From biomedicine to natural history research: EST resources for ambystomatid salamanders

BACKGROUND: Establishing genomic resources for closely related species will provide comparative insights that are crucial for understanding diversity and variability at multiple levels of biological organization. We developed ESTs for Mexican axolotl (Ambystoma mexicanum) and Eastern tiger salamander (A. tigrinum tigrinum), species with deep and diverse research histories. RESULTS: Approximately 40,000 quality cDNA sequences were isolated for these species from various tissues, including regenerating limb and tail. These sequences and an existing set of 16,030 cDNA sequences for A. mexicanum were processed to yield 35,413 and 20,599 high quality ESTs for A. mexicanum and A. t. tigrinum, respectively. Because the A. t. tigrinum ESTs were obtained primarily from a normalized library, an approximately equal number of contigs were obtained for each species, with 21,091 unique contigs identified overall. The 10,592 contigs that showed significant similarity to sequences from the human RefSeq database reflected a diverse array of molecular functions and biological processes, with many corresponding to genes expressed during spinal cord injury in rat and fin regeneration in zebrafish. To demonstrate the utility of these EST resources, we searched databases to identify probes for regeneration research, characterized intra- and interspecific nucleotide polymorphism, saturated a human – Ambystoma synteny group with marker loci, and extended PCR primer sets designed for A. mexicanum / A. t. tigrinum orthologues to a related tiger salamander species. CONCLUSIONS: Our study highlights the value of developing resources in traditional model systems where the likelihood of information transfer to multiple, closely related taxa is high, thus simultaneously enabling both laboratory and natural history research

Contribution à l'étude de la reproduction de l'urodèle Euproctus asper (Dugês) dans les Pyrénées centrales et Ariégeoises

La découverte d'une nouvelle station d'Euprocte pyrénéen à Aulus-les-Bains (Ariège) nous a permis d'étudier cette espèce à deux altitudes différentes : - à 2 328 m (déversoir du lac Supérieur, Réserve d'Estibère), la métamorphose de la larve s'opère durant le troisième été. - à l'altitude de 900-1 000 m (Aulus-les-Bains), cette transformation a déjà lieu dans le courant du deuxième été. Des conditions climatiques différentes amènent par conséquent des changements importants dans le mode de vie d'une même espèce. A basse altitude, le mode de vie de l'animal présente des analogies avec celui de l'Euprocte de Corse (Euproctus montanus), les adultes vivant dans l'eau pendant plus de la moitié de l'année

Evaluation of trenchless sewer construction at South Bethany Beach, Delaware /

Grant no. S-800690.Conducted in cooperation with Sussex County Council, Del.Mode of access: Internet

Local Activation and Degradation of Electrochemical Processes in a SOFC

The local electrochemistry is studied in a SOFC repeat-element using a test setup that allows a local control of the polarization. During long-term tests, the local current densities evolve, following activation and degradation periods. Electrochemical impedance spectroscopy (EIS) measurements performed at regular intervals are used to analyze the activation and degradation of the individual electrochemical processes. By computing the distribution of relaxation times (DRT) from the EIS spectra, a total of 6 electrochemical processes are revealed and their evolution studied separately. It is found that not only the activation/degradation rates but also their spatial evolution are strongly influenced by the choice of materials and by the operating conditions. In particular, the degradation of the anode propagates over the active area with important local differences, and in a wave-like manner that differs from one test to the other. Results are presented and analyzed for several long-term tests operated with hydrogen or steam-reformed methane as fuel

Performance evaluation of a 4-stack solid oxide module in electrolysis mode

International audienceTo support the current trend of testing bigger reversible Solid Oxide Cell (rSOC) modules, CEA has built the 120 kWDC Multistack platform. It was used to test SOLIDpower recently developed-Large Stack Module (LSM) in electrolysis mode. Results show high thermal performance of the LSM, with homogeneous temperature distribution and losses in the kilowatt range above 700°C. A performance map was recorded between 712 and 744°C over 22.4-to-29.6 kg h-1 steam flowrates using a fast control strategy to avoid endothermic operation. A peak power of 74 kWDC was converted into more than 50 kg day-1 of H2 (35.5 kWhDC kgH2-1). In addition, fuel utilization of more than 90% and steam conversion above 80% were demonstrated at the module level. In the end, the modular design of the LSM seems well suited for system scale up, paving the way for mutualization of auxiliaries and CAPEX reduction. Highlights CEA has built the Multistack platform to test rSOC modules of up to 120 kWDC SOLIDpower has developed the Large Stack Module integrating four G8X stack towers A peak power of 74 kWDC was converted into more than 50 kg day-1 of H2 Excellent thermal performances were recorded with losses in the kW range above 700°