588 research outputs found
Alimentar el Barrio: Farmers´ Market, a New Opportunity to Drive Change
In Barcelona, food markets have always been a symbol of the city. In recent decades, by adapting to new forms of consumption, they have conformed to largescale distribution, selling only a small percentage of local farmers’ products. Through the project described below—“Alimentar el Barrio”—actions have been undertaken to support farmers, by improving the current market system with low-impact micro-interventions. The research describes a way to create a new “system” of market making to promote local culture and products, thus regenerating the urban space, driving communities towards responsible food consumption, and spreading best practices. This paper shows how design and communication can provide farmers with an adequate physical and culture-driven infrastructure, to increase their competitiveness and decrease inequalities of the large-scale distribution
A model of protocell based on the introduction of a semi-permeable membrane in a stochastic model of catalytic reaction networks
In this work we introduce some preliminary analyses on the role of a
semi-permeable membrane in the dynamics of a stochastic model of catalytic
reaction sets (CRSs) of molecules. The results of the simulations performed on
ensembles of randomly generated reaction schemes highlight remarkable
differences between this very simple protocell description model and the
classical case of the continuous stirred-tank reactor (CSTR). In particular, in
the CSTR case, distinct simulations with the same reaction scheme reach the
same dynamical equilibrium, whereas, in the protocell case, simulations with
identical reaction schemes can reach very different dynamical states, despite
starting from the same initial conditions.Comment: In Proceedings Wivace 2013, arXiv:1309.712
A stochastic model of catalytic reaction networks in protocells
Protocells are supposed to have played a key role in the self-organizing
processes leading to the emergence of life. Existing models either (i) describe
protocell architecture and dynamics, given the existence of sets of
collectively self-replicating molecules for granted, or (ii) describe the
emergence of the aforementioned sets from an ensemble of random molecules in a
simple experimental setting (e.g. a closed system or a steady-state flow
reactor) that does not properly describe a protocell. In this paper we present
a model that goes beyond these limitations by describing the dynamics of sets
of replicating molecules within a lipid vesicle. We adopt the simplest possible
protocell architecture, by considering a semi-permeable membrane that selects
the molecular types that are allowed to enter or exit the protocell and by
assuming that the reactions take place in the aqueous phase in the internal
compartment. As a first approximation, we ignore the protocell growth and
division dynamics. The behavior of catalytic reaction networks is then
simulated by means of a stochastic model that accounts for the creation and the
extinction of species and reactions. While this is not yet an exhaustive
protocell model, it already provides clues regarding some processes that are
relevant for understanding the conditions that can enable a population of
protocells to undergo evolution and selection.Comment: 20 pages, 5 figure
The role of backward reactions in a stochastic model of catalytic reaction networks
We investigate the role of backward reactions in a stochastic model of catalytic reaction network, with specific regard to the influence on the emergence of autocatalytic sets (ACSs), which are supposed to be one of the pre-requisites in the transition between non-living to living matter.
In particular, we analyse the impact that a variation in the kinetic rates of forward and backward reactions may have on the overall dynamics.
Significant effects are indeed observed, provided that the intensity of backward reactions is sufficiently high. In spite of an invariant activity of the system in terms of production of new species, as backward reactions are intensified, the emergence of ACSs becomes more likely and an increase in their number, as well as in the proportion of species belonging to them, is observed. Furthermore, ACSs appear to be more robust to fluctuations than in the usual settings with no backward reaction.
This outcome may rely not only on the higher average connectivity of the reaction graph, but also on the distinguishing property of backward reactions of recreating the substrates of the corresponding forward reactions
A framework for assessing the impact of health research from a broad population perspective
Abstract
Background: research in the health sector is an activity associated with an uncertain return on investment. This study aims to outline a multidimensional framework for assessing the imact of research funded by public (or mixed public and private) sponsors.
Methods: a focus group representing different stakeholders was created to develop a sense of purpose that would be shared by the intended beneficiaries of the research assessment process, and others with a direct or indirect interest in a program’s implementation.
Results: a framework was designed that takes a holistic approach to the impact of research in which not only technical, but also economic, social and political dimensions are interrelated with the results achieved for the population and health services.
Conclusions: the framework reflected the views of different stakeholders, favoring the development of the positive, proactive relationships essential to orienting the process of transforming the evidence emerging from research into action for health. 
Active fixation coronary sinus lead in a patient with persistence of left superior vena cava
n/
Vibrational Spectroscopy Coupled to a Multivariate Analysis Tiered Approach for Argentinean Honey Provenance Confirmation
In the present work, the provenance discrimination of Argentinian honeys was used as case study to compare the capabilities of three spectroscopic techniques as fast screening platforms for honey authentication purposes. Multifloral honeys were collected among three main honey-producing regions of Argentina over four harvesting seasons. Each sample was fingerprinted by FT-MIR, NIR and FT-Raman spectroscopy. The spectroscopic platforms were compared on the basis of the classification performance achieved under a supervised chemometric approach. Furthermore, low- mid- and high-level data fusion were attempted in order to enhance the classification results. Finally, the best-performing solution underwent to SIMCA modelling with the purpose of reproducing a food authentication scenario. All the developed classification models underwent to a “year-by-year” validation strategy, enabling a sound assessment of their long-term robustness and excluding any issue of model overfitting. Excellent classification scores were achieved by all the technologies and nearly perfect classification was provided by FT-MIR. All the data fusion strategies provided satisfying outcomes, with the mid- and high-level approaches outperforming the low-level data fusion. However, no significant advantage over the FT-MIR alone was obtained. SIMCA modelling of FT-MIR data produced highly sensitive and specific models and an overall prediction ability improvement was achieved when more harvesting seasons were used for the model calibration (86.7% sensitivity and 91.1% specificity). The results obtained in the present work suggested the major potential of FT-MIR for fingerprinting-based honey authentication and demonstrated that accuracy levels that may be commercially useful can be reached. On the other hand, the combination of multiple vibrational spectroscopic fingerprints represents a choice that should be carefully evaluated from a cost/benefit standpoint within the industrial context.Fil: Damiani, Tito. Universita Degli Studi Di Parma. Departamento de Alimentos y Drogas; ItaliaFil: Alonso Salces, Rosa Maria. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Aubone, InĂ©s. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Baeten, Vincent. Walloon Agricultural Research Centre; BĂ©lgicaFil: Arnould, Quentin. Walloon Agricultural Research Centre; BĂ©lgicaFil: Dall'Asta, Chiara. Universita Degli Studi Di Parma. Departamento de Alimentos y Drogas; ItaliaFil: Fuselli, Sandra Rosa. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Fernández Pierna, Juan Antonio. Walloon Agricultural Research Centre; BĂ©lgic
- …