oalib
匹配条件: “” ,找到相关结果约100条。
列表显示的所有文章,均可免费获取
第1页/共100条
每页显示
Ophiostomatoid fungi associated with Ips typographus (L.) on Picea abies [(L.) H. Karst.] and Pinus sylvestris L. in north-eastern Poland
Robert Jankowiak,Jacek Hilszczański
Acta Societatis Botanicorum Poloniae , 2005, DOI: 10.5586/asbp.2005.043
Abstract: This study dealt with the species distribution and frequency of ophiostomatoid fungi associated with the bark beetle Ips typographus on Norway spruce and Scots pine in north-eastern Poland. At all locations high spruce bark beetle damage has occurred in 2002-2003. Fungi were isolated from beetles and from brood systems of trees infested by the spruce bark beetle. The ophiostomatoid fungi were represented by 13 species. A similar spectrum of ophiostomatoid fungi as that recorded from Picea abies was associated with I. typographus on Pinus sylvestris trees. The most frequent ophiostomatoid species isolated from beetles, phloem and sapwood of Norway spruce were O. bicolor and O. penicillatum. The frequency of occurrence of ophiostomatoid fungi varied significantly among the examined locations. O. bicolor was the most frequently found species on Scots pine infested by I. typographus. The potential role of ophiostomatoid fungi in the epidemiology of I. typographus is discussed. Additionally, we also recorded how the ophiostomatoid fungi associated with spruce bark beetle could grow into phloem and sapwood of Pinus sylvestris trees.
Heterologous Array Analysis in Pinaceae: Hybridization of Pinus taeda cDNA Arrays with cDNA from Needles and Embryogenic Cultures of P. taeda, P. sylvestris or Picea abies  [PDF]
Leonel van Zyl,Sara von Arnold,Peter Bozhkov,Yongzhong Chen,Ulrika Egertsdotter,John MacKay,Ronald R. Sederoff,Jing Shen,Lyubov Zelena,David H. Clapham
Comparative and Functional Genomics , 2002, DOI: 10.1002/cfg.199
Abstract: Hybridization of labelled cDNA from various cell types with high-density arrays of expressed sequence tags is a powerful technique for investigating gene expression. Few conifer cDNA libraries have been sequenced. Because of the high level of sequence conservation between Pinus and Picea we have investigated the use of arrays from one genus for studies of gene expression in the other. The partial cDNAs from 384 identifiable genes expressed in differentiating xylem of Pinus taeda were printed on nylon membranes in randomized replicates. These were hybridized with labelled cDNA from needles or embryogenic cultures of Pinus taeda, P. sylvestris and Picea abies, and with labelled cDNA from leaves of Nicotiana tabacum. The Spearman correlation of gene expression for pairs of conifer species was high for needles (r2 = 0.78 − 0.86), and somewhat lower for embryogenic cultures (r2 = 0.68 − 0.83). The correlation of gene expression for tobacco leaves and needles of each of the three conifer species was lower but sufficiently high (r2 = 0.52 − 0.63) to suggest that many partial gene sequences are conserved in angiosperms and gymnosperms. Heterologous probing was further used to identify tissue-specific gene expression over species boundaries. To evaluate the significance of differences in gene expression, conventional parametric tests were compared with permutation tests after four methods of normalization. Permutation tests after Z-normalization provide the highest degree of discrimination but may enhance the probability of type I errors. It is concluded that arrays of cDNA from loblolly pine are useful for studies of gene expression in other pines or spruces.
Resentment and History in the Scottish Enlightenment  [cached]
Neil Hargraves
Cromohs (Firenze) , 2009,
Abstract: This article explores the ways in which Scottish Enlightenment writers such as Lord Kames, Adam Smith, David Hume and William Robertson used the concept of ‘resentment’ as a means of understanding and, hopefully, taming the Scottish past. It argues that historical narrative was crucial to the process of analyzing the role of the passions in human relations, and that while it drew on the developing social theory of the Scottish Enlightenment, it also provided a distinctive and nuanced account of the various operations of resentment that more theoretical formulations could not adequately represent.
Characterization of variable EST SSR markers for Norway spruce (Picea abies L.)
Silvia Fluch, Agnes Burg, Dieter Kopecky, Andreas Homolka, Nadine Spiess, Giovanni G Vendramin
BMC Research Notes , 2011, DOI: 10.1186/1756-0500-4-401
Abstract: SSR sequences were identified by analyzing 14,022 publicly available EST sequences. Tri-nucleotide repeat motifs were most abundant in the data set followed by penta- and hexa-nucleotide repeats. Specific primer pairs were designed for sixty loci. Among these, 27 displayed polymorphism in a testing population of 16 P. abies individuals sampled across Austria and in an additional screening population of 96 P. abies individuals from two geographically distinct Austrian populations. Allele numbers per locus ranged from two to 17 with observed heterozygosity ranging from 0.075 to 0.99.We have characterized variable EST SSR markers for Norway spruce detected in expressed genes. Due to their moderate to high degree of variability in the two tested screening populations, these newly developed SSR markers are well suited for the analysis of stress related functional variation present in Norway spruce populations.Natural populations of Picea abies L. (Norway spruce) are found from north-western Europe outside permafrost areas down to northern Greece, westwards to the Massif Central (France) and east to the Ural Mountains. Picea abies is growing above 400-500 m and ascends close to 2000 m in the Alps. Studies on genetic variation based on allozymes have shown that Picea abies genetic differentiation among populations is rather low over its whole distribution range [1,2]. Previous studies on the genetic structure of P. abies using organelle markers showed pronounced differentiation between north-east boreal origins and areas in the central European mountains [3,4], supporting the hypothesis of two distinct main glacial refugia as postulated from pollen data [5].Initial reports on the occurrence of SSRs in conifers such as Pinus radiata [6], Pinus sylvestris [7] or Picea abies [8] have shown that marker development for such complex genomes is difficult. Frequently several DNA fragments in addition to the expected ones are amplified when using primers flanking putative SSR regio
The Second Scottish Otter Survey  [cached]
Green R.,Green J.
IUCN Otter Specialist Group Bulletin , 1988,
Abstract: The results of the second Scottish otter survey are modestly encouraging and parallel indications of a similar, modest improvement in status in Wales and parts of England. However, in all the areas of apparent improvement the otter probably remains a rather scarce animal whilst environmental change continues to affect otter habitat in an unplanned and sometimes explosive fashion. Of particular concern in Scotland at present is the extension of blanket forestry into wetland habitats in the north and the rapid development of a marine fish farm industry amongst the finest otter habitat in Britain.
On Scottish Book Problem 157  [PDF]
Kevin Beanland,Paul Humke,Trevor Richards
Mathematics , 2015,
Abstract: This paper describes our hunt for the solver of Problem 157 in the Scottish Book, a problem originally posed by A.~J. (Gus) Ward in 1937. We first make the observation that a theorem of Richard O'Malley from 1975 yields an immediate positive solution. A further look at O'Malley's references revealed a 1970 paper by Donald Ornstein that we now believe contains the first solution of {\em SB 157}. We isolate the common elements in the machinery used by both Ornstein and O'Malley and discuss several consequences. We also examine an example function given by Ornstein. There are some difficulties with this function but we provide a fix, and show moreover that functions of that kind are typical in the sense of the Baire category theorem.
Mitragyna ciliata and its trypanocidal activity
HA Ogbunugafor, VI Okochi, J Okpuzor, T Adedayo, S Esue
African Journal of Biotechnology , 2007,
Abstract: The trypanocidal activity of different fractions of hydroethanolic root extract of Mitragyna ciliata Aubrev and Pellegr (Rubiaceae) were evaluated in rats infected with Trypanosoma brucei field isolates from a cow. Oral administration of the fractions at a dose of 100 mg/kg for 5 days (10 days post-infection) indicated that only butanol fraction showed trypanocidal activity with inhibition percent of 68.68. The activities of oxidative stress enzymes; superoxide dismutase (SOD) and catalase in the infected rats were determined. SOD activity was significantly higher than control (1.64 ± 0.026 I/U) in all fractions except ethyl acetate (1.56 ± 0.031 I/U). Catalase showed a significant decrease in activity in butanol (2.05 ± 0.015 I/U) and chloroform (2.18 ± 0.061 I/U) fractions compared to control (2.30 ± 0.015 I/U). Butanol fraction might have affected the redox equilibrium of the infected animals causing oxidative stress to the parasites. This is the basis of inhibition of growth of the parasites by the butanol fraction.
Trypanocidal efficacy of diminazene in diabetic rats  [PDF]
U. S. Chigozie,A. B. Maduka,J. G. Ifeanyi
Iraqi Journal of Veterinary Sciences , 2012,
Abstract: The experiment was conducted to investigate the impact of hyperglycaemia on the trypanocidal efficacy of diminazene aceturate. Groups of alloxan-induced diabetic rats infected with T. brucei and T. congolense were treated with diminazene aceturate, and trypanocidal effects compared with normal non-diabetic controls. Results showed that the prepatent period was shorter in the diabetic (11.25±1.65 days) than non-diabetic-T. congolense (15.0±1.73 days), and also variations in responses to the trypanocidal therapy between the diabetic and non-diabetic groups were detected. Parasite clearance time did not differ significantly between the diabetic and non-diabetic (43.2±8.89 versus 52.8±8.89 hours in T. brucei and 33.6±5.9 versus 36.0±6.93 hours in T. congolense, respectively). The relapse intervals were shorter in the diabetic than non-diabetic (16 days versus 23 days in T. brucei, and 7 days versus 14 days in T. congolense, respectively). Proportion of relapses was greater in the diabetic- (100%) than non-diabetic-T. congolense (66.7%). We also find parasite species-related differences in susceptibility to the trypanocide, with a higher apparent cure rate in the T. brucei than T. congolense group. We conclude from the results of this study that the chemotherapeutic effectiveness of diminazene aceturate may be diminished in patients with diabetes mellitus. Further study is needed to validate this hypothesis.
Trypanocidal Activity of Marine Natural Products  [PDF]
Amy J. Jones,Tanja Grkovic,Melissa L. Sykes,Vicky M. Avery
Marine Drugs , 2013, DOI: 10.3390/md11104058
Abstract: Marine natural products are a diverse, unique collection of compounds with immense therapeutic potential. This has resulted in these molecules being evaluated for a number of different disease indications including the neglected protozoan diseases, human African trypanosomiasis and Chagas disease, for which very few drugs are currently available. This article will review the marine natural products for which activity against the kinetoplastid parasites; Trypanosoma brucei brucei, T.b. rhodesiense and T. cruzi has been reported. As it is important to know the selectivity of a compound when evaluating its trypanocidal activity, this article will only cover molecules which have simultaneously been tested for cytotoxicity against a mammalian cell line. Compounds have been grouped according to their chemical structure and representative examples from each class were selected for detailed discussion.
Trypanocidal activity of Meliaceae and Rutaceae plant extracts
Ambrozin, Alessandra Regina Pepe;Vieira, Paulo Cezar;Fernandes, Jo?o Batista;Silva, Maria Fátima das Gra?as Fernandes da;Albuquerque, Sérgio de;
Memórias do Instituto Oswaldo Cruz , 2004, DOI: 10.1590/S0074-02762004000200020
Abstract: the in vitro trypanocidal activity of 22 extracts and 43 fractions of plants belonging to the families meliaceae and rutaceae was evaluated. the extracts from leaves of conchocarphus heterophyllus and branches of trichilia ramalhoi were the most active. the trypanocidal activity seems to be increased by fractionation of the extracts. fractions from c. heterophyllus and galipea carinata were the most active and a 100% lysis of the parasites was observed for five fractions. from one of them were isolated two flavonoids: flavone and 7-methoxyflavone, which showed weak trypanocidal activity. the results obtained from the extracts and fractions revealed that the order rutales is a promising source for the search of new drugs for chagas disease. phytochemical studies with the other active fractions are underway in order to isolate compounds, which could be associated with observed activities.
第1页/共100条
每页显示


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.