Search results for "dike"
showing 10 items of 88 documents
Molecular markers for systematic identification and population genetics of the invasive Ponto-Caspian freshwater gammarid Dikerogammarus villosus (Cr…
2006
The Ponto-Caspian amphipod, Dikerogammarus villosus, is an invasive species of many European rivers. First, we show that size difference of nrDNA ITS1 allows discriminating D. villosus from Dikerogammarus bispinosus, a closely related but morphologically hardly distinguishable species. Second, we present two types of polymorphic markers for D. villosus, three microsatellites and two single nucleotide polymorphisms (SNPs) of mtDNA COI gene, which were scored by polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP). These markers will be very useful in studying population genetics of D. villosus.
Assembly and encapsulation of coordination tectons driven by hydrogen-bondingand space-filling
2001
[FR] Le composé ¿Fe(LI)3¿2¿Fe(H2O)6¿(ClO4)6 (2), LI = 1,10-phénanthroline-5,6-dione, a été synthétisé et caractérisé. La structure cristalline 2 est définie par un assemblage bidimensionnel non covalent, peu commun, constitué par des tectons chiraux ¿Fe(LI)3¿2+, assemblés par des cations ¿Fe(H2O)6¿2+ encapsulés dans des cages. Ces cages sont formées par 12 liaisons hydrogène établies entre les molécules d¿eau coordinées et les groupes dione appartenant à six molecules chirales ¿Fe(LI)3¿2+ ¿, ¿ alternées.
Untersuchungen zur Konformation von 2‐Diazo‐1,3‐diketonen
1988
Mit Hilfe von 1H- und 13C-NMR-Messungen in Losung (und im Festkorper) werden die Konformationen von 2-Diazo-1,3-diketonen (2a–f) mit sperrigen Resten untersucht. Investigation on the Conformation of 2-Diazo-1,3-diketones Conformational analyses of 2-diazo-1,3-diketones (2a–f) with bulky substituents are performed by applying 1H- and 13C-NMR measurements in solution (and in solid state).
Antidiabetische wirkstoffe, IV [1] trifluormethylsubstituierte 2-(4-toluidino)pyrimidine
1985
Zusammenfassung Durch Umsetzung von 4-Tolylguanidin mit den entsprechenden fluorierten β-Diketonen in Gegenwart von Natriumcarbonat im Schmelzfluβ sind die folgenden 4-Trifluormethyl-2-(4-toluidino) pyrimidine zuganglich gemacht worden: die 6-Methyl-, 6-Ethyl-, 6-Isopropyl-, 6-tert. Butyl- und 6-Isopentyl-Abkommlinge. Zur Charakterisierung der dargestellten Verbindungen sind IR-, 1H-NMR- und MS-Daten herangezogen worden. In dem neuen Strukturtyp sind besonders antidiabetische, antimykotische, trichomonazide und herbizide Wirksamkeit ausgepragt.
A short synthesis of dimethyl tricyclo[3.3.0.0 3,7 ]octane‐1,5‐dicarboxylate and its 3,7‐dimethyl derivative. A new route to the tricyclo[3.3.0.0 3,7…
1988
Five-step syntheses of dimethyl tricyclo[3.3.0.03,7]octane-1,5-dicarboxylate (13) and its 3,7-dimethyl derivative 14 from the readily available cis-bicyclo[3.3.0]octane-3,7-diones 1 and 2, respectively, are described. The key-step implies the iodine oxidation of the bis-enolate derived from the corresponding dimethyl cis-bicyclo-[3.3.0]octane-3,7-dicarboxylates 11 and 12, thus being developed a new synthetic entry into the tricyclo[3.3.0.03,7]octane skeleton. Also, some attempts to synthesize diester 13 by using known methodology for the synthesis of compounds containing this tricyclic skeleton are described. Eine kurze Synthese von Tricyclo [3.3.0.03,7]octan-1,5-dicarbonsaure-dimethylester…
Kinetische Untersuchungen zur Bildung der E ‐ und Z ‐Enole bei der Thermolyse von 2‐Diazo‐1,3‐dimesityl‐1,3‐propandion in Nucleophilen
1988
Bei der Thermolyse der Diazoverbindung 1 in Ethanol bzw. Piperidin oder Morpholin entstehen die Enole 3a–c von β-Ketocarbonsaurederivaten. Z- und E-Konfigurationen stehen miteinander im Gleichgewicht. Die Bestimmung der Geschwindigkeits-konstanten zeigt, das sich zunachst bevorzugt die Z-Formen bilden; im Gleichgewicht dominieren jedoch schlieslich in den Thermolysemedien die E-Isomeren. In aprotischen, apolaren oder masig polaren Medien uberwiegen dagegen die Z-Isomeren mit einer intramolekularen Wasserstoffbrucke. Investigation on the Kinetics of the Formation of E- and Z-Enols in the Thermolysis of 2-Diazo-1,3-propanedione in Nucleophiles Thermolysis of the diazo compound 1 in ethanol an…
A co-invasive microsporidian parasite that reduces the predatory behaviour of its host Dikerogammarus villosus (Crustacea, Amphipoda).
2014
SUMMARYParasites are known to affect the predatory behaviour or diet of their hosts. In relation to biological invasions, parasites may significantly influence the invasiveness of the host population and/or mediate the relationships between the invader and the invaded community. Dikerogammarus villosus, a recently introduced species, has had a major impact in European rivers. Notably, its high position in trophic web and high predatory behaviour, have both facilitated its invasive success, and affected other macroinvertebrate taxa in colonized habitats. The intracellular parasite Cucumispora dikerogammari, specific to D. villosus, has successfully dispersed together with this amphipod. Data…
Improved Regioselectivity in Pyrazole Formation through the Use of Fluorinated Alcohols as Solvents: Synthesis and Biological Activity of Fluorinated…
2008
The preparation of N-methylpyrazoles is usually accomplished through reaction of a suitable 1,3-diketone with methylhydrazine in ethanol as the solvent. This strategy, however, leads to the formation of regioisomeric mixtures of N-methylpyrazoles, which sometimes are difficult to separate. We have determined that the use of fluorinated alcohols such as 2,2,2-trifluoroethanol (TFE) and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) as solvents dramatically increases the regioselectivity in the pyrazole formation, and we have used this modification in a straightforward synthesis of fluorinated analogs of Tebufenpyrad with acaricide activity. Fil: Fustero, Santos. Universidad de Valencia; España Fil…
Formation mechanisms of Neptunian dikes in the Jurassic carbonates of Monte Maranfusa (western Sicily)
2013
Younger sediment infilling open fissures exposed on the sea floor are defined as neptunian dikes. These are peculiar features of carbonate platform successions deposited along the plate margins bounding the western Tethys during the Late Triassic time. During middle-Early Jurassic, a large part of these carbonate platforms were drowned, and became submerged plateaux covered by pelagic sediments during Jurassic (“Rosso Ammonitico”) and Cretaceous times (“Scaglia”). In western Sicily, several Neptunian dikes crop out (Monte Kumeta, Rocca Busambra, Monte Maranfusa, Monte Magaggiaro, etc.). They cut across mainly the carbonate sediments of the Inici Formation and in some cases the pelagic limes…
Genetics on Invasive Species
2002
Genetic markers are especially appropriate to reveal historical processes, as for example regarding biological invasions. Phylogenetic and population genetic methods enable to identify the taxa involved in an invasion (native and non-native species) and often lead to the perception of multiple or cryptic invasions. Phylogeographic and multi-locus approaches have been developed to assign individual invaders to potential source populations. The results may have implications for management measures. However, little is known about the genetic architecture of newly colonised populations. We introduce here genetic models for colonisations in linear habitats like rivers or coastlines. The expectat…