1,512 research outputs found

    Expression of Smooth Muscle Myosin Heavy Chains and Unloaded Shortening in Single Smooth Muscle Cells

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    The functional significance of the variable expression of the smooth muscle myosin heavy chain (SM-MHC) tail isoforms, SM1 and SM2, was examined at the mRNA level (which correlates with the protein level) in individual permeabilized rabbit arterial smooth muscle cells (SMCs). The length of untethered single permeabilized SMCs was monitored during unloaded shortening in response to increased Ca2+ (pCa 6.0), histamine (1 μM), and phenylephrine (1 μM). Subsequent to contraction, the relative expression of SM1 and SM2 mRNAs from the same individual SMCs was determined by reverse transcription-polymerase chain reaction amplification and densitometric analysis. Correlational analyses between the SM2-to-SM1 ratio and unloaded shortening in saponin- and α-toxin-permeabilized SMCs (n = 28) reveal no significant relationship between the SM-MHC tail isoform ratio and unloaded shortening velocity. The best correlations between SM2/SM1 and the contraction characteristics of untethered vascular SMCs were with the minimum length attained following contraction (n = 20 andr = 0.72 for α-toxin,n = 8 andr = 0.78 for saponin). These results suggest that the primary effect of variable expression of the SM1 and SM2 SM-MHC tail isoforms is on the cell final length and not on shortening velocity

    A chemoselective and continuous synthesis of m-sulfamoylbenzamide analogues

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    For the synthesis of m-sulfamoylbenzamide analogues, small molecules which are known for their bioactivity, a chemoselective procedure has been developed starting from m-(chlorosulfonyl) benzoyl chloride. Although a chemoselective process in batch was already reported, a continuous-flow process reveals an increased selectivity at higher temperatures and without catalysts. In total, 15 analogues were synthesized, using similar conditions, with yields ranging between 65 and 99%. This is the first automated and chemoselective synthesis of m- sulfamoylbenzamide analogues

    Myosin Isoform Heterogeneity in Single Smooth Muscle Cells

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    We review the current understanding of the myosin heavy chain (MHC) isoforms and show that the mRNA levels of smooth muscle (SM)1 and SM2 mimic the expressed levels of SM1 and SM2 protein. The reverse transcriptase-polymerase chain reaction technique has been shown to be sufficiently sensitive to examine SM-MHC expression at the single cell level. Most single smooth muscle cells isolated from adult rabbit carotid express both SM1 and SM2. However, expression of these SM-MHC isoforms at the cellular level is nonuniform and highly variable. This work provides a foundation for future investigations as to the possible unique functional characteristics of the SM-MHC isoforms, SM1 and SM2. This methodology may also prove useful when used with mechanical studies to determine the physiological significance of the alternatively spliced myosin isoforms, including the SM-MHC-head and LC17 isoforms

    A methodology for finding persons of national interest

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    The asymmetrical threats that challenge U.S. national policies are not large standing armies, but rather individuals who seek to usurp and coerce U.S. national interests. The nature of today's threats call for the U.S. military to change from finding, fixing, and destroying the enemy's forces to identifying, locating and capturing rogue individuals in order to destroy networks. To counter such threats, the USG will have to quickly and efficiently identify and find these targets globally. Unfortunately, no military doctrine, framework or process currently exists for finding and apprehending these Persons of National Interest (PONIs). Since military planners and intelligence analysts are neither educated nor trained in the methods or procedures necessary to find and capture PONIs, this thesis will propose a methodology to do so. This involves the development of an analytical process, and an organizational structure and procedure to identify and locate PONIs. Consequently, the United States government's ability to prosecute the war on terrorism today, and to find and apprehend PONIs in the future, depends on its ability to develop and institutionalize a comprehensive manhunting strategy now.http://archive.org/details/manhuntingmethod109451921US Air Force (USAF) author.Approved for public release; distribution is unlimited

    Einselection and Decoherence from an Information Theory Perspective

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    We introduce and investigate a simple model of conditional quantum dynamics. It allows for a discussion of the information-theoretic aspects of quantum measurements, decoherence, and environment-induced superselection (einselection).Comment: Proceedings of the Planck constant centenary meeting. Uses annalen.cls and fleqn.st

    Microstructures in subglacial and proglacial sediments : understanding faults, folds and fabrics, and the influence of water on the style of deformation

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    Macroscopic field and micromorphological studies have been carried out on subglacially and proglacially deformed glacigenic sequences at a number of sites throughout Scotland, UK. Examination of microstructures (folds, faults, hydrofractures, plasmic fabrics) aided understanding of the deformation histories preserved in the sediments, but a similar range of structures were developed in both subglacial and proglacial settings. Discrimination between subglacial and proglacial deformation was only possible when micromorphological data was used in conjunction with larger-scale field observations. Variations in lithology and water content were controlling factors influencing the style and apparent intensity of deformation recorded. Changes in pore-water content and pressure during deformation can lead to liquefaction and hydrofracturing, with early formed structures locally controlling the pattern of water-escape. Liquefaction can also lead to homogenisation of the sediments and the destruction of earlier deformation structures, even at relatively low strains. Beds or zones of liquefied sand and silt may form highly ‘lubricated’ detachments within the sediment pile, resulting in a marked reduction in the amount of shear transmitted to underlying units. A multidisciplinary approach, involving sedimentological, geomorphological, stratigraphical and structural field observations, combined with micromorphological analysis, is recommended to confidently unravel the glacitectonic history and depositional environment of most deformed glacigenic sedimentary sequences

    Are Library Users Also Computer Users? A Survey of Faculty and Implications for Services.

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    Describes the results of a survey of faculty members at Western Michigan University which was conducted to explore the relationship between faculty use of university libraries and faculty use of computers. Implications for libraries are discussed, including computer databases, faculty assistance, collaboration with computing staff, and marketing of electronic services

    Macrostructural analysis : unravelling polyphase glacitectonic histories

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    Many Pleistocene glacial profiles look extremely simple, comprising till, or glacitectonite, overlying older sediments or bedrock (Figure 4.1). In more complex sequences the till may itself be overlain by younger sediments laid down as the ice retreated or during a completely separate, later phase of advance. Macroscopically, subglacial traction tills (Evans et al., 2007) are typically massive, unstructured deposits suggesting that it should be relatively straightforward to unravel the glacitectonic deformation history recorded by the sequence. Many reconstructions do indeed look very simple, slabs of sediment have been tilted and stacked and then overridden by the glacier to cap the structure with till. Added to this is the use of vertical exaggeration which makes the whole structure look like alpine tectonics (for an example see fig. 5 in van Gijssel, 1987). Dropping the exaggeration led to the recognition that actually we were looking at much more horizontal structures, i.e. overriding nappes and not imbricated slabs (van der Wateren, 1987). Traditionally (van der Meer, 1987) glaciotectonics was thought to relate to large structures like big push moraines and not to smaller structures like drag structures underneath tills (Figure 4.2), let alone to the tills themselves. With the notion that deforming bed tills are tectonically and not sedimentologically structured and could be regarded as tectomicts (Menzies et al., 2006), comes the realisation that glacitectonics happens across a wide range of scales, from the microscopic to tens of kilometres. Only by realising the full range of glaciotectonic scales can we hope to understand the processes
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