Habitat suitability modelling of four terrestrial slug species in the Iberian Peninsula (Arionidae: Geomalacus species)

Ecological niche modelling (ENM) determines habitat suitability of species by relating records of occurrence to environmental variables. Here, we investigated habitat suitability of four terrestrial slugs of the genus Geomalacus from the Iberian Peninsula using ENM. The potential distribution of these species was estimated using maximum entropy modelling. For this we used published presence records, together with observations from our fieldwork, and 10 layers of environmental variables in a crossvalidation design using ` minimum predicted area' as a measure of success. For each species, the models predicted distributions with high accuracy, while restricting predictions to minimum areas. Precipitation, and to a lesser extent temperature, were the most important variables to predict the distributions of the four species. We then compared the predicted distributions with the currently known distributions. For G. anguiformis and G. maculosus the predicted distributions included the known distributions, but also nearby mountain areas where these species have not previously been found. For G. malagensis and G. oliveirae the models predicted much wider distributions. Subsequent dedicated fieldwork could not confirm the presence of G. oliveirae in the newly predicted areas. Conversely, G. malagensis was found at five new and distant localities, including areas in Portugal where the species has not previously been recorded.Fundacao para a Ciencia e Tecnologia (Portugal) [SFRH/BD/30024/2006, PTDC/BIA-BDE/74349/2006]; BELSPO projects [MO/36/017]; IUAP-SPEEDYinfo:eu-repo/semantics/publishedVersio

Crayfish Recognize the Faces of Fight Opponents

The capacity to associate stimuli underlies many cognitive abilities, including recognition, in humans and other animals. Vertebrates process different categories of information separately and then reassemble the distilled information for unique identification, storage and recall. Invertebrates have fewer neural networks and fewer neural processing options so study of their behavior may reveal underlying mechanisms still not fully understood for any animal. Some invertebrates form complex social colonies and are capable of visual memory–bees and wasps, for example. This ability would not be predicted in species that interact in random pairs without strong social cohesion; for example, crayfish. They have chemical memory but the extent to which they remember visual features is unknown. Here we demonstrate that the crayfish Cherax destructor is capable of visual recognition of individuals. The simplicity of their interactions allowed us to examine the behavior and some characteristics of the visual features involved. We showed that facial features are learned during face-to-face fights, that highly variable cues are used, that the type of variability is important, and that the learning is context-dependent. We also tested whether it is possible to engineer false identifications and for animals to distinguish between twin opponents

Geographical variation in shell shape of the pod razor shell Ensis siliqua (Bivalvia: Pharidae)

The present study assessed the existence of variation in the shell shape of the pod razor shell (Ensis siliqua) throughout its distributional range in the north- eastern Atlantic. Shells of E. siliqua caught at seven collecting sites (three in Portugal, three in Spain and one in Ireland) were studied by geometric morphometric methods, using both landmark- and contour-based methods. Both approaches (landmarks inside the valves and shell outline) discriminated the shells from Aveiro (centre of Portugal) and Strangford Lough (Ireland) from those caught in the nearby localities (remaining Portuguese and Spanish sites,maximum distance of 550 km by sea). Landmark analysis revealed that shells from Aveiro were more similar to shells from Ireland (*1,500 km far away). Contour anal- ysis revealed that shells from Aveiro had a shape with a comparatively larger height-to-width ratio, whereas shells from Ireland showed a slightly more curved outline than in the remaining sites. Landmark- and contour-based methods provided coherent complementary information, confirming the usefulness of geometric morphometric analyses for discerning differences in shell shape among populations of E. siliqua. A brief review of previous applications of geometric morphometric methods to modern bivalve spe- cies is also provided.The authors would like to thank Dr. Dai Roberts and Adele Cromie for providing samples of pod razor shells from Ireland. This study was funded by Community Initiative Programmes (INTERREG-IIIB, Atlantic Area) Sustainable HARvesting of Ensis (090–SHARE) and Towards Integrated Management of Ensis Stocks (206–TIMES) from the European Community. Marta M. Rufino and Paulo Vasconcelos benefited from postdoctoral grants (SFRH/BPD/14935/2004 and SFRH/BPD/26348/2006, respectively) awarded by the Fundação para a Ciência e Tecnologia (FCT—Portugal). Finally, the authors acknowledge three anonymous referees for valuable comments and suggestions that greatly improved the revised manuscript.publishe

Potential therapeutic applications of microbial surface-activecompounds

Numerous investigations of microbial surface-active compounds or biosurfactants over the past two decades have led to the discovery of many interesting physicochemical and biological properties including antimicrobial, anti-biofilm and therapeutic among many other pharmaceutical and medical applications. Microbial control and inhibition strategies involving the use of antibiotics are becoming continually challenged due to the emergence of resistant strains mostly embedded within biofilm formations that are difficult to eradicate. Different aspects of antimicrobial and anti-biofilm control are becoming issues of increasing importance in clinical, hygiene, therapeutic and other applications. Biosurfactants research has resulted in increasing interest into their ability to inhibit microbial activity and disperse microbial biofilms in addition to being mostly nontoxic and stable at extremes conditions. Some biosurfactants are now in use in clinical, food and environmental fields, whilst others remain under investigation and development. The dispersal properties of biosurfactants have been shown to rival that of conventional inhibitory agents against bacterial, fungal and yeast biofilms as well as viral membrane structures. This presents them as potential candidates for future uses in new generations of antimicrobial agents or as adjuvants to other antibiotics and use as preservatives for microbial suppression and eradication strategies

RNA delivery by extracellular vesicles in mammalian cells and its applications.

The term 'extracellular vesicles' refers to a heterogeneous population of vesicular bodies of cellular origin that derive either from the endosomal compartment (exosomes) or as a result of shedding from the plasma membrane (microvesicles, oncosomes and apoptotic bodies). Extracellular vesicles carry a variety of cargo, including RNAs, proteins, lipids and DNA, which can be taken up by other cells, both in the direct vicinity of the source cell and at distant sites in the body via biofluids, and elicit a variety of phenotypic responses. Owing to their unique biology and roles in cell-cell communication, extracellular vesicles have attracted strong interest, which is further enhanced by their potential clinical utility. Because extracellular vesicles derive their cargo from the contents of the cells that produce them, they are attractive sources of biomarkers for a variety of diseases. Furthermore, studies demonstrating phenotypic effects of specific extracellular vesicle-associated cargo on target cells have stoked interest in extracellular vesicles as therapeutic vehicles. There is particularly strong evidence that the RNA cargo of extracellular vesicles can alter recipient cell gene expression and function. During the past decade, extracellular vesicles and their RNA cargo have become better defined, but many aspects of extracellular vesicle biology remain to be elucidated. These include selective cargo loading resulting in substantial differences between the composition of extracellular vesicles and source cells; heterogeneity in extracellular vesicle size and composition; and undefined mechanisms for the uptake of extracellular vesicles into recipient cells and the fates of their cargo. Further progress in unravelling the basic mechanisms of extracellular vesicle biogenesis, transport, and cargo delivery and function is needed for successful clinical implementation. This Review focuses on the current state of knowledge pertaining to packaging, transport and function of RNAs in extracellular vesicles and outlines the progress made thus far towards their clinical applications