Accumulation of paralytic shellfish poisoning toxins in planktonic copepods during a bloom of the toxic dinoflagellate<Emphasis Type="Italic"> Alexandrium tamarense</Emphasis> in Hiroshima Bay,western Japan

Concentrations of paralytic shellfish poisoning (PSP) toxins in toxic dinoflagellate cells and in marine planktonic copepods were monitored during the bloom of Alexandrium tamarense in Hiroshima Bay, western Japan. Concentration of the toxins retained by copepods was a function of the ambient toxin concentration, i.e. the product of A. tamarense cell density and cellular toxicity. The toxin concentration in copepods increased with the increase of toxicants in the seawater then leveled off, but decreased significantly at higher concentrations. In the field, the maximum toxin concentration was 1.2 pmol ind^-1, whereas in the laboratory, the copepod Acartia omorii accumulated a much higher concentration of PSP toxins (24 pmol ind^-1). Feeding avoidance against Alexandrium tamarense and a shift to alternative food sources such as diatoms in the field might keep their toxin levels lower than their potentially maximum level. The copepod toxin levels in the field were not so high as to cause an instantaneous lethal effect on their predator fishes but may reach possibly lethal levels after a few days' continuous feeding. Overall toxin retention by copepods after 12 h feeding and 2 h starvation was only 2.5% of total ingested toxins, which suggested that a significant amount of toxins was released into the seawater. Measurements of toxin reduction and gut evacuation suggested that the toxins were removed through both fecal evacuation and metabolism (e.g. excretion, decomposition and transformation). The results, as a whole, imply that copepods can be a link for PSP toxin flux in both pelagic and benthic food webs and can also be a sink for toxins by metabolizing and removing them from the environment.Communicated by T. Ikeda, Hakodate     

Effectiveness of interventions to induce waste segregation by households: evidence from a randomized controlled trial in Mozambique

Journal of Material Cycles and Waste Management - The City Council of Maputo (CMM) and the Japan International Cooperation Agency (JICA) began a pilot project to introduce segregated waste...     

Development of a Practical Method to Detect Noroviruses Contamination in Composite Meals

Various methods to detect foodborne viruses including norovirus (NoV) in contaminated food have been developed. However, a practical method suitable for routine examination that can be applied for the detection of NoVs in oily, fatty, or emulsive food has not been established. In this study, we developed a new extraction and concentration method for detecting NoVs in contaminated composite meals. We spiked NoV-GI.4 or -GII.4 stool suspension into potato salad and stir-fried noodles. The food samples were suspended in homogenizing buffer and centrifuged to obtain a food emulsion. Then, anti-NoV-GI.4 or anti-NoV-GII.4 rabbit serum raised against recombinant virus-like particles or commercially available human gamma globulin and Staphylococcus aureus fixed with formalin as a source of protein A were added to the food emulsion. NoV-IgG-protein A-containing bacterial complexes were collected by centrifugation, and viral RNA was extracted. The detection limits of NoV RNA were 10–35 copies/g food for spiked NoVs in potato salad and stir-fried noodles. Human gamma globulin could also concentrate other NoV genotypes as well as other foodborne viruses, including sapovirus, hepatitis A virus, and adenovirus. This newly developed method can be used as to identify NoV contamination in composite foods and is also possibly applicable to other foodborne viruses.     

Environmental impact evaluation of feeds prepared from food residues using life cycle assessment

There is increasing concern about feeds prepared from food residues (FFR) from an environmental viewpoint; however, various forms of energy are consumed in the production of FFR. Environmental impacts of three scenarios were therefore investigated and compared using life cycle assessment (LCA): production of liquid FFR by sterilization with heat (LQ), production of dehydrated FFR by dehydration (DH), and disposal of food residues by incineration (IC). The functional unit was defined as 1 kg dry matter of produced feed standardized to a fixed energy content. The system boundaries included collection of food residues and production of feed from food residues. In IC, food residues are incinerated as waste, and thus the impacts of production and transportation of commercial concentrate feeds equivalent to the FFR in the other scenarios are included in the analysis. Our results suggested that the average amounts of greenhouse gas (GHG) emissions from LQ, DH, and IC were 268, 1073, and 1066 g of CO(2) equivalent, respectively. The amount of GHG emissions from LQ was remarkably small, indicating that LQ was effective for reducing the environmental impact of animal production. Although the average amount of GHG emissions from DH was nearly equal to that from IC, a large variation of GHG emissions was observed among the DH units. The energy consumption of the three scenarios followed a pattern similar to that of GHG emissions. The water consumption of the FFR-producing units was remarkably smaller than that of IC due to the large volumes of water consumed in forage crop production.     

Remediation of cadmium contamination in paddy soils by washing with chemicals: selection of washing chemicals

The efficiencies of neutral salts, strong acids, and chelates were tested for extracting cadmium (Cd) from three paddy soils. The higher the selectivity of the cations of the added neutral salts toward soil adsorption sites, the lower the pH in the extracts and the more soil Cd could be extracted. In addition, soil carbon and nitrogen contents and mineral composition were closely associated with the amount of Cd extracted. Calcium chloride and iron(III) chloride were selected as wash chemicals to restore Cd-contaminated paddy soils in situ. Washing with calcium chloride led to the formation of Cd chloride complexes, enhancing Cd extraction from the soils. The washing also substantially decreased soil levels of exchangeable and acid-soluble Cd, which are the major forms of bioavailable Cd for rice (Oryza sativa L.). The optimum conditions for in situ soil washing were also determined for calcium chloride.     

Cadmium,copper, and zinc in carrots in Japan

Cadmium (Cd), copper (Cu), and zinc (Zn) in carrots obtained from different regions throughout Japan were assessed in a baseline study on the contents of trace metals in foods. These three metals were measured by flameless atomic absorption spectrophotometry. The geometric mean contents (with one geometric standard deviation indicated in parentheses) of Cd, Cu, and Zn were 0.02 (2.2), 0.7 (2.1), and 2.4 (1.6) mg?kg^?1 wet weight in carrots obtained in Japan. While there was a close relationship among the contents of the three metals in the carrots grown in Cambisols and Gleysols, a significant relationship was recognized only between the contents of Cd and Zn in those grown in Andosols and Fluvic Gleysols. Cd and Zn are classified as 2B metals in the periodic table of elements, and the authors speculate that the similarity of the metal characteristics between Cd and Zn may be responsible for the close relationship in the contents of the two metals, with no relation to the soil type.     

Trisomy 12 mosaicism in phenotypically normal fetuses following prenatal detection

We report three cases of amniocentesis in which mosaicism for trisomy 12 was detected in two or more independent cultures. The parents elected to terminate the pregnancy in all three cases. Follow-up studies in two of the cases confirmed the mosaicism in fetal tissues (in subcutaneous tissue in one case; in fetal lung in the other), but not in blood. No fetal anomalies were evident by ultrasound or at autopsy. These results along with other reported cases demonstrate the difficulty in counselling for mosaic trisomy 12.     

A Survey of Perception, Knowledge, Awareness, and attitude in Regard to Environmental Problems in a Sample of two Different Social Groups in Jakarta, Indonesia

A quantitative study was conducted in 1998 to investigate differences in perception, knowledge, awareness, and attitude with regard to environmental problems between educated and community groups and to identify human-dimension factors to improve public perception, knowledge, awareness, and attitude in relation to global environmental conservation concerns in developing countries. Educated and community groups in Jakarta were interviewed, and data obtained from a total of 537 males aged 30-49 years were analyzed. The data were evaluated by the chi-squared test and logistic regression was applied after factor analysis. The results show that: (1) The perception, knowledge, awareness, and attitude of educated subjects in regard to regional and global environmental problems were much better than those of subjects in the community group; (2) The highest 'yes' response in the community group was in regard to perception of AIDS (82.9%). Few subjects in the community group knew the effects and the cause or source of environmental problems, however, they were well informed about AIDS (86.4% for effects and 93.9% for cause or source). The conclusions are: (1) subjects in the educated group had better perception, more detailed knowledge, were more aware, and had better attitudes in regard to regional and global environmental problems than those in the community group; (2) more education is needed to develop environmental actions and ethics in developing countries; (3) non-formal environmental education through popular mass media should be used more widely and frequently, and more detailed information on the environment should be provided to literate people by newspapers and other means.     

Hesitation behaviour of hoverflies Sphaerophoria spp. to avoid ambush by crab spiders

Pollinators possess several antipredator adaptations that minimise predation risk during foraging. In addition to morphological adaptations, hoverflies might have behavioural antipredator adaptations. We conducted three field experiments to investigate whether the "hesitation behaviour" of hoverflies Sphaerophoria spp., moving backwards and forwards in front of a flower, is effective in avoiding ambush predators on flowers. First, we compared the behaviour of different flower visitors, including several bees and other hoverflies, with Sphaerophoria spp. behaviour. Only Sphaerophoria spp. exhibited the hesitation behaviour in front of flowers. The flight behaviour was observed more frequently before landing on flowers than on leaves. Second, we investigated rejection by Sphaerophoria spp. to artificially placed corpses of the crab spider Thomisus labefactus. The rejection rate of flowers with a crab spider placed on or under it was significantly higher than that of non-treated flowers. Moreover, the presence of a spider on the flower decreased the number of hesitation displays, compared with non-treated flowers. Finally, to determine whether hesitation behaviour could be a consequence of floral assessment, we investigated hoverfly rejection of previously foraged flowers. Sphaerophoria spp. did not reject flowers that had been visited by the same individual or conspecifics within 3 min. We suggest that hesitation behaviour may be adaptive, enabling assessment of predation risk and hence avoiding ambush predators on flowers.