应用理论线性溶解能关系预测部分卤代芳烃的正辛醇／空气分配系数

以线笥溶解能关系（ＬＳＥＲ）理论为基础推导出一种理论线性溶解能关系（ＴＬＳＥＲ）模型。采用量子化学ＰＭ３算法，计算了部分卤代芳烃的分子平均极化率（α）等参数，并成功地应用于部分卤代芳烃正辛醇／空气分配系数（Ｋｏａ）的拟合与预测。研究表明，极化率是影响这些卤代芳烃的Ｋｏａ值的唯一参数，Ｋｏａ值随着极化的增大而增大。     

有机毒物对水蚤的急性毒性

对水蚤的毒笥试验数据是被广泛用于评价化合物水生生态效应的重要依据，检测有机化合物的毒性时，需特别注意待测物的难溶性，挥发性及易光解性，检测了多种氯代芳烃的ＥＣ５０值，其１８ｈ的结果与２４ｈ的结果相近，检测了２４种硝基芳烃的毒性，不同方法计算的ＥＣ５０值一致。     

硝基芳烃化合物急性毒性预测的理论研究

硝基芳烃是重要的化工原料,但对生物具有一定的毒性。为建立硝基芳烃对梨形四膜虫(Tetrahymena pyriformis)急性毒性的定量结构-活性相关性(QSAR)模型,分析了45种硝基芳烃的分子结构与其对梨形四膜虫毒性之间的相关关系,计算了硝基芳烃的电性拓扑状态指数和电性距离矢量,并优化筛选了电性拓扑状态指数的E_9和E_(28)、电性距离矢量的m_(15)、m_(26)和m_(66)等5种结构参数,将其与硝基芳烃对梨形四膜虫的毒性进行多元回归分析,得到多元回归方程的相关系数r为0.985。为提高预测精度,将这5种分子结构参数作为神经网络的输入层变量,急性毒性值作为输出层变量,采用5∶4∶1的网络结构,获得令人满意的QSAR神经网络预测模型,总相关系数r_t为0.994,计算得到的急性毒性预测值与实验值非常吻合,平均误差仅为0.04。结果表明,该模型具有良好的预测硝基芳烃急性毒性的能力,神经网络法预测结果比多元线性回归法更为准确。该研究揭示了硝基等基团对生物急性毒性影响的变化规律,有利于对硝基芳烃化合物在环境中的危害性进行有效评价。     

稠环芳烃在Pluronic嵌段共聚物胶束水溶液中的增溶

三种Pluronic嵌段共聚物（F108,P94和L64）胶束水溶液对萘、蒽、芘的增溶研究表明,它们在胶束和水相间的分配系数Kv值大小的顺序为：P94＞F108＞L64,这是由于具有较长PPO嵌段的Pluronic共聚物分子形成了较大内核的胶束,这种胶束有利于稠环芳烃的增溶。当指定Pluronic胶束体系时,Kv值随着稠环芳烃分子憎水性的增强（即分子苯环数目增加）而增大。这些规律同样反映在吸附等温线中。     

含硫苯衍生物对发光细菌的毒性效果及其定理结构活性相关分析

利用发光细菌法测定了２９种氯取代和硝苯取代的苯硫（砜、亚砜）基乙酸酯的毒性，通过定量结构活性相关（ＱＳＡＲ）分析发现：此类化合物的毒性主要与其取代基的电荷效应相关，电荷的区域分布对化合物的毒性效应有重要影响。推测该化合物的毒性机理是毒物分子与发光反应中的主要辅酶ＦＭＮＨ２形成了氢键。还发明：在这类链状毒物分子中，远离活性中心一端的基团具有脱毒作用。     

部分取代芳烃对绿藻毒性的研究和QSAR分析

本文测定了３０余种取代芳烃对一种绿藻（斜生栅藻）的ＥＣ５０值（即与对照相比，使藻的生长率下降５０％的有机物浓度）并结合发光菌的毒性数据，研究了这类物质结合与活性的定量关系，用辛醇水分配系数和特殊分子连接性指数可以较好地预测反应性有机物的毒性。     

松花江水中酚类化合物生物降解性的测定及QSBR研究

以松花江水中细菌为接种源,用碘量法分别测定了１８种酚类化合物的ＢＯＤ５值采用ＱＳＡＲ程序软件计算得分子量ＭＷ、分子体积ＭＶ、疏水性参数ｌｇＰ及电离常数ｐＫａ．用ＭＭＰ软件计算了四种分子连接性指数(２ｘ,４Ｘ,２ｘＶ及４ｘＶ)．对１８种及训练组中的１４种酚类化合物ＢＯＤＴ值分别与其结构参数进行了回归分析,得到如下最佳回归方程:应用所得ＱＳＢＲ模型,拟合了１８种化合物的ＢＯＤ５值,计算了残差,预测了实验组中４个化合物的ＢＯＤＴ值,并初步探讨了生物降解机理．     

有机污染物对藻类毒性的测定

藻类是研究水生毒理学的很好的材料之一，对其毒性是评价化合物危害的基本数据，也是研究化合物结构与生物效应的手段之一，通过测定工业废水，数种硝基芳烃及多种有机锡对藻类的毒性，发现剂量与效应时间有很好的相关性，化合物结构与效应之间也有一定的规律。     

利用前线分子轨道能预测有机物生物毒性的方法

本文以线性自由能理论为基础提出了一种利用分子轨道能预测有机物生物毒性的方法，并利用这种方法建立了预测氯代芳烃化合物发光菌毒性的定量相关方程。     

利用SOS/umu测试方法鉴定沙颍河河水中的遗传毒性物质

采用HPLC分割导向的SOS/umu测试方法鉴定了沙颍河河水中的遗传毒性物质。当采用TA1535/pSK1002菌株测定HPLC分割的各馏分时,如果不经大鼠肝微粒体酶(S9)代谢活化,只有馏分F10显示遗传毒性,加入大鼠肝微粒体酶代谢活化后,馏分F10和馏分F15都显示有遗传毒性,说明河水中存在某些需经过大鼠肝微粒体酶代谢活化才能显示出遗传毒性的物质。当采用过量表达O-乙酰转移酶(O-AT),对芳香胺类物质和硝基芳烃化合物有特殊响应的NM2009菌株测定时,馏分F8、F9和F10均呈现遗传毒性;特别是对于馏分F10,用NM2009菌株测定的遗传毒性远高于原始菌,说明这3个馏分中都含有芳香胺类或硝基芳烃类物质。     

Rapid,recurring, structured survey versus bioblitz for generating biodiversity data and analysis with a multispecies abundance model

A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity.     

Compliance with and ecosystem function of biodiversity offsets in North American and European freshwaters

Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects’ compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes.     

A palaeo-hydrogeological model for arsenic contamination in southern and south-east Asia

An argument is presented in which areas of natural arsenic contamination of modern groundwaters throughout Asia have a common origin. Arsenic originally accumulated in oceanic ferro-manganoan sediments of the eastern Palaeo-Tethys. This was further concentrated through oceanic crustal extinction in what later became the south-east Chinese accreted mineralised terrain. Proto-Himalayan uplift of this area created the palaeo-drainage systems of the Ganges – Brahmaputra, Irrawaddy, Mekong, and Red Rivers, with consequent headwater erosion of arsenic-rich sediments. Their downstream deposition as immature and easily redistributed Neogene sandstones, silts, and iron-rich clays has created secondary and tertiary reservoirs of adsorbed and authigenic arsenic, from which the current arsenic-rich groundwaters have evolved. Considering river basins within the above palaeo-hydrogeological framework provides a basis for assessing the risk of arsenic in groundwater basins of south and south-eastern Asia.     

Cost‐effective conservation of an endangered frog under uncertainty

How should managers choose among conservation options when resources are scarce and there is uncertainty regarding the effectiveness of actions? Well‐developed tools exist for prioritizing areas for one‐time and binary actions (e.g., protect vs. not protect), but methods for prioritizing incremental or ongoing actions (such as habitat creation and maintenance) remain uncommon. We devised an approach that combines metapopulation viability and cost‐effectiveness analyses to select among alternative conservation actions while accounting for uncertainty. In our study, cost‐effectiveness is the ratio between the benefit of an action and its economic cost, where benefit is the change in metapopulation viability. We applied the approach to the case of the endangered growling grass frog (Litoria raniformis), which is threatened by urban development. We extended a Bayesian model to predict metapopulation viability under 9 urbanization and management scenarios and incorporated the full probability distribution of possible outcomes for each scenario into the cost‐effectiveness analysis. This allowed us to discern between cost‐effective alternatives that were robust to uncertainty and those with a relatively high risk of failure. We found a relatively high risk of extinction following urbanization if the only action was reservation of core habitat; habitat creation actions performed better than enhancement actions; and cost‐effectiveness ranking changed depending on the consideration of uncertainty. Our results suggest that creation and maintenance of wetlands dedicated to L. raniformis is the only cost‐effective action likely to result in a sufficiently low risk of extinction. To our knowledge we are the first study to use Bayesian metapopulation viability analysis to explicitly incorporate parametric and demographic uncertainty into a cost‐effective evaluation of conservation actions. The approach offers guidance to decision makers aiming to achieve cost‐effective conservation under uncertainty.     

Parasitic wasps orient to green leaf volatiles

Summary Undamaged plants emit low levels of green leaf volatiles (GLVs), while caterpillar-damaged and artificially damaged plants emit relatively higher levels of certain GLVs. Female braconid parasitoids,Microplitis croceipes, oriented to both damaged plants and to individual GLVs in no-choice tests in a wind tunnel, but seldom oriented to undamaged plants. Female ichneumonid parasitoids,Netelia heroica, also oriented to individual GLVs in a wind tunnel. Males of both wasp species failed to orient to the GLVs. These data show that leaf-feeding caterpillars can cause the release of GLVs, and that parasitic wasps can respond to these odors by flying upwind (chemoanemotactic response), which brings the wasps to their caterpillar hosts. This supports the hypothesis that plants communicate with members of the third trophic level,i.e., plants under herbivore attack emit chemical signals that guide natural enemies of herbivores to sites of plant damage. In this interaction, the GLVs serve as tritrophic plant-to-parasitoid synomones. That parasitoids from two different wasp families oriented to GLVs suggests that the response may be widespread among the Hymenoptera.Mention of a commercial or proprietary product does not constitute an endorsement by the U.S. Department of Agriculture     

Potential for Electropositive Metal to Reduce the Interactions of Atlantic Sturgeon with Fishing Gear

Atlantic sturgeon (Acipenser oxyrhynchus) populations have been declared either endangered or threatened under the U.S. Endangered Species Act. Effective measures to repel sturgeon from fishing gear would be beneficial to both fish and fishers because they could reduce both fishery‐associated mortality and the need for seasonal and area closures of specific fisheries. Some chondrostean fishes (e.g., sturgeons and paddlefishes) can detect weak electric field gradients (possibly as low as 5 Μv/cm) due to arrays of electroreceptors (ampullae of Lorenzini) on their snout and gill covers. Weak electric fields, such as those produced by electropositive metals (typically mixtures of the lanthanide elements), could therefore potentially be used as a deterrent. To test this idea, we recorded the behavioral responses of juvenile Atlantic sturgeon (31–43 cm fork length) to electropositive metal (primarily a mixture of the lanthanide elements neodymium and praseodymium) both in the presence and absence of food stimuli. Trials were conducted in an approximately 2.5 m diameter × 0.3 m deep tank, and fish behaviors were recorded with an overhead digital video camera. Video records were subsequently digitized (x, y coordinate system), the distance between the fish and the electropositive metal calculated, and data summarized by compiling frequency distributions with 5‐cm bins. Juvenile sturgeon showed clear avoidance of electropositive metal but only when food was present. On the basis of our results, we conclude that the electropositive metals, or other sources of weak electric fields, may eventually be used to reduce the interactions of Atlantic sturgeon with fishing gear, but further investigation is needed. El Potencial del Metal Electropositivo para Reducir las Interacciones del Esturión Atlántico con Instrumentos de Pesca Bouyoucos, Bushnell & Brill 13–003     

The role of time and species identities in spatial patterns of species richness and conservation

Many conservation actions are justified on the basis of managing biodiversity. Biodiversity, in terms of species richness, is largely the product of rare species. This is problematic because the intensity of sampling needed to characterize communities and patterns of rarity or to justify the use of surrogates has biased sampling in favor of space over time. However, environmental fluctuations interacting with community dynamics lead to temporal variations in where and when species occur, potentially affecting conservation planning by generating uncertainty about results of species distribution modeling (including range determinations), selection of surrogates for biodiversity, and the proportion of biodiversity composed of rare species. To have confidence in the evidence base for conservation actions, one must consider whether temporal replication is necessary to produce broad inferences. Using approximately 20 years of macrofaunal data from tidal flats in 2 harbors, we explored variation in the identity of rare, common, restricted range, and widespread species over time and space. Over time, rare taxa were more likely to increase in abundance or occurrence than to remain rare or disappear and to exhibit temporal patterns in their occurrence. Space–time congruency in ranges (i.e., spatially widespread taxa were also temporally widespread) was observed only where samples were collected across an environmental gradient. Fifteen percent of the taxa in both harbors changed over time from having spatially restricted ranges to having widespread ranges. Our findings suggest that rare species can provide stability against environmental change, because the majority of species were not random transients, but that selection of biodiversity surrogates requires temporal validation. Rarity needs to be considered both spatially and temporally, as species that occur randomly over time are likely to play a different role in ecosystem functioning than those exhibiting temporal structure (e.g., seasonality). Moreover, temporal structure offers the opportunity to place management and conservation activities within windows of maximum opportunity.     

Main nutrient compounds in food bodies of Mexican <Emphasis Type="Italic">Acacia</Emphasis> ant-plants

Summary. Myrmecophytic plants use obligate ant mutualists as a constitutive indirect defence mechanism. These plants often produce cellular food bodies (FBs) to nourish their resident ants. Lipids, proteins, and even highly specialised compounds such as glycogen have been reported from FBs, but detailed chemical analyses of FB composition have so far been presented only for Southeast Asian Macaranga and Central American Piper myrmecophytes. Here we report the chemical composition of FBs of five myrmecophytic Acacia (Fabaceae) species from Mexico using HPLC (carbohydrates and proteins) and GC-MS (lipids). Feeding experiments revealed no hints on any use of external food sources by the inhabiting Pseudomyrmex ants. These ants obviously rely completely on FBs and extrafloral nectar provided by their hosts. The total content of nutrients in Acacia FBs was 15-25% of FB dry mass, being much lower than in Macaranga or Piper FBs. Proteins were dominating (8-14 % dm) in Acacia FBs and thus were present in higher amounts than in Macaranga FBs, yet in lower amounts than in Piper. Lipids contributed 1-9 % of dry mass, showing a lower proportion than in FBs of Macaranga or Piper. Carbohydrates made up 3-11 % dm, reaching in most Acacia species the same range as observed in Macaranga and in Piper FBs. Water content was 18-24 % of FB fresh mass, and structural tissue obviously made up a much higher proportion in Acacia FBs than in Macaranga or Piper FBs. Both characters might represent an adaptation to producing FBs unprotected at the leaf tips under dry conditions. Acacia FBs contain all amino acids and all fatty acids that are considered essential for insects, and their contents of lipids and proteins are higher than in the leaves from which they are ontogenetically derived. This indicates a putatively adaptive enrichment of nutritionally valuable compounds in structures functioning as ant-food.     

Examining the uncertain origin and management role of martens on Prince of Wales Island,Alaska

Conservation biologists are generally united in efforts to curtail the spread of non‐native species globally. However, the colonization history of a species is not always certain, and whether a species is considered non‐native or native depends on the conservation benchmark. Such ambiguities have led to inconsistent management. Within the Tongass National Forest of Alaska, the status of American marten (Martes americana) on the largest, most biologically diverse and deforested island, Prince of Wales (POW), is unclear. Ten martens were released to POW in the early 1930s, and it was generally believed to be the founding event, although this has been questioned. The uncertainty surrounding when and how martens colonized POW complicates management, especially because martens were selected as a design species for the Tongass. To explore the history of martens of POW we reviewed other plausible routes of colonization; genetically and isotopically analyzed putative marten fossils deposited in the late Pleistocene and early Holocene to verify marten occupancy of POW; and used contemporary genetic data from martens on POW and the mainland in coalescent simulations to identify the probable source of the present‐day marten population on POW. We found evidence for multiple routes of colonization by forest‐associated mammals beginning in the Holocene, which were likely used by American martens to naturally colonize POW. Although we cannot rule out human‐assisted movement of martens by Alaskan Natives or fur trappers, we suggest that martens be managed for persistence on POW. More generally, our findings illustrate the difficulty of labeling species as non‐native or native, even when genetic and paleo‐ecological data are available, and support the notion that community resilience or species invasiveness should be prioritized when making management decisions rather than more subjective and less certain conservation benchmarks.