Early recognition by Ball and Hooker in 1878 of plant back-colonization (boomerang) events from Macaronesia to Africa

Recent work in island biogeography has shown that back-colonization (‘boomerang’ events) from islands to continents have occurred more frequently than previously understoodWe report possibly the earliest inference of this pattern, by John Ball and Joseph Dalton Hooker in a book published in 1878

The determinants of the quality of Sales-Marketing Interface in a Multinational Customer Brand Focused Company: The Latin American Branches

Customer evolution and changes in consumers, determine the fact that the quality of the interface between marketing and sales may represent a true competitive advantage for the firm. Building on multidimensional theoretical and empirical models developed in Europe and on social network analysis, the organizational interface between the marketing and sales departments of a multinational high-growth company with operations in Argentina, Uruguay and Paraguay is studied. Both, attitudinal and social network measures of information exchange are used to make operational the nature and quality of the interface and its impact on performance. Results show the existence of a positive relationship of formalization, joint planning, teamwork, trust and information transfer on interface quality, as well as a positive relationship between interface quality and business performance. We conclude that efficient design and organizational management of the exchange network are essential for the successful performance of consumer goods companies that seek to develop distinctive capabilities to adapt to markets that experience vertiginous change

Emergence of half-metallicity in suspended NiO chains

Contrary to the antiferromagnetic and insulating character of bulk NiO, one-dimensional chains of this material can become half-metallic due to the lower coordination of their atoms. Here we present ab initio electronic structure and quantum transport calculations of ideal infinitely long NiO chains and of more realistic short ones suspended between Ni electrodes. While infinite chains are insulating, short suspended chains are half-metallic minority-spin conductors which display very large magnetoresistance and a spin-valve behaviour controlled by a single atom.Comment: 5 pages, 4 figures; accepted version; minor changes in introduction and reference

Transport in magnetically ordered Pt nanocontacts

Pt nanocontacts, like those formed in mechanically controlled break junctions, are shown to develop spontaneous local magnetic order. Our density functional calculations predict that a robust local magnetic order exists in the atoms presenting low coordination, i. e., those forming the atom-sized neck. In contrast to previous work, we thus find that the electronic transport can be spin-polarized, although the net value of the conductance still agrees with available experimental information. Experimental implications of the formation of this new type of nanomagnet are discussed.Comment: 4 pages, 3 figure

On the link between the coefficient of determination and polarization

In this paper, taking as starting point the link between polarization and dispersion, we reformulate the measure of polarization of Zhang and Kanbur (2001) using the decomposition of the variance instead of the decomposition of the Theil index. The proposed measure is equivalent to the coefficient of determination of an ANOVA Linear Model, that explains the income of the households as a function of any population characteristic e.g. education, gender, occupation etc. This result provides an alternative way to analyze polarization by household characteristics and at the same time allows us to compare sub-populations via the estimated coefficients of the ANOVA model.Polarization, coefficient of determination, ANOVA model.

Single exciton spectroscopy of semimagnetic quantum dots

A photo-excited II-VI semiconductor nanocrystal doped with a few Mn spins is considered. The effects of spin-exciton interactions and the resulting multi-spin correlations on the photoluminescence are calculated by numerical diagonalization of the Hamiltonian, including exchange interaction between electrons, holes and Mn spins, as well as spin-orbit interaction. The results provide a unified description of recent experiments of photoluminesnce of dots with one and many Mn atoms as well as optically induced ferromagnetism in semimagnetic nanocrystals.Comment: 5 pages, 3 figure

Edición de genes mediante crispr-cas9: más que Cortar y pegar

En esta revisión se exponen las características y aplicaciones de CRISPR-Cas9, un sistema inmune adaptativo propio de algunas especies de bacterias y arqueas que lo utilizan para defenderse de bacteriófagos. Fue descubierto por el doctor español Francisco Mojica cuando se encontraba investigando sobre un tipo de arquea en las salinas de Santa Pola (Alicante). El mecanismo inmune de estos sistemas consta de tres fases donde un ARN guía forma un complejo proteico con una proteína nucleasa llamada Cas9 para así poder escindir el ADN del organismo exógeno y evitar su infección. Debido a la simpleza de su mecanismo, CRISPR-Cas9 lleva siendo utilizado por diversos grupos de investigadores desde 2013 con el objetivo de convertirse en una nueva herramienta de terapia génica que permita modificar el genoma de personas que sufran enfermedades con componente genético. El propósito es introducir los componentes en un vector, viral o no viral, que sea capaz de alcanzar la célula diana y cortar selectivamente una secuencia del ADN que posteriormente será reparada por los métodos de recombinación HDR Y NHEJ. Los sistemas CRISPR-Cas9 presentan numerosas ventajas frente a otros tipos de terapia génica como ZFN o TALEN como son su bajo coste y su fácil diseño. Sin embargo, la reparación del gen anómalo y los cambios no deseados en el genoma son aspectos que los investigadores deberán de solventar para conseguir una herramienta biológica segura y eficaz. Por último, se recoge información sobre los últimos avances hasta la fecha y sobre los ensayos preclínicos basados en este sistema, profundizando en las enfermedades hereditarias retinianas debido a las características particulares del ojo que lo convierten en un órgano ideal para ser tratado con sistemas CRISPR-Cas9.Universidad de Sevilla. Doble Grado en Farmacia y Óptica y Optometrí

Personal aircraft: a more affordable luxury

Access to luxury products has been limited traditionally to the upper classes. Products and services related to the means of transport have usually been considered of luxury and industrialization has made accessible to much of the population in developed countries. An emerging market is personal aircraft which is currently restricted to certain layers of society but it is expected that their use will represent the next great advance in transport. This article has the object of presenting the results of ongoing research and it focuses on possible demand and the tendency to use this transport option in Spanish societ

La religión en Tíbulo

El artículo aborda el estudio de la religión en Tibulo proponiendo que, al\ud menos en parte como reflejo de la personalidad contradictoria del poeta, se pueden\ud dividir los dioses que aparecen en sus elegías en tres grupos: los perturbadores, los\ud conciliadores y los pertiu-bados, haciéndose hincapié en que tal división no es rígida\ud ni tampoco tiene connotaciones peyorativas, y poniendo de manifiesto la importancia\ud del Amor en dicho esquema y, por tanto, en todo su sentimiento religioso. También\ud se hacen algimos coméntanos a propósito de algunas fiestas y cultos que parecen\ud en los carmina tibulianos.This paper is devoted to the study of the religion in Tibullus and proposes to classify the gods of his elegies into three groups: the disturbatives, the conciliators\ud and the perturbed. This division reflects, at least in some measure, the contradictory\ud personality of the poet but it is not rigid or pejorative. The god Amor is the key for\ud the comprehension of his religious sentiment and so for the reason of the displayed\ud classification. Several commentaries on some festivities and cults appearing in the\ud tibullian carmina are offered as well