Abstract: Aims One critical challenge for plants is to maintain an adequate nutrient supply under fluctuating environmental conditions. This is particularly true for epiphytic species that have limited or no access to the pedosphere and often live in harsh climates. Bromeliads have evolved key innovations such as epiphytism, water-absorbing leaf trichomes, tank habit and Crassulacean acid metabolism (CAM) photosynthesis that enable them to survive under various environmental conditions. Bromeliads encompass diverse ecological types that live on different substrates (they can be terrestrial, epilithic or epiphytic) and vary in their ability to retain water (they can be tank-forming or tankless) and photosynthetic pathway (i.e. C3 or CAM). In this review, we outline the nutritional modes and specializations that enable bromeliads to thrive in a wide range of nutrient-poor (mostly nitrogen-depleted) environments. Important Findings Bromeliads have evolved a great diversity of morphologies and functional adaptations leading to the existence of numerous nutritional modes. Focusing on species that have absorptive foliar trichomes, we review evidence that bromeliads have evolved multi-faceted nutritional strategies to respond to fluctuations in the supply of natural nitrogen (N). These plants have developed mutualistic associations with many different and functionally diverse terrestrial and aquatic microorganisms and metazoans that contribute substantially to their mineral nutrition and, thus, their fitness and survival. Bacterial and fungal microbiota-assisted N provisioning, protocarnivory, digestive mutualisms and myrmecotrophic pathways are the main strategies used by bromeliads to acquire nitrogen. The combination of different nutritional pathways in bromeliads represents an important adaptation enabling them to exploit nutrient-poor habitats. Nonetheless, as has been shown for several other vascular plants, multiple partners are involved in nutrient acquisition indicating that there have been convergent adaptations to nutrient scarcity. Finally, we point out some gaps in the current knowledge of bromeliad nutrition that offer fascinating research opportunities. © The Author 2015. Published by Oxford University Press on behalf of the Institute of Botany, Chinese Academy of Sciences and the Botanical Society of China.

Abstract: Ants have evolved venoms rich in peptides and proteins used for predation, defense, and communication. However, they remain extremely understudied due to the minimal amount of venom secreted by each ant. The present study investigated the differences in the proteome and peptidome of the venom from the bullet ant, Paraponera clavata. Venom samples were collected from a single colony either by manual venom gland dissection or by electrical stimulation and were compared using proteomic methods. Venom proteins were separated by 2D-PAGE and identified by nanoLC-ESI-QTOF MS/MS. Venom peptides were initially separated using C18 reversed-phase high-performance liquid chromatography, then analyzed by MALDI-TOF MS. The proteomic analysis revealed numerous proteins that could be assigned a biological function (total 94), mainly as toxins, or roles in cell regulation and transport. This investigation found that ca. 73% of the proteins were common to venoms collected by the two methods. The peptidomic analysis revealed a large number of peptides (total 309) but with <20% shared by the two collection methods. There was also a marked difference between venoms obtained by venom gland dissection from different ant colonies. These findings demonstrate the rich composition and variability of P. clavata venom.

Abstract: The rise of integrative taxonomy, a multi-criteria approach used in characterizing species, fosters the development of new tools facilitating species delimitation. Mass spectrometric (MS) analysis of venom peptides from venomous animals has previously been demonstrated to be a valid method for identifying species. Here we aimed to develop a rapid chemotaxonomic tool for identifying ants based on venom peptide mass fingerprinting. The study focused on the biodiversity of ponerine ants (Hymenoptera: Formicidae: Ponerinae) in French Guiana. Initial experiments optimized the use of automated matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) to determine variations in the mass profiles of ant venoms using several MALDI matrices and additives. Data were then analyzed via a hierarchical cluster analysis to classify the venoms of 17 ant species. In addition, phylogenetic relationships were assessed and were highly correlated with methods using DNA sequencing of the mitochondrial gene cytochrome c oxidase subunit 1. By combining a molecular genetics approach with this chemotaxonomic approach, we were able to improve the accuracy of the taxonomic findings to reveal cryptic ant species within species complexes. This chemotaxonomic tool can therefore contribute to more rapid species identification and more accurate taxonomies. Biological significance: This is the first extensive study concerning the peptide analysis of the venom of both Pachycondyla and Odontomachus ants. We studied the venoms of 17 ant species from French Guiana that permitted us to fine-tune the venom analysis of ponerine ants via MALDI-TOF mass spectrometry. We explored the peptidomes of crude ant venom and demonstrated that venom peptides can be used in the identification of ant species. In addition, the application of this novel chemotaxonomic method combined with a parallel genetic approach using COI sequencing permitted us to reveal the presence of cryptic ants within both the Pachycondyla apicalis and Pachycondyla stigma species complexes. This adds a new dimension to the search for means of exploiting the enormous biodiversity of venomous ants as a source for novel therapeutic drugs or biopesticides. This article is part of a Special Issue entitled: Proteomics of non-model organisms. © 2014 Elsevier B.V.

Abstract: A comparative study of two Sn-based composite materials as negative electrode for Li-ion accumulators is presented. The former SnB0.6P0.4O2.9 obtained by in-situ dispersion of SnO in an oxide matrix is shown to be an amorphous tin composite oxide (ATCO). The latter Sn-0.72[BPO4](0.28) obtained by ex-situ dispersion of Sri in a borophosphate matrix consists of Sri particles embedded in a crystalline BPO4 matrix. The electrochemical responses of ATCO and Sn-0.72.[BPO4](0.28) composite in galvanostatic mode show reversible capacities of about 450 and 530 mAhg(-1), respectively, with different irreversible capacities (60% and 29%). Analysis of these composite materials by Sn-119 Mossbauer spectroscopy in transmission (TMS) and emission (CEMS) modes confirms that ATCO is an amorphous Sn-II composite oxide and shows that in the case of Sn-0.72[BPO4](0.28), the Surface of the tin clusters is mainly formed by Sn-II in an amorphous interface whereas the bulk of the clusters is mainly formed by Sn-0. The determination of the recoilless free fractions f (Lamb-Mossbauer factors) leads to the effective fraction of both Sn-0 and Sn-II species in such composites. The influence of chemical composition and especially of the surface-to-bulk tin species ratio oil the electrochemical behaviour has been analysed for several Sn-x[BPO4](1-x) composite materials (0.17 < x < 0.91). The cell using the compound Sn-0.72[BPO4](0.28) as active material exhibits interesting electrochemical performances (reversible capacity of 500 mAh g(-1) at C/5 rate). (C) 2009 Elsevier Inc. All rights reserved.

Abstract: The dbmss package for R provides an easy-to-use toolbox to characterize the spatial structure of point patterns. Our contribution presents the state of the art of distance-based methods employed in economic geography and which are also used in ecology. Topographic functions such as Ripley’s K, absolute functions such as Duranton and Overman’s Kd and relative functions such as Marcon and Puech’s M are implemented. Their confidence envelopes (including global ones) and tests against counterfactuals are included in the package. © 2015, American Statistical Association. All rights reserved.