期刊文献+
共找到55篇文章
< 1 2 3 >
每页显示 20 50 100
基于物种落差分析的湿地公园提升设计——以珠海淇澳红树林湿地公园为例
1
作者 吴任之 方小山 +2 位作者 袁莉 刘爽 胡慧建 《西部人居环境学刊》 CSCD 2021年第3期65-72,共8页
物种落差分析法(Species Differential Analysis,SDA)通过对目标湿地公园现存、周边和历史鸟类名录进行集合运算来确定目标物种,再根据这些目标物种的栖息需求和存在情况,推导出具体的栖息地设计方案和水鸟招引策略。以2015年启动的珠... 物种落差分析法(Species Differential Analysis,SDA)通过对目标湿地公园现存、周边和历史鸟类名录进行集合运算来确定目标物种,再根据这些目标物种的栖息需求和存在情况,推导出具体的栖息地设计方案和水鸟招引策略。以2015年启动的珠海淇澳红树林湿地公园(一期)提升工程为例,通过实地监测和文献查阅发现目标区域共有水鸟15种,周边21种,历史27种,基于该数据运用物种落差分析方法确定目标水鸟共34种;这些目标水鸟按存在情况被分配不同的招引对策,按栖息需求被分为鹭类、鸻鹬类、秧鸡类、雁鸭类和鸥类5大类型;结合场地原始条件,确定目标区域营造包括林地、滩涂等8种生态类型;根据以上分析结果,对湿地公园进行场地分区,地形改造,植物种植与集中施策,实现湿地公园生态环境和水鸟多样性的恢复与提升。 展开更多
关键词 物种落差分析 水鸟 物种多样性 生境营造 湿地公园 提升设计
下载PDF
人与恒河猴下颌骨骨膜干细胞的分离、鉴定和跨物种单细胞分析
2
作者 王子硕 李阳阳 +2 位作者 王海涛 邹多宏 张志愿 《中华口腔医学杂志》 CAS CSCD 北大核心 2024年第7期696-705,共10页
目的探究人与非人灵长类动物(恒河猴)的下颌骨骨膜中是否存在有别于传统间充质干细胞的干细胞群体及其在膜内成骨过程中的特性,并提供区别于其他解剖区域骨膜干细胞(PSCs)的下颌骨PSCs的稳定分离、培养、扩增的标准化流程。方法分别从... 目的探究人与非人灵长类动物(恒河猴)的下颌骨骨膜中是否存在有别于传统间充质干细胞的干细胞群体及其在膜内成骨过程中的特性,并提供区别于其他解剖区域骨膜干细胞(PSCs)的下颌骨PSCs的稳定分离、培养、扩增的标准化流程。方法分别从上海交通大学医学院附属第九人民医院的18~24岁行第三磨牙拔除术3例患者翻瓣去骨过程中的骨块表面和3只6岁龄恒河猴下颌骨的前磨牙区颊侧获取骨膜,使用Illumina平台Novaseq 6000测序仪进行单细胞测序,并通过同源基因匹配进行跨物种单细胞转录组测序的结果比较。使用37℃和低温两种消化方式从原代组织中分离PSCs,经流式细胞术分析鉴定其表面标志物(CD200、CD31、CD45和CD90)并通过免疫荧光鉴定组织蛋白酶K(CTSK)与CD200的共定位情况。接着评估了体外扩增至第三代的不同物种PSCs的细胞增殖能力和三系分化能力。最后比较了PSCs和骨髓间充质干细胞(BMSCs)在成骨方面的特性异同。结果单细胞测序结果提示直系同源基因匹配降维后获得了18个聚类的细胞群,基于各细胞标志物数据库对各聚类进行细胞注释。低温消化方案可以稳定地从人、恒河猴下颌骨骨膜中分离出PSCs,细胞呈成纤维细胞状。细胞计数法结果显示人与恒河猴的PSCs增殖能力差异无统计学意义,流式细胞术分析鉴定结果显示,从骨膜分离的细胞表面抗原表达CD200^(+)、CD31^(-)、CD45^(-)和CD90^(-),免疫荧光提示CTSK与CD200共定位于此细胞中。茜素红染色、油红O染色和阿尔率蓝染色结果显示,人和恒河猴的PSCs均具备成骨、成脂、成软骨的三系分化能力。与BMSCs的成骨能力相比,PSCs增殖能力略优,分化过程中,PSCs在早期有良好的成骨表现。结论本研究成功稳定分离并鉴定出人和非人灵长类动物(恒河猴)的正常下颌骨PSCs,为探索下颌骨膜内成骨的机制、建立理想的非人灵长类动物模型以及下颌骨缺损修复新型策略提供了细胞学基础。 展开更多
关键词 灵长目 下颌骨 骨膜干细胞 成骨分化 膜内成骨 单细胞测序 物种分析
原文传递
基于DICE模式的跨境电子商务生态圈构建与策略分析 被引量:8
3
作者 李琴 马明 《商业经济研究》 北大核心 2020年第8期125-127,共3页
构建跨境电商生态圈是践行"资源共享、协同整合、合作共赢"可持续发展战略的重要举措。本文以生态学理论为基础,构建基于DICE模式跨境电商生态体系,提出良性运营的对策建议。
关键词 跨境电商 生态圈 DICE模式 组成架构 物种分析
下载PDF
HPLC-ESI/MS分析对苯二甲酸和1,3-丙二醇酯化反应产物(英文)
4
作者 刘坚 《化学研究与应用》 CAS CSCD 北大核心 2013年第3期292-296,共5页
报道了对苯二甲酸(TPA)与1,3-丙二醇(PDO)在SO42-/6TiO2-ZrO2催化剂作用下发生的酯化反应。使用高效液相色谱-电喷雾电离质谱对酯化反应产物的成份进行了分析。分析结果表明:主要的物质是对苯二甲酸-1,3-丙二醇单酯(HPCBA)形成的二聚体... 报道了对苯二甲酸(TPA)与1,3-丙二醇(PDO)在SO42-/6TiO2-ZrO2催化剂作用下发生的酯化反应。使用高效液相色谱-电喷雾电离质谱对酯化反应产物的成份进行了分析。分析结果表明:主要的物质是对苯二甲酸-1,3-丙二醇单酯(HPCBA)形成的二聚体和环状二聚体,也有较多的HPCBA形成的三聚体。有少量的可能没有端羟基和端羧基的未知结构物质。本文章研究结果对于TPA和PDO缩聚获得高分量的聚对苯二甲酸-1,3-丙二醇酯(PTT)具有指导作用。 展开更多
关键词 TPA和PDO的酯化 酯化反应物种分析 高效液相色谱-电喷雾电离质谱
下载PDF
宏蛋白质组学信息分析的基本策略及其挑战 被引量:5
5
作者 徐洪凯 闫克强 +3 位作者 何燕斌 闻博 杨焕明 刘斯奇 《生物化学与生物物理进展》 SCIE CAS CSCD 北大核心 2018年第1期23-35,共13页
宏蛋白质组学是一门新型科学,它运用质谱技术规模化地采集自然界微生物种群的蛋白质信息,并结合多种组学数据,开展微生物种群的遗传特征及其生物功能的研究.宏蛋白质组学的信息分析与传统蛋白质组学方法有较大的不同,亟需拓展新的分析思... 宏蛋白质组学是一门新型科学,它运用质谱技术规模化地采集自然界微生物种群的蛋白质信息,并结合多种组学数据,开展微生物种群的遗传特征及其生物功能的研究.宏蛋白质组学的信息分析与传统蛋白质组学方法有较大的不同,亟需拓展新的分析思路.由于宏蛋白质组的研究对象是复杂度极高的微生物样品,因此,需要构建尽可能囊括样本中所含微生物的基因组信息的物种数据库.面对庞大的数据库,必须考虑到分析过程中所消耗的计算资源和鉴定结果的质控标准,因此,需要高度优化库容量、搜库、假阳性控制等参数.鉴于宏蛋白质组数据中广泛存在复杂的同源蛋白质序列,因此,需要充分利用NCBI数据库中的分类信息进行匹配,并运用LCA算法过滤处理才能将蛋白质有效地归组到物种.本文立足于宏蛋白质组学信息分析,从宏蛋白质组的数据库建立、蛋白质归并、生物学意义发掘等几个方面着手,对该领域的发展现状、面临挑战以及未来研究方向进行了评述. 展开更多
关键词 宏蛋白质组学 数据库 数据分析 蛋白归并 物种分析
下载PDF
深圳市夏季大气挥发性有机物的光化学反应特征及来源解析
6
作者 吴浩然 彭杏 +4 位作者 符楠 李志杰 钟文君 何凌燕 黄晓锋 《中国环境科学》 EI CAS CSCD 北大核心 2024年第8期4145-4154,共10页
选取深圳市城市点位在2022年6~8月(夏季)光化学反应活跃季节开展VOCs连续在线观测,利用光化学龄的参数化方法对VOCs测量浓度进行光化学损失校正以获得VOCs初始浓度,并分析VOCs的光化学反应特征,使用特征物种比值分析法和正交矩阵因子模... 选取深圳市城市点位在2022年6~8月(夏季)光化学反应活跃季节开展VOCs连续在线观测,利用光化学龄的参数化方法对VOCs测量浓度进行光化学损失校正以获得VOCs初始浓度,并分析VOCs的光化学反应特征,使用特征物种比值分析法和正交矩阵因子模型(PMF)进行VOCs来源解析.研究表明,各类VOCs光化学消耗的浓度在总VOCs(TVOCs)消耗浓度占比为:烯烃(53.5%)、OVOCs(30.8%)、烷烃(10.9%)、芳香烃(4.7%)、乙炔(0.2%).烷烃的初始浓度与测量浓度均在TVOCs中占主导地位,但其光化学损失OFP仅有1.2×10^(-9)远低于烯烃(47.8×10^(-9))、OVOCs(15.8×10^(-9))和芳香烃(4.7×10^(-9)),所以烯烃是臭氧污染防治的关键物种.本研究基于初始值与测量值进行PMF源解析得到6个主要排放源的浓度贡献为(初始-PMF,测量-PMF):工业过程(0.91×10^(-9),0.87×10^(-9))、溶剂使用(2.75×10^(-9),1.84×10^(-9))、汽车尾气(3.49×10^(-9),2.01×10^(-9))、汽油挥发(3.20×10^(-9),2.62×10^(-9))、天然源(0.74×10^(-9),0.56×10^(-9))、燃烧源(2.35×10^(-9),1.16×10^(-9)).结果显示PMF源解析结果受光化学反应影响显著,在进行源解析时应考虑到利用VOCs的初始值而非测量值,否则会对烯烃占主导的汽车尾气与天然源造成显著的低估. 展开更多
关键词 挥发性有机物(VOCs) 光化学损失 特征物种比值分析 正交矩阵因子分析
下载PDF
基于肠道菌群研究瘀血痹片对类风湿关节炎的作用
7
作者 邵平 韩凌 +4 位作者 齐沐爽 任颖 朱婉君 代春美 胡相卡 《石河子大学学报(自然科学版)》 CAS 北大核心 2024年第3期358-368,共11页
目的基于肠道菌群探讨瘀血痹片对类风湿关节炎的作用。方法36只SD大鼠随机分为正常对照组、胶原诱导型类风湿关节炎(CIA)组、甲氨蝶呤0.002 g·kg^(-1)剂量组、瘀血痹片0.4、0.8、1.6 g·kg^(-1)(YXBL、YXBM、YXBH)剂量组,后5... 目的基于肠道菌群探讨瘀血痹片对类风湿关节炎的作用。方法36只SD大鼠随机分为正常对照组、胶原诱导型类风湿关节炎(CIA)组、甲氨蝶呤0.002 g·kg^(-1)剂量组、瘀血痹片0.4、0.8、1.6 g·kg^(-1)(YXBL、YXBM、YXBH)剂量组,后5组采用牛Ⅱ型胶原乳剂诱导类风湿关节炎模型,除正常组和CIA组大鼠给予三蒸水外,其余各组按上述剂量灌胃给药。30 d后,测量各组大鼠脾脏、胸腺质量,计算脾脏、胸腺指数;HE染色观察滑膜组织、脾脏和结肠病理变化;16S rRNA高通量测序技术测定各组大鼠肠道菌群变化。结果瘀血痹片可使CIA大鼠脾脏指数、胸腺指数下降(P>0.05),足爪体积、踝周长、关节炎评分减少(P<0.01),滑膜组织增生减轻、炎性细胞浸润减少,改善脾脏和结肠病理变化,降低CIA大鼠肠道菌群中Fusicatenibacter、Erysipelotrichaceae_UCG-003、Monoglobus、UCG-005菌属的相对丰度(P<0.05),增加Prevotellaceae_UCG-003菌属的相对丰度(P<0.05)。结论瘀血痹片对类风湿关节炎具有改善作用,可能与其调控肠道菌群有关。 展开更多
关键词 瘀血痹片 类风湿关节炎 16S rRNA高通量测序技术 肠道菌群 物种差异性分析
下载PDF
云南省虎甲科昆虫区系与物种多样性研究 被引量:3
8
作者 黄甫则 李国锋 +1 位作者 周建 林平 《林业调查规划》 2012年第3期43-47,共5页
在云南省8个地州27个县的不同生境中进行虎甲科昆虫的种类调查,共采集虎甲科昆虫标本2 218只,经鉴定,隶属2亚科13属45种,分别占中国已知虎甲科昆虫种、属的28.13%和54.17%。在13个属中,genera Neocol-lyris和genera Cylindera是2个优势... 在云南省8个地州27个县的不同生境中进行虎甲科昆虫的种类调查,共采集虎甲科昆虫标本2 218只,经鉴定,隶属2亚科13属45种,分别占中国已知虎甲科昆虫种、属的28.13%和54.17%。在13个属中,genera Neocol-lyris和genera Cylindera是2个优势属,genera Neocollyris拥有最多的物种数。文章从分类阶元、特有物种、动物地理区划3个方面分析云南省虎甲科昆虫的物种多样性。在云南省已知83种虎甲科昆虫中,64种为东洋种,19种为古北和东洋两界兼有种,广布种10种。在云南省现有虎甲科昆虫的20个属中,3个属为云南特有属,特有种35种,占云南省已知的虎甲科昆虫种类的42.17%。虎甲科昆虫在7个地理小区的分布,以西双版纳小区和元江小区的物种多样性较高。相对全国而言,云南省虎甲科昆虫的物种多样性较高。 展开更多
关键词 虎甲科昆虫 物种多样性 区系分析 特有物种 云南省
下载PDF
酱香型白酒高温大曲发酵过程中真菌多样性研究 被引量:2
9
作者 吴成 程平言 +6 位作者 谢丹 黄魏 李岭卓 张健 尤小龙 胡峰 钟方达 《食品与生物技术学报》 CAS CSCD 北大核心 2023年第6期95-103,共9页
基于传统可培养方法和单分子实时测序技术对酱香型白酒仿生机制曲和传统人工曲发酵过程的真菌群落组成及特征进行了研究。结果表明,Wicherhanmomyces anomalus、Pichia kudriavzevii、Candida tropicalis、Kodamaea ohmeri、Kazachstani... 基于传统可培养方法和单分子实时测序技术对酱香型白酒仿生机制曲和传统人工曲发酵过程的真菌群落组成及特征进行了研究。结果表明,Wicherhanmomyces anomalus、Pichia kudriavzevii、Candida tropicalis、Kodamaea ohmeri、Kazachstania humilis、Kluveromyces marxianus和Aspergillus属丝状真菌,可以同时被2种方法检出,从曲坯成型入仓到发酵结束出仓,真菌多样性呈现逐渐降低的趋势。同时,与二代高通量测序结果相比,单分子实时测序技术在种水平上更适合于小类真菌多样性的鉴定。此外,高温大曲多数优势真菌属之间呈显著正相关调节机制,其中包括55个真菌属呈显著正相关,6个真菌属呈显著负相关。本研究揭示了酱香型白酒高温大曲制作过程的真菌群落组成及其特征,旨在为挖掘高温大曲中功能微生物及阐明高温大曲发酵机理提供依据。 展开更多
关键词 高温大曲 单分子实时测序 可培养方法 物种相关性分析
下载PDF
AI红外相机监测系统在野生动物深入监测与保护中的研究与应用
10
作者 朱睿 牛金帅 王新伟 《中文科技期刊数据库(全文版)自然科学》 2023年第4期167-171,共5页
红外相机的应用,对目前国内野生动物监测与研究有重大意义,在相关红外相机技术的辅助下,可以完成野生动物本底调查,也能完成对野生动物种群参数的评估,从而对动物行为进行深入研究和分析。本文介绍的AI红外相机监测系统,可以自动采集4G... 红外相机的应用,对目前国内野生动物监测与研究有重大意义,在相关红外相机技术的辅助下,可以完成野生动物本底调查,也能完成对野生动物种群参数的评估,从而对动物行为进行深入研究和分析。本文介绍的AI红外相机监测系统,可以自动采集4G红外相机抓拍的动物相片,通过AI技术智能识别相片中的动物种类,在此基础上通过大数据算法分析动物物种活动规律,动物与生境相关性和动物物种间的相关性,为深入分析动物物种与生态环境的相关性、制定有效的动物保护策略提供决策依据。 展开更多
关键词 红外相机 野生动物 动物监测系统 动物物种智能识别 动物环境相关性统计 动物物种相关性分析
下载PDF
基于底栖动物的松花江流域不同地形分区水质指标阈值研究 被引量:9
11
作者 程佩瑄 孟凡生 +3 位作者 王业耀 张铃松 杨琦 薛浩 《环境科学研究》 EI CAS CSCD 北大核心 2020年第9期2061-2073,共13页
为全面了解松花江流域不同地形分区内底栖动物群落对水质指标的响应规律,识别不同分区水质指标指示物种的差异,于2016-2018年对松花江流域97个采样点的水质指标[EC、ρ(DO)、ρ(CODMn)、ρ(NH3-N)、ρ(TN)、ρ(TP)]和大型底栖动物群落... 为全面了解松花江流域不同地形分区内底栖动物群落对水质指标的响应规律,识别不同分区水质指标指示物种的差异,于2016-2018年对松花江流域97个采样点的水质指标[EC、ρ(DO)、ρ(CODMn)、ρ(NH3-N)、ρ(TN)、ρ(TP)]和大型底栖动物群落进行调查分析,采用临界指示物种分析法(threshold indicator taxa analysis,TITAN)分别探讨松花江流域山区、丘陵区和平原区水质指标的生态阈值,当污染物浓度超过负响应阈值时敏感种密度降低,当超过正响应阈值时耐受种也会受到明显影响,底栖动物群落结构会发生显著变化.将TITAN法所得的负响应阈值作为触发底栖动物群落发生变化的最低值,正响应阈值为底栖动物群落的耐受极限值.结果表明:①松花江流域水质指标在不同地形分区内的阈值不同,除ρ(DO)和ρ(CODMn)外,其他指标负响应阈值均表现为山区<丘陵区<平原区,ρ(DO)则表现相反,ρ(CODMn)在丘陵区出现最高阈值(5.46 mg/L)、山区出现最低阈值(4.01 mg/L).除ρ(DO)以外,其他指标的正响应阈值均呈山区<丘陵区<平原区的趋势,ρ(DO)正响应阈值的变化趋势则与之相反.②松花江流域内超过50%的采样点水质指标值均超过其负响应阈值,超出正响应阈值的采样点比例在6%~40%之间,说明流域受到一定的干扰,但干扰程度不严重.③同一物种在不同地形分区内对水体理化指标的指示方向可能相反.萝卜螺属在丘陵区为ρ(NH3-N)的正响应指示物种,在平原区则转变为负响应指示物种;短沟蜷属在丘陵区为ρ(TN)和ρ(TP)的正响应物种,在平原区则转变为负响应物种.研究显示,大型底栖动物群落结构的分布特征是影响水质指标阈值指示物种识别的主要原因,而不同分区的自然地理状况、栖境状况和水质状况则是造成大型底栖动物群落结构分布差异的主要因素. 展开更多
关键词 松花江流域 地形分区 阈值 临界指示物种分析法(TITAN) 底栖动物
下载PDF
Cranial morphometric study of four giant flying squirrels(Petaurista)(Rodentia:Sciuridae) from China 被引量:6
12
作者 李松 俞发宏 吕雪霏 《Zoological Research》 CAS CSCD 北大核心 2012年第2期119-126,共8页
The present study revisited the controversial taxonomic status ofPetaurista yunanensis, P. philippensis, P. hainana, and P. petaurista by using a considerably extended set of morphometrical characters (26 cranial var... The present study revisited the controversial taxonomic status ofPetaurista yunanensis, P. philippensis, P. hainana, and P. petaurista by using a considerably extended set of morphometrical characters (26 cranial variables from 60 adult specimen skulls). The results revealed no sexual dimorphism in any of the four species but confirmed significant craniometric differences among the four species in both the principal components analysis (PCA) and discriminant function analysis (DFA), with the greatest distinction observed between P. petaurista and other Petaurista species. Both univariate and multivariate analysis indicated that the morphological differences between P. yunanensis and P. philippensis were less than that between P. philippensis and P. hainana. The morphometric results were concordant in geographic patterns with mtDNA data from previous studies and indicated that P. petaurista, P. hainana, P. philippensis, and P. yunanensis could be recognized as valid species. 展开更多
关键词 Petaurista Cranial variables Statistical analysis SPECIES
下载PDF
Spatial and environmental effects on plant communities in the Yellow River Delta, Eastern China 被引量:8
13
作者 宋创业 刘高焕 刘庆生 《Journal of Forestry Research》 SCIE CAS CSCD 2009年第2期117-122,I0002,共7页
Types and structure of plant communities in the Yellow River Delta were investigated by using detrended canonical correspondence analyses (DCCAs) and a two-way indicator species analysis (TWINSPAN). The distributi... Types and structure of plant communities in the Yellow River Delta were investigated by using detrended canonical correspondence analyses (DCCAs) and a two-way indicator species analysis (TWINSPAN). The distribution pattern and influential factors of the plant communities were also analyzed by testing elevation, slope, soil characteristics, longitude and latitude of 134 vegetation samples collected by representative plot sampling methods. Results showed that all the 134 vegetation samples could be divided into seven vegetation groups, separately dominated by Robinia pseucdoacacia, Imperata cylindrical, Miscanthus saccharifleus, Suaeda salsa, Aeluropus sinensis, Phragmites australis and Tamarix chinensis. The vegetation distribution pattern was mainly related to elevation, ground water depth and soil characteristics such as salinity and soluble potassium. Among the factors affecting distribution pattern of the plant communities, the species matrix explained by non-spatial environmental variation accounts for 45.2% of total variation. Spatial variation and spatial-structured environmental variation explain 11.8%, and 2.2%, respectively. Remained 40.8% of undetermined variation is attributed to biological and stochastic factors. 展开更多
关键词 detrended canonical correspondence analyses environmental factors plant communities spatial factors Yellow River Delta two-way indicator species analysis
下载PDF
我国土壤受试植物筛选与毒性预测 被引量:5
14
作者 罗晶晶 吴凡 +3 位作者 张加文 刘征涛 张聪 王晓南 《中国环境科学》 EI CAS CSCD 北大核心 2022年第7期3295-3305,共11页
生态毒性数据缺乏是我国土壤基准与生态风险评估研究中一直存在的问题,开展本土受试植物的筛选可提供更多的生态毒理试验选材,从而获得不同物种的生态毒性数据.鉴于植物对土壤污染物的敏感性,从被子植物中依据分布范围、代表性和易于获... 生态毒性数据缺乏是我国土壤基准与生态风险评估研究中一直存在的问题,开展本土受试植物的筛选可提供更多的生态毒理试验选材,从而获得不同物种的生态毒性数据.鉴于植物对土壤污染物的敏感性,从被子植物中依据分布范围、代表性和易于获得性等原则,对我国潜在的受试植物进行筛选,结果发现,13科53种被子植物分布广泛且易于获取,可作为本土受试植物;结合生态毒性数据的搜集与分析,其中12种受试植物的生态毒性数据相对丰富,并对部分典型污染物表现高敏感.此外在受试植物生态毒性预测模型研究方面,对12种受试植物两两进行建模预测,共得到132个物种种间关系估算模型(Interspecies Correlation Estimation,ICE),其中88个为显著性模型(F检验P<0.05);此处,回归分析了已构建ICE模型的评价参数,得出预测效果较好的ICE模型应满足交叉验证成功率≥80.00%、MSE≤0.62、R^(2)≥0.76和分类学距离≤4的标准.最终筛选出25个符合上述标准的ICE模型,涉及禾本科-禾本科、十字花科-十字花科的相互预测,其中当燕麦Avena sativa、芜青Brasrapa、普通小麦Triticurn aestivum、玉蜀黍Zea mays和黑麦草Lolium perenne等作为替代物种时,预测物种的实际生态毒性值与预测值较为接近.受试植物的筛选与生态毒性预测模型的建立有助于生态毒性数据的产生,并为土壤污染管理和生态风险评估提供科学依据. 展开更多
关键词 土壤生态基准 受试生物筛选 被子植物 物种敏感度分析 ICE模型预测
下载PDF
Grateloupia ramosa Wang & Luan sp. nov. (Halymeniaceae, Rhodophyta), a new species from China based on morphological evidence and comparative rbcL sequences 被引量:5
15
作者 曹翠翠 刘淼 +3 位作者 郭少茹 赵丹 栾日孝 王宏伟 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2016年第2期283-294,共12页
Grateloupia ramosa Wang & Luan sp. nov.(Halymeniaceae, Rhodophyta) is newly described from Hainan Province, southern China. The organism has the following morphological features:(1) purplish red, cartilaginous and... Grateloupia ramosa Wang & Luan sp. nov.(Halymeniaceae, Rhodophyta) is newly described from Hainan Province, southern China. The organism has the following morphological features:(1) purplish red, cartilaginous and lubricous thalli 5–10 cm in height;(2) compressed percurrent axes bearing abundant branches with opposite arrangement;(3) claw-like apices on top, constricted to 2–4 cm at the base;(4) cortex consisting of 3–6 layers of elliptical or anomalous cells and a medulla covered by compact medullary filaments;(5) reproductive structures distributed throughout the thallus, especially centralized at the bottom of the end portion of the branches; and(6) 4-celled Carpogonial branches and 3-celled auxiliary-cell branches, both of the Grateloupia-type. The morphological diff erences were supported by molecular phylogenetics based on ribulose-1, 5-bisphosphate carboxylase/oxygenase( rbc L) gene sequence analysis. There was only a 1 bp divergence between specimens collected from Wenchang and Lingshui of Hainan province. The new species was embedded in the large Grateloupia clade of the Halymeniaceae. The pairwise distances between G. ramosa and other species within Grateloupia ranged from 26 to 105 bp, within pairwise distances of 13–111 bp between species of the large genus Grateloupia in Halymeniaceae. Thus, we propose this new species as G. ramosa Wang & Luan sp. nov. 展开更多
关键词 GRATELOUPIA Grateloupia ramosa HALYMENIACEAE morphology rbcL sequence Rhdophyta
下载PDF
Diversity patterns and phylogenetic structure of vascular plants along elevational gradients in a mountain ecosystem, South Korea 被引量:7
16
作者 CHUN Jung-Hwa LEE Chang-Bae 《Journal of Mountain Science》 SCIE CSCD 2018年第2期280-295,共16页
Recently, a phylogenetic diversity and community structure analysis as complementary to species-centric approaches in biodiversity studies provides new insights into the processes of community assembly. In this study,... Recently, a phylogenetic diversity and community structure analysis as complementary to species-centric approaches in biodiversity studies provides new insights into the processes of community assembly. In this study, we analyzed species and phylogenetic diversity and community structures for woody and herbaceous plants along two elevational transects on Mt. Baekhwa, South Korea. The species richness and phylogenetic diversity of woody plants showed monotonic declining patterns with increasing elevation along all transects, whereas herbaceous plants showed different patterns, such as no relationship and a reversed unimodal pattern, between the study transects. The main drivers of these patterns were climate and habitat variables for woody and herbaceous plants, respectively. In addition, the phylogenetic community structure primarily showed phylogenetic clustering regulated by deterministic processes, especially environmental filtering, such as climate or habitat factors, along the two transects, although herbaceous plants along a transect depicted phylogenetic randomness as a result of a neutral process. Our findings suggest that deterministic and neutral processes may simultaneously control the community structures along small-scale elevational gradients such as local transects, although the deterministic process may be the predominant type. 展开更多
关键词 Community structure Deterministicprocess Elevational gradient Neutral process Phylogenetic diversity Species richness
下载PDF
Farmer Participatory Breeding - The Foster Parent in the Breeding of Dioscorea spp. in Ghana 被引量:1
17
作者 E. Otoo 《Journal of Agricultural Science and Technology(B)》 2011年第2期205-215,共11页
Yam (Dioscorea spp.), has been aptly described as an orphan crop. It has suffered institutional neglect from time immemorial. Until this study there were no formally released yam varieties in Ghana. The farmer parti... Yam (Dioscorea spp.), has been aptly described as an orphan crop. It has suffered institutional neglect from time immemorial. Until this study there were no formally released yam varieties in Ghana. The farmer participatory breeding approach was adapted to fast-track the development and release of three new yam varieties in Ghana. This paper uses the breeding process as a case study and conducts a SWOT analysis to provide guidelines for breeding for crops in Low External Input Agriculture. It was faster than conventional breeding in varietal development. Scientific quality of Farmer Participatory Breeding is as good as conventional breeding. Farmer Participatory Breeding is a must for breeding yam in Ghana. Ultimately, three genotypes 2000/001, KUP2000/001 and TDr89/02665 were accepted and released as new varieties "CRIKukrupa", "CRIPona" and "Mankrong Pona" respectively in March 2005. Danger of omission of some promising genotypes in the course of varietal development and danger of opinion group cabalizing the group discussions were identified as potential threats to the approach. Effective research-extension-farmer linkage was identified as extremely vital to the success of the approach. Farmer participatory breeding process was also sustainable and more efficient than conventional breeding in varietal selection in yam breeding. 展开更多
关键词 DIOSCOREA Farmer Participatory Breeding Ghana Yam (Dioscorea spp.).
下载PDF
Distribution patterns of benthic diatoms during summer in the Niyang River,Tibet,China 被引量:2
18
作者 裴国凤 刘国祥 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2011年第6期1192-1198,共7页
The aim of this study was to investigate the distribution, density, community structure and biodiversity characteristics of benthic diatoms, and to analyze whether differences in species composition and abundance exis... The aim of this study was to investigate the distribution, density, community structure and biodiversity characteristics of benthic diatoms, and to analyze whether differences in species composition and abundance exist in different regions of the Niyang River, Tibet. Among the 157 taxa observed in 15 sampling sites in the main river and tributary, most were casual species (〉100), the relative abundance of the genera Achnantkes and Fragilaria was 67% of the total relative abundance. Acknantkes minutissima was the most important species and dominated the whole river reaches (average relative abundance was 30%); the average diatom densities were 7.4 x 105 cell/cm2 at all sites, and increased slowly from the upper section to downriver. The significant indicator taxa with higher relative abundance were Achnanthes biasolettiana (18.0%) and Fragilaria arcus (18.2%), Fragilaria capucina var. vaucheriae (31.2%), Fragilaria construens var. renter (11.3%) and Cymbella affinis (11.0%) in the upper, tributary and mid-river sections, respectively. Achnanthes minutissima was the most abundant species (56%) in the downriver section. Biodiversity indices showed a gradual decrease from the up- to down-river section, and dominant species were more abundant in the upper and mid-river sections than in the downriver section. A two-way indictor species analysis (TWINSPAN) of diatom composition clearly showed four different groups, namely the upper, mid, lower and tributary sections. Detrended correspondence analysis (DCA) supported the results of TW1NSPAN, and the characteristics of site distribution and species composition in the Niyang River supported the spatial structure of diatom assemblages. This study indicates that bio-assessment programs utilizing benthic diatoms could clearly benefit lotic water with regional stratification. 展开更多
关键词 benthic diatoms diatom density BIODIVERSITY bio-assessment Niyang River
下载PDF
Homotopy Analysis Method for Solving Biological Population Model 被引量:2
19
作者 A.A.M.Arafa S.Z.Rida H.Mohamed 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第11期797-800,共4页
In this paper,the homotopy analysis method (HAM) is applied to solve generalized biological populationmodels.The fractional derivatives are described by Caputo's sense.The method introduces a significant improveme... In this paper,the homotopy analysis method (HAM) is applied to solve generalized biological populationmodels.The fractional derivatives are described by Caputo's sense.The method introduces a significant improvementin this field over existing techniques.Results obtained using the scheme presented here agree well with the analyticalsolutions and the numerical results presented in Ref.[6].However,the fundamental solutions of these equations stillexhibit useful scaling properties that make them attractive for applications. 展开更多
关键词 biological populations model fractional calculus homotopy analysis method Mittag-Leffier function
下载PDF
Diarrhoea-predominant irritable bowel syndrome distinguishable by 16S rRNA gene phylotype quantification 被引量:26
20
作者 Anna Lyra Teemu Rinttil +6 位作者 Janne Nikkil Lotta Krogius-Kurikka Kajsa Kajander Erja Malinen Jaana Mtt Laura Mkel Airi Palva 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第47期5936-5945,共10页
AIM:To study whether selected bacterial 16S ribosomal RNA(rRNA)gene phylotypes are capable of disting- uishing irritable bowel syndrome(IBS). METHODS:The faecal microbiota of twenty volunteers with IBS,subdivided into... AIM:To study whether selected bacterial 16S ribosomal RNA(rRNA)gene phylotypes are capable of disting- uishing irritable bowel syndrome(IBS). METHODS:The faecal microbiota of twenty volunteers with IBS,subdivided into eight diarrhoea-predominant (IBS-D),eight constipation-predominant(IBS-C)and four mixed symptom-subtype(IBS-M)IBS patients,and fifteen control subjects,were analysed at three time-points with a set of fourteen quantitative real-timepolymerase chain reaction assays.All assays targeted 16S rRNA gene phylotypes putatively associated with IBS,based on 16S rRNA gene library sequence analysis. The target phylotypes were affiliated with Actinobac-teria,Bacteroidetes and Firmicutes.Eight of the target phylotypes had less than 95%similarity to cultured bacterial species according to their 16S rRNA gene sequence.The data analyses were made with repeated-measures ANCOVA-type modelling of the data and principle component analysis(PCA)with linear mixed-effects models applied to the principal component scores. RESULTS:Bacterial phylotypes Clostridium cocleatum 88%,Clostridium thermosuccinogenes 85%,Coprobacillus catenaformis 91%,Ruminococcus bromii-like, Ruminococcus torques 91%,and R.torques 93%were detected from all samples analysed.A multivariate analysis of the relative quantities of all 14 bacterial 16S rRNA gene phylotypes suggested that the intestinal microbiota of the IBS-D patients differed from other sample groups.The PCA on the first principal component(PC1),explaining 30.36%of the observed variation in the IBS-D patient group,was significantly altered from all other sample groups(IBS-D vs control, P=0.01;IBS-D vs IBS-M,P=0.00;IBS-D vs IBS-C, P=0.05).Significant differences were also observed in the levels of distinct phylotypes using relative values in proportion to the total amount of bacteria.A phy- lotype with 85%similarity to C.thermosuccinogenes was quantified in significantly different quantities among the IBS-D and control subjects(-4.08±0.90 vs -3.33±1.16,P=0.04)and IBS-D and IBS-M subjects (-4.08±0.90 vs-3.08±1.38,P=0.05).Furthermore,a phylotype with 94%similarity to R.torques was more prevalent in IBS-D patients'intestinal micro- biota than in that of control subjects(-2.43±1.49 vs -4.02±1.63,P=0.01).A phylotype with 93%simi- larity to R.torques was associated with control sam- ples when compared with IBS-M(-2.41±0.53 vs -2.92±0.56,P=0.00).Additionally,a R.bromii-like phylotype was associated with IBS-C patients in com- parison to control subjects(-1.61±1.83 vs-3.69± 2.42,P=0.01).All of the above mentioned phylotype specific alterations were independent of the effect of time. CONCLUSION:Significant phylotype level alterationsin the intestinal microbiotas of IBS patients were observed,further emphasizing the possible contribution of the gastrointestinal microbiota in IBS. 展开更多
关键词 Irritable bowel syndrome Diarrhoea-predominant irritable bowel syndrome Intestinal microbiota Quantitative real-time polymerase chain reaction 16S ribosomal RNA
下载PDF
上一页 1 2 3 下一页 到第
使用帮助 返回顶部