Impact of Alien Plant Invaders on Pollination Networks in Two Archipelagos

Mutualistic interactions between plants and animals promote integration of invasive species into native communities. In turn, the integrated invaders may alter existing patterns of mutualistic interactions. Here we simultaneously map in detail effects of invaders on parameters describing the topology of both plant-pollinator (bi-modal) and plant-plant (uni-modal) networks. We focus on the invader Opuntia spp., a cosmopolitan alien cactus. We compare two island systems: Tenerife (Canary Islands) and Menorca (Balearic Islands). Opuntia was found to modify the number of links between plants and pollinators, and was integrated into the new communities via the most generalist pollinators, but did not affect the general network pattern. The plant uni-modal networks showed disassortative linkage, i.e. species with many links tended to connect to species with few links. Thus, by linking to generalist natives, Opuntia remained peripheral to network topology, and this is probably why native network properties were not affected at least in one of the islands. We conclude that the network analytical approach is indeed a valuable tool to evaluate the effect of invaders on native communities

Impact of Alien Plant Invaders on Pollination Networks in Two Archipelagos

Mutualistic interactions between plants and animals promote integration of invasive species into native communities. In turn, the integrated invaders may alter existing patterns of mutualistic interactions. Here we simultaneously map in detail effects of invaders on parameters describing the topology of both plant-pollinator (bi-modal) and plant-plant (uni-modal) networks. We focus on the invader Opuntia spp., a cosmopolitan alien cactus. We compare two island systems: Tenerife (Canary Islands) and Menorca (Balearic Islands). Opuntia was found to modify the number of links between plants and pollinators, and was integrated into the new communities via the most generalist pollinators, but did not affect the general network pattern. The plant uni-modal networks showed disassortative linkage, i.e. species with many links tended to connect to species with few links. Thus, by linking to generalist natives, Opuntia remained peripheral to network topology, and this is probably why native network properties were not affected at least in one of the islands. We conclude that the network analytical approach is indeed a valuable tool to evaluate the effect of invaders on native communities

Notes on the feeding habits of the Caribbean Watersnake, Tretanorhinus variabilis (Dipsadidae)

The Caribbean Watersnake, Tretanorhinus variabilis (Dipsadidae) is one of two aquatic West Indian snakes. Despite being a relatively common species in Cuba and the Cayman Islands, its feeding habits have been poorly stud­ied. Herein we report several new instances of predation by this species on fishes, frogs, and a freshwater crab. The latter represents the first record of durophagy in this species and the third snake reported as a crab eater in the West Indies. &nbsp

A small molecule tubulin depolymerizing agent identified by a phenotypic drug discovery approach

In the scenario of drug discovery, numerous in vitro testing initiatives had been established. Thus far, no general methodology is reputable and literature on this hot topic is scarce. In this respect, we propose a strategy based on a Phenotypic Drug Discovery approach. Within our program directed at the discovery of new antitumor agents, we have focused our attention on compounds that disturb the cell cycle. Our strategy relies on the use of a set of biological assays organized in a modular fashion. Herein, we exemplified this strategy with a family of propargylic enol ether derivatives. Using different assays in sequential stages and in a stepwise manner, our studies allowed us to understand the bioactivity of this family of compounds and led us to identify tubulin as the main molecular target.info:eu-repo/semantics/publishedVersio

Synthesis and biological evaluation of crown ether acyl derivatives

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High-resolution spectroscopy of Boyajian's star during optical dimming events

Financial support from the Spanish Ministry of Economy and Competitiveness through projects AYA2014-60833-P, AYA2014-60476-P, and AYA2017-86389-P are gratefully acknowledged. MJMG and JIGH also acknowledge financial support through the Ramón y Cajal fellowship. GMK is supported by the Royal Society as a Royal Society University Research Support Fellow.Boyajian’s star is an apparently normal main-sequence F-type star with a very unusual light curve. The dipping activity of the star, discovered during the Kepler mission, presents deep, asymmetric, and aperiodic events. Here we present high-resolution spectroscopic follow-up during some dimming events recorded post-Kepler observations, from ground-based telescopes. We analyse data from the HERMES, HARPS-N, and FIES spectrographs to characterize the stellar atmosphere and to put some constraints on the hypotheses that have appeared in the literature concerning the occulting elements. The star’s magnetism, if existing, is not extreme. The spots on the surface, if present, would occupy 0.02 per cent of the area, at most. The chromosphere, irrespective of the epoch of observation, is hotter than the values expected from radiative equilibrium, meaning that the star has some degree of activity. We find no clear evidence of the interstellar medium or exocoments being responsible for the dimmings of the light curve. However, we detect at 1–2σ level, a decrease of the radial velocity of the star during the first dip recorded after the Kepler observations. We claim the presence of an optically thick object with likely inclined and high impact parameter orbits that produces the observed Rossiter–McLaughlin effect.Publisher PDFPeer reviewe

Repeated magmatic intrusions at El Hierro Island following the 2011–2012 submarine eruption

After more than 200 years of quiescence, in July 2011 an intense seismic swarm was detected beneath the center of El Hierro Island (Canary Islands), culminating on 10 October 2011 in a submarine eruption, 2 km off the southern coast. Although the eruption officially ended on 5 March 2012, magmatic activity continued in the area. From June 2012 to March 2014, six earthquake swarms, indicative of magmatic intrusions, were detected underneath the island. We have studied these post-eruption intrusive events using GPS and InSAR techniques to characterize the ground surface deformation produced by each of these intrusions, and to determine the optimal source parameters (geometry, location, depth, volume change). Source inversions provide insight into the depth of the intrusions (~ 11–16 km) and the volume change associated with each of them (between 0.02 and 0.13 km3). During this period, > 20 cm of uplift was detected in the central-western part of the island, corresponding to approximately 0.32–0.38 km3 of magma intruded beneath the volcano. We suggest that these intrusions result from deep magma migrating from the mantle, trapped at the mantle/lower crust discontinuity in the form of sill-like bodies. This study, using joint inversion of GPS and InSAR data in a post-eruption period, provides important insight into the characteristics of the magmatic plumbing system of El Hierro, an oceanic intraplate volcanic island