492 research outputs found

    A theoretical study on trehalose + water mixtures for dry preservation purposes

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    The properties of trehalose + water mixtures are studied as a function of mixture composition and temperature using molecular dynamics simulations. As trehalose disaccharide has been proposed for dry preservation purposes, the objective of this work is to analyse the nanoscopic properties of the considered mixtures, in terms of aggregation, clustering, interactions energies, and local dynamics, and their relationships with hydrogen bonding. The reported results allow a detailed characterization of hydrogen bonding and its evolution with mixture composition and thus inferring the effects of trehalose on water structuring providing results to justify the mechanisms of trehalose acting as preservation agent

    The innovation potential of Islamic crowdfunding platforms in contributing to sustainable development

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    Purpose: This paper aims at explaining variances in the contribution of Islamic crowdfunding platforms (ICFPs) to sustainable development (SD), by adopting an institutional logic perspective (ILP). ICFPs represent a dual institutional overlap between two logics (the Western-mainstream and the Islamic logic) which have an impact on corporate social responsibility (CSR) interpretations, practices, and decisions and whose conflicts are mitigated by choosing different resolution strategies. The authors aim at showing that this choice affects SD differently. Design/methodology/approach: The authors develop a conceptual typology through the following steps: (1) choice of variables and identification of corresponding variable domains, through literature review. Variables chosen are the elemental CSR dimensions related to various social and environmental corporate responsibilities to whom diverse meaning and emphasis are given under the Western-mainstream and Islamic logics. (2) Identification of three distinct ideal types of ICFPs, building on different resolution strategies to mitigate conflicts between logics; (3) development, for each ideal type, of a set of implications related to SD; (4) implementation of a first test aiming at assigning real cases to each ideal type. Findings: The authors identify Western-mimicking (platforms adopting as resolution strategy decoupling or compartmentalizing strategies), Islamic-driven (platforms focusing on one prevailing logic) and Syncretism-inspired (platforms adopting hybridizing practices) ideal-types. Originality/value: It is the first paper suggesting ILP to explain variances in crowdfunding platforms' role in addressing SD. It focuses on a specific type of CF platforms till now neglected

    Assessment of the economic and social impact using SROI: An application to sport companies

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    This paper evaluates the social impact of a football club and its philanthropic organization on the local community and its stakeholders, namely supporters, sponsors, players, and shopkeepers. The methodology used is the Social Return on Investment (SROI). SROI methodology includes all the beneficiaries that are beyond the scope of the company's accounting and its fiscal and financial statements. The aim is to assess both the benefits and the negative impacts of a company's activities on stakeholders. This type of analysis combines the use of qualitative, quantitative and financial information gathered and analyzes them in order to estimate the amount of "value", including mental health and well-being, created or destroyed by a business activity, by a project or by the overall operation of an organization. The sport club under review in the present analysis is called Virtus Entella, an Italian football club playing in the second division. An SROI indicator was applied in reference to the business activity that took place during the championship season 2017/2018. Results show that the social impact created during the championship amounts to approximately 44 million Euro against a financial investment of 15 million Euro, producing an SROI ratio of 2.98:1. This outcome suggests that for every euro invested by the football club, about 3 Euros of social value is created

    An economic and financial exploratory

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    This paper describes the vision of a European Exploratory for economics and finance using an interdisciplinary consortium of economists, natural scientists, computer scientists and engineers, who will combine their expertise to address the enormous challenges of the 21st century. This Academic Public facility is intended for economic modelling, investigating all aspects of risk and stability, improving financial technology, and evaluating proposed regulatory and taxation changes. The European Exploratory for economics and finance will be constituted as a network of infrastructure, observatories, data repositories, services and facilities and will foster the creation of a new cross-disciplinary research community of social scientists, complexity scientists and computing (ICT) scientists to collaborate in investigating major issues in economics and finance. It is also considered a cradle for training and collaboration with the private sector to spur spin-offs and job creations in Europe in the finance and economic sectors. The Exploratory will allow Social Scientists and Regulators as well as Policy Makers and the private sector to conduct realistic investigations with real economic, financial and social data. The Exploratory will (i) continuously monitor and evaluate the status of the economies of countries in their various components, (ii) use, extend and develop a large variety of methods including data mining, process mining, computational and artificial intelligence and every other computer and complex science techniques coupled with economic theory and econometric, and (iii) provide the framework and infrastructure to perform what-if analysis, scenario evaluations and computational, laboratory, field and web experiments to inform decision makers and help develop innovative policy, market and regulation designs. Graphical abstrac

    heterogeneous information based artificial stock market

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    In this paper, an information-based artificial stock market is considered. The market is populated by heterogeneous agents that are seen as nodes of a sparsely connected graph. Agents trade a risky asset in exchange for cash. Besides the amount of cash and assets owned, each agent is characterized by a sentiment. Moreover, agents share their sentiments by means of interactions that are identified by the graph. Interactions are unidirectional and are supplied with heterogeneous weights. The agent's trading decision is based on sentiment and, consequently, the stock price process depends on the propagation of information among the interacting agents, on budget constraints and on market feedback. A central market maker (clearing house mechanism) determines the price process at the intersection of the demand and supply curves. Both closed- and open-market conditions are considered. The results point out the validity of the proposed model of information exchange among agents and are helpful for understanding the role of information in real markets. Under closed market conditions, the interaction among agents' sentiments yields a price process that reproduces the main stylized facts of real markets, e.g. the fat tails of the returns distributions and the clustering of volatility. Within open-market conditions, i.e. with an external cash inflow that results in asset price inflation, also the unitary root stylized fact is reproduced by the artificial stock market. Finally, the effects of model parameters on the properties of the artificial stock market are also addressed

    Osmotic behaviour of human mesenchymal stem cells: implications for cryopreservation

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    Aimed at providing a contribution to the optimization of cryopreservation processes, the present work focuses on the osmotic behavior of human mesenchymal stem cells (hMSCs). Once isolated from the umbilical cord blood (UCB) of three different donors, hMSCs were characterized in terms of size distribution and their osmotic properties suitably evaluated through the exposure to hypertonic and isotonic aqueous solutions at three different temperatures. More specifically, inactive cell volume and cell permeability to water and di-methyl sulfoxide (DMSO) were measured, being cell size determined using impedance measurements under both equilibrium and dynamic conditions. Experimental findings indicate that positive cell volume excursions are limited by the apparent increase of inactive volume, which occurs during both the shrink-swell process following DMSO addition and the subsequent restoration of isotonic conditions in the presence of hypertonic solutions of impermeant or permeant solutes. Based on this evidence, hMSCs must be regarded as imperfect osmometers, and their osmotic behavior described within a scenario no longer compatible with the simple two-parameter model usually utilized in the literature. In this respect, the activation of mechano-sensitive ion-channels seemingly represents a reasonable hypothesis for rationalizing the observed osmotic behavior of hMSCs from UCB

    Proof-of-Principle of a Brain-Computer Interface approach to support post-stroke arm rehabilitation in hospitalized patients: design, acceptability and usability

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    Objective To evaluate the feasibility of brain-computer interface (BCI)-assisted motor imagery training to support hand/arm motor rehabilitation after stroke during hospitalization. Design Proof-of-principle study. Setting Neurorehabilitation hospital. Participants Convenience sample of patients (N=8) with new-onset arm plegia or paresis caused by unilateral stroke. Interventions The BCI-based intervention was administered as an "add-on" to usual care and lasted 4 weeks. Under the supervision of a therapist, patients were asked to practice motor imagery of their affected hand and received as a discrete feedback the movements of a "virtual" hand superimposed on their own. Such a BCI-based device was installed in a rehabilitation hospital ward. Main Outcome Measures Following a user-centered design, we assessed system usability in terms of motivation, satisfaction (by means of visual analog scales), and workload (National Aeronautics and Space Administration-Task Load Index). The usability of the BCI-based system was also evaluated by 15 therapists who participated in a focus group. Results All patients successfully accomplished the BCI training. Significant positive correlations were found between satisfaction and motivation (P=.001, r=.393). BCI performance correlated with interest (P=.027, r=.257) and motivation (P=.012, r=.289). During the focus group, professionals positively acknowledged the opportunity offered by BCI-assisted training to measure patients' adherence to rehabilitation. Conclusions An ecological BCI-based device to assist motor imagery practice was found to be feasible as an add-on intervention and tolerable by patients who were exposed to the system in the rehabilitation environment. © 2015 American Congress of Rehabilitation Medicine

    A complex systems approach to constructing better models for managing financial markets and the economy

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    We outline a vision for an ambitious program to understand the economy and financial markets as a complex evolving system of coupled networks of interacting agents. This is a completely different vision from that currently used in most economic models. This view implies new challenges and opportunities for policy and managing economic crises. The dynamics of such models inherently involve sudden and sometimes dramatic changes of state. Further, the tools and approaches we use emphasize the analysis of crises rather than of calm periods. In this they respond directly to the calls of Governors Bernanke and Trichet for new approaches to macroeconomic modelling. Graphical abstrac

    The Estimation of Cortical Activity for Brain-Computer Interface: Applications in a Domotic Context

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    In order to analyze whether the use of the cortical activity, estimated from noninvasive EEG recordings, could be useful to detect mental states related to the imagination of limb movements, we estimate cortical activity from high-resolution EEG recordings in a group of healthy subjects by using realistic head models. Such cortical activity was estimated in region of interest associated with the subject's Brodmann areas by using a depth-weighted minimum norm technique. Results showed that the use of the cortical-estimated activity instead of the unprocessed EEG improves the recognition of the mental states associated to the limb movement imagination in the group of normal subjects. The BCI methodology presented here has been used in a group of disabled patients in order to give them a suitable control of several electronic devices disposed in a three-room environment devoted to the neurorehabilitation. Four of six patients were able to control several electronic devices in this domotic context with the BCI system
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