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Critical theory

Shanshan Qin, Chao Tang
Complex dynamical systems often have tipping points and exhibit catastrophic regime shift. Despite the notorious difficulty of predicting such transitions, accumulating studies have suggested the existence of generic early-warning signals (EWSs) preceding upcoming transitions. However, previous theories and models were based on the effect of the intrinsic noise (IN) when a system is approaching a critical point, and did not consider the pervasive environmental fluctuations or the extrinsic noise (EN). Here, we extend previous theory to investigate how the interplay of EN and IN affects EWSs...
March 2018: Physical Review. E
Marta Bigus-Kwiatkowska, Agata Fronczak, Piotr Fronczak
Inspired by albatrosses that use thermal lifts to fly across oceans we develop a simple model of gliders that serves us to study theoretical limitations of unlimited exploration of the Earth. Our studies, grounded in physical theory of continuous percolation and biased random walks, allow us to identify a variety of percolation transitions, which are understood as providing potentially unlimited movement through a space in a specified direction. We discover an unexpected phenomenon of self-organization of gliders in clusters, which resembles the flock organization of birds...
March 2018: Physical Review. E
E S Loscar, C M Horowitz
Small systems consisting of particles interacting with long-range potentials exhibit enormous size effects. The Tsallis conjecture [Tsallis, Fractals 3, 541 (1995)FRACEG0218-348X10.1142/S0218348X95000473], valid for translationally invariant systems with long-range interactions, states a well-known scaling relating different sizes. Here we propose to generalize this conjecture to systems with this symmetry broken, by adjusting one parameter that determines an effective distance to compute the strength of the interaction...
March 2018: Physical Review. E
Hiie Hinrikus, Maie Bachmann, Jaanus Lass
PURPOSE: This topic review aims to explain the mechanism of low-level microwave radiation effect based on published research results. The review presents the analysis of theoretical and experimental results comprising underlying physics and derived biological-physiological consequences supported by experimental data. CONCLUSIONS: The rotation of dipolar molecules causes polarization of dielectric medium and restructuring of hydrogen bonds between these molecules...
May 18, 2018: International Journal of Radiation Biology
Urna Basu, Laurent Helden, Matthias Krüger
Nonlinear response theory, in contrast to linear cases, involves (dynamical) details, and this makes application to many-body systems challenging. From the microscopic starting point we obtain an exact response theory for a small number of coarse-grained degrees of freedom. With it, an extrapolation scheme uses near-equilibrium measurements to predict far-from-equilibrium properties (here, second order responses). Because it does not involve system details, this approach can be applied to many-body systems...
May 4, 2018: Physical Review Letters
Patricia S Groves, Jacinda L Bunch
The aim of this paper is discussion of a new middle-range theory of patient safety goal priming via safety culture communication. Bedside nurses are key to safe care, but there is little theory about how organizations can influence nursing behavior through safety culture to improve patient safety outcomes. We theorize patient safety goal priming via safety culture communication may support organizations in this endeavor. According to this theory, hospital safety culture communication activates a previously held patient safety goal and increases the perceived value of actions nurses can take to achieve that goal...
May 18, 2018: Nursing Inquiry
Daniele Coslovich, Misaki Ozawa, Walter Kob
The physical behavior of glass-forming liquids presents complex features of both dynamic and thermodynamic nature. Some studies indicate the presence of thermodynamic anomalies and of crossovers in the dynamic properties, but their origin and degree of universality is difficult to assess. Moreover, conventional simulations are barely able to cover the range of temperatures at which these crossovers usually occur. To address these issues, we simulate the Kob-Andersen Lennard-Jones mixture using efficient protocols based on multi-CPU and multi-GPU parallel tempering...
May 17, 2018: European Physical Journal. E, Soft Matter
Hai-Hui Zhang, Yao-Ping Xie, Mei-Yi Yao, Jing-Xiang Xu, Jin-Long Zhang, Li-Juan Hu
The anisotropy of metal oxidation is a fundamental issue, and the oxidation of Zr surfaces also attracts much attention due to the application of Zr alloys as cladding materials for nuclear fuels in nuclear power plants. In this study, we systematically investigate the diagram of O adsorption on low Miller index Zr surfaces by using first-principles calculations based on density functional theory calculations. We find that O adsorption on the basal surface, Zr(0001), is more favourable than that on the prism surfaces, Zr(112[combining macron]0) and Zr(101[combining macron]0), under strong O-reducing conditions, while O adsorption on the prism surface is more favourable than that of the basal surface under weak O-reducing conditions and the O-rich conditions...
May 18, 2018: Physical Chemistry Chemical Physics: PCCP
Zhanshan Wang, Lei Liu, Yanming Wu, Huaguang Zhang
This paper investigates the problem of optimal fault-tolerant control (FTC) for a class of unknown nonlinear discrete-time systems with actuator fault in the framework of adaptive critic design (ACD). A pivotal highlight is the adaptive auxiliary signal of the actuator fault, which is designed to offset the effect of the fault. The considered systems are in strict-feedback forms and involve unknown nonlinear functions, which will result in the causal problem. To solve this problem, the original nonlinear systems are transformed into a novel system by employing the diffeomorphism theory...
June 2018: IEEE Transactions on Neural Networks and Learning Systems
Huaguang Zhang, Qiuxia Qu, Geyang Xiao, Yang Cui
Based on integral sliding mode and approximate dynamic programming (ADP) theory, a novel optimal guaranteed cost sliding mode control is designed for constrained-input nonlinear systems with matched and unmatched disturbances. When the system moves on the sliding surface, the optimal guaranteed cost control problem of sliding mode dynamics is transformed into the optimal control problem of a reformulated auxiliary system with a modified cost function. The ADP algorithm based on single critic neural network (NN) is applied to obtain the approximate optimal control law for the auxiliary system...
June 2018: IEEE Transactions on Neural Networks and Learning Systems
Keith Wachowicz, Brad Murray, B Gino Fallone
The recent interest in the integration of external beam radiotherapy with a magnetic resonance (MR) imaging unit offers the potential for real-time adaptive tumour tracking during radiation treatment. The tracking of large tumours which follow a rapid trajectory may best be served by the generation of a projection image from the perspective of the beam source, or "beam's eye view" (BEV). This type of image projection represents the path of the radiation beam, thus enabling rapid compensations for target translations, rotations and deformations, as well time-dependent critical structure avoidance...
May 17, 2018: Physics in Medicine and Biology
Georgios D Sideridis, Panagiotis Simos, Angeliki Mouzaki, Dimitrios Stamovlasis, George K Georgiou
The purpose of the present study was to explain the moderating role of rapid automatized naming (RAN) in word reading with a cusp catastrophe model. We hypothesized that increases in RAN performance speed beyond a critical point would be associated with the disruption in word reading, consistent with a "generic shutdown" hypothesis. Participants were 587 elementary schoolchildren (Grades 2-4), among whom 87 had reading comprehension difficulties per the IQ-achievement discrepancy criterion. Data were analyzed via a cusp catastrophe model derived from the nonlinear dynamics systems theory...
May 1, 2018: Journal of Learning Disabilities
Miguel Aguilera, Manuel G Bedia
Many biological and cognitive systems do not operate deep within one or other regime of activity. Instead, they are poised at critical points located at phase transitions in their parameter space. The pervasiveness of criticality suggests that there may be general principles inducing this behaviour, yet there is no well-founded theory for understanding how criticality is generated at a wide span of levels and contexts. In order to explore how criticality might emerge from general adaptive mechanisms, we propose a simple learning rule that maintains an internal organizational structure from a specific family of systems at criticality...
May 16, 2018: Scientific Reports
José Roberto Pereira Guedes, Leoni Villano Bonamin, Vera Luiza Capelozzi
INTRODUCTION:  There are two critical pillars of homeopathy that contrast with the dominant scientific approach: the similitude principle and the potentization of serial dilutions. Three main hypotheses about the mechanisms of action are in discussion: nanobubbles-related hormesis; vehicle-related electric resonance; and quantum non-locality. OBJECTIVES:  The aim of this paper is to review and discuss some key points of such properties: the imprint of supramolecular structures based on the nanoparticle-allostatic, cross-adaptation-sensitization (NPCAS) model; the theory of non-molecular electromagnetic transfer of information, based on the coherent water domains model, and relying (like the NPCAS model) on the idea of local interactions; and the hypothesis of quantum entanglement, based on the concept of non-locality...
May 16, 2018: Homeopathy: the Journal of the Faculty of Homeopathy
Tirta Rona Mayangsari, Jae-Min Park, Luchana Lamierza Yusup, Jiyeon Gu, Jin-Hyuk Yoo, Heon-Do Kim, Won-Jun Lee
We report the catalyzed atomic layer deposition (ALD) of silicon oxide using Si2 Cl6 , H2 O, and various alkylamines. The density functional theory (DFT) calculations using periodic slab model of the SiO2 surface were performed for the selection of alternative Lewis-base catalysts with high catalytic activities. During the first half-reaction, the catalysts with less steric hindrance such as pyridine would be more effective than bulky alkylamines despite lower nucleophilicity. On the other hand, during the second half-reaction, the catalysts with a high nucleophilicity such as triethylamine (Et3 N) would be more efficient because the steric hindrance is less critical...
May 16, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
David Černý
The current discussion of the moral admissibility or inadmissibility of euthanasia should, in my opinion, consider the greatest possible number of the shared premises of the two opinion camps. That is why I followed a thesis in this paper that the question of the good life is the focus of ethical interest, as this is what connects the advocates and the opponents to euthanasia. In the first part of the paper I critically discuss the two main theories of the good life widely embraced among the advocates of euthanasia: hedonism and desire-fulfilment theory...
2018: Vnitr̆ní Lékar̆ství
Pabitra Narayan Samanta, Jerzy Leszczynski
The thermoelectric transport properties of a metal-ceramic interface based on Al and γ-Al2O3 are explored by employing the non-equilibrium Green's function formalism (NEGF) coupled with density functional theory (DFT). However, to acquire the phonon thermal conductance, the parameterized ReaxFF potential is utilized for computing the intrinsic force constants of propagating phonons across the interface. Several interfacial electronic properties such as the charge transfer, the potential barrier, and the atomic orbital overlap are critically analyzed based on the DFT derived results of the electrostatic difference potential, the electron density difference, and the spin-polarized density of states in the fully relaxed structure of the interface...
May 16, 2018: Physical Chemistry Chemical Physics: PCCP
Adam Pate, Jennifer Smith, David Caldwell, Alexis Horace, Michelle Zagar
PURPOSE: To develop, implement, and evaluate the effect of a faculty engagement and professional growth program targeted at junior faculty members. EDUCATIONAL ACTIVITY: A faculty engagement and growth program based on adult learning theory was piloted in a clinical sciences department. Effect of the model was evaluated using a pre/post-survey evaluating faculty output and work engagement using the Utrecht Work Engagement Scale (UWES). FINDINGS: Average number of publications/projects with cross-campus collaboration increased (0...
March 2018: Currents in Pharmacy Teaching & Learning
Young Chan Chae, Jae Ho Kim
Increasing evidence suggests that cancer stem cell (CSC) theory represents an important mechanism underlying the observed failure of existing therapeutic modalities to fully eradicate cancers. In addition to their more established role in maintaining minimal residual disease after treatment and forming the new bulk of the tumor, CSCs might also critically contribute to tumor recurrence and metastasis. For this reason, specific elimination of CSCs may thus represent one of the most important treatment strategies...
May 16, 2018: BMB Reports
Abhishek K Sharma, Fernando A Escobedo
Classical Nucleation Theory (CNT) has recently been used in conjunction with a seeding approach to simulate nucleation phenomena at small-to-moderate supersaturation conditions when large free-energy barriers ensue. In this study, the conventional seeding approach [J. R. Espinosa et al., J. Chem. Phys. 144, 034501 (2016)] is improved by a novel, more robust method to estimate nucleation barriers. Inspired by the interfacial pinning approach [U. R. Pedersen, J. Chem. Phys. 139, 104102 (2013)] used before to determine conditions where two phases coexist, the seed of the incipient phase is pinned to a preselected size to iteratively drive the system toward the conditions where the seed becomes a critical nucleus...
May 14, 2018: Journal of Chemical Physics
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