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In the intertidal limpet Patelloida pygmaea, two distinctive morphs, the forms pygmaea and conulus, have been recorded. The former possesses a flat elongated shell, and the latter has an extremely high round shell. It has been observed in the field that pygmaea is found on oyster shells Crassostrea gigas. The form conulus uses an unusual substrate for attachment. It is found on the living shells of the intertidal gastropod Batillaria cumingi. Although conulus is normally found only on shells of Batillaria, it can also be found on oyster shells when pygmaea and Batillaria shells are not present in nature. An electrophoretic analysis of allozymes showed that these two forms are reproductively isolated from each other and coexist without gene exchange on the same mudflat. Laboratory experiments showed that pygmaea prefers oyster shells and conulus prefers Batillaria shells as substrates for attachment when both oyster and Batillaria shells are present. The form pygmaea did not attach to Batillaria shells, even when only Batillaria shells were available. However, conulus also attached to oyster shells when Batillaria shells were not available. The proportion of individuals of conulus that attached to oyster shells decreased significantly when pygmaea was attaching to the oyster shells. These results suggest that pygmaea is ecologically more specialized to living on oyster shells than conulus.  相似文献   
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A Chinese praying mantis, Tenodera sinensis, was observed feeding on a living red-spotted newt, Notophthalmus viridescens. Specimens of that newt’s population are known to contain high concentrations of tetrodotoxin (TTX), a specific blocker of voltage-gated sodium channels. After experimental oral administration of a TTX-solution (1 mg/ml) to adult specimens of four mantis species, all survived high TTX concentrations (up to 30.8 μg/g body mass) as revealed by analysis of their body extracts, but they are rapidly killed by intra-abdominal injection of 1 μg TTX. The toxin was found to be gradually excreted with faeces. As demonstrated by monoclonal antibody-based immunohistochemical technique, TTX does not penetrate the mid-gut membrane, since it was localized only in the gut lumen, but not in the epithelial cells. This prevents the toxin to reach its target, the sodium channels of the insect’s nervous system, and enables the mantids to feed on toxic prey without risking poisoning.  相似文献   
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Intertidal organisms commonly form zonation bands along the shore. Environmental stressors often determine the vertical position of each zonation band. These stressors may similarly affect the distribution pattern of endogenous species in their intertidal hosts. To evaluate this possibility, we investigated the distribution pattern of endosymbiotic zooxanthellae in the genus Symbiodinium in a population of the intertidal sea anemone Anthopleura uchidai. We used molecular genetics to identify the Symbiodinium clades and found that A. uchidai has two clades of Symbiodinium, clades A and F. These Symbiodinium clades were disproportionally distributed along the vertical gradient of the intertidal shore. Anemones on the upper shore exclusively possessed clade F Symbiodinium while clade A Symbiodinium became dominant in the sea anemones on the lower shore. Photosynthesis activity assays showed that these Symbiodinium clades had similar net productivities at 23.3 and 31.8 °C at all irradiance levels. At 35 °C, however, clade A Symbiodinium exhibited substantially lower net productivities than clade F Symbiodinium, demonstrating that these Symbiodinium clades have distinct tolerances to thermal stress. These results suggest that the thermal gradient across tidal height is a major factor shaping the zonation pattern of Symbiodinium clades in A. uchidai.  相似文献   
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First, this paper evaluates the current building material stock and future demolition waste for urban residential buildings in the cities of Jakarta and Bandung using a material-flow analysis. The actual on-site building measurements were conducted in Jakarta (2012) and Bandung (2011), focusing particularly on unplanned houses, to obtain building material inventory data. A total of 297 houses were investigated in Jakarta, whereas 247 houses were measured in Bandung. Second, this paper analyses the embodied energy and CO2 emissions of building materials through an input–output analysis. The results show that, overall, the total material input intensity for the houses is 2.67 ton/m2 in Jakarta and 2.54 ton/m2 in Bandung. Two scenarios with zero and maximum reuse/recycling rates were designed to predict future demolition waste and the embodied energy/CO2 emissions of building materials in Jakarta. Closed- and open-loop material flows were applied. If the maximum reuse/recycling rates are applied to the closed- and open-loop material flows in Jakarta, then it would become possible to not only decrease the final disposal waste (from 123.9 to 2.1 million ton) but also reduce the corresponding embodied energy (from 247.8 to 192.1 PJ) and CO2 emissions (from 24.3 to 19.2 million ton CO2-eq) compared with the zero reuse/recycling scenario from 2012 to 2020.  相似文献   
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In sustainability science (SS), it is difficult to identify what needs to be solved, and it is also not clear how to solve the problems that are identified. There has been no consensus on the underlying question of “What is structuring knowledge in SS?” This paper focuses on knowledge structuring accompanied by supporting of thinking. It addresses the key challenges associated with knowledge structuring in SS, identifies the requirements for the structuring of knowledge, proposes a reference model, and develops an ontology-based mapping tool as a solution to one layer of the reference model. First, we identify the important requirements for SS knowledge structuring. Second, we develop a reference model composed of five layers based on three of the requirements. Third, we develop an ontology-based mapping tool at Layer 2 of the reference model for meeting the two major challenges for SS, namely, identifying what problems should be addressed in SS itself and proposing solutions for those problems. The tool is designed to store and retrieve information regarding SS, to provide access to a prototype ontology for SS, and to create multiple maps of conceptual chains depending on a user’s interests and perspectives. Finally, we assess whether the developed tool successfully realizes the targeted part of the reference model for SS by examining the tool’s conformity to the reference model, as well as its usability, effectiveness, and constraints. Although several issues were identified in the prototype ontology and the mapping tool, the study concluded that the mapping tool is useful enough to facilitate the function of Layer 2. In particular, the mapping tool can support thinking about SS from the viewpoint of: (a) finding new potentials and risks of technological countermeasures studied in SS; (b) helping users to get a more comprehensive picture of problems and their potential solutions; and (c) providing an effective opportunity to come up with new ideas that might not be thought of without such a tool.  相似文献   
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At present, little is known about the occurrence of polybrominated diphenyl ethers (PBDEs) in fish and food products sold in Japan. To investigate whether human exposure to PBDEs through the diet is significant, the concentrations of PBDEs were determined in fish and in meat and vegetables sold in two food markets in the city of Hirakata, Osaka prefecture. The concentrations of PBDEs in the breast milk of 12 primiparae nursing women at one month after delivery also were determined to ascertain the relationship between the levels found in the diet and levels in humans. sigma PBDE concentrations ranged between 21 and 1650 pg/g fresh weight in the edible tissues of five species of fish and one shellfish species. The highest concentrations were measured in yellow-fin tuna, followed by short-necked clam, salmon, yellowtail, mackerel and young yellowtail. Interestingly, sigma PBDE concentrations were not statistically significantly different in two cultured mackerel samples from Japan and mackerel collected from northern European waters. sigma PBDE concentrations in beef, pork and chicken meat (ranging between 6.25 and 63.6 pg/g fresh weight) and in three different vegetables (ranging between 38.4 and 134 pg/g fresh weight) were significantly lower than the concentrations in fish. In human milk, sigma PBDE concentrations ranged between 668 and 2840 pg/g lipid basis, which is comparable to the levels in populations of nursing women reported in Sweden and elsewhere. There was a strong positive relationship between PBDE concentrations in human milk and dietary intake of fish and shellfish, which was established in the women from responses to a questionaire on food consumption habits. The results of this study of food products commonly consumed in Japan and the levels found in nursing women raise a concern about low level PBDE contamination of fish and other foods intended for human consumption.  相似文献   
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To perform high quality and high throughput measurements, complicated purification procedure by two rounds of open column chromatography was simplified by appraising the components and adding a sufficient amount of adsorbents to the column. The procedure consists of two open column techniques using a multi-layer silica gel column and an active carbon dispersed silica gel column. This purification procedure is used in "Standard manual for dioxin analysis in human blood" published in 2000 (Ministry of Health and Welfare, Japan, 2000). Consequently, a purification procedure using only 1 g of 10% AgNO(3)/silica gel can remove the matrix of blood serum as effectively as a multi-layer silica gel column. In addition, 0.1 g of carbon silica gel, equivalent to 1/10 the weight used currently in analyses, separates and recovers the dioxins in purified extract of blood serum. Furthermore, changes in the background level in the general population were clarified by monitoring the dioxin concentrations in human blood. The dioxin concentrations and ratios in blood in the general population remained at a tolerable level for three months. Therefore, the blood serum was available for the detection of a remarkable elevation in dioxins level considered to be indicative of contamination due to high-density exposure.  相似文献   
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