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11.
Although recent studies have demonstrated that calcification in a wide range of marine organisms is profoundly affected by CO2-induced ocean acidification, the mechanism of this phenomenon is still unclear. To clarify the effects of ocean acidification on the calcification process at the molecular level, we evaluated the expression of three biomineralization-related genes in the sea urchin Hemicentrotus pulcherrimus exposed under control, 1,000, and 2,000?ppm CO2 from egg to pluteus larval stage. We found that the expression of the gene msp130, which is proposed to transport Ca2+ to the calcification site, is suppressed by increased CO2 at pluteus larval stage. Meanwhile, expression of the spicule protein matrix genes SM30 and SM50 was apparently not affected. The results suggest that the combined effects of ocean acidification on the expression of skeletogenesis-related genes as well as the change in seawater carbonate chemistry affect the biomineralization ability of sea urchins. 相似文献
12.
Atsushi Nanami Yuuki Kawabata Taku Sato Tomofumi Yamaguchi Ryo Kawabe Kiyoshi Soyano 《Marine Biology》2014,161(3):669-680
White-streaked grouper (Epinephelus ongus) is an important fishery target that forms fish spawning aggregations (FSAs) at specific spawning grounds. The aims of the present study were to investigate migration behavior and returning behavior in terms of FSA using acoustic telemetry. Among the 30 specimens tracked, three types of movement pattern were observed: type 1, high site fidelity at the release area before the spawning period, migration to the spawning ground during the spawning period and return to the release area just after the spawning period (17 specimens); type 2, high site fidelity at the release area, disappearance from the area during the spawning period but was not detected at the spawning ground and return to the release area (8 specimens); and type 3, high site fidelity at the release area was observed before, during and after the spawning period (5 specimens). For the 17 specimens that were categorized into type 1, the dates of departure from their release area and the dates of return to the release area of males were, respectively, significantly earlier and later than those of females. The duration between the departure date and the return date (“duration away”) of males was significantly longer than that of females. The duration away tended to be positively related to the condition factor. All 25 specimens that were categorized as type 1 and type 2 showed returning behaviors to the release area. 相似文献
13.
Haruhiro Ino Yoshihisa Matsumoto Ryo Takahashi Kazukiyo Takami Junya Nishino Masaaki Itoh 《Journal of Material Cycles and Waste Management》2008,10(2):129-133
H-ZSM-5 zeolite-supported gallium oxides were studied as aromatization catalysts for polyolefin pyrolysate. The catalysts
were prepared by a conventional physical mixing method with a gallium content of 1.0 and 4.5 wt% and were reduced in flowing
hydrogen at 585°C. To test their activity, a polyolefin sample was pyrolyzed and passed over a heated catalyst layer; the
product was analyzed by gas chromatography/mass spectrometry. A continuous-flow fixed-bed reactor was used for aromatization
of a model gas of polyolefin pyrolysate. For chlorine-free sources at 450°C, the catalyst with only 1.0 wt% gallium exhibited
activity comparable to a gallium silicate catalyst. For chlorine-contaminated sources, the catalyst with 4.5 wt% gallium sustained
catalytic activity for long periods. From the activity test results, it was found that zeolite-supported gallium catalysts
prepared by the physical mixing method are suitable for converting polyolefin into aromatic hydrocarbons. 相似文献
14.
Masahiro Kamiya Yasuki Mori Takashi Kojima Ryo Sasai Hideaki Itoh 《Journal of Material Cycles and Waste Management》2007,9(1):27-33
The recycling process for 3 mol% yttria-stabilized tetragonal zirconia polycrystals (3Y-TZP) sintered at 1450°–1550°C was
examined by applying low-temperature degradation of zirconia ceramics under hydrothermal conditions. Hydrothermal treatment
at a temperature from 200° to 240°C can lead to the spontaneous disintegration of 3Y-TZP sintered bodies into powdery particles.
The hydrothermally obtained zirconia powder was found to consist of primary particles and aggregated particles. Detailed X-ray
diffraction measurement revealed the formation of a cubic zirconia phase in the 3Y-TZP sintered bodies, which seemed to inhibit
the disintegration of aggregated particles toward the primary particle level. The reclaimed 3Y-TZP powder was sintered again
through a conventional powder processing route. The mechanical properties and microstructure of recycled 3Y-TZP sintered specimens
were examined by comparison with those of the original 3Y-TZP sintered bodies. Dense recycled 3Y-TZP sintered at a higher
temperature exhibited higher fracture toughness to some degree than the original 3Y-TZP. 相似文献
15.
Takeo Kurihara Hideki Takami Takeharu Kosuge Susumu Chiba Masatsugu Iseda Takenori Sasaki 《Marine Biology》2011,158(9):2095-2107
Increases of low-latitude species in various sea areas and poleward shifts of ranges of many species have been reported and
linked to warming environments. To examine the generality of these trends for mollusks, we conducted 7 quadrat surveys during
1978–2006 on Pacific rocky shores in Japan (26.6–45.0°N). Results showed that the dominance of southern species increased
on 11 of the 15 shores in a southern, warming sea area but on only 1 of the 6 shores in a northern area with no warming trend.
The latitudes of species ranges increased on average but showed large interspecific variations which showed a weak, positive
correlation with interspecific taxonomic distance. The differences of these results from the previously reported trends are
discussed in relation to the unique current patterns in our study area and the phylogenetic constraints of species-specific
responses to a warming environment. 相似文献
16.
Ichiro Naruse Ryo Yoshiie Tsutomu Kameshima Tsuyoshi Takuwa 《Journal of Material Cycles and Waste Management》2010,12(2):154-160
Homogeneous oxidation reactions of gaseous elemental mercury were experimentally tested to study the behavior of mercury compounds
that contribute to toxic emissions in combustion flue gas. Chemical equilibrium calculations and reaction kinetics analysis
were also carried out to help explain the experimental results. In particular, the chemical forms of oxidized mercury and
their reaction paths were verified in detail. Among the experimental results, molecular chlorine was confirmed to have a higher
oxidizing ability toward elemental mercury than hydrogen chloride does. From the chemical equilibrium calculation, the final
product of mercury compounds oxidized by chlorine was confirmed to be mercury chloride (HgCl2). Numerical analyses of reaction kinetics were mostly consistent with the experimental results and the chemical equilibrium
calculations. The ratio of mercury oxidization by chlorine increases with temperature from 473 K to 873 K, although it decreases
at temperatures higher than 1000 K. Sensitivity analysis revealed the dominant reaction path of the mercury oxidation by chlorine.
First, elemental mercury reacts with Cl radicals to form HgCl. Then, the HgCl reacts with Cl2 to produce HgCl2. 相似文献
17.
Many African countries have adopted community-based forest management (CBFM) to prevent deforestation. However, empirical studies have not reached a consensus on the effectiveness of CBFM. The purpose of this study is to examine the impact of the establishment of participatory forest management associations in Ethiopia. We used remote sensing data to gauge the change in forest area and employed a two-stage least squares model to correct for possible biases. The results indicate that the forest area managed by forest associations declines more in the year of establishment than forest areas with no association. This finding suggests that villagers may engage in "last-minute" logging. However, 1 year after the establishment of the forest associations, the forest area of the associations increased substantially, most likely because the associations monitor illegal logging, enabling the regeneration of open areas within the registered forest area. On average, the forest area of the forest associations increased by 1.5?% in the first 2 years, whereas forest areas not managed as part of an association declined by 3.3?%. The cumulative impact over 2 years yields a net increase in the rate of change of 4.8?%. These results demonstrate that it is important to improve the monitoring of forest areas during the initial establishment of participatory forest management associations to maximize the effects of association establishment. 相似文献
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