Charge distribution in two-dimensional electrostatics

We examine the stability of ringlike configurations of N charges on a plane interacting through the potential $V(z_1,...,z_N)=\sum_i |z_i|^2-\sum_{i<j} ln|z_i-z_j|^2$. We interpret the equilibrium distributions in terms of a shell model and compare predictions of the model with the results of numerical simulations for systems with up to 100 particles.Comment: LaTe

A socially assistive robot for long-term cardiac rehabilitation in the real world

What are the benefits of using a socially assistive robot for long-term cardiac rehabilitation? To answer this question we designed and conducted a real-world long-term study, in collaboration with medical specialists, at the Fundacion Cardioinfantil-Instituto de Cardiologia clinic (Bogota, Colombia) lasting 2.5 years. The study took place within the context of the outpatient phase of patients' cardiac rehabilitation programme and aimed to compare the patients' progress and adherence in the conventional cardiac rehabilitation programme (control condition) against rehabilitation supported by a fully autonomous socially assistive robot which continuously monitored the patients during exercise to provide immediate feedback and motivation based on sensory measures (robot condition). The explicit aim of the social robot is to improve patient motivation and increase adherence to the programme to ensure a complete recovery. We recruited 15 patients per condition. The cardiac rehabilitation programme was designed to last 36 sessions (18 weeks) per patient. The findings suggest that robot increases adherence (by 13.3%) and leads to faster completion of the programme. In addition, the patients assisted by the robot had more rapid improvement in their recovery heart rate, better physical activity performance and a higher improvement in cardiovascular functioning, which indicate a successful cardiac rehabilitation programme performance. Moreover, the medical staff and the patients acknowledged that the robot improved the patient motivation and adherence to the programme, supporting its potential in addressing the major challenges in rehabilitation programmes

Predicting perceived exhaustion in rehabilitation exercises using facial action units

Physical exercise has become an essential tool for treating various non-communicable diseases (also known as chronic diseases). Due to this, physical exercise allows to counter different symptoms and reduce some risk of death factors without medication. A solution to support people in doing exercises is to use artificial systems that monitor their exercise progress. While one crucial aspect is to monitor the correct physical motions for rehabilitative exercise, another essential element is to give encouraging feedback during workouts. A coaching system can track a user’s exhaustion and give motivating feedback accordingly to boost exercise adherence. For this purpose, this research investigates whether it is possible to predict the subjective exhaustion level based on non-invasive and non-wearable technology. A novel data set was recorded with the facial record as the primary predictor and individual exhaustion levels as the predicted variable. 60 participants (30 male, 30 female) took part in the data recording. 17 facial action units (AU) were extracted as predictor variables for the perceived subjective exhaustion measured using the BORG scale. Using the predictor and the target variables, several regression and classification methods were evaluated aiming to predict exhaustion. The results showed that the decision tree and support vector methods provide reasonable prediction results. The limitation of the results, depending on participants being in the training data set and subjective variables (e.g., participants smiling during the exercises) were further discussed

The structure of the PapD-PapGII pilin complex reveals an open and flexible P5 pocket

P pili are hairlike polymeric structures that mediate binding of uropathogenic Escherichia coli to the surface of the kidney via the PapG adhesin at their tips. PapG is composed of two domains: a lectin domain at the tip of the pilus followed by a pilin domain that comprises the initial polymerizing subunit of the 1,000-plus-subunit heteropolymeric pilus fiber. Prior to assembly, periplasmic pilin domains bind to a chaperone, PapD. PapD mediates donor strand complementation, in which a beta strand of PapD temporarily completes the pilin domain's fold, preventing premature, nonproductive interactions with other pilin subunits and facilitating subunit folding. Chaperone-subunit complexes are delivered to the outer membrane usher where donor strand exchange (DSE) replaces PapD's donated beta strand with an amino-terminal extension on the next incoming pilin subunit. This occurs via a zip-in-zip-out mechanism that initiates at a relatively accessible hydrophobic space termed the P5 pocket on the terminally incorporated pilus subunit. Here, we solve the structure of PapD in complex with the pilin domain of isoform II of PapG (PapGIIp). Our data revealed that PapGIIp adopts an immunoglobulin fold with a missing seventh strand, complemented in parallel by the G1 PapD strand, typical of pilin subunits. Comparisons with other chaperone-pilin complexes indicated that the interactive surfaces are highly conserved. Interestingly, the PapGIIp P5 pocket was in an open conformation, which, as molecular dynamics simulations revealed, switches between an open and a closed conformation due to the flexibility of the surrounding loops. Our study reveals the structural details of the DSE mechanism

Engineering the Controlled Assembly of Filamentous Injectisomes in E. coli K-12 for Protein Translocation into Mammalian Cells.

Bacterial pathogens containing type III protein secretion systems (T3SS) assemble large needle-like protein complexes in the bacterial envelope, called injectisomes, for translocation of protein effectors into host cells. The application of these molecular syringes for the injection of proteins into mammalian cells is hindered by their structural and genomic complexity, requiring multiple polypeptides encoded along with effectors in various transcriptional units (TUs) with intricate regulation. In this work, we have rationally designed the controlled expression of the filamentous injectisomes found in enteropathogenic Escherichia coli (EPEC) in the nonpathogenic strain E. coli K-12. All structural components of EPEC injectisomes, encoded in a genomic island called the locus of enterocyte effacement (LEE), were engineered in five TUs (eLEEs) excluding effectors, promoters and transcriptional regulators. These eLEEs were placed under the control of the IPTG-inducible promoter Ptac and integrated into specific chromosomal sites of E. coli K-12 using a marker-less strategy. The resulting strain, named synthetic injector E. coli (SIEC), assembles filamentous injectisomes similar to those in EPEC. SIEC injectisomes form pores in the host plasma membrane and are able to translocate T3-substrate proteins (e.g., translocated intimin receptor, Tir) into the cytoplasm of HeLa cells reproducing the phenotypes of intimate attachment and polymerization of actin-pedestals elicited by EPEC bacteria. Hence, SIEC strain allows the controlled expression of functional filamentous injectisomes for efficient translocation of proteins with T3S-signals into mammalian cells

Comercio Electrónico de flora y fauna exótica invasora (código de conducta)

Este código de conducta pretende alertar de la venta y adquisición on-line de especies invasoras y fomentar una serie de recomendaciones que ayuden a reducir el riesgo que conlleva el comercio electrónico como vía de introducción de fauna y flora invasora. Los principales destinatarios de este código de conducta son: Profesionales dedicados al comercio de plantas y animales de compañía y a la acuariofilia: importadores (mayoristas), intermediarios (comercializadores y distribuidores) y tiendas (minoristas).Consumidores: aficionados y usuarios de jardinería, mascotismo o acuariofilia. Este código de conducta ha sido redactado en el marco del proyecto LIFE INVASAQUA (LIFE17 GIE/ES/000515) con la contribución de la Comisión Europea a través del programa LIFE. El proyecto LIFE INVASAQUA tiene entre sus objetivos facilitar y apoyar las políticas europeas sobre gestión de especies exóticas invasoras generando información útil para su implementación. Los códigos de conducta son documentos que pretenden fomentar una serie de recomendaciones y buenas prácticas para reducir la problemática asociada a la introducción de fauna y flora invasora. Esta versión 1.0 del documento tiene por objeto difundir la información entre organismos, asociaciones y entidades relacionadas para fomentar la adopción de sus recomendaciones y recoger nuevas aportaciones.El proyecto LIFE INVASAQUA (LIFE17 GIE/ES/000515) está financiado por el Programa LIFE de la Unión Europe

Conociendo a los tutores de Medicina Interna: nuevas necesidades para la formación

Introducción y objetivos Los tutores son los responsables de planificar el aprendizaje de los residentes. El objetivo de este trabajo es conocer la situación de los tutores de Medicina Interna en España y detectar áreas de mejora que puedan facilitar su trabajo. Material y métodos Encuestas online a tutores de Medicina Interna de mayo a julio de 2017 con análisis posterior de los datos. Resultados Respondieron 110 tutores, de 13 comunidades autónomas y hospitales de todos los niveles con docencia en Medicina Interna. Sesenta y tres fueron hombres (57, 3%), la media de edad fue de 48 años y tenían una experiencia como tutores de 8, 5 años. En el 88, 2% de los casos se respeta la ratio de cinco residentes por tutor; un 46% piensa que debería disminuirse esta ratio para optimizar su labor. Un tercio había sido elegido por el responsable del servicio y el 30% nunca ha realizado cursos sobre formación. La entrevista tutor-residentes es utilizada por la mayoría de los tutores (96, 4%) como herramienta de comunicación. En relación a las rotaciones, la cuarta parte no son planificadas por los tutores y, solo la mitad, contacta con los centros donde los residentes realizan las rotaciones externas. El 61% cree que no se realiza bien la evaluación de residentes, con muy escasa utilización de las nuevas herramientas de evaluación. Conclusiones Disminuir la ratio tutor/residente y la formación en técnicas de evaluación y desarrollo del aprendizaje podría mejorar la calidad de la tutorización. Introduction and objectives: Mentors are responsible for planning the residents’ learning. The aim of this study was to determine the situation of internal medicine mentors in Spain and detect areas of improvement that can facilitate their work. Material and methods: Online surveys were sent to internal medicine mentors from May to July 2017, the results of which were subsequently analysed. Results: A total of 110 mentors from 13 autonomous communities and from hospitals of all levels with courses in internal medicine responded to the survey. Of these mentors, 63 were men (57.3%), and the mean age was 48 years. The mean experience as mentors was 8.5 years. Some 88.2% of the cases had a ratio of 5 residents to 1 mentor; 46% of the mentors believed this ratio should be decreased to optimize their work. A third of the mentors were chosen by the heads of the department, and 30% had not previously taken courses on training. The mentor-resident interview was used by most mentors (96.4%) as a communication tool. A quarter of the rotations were not planned by the mentors, and only half had contact with the centres where the residents performed the external rotations. Sixty-one percent of the mentors were of the opinion that resident assessments were not conducted properly, with very little use of the new assessment tools. Conclusions: Reducing the mentor-resident ratio and adding training in assessment techniques and learning development could improve the quality of the mentoring

Direct Injection of Functional Single-Domain Antibodies from E. coli into Human Cells

Intracellular proteins have a great potential as targets for therapeutic antibodies (Abs) but the plasma membrane prevents access to these antigens. Ab fragments and IgGs are selected and engineered in E. coli and this microorganism may be also an ideal vector for their intracellular delivery. In this work we demonstrate that single-domain Ab (sdAbs) can be engineered to be injected into human cells by E. coli bacteria carrying molecular syringes assembled by a type III protein secretion system (T3SS). The injected sdAbs accumulate in the cytoplasm of HeLa cells at levels ca. 105–106 molecules per cell and their functionality is shown by the isolation of sdAb-antigen complexes. Injection of sdAbs does not require bacterial invasion or the transfer of genetic material. These results are proof-of-principle for the capacity of E. coli bacteria to directly deliver intracellular sdAbs (intrabodies) into human cells for analytical and therapeutic purposes