Population size estimation of the pond smelt Hypomesus nipponensis in Lake Kasumigaura and Lake Kitaura,Japan     

Daisuke Sakamoto  Takashi Nemoto  Noriyuki Sunoh  Jun Iwasaki  Shintaro Niwa  Kazunori Arayama  Naoki Suzuki  Pai-Son  Kaori Takagi  Kazumi Sakuramoto 《Fisheries Science》2014,80(5):907-914

We estimated the population size of the pond smelt Hypomesus nipponensis at the beginning of the fishing season in Lake Kasumigaura and Lake Kitaura, Japan using two DeLury methods and cohort analysis. A growth curve was estimated on the basis of monthly standard length. The relationship between standard length and weight was utilized for calculating the mean weight on the survey day in a particular month. Total monthly catches in Lake Kasumigaura and Lake Kitaura were calculated using partial monthly pond smelt catch obtained from processing plants located near the lakes between July and December. The total monthly catch was calculated from the total monthly catch weight and the monthly mean weight. The number of boats operating each month, compiled by the Kasumigaura-Kitaura Fisheries Office of Ibaraki Prefecture, was also employed. The estimated initial population sizes were compared with the population level index (PLI) estimated from survey data before the start of the fishing season. No significant differences were detected among the initial population sizes estimated by DeLury method, cohort analysis and PLI. The estimates ranged from 7.4 million to 410 million in Lake Kasumigaura, and from 7.7 million to 44 million in Lake Kitaura.  相似文献   

A Canine Case of Primary Intra-Right Atrial Paraganglioma     

Hirotaka YANAGAWA  Hitoshi HATAI  Takahiro TAODA  Hassadin BOONSRIROJ  Kazunori KIMITSUKI  Chun-Ho PARK  Toshifumi OYAMADA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(7):1051-1053

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A Case Report of Feline Pituitary Carcinoma with Hypercortisolism     

Kazunori KIMITSUKI  Hassadin BOONSRIROJ  Daisuke KOJIMA  Chun-Ho PARK 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(1):133-138

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Microbial biomass and nitrogen transformations in surface soils strongly acidified by volcanic hydrogen sulfide deposition in Osorezan, Japan     

Mirai WATANABE  Shigeki YAMAMURA  Takejiro TAKAMATSU  Masami K. KOSHIKAWA  Seiji HAYASHI  Tomoyoshi MURATA  Shoko S. SAITO  Kazuyuki INUBUSHI  Kazunori SAKAMOTO 《Soil Science and Plant Nutrition》2010,56(1):123-132

Volcanic acidification has created unique ecosystems that have had to adapt to the acidic environments in volcanic regions. To characterize the primary microbial properties of strongly acidified soils in such environments, we investigated microbial biomass, nitrogen transformations and other relevant chemical properties in the surface soils of solfatara and forests from Osorezan, a typical volcanic region in Japan, and compared the results to common Japanese forest soils. Soil microbial biomass C (MBC) and N (MBN) were determined using the chloroform fumigation–extraction method. Potential net N mineralization and net nitrification were measured in aerobic laboratory incubations. Long-term acidification in the Osorezan soils by volcanic hydrogen sulfide deposition caused low soil pH (3.0–3.8), base cation deficiency and increased concentrations of toxic ions such as Al³⁺. The proportions of MBC to total carbon (MBC/TC ratio) and MBN to total nitrogen (MBN/TN ratio) were lower than those in common Japanese forest soils. The extreme acidic conditions may have inhibited microbial survival in the Osorezan acid soils. Net N mineralization occurred at rates comparable to those in common Cryptomeria japonica forest soils, probably because of the presence of acid-tolerant soil microorganisms. Net nitrification was completely inhibited and autotrophic ammonia oxidizers were not detected by the MPN method. The inhibition of nitrification prevents nitrogen leaching from the soils, thus maintaining a nitrogen cycle in the volcanic acid region in which     (and NH₃) is recycled among microorganisms and plants.  相似文献   

Genomic expression patterns of mitral valve tissues from dogs with degenerative mitral valve disease     

Oyama MA  Chittur SV 《American journal of veterinary research》2006,67(8):1307-1318

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Neurohormonal activation in canine degenerative mitral valve disease: implications on pathophysiology and treatment     

M. A. Oyama 《The Journal of small animal practice》2009,50(S1):3-11

Neurohormonal systems play a critical role in canine degenerative mitral valve disease (DMVD). DMVD results in mitral regurgitation, which reduces forward cardiac output and increases intracardiac pressures. These changes trigger neurohormonal responses that ultimately result in maladaptive cardiac remodelling, congestion and heightened morbidity and mortality. Medical therapies such as ACE inhibitors and spironolactone derive their benefit by interrupting or suppressing these neurohormonal responses. Thus, knowledge of neurohormonal mechanisms can lead to a better understanding of how to treat DMVD.  相似文献   

Annual changes in testicular activity and plasma steroid hormones in the golden rabbitfish Siganus guttatus (Bloch)   总被引：1，自引：0，他引：1  

Md Saydur Rahman  Akihiro Takemura  Kazunori Takano 《Fisheries Science》2000,66(5):894-900

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Population Genetics of <Emphasis Type="Italic">Escontria chiotilla</Emphasis> in Wild and Silvicultural Managed Populations in the Tehuacán Valley,Central Mexico     

Alma?Tinoco  Alejandro?CasasEmail author  Rosaura?Luna  Ken?Oyama 《Genetic Resources and Crop Evolution》2005,52(5):525-538

Escontria chiotilla is a columnar cactus that grows in the arid and semiarid lands of Central Mexico and produces edible fruit with economic. In the wild, this plant species is distributed as part of thorn-scrub and tropical deciduous forests, but in the Tehuacán Valley also occurs in silvicultural managed in situ populations, in which people practise artificial selection enhancing phenotypes with larger fruits. The population genetics of wild and managed populations was studied to analyse the effects of management on genetic structure of E. chiotilla. A total of 150 individuals from six populations were studied, analysing 13 loci for eight enzymes by starch gel electrophoresis. The genetic variation in wild populations was significantly higher than in managed populations (H_o = 0.079, H_e = 0.134, H_T = 0.370, and H_o = 0.052, H_e = 0.110, H_T = 0.298, respectively), indicating that silvicultural management has caused a reduction of the genetic variation in populations. Most of the genetic variation in both wild and managed populations occurs within populations (D_ST = 0.027 in the wild and 0.018 in managed populations). The genetic distance coefficients were slightly different for silvicultural managed populations than in wild ones, illustrating an incipient effect of management on the genetic structure of populations. However, values of Nm_GST = 3.845 and Nm_FST = 3.848 indicate that a high gene flow counteracts the effects of human selection on the differentiation of populations.  相似文献   

Measurement of concentrations of trace metals in arable soils with animal manure application using instrumental neutron activation analysis and the concentrated acid digestion method     

Shinichi OGIYAMA  Kazunori SAKAMOTO  Hiroyuki SUZUKI  Shingo USHIO  Tetsuo ANZAI  Kazuyuki INUBUSHI 《Soil Science and Plant Nutrition》2006,52(1):114-121

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Accumulation of Zinc and Copper in an Arable Field after Animal Manure Application   总被引：1，自引：0，他引：1  

Shinichi Ogiyama  Kazunori Sakamoto  Hiroyuki Suzuki  Shingo Ushio  Tetsuo Anzai  Kazuyuki Inubushi 《Soil Science and Plant Nutrition》2005,51(6):801-808

An experiment was conducted to examine the accumulation and mobility of heavy metals (Zn and Cu) at different depths in three types of arable soils (Brown Lowland soil, Andosol, and Brown Forest soil) amended with cattle and pig farmyard manures for 5 years. Nitric-perchloric acid digestion was performed for the determination of the total amounts of heavy metals, and 0.1 M hydrochloric acid extraction was performed for the determination of the amounts of soluble heavy metals. Results of the soil analysis indicated that pig farmyard manure application resulted in serious contamination of arable soils with Zn and potentially Cu. Especially, the Brown Forest soil displayed a high ability to accumulate heavy metals on the soil surface. Total-Zn concentration in surface soils was considerably affected by the holding capacity of soluble-Zn traction. Although the Andosol amended with pig farmyard manure showed higher concentrations of heavy metals related to the higher ability of retention on a weight basis, the soil did not contribute to high heavy metal accumulation because of its low bulk density. Heavy metals were easily leached in sandy soils such as Brown Lowland soil, and Cu was potentially stable compared with Zn. We suggest that long-term pig farmyard manure application to the Brown Lowland soil and Andosol with a light soil texture is associated with a higher risk of groundwater pollution than the application to the Brown Forest soil.  相似文献