Heavy Metal Concentrations in Rice from Guangzhou and Associated Health Risks   总被引：1，自引：1，他引：0  

CHEN Nengchang  ZHANG Xiaoxia  ZHENG Yuji 《资源与生态学报(英文版)》2018,9(1):85-91

In recent years, excessive levels of cadmium (Cd) in rice have been a focus of attention of the government, the public and scientists. In Guangzhou rice is a staple food for most citizens and understanding the level of Cd and other heavy metals in rice is important for food safety and health. Consumers in different income groups purchase rice from various sources at different prices but we know little about the relationship between price and safety. At the same time, the presence of zinc (Zn) can also affect the level of risk from Cd in rice and so affect food safety. This study offers a preliminary exploration of interactions between price, safety and nutritional quality. 125 rice samples were collected from markets and from the homes of high-income, middle-income and low-income groups in Guangzhou city, and were tested for the content of Cd and Zn. The results showed that 25.6% of the rice samples contained Cd in excess of the national standard, with higher levels of Cd in Indica rice than in Japonica. At the same time, we designed a questionnaire survey for groups with different incomes to assess their exposure to risks from rice with Cd and their perceptions and sources of information about risks. The survey showed that, as a whole, the low-income group faces higher risks from rice with Cd, and that there is strong public demand for scientific information about Cd in rice.  相似文献   

Molecular Cloning,Characterization, and Expression of a Catalase Gene in the Japanese Scallop <Emphasis Type="Italic">Mizuhopecten yessoensis</Emphasis> Induced in the Presence of Cadmium     

Jialong Gao  Shoichiro Ishizaki  Yuji Nagashima 《Ocean Science Journal》2016,51(2):223-233

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Influence of evaporation from the forest floor on evapotranspiration from the dry canopy     

Kenichi Daikoku  Shigeaki Hattori  Aiko Deguchi  Yu Aoki  Mari Miyashita  Kazuho Matsumoto  Junichi Akiyama  Shinichi Iida  Tae Toba  Yuji Fujita  Takeshi Ohta 《水文研究》2008,22(20):4083-4096

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Underplating of mélange evidenced by the depositional ages: U–Pb dating of zircons from the Shimanto accretionary complex, southwest Japan     

Tadahiro  Shibata  Yuji  Orihashi  Gaku  Kimura  Yoshitaka  Hashimoto 《Island Arc》2008,17(3):376-393

Abstract   Growth of an accretionary prism is effected by frontal accretion and deep subsurface underplating at the base of the prism. A systematic oceanward and structurally downward younging of underplated sequences is expected as the prism thickens and grows. To test this hypothesis and explore the processes of underplating, the U–Pb ages of zircon grains contained in underplated mélange sequences or packages of the Late Cretaceous and early Paleogene accretionary complex of the Shimanto Belt, southwest Japan, were determined using LA–ICP–MS laser technology. The results document systematic but intermittent younging ages within a single underplated mélange package. This finding suggests that underplating took place episodically during a period of several million years and that between episodes of underplating, a large amount of sediment was subducted to depths much greater than where underplating was occurring.  相似文献   

Modeling deforestation in Dzalanyama Forest Reserve,Lilongwe, Malawi: a multi-agent simulation approach     

Kondwani Godwin Munthali  Yuji Murayama 《GeoJournal》2015,80(5):743-757

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Petrogenetic evolution of basaltic lavas from Balhaf–Bir Ali Plio-Quaternary volcanic field, Arabian Sea, Republic of Yemen     

Mohamed T. S. Heikal  El-Metwally M. Lebda  Yuji Orihashi  Abdalmenam Habtoor 《Arabian Journal of Geosciences》2014,7(1):69-86

The Plio-Quaternary Balhaf–Bir Ali volcanic field (BBAVF) constitutes one of the largest volcanic fields in SE Yemen, covering some 500 km². It comprises cinder cones complexes associated with vesicular lava flows and scoria–spatter cones. In many places, ultramafic xenoliths are encountered within these volcanics. The explosive volcanism is mainly of alkaline character including alkali olivine basalt, hawaiite and mugearite together with subordinate tuffaceous trachytes. Major, trace and REEs data from the basaltic rocks of the BBAVF are interpreted in terms of a mantle-lithospheric origin in which crustal contribution during the initial stage of rift magmatism has occurred. Magma genesis may have resulted from plume-derived melt introducing into the base of the lithosphere. A mantle plume source is proposed for the Balhaf–Bir Ali basaltic lavas that are here interpreted as having been generated by partial melting of garnet lherzolite in the uppermost part of asthenosphere. The magmatic evolution of Balhaf–Bir Ali volcanic field may be accounted for by the recent models developed for plume structure.  相似文献   

Source distribution of acoustic emissions during an in-situ direct shear test: Implications for an analog model of seismogenic faulting in an inhomogeneous rock mass     

Tsuyoshi Ishida  Tadashi Kanagawa  Yuji Kanaori 《Engineering Geology》2010,110(3-4):66-76

We monitored acoustic emission (AE) events during an in-situ direct shear test on a specimen composed of a slate-dominant alternation of slate and sandstone, measuring 0.5 m long, 0.5 m wide and 0.2 m high. The test was conducted in a survey tunnel for an underground powerhouse in central Japan. The AE epicenters located on a fractured plane are compared with the locations of joints and a loosening seam, the height distribution of the fractured plane, and the horizontal movement of the test block prior to failure. We conclude that an initially intact region of rock bounded by the joints and the seam is fractured, generating the AE. Considering these results in connection with asperity models of seismogenic faulting for a subduction-zone earthquake, the significant contrast of stress conditions derived from the geological inhomogeneity and the uneven fractured plane is analogous to that due to subducted seamounts and horst-graben structures on a subducted oceanic plate. For an inland earthquake, the intact regions on an expected shear plane can be considered to be a portion of the fault asperity that causes strong ground motion, while the weakened portion can be considered to correspond to a region of aseismic creep. Consequently, large-scale inhomogeneous rock fracturing experiments such as the in-situ direct shear test may provide useful insights as analog models of seismogenic faulting. Furthermore, understanding of inhomogeneous rock-mass fracturing obtained from such experiments will not only contribute to a better understanding of the mechanism of earthquakes but also provide valuable knowledge for AE monitoring applications in rock engineering, such as the predictions of rockbursts in mines and the monitoring of fractures around large underground chambers.  相似文献   

Cell contact-dependent lethal effect of the dinoflagellate Heterocapsa circularisquama on phytoplankton–phytoplankton interactions     

Yasuhiro Yamasaki  Yanan Zou  Jyoji Go  Tomoyuki Shikata  Yukihiko Matsuyama  Kiyohito Nagai  Yohei Shimasaki  Kenichi Yamaguchi  Yuji Oshima  Tatsuya Oda  Tsuneo Honjo 《Journal of Sea Research》2011,65(1):76-83

We used bi-algal culture experiments to investigate and verify the roles of growth interaction between Heterocapsa circularisquama and Prorocentrum dentatum in monospecific bloom formation. Growth of H. circularisquama was slightly inhibited when inoculated at 10² cells mL^–1 along with P. dentatum at 10⁴ cells mL^–1. In other combinations of inoculation densities, P. dentatum density rapidly decreased to extremely low levels in the presence of H. circularisquama. We used a mathematical model to simulate growth and interactions of H. circularisquama and P. dentatum in bi-algal cultures. The model indicates that one species will always inhibit the growth of the other and that the relative initial cell densities of the species are critical in determining the outcome. When cultured together under conditions without cell contact, growth of H. circularisquama and P. dentatum was not inhibited. As with P. dentatum, the growth of Heterosigma akashiwo and Skeletonema costatum was inhibited in intact cell suspensions with H. circularisquama, but a nontoxic species, Heterocapsa triquetra, did not affect the growth of P. dentatum or the other species. Similarly, cell suspensions of H. circularisquama showed hemolytic activity toward rabbit erythrocytes, but those of H. triquetra did not. In addition, the cell-free supernatant of H. circularisquama cultures showed no significant hemolytic activity. These results suggest that H. circularisquama causes lethality in P. dentatum by direct cell contact in which live-cell-mediated hemolytic activity might be a contributing factor.  相似文献   

城市土地利用变化中邻域相互作用的特征——日本三大都市圈的比较研究     

赵耀龙  崔秉良  村山祐司 《地理学报(英文版)》2011,21(1):65-78

Local spatial interaction between neighborhood land-use categories (i.e. neighborhood interaction) is an important factor which affects urban land-use change patterns. Therefore,it is a key component in cellular automata (CA)-based urban geosimulation models towards the simulation and forecast of urban land-use changes. Purpose of this paper is to interpret the similarities and differences of the characteristics of neighborhood interaction in urban land-use changes of different metropolitan areas in Japan for providing empirical materials to understand the mechanism of urban land-use changes and construct urban geosimulation models. Characteristics of neighborhood interaction in urban land-use changes of three metropolitan areas in Japan,i.e. Tokyo,Osaka,and Nagoya,were compared using such aids as the neighborhood interaction model and similarity measure function. As a result,urban land-use in the three metropolitan areas was found to have had similar structure and patterns during the study period. Characteristics of neighborhood interaction in urban land-use changes are quite different from land-use categories,meaning that the mechanism of urban land-use changes comparatively differs among land-use categories. Characteristics of neighborhood interaction reveal the effect of spatial autocorrelation in the spatial process of urban land-use changes in the three metropolitan areas,which correspond with the characteristics of agglomeration of urban land-use allocation in Japan. Neighborhood interaction amidst urban land-use changes between the three metropolitan areas generally showed similar characteristics. The regressed neighborhood interaction coefficients in the models may represent the general characteristics of neighborhood effect on urban land-use changes in the cities of Japan. The results provide very significant materials for exploring the mechanism of urban land-use changes and the construction of universal urban geosimulation models which may be applied to any city in Japan.  相似文献   

Ion microprobe U‐Th‐Pb dating of phosphates in martian meteorite ALH 84001     

Kentaro Terada  Tsuyoshi Monde  Yuji Sano 《Meteoritics & planetary science》2003,38(11):1697-1703

Abstract— Phosphates in martian meteorites are important carriers of trace elements, although, they are volumetrically minor minerals. PO₄ also has potential as a biomarker for life on Mars. Here, we report measurements of the U‐Th‐Pb systematics of phosphates in the martian meteorite ALH 84001 using the Sensitive High Resolution Ion MicroProbe (SHRIMP) installed at Hiroshima University, Japan. Eleven analyses of whitlockites and 1 analysis of apatite resulted in a total Pb/U isochron age of 4018 ± 81 Ma in the ²³⁸U/²⁰⁶Pb‐²⁰⁷Pb/²⁰⁶Pb‐²⁰⁴Pb/²⁰⁶ Pb 3‐D space, and a ²³²Th‐²⁰⁸Pb age of 3971 ± 860 Ma. These ages are consistent within a 95% confidence limit. This result is in agreement with the previously published Ar‐Ar shock age of 4.0 ± 0.1 Ga from maskelynite and other results of 3.8–4.3 Ga but are significantly different from the Sm‐Nd age of 4.50 ± 0.13 Ga based on the whole rock and pyroxene. Taking into account recent studies on textural and chemical evidence of phosphate, our result suggests that the shock metamorphic event defines the phosphate formation age of 4018 ± 81 Ma, and that since then, ALH 84001 has not experienced a long duration thermal metamorphism, which would reset the U‐Pb system in phosphates.  相似文献