Translocating the blood-brain barrier using electrostatics

Copyright © 2012 Ribeiro,Domingues, Freire,Santos and Castanho. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and subject to any copyright notices concerning any third-party graphics etc.Mammalian cell membranes regulate homeostasis, protein activity, and cell signaling. The charge at the membrane surface has been correlated with these key events. Although mammalian cells are known to be slightly anionic, quantitative information on the membrane charge and the importance of electrostatic interactions in pharmacokinetics and pharmacodynamics remain elusive. Recently, we reported for the first time that brain endothelial cells (EC) are more negatively charged than human umbilical cord cells, using zeta-potential measurements by dynamic light scattering. Here, we hypothesize that anionicity is a key feature of the blood-brain barrier (BBB) and contributes to select which compounds cross into the brain. For the sake of comparison, we also studied the membrane surface charge of blood components—red blood cells (RBC), platelets, and peripheral blood mononuclear cells (PBMC).To further quantitatively correlate the negative zeta-potential values with membrane charge density, model membranes with different percentages of anionic lipids were also evaluated. From all the cells tested, brain cell membranes are the most anionic and those having their lipids mostly exposed, which explains why lipophilic cationic compounds are more prone to cross the blood-brain barrier.Fundação para a Ciência e Tecnologia — Ministério da Educação e Ciência (FCT-MEC, Portugal) is acknowledged for funding (including fellowships SFRH/BD/42158/2007 to Marta M.B. Ribeiro, SFRH/BD/41750/2007 to Marco M. Domingues and SFRH/BD/70423/2010 to João M. Freire) and project PTDC/QUI-BIQ/119509/2010. Marie Curie Industry-Academia Partnerships and Pathways (European Commission) is also acknowledged for funding (FP7-PEOPLE-2007-3-1-IAPP, Project 230654)

Patterns of Social Activity Engagement Among Older Hispanics and Their Relationship to Sociodemographic and Health Variables

The purpose of this study was to examine patterns of social activity engagement in a sample of older Hispanics (Puerto Rican, Dominican, and other Hispanic) and determine whether these patterns differed significantly from the comparison non-Hispanic White group. This article also analyzes how ethnicity, sociodemographic, and health variables (health problems and depression) relate to each of the activity engagement patterns. The factor analysis of social activities from the Norbeck Social Support Questionnaire yielded three factors, which describe engagement in social activities as: children and relatives active, friends and activities active, and senior services active. The results from the regression analyses show that Hispanic ethnicity and education are positively associated with being more engaged in activities with children and relatives, whereas being male and especially a male living alone is inversely associated with this pattern. In addition, being friends and activities active shows positive association with education, the participant living alone, and experiencing more language inclusion; however, it is inversely associated with depression, age, being male, and number of health problems. Finally, engaging in activities offered by senior services is only significantly associated with increased age and the number of health problems. The interpretations of these findings, directions for future research, and implications for activity professionals/recreation therapists are also discussed

Perubahan Bentuk P Oleh Mikroba Pelarut Fosfat Dan Bahan Organik Terhadap P-tersedia Dan Produksi Kentang (Solanum Tuberosum L.) Pada Tanah Andisol Terdampak Erupsi Gunung Sinabung

Andisol was soil with high phosphate retension (>85 %) so that Phosphate not available to plants. Phosphate (P) was important nutrient that used in photosynthesis process, roots growth, flower, fruit and seed forming. The object of this research is to know the effect of phosphate solubilizing microbe (MPF) application, some organic matter sources and both of interaction to changes of phosphate form to phosphate availability and potatos (Solanum tuberosum L.) production at Andisol soil impacted Sinabung Mountain eruption. This research was conducted in Kuta Rakyat Village, Naman Teran Subdistrict, Karo Regency on February until July 2015. The research used factorial Random Device Group Methode (RDG) consists of two treatments and two replications. The first factor is phosphate solubilizing microbe with four treatments: control, phosphate solubilizing bacterial (30 ml), phosphate solubilizing fungi (30 ml), phosphate solubilizing bacterial and fungi (15 ml + 15 ml). The second factor is organic matter with five treatments: control, cow manure (100 g/plant), chicken manure (100 g/ plant), straw (100 g/ plant), Tithonia diversifolia (100 g/ plant). The result showed that phosphate solubilizing fungi and chicken manure application, increased P availability and productions of potato (Solanum tuberosum L.) plants.Key Words : Andisol, Phosphate solubilizing microbe, organic matter, availability phosphate,production of potatos (Solanum tuberosum L.)Andisol was soil with high phosphate retension (>85 %) so that Phosphate not available to plants. Phosphate (P) was important nutrient that used in photosynthesis process, roots growth, flower, fruit and seed forming. The object of this research is to know the effect of phosphate solubilizing microbe (MPF) application, some organic matter sources and both of interaction to changes of phosphate form to phosphate availability and potatos (Solanum tuberosum L.) production at Andisol soil impacted Sinabung Mountain eruption. This research was conducted in Kuta Rakyat Village, Naman Teran Subdistrict, Karo Regency on February until July 2015. The research used factorial Random Device Group Methode (RDG) consists of two treatments and two replications. The first factor is phosphate solubilizing microbe with four treatments: control, phosphate solubilizing bacterial (30 ml), phosphate solubilizing fungi (30 ml), phosphate solubilizing bacterial and fungi (15 ml + 15 ml). The second factor is organic matter with five treatments: control, cow manure (100 g/plant), chicken manure (100 g/ plant), straw (100 g/ plant), Tithonia diversifolia (100 g/ plant). The result showed that phosphate solubilizing fungi and chicken manure application, increased P availability and productions of potato (Solanum tuberosum L.) plants

Significance analysis and statistical mechanics: an application to clustering

This paper addresses the statistical significance of structures in random data: Given a set of vectors and a measure of mutual similarity, how likely does a subset of these vectors form a cluster with enhanced similarity among its elements? The computation of this cluster p-value for randomly distributed vectors is mapped onto a well-defined problem of statistical mechanics. We solve this problem analytically, establishing a connection between the physics of quenched disorder and multiple testing statistics in clustering and related problems. In an application to gene expression data, we find a remarkable link between the statistical significance of a cluster and the functional relationships between its genes.Comment: to appear in Phys. Rev. Let

Finding non-dominated bicriteria shortest pairs of disjoint simple paths

http://www.sciencedirect.com/science/article/B6VC5-4VBDKNX-1/2/b7e59602a9fb4eb885f498b0d8c779c

Antecedents of the Sharing Economy in a Pandemic Scenario: Prosocial Attitudes, Past Behaviour and Transformation Expectations

The COVID-19 pandemic is expected to have a significant impact on most sharing economy activities, and at present, it is particularly challenging to achieve a consensual model to predict sharing economy behaviour. Based on empirical and theoretical premises established before the pandemic, we intend to explore the association between a set of psychosocial variables (i.e., cooperation, environmental awareness, past behaviour) and sharing economy behaviour, particularly the use of shared assets (i.e., cars and accommodation) during the COVID-19 pandemic. Furthermore, the present study analyses the mediating role of transformation expectations, as the decision to engage or not in sharing behaviour may be influenced by beliefs about the consequences of those actions from the user’s perspective. This study comprised a total of 596 participants. Data was collected through a self-administered questionnaire and was statistically analysed and interpreted using PLS 3.0. Structural Equation Modelling statistical software. Contrary to our predictions, the results show that cooperation negatively influenced the willingness to participate in sharing activities during the COVID-19 pandemic, that environmental awareness was not a significant predictor, and that past sharing behaviour has the strongest influence on the willingness to share during pandemic times. Finally, the mediating effect of transformation expectations was significant in both associations, i.e., pro-environmental consciousness and past sharing experiences, and the willingness to adopt sharing behaviour during COVID-19.Se espera que la pandemia de COVID-19 tenga un impacto importante en la mayoría de las actividades de la economía colaborativa, y en la actualidad, es particularmente difícil lograr un modelo consensual para predecir el comportamiento de la economía colaborativa. Sobre la base de premisas empíricas y teóricas establecidas antes de la pandemia, pretendemos explorar la asociación entre un conjunto de variables psicosociales (es decir, cooperación, consciencia ambiental, comportamiento pasado) y el comportamiento de la economía colaborativa, en particular el uso de activos compartidos (automóviles y alojamiento), durante la pandemia de COVID-19. Además, el presente estudio analiza el papel mediador de las expectativas de transformación, ya que la decisión de participar o no en el comportamiento de compartir puede estar influenciada por creencias sobre las consecuencias de esas acciones desde la perspectiva del usuario. Este estudio comprendió un total de 596 participantes. Los datos se recopilaron a través de un cuestionario autoadministrado y se analizaron e interpretaron estadísticamente utilizando el PLS 3.0., un software estadístico de modelación de ecuaciones estructurales. Contrariamente a nuestras predicciones, los resultados muestran que la cooperación influyó negativamente en la voluntad de participar en actividades compartidas durante la pandemia de COVID-19, que la conciencia ambiental no fue un predictor significativo y que el comportamiento de compartir en el pasado tiene la influencia más fuerte en la voluntad de compartir durante tiempos de pandemia. Finalmente, el efecto mediador de las expectativas de transformación fue significativo en ambas asociaciones, es decir, la conciencia proambiental y las experiencias pasadas de intercambio, y la disposición a adoptar un comportamiento de intercambio durante COVID-19.info:eu-repo/semantics/publishedVersio

The Certification of the Contents (Mass Fractions) of Flumequine and Oxolinic Acid in Freeze-dried Salmon Tissue. BCR 725

Abstract not availableJRC.D-Institute for Reference Materials and Measurements (Geel