International study on <i>Artemia</i> : 32. Combined effects of temperature and salinity on the survival of <i>Artemia</i> of various geographical origin

The brine shrimp inhabits geographically isolated biotopes with specific biotic and abiotic conditions. This has resulted in various geographical strains between which marked genetica, biological and chemical differentiation exists. The response of 13 different Artemia strains to the combined effect of temperature and salinity has been studied. Experimental temperatures tested ranged from 18 to 34°C and salinities from 5 to 120 promille. Except for Chaplin Lake (Canada) Artemia , all strains showed high survival over a wide range of salinities (35-110 promille). For all strains the common temperature optimum was between 20 and 25°C. Interaction between temperature and salinity was negligible or very limited. Substantial differences in tolerance were recorded in particular at the lower end of the range of experimental salinities and at the upper end of the range temperatures. Resistance to high temperature seems to be related to the genetic classification of the Artemia strains in different sibling species. Differences, however, also exist among strains from the same sibling species. Genetic adaptation to high temperature seems to take place in Artemia . The data obtained provide a first guideline for strain selection for specific aquacultural purposes

Characteristic attributes in cancer microarrays

AbstractRapid advances in genome sequencing and gene expression microarray technologies are providing unprecedented opportunities to identify specific genes involved in complex biological processes, such as development, signal transduction, and disease. The vast amount of data generated by these technologies has presented new challenges in bioinformatics. To help organize and interpret microarray data, new and efficient computational methods are needed to: (1) distinguish accurately between different biological or clinical categories (e.g., malignant vs. benign), and (2) identify specific genes that play a role in determining those categories. Here we present a novel and simple method that exhaustively scans microarray data for unambiguous gene expression patterns. Such patterns of data can be used as the basis for classification into biological or clinical categories. The method, termed the Characteristic Attribute Organization System (CAOS), is derived from fundamental precepts in systematic biology. In CAOS we define two types of characteristic attributes (‘pure’ and ‘private’) that may exist in gene expression microarray data. We also consider additional attributes (‘compound’) that are composed of expression states of more than one gene that are not characteristic on their own. CAOS was tested on three well-known cancer DNA microarray data sets for its ability to classify new microarray samples. We found CAOS to be a highly accurate and robust class prediction technique. In addition, CAOS identified specific genes, not emphasized in other analyses, that may be crucial to the biology of certain types of cancer. The success of CAOS in this study has significant implications for basic research and the future development of reliable methods for clinical diagnostic tools

Active faulting within the offshore western Gulf of Corinth, Greece: implications for models of continental rift deformation

Discrimination between different lithospheric extension models focusing on the roles of low-angle vs. high-angle faulting, and how strain is distributed, requires high-fidelity imaging of brittle deformation. High-resolution seismic reflection and multibeam bathymetric data in the western Gulf of Corinth continental rift were collected to establish the contribution of offshore faults to extension. Onshore fault slip here is significantly less than expected from geodetic strain rates. The rift at this location is a half-graben tilted to the north by S-dipping faults within the uppermost crust. A basement horst on the northern margin is uplifted by the North and South Eratini faults, and the axial channel is fault controlled. Subsided lowstand shorelines in the hanging wall of the North Eratini and the well-studied Aigion fault suggest that the faults have similar displacements. Summed extension from the four major faults across this part of the rift (Eliki, Subchannel, South Eratini, North Eratini) is 8–16 mm/yr, thereby reconciling geologic and geodetic data sets. Distributed deformation across isolated multiple faults can model this part of the rift without recourse to, and potentially incompatible with, an underlying low-angle detachment