scholarly journals Global Transmission, Spatial Segregation, and Recombination Determine the Long-Term Evolution and Epidemiology of Bovine Coronaviruses

Viruses ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 534 ◽  
Author(s):  
Elias Salem ◽  
Vijaykrishna Dhanasekaran ◽  
Herve Cassard ◽  
Ben Hause ◽  
Sarah Maman ◽  
...  
Keyword(s):  
Adult Cattle ◽  
Spike Gene ◽  
Evolutionary Origins ◽  
Term Evolution ◽  
Whole Genomes ◽  
Young Cattle ◽  
The 1960S ◽  
Neonatal Calf Diarrhea ◽  
Winter Dysentery

Bovine coronavirus (BCoV) is widespread in cattle and wild ruminant populations throughout the world. The virus causes neonatal calf diarrhea and winter dysentery in adult cattle, as well as upper and lower respiratory tract infection in young cattle. We isolated and deep sequenced whole genomes of BCoV from calves with respiratory distress in the south–west of France and conducted a comparative genome analysis using globally collected BCoV sequences to provide insights into the genomic characteristics, evolutionary origins, and global diversity of BCoV. Molecular clock analyses allowed us to estimate that the BCoV ancestor emerged in the 1940s, and that two geographically distinct lineages diverged from the 1960s–1970s. A recombination event in the spike gene (breakpoint at nt 1100) may be at the origin of the genetic divergence sixty years ago. Little evidence of genetic mixing between the spatially segregated lineages was found, suggesting that BCoV genetic diversity is a result of a global transmission pathway that occurred during the last century. However, we found variation in evolution rates between the European and non-European lineages indicating differences in virus ecology.

scholarly journals Quorum sensing provides a molecular mechanism for evolution to tune and maintain investment in cooperation

2020 ◽  
Author(s):  
Eric L. Bruger ◽  
Daniel J. Synder ◽  
Vaughn S. Cooper ◽  
Christopher M. Waters
Keyword(s):  
Quorum Sensing ◽  
Cell Communication ◽  
Protease Production ◽  
Potential Mechanism ◽  
Wild Type ◽  
Evolutionary Origins ◽  
Term Evolution ◽  
Evolution Experiment ◽  
The Impact

AbstractAs selection frequently favors non-cooperating defectors in mixed populations with cooperators, mechanisms that promote cooperation stability clearly exist. One potential mechanism is bacterial cell-to-cell communication, quorum sensing (QS), which can allow cooperators to prevent invasion by defectors. However, the impact of QS on widespread maintenance of cooperation in well-mixed conditions has not been experimentally demonstrated over extended evolutionary timescales. Here, we use wild-type (‘WT’) Vibrio harveyi that regulates cooperation with QS and an unconditionally cooperating (‘UC’) mutant to examine the evolutionary origins and subsequent dynamics of novel defectors during a long-term evolution experiment. We found that UC lineages were completely outcompeted by defectors, whereas functioning QS enabled the maintenance of cooperative variants in most WT populations. Sequencing of evolved populations revealed multiple luxR mutations that swept the UC lineages. However, the evolution of mutant lineages with reduced levels of bioluminescence (‘dims’) occurred in many WT lineages. These dim variants also decreased other cooperative phenotypes regulated by QS, such as protease production, indicating they result from changes to QS regulation. This diminished investment phenotype optimizes a trade-off between cooperative input and growth output, allowing cooperation to be maintained under QS control even in the presence of evolved defectors.

Link-Level Simulator for Wireless local Area Network

2018 ◽  
Vol 6 (7) ◽  
pp. 314
Author(s):  
Chaithra. H. U ◽  
Vani H.R
Keyword(s):  
Wireless Local Area Network ◽  
Local Area Network ◽  
Local Area Networks ◽  
Local Area ◽  
Long Term Evolution ◽  
Wireless Local Area Networks ◽  
Area Network ◽  
Network Simulator ◽  
Term Evolution

Now a days in Wireless Local Area Networks (WLANs) used in different fields because its well-suited simulator and higher flexibility. The concept of WLAN  with  advanced 5th Generation technologies, related to a Internet-of-Thing (IOT). In this project, representing the Network Simulator (NS-2) used linked-level simulators for Wireless Local Area Networks and still utilized IEEE 802.11g/n/ac with advanced IEEE 802.11ah/af technology. Realization of the whole Wireless Local Area Networking linked-level simulators inspired by the recognized Vienna Long Term Evolution- simulators. As a outcome, this is achieved to link together that simulator to detailed performances of Wireless Local Area Networking with Long Term Evolution, operated in the similar RF bands. From the advanced 5th Generation support cellular networking, such explore is main because different coexistences scenario can arise linking wireless communicating system to the ISM and UHF bands.

Simulación de cobertura del modelo de radio propagación 3GPP para un entorno urbano en una red 4G – LTE

2013 ◽  
Vol 8 (15) ◽  
pp. 33-40
Author(s):  
Javier Enrique Arévalo Peña
Keyword(s):  
Long Term Evolution ◽  
Term Evolution ◽  
Nuevas Tecnologías ◽  
4G Lte ◽  
3Rd Generation Partnership Project

En la planeación de las próximas generaciones de redes inalámbricas es importante contar con estudios de radio propagación que permitan establecer diseños adecuados para ofrecer los servicios proyectados por las nuevas tecnologías a los usuarios móviles. En este artículo se presentan aspectos relacionados con el comportamiento de cobertura de radio propagación del modelo propuesto por el 3GPP (3rd Generation Partnership Project) para un entorno urbano en una red LTE (Long Term Evolution) empleando sistemas de antenas convencionales y sistemas de antena adaptativas (AAS). Para ello se utiliza la herramienta de software ICS Designer y se establece como escenario los alrededores la Fundación Universidad Autónoma de Colombia ubicada en el centro urbano de la ciudad de Bogotá D. C.

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