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51.
Blooms of toxic dinoflagellates of the genus Ostreopsis, which is known as a producer of palytoxin (PTX) analogs, may pose a threat to human health in tropical, subtropical, and temperate regions around the world. In the present study, we established a suitable culture method for Ostreopsis spp. isolated from Japanese coastal waters and characterized their growth potential using the method to discuss their bloom dynamics. Each clonal strain of Ostreopsis cf. ovata, Ostreopsis sp.?1, Ostreopsis sp.?5, and Ostreopsis sp.?6 was incubated in 25?×?150?mm test tubes with a flat bottom containing various kinds of medium. Since Ostreopsis spp. strains grew well in IMK and/or f/2 media, we selected these media for cultivation of all the Ostreopsis spp. isolates. Growth rates of O. cf. ovata (0.834?divisions/day), Ostreopsis sp.?1 (0.619?divisions/day), and Ostreopsis sp.?6 (1.04?divisions/day) that produce PTX analogs significantly differed (p?<?0.05) respectively and are clearly higher than those of other reported epiphytic dinoflagellate Gambierdiscus toxicus, Prorocentrum lima, and Coolia monotis cultures, which suggest that these species have ecological advantages to predominate through the algal succession in Japanese coastal waters, resulting in a potential risk to human health in this region.  相似文献   
52.
A set of near-isogenic lines for blast resistance genes was developed by using an Indica-type elite rice variety, IR49830-7-1-2-2, suitable for the rainfed lowland conditions in the tropics, as a genetic background. Initially, we revealed that IR49830-7-1-2-2 harbors five blast resistance genes - Pia, Pib, Pik-s, Pita, and Pi11(t) - by using a differential system involving 19 selected standard blast isolates from the Philippines. Based on this result, we developed nine near-isogenic lines (NILs) targeting eight resistance genes - Pik, Pi7(t), Pi3, Pi5, Pita-2, Piz-5, Pish, and Pi9 - by recurrent backcrossing. The introgression of each resistance gene in the NILs was confirmed by reaction patterns to the blast isolates, allelism tests, and DNA marker analysis. In addition, a genome-wide DNA marker survey revealed that most of the chromosome regions in each NIL were of the IR49830-7-1-2-2 type. The agricultural characteristics of most of the developed NILs were almost the same as those of IR49830-7-1-2-2. Moreover, with one exception, they showed submergence tolerance similar to IR49830-7-1-2-2. The developed NILs could be used as a multiline variety suitable for the rainfed lowland in the tropics.  相似文献   
53.
Lodging tolerance (LT) is an important trait for high yield and combine-harvesting efficiency in soybean [Glycine max (L.) Merr.]. Many previous studies have investigated quantitative trait loci (QTLs) for lodging score (LS) in soybean. Most of the investigated QTLs were located in the proximal region of maturity or growth habit loci. The aim of this study was to identify genetic factors for LT not associated with maturity or growth habit. QTL analysis was performed using a recombinant inbred line (RIL) population derived from a cross between ‘Toyoharuka’ (TH), a lodging-tolerant cultivar, and ‘Toyomusume’ (TM). The genotypes of TH and TM were estimated as both e1e2E3E4 and dt1. The average LS over 4 years was used for QTL analysis, identifying a major and stable QTL, qLS19-1, on chromosome 19. The LS of the near-isogenic line (NIL) with the TH allele at Sat_099, the nearest marker to qLS19-1, was significantly lower than the NIL with the TM allele at that position. The TH allele at Sat_099 rarely had a negative influence on seed yield or other agronomic traits in both NILs and the TM-backcrossed lines. Our results suggest that marker-assisted selection for qLS19-1 is effective for improving LT in breeding programs.  相似文献   
54.
In order to understand the kraft pulp decolouring mechanism on using a nonionic detergent, the pulp washing process and the resulting pulp handsheets were investigated by examining the brightness, kappa number, thioacidolysis product yield, and dewatering efficiency in the pressing sheet making process. The pulp decolouring could be attributed to a decrease in the lignin content and an improvement in the dewatering efficiency. Furthermore, the detergent distribution in the aqueous pulp suspension obtained during the pulp washing process was visualised using cryo-time-of-flight secondary ion mass spectrometry/scanning electron microscopy (cryo-TOF-SIMS/SEM). The detergent was clearly observed at the transverse surface of the pulp fibre cell wall and was also detected in the lumen of the fibres, suggesting the permeation of the detergent into the pulp fibre cell wall. Based on these results, the pulp decolouring mechanism can be proposed as follows: the detergent permeates into the pulp fibre cell wall and promotes the solution-exchange between the inside and the outside parts of the fibre cell wall, finally washing away the chromophoric substances such as lignin and its degradation products owing to the enhanced dewatering efficiency.  相似文献   
55.
An exploratory survey was carried out to assess economics and employment generation of the trade of bamboo and bamboo-based secondary products in the eastern Bangladesh, to obtain reliable information about their status, socio-economic significance, production and marketing. The study was undertaken over 30 bamboo-based enterprises in a suburban market of eastern Bangladesh, to investigate regional product details, economic profitability and employment opportunities. The sample entrepreneurs, corresponding to about 25% of the bamboo enterprise population were interviewed using a semi-structured questionnaire. About 202 full and part-time workers were employed in the factories, under categories of artisan (who manufactured secondary products). The average number of worker’s in the large, medium and small factories were 9 (artisan 40%), 6.45 (artisan 35%) and 5 (artisan 25%) respectively. The study revealed that there was always a satisfied demand of skilled artisans. Most of the workers were relatively newly employed (not more than 5 years). The daily wage rate varied between 70 and 130 Tk. ($US 1 equals approximately 70 Bangladeshi Taka (Tk.), as at December 2008). Bambusa balcooa was the most utilized species (39.96%) in terms of monetary value. The price of a single B. balcooa culm in the local market was Tk. 160–210. Nine sizes of articles under seven bamboo categories were identified, these being bera (36″ × 120″ and 72″ × 96″), bookshelf (36″ × 24″), chaluni (12″ × 12″), chatai (48″ × 60″ and 36″ × 48″), jhuri, rickshaw hood and tukri. Net average profit per article was the highest for rickshaw hoods (Tk. 400 at the retailer stage). The total expected annual income for an enterprises from all articles types sold was estimated to be Tk. 85,800. Three distinct marketing channels were identified for selling bamboo and value-added secondary products. The study also generated policy implications for effective management of bamboo-based enterprises.  相似文献   
56.
Traditional systems of medicine have become a topic of global importance recently. Increased commercialization of economically important medicinal plants has resulted in overharvesting, threatening their survival. The present study was carried out to document the indigenous uses of medicinal plants by the local communities in and around Rema-Kalenga Wildlife Sanctuary, Bangladesh. Data collection was predominantly qualitative recording the species use, identifying their relative importance (RI) and assessing the informants’ consensus factor (Fic) on associated knowledge. We interviewed 140 households of the local community and 5 local herbal practitioners. A total of 44 plant species were in use to treat 33 ailments under 10 broad disease categories. Five species were found to have high use versatility (RI > 1), Emblica officinale L. being the most versatile. Respiratory problems scored the highest Fic value (0.56) involving the use of 30% of the species recorded. Terminalia bellerica Roxb., Sterculia villosa Roxb., Dillenia pentagyna Roxb. and Terminalia arjuna Bedd. were being harvested commercially. Use by the community, particularly for subsistence consumption, seemed to be sustainable, but commercial extraction of some species appeared unsustainable. Buffer zone-based commercial farming of medicinal plants with a commercial value could serve a dual purpose of assuring sustainable alternative income generation for local communities as well as conserving the natural resources in protected areas.  相似文献   
57.
Because lack of data impedes the assessment of the conservation of medicinal plants, ethno-medicinal studies are important to fill this gap. This study considered the traditional use of plants for health care by the rural communities in two forested and non-forested regions of Bangladesh. A total of 230 respondents were interviewed accompanied by field observation and voucher specimen collection. Altogether, 68 species of medicinal plants belonging to 38 families distributing over 58 genera were recorded, of which 22 species were common in both regions. Trees were the most commonly utilized growth form and leaves were the most commonly used plant part. Forests and homesteads were the major sources of medicinal plants in forested and non-forested regions, respectively. High use versatility (Relative Importance >1) was represented by 14 species; Emblica officinale L. and Allium sativum L. were the most versatile species. Forty-one individual ailments were treated with the medicinal plants recorded. The ailment categories ‘respiratory problems’ and ‘sexual problems’ received the highest score from the calculation of informants’ consensus factor (F ic) in forested and non-forested regions, respectively. The findings could contribute in the pharmaceutical sector by directing further investigation of bio-active compounds in medicinal plants. Secondly, results could inform the clues for conservation strategies of forest resources in that region.  相似文献   
58.
利用反向PCR、定量PCR以及免疫共沉淀等方法分析研究转基因家蚕的丝素蛋白及基因的结构和性质。结果表明:(1)在DNA水平上,MaSp1基因整合进了家蚕的基因组,插入位点位于scaffold 868;(2)在RNA水平上,MaSp1的表达并不干扰其他3个基因(Fib-H,Fib-L and P25)的表达水平,并且外源基因MaSp1的表达水平略高于Fib-H;(3)在蛋白质水平上,MaSp1蛋白的丰度大约占丝素总蛋白的2%,而且通过自身的LBS区段和轻链蛋白(Fib-L)形成分子间二硫键,从而融入蚕丝蛋白复合体。  相似文献   
59.
It has been reported that epigallocatechin-3-O-(3″-O-methyl)-gallate (EGCG3″Me) and the EGCG3″Me-rich green tea ( Camellia sinensis L.) cultivar 'Benifuuki' exhibit antiallergic effects. The objective of this study was to investigate the effect of various tea leaf catechins on histamine release from murine bone marrow mast cells (BMMC). At a dose of 50 μg/mL, the rank order of histamine release inhibition was observed to be epicatechin-3-O-(3″-O-methyl)-gallate (ECG3″Me) > gallocatechin-3-O-(3″-O-methyl)-gallate (GCG3″Me) > EGCG3″Me > gallocatechin-gallate (GCG) > catechin-gallate (CG) > EGCG > epicatechin-gallate (ECG) > epigallocatechin (EGC) > gallocatechin (GC). Of the various tea cultivars analyzed by HPLC, the greatest content of ECG3″Me was found in the third crop of 'Benifuuki' (1.05% dry weight). Moreover, ECG3″Me content was positively correlated with EGCG3″Me content in 'Benifuuki' tea leaves. In an assay of mixtures of ECG3″Me and EGCG3″Me, inhibitory activity (50 μg/mL in total) was increased as the content of ECG3″Me increased. This suggests that ECG3″Me might link to the antiallergic effect of 'Benifuuki' tea, as has been reported for EGCG3″Me.  相似文献   
60.
We have shown phosphoinositide 3-kinase (PI3K)/Akt signaling activation in thyroid capsular invasive carcinomas (CICs), which are highly induced by promotion with sulfadimethoxine (SDM) in a rat 2-stage thyroid carcinogenesis model. To examine the potency of calcitriol, a synthetic vitamin D3 analog, on the development or progression of CICs, male F344 rats were injected with calcitriol (0.1 μg/kg body weight) three times a week intraperitoneally, during an entire period of SDM-promotion for 13 weeks (Experiment 1) or during the last 2 weeks of a 15-week SDM-promotion (Experiment 2). Initiation with N-bis(2-hydroxypropyl)nitrosamine preceded all treatments. In Experiment 1, long-term calcitriol treatment reduced the multiplicity of CICs, while cell proliferation activity, estimated by Ki-67 cell index in the induced CICs, was unchanged with SDM-promotion alone. Considering the strong dependency of promotion with SDM during the early stages on thyroid-stimulating hormone, the reduced multiplicity in Experiment 1 may be due to the effect on an early stage of neoplastic proliferation. Although the magnitude was mild, cell proliferation activity was decreased in existing CICs after short-term calcitriol treatment in Experiment 2, which was associated with a mild decrease in cyclin-dependent kinase-2-positive cells, cytoplasmic immunolocalization of phosphorylated, inactive, Rb protein and a mild increase in nucleocytoplasmic expression of p27(kip1). Although the effect was mild at the late stage of SDM-promotion in this hypothyroidism-related thyroid carcinogenesis model, our results suggest that calcitriol targets cell proliferation via inhibition of a molecular cascade downstream of PI3K/Akt signaling, controlling G1/S transition.  相似文献   
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