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排序方式: 共有279条查询结果,搜索用时 265 毫秒
131.
Keiji Watabe Yutaro Senga Atsushi Mori Noriyuki Koizumi Takeshi Takemura Kazuya Nishida 《Paddy and Water Environment》2012,10(3):223-229
Agricultural canals with deep concrete walls are commonly installed in paddy field areas following land consolidation projects in Japan. Such canals create a critical migration barrier for frogs, as escape is not possible after falling in. Hence, countermeasures that allow migrating frogs to cross agricultural canals, such as lid structures to prevent frogs from falling in or the creation of partial slopes to allow escape, have been developed to conserve endangered frog populations. The objective of this study was to design a method for evaluating the population viability of the endangered Japanese Brown Frog, Rana japonica, following the implementation of countermeasures. Two types of model simulations were examined: (1) a ??basic model,?? based on an age-structured model and (2) a ??crossing model,?? to evaluate migrating frogs crossing canals. Parameters, such as survival rate and fecundity, were estimated from field observation data of age-dependent population fluctuations. Comparison of a basic model simulation with the field observation data suggests model validation. The crossing model simulation, which had an initial population of 1,000 individuals, showed that a crossing proportion of greater than 30?C40% would achieve 95% population viability after 5?years. The simulation also showed that a crossing proportion of over 80% would also achieve 95% population viability after 40?years. These results indicate that frog survival during the migration period is insured, as long as no additional countermeasures are necessary after installation. 相似文献
132.
133.
Kazuya Kuzutani Toshiyuki Shibanushi Yumi Kangawa Tohru Kihara 《Journal of toxicologic pathology》2012,25(3):221-224
Spontaneous mammary adenocarcinoma was observed in a 12-week-old female SD rat. A
movable mass in the right cervical region was found at 11 weeks of age, and the rat was
sacrificed the following week. The mass was located in the vicinity of the right salivary
gland and measured 38 mm × 26 mm × 16 mm in gross size. It was a firm whitish mass, with a
cut surface that was also whitish in appearance. Histopathologically, neoplastic cells
formed glandular structures that contained secreted eosinophilic material.
Ultrastructurally, similar secreted material and lipid droplets were in the cytoplasm of
the neoplastic cells. Immunohistochemically, the neoplastic cells were positive for
cytokeratin 8, cytokeratin 18 and estrogen receptor α. Based on these findings, the tumor
was diagnosed as a mammary gland adenocarcinoma, and we therefore conclude that this tumor
type can occur spontaneously in female SD rats as young as 12 weeks of age. 相似文献
134.
Sasaoka F Suzuki J Fujihara M Watanabe Y Nagai K Harasawa R 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(1):83-87
The intergenic spacer region between the 16S and 23S rRNA genes of mycoplasmas has been used for a genetic marker for identification of the species. Here we show the intergenic spacer regions of two hemotropic mycoplasmas, Mycoplasma haemofelis and 'Candidatus Mycoplasma haemobos (synonym: 'C. M. haemobovis')' are also useful for classification of this particular group of mycoplasms. The spacer region of M. haemofelis and `C. M. haemobos' consisted of 209 and 210 base pairs, respectively, and both lacked the spacer tRNA genes. Phylogenetic analysis suggested a monophyletic relationship among hemoplasmas and M. fastidiosum. A hypothetical secondary structure predicted in the spacer regions tentatively assigned the boxA and boxB motifs peculiar to the members of the genus Mycoplasma. M. haemofelis and 'C. M. haemobos' possessed a stem-loop structure in common, despite the presence of a palindromic nucleotide substitution in the stem region. 相似文献
135.
Kido N Edamura K Inoue N Shibuya H Sato T Kondo M Shindo I 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(8):1029-1032
A male Queensland koala (Phascolarctos cinereus adustus) at Kanazawa Zoological Gardens (Kanagawa, Japan) exhibited paralytic symptoms in the hind limbs. Computed tomography and magnetic resonance imaging revealed a mass on the left ventral side of the 11th to 13th thoracic vertebrae, and the presence of myelitis or edema in the spinal cord. The koala was under anesthesia during the examination and suddenly developed ventricular fibrillation and died. Necropsy revealed a firm flat ovoid hemorrhagic mass on the vertebrae. Following a microscopic examination including immunohistochemistry, the perivertebral mass was diagnosed as B cell lymphoma. Therefore, neoplastic cell infiltration into the spinal cord may cause paralytic symptoms in the hind limbs. 相似文献
136.
Edamura K Itakura S Nasu K Iwami Y Ogawa H Sasaki N Ohgawara H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(5):549-556
Xenotransplantation of porcine pancreatic endocrine (PE) cells in a diffusion chamber, a bioartificial endocrine pancreas (Bio-AEP), was conducted to total pancreatectomized dogs. Six pancreatectomized dogs were divided into two groups of 3 dogs each. In three dogs of the control group, exogenous insulin was administered twice a day for 30 weeks to maintain fasting blood glucose (FBG) levels within the normal range. The remaining three dogs were implanted with Bio-AEPs (implantation group), in addition to daily insulin administration. In the implantation group, Bio-AEPs containing 1.3 to 1.8 x 10(7) cells per kg of body weight of the recipient were implanted without fixation into the abdominal cavity. In the control group, exogenous insulin requirements did not decrease during the experimental period, whereas it significantly decreased for a certain period (3, 11, 17 weeks) after implantation in all implanted dogs. In the implantation group, laparotomy was performed after FBG and the exogenous insulin requirement increased again and Bio-AEPs were removed. Two Bio-AEPs were completely destroyed, and the remaining one was encapsulated by thin fibrous tissue. In this dog, effusion was present within the capsule, but the Bio-AEP was not destroyed. Histopathologically, the necrosis, presumably caused by hypoxia, of the PE-cells was observed on transmission electron microscopy. In conclusion, Bio-AEP could function for a certain period after implantation in this study. However, more preclinical researches should be needed to apply this technique for the treatment of diabetic dogs. 相似文献
137.
Sarunya NALUMPANG Yukie GOTOH Hiroyuki TSUBOI Kenji GOMI Hiroyuki YAMAMOTO Kazuya AKIMITSU 《Journal of General Plant Pathology》2002,68(2):118-127
A cDNA encoding a polygalacturonase-inhibiting protein gene (SaiPGIPA) was identified from the citrus cultivar Sainumphung (Citrus sp.), one of the most popular cultivars in northern Thailand. SaiPGIPA was expressed in Escherichia coli cells, and the functional properties of citrus PGIP were analyzed. The PGIP fusion protein inhibited by a maximum of about
60% of the endopolygalacturonase activity, and a mixture of the PGIP and fungal endopoly-galacturonase released oligogalacturonides
from polygalacturonic acid. The mixture containing the oligogalactur-onides, endopolygalacturonase and PGIP induced expression
of the PGIP gene and a chalcone synthase gene in citrus leaves. The mixture also induced resistance in cucumber leaves against
Colletotrichum lagenarium.
Received 5 September 2001/ Accepted in revised form 20 November 2001 相似文献
138.
139.
Cellulose isolated from wood is more susceptible than cotton cellulose to homogeneous hydrolysis in phosphoric acid. The influence of carboxyl group introduction at the C6 position on the hydrolysis rate of cellulose in 82.5% phosphoric acid was studied as a model of the oxidation of cellulose during pulping. The rate constant of hydrolysis for dissolving pulp was larger than that of cotton cellulose at temperatures of 25°–35°C. Mercerized cotton cellulose was partially oxidized regioselectively at the C6 position by a free radical system using 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO). The oxidized cellulose was obtained at a range of 1.7–12.7 mEq carboxyl content per 100 g of cellulose. The hydrolysis rate of the oxidized cellulose samples accelerated with increasing carboxyl content in the samples.Part of this work was presented at the 5th Annual Meeting of the Cellulose Society of Japan, Kyoto, July 1998 相似文献
140.
Sitka spruce (Picea sitchensis Carr.) was treated with water-soluble extractive components of pernambuco (Guilandina echinata Spreng. syn Caesalpinia echinata Lam.) by two methods: impregnation under evacuation using an aspirator and repetitive surface application using a brush. The influence of these treatments on the vibrational properties were examined. The loss tangent (tan ) of the impregnated specimen decreased, up to nearly a half of its original value, with increasing weight gain. It is suggested that the decrease in tan results from impregnation of the extractive components into the amorphous region of cell walls, forming secondary bonds between matrix substances. The surface application of the extractive components, on the other hand, hardly brought about the desirable change in vibrational properties.Part of this work was presented at the 47th annual meeting of the Japan Wood Research Society, Kochi, April 1997, and the 48th annual meeting of the Japan Wood Research Society, Shizuoka, April 1998 相似文献