1,720,963 research outputs found
Asymmetric allele-specific expression in relation to developmental variation and drought stress in barley hybrids
No full textGenetic diversity of Pinus brutia in Syria as revealed by DNA markers
No full textRandom amplified polymorphic DNAs (RAPDs) and amplified fragment length polymorphisms (AFLPs) were used to estimate the genetic diversity between and within 21 populations of Pinus brutia collected from five different regions of Syria. After screening 400 Operon Primers, only nine were able to detect polymorphism between the tree samples. The AFLP analysis also confirmed the low genetic variability. Even after digestion of monomorphic RAPD fragments with three restriction enzymes, no increased polymorphism between samples was revealed. The total number of identified polymorphic fragments (loci) between the 311 trees was 111 (74 RAPDs and 37 AFLPs). The highest level of genetic diversity was detected in the region of Latakia and the lowest one was detected in the region of Idleb. The genetic diversity detected within populations was higher than the one detected between populations. A dendrogram based on the results of the polymorphic RAPD and AFLP fragments reflecting the genetic distance between the analyzed P. brutia populations was developed. Our results showed that the general level of genetic variability in P. brutia populations collected in Syria was low. Relative uniformity of the landscape in the North Western part of Syria might add to the low genetic variability observe
Analyse de la variabilite genetique dans le genre Helianthus a travers la structure des genes ribosomiques
No full textSIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc
Conservation of microsatellite flanking sequences in different taxa of Leguminosae
No full textTo test if locus-specific microsatellite markers designed for one genus are informative when used with related genera, the conservation of microsatellite-flanking intergeneric primer binding sites was tested in the closely related tribes Vicieae and Cicereae, from the subfamily Papilionoideae of the Leguminosae family. A total of 123 sequence-tagged microsatellite sites (STMS) markers derived from chickpea were used to amplify loci in lentil (Lens) and dry pea (Pisum). The percentage of chickpea primer binding sites conserved between the three genera was 54.4%. Hybridisation of 63 selected amplified loci to the digoxigenin-labelled oligonucleotide probe (TAA)5 showed that 69.8% of loci from dry pea and 66.6% of loci from lentil hybridised to the probe. Sequencing of amplified products from chickpea with the primer Ta176 demonstrated that one amplicon contained a microsatellite, whereas another amplicon amplified with the same particular STMS primer pair did not. Amplicons produced from lentil and pea with this primer pairs did not contain microsatellite sequences. Results obtained with Tr7, which amplified a PCR product in lentil and chickpea but not in pea, showed that microsatellite sequences were present in chickpea and absent in lentil. Similar results were obtained with Ts35, which produces amplicons in pea and chickpea; but, again, microsatellite sequences were only present in chickpea. We therefore conclude that STMS derived from chickpea could be used to detect variability between other Leguminosae genera, but it is necessary to verify whether homologous loci are revealed
Conservation and variability of sequence-tagged microsatellite sites (STMSs) from chickpea (Cicer aerietinum L.) within the genus Cicer
No full textThe conservation of 90 microsatellite-flanking sequences from chickpea in 39 accessions of eight annual and 1 accession of a perennial species of the genus Cicer was investigated. All of the primer sequences successfully amplified microsatellites in related species, indicating the conservation of microsatellite-flanking sequences in chickpea's relatives. However, the degree of conservation of the primer sites varied between species depending on their known phylogenetic relationship to chickpea, ranging from 92.2% in C. reticulatum, chickpea's closest relative and potential ancestor, down to 50% for C. cuneatum. A phylogenetic tree revealed that chickpea and the other members of its crossability group were more closely related to the perennial C. anatolicum than to other annual species of the genus. Considerable variation in size and number of amplification products between and within species was observed. Sequence analysis of highly divergent amplification products proved that variation is either due to large differences in the number of microsatellite repeats or to the amplification of a locus unrelated to the one amplified from chickpea. Sequence information and bootstrapping using PAUP suggested that STMSs derived from chickpea may be efficiently and reliably used for synteny studies in chickpea's crossability group, including C. anatolicum. However, care should be taken when applying these markers to other species of the genus. Considering the data presented here and the known historical record, the age of section Monocicer including chickpea, is estimated to be about 100,000 years
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Physiochemical Juice Characteristics of Various Citrus Species in Syria
No full textAims: The investigation of some physiochemical juice characteristics of 37 varieties of Citrus genus, maintained in the Department of Citrus Research in Tartous, Syria. Place and Duration of Study: Laboratory of Molecular Genetic, Faculty of Agriculture, Tishreen University, Lattakia, Syria, from 2011 to 2013. Methodology: Thirty seven varieties belonging to 4 groups of Citrus genus (Lemon, Sweet orange, Mandarin and Grapefruit) were used in this study. Three trees/variety, and 10 fruits/tree were used in the analysis. Fruits were harvested from trees at mature stage and juice was extracted and promptly used for physicochemical analysis. The following parameters of fruit quality were evaluated: percentage of juice/fruit, total soluble solids (TSS), pH and titratable acidity (TA) and ascorbic acid (Vitamin C) content. Results: The varieties produced the highest juice percentage were Meyer of lemon group (58.42%), Balady of sweet orange (57.61%), Ortanique from mandarin (56.10%) and Red blush of grapefruit group (49.41%). For TSS parameter, Mandarin varieties showed the highest TSS values (9.5-13.9) while Lemon varieties showed the lowest ones (6.11-7.9). Varieties of Lemon group exhibited the lowest pH values (2.21-2.46) while the highest pH value was detected in sweet orange varieties (5.94). Percentage of total acidity in citrus juice varied and ranged from 0.08g\100ml in Succary (Sweet orange group) to 5g\100ml in Eureka (Lemon group). Ascorbic acid (Vitamin C) content showed large variations within and between Citrus groups where the highest value (50.66mg\100ml) was revealed in Clementine while the lowest one (22.52mg\100ml) was found in Nova (Mandarin group). Conclusion: The citrus varieties grown in Syria showed large variations in their juice physiochemical characteristics between and within Citrus groups. The juice of all varieties was of a good quality on the base of the different studied parameters
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