Framing of Geoengineering Affects Support for Climate Change Mitigation

The growing recognition that climate change mitigation alone will be inadequate has led scientists and policymakers to discuss climate geoengineering. An experiment with a US sample found, contrary to previous research, that reading about geoengineering did not reduce conservatives’ skepticism about the existence of anthropogenic climate change. Moreover, depending on how it is framed, geoengineering can reduce support for mitigation among both conservatives and non-conservatives. When geoengineering is framed as a major solution, people worry less about climate change, leading to reduced mitigation support. When framed as disastrous, people perceived geoengineering as riskier, also leading to a decrease in mitigation support. A more moderate framing of geoengineering as a partial solution is less susceptible to moral hazard effects. Overall, results suggest that geoengineering will not lessen political polarization over anthropogenic climate change, and could undercut support for mitigation efforts. Instead, framing geoengineering as a small piece to solving a big puzzle seems to be the best strategy to weaken this potential moral hazard.     

Effect of different soil layers on porewater to remediate acidic surface environment at a close mine site

This paper describes the chemistry of porewater when constructing different soil layers on acidic weathered rock of a closed mine to remediate the surface environment. Three cases were set on a flat surface of the site, all under different layer systems. Case 1 was only composed of weathered rocks. A top neutralization layer was constructed on the weathered rocks in case 2, whereas both an upper low-permeable and middle neutralization layers were constructed on the weathered rocks in case 3. The low-permeable layer of 30?cm thick consists of clay, and the neutralization layer of 30?cm thick consists of the mixture of the weathered rock and calcium carbonate as a neutralizer. Porewater sampling systems and soil sensors to measure temperature, water content, and electrical conductivity were set at different depths. In case 1, steadily high concentrations of heavy metals were observed regardless of the depth, and the pH ranged from 2 to 4. In cases 2 and 3, a dramatic decrease in concentrations of heavy metals was observed, even below the neutralization layer. For both cases, pH values were circumneutral. There were no significant seasonable changes in heavy metals concentrations and pH of porewater by considering the temperature and precipitation. In addition, the water content of the layers in case 3 fluctuated more mildly than that in cases 1 and 2, indicating that the low-permeable layer reduced the rate of infiltration. Therefore, a significant reduction in the load of heavy metals released from the site can be achieved by both implementing neutralization and low-permeable layers.     

Time series analysis for the estimation of tidal fluctuation effect on different aquifers in a small coastal area of Saijo plain, Ehime prefecture, Japan

Considering the current poor understanding of the seawater–freshwater (SW–FW) interaction pattern at dynamic hydro-geological boundary of coastal aquifers, this work strives to study tidal effect on groundwater quality using chemical tracers combined with environmental isotopes. In situ measurement data of electrical conductivity and groundwater level along with laboratory measurement data of hydro-chemical species were compared with tidal level data measured by Hydrographic and Oceanographic Department, Saijo City, Japan for time series analysis. Result shows that diurnal tides have significant effect on groundwater level as well as its chemical characteristics; however, the magnitude of effect is different in case of different aquifers. Various scatter diagrams were plotted in order to infer mechanisms responsible for water quality change with tidal phase, and results show that cations exchange, selective movement and local SW–FW mixing were likely to be the main processes responsible for water quality changes. It was also found that geological structure of the aquifers is the most important factor affecting the intensity of tidal effect on water quality.     

Inhibition of attachment of larval barnacles,Balanus amphitrite,by bacterial surface films

Films of bacteria on solid substrata can positively or negatively influence the attachment of marine invertebrate larvae. Effects of marine bacteria on the attachment of cypris larvae of the barnacle Balanus amphitrite Darwin were examined in the laboratory. Bacteria, grown to mid-exponential phase and allowed to adsorb irreversibly to polystyrene petri dishes, attached in densities of 10⁷ cells cm^-2. Assays (22h) were used to compare the effects of adsorbed cells of 18 different bacterial species on larval barnacle attachment. Most of the adsorbed bacteria either inhibited or had no effect on larval attachment compared to clean surfaces. Experiments testing the effect of larval age on barnacle attachment were conducted with six species of bacteria and showed that older larvae attached in higher percentages to clean surfaces and that bacterial films generally inhibited larval attaschment. Both the species of bacteria and the in situ age of the adsorbed bacteria affected barnacle attachment response: older films of Deleya (Pseudomonas) marina were more inhibitory. Bacterial extracellular materials may be involved in the inhibitory process.     

Salmonella typhimurium survival and viability is unaltered by suspended particles in freshwater

Rolling microcosm experiments were conducted to determine whether suspended particles affect the survival and viability of a model pathogen, Salmonella choleraesuis, serotype typhimurium (American Type Culture Collection no. 23567), in a freshwater microbial community. Water from the Duluth, MN harbor of Lake Superior (including native microorganisms) was inoculated with clay, silt, or flocculent organic particles in a range of concentrations and a streptomycin-resistant strain of S. typhimurium. Microcosms (incubated at 20 degrees C) were rolled horizontally (3 rpm) and sampled periodically for total bacteria and total, viable, and culturable S. typhimurium. Total S. typhimurium abundance decreased rapidly in all experiments (8.5-73.1% d-1). Total bacteria did not decrease as rapidly as the S. typhimurium population in any experiment, suggesting that a microcosm effect was not responsible for the decline in S. typhimurium populations. Loss rates of attached and free cells were similar, indicating that attachment to particles did not enhance the persistence of Salmonella cells beyond our minimum detectable differences. After eight days, only 0.1 to 11.9% of the initial S. typhimurium inocula were detected by direct counts. Suspended particles had a minimal effect on the survival and viability of S. typhimurium; the losses of total, viable, or culturable Salmonella were generally the same across particle treatments and concentrations. Silt and flocculent particles affected loss rates of total and viable S. typhimurium similarly to inorganic particles (clay). It appears unlikely that suspended particles would provide a means for S. typhimurium to persist at hazardous levels in freshwater.     

沙漠绿洲的开发与环境变化的相互影响

干旱区的农业活动、特别是沙漠绿洲的开发,改变了地-气系统的能量交换。几年来的沙漠绿洲气候与防风林的研究、气候资料的分析和实地考察表明,中国西部干旱区最近４３年来的沙漠绿洲开发已改变着那里的局地气候环境,使其向有利于人类和农业的方向发展着。在沙漠绿洲的开发利用与局地环境变化之间,存在着两种截然相反的反馈作用：环境变好→绿洲发展→环境更好→绿洲再发展;环境恶化→绿洲退化→环境更坏→绿洲再退化,甚至消失。决定这两种反馈作用的是大环境的变迁和绿洲开发利用中是否合理利用资源和按自然规律办事。     

Persistent organochlorines in raccoon dogs (Nyctereutes procyonoides) from Japan: Hepatic sequestration of oxychlordane

The present study determined the accumulation features of persistent organochlorines (OCs) such as polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), hexachlorobenzene (HCB), and chlordane compounds (CHLs) in wild raccoon dogs (RDs; Nyctereutes procyonoides) collected from Kanagawa prefecture in Japan during 2001. In livers of RDs, CHLs were remarkably dominant (20 times higher than PCBs) followed by PCBs>DDTs>HCHs>HCB, whereas the chemicals in muscles were in the order of CHLs>PCBs>HCHs>DDTs>HCB. The accumulation pattern of OCs in RDs was different from those in Japanese humans and avian species reported previously, which generally accumulate higher levels of DDTs and PCBs than CHLs. This result indicates that RDs have been exposed to relatively high levels of CHLs and have high metabolic and elimination capacity for DDTs. In fact, CHL levels in RDs were higher than those in humans and some avian species, while DDT levels in RDs were much lower than other animals. In particular, extremely high accumulation levels of oxychlordane, which is a metabolite from chlordanes and nonachlors, were observed in RD livers. The higher toxic potency of oxychlordane than parent compounds may suggest that RDs are at high risk by this metabolite. On lipid weight basis, PCBs, HCHs and HCB levels were almost similar in livers and muscles, suggesting that the tissue distribution of these compounds principally followed the lipid-dependent accumulation. However, accumulation levels of oxychlordane and p,p'-DDD in livers were significantly higher than those in muscles, and concentration ratios of liver to muscle (L/M ratios) of these compounds were greater than 1.0 in all the specimens. This phenomenon was similar to PCDD/DF congener accumulation patterns observed previously in RDs. When relationships between hepatic TEQs and L/M ratios were examined for oxychlordane and p,p'-DDD, L/M ratios for these compounds significantly increased with hepatic TEQ levels, suggesting their hepatic sequestration in TEQs-dependent manner.     

PCDDs, PCDFs, and coplanar PCBs in wild terrestrial mammals from Japan: congener specific accumulation and hepatic sequestration

The present study determined the contamination levels and congener-specific accumulation features of dioxins and related compounds (DRCs) in wild terrestrial mammals such as large Japanese field mice (LJFM), lesser Japanese moles (LJMs), and raccoon dogs (RDs) collected from Kanto region in Japan during 2001. The toxic equivalent quantity (TEQ) levels in the carcasses or adipose tissues were in the order of RDs > or = LJMs > LJFM. Comparison of DRC congener profiles in the three species and principal component analysis (PCA) demonstrated a higher contribution of OCDD, T4CB77, and P5CB118 in LJMs. Analysis of liver-adipose distribution of DRC congeners in RDs showed that livers contained significantly higher TEQs than adipose tissues, indicating that liver is a depository organ and critical for determining the toxicokinetics of DRCs. As for most T4, P5, H6CDD/DFs and for P5CB126, H6CB169 and mono-ortho PCB congeners, their liver/adipose concentration ratios in RDs revealed a tendency to increase with hepatic TEQ levels, suggesting TEQ-dependent hepatic sequestration.     

Potential increase in mating frequency of queens in feral colonies of Bombus terrestris introduced into Japan

With the exception of several species, bumblebees are monandrous. We examined mating frequency in feral colonies of the introduced bumblebee Bombus terrestris in Japan. Using microsatellite markers, genotyping of sperm DNA stored in the spermatheca of nine queens detected multiple insemination paternities in one queen; the others were singly mated. The average effective paternity frequency estimated from the genotypes of queens and workers was 1.23; that estimated from the workers’ genotype alone was 2.12. These values were greater than those of laboratory-reared colonies in the native ranges of B. terrestris. The genotypes of one or two workers did not match those of their queens or showed paternities different from those of their nestmates; this may have arisen from either queen takeover or drifting of workers. These alien workers were responsible for the heterogeneous genotype distribution within each B. terrestris colony, resulting in higher estimates of paternity frequency than of insemination frequency. The high mating frequency of introduced B. terrestris may have occurred by artificial selection through mass breeding for commercialization. Moreover, polyandrous queens may be selectively advantageous, because reproduction by such queens is less likely to be disturbed by interspecific mating than that by monandrous queens.     

Polychlorinated biphenyl (118) activates osteoclasts and induces bone resorption in goldfish

To analyze the effect of polychlorinated biphenyl (PCB) 118 on fish bone metabolism, we examined osteoclastic and osteoblastic activities, as well as plasma calcium levels, in the scales of PCB (118)-injected goldfish. In addition, effect of PCB (118) on osteoclasts and osteoblasts was investigated in vitro. Immature goldfish, in which the endogenous effects of sex steroids are negligible, were used. PCB (118) was solubilized in dimethyl sulfoxide at a concentration of 10 ppm. At 1 and 2 days after PCB (118) injection (100 ng/g body weight), both osteoclastic and osteoblastic activities, and plasma calcium levels were measured. In an in vitro study, then, both osteoclastic and osteoblastic activities as well as each marker mRNA expression were examined. At 2 days, scale osteoclastic activity in PCB (118)-injected goldfish increased significantly, while osteoblastic activity did not change significantly. Corresponding to osteoclastic activity, plasma calcium levels increased significantly at 2 days after PCB (118) administration. Osteoclastic activation also occurred in the marker enzyme activities and mRNA expressions in vitro. Thus, we conclude that PCB (118) disrupts bone metabolism in goldfish both in vivo and in vitro experiments.