From mesoscale back to microscale: reconstruction schemes for coarse-grained stochastic lattice systems

Starting from a microscopic stochastic lattice spin system and the corresponding coarse-grained model we introduce a mathematical strategy to recover microscopic information given the coarse-grained data. We define “reconstructed” microscopic measures satisfying two conditions: (i) they are close in specific relative entropy to the initial microscopic equilibrium measure conditioned on the coarse-grained, data, and (ii) their sampling is computationally advantageous when compared to sampling directly from the conditioned microscopic equilibrium measure. By using different techniques we consider the cases of both short and long range microscopic models

3-D Registration on Carotid Artery imaging data: MRI for different timesteps

A common problem which is faced by the researchers when dealing with arterial carotid imaging data is the registration of the geometrical structures between different imaging modalities or different timesteps. The use of the "Patient Position" DICOM field is not adequate to achieve accurate results due to the fact that the carotid artery is a relatively small structure and even imperceptible changes in patient position and/or direction make it difficult. While there is a wide range of simple/advanced registration techniques in the literature, there is a considerable number of studies which address the geometrical structure of the carotid artery without using any registration technique. On the other hand the existence of various registration techniques prohibits an objective comparison of the results using different registration techniques. In this paper we present a method for estimating the statistical significance that the choice of the registration technique has on the carotid geometry. One-Way Analysis of Variance(ANOVA) showed that the p-values were <0.0001 for the distances of the lumen from the centerline for both right and left carotids of the patient case that was studied.Comment: 4 pages, 4 figures, 1 table, preprint submitted to IEEE-EMBC 201

Linear and nonlinear waves in surface and wedge index potentials

We study optical beams that are supported at the surface of a medium with a linear index potential and by a piecewise linear wedge type potential. In the linear limit the modes are described by Airy functions. In the nonlinear regime we find families of solutions that bifurcate from the linear modes and study their stability for both self-focusing and self-defocusing Kerr nonlinearity. The total power of such nonlinear waves is finite without the need for apodization

Retirement and Household Expenditure in Turbulent Times

We examine the impact of own and spousal retirement on household expenditure during a period of financial deterioration. We use detailed household data covering the period 2009-2016 in Greece, during which the country experienced a severe financial crisis that affected retirees in ways that were not anticipated. Similar to Moreau and Stancanelli (2015) our empirical strategy allows for the household expenditure to depend on both own and spousal retirement status. We employ an instrumental variable identification strategy by exploiting variation coming from the early retirement age threshold. Our Two-Stage Least Squares estimates show that, even after controlling for income, total expenditure drops significantly when the husband retires and as he becomes older. The reduction is stronger in 2010, when the first wave of austerity plans, including measures affecting pensioners were announced, and after 2014 when horizontal pension cuts were implemented. Expenditure does not change significantly when the wife retires neither the older she gets. A drop-in expenditure for clothing, transport, housing and communication drives the overall reduction in expenditure. Overall, our results can have significant policy implications in the design of structural pension reforms in a period of financial hardship

X-Ray Spectra of Z Sources

A simple, physically consistent model has been proposed that seeks to explain in a unified way the X-ray spectra and rapid X-ray variability of the so-called Z sources and other accreting neutron stars in low-mass systems. Here we summarize the results of detailed numerical calculations of the X-ray spectra of the Z sources predicted by this model. Our computations show that in the Z sources, photons are produced primarily by electron cyclotron emission in the neutron star magnetosphere. Comptonization of these photons by the hot central corona and radial inflow produces X-ray spectra, color-color tracks, and countrate variations like those observed in the Z sources.Comment: 6 pages, 2 Postscript figures in 4 files, uses aas2pp4.sty, submitted to ApJ (Letters) 1995 May 3

Assessing the use of social media in physician assistant education.

Objectives: This study aims to assess physician assistant (PA) students\u27 experiences with social media (SM) as a part of their medical education. Methods: The study is split into two phases: Phase 1- A cross-sectional survey emailed to all PA students at four PA school campuses to assess students\u27 prior SM experiences (226 responses, 71.1% response rate); and Phase 2- Inclusion of SM educational resources, via Twitter, within lectures performed at two PA schools. A phase-2 survey assessed students\u27 opinions of educational SM (50 responses, 59.5% response rate) and SM usage was tracked. Results: The phase-1 survey respondents indicated that 97.3% (n=220) use social media; often used as a part of their education, 65% (n=147) informally and 2.7% (n=6) formally incorporated. Students most commonly use Facebook, YouTube, and Instagram, but rarely use Twitter. Currently using SM for medical education was significantly associated with predicting that future PA education will formally include SM [r Conclusions: Many PA students are currently using various forms of social media to augment their education. Most PA students support formal incorporation of social media into their education. PA educators should consider using our data and methods of social media inclusion when designing curricula and while clinically precepting PA students

Constraints on Braneworld Gravity Models from a Kinematic Limit on the Age of the Black Hole XTE J1118+480

In braneworld gravity models with a finite AdS curvature in the extra dimension, the AdS/CFT correspondence leads to a prediction for the lifetime of astrophysical black holes that is significantly smaller than the Hubble time, for asymptotic curvatures that are consistent with current experiments. Using the recent measurements of the position, three-dimensional spatial velocity, and mass of the black hole XTE J1118+480, I calculate a lower limit on its kinematic age of 11 Myr (95% confidence). This translates into an upper limit for the asymptotic AdS curvature in the extra dimensions of 0.08 mm, which significantly improves the limit obtained by table-top experiments of sub-mm gravity.Comment: 4 pages, to appear in the Physical Review Letter

Greening the canned peach production

The paper proposes an approach for measuring the environmental performance of canned peach production based on Lean Thinking techniques. Among the various stages of a typical production line of canned peach, peeling and pasteurizing are the most energy consuming. In these stages specific actions have been suggested and applied. Considering the findings that were observed following the implementation of these actions, the research project provided viable evidence that Lean techniques a positive impact in the production and logistics operations.</jats:p