51 research outputs found
The Foraminifera.eu Project: A paleoinformatics bridge between science and community
Foraminifera.eu is a non-commercial international project to foster the interest in foraminifera. A freely accessible image database with an online multi-criteria search facility based on high quality SEM and optical images and drawings has been developed. The website has become a popular resource with more than 5000 monthly unique visitors viewing more than 50000 pages. About 120 scientists and amateurs are contributing samples, images, drawings, ideas and working on projects, publications, exhibitions, talks and collection. Foraminifera from the Oporto Seamount, from the Luz Formation and from the Mem Moniz spongolithic limestone are the first Portuguese contributions to this project.publishersversionpublishe
A New Integrated Approach to Taxonomy: The Fusion of Molecular and Morphological Systematics with Type Material in Benthic Foraminifera
This work was supported by NERC grant NE4/G018502/1 and NE/G020310/1 (Website: http://www.nerc.ac.uk). The authors also thank the following for their support the Carnegie Trust for the Universities of Scotland (Website: http://www.carnegie-trust.org) and the Estuarine Coastal and Shelf Science Association (Website: http://www.ecsanews.org). M.S. was also supported by the Swiss National Science Foundation (SNSF), fellowships for advanced researchers PA00P2_126226 and PA00P2_142065 (Website: http://www.snf.ch/en/Pages/default.aspx).A robust and consistent taxonomy underpins the use of fossil material in palaeoenvironmental research and long-term assessment of biodiversity. This study presents a new integrated taxonomic protocol for benthic foraminifera by unequivocally reconciling the traditional taxonomic name to a specific genetic type. To implement this protocol, a fragment of the small subunit ribosomal RNA (SSU rRNA) gene is used in combination with 16 quantitative morphometric variables to fully characterise the benthic foraminiferal species concept of Elphidium williamsoni Haynes, 1973. A combination of live contemporary topotypic specimens, original type specimens and specimens of genetic outliers were utilised in this study. Through a series of multivariate statistical tests we illustrate that genetically characterised topotype specimens are morphologically congruent with both the holotype and paratype specimens of E. williamsoni Haynes, 1973. We present the first clear link between morphologically characterised type material and the unique SSU rRNA genetic type of E. williamsoni. This example provides a standard framework for the benthic foraminifera which bridges the current discontinuity between molecular and morphological lines of evidence, allowing integration with the traditional Linnaean roots of nomenclature to offer a new prospect for taxonomic stability.Publisher PDFPeer reviewe
Asymmetric hydrosilylation of ketones catalyzed by complexes formed from trans-diaminocyclohexane-based diamines and diethylzinc
Somaclonal variation of the mitochondrial ATPase subunit 6 gene region in regenerated triticale shoots and full-grown plants
Aerobic oxidation of alcohols in carbon dioxide with silica-supported ionic liquids doped with perruthenate
The replacement of toxic and carginogenic chromium (VI) and bioaccumulating chlorinated solvents used in the
oxidation of alcohols with oxygen and carbon dioxide (or ionic liquids) remains hindered by the low selectivity and
activity of the heterogeneous catalysts developed thus far. We have developed an integrated method that combines
entrapped perruthenate, as highly selective aerobic catalyst, with encapsulated ionic liquid, as solubility booster, and
supercritical carbon dioxide as reaction solvent. The system is capable of converting a variety of organic alcohols into
carbonyl compounds with complete selectivity, including substrates normally difficult to oxidise such as long-chain
primary aliphatic alcohols. The technology opens up the opportunity for rapid, waste-free and economically convenient
conversion of carbinols into commercially valuable aldehydes and ketones enabling noxious substances to be eliminated
from employment in the synthesis of fine chemicals
Pd@ionosilica as heterogeneous hydrogenation catalyst for continuous flow reductive upgrade of cinnamaldehyde
Background: The effective exploitation of biomass for the preparation of fuels and platform chemicals requires the development of novel catalysts and catalytic methods. In this regard, ionosilicas appear as promising candidates due to their properties and tenability. Results: A novel Pd@ionosilica is prepared by a straightforward ion exchange method based on amorphous ionosilica and sodium tetrachloropalladate. The resulting hybrid material is evaluated as catalyst for the continuous flow reduction of cinnamaldehyde as exemplary biorefinery case study. Conclusion: This work reports the application of metal@ionosilica hybrid materials as catalysts for the continuous flow upgrade of bio-sourced molecules, showing promising results in the case of cinnamaldehyde, here used as exemplary compound. The findings disclosed in this paper provide interesting insights for the development of second generation metal@ionosilica composites for catalytic applications within biorefinery
Phase transfer of TiO2 nanoparticles from water to ionic liquid triggered by phosphonic acid grafting
International audienceControlling the interface between TiO2 nanocrystals and ionic liquids is of high fundamental and applied interest for energy storage and conversion devices. Phase transfer of nanoparticles from a synthesis medium to a processing or an application medium plays a significant role in nanotechnology. Here we demonstrate that surface modification with phosphonic acids bearing cationic end-groups can trigger the phase transfer of TiO2 nanoparticles from an aqueous sol to a typical water-immiscible ionic liquid, [Emim][NTf2]. The transfer involves both the grafting of the phosphonic acid moiety and the exchange of the counter ion of the cationic end-group by NTf2 anions, as demonstrated by solid-state NMR, elemental analysis and independent grafting and ion exchange experiments. Furthermore, the colloidal stability of the TiO2 sols in [Emim][NTf2] strongly depends on the hydrophobic character of the cationic end-groups
A Modular Approach towards Mesoporous Silica Monoliths with Organically Modified Pore Walls: Nucleophilic Addition, Olefin Metathesis, and Cycloaddition
International audienceWe have synthesized mesoporous silica (monoliths) with defined surface chemistry by means of a number of addition reactions: (i) coupling of an isocyanate to a surface-immobilized thiol, (ii) addition of an epoxide to a surface-immobilized thiol, (iii) cross-metathesis between two olefins, and (iv) Huisgen [2+3] cycloaddition of an alkyne-functionalized silica monolith with an azide. Functionalization of the mesopores was observed, but there are significant differences between individual approaches. Isocyanate and epoxide additions lead to high degrees of functionalization, whereas olefin metathesis and [2+3] cycloaddition are less effective. We further show that the efficiency of the modification is about twice as high in mesoporous silica particles than in macroscopic silica monoliths
chapter 13
International audienceIonic liquids (ILs) have attracted tremendous interest in the last decades. This is due to their high chemical variability and their interesting and useful chemical, physical, and biological properties. The current chapter provides an overview on the use and the potential of ILs for biopolymer dissolution and processing, for chemical modification of biopolymers in ILs, and on the use of ILs for the fabrication of biocompatible materials and composites from renewable resources
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