710 research outputs found
LC4SV: A Denoising Framework Learning to Compensate for Unseen Speaker Verification Models
The performance of speaker verification (SV) models may drop dramatically in
noisy environments. A speech enhancement (SE) module can be used as a front-end
strategy. However, existing SE methods may fail to bring performance
improvements to downstream SV systems due to artifacts in the predicted signals
of SE models. To compensate for artifacts, we propose a generic denoising
framework named LC4SV, which can serve as a pre-processor for various unknown
downstream SV models. In LC4SV, we employ a learning-based interpolation agent
to automatically generate the appropriate coefficients between the enhanced
signal and its noisy input to improve SV performance in noisy environments. Our
experimental results demonstrate that LC4SV consistently improves the
performance of various unseen SV systems. To the best of our knowledge, this
work is the first attempt to develop a learning-based interpolation scheme
aiming at improving SV performance in noisy environments
Re-Encryption Method Designed by Row Complete Matrix
With the prevalence of Internet access, document storage has become a fundamental web service in recent years. One important topic is how to design a secure channel for efficiently sharing documents with another receiver. In this paper, we demonstrate a re-encryption method that is designed with row complete matrices. With this new method, the document owner can share a ciphertext in the cloud with another receiver by sending a serial number to the server and giving the receiver a corresponding key at the same time. This method ensures that the server cannot obtain the information about key and plaintext and that the receiver cannot obtain the original key of the owner either. Only the owner has the knowledge of all the information. Using this re-encryption system, the cloud server can provide a secure file-sharing service without worrying about the shared key management problem. Moreover, the cost of re-encryption will not increase even when the encryption is strengthened with longer encryption keys
Site-directed in vitro immunization leads to a complete human monoclonal IgG4λ that binds specifically to the CDR2 region of CTLA-4 (CD152) without interfering the engagement of natural ligands
<p>Abstract</p> <p>Background</p> <p>The ability to acquire fully human monoclonal antibodies (mAbs) with pre-defined specificities is critical to the development of molecular tags for the analysis of receptor function in addition to promising immunotherapeutics. Yet most of the arriving affinity maturated and complete human immunoglobulin G (IgG) molecules, which are actually derived from single human B cells, have not widely been used to study the conserved self antigens (Ags) such as CD152 (cytotoxic T lymphocyte antigen-4, CTLA-4) because proper hosts are lacking.</p> <p>Results</p> <p>Here we developed an optimized protocol for site-directed <it>in vitro </it>immunizing peripheral blood mononuclear cells (PBMC) by using a selected epitope of human CD152, an essential receptor involved in down-regulation of T cell activation. The resultant stable trioma cell lines constantly produce anti-CD152 mAb (γ4λhuCD152), which contains variable (V) regions of the heavy chain and the light chain derived from the VH3 and Vλ human germline genes, respectively, and yet displays an unusual IgG4 isotype. Interestingly, γ4λhuCD152 has a basic pI not commonly found in myeloid monoclonal IgG4λs as revealed by the isoelectric focusing (IEF) analysis. Furthermore, γ4λhuCD152 binds specifically, with nanomolar affinity, to an extracellular constituency encompassing the putative second complementarity determining region (CDR2) of CD152, whereby it can react to activated CD3<sup>+ </sup>cells.</p> <p>Conclusion</p> <p>In a context of specific cell depletion and conditioned medium,<it>in vitro </it>induction of human Abs against a conserved self Ag was successfully acquired and a relatively basic mAb, γ4λhuCD152, with high affinity to CDR2 of CD152 was thus obtained. Application of such a human IgG4λ mAb with designated CDR2 specificity may impact upon and prefer for CD152 labeling both <it>in situ </it>and <it>ex situ</it>, as it does not affect the binding of endogenous B7 ligands and can localize into the confined immunological synapse which may otherwise prevent the access of whole IgG1 molecules.</p
INFLUENCE OF APPROACH SPEED AND DISTANCE ON BIOMECHANICS DURING SINGLE-LEGGED RUNNING VERTICAL JUMP
The purpose of this study was to look into the kinematics, kinetics and EMG of the single legged running vertical jumps in different approach speed and distance. 12 basketball player performed single-legged running vertical jumps with 2 approach speed and 3 distance randomly. Kinematic and Kinetic data were collected by a force and 11 infrared high speed cameras. EMG data were recorded by Delsys surface EMG system. Two-way repeated measures AMOVA (2 speeds x 3 distance) was used for establishing differences (significance level p< .05). The jump height, jumt moment of lower extremity, knee power and the activation of tibialis anterior and gastrocnemius were found significantly larger in fast approach speed. We suggested using fast approach speed and 9m approach distance to enhance the single-legged running vertical jump ability
A Millennial-Scale Tephra Event-Stratigraphic Record of the South China Sea since the Penultimate Interglacial
AbstractLarge volcanic eruptions have significant impacts on climate and environmental changes. The deposition of tephra in marine sediments may serve as an eruption recorder, but it has not been extensively studied in the western Pacific. This study explored a millennial-scale tephra event-stratigraphy with multiple indicators in a sediment core collected from the eastern South China Sea (SCS) basin. The magnetic susceptibility (MS), Fe and Mn concentrations determined by X-ray fluorescence (XRF), and identification of individual ash particles were used to identify tephra layers and reconstruct the history of volcanic activity. Nine visible volcaniclastic units (VVU) and two cryptotephra layers have been identified based on their distinct features, as manifested by high MS, Fe, and Mn concentrations and single-peak grain size distribution. The VVUs and cryptotephra layers reveal elevated volcanic activities. Using the radiocarbon age model and oxygen isotope stratigraphy, these episodes could roughly correspond to the following periods: 1-11 ka, 16-17 ka, 27-31 ka, 41-42 ka, 45-46 ka, 49-50 ka, 77-80 ka, 90-91 ka, 97-99 ka, 116-126 ka, and 132-140 ka. The alkenone-derived SST has significant glacial cycles and good synchronicity with other SCS SST records, which could partially help build the preliminary age model. Despite possible age errors larger than 1 kyr, the discovery and timing of tephra layers provide a preliminary framework to further investigate the impact of historical volcanic eruptions on climate changes
The Design and Implementation of the Defender Cloud on TWAREN Backbone
Defender Cloud is a cloud based backbone network defending system having full scope over the whole backbone network. Rather than detecting suspicious network activities on a local area network, it collects and integrates the flow data from all connecting members and all entrances of a backbone network. After analyzing by a proposed cloud based distributed processing model, the corresponding defensive reaction can be carried out in a global basis. Thus its protection can cover the whole network, even including member institutions without their own firewall. This paper illustrates the design, verification and future perspective of the Defender Cloud, with an emphasis on the distributed processing of the flow data
Exploring impacts of project leaders’ written expressions in virtual and fluid projects: The role of personality and emotion
This paper aims to tackle challenges of managing projects in highly virtual and fluid contexts, characterized by diversity, dispersion, digital dependence, unstable membership, and dynamic coordination and configuration. We investigate project leaders’ personality and emotion expressed in written expression and examine their impacts on collaboration outcomes. IBM Watson Personality Insights and Tone Analyzer were adopted to assess the leader’s personality and emotion. A computation model to classify collaboration patterns into taskwork-related and teamwork-related communication is under development. We report preliminary findings based on 417 weekly meetings between October 2018 and February 2020 in 8 open-source software teams around WordPress. The research results have the potential to inform researchers and practitioners about what personality profiles and emotions should be considered to foster collaboration in virtual and fluid projects. It is possible to extend the boundary condition of the traits school of leadership for project management in the new context
Simulating Shallow Soil Response Using Wave Propagation Numerical Modelling in the Western Plain of Taiwan
This study used the results from 45 microtremor array measurements to construct a shallow shear wave velocity structure in the western plain of Taiwan. We constructed a complete 3D velocity model based on shallow and tomography models for our numerical simulation. There are three major subsurfaces, engineering bedrock (VS = 600 m s-1), Pliocene formation and Miocene formation, constituted in the shallow model. The constant velocity is given in each subsurface. We employed a 3D-FD (finite-differences) method to simulate seismic wave propagation in the western plain. The aim of this study was to perform a quantitative comparison of site amplifications and durations obtained from empirical data and numerical modelling in order to obtain the shallow substructure soil response. Modelling clearly revealed that the shallow substructure plays an important role in strong ground motion prediction using 3D simulation. The results show significant improvements in effective shaking duration and the peak ground velocity (PGV) distribution in terms of the accuracy achieved by our developed model. We recommend a high-resolution shallow substructure as an essential component in future seismic hazard analyses
Establishment of a Knock-In Mouse Model with the SLC26A4 c.919-2A>G Mutation and Characterization of Its Pathology
Recessive mutations in the SLC26A4 gene are a common cause of hereditary hearing impairment worldwide. Previous studies have demonstrated that different SLC26A4 mutations may have different pathogenetic mechanisms. In the present study, we established a knock-in mouse model (i.e., Slc26a4tm1Dontuh/tm1Dontuh mice) homozygous for the c.919-2A>G mutation, which is a common mutation in East Asians. Mice were then subjected to audiologic assessment, a battery of vestibular evaluations, and inner ear morphological studies. All Slc26a4tm1Dontuh/tm1Dontuh mice revealed profound hearing loss, whereas 46% mice demonstrated pronounced head tilting and circling behaviors. There was a significant difference in the vestibular performance between wild-type and Slc26a4tm1Dontuh/tm1Dontuh mice, especially those exhibiting circling behavior. Inner ear morphological examination of Slc26a4tm1Dontuh/tm1Dontuh mice revealed an enlarged endolymphatic duct, vestibular aqueduct and sac, atrophy of stria vascularis, deformity of otoconia in the vestibular organs, consistent degeneration of cochlear hair cells, and variable degeneration of vestibular hair cells. Audiologic and inner ear morphological features of Slc26a4tm1Dontuh/tm1Dontuh mice were reminiscent of those observed in humans. These features were also similar to those previously reported in both knock-out Slc26a4−/− mice and Slc26a4loop/loop mice with the Slc26a4 p.S408F mutation, albeit the severity of vestibular hair cell degeneration appeared different among the three mouse strains
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