Discovery of mycangia and the associated xylose-fermenting yeasts in stag beetles (Coleoptera: Lucanidae)

Most wood-feeding insects need an association with microbes to utilize wood as food, and some have special organs to store and convey the microbes. We report here the discovery of the microbe-storage organ (mycangium) in stag beetles (Coleoptera: Lucanidae), which develop in decayed wood. The mycangium, which was discovered in the abdomen, is present in all adult females of 22 lucanid species examined in this study, but absent in adult males. By contrast, adult insects of both sexes of selected Passalidae, Geotrupidae, and Scarabaeidae, which are related to Lucanidae, lacked mycangia similar to those of the lucanid species. Yeast-like microbes were isolated from the mycangium of five lucanid species. DNA sequence analyses indicate that the microbes are closely related to the xylose-fermenting yeasts Pichia stipitis, Pichia segobiensis, or Pichia sp. known from the gut of a passalid species.     

Collaborative activity with business partners for improvement of product environmental performance using LCA

Collaborative activities with business partners have potential to improve environmental performance of product and life cycle assessment (LCA) is an essential technique to implement eco-design of product and production process. However, collection of LCA data from supply chain is a major issue for LCA practitioners. We propose a Supply Chain Collaboration Model (SCCM), which is a framework for collecting producer-specific LCA data from business partners and for promoting improvement activity of product environmental performance. We demonstrate the practicability of the SCCM using three case studies. In each case study, two or three partner companies organized a product improvement project and carried out process analysis techniques such as LCA and material flow cost accounting (MFCA). As a result, improvement activities from the economical standpoint could provide an incentive for business partners to collect LCA data, and thus the SCCM is an effective framework for eco-design.     

Start-up performances of dry anaerobic mesophilic and thermophilic digestions of organic solid wastes

Two dry anaerobic digestions of organic solid wastes were conducted for 6 weeks in a lab-scale batch experiment for investigating the start-up performances under mesophilic and thermophilic conditions. The enzymatic activities, i.e., β-glucosidase, N-α-benzoyl-Largininamide （BAA）-hydrolysing protease, urease and phosphatase activities were analysed. The BAA-hydrolysing protease activity during the first 2-3 weeks was low with low pH, but was enhanced later with the pH increase. β-Glucosidase activity showed the lowest values in weeks 1-2, and recovered with the increase of BAA-hydrolysing protease activity. Acetic acid dominated most of the total VFAs in thermophilic digestion, while propionate and butyrate dominated in mesophilic digestion. Thermophilic digestion was confirmed more feasible for achieving better performance against misbalance, especially during the start-up period in a dry anaerobic digestion process.     

Investigation of air pollution concentration in Kathmandu valley during winter season

The monthly concentrations of NO2, NOx, SO2 and O3 measured by a passive sampler from February 2003 to January 2004 showed that the air pollution during the winter season in Kathmandu valley was higher than the summer season. The O3 level was found the highest during April, May and June due to strong radiation. The hourly concentrations of NO2, NOx, O3 and suspended particulate matter（SPM） were also measured by automatic instruments on December 2003. Temperature at the height of 60 m and 400 m at Raniban Mountain in the northwest of Kathmandu valley was measured on February 2001 in the winter season and the average potential temperature gradient was estimated from observed temperature. Wind speed was also measured at the department of hydrology, airport section, from 18 February to 6 March 2001. It was found that the stable layer and the calm condition in the atmosphere strongly affected the appearance of the maximum concentrations of NO2 and SPM in the morning, and that the unstable layer and the windy condition in the atmosphere was considerably relevant to the decrease of air pollution concentrations at daytime. The emission amounts of NOx, HCs and total suspended particle（TSP） from transport sector in 2003 were estimated from the increasing rate of vehicles on the basis of the emission amounts in 1993 to be 3751 t/a, 30570 t/a and 1317 t/a, respectively. The diurnal concentrations in 2003 calculated by the two-layers box model reproduced the characteristics of air pollution in Kathmandu valley such as the maximum value of O3 and its time, the maximum value of NO in the morning, and the decrease of NO and NO2 at daytime. The comparison with the concentrations in 1993 calculated suggested that the main cause of air pollution was the emission from transport sector.     

Elementary budget of stag beetle larvae associated with selective utilization of nitrogen in decaying wood

Wood degradation by insects plays important roles for the forest matter cycling. Since wood is deficient in nitrogen compared to the insect body, wood-feeding insects need to assimilate the nitrogen selectively and discard an excess carbon. Such a stoichiometric imbalance between food and body will cause high metabolic cost; therefore, wood-feeding insects may somehow alleviate the stoichiometric imbalance. Here, we investigated the carbon and nitrogen budgets of the larvae of stag beetle, Dorcus rectus, which feed on decaying wood. Assimilation efficiency of ingested wood was 22%, and those values based on the carbon and nitrogen were 27 and 45%, respectively, suggesting the selective digestion of nitrogen in wood. Element-based gross growth efficiency was much higher for nitrogen (45%) than for carbon (3%). As a result, the larvae released 24% of the ingested carbon as volatile, whereas almost no gaseous exchange was observed for nitrogen. Moreover, solubility-based elementary analysis revealed that the larvae mainly utilized alkaline-soluble-water-insoluble fraction of wood, which is rich in nitrogen. Actually, the midgut of the larvae was highly alkaline (pH 10.3). Stag beetle larvae are known to exhibit coprophagy, and here we also confirmed that alkaline-soluble-water-insoluble nitrogen increased again from fresh feces to old feces in the field. Stable isotope analysis suggested the utilization of aerial nitrogen by larvae; however, its actual contribution is still disputable. Those results suggest that D. rectus larvae selectively utilize alkaline-soluble nitrogenous substrates by using their highly alkaline midgut, and perhaps associate with microbes that enhance the nitrogen recycling in feces.     

Measuring marginal willingness to pay using conjoint analysis and developing benefit transfer functions in various Asian cities

We need a consistent methodology to measure the co-benefits of climate change mitigation across Asian countries. This study chose a strategy of modifying the Japan-specific life-cycle impact assessment method based on endpoint modeling (LIME) for wider application across countries. LIME has two dimensions. First, it is an environmental science that links the cause-and-effect chain. Second, it is an environmental valuation that weighs four endpoint damages in monetary terms through a conjoint analysis that is derived from an Internet-based questionnaire survey. This article describes the modification of the methodology for application of the conjoint analysis to weigh environmental impacts. We approached the investigation as follows. First, we conducted Internet surveys to measure marginal willingness-to-pay (MWTP). We used a sample of 112 respondents in their 20 s to 40 s, divided equally between men and women, in 11 cities across China, India, and Southeast Asia. The results obtained showed clear statistical significance and were comparable across the cities. Second, we attempted to develop functions (called benefit transfer functions) to simplify the measured MWTP in order to apply it across different Asian countries. The functions were derived through a stepwise meta-analytic method, a type of multiple regression analysis whose independent variable was MWTP and dependent variables were attributes of both respondents and surveyed cities. The functions showed that coal consumption and percentage of nature reserve were dependent variables. Then, the MWTPs estimated from the functions were compared with the measured MWTP for transfer error, which is calculated by the absolute value of the difference between the estimated value and the measured value divided by the latter. The transfer error was below 50% in about 90% of the 44 results (a combination of four endpoints and 11 cities), implying that the developed functions were statistically significant.     

Suppression of arsenic leaching from excavated soil and the contribution of soluble and insoluble components in steel slag on arsenic immobilization

Environmental Science and Pollution Research - A huge amount of soil is excavated by tunnel and road construction projects in urban, coastal, and mountainous regions. These projects enable the...     

How do different process options and evaluation settings affect economic and environmental assessments? A case study on methyl methacrylate (MMA) production processes

We present an investigation on how economic and environmental assessment results change when different process options or evaluation settings are considered. As the main case study the production technology of methyl methacrylate (MMA) is investigated. Six commercial processes using different reaction routes are modelled and evaluated with respect to their economic and environmental performance. On these six base case models different process options and evaluation settings are considered and the resulting impacts on the assessment results are quantified. Major findings of the study are that the more decision-variables become fixed, the smaller becomes the impact of the decisions still to be taken—but not only with respect to the economic performance but also with regard to the environmental assessment result. Along the process development steps the potential impacts on the economic and environmental performance decrease to the same degree. The results obtained for the evaluation settings do not show such a systematic pattern as those for the process options. This finding indicates that decision makers face many options in the economic and especially the environmental assessment of chemical processes which might lead to quite different magnitudes in variability due to either the choice of method or the choice of method parameters. This paper demonstrates that the resulting variability might be crucial with respect to the decision making outcome.     

Seasonal variation in the atmospheric deposition of inorganic constituents and canopy interactions in a Japanese cedar forest

The seasonal changes in throughfall (TF) and stemflow (SF) chemistry and the canopy interactions of K+ and N compounds were studied in a Japanese cedar forest near the Sea of Japan. The fluxes of most ions, including non-sea-salt SO4(2-), from TF, SF, and rainfall showed distinct seasonal trends, increasing from autumn to winter, owing to the seasonal west wind, while the fluxes of NH4+ and K+ ions from TF+SF might have a large effect of canopy interactions. The contact angle (CA) of water droplets on leaves decreased with leaf aging, suggesting that surface wettability increases with leaf age. The K+ concentration in TF was negatively correlated with the CA of 1-year-old leaves, while the NH4+ concentration was positively correlated with the CA. The net fluxes of NH4+ and NO3(-) from TF were positively correlated with the CA. The increase in wettability may accelerate leaching of K+ or uptake of NH4+.