金华市义乌江沉积物磁性特征与重金属污染

对浙江省金华市义乌江采集的边滩沉积物柱样,进行了系统的环境磁学、粒度、地球化学分析,以探讨环境磁学方法诊断河流沉积物重金属污染的可行性.结果表明,柱样磁性特征由亚铁磁性矿物主导,其垂向变化受到粒度和早期成岩作用的一定影响.柱样中重金属Cr、Ni、Cu、Zn、Cd、Pb含量及其富集因子除底部外,自下而上呈增加趋势,指示了柱样上部存在人为来源的重金属污染.柱样沉积物磁性特征与重金属含量及其富集因子的垂向变化存在相似性,其中磁化率(χ)、频率磁化率(χfd%)和硬剩磁(HIRM)与Cr、Cu、Zn、Cd、Pb的含量具有显著的正相关关系,反映了磁性矿物与重金属具有相同的来源,或者细颗粒磁性矿物对重金属的吸附作用.上述结果表明,磁学方法可用于指示义乌江的重金属污染.但由于义乌江属于开放性的河流环境系统,磁性特征变化受多重因素影响,增加了利用磁学手段定量诊断重金属污染的复杂性.     

Early murine immune responses from endotracheal exposures to biotechnology-related Bacillus strains

An immunology-based in vivo screening regime was used to assess the potential pathogenicity of biotechnology-related microbes. Strains of Bacillus cereus (Bc), Bacillus subtilis (Bs), Bacillus thuringiensis (Bt), and Bt commercial products (CPs) were tested. Balb/c mice were endotracheally instilled with purified spores, diluted CP, or vegetative cells (VC) (live or dead). Exposed mice were evaluated for changes in behavioral and physical symptoms, bacterial clearance, pulmonary granulocytes, and pulmonary and circulatory pyrogenic cytokines (interleukins (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α), as well as acute phase biomarkers (fibrinogen and serum amyloid A). Except for some differences in clearance rates, no marked effects were observed in mice exposed to any spore at 10⁶ or 10⁷ colony forming units (cfu). In contrast, live Bc or Bt VCs (10⁵ or 10⁶?cfu) produced shock-like symptoms (lethargy, hunched appearance, ruffled fur, and respiratory distress), and 11–200-fold elevations in pyrogenic cytokines at 2-h post-exposure. In the study, 4-h effects included increased lethargy, ocular discharge, and 1.5–4-fold rise in circulatory acute phase markers, but no indications of recovery. Bs VC did not produce any changes in symptoms or biomarkers. After 2 or 4?h of exposure to dead VC, increases of only plasma IL-1β and TNF-α (4.6- and 12.4-fold, respectively) were observed. These findings demonstrate that purified spores produced no marked effects in mice compared to that of metabolically active bacteria. This early screening regime was successful in distinguishing the pathogenicity of the different Bacillus species, and might be useful for assessing the relative hazard potential of other biotechnology-related candidate strains.     

Treatment and skin decontamination of sarin intoxicated mice

Abstract

This study aimed at evaluating the efficacy of oral treatment and skin decontamination with the mineral cationic carrier in sarin-intoxicated mice. Mice were contaminated with increasing percutaneous sarin doses and decontaminated. Furthermore, the surviving mice were treated per os. The behavioral patterns of the surviving animals were monitored for 72?h, including the animals’ posture, desire for food and water, and approach and touch response. The results showed the mineral cationic carrier to be capable of efficiently decontaminating animals percutaneous poisoned with triple lethal dose. The comparison of behavioral pattern of control animals against those treated per os showed statistically significant differences. Oral treatment with mineral cationic carrier may be a detoxification tool against nerve agents’ poisoning, and this merits further research.     

Die Fungizide Hexachlorbenzol und Pentachlornitrobenzol und ihre Stoffwechselwege

Die Kenntnis biochemischer Veränderungen von lipophilen körperfremden Stoffen ist hinsichtlich deren Elimination aus dem Organismus, sowie bei Überlegungen zur Voraussage toxischer, insbesondere carcinogener Wirkungen von vorrangiger Bedeutung     

Individual differences in sampling behaviour predict social information use in zebra finches

When animals have to decide where to forage, what to eat or with whom to mate, they can base their decisions on either socially or personally acquired information. In accordance with theoretical predictions, there is experimental evidence that animals adjust the weight they give to both sources of information depending on circumstances. Notably, several studies have demonstrated that individuals rely more on social information when personal information is difficult to acquire or unreliable, because these conditions leave them uncertain as how to behave. Yet, even when individuals are exposed to the same conditions, they generally differ widely in the value they attribute to social and personal information. These differences suggest that the tendency to rely on social information would also depend on intrinsic characteristics that affect, for instance, individual efficiency in collecting personal information. To address this issue, we conducted laboratory experiments using female zebra finches (Taeniopygia guttata) and we tested them under three consecutive conditions. First, we evaluated their reliance on social information in a mating context and in a foraging context. Then, we measured their efficiency in acquiring personal information by recording their sampling behaviour when searching for hidden food. We found that females that sampled their environment less actively consistently relied on social information to a greater extent compared with those that invested more in sampling. Contrary to what is generally assumed, then, our study demonstrates that social information use is not entirely flexible and context dependent.     

Energy reduction of a submerged membrane bioreactor using a polytetrafluoroethylene (PTFE) hollow-fiber membrane

The fiber length and packing density of the PTFE membrane element were increased. The MBR was stably operated under an SAD^m of 0.13 m³·m^-2·hr^-1. Specific energy consumption was estimated to be less than 0.4 kWh·m^-3. In this study, we modified a polytetrafluoroethylene (PTFE) hollow-fiber membrane element used for submerged membrane bioreactors (MBRs) to reduce the energy consumption during MBR processes. The high mechanical strength of the PTFE membrane made it possible to increase the effective length of the membrane fiber from 2 to 3 m. In addition, the packing density was increased by 20% by optimizing the membrane element configuration. These modifications improve the efficiency of membrane cleaning associated with aeration. The target of specific energy consumption was less than 0.4 kWh·m^-3 in this study. The continuous operation of a pilot MBR treating real municipal wastewater revealed that the MBR utilizing the modified membrane element can be stably operated under a specific air demand per membrane surface area (SAD_m) of 0.13 m³·m^-2·hr^-1 when the daily-averaged membrane fluxes for the constant flow rate and flow rate fluctuating modes of operation were set to 0.6 and 0.5 m³·m^-2·d^-1, respectively. The specific energy consumption under these operating conditions was estimated to be less than 0.37 kWh·m^-3. These results strongly suggest that operating an MBR equipped with the modified membrane element with a specific energy consumption of less than 0.4 kWh·m^-3 is highly possible.     

Anthropogenic influence on surface water quality of the Nhue and Day sub-river systems in Vietnam

In order to investigate the temporal and spatial variations of 14 physical and chemical surface water parameters in the Nhue and Day sub-river systems of Vietnam, surface water samples were taken from 43 sampling sites during the dry and rainy seasons in 2007. The results were statistically examined by Mann–Whitney U-test and hierarchical cluster analysis. The results show that water quality of the Day River was significantly improved during the rainy season while this was not the case of the Nhue River. However, the river water did not meet the Vietnamese surface water quality standards for dissolved oxygen (DO), biological oxygen demand (BOD₅), chemical oxygen demand (COD), nutrients, total coliform, and fecal coliform. This implies that the health of local communities using untreated river water for drinking purposes as well as irrigation of vegetables may be at risk. Forty-three sampling sites were grouped into four main clusters on the basis of water quality characteristics with particular reference to geographic location and land use and revealed the contamination levels from anthropogenic sources.     

Rice straw-base power generation: a potential and economic cost–benefit analysis for a small power plant (10 MWe) in Vietnam

Journal of Material Cycles and Waste Management - The main objective of the study is to explore the economic feasibility of power generation from rice straw, a potential biomass energy resource, in...     

Peracetic Acid Sanitation on Arugula Microgreens Contaminated with Surface-Attached and Internalized Tulane Virus and Rotavirus

Food and Environmental Virology - Hydroponic production of vegetables is becoming more common, especially in regions with unfavorable climate for year-round crop production. However, if viruses are...     

Lead contamination in surface soil on roads from used lead–acid battery recycling in Dong Mai,Northern Vietnam

Used lead–acid battery (ULAB) recycling has caused numerous health and environmental issues in developing countries. Surface soil pollution from ULAB recycling activities has been linked with elevated levels of lead in human blood. We measured surface soil lead in and surrounding the ULAB recycling village of Hung Yen in northern Vietnam in 2011, 2013, and 2014. The data were analyzed statistically and discussed with respect to distance from the contamination source, year of measurement, contamination pathway, and countermeasures against the contamination. Transportation routes from the smelter or collection site displayed the greatest concentration of surface soil lead (median 6400–10,000 mg/kg). Surface soil lead decreased significantly with distance along the road from the ULAB recycling site, although such a decrease was not observed for rice fields, agricultural roads, or garden soil. Re-suspension and adherence by traffic were identified as key pollution pathways. Distance from the source, covering of the surface of roads, construction of walls, and position relative to the source were shown to be the most effective factors in the reduction of surface soil lead pollution. Application of a combination of these measures should result in improvement in the health of residents.