Orthorexia nervosa and self-attitudinal aspects of body image in female and male university students.

The present study was designed to investigate orthorexia nervosa, or the phenomenon of being preoccupied with consuming healthy food. Specific aims were to explore relationships between orthorexia features and attitudes towards body image, fitness and health in normal weight female and male university students with high levels of healthy food preoccupation, i.e. orthorexia nervosa. METHODS Participants were 327 female (N = 283) and male (N = 44) students aged 18 to 25 years. All participants completed the Polish adaptation of the 15-item questionnaire assessing orthorexia eating behaviours (the ORTHO-15) and the Multidimensional Body-Self Relations Questionnaire (the MBSRQ). Relationships between scores on the ORTHO-15 and MBSRQ were explored in the 213 students who had high levels of preoccupation with a healthy food intake (68.55% women and 43.18% men, respectively). RESULTS: There were no statistically significant differences in the levels of orthorexia behaviours between females and males. In female students with orthorexia nervosa, preoccupation with consuming healthy food was significantly correlated with the MBSRQ subscale scores for overweight preoccupation, appearance orientation, fitness orientation, health orientation, body areas satisfaction and appearance evaluation. Conversely, in male students with orthorexia nervosa there were no correlations between orthorexic behaviours and the MBSRQ subscales. In female students with orthorexia nervosa multivariable linear regression analysis found high body areas (parts) satisfaction, low fitness orientation, low overweight preoccupation and low appearance orientation were independent predictors of greater fixation on eating healthy food. In male students, we found that aspects of body image were not associated with preoccupation with healthy eating. CONCLUSION: A strong preoccupation with healthy and proper food was not associated with an unhealthy body-self relationship among Polish female student with orthorexia nervosa

Unstable Attractors: Existence and Robustness in Networks of Oscillators With Delayed Pulse Coupling

We consider unstable attractors; Milnor attractors $A$ such that, for some neighbourhood $U$ of $A$, almost all initial conditions leave $U$. Previous research strongly suggests that unstable attractors exist and even occur robustly (i.e. for open sets of parameter values) in a system modelling biological phenomena, namely in globally coupled oscillators with delayed pulse interactions. In the first part of this paper we give a rigorous definition of unstable attractors for general dynamical systems. We classify unstable attractors into two types, depending on whether or not there is a neighbourhood of the attractor that intersects the basin in a set of positive measure. We give examples of both types of unstable attractor; these examples have non-invertible dynamics that collapse certain open sets onto stable manifolds of saddle orbits. In the second part we give the first rigorous demonstration of existence and robust occurrence of unstable attractors in a network of oscillators with delayed pulse coupling. Although such systems are technically hybrid systems of delay differential equations with discontinuous `firing' events, we show that their dynamics reduces to a finite dimensional hybrid system system after a finite time and hence we can discuss Milnor attractors for this reduced finite dimensional system. We prove that for an open set of phase resetting functions there are saddle periodic orbits that are unstable attractors.Comment: 29 pages, 8 figures,submitted to Nonlinearit

Robust bursting to the origin: heteroclinic cycles with maximal symmetry equilibria

Preprint version of an article published in International Journal of Bifurcation and Chaos, 15, 9, 2005, pp. 2819-2832. DOI: 10.1142/S0218127405013708 © copyright World Scientific Publishing Company. http://www.worldscinet.com/ijbc/ijbc.shtmlRobust attracting heteroclinic cycles have been found in many models of dynamics with symmetries. In all previous examples, robust heteroclinic cycles appear between a number of symmetry broken equilibria. In this paper we examine the first example where there are robust attracting heteroclinic cycles that include the origin, ie a point with maximal symmetry. The example we study is for vector fields on R3 with (Z2)3 symmetry. We list all possible generic (codimension one) local and global bifurcations by which this cycle can appear as an attractor; these include a resonance bifurcation from a limit cycle, direct bifurcation from a stable origin and direct bifurcation from other and more familiar robust heteroclinic cycles

Piezoresistive sensors based on electrospun mats modified by 2D Ti3C2Tx MXene

The preparation methodology and properties of electroconductive, electrospun mats composed of copolyamide 6,10 and Ti3C2Tx are described in this paper. Mats of several compositions were prepared from a solution of n-propanol. The obtained electrospun mats were then tested as piezoresistive sensors. The relative resistance (AR) of the sensor increased with an increase in the Ti3C2Tx content, and materials with relatively higher electrical conductivity displayed noticeably higher sensitivity to applied pressure. The pressure-induced changes in resistivity increased with an increment in the applied force. - 2019 by the authors. Licensee MDPI, Basel, Switzerland.Funding: This publication was supported by Qatar University Collaborative High Impact Grant QUHI-CENG-18/19-1. The findings accomplished here in are solely the responsibility of the authors.Scopu

Absorption and emission spectra of U4 + diluted in the incommensurate structure of ThCl4

The absorption and fluorescence spectra of U4+ diluted in single crystals of ThCl4 have been measured at temperatures ranging from 4.2 K to room temperature. β-ThCl4 exhibits on incommensurate structure below 70 K with a loss of periodicity along the c axis. This results in a variation of the distance between the metal and the halogen from one cell to another. The site symmetry of the actinide ions is then reduced. The lines corresponding to the sites of the resulting symmetries S4 and D2 are identified spectroscopically. The S4 symmetry is approximated by the D2d one and a parametric analysis of the energy levels of U4 + in the D2d and D 2 symmetries is reported. For 25 levels in the D2d site the root mean square deviation σ is 46 cm-1 and for 34 levels in D2, σ = 56 cm-1. The parameters which occur in both symmetries are only slightly changed

Infinities of stable periodic orbits in systems of coupled oscillators

We consider the dynamical behavior of coupled oscillators with robust heteroclinic cycles between saddles that may be periodic or chaotic. We differentiate attracting cycles into types that we call phase resetting and free running depending on whether the cycle approaches a given saddle along one or many trajectories. At loss of stability of attracting cycling, we show in a phase-resetting example the existence of an infinite family of stable periodic orbits that accumulate on the cycling, whereas for a free-running example loss of stability of the cycling gives rise to a single quasiperiodic or chaotic attractor