THE ROLE OF EXTRACELLULAR POLYMERIC SUBSTANCES IN THE ACCUMULATION AND TRANSPORT OF POLYSTYRENE NANOPARTICLES IN BIOFILMS

With the increasing number of nanotechnology applications, it is reasonable to expect nanoparticles to be ubiquitous in biofilms found in natural and engineered aquatic systems. We studied the impact of the degree of cross-linking on the deposition and diffusion of polystyrene nanoparticles (NPs) in alginate model biofilm matrices in the presence and absence of calcium cross-linkers using image correlation methods and single particle tracking. We found that cross-linking increases the viscoelasticity and hydration of the polymeric matrix and leads to structural changes that can restrict and alter the diffusive behavior of NPs, but the magnitude of the effects on diffusion depends on NP size. Nonetheless, all sizes of particles considered in the study experienced a degree of confinement and partial confinement demonstrating that diffusion in heterogeneous biofilm matrices should not be assumed to be isotropic. In bacterial biofilms, investigated using the same techniques, NP diffusion modes are dependent on biofilm age and NP functional groups and were affected by the intrinsic variability of biological systems, even when the biofilms were formed in similar conditions and by the same microorganism. Living biofilms are dynamic and active with responsive interchange between the microbial inhabitants and the biofilm structure. The results from our studies suggest that when NPs accumulate in biofilms, NPs can stress the microbes and alter gene expression of key extracellular polymeric substances production and quorum sensing systems. These changes depend on NP surface charge, gene function and biofilm age and could end up affecting biofilm architecture and metabolic efficiency. These findings elucidating the conditions that affect biofilm structure add to our knowledge of the interactions between biofilms and nanoparticles, leading to a better understanding of the fate, transport, and effect of NPs in the environment and should be useful in the development of biofilm related applications to achieve specific objectives. For example, in medicine, to eradicate biofilm infections by improving the penetration of antibiotics delivered by nanomaterials, or in environmental engineering, to determine how environmental conditions can impact the accumulation of NPs in biofilms in the environment

Performance evaluation of different machine learning methods applied on churn database

The growth of data and its storage is becoming more and more important every day. However, occasionally this information is gathered but never used, or perhaps it is improperly gathered, making the extraction of the insides difficult. As a result, while beginning any project, choosing the analysis method is just as crucial as choosing the design of the data collection strategy. Most of the time, we only focus on the analysis of the data and do not consider how it was gathered or whether the fields were actually valuable or just added noise to what we were searching for. For this reason, a trustworthy data set has been chosen for this project. The data came from a telecom company, which, like other modern businesses, collects a lot of data. However, in this case, the data was published on the machine learning web competition Kaggle, where participants competed to build the best model to predict consumer behaviour. One of the key considerations in optimizing any organization's income is preventing customer churn. It happens when customers quit utilizing a company's goods or services, and is also referred to as customer attrition. The main goal of this master's thesis is to analyse a Churn database and categorise the clients in order to determine whether they are likely to leave the company. To do this, two machine learning techniques will be used in the current document. Extreme Gradient Boosting and Random Forest. In order to achieve high performance, the Random Forest (RF) method creates a large number of low-performance models and combines them. In this case, the lower-performance method is called Decision Tree, so it will be explained in more detail in the following document. Similar work is done by eXtreme Gradient Boosting (XGB), although it builds new models based on earlier findings. Both are quite effective predictor models, even with unbalanced data, as will be demonstrated in the next document. This adds another level of complexity that the algorithms must overcome to execute effectively. Different performance indicators will be provided and examined in order to determine which one is the greatest indicator to choose the best model during the process of determining the best model. Sensitivity, Specificity, Precision, F1 Score, and Geometric Mean are a few of the markers that are listed. Additionally, their trends for the various parameter values of the examined models will be shown and analysed. The strong performance of these machine learning algorithms will once more be supported in this thesis. the affirmation of the significance and practical use of these methodologies, as in the case of this project, to comprehend processes and behaviours. All fields can benefit from the information gleaned, and a successful application will undoubtedly yield financial rewards. The two machine learning applied algorithms' default and best models are finally shown, and their advantages and disadvantages will be evaluated while taking into account the many scenarios that exist. This thesis will demonstrate the good performance of both models, with XGB significantly outperforming RF. It will also demonstrate that while XGB performs better on precision and RF has better results on sensitivit

Caracterización y propuesta para manejo y aprovechamiento de los residuos sólidos no peligrosos generados en la Universidad ECCI.

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Rol protagónico de mujeres durante la etapa pre y postrevolucionaria en la ciudad de Esteli, Nicaragua

Es un estudio cualitativo, cuya estrategia metodológica es el método biográfico. Su objetivo general es la reconstrucción de las vivencias de una mujer para visibilizar el rol protagónico de las mujeres, que contribuyeron al desarrollo psicosocial en sus ámbitos personales, familiares, comunitarios y sociales en momentos históricos relevantes, en la ciudad de Estelí. El Método Biográfico estrategia apropiada para generar aprendizajes a través de la sistematización y la reflexión. Para J. Pujadas (2000), la construcción de la memoria, junto a las formas de afirmación de la identidad individual, reflejadas en las autobiografías y en otros tipos de documentos personales, muestra una pluralidad de voces y de sensibilidades en la interpretación de la realidad social. Los resultados demuestran la beligerancia de las mujeres en los momentos históricos, la limitantes sociales que obstaculizan su protagonismos en el desarrollo psicosocial de los entornos diversos. Los elementos facilitadores vividos como país que propician el desarrollo de oportunidades y espacios para que las mujeres asuman roles que trascienden de los tradicionalmente asignados, perpetuados por las instituciones sociales como la familia, la escuela y la religión

Caracterización de las funciones ejecutivas (Planeación, control inhibitorio y flexibilidad mental) y representaciones sociales de suicidio en personas con historia de intento de suicidio.

This study aims to characterize the executive function: inhibitory control, sequential planning, mentalflexibility and social representations of suicide. This was a mixed-method research with a dominantquantitative approach. People who took part in the study were patients admitted to the emergency room atUniversity Hospital Moncaleano Hernando Perdomo for attempted suicide from 1st January 2007 to 30thJune 2009. Data was collected through a number of instruments: psychological clinical history, suiciderisk scale of Plutchik (1994); Buss and Perry’s aggression questionnaire, Spanish version 2002; impulsivityfunctional / dysfunctional scale of Dickman, Spanish version 2003; Minimult personality inventory; Towerof Hanoi Seville, Stroop Color Test 3rd edition 2001; Wisconsin Card Sorting Test, long version 2nd edition2001; and Network Association proposed by Annamaria Silvana De Rosa (1996). The findings demonstrated  that a suicide attempt is not due to a fault in the control of impulses, but it can be the result of inadequatestrategies to solve problems.El objetivo del presente estudio fue caracterizar las funciones ejecutivas: control inhibitorio, planeaciónsecuencial y flexibilidad mental; así como elaborar una interpretación comprensiva de las representacionessociales de suicidio de las personas con historia de intento suicida. La metodología del estudiofue de enfoque mixto o multimétodo con enfoque cuantitativo dominante. La muestra de estudio estuvoformada por cuatro pacientes con previo ingreso al servicio de urgencias del Hospital UniversitarioHernando Moncaleano Perdomo por diagnóstico de intento de suicidio, en el periodo comprendidoentre el 1 de enero de 2007 hasta el 30 de junio de 2009. La información se recolectó por medio de lossiguientes instrumentos: historia clínica psicológica, escala de riesgo suicida de Plutchik (1994); cuestionariode agresión de Buss y Perry, versión Española 2002; escala de impulsividad funcional/disfuncionalde Dickman, versión española 2003; inventario de personalidad Minimult; Torre de Hanoi Sevilla, Test de coloresSTROOP 3. ra edición 2001; Test de clasificación de tarjetas Wisconsin, versión larga, 128cartas, 2.daedición 2001; y Red de Asociaciones Annamaría Silvana de Rosa (1996). En los resultados seevidenció al intento de suicidio no como resultado de una falla en el control de impulsos, sino comoconsecuencia de inadecuadas estrategias para la solución de problemas

Esperimentazioa Kimika Fisikoan Kimika graduko irakasgaiaren terminologia-glosategia egitea eta terminologia aztertzea

Lan honetan Kimika arloko euskarazko terminologia akademikoaren deskripzioan eta finkapenean ekarpen bat egin da UPV/EHUko Zientzia eta Teknologia Fakultateko Kimika graduan irakasten den Esperimentazioa Kimika Fisikoan irakasgaian erabiltzen den terminologia errealetik abiatuta. Terminologia Sareak Ehunduz (TSE) programan garatutako metodologia erabiliz bildu da terminologia eta euskara-gaztelania-ingelesa glosategi eleaniztun bat prestatu da Terminologia Zerbitzurako Online Sisteman (TZOS) kontsultagai jartzeko. Bestalde, bildutako terminologia erkatu da, batetik, aldez aurretik TZOSen jasota zegoen terminologiarekin eta, bestetik, Elhuyarren Zientzia eta Teknologiaren Hiztegi Entziklopedikoan eta Euskalterm datu-base terminologikoan kodifikatuta dagoenarekin. Egindako azterketak agerian utzi du Euskalterm datu-baseak glosategiko termino gehien jasotzen dituena dela (% 64,6), TZOSen terminoen erdia ageri direla (% 50,4) eta Elhuyarren ZT Hiztegi Entziklopedikoan, aldiz, erdia baino gutxiago (% 45,7) ageri direla. Azkenik, egindako glosategian bildutako terminologiaren azterketa linguistikoa egin da, irakasgai honetan erabiltzen den terminologiaren profila irudikatzeko helburuaz

El relieve, factor para la génesis, desarrollo y gestión del riesgo

Se expone la importancia que tiene el relieve como variable de origen, desarrollo y gestión del riesgo. Asimismo, se presenta la síntesis de algunos desastres ocurridos en el mundo y en México y se señala la vinculación que poseen con el relieve. A su vez, se expone una matriz que involucra las relaciones teóricas entre la exposición física a un desastre y la vulnerabilidad. Al respecto, se discute acerca del sistema de correlación formado por la naturaleza y la sociedad en un vínculo de evolución y dinámica y la relación entre variables que se asocian con el desarrollo y cambio de los geosistemas perturbadores y los de enlace. Finalmente, se ofrece un esbozo idealizado referente a la gestión del riesgo y a sus componentes principales

Prensa y revolución. El proceso revolucionario cubano a través de las publicaciones periódicas de España y Cuba (1959-1961)

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Filosofía y Letras, Departamento de Historia Contemporánea .Fecha de lectura:17-02-2017Esta tesis tiene embargado el acceso al texto completo hasta el 17-08-2018Esta tesis doctoral expone el proceso de trasformación de la Cuba revolucionaria desde la entrada de Fidel Castro en La Habana en enero de 1959 hasta la proclamación del carácter socialista de la revolución a mediados de abril de 1961 y lo hace a través de una selección de publicaciones periódicas de España y Cuba editadas durante el período analizado. Con este objetivo en cartera, esta tesis se centra en tres aspectos fundamentales: en el análisis de la paulatina y progresiva decantación ideológica del socialismo cubano de impronta fidelista; en el modo en que esta transformación fue contada en aquel momento, y en las razones del cambio orquestado: del cambio del propio proceso en su desarrollo, del cambio del relato o los relatos durante el proceso y de los procesos de cambio acaecidos en una revolución que llegó bajo la bandera nacionalista y humanista y que devino socialista sin perder sus atributos de origen. En definitiva, se centra en las causas por las que la Cuba revolucionaria asumió el socialismo; en el por qué lo hizo; en el cómo lo hizo, y en el modo en el que se explicó este proceso a los cubanos y a los españoles. Así pues, este trabajo está volcado en los relatos de la revolución, en cómo fue contada aquella revolución a los que la protagonizaron desde la proximidad y la implicación absoluta y a los que la contemplaron desde la distancia, las reservas o los afectos. Se acomete un análisis de las lecturas de la revolución desde la lógica del cambio revolucionario y desde la recuperación del cambiante panorama que acompañó al proceso; un análisis que se realiza desde las publicaciones periódicas, pues son ellas las que nos hablan de la imagen de la revolución en cada momento y son ellas también las que nos ofrecen la visión que se difunde a escala social de un proyecto revolucionario que afectó no solamente a Cuba, sino también a todo el ámbito iberoamericano. Lo que aquí se muestra es un estudio de la revolución que coloca en el centro del debate al sujeto real, al protagonista del cambio, a sus razones, y a las visiones que sobre él lanzaron sus contemporáneos. En este trabajo se apuesta por el sujeto real frente al sujeto político del que nos habla la teoría, se apuesta por el relato del cubano y sobre el cubano que encabeza la revolución, pues sólo así se puede entender la naturaleza del cambio y sólo así se pueden comprender las contradicciones habidas durante este proceso y los mecanismos que se orquestaron paraThis doctoral thesis exposes the transformation process of revolutionary Cuba from the entrance of Fidel Castro in Havana in January 1959 to the proclamation of the socialist character of the revolution in mid-April 1961 and does so through a selection of publications, newspapers and magazines, from Spain and Cuba published during the period analyzed. With this aim in mind, this thesis focuses on three fundamental aspects. The first one is the analysis of the gradual and progressive ideological decantation of Cuban socialism from its “fidelista” dimension. The second focuses on the way in which this transformation was narrated at that time. And the third is centered on the reasons for this orchestrated change: the change of the process itself in its development, the change of the story or the stories during the processand the processes of change that occurred in a revolution that came under the nationalist and humanist banner and became socialist without losing its attributes of origin. In short, it focuses on the causes for which revolutionary Cuba assumed socialism, on why it did it, on how it did it, and in the way that this process was explained to Cubans and Spaniards. Thus, this work focuses on the revolution readings, on how the revolution was explained to those who played a role from the proximity and absolute involvement and those who followed the revolution from distance, reservations or affections. An analysis of the readings of the revolution that is undertaken from the logic of revolutionary change and from the recovery of the changing panorama that accompanied the process. An analysis that is built from the newspapers and magazines because these publications are the ones who tell us about the image of the revolution at every moment and these publications also offer us the vision that is spread on a social scale of a revolutionary project that not only affected Cuba, but also to the entire Ibero-American sphere. What is shown here is a study of the revolution that places the real subject at the center of the debate, the protagonist of change is the focus, its reasons, and the visions that his contemporaries casted about him. This work takes as reference the real subject instead of the political subject reflected in the political theory. This work bets on the history of the Cuban and about the Cuban who leads the revolution, because only then we can understand the nature of the change and only then we can understand the contradictions that have occurred during this process and the mechanisms that were orchestrated to solve them

Development of Nano-Emulsions of Essential Citrus Oil Stabilized with Mesquite Gum

The use of nano-emulsions has great advantages over conventional macro-emulsions since the small droplet size allows to expand the options of applications besides presenting a greater surface area. This chapter focuses on the formulation of nano-emulsions of citrus essential oils in water, stabilized with a natural gum (mesquite gum), using a high pressure microfluidic homogenizer to obtain appropriate physicochemical characteristics and kinetic stability. When establishing the general conditions of the methods for obtaining nano-emulsions by high pressure homogenization, several formulations presented stability and size corresponding to nano-emulsions, and these were monitored during 4 months in order to study their stability as a function of time. Taking into account the results of size and stability, the best nano-emulsion obtained had a composition of Persian lemon oil (9.86%), mesquite gum (4.93%) Tween 80 (4.89%), Span 20 (1.45%), and deionized water (78.86%) with an average droplet size of 40 nm. In addition, the antibacterial activity studies also showed that this formulation had the best performance against common bacteria such as Staphylococcus aureus and Escherichia coli. The analysis of the minimum inhibitory concentration (MIC) shows that it is possible to prevent the growth of these particular bacteria using 6.25% of the best nano-emulsion formulations