1,721,251 research outputs found
Microevolution of <i>Neisseria lactamica</i> during prolonged colonisation of the nasopharynx
No full textCarriage of Neisseria lactamica occurs naturally at high frequency in infants and low frequency in young adults. There is an inverse epidemiological relationship between N. lactamica carriage and disease caused by Neisseria meningitidis (meningococcus). Serogroup B meningococci remain the dominant cause of invasive meningococcal disease in the developed world and have frustrated the production of polysaccharide-conjugate vaccines. While two, recombinant, OMV based vaccines (Richmond et al., 2012; Vernikos and Medini, 2014) have been created and elicit immunological responses, they are less effective on infants (one of the groups most at risk of IMD) and have limited effect on meningococcal carriage and subsequently, on herd immunity. A human experimental challenge study in which healthy, young adult volunteers were inoculated with N. lactamica Y92-1009 showed that carriage of N. lactamica both displaced and inhibited reacquisition of wild type N. meningitidis, and although rare, co-colonization of the two species was also observed in a small number of cases (Deasy et al., 2015). This study provided the opportunity to investigate whether there is a genomic basis for N. lactamica’s effect on meningococcal carriage as the mechanism for this interaction remains unknown. Secondly, the use of whole genome sequencing, paired with mutation analysis via the breseq pipeline (Barrick et al., 2014) will comment on the mutability of N. lactamica, a potential bacterial medicine, during 6 months of in vivo, human challenge. Thirdly, this allows us to track the within-host microevolution of an identically administered commensal Neisseria spp. over the course of 6 months of carriage (chapter 5).Isolates obtained from individuals who were co-colonised by N. meningitidis and N. lactamica for a prolonged period were examined for evidence of the effect of recombination (r/m) as well as loci affected by it (chapter 6). In addition to the majority of volunteers who solo carried N. lactamica Y92-1009. Recombination was determined for; volunteers in which inoculated N. lactamica was the sole Neisseria spp. detected, seven, artificially inoculated, N. lactamica/meningococcal co-carriers and two extra volunteers who were naturally co-colonised. Using ClonalFrameML (Didelot and Wilson, 2015), we detected minimal homologous recombination events among N. lactamica Y92-1009 and no examples of interspecific allele transferred with co-colonising meningococci. In contrast, we found evidence of a dynamic, interspecific relationship and a number of recombination events occurring among co-colonised volunteers with naturally acquired Neisseria.A separate, short term clinical trial utilizing multiple colony sampling (chapter 4) examined the difference in mutational profiles of longitudinal samples N. lactamica strain Y92-1009 sourced from in vitro conditions versus in vivo conditions over one month. Larger numbers of SNPs, nonsense and recurring mutations were observed among the in vitro cohort and the quantity/diversity of phase variable mutations was more pronounced among the in vivo cohort. Chapters 4 and 5 are supported by a highly-accurate reference genome. The sequencing, assembly, annotation and characterisation of the first complete N. lactamica Y92-1009 genome is described in chapter 3 (Pandey et al., 2017). This chapter also revealed the presence of a large but uncharacterised prophage sequence in the strain. The very first example of a species encompassing, pan genomic analysis of N. lactamica (chapter 7) revealed that N. lactamica Y92-1009 possess fewer unique genes/alleles than other members of the species with no virulence factors detected among the results.In conclusion, the N. lactamica Y92-1009 genome is a self-curated system with plastic elements that (like other Neisseria spp.) could facilitate rapid changes in expression via its phase variable elements. However, it appears to have remained genetically stable during the 6-month course of carriage in human volunteers. Demonstrating little recombination, no interspecific gene transfer with co-colonising meningococci and an average mutation rate for a Neisseria species. While efforts need to be made to improve the acquisition and retention of carriage, N. lactamica appears to be a safe, naturally competent, potential bacterial therapeutic, capable of a broadspectrum reduction of meningococcal carriage.<br/
sj-docx-1-hol-10.1177_09596836241236347 – Supplemental material for A high-resolution record of Mid- to Late-Holocene environmental changes from a land-locked lake in Schirmacher Oasis, East Antarctica
No full textSupplemental material, sj-docx-1-hol-10.1177_09596836241236347 for A high-resolution record of Mid- to Late-Holocene environmental changes from a land-locked lake in Schirmacher Oasis, East Antarctica by GS Joju, Anish Kumar Warrier, BS Mahesh, AS Yamuna Sali, Cheryl A Noronha-D’Mello, K Balakrishna and Rahul Mohan in The Holocene</p
A REVIEW ON THE STATE OF THE ART IN WIRE ELECTRIC DISCHARGE MACHINING (WEDM) PROCESS
No full textANISH KUMAR 1 Dr. VINOD KUMAR 2, Dr. JATINDER KUMAR
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
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