A cross‐taxa assessment of pelagic longline by‐catch mitigation measures: conflicts and mutual benefits to elasmobranchs

Elasmobranch mortality in pelagic longline fisheries poses a risk to some populations, alters the distribution of abundance between sympatric competitors, changing ecosystem structure, processes and stability. Individual and synergistic effects on elasmobranch catch and survival from pelagic longline gear factors, including methods prescribed to mitigate bycatch of other vulnerable taxa, were determined. Overall relative risk of higher circle vs. J‐shaped hook shark catch rates conditioned on potentially informative moderators, from 30 studies, was estimated using an inverse‐precision weighted mixed‐effects meta‐regression modelling approach. Sharks had a 1.20 times (95% CI: 1.03–1.39) significantly higher pooled relative risk of capture on circle hooks, with two significant moderators. The pooled relative risk estimate of ray circle hook catch from 15 studies was not significant (RR = 1.22, 95% CI: 0.89–1.66) with no significant moderators. From a literature review, wire leaders had higher shark catch and haulback mortality than monofilament. Interacting effects of hook, bait and leader affect shark catch rates: hook shape and width and bait type determine hooking position and ability to sever monofilament leaders. Circle hooks increased elasmobranch catch, but reduced haulback mortality and deep hooking relative to J‐shaped hooks of the same or narrower width. Using fish vs. squid for bait increased shark catch and deep hooking. Pelagic stingray (Pteroplatytrygon violacea) catch and mortality were lower on wider hooks. Using circle instead of J‐shaped hooks and fish instead of squid for bait, while benefitting sea turtles, odontocetes and possibly seabirds, exacerbates elasmobranch catch and injury, therefore warranting fishery‐specific assessments to determine relative risks.     

壶瓶枣果实发育过程中果柄导管形态变化与裂果关系

【目的】阐明壶瓶枣果实发育过程中果柄导管形态及运输效率的变化,明确果实通过维管束系统吸水与其裂果的关系,完善枣裂果机理。【方法】以壶瓶枣（Ziziphus jujube Mill. cv. Huping）为试材,于白熟期（8月19日）开始对选定枣树进行定量灌溉处理,每7 d测定、灌溉一次,使处理组土壤含水量维持在田间最大持水量的（80±5）%,对照组的土壤含水量控制在田间最大持水量的（20±5）%。于果实发育后期分别调查降雨前（9月18日）、降雨后（9月22日）枣果的裂果率;分别在幼果期（7月28日）、白熟期（8月15日）、半红期（9月5日）和全红期（9月17日）进行采样,跟踪枣果实发育进程。品红示踪试验中采用二次枝浸泡和枣吊浸泡两种形式,观察不同时期二次枝、枣吊和果柄维管束系统运输效率的变化;取健康枣果的果柄进行石蜡切片,经FAA液固定、常规方法包埋、制作切片、番红-固绿复染,观察枣果果柄导管形态随果实发育的变化规律。【结果】裂果率调查结果显示,枣果发育后期灌溉和对照两种处理的裂果率分别为2.60%和2.58%,二者间差异不显著,表明充足灌溉并未引起裂果;降雨后,灌溉组和对照组处理的裂果率与降雨前相比均显著升高,分别达到42.90%和40.80%,且两组间差异并不显著,表明降雨会明显导致裂果率上升。品红示踪试验结果表明,在整个果实发育期,品红溶液均能通过二次枝顺畅运送至枣吊,但能否运送至枣果与果实发育期密切相关。幼果期,品红溶液在5 min之内便可顺利输送至枣果,且输送数量和范围随着时间延长而逐渐增大;随着果实发育,品红运输至枣果的难度逐渐增大,白熟期时处理40 min后仅有少许品红输送至枣果;至半红期和全红期,品红溶液几乎不能输送至枣果,这表明果柄可能是品红不能顺利运输至枣果的主要障碍。石蜡切片结果表明,幼果期正常导管所占比例为97.22%,白熟期时正常导管的比例下降至34.95%,且开始出现断裂、退化和畸形,半红期和全红期正常导管的比例仅剩13%左右,导管断裂、退化和畸形进一步加剧,并且开始出现导管堵塞现象,且全红期导管堵塞的数量和程度均高于半红期。【结论】壶瓶枣果实发育后期,果柄导管出现断裂、畸形、退化、堵塞等现象,其运输能力受损或丧失,导致根系吸收的水分难以通过“根系-枝干-二次枝-枣吊-果柄-果实”维管束系统大量进入果实,从而不会引发大量裂果。     

液化天然气渔船改造相关技术分析

为降低渔船燃油能耗,减少渔船污染排放,研究了液化天然气渔船（ LNG渔船）相关技术。 LNG渔船的核心技术在于双燃料发动机动力装置,围绕双燃料发动机动力装置所需空间的利用和布置是LNG渔船改造的一大难点。双燃料发动机动力装置相关配套设备科学合理的设计也是保证LNG渔船高效航行的重要因素。通过对LNG渔船船体改造、双燃料发动机动力装置改造和LNG燃料存储技术等方面进行分析,认为LNG渔船作为一种新型船舶,能有效地降低渔民燃料成本,改善船员作生活环境。     

不同品种梨新梢木质部细胞的解剖学比较分析

研究‘水晶梨’、‘丰水梨’的细胞解剖学结构,试图为梨树的生理生态特性及其进化提供理论依据。以‘水晶梨’、‘丰水梨’与对照品种‘酥梨’的新梢木质部细胞为试材,对3个梨品种的导管分子、管胞分子以及纤维分子等细胞解剖学特征进行了比较分析。结果表明：‘水晶梨’较‘丰水梨’和‘酥梨’导管细胞上的纹孔大且致密,畸形导管明显比‘丰水梨’和‘酥梨’少。‘丰水梨’导管分子的最大直径较‘水晶梨’和‘酥梨’大,差异达到极显著水平;端尾长度较‘水晶梨’和‘酥梨’短,差异达到极显著水平;纤维分子长度较‘水晶梨’和‘酥梨’无显著差异;纤维分子直径较‘水晶梨’和‘酥梨’小,差异达到极显著水平。与‘酥梨’相比,‘水晶梨’导管的横向运输能力强,‘丰水梨’导管的纵向运输能力强,这些特征有利于提高它们的生态适应性。     

Connection of growth and wood density with wood anatomy in downy birch grown in two different soil types

Soil affects the anatomy of downy birch wood (Betula pubescens), which raises the question whether the growth of this species differs between mineral and peat soils. The aim of this study was to compare growth, density and structure of xylem of B. pubescens between trees grown in different soils. Both growth and density differed between trees grown in different soils. All measured anatomical characteristics, except double thickness of fibre walls, percentage vessel area and ray number, showed differences between the soil types: the cell dimensions were larger and numbers smaller in trees grown in mineral soil. In peat, high growth rates decreased the wall:lumen ratio of fibres in maturing wood, while no such correlation was observed in trees grown in mineral soil at any studied cambial age. In addition, axial parenchyma may have a different role in trees grown in different soils, as the rapid growth decreased and increased axial parenchyma in mineral and peat soil, respectively. The characteristics affecting wood strength were more similar between trees grown in different soils than those affecting water conductance. The observed differences between trees grown in different soils emphasise rapid growth particularly at young ages and shorter reasonable rotation period in mineral soil.     

我国渔业船舶技术法规体系的研究

通过梳理我国渔业船舶技术法规体系的发展现状,发现我国渔业船舶法规技术体系存在三大问题。一是渔业船舶技术法规体系不健全,现有法规与渔业发展实际状况偏差较大。二是渔业行政管理体系与技术条款执行关系模糊。三是渔业船舶技术研究技术力量薄弱。研究表明:(1)应完善顶层设计,在渔船检验领域逐步引入市场竞争机制,形成政府主导、市场调节的渔船检验体制;(2)应通过技术创新和引进吸纳技术创新,提高指标参数的先进性和国际化水准;(3)应创新管理和组织制度,规范采标、制标流程,避免盲目采标和制标;(4)政府应加大政策与法规等制度的研究性投入,为技术标准和法规体系建设储备知识要素,为体系建设提供可靠的智力支撑。     

The Analysis of Xylem Vessel Structure of Populus euphratica Oliv.Fresh Branch by HRCT

Analysis of the xylem vessels of Populus euphratica Oliv. (P. euphratica) branch anatomical characteristics is usually performed using microtomy. It is time-consuming to obtain an abundance of cross-sections using microtomy, and the sample was dried and sliced. The more effective technology for the analysis of the anatomical characteristics of P. euphratica fresh branch would be of significance for the study of the tolerance mechanism. In this paper, the xylem vessels structure of P. euphratica branches were investigated by high-resolution computed tomography(HRCT) and scanning electron microscope (SEM) to establish an efficient method to research the tolerance mechanism of P. euphratica. Analysis of the images allowed characterisation of the internal morphological and histology structural features of the fresh and dried branches of P. euphratica. Drying process caused distinct changes in the microstructure of the branches with shrinking in the more external regions and the interspace between vessels compared with fresh branches. The SEM slice of the same sample that clearly has a higher resolution than the HRCT slice, and the structure of the xylem vessels is distinct in the SEM. However, SEM is a destructive process that requires complex sample preparation, and the quality of the sample preparation and staining directly affect the resulting images. It can be concluded that the xylem vessel of P. euphratica branches can be observed using HRCT, which offers an effective means of obtaining the needed quantitative data on the tolerance mechanism of P. euphratica.     

Significance of CK19 expression in detecting lymph node micrometastases in patients with laryngeal carcinoma

AIM: To evaluate the significance of cytokeratin19 (CK19) expression in diagnosing micrometastases in lymph nodes in patients with laryngeal carcinoma. METHODS: Forty cases of laryngeal carcinoma together with 163 lymph nodes were studied by the staining with hematoxylin and eosin(HE)and immunostaining with antibody against cytokeratin 19 (CK19) on histological sections of the primary tumor and regional lymph nodes. RESULTS: In all cases, CK19 was positively expressed in the primary tumor. Among 163 lymph nodes, metastases were confirmed by HE in 23 lymph nodes, and in 42 lymph nodes staining with immunohistochemistry, micrometastases were found in 19 lymph nodes. Micrometastases in the lymphonodes were significantly related to the T staging. CONCLUSION: Immunohistochemical staining is a valuable method for the detection of node micrometastases in patients with laryngeal carcinoma.     

Isolation,characterization, and functional analysis of ferret lymphatic endothelial cells

The lymphatic endothelium (LE) serves as a conduit for transport of immune cells and soluble antigens from peripheral tissues to draining lymph nodes (LNs), contributing to development of host immune responses and possibly dissemination of microbes. Lymphatic endothelial cells (LECs) are major constituents of the lymphatic endothelium. These specialized cells could play important roles in initiation of host innate immune responses through sensing of pathogen-associated molecular patterns (PAMPs) by pattern recognition receptors (PRRs), including toll-like receptors (TLRs). LECs secrete pro-inflammatory cytokines and chemokines to create local inflammatory conditions for recruitment of naïve antigen presenting cells (APCs) such as dendritic cells (DCs) to sites of infection and/or vaccine administration. In this study, we examined the innate immune potential of primary LEC populations derived from multiple tissues of an animal model for human infectious diseases – the ferret. We generated a total of six primary LEC populations from lung, tracheal, and mesenteric LN tissues from three different ferrets. Standard RT-PCR characterization of these primary LECs showed that they varied in their expression of LEC markers. The ferret LECs were examined for their ability to respond to poly I:C (TLR3 and RIG-I ligand) and other known TLR ligands as measured by production of proinflammatory cytokine (IFNα, IL6, IL10, Mx1, and TNFα) and chemokine (CCL5, CCL20, and CXCL10) mRNAs using real time RT-PCR. Poly I:C exposure induced robust proinflammatory responses by all of the primary ferret LECs. Chemotaxis was performed to determine the functional activity of CCL20 produced by the primary lung LECs and showed that the LEC-derived CCL20 was abundant and functional. Taken together, our results continue to reveal the innate immune potential of primary LECs during pathogen-host interactions and expand our understanding of the roles LECs might play in health and disease in animal models.     

异种材料罐体焊接工艺的研究

在异种材料焊接性能分析和MAG焊接试验的基础上,探讨了奥氏体不锈钢(0Cr18Ni9)和低温压力容器用钢(16MnDR)角接接头的焊接工艺。通过电网变电站高压开关设备(GIS)的焊接实践,获得较好的焊接接头,满足了压力容器规程对罐体的焊接要求。