123 research outputs found

    Estrategias competitivas y cadena productiva de las Mipymes exportadoras del cuero y calzado del Citeccal – Lima 2018

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    La investigación realizada tuvo como objetivo principal determinar si existe relación entre las Estrategias Competitivas y la Cadena Productiva de las Mipymes exportadoras del cuero y calzado del Citeccal Lima 2018. Para la presente investigación se utilizó como fundamento teórico para la variable Estrategias Competitivas a Michael Porter y para la variable Cadena Productiva a Cerutti Julia. El tipo de investigación es aplicada, el nivel de investigación es correlacional, de diseño no experimental, de corte transversal y de enfoque cuantitativo. La población de estudio estuvo conformada por 182 empresas de la cadena productiva, la muestra fue 87 empresas agrupadas por estratos, para lo cual se utilizó el muestreo aleatorio simple y el muestreo estratificado. Se utilizó la técnica de encuesta y como instrumento, dos cuestionarios conformados por 25 ítems para cada variable. La validez del instrumento se obtuvo mediante un juicio de expertos y la confiabilidad con el coeficiente Alfa de Cronbach. El análisis de los datos se realizó en el programa estadístico SPSS versión 24.0 donde se utilizó la estadística descriptiva permitiendo obtener tablas de frecuencias, gráficos y tablas cruzados; según lo planteado en los objetivos de la investigación. En los resultados de la presente investigación se obtuvo un (Rho de Spearman de =0.569) lo que permite concluir que las estrategias competitivas y cadena productiva poseen una relación positiva medi

    Measuring trace element fingerprinting for cereal bar authentication based on type and principal ingredient

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    This paper introduces a method for determining the authenticity of commercial cereal bars based on trace element fingerprints. In this regard, 120 cereal bars were prepared using microwave-assisted acid digestion and the concentrations of Al, Ba, Bi, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Pb, Rb, Se, Sn, Sr, V, and Zn were later measured by ICP-MS. Results confirmed the suitability of the analyzed samples for human consumption. Multielemental data underwent autoscaling preprocessing for then applying PCA, CART, and LDA to input data set. LDA model accomplished the highest classification modeling performance with a success rate of 92%, making it the suitable model for reliable cereal bar prediction. The proposed method demonstrates the potential of trace element fingerprints in distinguishing cereal bar samples according to their type (conventional and gluten-free) and principal ingredient (fruit, yogurt, chocolate), thereby contributing to global efforts for food authentication.Fil: Pérez Rodríguez, Michael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; Argentina. Instituto Tecnologico de Monterrey. Escuela de Ingenieria y Ciencias.; MéxicoFil: Hidalgo, Melisa Jazmin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Mendoza, Alberto. Instituto Tecnologico de Monterrey. Escuela de Ingenieria y Ciencias.; MéxicoFil: González, Lucy T.. Instituto Tecnologico de Monterrey. Escuela de Ingenieria y Ciencias.; MéxicoFil: Longoria Rodríguez, Francisco. Centro de Investigacion En Materiales Avanzados; MéxicoFil: Goicoechea, Hector Casimiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Laboratorio de Desarrollo Analítico y Quimiometría; ArgentinaFil: Pellerano, Roberto Gerardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; Argentin

    Evaluación de las formulaciones de película comestible de Nostoc sphaericum aplicadas a la conservación de fresas

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    The high perishability rate in strawberries (Fragaria x ananassa) complicates their post-harvest storage, creating the need to develop effective means of preservation. The research studied the physicochemical qualities of strawberries coated with edible films based on Nostoc (Nostoc Sphaericum). The films were generated by immersing the fruit in solutions of Nostoc polysaccharides at 0,7% (A), 1,0% (B) and 1,3% (C) concentration (p/v). The product was stored for 8 days at room temperature (18 ± 2 ° C), subsequently the quality parameters were measured. The DBCA design was applied with a significance level of 5%. The texture was found to vary directly with the polysaccharide concentration in the coating. The average weight loss for treatments A, B, C and the pattern were 66,92%, 60,92%, 49,06% and 41,72%, respectively. In all cases, a variation of less than 0,3 was observed in the pH scale and greater than 0,3% for acidity, without significant differences. The variation in SST for the treatments was 4,9 (C), 5,2 (A) and 7,4 (B) ° brix. An extension of the useful life of 16% of strawberries up to two days was determined. It was determined that the application of Nostoc films prolong the useful life of strawberries, highlighting their performance in weight loss and texture compared to the control sample, on the descending scale C> B> A.La alta tasa de perecibilidad en fresas (Fragaria x ananassa) complica su almacenamiento postcosecha, surgiendo la necesidad de desarrollar medios de conservación eficaces. En la investigación se estudiaron las cualidades físicoquímicas de fresas recubiertas con películas comestibles a base de Nostoc (Nostoc Sphaericum). Las películas se generaron al sumergir el fruto en soluciones de polisacáridos de Nostoc al 0,7 % (A), 1,0 % (B) y 1,3 % (C) de concentración (p/v). El producto se almacenó durante 8 días a temperatura ambiente (18 ± 2 °C), posteriormente se midieron los parámetros de calidad. Se aplicó el diseño DBCA con nivel de significancia 5%. Se determinó que la textura varía directamente con la concentración de polisacárido en la cobertura. La pérdida promedio de peso para los tratamientos A, B, C y el control fueron 66,92%, 60,92%, 49,06% y 41,72%, respectivamente. En todos los casos se observó una variación inferior a 0,3 en la escala de pH y superior al 0,3% para la acidez, sin diferencias significativas. La variación en SST para los tratamientos fue de 4,9 (C), 5,2 (A) y 7,4 (B) °brix. Se determinó una extensión de la vida útil del 16% de fresas  hasta dos días. Se determinó que la aplicación de películas de Nostoc prolongan la vida útil de fresas, resaltando su desempeño en la pérdida de peso y textura frente a la muestra control, en la escala descendiente C > B > A

    La Legislatura de la provincia del Mendoza al Gobernador de Mendoza

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    Resolución de la legislatura de Mendoza autorizando al Juan Manuel de Rosas a entablar negociaciones de paz con las tribus indígenas. Incluye el cúmplase del gobernadorCopi

    Depression, anxiety and stress associated with insomnia in Peruvian military cadets during a pandemic

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    Introduction: Cadets are still young trainees, and they were also exposed to the pandemic, generating possible alterations in their mental health. Objective: To determine whether depression, anxiety and stress were associated with insomnia in Peruvian military cadets during the pandemic. Methods: Analytical cross-sectional study, which through a survey inquired about 3 mental health pathologies (DASS-21 scale) and insomnia (Insomnia Severity Index scale, in Spanish), the results of both were crossed and adjusted. Results: Of the 752 cadets, insomnia was associated with moderate or higher levels of anxiety (p-value 0.05). Conclusions: Insomnia was associated with having anxiety at moderate or higher levels or even at severe levels. It was also associated with gender (females were the most affected) and with cadets being older

    Variation in stem mortality rates determines patterns of above-ground biomass in Amazonian forests: implications for dynamic global vegetation models

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    Understanding the processes that determine above-ground biomass (AGB) in Amazonian forests is important for predicting the sensitivity of these ecosystems to environmental change and for designing and evaluating dynamic global vegetation models (DGVMs). AGB is determined by inputs from woody productivity [woody net primary productivity (NPP)] and the rate at which carbon is lost through tree mortality. Here, we test whether two direct metrics of tree mortality (the absolute rate of woody biomass loss and the rate of stem mortality) and/or woody NPP, control variation in AGB among 167 plots in intact forest across Amazonia. We then compare these relationships and the observed variation in AGB and woody NPP with the predictions of four DGVMs. The observations show that stem mortality rates, rather than absolute rates of woody biomass loss, are the most important predictor of AGB, which is consistent with the importance of stand size structure for determining spatial variation in AGB. The relationship between stem mortality rates and AGB varies among different regions of Amazonia, indicating that variation in wood density and height/diameter relationships also influences AGB. In contrast to previous findings, we find that woody NPP is not correlated with stem mortality rates and is weakly positively correlated with AGB. Across the four models, basin-wide average AGB is similar to the mean of the observations. However, the models consistently overestimate woody NPP and poorly represent the spatial patterns of both AGB and woody NPP estimated using plot data. In marked contrast to the observations, DGVMs typically show strong positive relationships between woody NPP and AGB. Resolving these differences will require incorporating forest size structure, mechanistic models of stem mortality and variation in functional composition in DGVMs

    Trivalent Adenovirus Type 5 HIV Recombinant Vaccine Primes for Modest Cytotoxic Capacity That Is Greatest in Humans with Protective HLA Class I Alleles

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    If future HIV vaccine design strategies are to succeed, improved understanding of the mechanisms underlying protection from infection or immune control over HIV replication remains essential. Increased cytotoxic capacity of HIV-specific CD8+ T-cells associated with efficient elimination of HIV-infected CD4+ T-cell targets has been shown to distinguish long-term nonprogressors (LTNP), patients with durable control over HIV replication, from those experiencing progressive disease. Here, measurements of granzyme B target cell activity and HIV-1-infected CD4+ T-cell elimination were applied for the first time to identify antiviral activities in recipients of a replication incompetent adenovirus serotype 5 (Ad5) HIV-1 recombinant vaccine and were compared with HIV-negative individuals and chronically infected patients, including a group of LTNP. We observed readily detectable HIV-specific CD8+ T-cell recall cytotoxic responses in vaccinees at a median of 331 days following the last immunization. The magnitude of these responses was not related to the number of vaccinations, nor did it correlate with the percentages of cytokine-secreting T-cells determined by ICS assays. Although the recall cytotoxic capacity of the CD8+ T-cells of the vaccinee group was significantly less than that of LTNP and overlapped with that of progressors, we observed significantly higher cytotoxic responses in vaccine recipients carrying the HLA class I alleles B*27, B*57 or B*58, which have been associated with immune control over HIV replication in chronic infection. These findings suggest protective HLA class I alleles might lead to better outcomes in both chronic infection and following immunization due to more efficient priming of HIV-specific CD8+ T-cell cytotoxic responses

    Does the disturbance hypothesis explain the biomass increase in basin-wide Amazon forest plot data?

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    Positive aboveground biomass trends have been reported from old-growth forests across the Amazon basin and hypothesized to reflect a large-scale response to exterior forcing. The result could, however, be an artefact due to a sampling bias induced by the nature of forest growth dynamics. Here, we characterize statistically the disturbance process in Amazon old-growth forests as recorded in 135 forest plots of the RAINFOR network up to 2006, and other independent research programmes, and explore the consequences of sampling artefacts using a data-based stochastic simulator. Over the observed range of annual aboveground biomass losses, standard statistical tests show that the distribution of biomass losses through mortality follow an exponential or near-identical Weibull probability distribution and not a power law as assumed by others. The simulator was parameterized using both an exponential disturbance probability distribution as well as a mixed exponential–power law distribution to account for potential large-scale blowdown events. In both cases, sampling biases turn out to be too small to explain the gains detected by the extended RAINFOR plot network. This result lends further support to the notion that currently observed biomass gains for intact forests across the Amazon are actually occurring over large scales at the current time, presumably as a response to climate change

    Evolutionary Heritage Influences Amazon Tree Ecology

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    Lineages tend to retain ecological characteristics of their ancestors through time. However, for some traits, selection during evolutionary history may have also played a role in determining trait values. To address the relative importance of these processes requires large-scale quantification of traits and evolutionary relationships among species. The Amazonian tree flora comprises a high diversity of angiosperm lineages and species with widely differing life-history characteristics, providing an excellent system to investigate the combined influences of evolutionary heritage and selection in determining trait variation. We used trait data related to the major axes of life-history variation among tropical trees (e.g. growth and mortality rates) from 577 inventory plots in closed-canopy forest, mapped onto a phylogenetic hypothesis spanning more than 300 genera including all major angiosperm clades to test for evolutionary constraints on traits. We found significant phylogenetic signal (PS) for all traits, consistent with evolutionarily related genera having more similar characteristics than expected by chance. Although there is also evidence for repeated evolution of pioneer and shade tolerant life-history strategies within independent lineages, the existence of significant PS allows clearer predictions of the links between evolutionary diversity, ecosystem function and the response of tropical forests to global change

    Variation in stem mortality rates determines patterns of above-ground biomass in Amazonian forests: implications for dynamic global vegetation models

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    This is the final version of the article. Available from Wiley via the DOI in this record.Understanding the processes that determine above-ground biomass (AGB) in Amazonian forests is important for predicting the sensitivity of these ecosystems to environmental change and for designing and evaluating dynamic global vegetation models (DGVMs). AGB is determined by inputs from woody productivity [woody net primary productivity (NPP)] and the rate at which carbon is lost through tree mortality. Here, we test whether two direct metrics of tree mortality (the absolute rate of woody biomass loss and the rate of stem mortality) and/or woody NPP, control variation in AGB among 167 plots in intact forest across Amazonia. We then compare these relationships and the observed variation in AGB and woody NPP with the predictions of four DGVMs. The observations show that stem mortality rates, rather than absolute rates of woody biomass loss, are the most important predictor of AGB, which is consistent with the importance of stand size structure for determining spatial variation in AGB. The relationship between stem mortality rates and AGB varies among different regions of Amazonia, indicating that variation in wood density and height/diameter relationships also influences AGB. In contrast to previous findings, we find that woody NPP is not correlated with stem mortality rates and is weakly positively correlated with AGB. Across the four models, basin-wide average AGB is similar to the mean of the observations. However, the models consistently overestimate woody NPP and poorly represent the spatial patterns of both AGB and woody NPP estimated using plot data. In marked contrast to the observations, DGVMs typically show strong positive relationships between woody NPP and AGB. Resolving these differences will require incorporating forest size structure, mechanistic models of stem mortality and variation in functional composition in DGVMs.This paper is a product of the European Union's Seventh Framework Programme AMAZALERT project (282664). The field data used in this study have been generated by the RAINFOR network, which has been supported by a Gordon and Betty Moore Foundation grant, the European Union's Seventh Framework Programme projects 283080, ‘GEOCARBON’; and 282664, ‘AMAZALERT’; ERC grant ‘Tropical Forests in the Changing Earth System’), and Natural Environment Research Council (NERC) Urgency, Consortium and Standard Grants ‘AMAZONICA’ (NE/F005806/1), ‘TROBIT’ (NE/D005590/1) and ‘Niche Evolution of South American Trees’ (NE/I028122/1). Additional data were included from the Tropical Ecology Assessment and Monitoring (TEAM) Network – a collaboration between Conservation International, the Missouri Botanical Garden, the Smithsonian Institution and the Wildlife Conservation Society, and partly funded by these institutions, the Gordon and Betty Moore Foundation, and other donors. Fieldwork was also partially supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico of Brazil (CNPq), project Programa de Pesquisas Ecológicas de Longa Duração (PELD-403725/2012-7). A.R. acknowledges funding from the Helmholtz Alliance ‘Remote Sensing and Earth System Dynamics’; L.P., M.P.C. E.A. and M.T. are partially funded by the EU FP7 project ‘ROBIN’ (283093), with co-funding for E.A. from the Dutch Ministry of Economic Affairs (KB-14-003-030); B.C. [was supported in part by the US DOE (BER) NGEE-Tropics project (subcontract to LANL). O.L.P. is supported by an ERC Advanced Grant and is a Royal Society-Wolfson Research Merit Award holder. P.M. acknowledges support from ARC grant FT110100457 and NERC grants NE/J011002/1, and T.R.B. acknowledges support from a Leverhulme Trust Research Fellowship
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