Density of States and Critical Behavior of the Coulomb Glass

We present zero-temperature simulations for the single-particle density of states of the Coulomb glass. Our results in three dimensions are consistent with the Efros and Shklovskii prediction for the density of states. Finite-temperature Monte Carlo simulations show no sign of a thermodynamic glass transition down to low temperatures, in disagreement with mean-field theory. Furthermore, the random-displacement formulation of the model undergoes a transition into a distorted Wigner crystal for a surprisingly broad range of the disorder strength.Comment: 4 pages, 2 figures, 1 tabl

Characterization of an emergent clone of enteroinvasive Escherichia coli circulating in Europe

Enteroinvasive Escherichia coli (EIEC) cause intestinal illness indistinguishable from that caused by Shigella, mainly in developing countries. Recently an upsurge of cases of EIEC infections has been observed in Europe, with two large outbreaks occurring in Italy and in the United Kingdom. We have characterized phenotypically and genotypically the strains responsible for these epidemics together with an additional isolate from a sporadic case isolated in Spain. The three isolates belonged to the same rare serotype O96:H19 and were of sequence type ST-99, never reported before in EIEC or Shigella. The EIEC strains investigated possessed all the virulence genes harboured on the large plasmid conferring the invasive phenotype to EIEC and Shigella while showing only some of the known chromosomal virulence genes and none of the described pathoadaptative mutations. At the same time, they displayed motility abilities and biochemical requirements resembling more closely those of the non-pathogenic E. coli rather than the EIEC and Shigella strains used as reference. Our observations suggested that the O96:H19 strains belong to an emerging EIEC clone, which could be the result of a recent event of acquisition of the invasion plasmid by commensal E. coli

Seismic Behavior and Failure Mechanisms Identification of Ancient Masonry Towers

Strong damage or complete loss suffered by the cultural patrimony when subjected to considerable earthquake ground shaking has been occurring through the history of humanity. The occurrence of these unexpected and unavoidable events has demonstrated that ancient masonry towers are one of the most vulnerable structural types to suffer strong damage or collapse. There are certain relevant aspects determining the seismic vulnerability of towers in terms of behavior and failure mechanisms that differentiate these vertical structures from most of compact historical constructions. This is the first stage of an international scientific research between the University of Braunschweig and the University of Florence, aimed to develop a methodology to mitigate the seismic risk of ancient masonry towers located in seismic zones with the use of prestressing devices of smart materials. Therefore results quite important a deep understanding and identification of all the most important aspects that determine the seismic vulnerability of ancient masonry towers in terms of behavior and failure mechanisms. For achieving this, it is considered the relevant literature, observed damage after real earthquakes and mainly engineering experience.Technical University of Braunschwei

Freezing transition of the vortex liquid in anisotropic superconductors

We study the solid-liquid transition of a model of pancake vortices in laminar superconductors using a density functional theory of freezing. The physical properties of the system along the melting line are discussed in detail. We show that there is a very good agreement with experimental data in the shape and position of the first order transition in the phase diagram and in the magnitude and temperature dependence of the magnetic induction jump at the transition. We analyze the validity of the Lindemann melting criterion and the Hansen-Verlet freezing criterion. Both criteria are shown to be good to predict the phase diagram in the region where a first order phase transition is experimentally observed.Comment: 9 pages, 10 figure

Melittis melissophyllum L. subsp. melissophyllum (Lamiaceae) from central Italy: a new source of a mushroom-like flavor

1-Octen-3-ol is the most important C8 mushroom aromatic compound produced by many species of edible fungi and is also an aroma component in several food and beverages products. Under this view, the essential oil of flowering aerial parts of Melittis melissophyllum subsp. melissophyllum (Lamiaceae) growing in central Italy, obtained by hydrodistillation was characterised by GC–FID and GC–MS. This oil contained extremely high amount of the mushroom-like aroma component 1-octen-3-ol (43.6–54.2%), and could be considered as a new natural product for the use as flavouring agent in the food industry. Furthermore, headspace analysis suggested that this aromatic compound is only present in low concentration in the plant part, and is primarily formed in higher amount during hydrodistillation of this material

Waist-to-height ratio, waist circumference and BMI as indicators of percentage fat mass and cardiometabolic risk factors in children aged 3–7 years

SummaryObjectiveTo assess whether waist-to-height-ratio (WHtR) is a better estimate of body fat percentage (BF%) and a better indicator of cardiometabolic risk factors than BMI or waist circumference (WC) in young children.MethodsWHtR, WC and BMI were measured by trained staff according to standardized procedures. 2H2O and 2H218O isotope dilution were used to assess BF% in 61 children (3–7 years) from the general population, and bioelectrical impedance (Horlick equation) was used to assess BF% in 75 overweight/obese children (3–5 years). Cardiometabolic risk factors, including diastolic and systolic blood pressure, HOMA2-IR, leptin, adiponectin, triglycerides, total cholesterol, HDL- and LDL-cholesterol, TNFα and IL-6 were determined in the overweight/obese children.ResultsIn the children from the general population, after adjustments for age and gender, BMI had the highest explained variance for BF% compared to WC and WHtR (R2 = 0.32, 0.31 and 0.23, respectively). In the overweight/obese children, BMI and WC had a higher explained variance for BF% compared to WHtR (R2 = 0.68, 0.70 and 0.50, respectively). In the overweight/obese children, WHtR, WC and BMI were all significantly positively correlated with systolic blood pressure (r = 0.23, 0.30, 0.36, respectively), HOMA2-IR (r = 0.53, 0.62, 0.63, respectively), leptin (r = 0.70, 0.77, 0.78, respectively) and triglycerides (r = 0.33, 0.36, 0.24, respectively), but not consistently with other parameters.ConclusionIn young children, WHtR is not superior to WC or BMI in estimating BF%, nor is WHtR better correlated with cardiometabolic risk factors than WC or BMI in overweight/obese children. These data do not support the use of WHtR in young children

Superconducting gap anisotropy of LuNi2B2C thin films from microwave surface impedance measurements

Surface impedance measurements of LuNi2B2C superconducting thin films as a function of temperature have been performed down to 1.5 K and at 20 GHz using a dielectric resonator technique. The magnetic penetration depth closely reproduces the standard B.C.S. result, but with a reduced value of the energy gap at low temperature. These data provide evidence for an anisotropic s-wave character of the order parameter symmetry in LuNi2B2C. From the evaluation of the real part of complex conductivity, we have observed constructive (type II) coherence effects in the electromagnetic absorption below Tc.Comment: 15 pages, 4 figure