Kon-tiki/Perdido enhances PS2 integrin adhesion and localizes its ligand, Thrombospondin, in the myotendinous junction.

Cell-extracellular matrix adhesion is mediated by cell receptors, mainly integrins and transmembrane proteoglycans, which can functionally interact. How these receptors are regulated and coordinated is largely unknown and key to understand cell adhesion in development. We show that the conserved transmembrane proteoglycan Kon-tiki/Perdido (Kon) interacts with αPS2βPS integrin to mediate muscle-tendon adhesion. Double mutant embryos for kon and inflated show a synergistic increase in muscle detachment. Furthermore, Kon modulates αPS2βPS signaling at the muscle attachment, since P-Fak is reduced in kon mutants. This reduction in integrin signaling can be rescued by the expression of a truncated Kon protein containing the transmembrane and extracellular domains, suggesting that these domains are sufficient to mediate this signaling. We show that these domains are sufficient to properly localize the αPS2βPS ligand, Thrombospondin, to the muscle attachment, and to partially rescue Kon dependent muscle-tendon adhesion. We propose that Kon can engage in a protein complex with αPS2βPS and enhance integrin-mediated signaling and adhesion by recruiting its ligand, which would increase integrin-binding affinity to the extracellular matrix, resulting in the consolidation of the myotendinous junction.Ramón y Cajal program and the Universidad Pablo de Olavide. Research was funded by the Ministerio de Economıa y Competitividad ́ (Spanish Ministry of Science and Innovation) (BFU2008-036550, BFU2011-26745). Proyecto de Excelencia of the Consejerıa de Econom ́ ıa, ́ Innovación, Ciencia y Empleo, Junta de Andalucıa (PO9-CVI-5058). A.G.E.-Z. and ́ the Ministerio de Ciencia e Innovación (Spanish Ministry of Science and Innovation) (BFU2008-036550, BFU2011-26745)

Analytic Kramer kernels, Lagrange-type interpolation series and de Branges spaces

The classical Kramer sampling theorem provides a method for obtaining orthogonal sampling formulas. In particular, when the involved kernel is analytic in the sampling parameter it can be stated in an abstract setting of reproducing kernel Hilbert spaces of entire functions which includes as a particular case the classical Shannon sampling theory. This abstract setting allows us to obtain a sort of converse result and to characterize when the sampling formula associated with an analytic Kramer kernel can be expressed as a Lagrange-type interpolation series. On the other hand, the de Branges spaces of entire functions satisfy orthogonal sampling formulas which can be written as Lagrange-type interpolation series. In this work some links between all these ideas are established

Validaciones perceptivas y deductivas en geometría: un estudio con docentes en formación continua

La comunicación breve evidencia resultados parciales del proyecto de investigación Processo de Ensino e Aprendizagem em Matemática em ambientes tecnológicos desarrollado por investigadores del grupo Didáctica de las Matemáticas (DIMAT) de la Pontificia Universidad Católica del Perú y del grupo Processo de Ensino e Aprendizagem em Matemática (PEA-MAT) de la Pontificia Universidad Católica de Sao Paulo/Brasil. Presentamos uno de los cuatro encuentros de la formación en geometría que realizamos con dieciséis docentes peruanos de Educación Básica Regular-nivel secundario. Analizamos una tarea de la secuencia basados en el Enfoque de Parzysz que determina los procesos y mecanismos relacionados con la enseñanza y con el aprendizaje de la geometría y propone una clasificación o tipos de geometría que considera los objetos como físicos o teóricos y los modos de validación perceptiva y deductiva. En la tarea que analizamos, los docentes utilizan diversas estrategias de resolución y realizan un análisis matemático y didáctico la misma. En cuanto a los resultados, observamos que los docentes utilizan estrategias de resolución del tipo G1-geometría concreta y G2 geometría protoaxiomática, en el sentido de Parzysz, sin embargo muestran dificultad en identificar qué tipo de validaciones están utilizando y se les hace difícil elaborar una estrategia en G0

Abordagem instrumental: uma revisão da literatura no Peru e no Brasil dos anos 2013 a 2017

Este estudo é um levantamento de dissertações e teses produzidas no Peru e no Brasil de 2013 a 2017. Tem como objetivo apresentar um panorama das pesquisas que usam a Abordagem Instrumental como quadro teórico, tendo como critérios: as instituições das pesquisas, o objeto matemático, o tipo de artefato usado, os sujeitos envolvidos, e as fases da Gênese Instrumental usadas. A metodologia foi uma pesquisa bibliográfica do tipo estado da arte. Concluímos que as pesquisas no Brasil usam diversos artefatos, em diferentes níveis de ensino e utilizam as duas fases das Gênese Instrumental. Enquanto no Peru, usam artefatos simbólicos, são do nível médio e superior e maioritariamente usam uma das fases

Effect of Biodiversity Changes in Disease Risk: Exploring Disease Emergence in a Plant-Virus System

The effect of biodiversity on the ability of parasites to infect their host and cause disease (i.e. disease risk) is a major question in pathology, which is central to understand the emergence of infectious diseases, and to develop strategies for their management. Two hypotheses, which can be considered as extremes of a continuum, relate biodiversity to disease risk: One states that biodiversity is positively correlated with disease risk (Amplification Effect), and the second predicts a negative correlation between biodiversity and disease risk (Dilution Effect). Which of them applies better to different host-parasite systems is still a source of debate, due to limited experimental or empirical data. This is especially the case for viral diseases of plants. To address this subject, we have monitored for three years the prevalence of several viruses, and virus-associated symptoms, in populations of wild pepper (chiltepin) under different levels of human management. For each population, we also measured the habitat species diversity, host plant genetic diversity and host plant density. Results indicate that disease and infection risk increased with the level of human management, which was associated with decreased species diversity and host genetic diversity, and with increased host plant density. Importantly, species diversity of the habitat was the primary predictor of disease risk for wild chiltepin populations. This changed in managed populations where host genetic diversity was the primary predictor. Host density was generally a poorer predictor of disease and infection risk. These results support the dilution effect hypothesis, and underline the relevance of different ecological factors in determining disease/infection risk in host plant populations under different levels of anthropic influence. These results are relevant for managing plant diseases and for establishing conservation policies for endangered plant species

Linking forest cover, soil erosion and mire hydrology to late-Holocene human activity and climate in NW Spain

This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 3.0 License (http://www.creativecommons.org/licenses/by-nc/3.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access page (http://www.uk.sagepub.com/aboutus/openaccess.htm).This article has been made available through the Brunel Open Access Publishing Fund.Forest clearance is one of the main drivers of soil erosion and hydrological changes in mires, although climate may also play a significant role. Because of the wide range of factors involved, understanding these complex links requires long-term multi-proxy approaches and research on the best proxies to focus. A peat core from NW Spain (Cruz do Bocelo mire), spanning the last ~3000 years, has been studied at high resolution by physical (density and loss on ignition (LOI)), geochemical (elemental composition) and palynological (pollen and non-pollen palynomorphs) analyses. Proxies related to mineral matter fluxes from the catchment (lithogenic tracers, Glomus and Entorrhiza), rainfall (Bromine), mire hydrology (HdV-18), human pressure (Cerealia-type, nitrophilous taxa and coprophilous fungi) and forest cover (mesophilous tree taxa) were the most useful to reconstruct the evolution of the mire and its catchment. Forest clearance for farming was one of the main drivers of environmental change from at least the local Iron Age (~2685 cal. yr BP) onwards. The most intense phase of deforestation occurred during Roman and Germanic times and the late Middle Ages. During these phases, the entire catchment was affected, resulting in enhanced soil erosion and severe hydrological modifications of the mire. Climate, especially rainfall, may have also accelerated these processes during wetter periods. However, it is noteworthy that the hydrology of the mire seems to have been insensitive to rainfall variations when mesophilous forest dominated. Abrupt changes were only detected once intense forest clearance commenced during the Iron Age/Roman transition (~2190 cal. yr BP) phase, which represented a tipping point in catchment's ability to buffer impacts. Overall, our findings highlight the importance of studying ecosystems' long-term trajectories and catchment-wide processes when implementing mire habitat protection measures.This work was funded by the projects CGL2010-20672 (Plan Nacional I+D+i, Spanish Ministry of Science and Innovation) and 10PXIB200182PR (General Directorate of I+D, Xunta de Galicia). N Silva-Sánchez and L López-Merino are currently supported by a FPU predoctoral scholarship (AP2010-3264) funded by the Spanish Government and a MINT postdoctoral fellowship funded by the Brunel Institute for the Environment, respectively

Ancient coins: cluster analysis applied to find a correlation between corrosion process and burial soil characteristics

Although it is well known that any material degrades faster when exposed to an aggressive environment as well as that "aggressive" cannot be univocally defined as depending also on the chemical-physical characteristics of material, few researches on the identification of the most significant parameters influencing the corrosion of metallic object are available

Formation and Propagation of Matter Wave Soliton Trains

Attraction between atoms in a Bose-Einstein-Condensate renders the condensate unstable to collapse. Confinement in an atom trap, however, can stabilize the condensate for a limited number of atoms, as was observed with 7Li, but beyond this number, the condensate collapses. Attractive condensates constrained to one-dimensional motion are predicted to form stable solitons for which the attractive interactions exactly compensate for the wave packet dispersion. Here we report the formation or bright solitons of 7Li atoms created in a quasi-1D optical trap. The solitons are created from a stable Bose-Einstein condensate by magnetically tuning the interactions from repulsive to attractive. We observe a soliton train, containing many solitons. The solitons are set in motion by offsetting the optical potential and are observed to propagate in the potential for many oscillatory cycles without spreading. Repulsive interactions between neighboring solitons are inferred from their motion

LOS CUADRILÁTEROS COMO SABER A ENSEÑAR EN EL CURRÍCULO PERUANO

El presente artículo tiene como objetivo presentar un análisis de los cuadriláteros como saber a enseñar en el currículo de Perú. Los elementos teóricos en que nos basamos están sustentados por la Teoría Antropológica de lo Didáctico (TAD) y en su perspectiva ecológica. Realizamos un estudio del sistema Educativo Peruano, de las reformas curriculares y luego analizamos cómo y porqué está presente el estudio de los cuadriláteros en el sistema escolar peruano. Como resultados, obtuvimos que, en el currículo de peruano, existe atomización de los contenidos, específicamente enGeometría, es decir, los contenidos son propuestos para ser enseñados de manera separada sin interrelacionarse, por lo cual se pudo dilucidar que, en el caso de los cuadriláteros, se da el fenómeno del autismo temático, que quiere decir que existe un encierro en el nivel temático dentro de la escalade codeterminación didáctica

Vortex nucleation as a case study of symmetry breaking in quantum systems

Mean-field methods are a very powerful tool for investigating weakly interacting many-body systems in many branches of physics. In particular, they describe with excellent accuracy trapped Bose-Einstein condensates. A generic, but difficult question concerns the relation between the symmetry properties of the true many-body state and its mean-field approximation. Here, we address this question by considering, theoretically, vortex nucleation in a rotating Bose-Einstein condensate. A slow sweep of the rotation frequency changes the state of the system from being at rest to the one containing one vortex. Within the mean-field framework, the jump in symmetry occurs through a turbulent phase around a certain critical frequency. The exact many-body ground state at the critical frequency exhibits strong correlations and entanglement. We believe that this constitutes a paradigm example of symmetry breaking in - or change of the order parameter of - quantum many-body systems in the course of adiabatic evolution.Comment: Minor change