一种提取土壤样品中麻疯树核糖体失活蛋白curcin的方法

建立并优化了一种土壤麻疯树核糖体失活蛋白curcin的提取方法.优化后的提取步骤和参数为:0.1 g含curcin的土壤样品加入1 m L的提取缓冲液(5 mmol/L磷酸盐,0.1 mmol/L EDTA,0.2%SDS(m/V),20 mmol/Lβ-巯基乙醇,p H7.2),在18℃以上的室温条件下振荡混匀1 h,离心取上清液.重复该过程一次,合并上清液.上清液于4℃放置过夜,离心取上清液,即为样品粗提液.该样品粗提液即可用单克隆抗体间接酶联免疫吸附法(ELISA)进一步检测其中的curcin含量.该方法对curcin含量高于8μg/g土壤可进行定性检测,对于curcin含量分别为100、500、1 000μg/g的土壤样品的回收率分别达到49.3%±2.8%、64.2%±3.62%和78.33%±4.24%.该方法的变异系数保持在5%左右,对来自四川3个样地的土壤有较好的适用性.本研究建立优化的提取方法可为评估curcin蛋白在农业领域应用的生态风险提供技术支持.     

可吸入尘中苯并（a）芘超声提取的高效液相色谱测定法

本文介绍一种简便、快速的可吸入尘中苯并(a)茈高效液相色谱测定方法.本法仅需5mL乙腈,超声处理10min即可完成提取过程.提取液离心后,上清液可直接进行HPLC分析.色谱条件:反相C18柱,用乙腈/水梯度洗脱,紫外检测器,λ=254nm.方法的最小检出量10~(-10)g.回收率95%,变异系数4、3%.此方法可用于大气可吸入尘中Bap的监测.     

溶藻微生物菌群的富集及其溶藻因素

为探索行之有效的抑制藻类水华暴发的途径,采集重庆地区蓝藻爆发水域的环境水样,与铜绿微囊藻多次重复共培养富集出具有溶藻能力的高效溶藻液,显示出强而稳定的溶藻能力.通过离心、膜过滤、温度及抗生素因素分析溶藻活性物的主要特性.结果显示:离心处理该高效溶藻液,3 000 r/min离心5 min便可沉淀溶藻活性物,7 000 r/min离心5 min后上清液便失去溶藻能力;膜过滤处理该高效溶藻液,溶藻活性物不能通过2μm的滤膜;温度处理该高效溶藻液,45℃水浴处理10 min即可使其溶藻活性显著降低,48℃水浴处理10 min便可使其完全失去溶藻能力;抗生素处理该高效溶藻液,加入放线菌酮对其溶藻能力没有影响,加入氯霉素对其溶藻能力稍有影响,加入四环素则丧失溶藻能力,抗生素处理结果说明溶藻活性物不是真菌,革兰氏阳性菌的缺失对溶藻活性的影响要大于革兰氏阴性菌;LB培养基分离的单菌落都没有显示出显著的溶藻活性.本研究表明多轮富集的高效溶藻液具有显著稳定的溶藻效果,溶藻液经离心、膜过滤、高温及添加抗生素的结果均显示溶藻因素是细菌,单菌落培养结果说明其溶藻活性依赖于多种细菌组成的微生物菌群共同作用.     

气相色谱-质谱联用法测定塑胶跑道面层中18种多环芳烃

本文对气相色谱-质谱联用法(GC-MS)测定塑胶跑道面层中18种多环芳烃(PAHs)的前处理方法进行了讨论.以样品颗粒物直径、超声萃取时间、颗粒物存放时间、样品净化方式为试验因素,优选出测定多环芳烃的最佳样品处理条件.称取10目到20目之间的样品0.2 g,加入10 mL乙酸乙酯,60℃超声萃取60 min,取上清液,净化时采用12 mL洗脱剂,氮吹近干后加入3种混合内标溶液,用GC-MS分离和检测.以3倍信噪比计算18种多环芳烃检出限,以10倍信噪比计算定量限,各组分检出限范围为0.0048—0.030 mg·kg~(-1),定量限范围为0.010—0.099 mg·kg~(-1).6次平行测定RSD%均小于10%,样品加标回收率在75.50%—125.19%.方法精密度好,准确度高,适用于塑胶跑道中18种PAHs的日常检测.     

酶联免疫吸附法测定麻疯树核糖体失活蛋白

建立了一种检测麻疯树核糖体失活蛋白(Curcin)的简便、快速的酶联免疫吸附测定法(ELISA).ELISA条件优化试验结果显示:最佳条件为costar酶标板在紫外线下照射45 min后进行包被;抗原最适稀释度为1:640倍(2.5μg/mL);curcin抗血清最适稀释度为1:12 800倍;2%封闭用山羊血清封闭120 min;二抗最适稀释度为1:5 000倍.在此试验条件下检测curcin含量,得到回归方程y=31.722x+106.88,相关系数R2=0.993 3.Curcin浓度在0.08～11μg/mL之间,曲线呈良好的线性关系.本方法的最低检测限为0.08μg/mL.高、中、低3个浓度的添加回收率分别为95.56%、102.27%、98.40%,平均回收率为98.74%.板内和板间的平均变异系数分别为4.78%和6.71%.Curcin抗血清与2种大戟科同类蛋白均无交叉反应.利用本方法成功检测了麻疯树种仁及脱毒饼粕中的curcin含量.     

红花石蒜球茎凝集素的纯化及部分性质

石蒜科植物红花石蒜(Lycorisradiata)球茎经生理盐水浸取、硫酸铵分级沉淀、DEAE-Sepharose和SephacrylS-100分子筛层析得到石蒜凝集素(L. radiataagglutinin, LRA).经SDS-PAGE检测为单一蛋白带,亚基相对分子量Mr为12×103,SephacrylS-100凝胶过滤测定Mr约为45×103,表明LRA是由4个相同亚基组成的蛋白.LRA能凝集兔红细胞和大肠杆菌,最低凝集浓度分别为0. 95μg/mL和1. 9μg/mL;LRA还能凝集啤酒酵母细胞.糖抑制实验显示,甘露聚糖和甲状腺球蛋白能有效抑制LRA的凝血活性.促淋巴细胞有丝分裂试验结果表明,LRA对外周血淋巴细胞具有很强的促有丝分裂能力;同时,LRA能有效地降低II型人类单纯疱疹病毒(HSV-II)对Vero细胞(非洲绿猴肾细胞)的感染,ρ(IC50 ) =5~10μg/mL之间,并且在500μg/mL时对正常Vero细胞无细胞毒性. 图1表6参15     

超高效液相色谱-串联质谱法同时测定PIVAS工作环境中5种细胞毒性药物残留

建立超高效液相色谱-串联质谱技术同时测定医院静脉用药调配中心(PIVAS)工作环境中5种细胞毒性药物吉西他滨、环磷酰胺、表柔比星、依托泊苷及紫杉醇在玻璃、不锈钢和PVC材质表面残留含量的检测方法.将2 cm×2 cm滤纸用100μL 80%乙腈-0.1%甲酸溶液润湿后对10 cm×10 cm物表进行擦拭取样，擦拭样品用1 mL 20%乙腈含0.1%甲酸溶液重复提取2次，合并提取液离心后取上清液，以水-乙腈(0.1%甲酸)为流动相梯度洗脱，采用电喷雾电离源正离子模式和MRM模式检测.结果表明，吉西他滨和环磷酰胺在0.1—800 ng·mL^-1、表柔比星和依托泊苷在0.1—200 ng·mL^-1、紫杉醇在0.2—200 ng·mL^-1范围内线性关系良好，相关系数均大于0.999，方法的检出限为0.2—1 pg·cm^-2，定量限(LOQ)为0.6—3.2 pg·cm^-2.在玻璃、PVC和不锈钢3种材质上3个加标水平(200、1000、4000 ng·mL^-1)的...     

基于代谢组学技术分析磷酸三苯酯诱导斑马鱼胚胎发育毒性的分子机制

磷酸三苯酯(TPhP)是广泛存在于环境介质和生物体内的一种典型有机磷阻燃剂。为探求TPhP诱发水生动物发育毒性的分子机制,本研究以斑马鱼为模式动物,将发育至2.5 hpf (hours post fertilization)的斑马鱼胚胎暴露于0.0025、0.1、1、10、100和1 000μg·L~(-1)TPhP溶液至7 dpf (days post fertilization),考察斑马鱼胚胎生长发育指标和线粒体功能的变化,通过代谢组学分析揭示相关分子机制。结果表明,环境相关浓度(0.0025、0.1和1μg·L~(-1)) TPhP对斑马鱼胚胎发育无显著影响,但是轻微干扰了斑马鱼的代谢过程。100和1 000μg·L~(-1)TPhP暴露引起斑马鱼心跳速率、孵化率和线粒体膜电位明显下调,畸形率分别增加6.8倍和12.5倍,死亡率分别增加7.2倍和16.5倍。代谢组学分析发现,10、100和1 000μg·L~(-1)TPhP显著抑制斑马鱼氨基酸代谢,降低缬氨酸、亮氨酸和异亮氨酸水平,抑制氨酰-tRNA生物合成过程;同时引起葡萄糖糖酵解过程和三羧酸循环发生障碍。氨基酸和糖代谢异常可能是TPhP引起斑马鱼发育畸形的主要原因,线粒体功能紊乱可能是TPhP诱发三羧酸循环障碍的原因。上述研究结果为TPhP发育毒性机制分析提供了新思路。     

气相色谱质谱法测定土壤中的阿特拉津

建立了索氏提取、弗洛里硅土固相柱净化,质谱法测定土壤中的阿特拉津,考察了进样口分流模式、柱升温程序、索氏提取时间对测定的影响,确定了最佳测定条件:无分流进样;流速:1.0 mL·min-1;柱升温程序:100℃(1 min),10℃.min-1到250℃(3 min);离子源温度:250℃;索氏提取:4 h.方法的线性范围良好,相关系数为0.9997,线性范围:5.0—100.0μg.kg-1,方法检出限(S/N=3)为0.38μg.kg-1,相对标准偏差1.1%,平均回收率100.1%.     

快速溶剂萃取/气相色谱-质谱联用法测定土壤中15种邻苯二甲酸酯类增塑剂

建立了测定土壤中15种邻苯二甲酸酯类增塑剂的快速溶剂萃取/气相色谱-质谱联用(GC-MS)分析方法.样品用快速溶剂萃取仪(ASE)提取,样液经NH2粉净化,4000 r·min-1离心5 min,取上清液氮吹浓缩定容后,采用气相色谱-质谱联用(GC-MS)测定,外标法定量.在0.05—5.00μg·m L-1范围内,相关系数R20.992,样品在0.10—2.00 mg·kg-1范围内加标,平均回收率在64.5%—119.4%之间,相对标准偏差(RSD)为2.1%—11.8%,检出限(LOD)在0.02—0.05 mg·kg-1之间,定量限(LOQ)在0.06—0.15 mg·kg-1.采用该方法对7个土壤样品进行测定,结果表明该法简便、快速、结果准确可靠、灵敏度高、对人体毒害性小,能够满足土壤中15种邻苯二甲酸酯增塑剂检测需求.     

Achieving Open Access to Conservation Science

Conservation science is a crisis discipline in which the results of scientific enquiry must be made available quickly to those implementing management. We assessed the extent to which scientific research published since the year 2000 in 20 conservation science journals is publicly available. Of the 19,207 papers published, 1,667 (8.68%) are freely downloadable from an official repository. Moreover, only 938 papers (4.88%) meet the standard definition of open access in which material can be freely reused providing attribution to the authors is given. This compares poorly with a comparable set of 20 evolutionary biology journals, where 31.93% of papers are freely downloadable and 7.49% are open access. Seventeen of the 20 conservation journals offer an open access option, but fewer than 5% of the papers are available through open access. The cost of accessing the full body of conservation science runs into tens of thousands of dollars per year for institutional subscribers, and many conservation practitioners cannot access pay‐per‐view science through their workplace. However, important initiatives such as Research4Life are making science available to organizations in developing countries. We urge authors of conservation science to pay for open access on a per‐article basis or to choose publication in open access journals, taking care to ensure the license allows reuse for any purpose providing attribution is given. Currently, it would cost $51 million to make all conservation science published since 2000 freely available by paying the open access fees currently levied to authors. Publishers of conservation journals might consider more cost effective models for open access and conservation‐oriented organizations running journals could consider a broader range of options for open access to nonmembers such as sponsorship of open access via membership fees. Obtención de Acceso Abierto a la Ciencia de la Conservación     

Some polyphagous Homoptera gain protection from their natural enemies by feeding on the toxic plantsSpartium junceum andErythrina corallodendrum (Leguminosae)

Summary Interactions were studied among alkaloid-containing legumes (Erythrina corallodendrum andSpartium junceum) and non-toxic plants (Citrus sinensis, Cucurbita moschata andEuphorbia tirucalli), several polyphagous homopterans,Aphis craccivora (Aphididae),Icerya purchasi, I. aegyptiaca (Margarodidae),Lepidosaphes ulmi (Diaspididae) andPlanococcus citri (Pseudococcidae), and some major natural enemies of these homopterans. Significant reductions in survival due to negative effects of alkaloid containing as compared with non-alkaloidal plants were recorded for the predatorsRodolia cardinalis andChilocorus bipustulatus, but not forCryptolaemus montrouzieri (Coleoptera: Coccinellidae),Chrysoperla carnea (Neuroptera: Chrysopidae) andSympherobius sanctus (Neuroptera: Sympherobiidae). The development time of the larvae or pupae ofR. cardinalis, C. carnea andS. sanctus was longer on the toxic plants than on the non-toxic ones. The percentage of parasitism ofA. craccivora collected from the non-alkaloidal plantsVicia palaestina andMelilotus albus was much higher than that onS. junceum. The parasitoid complexes ofA. craccivora differed between both plant groups. The nutritive value of honeydew ofI. purchasi andA. craccivora, as expressed by the life span ofEncyrtus infelix (Hymenoptera: Encyrtidae) adults, was also investigated. Life spans were significantly longer when the wasps fed on honeydew produced on non-alkaloidal plants (C. sinensis andPittosporum tobira) than on alkaloid containing plants whenI. purchasi — but notA. craccivora — was the producer. It is suggested that the chemical defense ofE. corallodendrum andS. junceum is exploited by polyphagous phytophages to reduce predation. In nature, population growth and density of four of the investigated homopterans are conspicuously high when they developed on the alkaloid containing plant species, and very low on non-alkaloid plants. The efficiency of their natural enemies may be reduced by sequestration of alkaloids (or other toxic plant compounds) or their transfer into excreted honeydew. Therefore it is assumed that a generalist phytophagous homopteran may be protected from its natural enemies, although at different rates of efficiency, if it can safely sequester the host allelochemical when it develops on toxic species within its host range.     

Sequestration of cucurbitacin analogs by New and Old World chrysomelid leaf beetles in the tribe Luperini

Summary Two South American polyphagous leaf beetles,Diabrotica speciosa andCerotoma arcuata, selectively accumulated the bitter tasting compound 23,24-dihydrocucurbitacin D in their body after ingesting root tissues of cucurbit plants. Similarly, three Asian Cucurbitaceae-feeding specialists in the genusAulacophora were found to sequester the same compound. Cucurbitacin analogs were shown to deter feeding by a bird predator, indicating an allomonal role for these compounds in cucurbitacin-associated chrysomelid leaf beetles both of New and Old Worlds. The strong affinity to cucurbitacins, selective sequestration of the analogs and consequent protection from predators suggested an ecological adaptation mechanism developed in common among these two geographically isolated subtribes in the Luperini.     

Effects of Controlled Fire and Livestock Grazing on Bird Communities in East African Savannas

Abstract: In East Africa fire and grazing by wild and domestic ungulates maintain savannas, and pastoralists historically set fires and herded livestock through the use of temporary corrals called bomas. In recent decades traditional pastoral practices have declined, and this may be affecting biodiversity. We investigated the effects of prescribed fires and bomas on savanna bird communities in East Africa during the first and second dry seasons of the year (respectively before and after the rains that mark the onset of breeding for most birds). We compared abundance, richness, and community composition on 9‐ha burned plots, recently abandoned bomas, and control plots in the undisturbed matrix habitat over a 3‐year period. Generally, recently burned areas and abandoned bomas attracted greater densities of birds and had different community assemblages than the surrounding matrix. The effects of disturbances were influenced by interactions between primary productivity, represented by the normalized difference vegetation index, and time. Bird densities were highest and a greater proportion of species was observed on burned plots in the months following the fires. Drought conditions equalized bird densities across treatments within 1 year, and individuals from a greater proportion of species were more commonly observed on abandoned bomas. Yearly fluctuations in abundance were less pronounced on bomas than on burns, which indicate that although fire may benefit birds in the short term, bomas may have a more‐lasting positive effect and provide resources during droughts. Several Palearctic migrants were attracted to burned plots regardless of rainfall, which indicates continued fire suppression may threaten their already‐declining populations. Most notably, the paucity of birds observed on the controls suggests that the current structure of the matrix developed as a result of fire suppression. Traditional pastoralism appears critical to the maintenance of avian diversity in these savannas.     

Effects of Coffee Management on Deforestation Rates and Forest Integrity

Knowledge about how forest margins are utilized can be crucial for a general understanding of changes in forest cover, forest structure, and biodiversity across landscapes. We studied forest‐agriculture transitions in southwestern Ethiopia and hypothesized that the presence of coffee (Coffea arabica)decreases deforestation rates because of coffee's importance to local economies and its widespread occurrence in forests and forest margins. Using satellite images and elevation data, we compared changes in forest cover over 37 years (1973–2010) across elevations in 2 forest‐agriculture mosaic landscapes (1100 km² around Bonga and 3000 km² in Goma‐Gera). In the field in the Bonga area, we determined coffee cover and forest structure in 40 forest margins that differed in time since deforestation. Both the absolute and relative deforestation rates were lower at coffee‐growing elevations compared with at higher elevations (?10/20% vs. ?40/50% comparing relative rates at 1800 m asl and 2300–2500 m asl, respectively). Within the coffee‐growing elevation, the proportion of sites with high coffee cover (>20%) was significantly higher in stable margins (42% of sites that had been in the same location for the entire period) than in recently changed margins (0% of sites where expansion of annual crops had changed the margin). Disturbance level and forest structure did not differ between sites with 30% or 3% coffee. However, a growing body of literature on gradients of coffee management in Ethiopia reports coffee's negative effects on abundances of forest‐specialist species. Even if the presence of coffee slows down the conversion of forest to annual‐crop agriculture, there is a risk that an intensification of coffee management will still threaten forest biodiversity, including the genetic diversity of wild coffee. Conservation policy for Ethiopian forests thus needs to develop strategies that acknowledge that forests without coffee production may have higher deforestation risks than forests with coffee production and that forests with coffee production often have lower biodiversity value. Efectos de la Administración Cafetalera sobre las Tasas de Deforestación y la Integridad de los Bosques     

What Every Conservation Biologist Should Know about Economic Theory

Abstract: The last century has seen the ascendance of a core economic model, which we will refer to as Walrasian economics. This model is driven by the psychological assumptions that humans act only in a self‐referential and narrowly rational way and that production can be described as a self‐contained circular flow between firms and households. These assumptions have critical implications for the way economics is used to inform conservation biology. Yet the Walrasian model is inconsistent with a large body of empirical evidence about actual human behavior, and it violates a number of basic physical laws. Research in behavioral science and neuroscience shows that humans are uniquely social animals and not self‐centered rational economic beings. Economic production is subject to physical laws including the laws of thermodynamics and mass balance. In addition, some contemporary economic theory, spurred by exciting new research in human behavior and a wealth of data about the negative global impact of the human economy on natural systems, is moving toward a world view that places consumption and production squarely in its behavioral and biophysical context. We argue that abandoning the straightjacket of the Walrasian core is essential to further progress in understanding the complex, coupled interactions between the human economy and the natural world. We call for a new framework for economic theory and policy that is consistent with observed human behavior, recognizes the complex and frequently irreversible interaction between human and natural systems, and directly confronts the cumulative negative effects of the human economy on the Earth's life support systems. Biophysical economics and ecological economics are two emerging economic frameworks in this movement.     

Globalization of the Cashmere Market and the Decline of Large Mammals in Central Asia

As drivers of terrestrial ecosystems, humans have replaced large carnivores in most areas, and human influence not only exerts striking ecological pressures on biodiversity at local scales but also has indirect effects in distant corners of the world. We suggest that the multibillion dollar cashmere industry creates economic motivations that link western fashion preferences for cashmere to land use in Central Asia. This penchant for stylish clothing, in turn, encourages herders to increase livestock production which affects persistence of over 6 endangered large mammals in these remote, arid ecosystems. We hypothesized that global trade in cashmere has strong negative effects on native large mammals of deserts and grassland where cashmere‐producing goats are raised. We used time series data, ecological snapshots of the biomass of native and domestic ungulates, and ecologically and behaviorally based fieldwork to test our hypothesis. In Mongolia increases in domestic goat production were associated with a 3‐fold increase in local profits for herders coexisting with endangered saiga (Saiga tatarica).That increasing domestic grazing pressure carries fitness consequences was inferred on the basis of an approximately 4‐fold difference in juvenile recruitment among blue sheep (Pseudois nayaur)in trans‐Himalayan India. Across 7 study areas in Mongolia, India, and China's Tibetan Plateau, native ungulate biomass is now <5% that of domestic species. Such trends suggest ecosystem degradation and decreased capacity for the persistence of native species, including at least 8 Asian endemic species: saiga, chiru (Pantholops hodgsoni), Bactrian camel (Camelus bactrianus), snow leopard(Panthera uncia), khulan(Equus hemionus), kiang (E. kiang), takhi (E. przewalski), and wild yak (Bos mutus). Our results suggest striking yet indirect and unintended actions that link trophic‐level effects to markets induced by the trade for cashmere. Globalización del Mercado de Cachemira y la Declinación de Mamíferos Mayores en Asia Central     

The lichen-rich coastal heath vegetation on the isle of Anholt, Denmark — conservation and management

The high conservational value of the lichen-rich vegetation and landscape of the marine foreland Ørkenen on the isle of Anholt is treated from a Danish as well as a European perspective. The sensitivity of the lichen-rich vegetation to physical disturbance is emphasized. The impact of invasive species such asPinus mugo as well as the effect of atmospheric deposition of nutrients on the heaths at Anholt is described. Considerations related to the development of a management plan for Ørkenen are presented.     

Behavior and ecology of Old World Luperini beetles of the genusAulacophora (Coleoptera: Chrysomelidae)

Summary The attraction of Old World leaf beetles in the genusAulacophora to kairomones and parakairomones which are effective lures for New WorldDiabrotica andAcalymma were investigated. Beetles captured on sticky traps baited with single and multicomponent lures were no different from the control traps for two species ofAulacophora. Yellow colored traps and squash blossoms are attractive toAulacophora beetles which detect sub-microgram quantities of cucurbitacins on silica gel. Leaf feeding behavior and flight activity data are correlated with varietal preference of threeAulacophora species. The common response byDiabrotica andAulacophora to cucurbitacins reinforces the two groups' coevolutionary association with the Cucurbitaceae. The apparent lack of a common response toCucurbita blossom volatiles suggests recent evolutionary pathways are substantially different for these two groups of beetles.     

Use of stochastic patch occupancy models in the California red-legged frog for Bayesian inference regarding past events and future persistence

Assessing causes of population decline is critically important to management of threatened species. Stochastic patch occupancy models (SPOMs) are popular tools for examining spatial and temporal dynamics of populations when presence–absence data in multiple habitat patches are available. We developed a Bayesian Markov chain method that extends existing SPOMs by focusing on past environmental changes that may have altered occupancy patterns prior to the beginning of data collection. Using occupancy data from 3 creeks, we applied the method to assess 2 hypothesized causes of population decline—in situ die-off and residual impact of past source population loss—in the California red-legged frog. Despite having no data for the 20–30 years between the hypothetical event leading to population decline and the first data collected, we were able to discriminate among hypotheses, finding evidence that in situ die-off increased in 2 of the creeks. Although the creeks had comparable numbers of occupied segments, owing to different extinction–colonization dynamics, our model predicted an 8-fold difference in persistence probabilities of their populations to 2030. Adding a source population led to a greater predicted persistence probability than did decreasing the in situ die-off, emphasizing that reversing the deleterious impacts of a disturbance may not be the most efficient management strategy. We expect our method will be useful for studying dynamics and evaluating management strategies of many species.