272 research outputs found

    Individual, Organizational and Institutional Determinants of Formal and Informal Inter-firm Cooperation in SMEs

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    Inter-firm cooperation has been considered an important strategy for SMEs to overcome competitive difficulties. Despite the relevance of this strategy there are no studies that jointly consider how entrepreneurs’ characteristics, organizational factors and institutional features influence SMEs to establish cooperative agreements. In order to bridge this gap, we analyze what factors at these three levels explain inter-firm cooperation and whether formal and informal inter-firm agreements are explained by different factors. Our research is based on a survey of 1,587 Spanish SMEs and the results show that individual, organizational and institutional factors contribute to jointly shape the decisions concerning inter-firm cooperation

    IGF-1 Regulates the extracellular level of active MMP-2 and promotes Müller glial cell motility

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    In ischemic proliferative retinopathies, Müller glial cells (MGCs) acquire migratory abilities. However, the mechanisms that regulate this migration remain poorly understood. In addition, proliferative disorders associated with enhanced activities of matrix metalloproteinases (MMPs) also involve insulin-like growth factor (IGF)-1 participation. Therefore, the main interest of this work was to investigate the IGF-1 effect on the extracellular proteolytic activity in MGCs.Methods: Cell culture supernatants and cell lysates of the human MGC line MIO-M1 stimulated with IGF-1 were analyzed for MMP-2 by zymographic and Western blot analysis. The MGCs´ motility was evaluated by scratch wound assay. The MMP-2, β1-integrin, and focal adhesions were detected by confocal microscopy. The localization of active MMPs and actin cytoskeleton were evaluated by in situ zymography.Results: The IGF-1 induced the activation of canonical signaling pathways through the IGF-1R phosphorylation. Culture supernatants showed a relative decrease in the active form of MMP-2, correlating with an increased accumulation of MMP-2 protein in the MGCs´ lysate. The IGF-1 effect on MMP-2 was abolished by an IGF-1R blocking antibody, αIR3, as well as by the PI3-kinase inhibitor, LY294002. The IGF-1 increased the migratory capacity of MGCs, which was blocked by the GM6001 MMP inhibitor, LY294002 and αIR3. Finally, IGF-1 induced the intracellular distribution of MMP-2 toward cellular protrusions and the partial colocalization with β1-integrin and phospo-focal adhesion kinase signals. Gelatinase activity was concentrated along F-actin filaments.Conclusions: Taken together, these data indicate that IGF-1, through its receptor activation, regulates MGCs´ motility by a mechanism that involves the MMP-2 and PI3K signaling pathway.Fil: Lorenc, Valeria Erika. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Jaldín Fincati, Javier Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Luna Pinto, Jose Domingo. Departamento de Vítreo-retina, Centro Privado de Ojos R; ArgentinaFil: Chiabrando, Gustavo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Sanchez, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentin

    Determinants of digital transformation in the restaurant industry

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    This article aims to identify the factors that influence the digital transformation process in the restaurant industry. The proposed theoretical framework differentiates three groups of conditioning factors of digitalisation in small and medium-sized enterprises (SMEs) in this sector: (1) the personal characteristics of the entrepreneurs/managers; (2) the characteristics of the businesses; and (3) the spatial location of the restaurants. The data used in the empirical research were compiled from a representative survey of restaurant SMEs in Spain. The study uses an ordinal logistic regression specification to test the hypotheses. The results obtained indicate that the education of entrepreneurs/managers, their entrepreneurial motivations, and their ambition for growth condition the digital transformation of their businesses. Furthermore, the characteristics of the company, such as the number of establishments, belonging to a corporate group, and the employees’ educational level, influence the digitalisation of restaurants. Likewise, it is observed that the digitalisation process is stimulated in inland towns compared to coastal areas, as well as in intermediate municipalities with populations of between 10,000 and 100,000 inhabitants.Ministerio de Ciencia e Innovación (MICIN). España PID2020-113384GB-I00Ministerio de Economía y Competitividad (MINECO). España ECO2013-42889-

    Homogenization of very thin elastic reticulated structures

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    This work is devoted to the homogenization of the anisotropic, linearized elasticity system posed on thin reticulated structures involving several parameters. We show that the result depends on the relative size of the parameters. In every case, we obtain a limit problem where both the microscopic and macroscopic scales appear together. From this problem, we get an asymptotic development which gives an approximation in L2 of the displacements and the linearized strain tensor.Ministerio de Ciencia y Tecnologí

    Circulating anti-galectin-1 antibodies are associated with the severity of ocular disease in autoimmune and infectious uveitis

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    Galectin (Gal)-1, an endogenous lectin found at sites of immune privilege, plays a critical role in the regulation of the immune response. Therapeutic administration of Gal-1 or its genetic delivery suppresses chronic inflammation in experimental models of autoimmunity. The purpose of this work was to investigate the occurrence of circulating anti-Gal-1 antibodies in patients with autoimmune and infectious uveitis as potential determinant factors of disease progression.Fil: Romero, Marta D.. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Fundación Ver; Argentina. Laboratorio Inmunopatología Investigación y Docencia LIIDO; ArgentinaFil: Muiño, Juan Carlos. Universidad Nacional de Córdoba; Argentina. Fundación Ver; ArgentinaFil: Bianco, German Ariel. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Ferrero, Mercedes. Laboratorio Inmunopatología Investigación y Docencia LIIDO; Argentina. Fundación Ver; ArgentinaFil: Juarez, Claudio P.. Fundación Ver; ArgentinaFil: Luna, José Domingo. Fundación Ver; ArgentinaFil: Rabinovich, Gabriel A.. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin

    On the influence of the thickness of the sediment moving layer in the definition of the bedload transport formula in Exner systems

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    In this paper we study Exner system and introduce a modified general definition for bedload transport flux. The new formulation has the advantage of taking into account the thickness of the sediment layer which avoids mass conservation problems in certain situations. Moreover, it reduces to a classical solid transport discharge formula in the case of quasi-uniform regime. We also present several numerical tests where we compare the proposed sediment transport formula with the classical formulation and we show the behavior of the new model in different configurations

    Unexpected Ground-Glass Opacities on Abdominopelvic CT of a Patient With a Negative SARS-CoV-2 Antigen Test Result and No Respiratory Symptoms Upon Admission

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    One of the biggest challenges during the coronavirus disease 2019 (COVID-19) pandemic continues to be the detection of asymptomatic and presymptomatic persons infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Persons infected with SARS-CoV-2 who do not have symptoms of COVID-19 may transmit the virus to others and may have subclinical lung abnormalities. Some hospitals use SARSCoV-2 antigen tests for pre-admission screening testing because they are relatively inexpensive, have a rapid turnaround time, and can be performed at the point of care; however, antigen tests are generally less sensitive than nucleic acid amplification tests with reverse transcription polymerase chain reaction (RT-PCR) assay. Moreover, as the local COVID-19 prevalence increases, the negative predictive value of antigen tests may decrease, meaning that the probability of having false-negative results may increase. We present a case of a patient who, prior to admission for a surgical procedure, had a negative antigen test result for SARSCoV-2, had no respiratory symptoms, and had no suspected or known exposure to SARS-CoV-2; however, she tested positive for SARS-CoV-2 RNA after admission. The only factor that led the healthcare team to suspect SARS-CoV-2 infection was an unexpected finding of bilateral ground-glass opacities on an abdominopelvic computed tomography (CT), which was performed to assess the extent of a perianal abscess the patient presented. This case highlights the importance of using highly sensitive SARS-CoV-2 tests for pre-admission screening testing in the hospital settin

    A multilayer shallow water system for polydisperse sedimentation

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    This work considers the flow of a fluid containing one disperse substance consisting of small particles that belong to different species differing in size and density. The flow is modelled by combining a multilayer shallow water approach with a polydisperse sedimentation process. This technique allows one to keep information on the vertical distribution of the solid particles in the mixture, and thereby to model the segregation of the particle species from each other, and from the fluid, taking place in the vertical direction of the gravity body force only. This polydisperse sedimentation process is described by the well-known Masliyah-Lockett-Bassoon (MLB) velocity functions. The resulting multilayer sedimentation-ow model can be written as a hyperbolic system with nonconservative products. The definitions of the nonconservative products are related to the hydrostatic pressure and to the mass and momentum hydrodynamic transfer terms between the layers. For the numerical discretization a strategy of two steps is proposed, where the first one is also divided into two parts. In the _rst step, instead of approximating the complete model, we approximate a reduced model with a smaller number of unknowns. Then, taking advantage of the fact that the concentrations are passive scalars in the system, we approximate the concentrations of the different species by an upwind scheme related to the numerical flux of the total concentration. In the second step, the effect of the transference terms defined in terms of the MLB model is introduced. These transfer terms are approximated by using a numerical ux function used to discretize the 1D vertical polydisperse model (see Bürger, García, Karlsen and Towers, J. Eng. Math. 60 (2008), 387{425). Finally, some numerical examples are presented. Numerical results suggest that the multilayer shallow water model could be adequate in situations where the settling takes place from a suspension that undergoes horizontal movement
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