276 research outputs found

    RECONVERSIÓN INDUSTRIAL DE LAS PYMES PERUANAS: CAMBIO PARA LA COMPETITIVIDAD

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    This research explores the main constraints of Peruvian SMEs on their way towards export potential competitiveness for international markets. The research is descriptive and explanatory, non - experimental design and qualitative approach through 114 interviews of a selection of 45 typical SMEs sampled in a non - random way of intentional type. The research shows the opinion of SME entrepreneurs on the main perceived constraints affecting the competitiveness of Peruvian SMEs and conceptually defines the needs of industrial reconversion, modernization, integration and change that are required to achieve global competitiveness.El presente artículo explora las principales restricciones de las pymes peruanas en su camino hacia la competitividad potencial exportadora para mercados internacionales. La investigación es de tipo descriptiva y explicativa, de diseño no experimental y enfoque cualitativo por medio de 114 entrevistas de una selección de 45 pymes típicas muestreadas de manera no aleatoria de tipo intencional. La investigación muestra la opinión de empresarios de pymes sobre las principales restricciones percibidas que afectan la competitividad de las pymes peruanas y define conceptualmente las necesidades de reconversión industrial, modernización, integración y cambio que se requieren para lograr alcanzar competitividad global

    RECONVERSIÓN INDUSTRIAL DE LAS PYMES PERUANAS: CAMBIO PARA LA COMPETITIVIDAD

    Get PDF
    This research explores the main constraints of Peruvian SMEs on their way towards export potential competitiveness for international markets. The research is descriptive and explanatory, non - experimental design and qualitative approach through 114 interviews of a selection of 45 typical SMEs sampled in a non - random way of intentional type. The research shows the opinion of SME entrepreneurs on the main perceived constraints affecting the competitiveness of Peruvian SMEs and conceptually defines the needs of industrial reconversion, modernization, integration and change that are required to achieve global competitiveness.El presente artículo explora las principales restricciones de las pymes peruanas en su camino hacia la competitividad potencial exportadora para mercados internacionales. La investigación es de tipo descriptiva y explicativa, de diseño no experimental y enfoque cualitativo por medio de 114 entrevistas de una selección de 45 pymes típicas muestreadas de manera no aleatoria de tipo intencional. La investigación muestra la opinión de empresarios de pymes sobre las principales restricciones percibidas que afectan la competitividad de las pymes peruanas y define conceptualmente las necesidades de reconversión industrial, modernización, integración y cambio que se requieren para lograr alcanzar competitividad global

    Polyolefin fiber-reinforced concrete enhanced with steel-hooked fibers in low proportions

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    Over the past few years, polyolefin fiber reinforced self-compacting concrete has shown high performance in both fresh and hardened state. Its fracture behavior for small deformations could be enhanced with a small amount of steel-hooked fibers, obtaining a hybrid fiber-reinforced concrete well suited for structural use. Four types of conventional fiber-reinforced concrete with steel and polyolefin fibers were produced on the basis of the same self-compacting concrete also manufactured as reference. These concrete mixtures were manufactured separately with the same fiber contents being subsequently used for two more hybrid mixtures. Fracture properties, in addition to fresh and mechanical properties, were assessed. The research showed both synergies (with the two types of fibers working together in the fracture processes) and an improvement of the orientation and distribution of the fibers on the fracture surfac

    Antimicrobial activity of an aspartic protease from Salpichroa origanifolia fruits

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    Abstract: Plant proteases play a fundamental role in several processes like growth, development and in response to biotic and abiotic stress. In particular, aspartic proteases (AP) are expressed in different plant organs and have antimicrobial activity. Previously, we purified an AP from Salpichroa origanifolia fruits called salpichroin. The aim of this work was to determine the cytotoxic activity of this enzyme on selected plant and human pathogens. For this purpose, the growth of the selected pathogens was analysed after exposure to different concentrations of salpichroin. The results showed that the enzyme was capable of inhibiting Fusarium solani and Staphylococcus aureus in a dose-dependent manner. It was determined that 1·2 μmol l−1 of salpichroin was necessary to inhibit 50% of conidial germination, and the minimal bactericidal concentration was between 1·9 and 2·5 μmol l−1. Using SYTOX Green dye we were able to demonstrate that salpichroin cause membrane permeabilization. Moreover, the enzyme treated with its specific inhibitor pepstatin A did not lose its antibacterial activity. This finding demonstrates that the cytotoxic activity of salpichroin is due to the alteration of the cell plasma membrane barrier but not due to its proteolytic activity. Antimicrobial activity of the AP could represent a potential alternative for the control of pathogens that affect humans or crops of economic interest. Significance and Impact of the Study: This study provides insights into the antimicrobial activity of an aspartic protease isolated from Salpichroa origanifolia fruits on plant and human pathogens. The proteinase inhibited Fusarium solani and Staphylococcus aureus in a dose-dependent manner due to the alteration of the cell plasma membrane barrier but not due to its proteolytic activity. Antimicrobial activity of salpichroin suggests its potential applications as an important tool for the control of pathogenic micro-organisms affecting humans and crops of economic interest. Therefore, it would represent a new alternative to avoid the problems of environmental pollution and antimicrobial resistance.Fil: Díaz, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Luján; ArgentinaFil: Rocha, Gabriela Fernanda. Universidad Nacional de Luján; ArgentinaFil: Kise, Francisco. Universidad Nacional de Luján; ArgentinaFil: Rosso, A. M.. Universidad Nacional de Luján; ArgentinaFil: Guevara, Maria Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; ArgentinaFil: Parisi, M.G.. Universidad Nacional de Luján; Argentin

    Electrical transport studies of quench condensed Bi films at the initial stage of film growth: Structural transition and the possible formation of electron droplets

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    The electrical transport properties of amorphous Bi films prepared by sequential quench deposition have been studied in situ. A superconductor-insulator (S-I) transition was observed as the film was made increasingly thicker, consistent with previous studies. Unexpected behavior was found at the initial stage of film growth, a regime not explored in detail prior to the present work. As the temperature was lowered, a positive temperature coefficient of resistance (dR/dT > 0) emerged, with the resistance reaching a minimum before the dR/dT became negative again. This behavior was accompanied by a non-linear and asymmetric I-V characteristic. As the film became thicker, conventional variable-range hopping (VRH) was recovered. We attribute the observed crossover in the electrical transport properties to an amorphous to granular structural transition. The positive dR/dT found in the amorphous phase of Bi formed at the initial stage of film growth was qualitatively explained by the formation of metallic droplets within the electron glass.Comment: 7 pages, 6 figure

    Spallation reactions. A successful interplay between modeling and applications

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    The spallation reactions are a type of nuclear reaction which occur in space by interaction of the cosmic rays with interstellar bodies. The first spallation reactions induced with an accelerator took place in 1947 at the Berkeley cyclotron (University of California) with 200 MeV deuterons and 400 MeV alpha beams. They highlighted the multiple emission of neutrons and charged particles and the production of a large number of residual nuclei far different from the target nuclei. The same year R. Serber describes the reaction in two steps: a first and fast one with high-energy particle emission leading to an excited remnant nucleus, and a second one, much slower, the de-excitation of the remnant. In 2010 IAEA organized a worskhop to present the results of the most widely used spallation codes within a benchmark of spallation models. If one of the goals was to understand the deficiencies, if any, in each code, one remarkable outcome points out the overall high-quality level of some models and so the great improvements achieved since Serber. Particle transport codes can then rely on such spallation models to treat the reactions between a light particle and an atomic nucleus with energies spanning from few tens of MeV up to some GeV. An overview of the spallation reactions modeling is presented in order to point out the incomparable contribution of models based on basic physics to numerous applications where such reactions occur. Validations or benchmarks, which are necessary steps in the improvement process, are also addressed, as well as the potential future domains of development. Spallation reactions modeling is a representative case of continuous studies aiming at understanding a reaction mechanism and which end up in a powerful tool.Comment: 59 pages, 54 figures, Revie

    Correlation Between Anti-TNF Serum Levels and Endoscopic Inflammation in Inflammatory Bowel Disease Patients

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    Objectives: (a) To evaluate the diagnostic accuracy of anti-TNF trough levels to predict mucosal healing in inflammatory bowel disease (IBD); (b) to determine the best cut-off point to predict mucosal healing in IBD patients treated with anti-TNF. Methods: This is a multicenter, prospective study. IBD patients under anti-TNF treatment for at least 6 months that had to undergo an endoscopy were included. Mucosal healing was defined as: Simple endoscopic score for Crohn’s Disease < 3 for Crohn’s disease (CD), Rutgeerts score < i2 for CD in postoperative setting, or Mayo endoscopic score = 1 for ulcerative colitis (UC). Anti-TNF concentrations were measured using SMART ELISAs at trough. Results: A total of 182 patients were included. Anti-TNF trough levels were significantly higher among patients that had mucosal healing than among those who did not. The area under the curve of infliximab for mucosal healing was 0.63 (best cutoff value 3.4 µg/mL), and for adalimumab 0.60 (best cutoff value 7.2 µg/mL). In the multivariate analysis, having anti-TNF drug levels above the cutoff values [odds ratio (OR) 3.1]) and having UC instead of CD (OR 4) were associated with a higher probability of having mucosal healing. Additionally, the need for an escalated dosage (OR 0.2) and current smoking habit (OR 0.2) were also associated with a lower probability of mucosal healing. Conclusions: There was an association between anti-TNF trough levels and mucosal healing in IBD patients; however, the accuracy of the determination of infliximab and adalimumab concentrations able to predict mucosal healing was suboptimal

    Physics of Solar Prominences: II - Magnetic Structure and Dynamics

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    Observations and models of solar prominences are reviewed. We focus on non-eruptive prominences, and describe recent progress in four areas of prominence research: (1) magnetic structure deduced from observations and models, (2) the dynamics of prominence plasmas (formation and flows), (3) Magneto-hydrodynamic (MHD) waves in prominences and (4) the formation and large-scale patterns of the filament channels in which prominences are located. Finally, several outstanding issues in prominence research are discussed, along with observations and models required to resolve them.Comment: 75 pages, 31 pictures, review pape
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