Determinación de la Cinética de Reacción de Transesterificación para la obtención de Biodiesel a partir de aceite de Cartamo con Metanol utilizando como Catalizador NA2O/NAX

El biodiesel está constituido por ésteres monoalquílicos de ácidos grasos de cadena larga producidos a partir de aceites vegetales y grasas animales, siendo la colza, el girasol y la soya las materias primas más utilizadas para este fin. El método convencional para la obtención de biodiesel, es la transesterificación de aceites vegetales y un alcohol, utilizando catalizadores homogéneos como NaOH y KOH sin embargo, este sistema necesita grandes cantidades de agua para la purificación del biodiesel, por lo que no es considerado un método medioambientalmente amigable. Por ello, en los últimos años se han desarrollado sistemas heterogéneos para la reacción de transesterificación ya que estos no requieren de grandes cantidades de agua para lavar los productos. De estos a nivel laboratorio, el catalizador Na2O/NaX se ha utilizado en la transesterificación del aceite de girasol con metanol alcanzando un porcentaje alto de esteres metílicos (> 95 %), a condiciones moderadas de operación. Por lo anterior, se considera a este catalizador como una opción para trabajar a nivel de planta piloto. Para escalar dicho proceso es necesario conocer la cinética de la reacción, ya que a partir de esta es posible establecer parámetros para el diseño del reactor, determinar el tiempo de reacción y las condiciones de operación. El objetivo del presente trabajo fue obtener la cinética de la reacción de transesterificación en un sistema heterogéneo básico para la obtención de biodiesel a partir de aceite de cártamo con metanol utilizando como catalizador Na2O/NaX. Se trabajó a condiciones moderadas de operación (60o C y presión atmosférica) con tres relaciones molares alcohol: aceite 12:1, 9:1 y 6:1 con un 10% en peso de catalizador respecto al peso del aceite, con 4.5% de sodio. Para determinar la cinética de reacción se empleó el método integral, de manera que se obtuvieron muestras a diferentes tiempos de la reacción para después ser monitoreadas en cromatografía de gases y obtener su contenido de porcentaje de triglicéridos de acuerdo con la Norma Europea UNE-EN 14105, los órdenes de reacción global obtenidos para cada relación (12:1, 9:1 y 6:1) fueron de tercer orden con una constante de velocidad de 2X10-5 , 1X10-5 y 3X10-5 L 3 /mol2 *(gr-1 cat. min-1 ), respectivamente

Avian scavengers' contributions to people: the cultural dimension of wildlife-based tourism

Scavengers provide significant nature's contributions to people (NCP), including disease control through carcass removal, but their non-material NCP are rarely considered. For the first time, we assess the extent and value of the NCP provided by European avian scavengers through a scavenger-based tourism at Pyrenean supplementary feeding sites (SFS). Using a two-step cluster analysis, two different types of visitor were identified (specialist avian scavenger-watchers and generalist nature-lovers) at those SFS offering recreational experiences (n = 20, i.e. birdwatching, educational, or photographic activities). Most visitors (85%) perceived avian scavengers as beneficial NCP providers, associating this guild with non-material NCP (mostly supporting identities), followed by regulating and maintenance of options NCP (<1%). Our findings help to characterize the type of people who participate in scavenger related recreation and to identify and value their perceptions of avian scavengers. There has not been much previous research on positive human-wildlife interactions, even though ignoring people emotional bonds with nature can be perilous for biodiversity conservation.FundingThis study was funded by the Spanish Ministry of Economy, Industryand Competitiveness (project CGL2015-66966-C2-2-R), Ministry ofScience, Innovation and Universities (project RTI2018-099609-B-C22),and European Regional Development Fund (ERDF) through theINTERREG V - A - España - Francia - Andorra (POCTEFA 2014 - 2020program, project ECOGYP EFA 089/15). RGJ was supported by a pre-doctoral grant (FPI/BES-2016-077510) granted by the Spanish Ministryof Economy and Competitiveness. JMPG was supported by a SpanishMinistry of Science, Innovation and Universities postdoctoral contract(IJC-2019-038968). ZMR was supported by a postdoctoral contract co-funded by the Generalitat Valenciana and the European Social Fund(APOSTD/2019/016)

Condiciones de la innovación pecuaria y producción de lácteos en comunidades altoandinas

Summary The study explores the conditions of the changes that have occurred in the livestock activity of two communities in the southern Andes of Peru, based on innovation in the processes of cattle production for obtaining milk. A mixed methodology was used that involved the development of interviews and surveys with the families of producers in the district of Ocongate. The results show an increase in the number of heads of cattle and cattle breeders, improvements in milk production, an increase in family income, and other changes in the family life of producers. In addition, it is argued that the involvement of both governmental and private institutions contributed to livestock innovation.Resumen El estudio explora las condiciones de los cambios ocurridos en la actividad pecuaria del de dos comunidades del sur andino de Perú, a partir de la innovación en los procesos de producción de ganado vacuno para la obtención de leche. Se utilizó una metodología mixta que involucró el desarrollo de entrevistas y encuestas con las familias de productores del distrito de Ocongate. Se evidencia el incremento de cabezas y criadores de vacunos, mejoras de la producción de leche, incremento de los ingresos familiares, así como otros cambios en la vida familiar de los productores. Además, se argumenta que la participación de instituciones gubernamentales y privadas coadyuvó a la innovación pecuaria

The Influence of the media and advertising on eating disorders

This article describes a literature review of the influence of advertising and the media on Eating Disorders (ED). Research published in scientific journals in various fields of social sciences such as sychology, psychiatry and communication science has enabled us to conclude that the content displayed in the media, including advertising, are enhancers of disorders and contribute significantly to body issatisfaction in relation to the perceived idea of beauty, it also facilitates the development of weight loss strategies in women and gain of muscle mass in men

Validation of a Spanish version of the Foreign Language Classroom Anxiety Scale in Peruvian secondary education students

BackgroundAnxiety in learning foreign languages is a global phenomenon that impacts students’ academic performance, with English being a critical language in secondary education. The Foreign Language Classroom Anxiety Scale (FLCAS) has been widely used to assess this anxiety. However, the need to validate and adapt the scale for specific cultural contexts remains a priority in educational research.ObjectiveTo assess the validity and reliability of a Spanish version of the FLCAS among a sample of Peruvian secondary education students, in order to better understand the structure of language learning anxiety in this context.MethodsA total of 818 students from four public educational institutions in southern Peru participated. An instrumental design was used, which included descriptive analysis, exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and assessments of convergent, divergent validity, and measurement invariance by gender.ResultsThe EFA recommended a four-factor model that explained 32% of the total variance. Subsequent CFA adjusted this model to 24 items with optimal fit indices (CFI = 0.969; RMSEA = 0.045). The reliability of the factors was acceptable (α &gt; 0.70 for all factors). Convergent and divergent validity was confirmed through significant correlations with related constructs (Fear of Negative Evaluation and Enjoyment of Foreign Language). Gender invariance analysis indicated that the scale is equally applicable to men and women.ConclusionThe Spanish version of the FLCAS is a valid and reliable tool for assessing foreign language classroom anxiety among Peruvian secondary education students. This study contributes to the field of language teaching by providing evidence of the cultural applicability of the FLCAS in the Peruvian context, thus facilitating more effective pedagogical interventions to address language learning anxiety

La malacofauna marina de las fases holocenas en la Cueva del Toll (Moià, Barcelona): nuevas aportaciones para el Neolítico nororiental

[EN]: The entrance to the South Gallery of the Toll Cave was discovered in the 40's of the last century. Since then, several works have highlighted the importance of the archaeo-pale-ontological site at both regional and peninsular levels. Focusing on the Holocene levels, the research suggests prolonged use of it, at least from Epicardial times to the late Bronze Age. Among the vast amount of material recovered, we highlight, to the interest of our study, several marine shells. Under the current research project, new specimens have been recovered. Tax-onomic identification shows that they are marine gastropods. The technology, use-wear and chemical analysis suggests that they were anthropically modified by making holes for use as hanging elements. The shells were being tinted with red pigment. The spatial and stratigraphic position of the specimens lead, us to interpret them as part of a single bead, deposited at the bottom of a Neolithic structure.[ES]: La entrada a la Galería Sur de la Cueva del Toll (Moià, Barcelona) fue descubierta en los años 40 del pasado siglo. Desde entonces, las distintas intervenciones realizadas han puesto de manifiesto la importancia del yacimiento arqueo-paleontológico tanto a nivel regional como peninsular. Centrándonos en los niveles holocenos de la cavidad, las investigaciones realizadas indican un uso prolongado de la misma, al menos desde el Neolítico Antiguo, hasta finales del Bronce inicial. Entre la variada cantidad de materiales recuperados destacan por el interés del presente estudio, varios restos de malacofauna marina. En el marco del actual proyecto de investigación, han sido recuperados nuevos ejemplares pertenecientes a las especies Columbella rustica y Nassarius cuvieri. El análisis tecnológico, traceológico y químico de las mismas sugiere que fueron modificadas antrópicamente mediante la realización de perforaciones para su uso, siendo tintadas con pigmentos rojizos. La posición estratigráfica y espacial de los ejemplares nos lleva a interpretar las mismas como parte de un único abalorio, depositado en el fondo de una estructura neolítica.El proyecto de intervención arqueológica esta cofinanciado por el Departamento de Cultura y Medios de Comunicación de la Generalitat de Cataluña.Peer Reviewe

Declaratoria de sociedad de hecho

T 346.016 6 M71; 67 p.Determinar las razones jurídicas, económicas y sociales que conducen a la solicitud judicial de declaratoria de existencia de sociedad comercial de hecho entre compañeros permanentes en los municipios de Manizales y Riosucio - Caldas, durante el período comprendido entre los años 2004 - 2010.Universidad Libre de Pereir

Bactericide, Antioxidant and Cytotoxic Activities from Marine Algae of Genus Laurencia Collected in Baja California Sur, Mexico

Abstract Background and Objective: Marine environment represents countless and diverse resource for new drugs to combat major diseases. Extracts from four Laurencia species ( L. johnstonii, L. pacifica, L. gardneri and L. papillosa) from Baja California Sur, México were evaluated for their antioxidant, antibacterial and cytotoxic activity. Methodology: The antioxidants activity of Laurencia sp. were evaluated using the radical scavenging activity in three in vitro radicals: 1,1-Diphenyl-2-picrylhydrazyl (DPPH), 2,2'-Azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and nitric oxide (NO). The antibacterial activity was evaluated by the broth microdilution method to determinate the Minimum Inhibitory Concentrations (MIC) against Staphylococcus aureus, Bacillus subtilis, Enterococcus faecalis, Micrococcus luteus, Pseudomonas aerugi nosa and Klebsiella pneumoniae . The cytotoxicity was analyzed on HeLa (cervix adenocarcinoma) and Vero (kidney epithelial) cells, using the reduction of tetrazolium salt WST-1. Results: The seaweed of genus Laurencia demonstrated an overall low activity, with half maximal effective concentration (EC50) values >1.5 mg mLG1. Laurencia pacifica showed the best biocide effects with MIC of 6.25 µg mLG1 against Gram positive bacterial and cytotoxic potential with half inhibitory concentration (IC50) <30 µg mLG1 against Vero and HeLa cells. Conclusion: Some Laurencia species have a great antibacterial and cytotoxic activity which could be considered for future studies

NRF2-dependent gene expression promotes ciliogenesis and Hedgehog signaling

The transcription factor NRF2 is a master regulator of cellular antioxidant and detoxification responses, but it also regulates other processes such as autophagy and pluripotency. In human embryonic stem cells (hESCs), NRF2 antagonizes neuroectoderm differentiation, which only occurs after NRF2 is repressed via a Primary Cilia-Autophagy-NRF2 (PAN) axis. However, the functional connections between NRF2 and primary cilia, microtubule-based plasma membrane protrusions that function as cellular antennae, remain poorly understood. For instance, nothing is known about whether NRF2 affects cilia, or whether cilia regulation of NRF2 extends beyond hESCs. Here, we show that NRF2 and primary cilia reciprocally regulate each other. First, we demonstrate that fibroblasts lacking primary cilia have higher NRF2 activity, which is rescued by autophagy-activating mTOR inhibitors, indicating that the PAN axis also operates in differentiated cells. Furthermore, NRF2 controls cilia formation and function. NRF2-null cells grow fewer and shorter cilia and display impaired Hedgehog signaling, a cilia-dependent pathway. These defects are not due to increased oxidative stress or ciliophagy, but rather to NRF2 promoting expression of multiple ciliogenic and Hedgehog pathway genes. Among these, we focused on GLI2 and GLI3, the transcription factors controlling Hh pathway output. Both their mRNA and protein levels are reduced in NRF2-null cells, consistent with their gene promoters containing consensus ARE sequences predicted to bind NRF2. Moreover, GLI2 and GLI3 fail to accumulate at the ciliary tip of NRF2-null cells upon Hh pathway activation. Given the importance of NRF2 and ciliary signaling in human disease, our data may have important biomedical implicationsThis work was supported by European Regional Development Fund (ERDF)-cofunded grants from the Spanish Ministry of Economy and Competitiveness (MINECO) to FRGG (SAF2015-66568-R and RYC2013-14887) and to A.C. and I.L.B. (SAF2016-76520-R