1,345 research outputs found

    Affective responses to chromatic ambient light in a vehicle

    Full text link
    This study investigates the emotional responses to the color of vehicle interior lighting using self-assessment and electroencephalography (EEG). The study was divided into two sessions: the first session investigated the potential of ambient lighting colors, and the second session was used to develop in-vehicle lighting color guidelines. Every session included thirty subjects. In the first session, four lighting colors were assessed using seventeen adjectives. As a result, 'Preference, Softness, Brightness, and Uniqueness were found to be the four factors that best characterize the atmospheric properties of interior lighting in vehicles. Ambient illumination, according to EEG data, increased people's arousal and lowered their alpha waves. The following session investigated a wider spectrum of colors using four factors extracted from the previous session. As a result, bluish and purplish lighting colors had the highest preference and uniqueness among ten lighting colors. Green received an intermediate preference and a high uniqueness score. With its great brightness and softness, Neutral White also achieved an intermediate preference rating. Despite receiving a low preference rating, warm colors were considered to be soft. Red was the least preferred color, but its uniqueness and roughness were highly rated. This study is expected to provide a basic theory on emotional lighting guidelines in the vehicle context, providing manufacturers with objective rationale

    Link between allosteric signal transduction and functional dynamics in a multi-subunit enzyme: S-adenosylhomocysteine hydrolase

    Full text link
    S-adenosylhomocysteine hydrolase (SAHH), a cellular enzyme that plays a key role in methylation reactions including those required for maturation of viral mRNA, is an important drug target in the discovery of antiviral agents. While targeting the active site is a straightforward strategy of enzyme inhibition, evidences of allosteric modulation of active site in many enzymes underscore the molecular origin of signal transduction. Information of co-evolving sequences in SAHH family and the key residues for functional dynamics that can be identified using native topology of the enzyme provide glimpses into how the allosteric signaling network, dispersed over the molecular structure, coordinates intra- and inter-subunit conformational dynamics. To study the link between the allosteric communication and functional dynamics of SAHHs, we performed Brownian dynamics simulations by building a coarse-grained model based on the holo and ligand-bound structures. The simulations of ligand-induced transition revealed that the signal of intra-subunit closure dynamics is transmitted to form inter-subunit contacts, which in turn invoke a precise alignment of active site, followed by the dimer-dimer rotation that compacts the whole tetrameric structure. Further analyses of SAHH dynamics associated with ligand binding provided evidence of both induced fit and population shift mechanisms, and also showed that the transition state ensemble is akin to the ligand-bound state. Besides the formation of enzyme-ligand contacts at the active site, the allosteric couplings from the residues distal to the active site is vital to the enzymatic function.Comment: 35 pages, 14 figures, 3 Table

    SERS Application for Analysis of Live Single Cell

    Get PDF
    Monitoring changes of the protein contents and other macromolecules inside a living single cell during the key cellular processes such as cell differentiation, division, and apoptosis is a challenge for researchers. Raman spectroscopy is a powerful analytical technique for several biomedical applications that is rapid, reagent-free, and non-destructive while limited application with its weak signal. Surface-enhanced Raman scattering (SERS) technique is widely used to enhance the Raman signal (109-15 fold) by using surface Plasmon resonance of noble metal nanostructures (e.g. silver, gold, copper). SERS is a non-destructive spectroscopic method applied for biomedical samples. In this chapter, we will discuss the principles and fundamentals of SERS technique, theories and different strategies to obtain SERS signals such as immobilization of metal colloids on a substrate. Also, we show the SERS applications including the identification and discrimination of different types of cells (healthy and nonhealthy cells, e.g., cancer cells), and the interaction of cells with different drugs will also be discussed on monolayer bulk cells as well as on single-cell basis and for stem cell differentiation. In addition, we show the coupling of SERS with electrochemical techniques (EC-SERS) as spectroelectrochemical technique and its applications in biology, bioanalytical, and life science

    De novo identification of LTR retrotransposons in eukaryotic genomes

    Get PDF
    BACKGROUND: LTR retrotransposons are a class of mobile genetic elements containing two similar long terminal repeats (LTRs). Currently, LTR retrotransposons are annotated in eukaryotic genomes mainly through the conventional homology searching approach. Hence, it is limited to annotating known elements. RESULTS: In this paper, we report a de novo computational method that can identify new LTR retrotransposons without relying on a library of known elements. Specifically, our method identifies intact LTR retrotransposons by using an approximate string matching technique and protein domain analysis. In addition, it identifies partially deleted or solo LTRs using profile Hidden Markov Models (pHMMs). As a result, this method can de novo identify all types of LTR retrotransposons. We tested this method on the two pairs of eukaryotic genomes, C. elegans vs. C. briggsae and D. melanogaster vs. D. pseudoobscura. LTR retrotransposons in C. elegans and D. melanogaster have been intensively studied using conventional annotation methods. Comparing with previous work, we identified new intact LTR retroelements and new putative families, which may imply that there may still be new retroelements that are left to be discovered even in well-studied organisms. To assess the sensitivity and accuracy of our method, we compared our results with a previously published method, LTR_STRUC, which predominantly identifies full-length LTR retrotransposons. In summary, both methods identified comparable number of intact LTR retroelements. But our method can identify nearly all known elements in C. elegans, while LTR_STRUCT missed about 1/3 of them. Our method also identified more known LTR retroelements than LTR_STRUCT in the D. melanogaster genome. We also identified some LTR retroelements in the other two genomes, C. briggsae and D. pseudoobscura, which have not been completely finished. In contrast, the conventional method failed to identify those elements. Finally, the phylogenetic and chromosomal distributions of the identified elements are discussed. CONCLUSION: We report a novel method for de novo identification of LTR retrotransposons in eukaryotic genomes with favorable performance over the existing methods

    Intelligent CCTV Surveillance Based on Sound Recognition and Sound Localization

    Get PDF
    CCTV is used for many purposes, especially for surveillance and fortraffic condition monitoring. This paper proposesan intelligent CCTV system that tracks sound events based on sound recognition and sound localization. From the experimental results, it is evident that the proposed method can be successfully used for the intelligent CCTV system of CCTV

    Dysfunction of 67-kDa Laminin Receptor Disrupts BBB Integrity via Impaired Dystrophin/AQP4 Complex and p38 MAPK/VEGF Activation Following Status Epilepticus

    Get PDF
    Status epilepticus (SE, a prolonged seizure activity) impairs brain-blood barrier (BBB) integrity, which results in secondary complications following SE. The non-integrin 67-kDa laminin receptor (67-kDa LR) plays a role in cell adherence to laminin (a major glycoprotein component in basement membrane), and participates laminin-mediated signaling pathways including p38 mitogen-activated protein kinase (p38 MAPK). Thus, we investigated the role of 67-kDa LR in SE-induced vasogenic edema formation in the rat piriform cortex (PC). SE diminished 67-kDa LR expression, but increased laminin expression, in endothelial cells accompanied by the reduced SMI-71 (a rat BBB barrier marker) expression. Astroglial 67-kDa LR expression was also reduced in the PC due to massive astroglial loss. 67-kDa LR neutralization led to serum extravasation in the PC concomitant with the reduced SMI-71 expression. 67-kDa LR neutralization also decreased expressions of dystrophin and aquaporin-4 (AQP4). In addition, it increased p38 MAPK phosphorylation and expressions of vascular endothelial growth factor (VEGF), laminin and endothelial nitric oxide synthase (eNOS), which were abrogated by SB202190, a p38 MAPK inhibitor. Therefore, our findings indicate that 67-kDa LR dysfunction may disrupt dystrophin-AQP4 complex, which would evoke vasogenic edema formation and subsequent laminin over-expression via activating p38 MAPK/VEGF axis

    Gene discovery in the horned beetle Onthophagus taurus

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Horned beetles, in particular in the genus <it>Onthophagus</it>, are important models for studies on sexual selection, biological radiations, the origin of novel traits, developmental plasticity, biocontrol, conservation, and forensic biology. Despite their growing prominence as models for studying both basic and applied questions in biology, little genomic or transcriptomic data are available for this genus. We used massively parallel pyrosequencing (Roche 454-FLX platform) to produce a comprehensive EST dataset for the horned beetle <it>Onthophagus taurus</it>. To maximize sequence diversity, we pooled RNA extracted from a normalized library encompassing diverse developmental stages and both sexes.</p> <p>Results</p> <p>We used 454 pyrosequencing to sequence ESTs from all post-embryonic stages of <it>O. taurus. </it>Approximately 1.36 million reads assembled into 50,080 non-redundant sequences encompassing a total of 26.5 Mbp. The non-redundant sequences match over half of the genes in <it>Tribolium castaneum</it>, the most closely related species with a sequenced genome. Analyses of Gene Ontology annotations and biochemical pathways indicate that the <it>O. taurus </it>sequences reflect a wide and representative sampling of biological functions and biochemical processes. An analysis of sequence polymorphisms revealed that SNP frequency was negatively related to overall expression level and the number of tissue types in which a given gene is expressed. The most variable genes were enriched for a limited number of GO annotations whereas the least variable genes were enriched for a wide range of GO terms directly related to fitness.</p> <p>Conclusions</p> <p>This study provides the first large-scale EST database for horned beetles, a much-needed resource for advancing the study of these organisms. Furthermore, we identified instances of gene duplications and alternative splicing, useful for future study of gene regulation, and a large number of SNP markers that could be used in population-genetic studies of <it>O. taurus </it>and possibly other horned beetles.</p
    • …
    corecore