1,720,958 research outputs found
Impact of Bukit Dua Belas rainforest transformation to oil palm plantation on phylogenetic of soil bacterial communities in Sarolangun, Jambi, Sumatra, Indonesia
No full textAbstract. Wijayanti M, Wahyudi AT, Yuhana M, Engelhaupt M, Meryandini A. 2019. Impact of Bukit Dua Belas rainforest transformation to oil palm plantation on phylogenetic of soil bacterial communities in Sarolangun, Jambi, Sumatra, Indonesia. Biodiversitas 20: 811-818. Land use change from forest to oil palm plantation at Sumatra could decrease biodiversity, including bacterial diversity. The case of Bukit Dua Belas transformation from forest to oil palm plantation was gotten for measuring shift community of soil bacterial in both areas. The diversity of bacterial communities from rainforest and oil palm plantation topsoil in Sumatra was studied using pyrosequencing of 16S rRNA gene and common biodiversity indices. Phylogenetic approach was used to reveal the community shift of bacterial phyla and genera in both areas. Ecological approach was carried out by measuring soil pH, TC (total carbon), TN (total nitrogen), AP (available phosphorous), bacterial diversity with Shannon and Simpson indices, and bacterial richness with Chao1-ACE index and OTUs. Bacterial diversity and richness on lowland forest topsoil and oil palm plantation soil were not different, as soil pH, TC, and TN as substrate factors were not different significantly. The majority of sequences related to Acidobacteria (56.33%), Proteobacteria (27.43%), Actinobacteria (7.11%), and Cyanobacteria (5.55%) were from forest; whereas those related to Acidobacteria (50.11%), Proteobacteria (31.63%), Actinobacteria (7.58%), Chloroflexi (2.60%), and Gemmatimonadetes (2.71%) invented from oil palm plantation. Acidobacteria was the most dominant phyla in both habitats, because soil pH in both areas was acidic (3.77 - 4.80 pHH2O). The genera of alpha-proteobacteria dominated in genera phylotype of bacterial 16S rRNA phylogenetic revealed in both forest and oil palm plantation topsoil. The most genera in phylogenetic tree are Burkholderia from Beta-proteobacteria. The bacterial community shift occurred in forest transformation, even though the oil palm plantation showed more bacterial phyla and genera than the lowland rainforest
Identification of novel lipolytic genes and gene families by screening of metagenomic libraries derived from soil samples of the German Biodiversity Exploratories
No full textMicrobial metagenomes derived from soils are rich sources for the discovery of novel genes and biocatalysts. Fourteen environmental plasmid and seven fosmid libraries obtained from 10 German forest soils (A horizons) and six grassland soils (A and B horizons) were screened for genes conferring lipolytic activity. The libraries comprised approximately 29.3 Gb of cloned soil DNA. Partial activity-based screening of the constructed libraries resulted in the identification of 37 unique lipolytic clones. The amino acid sequences of the 37 corresponding lipolytic gene products shared 29-90% identity to other lipolytic enzymes, which were mainly uncharacterized or derived from uncultured microorganisms. Multiple sequence alignments and phylogenetic tree analysis revealed that 35 of the predicted proteins were new members of known families of lipolytic enzymes. The remaining two gene products represent two putatively new families. In addition, sequence analysis indicated that two genes encode true lipases, whereas the other genes encode esterases. The determination of substrate specificity and chain-length selectivity using different triacylglycerides and p-nitrophenyl esters of fatty acids as substrates supported the classification of the esterases.DFG [1374, DA 374/4-1]; Biodiversity Exploratories Office (BEO
How Rainforest Conversion to Agricultural Systems in Sumatra (Indonesia) Affects Active Soil Bacterial Communities
Full text linkPalm oil production in Indonesia increased constantly over the last decades, which led to massive deforestation, especially on Sumatra island. The ongoing conversion of rainforest to agricultural systems results in high biodiversity loss. Here, we present the first RNA-based study on the effects of rainforest transformation to rubber and oil palm plantations in Indonesia for the active soil bacterial communities. For this purpose, bacterial communities of three different converted systems (jungle rubber, rubber plantation, and oil palm plantation) were studied in two landscapes with rainforest as reference by RT-PCR amplicon-based analysis of 16S rRNA gene transcripts. Active soil bacterial communities were dominated by Frankiales (Actinobacteria), subgroup 2 of the Acidobacteria and Alphaproteobacteria (mainly Rhizobiales and Rhodospirillales). Community composition differed significantly between the converted land use systems and rainforest reference sites. Alphaproteobacteria decreased significantly in oil palm samples compared to rainforest samples. In contrast, relative abundances of taxa within the Acidobacteria increased. Most important abiotic drivers for shaping soil bacterial communities were pH, calcium concentration, base saturation and C:N ratio. Indicator species analysis showed distinct association patterns for the analyzed land use systems. Nitrogen-fixing taxa including members of Rhizobiales and Rhodospirillales were associated with rainforest soils while nitrifiers and heat-resistant taxa including members of Actinobacteria were associated with oil palm soils. Predicted metabolic profiles revealed that the relative abundances of genes associated with fixation of nitrogen significantly decreased in plantation soils. Furthermore, predicted gene abundances regarding motility, competition or gene transfer ability indicated rainforest conversion-induced changes as well
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
Identification and characterization of novel cellulolytic and hemicellulolytic genes and enzymes derived from German grassland soil metagenomes
Full text linkSoil metagenomes represent an unlimited resource for the discovery of novel biocatalysts from soil microorganisms. Three large-inserts metagenomic DNA libraries were constructed from different grassland soil samples and screened for genes conferring cellulase or xylanase activity. Function-driven screening identified a novel cellulase-encoding gene (cel01) and two xylanase-encoding genes (xyn01 and xyn02). From sequence and protein domain analyses, Cel01 (831 amino acids) belongs to glycoside hydrolase family 9 whereas Xyn01 (170 amino acids) and Xyn02 (255 amino acids) are members of glycoside hydrolase family 11. Cel01 harbors a family 9 carbohydrate-binding module, previously found only in xylanases. Both Xyn01 and Xyn02 were most active at 60A degrees C with high activities from 4 to 10 and optimal at pH 7 (Xyn01) and pH 6 (Xyn02). The cellulase gene, cel01, was expressed in E. coli BL21 and the recombinant enzyme (91.9 kDa) was purified. Cel01 exhibited high activity with soluble cellulose substrates containing beta-1,4-linkages. Activity with microcrystalline cellulose was not detected. These data, together with the analysis of the degradation profiles of carboxymethyl cellulose and barley glucan indicated that Cel01 is an endo 1,4-beta-glucanase. Cel01 showed optimal activity at 50A degrees C and pH 7 being highly active from pH range 5 to 9 and possesses remarkable halotolerance.DFG [DA 374/4-1, DA 374/6-1]; BEO (biodiversity exploratories office
Bacterial Communities in Aquatic Sediment from Bukit Duabelas Raintforest and Oil Palm Plantation at Sumatra Indonesia
Full text linkThe diversity of bacterial communities in aquatic sediment of rainforest and oil palm plantation at Sumatra was studied using pyrosequencing of 16S rRNA gene and common biodiversity indices. Phylogenetic approach was used for revealing the community shift of bacterial phyla and genera in both areas. Ecological approach used soil pH, total Carbon (TC), total Nitrogen (TN), available Phosphorus (AP) measurement and bacterial diversity with Shanon and Simpson indices, and bacterial richness with Chao1-ACE indices and OTUs. Bacterial diversity and richness in aquatic sediment of forest area was higher than that ones in oil palm plantation area, although their pH, TC, and TN in both areas were not different significantly. The majority of sequences related to Proteobacteria (34.85%), Acidobacteria (32.67%), Nitrospirae (6.86%), Chloroflexi (4.31%), and Actinobacteria (4.02%) were from forest; whereas those related to Acidobacteria (46.10%), Proteobacteria (25.86%), Nitrospirae (9.20%), Chloroflexi (4.99%), and Actinobacteria (2.34%) invented from oil palm plantation. The genera of Alphaproteobacteria and Betaproteobacteria dominated in genera phylotype of bacterial 16S rRNA phylogenetic revealed both aquatic sediment of forest and oil palm plantation. The most genera in the phylogenetic tree from aquatic sediment of both areas was Burkholderia. The bacterial community shift in aquatic sediment of forest transformation indicated higher bacterial diversity index, richness index, some of phyla and genera in aquatic sediment from forest than from oil palm plantation
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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