Walkway on coastal dunes negatively affects mobility of the spiny–footed lizard Acanthodactylus erythrurus

Las pasarelas en las dunas costeras perjudican la movilidad de la lagartija colirroja Acanthodactylus erythrurus Los sistemas dunares son los ecosistemas más degradados de toda la costa europea y la actividad humana ha causado una profunda transformación en la costa mediterránea de España. En Torredembarra (Tarragona, España) habita una población de lagartija colirroja Acanthodactylus erythrurus en algunas de las dunas naturales y parches de vegetación que aún existen, donde la fauna silvestre coexiste con unas intensas actividades turísticas. Nuestro objetivo fue conocer si las pasarelas instaladas sobre las dunas estaban afectando a la movilidad de la lagartija colirroja. Se comparó la movilidad de lagartijas marcadas entre dos zonas con hábitat similar, pero una con pasarelas y otra sin. Se observó que las pasarelas acortaron las distancias entre reavistamientos consecutivos y que afectaban más a los juveniles de lagartija colirroja que a los adultos. Llegamos a la conclusión de que la pasarela puede estar afectando a las interacciones sociales naturales de la especie.Dune systems are the most degraded ecosystems of the entire European coast, and human activity on the Mediterranean coast of Spain has caused dramatic transformation. In Torredembarra (Tarragona, Spain), a population of spiny–footed lizards Acanthodactylus erythrurus inhabits the few remaining natural dunes and vegetation patches where wildlife coexists with intensive tourism activities. Our aim was to know whether walkways installed across the dunes were affecting the mobility of the spiny–footed lizard. We compared the mobility of marked lizards in two areas with a similar habitat, one with and one without a walkway. We found that the walkway reduced the distances between consecutive resightings, affecting juveniles more than adults. We conclude that the walkway may affect social interactions in the species.Las pasarelas en las dunas costeras perjudican la movilidad de la lagartija colirroja Acanthodactylus erythrurus Los sistemas dunares son los ecosistemas más degradados de toda la costa europea y la actividad humana ha causado una profunda transformación en la costa mediterránea de España. En Torredembarra (Tarragona, España) habita una población de lagartija colirroja Acanthodactylus erythrurus en algunas de las dunas naturales y parches de vegetación que aún existen, donde la fauna silvestre coexiste con unas intensas actividades turísticas. Nuestro objetivo fue conocer si las pasarelas instaladas sobre las dunas estaban afectando a la movilidad de la lagartija colirroja. Se comparó la movilidad de lagartijas marcadas entre dos zonas con hábitat similar, pero una con pasarelas y otra sin. Se observó que las pasarelas acortaron las distancias entre reavistamientos consecutivos y que afectaban más a los juveniles de lagartija colirroja que a los adultos. Llegamos a la conclusión de que la pasarela puede estar afectando a las interacciones sociales naturales de la especie

Searching for molecular outflows in Hyper-Luminous Infrared Galaxies

We present constraints on the molecular outflows in a sample of five Hyper-Luminous Infrared Galaxies using Herschel observations of the OH doublet at 119 {\mu}m. We have detected the OH doublet in three cases: one purely in emission and two purely in absorption. The observed emission profile has a significant blueshifted wing suggesting the possibility of tracing an outflow. Out of the two absorption profiles, one seems to be consistent with the systemic velocity while the other clearly indicates the presence of a molecular outflow whose maximum velocity is about ~1500 km/s. Our analysis shows that this system is in general agreement with previous results on Ultra-luminous Infrared Galaxies and QSOs, whose outflow velocities do not seem to correlate with stellar masses or starburst luminosities (star formation rates). Instead the galaxy outflow likely arises from an embedded AGN.Comment: Accepted for publication in MNRAS. 13 pages, 11 figures, 4 table

Evolution of the ISM in Luminous IR Galaxies

Molecules that trace the high-density regions of the interstellar medium may be used to evaluate the changing physical and chemical environment during the ongoing nuclear activity in (Ultra-)Luminous Infrared Galaxies. The changing ratios of the HCN(1-0), HNC(1-0), HCO+(1-0), CN(1-0) and CN(2-1), and CS(3-2) transitions were compared with the HCN(1-0)/CO(1-0) ratio, which is proposed to represent the progression time scale of the starburst. These diagnostic diagrams were interpreted using the results of theoretical modeling using a large physical and chemical network to describe the state of the nuclear ISM in the evolving galaxies. Systematic changes are seen in the line ratios as the sources evolve from early stage for the nuclear starburst (ULIRGs) to later stages. These changes result from changing environmental conditions and particularly from the lowering of the average density of the medium. A temperature rise due to mechanical heating of the medium by feedback explains the lowering of the ratios at later evolutionary stages. Infrared pumping may affect the CN and HNC line ratios during early evolutionary stages. Molecular transitions display a behavior that relates to changes of the environment during an evolving nuclear starburst. Molecular properties may be used to designate the evolutionary stage of the nuclear starburst. The HCN(1-0)/CO(1-0) and HCO+(1-0)/HCN(1-0) ratios serve as indicators of the time evolution of the outburst.Comment: To be published in Astronomy and Astrophysics - 11 pages, 9 figures, 1 tabl

Axisymmetric pulse recycling and motion in bulk semiconductors

The Kroemer model for the Gunn effect in a circular geometry (Corbino disks) has been numerically solved. The results have been interpreted by means of asymptotic calculations. Above a certain onset dc voltage bias, axisymmetric pulses of the electric field are periodically shed by an inner circular cathode. These pulses decay as they move towards the outer anode, which they may not reach. As a pulse advances, the external current increases continuously until a new pulse is generated. Then the current abruptly decreases, in agreement with existing experimental results. Depending on the bias, more complex patterns with multiple pulse shedding are possible.Comment: 8 pages, 15 figure

Edge dislocations in crystal structures considered as traveling waves of discrete models

The static stress needed to depin a 2D edge dislocation, the lower dynamic stress needed to keep it moving, its velocity and displacement vector profile are calculated from first principles. We use a simplified discrete model whose far field distortion tensor decays algebraically with distance as in the usual elasticity. An analytical description of dislocation depinning in the strongly overdamped case (including the effect of fluctuations) is also given. A set of $N$ parallel edge dislocations whose centers are far from each other can depin a given one provided $N=O(L)$, where $L$ is the average inter-dislocation distance divided by the Burgers vector of a single dislocation. Then a limiting dislocation density can be defined and calculated in simple cases.Comment: 10 pages, 3 eps figures, Revtex 4. Final version, corrected minor error

Reaction-Diffusion System in a Vesicle with Semi-Permeable Membrane

We study the Schloegl model in a vesicle with semi-permeable membrane. The diffusion constant takes a smaller value in the membrane region, which prevents the outflow of self-catalytic product. A nonequilibrium state is stably maintained inside of the vesicle. Nutrients are absorbed and waste materials are exhausted through the membrane by diffusion. It is interpreted as a model of primitive metabolism in a cell.Comment: 8 pages, 6 figure

Profilaxis de los puentes óseos fisarios mediante interposición de injerto autólogo de periostio. Estudio experimental en conejos

Se ha realizado un trabajo experimental sobre la profilaxis de los puentes óseos epifisometafisarios mediante la interposición de injerto autólogo de periostio, planteando los siguientes objetivos: 1) Conseguir una barrera epifisometafisaria que impida la comunicación de los vasos epifisarios y metafisarios y 2) Estudiar la capacidad condrogénica del periostio. Se han utilizado 48 conejos, distribuidos en dos Series de cuatro Grupos cada una, según el momento del sacrificio a la 1a, 2a, 4a y 8a semanas. En la serie Control, se procedió a la extirpación de 1/3 de la fisis distal externa, mientras que en la Experimental se interpuso un injerto Ubre de periostio. Todos los especímenes se estudiaron macroscópica, radiológica e histológicamente. Las conclusiones han sido, que el periostio como injerto Ubre: 1) Actúa como barrera pasiva en las lesiones fisarias en las primeras semanas. 2) Tiene capacidad condrogénica en las primeras semanas. 3) A largo plazo no es un material efectivo en la profilaxis de los puentes óseos epífiso-metafisarios.An experimental work has been carried out on prevention of fiseal bone bridges formation by means of interposing autologus periosteum graft, bringing up the following objetives: 1) To achieve a barrier which can prevent the communication between epiphyseal and metaphyseal vessels, and 2) To study the condrogenic potencial of periosteum. A total of 48 rabbits have been used, arranged in three series of four groups each, acording to the moment of sacrifice in the 1st, 2nd, 4th and 8 t h weeks. They were all operated on the right femur. In the control serie an extirpation of 1/3 of the outer and distal growth plate was carried out, while in the experimental series the created defect was filled up with a free periosteum graft. All the specimens were studied macroscopically, radiologically and histologically. As conclusions, the periosteum used as a free graft: 1) In the first weeks act like a pasive barrier in physeal lesions, 2) It has also condrogenic capacity in the first weeks and, 3) On large follow-up studies, the periosteum do not seems to be a efective material to prevent physeal bone bridges

Can Eucalyptus plantations influence the distribution range of mesocarnivores?

Context The expansion of exotic plantations can impose conservation challenges on wildlife, and the Iberian Peninsula has one of the widest planted areas of exotic Eucalyptus sp. in Europe. Since mesocarnivores are pivotal elements of ecosystems’ functioning and Eucalyptus have been modifying the Portuguese landscape context in the last half century, it is crucial to understand how these systems may affect carnivores’ range. Objectives We aim to identify the drivers of five mesocarnivores’ distribution in Portugal (e.g., land-cover, ecogeographic predictors, mammal prey availability) and understand the influence of Eucalyptus plantations in their distribution range. Methods Using generalized linear models, we modelled the distribution range of mesocarnivores. The initial dataset was randomly split for model training and validation, and the multicollinearity between the predictors was tested. Then, we examined the potential relationship between the Eucalyptus plantations area and the predicted probability presence of each species. Results We detected species-specific patterns explained by different drivers, including climatic, land cover and mammal prey related ones. Furthermore, in areas of Eucalyptus plantations, the probability of occurrence of most Portuguese mesocarnivores is lower: red fox,stone marten,European badger, and Egyptian mongoose. Conclusions Managers must take action to adapt their management to promote native forest patches within plantation, and allow the development of some understory within stands, to improve this plantation’s permeability to mesocarnivores. This will increase the spatial heterogeneity and enhance resource availability, reducing the constraints that plantations might have on the range of mesocarnivores in Portugal.info:eu-repo/semantics/publishedVersio