Pseudochaotic poloidal transport in the laminar regime of the resistive ballooning instabilities

In toroidal geometry, and prior to the establishment of a fully developed turbulent state, the so-called topological instability of the pressure-gradient-driven turbulence is observed. In this intermediate state, a narrow spectral band of modes dominates the dynamics, giving rise to the formation of iso-surfaces of electric potential with a complicated topology. Since E x B advection of tracer particles takes place along these iso-surfaces, their topological complexity affects the characteristic features of radial and poloidal transport dramatically. In particular, they both become strongly non-diffusive and non-Gaussian. Since radial transport determines the system confinement properties and poloidal transport controls the equilibration dynamics (on any magnetic surface), the development of non-diffusive models in both directions is thus of physical interest. In previous work, a fractional model to describe radial transport was constructed by the authors. In this contribution, recent results on periodic fractional models are exploited for the construction of an effective model of poloidal transport. Numerical computations using a three-dimensional reduced magnetohydrodynamic set of equations are compared with analytical solutions of the fractional periodic model. It is shown that the aforementioned analytical solutions accurately describe poloidal transport, which turns out to be superdiffusive with index $\alpha=1$.Comment: 17 pages, 6 figures. Accepted for publication in Phys. Plasma

La influencia del autoconcepto en el rendimiento académico en estudiantes universitarios

ABSTRACTThere are some researches that confirm the positive relationship between self-concept and academic achievement, usually of the academic self‐concept dimension and almost always in non‐university students. In this work we were looking for confirming the influence of self-concept in the academic achievement of the university students. In order to do it we worked with a sample of 1298 students from the three universities located in the city of Valencia (Spain): the University of Valencia, the Polytechnic University of Valencia and the Catholic University of Valencia. The first two were public universities and the third one was private. We assessed the self‐concept by means of the AF5 questionnaire, which gives scores of five types of self-concept: academic/labour, emotional, family self‐concept, physical and social. We also took data from the academic achievement of university students by using the mean score of grades of five compulsory subjects of the academic year in which the research was conducted. From these scores we carried out correlations between self‐concept scores and grades, and also linear multiple regression analysis that showed a moderate relationship between three of the five types of self-concept that assesses the questionnaire (academic, physical and family self‐concept) and academic achievement. We also conducted hierarchical cluster analysis (k-means) with self-concept scores, finding three groups of students, one of them with a good profile of self-concept and the other two with a weaker profile. The first one had better grades, although di‐ fferences between the three groups were not significant in ANOVA. These results help us to realize the importance of supporting, as teachers, the development of a good self‐concept in our university students. Additionally, they complement the results of other studies that have examined other constructs and its impact on the academic achievement of university students.RESUMEN Existen algunas investigaciones que confirman la relación positiva existente entre autoconcepto y rendimiento académico, generalmente de la dimensión autoconcepto académico y casi siempre en estudiantes no universitarios. En este trabajo se busca confirmar la influencia del autoconcepto en el rendimiento académico de los estudiantes universitarios. Para ello trabajamos con una muestra de 1298 estudiantes de las tres universidades de la ciudad de Valencia (España): Universidad de Valencia, Universidad Politécnica de Valencia y Universidad Católica de Valencia. Las dos primeras eran universidades públicas y la tercera lo era privada. Evaluamos el autoconcepto mediante el cuestionario AF5, que permite obtener puntuaciones de cinco tipos de autoconcepto: académico/laboral, emocional, familiar, físico y social. También tomamos datos del rendimiento obteniendo la media de cinco asignaturas troncales y obligatorias del curso en que se realizó la investigación. A partir de estas puntuaciones llevamos a cabo correlaciones entre puntuaciones de autoconcepto y calificaciones, y también análisis de regresión lineal que reflejaron una relación moderada entre tres de los cinco tipos de autoconcepto que evalúa el cuestionario (académico, familiar y físico) y el rendimiento. También realizamos análisis jerárquico de conglomerados (k‐medias) con las puntuaciones de autoconcepto, encontrando tres grupos de estudiantes, uno con buen perfil de autoconcepto y dos con peor perfil. El grupo con buen perfil tenía mejores calificaciones, aunque las diferencias existentes entre los tres grupos no llegaron a ser significativas en el ANOVA realizado. Estos resultados ayudan a tomar conciencia de la importancia de apoyar, como profesores, el desarrollo de un buen autoconcepto en nuestros estudiantes universitarios. Además complementan los resultados de otras investigaciones que han analizado otros constructos y su incidencia en el rendimiento de estos estudiantesABSTRACT There are some researches that confirm the positive relationship between self-concept and academic achievement, usually of the academic self‐concept dimension and almost always in non‐university students. In this work we were looking for confirming the influence of self-concept in the academic achievement of the university students. In order to do it we worked with a sample of 1298 students from the three universities located in the city of Valencia (Spain): the University of Valencia, the Polytechnic University of Valencia and the Catholic University of Valencia. The first two were public universities and the third one was private. We assessed the self‐concept by means of the AF5 questionnaire, which gives scores of five types of self-concept: academic/labour, emotional, family self‐concept, physical and social. We also took data from the academic achievement of university students by using the mean score of grades of five compulsory subjects of the academic year in which the research was conducted. From these scores we carried out correlations between self‐concept scores and grades, and also linear multiple regression analysis that showed a moderate relationship between three of the five types of self-concept that assesses the questionnaire (academic, physical and family self‐concept) and academic achievement. We also conducted hierarchical cluster analysis (k-means) with self-concept scores, finding three groups of students, one of them with a good profile of self-concept and the other two with a weaker profile. The first one had better grades, although di‐ fferences between the three groups were not significant in ANOVA. These results help us to realize the importance of supporting, as teachers, the development of a good self‐concept in our university students. Additionally, they complement the results of other studies that have examined other constructs and its impact on the academic achievement of university students

Triplet Exciton Generation in Bulk-Heterojunction Solar Cells based on Endohedral Fullerenes

Organic bulk-heterojunctions (BHJ) and solar cells containing the trimetallic nitride endohedral fullerene 1-[3-(2-ethyl)hexoxy carbonyl]propyl-1-phenyl-Lu3N@C80 (Lu3N@C80-PCBEH) show an open circuit voltage (VOC) 0.3 V higher than similar devices with [6,6]-phenyl-C[61]-butyric acid methyl ester (PC61BM). To fully exploit the potential of this acceptor molecule with respect to the power conversion efficiency (PCE) of solar cells, the short circuit current (JSC) should be improved to become competitive with the state of the art solar cells. Here, we address factors influencing the JSC in blends containing the high voltage absorber Lu3N@C80-PCBEH in view of both photogeneration but also transport and extraction of charge carriers. We apply optical, charge carrier extraction, morphology, and spin-sensitive techniques. In blends containing Lu3N@C80-PCBEH, we found 2 times weaker photoluminescence quenching, remainders of interchain excitons, and, most remarkably, triplet excitons formed on the polymer chain, which were absent in the reference P3HT:PC61BM blends. We show that electron back transfer to the triplet state along with the lower exciton dissociation yield due to intramolecular charge transfer in Lu3N@C80-PCBEH are responsible for the reduced photocurrent

Laparoscopic versus open extended radical left pancreatectomy for pancreatic ductal adenocarcinoma: an international propensity-score matched study

Background A radical left pancreatectomy in patients with pancreatic ductal adenocarcinoma (PDAC) may require extended, multivisceral resections. The role of a laparoscopic approach in extended radical left pancreatectomy (ERLP) is unclear since comparative studies are lacking. The aim of this study was to compare outcomes after laparoscopic vs open ERLP in patients with PDAC. Methods An international multicenter propensity-score matched study including patients who underwent either laparoscopic or open ERLP (L-ERLP; O-ERLP) for PDAC was performed (2007-2015). The ISGPS definition for extended resection was used. Primary outcomes were overall survival, margin negative rate (R0), and lymph node retrieval. Results Between 2007 and 2015, 320 patients underwent ERLP in 34 centers from 12 countries (65 L-ERLP vs. 255 O-ERLP). After propensity-score matching, 44 L-ERLP could be matched to 44 O-ERLP. In the matched cohort, the conversion rate in L-ERLP group was 35%. The L-ERLP R0 resection rate (matched cohort) was comparable to O-ERLP (67% vs 48%; P = 0.063) but the lymph node yield was lower for L-ERLP than O-ERLP (median 11 vs 19, P = 0.023). L-ERLP was associated with less delayed gastric emptying (0% vs 16%, P = 0.006) and shorter hospital stay (median 9 vs 13 days, P = 0.005), as compared to O-ERLP. Outcomes were comparable for additional organ resections, vascular resections (besides splenic vessels), Clavien-Dindo grade >= III complications, or 90-day mortality (2% vs 2%, P = 0.973). The median overall survival was comparable between both groups (19 vs 20 months, P = 0.571). Conversion did not worsen outcomes in L-ERLP. Conclusion The laparoscopic approach may be used safely in selected patients requiring ERLP for PDAC, since morbidity, mortality, and overall survival seem comparable, as compared to O-ERLP. L-ERLP is associated with a high conversion rate and reduced lymph node yield but also with less delayed gastric emptying and a shorter hospital stay, as compared to O-ERLP

X-ray Crystallographic Structure of an Artificial β-Sheet Dimer

This paper describes the X-ray crystallographic structure of a designed cyclic beta-sheet peptide that forms a well-defined hydrogen-bonded dimer that mimics beta-sheet dimers formed by proteins. The 54-membered ring macrocyclic peptide (1a) contains molecular template and turn units that induce beta-sheet structure in a heptapeptide strand that forms the dimerization interface. The X-ray crystallographic structure reveals the structures of the two "Hao" amino acids that help template the beta-sheet structure and the two delta-linked ornithine turn units that link the Hao-containing template to the heptapeptide beta-strand. The Hao amino acids adopt a conformation that resembles a tripeptide in a beta-strand conformation, with one edge of the Hao unit presenting an alternating array of hydrogen-bond donor and acceptor groups in the same pattern as that of a tripeptide beta-strand. The delta-linked ornithines adopt a conformation that resembles a hydrogen-bonded beta-turn, in which the ornithine takes the place of the i+1 and i+2 residues. The dimers formed by macrocyclic beta-sheet 1a resemble the dimers of many proteins, such as defensin HNP-3, the lambda-Cro repressor, interleukin 8, and the ribonuclease H domain of HIV-1 reverse transcriptase. The dimers of 1a self-assemble in the solid state into a barrel-shaped trimer of dimers in which the three dimers are arranged in a triangular fashion. Molecular modeling in which one of the three dimers is removed and the remaining two dimers are aligned face-to-face provides a model of the dimers of dimers of closely related macrocyclic beta-sheet peptides that were observed in solution

Knowledge and social capacity building for sustainable urban transformation

No abstract available

Water management

No abstract available

Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field