pH-Dependent Capping Interactions Induce Large-Scale Structural Transitions in i-Motifs

We study here a DNA oligonucleotide having the ability to form two different i-motif structures whose relative stability depends on pH and temperature. The major species at neutral pH is stabilized by two C:C+ base pairs capped by two minor groove G:C:G:C tetrads. The high pH and thermal stability of this structure are mainly due to the favorable effect of the minor groove tetrads on their adjacent positively charged C:C+ base pairs. At pH 5, we observe a more elongated i-motif structure consisting of four C:C+ base pairs capped by two G:T:G:T tetrads. Molecular dynamics calculations show that the conformational transition between the two structures is driven by the protonation state of key cytosines. In spite of large conformational differences, the transition between the acidic and neutral structures can occur without unfolding of the i-motif. These results represent the first case of a conformational switch between two different i-motif structures and illustrate the dramatic pH-dependent plasticity of this fascinating DNA motif

Las matemáticas para la empresa : un reto pendiente

El fracaso académico en las asignaturas relacionadas con las Matemáticas en la Facultad de Ciencias Empresariales de la Universidad de Huelva es una realidad ampliamente contrastada. La falta de una base sólida para afrontar los nuevos conocimientos, unida a la ausencia de un esfuerzo personal diario y a una aversión generalizada entre nuestros alumnos hacia las Matemáticas, sean quizás las causas principales de esos resultados adversos. Hemos realizado un estudio, mediante un cuestionario elaborado para tal fin y contestado por los alumnos el primer día de clase, sobre los conocimientos matemáticos básicos con los que llegan éstos al primer curso de nuestra Facultad. El objetivo es establecer un marco de actuación adecuado para enfrentarnos a la docencia de nuestras asignaturas e intentar paliar, en lo posible, las carencias del alumnado

METIS D3.4: Final workshops packages: workshops for different educational levels and education contexts

Several decades of research in technology-enhanced learning (TEL) have clearly demonstrated the potential of digital technology to transform education. Yet the impact of TEL research on daily teaching-learning practices is still far from fulfilling this potential. Arguably, this is a gap in the capacity for learning design: educators need the tools and competencies which would allow them to identify educational challenges, describe the context in which they arise, identify the opportunities afforded by technology, project the insights derived from research, and devise new learning experiences. To address this gap, educators need tools and practices. Tools that would support them through the cycle of learning design – from conception to deployment and evaluation of techno-educational innovations. Professional practices that use such tools to ensure the robustness and effectiveness of their innovations and make learning design a daily habit and part of their professional identity. The METIS project (http://metis-project.org/) aims to contribute to this aim, by providing educators with an Integrated Learning Design Environment (ILDE) (Hernández-Leo, Asensio-Pérez, Derntl, Prieto, & Chacón, 2014; Hernández-Leo et al., 2015) and a workshop package for training educators in using the ILDE to support effective learning design. Work Package 3, led by the OU (UK), is concerned with the design and development of the workshop package. This deliverable is the final version of the METIS workshop package. It includes • a meta-design for METIS workshops that provides a flexible reusable structure so that workshops can be customised to meet different needs , • a description of the rationale and pedagogical methodology on which the meta-design is based • guidance for instantiating the meta-design in different contexts and • example workshop packages based on the meta-design for three different educational sectors. This document provides educators with a basis for delivering workshops about using the ILDE to support effective learning design. To create and run a workshop suitable for your own context, please proceed in the following way. Firstly, consider the meta-design; then choose one of the example workshop packages closest to your context; finally, use the guidelines to adapt it for your needs

Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU

Contains fulltext : 172380.pdf (publisher's version ) (Open Access

Evolution and domestication of lima bean in Mexico : Evidence from ribosomal DNA

Phaseolus lunatus L., Lima bean, has been domesticated at least twice in the Americas, once in the Andean region and at another time in Mesoamerica; however, the domestication history of this crop in the latter region remains unclear. In this study, a phylogeographic analysis of DNA polymorphisms in the internal transcribed spacer (ITS) region of the ribosomal DNA from a collection of wild and domesticated accessions was applied to establish where and how many times in Mesoamerica Lima bean was domesticated. The results showed evidence for two wild Mesoamerican gene pools with contrasting geographical distributions. While the MI gene pool occurs in central western Mexico, including the Pacific coastal range, the MII gene pool is widespread and occurs toward the Gulf of Mexico, the Yucatan peninsula, and Central and South America. In a cluster analysis, all Mesoamerican landraces clustered together with wild accessions from the MI gene pool (L haplotype) suggesting a unique domestication event in central western Mexico. The most likely domestication region is an area of the states of Nayarit–Jalisco or Guerrero–Oaxaca and not areas such as the Peninsula of Yucatan where the crop is currently widespread and diverse. A strong founder effect due to domestication was quantified and several recently diversified haplotypes were identified. A hypothesis about possible dispersal routes of the crop within Mesoamerica is proposed as well as an apparent late adoption of the crop into the milpa system