269 research outputs found

    Soft and hard wall in a stochastic reaction diffusion equation

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    We consider a stochastically perturbed reaction diffusion equation in a bounded interval, with boundary conditions imposing the two stable phases at the endpoints. We investigate the asymptotic behavior of the front separating the two stable phases, as the intensity of the noise vanishes and the size of the interval diverges. In particular, we prove that, in a suitable scaling limit, the front evolves according to a one-dimensional diffusion process with a non-linear drift accounting for a "soft" repulsion from the boundary. We finally show how a "hard" repulsion can be obtained by an extra diffusive scaling.Comment: 33 page

    A general framework for stochastic traveling waves and patterns, with application to neural field equations

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    In this paper we present a general framework in which to rigorously study the effect of spatio-temporal noise on traveling waves and stationary patterns. In particular the framework can incorporate versions of the stochastic neural field equation that may exhibit traveling fronts, pulses or stationary patterns. To do this, we first formulate a local SDE that describes the position of the stochastic wave up until a discontinuity time, at which point the position of the wave may jump. We then study the local stability of this stochastic front, obtaining a result that recovers a well-known deterministic result in the small-noise limit. We finish with a study of the long-time behavior of the stochastic wave.Comment: 43 pages, 3 figure

    Cod skin collagen extraction and characterization

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    Front fluctuations for the stochastic Cahn–Hilliard equation

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    We consider the Cahn–Hilliard equation in one space dimension, perturbed by the derivative of a space and time white noise of small intensity, and we investigate the effect of the noise on the solutions when the initial condition is a front that separates the two stable phases. We prove that, given with probability going to one as the noise intensity vanishes, the solution remains close to a front for long times, and we study the fluctuations of the front in this time scaling. They are given by a one dimensional continuous process, self similar of order one and non-Markovian, related to a fractional Brownian motion and for which a couple of representations are given

    Bioproducts for health II

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    In order to build a promising future, health and sustainability must be interelated. Marine, forestry, agriculture, and food systems are important sources of bioproducts used in health applications. To explore the potential of such sources for the development of natural products capable of biological activities, it is necessary to develop new technologically sustainable strategies. Despite the range of natural compounds already available, there is a need to identify bioactive molecules (e.g., polysaccharides, proteins and peptides, polyunsaturated fatty acids, and polyphenols) from different natural sources with positive health properties, including antihypertensive, antidiabetic, anti-obesity, antimicrobial, anti-atherosclerotic, antioxidant, antithrombotic, immune-modulatory, relaxing, and satiety-inducing effects. The Second Edition of this Special Issue aimed to identify and gather works on the latest varied sources of bioproducts, the biological and functional activities of these bioactive compounds, their mechanisms of action, and the methods used for extraction and purification, without losing our focus on alignment with the concept of green technology.info:eu-repo/semantics/publishedVersio

    Phase fluctuations in the ABC model

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    We analyze the fluctuations of the steady state profiles in the modulated phase of the ABC model. For a system of LL sites, the steady state profiles move on a microscopic time scale of order L3L^3. The variance of their displacement is computed in terms of the macroscopic steady state profiles by using fluctuating hydrodynamics and large deviations. Our analytical prediction for this variance is confirmed by the results of numerical simulations

    Salt-cured Atlantic cod skin: a sustainable source of acid-soluble type I collagen

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    Collagen is the most abundant protein in the animal kingdom. Industrial collagen is mainly bovine and porcine origin. However, due to religious beliefs, allergic issues, and infectious diseases, alternative sources of collagen as marine are gaining increasing interest. In this work, the acid-soluble collagen (ASC) were extracted from salt-cured Atlantic cod (Gadus morhua) skin and characterized. The extraction yield was about 2.0%, equivalent to the extraction yield reported for other fish skins. The electrophoretic pattern showed the typical type I structure (α, β and γ chains). UV-VIS and FTIR absorbance spectra suggested a very pure ASC with an intact triple helical structure. The integrity and the adequate porosity required for different applications were then confirmed by electron micrograph. Our findings allow us to say that, for the first time, we extracted acid-soluble type I collagen from salt-cured Atlantic cod skin, with characteristics suitable for application in various fields, such as biomedical.info:eu-repo/semantics/publishedVersio

    Opening the black box: How staff training and development may affect the innovation of enterprises

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    We describe a research on the interplay that appears to exist in companies between Human Resource Management and innovation. This complex, multicomponent, non-linear and dynamic interplay is often viewed as a "black box". To help open the black box, we outline both a theoretical framework and preliminary empirical data. We view innovation as an organization-level property, favored by the organization's self-perception as a knowledge engine. Therefore, we devised a protocol to study the companies' strategies for training and development and their innovation profile. The protocol consisted in a questionnaire with 100 closed questions, suitable for companies which rely mostly on an inner training and development service. The questionnaire was administered to a sample of Italian firms from the Food & beverages and Fashion markets. The results show that certain facets of training and development are indeed correlated to innovation. Finally, we discuss the results
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