Stability in microcanonical many-body spin glasses

We generalize the de Almeida-Thouless line for the many-body Ising spin glass to the microcanonical ensemble and show that it coincides with the canonical one. This enables us to draw a complete microcanonical phase diagram of this model

Ensemble Inequivalence and the Spin-Glass Transition

We report on the ensemble inequivalence in a many-body spin-glass model with integer spin. The spin-glass phase transition is of first order for certain values of the crystal field strength and is dependent whether it was derived in the microcanonical or the canonical ensemble. In the limit of infinitely many-body interactions, the model is the integer-spin equivalent of the random-energy model, and is solved exactly. We also derive the integer-spin equivalent of the de Almeida-Thouless line.Comment: 19 pages, 7 figure

Ensemble Inequivalence in the Spherical Spin Glass Model with Nonlinear Interactions

We investigate the ensemble inequivalence of the spherical spin glass model with nonlinear interactions of polynomial order $p$. This model is solved exactly for arbitrary $p$ and is shown to have first-order phase transitions between the paramagnetic and spin glass or ferromagnetic phases for $p \geq 5$. In the parameter region around the first-order transitions, the solutions give different results depending on the ensemble used for the analysis. In particular, we observe that the microcanonical specific heat can be negative and the phase may not be uniquely determined by the temperature.Comment: 15 pages, 10 figure

Ensemble equivalence in spin systems with short-range interactions

We study the problem of ensemble equivalence in spin systems with short-range interactions under the existence of a first-order phase transition. The spherical model with nonlinear nearest-neighbour interactions is solved exactly both for canonical and microcanonical ensembles. The result reveals apparent ensemble inequivalence at the first-order transition point in the sense that the microcanonical entropy is non-concave as a function of the energy and consequently the specific heat is negative. In order to resolve the paradox, we show that an unconventional saddle point should be chosen in the microcanonical calculation that represents a phase separation. The XY model with non-linear interactions is also studied by microcanonical Monte Carlo simulations in two dimensions to see how this model behaves in comparison with the spherical model.Comment: 17 pages, 19 figures, revised versio

Evaluation of DSD training schools organized by cost action BM1303 "DSDnet"

Abstract Background The Differences of Sex Development network (DSDnet) aims to establish interactive relationships between clinicians, scientists, support groups and people with a difference of sex development (DSD) to improve the overall care for people affected by such condition. DSDnet has hosted three Training Schools (TSs) in Ghent, Bologna and Budapest between 2015 and 2017 with the primary purpose of providing multidisciplinary training to young professionals and encouraging ongoing activity in the field of DSD. The aim of our study was to evaluate the success and long-term effect effectiveness of these three TSs. Methods and results Eighty-seven trainees (70 women, 17 men) attended one of three TSs. The distribution of trainees according to their professional field was: 47 (54.0%) from Pediatrics/Endocrinology, 13 (14.9%) from Biology/Genetics, 12 (13.8%) from Psychology/Psychiatry and 15 (17.2%) from Surgical Professions. All trainees were asked to complete an evaluation form on the last day of the TS to gain feedback on how to improve the next one. A further survey was sent at the end of 2017 to provide information about the overall long-term impact of the TSs. Seventy-eight (89.7%) trainees completed evaluation forms at the end of the respective TSs. Replies to the subsequent survey were received from 76 (87.4%) of trainees. A total of 72/76 (94.7%) responders reported that they continue to be active in the field of DSD. The vast majority (64/68, 94.1%) reported that the TSs had enlarged their professional networks. Among the 76 respondent trainees, 11.8% (n = 9) had applied for a research grant and 10.5% (n = 8) had received a fellowship related to DSD since their TS attendance. Conclusions According to our results, the majority of TS participants continue to be active in the field of DSD and have enlarged their professional networks following participation at the TS. These findings indicate the need of this type of educational program and justify ongoing efforts to provide postgraduate multidisciplinary training in rare diseases such as DSD

A SHOX géndeletio előfordulása idiopathiás alacsonynövésben

INTRODUCTION: The isolated haploinsufficiency of the SHOX gene is one of the most common cause of short stature determined by monogenic mutations. The heterozygous deviation of the gene can be detected in 2-15% of patients with idiopathic short stature (ISS), in 50-90% of patients with Leri-Weill dyschondrosteosis syndrome (LWS), and in almost 100% of patients with Turner syndrome. AIM: The aim of our study was to evaluate the frequency of SHOX gene haploinsufficiency in children with ISS, LWS and in patients having Turner syndrome phenotype (TF), but normal karyotype, and to identify the dysmorphic signs characteristic for SHOX gene deficiency. METHOD: A total of 144 patients were included in the study. Multiplex Ligation-dependent Probe Amplification (MLPA) method was used to identify the SHOX gene haploinsufficiency. The relationships between clinical data (axiological parameters, skeletal disorders, dysmorphic signs) and genotype were analyzed by statistical methods. RESULTS: 11 (7.6%) of the 144 patients showed SHOX gene deficiency with female dominance (8/11, 81% female). The SHOX positive patients had a significantly higher BMI (in 5/11 vs. 20/133 cases, p<0.02) and presented more frequent dysmorphic signs (9/11vs 62/133, p = 0.02). Madelung deformity of the upper limbs was also significantly more frequent among the SHOX positive patients (4/11, i.e. 36%, vs. 14/133, i.e. 10%, p = 0.0066). There were no statistically significant differences between the mean age, mean height and auxological measurements (sitting height/height, arm span/height) between the two groups of patients. CONCLUSIONS: The occurrence of SHOX gene haploinsufficiency observed in our population corresponds to the literature data. In SHOX positive patients, in addition to short stature, the dysmorphic signs have a positive predictive value for SHOX gene alterations. However, the SHOX deletion detected in a patient with idiopathic short stature without dysmorphic signs suggest that SHOX deletion analysis can be recommended in patients with ISS. Orv Hetil. 2017; 158(34): 1351-1356

Microcanonical Analysis of Spin Glasses Using Gauge Symmetry

We apply the method of gauge transformation to spin glasses under the microcanonical ensemble to study the possibility of ensemble inequivalence in systems with long-range interactions and quenched disorder. It is proved that all the results derived under the canonical ensemble on the Nishimori line (NL) can be reproduced by the microcanonical ensemble irrespective of the range of interactions. This establishes that ensemble inequivalence should take place away from the NL if it happens in spin glasses. It is also proved on the NL that the microcanonical configurational average of the energy as a function of temperature is exactly equal to the average energy in the canonical ensemble for any finite-size systems with Gaussian disorder. In this sense, ensembles are equivalent even for finite systems