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661.
Resonance frequencies of bars with various types of end supports were examined in terms of flexural vibration. Sugi (Japanese cedar, Cryptomeria japonica D. Don) was used for the specimens. Small rectangular bars with dimensions of 25?mm (R)?×?5?mm (T)?×?300?mm (L), small round bars of 25?mm in diameter and 250?mm in length, actual-size rectangular bars with the dimensions of 45?mm (R)?×?95?mm (T)?×?1500?mm (L) and actual-size round bars of 180?mm in diameter and 2000?mm in length were made. Varying compression stress was applied to the parts around both ends of test specimen, whereupon flexural vibration tests were performed. The measured resonance frequency rose rapidly early in the increasing compression load process and was nearly stable for the larger compression load. The significant increases in the resonance frequency for round bars are thought to be derived from the wide area between the round bar and jig. It is necessary to compare the resonance frequency of a bar tightly fixed to a post with that of the same bar loosely fixed to the post.  相似文献   
662.
The development of vertical gradients of specific leaf nitrogen (SLN) in accordance with light gradients within a canopy is important for maximising resource‐use efficiency. In this study, we aimed to clarify the effect of chronic soil water deficit on the SLN gradient in rice. In a series of field experiments, SLN gradients of an indica cultivar and a tropical japonica cultivar were investigated under chronic soil water deficit. As a result, SLN gradient of an indica cultivar tended to be more uniform than that of a tropical japonica cultivar during the recovery period after dry spells under aerobic conditions: an indica cultivar distributed much N in shaded leaves while a japonica cultivar enhanced the SLN in the upper layers. We conclude that vertical gradient of SLN of indica cultivars becomes less optimal for photo‐assimilation under chronic soil water deficit, although they can take‐up sufficient amounts of N. This would be attributable to the rapid increase in tiller number upon rainfall or irrigation and prolonged tillering period for their recovery growth, leading to a more compact canopy architecture. The tillering habit in the current indica irrigated rice cultivars would be associated with the response of SLN gradients to chronic soil water deficit.  相似文献   
663.
A total of 334 introgression lines (INLs: BC3-derived lines) derived from crosses between a recurrent parent of Indica rice cultivar IR64 and 10 donor parents, including new plant type (NPT) lines IR65600-87-2-2-3, IR65598-112-2, IR65564-2-2-3, IR69093-41-2-3-2, IR69125-25-3-1-1, Hoshiaoba, IR66215-44-2-3, IR68522-10-2-2, IR71195-AC1, and IR66750-6-2-1, have been developed. These INLs with IR64 genetic background were characterized for eight agronomic traits: days to heading, culm length, leaf width, leaf length, panicle length, panicle number, 100-grain weight, and total spikelet number per panicle at the International Rice Research Institute from 2005 to 2007. To identify introgressed segments from the donor parents, genotypes of the 334 INLs were detected using more than 200 polymorphic simple sequence repeat markers. These segments detected on chromosomes 1, 2, 4, 5, and 6 were commonly introgressed across the INLs from more than four donor varieties. Based on the data of phenotype and genotype for the 334 INLs, associations between agronomic traits and introgressed chromosomal segments in the 334 INLs were investigated. A total of 54 regions for the eight traits were detected: seven regions for days to heading, eight regions for culm length, eight regions for leaf width, four regions for leaf length, six regions for panicle length, three regions for panicle number per plant, seven regions for 100-grain weight, and 11 regions for total spikelet number per panicle. Among them, the region on the long arm of chromosome 4 was associated with characteristics of the NPT such as long leaf, broad leaf, and high spikelet number. The developed 334 INLs with the IR64 genetic background will be useful materials for genetic analysis of agronomic traits.  相似文献   
664.
This study evaluates the sustainability of the innovative practices of smallholders who have extended their traditional farming and backyard gardening to other production parcels, such as agroforest systems in Eastern Amazon, Northeast Pará, under the PROAMBIENTE Program at Capim River Pole. According to these smallholders, these practices have assured food supplies and yields with the inclusion into the consumer market through produce diversity obtained by agroforest arrangement and increased purchase of material goods to the system. The smallholders’ perceptions also permit the evaluation of the sustainability of their experiences through the “Amoeba” method, which consolidates economic, social, cultural, and environmental indicators.  相似文献   
665.
666.
ABSTRACT:   Physical conditions such as oceanic turbulence related to food availability are considered to be important factors affecting fish larval survival. Rearing experiments were conducted to elucidate the effects of turbulence on the survival and feeding rates during the initial feeding period of Pacific bluefin tuna Thunnus orientalis . Six levels of turbulence intensity were provided by changing flow rates from pipes set on the bottom of rearing tanks. The result showed a dome-shaped relationship between turbulence level and survival rate, in which the feeding rate appeared higher at a logged turbulence energy dissipation rate of −6.32, and decreased at both higher and lower turbulence levels. Compared with the turbulence intensity in the ocean, the optimal turbulence level for Pacific bluefin tuna larvae corresponded to the turbulence caused by sea surface winds with speeds of 4–12.5 m/s. The estimated optimal turbulence intensity for Pacific bluefin tuna larvae is comparable to that for yellowfin tuna Thunnus albacares .  相似文献   
667.
Chinese violet (Asystasia gangetica (L.) T. Anderson) is a perennial invasive weed belonging to Acanthaceae. Leaves of this weed have been suggested to possess phytotoxic activity. However, phytotoxic substances in this weed have not yet been reported. Therefore, the present study investigated phytotoxic activity of Chinese violet extracts and phytotoxic substances. The extracts of Chinese violet leaves inhibited the root and shoot growth of cress, lettuce, alfalfa, barnyard grass, ryegrass, and timothy, where the level of inhibition increased with increasing extract concentrations. Bioassay‐guided separations of the extracts led to isolation of two phytotoxic substances, indole‐3‐carboxaldehyde and (6R,9S)‐3‐oxo‐α‐ionol. Indole‐3‐carboxaldehyde significantly inhibited the root and shoot growth of cress at concentrations ≥100 and 30 μmol L?1, respectively, and concentrations of the substance required for 50% growth inhibition were 210 and 127 μmol L?1 for cress roots and shoots, respectively. The other substance, (6R,9S)‐3‐oxo‐α‐ionol, was reported to have strongly inhibited cress roots and shoots. The present results suggest that Chinese violet contains two phytotoxic substances indole‐3‐carboxaldehyde and (6R,9S)‐3‐oxo‐α‐ionol, and those substances may play an important role in the phytotoxic activity of Chinese violet.  相似文献   
668.
Twelve isolates of Japanese Phytophthora infestans, which differed from the major genotypes US-1, JP-1, JP-2, and JP-3, were analyzed for RG57 fingerprints, mtDNA haplotypes, two allozyme genotypes, and mating types. Genotypes JP-1.1, JP-2.1, JP-2.2, JP-3.1, and JP-4 were newly defined. JP-1.1 and JP-2.1 were isolated discontinuously from potato fields in several years, and JP-1.1 was found in Hokkaido and Kagoshima. These results show that some minor genotypes can overwinter and disperse from their original site.  相似文献   
669.
BACKGROUND: Imatinib mesylate is a small molecule targeted at dysregulated protein-tyrosine kinase. Mutation of c-kit exon 11, which induces constitutive phosphorylation of KIT, is one of the mechanisms for the development or progression of mast cell tumor (MCT) in dogs. The purpose of this study was to examine the therapeutic potential of imatinib mesylate in canine MCT. HYPOTHESIS: Imatinib mesylate has activity against MCT in dogs, and response to treatment can be correlated to presence of mutation within exon 11 of c-kit. ANIMALS: Twenty-one dogs with MCT with gross tumor burden and median tumor size of 7.2 cm (range, 1.0-25.3 cm) before treatment. METHODS: Tumors were analyzed for mutation of c-kit exon 11. Imatinib mesylate was administered PO to the dogs at a dose of 10 mg/kg daily for 1-9 weeks. RESULTS: Ten of 21 dogs (48%) had some beneficial response to imatinib mesylate treatment within 14 days of treatment initiation. All 5 dogs with a demonstrable c-kit mutation in exon 11 responded to the drug (1 complete remission, 4 partial remission). CONCLUSIONS AND CLINICAL IMPORTANCE: Imatinib mesylate has clinical activity against MCT in dogs. Response could not be predicted based on presence of absence of a mutation in exon 11 of c-kit.  相似文献   
670.
Characterization of feline T and B cells   总被引:1,自引:0,他引:1  
Feline peripheral-blood lymphocyte populations (n = 22) were examined for the following markers: rosette formation with guinea pig erythrocytes (GPE-T cells), rosette formation with human RBC (HRBC-T cells), rosette formation with sheep RBC, mixed rosette formation with GPE-T cells and HRBC-T cells (total T cells), erythrocyte antibody-complement rosettes, and surface immunoglobulin. An average of 28% +/- 7% (range, 16% to 39%) of the feline lymphocytes formed rosettes with GPE-T cells, and 27% +/- 7% (range, 11% to 36%), with HRBC-T cells. An average of 57% +/- 9% (range, 33% to 75%) of the lymphocytes formed mixed rosettes. The erythrocyte antibody-complement rosette-forming cells and surface immunoglobulin-bearing cells were found in peripheral blood lymphocytes (10% +/- 6% and 24% +/- 8%, respectively). The murine monoclonal antibodies OKT 11 and HuLy-m1, specific for a framework determinant of human E-rosette receptor antigens, cross-reacted with feline cell membrane molecules recognizing a bimolecular complex (45,000 to 50,000 daltons) similar to that described in persons. We investigated the distribution of these E-rosette receptor-like antigens on feline lymphocytes. By complement-mediated lymphocytotoxicity, about 30% of the feline lymphocytes expressed the antigens. When lymphocytes were treated with HuLy-m1 antibody, spontaneous rosette formation with HRBC-T cells was significantly inhibited.  相似文献   
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