Active privacy-utility trade-off against inference in time-series data sharing

Internet of things devices have become highly popular thanks to the services they offer. However, they also raise privacy concerns since they share fine-grained time-series user data with untrusted third parties. We model the users personal information as the secret variable, to be kept private from an honest-but-curious service provider, and the useful variable, to be disclosed for utility. We consider an active learning framework, where one out of a finite set of measurement mechanisms is chosen at each time step, each revealing some information about the underlying secret and useful variables, albeit with different statistics. The measurements are taken such that the correct value of useful variable can be detected quickly, while the confidence on the secret variable remains below a predefined level. For privacy measure, we consider both the probability of correctly detecting the secret variable value and the mutual information between the secret and released data. We formulate both problems as partially observable Markov decision processes, and numerically solve by advantage actor-critic deep reinforcement learning. We evaluate the privacy-utility trade-off of the proposed policies on both the synthetic and real-world time-series datasets

Two-dimensional boson-fermion mixtures in harmonic traps

The density profiles of bosonic and fermionic components in a system of trapped two-dimensional (2D) boson-fermion (BF) mixture are studied. We employ the variational approach to minimize the total energy functional of the BF mixture subject to the conservation of particle numbers of the species. We consider repulsive interactions between bosons and investigate the repulsive and attractive interactions between bosons and fermions. Our results are qualitatively similar to those in 3D, despite the fact that the structure of equations in 2D are different. © 2003 Elsevier Science B.V. All rights reserved

q-Gaussian trial function in high density Bose-Einstein condensates

We study the ground-state static properties of Bose-Einstein condensates in the high density regime using a trial wave function of the form of a q-Gaussian. The flexibility afforded by a q-Gaussian trial function yields very accurate ground-state energies for large number of particles. The resulting condensate wave function profiles are also in good agreement in the high density regime. Comparing our results with those of numerical calculations we provide information on the possible limitations of the q-Gaussian trial functions. © 2002 Elsevier Science B.V. All rights reserved

Synthesis of diamondlike carbon films with superlow friction and wear properties

In this study, the authors introduce a new diamondlike carbon (DLC) film providing a friction coefficient of 0.001 and wear rates of 10{sup {minus}9} to 10{sup {minus}10} mm{sup 3}/N.m in inert-gas environments (e.g., dry nitrogen and argon). The film was grown on steel and sapphire substrates in a plasma enhanced chemical vapor deposition system that uses using a hydrogen-rich plasma. Employing a combination of surface and structure analytical techniques, they explored the structural chemistry of the resultant DLC films and correlated these findings with the friction and wear mechanisms of the films. The results of tribological tests under a 10-N load (creating initial peak Hertz pressures of 1 and 2.2 GPa on steel and sapphire test pairs, respectively) and at 0.2 to 0.5 m/s sliding velocities indicated that a close correlation exists between the friction and wear coefficients of DLC films and the source gas chemistry. Specifically, films grown in source gases with higher hydrogen-to-carbon ratios had the lowest fiction coefficients and the highest wear resistance. The lowest friction coefficient (0.001) was achieved with a film on sapphire substrates produced in a gas discharge plasma consisting of 25% methane and 75% hydrogen

Argon plasma treatment techniques on steel and effects on diamond-like carbon structure and delamination

Copyright © 2011 Elsevier B.V. All rights reserved.We demonstrate alteration in diamond-like carbon (DLC) film structure, chemistry and adhesion on steel, related to variation in the argon plasma pretreatment stage of plasma enhanced chemical vapour deposition. We relate these changes to the alteration in substrate structure, crystallinity and chemistry due to application of an argon plasma process with negative self bias up to 600 V. Adhesion of the DLC film to the substrate was assessed by examination of the spallated fraction of the film following controlled deformation. Films with no pretreatment step immediately delaminated. At 300 V pretreatment, the spallated fraction is 8.2%, reducing to 1.2% at 450 V and 0.02% at 600V. For bias voltages below 450V the adhesion enhancement is explained by a reduction in carbon contamination on the substrate surface, from 59at.% with no treatment to 26at.% at 450V, concurrently with a decrease in the surface roughness, Rq, from 31.5nm to 18.9nm. With a pretreatment bias voltage of 600V a nanocrystalline, nanostructured surface is formed, related to removal of chromium and relaxation of stress; X-ray diffraction indicates this phase is incipient at 450V. In addition to improving film adhesion, the nanotexturing of the substrate prior to film deposition results in a DLC film that shows an increase in sp3/sp2 ratio from 1.2 to 1.5, a reduction in surface roughness from 31nm to 21nm, and DLC nodular asperities with reduced diameter and increased uniformity of size and arrangement. These findings are consistent with the substrate alterations due to the plasma pretreatment resulting in limitation of surface diffusion in the growth process. This suggests that in addition to deposition phase processes, the parameters of the pretreatment process need to be considered when designing diamond-like carbon coatings.This work is partially supported by the Technology Strategy Board, reference BD266E

Reproducibility in modeling and simulation of the knee:Academic, industry, and regulatory perspectives

Stakeholders in the modeling and simulation (M&amp;S) community organized a workshop at the 2019 Annual Meeting of the Orthopaedic Research Society (ORS) entitled “Reproducibility in Modeling and Simulation of the Knee: Academic, Industry, and Regulatory Perspectives.” The goal was to discuss efforts among these stakeholders to address irreproducibility in M&amp;S focusing on the knee joint. An academic representative from a leading orthopedic hospital in the United States described a multi-institutional, open effort funded by the National Institutes of Health to assess model reproducibility in computational knee biomechanics. A regulatory representative from the United States Food and Drug Administration indicated the necessity of standards for reproducibility to increase utility of M&amp;S in the regulatory setting. An industry representative from a major orthopedic implant company emphasized improving reproducibility by addressing indeterminacy in personalized modeling through sensitivity analyses, thereby enhancing preclinical evaluation of joint replacement technology. Thought leaders in the M&amp;S community stressed the importance of data sharing to minimize duplication of efforts. A survey comprised 103 attendees revealed strong support for the workshop and for increasing emphasis on computational modeling at future ORS meetings. Nearly all survey respondents (97%) considered reproducibility to be an important issue. Almost half of respondents (45%) tried and failed to reproduce the work of others. Two-thirds of respondents (67%) declared that individual laboratories are most responsible for ensuring reproducible research whereas 44% thought that journals are most responsible. Thought leaders and survey respondents emphasized that computational models must be reproducible and credible to advance knee M&amp;S.</p

Chondrocyte Deformations as a Function of Tibiofemoral Joint Loading Predicted by a Generalized High-Throughput Pipeline of Multi-Scale Simulations

Cells of the musculoskeletal system are known to respond to mechanical loading and chondrocytes within the cartilage are not an exception. However, understanding how joint level loads relate to cell level deformations, e.g. in the cartilage, is not a straightforward task. In this study, a multi-scale analysis pipeline was implemented to post-process the results of a macro-scale finite element (FE) tibiofemoral joint model to provide joint mechanics based displacement boundary conditions to micro-scale cellular FE models of the cartilage, for the purpose of characterizing chondrocyte deformations in relation to tibiofemoral joint loading. It was possible to identify the load distribution within the knee among its tissue structures and ultimately within the cartilage among its extracellular matrix, pericellular environment and resident chondrocytes. Various cellular deformation metrics (aspect ratio change, volumetric strain, cellular effective strain and maximum shear strain) were calculated. To illustrate further utility of this multi-scale modeling pipeline, two micro-scale cartilage constructs were considered: an idealized single cell at the centroid of a 100×100×100 μm block commonly used in past research studies, and an anatomically based (11 cell model of the same volume) representation of the middle zone of tibiofemoral cartilage. In both cases, chondrocytes experienced amplified deformations compared to those at the macro-scale, predicted by simulating one body weight compressive loading on the tibiofemoral joint. In the 11 cell case, all cells experienced less deformation than the single cell case, and also exhibited a larger variance in deformation compared to other cells residing in the same block. The coupling method proved to be highly scalable due to micro-scale model independence that allowed for exploitation of distributed memory computing architecture. The method’s generalized nature also allows for substitution of any macro-scale and/or micro-scale model providing application for other multi-scale continuum mechanics problems

Tribological performance of novel Nickel-based composite coatings with lubricant particles

Abstract The present study is focused on the evaluation of the tribological performance of novel Ni/hBN and Ni/WS2 composite coatings electrodeposited from an additive-free Watts bath with the assistance of ultrasound. Lubricated and non-lubricated scratch tests were performed on both novel composite coatings and on standard Ni deposits used as a benchmark coating to have an initial idea of the effect of the presence of particles within the Ni matrix. Under lubricated conditions, the performance of the Ni/hBN composite coating was very similar to the benchmark Ni coating, whereas the Ni/WS2 behaved quite differently, as the latter did not only show a lower coefficient of friction, but also prevented the occurrence of stick-slip motion that was clearly observed in the other coatings. Under non-lubricated conditions, whereas the tribological performance of the Ni/hBN composite coating was again very similar to that of the benchmark Ni coating, the Ni/WS2 composite coatings again showed a remarkable enhancement, as the incorporation of the WS2 particles into the Ni coating not only resulted in a lower coefficient of friction, but also in the prevention of coating failure

Clinical comprehensive and experimental assessment of the radioprotective effect of Annona muricata leaf extract to prevent cellular damage in the ileum tissue

We report the radioprotective attitude of Annona muricata (AM) leaf extract as antioxidant material to prevent cellular damage in the ileum tissue. The protective effects of an ethyl acetate extract of AM leaves are comprehensively investigated against radiation-induced ileal damage in numerous rats. Thirty-two adult female rats were separated into 4 groups (3 intervention groups and 1 control) as follows: controls received 0.01 mL/kg distilled water, the AM group received 300 mg/kg AM leaf extract, the ionizing radiation (IR) group received a single dose of whole body radiation (8.3 Gy) after 0.01 mL/kg saline treatment, and the AM + IR group received 300 mg/kg AM leaf extract treatment and were subjected to whole body radiation (8.3 Gy) 1 h after the last gavage. All treatments are administered by oral gavage once a day for 9 days. At the end of the experiment, biochemical total oxidant status (TOS, interleukin-6, and caspase) and histological examinations are performed on blood samples as well as ileum tissue. TOS levels are found to be significantly high in rats, which received irradiation, and those in the AM group when compared to controls. These findings suggest that AM has radioprotective effects on ileum tissue, likely because of its antioxidative properties. The findings of this research may contribute to the minimizing of major side effects induced by excessive radiation exposure in patients undergoing radiotherapy and may serve as a significant impetus for further assessments. However, future studies are highly recommended to confirm safety and to determine extraction technique and dosage before human use can be considered. © 2022 Ozlem Elmas et al.Dunarea de Jos” University of Galati, (RF 3621/2021)Universitatea 'Dunărea de Jos' Galați, UDJGFunding text 1: Funding information: The work of Antoaneta ENE and the APC were supported by Dunarea de Jos University of Galati, Romania through the grant no. RF 3621/2021.Funding text 2: Author contributions: O.E., H.H.K.S., and H.O.T.: – conceptualization and methodologyE.K., B.G., G.A., and R.U.E.: validationG.A. and H.M.H.Z.: formal analysisO.E., H.H.K.S., E.K., B.G., and H.O.T.: writing and reviewO.E., H.H.K.S., E.K., B.G., and A.E.: investigationA.E.: funding acquisition through APC by “Dunarea de Jos” University of Galati, Romania through the grant no. RF 3621/2021