216 research outputs found
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Mass Loaded Tensioned Mechanical Resonators
Highly tensioned micromechanical and nanomechanical resonators have enabled novel experiments in quantum optomechanics and numerous applications in the field of precision sensing. This is in part due to engineering efforts that have allowed for resonator modes with ultrahigh quality factors. Typically, sensing applications require functionalizing resonators by adding local mass to them. However, this may dramatically lower the resonator mode quality factor, and hence its sensitivity. This thesis studies the effect of a local mass load on the shape and quality factor of a tensioned resonator mode. Through analytical models, finite element analysis, and tabletop experiments, we show that in the limit of a large mass load, the resonator mode quality factor saturates. This effect paves the way for engineering resonators with improved sensitivity for certain applications such as magnetic force detection, accelerometry, and gravitational force sensing.
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Basic FGF regulates the expression of a functional 71 kDa NMDA receptor protein that mediates calcium influx and neurotoxicity in hippocampal neurons
This is the publisher's version, also available electronically from "http://www.jneurosci.org".Basic fibroblast growth factor (bFGF) was recently found to modulate the outgrowth-regulating effects of glutamate, and protected neurons from several brain regions against excitotoxi/ischemic damage. We provide evidence that the excitoprotective mechanism of bFGF involves suppression of the expression of a 71 kDa NMDA receptor protein (NMDARP- 71). NMDARP-71 protein and mRNA levels were reduced in neurons in bFGF- treated hippocampal cell cultures. The levels of the NMDARP-71 were not reduced by NGF or epidermal growth factor, and bFGF did not reduce the level of mRNA for the GluR1 kainate/AMPA receptor, demonstrating the specificity of the effect of bFGF on the NMDARP-71. The reduction in NMDARP-71 expression in bFGF-treated neurons was correlated with reduced vulnerability to NMDA neurotoxicity. A major role for NMDARP-71 in calcium responses to NMDA and excitotoxicity was demonstrated using antisense oligonucleotides directed against NMDARP-71. Northern and Western blot analysis and immunocytochemistry showed that NMDARP-71 antisense oligonucleotides caused a selective suppression of NMDARP-71 mRNA and protein levels during 12–44 hr exposure periods. Elevations in intracellular calcium levels normally caused by glutamate and NMDA were attenuated in neurons exposed to NMDARP-71 antisense oligonucleotide; calcium responses to kainate were relatively unaffected. NMDARP-71 antisense oligonucleotides protected the neurons against excitotoxicity. Thus, NMDARP-71 is a necessary component of an NMDA receptor mediating calcium responses and neurotoxicity in hippocampal neurons. Taken together, these data identify a mechanism whereby bFGF can modify neuronal responses to glutamate, and suggest that regulating the expression of excitatory amino acid receptors may provide a means for growth factors to influence the plasticity and degeneration of neural circuits
Chaotic Sequence based Steganography for Pair-Wise Communication
Steganography is the art and science of hiding sensitive data inside an image. There are so many cryptosystems that use Steganography as a major tool. Also in recent years there is a rising trend towards chaotic sequence based cryptosystems. This paper attempts to combine the two with a new algorithm for data hiding. Here key images required for Steganography are generated using chaotic sequence. Also an attempt is made to overcome the limitations of Steganography on the file size ratio and the security offered by Steganography
Off-line Handwritten Kannada Text Recognition using Support Vector Machine using Zernike Moments
Abstract It is a well-known fact that building a character recognition system is one of the hottest areas of research as it is shown over the Internet and due to its wide range of prospects. The objective of this paper is to describe an OCR system for handwritten text documents in Kannada. The input to the system is a scanned image of a text and the output is a machine editable file compatible with most typesetting Kannada software. The system first extracts characters from the document image and a set of features are extracted from the character image using Zernike moments. The final recognition is achieved using support vector machine (SVM). The recognition is independent of the size of the handwritten text and the system is seen to deliver reasonable performance
Extracellular Vesicles in Triple–Negative Breast Cancer: Immune Regulation, Biomarkers, and Immunotherapeutic Potential
Triple–negative breast cancer (TNBC) is an aggressive subtype accounting for ~10–20% of all human BC and is characterized by the absence of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) amplification. Owing to its unique molecular profile and limited targeted therapies, TNBC treatment poses significant challenges. Unlike other BC subtypes, TNBC lacks specific molecular targets, rendering endocrine therapies and HER2–targeted treatments ineffective. The chemotherapeutic regimen is the predominant systemic treatment modality for TNBC in current clinical practice. However, the efficacy of chemotherapy in TNBC is variable, with response rates varying between a wide range of patients, and the emerging resistance further adds to the difficulties. Furthermore, TNBC exhibits a higher mutational burden and is acknowledged as the most immunogenic of all BC subtypes. Consequently, the application of immune checkpoint inhibition has been investigated in TNBC, yielding promising outcomes. Recent evidence identified extracellular vesicles (EVs) as an important contributor in the context of TNBC immunotherapy. In view of the extraordinary ability of EVs to transfer bioactive molecules, such as proteins, lipids, DNA, mRNAs, and small miRNAs, between the cells, EVs are considered a promising diagnostic biomarker and novel drug delivery system among the prospects for immunotherapy. The present review provides an in–depth understanding of how EVs influence TNBC progression, its immune regulation, and their contribution as a predictive biomarker for TNBC. The final part of the review focuses on the recent key advances in immunotherapeutic strategies for better understanding the complex interplay between EVs and the immune system in TNBC and further developing EV–based targeted immunotherapies
Finite Element Analysis of Free Vibration of the Delaminated Composite Plate with Variable Kinematic Multilayered Plate Elements
Composite laminates are prone to delamination. Implementation of delamination in the Carrera Unified Formulation frame work using nine noded quadrilateral MITC9 element is discussed in this article. MITC9 element is devoid of shear locking and membrane locking. Delaminated as well as healthy structure is analyzed for free mode vibration. The results from the present work are compared with the available experimental or/and research article or/and the three dimensional finite element simulations. The effect of different kinds and different percentages of area of delamination on the first three natural frequencies of the structure is discussed. The presence of open-mode delamination mode shape for large delaminations within the first three natural frequencies is discussed. Also, the switching of places between the second bending mode, with that of the first torsional mode frequency is discussed. Results obtained from different ordered theories are compared in the presence of delamination. Advantage of layerwise theories as compared to equivalent single layer theories for very large delaminations is stated. The effect of different kinds of delamination and their effect on the second bending and first torsional mode shape is discussed. (C) 2014 Elsevier Ltd. All rights reserved
Integrating transcriptomic and proteomic data for accurate assembly and annotation of genomes
© 2017 Wong et al.; Published by Cold Spring Harbor Laboratory Press. Complementing genome sequence with deep transcriptome and proteome data could enable more accurate assembly and annotation of newly sequenced genomes. Here, we provide a proof-of-concept of an integrated approach for analysis of the genome and proteome of Anopheles stephensi, which is one of the most important vectors of the malaria parasite. To achieve broad coverage of genes, we carried out transcriptome sequencing and deep proteome profiling of multiple anatomically distinct sites. Based on transcriptomic data alone, we identified and corrected 535 events of incomplete genome assembly involving 1196 scaffolds and 868 protein-coding gene models. This proteogenomic approach enabled us to add 365 genes that were missed during genome annotation and identify 917 gene correction events through discovery of 151 novel exons, 297 protein extensions, 231 exon extensions, 192 novel protein start sites, 19 novel translational frames, 28 events of joining of exons, and 76 events of joining of adjacent genes as a single gene. Incorporation of proteomic evidence allowed us to change the designation of more than 87 predicted noncoding RNAs to conventional mRNAs coded by protein-coding genes. Importantly, extension of the newly corrected genome assemblies and gene models to 15 other newly assembled Anopheline genomes led to the discovery of a large number of apparent discrepancies in assembly and annotation of these genomes. Our data provide a framework for how future genome sequencing efforts should incorporate transcriptomic and proteomic analysis in combination with simultaneous manual curation to achieve near complete assembly and accurate annotation of genomes
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