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In this paper, we prove the uniqueness and generic regularity of the energy conservative solution for a system of wave equations modeling nematic liquid crystal.
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In this paper, we prove the uniqueness and generic regularity of the energy conservative solution for a system of wave equations modeling nematic liquid crystal.
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Silicon photonics leverages the optical, electrical and material properties of silicon and the mature complementary metal-oxide semiconductor (CMOS) nanofabrication technique to develop on-chip photonic integration, which has been...
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Silicon photonics leverages the optical, electrical and material properties of silicon and the mature complementary metal-oxide semiconductor (CMOS) nanofabrication technique to develop on-chip photonic integration, which has been making significant impacts in various frontiers including next-generation optical communications networks, on-chip optical interconnects for high-speed energy-efficient computing and biosensing. Among many optical structures fabricated on silicon chips, microresonators due to their high-Q resonances and small footprints play important roles in various devices including lasers, filters, modulators, switches, routers, delays, detectors and sensors. This paper reviews from a microresonator perspective some of the latest progress in the field, summarizes design considerations in various applications and points out key challenges and potentials.
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The ever‐increasing concerns over indoor/outdoor air quality, industrial gas leakage, food freshness, and medical diagnosis require miniaturized gas sensors with excellent sensitivity, selectivity, stability, low power consumptio...
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The ever‐increasing concerns over indoor/outdoor air quality, industrial gas leakage, food freshness, and medical diagnosis require miniaturized gas sensors with excellent sensitivity, selectivity, stability, low power consumption, cost‐effectiveness, and long lifetime. Metal‐organic frameworks (MOFs), featuring structural diversity, large specific surface area, controllable pore size/geometry, and host‐guest interactions, hold great promises for fabricating various MOF‐based devices for diverse applications including gas sensing. Tremendous progress has been made in the past decade on the fabrication of MOF‐based sensors with elevated sensitivity and selectivity toward various analytes due to their preconcentrating and molecule‐sieving effects. Although several reviews have recently summarized different aspects of this field, a comprehensive review focusing on MOF‐based gas sensors is absent. In this review, the latest advance of MOF‐based gas sensors relying on different transduction mechanisms, for example, chemiresistive, capacitive/impedimetric, field‐effect transistor or Kelvin probe‐based, mass‐sensitive, and optical ones are comprehensively summarized. The latest progress for making large‐area MOF films essential to the mass‐production of relevant gas sensors is also included. The structural and compositional features of MOFs are intentionally correlated with the sensing performance. Challenges and opportunities for the further development and practical applications of MOF‐based gas sensors are also given.
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Within the 16SrII phytoplasma group, subgroups A–X have been classified based on restriction fragment length polymorphism of their 16S rRNA gene, and two species have been described, namely ‘Candidatus Phytoplasma aurantifolia’...
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Within the 16SrII phytoplasma group, subgroups A–X have been classified based on restriction fragment length polymorphism of their 16S rRNA gene, and two species have been described, namely ‘Candidatus Phytoplasma aurantifolia’ and ‘Ca. Phytoplasma australasia’. Strains of 16SrII phytoplasmas are detected across a broad geographic range within Africa, Asia, Australia, Europe and North and South America. Historically, all members of the 16SrII group share ≥97.5?% nucleotide sequence identity of their 16S rRNA gene. In this study, we used whole genome sequences to identify the species boundaries within the 16SrII group. Whole genome analyses were done using 42 phytoplasma strains classified into seven 16SrII subgroups, five 16SrII taxa without official 16Sr subgroup classifications, and one 16SrXXV-A phytoplasma strain used as an outgroup taxon. Based on phylogenomic analyses as well as whole genome average nucleotide and average amino acid identity (ANI and AAI), eight distinct 16SrII taxa equivalent to species were identified, six of which are novel descriptions. Strains within the same species had ANI and AAI values of >97?%, and shared ≥80?% of their genomic segments based on the ANI analysis. Species also had distinct biological and/or ecological features. A 16SrII subgroup often represented a distinct species, e.g., the 16SrII-B subgroup members. Members classified within the 16SrII-A, 16SrII-D, and 16SrII-V subgroups as well as strains classified as sweet potato little leaf phytoplasmas fulfilled criteria to be included as members of a single species, but with subspecies-level relationships with each other. The 16SrXXV-A taxon was also described as a novel phytoplasma species and, based on criteria used for other bacterial families, provided evidence that it could be classified as a distinct genus from the 16SrII phytoplasmas. As more phytoplasma genome sequences become available, the classification system of these bacteria can be further refined at the genus, species, and subspecies taxonomic ranks.
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In this paper, the non-isentropic compressible Navier-Stokes-Korteweg system with a time periodic external force is considered in R~n. The optimal time decay rates are obtained by spectral analysis. Using the optimal decay estimat...
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In this paper, the non-isentropic compressible Navier-Stokes-Korteweg system with a time periodic external force is considered in R~n. The optimal time decay rates are obtained by spectral analysis. Using the optimal decay estimates, we show that the existence, uniqueness and time-asymptotic stability of time periodic solutions when the space dimension n ≥ 5. Our proof is based on a combination of the energy method and the contraction mapping theorem.
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The ciliate Tetrahymena thermophila is a model organism for molecular and cellular biology. Like other ciliates, this species has separate germline and soma functions that are embodied by distinct nuclei within a single cell. The ...
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The ciliate Tetrahymena thermophila is a model organism for molecular and cellular biology. Like other ciliates, this species has separate germline and soma functions that are embodied by distinct nuclei within a single cell. The germline-like micronucleus (MIC) has its genome held in reserve for sexual reproduction. The soma-like macronucleus (MAC), which possesses a genome processed from that of the MIC, is the center of gene expression and does not directly contribute DNA to sexual progeny. We report here the shotgun sequencing, assembly, and analysis of the MAC genome of T. thermophila, which is approximately 104 Mb in length and composed of approximately 225 chromosomes. Overall, the gene set is robust, with more than 27,000 predicted protein-coding genes, 15,000 of which have strong matches to genes in other organisms. The functional diversity encoded by these genes is substantial and reflects the complexity of processes required for a free-living, predatory, single-celled organism. This is highlighted by the abundance of lineage-specific duplications of genes with predicted roles in sensing and responding to environmental conditions (e.g., kinases), using diverse resources (e.g., proteases and transporters), and generating structural complexity (e.g., kinesins and dyneins). In contrast to the other lineages of alveolates (apicomplexans and dinoflagellates), no compelling evidence could be found for plastid-derived genes in the genome. UGA, the only T. thermophila stop codon, is used in some genes to encode selenocysteine, thus making this organism the first known with the potential to translate all 64 codons in nuclear genes into amino acids. We present genomic evidence supporting the hypothesis that the excision of DNA from the MIC to generate the MAC specifically targets foreign DNA as a form of genome self-defense. The combination of the genome sequence, the functional diversity encoded therein, and the presence of some pathways missing from other model organisms makes T. thermophila an ideal model for functional genomic studies to address biological, biomedical, and biotechnological questions of fundamental importance.
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In this paper, the compressible magnetohydrodynamic system with some smallness and symmetry assumptions on the time periodic external force is considered in R~3. Based on the uniform estimates and the topological degree theory, we...
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In this paper, the compressible magnetohydrodynamic system with some smallness and symmetry assumptions on the time periodic external force is considered in R~3. Based on the uniform estimates and the topological degree theory, we prove the existence of a time periodic solution in a bounded domain. Then by a limiting process, the result in the whole space R~3 is obtained.
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To obtain high-spatial-resolution land surface temperature (LST) in karst areas, it is necessary to select a downscale regression model with a better simulation effect and the scale factors that can best represent the topographic ...
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To obtain high-spatial-resolution land surface temperature (LST) in karst areas, it is necessary to select a downscale regression model with a better simulation effect and the scale factors that can best represent the topographic characteristics of karst mountainous areas. In Guiyang, a typical karst mountain city, two areas are selected as the study area, which is dominated by natural surface and construction land. Based on the data of Landsat-8 Thermal Infrared Sensor (TIRS), Sentinel-2, Advanced Land Observing Satellite Digital Elevation Model (ALOS DEM), and meteorological stations, the scale factors representing bare land: bare soil index and topographic relief: mountain shadow (hillshade), relief degree of land surface (RDLS), solar incident angle, and sky view factor (SVF) are added on the basis of the conventional factors. At the same time, random forest (RF) and extreme gradient boosting (XGBoost) models are used to construct an LST downscaling method that is more suitable for karst mountain cities. After the above steps, the LST product with a spatial resolution of 10 m is finally estimated. The results show that, due to the characteristics of large elevation variation, fragmentation, and high heterogeneity of surface landscape in karst areas, digital elevation model (DEM), RDLS, and SVF factors need to be considered in the downscaling of surface temperature, and the contribution rates of these factors are all more than 6% in the model. In terms of accuracy evaluation of ground temperature, XGBoost model has the highest accuracy with an average absolute error of 1.67K, RF model has an average error of 1.90K, and thermal image sharpening has the worst accuracy with an average error of 2.41K. In terms of accuracy evaluation of ascending scale, the XGBoost model also shows higher accuracy and richer texture details. The research results can provide basic data for the acquisition of high-resolution LST and its intermediate parameters in this area and also provide a method reference for the reduction of high-resolution LST in similar areas.
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Malaria has caused millions of deaths over the years and it is still a major scourge in its endemic regions. Resistance to even the most recently developed effective treatments has emerged. A deeper understanding of parasite biolo...
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Malaria has caused millions of deaths over the years and it is still a major scourge in its endemic regions. Resistance to even the most recently developed effective treatments has emerged. A deeper understanding of parasite biology and host-parasite interactions will enable new, robust measures against the malaria parasite. In this paper, we developed a novel PageRank-based network analysis approach to identify proteins that are potentially influential in protein-protein association networks in Plasmodium falciparum. The proteins that were predicted to be most influential are involved in transcriptional regulation, signalling, proteolysis, and heat shock response. They are associated with proteins that may play a role in fundamental processes that range from genetic information processing, metabolism, transport, development, to virulence to the host. Functional characterisation of these proteins may open venues for novel therapeutics for effective malaria eradication.
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