Relationship between egg productivity and RNA/DNA ratio in Paracalanus sp. in the frontal waters of the Kurshio

The relationship between RNA/DNA ratio and egg productivity of adult Paracalanus sp. females was investigated in the frontal area of the Kuroshio current off Kinkazan Island and Boso Peninsula, Pacific coast of Japan in 1989 and 1990, respectively. In the Kuroshio front off Kinkazan Island, the RNA/DNA ratio of females in the surface layer ranged from 3.87 to 6.92 along a transect 8 miles across the front. In the Kuroshio front off Boso Peninsula, the RNA/DNA ratio varied between 5.15 and 7.27 for 32 h in the course of tracking a drifter launched in the front. The RNA/DNA ratio of the females in both frontal areas tended to increase together with ambient chlorophyll-a concentration, and the relationship fitted to Ivlev's formula (P<0.05). The number of eggs laid in filtered sea-water during 24 h (egg productivity) was also positively correlated with the ambient chlorophyll a concentration (P<0.05). There was a positive correlation (P<0.001) between RNA/DNA ratio and egg productivity, and RNA/DNA ratios accounted for about 70% of variation of the egg productivity. Judging from RNA/DNA ratios and female egg productivity in both frontal areas, relatively large physiological or reproductive changes could possibly occur in small temporal and spatial scales in association with change in phytoplankton abundance.     

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.     

Trends in the enantiomeric composition of polychlorinated biphenyl atropisomers in human breast milk

For the precise estimation of the risk to human health caused by persistent organic pollutants (POPs), it is important to discuss enantiomer fraction value (EF value) because it is reported that behaviors such as stability and toxicity of enantiomers are quite different in human body. Among POPs, polychlorinated biphenyl (PCB) is known as one of the most persistent compounds in human breast milk samples. The main exposure source of PCB for human body is mostly from food especially in seafood. The contamination of fish and shellfish has been a serious problem for the Japanese, who consume a large amount of fish in their diet. PCBs have 19 congeners which are chlorine-substituted in 3- or 4- ortho positions are known to have enantiomers. In this study, we analyzed PCB 183 (2,2′,3,4,4′,5′,6-hepta CB) in human breast milk and fish samples enantioselectively and revealed the time trends of the EF value. Though EF value of PCB 183 in fish samples sustained close to racemate (EF?=?0.5) from 1982 to 2012, that in breast milk increased over time. This fact indicates that (+)-PCB-183 has greater bioaccumulation potential than (-)-PCB-183 in human body; therefore, the toxicity of (+)-PCB-183 should be emphasized.     

Toward knowledge structuring of sustainability science based on ontology engineering

In sustainability science (SS), it is difficult to identify what needs to be solved, and it is also not clear how to solve the problems that are identified. There has been no consensus on the underlying question of “What is structuring knowledge in SS?” This paper focuses on knowledge structuring accompanied by supporting of thinking. It addresses the key challenges associated with knowledge structuring in SS, identifies the requirements for the structuring of knowledge, proposes a reference model, and develops an ontology-based mapping tool as a solution to one layer of the reference model. First, we identify the important requirements for SS knowledge structuring. Second, we develop a reference model composed of five layers based on three of the requirements. Third, we develop an ontology-based mapping tool at Layer 2 of the reference model for meeting the two major challenges for SS, namely, identifying what problems should be addressed in SS itself and proposing solutions for those problems. The tool is designed to store and retrieve information regarding SS, to provide access to a prototype ontology for SS, and to create multiple maps of conceptual chains depending on a user’s interests and perspectives. Finally, we assess whether the developed tool successfully realizes the targeted part of the reference model for SS by examining the tool’s conformity to the reference model, as well as its usability, effectiveness, and constraints. Although several issues were identified in the prototype ontology and the mapping tool, the study concluded that the mapping tool is useful enough to facilitate the function of Layer 2. In particular, the mapping tool can support thinking about SS from the viewpoint of: (a) finding new potentials and risks of technological countermeasures studied in SS; (b) helping users to get a more comprehensive picture of problems and their potential solutions; and (c) providing an effective opportunity to come up with new ideas that might not be thought of without such a tool.     

Techniques to separate metal from waste printed circuit boards from discarded personal computers

Waste printed circuit boards contain valuable metals such as Au, Pd, Ag, and Cu that can be reutilized and harmful elements such as Pb, Br, and Cr that must be removed from the viewpoint of environmental conservation. In this research, we examined a method that separates the materials from printed circuit boards contained in discarded personal computers. After cutting the printed circuit boards to a size of 20 × 20 mm, they were heated at 873 K under an Ar atmosphere to remove organic resins containing elements such as C, H, and N. After heat treatment, the printed circuit boards were crushed using a planetary ball mill and the pulverized powders were filtered. The fraction with a granularity of greater than 250 μm was separated into magnetic and nonmagnetic materials by a magnetic field. Because the fraction with a granularity of less than 250 μm contained 39 mass% of C, it was heated at 1273 K in an atmosphere of 95% Ar and 5% O₂ to allow carbon combustion to take place, followed by metal reduction processing at the same temperature in an atmosphere of 97% Ar and 3% H₂. The basicity of the resulting powder was adjusted and the powder was heated at 1773 K under an Ar atmosphere. The proposed method separated the slag and metal, and 80% of the valuable metals contained in printed circuit boards could be collected.     

Polychlorinated biphenyl (118) activates osteoclasts and induces bone resorption in goldfish

To analyze the effect of polychlorinated biphenyl (PCB) 118 on fish bone metabolism, we examined osteoclastic and osteoblastic activities, as well as plasma calcium levels, in the scales of PCB (118)-injected goldfish. In addition, effect of PCB (118) on osteoclasts and osteoblasts was investigated in vitro. Immature goldfish, in which the endogenous effects of sex steroids are negligible, were used. PCB (118) was solubilized in dimethyl sulfoxide at a concentration of 10 ppm. At 1 and 2 days after PCB (118) injection (100 ng/g body weight), both osteoclastic and osteoblastic activities, and plasma calcium levels were measured. In an in vitro study, then, both osteoclastic and osteoblastic activities as well as each marker mRNA expression were examined. At 2 days, scale osteoclastic activity in PCB (118)-injected goldfish increased significantly, while osteoblastic activity did not change significantly. Corresponding to osteoclastic activity, plasma calcium levels increased significantly at 2 days after PCB (118) administration. Osteoclastic activation also occurred in the marker enzyme activities and mRNA expressions in vitro. Thus, we conclude that PCB (118) disrupts bone metabolism in goldfish both in vivo and in vitro experiments.     

Environmental risk assessment and concentration trend of atmospheric volatile organic compounds in Hyogo Prefecture, Japan

Purpose  

The purpose of this study was to evaluate the influences of volatile organic compounds (VOCs) emissions on hazardousness and photochemical reactivity and to propose efficient VOCs abatement strategies.