Identification of students' mental models about the milk transformation in yogurt

A review of the scientific literature reveals that there are still few researches on the conceptions of secondary school students about chemical reactions involving microorganisms, especially those related to the mental models that students use in their explanations. This paper describes a study concerning the different mental models related to the milk transformation into yogurt with 83 students from a Spanish secondary school of 8th and 9th grade (13-16 years) developed in the framework of a research that intends to use the elaboration of this product as a context for the teaching and learning of chemical reactions through modeling approaches. In order to identify the mental models of the students, in this paper we consider the milk transformation into yogurt as a process in which its main components are: the entities involved (milk and bacteria), the interaction between them and the result (yogurt). A simplified school model of this process would involve students considering that bacteria use the sugar in milk to transform it into lactic acid through a chemical reaction to obtain the necessary energy. Using this scheme in interaction with the students' answers, the underlying mental models were identified. Although almost half of the students showed great difficulties explaining the process, five models have been identified. Students often consider the milk transformation into yogurt primarily as a physical process of agglutination or change of state. These models are far from a school model of reference in which the bacteria have a fundamental role in the transformation of milk into yogurt by a chemical reaction.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Down-regulation of a pectin acetylesterase gene modifies strawberry fruit cell wall pectin stracture and increases fruit firmness

Antisense-mediated down-regulation of several fruit-specific genes has previously demonstrated how the cell wall disassembly in strawberry fruit is mediated by a series of enzymes that act sequentially (Posé et al. 2011). An interesting example, the silencing of the polygalacturonase gene FaPG1, was also related with a significant increase of the post-harvest strawberry fruit firmness (Posé et al. 2013). Our research group has isolated a pectin acetylesterase gene, FaPAE1, which expression is enhanced during strawberry ripening. The main goal of this work was to elucidate the role of the degree of acetylation in cell wall integrity and fruit firmness through the antisense-mediated down-regulation of FaPAE1 in strawberry plants. Several transgenics lines were generated and 5 of them produced fruits 5-15% firmer than controls. Cell wall from ripe fruits was isolated from two independent transgenic lines and a control line, and sequentially extracted with different solvents (PAW, H2O, CDTA, Na2CO3). Modifications in fraction yield, its sugar composition and the degree of acetylation in each fraction were determined. Higher amounts of CDTA and Na2CO3 fractions were obtained in transgenic fruits, suggesting a decreased pectin solubilization as results of FaPAE1 silencing. Accordingly, the degree of acetylation of the Na2CO3-soluble pectins was greater in the transgenic lines than the control, but the opposite result was found in pectins from the CDTA fraction. These results suggest that PAE is preferentially active in pectis that are tightly bound to the cellulose-hemicellulose network and its activity could reduce the complexity of the cell wall structure, allowing that other hydrolytic enzymes could access the pectin chains. Thus, the increased fruit firmness observed in the transgenic FaPAE1 lines could be attributed to the direct effect of the silencing of the PAE enzyme and also to the indirect effect that the increase of the degree of acetylation of pectins has on the activity of other enzymes involved in the cell wall degradation. * Posé et al. (2011). Genes, Genomes and Genomics, 5 (Special Issue 1):40-48 * Posé et al. (2013). Plant Physiology, 150: 1022-1032 We acknowledge support from the Spanish Ministry of Economy and competitivity and Feder EU Funds (grant reference AGL2011-24814), FPI fellowships support for SP (BES-2006-13626) and CP (BES-2009027985), and grant "Ramón y Cajal" support for AJMA (RYC-2011-08839).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Validez de la evaluación electroencefalográfica en la identificación del Trastorno por Déficit de Atención con Hiperactividad

Referencia de la publicación original: Moreno García, I., Lora Muñoz, J.A. y Sánchez Blanco, J. (2011). Validez de la evaluación electroencefalográfica en la identificación del Trastorno por Déficit de Atención con Hiperactividad. Apuntes de Psicología, 29 (2), 227-242.En este trabajo se analiza la validez del EEG como prueba añadida en el diagnóstico del TDAH así como de la SNAP-IV, instrumento empleado con frecuencia en atención primaria para la detección de este trastorno. Han participado 108 niños con edades comprendidas entre 7 y 14 años, derivados por presentar sintomatología hiperactiva– atencional. La validez del EEG se ha estimado a partir de la ratio theta/beta y considerando las variables tarea realizada (mirar un punto fijo, leer, escuchar y dibujar) mientras se realizaba la evaluación y grupo de edad de los menores que han participado. Los resultados muestran índices de sensibilidad y especificidad entre el 70% y el 80%, con una eficacia en la clasificación real superior al 75%. La edad se establece como un criterio fundamental tanto a la hora de seleccionar la ratio theta/beta más adecuada, como las tareas a emplear durante la evaluación. Estos datos avalan la utilidad del EEG en el diagnóstico del TDAH.This paper examines the validity of the EEG as an additional diagnostic test of ADHD as well as the SNAP-IV, an instrument ofien used in primary care screening for this disorder. It has be en included a total of 108 children, aged between 7 and 14 years, with hyperactive–attention symptomatology. The validity of the EEG has been estimated from the ratio of theta / beta variables and considering the work done (look at a fixed point, reading, listening and drawing) while performing the evaluation and age group of children who participated. The results show sensitivity and specificity rates between 70% and 80%, with an efficacy in the real c1assification aboye 75%. The age is a fundamental criterion for selecting the adequate ratio theta/ beta and the tasks used during the evaluation.These data support the utility of EEG in the diagnosis of ADHD

Rhamnogalacturonase lyase gene downregulation in strawberry and its potential on mechanical fruit properties

Strawberry softening is one of the main factors that reduces fruit quality and leads to economically important losses. Textural changes during fruit ripening are mainly due to the dissolution of middle lamellae, a reduction in cell-to-cell adhesion and the weakening of parenchyma cell walls as a result of the action of cell wall modifying enzymes. Functional studies of genes encoding pectinase enzymes (polygalacturonase, pectate lyase and -galactosidase) support a key role of pectin disassembly in strawberry softening. Evidence that RG-I may play an important role in strawberry texture has been obtained from the transient silencing of a RG-lyase gene. Pectins are major components of fruit cell walls and highly dynamic polysaccharides, but due to their heterogeneity the precise relation between the structures and functions is incomplete. In this work, stable transgenic strawberry lines with a rhamnogalacturonate lyase gene (FaRGLyase1) down-regulated have been analyzed. Several transgenic lines showing more than 95% silencing of FaRGLyase1 displayed fruit firmness values higher than control. Cell walls from these lines were extracted and analyzed by ELISA and Epitope Detection Chromatography (EDC). This last technique is based on the detection of specific cell wall oligosaccharide epitopes and provides information on sub-populations of pectins containing homogalacturonan and RG-I domains, but also reveals potential links with other cell wall polysaccharides such as xyloglucan. The results obtained indicate that the silencing of FaRGLyase1 reduces degradation of RG-I backbones, but also homogalacturonan, in cell walls, especially in pectin fractions covalently bound to the cell wall. These changes contribute to the increased firmness of transgenic fruits.This research was supported by FEDER EU Funds and the Ministerio de Economía y Competitividad of Spain (grant reference AGL2014-55784-C2), a Marie Curie IEF within the 7th European Community Framework Programme (reference: PIEF-2013-625270) for SP and a FPI fellowship (BES-2015-073616) to support PR-V. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Implementacion y análisis de métodos numéricos basados en flujo potencial con aplicación en turbomáquinas

Este artículo aborda la resolución de flujos no viscosos y en particular su aplicación al estudio de cascada de álabes. Para ello se analizarán modelos de flujo potencial resolviendo la ecuación de Laplace mediante diferentes variaciones del método de los Paneles. Se ha realizado una validación de los resultados obtenidos para perfiles aislados con valores experimentales obtenidos por la NACA. Además, se ha realizado un estudio comparativo entre los distintos resultados obtenidos con los diferentes métodos de los paneles implementados(Source, Vortex y Source-Vortex). Una vez comprobada la bondad de los distintas variantes del método de los paneles para perfiles aislados se ha ampliado el método a cascadas de álabes y se ha realizado también una validación con valores experimentales obtenidos de la bibliografía.In this work an analysis of different panel methods applied to turbomachinery has been presented, within the conditions of potential flow as well its behaviour with different shapes and its advantadges and inconvenients applied to aerodynamics profiles. Finally one of these methods have been extended and corrected to the analysis of compressor cascade

Big data in tourism marketing: past research and future opportunities

[EN] Purpose – The purpose of this study was to uncover representative emergent areas and to examine the research area of marketing, tourism and big data (BD) to assess how these thematic areas have developed over a 27-year time period from 1996 to 2022. This study analyzed 1,152 studies to identify the principal thematic areas and emergent topics, principal theories used, predominant forms of analysis and the most productive authors in terms of research. Design/methodology/approach – The articles for this research were all selected from the Web of Science database. A systematic and quantitative literature review was performed. This study used SciMAT software to extract indicators. Specifically, this study analyzed productivity and produced a science map. Findings – The findings suggest that interest in this area has increased gradually. The outputs also reveal the innovative effort of industry in new technologies for developing models for tourism marketing. Ten research areas were identified: “destination marketing,” “mobility patterns,” “co-creation,” “gastronomy,” “sustainability,” “tourist behavior,” “market segmentation,” “artificial neural networks,” “pricing” and “tourist satisfaction.” Originality/value – This work is unique in proposing an agenda for future research into tourism marketing research with new technologies such as BD and artificial intelligence techniques. In addition, the results presented here fill the current gap in the research since while there have been literature reviews covering tourism with BD or marketing, these areas have not been studied as a whole.[ES] El objetivo de esta investigación fue descubrir nichos representativos de áreas emergentes y examinar el área de Marketing, Turismo y Big Data, evaluando cómo han evolucionado estas áreas temáticas durante un período de 27 años desde 1996–2022. Analizamos 1.152 investigaciones para identificar las principales áreas temáticas y temas emergentes, las principales teorías utilizadas, las formas de análisis predominantes y los autores mas productivos en términos de investigación. Metodología – Todos los artículos para esta investigación fueron seleccionados de la base de datos Web of Science. Realizamos una revisión sistemática y cuantitativa de la literatura. Utilizamos el software SciMAT para extraer indicadores. Específicamente, analizamos la productividad y elaboramos un mapeo científico. Hallazgos – Los hallazgos sugieren que el inter es en esta área ha aumentado gradualmente. Los resultados también revelan el esfuerzo innovador de la industria en nuevas tecnologías para desarrollar modelos de marketing turístico. Se identificaron diez áreas de investigación (“marketing de destinos”, “patrones de movilidad”, “cocreación”, “gastronomía”, “sostenibilidad”, “comportamiento turístico”, “segmentación de mercado”, “redes neuronales artificiales”, “precios”, y “satisfacción del turista”). Valor – Este trabajo es único al proponer una agenda para futuras investigaciones en investigación de Marketing Turístico con nuevas tecnologías como Big Data y técnicas de Inteligencia Artificial. Además, los resultados presentados aquí llenan el vacío actual en la investigación ya que si bien se han realizado revisiones de literatura que cubren Turismo con Big Data o Marketing, estas áreas no se han estudiado como un conjunto.SIThis research was funded by Ministerio de Industria, Comercio y Turismo (Spain), AEI-010500–2020-253(DTI^A Project: 4.0 technological tools for measurement, evaluation and monitoring of the Friendliness concept linked to the Smart Tourist Destinations

How can destinations get engagement on Instagram? Artificial Intelligence as a tool for photo analysis

[EN] What type of content should be published on Instagram to get more engagement? This article highlights the different characteristics that the images of tourists show on Instagram with the most engagement, that is likes and comments. Understanding the behavior in a destination helps tourism managers in marketing strategies. Based on the stimulus-organism-response model, a content analysis of 49,540 photographs shared by tourists that received 3,734,384 likes and 133,497 comments is carried out. By combining the content analysis with Kruskal-Wallis non-parametric tests, the results show that the different characteristics found in the images imply different amounts between comments and likes, demonstrating that the behavior of users on Instagram is influenced by the different attributes of the images. Specifically, images that feature people get more engagement than destination-focused ones. Additionally, scenes such as gastronomy and nature get less engagement than scenes such as old and new heritage, outdoors, and entertainment. Specifically, photos with people get greater rate of comments than likes, and if the format is selfie, they also get more comments. The implications of this research directly affect destination managers, offering clues about the content generated by tourists that produces the most engagement, thus attracting potential tourists and Instagram users.Blanco-Moreno, S.; González-Fernández, AM.; Muñoz-Gallego, PA. (2023). How can destinations get engagement on Instagram? Artificial Intelligence as a tool for photo analysis. Editorial Universitat Politècnica de València. 123-124. http://hdl.handle.net/10251/20171412312

Efecto de la densidad de gallinas por jaula y de la estirpe sobre la producción y la calidad del huevo

La nueva normativa de la UE referida al bienestar de las gallinas ponedoras exige, en sus alojamientos, una superficie útil (S.U.) por gallina muy superior a la que es habitual fuera de sus fronteras. El objetivo de este trabajo es estudiar la influencia de una S.U. inferior a la indicada en la normativa UE sobre los resultados productivos. La población estudiada fue de 1008 gallinas ponedoras, 504 de estirpe semi pesada y 504 de estirpe ligera, alojadas en 168 jaulas (84 por estirpe), dispuestas en 8 filas, a razón de 4 y 5 gallinas/jaula (571,5 Y 457,2 cm2/ave, respectivamente). Las gallinas alojadas con una mayor densidad produjeron huevos de mayor peso medio (64,8 vs 63,6 g; P=0,012) y, por ende, también un mayor porcentaje de huevos de gramaje elevado (XL), de más de 73 g (12,3 vs 8,96%; P=0,0015). También se observó el mismo efecto en las gallinas semi pesadas (64,8 vs 63,5 g; P=0,03), con un porcentaje de huevos XL superior al doble (15,3 vs 7,11 %; P<0,001). No hubo diferencias en la intensidad de puesta media a lo largo de la puesta. El color de la yema tendió a ser más elevado en las gallinas alojadas con mayor densidad (10,1 vs 9,74). Las gallinas ligeras mostraron una mejor calidad de albumen (95,1 U Haugh vs 92,1; P<0,001) y menos color de la yema (9,55 vs 10,3; P<0,001). No hubo efecto de la densidad sobre la mortalidad, siendo ésta de un 10% en las gallinas que dispusieron de menos espacio, frente al 7,81

Efecto del silenciamiento de genes que codifican poligalacturonasas sobre el reblandecimiento del fruto de fresa asociado a la maduración

La degradación de las pectinas de la pared celular mediada por poligalacturonasas juega un papel clave en el reblandecimiento de la fresa. Así, el silenciamiento del gen FaPG1 incrementa la firmeza del fruto maduro y alarga su vida postcosecha. Además de FaPG1, en fresa se ha descrito otro gen que codifica una poligalacturonasa específica de maduración, FaPG2. Con el fin de profundizar en el papel de estos genes, se han obtenido plantas transgénicas con el gen FaPG2 silenciado (líneas BPG), así como plantas con FaPG1 y FaPG2 silenciados (líneas ABPG), obtenidas mediante retransformación de una línea antiFaPG1 (APG29) que mostraba un fuerte silenciamiento del gen y un incremento en la firmeza de fruto. Se obtuvieron 24 líneas BPG y 15 ABPG. Estas plantas, junto con la línea APG29 y controles sin transformar, fueron analizadas durante 3 años consecutivos. El 50% de las líneas BPG mostraron mayor firmeza de fruto rojo que el control sin transformar, aunque el incremento en firmeza fue similar al obtenido en la línea APG29. Todas las líneas dobles transformantes dieron frutos de mayor firmeza que el control, siendo los valores ligeramente superiores a los de la línea APG29 en alguna de ellas. A nivel de expresión, las líneas BPG seleccionadas mostraron un silenciamiento del gen FaPG2 que varió entre el 60-70%, e inesperadamente, un silenciamiento significativo de FaPG1, a pesar de la baja homología entre ambos genes. El silenciamiento de FaPG1 en las líneas ABPG fue superior al 95%; sin embargo, el silenciamiento de FaPG2 fue similar al obtenido en las plantas BPG. Estos resultados confirman el papel clave de las poligalacturonasas en el reblandecimiento de la fresa y sugieren la existencia de una regulación compleja en la expresión de ambos genes. Este trabajo ha sido financiado por el proyecto AGL2011-24814 y Fondos FEDERUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Optimización del diseño del conducto de admisión del motor F1L2006

En el presente trabajo se describe la caracterización aerodinámica del conducto de admisión de un motor de encendido por compresión monocilíndrico con refrigeración por aire. Para ello se estudia la evolución para cada configuración operativa del coeficiente de descarga y del swirl mediante experimentación y simulación con un código de cálculo fluidodinámicoIn the present work the aerodynamic characterization of the intake duct of an air cooled single cylinder compression ignition engine is described. The discharge coefficient and swirl for each configuration is studied by means of experimentation and simulation with a computational fluid dynamics code