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1.
利用图像处理方法对不同质量浓度的阿特拉津溶液(1mg/L、5mg/L、10mg/L、15me/L)中弹琴蛙(Rana ade-nopleura)蝌蚪行为进行了图像的识别及分析.根据实验结果,利用MATLAB语言编写了弹琴蛙蝌蚪在水族缸中具体分布型判定的程序,采用了负二项分布的参数κ值来反应不同溶液中蝌蚪聚集程度的差异,并作为该指示生物监测阿特拉津水体污染情况的一个指标.结果显示,该程序可如实反映不同污染水体中蝌蚪的聚集程度:经χ^2检验各种水体中蝌蚪均符合负二项分布,同时阿特拉津溶液中蝌蚪的κ值均小于空白对照和丙酮对照,表明阿特拉津溶液的浓度和蝌蚪的聚集程度相关.图9表1参14  相似文献   

2.
阿特拉津溶液对弹琴蛙(Rana adenopleura)蝌蚪形态发育的影响   总被引:3,自引:2,他引:3  
研究了弹琴蛙(Rana adenopleura)蝌蚪在不同阿特拉津浓度(p/mg L^-1:5,10,15,20)溶液中经不同时间处理(10d、20d)后的形态发育特征.结果表明:20d处理组蝌蚪的全长增长率和后肢长增长率低于空白对照组(CKH20),全长出现负增长,而丙酮对照组(CKacetone)蝌蚪的全长增长率高于CKH2o.实验证明,阿特拉津可抑制蝌蚪的生长和发育,而丙酮却促进蝌蚪的生长.各环境因素的多因素方差分析结果显示,pH和电导率与阿特拉津对蝌蚪的生长、发育作用效应相一致.图2表8参14  相似文献   

3.
研究了不同条件下阿特拉津溶液中 (ρ1~ 4/mgL-1:5 ,10 ,15 ,2 0 )弹琴蛙 (Ranaadenopleura)蝌蚪的行为 ,运用方差分析 (ANOVA)检验了蝌蚪在不同浓度的阿特拉津、时间段、pH值、溶氧量等条件下的行为差异性 .根据实验结果 ,确立了正常及异常行为模式 .结果表明 :在水温 (15 .0± 0 .5 )℃的条件下 ,弹琴蛙蝌蚪异常行为的出现主要与阿特拉津的浓度有关 ,同时与实验时间的长短也有一定的关系 ,而与 pH值、溶氧量关系不大 .实验组与对照组相比 ,蝌蚪出现异常行为的频次差异极显著 (P <0 .0 1) ;其中在实验组中 ,蝌蚪在 5mg/L的阿特拉津溶液中与 10mg/L、15mg/L、2 0mg/L中出现异常行为的频次差异极显著 (P <0 .0 1) ,而在 10mg/L、15mg/L、2 0mg/L阿特拉津溶液中出现异常行为的频次差异不显著 (P >0 .0 5 ) ,相关性分析表明 ,蝌蚪异常行为的出现与阿特拉津的浓度没有剂量反应关系 (r2 =0 .4 94 ) ;在对照组中 ,0 .5mL/L丙酮对照和空白对照中蝌蚪出现异常行为的频次差异不显著 (P >0 .0 5 ) .图 3表 2参 17  相似文献   

4.
阿特拉津对弹琴蛙(Rana adenopleura)蝌蚪微核和核异常的影响   总被引:2,自引:0,他引:2  
分别在d1、d3、d7、d14,观察空白对照(CK-)、水溶助剂0.1mL/L二甲基亚砜对照(CK )、阿特拉津0.01mg/L(ρ1)、0.1mg/L(ρ2)、1mg/L(ρ3)和10mg/L(ρ4)溶液中弹琴蛙(Ranaadenopleura)蝌蚪血红细胞微核和核异常细胞数.结果表明,d14时,ρ1、ρ2、ρ3和ρ4组蝌蚪的微核率分别是CK-的2.25、2.50、4.25、5.11倍(P<0.05),说明阿特拉津可引起蝌蚪血红细胞微核率升高;且与d1、d3、d7相比较,微核率随着时间的延长有升高的趋势.d14时,ρ2、ρ3和ρ4组蝌蚪的总核异常率(含微核率)分别是CK-的2.59、2.17、1.96倍(P<0.05),说明阿特拉津也可引起蝌蚪血红细胞总核异常率升高.图2表1参17  相似文献   

5.
阿特拉津对弹琴蛙(Rana adenopleura)蝌蚪微核   总被引:5,自引:0,他引:5  
分别在d1、d3、d7、d14,观察空白对照(CK-)、水溶助剂0.1mL/L二甲基亚砜对照(CK )、阿特拉津0.01mg/L(ρ1)、0.1mg/L(ρ2)、1mg/L(ρ3)和10mg/L(ρ4)溶液中弹琴蛙(Ranaadenopleura)蝌蚪血红细胞微核和核异常细胞数.结果表明,d14时,ρ1、ρ2、ρ3和ρ4组蝌蚪的微核率分别是CK-的2.25、2.50、4.25、5.11倍(P<0.05),说明阿特拉津可引起蝌蚪血红细胞微核率升高;且与d1、d3、d7相比较,微核率随着时间的延长有升高的趋势.d14时,ρ2、ρ3和ρ4组蝌蚪的总核异常率(含微核率)分别是CK-的2.59、2.17、1.96倍(P<0.05),说明阿特拉津也可引起蝌蚪血红细胞总核异常率升高.图2表1参17  相似文献   

6.
通过实验室蝌蚪微空间温度行为变化频次统计分析,发现10℃时的所有西藏齿突蟾(Scutiger boulengeri)蝌蚪、15℃时除低海拔种群外的所有西藏齿突蟾蝌蚪的聚集分布均符合负二项分布,也符合NeymanⅡ型分布,在5℃、0℃时,不同分组的西藏齿突蟾蝌蚪行为分布有差异.西藏齿突蟾蝌蚪在低温5℃、0℃时的行为分布方式改变可能是对低温冻害的一种适应性反应,由环境温度改变导致蝌蚪行为分布方式的改变可能是高海拔两栖类蝌蚪对分布区域水温改变规律长期形成的一种适应对策.图1表2参12  相似文献   

7.
除草剂西玛津对非洲爪蟾生存和性腺发育的影响   总被引:1,自引:1,他引:1  
为了研究三嗪类除草剂西玛津对两栖动物非洲爪蟾(Xenopus laevis)生存和性腺发育的毒性作用,并且与另一种三嗪类除草剂阿特拉津的毒性进行比较,将非洲爪蟾从46/47阶段开始暴露西玛津和阿特拉津到变态1个月后停止,再饲养2个月后将其解剖,取性腺做形态学和组织学观察.暴露期间,每天记录蝌蚪的生长发育情况和存活率.结果显示,在暴露的第1周内(蝌蚪处于46~50阶段),西玛津可导致蝌蚪死亡率明显升高,随后的时间内西玛津对非洲爪蟾的生存不再有明显影响,但却使发育阶段明显的不整齐.阿特拉津对非洲爪蟾的生存和发育则没有明显影响.西玛津和阿特拉津对非洲爪蟾性腺的总体形态和性别比没有明显影响,然而两种除草剂均在一定程度上导致了睾丸组织学的改变.西玛津可能与阿特拉津一样能够通过雌性化/去雄性化作用影响非洲爪蟾睾丸的发育.  相似文献   

8.
水体阿特拉津残留对千屈菜的毒性效应   总被引:4,自引:0,他引:4  
为向水体污染的植物修复技术提供依据,采用营养液水培法研究5个阿特拉津浓度(1、2、4、8和16 mg L-1)下千屈菜鲜重增量、叶片相对含水量(RWC)、丙二醛(MDA)含量、过氧化物酶(POD)活性、根系活力和叶绿素含量等的变化差异.结果表明,阿特拉津胁迫下,千屈菜在实验浓度范围内均可存活和生长;但鲜重增量、RWC、叶绿素含量均有不同程度的下降,根系活力和POD活性降低,同时MDA含量上升,膜脂过氧化程度加剧.阿特拉津浓度越高,其对千屈菜的毒性越高.1 mg L-1处理下,除POD活性外植物其他生长和生理指标均与空白对照无显著差异;但16 mgL-1处理下,鲜重增量、MDA含量和POD活性则显著低于正常水平.由于阿特拉津的降解,这种不良影响随处理时间的延长而减弱.千屈菜对低浓度阿特拉津(≤1 mg L-1)具有较高耐受性.  相似文献   

9.
通过将Cu改性悬浮型光催化氧化过程与纳滤分离膜技术进行耦合构成悬浮型光催化纳滤膜反应器联合处理阿特拉津(Atrazine)溶液.在Atrazine初始浓度ρ0分别为5,15和25mg·l-1,光催化剂浓度ρTiO2为1500mg·l-1,废水pH值为5.5,UV强度为45mW·cm-2,膜分离压力和错流流速分别控制在1250kPa和3m·s-1,反应温度20±1℃的最佳实验条件下,35min之内目标污染物基本被彻底光催化降解,矿化率达到90%以上,出现显著耦合效应;当目标污染物浓度分别为5mg·l-1,15mg·l-1和25mg·l-1时,在ρ/ρ0≥0.6的范围内,光催化降解过程分别遵循一级、零级和一级的混合以及零级反应动力学模型.  相似文献   

10.
采用静态水质接触染毒法将鲫鱼(Carassius auratus)分别暴露于质量浓度为0、0.1、0.5、1.0、5.0和10.0 mg·L-1的阿特拉津溶液中,分别在染毒后的第3、6、10、14、19和24 d对所有染毒组鲫鱼进行尾静脉采血;研究在不同作用时间和不同质量浓度下,阿特拉津对鲫鱼外周血红细胞微核和总核异常的影响.结果表明:阿特拉津能使鲫鱼外周血红细胞微核率和总核异常率显著升高,并在一定条件下存在剂量-效应和时间-效应关系.短时间(≤6 d)暴露时,阿特拉津与外周血红细胞微核率之间在0~10.0 mg·L-1范围内存在剂量-效应关系;长时间(≥10 d)暴露时,仅在0.1~5.0 mg·L-1范围内存在剂量-效应关系.而阿特拉津与外周血红细胞总核异常率之间则在所有测定时间下均存在剂量-效应关系.同时,时间-效应的研究结果表明,在所有质量浓度下,鲫鱼外周血红细胞微核率和总核异常率均随着污染胁迫时间的延长而先升高后降低,且外周血红细胞微核率和总核异常率达到峰值所需时间表现为低质量浓度的滞后于高质量浓度的.试验显示,除草剂阿特拉津对鲫鱼具有潜在的致突变作用,其能对鲫鱼产生较强的遗传损伤,且遗传损伤程度随阿特拉津质量浓度的增加或污染胁迫时间的延长而增强.  相似文献   

11.
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  相似文献   

12.
Protected areas (PAs) are often implemented without consideration of already existing PAs, which is likely to cause an overrepresentation of certain biophysical conditions. We assessed the representativeness of the current PA network with regard to the world's biophysical conditions to highlight which conditions are underprotected and where these conditions are located. We overlaid terrestrial and marine PAs with information on biophysical conditions (e.g., temperature, precipitation, and elevation) and then quantified the percentage of area covered by the PA network. For 1 variable at a time in the terrestrial realm, high temperature, low precipitation, and medium and very high elevation were underrepresented. For the marine realm, low and medium sea surface temperature (SST), medium and high sea surface salinity (SSS), and the deep sea were underrepresented. Overall, protection was evenly distributed for elevation across the terrestrial realm and SST across the marine realm. For 2 variables at a time, cold and very dry terrestrial environments had mostly low protection, which was also the case for low SST and low and medium SSS across most depths for marine environments. Low protection occurred mostly in the Sahara and the Arabian Peninsula for the terrestrial realm and along the Tropic of Capricorn and toward the poles for the marine realm. Although biodiversity measures are of prime importance for the design of PA networks, highlighting biophysical gaps in current PAs adds a frequently overlooked perspective. These gaps may weaken the potential of PAs to conserve biodiversity. Thus, our results may provide useful insights for researchers, practitioners, and policy makers to establish a more comprehensive global PA network.  相似文献   

13.
Summary The adaptation of defensive secretions to their target organisms was examined for the abdominal gland secretions ofBledius furcatus, B. spectabilis andB. arenarius. Therefore the target organisms of the secretion of theseBledius species (i.e. their predators) had to be identified. At the collection sites examined these were the earwigLabidura riparia, the antCataglyphis bicolor, the flyLispe candicans, different carabids of the generaPogonus, Dichirotrichus, Dyschirius, Bembidion andCalathus and the wading birdsHaematopus ostralegus andCalidris alba. The secretion of the abdominal glands contains the toxin ptoluquinone dissolved in either-dodecalactone and 1-undecene (B. furcatus andB. spectabilis) or in octanoic acid and octyloctanoate (B. arenarius). The ratio of these solvents is species-specific. Application experiments using some of the natural insect predators (L. riparia, C. bicolor, Pogonus, Di. gustavii, Dyschirius) revealed that these solvent ratios provided a more effective deterrent than other possible ratios. Thus by combining the solvents in certain ratios, the capability of cuticular penetration and therefore the effectiveness of the defensive secretions are adapted to their natural targets.  相似文献   

14.
The politics of development includes subtexts of choice, as underpinned by community consensus (or lack of it), against the larger backdrop of a liberal democracy, with its intricate power structures that influence the choice of concepts and often lead to complicity rather than consent. A dilemma exists between the understanding of field-level practitioners and that of academics, whose understandings of progress differ. Progress can (and often does) imply long-term change across generations whereas development is often more a matter of crisis management and delivering tangible results to end-users. This makes it a bone of contention across political systems, irrespective of local or global dynamics. Development can emerge as a tool to be wielded for power and further political mileage at the expense of progress. Progress cannot be studied as a counterpoint to development as the sense of history is often missing in development interventions. Development tends to be piecemeal as its very logic often stems from the rationale of power. This is not to suggest, however, that development is only about politics; it is definitely more than the politics of everyday life and involves all of civil society that requires its critical and immediate attention. In this sense, it has become a priority for politicians with an underlying agenda designed to out-manouevre dissent and all statements of protest.  相似文献   

15.
As landscapes continue to fall under human influence through habitat loss and fragmentation, fencing is increasingly being used to mitigate anthropogenic threats and enhance the commercial value of wildlife. Subsequent intensification of management potentially erodes wildness by disembodying populations from landscape-level processes, thereby disconnecting species from natural selection. Tools are needed to measure the degree to which populations of large vertebrate species in formally protected and privately owned wildlife areas are self-sustaining and free to adapt. We devised a framework to measure such wildness based on 6 attributes relating to the evolutionary and ecological dynamics of vertebrates (space, disease and parasite resistance, exposure to predation, exposure to limitations and fluctuations of food and water supply, and reproduction). For each attribute, we set empirical, species-specific thresholds between 5 wildness states based on quantifiable management interventions. We analysed data from 205 private wildlife properties with management objectives spanning ecotourism to consumptive utilization to test the framework on 6 herbivore species representing a range of conservation statuses and commercial values. Wildness scores among species differed significantly, and the proportion of populations identified as wild ranged from 12% to 84%, which indicates the tool detected site-scale differences both among populations of different species and populations of the same species under different management regimes. By quantifying wildness, this framework provides practitioners with standardized measurement units that link biodiversity with the sustainable use of wildlife. Applications include informing species management plans at local scales; standardizing the inclusion of managed populations in red-list assessments; and providing a platform for certification and regulation of wildlife-based economies. Applying this framework may help embed wildness as a normative value in policy and mitigate the shifting baseline of what it means to truly conserve a species.  相似文献   

16.
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.  相似文献   

17.
Abstract: In the United States, as elsewhere, a growing debate pits national energy policy and homeland security against biological conservation. In rural communities the extraction of fossil fuels is often encouraged because of the employment opportunities it offers, although the concomitant itinerant workforce is often associated with increased wildlife poaching. We explored possible positive and negative factors associated with energy extraction in the Greater Yellowstone Ecosystem (GYE), an area known for its national parks, intact biological diversity, and some of the New World's longest terrestrial migrations. Specifically, we asked whether counties with different economies—recreation (ski), agrarian (ranching or farming), and energy extractive (petroleum)—differed in healthcare (gauged by the abundance of hospital beds) and in the frequency of sexual predators. The absolute and relative frequency of registered sex offenders grew approximately two to three times faster in areas reliant on energy extraction. Healthcare among counties did not differ. The strong conflation of community dishevel, as reflected by in‐migrant sexual predators, and ecological decay in Greater Yellowstone is consistent with patterns seen in similar systems from Ecuador to northern Canada, where social and environmental disarray exist around energy boomtowns. In our case, that groups (albeit with different aims) mobilized campaigns to help maintain the quality of rural livelihoods by protecting open space is a positive sign that conservation can matter, especially in the face of rampant and poorly executed energy extraction projects. Our findings further suggest that the public and industry need stronger regulatory action to instill greater vigilance when and where social factors and land conversion impact biological systems.  相似文献   

18.
Summary Acanthoscelides obtectus (Say) is one of the most damaging pests of kidney beans,Phaseolus vulgaris L. worldwide. However, aromatic plants from the families Lamiaceae, Lauraceae, Myrtaceae and Poaceae can protect kidney beans by direct or delayed insecticidal effect, through increased adult mortality and inhibition of beetle reproduction (both oviposition and adult emergence). The efficiency of hydrodistillated and intact plants fromThymus vulgaris andT. serpyllum, Mentha piperata, Rosmarinus officinalis, Satureia hortensis, Eucalyptus globulus, Laurus nobilis, Origanum vulgare, andCymbopogon nardus was compared. For both extracts,Origanum vulgare had the best effect. The insecticidal effect was induced by more than the essential oils because no significant difference was noticed between distilled and intact plants extract. Inhibition of reproduction was particularly important. These results suggest that lipidic as well as non lipidic, allelochemicals, such as phenolics, or non-protein amino-acids, or flavonoids may be involved in the toxicity of aromatic plants to this beetle.  相似文献   

19.
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.  相似文献   

20.
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.  相似文献   

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