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51.
Masami Obuchi Yoshihisa Fujita Yoshikatsu Nakano Tsuyoshi Uehara Tatsuo Motokawa 《Marine Biology》2010,157(6):1191-1201
Reproduction and larval/post-larval development of the one of the smallest known comatulid Dorometra sesokonis were studied on the coral reefs of Sesoko-jima Island, Okinawa, Japan. Breeding individuals were found every month from May
2003 to April 2004 indicating continuous reproduction. Individuals possessed both mature ovaries and testes, and were therefore
characterized as simultaneous hermaphrodites. This species was observed to be an external brooder in which the embryos developed
on the surface of parental genital pinnules until the doliolaria larval stage, and subsequently released doliolariae settled
on substrata within 4 days after hatching. Larvae then metamorphosed into the post-larval cystidean stage, which lasted for
more than a month. The reproductive features of this species are unique among crinoids, and, together with juvenile morphological
features observed in adults, can be interpreted as adaptations to their cryptic habitat, which is subject to frequent natural
disturbances. 相似文献
52.
Izumi Noguchi Kentaro Hayashi Masahide Aikawa Tsuyoshi Ohizumi Yukiya Minami Moritsugu Kitamura Akira Takahashi Hiroshi Tanimoto Kazuhide Matsuda Hiroshi Hara 《Water, Air, & Soil Pollution: Focus》2007,7(1-3):67-75
Temporal trends of non-sea salt (nss-) sulfate and nitrate were analyzed from nationwide precipitation chemistry measurements
provided by the Ministry of the Environment (MOE) for the 1988–2002 fiscal years (April–March). The concentrations and deposition
of nss-sulfate were found to be decreasing, and those of nitrate were stable or slightly increasing at most sites. These deposition
trends were discussed from the viewpoint of emissions of SO2 and NOX during the period of interest. Because monitoring techniques have changed in the number of active sites, samplers, and analytical
methods during the operation period, the median of all annual depositions measured in Japan in a specific year was selected
as the annual representative. The contribution of specific emission sources was also calculated for 1990 on the basis of the
nss-sulfate and nitrate deposition in Japan obtained with a model simulation in which the model did not include volcanic emissions
from Mt. Oyama, Miyakejima Island, which began to erupt suddenly and violently in 2000. For nss-sulfate, the calculated deposition
agrees well with the intensity and trends of the median up to 1999. After 2000, a higher deposition than calculated in the
preceding years was evident, which is attributable to the volcanic SO2 from Mt. Oyama. For nitrate, both the calculated and observed depositions were slightly increasing; however, the calculation
was found to exceed the observation. 相似文献
53.
Hideko Mitobe Tsuyoshi Ibaraki Akiko Tanabe Kuniaki Kawata Akio Yasuhara 《毒物与环境化学》2013,95(3-4):97-110
A high performance liquid chromatographic method has been developed to determine pesticides in river water as both dissolved phase and suspended phase. The target pesticides were eight herbicides, asulam, diuron, flazasulfuron, linuron, MCPB, mecoprop, pyrazosulfuron‐ethyl and siduron, and two fungicides, oxine‐copper and thiram. The pesticides in filtered river water were extracted with styrene‐divinylbenzene copolymer and were eluted with acetonitrile. The pesticides on suspended solids were extracted ultrasonically with acetonitrile. Each eluate was concentrated and analyzed by HPLC with multiwavelength detector. Recoveries of the pesticides in the overall procedure of this method were 78–114% for filtered river water and 75–107% for suspended solids. The limits of detection in water and suspended solids ranged from 0.1 to 0.9 μg/L and 1 to 7 μg/g, respectively. Pesticide distribution between soluble phase and suspended phase in river water was measured by this method. 相似文献
54.
Hasan Muhammad Abdullah Tsuyoshi Akiyama Michio Shibayama Yoshio Awaya 《国际发展与全球生态学杂志》2013,20(5):384-392
Biomass estimation in agroecosystems (AESs) is important to understand their role in carbon exchange for a sustainable environment. We used field spectra and sampled biomass of an AES including cultivated and abandoned croplands to develop a simple biomass estimation model. The digital number (DN) of a QuickBird (QB) satellite image was converted to a reflectance factor using the dark object subtraction method and the spectral reflectance of asphalt. The relationship between the reflectance factor of field-based spectra and the QB image obtained in early July 2007 was insignificant in the blue (R 2 = 0.15) and green (R 2 = 0.18) bands but was significant (p < 0.05) in the red (R 2 = 0.57) and near-infrared (NIR, R 2 = 0.45) bands in the AES. Better correlations were obtained between field-based and QB-based vegetation indices (VIs). The best correlations were obtained with the normalized difference vegetation index (NDVI) (R 2 = 0.97, p < 0.001) and the ratio vegetation index (RVI) (R 2 = 0.99, p < 0.001). Biomass was significantly correlated with both field-based NDVI and RVI (R 2 = 0.79 and 0.72, respectively, p < 0.001). Although RVI saturated at higher biomass densities (>600 g m?2), NDVI showed a linear relationship. Other field-based VIs showed poorer correlations with biomass. The model was evaluated by incorporating it into high-resolution QB images to obtain the observed biomass. The relationship between field-estimated and QB-observed biomass appeared to be a one-to-one linear relationship (R 2 = 0.79). Thus, models using field spectra and sampled biomass can be applied to QB images for remote estimation of biomass in an AES. 相似文献
55.
This paper describes an application of the quasi-partition law of radon-222 (222Rn) to a deep unsaturated vadose zone in a field. 222Rn is a very useful tracer to investigate not only saturated but also unsaturated water flows in vadose zones. Concentrations of 222Rn in water in unsaturated soils are, based on the quasi-partition law, lower than those in saturated soils. However, no study has previously applied quasi-partition law of 222Rn to analyze saturated and unsaturated water flows in vadose zones. In this study, we observed the applicability of existing theoretical equations of quasi-partition law of 222Rn experimentally. After confirming the validity of the theoretical equation, we applied this equation to estimate the unsaturated water flow in an actual vadose zone. By comparing the estimated degree of saturation from 222Rn measurement with that from a neutron moisture meter measurement, we obtained a beautiful agreement between them. 相似文献
56.
Sasai Ryo Fujimura Takuya Uesugi Ryohei Aketo Tsuyoshi Komatsu Kohei 《Journal of Material Cycles and Waste Management》2023,25(1):389-395
Journal of Material Cycles and Waste Management - To cater to the increasing demand for secondary lithium-ion batteries, the recovery of valuable metal species in spent batteries is increasingly... 相似文献