Diel Changes in Vertical Distribution and Feeding Conditions of the Chaetognath Parasagitta elegans (Verill) in the Subarctic Pacific in Summer     

Sohey Matsuda  Akira Taniguchi 《Journal of Oceanography》2001,57(3):353-360

Diel changes in vertical distribution and feeding conditions of the chaetognath Parasagitta elegans (Verill) were observed in three regions of the subarctic North Pacific in the summer of 1997. Samples were collected by repeated vertical hauls with a Vertical Multiple Plankton Sampler (VMPS) for 15–45 hours by demarcating the 0–500 m water column into four sampling layers. Integrated abundance through the entire water column and the proportion of juveniles were higher in the Bering Sea than the western and eastern subarctic Pacific. Juveniles always inhabited the surface layer in the western subarctic Pacific and Bering Sea, but they inhabited the underlying layer in the eastern subarctic Pacific. Stages I–III concentrated into the upper 150 m in the western subarctic Pacific but were distributed widely from 20–300 m in the Bering Sea. Among them, Stages II and III migrated rather synchronously over a wide vertical range in the eastern subarctic Pacific. The feeding rate of P. elegans was calculated to be 0.18 prey/chaetognath/day in the western subarctic Pacific, 0.27 prey/chaetognath/day in the Bering Sea and 0.07 prey/chaetognath/day in the eastern subarctic Pacific.  相似文献   

Contractual solution to the tragedy of property right in coastal fisheries     

Arif Satria  Yoshiaki Matsuda  Masaaki Sano 《Marine Policy》2006

This article aims to analyze how private property regimes can co-exist with common property regimes in a coastal area. The case study shows how the dynamics of private property and common property right holders is in creating commitment to make symbiosis in resource use. This is based on a case study in two villages in West Lombok, Indonesia, where pearl-culture as a private property resource exists in a common property regime. This is a successful story in dealing with the tragedy of property rights in the country wherein established institutional arrangement is still absent. Nevertheless, this may be site specific, and fragile if there is no institutional arrangement combining formal and informal rules and involving both formal and informal authorities. To make a robust solution, multilevel solution must be considered: national, local, and community level, with reference to Japan case.  相似文献   

Target strength of mesopelagic lanternfishes (family Myctophidae) based on swimbladder morphology   总被引：3，自引：1，他引：3  

Yasuma  Hiroki; Sawada  Kouichi; Ohshima  Tatsuki; Miyashita  Kazushi; Aoki  Ichiro 《ICES Journal of Marine Science》2003,60(3):584-591

  相似文献   

Primordial black holes from monopoles connected by strings     

Tomohiro Matsuda   《Astroparticle Physics》2009,30(6):333-337

Primordial black holes (PBHs) are known to be produced from collapsing cosmic defects such as domain walls and strings. In this paper we show how PBHs are produced in monopole-string networks.  相似文献   

Influence of Source/Sink Distributions on Flux–Gradient Relationships in the Roughness Sublayer Over an Open Forest Canopy Under Unstable Conditions     

Hiroki Iwata  Yoshinobu Harazono  Masahito Ueyama 《Boundary-Layer Meteorology》2010,136(3):391-405

The flux–gradient relationships in the unstable roughness sublayer (RSL) over an open canopy of black spruce forest were examined using long-term observations from an instrumented tower. The observed gradients normalised with the surface fluxes and height above the zero-plane displacement showed differences from a universal function established in the surface layer. The magnitude of differences was not constant throughout the year even at the same observation height. Also the magnitude of the differences was different for each scalar, and scalar similarity in the context of the flux–gradient relationship did not always hold. The variation of the differences was explained by the relative contribution of overstorey vegetation to the total flux from the entire ecosystem. This suggests that a mismatch of the vertical source/sink distributions between scalars leads to a different strength of the near-field dispersion effect for each scalar, and this resulted in inequality of eddy diffusivity among scalars in the RSL. An empirical method that predicts the magnitude of differences is proposed. With this method, it is possible to estimate the eddy diffusivity of scalars provided that the relative contribution of overstorey vegetation to the total flux from the ecosystem is known. Also this method can be used to estimate the eddy diffusivity for scalars whose primary sources are at ground level, such as methane and nitrous oxide.  相似文献   

Loss of human lives induced by the Cyclone of 29–30 April, 1991 in Bangladesh     

Iware Matsuda 《GeoJournal》1993,31(4):319-325

The 1991 Cyclone claimed more than 140,000 lives in Bangladesh. However, comparison of human casualty figures between the cyclones of 1970 and 1991 points to the effectiveness of cyclone shelters constructed after the 1970 disaster. Many inaccuracies of the regional data on social and natural circumstances affecting human losses, such as location of cyclone shelters, refuge-seeking behavior and poor population data are discussed. Based on field studies, comprehensive countermeasures are recommended, and it is mentioned that non-structural countermeasures are important to make structural ones more effective.  相似文献   

Isotopic anomalies of noble gases in meteorites and their origins—VII. C3V carbonaceous chondrites     

Jun-Ichi Matsuda  Roy S. Lewis  Hiroshi Takahashi  Edward Anders 《Geochimica et cosmochimica acta》1980,44(11):1861-1874

Noble gases were measured in bulk samples of the C3V chondrites Grosnaja, Vigarano, and Leoville, and in HF,HCl-insoluble residues before and after etching with HNO₃. The residues were characterized by INAA and SEM. Gas components were determined, directly or by subtraction, for the following fractions: HF,HCl-solubles (?98% of the meteorite), ‘sphase Q’, a poorly characterized trace mineral that is insoluble in HCl-HF but soluble in HNO₃, and an insoluble residue, consisting of ferrichromite, carbonaceous matter, and spinel.Bulk meteorites show some correlation of the noble-gas pattern with McSween's subclasses: two ‘oxidized’ C3V's—Allende (LEWIS et al, 1975) and Grosnaja— have lower Ar/Xe but higher Ne/Xe ratios than the ‘reduced’ C3V's—Vigarano and Leoville—which are transitional to LL3's and C3O chondrites in both respects. An HCl-soluble mineral of high Ar/Xr ratio seems to be responsible. In other respects, the 3 C3V's of this study resemble Allende, with only moderate differences. Phase Q contains most of the Ar, Kr, Xe, but only small amounts of Ne; the etched residues contain planetary Ne ($\text{Ne}{}^{20}\text{Ne}{}^{22}\text{? 8.5}$) and the controversial CCFXe component, enriched in the heavy Xe isotopes ($\text{Xe136}\text{Xe132 ? 0.4–0.5}$). The CCFXe is accompanied by an ‘L-Xe’ component that is enriched in the light Xe isotopes. The proportion of the two is virtually constant in C3V's. as in all other C-chondrites. in contrast to the ~ 2-fold variation in ordinary chondrites.C3V's have systematically higher $\text{Xe}{}^{136}\text{Xe}{}^{132}$ ratios, and hence higher ratios of CCFXe to planetary Xe, than do other chondrite classes. This may reflect some peculiarity in their formation conditions, favoring uptake of CCFXe.  相似文献   

Digital national land information   总被引：1，自引：0，他引：1  

H. Matsuda 《GeoJournal》1980,4(4):313-318

The digital land data maintained in the Geographic Survey Institute are listed in Tab 1. They are computerized for the digital national land information to establish a geographical data bank of land information.The digital national land information contains many kinds of land data, which have been maintained mainly as maps, aerial photos and statistics, and is stored as magnetic tape.The smallest geographical unit is either the standard mesh, geodetic coordinate or dots, according to accuracy of the original data.The digital national land information can be used in the various fields of geographical researches and in national or local land planning.In this paper, as an example of application, the housing land selection method is introduced, using the natural land data and the land use data.  相似文献   

Fish,fishing, and sea boundaries: Tuna stocks and fishing policies in Southeast Asia and the South Pacific     

J. E. Bardach  Y. Matsuda 《GeoJournal》1980,4(5):467-478

The distribution of various tuna species in the Pacific Ocean is bounded by the 20°C isotherm while their migrations are influenced by the major current systems and other oceanographic parameters which are here described. Tuna fisheries are important for the island nations of the tropical Pacific with Japan, the USA, Korea, Taiwan and the Philippines prominently engaged in them. The fishery relies on longline, bait-dependent pole and line and purse seining techniques. The various tuna species are among the highest priced fishery commodities vigorously entering international trade in the frozen state or canned. However, with 200 nautical mile extended economic zones now being customary international law, new patterns of resource ownership and management needs have arisen that call for enhanced international cooperation in fisheries research and in surveillance and enforcement; a discussion of possible patterns for such cooperation terminates this article.This article is a contribution of the Oceans Project of the East-West-Center, Honolulu, Hawaii  相似文献   

Early diagenesis of fatty acids in lacustrine sediments—I. Identification and distribution of fatty acids in recent sediment from a freshwater lake     

Hiromi Matsuda  Tadashiro Koyama 《Geochimica et cosmochimica acta》1977,41(6):777-783

Fatty acids have been isolated and quantitatively determined from a 1.5 m sediment core of Lake Suwa, a eutrophic lake in the central districts of Japan.The fatty acids identified by combined gas chromatography-mass spectrometry were straight-chain saturated (C₁₂ to C₃₄), monounsaturated with even carbon number (C₁₆ to C₂₄) and branched-chain (iso, anteiso, 10-methyloctadecanoic) acids. The concentrations of the higher molecular weight (? C₂₀) saturated fatty acids remained nearly constant throughout the core, suggesting a high degree of preservation of those acids, whereas the monounsaturated and the lower molecular weight saturated fatty acids indicated a great decrease in concentration with depth to an approximately 20cm level. It is suggested that the microbial activity in sediments causes a significant reconstruction of the fatty acid distribution during early diagenesis.  相似文献