Characterization of an in vitro fed-batch model to obtain cells released from S. epidermidis biofilms

Both dynamic and fed-batch systems have been used for the study of biofilms. Dynamic systems, whose hallmark is the presence of continuous flow, have been considered the most appropriate for the study of the last stage of the biofilm lifecycle: biofilm disassembly. However, fed-batch is still the most used system in the biofilm research field. Hence, we have used a fed-batch system to collect cells released from Staphylococcus epidermidis biofilms, one of the most important etiological agents of medical device-associated biofilm infections. Herein, we showed that using this model it was possible to collect cells released from biofilms formed by 12 different S. epidermidis clinical and commensal isolates. In addition, our data indicated that biofilm disassembly occurred by both passive and active mechanisms, although the last occurred to a lesser extent. Moreover, it was observed that S. epidermidis biofilm-released cells presented higher tolerance to vancomycin and tetracycline, as well as a particular gene expression phenotype when compared with either biofilm or planktonic cells. Using this model, biofilm-released cells phenotype and their interaction with the host immune system could be studied in more detail, which could help providing significant insights into the pathophysiology of biofilm-related infections.

Por detrás das câmaras: o "directo" e o "gravado"

Dissertação de mestrado em Ciências da Comunicação (área de especialização em Audiovisual e Multimédia)

The Need for Pedagogical Qualifications for Teaching Cardiology to Undergraduate Students

OBJECTIVE: To report a training program in cardiology emphasizing changes in its pedagogical practice. These changes were put into practice by some teachers at the Medical School of Porto Alegre of the University of Rio Grande do Sul (FAMED/UFRGS) aiming to make faculty and student activities more dynamic and to promote more efficacious learning. The training program is directed at 5th semester medical students and aims at a behavioral change in teachers and students to promote more interaction, to favor exchanges, and to make the teaching-learning process easier, always maintaining the patient in the center of the medical activity. METHODS: The program emphasizes the definition of general and specific objectives for each activity to be developed by the students, with training in the area of admission to the cardiology service, with special emphasis on behavioral change in the cognitive, motor, affective, and attitudinal areas. Knowledge was developed by means of interactive seminars with initial and final assessment tests to identify students' and teachers' performance. The students were evaluated in an immediate, continuous, and progressive way in their daily activities and through comparison of the results of 2 tests, one applied at the beginning of the training and the other at its end. These 2 tests contained the same questions. RESULTS: We systematically assessed 560 students over 4 years. The mean grades of the tests performed prior to and after the 244 seminars were 7.38±1.66 and 9.17± 0.82, respectively (p<0.0001). For the tests applied at the beginning and at the end of the training, the mean grades were 5.61±1.61 and 9.37±0.90, respectively (p<0.0001). CONCLUSION: The program proved to be efficient both for the students' learning and for assessing their performance in a systematic and objective way.

Enzymatic hydrophobic modification of jute fibers via grafting to reinforce composites

Horseradish peroxidase (HRP)/H2O2 system catalyzes the free-radical polymerization of aromatic compounds such as lignins and gallate esters. In this work, dodecyl gallate (DG) was grafted onto the surfaces of lignin-rich jute fabrics by HRP-mediated oxidative polymerization with an aim to enhance the hydrophobicity of the fibers. The DG-grafted jute fibers and reaction products of their model compounds were characterized by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The results clearly indicated the grafting of DG to the jute fiber by HRP. Furthermore, the hydrophobicity of jute fabrics was determined by measuring the wetting time and static contact angle. Compared to the control sample, the wetting time and static contact angle of the grated fabrics changed from ~1 s to 1 h and from ~0° to 123.68°, respectively. This clearly proved that the hydrophobicity of jute fabrics improved considerably. Conditions of the HRP-catalyzed DG-grafting reactions were optimized in terms of the DG content of modified jute fabrics. Moreover, the results of breaking strength and elongation of DG-grafted jute/ polypropylene (PP) composites demonstrated improved reinforcement of the composite due to enzymatic hydrophobic modification of jute fibers.

Modularity of auditory spatial representations

Abstract : Auditory spatial functions are of crucial importance in everyday life. Determining the origin of sound sources in space plays a key role in a variety of tasks including orientation of attention, disentangling of complex acoustic patterns reaching our ears in noisy environments. Following brain damage, auditory spatial processing can be disrupted, resulting in severe handicaps. Complaints of patients with sound localization deficits include the inability to locate their crying child or being over-loaded by sounds in crowded public places. Yet, the brain bears a large capacity for reorganization following damage and/or learning. This phenomenon is referred as plasticity and is believed to underlie post-lesional functional recovery as well as learning-induced improvement. The aim of this thesis was to investigate the organization and plasticity of different aspects of auditory spatial functions. Overall, we report the outcomes of three studies: In the study entitled "Learning-induced plasticity in auditory spatial representations" (Spierer et al., 2007b), we focused on the neurophysiological and behavioral changes induced by auditory spatial training in healthy subjects. We found that relatively brief auditory spatial discrimination training improves performance and modifies the cortical representation of the trained sound locations, suggesting that cortical auditory representations of space are dynamic and subject to rapid reorganization. In the same study, we tested the generalization and persistence of training effects over time, as these are two determining factors in the development of neurorehabilitative intervention. In "The path to success in auditory spatial discrimination" (Spierer et al., 2007c), we investigated the neurophysiological correlates of successful spatial discrimination and contribute to the modeling of the anatomo-functional organization of auditory spatial processing in healthy subjects. We showed that discrimination accuracy depends on superior temporal plane (STP) activity in response to the first sound of a pair of stimuli. Our data support a model wherein refinement of spatial representations occurs within the STP and that interactions with parietal structures allow for transformations into coordinate frames that are required for higher-order computations including absolute localization of sound sources. In "Extinction of auditory stimuli in hemineglect: space versus ear" (Spierer et al., 2007a), we investigated auditory attentional deficits in brain-damaged patients. This work provides insight into the auditory neglect syndrome and its relation with neglect symptoms within the visual modality. Apart from contributing to a basic understanding of the cortical mechanisms underlying auditory spatial functions, the outcomes of the studies also contribute to develop neurorehabilitation strategies, which are currently being tested in clinical populations.

Functional sphere profiling reveals the complexity of neuroblastoma tumor-initiating cell model.

Neuroblastoma (NB) is a neural crest-derived childhood tumor characterized by a remarkable phenotypic diversity, ranging from spontaneous regression to fatal metastatic disease. Although the cancer stem cell (CSC) model provides a trail to characterize the cells responsible for tumor onset, the NB tumor-initiating cell (TIC) has not been identified. In this study, the relevance of the CSC model in NB was investigated by taking advantage of typical functional stem cell characteristics. A predictive association was established between self-renewal, as assessed by serial sphere formation, and clinical aggressiveness in primary tumors. Moreover, cell subsets gradually selected during serial sphere culture harbored increased in vivo tumorigenicity, only highlighted in an orthotopic microenvironment. A microarray time course analysis of serial spheres passages from metastatic cells allowed us to specifically "profile" the NB stem cell-like phenotype and to identify CD133, ABC transporter, and WNT and NOTCH genes as spheres markers. On the basis of combined sphere markers expression, at least two distinct tumorigenic cell subpopulations were identified, also shown to preexist in primary NB. However, sphere markers-mediated cell sorting of parental tumor failed to recapitulate the TIC phenotype in the orthotopic model, highlighting the complexity of the CSC model. Our data support the NB stem-like cells as a dynamic and heterogeneous cell population strongly dependent on microenvironmental signals and add novel candidate genes as potential therapeutic targets in the control of high-risk NB.

Desarrollo y aplicación de estrategias de control avanzado en procesos biológicos de tratamiento de efluentes contaminados

En este proyecto se ha desarrollado estrategias de control avanzadas para plantas de depuración de aguas residuales urbanas que eliminan conjuntamente materia orgánica, nitrógeno y fósforo. Las estrategias se han basado en el estudio multivariable del comportamiento del sistema, que ha producido subsidios para la utilización de lazos de control feedforward, de control predictivo y de un control de costes que automáticamente enviaba las consignas más adecuadas para los controladores de proceso. Para el desarrollo de las estrategias, se ha creado un sistema virtual de simulación (simulador) de plantas de depuradoras, basado en datos de literatura. Para el caso de una planta real, se ha desarrollado un simulador de la planta de Manresa (Catalunya). Sin embargo, el sistema de Manresa se ha utilizado exclusivamente para auxiliar los ingenieros de la planta en la tomada de decisiones de cambio de configuración para que la eliminación de fósforo se dé por la ruta biológica y no por la ruta química. La implementación de los simuladores ha permitido hacer muchas pruebas que en una planta real demandarían mucho tiempo y consumirían muchos recursos energéticos y financieros. Las estrategias de control más elaboradas han podido ahorrar hasta 150.000,00 Euros por año en relación a la operación de la planta sin el control automático. Cuanto a los estudios del modelo de la planta real, se concluyó que la eliminación biológica de fósforo puede sustituir el actual proceso químico de eliminación de fósforo, bajando los costes operacionales (costes del agente precipitante).

Epidemiological risk sratification of malaria in the Américas

During the last years, malaria had a significant increase in Latin America, emerging again as one critical health problem in the Region of the Americas. More than 1.04 million new cases were reported in 1990. This resurgence of malaria needed a comprehensive strategy for its prevention and control. National malaria control programs recognized the epidemiological stratification of malaria as a valuable method to assist them in the recognition of local variations and factors that specifically contribute to the level and intensity of transmission in critical malarious areas. Also it serves as a useful instrument for the selection of needed malaria prevention and control activities. The principal feature of this approach is to provide a dynamic and ongoing process for assessing in the epidemiological importance of different risk factors (socio-economic, ecological, organizatuion of health services) in malaria transmission. health interventions are based on this assesment and are aimed directly at the reduction or elimination of the identified risk factors operating at the local level. Intersectorial co-participation and the integration of malaria programs in local health services are also important aspects of this public health approach.

Simulación de departamentos de urgencias empleando un modelo basado en agentes

Los servicios de salud son sistemas muy complejos, pero de alta importancia, especialmente en algunos momentos críticos, en todo el mundo. Los departamentos de urgencias pueden ser una de las áreas más dinámicas y cambiables de todos los servicios de salud y a la vez más vulnerables a dichos cambios. La mejora de esos departamentos se puede considerar uno de los grandes retos que tiene cualquier administrador de un hospital, y la simulación provee una manera de examinar este sistema tan complejo sin poner en peligro los pacientes que son atendidos. El objetivo de este trabajo ha sido el modelado de un departamento de urgencias y el desarrollo de un simulador que implementa este modelo con la finalidad de explorar el comportamiento y las características de dicho servicio de urgencias. El uso del simulador ofrece la posibilidad de visualizar el comportamiento del modelo con diferentes parámetros y servirá como núcleo de un sistema de ayuda a la toma de decisiones que pueda ser usado en departamentos de urgencias. El modelo se ha desarrollado con técnicas de modelado basado en agentes (ABM) que permiten crear modelos funcionalmente más próximos a la realidad que los modelos de colas o de dinámicas de sistemas, al permitir la inclusión de la singularidad que implica el modelado a nivel de las personas. Los agentes del modelo presentado, descritos internamente como máquinas de estados, representan a todo el personal del departamento de urgencias y los pacientes que usan este servicio. Un análisis del modelo a través de su implementación en el simulador muestra que el sistema se comporta de manera semejante a un departamento de urgencias real.

Banc electrònic d'objectes i recursos d'aprenentatge dels estudis de comunicació audiovisual

OdACAV és un banc electrònic d’objectes d’aprenentatge (OdA) que te com a finalitat principal servir als docents de les assignatures troncals dels Estudis de Comunicació Audiovisual (CAV) de la UB (obert també a altres universitats catalanes) implicats o que es vulguin implicar en la innovació docent i pretén facilitar i potenciar la documentació per a la investigació i la recerca a l’entorn del paper innovador dels OdA digitals; així com la patrimonialització dels mateixos. Què és i que no és un OdA de CAV? És tot allò que serveix en un procés d'ensinistrament, d'aprenentatge, de formació - que en els cas que ens ocupa, es tradueix en una col·lecció d'imatges fixes, en un hipertext, en una hipermèdia, un vídeo, etc.-, i la missió dels quals és suscitar l’interès i l'aprofitament en el transvasament dels continguts de les assignatures dels estudis actuals (de la Llicenciatura) i futurs (del Grau) de Comunicació Audiovisual. El projecte sorgeix com a necessitat orgànica de la mateixa naturalesa de l'ensenyament de Comunicació Audiovisual, on en el pla dels continguts els exemples, els referents, els models no són encara prou desenvolupats i costa molt disposar d'OdAs suficientment competents. Les fonts documentals del cinema, de la televisió i dels mitjans en general són la base sobre la que s’han bastit els OdA de la base de dades del web http://www.lmi.ub.es/repositori/ amb l’esperança que resultin adequats a la innovació en els Estudis de Comunicació Audiovisual. És, doncs, un repositori de condició cooperativa, dinàmic i flexible; amb esperit blog/wiki, els objectius del qual són: la creació d'un sistema de dipositació dels OdA; l'establiment d'un sistema de recuperació dels mateixos; la implantació de fluxos d'entrada i sortida; la consolidació d'un observatori d'investigació i de recerca sobre la innovació dels OdA en els entorns i els sistemes educatius actuals; l’articulació de possibles accions patrimonials al voltant de la creació i preservació d’aquests.

Indirect likelihood inference

Given a sample from a fully specified parametric model, let Zn be a given finite-dimensional statistic - for example, an initial estimator or a set of sample moments. We propose to (re-)estimate the parameters of the model by maximizing the likelihood of Zn. We call this the maximum indirect likelihood (MIL) estimator. We also propose a computationally tractable Bayesian version of the estimator which we refer to as a Bayesian Indirect Likelihood (BIL) estimator. In most cases, the density of the statistic will be of unknown form, and we develop simulated versions of the MIL and BIL estimators. We show that the indirect likelihood estimators are consistent and asymptotically normally distributed, with the same asymptotic variance as that of the corresponding efficient two-step GMM estimator based on the same statistic. However, our likelihood-based estimators, by taking into account the full finite-sample distribution of the statistic, are higher order efficient relative to GMM-type estimators. Furthermore, in many cases they enjoy a bias reduction property similar to that of the indirect inference estimator. Monte Carlo results for a number of applications including dynamic and nonlinear panel data models, a structural auction model and two DSGE models show that the proposed estimators indeed have attractive finite sample properties.

Apport de la systématique dans l'amélioration de la compréhension des systèmes de prise en compte des risques en entreprise

La gestion des risques est souvent appréhendée par l'utilisation de méthodes linéaires mettant l'accent sur des raisonnements de positionnement et de type causal : à tel événement correspond tel risque et telle conséquence. Une prise en compte des interrelations entre risques est souvent occultée et les risques sont rarement analysés dans leurs dynamiques et composantes non linéaires. Ce travail présente ce que les méthodes systémiques et notamment l'étude des systèmes complexes sont susceptibles d'apporter en matière de compréhension, de management et d'anticipation et de gestion des risques d'entreprise, tant sur le plan conceptuel que de matière appliquée. En partant des définitions relatives aux notions de systèmes et de risques dans différents domaines, ainsi que des méthodes qui sont utilisées pour maîtriser les risques, ce travail confronte cet ensemble à ce qu'apportent les approches d'analyse systémique et de modélisation des systèmes complexes. En mettant en évidence les effets parfois réducteurs des méthodes de prise en compte des risques en entreprise ainsi que les limitations des univers de risques dues, notamment, à des définitions mal adaptées, ce travail propose également, pour la Direction d'entreprise, une palette des outils et approches différentes, qui tiennent mieux compte de la complexité, pour gérer les risques, pour aligner stratégie et management des risques, ainsi que des méthodes d'analyse du niveau de maturité de l'entreprise en matière de gestion des risques. - Risk management is often assessed through linear methods which stress positioning and causal logical frameworks: to such events correspond such consequences and such risks accordingly. Consideration of the interrelationships between risks is often overlooked and risks are rarely analyzed in their dynamic and nonlinear components. This work shows what systemic methods, including the study of complex systems, are likely to bring to knowledge, management, anticipation of business risks, both on the conceptual and the practical sides. Based on the definitions of systems and risks in various areas, as well as methods used to manage risk, this work confronts these concepts with approaches of complex systems analysis and modeling. This work highlights the reducing effects of some business risk analysis methods as well as limitations of risk universes caused in particular by unsuitable definitions. As a result this work also provides chief officers with a range of different tools and approaches which allows them a better understanding of complexity and as such a gain in efficiency in their risk management practices. It results in a better fit between strategy and risk management. Ultimately the firm gains in its maturity of risk management.

Youth of the Eighties, Parents of 2000, Sociological Observations

(Résumé de l'ouvrage) This book is meant to honour the Belgian religious educationalist Herman Lombaerts reflecting on his legacy. He is internationally renowned as a scholar with a strong commitment to and a conceptual analysis of the social and cultural context in which people live and learn. This series of essays is build upon a thought provoking, streamlined design on the relationship between theology and education, relying on Lombaerts' societal and cultural analysis of contemporary religious education. Three key elements are at stake: the self-agency of the learner, the hermeneutic and communitive interpretation of religious traditions in the teaching of religion, and the radical re-imagination of Christian theology relying on this new model of religious educational praxis. For Lombaerts, the search processes of religious people have their own dynamic and dignity. Practical theology should listen carefully and empathetically to this quest. But he is also convinced of the need of solid fundamental research to understand critically its ambiguities and perspectives. Scholars from Europe, the United States and Australia lead the way in this process of "conceptual stretching". Issues such as happiness of children, identity formation of youth, educational and religious insecurity of parents, multi-faith education, tradition crisis of churches, theological education of lay ministers, narrativity and modern art in religious education, etc. are examined from a practical theological point of view, with a strong commitment to the philosophical, psychological, sociological, educational and political dimensions of three issues. With this book the editors hope to commemorate Lombaerts' international radiation, by building a collegial bridge between the different theoretical approaches in the German, Dutch, French, Italian and Anglo-Saxon religious educational research.

Vestidors nus

Vestidors nus presenta una descripció etnogràfica centrada en el vestidor femení d'una piscina pública. Les línies teòriques d'estudi parteixen de l'espai físic i la seva relació amb el comportament humà, tenint en compte les qualitats biològiques, culturals, socials i de gènere.

Le théologien, 'intellectuel organique' et chercheur indépendant : quelle loyauté, quelles tensions, quelle liberté ?

L'auteur s'interroge sur la catégorie d'intellectuel organique, que le philosophe marxiste Antonio Gramsci avait appliquée à l'Église catholique. Une relecture de ce concept conduit à développer un portrait critique du théologien comme penseur ecclésial, universitaire et public (à la suite de David Tracy). Cette triple appartenance du théologien, bien comprise, n'est pas contraire à sa liberté de parole et d'action, liberté qui découle de l'Évangile et qui peut s'affirmer dans le contexte d'une modernité revisitée. La tradition protestante offre une vision dynamique et réaliste de cette liberté du théologien, comprise comme loyauté critique, sans rien nier des tensions et des contraintes qui sont les siennes. The author examines the category of organic intellectual, applied by the Marxist philosopher Antonio Gramsci to the Catholic Church. A new interpretation of this category allows to develop a critical portrait of the theologian as ecclesial, academic and public thinker (following David Tracy). The well-interpreted dependence of the theologian towards church, university and society is not contradictory to his freedom of speech and action. This freedom is a consequence of the Gospel and has a good impact in the context of a revisited modernity. The protestant tradition offers a dynamic and realistic vision of such a freedom of the theologian, understood as critical loyalty, without denying the tensions and the constraints inherent to his or her situation.