日本Biwai湖-Yodo河水体系的可持续管理

Biwa湖 Yodo河水系为主要的居民中心及其周围的市政机构提供城市用水和工业用水 .它也提供农业用水，主要在 Biwa湖排水区域 .该水系服务的人口总数约为 1400万人 . 这个水系构成了 Keihanshin工业区的主要部分（按照字面上是指京都、大阪和神户），这是一个以沿大阪海湾－濑户内海的狭长地带发展为特征的一个区域 .Keihanshin的工业产值居日本的第三位，约占国内生产总值的 12.4％ .一个复杂的供水网和废水网支持着高水平的工业和农业活动 .     

Participation of the C-type hemolymph lectin in mineralization of the acorn barnacle Megabalanus rosa

BRA-2, a major C-type lectin in the hemolymph of the acorn barnacle Megabalanus rosa was detected in shell-associated proteins. Immobilized BRA-2 promoted CaCO₃ crystallization as determined by an in vitro pH-drift mineralization assay. In nature, calcification occurs as wound repair in M. rosa after breakage of the shell plate. To observe this phenomenon, we inserted a rubber cube inside the mantle cavity of M. rosa through the basal plate, and kept the organisms in a tank for several weeks. The rubber cube was covered first with brownish-colored material, probably a melanin, and then with CaCO₃ 5 weeks after the insertion. In the CaCO₃-associated proteins, BRA-3, a minor component of M. rosa hemolymph lectins, was present in addition to BRA-2. The presence of both the lectins and their ligands on the hemocyte was also observed. These results suggest that the C-type lectins of the M. rosa hemolymph participate in mineralization as well as defense in these organisms.     

A comparison of water solubilities by the flask and micro-column methods

A comparative examination of the two procedures of the OECD Test Guideline: Water Solubility was undertaken using carbazole, fluoranthene, anthracene, hexachlorobenzene, p-nitroaniline and diphenylamine. The flask method was modified to provide for dissolution of the solute from the surface of glass beads. By the proposed flask method, one can accurately measure the water solubility down to the order of 10 μg/L as well as those of the order of %. The micro-column method, which requires a number of concentration determinations to ensure that a saturated solution has been obtained, is recommended for the solubility range of 10 mg/L through 10 μg/L. The flask method using the procedures described in this study, covers the range of solubility above 10 μg/L with only two determinations one being a simple preliminary test and the other a precise measurement.     

Studies on automated survey system of environmental chemicals by gas chromatography-mass spectrometry-computer II. Three dimensional mass chromatography

A three dimensional mass chromatography (TDMC), which is the extended method of mass chromatography, has been developed for the analysis of environmental chemicals. A considerable performance was suggested by the combination of TDMC to gas chromatography-mass spectrometry-computer system.     

Changes in otolith strontium:calcium ratios in metamorphosing Conger myrisaster leptocephali

Content ratios of strontium (Sr) to calcium (Ca) in the otolith of Conger myriaster metamorphosing leptocephali and elvers increased with increasing increment number from the core to the 110th increment and subsequently decreased. The otolith region from the 110th increment to the edge corresponded to the metamorphic stage. The Sr:Ca ratios in otolith edges of metamorphosing leptocephali were inversely related to metamorphic stage, suggesting that the changes in otolith Sr:Ca ratios were influenced by some physiological factor(s) rather than by environmental factors. Sr concentration in leptocephalus somatic tissues was high and decreased as metamorphosis progressed until the late metamorphic stage when the preanal myomere to total myomere ratio was 0.4. Ca concentration was constant throughout ontogenesis. Body Sr:Ca ratios markedly decreased as metamorphosis progressed. Decrease in somatic Sr concentration and the consequent decrease in body Sr:Ca ratios seemed to be associated with the breakdown of glycosaminoglycan (GAG) in gelatinous matrix, which is the major constituent of soft tissue in leptocephali. Catabolism of GAG may also cause a decrease in otolith Sr:Ca ratios during metamorphosis. In leptocephalus otoliths, Sr:Ca ratios may change in association with the synthesis and breakdown of GAGs during ontogeny. Received: 29 November 1996 / Accepted: 6 January 1997     

The functional organization of resin work in honeybee colonies

Resin is an important building material in the nests of honeybees, but little is known about how it is handled within the nest and how its collection is controlled. We studied the functional organization of resin work to better understand how a colony adaptively controls its intake of resin. Two hypotheses have been proposed for how resin collectors stay informed of the need for additional resin: (1) the unloading difficulty hypothesis (resin need is sensed indirectly by the unloading delay) and (2) the caulking activity hypothesis (resin need is sensed directly while engaged in using resin). A falsifiable prediction of the latter hypothesis, but not of the former, is that resin collectors not only gather resin outside the hive but also regularly handle resin inside the hive (taking it from other bees and using it to caulk crevices). Consistent with this prediction are our findings that in the resin sector of a colony’s economy, unlike in the pollen, nectar, and water sectors, there is no strict division of labor between the collectors and the users of a material. Over the course of a day, bees seen collecting resin were also commonly seen using resin. Moreover, we found that the unloading locations of resin collectors are unlike those of water and nectar collectors, being deep inside the hive (at the sites of resin use) rather than at the hive entrance. This arrangement facilitates the engagement in resin use by resin collectors. We conclude that the caulking activity hypothesis is well-supported, but that the unloading difficulty hypothesis also remains viable, for we found that resin collectors experience variable delays in getting rid of their loads, from less than 15 min to more than an hour, consistent with this hypothesis. The stage is now set for experimental tests of these two hypotheses. Both may be correct, which if true will imply that social insect workers, despite their small brains, can acquire and integrate information from multiple sources to improve their knowledge of conditions within the colony.     

Evidence for seasonal mate limitation in populations of an intertidal amphipod, Corophium volutator (Pallas)

Potential rates of reproduction (PRR) differ between the sexes of many animal species. Adult sex ratios together with PRR are expected to determine the operational sex ratio (OSR) defined as the ratio of fertilizable females to sexually active males at any given time. OSR is expected to determine the degree to which one sex competes for another—the limiting sex. We explored the potential for mate limitation in an intertidal amphipod, Corophium volutator (Pallas). Males have higher PRR than females, but males may be limiting because of extreme female-biased sex ratios observed in this species. Consistent with this idea, late season females were less likely to be ovigerous and had smaller size-specific clutches, both of which were associated with seasonal declines in availability of males of reproductive size. Seasonal changes in ovigery could not be explained by seasonal changes across sites in other factors (e.g., female body size or phenology of breeding). Smaller females were less likely to become ovigerous later in the season at three of four sites. Seasonal reductions in clutch size also occurred among small females expected to be reproducing for their first time. In complimentary laboratory experiments, reduced likelihood of ovigery and reduced fecundity occurred when the number of receptive females was increased relative to availability of a reproductively active male. Our results suggest male mate limitation can occur seasonally in this species and that male limitation is regionally widespread and may affect recruitment.     

Fluorescence and metal-ion recognition properties of acetylacetone-based ligands

A new acetylacetone-based ligand (Ligand 1) bearing pyrene unit was synthesized and the fluorescence and metal-ion recognition properties were investigated in the presence of a different metal ion in acetonitrile solution. The fluorescence emission of Ligand 1 was strongly quenched by complexation with Cu²⁺ while no significant change was observed in the presence of other metal ions. The metal-ion selectivity changed from Cu²⁺ to Ni²⁺ when glycine moiety (–NH–CH₂–CO–) was introduced into Ligand 1 as spacer. This result implies that hydrogen-bonding induced by the glycine moiety affects the binding ability of ligands to metal ions, resulting in change of the metal-ion selectivity.     

Congener profiles of PCDDs, PCDFs, and dioxin-like PCBs in the breast milk samples in Tokyo, Japan

Exposure to dioxins has raised much public concern recently. We determined the congeners' distribution of polychlorinated-dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in the breast milk samples collected in Tokyo, Japan. Breast milk was taken from 240 mothers, 30 days after delivery in 1999 and 2000 in Tokyo, Japan. The actual concentration and TEQ concentration of PCDDs (14 congeners), PCDFs (15 congeners), and dl-PCBs (12 congeners), and each congener's contribution to the total TEQ level were calculated. Among all the samples, PCDDs accounted for 34.8%, PCDFs accounted for 23.5%, dl-PCBs accounted for 41.7%, which was also similar in the breast milk from the primiparae and secundiparae. The main contributors to the total TEQ with increasing percentages were 2,3,4,7,8-PeCDF, 1,2,3,7,8-PeCDD and 3,3',4,4',5-PCB (#126), and they accounted for more than 65% of the total TEQ. Detailed congener analysis in breast milk samples is effective to understand dioxin sources.     

Antimony mobility in Japanese agricultural soils and the factors affecting antimony sorption behavior

The mobility of antimony (Sb) in Japanese agricultural soils was studied by radiotracer experiments using 124Sb tracer. The soil-solution distribution coefficients (Kd) of Sb were measured for 110 soil samples. These Kds ranged from 1 to 2065 L kg(-1); the geometric mean was 62 L kg(-1) excluding one extremely high value, 2065 L kg(-1). Experimental measurement of Kd showed a decrease with both increasing pH and increasing phosphate concentration. The latter suggested that one aspect of the Sb sorption phenomena in Japanese soil was influenced by specific adsorption of anions such as phosphate. However, other aspects could not be explained by this specific adsorption mechanism, because only 20-40% of soil-sorbed Sb could be extracted by phosphate solution.