Test of a simple and flexible molecule model for alpha-, beta- and gamma-S8 crystals

S8 is the most stable compound of elemental sulfur in solid and liquid phases, at ambient pressure and below 400K. Three crystalline phases of S8 have been clearly identified in this range of thermodynamic parameters, although no calculation of its phase diagram has been performed yet. alpha- and gamma-S8 are orientationally ordered crystals while beta-S8 is measured as orientationally disordered. In this paper we analyze the phase diagram of S8 crystals, as given by a simple and flexible molecule model, via a series of molecular dynamics (MD) simulations. The calculations are performed in the constant pressure- constant temperature ensemble, using an algorithm that is able to reproduce structural phase transitions.Comment: RevTex,7 pages, 5 figures,to appear in J. Chem. Phy

Fluctuation-induced forces between rings threaded around a polymer chain under tension

We characterize the fluctuation properties of a polymer chain under external tension and the fluctuation-induced forces between two ring molecules threaded around the chain. The problem is relevant in the context of fluctuation-induced forces in soft-matter systems, features of liquid interfaces, and to describe the properties of polyrotaxanes and slide-ring materials. We perform molecular-dynamics simulations of the Kremer-Grest bead-spring model for the polymer and a simple ring-molecule model in the canonical ensemble. We study transverse fluctuations of the stretched chain as a function of chain stretching and in the presence of ring-shaped threaded molecules. The fluctuation spectra of the chains are analyzed in equilibrium at constant temperature, and the differences in the presence of two-ring molecules are compared. For the rings located at fixed distances, we find an attractive fluctuation-induced force between the rings, proportional to the temperature and decaying with the ring distance. We characterize this force as a function of ring distance, chain stretching, and ring radius, and we measure the differences between the free chain spectrum and the fluctuations of the chain constrained by the rings. We also compare the dependence and range of the force found in the simulations with theoretical models coming from different fields.Fil: Gilles, Facundo Matias. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Llubaroff, R.. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina. Universidad Tecnológica Nacional. Facultad Regional Avellaneda; ArgentinaFil: Pastorino, Claudio. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Distance learning training in genetics and genomics testing for Italian health professionals: results of a pre and post-test evaluation

BACKGROUND: Progressive advances in technologies for DNA sequencing and decreasing costs are allowing an easier diffusion of genetic and genomic tests. Physicians' knowledge and confidence on the topic is often low and not suitable for manage this challenge. Tailored educational programs are required to reach a more and more appropriate use of genetic technologies. METHODS: A distance learning course has been created by experts from different Italian medical associations with the support of the Italian Ministry of Health. The course was directed to professional figures involved in prescription and interpretation of genetic tests. A pretest-post-test study design was used to assess knowledge improvement. We analyzed the proportion of correct answers for each question pre and post-test, as well as the mean score difference stratified by gender, age, professional status and medical specialty. RESULTS: We reported an improvement in the proportion of correct answers for 12 over 15 questions of the test. The overall mean score to the questions significantly increased in the post-test, from 9.44 to 12.49 (p-value < 0.0001). In the stratified analysis we reported an improvement in the knowledge of all the groups except for geneticists; the pre-course mean score of this group was already very high and did not improve significantly. CONCLUSION: Distance learning is effective in improving the level of genetic knowledge. In the future, it will be useful to analyze which specialists have more advantage from genetic education, in order to plan more tailored education for medical professionals

Direction of Arrival Estimation Based on Support Vector Regression: Experimental Validation and Comparison with MUSIC

In this letter, the problem of estimating the directions of arrival (DOAs) of coherent electromagnetic waves impinging upon a uniform linear array (ULA) is considered. In particular, an efficient DOA estimation approach based on the support vector regression is assessed using experimental measurements. Moreover, the obtained results are compared with those yielded by the multiple signal classification (MUSIC) algorithm

Benefits and challenges of Bbg data in healthcare. An overview of the European initiatives

Healthcare systems around the world are facing incredible challenges due to the ageing population and the related disability, and the increasing use of technologies and citizen's expectations. Improving health outcomes while containing costs acts as a stumbling block. In this context, Big Data can help healthcare providers meet these goals in unprecedented ways. The potential of Big Data in healthcare relies on the ability to detect patterns and to turn high volumes of data into actionable knowledge for precision medicine and decision makers. In several contexts, the use of Big Data in healthcare is already offering solutions for the improvement of patient care and the generation of value in healthcare organizations. This approach requires, however, that all the relevant stakeholders collaborate and adapt the design and performance of their systems. They must build the technological infrastructure to house and converge the massive volume of healthcare data, and to invest in the human capital to guide citizens into this new frontier of human health and well-being. The present work reports an overview of best practice initiatives in Europe related to Big Data analytics in public health and oncology sectors, aimed to generate new knowledge, improve clinical care and streamline public health surveillance

Project MOSI: rationale and pilot-study results of an initiative to help protect zoo animals from mosquito-transmitted pathogens and contribute data on mosquito spatio–temporal distribution change

Mosquito-borne pathogens pose major threats to both wildlife and human health and, largely as a result of unintentional human-aided dispersal of their vector species, their cumulative threat is on the rise. Anthropogenic climate change is expected to be an increasingly significant driver of mosquito dispersal and associated disease spread. The potential health implications of changes in the spatio-temporal distribution of mosquitoes highlight the importance of ongoing surveillance and, where necessary, vector control and other health-management measures. The World Association of Zoos and Aquariums initiative, Project MOSI, was established to help protect vulnerable wildlife species in zoological facilities from mosquito-transmitted pathogens by establishing a zoo-based network of fixed mosquito monitoring sites to assist wildlife health management and contribute data on mosquito spatio-temporal distribution changes. A pilot study for Project MOSI is described here, including project rationale and results that confirm the feasibility of conducting basic standardized year-round mosquito trapping and monitoring in a zoo environment

Recent and subfossil diatom assemblages as indicators of environmental change (including fish introduction) in a high-mountain lake

We investigated modern-littoral and subfossil sediment-core diatoms in the shallow (max depth 6.4 m) high-mountain Lake Balma in the Orsiera Rocciavrè Nature Park (Italian Western Alps). Our study provided evidence that might be related to the response of diatom assemblages to fish introduction, in particular the decreasing of the nutrient-enrichment sensitive low-profile life-form/ecological guild and the increase in species known to react positively to the augmented nutrient availability due to fish excretions (e.g., Fragilaria nanana, Pseudostaurosira brevistriata, Staurosirella neopinnata). We are, however, aware that some of these effects could as well have been caused by pastures and cattle watering, and by increased temperatures due to global warming, and we acknowledge the typical complex-interaction pattern among different stressors. High-mountain lakes are ‘‘early warning systems’’ for the whole alpine system and can contribute valuable information also on the interactions between environmental global changes and anthropogenic impacts. Benthic diatoms, in particular, can provide useful indications on the deleterious effects of non-native fish introduction, cattle grazing, and global warming, and thus support an adaptive and sustainable management of high-mountain lakes for the sake of nature conservation