1,052 research outputs found
Alien Registration- Derosier, Ida (Houlton, Aroostook County)
https://digitalmaine.com/alien_docs/36124/thumbnail.jp
Alien Registration- Derosier, Joseph (Lewiston, Androscoggin County)
https://digitalmaine.com/alien_docs/29697/thumbnail.jp
Kinks, rings, and rackets in filamentous structures
Carbon nanotubes and biological filaments each spontaneously assemble into
kinked helices, rings, and "tennis racket" shapes due to competition between
elastic and interfacial effects. We show that the slender geometry is a more
important determinant of the morphology than any molecular details. Our
mesoscopic continuum theory is capable of quantifying observations of these
structures, and is suggestive of their occurrence in other filamentous
assemblies as well.Comment: This paper was originally published in PNAS 100: 12141-12146 (2003).
The present version has corrected Eq. 3, A1, and A2, and some minor typo
Reader perception of the usefulness and credibility of journalistic automotive reviews
"December 2013.""A thesis presented to the Faculty of the Graduate School University of Missouri In Partial Fulfillment Of the Requirements for the Degree Master of Arts."Thesis supervisor: Randall Smith.The aim of this research is to examine the usefulness of journalistic automotive reviews from the perspective of readers making purchase decisions. Additionally, this study also looked at the perceived credibility of the sources of those reviews. Intercept interviews were conducted at a new-car dealership in a Midwestern city to determine what sources of information buyers consulted in their decision-making processes. When it was found that journalistic automotive reviews played a role, additional questions were asked about the usefulness of the reviews and how credible users felt they were. Data was then transcribed, coded and grouped into themes. The results showed the majority of car buyers do not use journalistic automotive reviews or automotive journalism of any kind. This was in large part because outside factors such as money concerns, relationships with brands and people, enticements and personal circumstances limited purchase and information consideration sets. Those who did use automotive reviews believed them to be mostly credible, but they expressed skepticism depending on the presence or absence of the reviewer's stated professional background and of detailed information sensitive to the needs of the audience.Includes bibliographical references (pages 44-47)
Plastin 1 widens stereocilia by transforming actin filament packing from hexagonal to liquid
With their essential role in inner-ear function, stereocilia of sensory hair cells demonstrate the importance of cellular actin protrusions. Actin packing in stereocilia is mediated by crosslinkers of the plastin, fascin, and espin families. While mice lacking ESPN (espin) have no vestibular or auditory function, we found that mice that either lacked PLS1 (plastin 1) or had nonfunctional FSCN2 (fascin 2) had reduced inner-ear function, with double-mutant mice most strongly affected. Targeted mass spectrometry indicated that PLS1 was the most abundant crosslinker in vestibular stereocilia, and the second-most-abundant protein overall; ESPN only accounted for ~15% of the total crosslinkers in bundles. Mouse utricle stereocilia lacking PLS1 were shorter and thinner than wild-type stereocilia. Surprisingly, while wild-type stereocilia had random liquid packing of their actin filaments, stereocilia lacking PLS1 had orderly hexagonal packing. While all three crosslinkers are required for stereocilia structure and function, PLS1 biases actin towards liquid packing, which allows stereocilia to grow to a greater diameter
Structural Reorganization of Parallel Actin Bundles by Crosslinking Proteins: Incommensurate States of Twist
We construct a coarse-grained model of parallel actin bundles crosslinked by
compact, globular bundling proteins, such as fascin and espin, necessary
components of filapodial and mechanosensory bundles. Consistent with structural
observations of bundles, we find that the optimal geometry for crosslinking is
overtwisted, requiring a coherent structural change of the helical geometry of
the filaments. We study the linker-dependent thermodynamic transition of
bundled actin filaments from their native state to the overtwisted state and
map out the "twist-state'' phase diagram in terms of the availability as well
as the flexibility of crosslinker proteins. We predict that the transition from
the uncrosslinked to fully-crosslinked state is highly sensitive to linker
flexibility: flexible crosslinking smoothly distorts the twist-state of bundled
filaments, while rigidly crosslinked bundles undergo a phase transition,
rapidly overtwisting filaments over a narrow range of free crosslinker
concentrations. Additionally, we predict a rich spectrum of intermediate
structures, composed of alternating domains of sparsely-bound (untwisted) and
strongly-bound (overtwisted) filaments. This model reveals that subtle
differences in crosslinking agents themselves modify not only the detailed
structure of parallel actin bundles, but also the thermodynamic pathway by
which they form.Comment: Main Text (25 pages, 7 figures) with supporting material (12 pages, 9
figures, 2 tables
A clinical evaluation of corneal and refractive changes observed when switching from PMMA to Paraperm O2 contact lens wear
The purpose of this study was to observe the corneal and refractive changes that occur when a PMMA wearer is refit with a highly gas permeable contact lens. Pachometry data indicated that the corneal thickness of most subjects increased after having worn the lenses for two weeks. The corneal curvatures of nearly all subjects steepened and showed an increase in cylinder. Increases in myopia, which correlated with the steepened corneal curvatures, occurred after two weeks of Paraperm wear. These results could differ if the subjects were followed for a longer period of time
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