特征决定了其生物有效性较低. 沉积物有机磷赋存形态特征很可能是上覆水磷浓度相对较低的重要原因,而沉积物w(TOC)/w(OP)<200则意味着其有机磷的潜在释放风险较大.      

Potentials and limitations of using large-scale forest inventory data for evaluating forest succession models

Forest gap models have been applied widely to examine forest development under natural conditions and to investigate the effect of climate change on forest succession. Due to the complexity and parameter requirements of such models a rigorous evaluation is required to build confidence in the simulation results. However, appropriate data for model assessment are scarce at the large spatial and temporal scales of successional dynamics. In this study, we explore a data source for the evaluation of forest gap models that has been used only little in the past, i.e., large-scale National Forest Inventory data. The key objectives of this study were (a) to examine the potentials and limitations of using large-scale forest inventory data for evaluating the performance of forest gap models and (b) to test two particular models as case studies to derive recommendations for their future improvement.