868 research outputs found
Dielectric response of a polar fluid trapped in a spherical nanocavity
We present extensive Molecular Dynamics simulation results for the structure,
static and dynamical response of a droplet of 1000 soft spheres carrying
extended dipoles and confined to spherical cavities of radii , 3, and 4
nm embedded in a dielectric continuum of permittivity . The
polarisation of the external medium by the charge distribution inside the
cavity is accounted for by appropriate image charges. We focus on the influence
of the external permittivity on the static and dynamic properties
of the confined fluid. The density profile and local orientational order
parameter of the dipoles turn out to be remarkably insensitive to .
Permittivity profiles inside the spherical cavity are calculated
from a generalised Kirkwood formula. These profiles oscillate in phase with the
density profiles and go to a ``bulk'' value away from the
confining surface; is only weakly dependent on , except
for (vacuum), and is strongly reduced compared to the
permittivity of a uniform (bulk) fluid under comparable thermodynamic
conditions.
The dynamic relaxation of the total dipole moment of the sample is found to
be strongly dependent on , and to exhibit oscillatory behaviour when
; the relaxation is an order of magnitude faster than in the bulk.
The complex frequency-dependent permittivity is sensitive to
at low frequencies, and the zero frequency limit
is systematically lower than the ``bulk'' value
of the static primitivity.Comment: 12 pages including 17 figure
Are Small Reimbursement Changes Enough to Change Cancer Care? Reimbursement Variation in Prostate Cancer Treatment
The Centers for Medicare and Medicaid Services recently initiated small reimbursement adjustments to improve the value of care delivered under fee-for-service. To estimate the degree to which reimbursement influences physician decision making, we examined utilization of gonadotropin-releasing hormone (GnRH) agonists among urologists as Part B drug reimbursement varied in a fee-for-service environment
Brief of Corporate Law Professors as Amici Curie in Support of Respondents
The Supreme Court has looked to the rights of corporate shareholders in determining the rights of union members and non-members to control political spending, and vice versa. The Court sometimes assumes that if shareholders disapprove of corporate political expression, they can easily sell their shares or exercise control over corporate spending. This assumption is mistaken. Because of how capital is saved and invested, most individual shareholders cannot obtain full information about corporate political activities, even after the fact, nor can they prevent their savings from being used to speak in ways with which they disagree. Individual shareholders have no āopt outā rights or practical ability to avoid subsidizing corporate political expression with which they disagree. Nor do individuals have the practical option to refrain from putting their savings into equity investments, as doing so would impose damaging economic penalties and ignore conventional financial guidance for individual investors
Identifying prodromal symptoms at high specificity for Parkinsonās disease
IntroductionTo test drugs with the potential to prevent the onset of Parkinsonās disease (PD), it is key to identify individuals in the general population at high risk of developing PD. This is often difficult because most of the clinical markers are non-specific, common in PD but also common in older adults (e.g., sleep problems).ObjectiveWe aimed to identify the clinical markers at high specificity for developing PD by comparing individuals with PD or prodromal PD to healthy controls.MethodsWe investigated motor and non-motor symptoms (Movement Disorder Society Unified Parkinsonās Disease Rating Scale Part 1 and 2 items) in 64 prodromal PD and 422 PD individuals calculating the odds ratios, adjusting for age and gender, for PD and prodromal PD versus 195 healthy controls. Symptoms at high specificity were defined as having an adjusted odds ratio ā„ā6.ResultsConstipation had an adjusted odds ratio, 6.14 [95% CI: 2.94ā12.80] showing high specificity for prodromal PD, and speech difficulties had an adjusted odds ratio, 9.61 [95% CI: 7.88ā48.81] showing high specificity for PD. The proportion of participants showing these specific markers was moderate (e.g., prevalence of constipation was 43.75% in prodromal PD, and speech difficulties was 33.89% in PD), suggesting these symptoms may make robust predictors of prodromal PD and PD, respectively.DiscussionClinical markers at high specificity for developing PD could be used as tools in the screening of general populations to identify individuals at higher risk of developing PD
Supreme Court Amicus Brief of 19 Corporate Law Professors, Friedrichs v. California Teachers Association, No. 14-915
The Supreme Court has looked to the rights of corporate shareholders in determining the rights of union members and non-members to control political spending, and vice versa. The Court sometimes assumes that if shareholders disapprove of corporate political expression, they can easily sell their shares or exercise control over corporate spending. This assumption is mistaken. Because of how capital is saved and invested, most individual shareholders cannot obtain full information about corporate political activities, even after the fact, nor can they prevent their savings from being used to speak in ways with which they disagree. Individual shareholders have no āopt outā rights or practical ability to avoid subsidizing corporate political expression with which they disagree. Nor do individuals have the practical option to refrain from putting their savings into equity investments, as doing so would impose damaging economic penalties and ignore conventional financial guidance for individual investors
A Study of the Learnability of Relational Properties: Model Counting Meets Machine Learning (MCML)
This paper introduces the MCML approach for empirically studying the
learnability of relational properties that can be expressed in the well-known
software design language Alloy. A key novelty of MCML is quantification of the
performance of and semantic differences among trained machine learning (ML)
models, specifically decision trees, with respect to entire (bounded) input
spaces, and not just for given training and test datasets (as is the common
practice). MCML reduces the quantification problems to the classic complexity
theory problem of model counting, and employs state-of-the-art model counters.
The results show that relatively simple ML models can achieve surprisingly high
performance (accuracy and F1-score) when evaluated in the common setting of
using training and test datasets - even when the training dataset is much
smaller than the test dataset - indicating the seeming simplicity of learning
relational properties. However, MCML metrics based on model counting show that
the performance can degrade substantially when tested against the entire
(bounded) input space, indicating the high complexity of precisely learning
these properties, and the usefulness of model counting in quantifying the true
performance
Global standards of Constitutional law : epistemology and methodology
Just as it led the philosophy of science to gravitate around scientific practice, the abandonment of all foundationalist aspirations has already begun making political philosophy into an attentive observer of the new ways in which constitutional law is practiced. Yet paradoxically, lawyers and legal scholars are not those who understand this the most clearly. Beyond analyzing the jurisprudence that has emerged from the expansion of constitutional justice, and taking into account the development of international and regional law, the ongoing globalization of constitutional law requires comparing the constitutional laws of individual nations. Following Waldron, the product of this new legal science can be considered as ius gentium. This legal science is not as well established as one might like to think. But it can be developed on the grounds of the practice that consists in ascertaining standards. As abstract types of best āpracticesā (and especially norms) of constitutional law from around the world, these are only a source of law in a substantive, not a formal, sense. They thus belong to what I should like to call a āsecond order legal positivity.ā In this article I will undertake, both at a methodological and an epistemological level, the development of a model for ascertaining global standards of constitutional law
Plasma triglyceride concentrations are rapidly reduced following individual bouts of endurance exercise in women
It is known that chronic endurance training leads to improvements in the lipoprotein profile, but less is known about changes that occur during postexercise recovery acutely. We analyzed triglyceride (TG), cholesterol classes and apolipoproteins in samples collected before, during and after individual moderate- and hard-intensity exercise sessions in men and women that were isoenergetic between intensities. Young healthy men (nĀ =Ā 9) and young healthy women (nĀ =Ā 9) were studied under three different conditions with diet unchanged between trials: (1) before, during and 3Ā h after 90Ā min of exercise at 45% VO2peak (E45); (2) before, during and 3Ā h after 60Ā min of exercise at 65% VO2peak (E65), and (3) in a time-matched sedentary control trial (C). At baseline, high-density lipoprotein cholesterol (HDL-C) was higher in women than men (PĀ <Ā 0.05). In men and in women, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), HDL-C, apolipoprotein A-I (apoA-I), apolipoprotein B (apoB), and LDL peak particle size were unaltered by exercise either during exertion or after 3Ā h of recovery. In women, but not in men, average plasma TG was significantly reduced below C at 3Ā h postexercise by approximately 15% in E45 and 25% in E65 (PĀ <Ā 0.05) with no significant difference between exercise intensities. In summary, plasma TG concentration rapidly declines following exercise in women, but not in men. These results demonstrate an important mechanism by which each individual exercise session may incrementally reduce the risk for cardiovascular disease (CVD) in women
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