Earthquake in a maze: compressional rupture branching during the 2012 M(w) 8.6 Sumatra earthquake

Seismological observations of the 2012 moment magnitude 8.6 Sumatra earthquake reveal unprecedented complexity of dynamic rupture. The surprisingly large magnitude results from the combination of deep extent, high stress drop, and rupture of multiple faults. Back-projection source imaging indicates that the rupture occurred on distinct planes in an orthogonal conjugate fault system, with relatively slow rupture speed. The east-southeast-west-northwest ruptures add a new dimension to the seismotectonics of the Wharton Basin, which was previously thought to be controlled by north-south strike-slip faulting. The rupture turned twice into the compressive quadrant, against the preferred branching direction predicted by dynamic Coulomb stress calculations. Orthogonal faulting and compressional branching indicate that rupture was controlled by a pressure-insensitive strength of the deep oceanic lithosphere.     

污水处理后的陶粒废料改良土壤的机理及农用效果

为探索陶粒废料的农业资源化处置途径,对污水处理后的陶粒废料进行电子显微镜(SEM)观察和 X 射线扫描(XRD)分析,并将陶粒废料(350 g)和土壤(1.2 kg)混合,用于华农2008糯玉米(T1处理)和珍甜1号甜玉米(T2处理)盆栽试验,与未施加陶粒废料的空白对照组 CK1、CK2进行比较,对陶粒废料改良土壤的效果、原理及其对玉米生长的影响进行研究.结果表明:污水处理后的陶粒废料含有碱性物质,表面附着有一定量的磷酸钙水合物、三斜磷钙石和磷酸氢钙钠等含磷矿物;施加陶粒废料能显著提高土壤的 pH 值,显著增加有效磷和全磷含量,其中,T1处理土壤的有效磷含量比 CK1提高27.9%,T2处理较 CK2提高了27.3%;T1处理土壤的全磷含量较CK1提高了17.7%,T2处理的较 CK2提高了14.3%;T1处理玉米的株高比 CK1提高14.5%,茎粗增大16.2%,叶面积扩大75.9%,根长增长17.2%; T2处理玉米的株高比 CK2提高23.6%,茎粗增大24.5%,叶面积扩大64.6%,根长增长24.1%,且更能促进植株的干物质积累     

钾肥对骏枣枣头枝与二次枝抗寒性的影响

以四年生直播密植骏枣树为材料,研究钾肥不同施肥时期和施肥量对枣树枣头枝和二次枝抗寒性的影响.结果表明,增施钾肥在整体上提高了骏枣枝条的抗寒能力,且枣头枝的抗寒性要大于二次枝,在果实膨大期施30kg/667m2的钾肥显著提高了骏枣枝条的过氧化氢酶活性和脯氨酸含量,同时也显著降低了骏枣枝条的丙二醛含量,为钾肥的最佳施肥方案.     

色素万寿菊中叶黄素合成相关基因的表达分析

本项研究以生产中用于杂交制种的8个色素万寿菊品种资源的花蕾期(Ⅰ)、鲜花半开期(Ⅱ)、鲜花盛开期(Ⅲ)的花瓣以及盛开期时的叶子(Ⅳ)为材料,采用实时荧光定量PCR方法,检测了叶黄素合成过程中3个相关基因lcyb(lycopene b-cyclase)、lcye(lycopene e-cyclase)和zds(ζ-carotene desaturase)在8个供试品种的不同发育时期的相对表达量。结果表明:3个基因的表达量在叶片中依次为lcyb>zds>lcye,花瓣中依次为lcye>zds>lcyb。lcye在花瓣中的表达量随花瓣的开放程度呈现先升高后降低的趋势,并在Ⅱ期达到最大值,且均高于叶片中lcye的表达量。Zds的表达趋势为Ⅱ>Ⅳ>Ⅰ>Ⅲ。Lcyb在叶中的表达高于花瓣中的任何时期。父本花瓣Ⅲ期的lcye表达量高于其他品种,且它的叶片中的lcyb的表达也高于其它品种。本项研究结果将有助于进一步阐明lcyb、lcye和zds基因与色素万寿菊叶黄素合成积累之间的关系,为进行色素万寿菊的基因工程育种奠定基础。     

广东割手密SSR遗传多样性分析

割手密是甘蔗近缘野生种之一,在甘蔗育种中具有重要地位和作用。本研究采用Genomic-SSR和EST-SSR两种类型分子标记对来自广东各个地区的67个割手密种质进行分析。在20对SSR引物上共检测到341个多态性条带,每个引物上的平均多态性为17.05,其中11个Genomic-SSR的平均多态性为20.82,9个EST-SSR的平均多态性为12.44。广东割手密在Genomic-SSR上的多态性显著高于EST-SSR上的多态性。MantelTest分析表明:通过Genomic-SSR、EST-SSR以及Genomic-SSR+EST-SSR三种方法所计算的试验材料的遗传距离矩阵之间都呈极显著相关(p<0.01),说明应用两种类型SSR获得的各个材料间的遗传关系具有较高的一致性。广东割手密在20对SSR引物上的遗传多样性指数介于0.1064~0.2916之间,平均多样性指数为0.1943;各个材料间的遗传距离为0.0063~0.3082之间,平均为0.1935。UPGMA聚类分析表明:广东割手密之间的遗传关系和地理来源存在一定的相关,由南向北存在较为显著的地理分化。     

球孢白僵菌侵染光肩星天牛幼虫的扫描电镜及组织病理观察

应用扫描电镜和组织切片法研究球孢白僵菌侵染光肩星天牛幼虫体壁的过程以及寄主中肠发生的病理变化.结果表明:接菌后48h,芽管平均长度达到3.08μm时即可侵入幼虫体表.随着侵染时间延长,芽管伸长形成菌丝,逐渐萌发生成新的分生孢子,在后期菌丝间出现丝状物和网状结构,这2种现象在国内外未见报道.分生孢子多数以芽管方式侵入表皮,也可以产生附着胞再侵染.组织切片显示:侵染3天的幼虫腹部体腔中脂肪体组织变得模糊,细胞核不明显,马氏管出现空泡并变形.中肠围食膜被分解消失,肠壁肌肉层向内皱褶,排列紊乱,出现破裂,肠腔内变浑浊.     

核果类果树中microRNAs的生物信息学预测及验证

microRNA(miRNAs)是一类非编码小分子RNA,在植物生长发育、新陈代谢以及逆境生理中起重要作用。基于生物信息学的基因搜索和同源搜索,从NCBI数据库中登录的核果类果树的EST和GSS中寻找miRNAs。从核果类果树的107982条ESTs和48273条GSSs中搜寻到了11条miRNAs前体序列,编码11条成熟体序列,并预测到19个靶基因,分别编码与生长发育、新陈代谢和转录调节等相关的蛋白。利用miRbase数据库进一步分析表明:11条miRNAs属于8个microRNA家族,分别来自桃和梅,其大小为20～23bp,其中6条为21bp,而且ppe-miR162a和ppe-miR164f保守性最高。采用poly(A)RT-PCR方法随机对预测的ppe-miR156h,pmu-miR482,ppe-miR399a,ppe-miR171a进行组织表达验证,发现ppe-miR156h在果梅花芽中表达,pmu-miR482,ppe-miR399a,ppe-miR171a在桃叶片中表达。     

The biosynthetic products of Chinese insect medicine, Aspongopus chinensis

A new oxazole (1) was obtained from Chinese insect medicine Aspongopus chinensis, along with three known N-acetyldopamine derivatives (2-4). Their structures were determined on the basis of NMR and ESI-MS analyses. The possible biosynthetic pathways of the isolated compounds are discussed. Cytotoxicities of those compounds against 10 selected cancer cells were measured in vitro.     

Development of a loop-mediated isothermal amplification assay for rapid, sensitive and specific detection of a Campylobacter jejuni clone

Loop-mediated isothermal amplification (LAMP) assay is a simple, rapid and specific detection method and has been used for detection and identification of different Campylobacter species. In this study, we develop a LAMP assay specific for detection of a particular clone (clone SA) of Campylobacter jejuni, associated with the vast majority of recent sheep abortions in the U.S. Using a set of specific primers for C. jejuni IA3902 (a clone SA isolate) and genomic DNA or boiled cell extract as template, the target DNA was amplified at 63 °C for 50 min in a water bath. A positive reaction was identified visually as white precipitate or fluorescence under UV, and confirmed by gel electrophoresis. Detection limit of the assay was comparable to that of conventional PCR. The LAMP was shown to be specific for detection of clone SA when tested on a number of C. jejuni strains of different genetic backgrounds. Applicability of the LAMP assay for specific detection of clone SA was demonstrated in animal tissues experimentally infected with IA3902 or genetically diverse C. jejuni strains. Since clone SA is the predominant cause of sheep abortions in the U.S. and is a zoonotic pathogen, the LAMP assay may be a valuable detection tool in future epidemiological studies.     

南疆麦棉间作对棉花苗期风灾防范效果研究

为探究麦棉间作预防棉花苗期风灾技术在棉花生产中的应用效果,于2021年在新疆巴音郭楞蒙古自治州尉犁县兴平乡进行示范试验,以该技术的3种种植模式(麦棉同播间作垂直风向模式、麦棉同播间作同风向模式、先麦后棉错时播种间作模式)为处理,以常规种植模式为对照,对该技术防风固沙能力和减灾保产效果进行验证.结果表明,与采取补种和重播...