Optimal foraging strategies: Lévy walks balance searching and patch exploitation under a very broad range of conditions

While evidence for optimal random search patterns, known as Lévy walks, in empirical movement data is mounting for a growing list of taxa spanning motile cells to humans, there is still much debate concerning the theoretical generality of Lévy walk optimisation. Here, using a new and robust simulation environment, we investigate in the most detailed study to date (24×10(6) simulations) the foraging and search efficiencies of 2-D Lévy walks with a range of exponents, target resource distributions and several competing models. We find strong and comprehensive support for the predictions of the Lévy flight foraging hypothesis and in particular for the optimality of inverse square distributions of move step-lengths across a much broader range of resource densities and distributions than previously realised. Further support for the evolutionary advantage of Lévy walk movement patterns is provided by an investigation into the 'feast and famine' effect, with Lévy foragers in heterogeneous environments experiencing fewer long 'famines' than other types of searchers. Therefore overall, optimal Lévy foraging results in more predictable resources in unpredictable environments.

Widespread occurrence of the non-indigenous ascidian Corella eumyota Traustedt, 1882 on the shores of Plymouth Sound and Estuaries Special Area of Conservation, UK

The ascidian Corella eumyota, originally from the Southern Hemisphere, was first reported in the Northern Hemisphere in Brittany, France, in 2002. Since then, it has been recorded in Spain, Ireland, the south coast of England and South Wales. Most European records to date have been from artificial habitats such as marinas. In Plymouth, England, C. eumyota was first found in two marinas in 2005 but individuals were soon also detected in small numbers on nearby shores. Shore surveys in March and August of 2008 indicated that C. eumyota has established reproductive populations on natural and semi-natural shores of Plymouth Sound and the adjacent coastline, largely restricted to relatively sheltered sites in the lower reaches of estuaries. At these sites it is generally the most abundant non-colonial ascidian. The species clearly has the capacity to become a significant component of the biota of sheltered shores in the Northern Hemisphere.

Adiciones al catálogo de líquenes de la isla de Madeira (Portugal)

Se comentan 12 especies de líquenes que no estaban citadas anteriormente para la isla de Madeira. Blarneya hibernica es nueva cita para la región Macaronésica.

New records of interesting xenophytes in the Iberian Peninsula. V

As a continuation of previous research on the naturalization of non-native vascular plants in the Iberian Peninsula new chorological data are presented for 16 xenophytes recorded between 2010 and 2014, mostly in the provinces of Huelva and Barcelona (Spain) and in the Algarve and Estremadura (Portugal). For each taxon details about distribution, habitats occupied, previous records, degree of naturalization, etc. are provided. Lachenalia bulbifera and Cyperus albostriatus are probably reported for the first time in the wild in Europe, as are Gamochaeta filaginea, and Dysphania anthelmintica and Oenothera lindheimeri for Portugal and Spain respectively. Cosmos bipinnatus is cited as a novelty for the Algarve (Portugal). Newly reported or confirmed for the province of Huelva are: Amaranthus hypochondriacus, Epilobium brachycarpum, Nephrolepis cordifolia, Ficus microcarpa, Tamarix parviflora and Tamarix ramosissima, while Atriplex semibaccata, Chloris truncata, and Elymus elongatus subsp. ponticus are new for Barcelona. Finally, Passiflora caerulea is a novelty for both Barcelona and Huelva provinces.

Polycyclic aromatic hydrocarbons (PAHS) (I): Measures of prevention and control

Measures of prevention and control against polycyclic aromatic hydrocarbons (PAHs) focus on an official food control, a code of best practice to reduce PAHs levels by controlling industry and in the development of a chemopreventive strategy. Regulation (EU) 835/2011 establishes maximum levels of PAHs for each food group. In addition, Regulations (EU) 333/2007 and 836/2011 set up the methods of sampling and analysis for its official control. Scientific studies prove that the chemopreventive strategy is effective against these genotoxic compounds effects. Most chemopreventive compounds studied with proven protective effects against PAHs are found in fruit and vegetables.

La Inteligencia Competitiva en los procesos de internacionalización empresarial: Una guía de recursos de información para la empresa española y el periodismo económico

La información se ha convertido en un recurso imprescindible para el proceso de toma de decisiones en las empresas, y elemento fundamental en el proceso de Inteligencia Competitiva. La globalización económica y la libre circulación de mercancías, bien sea dentro de estructuras supranacionales o derivados de la firma de Tratados internacionales, han aumentado el número de competidores presentes en los mercados, pero también las oportunidades para acceder a otros mercados internacionales. Este trabajo describe los recursos de información más importantes que puede necesitar una empresa en su acceso a los mercados internacionales, y que proceden tanto de organismos públicos como privados.

Creación de una filmoteca de prácticas para la Facultad de Ciencias de la Información de la UCM: Adecuación de espacio y estrategias de catalogación

En el presente trabajo se da el primer paso para la creación de una Filmoteca de Prácticas en la facultad de Ciencias de la Información de la Universidad Complutense de Madrid. El Patrimonio Fílmico se ve gravemente expuesto al paso del tiempo y el abandono por lo que se necesita un rescate urgente. Mediante un riguroso trabajo de investigación, en el que se estudian diferentes propuestas y normativas expuestas por organismos especializados, se redacta un manual de inicio. Se han investigado, diseñado y propuesto las herramientas básicas y útiles para poner en funcionamiento la primera Filmoteca de Prácticas en el ámbito universitario español.

Divergent Paths of Development: The Modern World-System and Democratization in South Africa and Zambia

This article examines whether a Modern World- Systems (MWS) perspective can provide an improved understanding of the processes of democratization in Africa (and other developing regions of the world) by conducting a comparative case study of South Africa and Zambia in the 1990s, examining the transitions to democracy and divergent processes of democratic consolidation in each country. Semiperipheral South Africa has, due to its more advantageous position in the world-system, been better equipped than peripheral Zambia to safeguard democracy against erosion and reversal. Th e central irony of the MWS is that the weakest states in the MWS can be pushed around by core powers and are more easily forced to democratize while at the same time they are least likely to possess the resources necessary for democratic consolidation. Semiperipheral states can maintain their independence vis-à-vis the core to a higher degree, but if the decision is made to undertake a democratic transition they are more likely to possess the resources necessary for successful consolidation. Th e MWS perspective allows for an improved understanding of the causal pathway of how position in the MWS translates into the ability to consolidate democracy than does approaches that emphasize domestic factors.