Temperature effect on (2+1) experimental Kardar-Parisi-Zhang growth

We report on the effect of substrate temperature (T) on both local structure and long-wavelength fluctuations of polycrystalline CdTe thin films deposited on Si(001). A strong T-dependent mound evolution is observed and explained in terms of the energy barrier to inter-grain diffusion at grain boundaries, as corroborated by Monte Carlo simulations. This leads to transitions from uncorrelated growth to a crossover from random-to-correlated growth and transient anomalous scaling as T increases. Due to these finite-time effects, we were not able to determine the universality class of the system through the critical exponents. Nevertheless, we demonstrate that this can be circumvented by analyzing height, roughness and maximal height distributions, which allow us to prove that CdTe grows asymptotically according to the Kardar-Parisi-Zhang (KPZ) equation in a broad range of T. More important, one finds positive (negative) velocity excess in the growth at low (high) T, indicating that it is possible to control the KPZ non-linearity by adjusting the temperature.Comment: 6 pages, 5 figure

Dynamical analysis of the cluster pair: A3407 + A3408

We carried out a dynamical study of the galaxy cluster pair A3407 \& A3408 based on a spectroscopic survey obtained with the 4 meter Blanco telescope at the CTIO, plus 6dF data, and ROSAT All-Sky-Survey. The sample consists of 122 member galaxies brighter than $m_R=20$. Our main goal is to probe the galaxy dynamics in this field and verify if the sample constitutes a single galaxy system or corresponds to an ongoing merging process. Statistical tests were applied to clusters members showing that both the composite system A3407 + A3408 as well as each individual cluster have Gaussian velocity distribution. A velocity gradient of $\sim 847\pm 114$ $\rm km\;s^{-1}$ was identified around the principal axis of the projected distribution of galaxies, indicating that the global field may be rotating. Applying the KMM algorithm to the distribution of galaxies we found that the solution with two clusters is better than the single unit solution at the 99\% c.l. This is consistent with the X-ray distribution around this field, which shows no common X-ray halo involving A3407 and A3408. We also estimated virial masses and applied a two-body model to probe the dynamics of the pair. The more likely scenario is that in which the pair is gravitationally bound and probably experiences a collapse phase, with the cluster cores crossing in less than $\sim$1 $h^{-1}$ Gyr, a pre-merger scenario. The complex X-ray morphology, the gas temperature, and some signs of galaxy evolution in A3408 suggests a post-merger scenario, with cores having crossed each other $\sim 1.65 h^{-1}$Gyr ago, as an alternative solution.Comment: 17 pages, 12 figures, submitted to MNRAS, accepted 2016 May 9. Received 2016 May 9; in original form 2016 April 1

Entropy and holography constraints for inhomogeneous universes

We calculated the entropy of a class of inhomogeneous dust universes. Allowing spherical symmetry, we proposed a holographic principle by reflecting all physical freedoms on the surface of the apparent horizon. In contrast to flat homogeneous counterparts, the principle may break down in some models, though these models are not quite realistic. We refined fractal parabolic solutions to have a reasonable entropy value for the present observable universe and found that the holographic principle always holds in the realistic cases.Comment: 4 pages, revtex style, 3 figures in 8 eps-file

Pattern of video game usage and video game disorder in Portugueses adolescents: a study about parental and peer attachment, parenting styles, and communication in parenting

Introduction: Video game disorder has been a subject of increasing interest, being associated with patterns of insecure attachment and authoritarian and permissive parenting styles. However, there is still a gap concerning the relationship between video game disorder and parent-child communication, one of the fundamental components of attachment to parents. Particularly in the Portuguese context, research on these topics and their interrelations is still scarce, thus remaining relatively unexplored. Objectives: To explore the pattern of video game usage and video game disorder, as well as their relationships with parental and peer attachment, parenting styles, and communication in parenting within a sample of Portuguese adolescents. Methods: 150 Portuguese teenagers, recruited at public Portuguese schools, aged between 10 and 19 years old (mean age = 14.37, DP = 3.12; 52.7% girls (n = 79), and mostly living with both parents (79.7%, n = 106) fulfilled a sociodemographic and an academic questionnaire, a questionnaire on video game use patterns, the Video Game Disorder Scale - Short Version 9, the People in My Life Questionnaire, the Portuguese hetero-report version of the Parenting Styles and Dimensions Questionnaire: Short Versionand the Perception Scale of Parenting Communication. Results: The majority of the sample indicated 3rd childhood (n = 81, 54.0%), specifically at 8 years old, as the age of video game initiation and a playtime of less than or equal to 2 hours (n = 111, 74.0%), with only 2 participants found to have a video game disturbance index (1.3%). A positive association was found between video game disturbance and the average hours of gameplay, as well as a negative association with the age of game initiation. Additionally, relationships were explored, revealing that video game disturbance is negatively related to lower quality of attachment to parents and peers, positively related to an authoritative parenting style, and negatively related to less available, open, and affectionate parent-child communication. Conclusions: This study provides an in-depth understanding of adolescents’ behavior regarding video games, contributing to the knowledge of the topic in the Portuguese context. Furthermore, the identification of factors associated with video game disturbance allows for the development of remediation and prevention programs for this addictive disturbance, which are essential tools in psychological practice.info:eu-repo/semantics/publishedVersio

The Apparent Fractal Conjecture: Scaling Features in Standard Cosmologies

This paper presents an analysis of the smoothness problem in cosmology by focussing on the ambiguities originated in the simplifying hypotheses aimed at observationally verifying if the large-scale distribution of galaxies is homogeneous, and conjecturing that this distribution should follow a fractal pattern in perturbed standard cosmologies. This is due to a geometrical effect, appearing when certain types of average densities are calculated along the past light cone. The paper starts reviewing the argument concerning the possibility that the galaxy distribution follows such a scaling pattern, and the premises behind the assumption that the spatial homogeneity of standard cosmology can be observable. Next, it is argued that to discuss observable homogeneity one needs to make a clear distinction between local and average relativistic densities, and showing how the different distance definitions strongly affect them, leading the various average densities to display asymptotically opposite behaviours. Then the paper revisits Ribeiro's (1995: astro-ph/9910145) results, showing that in a fully relativistic treatment some observational average densities of the flat Friedmann model are not well defined at z ~ 0.1, implying that at this range average densities behave in a fundamentally different manner as compared to the linearity of the Hubble law, well valid for z < 1. This conclusion brings into question the widespread assumption that relativistic corrections can always be neglected at low z. It is also shown how some key features of fractal cosmologies can be found in the Friedmann models. In view of those findings, it is suggested that the so-called contradiction between the cosmological principle, and the galaxy distribution forming an unlimited fractal structure, may not exist.Comment: 30 pages, 2 figures, LaTeX. This paper is a follow-up to gr-qc/9909093. Accepted for publication in "General Relativity and Gravitation

Differential Expression Of Abcf2 In Newly Diagnosed And Dasatinib-treated Chronic Myeloid Leukemia Patients

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