Influence of heat treatment and natural antimicrobials in the viability of different microorganisms

Mención Europeo / Mención Internacional: Concedido[SPA] Los tratamientos térmicos se aplican profusamente en la industria alimentaria ya que permiten destruir a los microorganismos y a sus enzimas de forma controlada, garantizando, hasta ciertos niveles, la salubridad y estabilidad de los alimentos. Sin embargo, dichos tratamientos también afectan a algunos componentes termolábiles y a sus características organolépticas. El uso de antimicrobianos naturales es una alternativa que, mediante su combinación con los tratamientos térmicos, permitiría disminuir la intensidad de los mismos, conservando así sus características originales. En esta Tesis Doctoral se eligieron como microorganismos objeto de estudio aquellos responsables de toxiinfecciones alimentarias pertenecientes a grupos estructuralmente distintos, para comprobar si estas diferencias podrían afectar a la eficacia de los tratamientos aplicados. Para profundizar en el estudio de los tratamientos térmicos, se ha hecho una especial incidencia en la investigación del efecto de la velocidad de calentamiento, factor cuya influencia en la termorresistencia microbiana es bastante desconocido. Se ha elegido como antimicrobianos naturales, una bacteriocina (nisina) y dos compuestos presentes en los aceites esenciales de hierbas aromáticas y especias (carvacrol y timol). Los resultados obtenidos en esta Tesis Doctoral, junto con los modelos matemáticos utilizados, evidencian la posibilidad de desarrollar y optimizar tratamientos térmicos combinados con antimicrobianos naturales, que permitan a la industria alimentaria obtener productos seguros y de mayor calidad.[ENG] Heat treatments are widely extended in food industry since they are able to inactivate microorganisms and their enzymes in a controlled way, ensuring food safety and stability to certain levels. Nevertheless, these treatments have negative effects on heat sensitive compounds and on the organoleptic characteristics of foods. The use of natural antimicrobials is an alternative that, in combination with heat treatments, would help to decrease their intensity, preserving the natural characteristics of the products. In this Thesis, the microorganisms were chosen among those responsible for food poisoning outbreaks and belonging to different structural groups, in order to check if the differences would affect the efficiency of the treatments applied. A special emphasis has been paid to the heating rates applied during thermal treatments, since the influence of this factor on the heat resistance of microorganisms is quite unknown. As natural antimicrobials, a bacteriocin (nisin) and two compounds present in the essential oils of aromatic herbs and spices (carvacrol and thymol) were chosen. The results obtained in this Thesis, together with the mathematical models used, show the possibility to develop and optimize thermal treatments combined with natural antimicrobials, which would enable food industry to produce safer and better quality foods.Universidad Politécnica de CartagenaPrograma de doctorado en Técnicas Avanzadas en Investigación y Desarrollo Agrario y Alimentari

Model-assisted estimation of small area poverty measures: an application within the Valencia Region in Spain

This paper introduces small area estimators of poverty indexes, with special attention to the poverty rate (or Head Count Index), and studies the sampling design consistency and the asymptotic normality of these estimators. The estimators are assisted by nested error regression models and are model-assisted counterparts of model-based empirical best predictors. Simulation studies show that these estimators present a good balance between sampling bias and mean squared error. Data from the 2013 Spanish living conditions survey with respect to the region of Valencia are used to determine the performance of this new method for estimating the poverty rate.Valencian Governmen

Učinak nizina, karvakrola i njihovih kombinacija na sprečavanje rasta stanica bakterije Listeria monocytogenes nakon toplinske obrade

Listeria monocytogenes is a Gram-positive microorganism responsible for one of the most serious food-borne diseases in the world, listeriosis. The aim of this study is to evaluate the combined effect of a heat pretreatment with the use of antimicrobials, nisin and carvacrol, on the growth of L. monocytogenes, and their potential uses as food preservatives. Carvacrol showed a dose-dependent inhibitory effect, while nisin did not, it decreased the growth rate of L. monocytogenes up to 20 %, and it increased lag time for approx. 25 % at any of the concentrations tested (0.13–0.39 μM). When both antimicrobials were combined, a synergistic effect was observed. This effect was further increased when they were combined with a heat pretreatment for 15 min at 55 °C, where no growth was observed for at least 15 days, even at the lowest concentration tested. The effect was proved both in tryptic soy broth and in carrot juice. This study indicates the potential use of carvacrol and nisin applied simultaneously for preservation of minimally processed foods.Listeria monocytogenes je Gram-pozitivni mikroorganizam koji uzrokuje listeriozu, jednu od najopasnijih bolesti što se prenosi hranom. Svrha je ovoga rada bila procijeniti kombinirani učinak prethodne toplinske obrade i primjene antimikrobnih spojeva, nizina i karvakrola, na rast bakterije Listeria monocytogenes. Učinak je karvakrola ovisio o dozi, dok je nizin smanjio rast bakterije L. monocytogenes do 20 % i produljio lag fazu za 25 % pri svim koncentracijama (od 0,13 do 0,39 μM). Primjenom oba antimikrobna spoja postignut je sinergistički učinak. Učinak je još više pojačan prethodnom toplinskom obradom na 55 °C tijekom 5 minuta, nakon čega nije zamijećen rast bakterija ni nakon 15 dana, čak ni u uzorcima s najmanjom koncentracijom nizina. Učinak je potvrđen u TSB bujonu i soku mrkve. Ovo je ispitivanje potvrdilo da se nizin i karvakrol mogu zajedno koristiti u konzerviranju minimalno prerađene hrane

Comparación y validación de formulaciones aplicadas a cimentaciones monopilotadas en eólica marina

Las estructuras monopilotadas son la tipología de cimentación más común en eólica marina, con un porcentaje de centrales del 80 % en Europa, y con diámetros de hasta 8 metros. La tendencia en las construcciones offshore futuras parece estar encaminada al desarrollo de este tipo de estructuras, con lo cual los monopilotes seguirán siendo la principal cimentación en eólica marina, quedando aun mucho margen de evolución en esta tipología y avanzando cada vez hacia mayores diámetros y profundidades. Los objetivos perseguidos en la elaboración del trabajo están relacionados con el dimensionamiento de estas estructuras pilotadas. Para verificar si los modelos de cálculo de longitudes de monopilotes orientados a cimentaciones onshore pueden ser aplicadas en situaciones offshore. Además, se ha querido establecer una relación entre tipologías de suelo y longitudes de los pilotes

Small area estimation of proportions under area-level compositional mixed models

[Abstract]: This paper introduces area-level compositional mixed models by applying transformations to a multivariate Fay–Herriot model. Small area estimators of the proportions of the categories of a classification variable are derived from the new model, and the corresponding mean squared errors are estimated by parametric bootstrap. Several simulation experiments designed to analyse the behaviour of the introduced estimators are carried out. An application to real data from the Spanish Labour Force Survey of Galicia (north-west of Spain), in the first quarter of 2017, is given. The target is the estimation of domain proportions of people in the four categories of the variable labour status: under 16 years, employed, unemployed and inactive.Supported by the Instituto Galego de Estatística, by the grants PGC2018-096840-B-I00 and MTM2017-82724-R of the Spanish Ministerio de Economía y Competitividad and by the Xunta de Galicia (Grupos de Referencia Competitiva ED431C-2016-015 and Centro Singular de Investigación de Galicia ED431G/01), all of them through the ERDF.Xunta de Galicia; ED431C-2016-015Xunta de Galicia; ED431G/0

Small area estimation of expenditure means and ratios under a unit-level bivariate linear mixed model

This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Applied Statistics on 05 Aug 2020, available at: https://doi.org/10.1080/02664763.2020.1803809[Abstract]: Under a unit-level bivariate linear mixed model, this paper introduces small area predictors of expenditure means and ratios, and derives approximations and estimators of the corresponding mean squared errors. For the considered model, the REML estimation method is implemented. Several simulation experiments, designed to analyze the behavior of the introduced fitting algorithm, predictors and mean squared error estimators, are carried out. An application to real data from the Spanish household budget survey illustrates the behavior of the proposed statistical methodology. The target is the estimation of means of food and non-food household annual expenditures and of ratios of food household expenditures by Spanish provinces.Supported by the grants MTM2017-82724-R and PGC2018-096840-B-I00 of the Ministerio de Economía y Competitividad (MINECO) and by the Xunta de Galicia (Grupos de Referencia Competitiva ED431C-2016-015 and Centro Singular de Investigación de Galicia ED431G/01), all of them through the ERDF.Xunta de Galicia; ED431C-2016-015Xunta de Galicia; ED431G/0

Offshore Wind Farms

The coastal zone is the host to many human activities, which have significantly increased in the last decades. However, sea level rise and more frequent storm events severely affect beaches and coastal structures, with negative consequences and dramatic impacts on coastal communities. These aspects add to typical coastal problems, like flooding and beach erosion, which already leading to large economic losses and human fatalities. Modeling is thus fundamental for an exhaustive understanding of the nearshore region in the present and future environment. Innovative tools and technologies may help to better understand coastal processes in terms of hydrodynamics, sediment transport, bed morphology, and their interaction with coastal structures. This book collects several contributions focusing on nearshore dynamics, and span among several time and spatial scales using both physical and numerical approaches. The aim is to describe the most recent advances in coastal dynamics

Reusing digital collections from GLAM institutions

For some decades now, Galleries, Libraries, Archives and Museums (GLAM) institutions have published and provided access to information resources in digital format. Recently, innovative approaches have appeared such as the concept of Labs within GLAM institutions that facilitates the adoption of innovative and creative tools for content delivery and user engagement. In addition, new methods have been proposed to address the publication of digital collections as data sets amenable to computational use. In this article, we propose a methodology to create machine actionable collections following a set of steps. This methodology is then applied to several use cases based on data sets published by relevant GLAM institutions. It intends to encourage institutions to adopt the publication of data sets that support computationally driven research as a core activity.This work has been partially supported by ECLIPSE-UA RTI2018-094283-B-C32 (Spanish Ministry of Education and Science)

A benchmark of Spanish language datasets for computationally driven research

In the domain of Galleries, Libraries, Archives and Museums (GLAM) institutions, creative and innovative tools and methodologies for content delivery and user engagement have recently gained international attention. New methods have been proposed to publish digital collections as datasets amenable to computational use. Standardised benchmarks can be useful to broaden the scope of machine-actionable collections and to promote cultural and linguistic diversity. In this article, we propose a methodology to select datasets for computationally driven research applied to Spanish text corpora. This work seeks to encourage Spanish and Latin American institutions to publish machine-actionable collections based on best practices and avoiding common mistakes.This research has been funded by the AETHER-UA (PID2020-112540RB-C43) Project from the Spanish Ministry of Science and Innovation

Noves dades sobre fongs hipogeus. I: ascomicets

S'ha efectuat l'estudi detallat de 12 espécies d'ascomicets hipogeus recolectats a diferents localitats de la Península Ibérica, entre els quals destaquen Picoa juniperina y Terfezia claveryi. Per cadascuna d'aquestes espécies es dona una descripció macro i microscópica detallada, amb dibuixos originals, així com l'ecologia i la localitat.En el presente trabajo se estudian un total de 12 táxones de ascomicetes hipogeos recolectados en diferentes localidades de la Península Ibérica, entre los cuales destacan Picoa juniperina y Terfezia claveryi. Para cada una de las especies estudiadas se ofrece una descripción macro y microscópica con iconografía original, y datos de distribución y ecología