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Annual net production of the five Sargassaceae species in Yoro,western Wakasa Bay,Sea of Japan 总被引：1，自引：0，他引：1
Kousuke?YatsuyaEmail author Tomokazu?Nishigaki Akio?Douke Yozo?Wada 《Fisheries Science》2005,71(5):1098-1106
ABSTRACT: Annual net production of the five Sargassaceae species was investigated in Yoro, western Wakasa Bay, Sea of Japan. The Sargassaceae species were collected at a depth of 2.0–2.5 m and subjected to stratified clipping for 13 months. Annual net production was estimated at 2407 g dry wt/m2 for Sargassum patens , 2132 g dry wt/m2 for Sargassum macrocarpum , 1458 g dry wt/m2 for Sargassum siliquastrum , 1197 g dry wt/m2 for Myagropsis myagroides , and 1471 g dry wt/m2 for Sargassum piluliferum . The ratio of annual net production to maximum biomass (P/Bmax ) for these species ranged between 1.3 and 1.7, being higher than in previous studies which used the same method. Winter storms with strong wave exposure and relatively calm condition in Yoro were considered to augment P/Bmax . The total losses estimated from the different units of stratified clipping were compared. If larger and less segregated units were applied, the total loss would decrease. It was suggested that a 50 cm stratum would be applicable to the larger species (3 m or longer) and a stratum of 20 cm or less would be applicable to mid-sized or smaller species (less than 3 m). 相似文献
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Nagashima N Hisasue M Nishigaki K Miyazawa T Kano R Hasegawa A 《Research in veterinary science》2005,78(2):151-154
Molecularly cloned feline leukemia virus (FeLV)-clone 33 (C-33), derived from a cat with acute myelocytic leukemia (AML), was examined to assess its relation to the pathogenesis of AML and myelodysplastic syndrome (MDS). To evaluate in vitro pathogenicity of FeLV C-33, bone marrow colony-forming assay was performed on marrow cells infected with FeLV C-33 or an FeLV subgroup A strain (61E, a molecularly cloned strain with minimal pathogenicity). The myeloid colony-forming activity of feline bone marrow mononuclear cells infected with FeLV C-33 was significantly lower than that of cells infected with 61E. This suggests that FeLV C-33 has myeloid lineage-specific pathogenicity for cats, and that FeLV C-33 infection is useful as an experimental model for investigating pathogenesis of MDS and AML. 相似文献
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Kashiwase H Katsube T Kimura T Nishigaki T Yamashita M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2000,62(5):499-504
The inhibitory activities of various 8-difluoromethoxy-4-quinolone derivatives against feline immunodeficiency virus (FIV) replication in the chronically infected cell line P-CrFK were investigated. Certain derivatives were found to inhibit FIV production from P-CrFK cells in a dose-dependent manner without exhibiting cytotoxic effects at inhibitory concentrations. Based on this study, the structures important for anti-FIV activity are suggested to be (i) a carboxyl group at position C-3, and (ii) an aromatic modification at position 4 of the C-7 piperazinyl moiety. 相似文献
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Yuri Ichinose Tomohiro Nishigaki Makoto Shibata Method Kilasara Hitoshi Shinjo Shinya Funakawa 《Soil Use and Management》2023,39(3):1155-1171
Sustainable land management of smallholder farms is crucial for ensuring food security in sub-Saharan Africa. However, little is known about the nutrient dynamics of smallholder farming systems at the farm level based on primary data. In this study, carbon (C) and nutrient budgets of the home garden system in the Kilimanjaro highlands, where Andosols predominate, were quantified at the farmer's field. We evaluated (1) the soil C and nutrient flow in the main three land-use blocks (banana (Musa spp.) garden, maize (Zea mays L.) field and grassland) in one representative home garden and (2) the internal flow between farmland and livestock and the external nutrient flow across the inside and outside of the six home gardens. Intensive applications of livestock dung to the banana trees resulted in a positive C budget (7.2 Mg C ha−1 year−1) in the banana garden. Nitrogen loss through the harvesting of feed and crops was almost balanced with the livestock dung application, while nitrogen loss through leaching only accounted for 3% of that applied. Banana productivity has been maintained despite a negative potassium budget (−241 kg K ha−1 year−1), probably owing to the replenished exchangeable potassium from Andosols. In the maize field, the C budget was negative (−1.7 Mg C ha−1 year−1) owing to high organic matter decomposition. Carbon and nutrient budgets in the grassland were all negative. Our results revealed that the village average livestock density (4.4 TLU ha−1: TLU means tropical livestock unit) was sufficient for P, Ca and Mg balance in the home garden, whereas it was not sufficient for N and K balance. Increasing livestock density improved the nutrient balance of the system. However, it is noteworthy that 33%–47% of the feed supplied as C and nutrients was collected from outside the home gardens, suggesting a high reliance on external inflow to fulfil feed demands. In conclusion, intensive livestock dung application to banana cultivation was fundamental for maintaining agricultural productivity to replenish the nutrients lost from the system. At the same time, this system was sustained not only by C and nutrient cycling within the system, but also by transporting resources from the external environment into the system. 相似文献
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M. S. Akhtar Y. Oki Y. Nakashima T. Adachi M. Nishigaki 《Communications in Soil Science and Plant Analysis》2016,47(22):15-27
ABSTRACTPhosphorus (P) is a finite, non-renewable, and natural resource and a vital major nutrient for plant metabolic and developmental processes. However, adverse soil biogeochemical characteristics of alkaline-calcareous soils (especially Aridisols) and highly weathered acid soils (i.e., Ultisols and Oxisols) render orthophosphate (Pi) as the least available major nutrient due to P complexation, sorption, and/or fixation. In such soil environments, plant bioavailable P is only a small fraction of total soil P, seriously limiting crop growth and production. Different plant species, and even cultivars of the same species, may display a suite of growth responses that enable them to solubilize and scavenge soil P either by enhancing external Pi acquisition or reprioritizing internal Pi use under P-stress soil environments. This paper reports relative growth responses, P acquisition and P-use efficiency characteristics by 14 cultivars of spring wheat (Triticum aestivum L.) grown in solution culture with high/low P supply induced by applying soluble NH4H2PO4, sparingly soluble rock phosphate, and Ca3(PO4)2. The wheat cultivars exhibited considerable genetic diversity in biomass accumulation, P concentrations, P contents, factor (PSF) and P efficiency characteristics [i.e., P utilization efficiency (PUE), P efficiency (PE), and PE ratio (PER)]. Plant growth and PE parameters were significantly correlated, while P uptake was linearly related with biomass increase and solution pH decrease. The wheat cultivars with high PUE, PER and P uptake, and low PSF, and plant P concentration were more efficient in utilizing P and, hence, more tolerant under P-stress environment. Biomass and P contents of “P efficient/low-P tolerant” wheat cultivars were superior to “P inefficient/low-P sensitive” cultivars at all P-stress levels. Hence, “P efficient/low-P tolerant” cultivars are the most desirable wheat genotypes for P-stress environments because they are able to scavenge more P from sparingly soluble P sources or soil-bound P forms. 相似文献
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To obtain a value of soil total nitrogen, which represents nitrogen content of soils of rice field under experiment, statistical consideration will be required, because the value of total nitrogen of soil may differ from sample to sample, owing to heterogeneity of the soil in the field. 相似文献
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Tomohiro Nishigaki Soh Sugihara Method Kilasara Shinya Funakawa 《Soil Use and Management》2021,37(1):83-94
Crop residue management strategies must be adapted for improving carbon (C) balance and soil C stock in agroecosystems in sub‐Saharan Africa with consideration of the crop residue availability and site‐specific soil characteristics. We conducted field experiments to determine the effects of crop residue application method (incorporation/mulching) and quality (maize/cowpea) and N fertilizer application on the soil respiration rate and soil C stock in the surface soil layer (0–15 cm) in maize croplands with contrasting soil textures (clay/sandy) over 2 years from 2012 to 2014 in Tanzania. At the clay site, the incorporation of maize residues showed a 38% increase in CO2 flux compared to mulching, whereas, at the sandy site, mulching showed a 16% increase compared to the incorporation. At the sandy site, mulching practice retained soil moisture content and apparently enhanced the decomposition of the original soil organic C in the surface layer. It is, therefore, suggested that mulching practice may accelerate a long‐term depletion of soil C stock at the sandy site. The cowpea residue incorporation led to rapid decomposition because of its high biodegradability at both sites. The N fertilizer application stimulated the decomposition of labile soil organic matter. The soil C stock in the surface layer did not significantly change after the 2‐year experiment, irrespective of crop residue treatment and soil type. In conclusion, adequate crop residue management in terms of suppressing CO2 flux during a cropping season depends on soil type, but the long‐term effect on soil C stock is unclear. 相似文献
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ABSTRACT: Macrophytes stranded on a beach provide food and habitat for many kinds of animals and play important roles in coastal ecosystems. Macrophytes stranded on a sampling beach (56 m long) along a sargassacean forest (400 m long and 88 m wide) were collected every 10 days from late April 2003 to late May 2004. The weight of macrophytes stranded per meter of beach amounted to 1733 g dry wt/m per year. Sargassacean plants were dominant and constituted 72.9% (1263 g dry wt/m per year) of whole stranded macrophytes. Large numbers of macrophytes were stranded just after heavy winter storms and the maximum weight of stranded macrophytes in winter was 407 g dry wt/m. Stranded macrophytes also increased in May to July; the deterioration period of sargassacean species in this region, and the maximum weight in this period was 233 g dry wt/m. The number of sargassacean plants stranded with holdfast increased only in winter. These results suggest that winter storms have an important role in stranding sargassacean plants at Yoro Beach. 相似文献
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Hiroshi Kamitakahara Fusako Nishigaki Yuji Mikawa Michiko Hori Shigetomo Tsujihata Takashi Fujii Fumiaki Nakatsubo 《Journal of Wood Science》2002,48(3):204-209
Chemically synthesized (1 5)--d-glucofuranan, (1 5)--d-galactofuranan, (1 5)--d-xylofuranan, (1 5)--L-arabinofuranan, natural xylan, and curdlan were sulfated to investigate their inhibitory activities on B16-BL6 lung metastasis and anticoagulant activities. (1 5)--d-Glucofuranan sulfate, (1 5)--d-galactofuranan sulfate, xylan sulfate, and curdlan sulfate had binding abilities with B16-BL6 melanoma lysate. The inhibitory activities of sulfated polysaccharides on B16-BL6 lung metastasis selected by heparin binding assay were in the order (1 5)--d-galactofuranan sulfate > (1 5)---d-glucofuranan sulfate > xylan sulfate curdlan sulfate. Furthermore, (1 5)--d-galactofuranan sulfate, (1 5)--d-glucofuranan sulfate, and xylan sulfate had not only high inhibitory activity on B16-BL6 lung metastasis but also low anticoagulant activity. The correlation between chemical structure and biological activity is discussed.Part of this paper was presented at the 10th International Synposium on Wood and Pulping Chemistry, Yokohama, Japan, June 1999 相似文献