scholarly journals Genetic Analysis of Powassan virus Genotypes Circulating in North America [University of Findlay]

2019 ◽  
Author(s):  
Kristen Huseman ◽  
Abby L Levitt
Keyword(s):  
North America ◽  
Host Species ◽  
Evolutionary Dynamics ◽  
Genetic Recombination ◽  
Ixodes Scapularis ◽  
Geographic Location ◽  
Recombination Analysis ◽  
Phenotypic Characters ◽  
Geographical Regions ◽  
Powassan Virus

Powassan virus (POWV), a tick-borne flavivirus, is the only member of the tick-borne encephalitis serogroup found in North America. Two distinct lineages, prototype lineage (POWV, lineage I) and deer tick virus (DVT, lineage II) are maintained in enzootic transmission cycles by different tick species based on different geographical regions. In North America, Ixodes scapularis acts as the primary vector throughout the Northeast, and Ixodes cookei throughout the Midwest and much of Canada. Importantly, the incidence of human disease due to POWV has increased by 671% over the last 18 years; with DVT perhapes being the most worrisome genotype due to the wide spread range and prevalence of the vector species. The aim of this study is to assess the evolutionary dynamics of the POWV/DTV complex using the most current full-genome, envelope, and 3’UTR sequences available. Bayesian phylogenetic inferences support the two distinct, monophyletic lineages corresponding to POWV and DTV. Additional analysis were performed in order to quantify the degree to which viral phenotypic characters (such as geographic location, and host species utilization) are correlated with shared ancestry within the two different genotypes. The results of this phylogeny-trait correlation analysis suggest significant clustering of viral sequence by sample location. Such in situ evolution is compatible with the relatively limited distances traveled by most ticks and their prefered host species. Lastly, genetic recombination analysis shows no evidence of between genotype recombination, however further analysis needs to be conducted using within genotype recombination analysis as recombination events may be restricted to only closely genetically related viruses.

scholarly journals Is there an imbalance in the supply and demand for universal accessibility knowledge? Twenty years of UAIS papers viewed through the lens of WCAG

2021 ◽  
Author(s):  
Frode Eika Sandnes
Keyword(s):  
Latin America ◽  
North America ◽  
Supply And Demand ◽  
Research Focus ◽  
Universal Accessibility ◽  
Geographical Regions ◽  
Research Profile ◽  
The Impact ◽  
Over Time

AbstractPurpose: Some universal accessibility practitioners have voiced that they experience a mismatch in the research focus and the need for knowledge within specialized problem domains. This study thus set out to identify the balance of research into the main areas of accessibility, the impact of this research, and how the research profile varies over time and across geographical regions. Method: All UAIS papers indexed in Scopus were analysed using bibliometric methods. The WCAG taxonomy of accessibility was used for the analysis, namely perceivable, operable, and understandable. Results: The results confirm the expectation that research into visual impairment has received more attention than papers addressing operable and understandable. Although papers focussing on understandable made up the smallest group, papers in this group attracted more citations. Funded research attracted fewer citations than research without funding. The breakdown of research efforts appears consistent over time and across different geographical regions. Researchers in Europe and North America have been active throughout the last two decades, while Southeast Asia, Latin America, and Middle East became active in during the last five years. There is also seemingly a growing trend of out-of-scope papers. Conclusions: Based on the findings, several recommendations are proposed to the UAIS editorial board.

scholarly journals Sequence diversity and evolution of an iflavirus family associated with ticks

2020 ◽  
Author(s):  
Romain Daveu ◽  
Caroline Hervet ◽  
Louane Sigrist ◽  
Davide Sassera ◽  
Aaron Jex ◽  
...  
Keyword(s):  
Cell Line ◽  
Complete Genome ◽  
Evolutionary Dynamics ◽  
De Novo ◽  
Rna Viruses ◽  
Ixodes Scapularis ◽  
Fine Scale ◽  
Rna Seq ◽  
Strong Positive Selection ◽  
Synonymous Mutations

AbstractWe studied a family of iflaviruses, a group of RNA viruses frequently found in arthropods, focusing on viruses associated with ticks. Our aim was to bring insight on the evolutionary dynamics of this group of viruses, which may interact with the biology of ticks. We explored systematically de novo RNA-Seq assemblies available for species of ticks which allowed to identify nine new genomes of iflaviruses. The phylogeny of virus sequences was not congruent with that of the tick hosts, suggesting recurrent host changes across tick genera along evolution. We identified five different variants with a complete or near-complete genome in Ixodes ricinus. These sequences were closely related, which allowed a fine-scale estimation of patterns of substitutions: we detected a strong excess of synonymous mutations suggesting evolution under strong positive selection. ISIV, a sequence found in the ISE6 cell line of Ixodes scapularis, was unexpectedly nearidentical with I. ricinus variants, suggesting a contamination of this cell line by I. ricinus material. Overall, our work constitutes a step in the understanding of the interactions between this family of viruses and ticks.

scholarly journals IASL Conferences

2021 ◽  
Author(s):  
Paulette Stewart
Keyword(s):  
Professional Development ◽  
Geographic Location ◽  
Quantitative Approach ◽  
Pull Factors ◽  
Push And Pull Factors ◽  
Face To Face ◽  
Geographical Regions ◽  
Push And Pull

There are many reasons for librarians’ attendance at professional conferences and equally many why their attendance is either regular or irregular. This research was conducted to find out the push and pull factors that affected members’ attendance at annual conferences from 1998-2010. It also sought to ascertain whether virtual conferences would be accepted as an alternative to face-to-face conferences. A quantitative approach was used to conduct the research. Four hundred-fifty five members were randomly selected as the sample. Eighty-eight (88) responded. The findings revealed that participants attended mainly for professional development and only a very small number attended regularly over the 13 years. The main reason identified for the irregular attendance was the geographic location. A slight majority mentioned that they would recommend virtual conferences although there were disadvantages. Among the recommendations was the need for IASL to group countries by geographical regions to give members a better opportunity to attend more regularly.

scholarly journals Mammal body size evolution in North America and Europe over 20 Myr: similar trends generated by different processes

2017 ◽  
Vol 284 (1849) ◽  
pp. 20162361 ◽  
Author(s):  
Shan Huang ◽  
Jussi T. Eronen ◽  
Christine M. Janis ◽  
Juha J. Saarinen ◽  
Daniele Silvestro ◽  
...  
Keyword(s):  
Body Size ◽  
North America ◽  
Biological Properties ◽  
Species Selection ◽  
Minimum Size ◽  
Extinction Rate ◽  
Large Herbivores ◽  
Size Evolution ◽  
Geographical Regions ◽  
Body Size Evolution

Because body size interacts with many fundamental biological properties of a species, body size evolution can be an essential component of the generation and maintenance of biodiversity. Here we investigate how body size evolution can be linked to the clade-specific diversification dynamics in different geographical regions. We analyse an extensive body size dataset of Neogene large herbivores (covering approx. 50% of the 970 species in the orders Artiodactyla and Perissodactyla) in Europe and North America in a Bayesian framework. We reconstruct the temporal patterns of body size in each order on each continent independently, and find significant increases of minimum size in three of the continental assemblages (except European perissodactyls), suggesting an active selection for larger bodies. Assessment of trait-correlated birth-death models indicates that the common trend of body size increase is generated by different processes in different clades and regions. Larger-bodied artiodactyl species on both continents tend to have higher origination rates, and both clades in North America show strong links between large bodies and low extinction rate. Collectively, our results suggest a strong role of species selection and perhaps of higher-taxon sorting in driving body size evolution, and highlight the value of investigating evolutionary processes in a biogeographic context.

scholarly journals Deciphering the Impact of a Bacterial Infection on Meiotic Recombination in Arabidopsis with Fluorescence Tagged Lines

Genes ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 832
Author(s):  
Ariane Gratias ◽  
Valérie Geffroy
Keyword(s):  
Pseudomonas Syringae ◽  
Meiotic Recombination ◽  
Recombination Rate ◽  
Evolutionary Dynamics ◽  
Genetic Recombination ◽  
Dna Recombination ◽  
Resistance Mechanism ◽  
Sequence Exchange ◽  
Significant Difference ◽  
The Impact

Plants are under strong evolutionary pressure to maintain surveillance against pathogens. One major disease resistance mechanism is based on NB-LRR (NLR) proteins that specifically recognize pathogen effectors. The cluster organization of the NLR gene family could favor sequence exchange between NLR genes via recombination, favoring their evolutionary dynamics. Increasing data, based on progeny analysis, suggest the existence of a link between the perception of biotic stress and the production of genetic diversity in the offspring. This could be driven by an increased rate of meiotic recombination in infected plants, but this has never been strictly demonstrated. In order to test if pathogen infection can increase DNA recombination in pollen meiotic cells, we infected Arabidopsis Fluorescent Tagged Lines (FTL) with the virulent bacteria Pseudomonas syringae. We measured the meiotic recombination rate in two regions of chromosome 5, containing or not an NLR gene cluster. In all tested intervals, no significant difference in genetic recombination frequency between infected and control plants was observed. Although it has been reported that pathogen exposure can sometimes increase the frequency of recombinant progeny in plants, our findings suggest that meiotic recombination rate in Arabidopsis may be resilient to at least some pathogen attack. Alternative mechanisms are discussed.

scholarly journals Microbial control of host gene regulation and the evolution of host–microbiome interactions in primates

2020 ◽  
Vol 375 (1808) ◽  
pp. 20190598 ◽  
Author(s):  
Laura Grieneisen ◽  
Amanda L. Muehlbauer ◽  
Ran Blekhman
Keyword(s):  
Gene Expression ◽  
Gene Regulation ◽  
Host Species ◽  
Evolutionary Dynamics ◽  
Microbial Control ◽  
Host Gene ◽  
Primate Species ◽  
Microbiome Composition ◽  
Wide Range ◽  
Species Specific

Recent comparative studies have found evidence consistent with the action of natural selection on gene regulation across primate species. Other recent work has shown that the microbiome can regulate host gene expression in a wide range of relevant tissues, leading to downstream effects on immunity, metabolism and other biological systems in the host. In primates, even closely related host species can have large differences in microbiome composition. One potential consequence of these differences is that host species-specific microbial traits could lead to differences in gene expression that influence primate physiology and adaptation to local environments. Here, we will discuss and integrate recent findings from primate comparative genomics and microbiome research, and explore the notion that the microbiome can influence host evolutionary dynamics by affecting gene regulation across primate host species. This article is part of the theme issue ‘The role of the microbiome in host evolution’.

Allozyme Analysis of Trichinella Isolates from Various Host Species and Geographical Regions

1992 ◽  
Vol 78 (4) ◽  
pp. 641 ◽  
Author(s):  
Giuseppe La Rosa ◽  
Edoardo Pozio ◽  
Patrizia Rossi ◽  
K. Darwin Murrell
Keyword(s):  
Host Species ◽  
Allozyme Analysis ◽  
Geographical Regions

scholarly journals Avian Influenza Viruses in Wild Birds: Virus Evolution in a Multihost Ecosystem

2018 ◽  
Vol 92 (15) ◽  
Author(s):  
Divya Venkatesh ◽  
Marjolein J. Poen ◽  
Theo M. Bestebroer ◽  
Rachel D. Scheuer ◽  
Oanh Vuong ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Host Species ◽  
Phylogenetic Trees ◽  
Evolutionary Dynamics ◽  
Natural Host ◽  
Influenza Viruses ◽  
Seasonal Migration ◽  
The Black Sea ◽  
Avian Influenza Viruses ◽  
Stopover Site

ABSTRACTWild ducks and gulls are the major reservoirs for avian influenza A viruses (AIVs). The mechanisms that drive AIV evolution are complex at sites where various duck and gull species from multiple flyways breed, winter, or stage. The Republic of Georgia is located at the intersection of three migratory flyways: the Central Asian flyway, the East Africa/West Asia flyway, and the Black Sea/Mediterranean flyway. For six complete study years (2010 to 2016), we collected AIV samples from various duck and gull species that breed, migrate, and overwinter in Georgia. We found a substantial subtype diversity of viruses that varied in prevalence from year to year. Low-pathogenic AIV (LPAIV) subtypes included H1N1, H2N3, H2N5, H2N7, H3N8, H4N2, H6N2, H7N3, H7N7, H9N1, H9N3, H10N4, H10N7, H11N1, H13N2, H13N6, H13N8, and H16N3, and two highly pathogenic AIVs (HPAIVs) belonging to clade 2.3.4.4, H5N5 and H5N8, were found. Whole-genome phylogenetic trees showed significant host species lineage restriction for nearly all gene segments and significant differences in observed reassortment rates, as defined by quantification of phylogenetic incongruence, and in nucleotide sequence diversity for LPAIVs among different host species. Hemagglutinin clade 2.3.4.4 H5N8 viruses, which circulated in Eurasia during 2014 and 2015, did not reassort, but analysis after their subsequent dissemination during 2016 and 2017 revealed reassortment in all gene segments except NP and NS. Some virus lineages appeared to be unrelated to AIVs in wild bird populations in other regions, with maintenance of local AIVs in Georgia, whereas other lineages showed considerable genetic interrelationships with viruses circulating in other parts of Eurasia and Africa, despite relative undersampling in the area.IMPORTANCEWaterbirds (e.g., gulls and ducks) are natural reservoirs of avian influenza viruses (AIVs) and have been shown to mediate the dispersal of AIVs at intercontinental scales during seasonal migration. The segmented genome of influenza viruses enables viral RNA from different lineages to mix or reassort when two viruses infect the same host. Such reassortant viruses have been identified in most major human influenza pandemics and several poultry outbreaks. Despite their importance, we have only recently begun to understand AIV evolution and reassortment in their natural host reservoirs. This comprehensive study illustrates AIV evolutionary dynamics within a multihost ecosystem at a stopover site where three major migratory flyways intersect. Our analysis of this ecosystem over a 6-year period provides a snapshot of how these viruses are linked to global AIV populations. Understanding the evolution of AIVs in the natural host is imperative to mitigating both the risk of incursion into domestic poultry and the potential risk to mammalian hosts, including humans.

New state and host records for Agromyzidae (Diptera) in the United States, with the description of thirty new species

Zootaxa ◽  
2018 ◽  
Vol 4479 (1) ◽  
pp. 1 ◽  
Author(s):  
CHARLES S. EISEMAN ◽  
OWEN LONSDALE
Keyword(s):  
United States ◽  
New Species ◽  
North America ◽  
Host Species ◽  
The United States ◽  
Distribution Data ◽  
New Host ◽  
The Usa ◽  
New Host Species ◽  
State Records

We present rearing records of Agromyzidae (Diptera) from five years of collecting throughout the United States. We review host and distribution data, and describe leaf mines, for 93 species, plus 28 others that could not be confidently identified in the absence of male specimens. We report 147 new host species records, including the first rearing records for Agromyza bispinata Spencer, A. diversa Johnson, A. parca Spencer, A. pudica Spencer, A. vockerothi Spencer, Calycomyza michiganensis Steyskal, Ophiomyia congregata (Malloch), and Phytomyza aldrichi Spencer. Phytomyza anemones Hering and (tentatively identified) Cerodontha (Dizygomyza) iraeos (Robineau-Desvoidy) are new to North America; Agromyza albitarsis Meigen, Amauromyza shepherdiae Sehgal, Aulagromyza populicola (Walker), Liriomyza orilliensis Spencer, Phytomyza linnaeae (Griffiths), P. solidaginivora Spencer, and P. solidaginophaga Sehgal are new to the USA. We also present confirmed USA records for Calycomyza menthae Spencer (previous records were based only on leaf mines), Ophiomyia maura (Meigen) (reported from the USA in older literature but deleted from the fauna in the most recent revision (Spencer & Steyskal 1986)), and Phytomyza astotinensis Griffiths and P. thalictrivora Spencer (previously only tentatively recorded from the USA). We provide 111 additional new state records. We describe the following 30 new species: Agromyza fission, A. soka, Melanagromyza palmeri, Ophiomyia euthamiae, O. mimuli, O. parda, Calycomyza artemisivora, C. avira, C. eupatoriphaga, C. vogelmanni, Cerodontha (Dizygomyza) edithae, Cer. (D.) feldmani, Liriomyza ivorcutleri, L. valerianivora, Phytomyza actaeivora, P. aesculi, P. confusa, P. doellingeriae, P. erigeronis, P. hatfieldae, P. hydrophyllivora, P. palmeri, P. palustris, P. sempervirentis, P. tarnwoodensis, P. tigris, P. triangularidis, P. vancouveriella, P. verbenae, and P. ziziae. 

Sign in / Sign up

Export Citation Format

Share Document