Determination of estrogenic activity in landfill leachate by simplified yeast two-hybrid assay

We previously developed a simplified yeast two-hybrid assay of estrogenic activity. In the present study, the optimal conditions for sensitivity and stability of this assay were decided. The assay could determine the estrogenic activity of 4 x 10(-11) mol dm(-1) 17beta-estradiol and also anti-estrogenic activity by using 4-hydroxytamoxifen as a control. The assay was used to test various chemicals suspected of estrogenicity. Many kinds of chemical, including alkylphenols, naphthols, xylenols, methoxychlor, phthalates, and bisphenol-A, showed estrogenic activity, and several, such as 2,5-xylenol and di-iso-octyl phthalate, showed anti-estrogenic but no estrogenic activity. Copresence of two estrogenic chemicals produced additive activity. The assay was also used to test leachate and water samples from the sea-based landfill of Osaka North Port in Japan. Estrogenic activity was detected in leachate from a municipal waste-dumping site, but not in that from a dredged soil-dumping site, which did however cause inhibition of cell growth.     

Model prediction on the rise of pCO2 in uniform flows by leakage of CO2 purposefully stored under the seabed

A numerical study was conducted to predict pCO₂ change in the ocean on a continental shelf by the leakage of CO₂, which is originally stored in the aquifer under the seabed, in the case that a large fault connects the CO₂ reservoir and the seabed by an earthquake or other diastrophism. The leakage rate was set to be 6.025 × 10⁻⁴ kg/m²/sec from 2 m × 100 m fault band, which corresponds to 3800 t-CO₂/year, referring to the monitored seepage rate from an existing EOR field. The target space in this study was limited to the ocean above the seabed, the depth of which was 200 or 500 m. The computational domain was idealistically rectangular with the seabed fault-band perpendicular to the uniform flow. The CO₂ takes a form of bubbles or droplets, depending on the depth of water, and their behaviour and dissolution were numerically simulated during their rise in seawater flow. The advection–diffusion of dissolved CO₂ was also simulated. As a result, it was suggested that the leaked CO₂ droplets/bubbles all dissolve in the seawater before spouting up to the atmosphere, and that the increase in pCO₂ in the seawater was smaller than 500 μ atm.     

Simultaneous treatment of PVC and oyster-shell wastes by mechanochemical means

This work presents a new process for dechlorinating poly-vinyl chloride (PVC) by the use of oyster-shell waste. The process consists of milling of PVC waste with oyster-shell waste, followed by washing the milled sample with water. The milling of PVC and oyster-shell mixture results in size reduction and rupture in bonds, leading to mechanically induced reactions between the two to form CaCl2 and hydrocarbon with C=C bonds. Washing the milled mixtures with water at room temperature allows complete removal of chlorine from the milled sample. More than 95% of chlorine in PVC was removed when 2h grinding is conducted for the mixture. The present process could offer a potential route to the handling and disposal of oyster-shell and PVC wastes.     

Evolutionary ecology of settlement size in planktotrophic neritimorph gastropods

Body size during larval development is one of the most important attributes of aquatic animals. The optimal size for changing form or habitat may vary according to ecological traits of species, while phylogenetic constraints also play a significant role. The major goal of this study is to reveal the patterns in the settlement size of planktotrophic larvae in an archaic gastropod superorder Neritimorpha. We take advantage of the fact that size at various ontogenetic stages of neritimorphs can be rigorously estimated by measuring features of the adult opercula. This unique feature of neritimorphs has allowed us to generate the largest data set so far on larval settlement sizes within a group of marine invertebrates that recruit into very different post-metamorphic habitats. Eighty-eight species that represent most extant genera from rocky shores, seagrass beds, mangroves, estuaries, streams, submarine caves, deep-sea vents or seeps showed negligible intraspecific variation and considerable interspecific differences in settlement size, particularly between genera or families. Settlement size is determined primarily by phylogenetic constraints, while parallel evolution toward smaller sizes was shown to occur exclusively in four independent clades (two living and two extinct) of amphidromous snails with a marine larval period followed by a limnic adult phase. The smaller settlement size may possibly reduce the risk of being wafted away from the estuaries of their natal streams through less time achieving metamorphic competence, while ability to make occasional long-distance trips is retained by the presence of a sufficiently long delay period. This delay period also seems to obscure the possible correlation between settlement size and geographic distribution range of neritimorph species, both fully marine and amphidromous.     

基于RS/GIS的四湖地区湖泊水域百年变迁研究

四湖地区是长江中游江汉平原的重要湖泊分布区,在历史时期湖泊分布广阔,是著名的云梦泽的主体。由于江湖关系演变和人类活动的影响,湖泊面积变化迅速,尤以20世纪为甚。在野外调查和历史文献分析的基础上,利用不同时期的水利图、地形图、遥感影像图作为基本信息源,在GIS技术支持下,提取湖泊面积信息,对四湖地区近百年湖泊水域变化进行了研究。结果显示,从20世纪20年代开始湖泊面积和个数呈先增加后减少的趋势,50年代处于鼎盛时期,50年代初期到70年代初期迅速减少,70年代至2000年减幅明显减缓。这种动态变化是自然因素和人类活动综合作用的结果,人类活动的作用更为突出。针对湖泊水域日益减少的现状,应加强对湖泊资源的保护力度,并在此基础上进行合理开发和利用。     

Development of a novel hybrid microwave-heater reactor for paper-based waste treatment

It is necessary to develop a medical waste management system featuring nonburning treatment and safety functions for small medical institutions. In this article, the development of a waste management system without oxygen injection was achieved by means of hybrid heating using microwave energy and an electric heater. The shape of the microwave reactor was a rectangular parallelepiped with a volume of about 0.1 m³. In the experimental setup, microwave energy (2.45 GHz, about 800 W) was injected from the top of the reactor, while the heater (about 1 kW) was located at the bottom. Heat insulators were set into all the walls of the reactor. The gases generated in the system were vented through water and activated carbon. Five paper-based diapers with absorbed water were used as the waste sample. For the evaluation of performance, the reduction rate was defined as the ratio (in percent) of the weight before and after treatment. The reduction rate as a function of treatment time and the effect of the position of the waste in the reactor on the reduction rate and the uniformity of treatment were examined for about 3 kg of waste. It was found that the reduction rate reached as low as 4.2% at 3 h and then 3% after 8 h. The treated profile strongly depended on the position of the waste in the reactor. In particular, it was clarified that a metal cylindrical enclosure and a needle electrode played an important role in attaining uniform treatment of the waste.     

Estrogenic chemicals and estrogenic activity in leachate from municipal waste landfill determined by yeast two-hybrid assay

Estrogenic activity and estrogenic chemicals in landfill leachate were investigated by yeast two-hybrid assay and chemical analysis. Leachate sample extracted by liquid-liquid extraction with dichloromethane at pH 7.0 showed a higher dose-response curve than sample extracted at pH 3.0. or than sample extracted by solid phase extraction at either pH 7.0 or 3.0. The fraction extracted at pH 3.0 specifically inhibited not only growth of yeast but also estrogenic activity in this assay, suggesting that it contained anti-estrogenic chemicals. The greatest contributor to estrogenic activity among the chemicals identified in leachate extract was bisphenol A, with an estimated contribution ratio of 84%. The contribution ratios of 4-nonyl phenol (4-np) and 4-tert-octyl phenol (4-t-op) were estimated at 1.0%, and 0.1%, respectively, while natural estrogens such as 17beta-estradiol or estrone were below detection limit, so that their contribution ratio was estimated at no more than 10%. The estrogenic activity of leachate was decreased by aeration treatment alone after 7 days, and was no longer detected after 22 days. Concentrations of bisphenol A, 4-np and 4-t-op likewise decreased with aeration.     

Relation between mechanochemical dechlorination rate of polyvinyl chloride and mill power consumption

A sample of polyvinyl chloride (PVC) powder was milled with CaO powder in a planetary mill for various mill operational parameters. The milled product consisted of dechlorinated hydrocarbon and water-soluble CaOHCl. The dechlorination rate of PVC was determined by the concentration of Cl⁻ ions measured in solution after dispersing the milled product in water. To evaluate the power consumption during PVC dechlorination, the mill power consumption was measured during each experimental run. In addition, media motion during planetary milling was simulated using the discrete element method (DEM), enabling calculation of the mill power consumption. The power consumption calculated by the DEM simulation compared well with the power consumption measured experimentally. The dechlorination rate correlated well with the specific mill power consumption, regardless of the sample weight. The dechlorination rate of PVC when milled with oyster shells (CaCO₃) was observed to be faster than that of the PVC/CaO system, and oyster shells could be used as a reactant for the treatment of PVC wastes. This work should be useful for the design of a reactor for the dechlorination of PVC. Chemical Feedstock Recycling & Other Innovative Recycling Techniques 6     

Evaluation of mixture effects in a crude extract of compost using the CALUX bioassay and HPLC fractionation

Potential synergistic interactions between polycyclic aromatic hydrocarbons in a household sewage sludge compost extract were investigated using the Dioxin-Responsive Chemical-Activated Luciferase gene eXpression (DR-CALUX) assay and reverse-phase high-performance liquid chromatography (RP-HPLC) fractionation. The biological activity of the crude extract was measured in vitro using the CALUX assay. The CALUX activity of the extract was as potent as 360-pg CALUX-TEQ (2,3,7,8-TCDD equivalent value) per g sample, this was 70 times above the WHO-TEQ value which was derived from chemical analyses of dioxins/furans and dioxin-like PCBs of the mixture. The CALUX activity pattern of the crude extract and the retention times of 26 polycyclic aromatic compounds (PACs), as determined by RP-HPLC on an octadecylsilica column, suggested that the dioxin-like compounds with the log K(OW) (n-octanol/water partition coefficient) values corresponding to 6.0-7.0 contributed highly to the whole activity. The CALUX activity of the crude extract was three times the sum of the CALUX activities of the RP-HPLC separated fractions. Mixture effects were assessed by co-exposure of each HPLC fraction and 2,3,7,8-TCDD to the cells. The four concentration levels of added 2,3,7,8-TCDD corresponded to the TEQ value in the original compost sample. The experimental CALUX activity was higher than the predicted CALUX activity for some fractions. It was demonstrated that some compounds in the compost sample interacted synergistically with 2,3,7,8-TCDD in terms of dioxin-like activity. This finding points out the necessity for detailed investigation of synergistic effects in environmental samples.     

18S rRNA phylogeny of sea spiders with emphasis on the position of Rhynchothoracidae

The phylogenetic relationships among all living families of sea spiders (Arthropoda: Pycnogonida) are investigated using nearly complete 18S rRNA sequences from 57 ingroup species and five chelicerates under the Bayesian and maximum likelihood methods. Monophyly of Colossendeidae, Pycnogonidae, Phoxichilidiidae, Endeidae and Pallenopsidae is consistently supported. However, the genera formerly classified in the family Ammotheidae are split up into two distantly related groups. The genera Ascorhynchus and Eurycyde (here recognized as Ascorhynchidae) are possibly an early offshoot of sea spiders, whereas other ammotheids constitute a robust terminal clade with Pallenopsidae, Phoxichilidiidae and Endeidae. This topology also opposes the prevalent assumption of successive losses and simplification of three kinds of cephalic appendages like in a previous cladistic analysis. At least three independent losses are suggested for palps by the inferred topology, and both chelifores and female ovigers may have been lost twice. Our knowledge of early ontogeny and internal anatomy is more congruent with the present 18S rRNA data. The families Callipallenidae and Nymphonidae with unique “attaching larvae” are grouped together in present molecular trees, suggesting that extended paternal care of offspring evolved only once in Pycnogonida. Confident clustering of Pycnogonidae and Rhynchothoracidae indicates that the number of female genital pores is an evolutionary conservative character.