基于Ecopath模型的海州湾三疣梭子蟹增殖生态容量研究

为科学开展生态型增殖放流,对海州湾海域三疣梭子蟹(Portunus trituberculatus)开展生态容量评估。根据2018-2019年海州湾渔业资源调查数据,构建了由20个功能群组成的海州湾生态系统Ecopath模型,并对模型进行了不确定性及参数敏感性分析检验,系统分析了生态系统的总体特征、功能群间的营养关系和关键功能群,并评估了三疣梭子蟹的增殖生态容量。结果表明,Ecopath模型可信度Pedigree指数为0.482。三疣梭子蟹目前不是海州湾生态系统的关键功能群,其他底层鱼类、软体动物(Molluscs)以及底栖甲壳类(Benthic crustaceans)是海州湾生态系统的关键功能群。三疣梭子蟹生物量的增加对棘头梅童鱼(Collichthys lucidus)以及其他中上层鱼类产生正影响,对底层鱼类以及小黄鱼(Larimichthys polyactis)产生负影响;虾虎鱼科(Gobiidae)、口虾蛄(Oratosquilla oratoria)生物量的增加对三疣梭子蟹有较大负影响,多毛类(Polychaetes)生物量的增加对三疣梭子蟹有较大正影响。三疣梭子蟹的增殖...     

辽宁近海渔场海蜇增殖放流的回顾与发展

辽宁近海渔场海蜇放流经过1988-1993年、2004年在海洋岛渔场和2002年在辽东湾各渔场的增殖试验与2005-2006年的生产性增殖放流,探索了放流海域选择、放流时间和放流规格,跟踪监测技术,回捕效果检验等相关技术。笔者就海蜇增殖放流情况作系统回顾,并对其大规模发展做以探讨。     

酵母多糖对环磷酰胺所致免疫损伤大鼠的拮抗作用

为研究酵母多糖(YP)对环磷酰胺(CTX)所致免疫损伤大鼠的拮抗作用,本实验将80只雄性SD大鼠随机分为YP(50 mg/kg)+CTX组、YP(100 mg/kg)+CTX组、YP(200 mg/kg)+CTX组、CTX对照组和正常对照组。YP+CTX组按剂量灌胃并称重,CTX和正常对照组则灌胃给予等量生理盐水,连续给药10 d;在第8 d、9 d,除正常对照组外,其余4组腹腔注射CTX 100 mg/kg。第11 d采血及对相关的免疫器官组织进行检测。结果显示,YP(100 mg/kg)组平均日增重和饲料报酬比正常对照组显著增加(p<0.05);胸腺指数,血清中IgA、IgG、表皮生长因子(EGF)、碱性磷酸酶(AKP)含量及空肠SIgA水平显著(p<0.05)或极显著(p<0.01)高于CTX对照组;结肠壁中前列腺素E2(PGE2)含量与CTX对照组相比显著降低(p<0.05)。以上结果表明,YP能提高大鼠的生长性能;YP对CTX所致免疫损伤具有一定的拮抗保护作用,其中100 mg/kg剂量的YP效果最为显著。     

卫星遥感图像应用处理新模式的研究

卫星遥感图像增强与处理的研究旨在通过卫星遥感图像的处理,增强图像的显示质量,提高森林资源判读效果。通过应用ERDAS、ENYI遥感软件对TM、SPOT卫星数据的研究,实现资源调查卫片自主生产,降低了成本,提高了工作效率。     

大泷六线鱼放流群体与野生群体遗传多样性比较

基于线粒体DNA控制区高变区部分序列和4对微卫星标记,对大泷六线鱼放流群体及自然海域群体的遗传多样性与遗传差异进行了比较分析。线粒体DNA控制区序列分析的结果显示,413尾个体共检测到单倍型117种,其中仅Hap₃、 Hap₇和Hap₁7为共享单倍型,占总单倍型数目的 2.5%;放流、野生群体特有单倍型分别为20种和66种,分别占总单倍型数的17.09%和56.41%,放流群体特有单倍型数明显低于野生群体;放流群体和野生群体核苷酸多样性分别为0.005 1～0.006 7和0.005 8～0.007 5,单倍型多样性分别为0.856 7～0.949 9和0.883 1～0.954 9,遗传多样性均较高。微卫星标记分析结果显示,放流、野生群体平均等位基因数(Na)分别为13～44和13～27,平均多态信息含量为0.885 6和0.874 0,均具较高的遗传多态性;群体遗传结构分析结果表明,放流、野生群体间遗传分化水平较低。研究表明,山东近海大泷六线鱼放流群体与野生群体均具有较丰富的遗传多样性,且遗传结构未存在显著的群体分化...     

聊城市春季人工增雨作业天气条件分析

利用1970～2005年聊城市春季降水和高空探测资料,分析了春季降水的气候特征、主要影响天气系统及降水云系的变化。结果表明：西北冷锋和黄淮气旋是聊城市春季适合实施人工增雨作业的最为有利和作业机会最多的天气系统,3月以层状云为主要作业对象,4～5月则以层积混合云为主要作业对象。     

脑心肌炎增强型绿色荧光蛋白嵌合病毒的构建

携带增强型绿色荧光蛋白(Enhanced green fluorescent protein, EGFP)的脑心肌炎(Encephalomyocarditis virus, EMCV)嵌合病毒是研究该病毒体内外生物学特性的有力工具。因此,本研究基于前期构建的巨细胞病毒(Cytomegalovirus, CMV)感染性克隆,在EMCV基因组2A蛋白序列之后插入EGFP基因片段,并将重组质粒转染BHK-21细胞,获得携带EGFP的嵌合病毒。通过荧光定量PCR(real-time PCR)、间接免疫荧光(Indirect immunofluorescence assay, IFA)及半数组织细胞感染量测定(Median tissue culture infective dose, TCID₅₀)等方法对拯救病毒的基因组复制、蛋白表达及病毒粒子的感染性进行测定,结果证实嵌合病毒能够在BHK-21细胞上成功表达EGFP并产生完整的病毒粒子。然而,相较于野生型亲本拯救病毒,嵌合病毒在BHK-21细胞上的复制能力降低,并且在连续传代后逐渐失去绿色荧光信号,表明嵌合病毒中EGFP...     

基于改进YOLO的玉米幼苗株数获取方法

为快速准确获取玉米幼苗株数、评估播种质量、进行查缺补苗等管理,对YOLO算法进行改进,提出了一种基于特征增强机制的幼苗获取检测模型(FE-YOLO),实现了对玉米幼苗株数的快速获取.该方法根据玉米幼苗目标尺寸和空间纹理特征,构建了基于动态激活的轻量特征提取网络,融合了多感受野和空间注意力机制.实验表明:FE-YOLO模...     

Development and Molecular Characterization of Wheat-Aegilops peregrina Introgression Lines with Resistance to Leaf Rust and Stripe Rust

A wild non-progenitor species from wheat (Triticum aestivum L.) tertiary gene pool, Aegilops peregrina (Hack.) Maire & Weiller accession pau3519 (UUSS), was used for introgression of leaf rust (caused by Puccinia triticina) and stripe rust (caused by Puccinia striiformis f. sp. tritici) resistance in bread wheat. The accession was crossed and backcrossed with hexaploid wheat line Chinese Spring Ph^I to develop two homozygous BC₂F₆ wheat-Ae. peregrina introgression lines (ILs), viz., IL pau16058 and IL pau16061, through induced homoeologous recombination. Homozygous lines were screened against six Puccinia triticina and two Puccinia striiformis f. sp. tritici pathotypes at the seedling stage and a mixture of prevalent pathotypes of both species at the adult plant stage. IL pau16061 showed resistance to leaf rust only, whereas IL pau16058 was resistant to both leaf and stripe rust pathotypes throughout plant life. Molecular profiling of these ILs with simple sequence repeat (SSR) markers indicated that alien introgressions were mainly terminal and very few were interstitial. Identification of linked markers with advanced genomic technologies will aid in marker-assisted pyramiding of alien genes in cultivated wheat background.     

Contrast-enhanced fluid-attenuated inversion recovery vs. contrast-enhanced spin echo T1-weighted brain imaging

In humans, contrast-enhanced fluid-attenuated inversion recovery (FLAIR) imaging plays an important role in detecting brain disease. The aim of this study was to define the clinical utility of contrast-enhanced FLAIR imaging by comparing the results with those with contrast-enhanced spin echo T1-weighted images (SE T1WI) in animals with different brain disorders. Forty-one dogs and five cats with a clinical suspicion of brain disease and 30 normal animals (25 dogs and five cats) were evaluated using a 0.2 T permanent magnet. Before contrast medium injection, spin echo T1-weighted, SE T1WI, and FLAIR sequences were acquired in three planes. SE T1WI and FLAIR images were also acquired after gadolinium injection. Sensitivity in detecting the number, location, margin, and enhancement pattern and rate were evaluated. No lesions were found in a normal animal. In affected animals, 48 lesions in 34 patients were detected in contrast-enhanced SE T1WI whereas 81 lesions in 44 patients were detected in contrast-enhanced FLAIR images. There was no difference in the characteristics of the margins or enhancement pattern of the detected lesions. The objective enhancement rate, the mean value between lesion-to-white matter ratio and lesion-to-gray matter ratio, although representing an overlap of T1 and T2 effects and not pure contrast medium shortening of T1 relaxation, was better in contrast-enhanced FLAIR images. These results suggest a superiority of contrast-enhanced FLAIR images as compared with contrast-enhanced SE T1WI in detecting enhancing brain lesions.