Differential timing of larval starvation effects on filtration rate and growth in juvenile Crepidula onyx

This study demonstrates that the timing of larval starvation did not only determine the larval quality (shell length, lipid content, and RNA:DNA ratio) and the juvenile performance (growth and filtration rates), but also determine how the latent effects of larval starvation were mediated in Crepidula onyx. The juveniles developed from larvae that had experienced starvation in the first two days of larval life had reduced growth and lower filtration rates than those developed from larvae that had not been starved. Lower filtration rates explained the observed latent effects of early larval starvation on reduced juvenile growth. Starvation late in larval life caused a reduction in shell length, lipid content, and RNA:DNA ratio of larvae at metamorphosis; juveniles developed from these larvae performed poorly in terms of growth in shell length and total organic carbon content because of “depletion of energy reserves” at metamorphosis. Results of this study indicate that even exposure to the same kind of larval stress (starvation) for the same period of time (2 days) can cause different juvenile responses through different mechanisms if larvae are exposed to the stress at different stages of the larval life.     

The role of black carbon as a catalyst for environmental redox transformation

Black carbon (BC) is an important class of geosorbents that control the fate and transport of organic pollutants in soil and sediment. We previously demonstrated a new role of BC as an electron transfer mediator in the abiotic reduction of nitroaromatic and nitramine compounds by Oh and Chiu (Environ Sci Technol 43:6983-6988, 2009). We proposed that BC can catalyze the reduction of nitro compounds because it contains microscopic graphitic (graphene) domains, which facilitate both sorption and electron transfer. In this study, we assessed the ability of different types of BC--graphite, activated carbon, and diesel soot--to mediate the reduction of 2,4-dinitrotoluene (DNT) and 2,4-dibromophenol (DBP) by H(2)S. All three types of BC enhanced DNT and DBP reduction. H(2)S supported BC-mediated reduction, as was observed previously with a thiol reductant. The results suggest that BC may influence the fate of organic pollutants in reducing subsurface environments through redox transformation in addition to sorption.     

Sedimentary Pigments and Organic Matter in Relation to Benthic Fauna in the Tan-Shui Estuary,Taiwan

The benthic ecological structure of the Tan-Shui estuary, Taiwan is changed due to long term effects of dumping of urban wastewater and of engineering actions. to monitor these changes, we sampled and analyzed benthos and sediment from 12 stations on the estuary.

The composition of the dominant species of benthos varied seasonally, with molluscan and crustacean species having greater numbers and higher frequencies of occurrence than other species. the dominant taxa during winter were Nassarius sp. and Maldanidae at two stations. Analysis using Simpson's index and Shannon's index showed the benthic community varied more in coastal areas than in offshore areas.

Physicochemical analysis showed that most of the Tan-Shui estuary consisted of sandy sediment. the variations in concentrations of organic carbon and total nitrogen at each station were small. Although the concentrations of chlorophyll-a and carotenoid at all stations were generally low, the two stations had the highest concentrations, and we concluded that the concentration of pigments in these sediments was related to the abundance of benthos. the community structure of the benthos reflected the characteristics of the sediments, and benthic species exhibited selection of and adaptation to specific sedimentary environments.     

A survey of international urban search-and-rescue teams following the Ji Ji earthquake

On 21 September 1999, the Ji Ji earthquake killed 2,347 people. In the immediate aftermath the international community, mobilised rapidly and sent urban search-and-rescue (US&R) teams to the scene. This paper will present an annotated survey of the expertise and standard of equipment of international US&R teams following that earthquake which could serve as a blueprint for the establishment of US&R teams elsewhere at risk from earthquakes.     

Reductive transformation of dieldrin under anaerobic sediment culture

A pathway of dieldrin transformation to aldrin by epoxide reduction was found in this study. Investigation of dieldrin degradation under anaerobic conditions was performed with a mixed culture containing indigenous microorganisms obtained from sediment of the Er-Jen River in Taiwan. During the incubation, the transformation of dieldrin to aldrin was analyzed by GC-ECD and GC-MS. Effects of incubation factors including dieldrin concentrations, incubation temperatures and kinds of carbon sources on the degradation of dieldrin were also studied. Original concentrations (from 0.5 to 10 microg ml(-1)) of dieldrin affect the transformation rate of dieldrin, and lower concentrations indicated the higher degradation rates. But once the concentration higher than 100 microg ml(-1), almost no degradation occurred. The optimal temperature for degradation in mixed culture was found at 40 degrees C in this study. Dieldrin transformation rates varied with the type of major carbon sources in the mixed culture and were in order of yeast extract > sodium acetate > glucose. In addition, the denaturing gradient gel electrophoresis (DGGE) fingerprint revealed that four microbials evolved in dieldrin-amended cultures, but not in the dieldrin-free cultures. Partial sequence of 16S rDNA for these four organisms exhibited 94-99% similarity to those of genera Clostridium, Acidaminobacter and an uncultured bacterial group. These results suggest that the four microbials might promote the dieldrin transformation.     

Effect of metal chlorides on thermal degradation of (waste) polycarbonate

In this study, we investigated how to treat (waste) polycarbonate efficiently to reduce its degraded residue. The study was carried out in an isothermal reactor under continuous nitrogen flow at atmospheric pressure to pyrolyze polycarbonate (PC) alone and in the presence of metal chloride. Some metal chlorides were shown to be catalytic active for the degradation of PC at 400 degrees C, which increased degradation conversion from 8.5% to more than 58.3%. Among those active metal chlorides, ZnCl2 and SnCl2 can produce higher liquid product yields. Effects such as particle size of PC, temperature, the weight ratio of metal chloride/PC, and degradation time on the degradation conversion of PC without and with these two most active metal chlorides were studied. Results of the liquid product analysis by GC/MS demonstrated the product composition of PC degradation over the metal chlorides is much simpler than that of degradation alone. The main liquid product is phenol, p-isopropylphenol, diphenyl carbonate, and bisphenol A for all cases.     

Decoupling analysis of water consumption and economic development of arid and semiarid regions in Northwest China

The contradiction between China's economic development, its need for resources and the protection of the environment is ctitical. Scarce water resources have resulted in a considerable bottleneck restricting the economic development of water-deficient areas. An objective evaluation of the decoupling state of water consumption and economic development has become an important indicator of regional economic sustainable development. Based on panel data from 2000 to 2017 for six provinces in the arid and semiarid regions of Northwest China, the Logarithmic Mean Divisia Index method is employed to decompose the factors of the decoupling index and establish a decoupling relationship model between water consumption and economic development. The reasons that affect the decoupling state of water resource utilization and economic development are herein discussed, and the stability of the decoupling trend is analysed. Based on the overall regional trend, the decoupling state of the arid and semiarid regions in Northwest China improved from weak to strong, but the high decoupling stability index varied among the provinces. The intensity and structure were promotional factors for decoupling water consumption and economic development, and the contribution rate of the intensity factor was higher than that of the structure factor. Income and population were inhibiting factors for decoupling water consumption and economic development, and the contribution rate of the income factor was higher than that of the population factor. Based on these results, corresponding policy recommendations are provided.     

Distributive and procedural justice as predictors of employee outcomes in Hong Kong

This study examines the extent to which employee judgments about distributive and procedural justice predict job satisfaction, intent to stay and evaluation of supervision in Hong Kong. Distributive and procedural justice each plays a role in determining work outcomes of Hong Kong employees. However, some effects of these justice variables differ from results of previous studies in the United States (U.S.). First, in previous U.S. studies, procedural justice moderates the relationship of distributive justice with evaluation of supervision, but not with job satisfaction or intent to stay. For Hong Kong employees, procedural justice moderates the effects of distributive justice on job satisfaction and intent to stay, but not on evaluation of supervision. Second, previous U.S. studies have shown that procedural justice has a larger effect on work outcomes for women, while distributive justice has larger effects on outcomes for men. For Hong Kong employees, the effects of procedural and distributive justice are about the same for men and women. Differences in the effects of distributive and procedural justice between Hong Kong and the U.S. may reflect cultural dimensions, such as collectivism/individualism and power distance, as well as the relative availability of rewards for women in the work force. Practical implications and future research directions are discussed. Copyright © 2000 John Wiley & Sons, Ltd.     

Catalytic hydrogenation rate of polycyclic aromatic hydrocarbons in supercritical carbon dioxide containing polymer-stabilized palladium nanoparticles

Catalytic hydrogenation of polycyclic aromatic hydrocarbons (PAHs) with up to four fused benzene rings over high-density-polyethylene-stabilized palladium nanoparticles in supercritical carbon dioxide via in situ UV/Vis spectroscopy is presented. PAHs can be efficiently converted to saturated polycyclic hydrocarbons using this green technique under mild conditions at 20 MPa of CO₂ containing 1 MPa of H₂ at 40-50 °C. Kinetic studies based on in situ UV/Vis spectra of the CO₂ phase reveal that the initial hydrogenation of a given PAH and the subsequent hydrogenations of its intermediates are pseudo-first-order. The hydrogenation rate of the latter is always much smaller than that of the former probably due to increasing steric hindrance introduced by the hydrogenated benzene rings of PAHs which impedes the adsorption process and hydrogen access to PAHs on catalyst surfaces.     

Preparation and Properties of Poly (Lactic Acid) Nanocomposites Filled with Functionalized Single-Walled Carbon Nanotubes

This work prepared poly (lactic acid) (PLA)/single-walled carbon nanotubes (SWCNTs) composites using a solution blend method, and investigated the influence of the physical properties of PLA/SWCNTs composites. In order to enhanced interfacial interactions between PLA and SWCNTs, the purified SWCNTs were given functionalisation treatments with a nitric acid/sulfuric acid mixture. These acid-treated SWCNTs (A-SWCNTs) were then grafted with 3-isocyanatopropyl triethoxysilane (A-SWCNTs-Si). When these functionalized SWCNTs were used to fill the PLA matrix, the fractured surface of composite does not present the pullout phenomenon. The dimensional stability obviously increased by a factor of approximately 72. The storage modulus was also significantly improved. The surface resistivity of the PLA/SWCNTs composites decreased from 1 × 10¹⁶ to 2.22 × 10⁴ Ω/cm².