基于北斗卫星船位数据提取拖网航次方法研究

渔业生产管理、捕捞效益计算、资源调查等常把航次作为一个重要参考量。北斗卫星船位数据时间分辨率约为3 min,空间分辨率约为10 m,具有很好的时空特征,通过对北斗卫星船位数据挖掘可以提取航次。渔船作业过程中航次一般包括起航、海上作业、返航,渔船起航和返航的港口常不同,对港口所在的陆地和岛屿做向外缓冲形成一个面,以船位点与港口所在陆地缓冲面的距离作为离岸距离,根据离岸距离变化判断渔船的航次,并通过编程实现航次提取,6艘调查船提取的航次结果与实际记录的43个航次相比,起航时间差值在2 d内的占95.1%,返航时间差值在2 d内的占95.2%,网次可以根据航速提取,计算出每个航次中的网次数。     

山羊肺淋巴系的研究

24例山羊肺经肺实质和肺胸膜下注射30％普鲁士蓝氯仿溶液，剖查其器官内淋巴管及淋巴流向。结果表明，山羊肺的器官内淋巴管有浅淋巴管和深淋巴管2种。左肺尖叶淋巴管注入左支气管肺淋巴结和气管支气管左淋巴结，左肺心叶淋巴管注入左支气管肺淋巴结、气管支气管左淋巴结和气管支气管中淋巴结，左肺膈叶淋巴管注入气管支气管左淋巴结、气管支气管中淋巴结和纵隔后淋巴结；右肺尖叶淋巴管注入右支气管肺淋巴结和气管支气管前淋巴结，右肺心叶淋巴管注入右支气管肺淋巴结和气管支气管右淋巴结，右肺膈叶淋巴管注入气管支气管右淋巴结、气管支气管中淋巴结和纵隔后淋巴结，右肺副叶淋巴管注入右支气管肺淋巴结、气管支气管中淋巴结和纵隔后淋巴结。     

贵州省鸡淋巴性白血病J亚型血清学调查研究

为了解和掌握鸡淋巴白血病J亚型(ALV -J)在贵州的发生和流行的基本情况,在7个主要养殖地区的35个养鸡生产场共采集1 205份血清样本,采用ALV -J诊断试剂盒进行了ALV -J的ELISA血清学抗体检测.检测及相关流行病学调查结果表明:ALV -J亚群的平均阳性感染率为13.776％,其中肉鸡为20.050％,...     

渔船型线基于AutoCAD 2002的生成、编辑和光顺

从中小船厂应用AutoCAD的实际情况出发，阐述了渔船型线的特点及其数学型线的建立方法。分析了用AutoCAD绘制及编辑型线常规方法的局限性，并给出了用其绘制、编辑和光顺渔船型线的方法和技巧。实践表明，该方法简捷、有效、可行、实用。     

Quantifying fish avoidance of small acoustic survey vessels in boreal lakes and reservoirs

Mobile hydroacoustic surveys are increasingly used to assess the distribution and abundance of freshwater fish; yet, fish may avoid moving vessels, potentially introducing bias in these assessments. In this study, avoidance in boreal lakes and reservoirs was quantified by developing a simple method based on paired drift:drift (D:D) and drift:motor (D:M) transects. Two systems in eastern Manitoba, Canada were studied: Lac du Bonnet reservoir and Nopiming. Acoustic data were collected using a digital DTX echosounder (BioSonics, Seattle, WA, USA), with a downward facing 200‐kHz split‐beam transducer, deployed from 5.5‐m vessels (Boston Whalers) modified for acoustic research. An avoidance coefficient (Ac) was developed based on comparisons of acoustic fish densities while the vessel moved over the same transects by drifting, and by motoring at survey speeds. Ac did not differ significantly from 1 (no avoidance) at Nopiming (median of 0.81, n = 13), but did at Lac du Bonnet (median of 0.51, n = 31, P < 0.05). Variability in Ac was as high in transect pairs and was unrelated to fish depth (mean 6.9 m at Lac du Bonnet; 13.1 m at Nopiming) or survey speed (up to 3.70 m·s^?1, 7 knots). Results indicated that fishes did not dive in the presence of the motoring vessel, nor was avoidance size‐based. We did not detect any evidence of fish attraction to our drifting vessel. Our results suggest that boat avoidance during acoustic surveys of shallow boreal lakes may vary in relatively similar water bodies but can be quantified experimentally.     

渔业船联网工程体系应用现状分析

渔业船联网工程是通过在渔船上搭载信息感知、处理和传输装备,从而实现船与船、船与岸之间的信息交换和智能化服务,在渔业生产、海上通信、安全管理、渔政执法及海洋探测等领域具有的重要科学意义和实用价值。本文分析了渔业船联网工程体系的应用现状及演化趋势,详细总结了渔业船联网感知层、传输层和应用层的国内外现状及发展趋势,梳理了所涉及的关键技术和科学问题。围绕渔船探测、海洋通信、数据融合与挖掘等重大需求,分析了中国渔业船联网发展在基础研究、平台建设、尖端技术、装备工程、标准体系等方面存在的主要问题与障碍,指出了中国渔业船联网工程体系科技创新发展对策,提出了以“突破关键技术、研发核心装备、构建基础平台、形成创新能力”为目标、以“探索期、部署期、拓展期”为路线的系统工程发展建议。     

Adaptive Phenotypic Differences to Low Potassium Soil of Two Cotton Genotypes with Various Potassium-Use Efficiencies

Cotton (Gossypium hirsutum L.) is one of the most important cash crops in the world, and potassium (K) is an important limiting factor for cotton farming. Therefore, it is critical to improve K-use efficiency by selecting or breeding cotton genotypes with high K-use efficiency. Through a pot experiment with low-K soil, this article documentes the differences in vessel element anatomy and root hair traits between two cotton genotypes with different K-use efficiencies at both seedling and boll stages. Experimental results showed that at the seedling stage both frequency and length of root hair in the genotype with high K-use efficiency were significantly greater than those of the genotype with low K-use efficiency, but the frequency and diameter of vessels were not significantly different between the two genotypes. In the boll stage, the vessel frequencies in root, stem, petiole, and carpophore; root hair frequency, and length of high K-use-efficiency genotype were all significantly greater than those of the low K-use-efficiency genotype. The denser and longer root hairs were often found and accompanied by thicker vessel elements in the genotype with high K-use efficiency. This means the genotype had greater nutrient uptake and transportation capacity. The root hairs, vessel elements in root, stem, petiole, and carpophore, formed a complete system for nutrient uptake and translocation. The results from this study provide valuable information for the breeding of high K-use-efficiency cotton.     

Transgenic chimera quail production by microinjecting lentiviral vector into the blood vessel of the early embryo

In the past, several strategies have been used to generate transgenic birds. The most successful method has proven to be injection of lentiviral vector into the subgerminal cavity of the newly laid egg. In this study, we directly injected lentiviral vector into the blood vessel of HH13–15 quail embryos to produce transgenic chimeras. In the manipulated, hatched birds, the green fluorescent protein (GFP) gene driven by a cytomegalovirus (CMV) promoter was extensively expressed. All tissues analyzed were GFP‐positive, and gonad cells from some of the manipulated embryos expressed GFP. The semen genome of 21.4% of mature male birds was determined to be GFP‐positive by PCR, indicating these male birds were transgenic chimeras.     

我国渔船生产经营主体调查研究的文献综述

对我国渔船生产经营主体调查研究的相关文献进行了梳理,总结现有文献对不同时期渔船生产经营主体情况的研究,分析不同时期渔船生产经营主体存在的问题和解决对策。结果显示,现有研究多关注宏观层面的数据,缺少对微观组织的关注,研究的深度和范围不够。在存在的问题分析方面,多停留在问题表面,未对深层次问题进行分析。在解决问题的对策方面,过度关注政府的作用,而忽视了市场配置资源的作用。     

Activation of PKCalpha and pulmonary vascular remodelling in broilers

OBJECTIVE: The present study was conducted to examine the presence of protein kinase Calpha (PKCalpha) in the pulmonary arterioles of broilers during the development of pulmonary hypertension and pulmonary vascular remodelling. METHOD: One hundred and sixty day-old Avian-2000 broilers were divided equally into a control group and a cold temperature group. All the birds were reared in normal temperatures up to day 14, with the lighting schedule at 24 h per day. Thereafter, birds in the cold temperature group were subjected to low temperature by lowering 1-2 degrees C per day to 12-14 degrees C, and then kept constant until day 49, while birds in the control group were still brooded at normal temperatures. All the birds were fed a diet of pellets throughout the study. Samples of blood were taken from the wing vein, and of heart and lung collected after the birds were killed with an overdose of sodium pentobarbitial, at days 24, 32, 39 and 45 of age, respectively. Right ventricle to total ventricle ratio (RV/TV) and packed cell volume (PCV) were measured. Vessel wall area to vessel total area ratio (WA/TA) and mean media thickness in pulmonary arterioles (mMTPA) was examined using computer-image analytic software. Expression of PKC in pulmonary muscular arterioles was assessed by immunohistochemistry and quantified by measuring optical density (OD) using computer-image analytic software. RESULTS: The incidence of pulmonary hypertension syndrome (PHS) was 12.5% in birds exposed to cold, and 3.75% in the control group (P<0.05). PCV in the cold temperature group was elevated after day 32 (P<0.05), and RV/TV ratio increased on day 45 (P<0.05). Both the WA/TA and mMTPA of birds subjected to cold were significantly elevated (P<0.05). The OD values were not significantly increased before day 32 (P>0.05), however, one week later (at day 39 of age), the difference between the two groups was significant (P<0.05). The increased PKCalpha expression was positively correlated with the values of mMTPA and WA/TA. CONCLUSION: PKCalpha expression was up-regulated during the development of pulmonary hypertension. The activation of PKCalpha might be involved in the development of pulmonary vascular remodelling.