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451.
Social forestry as a development strategy has evolved since the 1970s, especially in the tropics, to address forest degradation and promote local community development amidst the burgeoning population in these areas. As a practice, however, social forestry has been in place since ancient times in many parts of the world, including Japanese forest communities. Forest-people relationships in Japan drastically changed through massive afforestation programs after the energy source change and with the industrialization of the forest sector in 1950s. The majority of the planted forests are underutilized today and forest communities are marginalized due to the decline of forestry operations, depopulation, and changes in people’s values. Some communities address this concern by inviting potential urban migrants who may be interested in settling in rural areas. Using the case of the Nishiawakura Village in Okayama Prefecture, this paper explores the recent challenges confronting social forestry in Japan. It is found that underutilization of forest resources can be a cause of serious environmental degradation and marginalization of forest communities, and that Nishiawakura’s journey to renew forest management in partnership with migrants is a process of revisiting and creating the forest-people relationship. This study advances two related arguments, namely (1) the interaction of the local people and the migrants brings new perspectives to forest management, and (2) in a community facing depopulation and underutilization of forest resources, social forestry can be an effective approach to rediscover traditional forest management in a new form and revitalize forests and local communities.  相似文献   
452.
Different types of water stress severely affect crop production, and the plant root system plays a critical role in stress avoidance. In the case of rice, a cereal crop cultivated under the widest range of soil hydrologic conditions, from irrigated anaerobic conditions to rainfed conditions, phenotypic root plasticity is of particular relevance. Recently, important plastic root traits under different water stress conditions, and their physiological and molecular mechanisms have been gradually understood. In this review, we summarize these plastic root traits and their contributions to dry matter production through enhancement of water uptake under different water stress conditions. We also discuss the physiological and molecular mechanisms regulating the phenotypic plasticity of root systems.  相似文献   
453.
We report that the organic salt (EDO-TTF)2PF6 with 3/4-filled-band (1/4-filled in terms of holes), which forms an organic metal with strong electron and lattice correlation, shows a highly sensitive response to photoexcitation. An ultrafast, photoinduced phase transition from the insulator phase to the metal phase can be induced with very weak excitation intensity at near room temperature. This response makes the material attractive for applications in switching devices with room-temperature operation. The observed photo-induced spectroscopic change shows that this photoinduced phase transition process is caused by the cooperative melting of charge ordering assisted by coherent phonon generation.  相似文献   
454.
The effect of energy balance on the growth hormone (GH) secretory responsiveness to growth hormone-releasing hormone (GHRH) has not been determined in ruminant animals. Therefore, we examined the effects of intravenous injections of 0, 3.3, and 6.6 μg ghrelin/kg body weight (BW), with and without GHRH at 0.25 μg/kg BW, on GH secretory responsiveness in both the fed and fasted sheep. The injections were carried out at 48 h (Fasting state) and 3 h (Satiety state) after feeding. Blood samples were taken every 10 minutes, from 30 minutes before to 120 minutes after the injection. Low (3.3 μg/kg BW) and high (6.6 μg/kg BW) doses of ghrelin stimulated GH secretion significantly (P < .05) greater in the Satiety state than in the Fasting state. Growth hormone-releasing hormone plus both doses of ghrelin stimulated GH secretion significantly (P < .05) greater in the Satiety state than in the Fasting state. Ghrelin and GHRH exerted a synergistic effect in the Satiety state, but not in the Fasting state. Plasma ghrelin levels were maintained significantly (P < .05) greater in the Fasting state than in the Satiety state except the temporal increases after ghrelin administration. Plasma free fatty acid (FFA) concentrations were significantly (P < .01) greater in the Fasting state than in the Satiety state. In conclusion, the present study has demonstrated for the first time that ghrelin differentially modulates GH secretory response to GHRH according to feeding states in ruminant animals.  相似文献   
455.
An autoantibody against canine brain tissue was detected in the cerebrospinal fluid (CSF) and serum of two Pug dogs (Nos. 1 and 2) by indirect immunofluorescence assay (IFA). Dog No. 1, a 2-year-old male, exhibited severe depression, ataxia, and generalized seizures and died 2 months after the onset of symptoms. Dog No. 2, a 9-month-old male, exhibited severe generalized seizures and died 17 months after the onset of symptoms. Histopathologic examination revealed a moderate to severe multifocal accumulation of lymphocytes, plasma cells, and a few neutrophils in both the gray and white matter of the cerebrum in dog No. 1. In dog No. 2, the cellular infiltrates were mild, but there was a severe, diffuse, and multifocal necrosis in the cerebral cortex with prominent astrocytosis. With the aid of IFA using fluorescein isothiocyanate-labeled antidog IgG goat serum and a confocal imaging system, specific reactions for glial cells were detected in the CSF of these Pug dogs but not in six canine control CSF samples. Double-labeling IFA using CSF from these Pug dogs and a rabbit antiserum against glial fibrillary acidic protein (GFAP) revealed that the autoantibody recognized GFAP-positive astrocytes and their cytoplasmic projections. By immunoblot analysis, the autoantibody from CSF of these Pug dogs recognized two common positive bands at 58 and 54 kd, which corresponded to the molecular mass of human GFAP. The role of this autoantibody for astrocytes is not yet clear. However, if the presence of the autoantibody is a specific feature of Pug dog encephalitis, it will be a useful clinical diagnostic marker and a key to the pathogenesis of this unique canine neurologic disease.  相似文献   
456.
457.
The Aegilops kotschyi cytoplasm and a 1BL-1RS translocation chromosome that consists of the long arm of wheat chromosome 1B and the short arm of rye chromosome 1R were transferred to six spring common wheat cultivars by repeated backcrossing. Resistance to leaf rust race 21B conditioned by the Lr26 gene and a secalin subunit encoded by the Sec-1 gene, both on the 1RS arm, were used as the selection markers of the translocation chromosome. Five of the six cultivars used were converted to complete male steriles, whereas the remaining one, cv. Kitamiharu 48, retained normal fertility, after transfer of both the 1BL-1RS chromosome and Ae. Kotschyi cytoplasm. Conventional gene analysis suggested that Kitamiharu 48 carries an incompletely dominant fertility-restoring gene. The F1 hybrids between the male steriles and ordinary common wheat cultivars recovered fertility only at a low level, indicating that a single dose of the Rfv1 gene on the 1BS arm of wheat is insufficient for full fertility restoration under spring-sowing condition. Our results are in clear contrast to complete fertility restoration under fall-sowing condition reported by Nonaka et al. (1993). Combination of the 1BL-1RS chromosome / Ae. Kotschyi cytoplasm system with a new fertility-restoring gene discovered in Kitamiharu 48 may provide a breakthrough for spring-type hybrid wheat. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
458.
We examined seasonal, annual variation and horizontal distribution of zooplankton in the Sea of Japan from 1966 to 1990. Zooplankton was most abundant in the spring. The spring maximum appeared in February–March and in April–May in the southern and eastern parts of the study areas, respectively. In the summer and autumn, a secondary peak was most conspicuous in the eastern part. The difference between the estimated biomass at night and day was large in the spring and small in summer and autumn. The biomass in the offshore southern area peaked about every 3 years between 1966 and 1983, and increased abruptly in 1990. The density in the area north of 39°N or 40°N was high. Total biomass estimated in the upper 150 m layer in the Sea of Japan (106 km2) was 9.5 × 106 t in the daytime and 16.6 × 106 t at night.  相似文献   
459.
To examine the efficacy of juvenile salmon research as a tool for forecasting adult returns, the results from a study on the early marine life stage of juvenile chum salmon, conducted in the Nemuro Strait during 1999–2002 (i.e., 1998–2001 brood years), were compared with the return rates of adult salmon. Among the four brood years, the 2000 brood year (i.e., salmon migrating to the sea in 2001) was previously reported as showing higher abundance, higher growth rate and better somatic condition during the coastal residency period. Consequently, we expected it to have the highest return rate, under a hypothesis that juvenile survival in coastal residency regulates brood-year strength. Contrary to this expectation, the 2000 brood year had almost the lowest return rate. Alternatively, a statistical model in which sea surface temperature during the first year of marine life and size at release were utilized as explanatory variables reconstructed the actual variability in return rates more accurately than that based on the early marine life stage. Possible reasons for the discrepancy between the results of the juvenile salmon research and adult returns are discussed, and we suggest improvements for future research on juvenile salmon.  相似文献   
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