20 research outputs found
What if Social Bots Be My Friends? Estimating Causal Effect of Social Bots Using Counterfactual Graph Learning
FluentEditor: Text-based Speech Editing by Considering Acoustic and Prosody Consistency
Text-based speech editing (TSE) techniques are designed to enable users to
edit the output audio by modifying the input text transcript instead of the
audio itself. Despite much progress in neural network-based TSE techniques, the
current techniques have focused on reducing the difference between the
generated speech segment and the reference target in the editing region,
ignoring its local and global fluency in the context and original utterance. To
maintain the speech fluency, we propose a fluency speech editing model, termed
\textit{FluentEditor}, by considering fluency-aware training criterion in the
TSE training. Specifically, the \textit{acoustic consistency constraint} aims
to smooth the transition between the edited region and its neighboring acoustic
segments consistent with the ground truth, while the \textit{prosody
consistency constraint} seeks to ensure that the prosody attributes within the
edited regions remain consistent with the overall style of the original
utterance. The subjective and objective experimental results on VCTK
demonstrate that our \textit{FluentEditor} outperforms all advanced baselines
in terms of naturalness and fluency. The audio samples and code are available
at \url{https://github.com/Ai-S2-Lab/FluentEditor}.Comment: Submitted to ICASSP'202
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
PMCHWT Solver Accelerated by Adaptive Cross Approximation for Efficient Computation of Scattering from Metal Nanoparticles
An accelerated algorithm that can efficiently calculate the light scattering of a single metal nanoparticle was proposed. According to the equivalent principle, the method of moment (MoM) transforms the Poggio–Miller–Chang–Harrington–Wu–Tsai (PMCHWT) integral equations into linear algebraic equations, which are solved by the flexible generalized minimal residual solver (FGMRES). Each element of near field MoM impedance matrix was described by Rao–Wilton–Glisson (RWG) basis functions and calculated by double surface integrals. Due to the low-rank property, the adaptive cross approximation (ACA) algorithm based on the octree data structure was applied to compress the MoM impedance matrix of far field action leading to the significant reduction of solution time and memory. Numerical results demonstrated that the proposed method is both accurate and efficient. Compared with the traditional MoM, the ACA algorithm can significantly reduce the impedance matrix filling time and accelerate the scattering field’s computation from actual metal nanoparticles using PMCHWT integral equations
Recent Progress on Wave Energy Marine Buoys
This study aims to introduce and discuss the recent research, development and application of wave energy marine buoys. The topic becomes increasingly appealing after the observation that wave energy technologies have been evolving in the recent decades, yet have not reached convergence. The power supply is usually the bottleneck for marine distributed systems such as buoys. Wave energy technologies are especially useful in this sense, as they can capture and convert the promising “native” renewable energy in the ocean (i.e., wave energy) into electricity. The paper enumerates the recent developments in wave energy capture (e.g., oscillating bodies) and power take-off (e.g., nanogenerators). The study also introduces the typical marine buoys and discusses the applicability of wave energy technologies on them. It is concluded that the wave energy technologies could be implemented as a critical addition to the comprehensive power solution of marine distributed systems. Wave energy buoys are likely to differentiate into “wave energy converter buoys” and “wave-energy-powered buoys”, which is indicated by the ratio of the generated power to the load power
Recent Progress on Wave Energy Marine Buoys
This study aims to introduce and discuss the recent research, development and application of wave energy marine buoys. The topic becomes increasingly appealing after the observation that wave energy technologies have been evolving in the recent decades, yet have not reached convergence. The power supply is usually the bottleneck for marine distributed systems such as buoys. Wave energy technologies are especially useful in this sense, as they can capture and convert the promising “native” renewable energy in the ocean (i.e., wave energy) into electricity. The paper enumerates the recent developments in wave energy capture (e.g., oscillating bodies) and power take-off (e.g., nanogenerators). The study also introduces the typical marine buoys and discusses the applicability of wave energy technologies on them. It is concluded that the wave energy technologies could be implemented as a critical addition to the comprehensive power solution of marine distributed systems. Wave energy buoys are likely to differentiate into “wave energy converter buoys” and “wave-energy-powered buoys”, which is indicated by the ratio of the generated power to the load power
Oligo-FISH of <i>Populus simonii</i> Pachytene Chromosomes Improves Karyotyping and Genome Assembly
Poplar was one of the first woody species whose individual chromosomes could be identified using chromosome specific painting probes. Nevertheless, high-resolution karyotype construction remains a challenge. Here, we developed a karyotype based on the meiotic pachytene chromosome of Populus simonii which is a Chinese native species with many excellent traits. This karyotype was anchored by oligonucleotide (oligo)-based chromosome specific painting probes, a centromere-specific repeat (Ps34), ribosomal DNA, and telomeric DNA. We updated the known karyotype formula for P. simonii to 2n = 2x = 38 = 26m + 8st + 4t and the karyotype was 2C. The fluorescence in situ hybridization (FISH) results revealed some errors in the current P. simonii genome assembly. The 45S rDNA loci were located at the end of the short arm of chromosomes 8 and 14 by FISH. However, they were assembled on pseudochromosomes 8 and 15. In addition, the Ps34 loci were distributed in every centromere of the P. simonii chromosome in the FISH results, but they were only found to be present in pseudochromosomes 1, 3, 6, 10, 16, 17, 18, and 19. Our results reveal that pachytene chromosomes oligo-FISH is a powerful tool for constructing high-resolution karyotypes and improving the quality of genome assembly
Applying Supercritical Fluid Technology to Prepare Ibuprofen Solid Dispersions with Improved Oral Bioavailability
In this study, supercritical fluid (SCF) technology was applied to prepare reliable solid dispersions of pharmaceutical compounds with limited bioavailability using ibuprofen (IBU) as a model compound. Solid-state characterization of the dispersions was conducted by differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and scanning electron microscopy (SEM). The PXRD and DSC results suggested that the amorphous form of IBU was maintained in the solid dispersions. Furthermore, in vitro dissolution and in vivo pharmacokinetic (PK) studies in rats were also performed. The dissolution performance of the SCF-prepared IBU dispersions was significantly improved compared to that of the physical mixtures of crystalline IBU and a polymer. In addition, the PK results revealed that the SCF-prepared IBU dispersions produced remarkably high blood drug concentrations (both the AUC and Cmax) and a rapid absorption rate (Tmax). Finally, molecular modeling was used to evaluate the binding energy of interactions between IBU and the polymers. The negative binding energy suggests a relatively stable system. Hence, SCF technology can be used as a very effective approach to prepare IBU solid dispersions with good physical stability and enhanced in vitro and in vivo performance
Evaluation of the Solid Dispersion System Engineered from Mesoporous Silica and Polymers for the Poorly Water Soluble Drug Indomethacin: In Vitro and In Vivo
This work explored absorption efficacy via an in vivo imaging system and parallel artificial membrane penetration in indomethacin (IMC) solid dispersion (SD) systems. Two different polymer excipients—hydroxypropyl methylcellulose (HPMC) and Kollicoat IR as precipitation inhibitors (PIs)—combined with mesoporous silica nanoparticles (MSNs) as carriers were investigated. The IMC–SDs were prepared using the solvent evaporation method and characterized by solubility analysis, infrared (IR) spectroscopy, powder X-ray diffraction (PXRD), field emission scanning electron microscopy (FESEM), and differential scanning calorimetry (DSC). It was confirmed that IMC successfully changed into an amorphous state after loading into the designed carriers. The in vitro release and stability experiments were conducted to examine the in vitro dissolution rates of IMC–SDs combined with HPMC and Kollicoat IR as PIs which both improved approximately three-fold to that of the pure drug. Finally, in vivo studies and in vitro parallel artificial membrane penetration (PAMPA) experiments ensured the greater ability of enhancing the dissolution rates of pure IMC in the gastrointestinal tract by oral delivery. In brief, this study highlights the prominent role of HPMC and Kollicoat IR as PIs in MSN SD systems in improving the bioavailability and gastrointestinal oral absorption efficiency of indomethacin
Using CYGNSS Data to Monitor China’s Flood Inundation during Typhoon and Extreme Precipitation Events in 2017
NASA’s Cyclone Global Navigation Satellite System (CYGNSS) mission, launched in 2016, is a small satellite constellation designed to measure the ocean surface wind speed in hurricanes and tropical cyclones. To explore its additional capabilities for applications on the land surface, this study investigated the advantages and limitations of using CYGNSS data to monitor flood inundation during typhoon and extreme precipitation events in southeast China in 2017. The results showed that despite the lack of quantitative evaluation, the CYGNSS-derived surface reflectivity (SR) and flood inundation area was qualitatively consistent with the Global Precipitation Measurement (GPM)-derived precipitation and Soil Moisture Active Passive (SMAP)/Soil Moisture and Ocean Salinity (SMOS)-derived total brightness temperature at circular polarization ( T b C ). The results provide supporting evidence for further designation of Global Navigation Satellite System (GNSS) reflectometry (GNSS-R) constellations to monitor land surface hydrology