1,720,964 research outputs found
Characterization of archaeal and bacterial communities thriving in methane-seeping on-land mud volcanoes, Niigata, Japan.
No full textSubmarine mud volcanoes (MVs) have attracted significant interest in the scientific community for obtaining clues on the subsurface biosphere. On-land MVs, which are much less focused in this context, are equally important, and they may even provide insights also for astrobiology of extraterrestrial mud volcanism. Hereby, we characterized microbial communities of two active methane-seeping on-land MVs, Murono and Kamou, in central Japan. 16S rRNA gene profiling of those sites recovered the dominant archaeal sequences affiliated with methanogens. Anaerobic methanotrophs (ANME), with the subgroups ANME-1b and ANME-3, were recovered only from the Murono site albeit a greatly reduced relative abundance in the community compared to those of typical submarine MVs. The bacterial sequences affiliated to Caldatribacteriota JS1 were recovered from both sites; on the other hand, sulfate-reducing bacteria (SRB) of Desulfobulbaceae was recovered only from the Murono site. The major difference of on-land MVs from submarine MVs is that the high concentrations of sulfate are not always introduced to the subsurface from above. In addition, the XRD analysis of Murono shows the absence of sulfate-, sulfur-related mineral. Therefore, we hypothesize one scenario of ANME-1b and ANME-3 thriving at the depth of the Murono site independently from SRB, which is similar to the situations reported in some other methane-seeping sites with a sulfate-depleted condition. We note that previous investigations speculate that the erupted materials from Murono and Kamou originate from the Miocene marine strata. The fact that SRB (Desulfobulbaceae) capable of associating with ANME-3 was recovered from the Murono site presents an alternative scenario: the old sea-related juvenile water somehow worked as the source of additional sulfur-related components for the SRB-ANME syntrophic consortium forming at a deeper zone of the site. However, the reason for the differences between Murono and Kamou is still unknown, and this requires further investigation
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
The Goshogake mud volcano field, Tohoku, northern Japan: An acidic, high-temperature system related to magmatic volcanism
No full textThe high-temperature (33–98 °C), highly acidic (pH 2.44–2.94) Goshogake mud volcano field in Akita Prefecture,
northern Japan, is a mud volcano system associated with the Quaternary andesitic composite volcano Akita
Yakeyama. The mud volcano features observed in Goshogake include salsa ponds, gryphons, and mud pots.
This is a rare example of mud volcano systems linked with magmatic volcanism with the full range of landforms
observed primarily in low-temperature mud volcanism in sedimentary settings. The Goshogake mud volcano
field is probably not a simple hydrothermal system related to a magmatic volcano. Instead, it appears to be a hybrid system: sedimentary volcanism linked with deep mud sources and strongly influenced by its surrounding
magmatic volcanism. The identified mineral species in the sampled mud include quartz group, hydrous silica,
muscovite, kaolinite, pyrite, and sulfur. The presence of high-temperature silica polymorphs (tridymite and
cristobalite) and/or microcrystalline opals (opal-C, opal-CT), and an amorphous form of silica (opal-A) in the
mineralogy indicates that the mud volcano system likely involves conditions and processes such as high temperature, hydrothermal circulation, dehydration reaction at certain depths underneath the Goshogake mud volcano
field. Although the source of the mud is not clearly determined, possible options include 1) hydrothermal alteration products of host rocks and sediments, 2) fine-grained sedimentary layer(s) at depth, or 3) a combination of
1) and 2). In-situ measurement of emitted gases from vents detected methane, which is possibly linked with the
organic-rich sedimentary layer(s) aside from being a product of thermodynamic equilibrium with CO2 under the
subsurface pressure-temperature conditions. The increases in δD and δ18O of water in Goshogake mud volcanoes
with respect to the values of current meteoric water indicates that the water was derived not only from meteoric
water, and deviation of the values may be explained by processes such as evaporation and mixing of other waters
from deeper sources. Regarding the driving mechanisms at the Goshogake mud volcanoes, buoyancy of muddy
sediment, high fluid pressure under overpressured or under-compacted conditions due to rapid sedimentation,
together with the presence of a gas phase in the sediment, could be key factors. Although the Goshogake mud
volcano field currently maintains a low-level activity resulting in only minor morphological changes of the
mud volcano landforms, enhanced activities have been documented in the last half century. The historical records
are inconclusive about the relationship between earthquakes and activity in the Goshogake mud volcano field
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