Diorganotin dihalide complexes of 2,2'-biimidazole. A preliminary study of their inhibitory effects on cell division

We report the synthesis of new complexes with the general formula (R2SnX2)y.H2BiIm, where y = 1 or 2; R = Me, Et, Bun; X = Cl or Br (for R = Et) and H2BiIm = 2,2'-Biimidazole. The complexes have been characterized by elemental analysis and M?ssbauer, infra-red and 1H n.m.r. spectroscopy and tested (like the ligand, Me2SnCl2 and Et2SnCl2) against P388D1 leukemic cells.     

Structural and ecophysiological adaptations to forest gaps

To survive new microclimatic conditions of a forest gap environment, plant species must physiologically and structurally adjust. A morpho-anatomical, ultrastructural and ecophysiological study was performed at three different times in a forest gap that was created by illegal selective logging. The study followed the early successional Actinostemon verticillatus and the late-successional Metrodorea brevifolia, to elucidate the adaptive strategies of acclimation to gaps. Additionally, Schinus terebinthifolius was included in the study in order to test the plasticity of a pioneer species that grows on forest edges, where this species had higher values of leaf thickness, leaf mass area and succulence. M. brevifolia had succulent leaves, high leaf area and a thin cuticle. A. verticillatus presented the densest leaves and was the only species to show leaf morpho-anatomical plasticity. Ultrastructural and physiological differences were observed only in A. verticillatus and M. brevifolia leaves from the gap: increase in the stroma volume, oil droplets, plastoglobuli, photochemical and non-photochemical quenching. Photosynthetic efficiency showed that the early stages of gap formation are the most critical. Acclimation strategies of A. verticillatus suggest this species invests in the efficiency of photosynthesis by increasing its leaf thickness, leaf mass area and in water content maintenance by increasing the density of its leaves, at the expense of gas exchange, was compensated by a high density of stomata. M. brevifolia compensates for the higher cost of leaves and lower leaf plasticity with ultrastructural changes that are used to adjust the photosynthetic process, which promotes a shorter leaf payback time.     

A spin label study of erythrocyte membranes during simulation of freezing

Summary Human erythrocytes were labeled with stearic acid spin labels, and no change was detected in membrane fluidity under hyperosmotic stress, going from isotonicity to about 3000 mOsm. Intact erythrocytes labeled with an androstane spin label and submitted to simulation of freezing show the onset of irreversible structural breakdown occurring in a saline solution at 2,000 mOsm. Ghosts labeled with maleimide spin label (4-maleimide-2,2,6,6-tetramethylpiperidinooxyl) when submitted to solutions of increasing osmolalities (pH 7.4), exhibit protein conformational changes that are irreversible after a simulated freeze-thaw cycle. After sonication of maleimide spin-labeled ghosts, membrane buried sulfhydryl groups become exposed. Such preparations showed behavior similar to the unsonicated when in saline hyperosmolal medium (pH 7.4). Such results suggest the ionic strength of the medium as the determining factor of the detected conformational changes. Maleimide spin-labeled ghosts in 300 mOsm saline solution (pH 7.4) were treated with ascorbic acid (spin destruction of nitroxides), and the kinetic analysis indicates that 65% of the labeled sites are located at the external interface of the membrane or in hydrophilic channels. Deformation and rearrangements of membrane components in solutions of increasing osmolalities apparently are related to protein conformational changes, on the outside surface of erythrocyte membranes, with a significant amount being structurally dissociated of lipids.     

Molecular and morphometric analyses identify new lineages within a large Eumida (Annelida) species complex

We report on two new lineages of the Eumida sanguinea complex from Great Britain and describe one of them as a new species using a multilocus approach, including the mitochondrial DNA COI-5P and the nuclear markers ITS (ITS1, 5.8S rRNA and ITS2) and 28S rRNA. The molecular analysis placed Eumida mackiei sp. nov. in a monophyletic clade with 19.1% (COI), 10.1% (ITS) and 1.7% (28S) mean distance to its nearest neighbour. Molecular diagnoses were also applied to nine lineages within the E. sanguinea complex. This was complemented with morphometric data employing multivariate statistical analysis and the incorporation of statistical dissimilarities against three other described species from the complex. Eumida mackiei sp. nov. can be distinguished from E. notata and E. maia by the larger distance between the eyes and differences in morphometric proportions mainly in the dorsal and ventral cirri as well as in the prostomial appendages. E. sanguinea sensu stricto failed to produce a cluster of its own in the morphometric analysis, probably due to juvenile bias. Integrative taxonomy provided strong evidence to formally describe a new cryptic species that can now be used in biomonitoring or other relevant ecological research.     

An African bat in Europe,Plecotus gaisleri: Biogeographic and ecological insights from molecular taxonomy and Species Distribution Models

Because of the high risk of going unnoticed, cryptic species represent a major challenge to biodiversity assessments, and this is particularly true for taxa that include many such species, for example, bats. Long‐eared bats from the genus Plecotus comprise numerous cryptic species occurring in the Mediterranean Region and present complex phylogenetic relationships and often unclear distributions, particularly at the edge of their known ranges and on islands. Here, we combine Species Distribution Models (SDMs), field surveys and molecular analyses to shed light on the presence of a cryptic long‐eared bat species from North Africa, Plecotus gaisleri, on the islands of the Sicily Channel, providing strong evidence that this species also occurs in Europe, at least on the islands of the Western Mediterranean Sea that act as a crossroad between the Old Continent and Africa. Species Distribution Models built using African records of P. gaisleri and projected to the Sicily Channel Islands showed that all these islands are potentially suitable for the species. Molecular identification of Plecotus captured on Pantelleria, and recent data from Malta and Gozo, confirmed the species' presence on two of the islands in question. Besides confirming that P. gaisleri occurs on Pantelleria, haplotype network reconstructions highlighted moderate structuring between insular and continental populations of this species. Our results remark the role of Italy as a bat diversity hotspot in the Mediterranean and also highlight the need to include P. gaisleri in European faunal checklists and conservation directives, confirming the usefulness of combining different approaches to explore the presence of cryptic species outside their known ranges—a fundamental step to informing conservation.