水肥耦合条件下小麦田根系层土壤总磷迁移特征

以小麦为研究对象,通过田间小区试验对生育期内水肥耦合条件下小麦根系层(0~100 cm)总磷浓度迁移过程的监测,系统分析了不同灌水量(高水7.6 mm、低水6.1 mm)及不同施肥量下(高肥125 kg/hm~2、低肥75 kg/hm~2)总磷在根系层的迁移转化规律。     

人居环境视角下居民垃圾分类意愿实证研究及政策建议——基于河南省郑州、洛阳、商丘和漯河四地市的调研

基于河南省人居环境现状,分别对郑州、洛阳、商丘和漯河四地市进行了实地调研,通过建立二元Logistic模型,分析了影响居民垃圾分类意愿高低的因素。结果表明:文化程度、经济发展、政策支持对提高居民垃圾分类意愿具有较强的正相关影响,而居民人居环境满意度对提高垃圾分类意愿具有负相关影响;女性相比男性的垃圾分类意愿更高,城市居民相比农村居民的垃圾分类意愿更高。基于此结论,从政府和社会两个方面分别提出了相关建议,以供参考。     

microRNA-146a通过靶向MAPK4和Myosin Va基因调控羊驼黑色素细胞增殖、迁移

旨在研究microRNA-146a(miR-146a)对羊驼黑色素细胞增殖和迁移的调控及其分子机制。本研究使用双荧光素酶试验验证MAPK4和Myosin Va是miR-146a的靶基因;利用荧光定量PCR和蛋白质免疫印迹试验检测在羊驼黑色素细胞中过表达miR-146a对相关下游基因表达的影响;利用CCK8和Transwell检测miR-146a过表达对羊驼黑色素细胞增殖和迁移的影响。结果显示,与对照组相比,将miR-146a和MAPK4或Myosin Va共转染293T细胞,双荧光素酶活性分别极显著下降36%和30%(P<0.001);MAPK4和Myosin Va基因转录水平分别极显著下调67%和47%(P<0.001,P<0.01);蛋白质水平的表达量分别显著或极显著下调38%和69%(P<0.05,P<0.01);增殖和迁移相关的基因CREB、MITF、MLPH和Rab27a在转录水平和蛋白水平的表达均极显著下调(P<0.01,P<0.001);CCK8和Transwell结果显示,过表达miR-146a使羊驼黑色素细胞的增殖和迁移能力极显著下调(P<0.01)。综上所述,miR-146a通过靶向调控MAPK4和Myosin Va,使增殖和迁移相关的基因MEK1、CREB、MITF、MLPH和Rab27a的表达下调,从而对羊驼黑色素细胞的增殖和迁移起抑制作用。     

Setaria digitata was the main cause of equine neurological ataxia in Korea: 50 cases (2015–2016)

This study was performed to examine and clarify the cause of hindlimb ataxia and neuropathy seen in the South Korean horse population. Fifty horses diagnosed with hindlimb ataxia and neuropathy were referred for this study. Neurological examination was performed on 47 horses while necropsy was performed in all 50 animals. The occurrence of neurological diseases increased rapidly in the summer and 47 out of 50 horses were referred after the end of July. The incidence of neurological diseases started from the southern part of Korea in July and proceeded northward in August and September. Although there was no correlation with age, Thoroughbred and Warmblood horses showed a higher incidence rate than Halla and Jeju horses. The incidence rate was 5 times higher in geldings than in mares and stallions. Of the 20 cases, 16 were diagnosed with eosinophilic meningoencephalomyelitis in 2015. The most common lesions observed in 2016 were parasitic meningoencephalomyelitis (10 cases, 33%) and eosinophilic meningomyelitis (7 cases, 23%). Histopathological analysis of the brain and spinal cord revealed nematodes of approximately 100–200 µm in diameter, microcavitation and infiltrates of eosinophils, and brown pigmented macrophage infiltrates. The nematodes were identified as Setaria digitata via DNA sequencing, performed subsequent to polymerase chain reaction using DNA isolated from formalin-fixed paraffin-embedded tissue sections of the spinal cord. These results show that aberrant migration of Setaria digitata larva in the brain and spinal cord was a major cause for neurological signs in horses.     

宁夏黄灌区退水过程中氮污染特征模拟

宁夏黄灌区是我国商品粮生产基地之一,农业高强度和化肥高投入对灌区水环境和黄河水安全造成了严重威胁。农田退水中氮素迁移流失的网室土柱模拟实验表明:1每次施肥1~2d后(穗肥是1周后),田面水中全氮量均出现峰值,不断下降后逐渐趋于稳定,全氮量随时间的变化符合对数衰减规律;23次施肥后,种植水稻的土柱各土层渗漏水中的全氮量高于未种植水稻的土柱,水稻根系的发育,一定程度上促进了氮素向下迁移,加剧了氮素流失的风险,水稻收获前控制氮的渗漏损失尤为重要。     

Plasma lipopolysaccharide elevations in cattle associated with early-stage infection by Fasciola hepatica

Fasciolosis is an endemic zoonotic parasitic disease with significant impacts on human health and both animal health and production. Early post-infection impacts on the host remain unclear. The objective of this study was to determine the changes, if any, to levels of endotoxin in cattle plasma in response to early-stage infection with Fasciola hepatica. Thirty-six (36) commercial bred cattle were experimentally infected with approximately 400 viable metacercariae. Plasma lipopolysaccharide (endotoxin) levels were examined on 24 occasions from 0 h before infection to 336 h after infection using the Limulus Amoebocyte Lysate chromogenic end point assay and compared with that of six (6) uninfected control animals. Peak lipopolysaccharide levels in infected animals were reached at 52 h after infection and returned to pre-infection levels at time 144 h after infection. Infected animals had significantly elevated lipopolysaccharide levels between 24 and 120 h after infection when compared to uninfected animals. The mean change in endotoxin units (EU)/mL over time after infection was statistically significant in infected animals. Elevations of lipopolysaccharide occurred in all infected animals suggesting a possible repeatable and titratable endotoxemia conducive to therapeutic agent model development.     

A STUOY ON TNE POLICYMAKING MODEL OF INVEST IN THE INDUSTRIAL PROJECTS TO BE INUNDATED IN TNE RESERVIOR AREA OF THE THREE GORGES PROJECT

In combination with the migration of industrial projects to be in undated in thereservior area of The Three Gorges project, a level analysis apptoach is used to formulate a policy-making model of invest optimization for the projectS to be migrated,in which various kinds of influ-encial factor on the projects are presented quantitatively and the restriction of limited resourccs isconsidered; An effective,overall and aaplicablc policymaking approach is provided for the migrationof the Three Gorges project.     

蔬菜种植农户对无公害农药的认知和购买意愿——基于河北省120家菜农的调查分析

为了考察我国农户对无公害农药的接受程度,从源头上保障农产品质量,笔者以河北省为例,通过问卷调查和访谈具体考察了蔬菜种植农户对无公害农药的认知程度和购买意愿.研究表明,户主年龄、文化程度、居住地到中心城市的距离是影响农户对无公害农药认知的重要因素;而无公害农药的价格、土地的获得成本、种植面积和市场检测机制直接决定着农户对无公害农药的购买意愿.     

农业机械化主要制约因素的制度创新研究

农业机械化是农业现代化建设的重要内容，其发展受很多因素的影响和制约。其中，耕地规模化经营是农机化发展的必要条件，资金投入是农机化发展的财政基础，农村剩余劳动力转移规模是农机化发展的客观前提。为此，在广泛研究国内外文献资料的基础上，提出了土地、资金和劳动力转移制度创新的建议和对策。     

双向链表人口迁移算法

最短路径搜索是路径分析中的热点问题.将双向链表和人口迁移算法的智能进化体制相结合,提出一种新的启发式智能仿生优化算法——双向链表人口迁移算法,并用于求解最短路径问题.仿真实验结果表明：双向链表人口迁移算法求解最短路径搜索问题是可行、有效的.