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首頁> 外文學位 >Integration of quantitative structure-activity relationships and ecological survivorship modeling to predict chronic toxicity to fish and amphibians.
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Integration of quantitative structure-activity relationships and ecological survivorship modeling to predict chronic toxicity to fish and amphibians.

機譯：整合定量構(gòu)效關(guān)系和生態(tài)生存模型，以預(yù)測對魚類和兩棲動物的慢性毒性。

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Species diversity is crucial to the perpetuation of functional ecosystems. Consequently, reductions in biodiversity threaten the long-term preservation of viable ecosystems, as well as their contributions to humanity. Significant species biodiversity loss during the last century has been attributed to chemical pollution. Environmental regulations intended to protect natural biota are based almost exclusively on toxicity tests performed on a few selected species. Data exist for only a small fraction of the 15,000 pollutants considered environmentally relevant. Regulatory strategies neglect effects of chemical stresses at population or ecosystem levels. This study involves three phases: (1) realization of a quantitative structure-activity relationship (QSAR) model for calculating chronic toxicological effects of pollutants on individual species, (2) a predictive model to estimate effects of such stress at the population level and (3) a means of coupling toxicological and population responses to give integrated predictors of survivorship for specific scenarios of chemical insult.; QSAR models were developed for predicting median and threshold toxicity values for embryolarval stages of fish and amphibians from standardized embryolarval toxicity test data. Descriptors included molecular weight, octanol/water partition coefficients, and molecular connectivity indices (MCIs). Within classes, QSAR models gave reliable estimates of toxicity. MCIs were more discriminating than other descriptors within and across chemical classes. These QSAR models will be useful in estimating chronic values (i.e., CV) for an increasing spectrum of organic pollutants and in applying QSAR to a greater number of species.; The influence of a population's life-history strategy on responses to chronic stress appears fundamental for biodiversity protection. The life-history strategies of aquatic vertebrates were modeled using projection matrices based upon generic fish life-history strategies to investigate how different strategies respond to toxic stressors. The influence of individual parameters conferring population sensitivity was estimated, weighted and used to compile a survivorship index (SI) for regulatory applications. SI metrics included lifespan, number of spawning events, life stages, parental care, and other factors and may help identify species exhibiting inherently sensitive life-history strategies. The toxicological-ecological approach was proposed as a tool for integrating toxicological findings and survivorship determinations to develop regulatory criteria (i.e. CV x SI) for protecting biodiversity.
機譯：物種多樣性對于功能生態(tài)系統(tǒng)的永續(xù)性至關(guān)重要。因此，生物多樣性的減少威脅到生存的生態(tài)系統(tǒng)的長期保存及其對人類的貢獻。上個世紀，物種生物多樣性的重大損失歸因于化學污染。旨在保護天然生物區(qū)系的環(huán)境法規(guī)幾乎完全基于對某些選定物種進行的毒性測試。在與環(huán)境相關(guān)的15,000種污染物中，只??有很小一部分存在數(shù)據(jù)。監(jiān)管策略忽略了人口或生態(tài)系統(tǒng)水平上化學脅迫的影響。這項研究包括三個階段：（1）實現(xiàn)定量構(gòu)效關(guān)系（QSAR）模型以計算污染物對單個物種的慢性毒理學影響;（2）預(yù)測模型以估計此類壓力在種群水平上的影響，以及（ 3）一種將毒理學和人群反應(yīng)耦合在一起的方法，以針對特定的化學侮辱場景提供綜合的生存預(yù)測因子;開發(fā)了QSAR模型，用于根據(jù)標準化的胚胎幼蟲毒性測試數(shù)據(jù)預(yù)測魚和兩棲動物的幼蟲階段的中值和閾值毒性值。描述符包括分子量，辛醇/水分配系數(shù)和分子連接指數(shù)（MCI）。在類別中，QSAR模型給出了可靠的毒性估計。與化學類別內(nèi)和化學類別內(nèi)的其他描述符相比，MCI更具區(qū)分性。這些QSAR模型將有助于估算隨著有機污染物光譜增加而產(chǎn)生的慢性值（ i.e 。，CV），以及將QSAR應(yīng)用于更多種類的物種。人口生活史策略對慢性應(yīng)激反應(yīng)的影響看來是保護生物多樣性的基礎(chǔ)?；谝话泗~類生命歷史策略，使用投影矩陣對水生脊椎動物的生命歷史策略進行建模，以研究不同策略對毒性應(yīng)激源的反應(yīng)。估計，加權(quán)個體參數(shù)對群體敏感性的影響，并將其用于編制生存指標（SI）以用于監(jiān)管應(yīng)用。 SI指標包括壽命，產(chǎn)卵事件數(shù)，生命階段，父母關(guān)懷和其他因素，可能有助于識別表現(xiàn)出內(nèi)在敏感的生命史策略的物種。提出了毒理學-生態(tài)學方法，作為整合毒理學發(fā)現(xiàn)和幸存者決定以制定保護生物多樣性的監(jiān)管標準（即。CV x SI）的工具。

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