Relationship between the growth and survival of larval Pacific bluefin tuna, Thunnus orientalis

We tested the hypothesis that a large body size and rapid growth rate affect the survival of larval Pacific bluefin tuna, Thunnus orientalis (PBT), and analyzed larval growth in relation to environmental conditions. Seven high density larval patches of PBT were tracked with reference buoys in the northwestern Pacific Ocean for 28–171 h in May–June from 2004 to 2008. The otolith radii and daily growth rates of the survivor larvae (collected on later tracking days of each tracking session) tended to be larger and more rapid, respectively, than those of original larvae (collected on earlier tracking days). A large body size was found to positively affect the survival of larval PBT, as did a rapid growth rate, even at an early larval stage (7 days after hatching). Generalized linear modeling showed that the otolith radius was influenced positively by the sea temperature, stratification parameter and food density, while the growth rate was influenced positively by the sea temperature and food density.     

Safety management by use of laser mass spectrometry of polychlorinated biphenyls (PCBs) in the processed gas and work environment of a PCB disposal plant

This study demonstrates the applicability of laser mass spectrometry for safety management of the processed gas and the work environment in a polychlorinated biphenyl (PCB) disposal plant. By utilization of laser ionization/ion trapping storage/time-of-flight mass spectrometry (LI-IT-TOFMS), we analyzed gaseous PCBs from scrap capacitors with on-line detection. It was confirmed that few contaminants were detected in the spectrum. By the effect of laser-induced selective ionization, it was considered that there was little interference with the mass range of PCBs. The accuracy of LI-IT-TOFMS when analyzing environmental gas was almost the same as that for the PCB standard gas. It was possible to perform on-line analysis of the work environment for over 2000 h (120 000 data points). LI-IT-TOFMS was thus shown to be a very useful method for ensuring the safety of the work environment in disposal plants for PCBs.     

Degradation of 2,7-dichlorodibenzo-p-dioxin by Fe(3+)-H(2)O(2) mixed reagent

Fe(3+)-H(2)O(2) mixed reagent, but not Fe(2+)-H(2)O(2), was found to be capable of degrading 2,7-dichlorodibenzo-p-dioxin (DCDD). A reaction mixture of FeCl(3) (8 mM) and H(2)O(2) (1%) caused approximately 50% degradation within 6 h and >90% degradation within 24 h at 27 degrees C. Increasing the temperature remarkably stimulated degradation: at 70 degrees C, approximately 100% degradation was achieved within 15 min. When DCDD-treated model soil (5 micrograms/g) was conducted, approximately 100% of the DCDD was degraded within 30 min at 70 degrees C (both reagents were added every 10 min). These results suggest that Fe(3+)-H(2)O(2) mixed reagent may be a new tool for combating persistent environmental pollutants such as dioxins and polychlorinated biphenyls.     

Performance and efficiency of removal of pharmaceutical compounds from hospital wastewater by lab-scale biological treatment system

The fate of pharmaceuticals after discharged from hospital into wastewater was clarified experimentally by using a new lab-scale conventional activated sludge (CAS) treatment reactor. The 43 target compounds belong to nine therapeutic classes (antivirals, antibacterials, anticancer drugs, psychotropics, antihypertensives, analgesic–antipyretics, contrast media, herbal medicines, and phytoestrogens) were selected with inclusion of 16 newly estimated compounds. The efficiency of the present reactor was estimated by comparing the reaction rate constant of the solid-water partition coefficients (log K_d) between liquid and solid samples and half-life during 48-h experiment obtained by using hospital effluents with those obtained by using STP wastewater. The results that no significant difference in removal efficiency was observed between both water samples (P?>?0.05) indicate high reliability of the present lab-scale reactor. The actual rates of removal when hospital effluent was applied varied widely (mean, 59?±?40%) independent of type of the pharmaceuticals. More than 90% of 17 compounds were removed after 8 h of treatment. However, the values for psychotropics (mean, 19?±?26%) and contrast media (mean, 24?±?17%) were generally low, indicating high stability. The log K_d values ranged from 1.3 to 4.8. Notably, clarithromycin, acridine, and glycitein could be removed in both liquid and solid phases. The dominant removal mechanisms were found to be different for individual pharmaceutical. These results suggest the effectiveness of introduction of the lab-scale biological treatment system for development of a new solution for discharge of pharmaceuticals from hospital.

     

Regimes of human and climate impacts on coastal changes in Vietnam

Vietnam is a tropical to subtropical country located on the eastern Asian coast where the Red (Song Hong) and Mekong rivers discharge into the sea. The catchments of these two transboundary rivers cover parts of six countries, and their water and sediment discharges greatly influence the coastal seas of Vietnam. The impact of human activities include changes in the supply and distribution of water, sediments, and nutrients; changes in the relationships and balance among dynamically interacting factors and processes; and changes in the quality of the coastal and marine environments due to the increased use and accumulation of pollutants and the loss of habitats. These impacts have resulted in increasing unpredictability and severity of coastal problems such as floods, erosion, sedimentation, and saltwater intrusion; environmental pollution; and the degradation of ecosystems, with accompanying decrease in biodiversity and fishery productivity.     

Global Supply of Biomass for Energy and Carbon Sequestration from Afforestation/Reforestation Activities

In this paper we provide an analytical framework to estimate the joint production of biomass and carbon sequestration from afforestation and reforestation activities. The analysis is based on geographical explicit information on a half-degree resolution. For each grid-cell the model estimates forest growth using a global vegetation model and chooses forest management rules. Land prices, cost of forest production and harvesting are determined as a function of grid specific site productivity, population density and estimates of economic wealth. The sensitivity of the results due to scenario storylines is assessed using different population and economic growth assumptions, which are consistent with B1 and A2 of the Intergovernmental Panel on Climate Change Special Report on Emission Scenarios (IPCC-SRES) marker scenarios. Considerable differences in the economic supply schedules are found. However, technical potentials seem to converge given constancy in other underlying assumptions of the model.     

Effects of low protein diet and sex difference on the amounts of metallothionein in liver and kidney of cadmium-administered rats

Cadmium (Cd) was orally administered in a dose of 100 μg daily for a total of 100 times to investigate the effects of the intake of low (5%) protein diet and sex difference on the amounts of metallothionein (MT) in the liver and kidney. The amount of MT in the liver was significantly increased by the intake of low protein diet. In females, the increase in the amount of MT was proportional to the amount of Cd accumulated. The concentration of copper-thionein in the liver was higher in females than in males and further increased after intake of low protein diet. The levels of MT, cadmium-thionein, zinc-thionein and copper-thionein in the kidney were not influenced by the intake of low protein diet nor did show a sex difference.     

Two-stage thermal gasification of polyolefins

Plastic pellets of polyethylene (PE), polypropylene (PP), and polystyrene (PS) were gasified in a two-stage thermal degradation process. The first stage is the conversion of polyolefins to distilled oils using a melting vessel. In the second stage, the oils from the first stage are gasified using a tubular reactor. The distilled oil yields of PE, PP, and PS in the first stage were 84, 89, 92 wt%, respectively, each at 470°C. The total gas yields of PE, PP, and PS in the second stage were 80, 74, and 6.2 wt%, respectively, each at 800°C. The main components of the product gas for PE and PP were methane and olefins such as ethene and propene. Some aromatic oils, including benzene, toluene, and xylene, were also produced as by-products. The amount of carbonaceous residue, or coke, was very low (less than 1 wt%). By dividing the process into two stages, the coking rate was considerably reduced compared with direct gasification of the polyolefins. Received: July 19, 2000 / Accepted: September 17, 2000     

Effects of amine, amine salt and amide on the behaviour of carbon dioxide absorption into calcium hydroxide suspension to precipitate calcium carbonate

The amount of carbon dioxide （CO2） absorption and calcium ion （Ca^2＋） concentration besides the pH of aqueous solution were observed during the COz absorption to precipitate calcium carbonate （CaCO3） from calcium hydroxide （Ca（OH）2）. A reaction rate-limiting effect of an amount of CO2 absorption without any organic additives in the early stage of the precipitation was observed, which was attributed to an interruption effect of bicarbonate ion （HCO3） on the precipitation of CaCO3. The improvement for the reaction rate was achieved not only by amine additives but also by neutral additives such as ε-caprolactam or amine salt. When the hexamethylene diamine was dissolved in the solution, successive change of crystal forms of CaCO3 aragonite to calcite in aqueous suspensions, confirmed by Ca^2＋ concentration change and X-ray diffraction, was concluded that a local environment around the amine group in aqueous solution and an interaction of the diamine with precipitated CaCO3 particles were important factors for these reactions.