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81.
Insects groom almost all parts of the body surface with their legs and mouth parts. However, some body regions are difficult to reach and keep clean. One is the genital chamber located in the last abdominal segment in males which houses the phallic complex for copulation and production of the spermatophore. In the male cricket, foreign substances can enter the genital chamber when it is opened during copulation and spermatophore formation. Moreover, the dorsal pouch and ventral lobes of the phallic complex, which mould the attachment plate, tube, and ampulla of the spermatophore, are inevitably soiled as a result of spermatophore production. We found a unique cleaning system in which foreign substances accumulated during copulation and spermatophore debris left in the dorsal pouch after copulation are quickly removed and collected in special pockets in the genital chamber. This trash is collected by undulation of the genital chamber’s membranous floor which is entirely covered by small scales (∼10 μm) similar to those in the ovipositor of female crickets. This self-filling trash collecting system may be used in some other insects which produce the spermatophore in a similar manner to that of crickets.  相似文献   
82.
Concentrations of As and other trace elements and their association were examined in groundwater (n = 25) and human hair (n = 59) collected at Gia Lam District and Thanh Tri District, suburban areas of Hanoi, Vietnam, in September 2001. Concentrations of As in the groundwater ranged from <0.10 to 330 microg/l, with about 40% of these exceeding WHO drinking water guideline of 10 microg/l. Also, 76% and 12% of groundwater samples had higher concentrations of Mn and Ba than WHO drinking water guidelines, respectively. Arsenic concentrations in hair of residents in Gia Lam and Thanh Tri Districts (range 0.088-2.77 microg/g dry wt.) were lower than those in other As-contaminated areas of the world, but were higher than those of people in non-contaminated areas. Concentrations of As and Mn in hair of some individuals from the Gia Lam and Thanh Tri Districts exceeded the level associated with their toxicity and, therefore, a potential health risk of As and Mn is a concern for the people consuming the contaminated water in this area. Cumulative As exposure was estimated to be lower than the threshold levels at the present, which might explain the absence of manifestations of chronic As poisoning and arsenicosis in the residents of Gia Lam and Thanh Tri Districts. To our knowledge, this study revealed for the first time that the residents are exposed not only to As but also Mn and Ba from groundwater in the Red River Delta, Vietnam.  相似文献   
83.
Special polychlorinated biphenyls (PCBs) standards (native and isotope labeled) were analyzed by isotope dilution method using HRGC-HRMS. Multiple analysis of special PCBs standards by three different laboratories produced the relative response factors (RRFs) and relative standard deviations (RSDs %) was in the average of 0.979 and 3.86, respectively. Additionally, inter-laboratory analysis of various forms of transformer oil revealed the PCBs concentrations were in the following order; PCBs fortified transformer oil (940-1300 ng/g)>PCB polluted transformer oil (490-680 ng/g)>chemically degraded-transformer oil (480-490 ng/g) and PCBs free oil (ND-17 ng/g). Chemical degradation resulted in an order of magnitude decrease in the PCB concentrations. Specifically, higher chlorinated PCBs degraded into lower chlorinated PCBs. Also, composition of PCBs have been determined in PCB formulations from Japan (Kanechlor), Germany (Clophen), USA (Aroclor), Russia (Sovol) and Poland (Chlorofen). Major PCBs (24-PCB congeners) contributed 54-67%, 55-68%, 16-69%, 71% and 72% in Kanechlor, Clophen, Aroclor, Sovol and Chlorofen, respectively to total PCBs. The homologue pattern of Kanechlor, Aroclor and Clophen in technical fromulation was similar (e.g., Kanechlor-300 resembled to those of Clophen A-30 and Aroclor-1242). Furthermore, congener-specific distributions of major PCBs/dioxin-like PCBs and toxic equivalency quantities (TEQ) were calculated. Based on our tentative assumption calculations, cumulative production of five different technical PCB formulations, WHO-TEQ emission was estimated to be approximately 16.05 tons.  相似文献   
84.
We investigated the epilithic diatom assemblage of samples collected from three sites of the Hakata River, Fukuoka, Japan, on November 26, 2008. Each taxon was photographed and identified. The 1747 diatom frustules collected were classified into 33 taxa belonging to 17 genera. Nitzschia fonticola was abundant at all sites. The DAIpo (the diatom assemblage index to organic water pollution) values for sites 1, 2, and 3 were 50.2, 44.1 and 48.0, respectively, indicating that the water quality of the Hakata River was at β-mesosaprobic level.  相似文献   
85.
This paper analyzes the functions of a government-oriented disclosure program in China, which rates company environmental performance into five colors and discloses the results to the public. The rating results and their annual changes during 2005–2007 are statistically summarized by using the detailed database provided by municipal environmental protection bureau of the study area: Changshu city in Jiangsu province. The reflexive, deterrent and enhancement mechanisms, preliminarily identified for the disclosure program, are qualitatively evaluated by using the information collected by onsite interviews to 32 program participating firms. In overall, the firms' environmental performances have been improved. The companies with worse rating records would be more likely to improve their environmental performances in the following years. The disclosure program encourages the firms to be more reflexive to their internal environmental problems. The deterrent and enhancement functions of the program are weak due to the marginal pressure from the classified stakeholders such as investors, business partners and creditors. The influence of the public, such as neighboring communities and environmental NGOs, is weak too. Encouraging serious reactions of firm's stakeholders to the disclosed rating results should be addressed in order to enhance the effectiveness of the disclosure strategy.  相似文献   
86.
We give an overview of the management systems of household hazardous waste (HHW) in Japan and discuss the management systems and their risks. To get basic information, we conducted a survey of consumers to discover their behavior and awareness of HHW items throughout the entire life cycle, which is made up of the purchase, use, and disposal of a product. The results showed that many people hold end-of-life batteries, fluorescent lamps, empty spray cans, and others in their houses after use. Also, the results showed that a lot of such waste items were discarded in waste streams different from those stipulated by local governments. In particular, many people do not remove NiCd batteries inside products such as shavers or cordless phones before discarding. On the other hand, people’s knowledge of and concern regarding the risks, collection, and recycling of HHW were high. When information about the risks was specifically presented in the questionnaire, people tended to show a more positive intention to participate in a collection and recycling system compared to those who were not presented with such information. Our studies on NiCd batteries and fluorescent lamps showed that it is important to collect and recycle HHW to control the domestic and international flows of cadmium and mercury.  相似文献   
87.
To prepare a substrate for microbial conversion of xylose into xylitol, the culm of Sasa senanensis was hydrolyzed with dilute sulfuric acid. When the reaction temperature was fixed at 121°C, an optimum yield of xylose was obtained by treatment with 2% sulfuric acid for 1 h. An increase in the sulfuric acid concentration or a prolonged reaction time resulted in a decrease in the xylose yield. A fermentable substrate with a relatively high xylose concentration (36.7 g l−1) was obtained by hydrolysis with 2% sulfuric acid with a liquid-to-solid ratio of 5 g g−1. During hydrolysis at elevated temperatures, certain undesired byproducts were also generated, such as degradation products of solubilized sugars and lignin, which are potential inhibitors of microbial metabolism. These compounds were, however, successfully removed from the hydrolysate by treatment with activated char.  相似文献   
88.
Environmentalism in China is under transformation from the traditional command and control model to emphasize the advantages of economic tools and encourage the participation of the public. Firms are much more aware of the importance of environmental issues, and some of them have practiced environmental activities beyond compliance. In order to help understand the driving mechanism of proactive corporate environmental behaviors from the firm’s perspective, this paper identifies the drivers affecting the proactive environmental management level (EMLp) based on the institutional theory, and gives an empirical study on the firms based in Changshu city of Jiangsu Province, China. The usable data, collected from the 117 valid respondents in a questionnaire survey, indicates that EMLp is still moderately low currently. Less than 10% of the samples are practicing all the six categorized types of voluntary environmental activities. The econometric exercise confirms a significantly positive effect of the externally mimetic pressure on EMLp, which may attribute to a higher sensitivity of Chinese companies to the market factors. However, the roles of the general public and industrial associations are not significant, showing the marginal power of selected normative pressures. Regarding internal factors, firms, which view environmental issues as opportunities and often arrange internal environmental training, are more likely to adopt proactive environmental activities. More concerns from the general public like neighborhood communities and mass media shall be addressed to enhance the normative power to improve EMLp in China from the future perspective.  相似文献   
89.
The requirement to assess the management effectiveness (ME) in protected areas (PAs) is increasing around the world to help improve management and accountability. An evaluation of ME for Khojir National Park (KNP), one of the Iran’s oldest PAs, was conducted using a multi-method approach that consisted of structured interviews, open interviews, and site visits. This was the first ME evaluation in Iran. The structured interview was based on the management effectiveness tracking tool methodology. KNP received an average score of 43 %, which is lower than the global average, illustrating that its general management was in the low-intermediate level. The indices of legal status, resource inventory, planning for land and water use, regulations, and objectives received the highest average scores, whereas education and awareness, community co-management, regular work plan, boundary demarcation, visitor facilities, budget sources, staff training, protection systems, and management plan received the lowest ones. The management system of KNP was generally established, but many problems of the management still need to be resolved. To improve ME, some countermeasures should be taken, such as increasing funding, strengthening capacity building, planning, and adaptive management, and implementing community participation.  相似文献   
90.
Recently, several countries agreed to adopt the Stockholm convention on persistent organic pollutants (POPs). One future obligation will be to add other POPs as new evidence becomes available. In vitro cell-based bioassays offer a rapid, sensitive, and relatively inexpensive solution to screen possible POP candidates. In the present study, we investigated the aryl hydrocarbon (Ah)-receptor activity of several dioxin-like POPs by using the Micro-EROD (Ethoxy-Resorufin-O-Deethylase) and DR-CALUX (Dioxin-Responsive-Chemical Activated Luciferase gene eXpression) bioassays, which are two state-of-the-art methods. The Micro-EROD system used in our study utilizes a wild-type rat liver cell line (rat liver H4IIEC3/T cells), while the DR-CALUX bioassay consists of a genetically modified rat hepatoma H4IIE cell line that incorporates the firefly luciferase gene coupled to dioxin-responsive elements (DREs) as a reporter gene. In the case of the DR-CALUX bioassay, we used an exposure time of 24 h, whereas we used a 72-h exposure time in the Micro-EROD bioassay. The aim of this study was to compare conventional dioxin-like POPs (such as polychlorinated dibenzodioxins and -furans, PCDD/Fs and coplanar polychlorinated biphenyls, PCBs) with several other classes of possible candidates to be added to the current toxicity equivalent factor (TEF) model in the future. Therefore, this study compares in vitro CYP1A1 (Micro-EROD bioassay) and firefly luciferase induction (DR-CALUX bioassay) in several mixed polyhalogenated dibenzodioxins and -furans (PXDD/Fs; X=Br, Cl, or F), alkyl-substituted polyhalogenated dibenzodioxins and -furans (PMCDD/Fs; M=methyl), polyhalogenated biphenyls (PXBs, X=Br, Cl ), polybrominated diphenyl ethers (PBDEs), pentabromophenols (PBPs), and tetrabromobisphenol-A (TBBP-A). We also evaluate congener-specific relative potencies (REPs) and efficacies (% of TCDD(max)) and discuss the dose-response curves of these compounds, as well as the dioxin-like potency of several other Ah-receptor agonists, such as those of the polyaromatic hydrocarbons (PAHs) and polychlorinated naphthalenes (PCNs). The highest REP values were found for several PXDD/F congeners, followed by some coplanar PXBs, trichlorinated PCDD/Fs, PAHs, PBDE-126, 1-6-HxCN, and some brominated flame retardants (TBBP-A). These in vitro investigations indicate that further research is necessary to evaluate more Ah-receptor agonists for dioxin-like potency.  相似文献   
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