Colicin S8 export: extracellular and cytoplasmic colicin are different

The properties of colicin S8 are different for the cytoplasmic, periplasmic and extracellular protein. Interactions with its specific receptors reflect this. Active cell extracts separate into a non-anionic along with an anionic fraction by DEAE-Sephacell chromatography. Previously, we have purified cell-associated colicin S8 as an aggregation of highly related polypeptides; cytoplasmic colicin S8 seems to be post-translationally processed into an aggregation of polypeptides of molecular mass ranging from 45,000 Da to 60,000 Da. We suggest that a conformational change to colicin S8 may occur related to the export process

Determinants demogràfics i actitudinals dels comportaments davant de la pràctica d’activitat fisicoesportiva de temps lliure a la ciutat de l’Havana (Cuba). Identificació del perfil poblacional mitjançant les xarxes de Bayes

Aquest estudi s’ha centrat a conèixer els comportaments de pràctica fisicoesportiva dels pobladors de l’Havana més grans de 15 anys, tot analitzant les relacions i les associacions probabilístiques que poden produir-se amb les variables sociodemogràfiques (sexe, edat, nivell d’estudis i ocupació principal) i les actitudinals (interès per la pràctica, valoració de l’educació física rebuda i actitud dels pares davant d’aquesta pràctica en temps lliure). La investigació s’ha desenvolupat a través d’entrevistes personals mitjançant un qüestionari estandarditzat a una mostra de 1.144 subjectes; hom ha utilitzat el procediment de mostreig estratificat polietàpic amb afixació proporcional, amb un marge d’error mostral del ± 3 % i un nivell de confiança del 95,5 %. Els resultats han posat de manifest, d’una banda, l’increment de pràctica entre els ciutadans de l’Havana; sobre els comportaments de pràctica són determinants, tant les variables sociodemogràfiques com les actitudinals tingudes en compte i, d’altra banda, de la xarxa de Bayes es desprèn la incidència directa de les classes d’Educació Física rebuda sobre els comportaments de pràctica i l’interès cap a aquesta

Imaging the cell-morphological response to 3D topography and curvature in engineered intestinal tissues

While conventional cell culture methodologies have relied on flat, two-dimensional cell monolayers, three-dimensional engineered tissues are becoming increasingly popular. Often, engineered tissues can mimic the complex architecture of native tissues, leading to advancements in reproducing physiological functional properties. In particular, engineered intestinal tissues often use hydrogels to mimic villi structures. These finger-like protrusions of a few hundred microns in height have a well-defined topography and curvature. Here, we examined the cell morphological response to these villus-like microstructures at single-cell resolution using a novel embedding method that allows for the histological processing of these delicate hydrogel structures. We demonstrated that by using photopolymerisable poly(ethylene) glycol as an embedding medium, the villus-like microstructures were successfully preserved after sectioning with vibratome or cryotome. Moreover, high-resolution imaging of these sections revealed that cell morphology, nuclei orientation, and the expression of epithelial polarization markers were spatially encoded along the vertical axis of the villus-like microstructures and that this cell morphological response was dramatically affected by the substrate curvature. These findings, which are in good agreement with the data reported for in vivo experiments on the native tissue, are likely to be the origin of more physiologically relevant barrier properties of engineered intestinal tissues when compared with standard monolayer cultures. By showcasing this example, we anticipate that the novel histological embedding procedure will have a positive impact on the study of epithelial cell behavior on three-dimensional substrates in both physiological and pathological situations

REMAR: REd Mercosur para la accesibilidad y la generación colaborativa de recursos educativos abiertos

REMAR es una iniciativa para la formación y consolidación de una red de docentes de Mercosur interesados en el desarrollo colaborativo de recursos educativos abiertos y accesibles. La principal contribución de este artículo es difundir los objetivos de REMAR y presentar los aspectos tecnológicos que se pretende explorar en la conformación de la red de docentes. El principal objetivo de la red consiste en desarrollar un espacio virtual de comunicación donde los docentes de la región interesados en el tema de formación inclusiva - en todos los aspectos que este tema implicapuedan compartir experiencias y disponer de herramientas que faciliten el uso de contenidos educativos abiertos y accesibles; dando preponderancia al papel de la universidad como ente socialmente responsable. Además, el proyecto propone reutilizar y compartir los numerosos recursos que existen y que se incorporarán a la red de tal forma que el conocimiento sea abierto y compartido, en beneficio de muchos. Para ellos se usarán repositorios de recursos educativos que sean abiertos y fomenten la colaboración.\nParticularmente se trabajarán con aplicaciones wikis que favorezcan no solo la edición colaborativa de los recursos sino también la edición de los metadatos de accesibilidad. Los metadatos de accesibilidad son necesarios para las búsquedas contextualizadas.Eje: Tecnología en Educació

Mimicking epithelial tissues in three-dimensional cell culture models

Epithelial tissues are composed of layers of tightly connected cells shaped into complex three-dimensional (3D) structures such as cysts, tubules, or invaginations. These complex 3D structures are important for organ-specific functions and often create biochemical gradients that guide cell positioning and compartmentalization within the organ. One of the main functions of epithelia is to act as physical barriers that protect the underlying tissues from external insults. In vitro, epithelial barriers are usually mimicked by oversimplified models based on cell lines grown as monolayers on flat surfaces. While useful to answer certain questions, these models cannot fully capture the in vivo organ physiology and often yield poor predictions. In order to progress further in basic and translational research, disease modeling, drug discovery, and regenerative medicine, it is essential to advance the development of new in vitro predictive models of epithelial tissues that are capable of representing the in vivo-like structures and organ functionality more accurately. Here, we review current strategies for obtaining biomimetic systems in the form of advanced in vitro models that allow for more reliable and safer preclinical tests. The current state of the art and potential applications of self-organized cell-based systems, organ-on-a-chip devices that incorporate sensors and monitoring capabilities,as well as microfabrication techniques including bioprinting and photolithography, are discussed. These techniques could be combined to help provide highly predictive drug tests for patient-specific conditions in the near future

Depression as an imprecise and heterogeneous mental disorder: Consequences for clinical practice

Los trastornos depresivos constituyen un grupo enormemente heterogéneo de cuadros clínicos, cuya severidad se distribuye en un continuum que abarca, desde cuadros de dudosa o inconsistente significación clínica y próximos a las reacciones emocionales no patológicas, hasta cuadros severos con gran afectación funcional y riesgo vital. El episodio depresivo y la depresión mayor son categorías heterogéneas e imprecisas y el término depresión, aunque ampliamente utilizado en medios profesionales y extra profesionales, es todavía más ambiguo. Se subrayan algunas características clínicas que diferencian los trastornos depresivos con significación clínica del resto. Frente a la heterogeneidad clínica de los trastornos depresivos existe una llamativa uniformidad en el abordaje terapéutico, basado en la administración indiscriminada de fármacos antidepresivos para cualquier cuadro del amplio espectro de trastornos depresivos. Sería necesario desarrollar protocolos de actuación, con abordajes específicos, biológicos, psicoterapéuticos y psicosociales en función de los datos de eficacia de cada tipo de abordaje y de cada paciente específico, restringiendo los tratamientos farmacológicos a los cuadros en que han mostrado eficaciaDepressive disorders constitute a very heterogeneous group of clinical syndromes which includes from depressive syndromes of doubtful clinical significance to very severe and disabled disorders of high risk for life. The depressive episode and major depression categories, according to diagnostic criteria, are also very heterogeneous and vague entities. The “depression” term, widely used in scientific literature, is excessively ambiguous. In spite of this clinical heterogeneity, there is a striking uniformity in therapeutic management of depressive syndromes, based excessively in antidepressant drugs. Development of practice guidelines including not only biological but psychotherapeutic and psychosocial techniques is needed. Pharmacologic treatments should be restricted to more severe depressive episode

Radiative forcing under mixed aerosol conditions

The mixture of mineral dust with biomass burning or urban-industrial aerosols presents significant differences in optical properties when compared to those of the individual constituents, leading to different impacts on solar radiation levels. This effect is assessed by estimating the direct radiative forcing (ΔF) of these aerosols from solar flux models using the radiative parameters derived from the Aerosol Robotic Network (AERONET). These data reveal that, in oceanic and vegetative covers (surface albedo (SA) 0.30 are not present in East Asia region. At the bottom of atmosphere (BOA) the maximum ΔF values are associated with the highest AOD levels obtained for the mixture of mineral dust and biomass burning aerosols (−130 ± 44 Wm−2 with AOD = 0.8 ± 0.4 for SA < 0.30).Support for this study was given by Spanish Ministry of Education and Science, projects CGL2005‐03428‐C04‐02, CGL2007‐66477‐C02‐02/CLI, PI042005/033, and CGL2008‐04740/CLI

Editorial: When the Shape Does Matter: Three-Dimensional In Vitro Models of Epithelial Barriers

The Research Topic presented here includes a collection of selected pre-reviewed manuscripts that describe relevant recent advances in the fields of bioengineering and biophysics with a focus on the generation and analysis of novel three-dimensional (3D) in vitro models of epithelial barriers

Social Network Analysis and Resilience in University Students: An Approach from Cohesiveness

13 p.The Social Network Analysis offers a view of social phenomena based on interactions. The aim of this study is to compare social reality through the cohesion variable and analyse its relationship with the resilience of university students. This information is useful to work with the students academically and to optimise the properties of the network that have an influence in academic performance. This is a descriptive transversal study with 90 students from the first and third year of the Nursing Degree. Cohesion variables from the support and friendship networks and the level of resilience were gathered. The UCINET programme was used for network analysis and the SPSS programme for statistical analysis. The students’ friendship and support networks show high intra-classroom cohesion although there are no differences between the support networks and friendship or minimal contact networks in both of the courses used for the study. The network cohesion indicators show less cohesion in the third year. No correlations were found between cohesion and resilience. Resilience does not appear to be an attribute related to cohesion or vice versa.S

Social Networks, Engagement and Resilience in University Students

16 p.Analysis of social networks may be a useful tool for understanding the relationship between resilience and engagement, and this could be applied to educational methodologies, not only to improve academic performance, but also to create emotionally sustainable networks. This descriptive study was carried out on 134 university students. We collected the network structural variables, degree of resilience (CD-RISC 10), and engagement (UWES-S). The computer programs used were excel, UCINET for network analysis, and SPSS for statistical analysis. The analysis revealed results of means of 28.61 for resilience, 2.98 for absorption, 4.82 for dedication, and 3.13 for vigour. The students had two preferred places for sharing information: the classroom and WhatsApp. The greater the value for engagement, the greater the degree of centrality in the friendship network among students who are beginning their university studies. This relationship becomes reversed as the students move to later academic years. In terms of resilience, the highest values correspond to greater centrality in the friendship networks. The variables of engagement and resilience influenced the university students’ support networks.S