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811.
812.
We tested if nesting habits influence ant feeding preferences and predatory behavior in the monophyletic genus Pseudomyrmex (Pseudomyrmecinae) which comprises terrestrial and arboreal species, and, among the latter, plant-ants which are obligate inhabitants of myrmecophytes (i.e., plants sheltering so-called plant-ants in hollow structures). A cafeteria experiment revealed that the diet of ground-nesting Pseudomyrmex consists mostly of prey and that of arboreal species consists mostly of sugary substances, whereas the plant-ants discarded all the food we provided. Workers forage solitarily, detecting prey from a distance thanks to their hypertrophied eyes. Approach is followed by antennal contact, seizure, and the manipulation of the prey to sting it under its thorax (next to the ventral nerve cord). Arboreal species were not more efficient at capturing prey than were ground-nesting species. A large worker size favors prey capture. Workers from ground- and arboreal-nesting species show several uncommon behavioral traits, each known in different ant genera from different subfamilies: leaping abilities, the use of surface tension strengths to transport liquids, short-range recruitment followed by conflicts between nestmates, the consumption of the prey’s hemolymph, and the retrieval of entire prey or pieces of prey after having cut it up. Yet, we never noted group ambushing. We also confirmed that Pseudomyrmex plant-ants live in a kind of food autarky as they feed only on rewards produced by their host myrmecophyte, or on honeydew produced by the hemipterans they attend and possibly on the fungi they cultivate.  相似文献   
813.
Biogas production from anaerobic digestion of chicken feathers with swine manure or slaughterhouse sludge was assessed in two separate experiments. Ground feathers without any pre-treatment were added to 42-L digesters inoculated with swine manure or slaughterhouse sludge, representing 37% and 23% of total solids, respectively and incubated at 25 °C in batch mode. Compared to the control without feather addition, total CH4 production increased by 130% (P < 0.001) and 110% (P = 0.09) in the swine manure and the slaughterhouse sludge digesters, respectively. Mixed liquor NH4N concentration increased (P < 0.001) from 4.8 and 3.1 g/L at the beginning of the digestion to 6.9 and 3.5 g/L at the end of digestion in the swine manure and the slaughterhouse sludge digesters, respectively. The fraction of proteolytic microorganisms increased (P < 0.001) during the digestion from 12.5% to 14.5% and 11.3% to 13.0% in the swine manure and the slaughterhouse sludge digesters with feather addition, respectively, but decreased in the controls. These results are reflective of feather digestion. Feather addition did not affect CH4 yields of the swine manure digesters (P = 0.082) and the slaughterhouse sludge digesters (P = 0.21), indicating that feathers can be digested together with swine manure or slaughterhouse sludge without negatively affecting the digestion of swine manure and slaughterhouse sludge.  相似文献   
814.
In the future, more electricity in the Netherlands will be produced using coal with co-combustion. Due to this, the generated annual ash volume will increase and the chemical composition will be influenced. One of the options for utilization if present markets are saturated and for use of fly ashes with different compositions, is as raw material for lightweight aggregates. This was selected as one of the best utilizations options regarding potential ash volume to be applied, environmental aspects and status of technology. Because of this, a study has been performed to assess the potential utilization of fly ash for the production of lightweight aggregate. Lightweight aggregate has been produced in a laboratory scale rotary kiln. The raw material consisted of class F fly ash with high free lime content. An addition of 8% clay was necessary to get green pellets with sufficient green strength. The basic properties of the produced lightweight aggregate and its behaviour in concrete have been investigated. The concrete has a good compressive strength and its leaching behaviour meets the most stringent requirements of Dutch environmental regulations. The carbon foot print of concrete will be negatively influenced if only the concrete itself is taken into account, but the reduction of the volume weight has advantages regarding design, transport emissions and isolation properties which may counteract this. In the Dutch situation the operational costs are higher than expected potential selling price for the LWA, which implies that the gate fee for the fly ash is negative.  相似文献   
815.
Pesticide contaminated wastewater resulting from leftover mixes, equipment cleaning, and container disposal are problems related to pesticide use. This study reports on the effectiveness of a soil‐based bioreactor (SBBR) to dissipate pesticides of differing concentrations and mixtures. In order to accomplish this study, soil columns were used to simulate the SBBR. A mixture of five herbicides and two insecticides from seven different chemical families (atrazine, dicamba, fluometuron, metolachlor, sulfentrazone, chlopyrifus, and λ‐cyhalothrin) were added to the SBBR‐simulated system as formulated products in three concentrations each: 0 part per million (control), 10 ppm, and 100 ppm. Additionally a 1,000 ppm treatment was added that included just the five herbicides to investigate how the system would respond to heavy loading. The system was run for 90 days with samples taken at day 4 (just prior to loading the columns), then at 30, 60, and 90 days. At low pesticide concentrations (10 and 100 ppm), there was significant dissipation (p < 0.05) of all pesticides in the columns except sulfentrazone. At 1,000 ppm, fluometuron, in addition to sulfentrazone, did not show significant dissipation. Overall, the system performed as expected and could be considered practical for use on farms or nurseries. ©2015 Wiley Periodicals, Inc.  相似文献   
816.
中国环境行政执法能力建设现状调查与问题分析   总被引:7,自引:0,他引:7  
环境行政执法能力建设正成为中国环境行政管理体制建设的一个重点.中国已建立起一个四级环境执法体系,最新成立的区域环境督查中心标志着中国环境行政执法体制建设又迈出了新的一步.对85个执法机构,162家企业就环境行政执法机构的人力投入、资金支持、技术保障、执法手段、执法产出、执法阻力、社会动员和企业激励8个方面进行了问卷和访谈形式的调查.从省、市、县三级执法角度全面分析了中国环境行政执法各方面存在的问题.研究认为,中国的环境行政执法总体而言已经建立起一个完备的框架,各地对环境执法日益重视,环境行政执法能力得到了提高;但是环境行政执法随着经济发展、公众环境意识的提高面临着越来越大的压力,承担的任务也更为繁重.为了应对挑战,环境法律、体制和各方面的投入以及执法理念都要进一步改进.  相似文献   
817.
美国洛杉矶空气管理经验分析   总被引:1,自引:0,他引:1  
过去35年间,洛杉矶的经济和人口持续增长、城市扩张,但是洛杉矶的空气污染水平得到了下降,在达到加利福利亚州和《清洁空气法》所规定的大气质量总体目标方面,有了长足的进步.期间起到重大作用的因素包括:①固定污染源和移动污染源气体污染物排放的控制技术和企业实践的巨大进步.②联邦、州和地区的清洁空气政策的发展.③强有力的专门负责清洁空气政策的监督和执行行政机构的设立.④公众压力.⑤从信任政府运用命令与控制手段到利用激励手段和市场手段完成许多政策目标(包括空气污染控制)的变革.同时,该地区的人口还在持续增长,经济继续繁荣扩张,意味着将产生更多的空气污染物,尤其是来自移动污染源的污染物.另外,在公众不太支持加强政府力量或增加税收的形势下,要求政策制定者解决空气污染的问题或大幅度改变洛杉矶居民的生活方式.  相似文献   
818.
819.
820.
This paper discusses the case of a pregnant woman with polychemotherapy during the second trimester of pregnancy for rhabdomyosarcoma of the face and cessation of fetal growth with disappearance of amniotic fluid after the first course of therapy.  相似文献   
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