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排序方式: 共有802条查询结果,搜索用时 31 毫秒
111.
Keigo Noda Masayasu Maki Kanae Miyaoka Koki Homma Hiroaki Shirakawa Kazuo Oki 《Paddy and Water Environment》2015,13(4):487-493
In Southeast Asia, economic and population growth are expected in the near future. Rapid change is anticipated especially in the Lao PDR. Concern has been expressed that population growth will lead to an increased demand for food and economic growth to changes in the use of land. For food production to keep pace with the growth of population, it is very important to understand decision-making in rice paddy cultivation in urbanizing areas; for this reason, this study with the SEM model was conducted. The original data were collected by a questionnaire survey in some Lao villages; the survey included questions on various conditions, such as the availability of water in the dry season (irrigation), the access to a city, and job opportunities other than farming. The findings of the study demonstrate that the planting of a second rice crop was related to such factors as the productivity of rain-fed rice and cash crops and, most importantly, job opportunities other than farming. 相似文献
112.
Satoyama is a traditional agricultural landscape in Japan. It contains many kinds of organisms, including endangered species. Satoyama is composed of several habitat types, including paddy fields, secondary forests, secondary grasslands, ponds, and streams. High species richness has been sustained in most habitats by anthropogenic disturbances of intermediate impact, mainly activities related to agriculture. The variety of habitats and connectivity among them have contributed to the high species diversity within satoyama. These factors allow organisms to move among habitats and use different habitat types to obtain different resources. The connectivity among habitats is often more vulnerable than the specific habitats themselves under anthropogenic influences. In satoyama, species that require connectivity among habitats (e.g., grey-faced buzzard [Butastur indicus] and Genji firefly [Luciola cruciata]) have tended to decrease. The grey-faced buzzard is categorized as a “vulnerable” species in the Japanese Red List. It usually nests in forest trees and forages in habitats such as paddy fields, grasslands, and forests. Its foraging locations shift seasonally depending on food availability. It is thought that the degradation of either paddy fields or forests in a landscape may result in the disappearance of this species. The Genji firefly spends its larval period in stream water, pupates underground along streams, and flies near streams after emergence. This species requires not only the integrity of streams and nearby areas, but also connectivity between these areas. The ecology of these species suggests that the variety of habitats and connectivity among them are critical factors for their survival. 相似文献
113.
Tomohiro TANAKA Nobuo SUZUI Hiroaki HAYASHI Tomoyuki YAMAYA Tadakatsu YONEYAMA 《Soil Science and Plant Nutrition》2009,55(1):102-106
The presence of glutamine synthetase (GS) in the rice sieve tube was examined. Proteins in the rice phloem sap from leaf sheaths were separated by sodium dodecylsulfate–polyacrylamide gel electrophoresis, transferred to polyvinylidine difluoride membranes and immunoblotted with anti-GS1 antibody. A cross-reacting band, thought to be GS1, was detected in the phloem sap. Moreover, the phloem sap contained a significant amount of GS transferase activity. Previous studies have shown that the concentrations of substrates and cofactors in the rice phloem sap are sufficient for cytosolic GS reaction. These data suggest that physiologically active GS1 is present in rice phloem sap, which might convert glutamate to glutamine in vivo . 相似文献
114.
Hironobu Watanuki Gunimala Chakraborty Hiroki Korenaga Tomoya Kono R.B. Shivappa Masahiro Sakai 《Veterinary immunology and immunopathology》2009,131(3-4):273-277
Human interferon-α (huIFN-α) is an important immunomodulatory substance used in the treatment and prevention of numerous infectious and immune-related diseases in animals. However, the immunostimulatory effects of huIFN-α in fish remain to be investigated. In the current study, the immune responses of the carp species Cyprinus carpio L. to treatment with huIFN-α were analyzed via measurement of superoxide anion production, phagocytic activity and the expression of cytokine genes including interleukin-1β, tumor necrosis factor-α and interleukin 10. Low doses of huIFN-α were administered orally once a day for 3 days, and sampling was carried out at 1, 3 and 5 days post-treatment. Our results indicate that a low dose of huIFN-α significantly increased phagocytic activity and superoxide anion production in the carp kidney. The huIFN-α-treated fish also displayed a significant upregulation in cytokine gene expression. The current study demonstrates the stimulatory effects of huIFN-α on the carp immune system and highlights the immunomodulatory role of huIFN-α in fish. 相似文献
115.
116.
Fisheries Science - Cytokines are low molecular weight glycoproteins involved in the regulation of the immune system, and more than 100 cytokines have hitherto been identified in humans. Cytokines... 相似文献
117.
We analyzed records of shark capture by tuna longline vessels during the period 1992–2006 to document the distribution and ecology of bigeye thresher in the Pacific Ocean. Catch per unit effort (CPUE) was highest in the area of 10–15°N in the north and 5–10°S in the south. Juveniles <150 cm were also distributed in this area. Seasonal changes in the distribution of abundance are thought to represent seasonal migrations in latitude. We observed an increase in the ratio of large individuals at high latitude, likely a result of their increased thermal capacity allowing them to migrate further. Males were captured more often than females, suggesting that there is segregation by sex. Pregnant females were observed from 0°N to 36°N in the north Pacific. Neonates were observed between 10–15°N/150–180°W, overlapping with the area in which large numbers of juveniles were captured. Thus, we hypothesize that this area represents the parturition and nursery grounds for bigeye thresher in this region. 相似文献
118.
Hiroaki Kato Shuta Asai Ayako Yamamoto-Katou Hirofumi Yoshioka Noriyuki Doke Kazuhito Kawakita 《Journal of General Plant Pathology》2008,74(1):15-23
During defense responses, plant cells produce nitric oxide (NO), which may control many physiological processes. In a previous
study, we reported that nitrate reductase (NR) is responsible in part for INF1 elicitor-induced NO production in Nicotiana benthamiana, but the possibility remains that other NO-generating system(s) contribute to NO production. In mammalian cells, NO production
is catalyzed by NO synthase (NOS). However, NOS-like enzyme(s) have never been identified in plants, and only the gene for
Arabidopsis thaliana nitric oxide-associated 1 (AtNOA1) has been identified as a putative regulator of NOS activity in plants. In this study, we cloned NbNOA1, a homolog of AtNOA1, from N. benthamiana and investigated its involvement in NO production induced by INF1. The NbNOA1 gene was silenced by a virus-induced gene-silencing (VIGS) technique. NbNOA1-silenced plants had yellowish leaves. Silencing NbNOA1 partially decreased INF1-induced NO production, while overexpressing NbNOA1 did not affect NO production. Silencing NbNOA1 suppressed INF1-induced PR1a gene expression and increased susceptibility to Colletotrichum lagenarium. These results suggest that NbNOA1 is involved in INF1-mediated NO production and is required for defense responses.
The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under accession number AB303300. 相似文献
119.
Although the causal agent of yellows of Brassica rapa (turnip, pak choi, and narinosa) in Japan was reported in 1996 to be Fusarium oxysporum f. sp. conglutinans, this classification has remained inconclusive because of a lack of detailed genetic and pathogenic studies. Therefore, we analyzed the taxonomic position of this organism using Japanese isolates of F. oxysporum complex obtained from diseased individuals of various B. rapa subspecies. Phylogenetic analyses using partial sequences of the rDNA intergenic spacer region and the mating-type gene (MAT1-1-1alpha-box) showed that B. rapa and cabbage isolates belong to different monophyletic clades that separated at early evolutionary stages. Additionally, correlations were observed between the molecular phylogeny and the vegetative compatibility groups. Isolates from turnip, komatsuna, and narinosa (B. rapa group) did not show pathogenicity against cabbage or broccoli (B. oleracea group), although they caused severe symptoms on their original host species. In contrast, cabbage isolates had significantly higher (P = 0.05) virulence on B. oleracea than on B. rapa crops. Our results indicate that F. oxysporum complex isolates from B. rapa and B. oleracea are not only phylogenetically distinct but also differ in host specificity. Therefore, we propose a novel forma specialis, F. oxysporum f. sp. rapae, which causes yellows on B. rapa, including turnip, komatsuna, pak choi, and narinosa. 相似文献
120.
Tran Thi Thu Hoai Hiroaki Matsusaka Yoshiko Toyosawa Tran Danh Suu Hikaru Satoh Toshihiro Kumamaru 《Breeding Science》2014,64(2):142-148
Amylose content is one of the most important factors influencing the physical and chemical properties of starch in rice. Analysis of 352 Vietnamese rice cultivars revealed a wide range of variation in apparent amylose content and the expression level of granule-bound starch synthase. On the basis of single-nucleotide polymorphisms (SNP) at the splicing donor site of the first intron and in the coding region of the granule-bound starch synthase I gene, Waxy gene, alleles can be classified into seven groups that reflect differences in apparent amylose content. The very low and low apparent amylose content levels were tightly associated with a G to T in the first intron whereas intermediate and high amylose was associated with a T genotype at SNP in exon 10. The correlation between the combination of T genotype at SNP in the first intron, C in exon 6, or C in exon 10 was predominant among low amylose rice varieties. Our analysis confirmed the existence of Wxop allele in Vietnamese rice germplasm. The results of this study suggest that the low amylose properties of Vietnamese local rice germplasm are attributable to spontaneous mutations at exons, and not at the splicing donor site. 相似文献