33 research outputs found

    Enhancing Egress Drills: Preparation and Assessment of Evacuee Performance

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    This article explores how egress drills-specifically those related to fire incidents-are currently used, their impact on safety levels, and the insights gained from them. It is suggested that neither the merits of egress drills are well understood, nor the impact on egress performance well characterized. In addition, the manner in which they are conducted varies both between and within regulatory jurisdictions. By investigating their strengths and limitations, this article suggests opportunities for their enhancement possibly through the use of other egress models to support and expand upon the benefits provided. It is by no means suggested that drills are not important to evacuation safety-only that their inconsistent use and the interpretation of the results produced may mean we (as researchers, practitioners, regulators, and stakeholders) are not getting the maximum benefit out of this important tool

    The mechanism of functional up-regulation of P2X3 receptors of trigeminal sensory neurons in a genetic mouse model of Familial Hemiplegic Migraine type 1 (FHM-1)

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    A knock-in (KI) mouse model of FHM-1 expressing the R192Q missense mutation of the Cacna1a gene coding for the \u3b11 subunit of CaV2.1 channels shows, at the level of the trigeminal ganglion, selective functional up-regulation of ATP -gated P2X3 receptors of sensory neurons that convey nociceptive signals to the brainstem. Why P2X3 receptors are constitutively more responsive, however, remains unclear as their membrane expression and TRPV1 nociceptor activity are the same as in wildtype (WT) neurons. Using primary cultures of WT or KI trigeminal ganglia, we investigated whether soluble compounds that may contribute to initiating (or maintaining) migraine attacks, such as TNF\u3b1, CGRP, and BDNF, might be responsible for increasing P2X3 receptor responses. Exogenous application of TNF\u3b1 potentiated P2X3 receptor-mediated currents of WT but not of KI neurons, most of which expressed both the P2X3 receptor and the TNF\u3b1 receptor TNFR2. However, sustained TNF\u3b1 neutralization failed to change WT or KI P2X3 receptor currents. This suggests that endogenous TNF\u3b1 does not regulate P2X3 receptor responses. Nonetheless, on cultures made from both genotypes, exogenous TNF\u3b1 enhanced TRPV1 receptor-mediated currents expressed by a few neurons, suggesting transient amplification of TRPV1 nociceptor responses. CGRP increased P2X3 receptor currents only in WT cultures, although prolonged CGRP receptor antagonism or BDNF neutralization reduced KI currents to WT levels. Our data suggest that, in KI trigeminal ganglion cultures, constitutive up-regulation of P2X3 receptors probably is already maximal and is apparently contributed by basal CGRP and BDNF levels, thereby rendering these neurons more responsive to extracellular ATP. \ua9 2013 Hullugundi et al

    High efficiency method to obtain supercoiled DNA with a commercial plasmid purification kit.

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    Supercoiled state corresponds to the active form for plasmid applications. The relaxed circular form of plasmids is often inactive or poorly active. To obtain significant amounts of almost fully supercoiled DNA, we modified the standard protocol of a commercially available Qiagen plasmid purification kit. Our changes led to isolation of almost 100% of the plasmids in the supercoiled state. The modified protocol was used to purify different plasmids with consistent results. The purified plasmids maintain supercoiled state for about two months. The modified protocol is very advantageous because it allows easy DNA production with high degree of supercoiled form at low cost

    A Sperm Nuclear Basic Protein from the Sperm of the Marine Worm Chaetopterus variopedatus with Sequence Similarity to the Arginine-Rich C-Termini of Chordate Protamine-Likes.

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    The sperm nuclear basic proteins (SNBPs) of the marine annelid worm Chaetopterus variopedatus have been shown previously to consist of a mixture of two SNBPs: histone H1-like (CvH1) and C.variopedatus protamine-like (CvPL). Here, we report the structural characterization of CvPL. The protein has a molecular weight of 8370.5 Da, a K/R ratio of 0.34, and a secondary structure, which are intermediate between those of protamine (P) and protamine-like (PL) SNBPs. The N-terminal sequence of CvPL shows a high extent of similarity with the arginine-rich C-terminal domain of chordate PL-type SNBPs. Furthermore, the protein binds to DNA in a similar fashion as vertebrate PLs and their own CvH1, but in a way that is different from that of the lysine-rich somatic H1 histones. We have experimentally determined the molar ratio CvH1:CvPL to be ∼1:6 in C. variopedatus sperm. Based on all of these, a model is proposed for the organization of the sperm chromatin by CvH1 and CvPL
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