Consideration of fuzziness: Is it necessary in modelling fish habitat preference of Japanese medaka (Oryzias latipes)?

The present study aims to clarify the necessity and effectiveness of considering fuzziness in modelling fish habitat preference, and the advantages which would be achieved by considering it. For this purpose, genetic algorithm (GA) optimized habitat preference models under three different levels of fuzzification were compared with regard to prediction ability of the habitat use of Japanese medaka (Oryzias latipes) dwelling in agricultural canals in Japan. Field surveys were conducted in agricultural canals in Japan to establish a relationship between fish habitat preference and physical environments of water depth, current velocity, lateral cover ratio and percent vegetation coverage. The habitat preference models employed for testing the fuzzy-based approach were category model, fuzzy habitat preference model, and fuzzy habitat preference model with fuzzy inputs. All the models were developed at 50 different initial conditions. The effectiveness of the fuzzification in fish habitat modelling was assessed by comparing mean square error and standard deviation of the models, and fluctuation in habitat preference curves evaluated by each model. As a result, the effect of fuzzification appeared as smoother curves and was found to reduce fluctuation in habitat preference curves in proportion to the level of fuzzification. The smooth curves would be appropriate for expressing uncertainty in habitat preference of the fish, by which fuzzy habitat preference model with fuzzy input achieve the best prediction ability among the models. In conclusion, the present study revealed that there are two advantages of fuzzification: reducing fluctuations in habitat preference evaluation and improving prediction ability of the model. Therefore, the consideration of fuzziness would be appropriate for representing fish habitat preference under natural conditions.     

Does interspecific competition influence relationships between heterozygosity and fitness-related behaviors in juvenile Atlantic salmon (<Emphasis Type="Italic">Salmo salar</Emphasis>)?

Very few studies have investigated the effect of genetic diversity on the behavioral and phenotypic traits linked to the competitive ability of individuals. In this study, we reared juvenile Atlantic salmon (Salmo salar) alone or with the competitive rainbow trout (Oncorhynchus mykiss) in order to: (1) to assess correlations between heterozygosity and traits related to individual competitive ability [i.e., heterozygosity–fitness correlations (HFCs)] in Atlantic salmon, and (2) to evaluate the effect of the competitive rainbow trout on any such HFCs. We also tested whether a few loci had a disproportionately large effect (i.e., the local effect hypothesis) or, on the contrary, if all loci contributed equally (i.e., the global effect hypothesis) in explaining the observed HFCs. We found significant HFCs for phenotypic traits related to the competitive ability of juvenile Atlantic salmon, i.e., the growth rate and the distance to the feeding source. Some HFCs were nonlinear, suggesting that individuals with intermediate levels of heterozygosity were favored. In addition, we found that the competition exerted by rainbow trout only weakly modified these HFCs as the relationships were highly consistent across treatments. We demonstrated that the local-effect hypothesis best explained both linear and nonlinear HFCs. Overall, our results illustrated the importance of genetic diversity in explaining the behavioral variability observed within populations. Moreover, we provide evidence that, even if a competitive species can have strong ecological effects, the relationships between genetic diversity and fitness-related traits in juvenile Atlantic salmon were not influenced by such effects.     

Efficacy of Land-Cover Models in Predicting Isolation of Marbled Salamander Populations in a Fragmented Landscape

Abstract:  Amphibians worldwide are facing rapid declines due to habitat loss and fragmentation, disease, and other causes. Where habitat alteration is implicated, there is a need for spatially explicit conservation plans. Models built with geographic information systems (GIS) are frequently used to inform such planning. We explored the potential for using GIS models of functional landscape connectivity as a reliable proxy for genetically derived measures of population isolation. We used genetic assignment tests to characterize isolation of marbled salamander populations and evaluated whether the relative amount of modified habitat around breeding ponds was a reliable indicator of population isolation. Using a resampling analysis, we determined whether certain land-cover variables consistently described population isolation. We randomly drew half the data for model building and tested the performance of the best models on the other half 100 times. Deciduous forest was consistently associated with lower levels of population isolation, whereas salamander populations in regions of agriculture and anthropogenic development were more isolated. Models that included these variables and pond size explained 65–70% of variation in genetically inferred isolation across sites. The resampling analysis confirmed that these habitat variables were consistently good predictors of isolation. Used judiciously, simple GIS models with key land-cover variables can be used to estimate population isolation if field sampling and genetic analysis are not possible.     

基于ANN分类的农田遥感动态监测模型研究

保护基本农田是我国农业可持续发展的基础和前提,动态监测基本农田在时间和空间上的变化能够为农业开发政策的制定,农业经济发展的规划与管理提供有效的辅助决策手段。论文利用人工神经网络的BP算法实现了对两个时期的遥感影像进行基本农田类型的分类提取,在保证精度的前提下,探索了一条把单要素监测和多要素监测相结合的遥感动态监测模型,并详细描述了模型实现的算法与步骤。最后利用该模型对实验区进行了监测,并对监测结果进行了分析,结果表明模型很好地评估了研究区基本农田的数量和发展潜力,定性、定量、定位地揭示了研究区基本农田类型在时空上的变化规律。     

Human dignity and the dignity of creatures

In their report for the Swiss government on the notion of the dignity of creatures, Philipp Balzer, Klaus-Peter Rippe, and Peter Schaber analyze the relationship between human dignity and the dignity of creatures, taking them as two categorically different concepts. Human dignity is defined as the “moral right not to be humiliated,” whereas the dignity of creatures is taken to be “the inherent value of non-human living beings.” To my mind there is no need to draw a categorical distinction between the two concepts. Both notions could be brought together under an all-encompassing concept of the inherent value of living beings, humans and non-humans alike, a concept one could name “the dignity of living beings.” Indeed, this very notion underlies the position taken in the report, although this is not made explicit by the authors themselves. As the aim of the paper is only to clarify the concepts used, I do not go beyond this “internal” critique of their position, i.e., I don’t assess how the claims articulated via these concepts — the claim that humans and/or creatures have an inherent value consisting in a supposed intrinsic good — are to be justified, although I myself would be rather skeptical that this might be successfully done.     

醛类化合物分子结构与对鼠急性毒性关系

通过检索美国国立职业与卫生研究所化学物质毒性效应登录 ( RTECS) 1998年版光盘系统 ,搜集了 88种醛类化合物对大鼠急性毒性口服 LD₅₀ 数据 ,并利用遗传神经网络建立了醛类化合物分子结构与对大鼠急性毒性关系的 BP神经网络模式 ,模式的交互检验相关系数达 0.83～ 0.87,具有较强的预报能力 .遗传神经网络是由遗传算法和神经网络耦合而成 ,文章详细讨论了遗传神经网络的构造以及利用遗传神经网络建立 QSAR模型的方法 .     

基于遗传算法的PLS分析在QSAR研究中的应用

将遗传算法和偏最小二乘法结合应用于定量结构活性关系研究中 ,进行变量选择和建立最终模型 .以较少的变量个数包含较多的变量信息 ,且变量间没有线性相关问题 ,因而得到较好的 QSAR模型 .将这种方法应用于氯代酚和单取代苯 2种系列化合物 ,可以得到几种常规多元回归分析方法不能得到的质量较高的 QSAR模型 .     

基于优化算法的弹药贮存寿命预测方法

目的 实现对缺失及不足的制导弹药贮存失效数据预测及补充的能力。方法 首先通过4种不同的预测算法（GA-BP、PSO-BP、GA-SVM、PSO-SVM）,对自然贮存条件下弹药贮存失效数据进行预测,其次根据最小二乘拟合法,实现弹药贮存寿命评估模型的构建,再通过寿命评估模型,计算出不同方法下对应的贮存寿命。结果 通过不同模型的构建,4种预测方法与无优化条件下均能实现弹药贮存失效数据的预测,并且在规定可靠度,GA-BP和PSO-BP预测精度比另外2种方法更低。结论 GA-SVM与PSO-SVM更适合弹药贮存失效数据的预测,且效果更好。     

地震灾害风险因素和风险评估指标的模糊算法

提出了影响地震灾害风险的主要因素 ,分析了地震震级、烈度、人口密度等因素与某些震害现象之间的相关性 ,以及建筑物的地震破坏程度与其它风险因素的关系。筛选出了地震灾害模糊风险分析指标———震损度DA(其用于风险评估的指标值为 (da) 0 )。给出了一种多变量信息分配算法的公式。在建立因果律模糊关系矩阵时 ,以归并、排序的方法解决了自变量在其样本空间组合后的重叠与错序问题 ,并简化了矩阵运算。在此基础上 ,建立了震损度指标值 (da) 0 的计算方法。     

氯代脂肪烃构效关系的遗传神经网络模式

通过检索美国国立职业与卫生研究所化学物质毒性效应登录（RTECS）1998年版光盘系统,搜集了65种氯代脂肪烃化合物对大鼠急性毒性口服LD₅₀数据,并利用遗传神经网络建立了氯代脂肪烃分子结构与对大鼠急性毒性关系的BP神经网络模式对预报集8种氯代脂肪烃测试结果表明,所建立的网络具有较好的实用性遗传神经网络是由遗传算法和神经网络耦合而成讨论了遗传神经网络的构造以及怎样利用遗传神经网络建立构效关系（QSAR）模式