3,187 research outputs found
Preaching to the Choir: Americans Prefer Communicating to Copartisan Elected Officials
Past work suggests that partisan attachments isolate citizens from encountering elite messages contrary to their points of view. Here, we present evidence that partisan attachments not only serve to filter the information citizens receive from political elites; they also work in the other direction, isolating politicians from encountering potentially contrary perspectives from citizens. In particular, we hypothesized that Americans prefer expressing their opinions to politicians who share their party identification and avoid contacting outpartisan politicians. Three studiesâdrawing on a mixture of observational, field experimental, and natural experimental approachesâsupport this hypothesis: Citizens prefer to âpreach to the choir,â contacting legislators of the same partisan stripe. In light of evidence that contact from citizens powerfully affects politiciansâ stances and priorities, these findings suggest a feedback loop that might aggravate political polarization and help explain how politicians of different parties could develop different perceptions of the same constituencies
Estimating metabolic rate for butadiene at steady state using a Bayesian physiologically-based pharmacokinetic model
In a study of 133 volunteer subjects, demographic, physiologic and pharmacokinetic
data through exposure to 1,3-Butadiene (BD) were collected in order to
estimate the percentage of BD concentration metabolized at steady state, and to determine
whether this percentage varies across gender, racial, and age groups. During the
20 min of continuous exposure to 2 parts per million (ppm) of BD, five measurements
of exhaled concentration were made on each subject. In the following 40 min washout
period, another five measurements were collected. A Bayesian hierarchical compartmental
physiologically-based pharmacokinetic model (PKPB) was used. Using prior
information on the model parameters, Markov Chain Monte Carlo (MCMC) simulation
was conducted to obtain posterior distributions. The overall estimate of the
mean percent of BD metabolized at steady state was 12.7% (95% credible interval:
7.7â17.8%). There was no significant difference in gender with males having a mean
of 13.5%, and females 12.3%. Among the racial groups, Hispanic (13.9%), White
(13.0%), Asian (12.1%), and Black (10.9%), the significant difference came from
the difference between Black and Hispanic with a 95% credible interval from â5.63
to â0.30%. Those older than 30 years had a mean of 12.2% versus 12.9% for the younger group; although this was not a statistically significant difference. Given a
constant inhalation input of 2 ppm, at steady state, the overall mean exhaled concentrationwas
estimated to be 1.75ppm (95% credible interval: 1.64â1.84).An equivalent
parameter, first-order metabolic rate constant, was also estimated and found to be consistent
with the percent of BD metabolized at steady state across gender, race, and age
strata
Rehebbilitating Memory
Amnesia is a deficit of memory function that can result from trauma, stress, disease, drug use, or ageing. Though efforts are made to prevent and treat the various causes of amnesia, there remains no treatment for the symptom of memory loss itself. Because the defining feature of amnesia is an inability recall memory, any given case may be due to the possibility that the
memory is damaged, or the alternative that it is present but irretrievable (Squire, 1982). Discriminating between these two scenarios would be of scientific value, because the neurobiology of memory formation is anchored in experimental amnesia. Pathological cases of amnesia that are due to retrieval deficits may in principal be treatable rather than merely preventable. Amnesia could be attributed to a retrieval deficit if the ostensible âlostâ memory could be evoked through brain stimulation. The challenge here is to identify exactly where in the brain a particular memory is stored.JPB FoundationRIKEN Brain Science Institut
Light-Regulated Molecular Trafficking in a Synthetic Water-Soluble Host.
Cucurbit[8]uril (CB[8])-mediated complexation of a dicationic azobenzene in water allows for the light-controlled encapsulation of a variety of second guest compounds, including amino acids, dyes, and fragrance molecules. Such controlled guest sequestration inside the cavity of CB[8] enables the regulation of the thermally induced phase transition of poly(N-isopropylacrylamide)-which is not photosensitive-thus demonstrating the robustness and relevancy of the light-regulated CB[8] complexation.J.D.B. thanks Marie Curie IEF (project no. 273807). S.T.J.R. acknowledges the Cambridge Home and European Scholarship Scheme and the Robert Gardiner memorial scholarship. This work was supported by the EPSRC (reference no. EP/G060649/ 1), an ERC Starting Investigator Grant (project no. 240629), and a Next Generation Fellowship from the Walters-Kundert Foundation. The authors thank HECBioSim (EPSRC grant no. EP/L000253/1) via ARCHER, and the Ada Kingâs HPC3 service.This is the author accepted manuscript. The final version is available from ACS Publications via http://dx.doi.org/10.1021/jacs.5b1164
A picogram and nanometer scale photonic crystal opto-mechanical cavity
We describe the design, fabrication, and measurement of a cavity
opto-mechanical system consisting of two nanobeams of silicon nitride in the
near-field of each other, forming a so-called "zipper" cavity. A photonic
crystal patterning is applied to the nanobeams to localize optical and
mechanical energy to the same cubic-micron-scale volume. The picrogram-scale
mass of the structure, along with the strong per-photon optical gradient force,
results in a giant optical spring effect. In addition, a novel damping regime
is explored in which the small heat capacity of the zipper cavity results in
blue-detuned opto-mechanical damping.Comment: 15 pages, 4 figure
Active Control for Object Perception and Exploration with a Robotic Hand
We present an investigation on active control for intelligent object exploration using touch with a robotic hand. First, uncertainty from the exploration is reduced by a probabilistic method based on the accumulation of evidence through the interaction with an object of interest. Second, an intrinsic motivation approach allows the robot hand to perform intelligent active control of movements to explore interesting locations of the object. Passive and active perception and exploration were implemented in simulated and real environments to compare their benefits in accuracy and reaction time. The validation of the proposed method were performed with an object recognition task, using a robotic platform composed by a three-fingered robotic hand and a robot table. The results demonstrate that our method permits the robotic hand to achieve high accuracy for object recognition with low impact on the reaction time required to perform the task. These benefits make our method suitable for perception and exploration in autonomous robotics
The TopClosureÂŽ 3S System, for skin stretching and a secure wound closure
The principle of stretching wound margins for primary wound closure is commonly practiced and used for various skin defects, leading at times to excessive tension and complications during wound closure. Different surgical techniques, skin stretching devices and tissue expanders have been utilized to address this issue. Previously designed skin stretching devices resulted in considerable morbidity. They were invasive by nature and associated with relatively high localized tissue pressure, frequently leading to necrosis, damage and tearing of skin at the wound margins. To assess the clinical effectiveness and performance and, to determine the safety of TopClosureÂŽ for gradual, controlled, temporary, noninvasive and invasive applications for skin stretching and secure wound closing, the TopClosureÂŽ device was applied to 20 patients for preoperative skin lesion removal and to secure closure of a variety of wound sizes. TopClosureÂŽ was reinforced with adhesives, staples and/or surgical sutures, depending on the circumstances of the wound and the surgeonâs judgment. TopClosureÂŽ was used prior to, during and/or after surgery to reduce tension across wound edges. No significant complications or adverse events were associated with its use. TopClosureÂŽ was effectively used for preoperative skin expansion in preparation for dermal resection (e.g., congenital nevi). It aided closure of large wounds involving significant loss of skin and soft tissue by mobilizing skin and subcutaneous tissue, thus avoiding the need for skin grafts or flaps. Following surgery, it was used to secure closure of wounds under tension, thus improving wound aesthetics. A sample case study will be presented. We designed TopClosureÂŽ, an innovative device, to modify the currently practiced concept of wound closure by applying minimal stress to the skin, away from damaged wound edges, with flexible force vectors and versatile methods of attachment to the skin, in a noninvasive or invasive manner
Associations of sedentary behaviour, physical activity, blood pressure and anthropometric measures with cardiorespiratory fitness in children with cerebral palsy
Background - Children with cerebral palsy (CP) have poor cardiorespiratory fitness in comparison to their peers with typical development, which may be due to low levels of physical activity. Poor cardiorespiratory fitness may contribute to increased cardiometabolic risk. Purpose - The aim of this study was to determine the association between sedentary behaviour, physical activity and cardiorespiratory fitness in children with CP. An objective was to determine the association between cardiorespiratory fitness, anthropometric measures and blood pressure in children with CP. Methods- This study included 55 ambulatory children with CP [mean (SD) age 11.3 (0.2) yr, range 6-17 yr; Gross Motor Function Classification System (GMFCS) levels I and II]. Anthropometric measures (BMI, waist circumference and waist-height ratio) and blood pressure were taken. Cardiorespiratory fitness was measured using a 10 m shuttle run test. Children were classified as low, middle and high fitness according to level achieved on the test using reference curves. Physical activity was measured by accelerometry over 7 days. In addition to total activity, time in sedentary behaviour and light, moderate, vigorous, and sustained moderate-to-vigorous activity (âĽ10 min bouts) were calculated. Results - Multiple regression analyses revealed that vigorous activity (β = 0.339, p<0.01), sustained moderate-to-vigorous activity (β = 0.250, p<0.05) and total activity (β = 0.238, p<0.05) were associated with level achieved on the shuttle run test after adjustment for age, sex and GMFCS level. Children with high fitness spent more time in vigorous activity than children with middle fitness (p<0.05). Shuttle run test level was negatively associated with BMI (r2 = -0.451, p<0.01), waist circumference (r2 = -0.560, p<0.001), waist-height ratio (r2 = -0.560, p<0.001) and systolic blood pressure (r2 = -0.306, p<0.05) after adjustment for age, sex and GMFCS level. Conclusions - Participation in physical activity, particularly at a vigorous intensity, is associated with high cardiorespiratory fitness in children with CP. Low cardiorespiratory fitness is associated with increased cardiometabolic risk
Forearm design for a myoelectric prosthetic hand
Due to the rapid growth of children and the complexity of myoelectric technology, children are often not given the same opportunities to use myoelectric prosthetics as adults. The Muscle Activated Prosthesis (MAP) team is working to create an affordable, transradial myoelectric prosthesis for a twelve-year-old girl. The basic mechanism by which this device operates is as follows: a muscle contraction emits an electrical signal that will be detected and processed through a microcontroller. Then the onboard software determines whether the hand opens or closes based on the level of muscle intensity. If the software determines to close or open the hand, a signal from the microcontroller is sent to linear actuators that control the tendon system running through the fingers. Currently the team has a working prototype that we plan to give to our client in the fall of 2020 to test.https://mosaic.messiah.edu/engr2020/1016/thumbnail.jp
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