85 research outputs found

    Systematics and biology of some species of Micrurapteryx Spuler (Lepidoptera, Gracillariidae) from the Holarctic Region, with re-description of M. caraganella (Hering) from Siberia

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    During a DNA barcoding campaign of leaf-mining insects from Siberia, a genetically divergent lineage of a gracillariid belonging to the genus Micrurapteryx was discovered, whose larvae developed on Caragana Fabr. and Medicago L. (Fabaceae). Specimens from Siberia showed similar external morphology to the Palearctic Micrurapteryx gradatella and the Nearctic Parectopa occulta but differed in male genitalia, DNA barcodes, and nuclear genes histone H3 and 28S. Members of this lineage are re-described here as Micrurapteryx caraganella (Hering, 1957), comb. n., an available name published with only a brief description of its larva and leaf mine. Micrurapteryx caraganella is widely distributed throughout Siberia, from Tyumen oblast in the West to Transbaikalia in the East. Occasionally it may severely affect its main host, Caragana arborescens Lam. This species has been confused in the past with Micrurapreryx gradatella in Siberia, but field observations confirm that M. gradatella exists in Siberia and is sympatric with M. caraganella, at least in the Krasnoyarsk region, where it feeds on different host plants (Vicia amoena Fisch. and Vicia sp.). In addition, based on both morphological and molecular evidence as well as examination of type specimens, the North American Parectopa occulta Braun, 1922 and Parectopa albicostella Braun, 1925 are transferred to Micrurapteryx as M. occulta (Braun, 1922), comb. n. with albicostella as its junior synonym (syn. n.). Characters used to distinguish Micrurapteryx from Parectopa are presented and illustrated. These findings provide another example of the potential of DNA barcoding to reveal overlooked species and illuminate nomenclatural problems

    Catalytic behavior of biosorbents supported in zeolites

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    The catalytic oxidation of 1,2-dichlorobenzene at 350 oC was investigated over a robust biosorption system consisting of a bacterial biofilm supported on NaY or NaX zeolites. The batch method has been employed using chromium concentrations in solution ranging from 50 to 250 mgCr/L. The results showed that the maximum removal efficiency was 20% for Cr in both systems based in NaY or NaX. The bacterial biofilm, Arthrobacter viscosus, supported on the zeolite reduces Cr(VI) to Cr(III). The Cr(III) is retained in the zeolite by ion exchange. The new biosorvents catalysts were characterized by spectroscopic methods (FTIR and ICP-AES), surface analysis (DRX) and thermal analysis (TGA). The various techniques of characterization used show that this biosorption process does not modify the morphology and structure of the FAUzeolites. These catalysts, Cr/FAU, prepared through this new procedure present good activity and selectivity for dichlorobenzene oxidation in wet air. The Cr50-Y was selected as the most active, selective and stable catalyst for oxidation of 1,2 dichlorobenzene in wet air.Fundação para a Ciência e a Tecnologia (FCT)Departamento de Ciências da Terra of Universidade do MinhoAgence de l’Environnement et de la Maîtrise de l’Energie (ADEME) and the Région Poitou-Charente

    Oxidation catalysts prepared from biosorbents supported on zeolites

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    The catalytic oxidation of 1,2-dichlorobenzene was investigated over NaYand NaX zeolites, loaded with chromiumthrough the action of a robust biosorption system consisting of a bacterial biofilm supported on the zeolites. The results of biosorption showed that the maximum metal removal efficiencywas 20%, in both systems based on NaYorNaX, starting fromsolutions with chromium(VI) concentrations ranging from 50 to 250 mgCr/L. The bacterial biofilm, Arthrobacter viscosus, supported on the zeolite reduces Cr(VI) to Cr(III). The Cr(III) is retained in the zeolite by ion exchange. The new catalysts were characterized by spectroscopic methods (FTIR ), chemical analyses (ICP-AES), surface analysis (XRD) and thermal analysis (TGA). The various techniques of characterization show that this biosorption process does not modify the morphology and structure of the FAUzeolites. These catalysts,Cr/FAU, prepared through this newprocedure present good activity and selectivity for dichlorobenzene oxidation in wet air at 350 ºC. The Cr50-Y was selected as the most active, selective and stable catalyst for oxidation of 1,2-dichlorobenzene in wet air.Departamento de Ciências da Terra of Universidade do Minho; Fundação para a Ciência e a Tecnologia (FCT) ; Agence de l’Environnement et de la Maîtrise de l’Energie (ADEME); Région Poitou-Charentes

    Italian guidelines for primary headaches: 2012 revised version

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    The first edition of the Italian diagnostic and therapeutic guidelines for primary headaches in adults was published in J Headache Pain 2(Suppl. 1):105–190 (2001). Ten years later, the guideline committee of the Italian Society for the Study of Headaches (SISC) decided it was time to update therapeutic guidelines. A literature search was carried out on Medline database, and all articles on primary headache treatments in English, German, French and Italian published from February 2001 to December 2011 were taken into account. Only randomized controlled trials (RCT) and meta-analyses were analysed for each drug. If RCT were lacking, open studies and case series were also examined. According to the previous edition, four levels of recommendation were defined on the basis of levels of evidence, scientific strength of evidence and clinical effectiveness. Recommendations for symptomatic and prophylactic treatment of migraine and cluster headache were therefore revised with respect to previous 2001 guidelines and a section was dedicated to non-pharmacological treatment. This article reports a summary of the revised version published in extenso in an Italian version

    Influence of hydrothermal treatment on the acid and redox functions of a Ga/HZSM5 catalyst

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    After steaming at 530° C for 30 minutes and for 6 hours, a Ga/HZSM5 catalyst was characterized by three model reactions (meta-xylene isomerization, propane aromatization and methylcyclohexane transformation). The activity and selectivity of this catalyst were compared to those of a fresh Ga/HZSM5 catalyst. It was demonstrated that hydrothermal treatment provokes a significant decrease in the dehydrogenation activity of the gallium species and a small decrease in the protonic acidity of the catalyst

    Alkylation du toluène par l’heptène-1 sur zéolithes HY et sur montmorillonite

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    L'alkylation du toluène par l'heptène-1 a été réalisée en phase liquide à 90°C sur une montmorillonite (K 10) et sur trois zéolithes HY de rapport Si/Al de réseau égal à 4, 16 et 100. Les produits formés sont des monoheptyltoluènes (M), des biheptyltoluènes (B) et des dimères de l'heptène (D). Sur les zéolithes les composés (M) et (D) sont des produits primaires, tandis que les biheptyltoluènes (B) résultent de la transformation secondaire des composés (M). En revanche sur la montmorillonite les trois familles (M), (B) et (D) apparaissent comme des produits primaires. Sur tous les catalyseurs l'isomérisation de position de l’heptène-1, sa dimérisation et l’alkylation du toluène sont de vitesse voisine. L’activité initiale apparente des catalyseurs n’est pas directement liée à leur acidité : ainsi la montmorillonite (K.10) est initialement 7 fois plus active que la zéolithe HY la moins désaluminée qui est nettement plus acide. Une désactivation des catalyseurs par rétention dans les pores des produits lourds de réaction est mise en évidence. Cette désactivation est très rapide sur les zéolithes les moins désaluminées, rapide sur la montmorillonite et très lente sur la zéolithe HY la plus désaluminée

    Effects of addition of clay minerals on the fatty acid fraction of a podzol soil

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    International audienceThe Al horizon of a sandy podzol soil, with a very small proportion of clay-sized material, was sampled and homogenized. Samples, both with and without supplementation with 150 g clay minerals kg-1, natural heteroionic bentonite (saturated with Na, Ca, Mg, K), Mg-bentonite or Fe-kaolinite, were moistened to two-thirds of water-holding capacity and incubated at 28°C for 16 weeks. After incubation, lipids were extracted with 3:1 light petroleum: ethylacetate mixture in a Soxhlet apparatus as unbound components (directly extractable by organic solvents) and bound components (only extractable after treatment with acids). Monoacids (free and esterified), diacids, ketoacids and hydroxyacids were isolated from the two lipidic fractions (unbound and bound) by column chromatography. The different components of each family were analyzed by gas chromatography (GC) or gas chromatography-mass spectrometry (GC-MS). Incubation without supplementation generated a selective decrease in abundance of free mono-acids in unbound and bound fractions. The decrease was in inverse proportion to the chain-length of components. Soil supplementation with bentonite (homoionic or heteroionic) did not induce an overall quantitative change, but promoted a transfer of fatty acids from the unbound to the bound fraction, increased the exchange between free and esterified monoacids (transesterification) and stimulated hydrolysis of glycerides. In contrast, soil supplementation with Fe-kaolinite caused much decomposition or biotransformation of monoacids but it did not induce change either in the intensity of transesterification in the wax ester fraction or in the intensity of hydrolysis in the glyceride fraction. Copyright \textcopyright 1995, Wiley Blackwell. All rights reserve
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