消费者生鲜水果线上购买迁徙行为及其影响因素

为探索消费者生鲜水果线上购买迁徙行为的影响因素和机制路径,本研究基于PPM理论,构建结构方程模型分析了消费者生鲜水果线上购买迁徙行为及其影响因素,并运用多群组分析不同消费者行为影响因素的差异性。结果表明：1）价格、信息、服务不满意构成正向影响消费者生鲜水果线上购买迁徙行为的推力因素;感知有用性、搜索、消费体验感构成正向影响迁徙行为的拉力因素;程序转移成本构成负向影响迁徙行为的锚定因素。2）锚定因素负向调节推力因素对迁徙行为的作用效果。3）性别、年龄、学历水平三个人口统计特征在不同假设路径中的影响较为显著。其中女性、30岁及以下、学历水平大专以上的群体更愿意在线上渠道购买生鲜水果。结论丰富了生鲜水果领域消费者迁徙行为的研究成果,并为生鲜电商可持续发展提供了启示。     

基于CRISPR/Cas9技术的水稻miR1866突变体构建

microRNA (miRNA)是长度为18～25个碱基的非编码单链RNA,在植物生长发育过程中起着重要的调节作用.水稻是世界上重要的粮食作物之一,近年来调控水稻生长发育的miRNA不断被发掘,但目前关于miR 1866的研究还比较少.本研究通过构建miR1866的CRISPR/Cas9表达载体,创制miR1866的突...     

柑橘溃疡病拮抗菌的分离筛选及其田间防效

从湖南衡阳、常德、长沙、永州等地的柑橘园采集标本,分离、筛选柑橘叶表微生物,共分离到225株细菌,9株真菌.平板拮抗试验结果表明,其中6个菌株有较好的防效,占分离菌株的13.7%.通过对菌株过滤液和定殖力的测定,菌株Kx15和Kx48效果明显,在温室对柑橘溃疡病的防治效果分别达到45.6%和55.6%,在重病果园中的防治效果分别为40.3%,47.7%,且Kx48要优于Kx15.菌株Kx15初步鉴定属于葡萄糖杆菌属,Kx48属于乳酸杆菌属.     

关于大庆市河蟹养殖情况的调查

文章通过对大庆市杜蒙、林句、肇源三县的实地调查,全面介绍了这些地方河蟹养殖的基本情况、突出特点,分析了河蟹养殖发展过程中存在的制约因素和问题,结合大庆市的实际情况,提出了今后发展河蟹养殖业的相关对策建议。     

An ecosystem-based assessment of the Korean blue crab trammel net fishery in the Yellow Sea and management implications

Landings in the blue crab, Portunus trituberculatus, fishery in Korean waters of the Yellow Sea have declined substantially from 11,000 t in the 1980s to 2,300 t in 2004. Blue crab habitat quality in the Yellow Sea has been degraded by anthropogenic activities including sand mining, land reclamation, and coastal pollution. Various traditional management measures have been implemented, including closed seasons during spawning and size limits, but these measures alone have been unsuccessful to conserve blue crab stocks. Consequently, a total allowable catch and a stock-rebuilding program using an ecosystem-based management approach were implemented in 2003 and 2006, respectively to rebuild blue crab stocks and restore habitats. This program involved assessment of both blue crab stock status and trammel-net fishery impacts at an ecosystem-level using an ecosystem-based fisheries assessment method ( [Zhang et al., 2009] and [Zhang et al., 2010]), which considered fishery data from catch and effort time-series, crab population biology, and ecosystem characteristics, including habitats and environmental conditions. Recent (2008) management status indices have shown significant positive change compared to conditions in 2000 with respect to sustainability of the stock and fishery and with regards to biodiversity and ecosystem habitat quality.     

天津重点水域底栖生物调查分析

于2018年9月,对天津大港,宝坻,华苑等地区的12个站点的大型底栖生物的群落结构及生物多样性进行了调查分析。结果表明,调查区共鉴定出大型底栖生物3门10种,其中软体动物4种,环节动物4种,水生昆虫2种,各站位丰度波动范围为20～840 ind/m^2,平均为205.33 ind/m^2,生物量范围为0.012～308.63 g/m^2,平均为59.69 g/m^2;囊螺为该地区绝对优势种。丰富度指数Margalefs.index在1.48～3.334之间波动, Goodnight修正指数在0.523～1之间波动。     

以法兴渔、促进渔业又好又快发展——就《河北省渔业条例》实施采访河北省农业厅副厅长、河北省水产局局长王进

为加强渔业资源保护、增殖、开发和合理利用,维护渔业生产者的合法权益,保障渔业生产安全和水产品质量安全,促进渔业发展,经修订后的《河北省渔业条例》,于2007年11月23日省十届人大常委会第三十一次会议审议通过,2008年1月1日起施行。     

Effects of different dietary copper sources on the growth and intestinal microbial communities of Pacific white shrimp (Litopenaeus vannamei)

An 8‐week feeding trial was conducted to evaluate the effects of dietary copper sources on growth performance and intestinal microbial communities of juvenile Pacific white shrimp (Litopenaeus vannamei). Four isonitrogenous (420 g/kg crude protein) and isolipidic (70 g/kg crude lipid) experimental diets were formulated to contain different copper sources, Diet NSC (no‐supplemented copper), Diet CS (copper sulphate), Diet Availa (copper amino acid complex from Availa^®Cu100) and Diet M (1:1, copper sulphate + copper amino acid complex). A total of 360 Pacific white shrimp juveniles (initial weight: 1.86 ± 0.03 g) were randomly allocated into four groups, with three replicates per group and 30 shrimps each replicate. An Illumina‐based sequencing method was used to analyse the intestinal bacterial composition of shrimp juveniles. The results revealed that shrimps fed Diet M had significantly higher percent weight gain (PWG) than that fed Diet NSC and Diet CS, while there were no significant differences between Diet M and Diet Availa. Survival was not affected by the dietary copper sources. Proteobacteria and Bacteroidetes were dominant in the intestines of Pacific white shrimp. Shrimps fed Diet M and Diet Availa had higher bacterial richness and diversity than those fed Diet NSC and Diet CS with no significant differences among all treatments. Furthermore, Diet M and Diet Availa which contained copper amino acid complex reduced the relative abundance of Vibrionaceae in shrimp intestinal tract. This study indicated that dietary copper sources could affect the intestinal microbial communities and diets supplemented with Availa^®Cu100 could have a positive impact on the growth performance and decrease the potential risk of disease in Pacific white shrimp.     

Effect of inhibiting nuclear factor-kappa B on TNF-α-induced expression of angiotensinogen and production of angiotensinⅡ in glomerular mesangial cells

AIM: To study the effect of inhibiting nuclear factor-kappa B (NF-κB) activity on the expression of angiotensinogen (AGT) and the production of angiotensinⅡ (AngⅡ) induced by tumor necrosis factor-α (TNF-α) in glomerular mesangial cells (MCs) of SD rats. METHODS: The MCs of SD rats were isolated and divided into three groups as follows: control; MCs treated with TNF-α, and the MCs treated with TNF-α + pyrrolidinedithiocarbamate (PDTC). The activity of nuclear factor-kappa B was measured by electrophoretic mobility shift assay. The expression of AGT was determined by RT-PCR for mRNA and Western blotting for protein. The concentration of angiotensinⅡ in supernatant was measured by RIA. RESULTS: The NF-κB activity in the MCs treated with TNF-α (20.67±9.14)×102 μg/cell was significantly higher than that in control cells ［(8.25±4.35)×102 μg/cell, P<0.01］ and the MCs treated with TNF-α+PDTC ［(7.20±4.57)×102 μg/cell, P<0.01］, and no significant difference was found between control and the MCs treated with TNF-α＋PDTC (P>0.05). The AGT mRNA level in the MCs treated with TNF-α (0.27±0.05) was higher than that in the control cells (0.20±0.05, P<0.05), and no significant difference was observed when compared with that in the MCs treated with TNF-α＋PDTC (0.22±0.06, P>0.05). The expression of AGT protein in the MCs treated with TNF-α (0.60±0.19) μg/cell was higher than that in the control ［(0.37±0.15)μg/cell, P＜0.05］ and the MCs treated with TNF-α＋PDTC ［(0.37±0.17)μg/cell, P<0.05］, and no significance was found between the MCs treated TNF-α＋PDTC and the control (P>0.05). The AngⅡ level in supernatant of cultured MCs treated with TNF-α ［(9.73±2.38)×10-5 ng·L-1/cell］ was significantly higher than that in the control ［(7.50±1.51)×10-5 ng·L-1/cell, P<0.05］ and in the MCs treated with TNF-α＋PDTC ［(6.94±1.46)×10-5 ng·L-1/cell, P<0.05］, however, the difference between the MCs treated with TNF-α＋PDTC and the control was of no significance (P>0.05). CONCLUSION: TNF-α activates the NF-κB in glomerular MCs, induces the AGT expression and the production of AngⅡ. Inhibition of NF-κB decreases the AGT expression and the production of AngⅡ. Therefore, the effects of TNF-α on AGT and AngⅡ may be mediated by NF-κB.