Towards institutional analysis of sustainability science: a quantitative examination of the patterns of research collaboration

This paper examines quantitatively the patterns of collaboration over geographical boundaries in the emerging field of sustainability science by empirically analyzing the bibliometric data of scientific articles. The results indicate that an increasing number of countries are engaged in research on sustainability, with the proportion of articles published through international collaboration rising as well. The number of countries engaged in international collaboration on sustainability research has been increasing, and the diversity of countries engaged in research collaboration beyond national borders is also increasing. The geographical patterns of collaboration on sustainability show that research collaboration tends to be conducted between countries which are geographically located closely, suggesting that communication and information exchange might be limited within the regional clusters. The focused fields of research activities on sustainability are significantly different between countries, as each country has its focused fields of research related to sustainability. The specialization of research activities is also observed in international collaboration. While these patterns of international collaboration within regional clusters focusing on specific fields could be effective in promoting the creation, transmission, and sharing of knowledge on sustainability utilizing the already existing regional networks, they could pose a serious obstacle to collecting, exchanging, and integrating diverse types of knowledge, especially when it is necessary to deal with problems involving large-scale complex interactions with long-term implications, such as climate change. It would be of critical importance to establish inter-regional linkages by devising appropriate institutional arrangements for global research collaboration on sustainability science.     

A method for determination of methyl chloride concentration in air trapped in ice cores

A method for measuring the concentration of methyl chloride (CH3Cl) in air trapped in an ice core was developed. The method combines the air extraction by milling the ice core samples under vacuum and the analysis of the extracted air with a cryogenic preconcentration/gas chromatograph/mass spectrometry system. The method was applied to air from Antarctic ice core samples estimated to have been formed in the pre-industrial and/or early industrial periods. The overall precision of the method deduced from duplicate ice core analyses was estimated to be better than +/-20 pptv. The measured CH3Cl concentration of 528+/-26 pptv was similar to the present-day concentration in the remote atmosphere as well as the CH3Cl concentration over the past 300 years obtained from Antarctic firn air and ice core analyses.     

Neighborhood influences on the diffusion of residential photovoltaic systems in Kyoto City,Japan

Environmental Economics and Policy Studies - This study investigates the factors influencing the diffusion of residential photovoltaic systems. Factors examined are related to social attributes,...     

Hydroponic technique using waste concrete and ferronickel slag instead of fertilizer

Journal of Material Cycles and Waste Management - This paper presents whether some minerals in waste concrete and ferronickel slag are available for hydroponics instead of commercial fertilizer....     

The effect of the increase in urban temperature on the concentration of photochemical oxidants

An atmospheric dispersion model, where the inputs of meteorological field were calculated using a meteorological model, was used to reproduce the observed air pollution conditions for the typical fine day in summer period, especially the concentration of the photochemical oxidants. As well, the effects of an increase in the urban temperature and VOC emissions on the concentration of photochemical oxidants were also considered. The following conclusions were drawn.The observed air pollution levels were well modeled by the atmospheric dispersion model using in this study, although modeled NO levels were slightly lower than the observed levels. An analysis of the temperature data showed that a 1 °C increase in temperature leads to a maximal photochemical oxidant concentration of 5.3 ppb, which is an increase of 11%. Additionally, the effect on the photochemical oxidant concentration due to an increase in the vegetation-derived VOCs was more than double the effect due to an increase in the photochemical reactions. It was found that the temperature and photochemical oxidant concentration were linearly related up to a temperature increase of 3 °C. When the temperature increases up to 3 °C, the concentration of photochemical oxidants increases by 19 ppb. An analysis of the effect of vegetation-derived VOCs on photochemical oxidant concentrations showed that, the concentration of photochemical oxidants was 30 ppb higher in the afternoon by the effect of vegetation-derived VOCs, so even in metropolitan areas with relatively little vegetation, vegetation-derived VOCs have a strong impact on photochemical oxidant concentrations.     

Molecular size as a limiting characteristic for bioconcentration in fish

The relationships between the bioconcentration factor (BCF) of chemicals in fish and their size, as characterized by molecular weight (MW), effective cross sectional diameter (Deff), and maximum diameter (Dmax) have been investigated using an experimental data set of 737 new and 441 existing chemicals monitored by the Japanese Chemical Substances Control Law (CSCL). Substances with BCF > or = 5000 (very high bioconcentration potential) typically have MW < 550, Deff < 1.1 nm and Dmax < 2.0 nm, respectively and the substances with BCF > or = 1000 (high bioconcentration potential) have MW < 550, Deff < 1.4 nm and Dmax < 2.9 nm, respectively Therefore, the previously suggested threshold values for Deff (0.95 nm) and Dmax (1.5 nm) used for discriminating between bioconcentrative and non-bioconcentrative substances were found to be somewhat small. We found that many substances with BCF > or = 1000 and Dmax > or = 1.5 nm have Deff < 0.95 nm.     

Creating an academic landscape of sustainability science: an analysis of the citation network

Sustainability is an important concept for society, economics, and the environment, with thousands of research papers published on the subject annually. As sustainability science becomes a distinctive research field, it is important to define sustainability clearly and grasp the entire structure, current status, and future directions of sustainability science. This paper provides an academic landscape of sustainability science by analyzing the citation network of papers published in academic journals. A topological clustering method is used to detect the sub-domains of sustainability science. Results show the existence of 15 main research clusters: Agriculture, Fisheries, Ecological Economics, Forestry (agroforestry), Forestry (tropical rain forest), Business, Tourism, Water, Forestry (biodiversity), Urban Planning, Rural Sociology, Energy, Health, Soil, and Wildlife. Agriculture, Fisheries, Ecological Economics, and Forestry (agroforestry) clusters are predominant among these. The Energy cluster is currently developing, as indicated by the age of papers in the cluster, although it has a relatively small number of papers. These results are compared with those obtained by natural language processing. Education, Biotechnology, Medical, Livestock, Climate Change, Welfare, and Livelihood clusters are uniquely extracted by natural language processing, because they are common topics across clusters in the citation network.     

Biochemical and Genetic Characterization of an Extracellular Poly(3-Hydroxybutyrate) Depolymerase from Acidovorax Sp. Strain TP4

To determine the properties of enzymes from bacteria that degrade polypropiolactone (PPL), we isolated 13 PPL-degrading bacteria from pond water, river water, and soil. Nine of these strains were identified as Acidovorax sp., three as Variovorax paradoxus, and one as Sphingomonas paucimobilis. All the isolates also degraded poly(3-hydroxybutyrate) (PHB). A PPL-degrading enzyme was purified to electrophoretical homogeneity from one of these bacteria, designated Acidovorax sp. TP4. The purified enzyme also degraded PHB. The molecular weight of the enzyme was estimated as about 50,000. The enzyme activity was inhibited by diisopropylfluorophosphate, dithiothreitol, and Triton X-100. The structural gene of the depolymerase was cloned in Escherichia coli. The nucleotide sequence of the cloned DNA fragment contained an open reading frame (1476 bp) specifying a protein with a deduced molecular weight of 50,961 (491 amino acids). The deduced overall sequence was very similar to that of a PHB depolymerase of Comamonas acidovorans YM1609. From these results it was concluded that the isolated PPL-degrading enzyme belongs to the class of PHB depolymerases. A conserved amino acid sequence, Gly-X₁-Ser-X₂-Gly (lipase box), was found at the N-terminal side of the amino acid sequence. Site-directed mutagenesis of the TP4 enzyme confirmed that ²⁰Ser in the lipase box was essential for the enzyme activity. This is the first report of the isolation a PHB depolymerase from Acidovorax.     

Effect of metabolism on bioconcentration of geometric isomers of d-phenothrin in fish

Yearling carp (Cyprinus carpio) were exposed to d-phenothrin (a 1:4 mixture of d-cis and d-trans isomers) in the absence and the presence of piperonyl butoxide under the flow-through test condition and the bioconcentration factors (BCF's) of the geometric isomers were separately evaluated. It was demonstrated that BCF values for the d-cis isomer were significantly higher by 1.1 to 2.2-fold than those for the d-trans isomer and the subsequent exposure in the presence of piperonyl butoxide resulted in elevated BCF values for the d-cis isomer, but no remarkable change in BCF's was observed for the d-trans isomer. The elevation observed here was presumably attributable to a reduced elimination caused by inhibited oxidative reactions characteristic to the d-cis isomer. The contribution of biotransformation to the elimination rate constant (K₃/K₂ was estimated to be 2.3–11. Thus, the result was well explained by a distinct oxidative metabolism of the d-cis isomer and a significance of metabolism in bioconcentration phenomenon was exemplified.