Efforts to Explain and Control the Prolonged Thermophilic Period in Two-phase Olive Oil Mill Sludge Composting

The aim of this paper was to evaluate the use of different bulking agents in different ratios as a means to control, optimise and eventually reduce the duration of the thermophilic period in two-phase olive oil mill sludge (OOMS) composting. The bulking agents used were: (i) olive tree leaves (OTL), (ii) olive tree shredded branches (OTB) and (iii) woodchips (WDC). The selection of these materials was based on their abundance and availability on the island of Crete, the southernmost point of Greece. The ratios studied were: Pile 1, OOMS:OTL in 1:1 v/v; Pile 2, OOMS:WDC in 1:1.5 v/v; Pile 3, OOMS:OTL in 1:2 v/v; Pile 4, OOMS:OTL:OTB in 1:1:1 v/v; and Pile 5, OOMS:OTL:OTB in 1:1:2 v/v. The composting system used was that of windrows with the volume of each pile approximately 20–25 m³. The experiments took place over two consecutive years. A composting turner was used and turnings were performed at one and two week intervals. In each pile a variety of physiochemical parameters were monitored. Temperature remained high in all five trials. Piles 1, 2, 3, 4 and 5 temperatures recorded values of above 50 °C for 106, 158, 160, 175 and 183 days, respectively. Volumes were reduced by approximately 67%, 62%, 63%, 80% and 84%, respectively. Temperature remained high, mainly due to the presence in large amounts of oily substances which during their complete oxidation release important amounts of energy and aid the cometabolism of more stable molecules such as lignin. This process is better described as the slow “burning” of a “fuel” mixture in an “engine” than composting. This approach is based on the extensive similarities of this process to that of crude oil sludge or similar waste composting.     

小桐子枝叶提取物对植物病原真菌的生物活性

采用菌丝生长抑制法,测定了小桐子枝叶6种不同溶剂提取物对小麦赤霉病菌、稻瘟病菌、烟草疫霉菌和辣椒疫霉菌的抑制作用,从中筛选出抑制作用最强的粗提物进行进一步的活性组分分离和抑菌活性测定。结果表明小桐子枝叶的乙醇提取物对4种植物病原菌抑制活性最高,在浓度为0.8 g·L^-1时,小桐子枝叶的乙醇提取物对小麦赤霉病菌、稻瘟病菌、烟草疫霉菌、辣椒疫霉菌菌丝生长抑制率分别为：87.1%、90.3%、86.4%、77.9%,其抗菌活性与农药世高均无显著差异;在小桐子枝叶乙醇提取物的不同溶剂萃取物对稻瘟病菌和烟草疫霉病菌进行生物活性追踪测试中发现,石油醚和水萃取物都具有较好的活性,当浓度为0.8 g·L^-1时,石油醚和水萃取物对两种病菌抑制率都达50%以上。表明小桐子枝叶含有丰富的抗植物病原真菌活性物质,且主要存在于小桐子枝叶乙醇提取物的石油醚相和水相中。     

Inducible recombination in the cardiac conduction system of minK: CreERT² BAC transgenic mice

Inducible Cre recombination is a powerful technology that allows for spatial and temporal modulation of gene expression in vivo. Diseases of the cardiac conduction system (CCS) pose a significant clinical burden but are not currently well understood at the molecular level. To enable inducible recombination in the murine CCS, we created a minK:CreERT(2) bacterial artificial chromosome (BAC) transgenic mouse line. Cre activity is present after tamoxifen administration in the atrioventricular (AV) node, AV bundle, and bundle branches of adult transgenic mice. We anticipate that by enabling inducible recombination specifically in the AV node, bundle, and bundle branches, minK:CreERT(2) BAC transgenic mice will prove useful in advancing our understanding of CCS disease and function.     

大豆全基因组分枝相关基因发掘及与QTL共定位

大豆(Glycine max)分枝在个体和群体水平上均与大豆产量关系密切, 因此大豆分枝相关基因的发掘及利用对大豆高产分子育种具有重要意义。文章通过GO(Gene ontology)分类和文献检索共获得植物分枝发育相关基因183个。基于序列相似和结构域相同的原则, 从大豆基因组中发掘出大豆分枝相关的候选基因406个。通过收集已发表的大豆分枝相关QTL, 利用BioMercator2.1软件, 将符合映射条件的35个QTL映射到公共图谱的12个染色体。通过共定位分析发现, 在20个分枝相关的QTL区间内存在大豆分枝相关候选基因57个。本文发掘的分枝发育相关基因信息为大豆分枝相关QTL的精细定位和克隆以及大豆分枝发育的分子生物学基础研究提供了参考。     

Sublepidodendron grabaui comb. nov., a lycopsid from the Upper Devonian of China

Sublepidodendron wusihense (Sze) Sze and Lepidostrobus grabaui Sze were based on compressions from the upper part of the Wutung Formation (Famennian) of Jiangsu, South China. After studying the morphology and anatomy of abundant well-preserved specimens from two localities, Sublepidodendron wusihense and Lepidostrobus grabaui are reconsidered and viewed as Sublepidodendron grabaui (Sze) comb. nov. This plant is an arborescent, heterosporous lycopsid known from trunk, branches and cones. Leaf bases are spirally arranged, fusiform in outline, with a vascular bundle scar and keel. One specimen is known with a cone attached at the tip of a distal branch. The trunk has an intrastelar parenchyma concentration (pith), exarch primary xylem and secondary xylem. The branch anatomy varies from exarch primary xylem with a small, centrally located pith, to a solid exarch primary xylem strand. Based on the morphology and anatomy of both vegetative and reproductive organs, Sublepidodendron grabaui is placed into Sublepidodendraceae ( sensu Kräusel & Weyland, 1949), and Isoëtales ( sensu DiMichele & Bateman, 1996).  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 149 , 299–311.     

多学科交叉下工科院校微生物学实验教学改革初探

微生物学是生物类专业举足轻重的基础学科,而微生物学的实验方法和技术手段更是微生物学建立和发展的基础。生命科学的不断发展也离不开微生物学。工科院校微生物学科旨在培养应用型研发人才,因此必须提高教师自身的实验素养,不断优化实验内容,基于学科交叉将科研课题融入实验教学中,培养学生的科研思维,为社会打造学科交叉创新型实验人才。     

中国长蠕孢属的分类研究II. 四川省的两个新种

报道生于四川省枯树枝上的长蠕孢属两个新种,假喙长蠕孢Helminthosporiumspurirostrum和四川长蠕孢Helminthosporiumsichuanense。假喙长蠕孢的分生孢子可产生假喙,这是首次报道长蠕孢属的一个新的特征。四川长蠕孢与黄檀长蠕孢H.dalbergiae较相似,但是黄檀长蠕孢的分生孢子大(长58-125靘,宽12-14靘),分生孢子梗细(宽10-12靘)。研究标本保存在山东农业大学植物病理学标本室(HSAUP)。     

Mechanical stresses of primary branches: a survey of 40 woody tree and shrub species

Land plants have evolved a large number of growth forms and each plant species has a unique morphology. For many tall plants, main stems serve the function of vertical growth while primary and higher order branches are responsible for lateral growth for greater light interception. Herein we search for a mechanical constant for primary branches. Primary branches were sampled from 40 species of trees and shrubs. Among the species sampled, branch lengths ranged from 1.8 to 12.2 m, weights from 0.056 to 16.6 kg, base diameters from 17 to 150 mm, bending moments from 7.1 to 2,200 N-m, and section moduli from 0.039 to 29.0 × 10⁻³ m³. Primary branches of all 40 tree and shrub species exhibited relatively constant bending stresses along each branch. Moreover stress values among the 40 species were relatively constant at about 11 MPa (mean = 11.1 MPa [range 5.2–18.9]; standard deviation = 3.3 MPa). Furthermore, primary branches without secondary branches attached (1) had similar bending moment distributions as tapered cantilever beams, (2) exhibited relatively constant slope values of stress versus length among all species (stresses increased linearly with length), and (3) exhibited both relatively constant density and relatively constant taper within each species. We conclude that the relatively constant stress of about 11 MPa of primary branches was due solely to the numbers, weights, and distributions of secondary branches and associated higher order branches along primary branches for the 40 plant species. To our knowledge, this is the first publication that shows a unifying mechanical constant for primary branches of plants.

The cytochrome b gene as a phylogenetic marker: the limits of resolution for analyzing relationships among cichlid fishes

The mitochondrial cytochrome b (cyt-b) gene is widely used in systematic studies to resolve divergences at many taxonomic levels. The present study focuses mainly on the utility of cyt-b as a molecular marker for inferring phylogenetic relationship at various levels within the fish family Cichlidae. A total of 78 taxa were used in the present analysis, representing all the major groups in the family Cichlidae (72 taxa) and other families from the suborders Labroidei and Percoidei. Gene trees obtained from cyt-b are compared to a published total evidence tree derived from previous studies. Minimum evolution trees based on cyt-b data resulted in topologies congruent with all previous analyses. Parsimony analyses downweighting transitions relative to transversions (ts1:tv4) or excluding transitions at third codon positions resulted in more robust bootstrap support for recognized clades than unweighted parsimony. Relative rate tests detected significantly long branches for some taxa (LB taxa) which were composed mainly by dwarf Neotropical cichlids. An improvement of the phylogenetic signal, as shown by the four-cluster likelihood mapping analysis, and higher bootstrap values were obtained by excluding LB taxa. Despite some limitations of cyt-b as a phylogenetic marker, this gene either alone or in combination with other data sets yields a tree that is in agreement with the well-established phylogeny of cichlid fish. Received: 11 October 2000 / Accepted: 26 February 2001