La naturalización en España: una política de claroscuros

El acceso a la nacionalidad da a los inmigrantes igualdad de derechos y deberes, asegura un mejor reconocimiento social y es, en definitiva, una vía importante de integración. Si bien en este proceso encontramos grandes diferencias en la UE, lo que parece común para todos los estados miembros es que el ordenamiento jurídico en esta materia está cargado de deficiencias y contradicciones. Este capítulo analiza este marco jurídico tanto para la UE como para España. En el caso español, se hará mención a los requisitos legales,a los trámites a los que se enfrenta un extranjero para poder obtener la nacionalidad. La premisa de la que se parte es que ambos aspectos suponen obstáculos que enfrentan al extranjero a un proceso de claroscuros y frenan la posibilidad de alcanzar la plena integración

Environmental change rate and dispersion pattern modulate the dynamics of evolutionary rescue of the cyanobacterium Microcystis aeruginosa

The rate of biodiversity loss is so high that some scientists affirm that we are being witnesses of the sixth mass extinction. In this situation, it is necessary to ask the following question: can the organisms be able to resist the environmental changes that are taking place? Recent studies have shown the possibility of a population recovering from a stress situation through evolutionary rescue (ER) events. These events depend on the size of the population, its previous history and the rate of the environmental change. The aim of this work is to add more knowledge about the ER dynamics creating stress situations with selective agents (sulphur and salinity) and using the toxic cyanobacterium Microcystis aeruginosa as a model organism. The experiments are based on exposing populations to severe stress and analyze the effect of previous dispersal events and deterioration rates on the occurrence of ER events among populations. The model consists in three different rates of environmental change (constant, slow and fast; under salinity stress we only used the first two treatments) and three dispersal models (isolated, local or global). In total, 324 and 720 populations were exposed to stressful conditions caused by sulphur and salinity, respectively. The results showed that the dispersal modes and the environmental deterioration rates modulated the occurrence of ER events. It has been observed that dispersal favours ER events for both selective agents. Regarding the rate of environmental change, we observed an increase of ER events under constant changes in the populations exposed to sulphur stress. However, ER events were higher when there was previous deterioration (i.e., slow environmental change rate) under saline stress. As a conclusion, ER events in M. aeruginosa depend on selective agent, being the probability higher for salinity than for sulphur. Thus, it could be hypothesized that general conclusions in ER studies must take into account the selective agent.This work has been financially supported by the projects CGL2014- 53682-P (Ministerio de Economía y Competitividad) and CGL2017-87314-P (Ministerio de Economía, Industria y Competitividad), and the Universidad de Málaga, Campus de Excelencia Internacional Andalucía Tech

Characterization of the cyanobacterium Oscillatoria sp. isolated from extreme sulphureous water from Los Baños de la Hedionda (S Spain)

Los Baños de la Hedionda (Málaga, S Spain) is a natural sulphureous spa (150-200 µM sulphide). Although this high sulphide levels can affect the photosynthetic process, there are numerous photosynthetic microorganisms inhabiting the spa. Among them, we isolated a strain of the cyanobacterium Oscillatoria sp., a genus well known by its tolerance to sulphide. Objectives Firstly, to analyze the photosynthetic characteristics and growth rate of the isolated strain, as well as the effect of the presence of sulphide in both processes. Secondly, to determine the limit of genetic adaptation of this strain to sulphide. Methods The resistance of the isolated strain to sulphide was studied by analyzing the effect of increasing sulphide levels (up to 1600 µM) on photosynthetic performance and growth. The limit of genetic adaptation was explored using an evolutionary experimental design named as ratchet protocol. This design allows discerning the maximum capacity of genetic adaptation of Oscillatoria sp. to the exposure of increasing doses of sulphide Conclusions The strain showed maximum growth rates at 200 µM sulphide although reduced rates can be found up to 800 µM sulphide. A significant increase in resistance was achieved in all derived populations during the ratchet experiment (surviving at sulphide concentrations higher than 2 mM). Moreover, they showed different evolutionary potential to adapt to sulphide, depending on historical contingency.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.Spanish Ministry of Science and Innovation through CGL2014-53682-P project. Predoctoral State Grant from Scientific and Technical Research and Innovation Plan, Spanish Ministry of Economy, Industry and Competitiveness I+D+i ECC/1402/2013, 201

Disentangling mechanisms involved in the adaptation of the cyanobacterium Microcystis aeruginosa to the extreme sulphureous water from Los Baños de la Hedionda (S Spain)

Backgrounds Los Baños de la Hedionda (Málaga, S Spain) is a natural sulphureous spa where sulphide can reach a concentration of 150-200 µM. Although this ion has biocide properties, including inhibition of the photosynthetic process, a rich flora can be found in this extreme environment. Objectives To study the adaptation mechanisms allowing resistance of photosynthetic microorganisms to these sulphureous waters Methods For this purpose, a modified Luria–Delbrück fluctuation analysis was carried out. The adaptation to La Hedionda waters of three different strains of the cyanobacterium Microcystis aeruginosa (Kützing) Kützing (isolated from a non-sulphureous freshwater reservoir) was analyzed in order to find out if it was achieved by a physiological adaptation process (acclimation) or by the selection of rare spontaneous mutations (genetic adaptation). Conclusions Several resistant strains were obtained after 6 weeks of cultivation with La Hedionda waters. The fluctuation analysis showed that genetic adaptation was the phenomenon that allowed resistant M. aeruginosa cells from the three strains to survive, with similar mutation rates in the order of magnitude of 1 mutant resistant cell per 106-107 cell division-1. It could be hypothesized that this cyanobacterium could adapt to sulphureous environment by the selection of favoured mutants.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.Spanish Ministry of Science and Innovation through CGL2014-53682-P project. Predoctoral State Grant from Scientific and Technical Research and Innovation Plan, Spanish Ministry of Economy, Industry and Competitiveness I+D+i ECC/1402/2013, 201

Differences in the degree of inhibition of NDP reductase by chemical inactivation and by the thermosensitive mutation nrdA101 in Escherichia coli suggest an effect on chromosome segregation.

NDP reductase activity can be inhibited either by treatment with hydroxyurea or by incubation of an nrdAts mutant strain at the non-permissive temperature. Both methods inhibit replication, but experiments on these two types of inhibition yielded very different results. The chemical treatment immediately inhibited DNA synthesis but did not affect the cell and nucleoid appearance, while the incubation of an nrdA101 mutant strain at the nonpermissive temperature inhibited DNA synthesis after more than 50 min, and resulted in aberrant chromosome segregation, long filaments, and a high frequency of anucleate cells. These phenotypes are not induced by SOS. In view of these results, we suggest there is an indirect relationship between NDP reductase and the chromosome segregation machinery through the maintenance of the proposed replication hyperstructure.post-print734 K

The limit of sulphide adaptation in the sulphide-sensitive cyanobacterium "Microcystis aeruginosa"

Libro de resúmenes de ponencias y comunicaciones. XXVII Congreso Nacional de Microbiología 2019, p 276 , ISBN 978-84-09-02644-9Although sulphide has played an important role in the evolution of photosynthesis, it produces a lethal effect on most photosynthetic organisms due to its redox activity on certain enzymes, inhibiting oxygenic photosynthetic and respiratory electron transport. However, cyanobacteria vary in sulphide tolerance, showing different degrees of sulphide resistant oxygenic photosynthesis and even some taxa have the capacity to perform anoxygenic sulphide-dependent photosynthesis. Microcystis aeruginosa is a sulphide-sensitive species. However, it is known that genetic adaptation of aquatic photosynthetic microorganisms to selective agents can be rapidly achieved, even at lethal levels, as the consequence of single mutations. The aim of this work was to determine the maximum sulphide concentration to which this sulphide-sensitive species is able to adapt in order to shed light on the process of sulphide adaptation in cyanobacteria. We used three M. aeruginosa strains, Ma1Vc, Ma5Vc and MaAVc, isolated from a non-sulphureous environment, and whose lethal doses were 0.10, 0.16 and 0.20 mM sulphide, respectively. To study the adaptation of these strains to sulphide a modified ratchet experiment was carried out [...]. The M. aeruginosa strains reached different limits of sulphide adaptation. Ma5Vc and Ma1Vc strains adapted up to 0.40 mM sulphide, i.e. 2,5-fold and 4-fold their initial lethal doses, respectively. However, the MaAVc strain, which showed an initial higher sulphide tolerance, adapted up to only 0.27 mM. Sulphide-lethal dose and photosynthetic performance of the resistant strains obtained in the ratchet experiment were characterized. The lethal dose of the M. aeruginosa Ma1Vc and Ma5Vc mutant strains was 0.40 and 0.72 mM sulphide, respectively. These resistant strains showed lower growth and photosynthetic rates than wild-type ones in the absence of sulphide, which indicates the physiological cost of the mutation conferring sulphide resistance.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Elección del modo de entrada y resultado de la estrategia internacional de las cadenas hoteleras, bajo el enfoque de opciones reales

Este trabajo presenta un modelo explicativo de la elección del modo de entrada a un mercado internacional y de la repercursión de dicha elección sobre el resultado de la estrategia internacional de las cadenas hoteleras, bajo el enfoque dinámico de la teoría de opciones reales. Para ello se analiza la aplicabilidad de dicha teoría a este campo de estudio, complementándola con las aportaciones de la teoría de los costes de transacción y la teoría del proceso de internacionalización.This paper presents an explanatory model for the entry mode choice to an international market and its implications on the performance of the international strategy in hotel chains, under the dynamic real options theory approach. We examine the applicability of this theory in this field of study, supplemented by contributions from transaction costs and internationalization process theories

CIRCULAR ECONOMY AND ENVIRONMENTAL BEHAVIOUR: A SYSTEMATIC LITERATURE REVIEW

The circular economy is a top priority issue on the European green agenda. However, despite this topic having been studied for decades, there seem to be no clear ideas about how to carry out the strategies and actions that allow achieving the presupposed objectives. For this reason, this paper aims to offer a systematic literature review that might provide researchers with a synthesis paper on what has been studied so far. To achieve that, descriptive and bibliometric analyses were performed on the bibliographic data obtained from the Web of Science. That, together with the study of the most prominent extant pieces of work in the field, both historical and present, allow offering a comprehensive picture of the state of arts. Thus, the main conclusions are that there is no clear study trend and, consequently, efforts are dissipating. In addition, the problem of the budget limitation is acknowledged since it might prevent researchers from carrying out solid experiments that may allow finding general solutions to the problems derived from the implementation of circular economy strategies or actions

Relationship between Fork Progression and Initiation of Chromosome Replication in E. coli

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