6,149 research outputs found

    Corrosion behavior of dental implants immersed into human saliva: Preliminary results of an in vitro study

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    Over the years, dif- ferent implant surfaces have been used to try to maximize bone to implant contact. The aim of this study was to compare levels of metallic ions and particles dissolution collected from two dif- ferent dental implants surfaces immersed into human saliva. PATIENTS AND METHODS: A total of 60 den- tal implants were tested. Group A: sanded with aluminium oxide medium grade particles and ac- id-etched; Group B: micro-sanded with calcium phosphate powders and acid-etched. Forty im- plants were immersed in 20 ml of human saliva, twenty, as a control, in sterile saline solution. ICP-MS was performed to detect any metallic ions released from dental implants at T0, on day 1 (T1), on day 3 (T2), after one week (T3), on day 14 (T4), after 3 months (T5) and after 6 months (T6). RESULTS: Dissolution of metallic particles of titanium and nickel, absent in human saliva (T0), were found after one week (T3) for Group B and after 3 months (T5) for Group A. Vanadium was already detected in small concentrations in either group after 1 day, with an exponential growth for Group B. CONCLUSIONS: Preliminary results reported signi cant values of Ti, Ni and V released by Group B, showing for the rst time statistically signi cant values of vanadium

    Modelling diffusion of innovations in a social network

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    A new simple model of diffusion of innovations in a social network with upgrading costs is introduced. Agents are characterized by a single real variable, their technological level. According to local information agents decide whether to upgrade their level or not balancing their possible benefit with the upgrading cost. A critical point where technological avalanches display a power-law behavior is also found. This critical point is characterized by a macroscopic observable that turns out to optimize technological growth in the stationary state. Analytical results supporting our findings are found for the globally coupled case.Comment: 4 pages, 5 figures. Final version accepted in PR

    Compulsory treatments in eating disorders: a systematic review and meta-analysis

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    Introduction: The aims of this systematic review and meta-analysis are to provide a summary of the current literature concerning compulsory treatments in patients with eating disorders (ED) and to understand whether compulsorily and involuntarily treated patients differ in terms of baseline characteristics and treatment outcomes. Methods: Relevant articles were identified following the PRISMA guidelines by searching the following terms: “treatment refusal”, “forced feeding”, “compulsory/coercive/involuntary/forced treatment/admission”, “eating disorders”, “feeding and eating disorders”, “anorexia nervosa”, “bulimia nervosa”. Research was restricted to articles concerning humans and published between 1975 and 2020 in English. Results: Out of 905 articles retrieved, nine were included for the analyses allowing the comparisons between 242 compulsorily and 738 voluntarily treated patients. Mean body mass index (BMI) was slightly lower in patients compelled to treatments. Mean illness duration, BMI at discharge and BMI variation showed no significant differences between the two groups. Average length of hospitalization was 3 weeks longer among compulsory-treated patients, but this did not result in a higher increase in BMI. No significant risk difference on mortality was estimated (three studies). Conclusions: Compulsory treatments are usually intended for patients having worse baseline conditions than voluntary ones. Those patients are unlikely to engage in treatments without being compelled but, after the treatments, albeit with longer hospitalisations, they do achieve similar outcomes. Therefore, we can conclude that forcing patients to treatment is a conceivable option. Level of evidence: Level I, systematic review and meta-analysis

    Fiber reinforced concrete. Part II: Application

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    The present paper is the second part of two companion papers related with the design and application of fiber reinforced concrete (FRC) in structural elements. It is presented a case study regarding the use of FRC in the development and construction of a new sustainable building system based on the assembly of structural prefabricated sandwich panels formed by thin outer layers of steel fiber reinforced self-compacting concrete (SFRSCC) and an insulation core. The outer layers of SFRSCC are connected with innovative glass fiber reinforced polymer (GFRP) connectors. The structural concept is presented and the numerical and experimental work carried out for the construction of a real scale prototype is briefly describe

    Mapeamento de solos das áreas de duas mesobacias hidrográficas no Nordeste paraense.

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    Este trabalho cumpre parte das necessidades de levantar e caracterizar os solos de duas áreas de mesobacias hidrográficas inseridas no projeto Gestabacias, previstas no diagnóstico do meio biofísico dessas áreas. O Projeto Gestabacias foi elaborado com o intuito de desenvolver uma rede de informações que permita integrar resultados de pesquisa sobre a integridade dos recursos solo, vegetação, água e fauna aquática em mesobacias hidrográficas relacionadas com diferentes sistemas de uso da terra praticados, como subsídio à construção de um modelo de gestão participativa dos recursos naturais nessas bacias. Ao ultrapassar os limites da academia e dos centros de pesquisa, prevê a socialização das informações disponíveis e a participação de diferentes atores envolvidos na elaboração de modelos de gestão dos recursos naturais em bacias hidrográficas localizadas no nordeste do Estado do Pará

    Competition and Selection Among Conventions

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    In many domains, a latent competition among different conventions determines which one will come to dominate. One sees such effects in the success of community jargon, of competing frames in political rhetoric, or of terminology in technical contexts. These effects have become widespread in the online domain, where the data offers the potential to study competition among conventions at a fine-grained level. In analyzing the dynamics of conventions over time, however, even with detailed on-line data, one encounters two significant challenges. First, as conventions evolve, the underlying substance of their meaning tends to change as well; and such substantive changes confound investigations of social effects. Second, the selection of a convention takes place through the complex interactions of individuals within a community, and contention between the users of competing conventions plays a key role in the convention's evolution. Any analysis must take place in the presence of these two issues. In this work we study a setting in which we can cleanly track the competition among conventions. Our analysis is based on the spread of low-level authoring conventions in the eprint arXiv over 24 years: by tracking the spread of macros and other author-defined conventions, we are able to study conventions that vary even as the underlying meaning remains constant. We find that the interaction among co-authors over time plays a crucial role in the selection of them; the distinction between more and less experienced members of the community, and the distinction between conventions with visible versus invisible effects, are both central to the underlying processes. Through our analysis we make predictions at the population level about the ultimate success of different synonymous conventions over time--and at the individual level about the outcome of "fights" between people over convention choices.Comment: To appear in Proceedings of WWW 2017, data at https://github.com/CornellNLP/Macro

    Collective Decision Dynamics in the Presence of External Drivers

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    We develop a sequence of models describing information transmission and decision dynamics for a network of individual agents subject to multiple sources of influence. Our general framework is set in the context of an impending natural disaster, where individuals, represented by nodes on the network, must decide whether or not to evacuate. Sources of influence include a one-to-many externally driven global broadcast as well as pairwise interactions, across links in the network, in which agents transmit either continuous opinions or binary actions. We consider both uniform and variable threshold rules on the individual opinion as baseline models for decision-making. Our results indicate that 1) social networks lead to clustering and cohesive action among individuals, 2) binary information introduces high temporal variability and stagnation, and 3) information transmission over the network can either facilitate or hinder action adoption, depending on the influence of the global broadcast relative to the social network. Our framework highlights the essential role of local interactions between agents in predicting collective behavior of the population as a whole.Comment: 14 pages, 7 figure

    Sentient Spaces: Intelligent Totem Use Case in the ECSEL FRACTAL Project

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    The objective of the FRACTAL project is to create a novel approach to reliable edge computing. The FRACTAL computing node will be the building block of scalable Internet of Things (from Low Computing to High Computing Edge Nodes). The node will also have the capability of learning how to improve its performance against the uncertainty of the environment. In such a context, this paper presents in detail one of the key use cases: an Internet-of-Things solution, represented by intelligent totems for advertisement and wayfinding services, within advanced ICT-based shopping malls conceived as a sentient space. The paper outlines the reference scenario and provides an overview of the architecture and the functionality of the demonstrator, as well as a roadmap for its development and evaluation
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