Molecular response of a sub-antarctic population of the blue mussel (Mytilus edulis platensis) to a moderate thermal stress.

The Kerguelen Islands (49°26'S, 69°50'E) represent a unique environment due to their geographical isolation, which protects them from anthropogenic pollution. The ability of the endemic mussel, part of the Mytilus complex, to cope with moderate heat stress was explored using omic tools. Transcripts involved in six major metabolic functions were selected and the qRT-PCR data indicated mainly changes in aerobic and anaerobic energy metabolism and stress response. Proteomic comparisons revealed a typical stress response pattern with cytoskeleton modifications and elements suggesting increased energy metabolism. Results also suggest conservation of protein homeostasis by the long-lasting presence of HSP while a general decrease in transcription is observed. The overall findings are consistent with an adaptive response to moderate stresses in mussels in good physiological condition, i.e. living in a low-impact site, and with the literature concerning this model species. Therefore, local blue mussels could be advantageously integrated into biomonitoring strategies, especially in the context of Global Change.

A Photomechanical Device for Triggering Digital Output on a GE Spectrophotometer.

Most applications of modern spectrophotometry demand that spectrophotometric measurements be recorded on media suitable for direct use by data processing equipment. This paper describes a photomechanical method for actuating the readout command for an old model GE recording spectrophotometer. This instrument has nonlinear wavelength representation in the near ultraviolet and near infrared. The method involves an opaque disk having a direct one-to-one rotation relation with the wavelength drive. The disk contains three sets of small holes on the circumference of concentric circles which represent the near ultraviolet, visible, and near infrared regions of the spectrum. The accurate angular separation of these holes, along with a photodiode and lamp which are aligned for each set of holes, makes available a selection of these three ranges and automatically actuates the readout command in the control chassis at 10-nm intervals for all wavelength ranges. The data are then punched into cards by an IBM 526 summary punch. The option of taking data at 5-nm intervals is provided by a suitable second disk.