815 research outputs found
Chaos in Robertson-Walker Cosmology
Chaos in Robertson-Walker cosmological models where gravity is coupled to one
or more scalar fields has been studied by a few authors, mostly using numerical
simulations. In this paper we begin a systematic study of the analytical
aspect. We consider one conformally coupled scalar field and, using the fact
that the model is integrable when the field is massless, we show in detail how
homoclinic chaos arises for nonzero masses using a perturbative method.Comment: 16 pages, Tex, no figures. Minor changes have been added. To appear
in Journal of Mathematical Physic
Genetic use restriction technologies: a review
Summary Genetic use restriction technologies (GURTs), developed to secure return on investments through protection of plant varieties, are among the most controversial and opposed genetic engineering biotechnologies as they are perceived as a tool to force farmers to depend on multinational corporations' seed monopolies. In this work, the currently proposed strategies are described and compared with some of the principal techniques implemented for preventing transgene flow and/or seed saving, with a simultaneous analysis of the future perspectives of GURTs taking into account potential benefits, possible impacts on farmers and local plant genetic resources (PGR), hypothetical negative environmental issues and ethical concerns related to intellectual property that have led to the ban of this technology
Development and characterization of sensors for human health
L'abstract è presente nell'allegato / the abstract is in the attachmen
Orthodontic Emergencies and Perspectives During and After the COVID-19 Pandemic: The Italian Experience
Objective: To investigate the types of dental emergencies that occurred during the lockdown period in Italy (12th March—4th May) and to investigate future therapeutic preferences related to the use of different types of appliances. Material and Methods: A questionnaire dedicated to assessing dental emergencies during the lockdown period and surveying the resumption of orthodontic practice was submitted to clinicians in digital form. The first part of the questionnaire, focused on the orthodontic emergencies that were encountered in relation to the different types of orthodontic appliances and how these were resolved. The second part of the questionnaire was devoted to the resumption of clinical practice; in particular, it was designed to assess whether and what percentage of clinicians are willing to change the duration of appointments in relation to the different types of appliance used, asking them whether their approach to orthodontic treatment would change in the coming months as compared to the pre-COVID-19 era. Results: Results show that in most cases (82%), the percentage of patients who experienced a dental emergency was less than 5% and that far fewer emergencies were attributable to removable (5.7%) than to fixed appliances (94.3%). Looking ahead, clinicians expressed a greater preference for using removable (60.8%) rather than fixed appliances (39.2%). Conclusion: During the lockdown, there relatively few orthodontic emergencies, many of which were handled by telephone consultation. However, a far lower percentage of emergencies were generated by removable (e.g., clear aligners) as opposed to fixed appliances (e.g., multibracket equipment), likely influencing the decision of the majority of clinicians to opt for removable appliances in the wake of the COVID-19 pandemic
Orthodontic Emergencies and Perspectives During and After the COVID-19 Pandemic: The Italian Experience
Objective: To investigate the types of dental emergencies that occurred during the lockdown period in Italy (12th March—4th May) and to investigate future therapeutic preferences related to the use of different types of appliances. Material and Methods: A questionnaire dedicated to assessing dental emergencies during the lockdown period and surveying the resumption of orthodontic practice was submitted to clinicians in digital form. The first part of the questionnaire, focused on the orthodontic emergencies that were encountered in relation to the different types of orthodontic appliances and how these were resolved. The second part of the questionnaire was devoted to the resumption of clinical practice; in particular, it was designed to assess whether and what percentage of clinicians are willing to change the duration of appointments in relation to the different types of appliance used, asking them whether their approach to orthodontic treatment would change in the coming months as compared to the pre-COVID-19 era. Results: Results show that in most cases (82%), the percentage of patients who experienced a dental emergency was less than 5% and that far fewer emergencies were attributable to removable (5.7%) than to fixed appliances (94.3%). Looking ahead, clinicians expressed a greater preference for using removable (60.8%) rather than fixed appliances (39.2%). Conclusion: During the lockdown, there relatively few orthodontic emergencies, many of which were handled by telephone consultation. However, a far lower percentage of emergencies were generated by removable (e.g., clear aligners) as opposed to fixed appliances (e.g., multibracket equipment), likely influencing the decision of the majority of clinicians to opt for removable appliances in the wake of the COVID-19 pandemic
HSimulator: Hybrid Stochastic/Deterministic Simulation of Biochemical Reaction Networks
HSimulator is a multithread simulator for mass-action biochemical reaction systems placed in a well-mixed environment. HSimulator provides optimized implementation of a set of widespread state-of-the-art stochastic, deterministic, and hybrid simulation strategies including the first publicly available implementation of the Hybrid Rejection-based Stochastic Simulation Algorithm (HRSSA). HRSSA, the fastest hybrid algorithm to date, allows for an efficient simulation of the models while ensuring the exact simulation of a subset of the reaction network modeling slow reactions. Benchmarks show that HSimulator is often considerably faster than the other considered simulators. The software, running on Java v6.0 or higher, offers a simulation GUI for modeling and visually exploring biological processes and a Javadoc-documented Java library to support the development of custom applications. HSimulator is released under the COSBI Shared Source license agreement (COSBI-SSLA)
Target motion estimation via a multistatic FSR
The focus of this paper is on the estimation of the kinematic parameters of moving targets
via a MIMO Forward Scatter Radar (FSR) system. A sub-optimum estimation technique is considered
that exploits the information concerning the time instants at which the target crosses the individual
baselines to retrieve the motion parameters. The accuracy of such technique is firstly investigated
from a theoretical point of view and then the effectiveness of the proposed approach is demonstrated
by applying it to live MIMO FSR data. Shown results prove the practical applicability of the proposed
technique
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