986 resultados para 29-278
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Recent and current initiatives in Southeast Asia for data harmonization, country reports, statistcs, data collection, stock assessment initiatives, recommendations and workplan
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Country overviews of Community Based Integrated Coastal Management (CB-ICM) for Bangladesh, The Maldives, Sri Lanka, India and Southeast Asia. Recommendations for the way forward
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Stock structure approaches and consequences of management in the eight member countries. Indian mackerel (Rastrelliger kanagurta) genetic stock studies and workplan
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Objectives of the workshop included; introduction to various Marine Protected Area (MPA) tools with a focus on Management Effectiveness Assessment Tool (MEAT); report on selected MPAs in Bangladesh; undertake initial assessments using MEAT; and develop workplans for other MPAs
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The main objective of the visit was to share the success of Marine Protected Area (MPA) management in Malaysia with Bangladeshi counterparts, representatives of donor organizations, NGOs and researchers.
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福尔马林固定标本是宝贵的遗传资源,但是如何有效利用其中的遗传信息一直存在问题。本文尝试从标本预处理、消化、PCR扩增各方面综合考虑和优化改进,成功提取并扩增21头福尔马林固定白豚标本线粒体DNA控制区410bp片段。采用了3种预处理方法尽量去除固定标本中残存的甲醛,从试验结果来看,从酒精梯度+临界点干燥处理的标本中提取的DNA在扩增时具有明显优势。通过蛋白酶K消化过程中对于酶的浓度、温浴时间的比较试验,发现随着采用大幅提高酶浓度、延长消化时间等高强度的蛋白酶消化操作后,DNA的质量和产量均得到显著提高。
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记述了在中国6个典型地带土壤中鉴定到的隶属于动基片纲的29种纤毛虫,其中5种为中国土壤原生动物新记录种.这些种类是:陆生拟裸口虫,恼斜板虫,吻瓶口虫,双核管形虫,琴刀口虫,长刀口虫,长尾刀口虫,斜叶苔叶虫,神螺流苏虫,土壤肾形虫,三分肾形虫,背沟肾形虫,无规肾形虫,直立肾形虫,粗糙拟肾形虫,莫氏拟肾形虫,贪食阔庭虫,大撕拉虫,吻吴氏虫,澳洲吴氏虫,大口匙口虫,尖锐密粒虫,卡氏颠毛虫,小拟匙口虫,尖锐篮环虫,丛林拟篮环虫,有肋薄咽虫,弧形微秀体虫和凤冠齿扇虫.
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A comparative limnological study was carried out to present a snapshot of crustacean zooplankton communities and their relations to environmental factors to test whether there is a consistent relationship between crustacean biomass and trophic indicators among lake groups with similar trophic conditions. The study lakes showed a wide range of trophic status, with total phosphorus (TP) ranging from 0.008 to 1.448mgL(-1), and chlorophyll a from 0.7 to 146.1 mu g L-1, respectively. About 38 species of Crustacea were found, of which Cladocera were represented by 25 taxa (20 genera), and Copepoda by 13 taxa (I I genera). The most common and dominant species were Bosmina coregoni, Moina micrura, Diaphanosoma brachyurum, Cyclops vicinus, Thermocyclops taihokuensis, Mesocyclops notius and Sinocalanus dorrii. Daphnia was rare in abundance. Canonical correspondence analysis showed that except for four species (D. hyalina, S. dorrii, C. vicinus and M. micrura), almost all the dominant species had the same preference for environmental factors. Temperature, predatory cyclopoids and planktivorous fishes seem to be the key factors determining species distribution. TP was a relatively better trophic indicator than chlorophyll a to predict crustacean biomass. Within the three groups of lakes, however, there was no consistent relationship between crustacean biomass and trophic indicators. The possible reason might be that top-down and bottom-up control on crustaceans vary with lake trophic state. The lack of significant negative correlation between crustacean biomass and chlorophyll a suggests that there was little control of phytoplankton biomass by macrozooplankton in these shallow subtropical lakes. (c) 2007 Elsevier GmbH. All rights reserved.
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We demonstrate 1.25-1.29 mu m metamorphic laser diodes grown on GaAs by molecular beam epitaxy (MBE) using an alloy-graded buffer layer (GBL). Use of Be in the GBL is effective to reduce surface/interface roughness and improves optical quality. The RMS surface roughness of the optimized metamorphic laser is only two atomic monolayers for 1 x 1 mu m(2). Cross-sectional transmission electron microscopy (TEM) images confirm that most dislocations are blocked in the GBL. Ridge waveguide lasers with 4 mu m wide ridge were fabricated and characterized. The average threshold current under the pulsed excitation is in 170-200 mA for a cavity length of 0.9-1.5 mm. This value can be further reduced to about 100 mA by high-reflectivity coating. Lasers can work in an ambient temperature up to at least 50 degrees C. (c) 2006 Elsevier B.V. All rights reserved.
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The morphological defects and uniformity of 4H-SiC epilayers grown by hot wall CVD at 1500 degrees C on off-oriented (0001) Si faces are characterized by atomic force microscope, Nomarski optical microscopy, and Micro-Raman spectroscopy. Typical morphological defects including triangular defects, wavy steps, round pits, and groove defects are observed in mirror-like SiC epilayers. The preparation of the substrate surface is necessary for the growth of high-quality 4H-SiC epitaxial layers with low-surface defect density under optimized growth conditions. (c) 2006 Elsevier Ltd. All rights reserved.
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The mobility of channel electron, for partially depleted Sol nMOSFET in this paper, decreases with the increase of implanted fluorine dose in buried oxide layer. But, the experimental results also show that it is larger for the transistor corresponding to the lowest implantation dose than no implanted fluorine in buried layer. It is explained in tern-is of a "lubricant" model. Mien fluorine atoms are implanted in the top silicon layer, the mobility is the largest. In addition, a positive shift of threshold voltage has also been observed for the transistors fabricated on the Sol wafers processed by the implantation of fluorine. The causes of all the above results are discussed.