Nachweis von DNA-Schäden in aquatischen Protozoen und Algen mit der Mikrogelelektrophorese (comet assay) für eine gentoxikologische Gewässergütebewertung von Oberflächenwasser

Die Beurteilung des gentoxischen Potentials in Oberflächenwasser erfordert Testmethoden, die DNA-Schäden in relevanten Organismen der aquatischen Biozönose hinreichend empfindlich erfassen. Die Mikrogelelektrophorese (MGE), auch comet assay genannt, ist solch ein gentoxikologischer Indikatortest, mit dem DNA-Strangbrüche und Alkalilabile Stellen der DNA eukaryontischer Organismen bzw. Zeilen sensitiv nachgewiesen werden können. In der vorliegenden Studie werden Ergebnisse des Einsatzes der Mikrogelelektrophorese an einzelligen Grünalgen der Spezies Chlamydomonas reinhardtii und Protozoen der Spezies Acanthamöba castellanii vorgestellt. Es werden Validierungsuntersuchungen mit gentoxischen Einzelsubstanzen wie z.B. 4-Nitrochinolin-1-oxid, Benzo(a)pyren usw. präsentiert. Außerdem wird die Untersuchung einer nativen Wasserprobe der Weißen Elster, die mit verschiedenen Konzentrationen eines EPA-Standards aufgestockt wurde, vorgestellt. Die beiden Testorganismen wiesen erwartungsgemäß eine unterschiedliche Sensitivität gegenüber verschiedenen Einzelsubstanzen auf. Die niedrigsten Effektkonzentrationen für beide Organismen konnten für 4-Nitrochinolin-1-oxid mit 1...10 μg/L ermittelt werden.     

Revision of the ammonite index species Berriasella jacobi Mazenot, 1939 and its consequences for the biostratigraphy of the Berriasian Stage

Berriasella jacobi is a key ammonite taxon that has been widely used for the definition of the Tithonian/Berriasian boundary and has been widely quoted in the literature as the index species for the lowest zone of the Berriasian Stage. The taxonomic revision of B. jacobi shows that it should be excluded from the genus Berriasella and transferred to the genus Strambergella. Analysis of the literature has convinced us that most specimens illustrated as B. jacobi have been misidentified. New collection at Le Font de Saint Bertrand (Les Combes, Glandage, Drôme, France) shows us the type series corresponds to the microconch form of a dimorphic pair. New integrated data on its stratigraphic distribution causes us to question its value as an index species for the base of the Berriasian.     

West versus East Mediterranean Sea: origin and genetic differentiation of the sea cucumber Holothuria polii

We studied the genetic structure of the sea cucumber Holothuria (Roweothuria) polii (Delle Chiaje 1823) by analysing the mitochondrial DNA variation in two fragments of cytochrome oxidase I (COI) and 16S genes. Individuals were collected in seven locations along the Mediterranean Sea, which cover a wide range of the species distribution. We found high haplotype diversity for COI and moderate diversity for 16S, and low nucleotide diversity for both genes. Our results for the COI gene showed many recent and exclusive haplotypes with few mutational changes, suggesting recent or ongoing population expansion. The Western and Eastern Mediterranean populations exhibited slight but significant genetic differentiation (COI gene) with higher genetic diversity in the East. The most ancient haplotype was not present in the westernmost sampling location (SE Spain). The oldest expansion time was observed in Turkey, corresponding to mid‐Pleistocene. Turkey had also the highest genetic diversity (number of total and exclusive haplotypes, polymorphisms, haplotype and nucleotide diversity). This suggests that this region could be the origin of the subsequent colonizations through the Mediterranean Sea, a hypothesis that should be assessed with nuclear markers in future research.     

Caractérisation géochimique et bactériologique des nappes d’une région à climat tropical sec au centre Sud de Madagascar

Résumé

Le district de Betroka, soumis à un climat tropical sec, connaît d’importants problèmes de ressource en eau. Cette situation se traduit pour de nombreux habitants par la consommation d’eau de très mauvaise qualité tant sur le plan physico-chimique, que sur le plan bactériologique. Pour tenter d’améliorer cette situation, le gouvernement malgache a entrepris un programme d’alimentation en eau potable et assainissement en milieu rural (projet 350 forages), cadre du présent travail, afin d’assurer à l’eau destinée à l’alimentation humaine une qualité suffisante en termes bactériologique et minéral. L’étude microbiologique de l’eau souterraine du district de Betroka a confirmé l’absence de bactéries d’origine fécale. L’étude hydrochimique a révélé différents processus conduisant à la minéralisation des eaux souterraines en relation avec : (a) la remontée d’eau saline d’origine profonde à partir des fractures transversales du cisaillement majeur de Betroka, et à partir des failles normales à l’origine du graben de Mangoky et du domaine du massif en dôme et bassin du complexe intrusif d’Ianakafy ; (b) la dissolution des aérosols et embruns marins déposés, dissous par la pluie et entraînés jusqu’aux aquifères ; et (c) l’interaction des eaux météoriques et souterraines avec les minéraux des roches encaissantes (scapolite, phlogopite, biotite, hornblende, pyroxène…) qui pourrait également contribuer à la forte minéralisation observée.     

Predictive phase equilibria for the aqueous ternary system(Li_2SO_4 + K_2SO_4 + H_2O) from 273.15 to 373.15 K

正1 Introduction Many variable temperature chemical models were developed to predict mineral solubility in the natural waters(Na+,K+,Ca2+,Mg2+//Cl-,SO42-–H2O)in the temperature range below 298.15 K(to near 213.15 K)and(Na+,K+,     

Évolution thermique des séries sédimentaires de la Marge ardéchoise : étude pétrographique de la matière organique et des argilesThermal evolution of the sedimentary series of the Ardèche Margin: petrological studies of organic matter and clays

Two wells, Balazuc (BA1) and Morte-Mérie (MM1), located in a confined area (1200 m apart) and separated by the Uzer fault (a Liassic structure with a dip fault of 1300 m) were analysed using conventional methodologies and techniques (PRV, TAI, XRD, STEM) in order to compare the diagenetic evolution of clays and organic matter. The thermal convective process allows the circulation of hot fluids and the oxidation of organic matter. The conductive process allows the maturation of the organic matter, the expulsion of hydrocarbons and the deposit of pyrobitumes in the migration channels. To cite this article: L. Martinez et al., C. R. Geoscience 334 (2002) 1021–1028.     

Population biology and recruitment of a vulnerable sea cucumber,Stichopus herrmanni,on a protected reef

Populations of tropical sea cucumbers, harvested for bêche‐de‐mer, are in a perilous state of conservation, yet there remains a paucity of information on the biology of many harvested species. We examined the population biology of the commercially important curryfish, Stichopus herrmanni, across 2 years on Heron Reef, a protected zone in the Great Barrier Reef (GBR) Marine Park. Stichopus herrmanni, a species recently listed as vulnerable to extinction, is a major target species for the fishery operating in the GBR. The size class distribution and density of S. herrmanni were documented for six sites across Heron Reef. There was distinct spatial variation in the size and density of S. herrmanni across sites, with no significant difference between the 2 years. The smallest individuals found were 10 cm long, some of the only juvenile S. herrmanni documented in nature. Juvenile and sub‐adult populations were found along the leeward reef edge of Heron Reef, a habitat characterized by shallow channels of sand between inter‐tidal coral reef and crustose coralline algae (CCA). Juvenile nurseries of sea cucumbers are rarely observed in nature, making this an important observation for understanding the recruitment and population biology of S. herrmanni. The presence of juveniles in the consolidated CCA habitat each year in autumn following the summer spawning period, and the absence of small individuals several months later in spring, suggests an ontogenetic migration or displacement of these individuals to adult habitat. The distribution of larger S. herrmanni suggests intra‐reef connectivity and migration into deeper lagoon areas. This study contributes to understanding the population dynamics of this vulnerable species, a consideration for fisheries management in light of increasing global harvest.     

某些岩土参数的对数正态分布特征

本文试图说明服从对数正态分布岩土参数频率直方图的分布特征和在累积频率概率格约牙作正态检验及求取参数特征值的统计方法。使岩土参数的统计更合理。