6,166 research outputs found
Investigating Myosin Light Chain Kinase Binding with Actin in Human Airway Smooth Muscle Cells
Myosin light chain kinase plays an integral role in initiating and regulating
smooth muscle contraction. These experiments were conducted to help illuminate and
better understand the process by which myosin light chain kinase interacts with actin and
myosin in the ventral stress fibers of permeabilized human airway smooth muscle cells.
The first 75 residues of the N-terminal end of MLCK (GST tagged N75) contain the three
DFRXXL motifs, which are sufficient for actin binding [1-4]. N75 binding to actin was
imaged using fluorescence microscopy and total internal reflection microscopy under
varying conditions. N75 binding was inhibited when cells were pre-treated with the S1
fragment of myosin heads. This suggests that the DFRXXL motifs of MLCK are
competing with S1 for actin binding sites. These experiments help better the
understanding of the role myosin light chain kinase plays in the regulation and
contraction of smooth muscle contraction
Comparison of solitary and collective foraging strategies of Caenorhabditis elegans in patchy food distributions
Collective foraging has been shown to benefit organisms in environments where food is patchily distributed, but whether this is true in the case where organisms do not rely on long range communications to coordinate their collective behaviour has been understudied. To address this question, we use the tractable laboratory model organism Caenorhabditis elegans, where a social strain (npr-1 mutant) and a solitary strain (N2) are available for direct comparison of foraging strategies. We first developed an on-lattice minimal model for comparing collective and solitary foraging strategies, finding that social agents benefit from feeding faster and more efficiently simply due to group formation. Our laboratory foraging experiments with npr-1 and N2 worm populations, however, show an advantage for solitary N2 in all food distribution environments that we tested. We incorporated additional strain43 specific behavioural parameters of npr-1 and N2 worms into our model and computationally identified N2âs higher feeding rate to be the key factor underlying its advantage, without which it is possible to recapitulate the advantage of collective foraging in patchy environments. Our work highlights the theoretical advantage of collective foraging due to group formation alone without long-range interactions, and the valuable role of modelling to guide experiments
Breathlessness is associated with urinary incontinence in men: A community-based study
<p>Abstract</p> <p>Background</p> <p>Urinary incontinence (UI) is a distressing problem for older people. To investigate the relationship between UI and respiratory symptoms among middle-aged and older men, a community-based study was conducted in Japan.</p> <p>Methods</p> <p>A convenience sample of 668 community-dwelling men aged 40 years or above was recruited from middle and southern Japan. The International Consultation on Incontinence Questionnaire-Short Form, the Medical Research Council's dyspnoea scale and the Australian Lung Foundation's Feeling Short of Breath scale, were administered by face-to-face interviews to ascertain their UI status and respiratory symptoms.</p> <p>Results</p> <p>The overall prevalence of UI was 7.6%, with urge-type leakage (59%) being most common among the 51 incontinent men. The presence of respiratory symptoms was significantly higher among incontinent men than those without the condition, especially for breathlessness (45% versus 30%, <it>p </it>= 0.025). The odds of UI for breathlessness was 2.11 (95% confidence interval 1.10-4.06) after accounting for age, body mass index, smoking and alcohol drinking status of each individual.</p> <p>Conclusions</p> <p>The findings suggested a significant association between UI and breathlessness in middle-aged and older men.</p
Oscillations of starless cores
If the split, asymmetric molecular spectral line profiles that are seen in
many starless cores are interpreted as indicative of global collapse or
expansion of the core then one possible implication is that most starless cores
have short lifetimes on the order of the collapse or sound crossing time scale.
An alternative interpretation of the line profiles as indicative of
perturbations on an underlying equilibrium structure leads to the opposite
implication, that many cores have long lifetimes. While evidence suggests that
some cores are collapsing on a free-fall time scale, we show that observations
of some other starless cores can be reproduced by a model of non-radial
oscillations about the equilibrium configuration of a pressure-bounded,
thermally-supported sphere (Bonnor-Ebert sphere). We model the oscillations as
linear perturbations following a standard analysis developed for stellar
pulsations and compare the column densities and molecular spectral line
profiles predicted from a particular model to observations of the Bok globule
B68.Comment: submitted to the Astrophysical Journa
Measurements of electron-proton elastic cross sections for
We report on precision measurements of the elastic cross section for
electron-proton scattering performed in Hall C at Jefferson Lab. The
measurements were made at 28 unique kinematic settings covering a range in
momentum transfer of 0.4 5.5 . These measurements
represent a significant contribution to the world's cross section data set in
the range where a large discrepancy currently exists between the ratio of
electric to magnetic proton form factors extracted from previous cross section
measurements and that recently measured via polarization transfer in Hall A at
Jefferson Lab.Comment: 17 pages, 18 figures; text added, some figures replace
Drug Adverse Event Detection in Health Plan Data Using the Gamma Poisson Shrinker and Comparison to the Tree-based Scan Statistic
Background: Drug adverse event (AE) signal detection using the Gamma Poisson Shrinker (GPS) is commonly applied in spontaneous reporting. AE signal detection using large observational health plan databases can expand medication safety surveillance. Methods: Using data from nine health plans, we conducted a pilot study to evaluate the implementation and findings of the GPS approach for two antifungal drugs, terbinafine and itraconazole, and two diabetes drugs, pioglitazone and rosiglitazone. We evaluated 1676 diagnosis codes grouped into 183 different clinical concepts and four levels of granularity. Several signaling thresholds were assessed. GPS results were compared to findings from a companion study using the identical analytic dataset but an alternative statistical methodâthe tree-based scan statistic (TreeScan). Results: We identified 71 statistical signals across two signaling thresholds and two methods, including closely-related signals of overlapping diagnosis definitions. Initial review found that most signals represented known adverse drug reactions or confounding. About 31% of signals met the highest signaling threshold. Conclusions: The GPS method was successfully applied to observational health plan data in a distributed data environment as a drug safety data mining method. There was substantial concordance between the GPS and TreeScan approaches. Key method implementation decisions relate to defining exposures and outcomes and informed choice of signaling thresholds
Limited morbidity and possible radiographic benefit of C2
Background: The study aims to evaluate differences in alignment and clinical outcomes between surgical cervical deformity (CD) patients with a subaxial upper-most instrumented vertebra (UIV) and patients with a UIV at C2. Use of CD-corrective instrumentation in the subaxial cervical spine is considered risky due to narrow subaxial pedicles and vertebral artery anatomy. While C2 fixation provides increased stability, the literature lacks guidelines indicating extension of CD-corrective fusion from the subaxial spine to C2.
Methods: Included: operative CD patients with baseline (BL) and 1-year postop (1Y) radiographic data, cervical UIV â„ C2. Patients were grouped by UIV: C2 or subaxial (C3-C7) and propensity score matched (PSM) for BL cSVA. Mean comparison tests assessed differences in BL and 1Y patient-related, radiographic, and surgical data between UIV groups, and BL-1Y changes in alignment and clinical outcomes.
Results: Following PSM, 31 C2 UIV and 31 subaxial UIV patients undergoing CD-corrective surgery were included. Groups did not differ in BL comorbidity burden (P=0.175) or cSVA (P=0.401). C2 patients were older (64
Conclusions: C2 UIV patients showed similar cervical range of motion and baseline to 1-year functional outcomes as patients with a subaxial UIV. C2 UIV patients also showed greater baseline to 1-year horizontal gaze improvement and had complication profiles similar to subaxial UIV patients, demonstrating the radiographic benefit and minimal functional loss associated with extending fusion constructs to C2. In the treatment of adult cervical deformities, extension of the reconstruction construct to the axis may allow for certain clinical benefits with less morbidity than previously acknowledged
Perspective from a Younger Generation -- The Astro-Spectroscopy of Gisbert Winnewisser
Gisbert Winnewisser's astronomical career was practically coextensive with
the whole development of molecular radio astronomy. Here I would like to pick
out a few of his many contributions, which I, personally, find particularly
interesting and put them in the context of newer results.Comment: 14 pages. (Co)authored by members of the MPIfR (Sub)millimeter
Astronomy Group. To appear in the Proceedings of the 4th
Cologne-Bonn-Zermatt-Symposium "The Dense Interstellar Medium in Galaxies"
eds. S. Pfalzner, C. Kramer, C. Straubmeier, & A. Heithausen (Springer:
Berlin
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