Functional characterization of Mucin-Associated Surface Protein (MASP) in the human parasite Trypanosoma cruzi

MASPs are members of a multigenic family recently identified during the sequencing of the T. cruzi CL Brener genome. This family contains around 1,400 members, consisting of approximately 6% of the whole coding genes. Highly conserved N- and C-terminal domains, which encode a signal peptide and GPI-anchor addition site respectively, and a hypervariable central region, characterize MASPs. Members of this family are predominantly expressed in the infective trypomastigote form. We hypothesized that members of the T. cruzi MASP protein family play a major role in the interaction of the parasite with the host cell. In order to investigate a putative role for T. cruzi MASP at the host-pathogen interface, we have used MASP as a bait protein against the human proteome using a high-throughput platform that we have recently established for identifying protein-protein interactions between pathogens and theirs hosts. Yeast two-hybrid screens identified human SNAPIN as one of two major MASP interacting proteins. SNAPIN is a member of the SNARE protein complex, which may have a role in a calcium-dependent exocytosis. The MASP-SNAPIN interaction was further validated using in vivo co-Affinity Purification and in vitro pull-down assays. Immunofluorescence assays showed human SNAPIN is recruited to the parasite surface during invasion. Co-localization experiments indicated that SNAPIN is associated with the late endosomes and lysosomes. Supporting our initial hypothesis, SNAPIN depletion using siRNA oligomers in HeLa cells and snapin-/- in Mouse Embryonic Fibroblast (MEF) cells significantly inhibited T. cruzi invasion, suggesting a role for SNAPIN in this process. Lysosomes in snapin-/- MEF cells displayed aberrant morphology and distribution and the parasites did not recruit host lysosomes efficiently when compared to wild-type cells. This was likely due to an impaired calcium-dependent lysosome exocytosis in snapin-/- MEF cells. SNAPIN was translocated to the plasma membrane upon calcium influx induced by a calcium ionophore (Ionomycin), resulting in the exposure of the luminal domain of SNAPIN to the extracelluar space. Leishmania tarentolae transgenic strains expressing two different MASP proteins were shown to trigger intracellular calcium transients in HeLa cells, presumably by injuring the cell membrane. We propose that T. cruzi MASP plays a role in wounding the plasma membrane of the host cell, which in turn elicits a transient intracellular calcium flux and leads to the translocation of lysosome-associated SNAPIN to the plasma membrane. Human SNAPIN, through its exposed luminal domain would then provide an anchor for the entry to the parasite into the cell. The mechanism of T. cruzi MASP evoked calcium influx in the host cell membrane remains under investigation

Improving Multi-Scale Aggregation Using Feature Pyramid Module for Robust Speaker Verification of Variable-Duration Utterances

Currently, the most widely used approach for speaker verification is the deep speaker embedding learning. In this approach, we obtain a speaker embedding vector by pooling single-scale features that are extracted from the last layer of a speaker feature extractor. Multi-scale aggregation (MSA), which utilizes multi-scale features from different layers of the feature extractor, has recently been introduced and shows superior performance for variable-duration utterances. To increase the robustness dealing with utterances of arbitrary duration, this paper improves the MSA by using a feature pyramid module. The module enhances speaker-discriminative information of features from multiple layers via a top-down pathway and lateral connections. We extract speaker embeddings using the enhanced features that contain rich speaker information with different time scales. Experiments on the VoxCeleb dataset show that the proposed module improves previous MSA methods with a smaller number of parameters. It also achieves better performance than state-of-the-art approaches for both short and long utterances.Comment: Accepted to Interspeech 202

Designing Re-materialized Interactive Object Using Makey Makey

As ICT (Information & Communication Technology) and microcontroller technology have been developed, physical characteristics in products have disappeared gradually because controlling and displaying data becomes main features of products. However, after the concept of Graspable User Interface was introduced, there have been many design experiments for materializing user interfaces inside 2D screens and products. These are very meaningful in terms of designing intuitive and natural interaction methods because a human being lives in the physical world. In order to design re-materialized interactive object, tangible interaction researches from journals, thesis, and articles about the experimental prototypes were collected and categorized with the human-system interaction model. The human-system interaction model is suggested in this paper to describe the relationship amongst a human, interfaces (i.e. mouse, keyboard, screen, tangible user interface), and control and data inside object. The collected cases are organized in three different phases with the human-system interaction model. This paper proposes new model to generate concepts for next generation tangible interactive object design. The Makey Makey was selected as the toolkit for the new experiment and two interactive product design courses were instructed at Yonsei University and Seoul National University of Science & Technology from 2014 to 2015 in Korea. Many interesting outcomes by mapping control and data with humans everyday behaviors were designed. This paper can contribute to the study on the future of products how objects can be designed in tangible and physical ways.OAIID:RECH_ACHV_DSTSH_NO:A201625592RECH_ACHV_FG:RR00200003ADJUST_YN:EMP_ID:A080155CITE_RATE:FILENAME:abstract-483.pdfDEPT_NM:디자인학부EMAIL:[email protected]_YN:FILEURL:https://srnd.snu.ac.kr/eXrepEIR/fws/file/f20faf7c-3d58-4837-b6d4-220eafeaa0c7/linkCONFIRM:

Physical Activity Recognition based on Rotated Acceleration Data using Orientation Filter

The purpose of the study was to examine the accuracy of physical activity (PA) classification algorithms using a rotational analysis