Quantitative stand structure of woody components of homestead forests and its implications on silvicultural management: a case study in Sylhet Sadar, Bangladesh     

Rahman M. Motiur  Jiro Tsukamoto  Yasushi Furukawa  Zenichiro Shibayama  Isao Kawata 《Journal of Forest Research》2005,10(4):285-294

This study determined existing quantitative stand structure and its implication on silvicultural management of homestead forestry. The results showed that fruit and timber species have importance values of 57% and 43%, respectively, in the study area, which is in contrast to the commonly held view of absolute domination of fruit species. The fruit species were only moderately dominant over timber species in relation to the quantitative stand structure of homestead forests. Two fruit species, Mangifera indica and Artocarpus heterophyllus, contribute about one third of the stand structure, while amongst the timber species Samanea saman and Albizia spp. are the most important species. A simulated evaluation of soil expectation value of homestead forest showed that the existing stand structure would not maximize the financial gain perpetually, in contrast, the quantitative stand structure could be effectively regulated to maximize grower benefit without compromising the existing biodiversity. Optimization of the quantitative stand structure of homestead forests could be achieved by changing the species composition, specifically by increasing the percentage of commercially valuable species like Michelia champaca, Tectona grandis, Artocarpus chapalasha, Gmelina arborea, Litchi chinensis, Citrus grandis, Psidium guajava, Lagerstroemia speciosa, Swietenia mahogany, etc., reducing the percentage of species like Mangifera indica, Artocarpus heterophyllus, Cocos nucifera, Samanea saman, Spondias pinnata, Phoenix sylvestris, etc., and eradicating species like Lannea coromandelica and Ficus benghalensis. It was estimated that the optimal relative density of fruit and timber species that would generate optimal financial benefit would be 40.4% and 59.6%, respectively.  相似文献   

Winter hardiness in Turkish populations of cocksfoot,Dactylis glomerata L.     

Jiro Abe 《Euphytica》1980,29(3):531-538

Summary Over a six-year period, Turkish populations of cocksfoot were investigated in the field at Sapporo, Japan, as to winter hardiness. After the first winter, only populations from the mild Marmara, Aegean and Mediterranean regions were badly damaged. As the differential plant survival among geographical groups widened with the elapsing of years, we were able to rank the groups in descending order of relative hardiness from Eastern Anatolia, through the Black Sea, Central Plateau, Marmara and Aegean regions, to the Mediterranean region. This order was maintained throughout the experimental period.Winter temperatures prevailing in the locality of origin was the most important determinant of winter survival of the populations. The growth pattern in autumn and whether plants continued to grow through the winter or were enforced to winter dormancy, were related to differential survival between maritime and mountainous populations. On the other hand, this simple relationship is complicated by introgression. The subspecies distribution in the coastal region is related to a higher level of survival in the populations from the Black Sea region, where the continental type of cocksfoot occurs, than in the populations from the other maritime regions, where introgression has occurred from Daetylis glomerata subsp. hispanica with poor winter hardiness.Present address: Tropical Agriculture Research Center, Okinawa Branch, Ishigaki 907-01, Japan.  相似文献   

Extractability of major and trace elements from agricultural soils using chemical extraction methods: Application for phytoavailability assessment     

Akira TAKEDA  Hirofumi TSUKADA  Yuichi TAKAKU  Shun'ichi HISAMATSU  Jiro INABA  Masami NANZYO 《Soil Science and Plant Nutrition》2006,52(4):406-417

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Enzyme-linked immunosorbent assay for detection of antibody against hemorrhagic fever with renal syndrome virus in sera from experimentally infected rats     

T Maeda  J Arikawa  I Takashima  N Hashimoto 《The Japanese journal of veterinary research》1987,35(3):215-219

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Characterization of in vitro and in vivo antiviral activity of lactoferrin and ribavirin upon hantavirus.   总被引：2，自引：0，他引：2  

M E Murphy  H Kariwa  T Mizutani  H Tanabe  K Yoshimatsu  J Arikawa  I Takashima 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2001,63(6):637-645

Mechanisms of anti-hantaviral activities of bovine lactoferrin (LF) and ribavirin (Rbv) were investigated. Hantavirus focus formation at 48 hr was 15% of the control in cells treated with 400 microg/ml LF for 1 hr at 37 degrees C prior to viral infection. Post infection treatment with 100 microg/ml Rbv also inhibited the focus formation to 2.5% of the control. Combined LF pre- and Rbv post-infection treatment completely inhibited focus formation. Viral glycoprotein (G2) and nucleocapsid protein (NP) syntheses were delayed in LF pretreated cells up to 24 hr post infection (hpi) but became comparable to the control by 48 hpi. Further, LF inhibited viral shedding at 24 hpi but did not inhibit shedding after 48 hpi. However, Rbv was able to inhibit synthesis of viral proteins, (+) and (-) strand RNAs also inhibited viral shedding after 24 hr. These results suggest that LF inhibits viral adsorption to cells, while Rbv inhibits viral RNA synthesis. For in vivo trials of LF and Rbv, LF pre- and Rbv post-treatment were evaluated in suckling mice infected with hantavirus, of which 7% survived. LF concentrations of 40 and 160 mg/kg administered prior to viral challenge improved survival rates to 15% and 70%, respectively for single administration and 85% and 94%, respectively, for double administration. Rbv concentrations of 25 and 50 mg/kg gave survival rates of 68% and 81%, respectively. This suggests that both LF and Rbv are efficacious in hantavirus infection in vivo.  相似文献   

Isolation and serological survey of chlamydiosis in feral pigeons and crows in Hokkaido   总被引：1，自引：0，他引：1  

N Chiba  J Arikawa  I Takashima  N Hashimoto 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1984,46(2):243-245

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Pharmacokinetics of cycloalliin, an organosulfur compound found in garlic and onion, in rats     

Ichikawa M  Mizuno I  Yoshida J  Ide N  Ushijima M  Kodera Y  Hayama M  Ono K 《Journal of agricultural and food chemistry》2006,54(26):9811-9819

Cycloalliin, an organosulfur compound found in garlic and onion, has been reported to exert several biological activities and also to remain stable during storage and processing. In this study, we investigated the pharmacokinetics of cycloalliin in rats after intravenous or oral administration. Cycloalliin and its metabolite, (3R,5S)-5-methyl-1,4-thiazane-3-carboxylic acid, in plasma, urine, feces, and organs was determined by a validated liquid chromatography-mass spectrometry method. When administered intravenously at 50 mg/kg, cycloalliin was rapidly eliminated from blood and excreted into urine, and its total recovery in urine was 97.8% +/- 1.3% in 48 h. After oral administration, cycloalliin appeared rapidly in plasma, with a tmax of 0.47 +/- 0.03 h at 25 mg/kg and 0.67 +/- 0.14 h at 50 mg/kg. Orally administered cycloalliin was distributed in heart, lung, liver, spleen, and especially kidney. The Cmax and AUC0-inf values of cycloalliin at 50 mg/kg were approximately 5 times those at 25 mg/kg. When administered orally at 50 mg/kg, cycloalliin was excreted into urine (17.6% +/- 4.2%) but not feces. However, the total fecal excretion of (3R,5S)-5-methyl-1,4-thiazane-3-carboxylic acid was 67.3% +/- 5.9% (value corrected for cycloalliin equivalents). In addition, no (3R,5S)-5-methyl-1,4-thiazane-3-carboxylic acid was detected in plasma (<0.1 microg/mL), and negligible amounts (1.0% +/- 0.3%) were excreted into urine. In in vitro experiments, cycloalliin was reduced to (3R,5S)-5-methyl-1,4-thiazane-3-carboxylic acid during anaerobic incubation with cecal contents of rats. These data indicated that the low bioavailability (3.73% and 9.65% at 25 and 50 mg/kg, respectively) of cycloalliin was due mainly to reduction to (3R,5S)-5-methyl-1,4-thiazane-3-carboxylic acid by the intestinal flora and also poor absorption in the upper gastrointestinal tract. These findings are helpful for understanding the biological effects of cycloalliin.  相似文献   

Toxicity of Residual Chlorines from Hypochlorite-treated Seawater to Marine Amphipod Hyale barbicornis and Estuarine Fish Oryzias javanicus     

Nathaniel C. Añasco  Jiro Koyama  Shoko Imai  Kuniaki Nakamura 《Water, air, and soil pollution》2008,195(1-4):129-136

To assess possible adverse effects of residual chlorines from hypochlorite-treated seawater to non-target marine organisms, bioassays were carried out on marine amphipod Hyale barbicornis and estuarine fish Oryzias javanicus. Acute toxicity tests were first conducted using various concentrations of sodium hypochlorite (NaOCl) followed by a long-term exposure to residual chlorines from a test water treated with 1 mg L^?1 NaOCl. Results showed that NaOCl was acutely toxic to both organisms. However, long-term exposure to residual chlorines from NaOCl-treated waters caused no major adverse effects to both organisms under laboratory conditions since free chlorines in the treated water was reduced to about 10% by 23-h holding and 1-h aeration. No H. barbicornis died but residual chlorine-exposed juveniles had significantly shorter body lengths at the end of exposure. Residual chlorine-exposed O. javanicus also showed no significant differences to that of the control in all measured endpoints except for hatching time. The results suggest that using 1 mg L^?1 NaOCl for disinfection of ballast waters will produce residual chlorines that is far below the LC50 and EC50 of H. barbicornis and O. javanicus even on a long-term basis.  相似文献   

Spontaneous Gingivitis Related to Hair Penetration in Rats     

Aya Goto  Jiro Sonoda  Yuki Seki  Yoshikazu Taketa  Etsuko Ohta  Kyoko Nakano  Akira Inomata  Kazuhiro Hayakawa  Toyohiko Aoki  Kazuo Tsukidate  Satoru Hosokawa 《Journal of toxicologic pathology》2012,25(3):229-232

Maxillary gingivae from male and female Crl:CD(SD) rats at 12, 16, 21, and 34 weeks of age were examined histologically. The incidence of gingivitis was approximately 40%, with no age or sex predilection, and was most frequent between the first and second molar. Lesions were characterized by acute focal neutrophilic infiltration into the gingival mucosa, occasionally with inflammatory exudate. In severe cases, inflammation extended to the periodontal ligament with abscess formation, and adjacent alveolar bone destruction/resorption. The most characteristic finding was the presence of hair shafts associated with the lesion, which was observed in approximately 80% of the rats with gingivitis. These findings suggest that molar gingivitis occurs in rats from an early age and persists thereafter, and that the main cause of gingivitis in rats is hair penetration into the gingiva. It would be prudent to keep these background lesions in mind as potential modifiers in toxicity studies.  相似文献   

Method for assessing resistance of wheat to speckled snow mold (<Emphasis Type="Italic">Typhula ishikariensis</Emphasis>) under controlled conditions     

Akira?KawakamiEmail author  Jiro?Abe 《Journal of General Plant Pathology》2003,69(5):307-309

A method was developed for assessing the resistance of wheat to speckled snow mold (Typhula ishikariensis) under controlled conditions in all steps. We modified the method of Nakajima and Abe and estimated the optimum conditions consisting of 2 weeks each for prehardening and hardening, 6 weeks for incubation at 8°C, and 2 weeks for regrowth in a greenhouse for screening resistance. The present method reduced the experimental period to 12 weeks and facilitated repeated experiments throughout the year.  相似文献