3,315 research outputs found
Genetic Evolution and Molecular Selection of the HE Gene of Influenza C Virus
Influenza C virus (ICV) was first identified in humans and swine, but recently also in cattle, indicating a wider host range and potential threat to both the livestock industry and public health than was originally anticipated. The ICV hemagglutinin-esterase (HE) glycoprotein has multiple functions in the viral replication cycle and is the major determinant of antigenicity. Here, we developed a comparative approach integrating genetics, molecular selection analysis, and structural biology to identify the codon usage and adaptive evolution of ICV. We show that ICV can be classified into six lineages, consistent with previous studies. The HE gene has a low codon usage bias, which may facilitate ICV replication by reducing competition during evolution. Natural selection, dinucleotide composition, and mutation pressure shape the codon usage patterns of the ICV HE gene, with natural selection being the most important factor. Codon adaptation index (CAI) and relative codon deoptimization index (RCDI) analysis revealed that the greatest adaption of ICV was to humans, followed by cattle and swine. Additionally, similarity index (SiD) analysis revealed that swine exerted a stronger evolutionary pressure on ICV than humans, which is considered the primary reservoir. Furthermore, a similar tendency was also observed in the M gene. Of note, we found HE residues 176, 194, and 198 to be under positive selection, which may be the result of escape from antibody responses. Our study provides useful information on the genetic evolution of ICV from a new perspective that can help devise prevention and control strategies
The large scale impact of offshore wind farm structures on pelagic primary productivity in the southern North Sea
The increasing demand for renewable energy is projected to result in a
40-fold increase in offshore wind electricity in the European Union by 2030.
Despite a great number of local impact studies for selected marine populations,
the regional ecosystem impacts of offshore wind farm structures are not yet
well assessed nor understood. Our study investigates whether the accumulation
of epifauna, dominated by the filter feeder Mytilus edulis (blue mussel), on
turbine structures affects pelagic primary productivity and ecosystem
functioning in the southern North Sea. We estimate the anthropogenically
increased potential distribution based on the current projections of turbine
locations and reported patterns of M. edulis settlement. This distribution is
integrated through the Modular Coupling System for Shelves and Coasts to
state-of-the-art hydrodynamic and ecosystem models. Our simulations reveal
non-negligible potential changes in regional annual primary productivity of up
to 8% within the offshore wind farm area, and induced maximal increases of the
same magnitude in daily productivity also far from the wind farms. Our setup
and modular coupling are effective tools for system scale studies of other
environmental changes arising from large-scale offshore wind-farming such as
ocean physics and distributions of pelagic top predators.Comment: 17 pages, 6 figures, re-revised manuscript submitted to Hydrobiologi
Low Carbon Energy Policy Research
AbstractCase study of Korea, Low carbon energy efficiency labeling schemes (Energy Efficiency Label and Standard Program, High efficiency Appliance Certification Program, e-Standby Program) play a key role in carrying out the energy efficiency improvement policy in the appliances and equipment sector in Korea. Korea operates these Programs in an effort to improve energy efficiency in appliances and equipments. Mandatory energy efficiency standard which bans production and sales of low energy efficiency products which fall below the minimum energy performance standard. Ministry of Knowledge of Economy (MKE) and Korea Energy Management Corporation (KEMCO) is the key organizations in implementing energy efficiency standards and labeling. National energy efficiency efforts can be realized through energy efficiency improvements with the successful implementation of an energy efficient appliances dissemination policy and the phase out of low efficiency appliances. Through the implementation of the Energy Efficiency Label and Standard Program (1992), High-efficiency Appliance Certification Program (1996) and e-Standby Program (1999), significant energy efficiency improvements have been achieved, and 1.37 billion USD worth of energy savings
Magnetosome Gene Duplication as an Important Driver in the Evolution of Magnetotaxis in the Alphaproteobacteria
The evolution of microbial magnetoreception (or magnetotaxis) is of great interest in the fields of microbiology, evolutionary biology, biophysics, geomicrobiology, and geochemistry. Current genomic data from magnetotactic bacteria (MTB), the only prokaryotes known to be capable of sensing the Earth’s geomagnetic field, suggests an ancient origin of magnetotaxis in the domain Bacteria. Vertical inheritance, followed by multiple independent magnetosome gene cluster loss, is considered to be one of the major forces that drove the evolution of magnetotaxis at or above the class or phylum level, although the evolutionary trajectories at lower taxonomic ranks (e.g., within the class level) remain largely unstudied. Here we report the isolation, cultivation, and sequencing of a novel magnetotactic spirillum belonging to the genus Terasakiella (Terasakiella sp. strain SH-1) within the class Alphaproteobacteria. The complete genome sequence of Terasakiella sp. strain SH-1 revealed an unexpected duplication event of magnetosome genes within the mamAB operon, a group of genes essential for magnetosome biomineralization and magnetotaxis. Intriguingly, further comparative genomic analysis suggests that the duplication of mamAB genes is a common feature in the genomes of alphaproteobacterial MTB. Taken together, with the additional finding that gene duplication appears to have also occurred in some magnetotactic members of the Deltaproteobacteria, our results indicate that gene duplication plays an important role in the evolution of magnetotaxis in the Alphaproteobacteria and perhaps the domain Bacteria
Surface Roughness Gradients Reveal Topography‐Specific Mechanosensitive Responses in Human Mesenchymal Stem Cells
The topographic features of an implant, which mechanically regulate cell behaviors and functions, are critical for the clinical success in tissue regeneration. How cells sense and respond to the topographical cues, e.g., interfacial roughness, is yet to be fully understood and even debatable. Here, the mechanotransduction and fate determination of human mesenchymal stem cells (MSCs) on surface roughness gradients are systematically studied. The broad range of topographical scales and high‐throughput imaging is achieved based on a catecholic polyglycerol coating fabricated by a one‐step‐tilted dip‐coating approach. It is revealed that the adhesion of MSCs is biphasically regulated by interfacial roughness. The cell mechanotransduction is investigated from focal adhesion to transcriptional activity, which explains that cellular response to interfacial roughness undergoes a direct force‐dependent mechanism. Moreover, the optimized roughness for promoting cell fate specification is explored
Modeling of fatigue crack in particle reinforced composites with Voronoi cell finite element method
AbstractThe modeling of fatigue crack initiation and propagation for particulate reinforced composites is facilitated with new Voronoi cell finite element method (VCFEM), considering the matrix-inclusion interfacial fatigue crack and matrix fatigue crack. In the new element, all possible contacts on the crack edge are considered by remeshing method, when the crack is closing under all possible changing loads. The fatigue crack initiates when the fatigue damage exceeds certain critical damage value, and fatigue crack propagation are simulated by gradual seeking crack propagating directions and new crack tips, using a remeshing method that a damaged node at the crack tip is replaced by a pair of nodes, a new crack tip node is assigned at the crack propagating directions and a more pair of nodes are needed to be added on the crack edge near the crack tip in order to better facilitate the free-traction boundary condition. The comparison of the results of proposed VCFEM and commercial finite element packages MARC. An example has been given for Particle-reinforced metal-matrix composites with 20 elliptical inclusions to simulate the fatigue crack initiation and propagation under plane stress conditions. It appears that this method is a more efficient way to deal with the interfacial damage of composite materials
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