Enhanced degradation of carbazole and 2,3-dichlorodibenzo-p-dioxin in soils by Pseudomonas resinovorans strain CA10

We studied the degradation of carbazole (CAR) and 2,3-dichlorodibenzo-p-dioxin (2,3-DCDD) in soils inoculated with carbazole- and dioxin-degrader Pseudomonas resinovorans strain CA10. By using Tn5-based transposon delivery systems, this bacterium was chromosomally marked with a tandem green fluorescent protein (gfp) gene. Real-time competitive PCR and direct counting using the (gfp) marker were employed to monitor the total number of carbazole 1,9a-dioxygenase gene (carAa) and survival of CA10 cells in the soil and soil slurry microcosms. Bioaugmentation studies indicated that the survival of the marked CA10 cells in soil microcosms was strongly influenced by pH and organic matter. While the number of the marked CA10 cells decreased rapidly in pH 6 with low organic matter, a high cell density was maintained in pH 7.3 with 2.5% organic matters up to 21 days after inoculation. In pH 7.3 soil, the period needed for complete degradation of CAR (100 microg kg(-1)) was markedly shortened from 21 to 7 days by the inoculation with the CA10 cells. Single inoculation of CA10 cells into the soil slurry system of 2,3-DCDD-contaminated soil enhanced the degradation of 2,3-DCDD from 25.0% to 37.0%. In this system, the population density of CA10 cells and the total number of carAa gene were maintained up to 14 days after inoculation. By repeated inoculation (every 2 days) with CA10 cells each at a density of 10(9) CFU g(-1) of soil, almost all of the 2,3-DCDD (1 microg kg(-1)) was degraded within 14 days. Results of these experiments suggest that P. resinovorans strain CA10 may be an important resource for bioremediation of CAR and chlorinated dibenzo-p-dioxin in contaminated soils.     

Evaluation of pesticides and metals in fish of the Dniester River, Moldova

The Dniester River is one of the largest rivers in Eastern Europe and receives input from numerous anthropogenic activities. In October 2001, fish samples (Abramis brama, Rutilus rutilus heckeli, Perca fluviatilis, Chondrostoma nasus, Carassius auratus gibelio, and Cyprinus carpio) were collected and analyzed for metals and various pesticides. Maximum total DDT pesticide concentrations were between 27.7 and 34.2 ng/g wet weight in muscles and gonads, respectively. DDE isomers comprised up to 70% of total DDT measurement in fish tissues, indicating historical rather than recent DDT pollution. Chlordane and lindane were also detected in amounts up to 37 and 76 ng/g wet weight in gonads, respectively. Among organophosphorous pesticides, malathion showed extremely high concentrations--3 microg/g wet weight in muscles and 46 microg/g wet weight in gonads, indicating recent exposure. Copper concentrations in muscles (1.8-7.2 microg/g) exceeded Threshold Effect Concentrations for copper in fish. Detection of high concentrations of malathion and copper in fish tissues indicated potential anthropogenic stress for more sensitive aquatic biota, likely from agricultural sources in the Dniester River.     

Diverse migration strategies in hoopoes (<Emphasis Type="Italic">Upupa epops</Emphasis>) lead to weak spatial but strong temporal connectivity

The annual cycle of migrating birds is shaped by their seasonal movements between breeding and non-breeding sites. Studying how migratory populations are linked throughout the annual cycle—migratory connectivity, is crucial to understanding the population dynamics of migrating bird species. This requires the consideration not only of spatial scales as has been the main focus to date but also of temporal scales: only when both aspects are taken into account, the degree of migratory connectivity can be properly defined. We investigated the migration behaviour of hoopoes (Upupa epops) from four breeding populations across Europe and characterised migration routes to and from the breeding grounds, location of non-breeding sites and the timing of key migration events. Migration behaviour was found to vary both within and amongst populations, and even though the spatial migratory connectivity amongst the populations was weak, temporal connectivity was strong with differences in timing amongst populations, but consistent timing within populations. The combination of diverse migration routes within populations and co-occurrence on the non-breeding grounds between populations might promote exchange between breeding populations. As a result, it might make hoopoes and other migrating bird species with similar strategies more resilient to future habitat or climatic changes and stabilise population trends.     

The importance of group‐focused transformational leadership and felt obligation for helping and group performance

Leaders face a challenge to simultaneously motivate workgroups and the individuals within them. Recent criticisms highlight the need to deconstruct broad leadership constructs to offer better theoretical insight into the effects of specific leadership behaviors on groups versus individuals. We address this call by exploring the effects of group‐focused and individual‐focused aspects of transformational leadership. Applying social identity theory, we theorize that group‐focused transformational leadership is key to fostering felt obligation, motivating helping behavior, and enhancing group performance, whereas individual‐focused leadership may only foster helping when individuals also feel a sense of obligation toward their workgroup. In a field study of 260 employees reporting to 36 supervisors in a skilled trade company, we find support for these predictions using multilevel structural equation modeling and multilevel mixed effects modeling. Thus, group‐focused (vs. individual‐focused) transformational leadership and subsequent felt obligation are important antecedents for encouraging helping and, in turn, workgroup performance.     

Estimating the amount of WEEE generated in South Korea by using the population balance model

We estimated the amount of waste electrical and electronic equipment (WEEE) generated in South Korea by using the population balance model (PBM) based on a lifespan distribution analysis. This is the first study to apply PBM to estimate WEEE generation in South Korea. The lifespan distribution analysis of electrical and electronic equipment (EEE) was based on the results of a questionnaire survey of 1000 households, which were analyzed with the Weibull distribution. As a result, we could estimate the domestic service lifespan and lifespan distribution shape parameter for eight selected products. Using the lifespan distribution analysis and other data, such as the shipment volume and the number of products owned by households, we estimated the amount of WEEE generated for the eight selected items from 2000 to 2020. We found that 1.2 million air conditioners, 2.5 million televisions, 1.3 million microwave ovens, 1.2 million kimchi refrigerators, 17.0 million mobile phones, 1.7 million refrigerators, 2.0 million vacuum cleaners, and 1.4 million washing machines were generated as WEEE in 2010. We also compared our WEEE estimates with the number of items collected through the official WEEE recycling program from 2003 to 2009 and found that in 2009 washing machines had the highest collection rate (28%) and air conditioners had the lowest rate (7%).     

Secondary materials transfer from Japan to China: destination analysis

China has been the largest importer of secondary materials for recycling from Japan during the past decade. In this study, we analyzed the transfer of major secondary materials (plastic, steel, copper, and aluminum scrap) from Japan to China. We identified specific destinations for secondary materials, and the characteristics of secondary materials transferred to China. The major destination for the transfer of secondary materials to China is Guangdong province and part of the Huadong area (Shanghai, Zhejiang, and Jiangsu). Most scrap metal imported into China is of low quality. The destinations of most high-quality nonferrous scrap, imported as processed goods on consignment or through the transit improvement trade, are the northeast border provinces, especially Xinjiang Uighur province. The coefficients of specialization for Chinese cities were different from those for the provinces. Guangdong shows an average recycling structure for China. The structure gradually changes from south to north.     

Determination of nonylphenol ethoxylates and octylphenol ethoxylates in environmental samples using 13C-labeled surrogate compounds

Alkylphenol polyethoxylates (APEOs) have been widely used as nonionic surfactants in a variety of industrial and commercial products. Typical compounds are nonylphenol polyethoxylates (NPEOs) and octylphenol polyethoxylates (OPEOs), which serve as precursors to nonylphenol (NP) and octylphenol (OP), respectively. NP and 4-t-OP are known to have endocrine disrupting effects on fish (medaka, Oryzias latipes), so it is important to know the concentrations of APEOs in the environment. Because the analytical characteristics of these compounds depend on the length of the ethoxy chain, it is necessary to use appropriate compounds as internal standards or surrogates. We synthesized two 13C-labeled surrogate compounds and used these compounds as internal standards to determine NPEOs and OPEOs by high-performance liquid chromatography (LC)-mass spectrometry. Method detection limits were 0.015 microg/L for NP (2)EO to 0.037 microg/L for NP(12)EO, and 0.011 microg/L for OP(3,6)EO to 0.024 microg/L for OP (4)EO. NPEO concentrations in water from a sewage treatment plant were less than 0.05-0.52 microg/L for final effluent and 1.2-15 microg/L for influent. OPEO concentrations were less than 0.05-0.15 microg/L for the final effluent and less than 0.05-1.1 microg/L for influent.     

Anaerobic biodegradation of biphenyl in various paddy soils and river sediment

The anaerobic degradation of biphenyl was investigated in four uncontaminated Japanese paddy soils and one river sediment sample contaminated with benzene and chlorinated aliphatics. Two of the paddy soils and the sediment were capable of degrading biphenyl anaerobically without any additional medium or electron acceptors. The half-lives of biphenyl biodegradation in the three samples were 212 d in the Kuridashi soil, 327 d in the Kamajima soil, and 429 d in the river sediment. The Kuridashi soil metabolized 1+/-0.3% of [U-14C]-biphenyl into CO2 and 5+/-2% into water-soluble metabolites after 45 d of incubation. Submerged conditions, which result in lower nitrate and iron oxide contents, and neutral pH, appeared to be the common properties among the samples that influenced their degradation capacities. The addition of 10mM sulfate and 20mM Fe(III) as electron acceptors did not enhance the biphenyl degradation rate, whereas 10mM nitrate completely inhibited biphenyl degradation. The addition of different electron donors (lactate, acetate, or pyruvate) slightly slowed the degradation. Molybdate (an inhibitor of sulfate-reducing bacteria) had an inhibitory effect on biphenyl biodegradation, but bromoethanesulfonic acid (an inhibitor of methanogens) did not. Most biphenyl degradation was observed when only water was added, with no other electron acceptors or donors. These results suggest that sulfate-reducing bacteria and fermentative microbial populations play important roles in anaerobic biphenyl biodegradation in paddy soil.