1,721,017 research outputs found
Viruses Facilitate Energy Acquisition Potential by Their Bacterial Hosts in Rhizosphere of Grafted Plants
No full textABSTRACT Viruses alter the ecological and evolutionary trajectories of bacterial host communities. Plant grafting is a technique that integrates two species or varietiies and have consequences on the rhizosphere functioning. The grafting effects on the taxonomic and functional assembly of viruses and their bacterial host in the plant rhizosphere remain largely elusive. Using shotgun metagenome sequencing, we recover a total of 1441 viral operational taxonomic units from the rhizosphere of grafted and ungrafted plants after 8‐year continuous monoculture. In the grafted and ungrafted rhizosphere, the Myoviridae , Zobellviridae and Kyanoviridae emerged as the predominant viral families, collectively representing around 40% of the viral community in each respective environment. Grafting enriched the members in viral family Kyanoviridae , Tectiviridae , Peduoviridae and Suoliviridae , and auxiliary metabolic genes related to pyruvate metabolism and energy acquisition (e.g., gloB , DNMT1 and dcyD ). The virus–bacterial interactions increased the rapid growth potential of bacteria, which explains the strong increase in abundance of specific bacterial hosts (i.e., Chitinophagaceae, Cyclobacteriaceae and Spirosomaceae) in the grafted‐plant rhizosphere. Overall, these results deepen our understanding of microbial community assembly and ecological services from the perspective of virus–host interactions.Summary Statement 1. Grafting increased the abundance rather than the richness of viral auxiliary metabolic genes in the rhizosphere soil. 2. Viruses in the grafted plant rhizosphere increased the ability of their bacterial hosts to obtain energy. 3. Viral hosts in grafted plant rhizosphere have greater potential for rapid growth than those in ungrafted treatment.ABSTRACT Viruses alter the ecological and evolutionary trajectories of bacterial host communities. Plant grafting is a technique that integrates two species or varietiies and have consequences on the rhizosphere functioning. The grafting effects on the taxonomic and functional assembly of viruses and their bacterial host in the plant rhizosphere remain largely elusive. Using shotgun metagenome sequencing, we recover a total of 1441 viral operational taxonomic units from the rhizosphere of grafted and ungrafted plants after 8‐year continuous monoculture. In the grafted and ungrafted rhizosphere, the Myoviridae , Zobellviridae and Kyanoviridae emerged as the predominant viral families, collectively representing around 40% of the viral community in each respective environment. Grafting enriched the members in viral family Kyanoviridae , Tectiviridae , Peduoviridae and Suoliviridae , and auxiliary metabolic genes related to pyruvate metabolism and energy acquisition (e.g., gloB , DNMT1 and dcyD ). The virus–bacterial interactions increased the rapid growth potential of bacteria, which explains the strong increase in abundance of specific bacterial hosts (i.e., Chitinophagaceae, Cyclobacteriaceae and Spirosomaceae) in the grafted‐plant rhizosphere. Overall, these results deepen our understanding of microbial community assembly and ecological services from the perspective of virus–host interactions.Summary Statement 1. Grafting increased the abundance rather than the richness of viral auxiliary metabolic genes in the rhizosphere soil. 2. Viruses in the grafted plant rhizosphere increased the ability of their bacterial hosts to obtain energy. 3. Viral hosts in grafted plant rhizosphere have greater potential for rapid growth than those in ungrafted treatment
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Compositional variations of active autotrophic bacteria in paddy soils with elevated CO2 and temperature
No full textElevated temperature and CO2 strongly affect the growth strategies of soil bacteria
No full textAbstract The trait-based strategies of microorganisms appear to be phylogenetically conserved, but acclimation to climate change may complicate the scenario. To study the roles of phylogeny and environment on bacterial responses to sudden moisture increases, we determine bacterial population-specific growth rates by 18 O-DNA quantitative stable isotope probing ( 18 O-qSIP) in soils subjected to a free-air CO 2 enrichment (FACE) combined with warming. We find that three growth strategies of bacterial taxa – rapid, intermediate and slow responders, defined by the timing of the peak growth rates – are phylogenetically conserved, even at the sub-phylum level. For example, members of class Bacilli and Sphingobacteriia are mainly rapid responders. Climate regimes, however, modify the growth strategies of over 90% of species, partly confounding the initial phylogenetic pattern. The growth of rapid bacterial responders is more influenced by phylogeny, whereas the variance for slow responders is primarily explained by environmental conditions. Overall, these results highlight the role of phylogenetic and environmental constraints in understanding and predicting the growth strategies of soil microorganisms under global change scenarios
DNA Stable-Isotope Probing Delineates Carbon Flows from Rice Residues into Soil Microbial Communities Depending on Fertilization
No full textDispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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