Major factors controlling late Pleistocene to Holocene soil development in the Vesuvius area (southern Italy)     

F. Scarciglia  V. Zumpano  R. Sulpizio  F. Terribile  I. Pulice  M. F. La Russa 《European Journal of Soil Science》2014,65(4):406-419

In this paper the role of time and late Pleistocene to middle Holocene climate changes in the Somma‐Vesuvius volcano foothill (southern Italy) is investigated with a multidisciplinary approach. Four volcanic soils inter‐layered between five well‐known and well‐dated primary tephra layers were characterized. Chronological constraints were provided by the pyroclastic layers identified in the field (Pomici di Base, Pomici Verdoline, Agnano Pomici Principali, Mercato and Avellino), ranging between 22 and 3.8 thousand years (ka) before present (BP). These represent products of explosive eruptions of Somma‐Vesuvius and the Phlegrean Fields. Another pyroclastic layer (Agnano Monte Spina) from the Phlegrean Fields was also identified, and other ash layers previously unknown in the Somma‐Vesuvius stratigraphy. These were characterized with SEM‐EDS analyses, and correlated with other eruptions from the Phlegrean Fields (Soccavo 4‐5 and Tufi Biancastri) around 12 and 21 ka BP, respectively, thus resulting in further time constraints for phases of soil development. A detailed characterization of the four pedons integrated morphological, physical, chemical, mineralogical and micromorphological analyses. Soil features were interpreted in terms of dominant genetic processes and environmental conditions. The extent of soil development, assessed with pedogenetic indices and the degree of weathering of primary pumices, was only in part consistent with time‐spans of soil formation, suggesting a more important role of climate than soil age. The different extents of expression of andic properties, pumice weathering and varying clay mineralogy allowed us to relate changes to the main climatic phases that occurred during the late Pleistocene to the mid Holocene.  相似文献   

Thermographic Assessment of Saddles Used on Jumping Horses     

Tiago Z. Arruda  Karin Erica Brass  Flavio D. De La Corte 《Journal of Equine Veterinary Science》2011,31(11):625-629

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Evidence that the 36 kb plasmid of Brachyspira hyodysenteriae contributes to virulence     

La T  Phillips ND  Wanchanthuek P  Bellgard MI  O'Hara AJ  Hampson DJ 《Veterinary microbiology》2011,153(1-2):150-155

Swine dysentery (SD) results from infection of the porcine large intestine with the anaerobic intestinal spirochaete Brachyspira hyodysenteriae. Recently the genome of virulent Australian B. hyodysenteriae strain WA1 was sequenced, and a 36 kilobase (kb) circular plasmid was identified. The plasmid contained 31 genes including six rfb genes that were predicted to be involved with rhamnose biosynthesis, and others associated with glycosylation. In the current study a set of PCRs was developed to amplify portions of nine of the plasmid genes. When used with DNA extracted from virulent strain B204, PCR products were generated, but no products were generated with DNA from avirulent strain A1. Analysis of the DNA using pulsed field gel electrophoresis (PFGE) identified a plasmid band in strains WA1 and B204, but not in strain A1. These results demonstrate that strain A1 does not contain the plasmid, and suggests that lack of the plasmid may explain why this strain is avirulent. To determine how commonly strains lacking plasmids occur, DNA was extracted from 264 Australian field isolates of B. hyodysenteriae and subjected to PCRs for three of the plasmid genes. Only one isolate (WA400) that lacked the plasmid was identified, and this absence was confirmed by PFGE analysis of DNA from the isolate and further PCR testing. To assess its virulence, 24 pigs were experimentally challenged with cultures of WA400, and 12 control pigs were challenged with virulent strain WA1 under the same conditions. Significantly fewer (P=0.03) of the pigs challenged with WA400 became colonised and developed SD (13/24; 54%) compared to the pigs infected with WA1 (11/12; 92%). Gross lesions in the pigs colonised with WA400 tended to be less extensive than those in pigs colonised with WA1, although there were no obvious differences at the microscopic level. The results support the likelihood that plasmid-encoded genes of B. hyodysenteriae are involved in colonisation and/or disease expression.  相似文献   

An oxygen monitoring and control system inside a malaxation machine to improve extra virgin olive oil quality     

Pietro Catania  Mariangela Vallone  Felice Pipitone  Paolo Inglese  Giuseppe Aiello  Giada La Scalia 《Biosystems Engineering》2013,114(1):1-8

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International Relations Committee Report     

R. L. Sawyer  John Niederhauser  Fermin De La Puente  R. V. Akeley  Homer Erickson  Ora Smith 《American Journal of Potato Research》1969,46(12):474-476

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农杆菌介导大豆未成熟子叶的遗传转化   总被引：2，自引：2，他引：2  

王萍  王罡  季静  周智明  郭威  拉巴  吴颖 《大豆科学》2004,23(2):86-90

用农杆菌LBA4404(pGBI121S4ABC)转化5个大豆品种的未成熟子叶,经卡那霉素筛选得到抗性植株,进一步用PCR检测,获得10株PCR阳性植株.同时发现,不同大豆品种农杆菌转化的效率是不同的,吉林43较易于转化;共培养时间是影响转化效率的主要因子.  相似文献   

灌区蓝绿水资源与作物生产水足迹多时空分布量化分析   总被引：2，自引：1，他引：1  

高洁  吴普特  谢朋轩  卓拉 《农业工程学报》2021,37(5):105-112

作物生产水足迹度量作物生产过程对不同类型水资源的消耗,为实现农业水资源管理与评价提供了更全面的新视角。该研究通过耦合土壤水分动态平衡模块,考虑输配水损失,构建灌区蓝、绿水资源与作物生产水足迹多时间尺度分布式量化模型;以宝鸡峡灌区为例,定量评价不同典型年灌区蓝绿水资源与作物生产水足迹多时间尺度演变规律。结果表明:宝鸡峡灌区蓝绿水资源总量在2008-2017年呈上升趋势。各作物对绿水资源利用效率均持续上升,而小麦蓝水资源利用效率呈下降趋势;玉米、小麦生产总水足迹整体呈上升趋势,多年平均值分别为573和779 m3/t;作物生产绿水足迹在拔节-灌浆期占比较高,成熟期占比较低;作物生产水足迹在日尺度波动幅度最大;平水年、丰水年灌区用水存在不合理现象,枯水年作物生产单产水平最高,总水足迹最低,水资源利用效率最高。该研究所构建模型可移植适用于无排水渠系灌区水文模拟,准确量化灌区农业生产耗水,解析日-月尺度作物生产水足迹演变特征,有助于明确灌区作物耗水规律,进而高效利用绿水资源,合理配置蓝水资源,提高作物产量,实现高效生产。  相似文献   

西藏地区油菜遗传改良     

萨如拉  拉巴扎西 《西藏农业科技》2008,30(4):41-43

分析了西藏未来油菜遗传改良趋势及其以后的发展思路;还提出了西藏油菜科研工作中存在的主要问题及其解决的措施。  相似文献   

新侵入害虫蔗扁蛾的寄主范围正在扩大   总被引：8，自引：0，他引：8  

张古忍  古德祥  刘秀玲  李秋剑  刘南欣 《植物保护学报》2000,27(3):283-284

蔗扁蛾Opogona sacchari (Bojer)是一种新传入我国的重要检疫害虫,给花卉生产、园林绿化和华南的经济作物生产造成严重威胁。该虫属鳞翅目Lepidoptera,辉蛾科Hieroxestidae,扁蛾属Opogona,广谱钻蛀性贪食者,已记载的寄主植物达22科49种,其中主要包括一些名贵观赏植物如巴西木[香龙血树Dracena fragrans(L.)]、发财树和经济作物如甘蔗、香蕉等。该虫在南美巴巴多斯为害甘蔗的程度超过蔗螟Diatraea saccharalis,在非洲加那利群岛对香蕉造成毁灭性为害。因此,许多国家将其列为重要的检疫对象。我国1997年正式报道在北京发现此虫,虫源是广州北运的巴西木。笔者在广州及其附近县市的初步调查表明,该虫除主要为害巴西木和发财树外,其寄主范围已扩大至  相似文献   

5%氯氰碘柳胺钠颗粒剂的研制和驱除效果试验   总被引：2，自引：0，他引：2  

吴钦斌  张耀生 《中国兽医寄生虫病》2000,8(1):8-10

采用添加ＰＶＰ粘合剂制备５％氯氰碘柳钠颗粒剂、方法回收率,线性试验及稳定性试验,该制剂符合质量标准。临床药效试验表明,当以１０ｍｇ／ｋｇ体重剂量投服,对绵羊肝片吸虫,前后盘吸虫,肺丝虫及体内外大部分消化道线虫有完全的驱杀作用,是羊驱虫的最佳肝片吸虫,前后盘吸虫,肺丝虫及体内外大部分消化道红虫有完全的驱杀作用,是羊驱虫的最佳使用剂量。该制剂为国内兽药首创剂型,具有广谱驱虫效果,且安全,适口性好,易于  相似文献