Why are larvae of the social parasite wasp <Emphasis Type="Italic">Polistes sulcifer</Emphasis> not removed from the host nest?

A challenge for parasites is how to evade the sophisticated detection and rejection abilities of potential hosts. Many studies have shown how insect social parasites overcome host recognition systems and successfully enter host colonies. However, once a social parasite has successfully usurped an alien nest, its brood still face the challenge of avoiding host recognition. How immature stages of parasites fool the hosts has been little studied in social insects, though this has been deeply investigated in birds. We look at how larvae of the paper wasp obligate social parasite Polistes sulcifer fool their hosts. We focus on cuticular hydrocarbons (CHCs), which are keys for adult recognition, and use behavioral recognition assays. Parasite larvae might camouflage themselves either by underproducing CHCs (odorless hypothesis) or by acquiring a chemical profile that matches that of their hosts. GC/MS analyses show that parasite larvae do not have lower levels of CHCs and that their CHCs profile is similar to the host larval profile but shows a reduced colony specificity. Behavioral tests show that the hosts discriminate against alien conspecific larvae from different colonies but are more tolerant towards parasite larvae. Our results demonstrate that parasite larvae have evolved a host larval profile, which overcomes the host colony recognition system probably because of the lower proportion of branched compounds compared to host larvae. In some ways, this is a similar hypothesis to the odorless hypothesis, but it assumes that the parasite larvae are covered by a chemical blend that is not meaningful to the host.     

First-Person Effects of Emotional and Informational Messages in Strategic Environmental Communications Campaigns

This study examined the first- and third-person effects of emotional and informational messages, particularly relating to the critical issue areas of energy, the environment, and global warming. Due to intense political polarization on such issues, it also explored the role of political party identification. The results of an experiment indicated that informational messages about the environment produced third-person effects, while environmental advertisements meant to evoke emotion caused first-person effects. Moreover, emotional environmental advertisements appealed more to Republicans and those who did not support a political party. As such, indirect, emotional messages appear to represent an opportunity for strategic environmental communicators to design campaigns that resonate with potentially unreceptive audiences.     

城市居民低碳购买行为模型研究——基于五个城市的调研数据

随着全球气候的变暖,低碳生活、低碳消费成为人们关注的热点。本文通过构建模型,从消费者的个人层面和文化层面研究了中国城市居民低碳购买行为的影响因素,结果表明,城市居民的个人因素(低碳认知、低碳情感)和文化因素(集体主义、天人合一)以低碳购买态度为中介,进而正向影响其低碳购买意向,但它们的影响程度存在差异,个人因素对低碳购买态度的影响要大于文化因素,在个人因素中,低碳情感的影响要大于低碳认知,在文化因素中,天人合一的影响要略高于集体主义;而在低碳购买态度到购买意向之间会受到居民对低碳产品信任程度的调节作用。     

经验正交函数方法和TRMM数据对长江流域降水模式与极端水文过程的研究

气候变化加剧了极端天气和水文事件的发生,降水是区域干旱与洪水事件最直接驱动因素。以TRMM/PR月累积降水反演遥感数据为基础,利用经验正交函数EOF（Empirical Orthogonal Function）方法对长江流域降水时空变化模式进行提取,并对比分析了主要模式振幅强弱与极端水文事件的对应关系。结果表明在流域尺度上EOF方法及TRMM/PR数据可以较好地识别降水主要模式,通过时空尺度变换成功揭示主要降水模式强弱与流域极端水文事件的对应关系。鉴于日益丰富的巨量水文气象时空数据,EOF方法在模式提取、水文模拟、极端事件预估及灾害适应性研究等方面具有应用潜力     

Pattern recognition and classification of sediments according to their metal content using chemometric tools. A case study: the estuary of Nerbioi-Ibaizabal River (Bilbao, Basque Country)

Chemometrics are increasingly used in environmental monitoring studies, but are still far from being accepted as routine tools by field specialists. The multivariate character of usually highly correlated environmental data recommends the use of advanced chemometrics as part of the analytical methodology in order to get information on the basic structure of data. In this work, we have applied a battery of non-supervised (Principal Component Analysis (PCA)) and supervised (k-Nearest Neighbour (k-NN), Soft Independent Modelling of Class Analogies (SIMCA), Linear Discriminant Analysis (LDA) and Artificial Neural Networks (ANNs)) multivariate techniques on a specific environmental dataset. The dataset consists on the concentration of 14 elements (Al, As, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Sn, V and Zn) in 95 sediments collected at eight different locations of the estuary of the Nerbioi-Ibaizabal River (Bilbao, Basque Country) during 12 sampling campaigns conducted every 3 months between 2005 and 2008. The study aims to present a simple methodology of general applicability which may result in a flexible and practical tool to assess chemical pollution in sediments of a given specific site.     

基于IIAHP-Entropy-ssd的采空区遗煤自燃危险性评价模型及应用

为了能够对煤矿采空区遗煤自燃危险性进行准确判定,提出基于IIAHP-Entropy-ssd最优综合赋权模糊评价模型。首先,结合影响采空区遗煤的自燃性及环境影响因素,建立危险性评价指标体系,并确定各评价指标的分级准则;其次,利用区间数代替数值评价打分,并运用可能度互补矩阵进行修正的改进区间数层次分析法（IIAHP）,结合熵权法（Entropy）,根据现场实测数据,得出各评价指标的主、客观权重,并运用离差平方和（ssd）的最大化思想进行最优综合赋权,克服评价过程中主、客观因素对评价结果的影响,运用属性数学理论,建立各评价指标的隶属函数;最后,运用该模型对忻州窑矿8914综放工作面采空区遗煤自燃危险性进行评价,并与现场实际情况进行对比,结果表明:该模型的评价结果与实际情况基本一致,验证了该评价模型的准确性,为采空区遗煤自燃危险性评价提供参考和借鉴思路。     

基于深度学习的复杂作业场景下安全帽识别研究

为有效预防由于个人防护缺失所造成的事故,着力探究复杂作业情况下施工人员安全帽佩戴情况的智能化识别.提出在Faster R-CNN目标检测算法的基础上,针对小目标的安全帽识别问题通过增加锚点提升检测能力,为解决数据集中类别不平衡问题采用Focal loss替代原本的损失函数,为解决安全帽预测区域不匹配问题,引入ROI A...     

基于熵权的属性识别模型在湖泊水质富营养化评价中的应用

针对模糊评价中对多因子赋权时因计算繁琐,工作量大,未考虑多个评价对象间联系等缺陷,提出利用熵权法对多评价因子赋权的新思路,建立了基于熵权的属性识别模型,并用此模型对福州市山仔水库的水质进行评价,比较了利用熵权法与传统的评价因子赋权的差异。此模型为湖泊水质的富营养化评价提供一种简便实用的评价方法。     

洪泽湖水域的环境演变遥感分析

针对传统水质监测的定点、定剖面采样分析时间及空间的局限性,为对湖泊水质进行全面系统的分析,在前人研究工作的基础上,建立了一种水域水质状况图像识别的主成分监督分类方法,通过对洪泽湖湖区的1991年12月15日和2000年1月7日,两个时相TM遥感图像数据,分别进行主成分变换,并依据不同类型水体的光学特性,分析各主成分图像的构成及其环境意义。研究表明：洪泽湖湖区的水质分布,具有从西向东,从北向南由清洁水（优）向一般水依次递减、逐年下降的特征。其清洁水体主要分布于洪泽湖西部的溧河洼、临淮头、西北部的安河洼和成子湖的北部。从1991--2000年,洪泽湖入湖的工业废水及生活污水量有所减少,湖水受污染程度明显减轻,相对“八五”期间水质污染日益加重的现象,“九五”以后水质逐渐改善。将其分类结果与所收集的洪泽湖历年水质资料对比分析表明：主成分监督分类结果与环境要素吻合较好,且基本反映了其水质环境的变化趋势。     

基于模糊综合识别技术的粉尘危害评价应用研究

针对目前粉尘危害评价存在的不足,采用最优权法确定各评价指标的权系数,利用模糊识别技术对粉尘危害程度进行综合评价,初步建立了粉尘危害评价指标体系和评价分级标准.结合某矿山实例,对粉尘危害进行模糊综合评价.评价结果表明,模糊综合识别技术能够较好反应实际情况,是一种有效的评价方法,对粉尘防治工作具有一定的指导意义.