Converting conventional agriculture to poplar bioenergy crops: soil greenhouse gas flux

Conversion of agricultural fields to bioenergy crops can affect greenhouse gases (GHG) such as carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O). Soil GHG emissions were measured seasonally in poplar bioenergy and agricultural fields at three Northwestern US locations. A forest stand was also used at one location for comparison. A portable gas analyzer was used to measure CO₂ efflux and CH₄ and N₂O fluxes were first measured with chambers and later with gradients. Agricultural soil had 17% larger CO₂ efflux rates than poplar soil. Chamber fluxes showed no differences in CH₄ uptake but did show higher N₂O fluxes in poplar than agricultural soil. Gradient CH₄ uptake rates were highest in agricultural soil in the summer but showed no N₂O flux differences. Forest soils had smaller quarterly CO₂ efflux rates than agricultural soils and greater CH₄ uptake rates than poplar soils. The largest GHG contributor to soil GHG flux was CO₂, with those being ～1000 times larger than CH₄ flux rates and ～500 times larger than N₂O flux rates based on CO₂ equivalences. Converting conventional agricultural cropland to poplar bioenergy production does not have adverse effects on soil greenhouse gas flux and these results could be useful for modeling or life cycle analysis of land use conversion.     

脂肪酸对奶牛乳腺上皮细胞乳蛋白和乳脂合成相关基因表达量的影响

本试验旨在探寻促进奶牛乳腺上皮细胞(BMECs)乳蛋白和乳脂合成的短链脂肪酸(乙酸、β-羟丁酸)和长链脂肪酸(油酸、亚油酸、亚麻酸)的组合添加模式,为调控乳成分合成提供理论依据。BMECs经分离、纯化后,选取第2代细胞,分为5组,对照组不添加脂肪酸,Ⅰ组和Ⅱ组添加的乙酸、β-羟丁酸浓度比例均为2.0(9.60 mmol/L)∶1.0(4.80 mmol/L),油酸、亚油酸、亚麻酸的浓度比例分别为2.0(17.30μmol/L)∶13.3(115.05μmol/L)∶1.0(8.65μmol/L)和9.6(75.20μmol/L)∶7.4(58.00μmol/L)∶1.0(7.80μmol/L);Ⅲ组和Ⅳ组添加的乙酸、β-羟丁酸的浓度比例均为1.0(7.20 mmol/L)∶1.0(7.20 mmol/L),油酸、亚油酸、亚麻酸的浓度比例分别为2.0∶13.3∶1.0和9.6∶7.4∶1.0,各组添加的短链脂肪酸(SCFA)和长链脂肪酸(LCFA)总浓度为14.541 mmol/L,每组3个重复。培养24 h后,检测细胞相对增殖率(RGR)、甘油三酯(TAG)的合成量以及乳蛋白和乳脂合成相关基因的表达量。结果表明:1)试验组BMECs RGR及TAG的合成量均显著高于对照组(P0.05);Ⅰ组RGR最高,TAG合成量最多。2)与对照组相比,Ⅱ组显著提高了核糖体蛋白S6激酶1(S6K1)、κ-酪蛋白(CSN3)基因的表达量(P0.05);Ⅳ组显著提高了CSN3、蛋白激酶B(AKT)、S6K1、真核翻译起始因子4E结合蛋白1(4EBP1)基因的表达量(P0.05);试验组信号转导和转录激活因子5(STAT5)基因的表达量显著降低(P0.05)。3)与对照组相比,试验组二酰甘油酰基转移酶2(DG AT2)基因的表达量显著提高(P0.05),脂肪酸合成酶(FASN)基因的表达量显著降低(P0.05)。综上所述,在培养液中添加7.20 mmol/L乙酸、7.20 mmol/Lβ-羟丁酸、75.20μmol/L油酸、58.00μmol/L亚油酸、7.80μmol/L亚麻酸对BM ECs乳蛋白和乳脂合成相关基因的表达量有较好的促进作用。     

Effects of Photoperiod on Stem Cells Activation in Cashmere Goat Hair Follicles

In order to extend the anagen of cashmere goat hair follicles and increase the production of cashmere,this study was performed with artificially shorten the daylight time among Arbas White cashmere goats. Skin tissue sections from cashmere goats were collected to compare the morphologic changes between artificial daylight and natural daylight,and immunohistochemical method was used to study the hair follicle cell proliferation and important protein expression in related signaling pathways. The results showed that strong cell proliferation occurred in cashmere goat hair follicle cells during artificial daylight,plenty of cytokeratin 15 (K15) positive signals were distributed in the outer root sheath,β-catenin protein was actively expressed in hair matrix and root sheath, indicating that the hair follicles were in the anagen growth phase;Meanwhile,cashmere goat hair follicles under natural daylight were in telogen with weak signals. Above all prove that short photoperiod played an important role in promoting hair follicle growth,the artificial short photoperiod could change hair follicle growth cycle and make hair follicles earlier enter to the anagen growth phase,causing a variety of typical gene expressions during hair follicle growth.     

簇毛麦6V染色体短臂特异性EST标记的开发及缺失定位

为了准确鉴定簇毛麦6VS易位染色体小片段的长度和断点位置,根据定位于小麦第6部分同源群染色体短臂不同区段的EST序列,利用PRIMER5.0软件设计PCR引物,成功开发出3个对6V染色体短臂特异的分子标记(CINAU89-740、CINAU90-730、CINAU91-390)。利用小麦和簇毛麦第六部分同源群染色体短臂的12个缺失系对簇毛麦6VS的8个特异性分子标记进行了定位。标记CINAU88-381、CINAU17-1086、CINAU15-902分别被定位在FL值为0.79~0.99、0.58~1.00、0.46~0.58的染色体区段,标记CI-NAU91-390、CINAU90-730、CINAU16-1650被定位在FL值为0.35~0.45的染色体区段,标记CINAU18-723、CINAU89-740被定位在FL值为0.00~0.45的染色体区段。利用这8个分子标记可以更准确地鉴定6VS小片段易位的断点和片段长度。     

浅谈文化在重庆三峡广场小品中的体现

园林小品是城市广场上非常重要的一部分,是广场文化的一个浓缩。从文化方面来分析园林小品在重庆三峡广场上的具体表现,将小品文化与广场文化相融合,为今后重庆广场小品设计提供借鉴。     

金针菇菇脚对肉鸡盲肠菌群及短链脂肪酸的影响

为探讨金针菇菇脚(Flammulina velutipes stembase,FVS)对肉鸡盲肠菌群及短链脂肪酸含量的影响,选用1d健康AA肉鸡270只,随机分成5个处理组,每组3个重复,每个重复18只。5个处理组分别为空白对照组(基础日粮)、抗生素阳性对照组(基础日粮+5mg/kg黄霉素)和3个FVS组(基础日粮中分别添加2%、4%和6%FVS)。在21和42d,每个重复选择3只屠宰,无菌采集盲肠内容物,提取细菌基因组总DNA,PCR扩增16srDNA V3区,采用变性梯度凝胶电泳技术结合聚合酶链式反应(PCR-DGGE)及条带的克隆测序分析盲肠细菌群的变化,同时采用聚类分析分析各试验组的多样性和相似性。用气相色谱仪检测盲肠中乙酸、丙酸、丁酸的含量。结果表明:1)与空白组相比,21和42d各FVS添加组条带数均高于空白组,且6%FVS添加组条带数显著升高(P0.05);2)与空白组相比,21和42d各FVS添加组聚类在一起,相似性系数均较高;3)21和42d,共性条带盲肠优势细菌主要是扭链胃球菌[Ruminococcus]torques、厌氧发酵产氢细菌Acetanaerobacterium elongatum、甲酸芽殖菌Gemmiger formicilis、热产琥珀酸梭菌[Clostridium]thermosuccinogenes、拟杆菌属Bacteroides sp.;而特异性条带主要是产丁酸菌Oscillibacter ruminantium、柔嫩梭菌[Clostridium]leptum、Stomatobaculum longum、解多糖梭菌[Clostridium]polysaccharolyticum、产乙醇杆菌Ethanoligenens harbinense strain YUAN-3、产丁酸盐罗氏菌Roseburia hominis、解纤维素梭菌[Clostridium]cellulolyticum strain、乳酸发酵梭菌[Clostridium]lactatifermentans等。4)与空白组相比,21和42d6%FVS添加组乙酸、丙酸、丁酸含量均显著升高,(P0.05)。以上结果提示:在肉鸡日粮中添加FVS可显著提高肉鸡盲肠菌群多样性,FVS可被有效利用产生降解多糖、纤维素和产酸的细菌,显著提高了短链脂肪酸的量,改善肠道菌的繁殖环境,改善动物肠道微生物菌群的结构,促进肉鸡健康生长。其中以6%FVS添加量效果最好。     

集成多业务的林业外业巡护系统研究与应用

集成多业务的林业外业巡护系统是指集成森林防火和生态公益林等林业多业务处理的,基于移动定位服务的,集外业移动终端和内业处理的支撑服务为一体的林业外业巡护系统。全面分析了林业各业务中与外业巡护和终端信息交互相关的业务,得出林业各业务之间进行协同作业的重要性和构建集成多业务处理的林业外业巡护系统的必要性;对系统进行了架构设计和物理部署设计,构建了集成多业务的林业外业巡护系统;提出了集成多业务林业外业巡护系统的关键技术,包括基于位置的服务（LBS）的终端信息采集技术、基于存储和转发服务（SMS）、通用分组无线服务（GPRS）的终端到各业务系统信息上传技术和基于LBS,SMS和GPRS的各业务系统到终端信息发布技术;并将以上技术及系统在云南省临沧市进行了应用实现。通过实际测试检验得出：系统的应用提高了外业巡护的工作效率,增强了业务处理的协同性,节约了林业部门的运营成本。系统是适合当前林业发展现状和符合信息化管理需求的。     

10kV架空线路常见故障及防范措施

从10kV架空线路的常见故障类型进行分析,并对10kV架空线路的反事故防范措施进行探讨,提高10kV架空线路的安全运行水平,提高供电可靠性。     

3个STR位点在中国7个民族遗传距离中的研究

应用PCR技术、质量分数4%变性聚丙烯酰胺凝胶电泳及银染技术,研究了D16S539,D7S820和D13S7133个STR位点在新疆锡伯族和哈萨克族中的遗传结构,结合汉族、黎族、朝鲜族、藏族和维吾尔族相同位点的相关遗传资料,应用亲缘系数和遗传距离研究了7个民族间的遗传关系,并根据遗传距离绘制遗传系统树。结果显示,汉族、朝鲜族、黎族、藏族和锡伯族为一群,而新疆哈萨克族和维吾尔族为一群。其中,汉族与朝鲜族遗传距离最近,其他依次为黎族、藏族和锡伯族。     

循环经济与人类社会可持续发展

循环经济是人类面临资源匮乏、环境恶化的严峻形势,为实现可持续发展而提出的.本文阐述了循环经济的涵义、循环经济与人类社会可持续发展的密切关系以及国内外循环经济的发展现状.