Large quantum gravity effects: Cylindrical waves in four dimensions

Linearly polarized cylindrical waves in four-dimensional vacuum gravity are mathematically equivalent to rotationally symmetric gravity coupled to a Maxwell (or Klein-Gordon) field in three dimensions. The quantization of this latter system was performed by Ashtekar and Pierri in a recent work. Employing that quantization, we obtain here a complete quantum theory which describes the four-dimensional geometry of the Einstein-Rosen waves. In particular, we construct regularized operators to represent the metric. It is shown that the results achieved by Ashtekar about the existence of important quantum gravity effects in the Einstein-Maxwell system at large distances from the symmetry axis continue to be valid from a four-dimensional point of view. The only significant difference is that, in order to admit an approximate classical description in the asymptotic region, states that are coherent in the Maxwell field need not contain a large number of photons anymore. We also analyze the metric fluctuations on the symmetry axis and argue that they are generally relevant for all of the coherent states.Comment: Version accepted for publication in Int. J. Mod. Phys.

Study of the Differential Activity of Thrombin Inhibitors Using Docking, QSAR, Molecular Dynamics, and MM-GBSA

Indexación: Web of Science; Scopus.Non-peptidic thrombin inhibitors (TIs; 177 compounds) with diverse groups at motifs P1 (such as oxyguanidine, amidinohydrazone, amidine, amidinopiperidine), P2 (such as cyano-fluorophenylacetamide, 2-(2-chloro-6-fluorophenyl)acetamide), and P3 (such as phenylethyl, arylsulfonate groups) were studied using molecular modeling to analyze their interactions with S1, S2, and S3 subsites of the thrombin binding site. Firstly, a protocol combining docking and three dimensional quantitative structure-activity relationship was performed. We described the orientations and preferred active conformations of the studied inhibitors, and derived a predictive CoMSIA model including steric, donor hydrogen bond, and acceptor hydrogen bond fields. Secondly, the dynamic behaviors of some selected TIs (compounds 26, 133, 147, 149, 162, and 177 in this manuscript) that contain different molecular features and different activities were analyzed by creating the solvated models and using molecular dynamics (MD) simulations.We used the conformational structures derived from MD to accomplish binding free energetic calculations using MM-GBSA. With this analysis, we theorized about the effect of van der Waals contacts, electrostatic interactions and solvation in the potency of TIs. In general, the contents reported in this article help to understand the physical and chemical characteristics of thrombin-inhibitor complexes. © 2015 Mena-Ulecia et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.http://journals.plos.org/plosone/article?id=10.1371/journal.pone.014277

Quantum Cylindrical Waves and Sigma Models

We analyze cylindrical gravitational waves in vacuo with general polarization and develop a viewpoint complementary to that presented recently by Niedermaier showing that the auxiliary sigma model associated with this family of waves is not renormalizable in the standard perturbative sense.Comment: 11 pages (DIN A4), accepted in International Journal of Modern Physics

Pengaruh Komunikasi Internal terhadap Kepuasan Kerja Karyawan Bagian Produksi pada PT. Duta Palma Nusantara Sei. Kuko, Benai

Internal communication is considered necessary to improve employee job satisfaction, because if the communication that exists between management and employees as well as fellow employees in harmony, it will create a pleasant climate so that employees can be comfortable in the work. The purpose of this study was to determine the effect of internal communications on employee job satisfaction in the production of PT. Duta Palma Nusantara Sei. Kuko, Benai, Kuantan Singingi.The method used in this research is a quantitative method. The sampling technique used was accidental sampling with a population of 135 people and the number of samples is 58 respondents. The data obtained through observation, questionnaires and interviews were measured using a Likert scale.The results of this research indicate that the influence of internal communications on employee job satisfaction in the production of PT. Duta Palma Nusantara Sei. Kuko shows the corresponding criteria.Keywords : The Influence, internal communication, job satisfaction

Electronic Properties of Topological Materials: Optical Excitations in Moebius Conjugated Polymers

Electronic structures and optical excitations in Moebius conjugated polymers are studied theoretically. Periodic and Moebius boundary conditions are applied to the tight binding model of poly(para-phenylene), taking exciton effects into account. We discuss that oligomers with a few structural units are more effective than polymers for observations of effects of discrete wave numbers that are shifted by the change in boundary condition. Next, calculations of optical absorption spectra are reported. Certain components of optical absorption for an electric field perpendicular to the polymer axis mix with absorption spectra for an electric field parallel to the polymer axis. Therefore, the polarization dependences of an electric field of light enable us to detect whether conjugated polymers have the Moebius boundary.Comment: 10 pages, 6 figures, to be published in J. Phys. Soc. Jpn., Vol. 74 No. 2 (February, 2005), Letter sectio

Enhancing students' well-being with a unified approach based on contextual behavioural science: A randomised experimental school-based intervention

A new generation of interventions has begun to move towards principles of acceptance that deal with the context and function of psychological events. The aim of this paper is to analyse the effectiveness of a brief contextual behavioural intervention to improve the psychological well-being of secondary school students. This intervention represents a unified model with key processes based on contextual behavioural science, including Acceptance and Commitment Therapy (ACT) and Functional Analytic Psychotherapy (FAP). We conducted an intervention with 94 students (age range 17–19 years), randomly assigned to an experimental group (n = 50) or control group (n = 44). Participants took a pretest and post-test of distress, life satisfaction, psychological flexibility and mindfulness. The intervention consisted of three sessions of 1 h each. The results showed significant differences between the groups in distress and significant differences for the interaction (group × pre–post) in all the other variables. The intervention had greater benefits for girls than for boys. These results may provide a breakthrough, thus leading to a process of evidence-based therapies, which would be responsible for inducing psychological improvements in brief periods, in a population with an increasing risk of distress.This study was carried out in Marbella (Spain), did not receive funding and was self-financed. Funding for open access charge: Universidad de Málaga / CBUA