ATM haplotypes and breast cancer risk in Jewish high-risk women

While genetic factors clearly play a role in conferring breast cancer risk, the contribution of ATM gene mutations to breast cancer is still unsettled. To shed light on this issue, ATM haplotypes were constructed using eight SNPs spanning the ATM gene region (142 kb) in ethnically diverse non-Ashkenazi Jewish controls (n=118) and high-risk (n=142) women. Of the 28 haplotypes noted, four were encountered in frequencies of 5% or more and accounted for 85% of all haplotypes. Subsequently, ATM haplotyping of high-risk, non-Ashkenazi Jews was performed on 66 women with breast cancer and 76 asymptomatic. One SNP (rs228589) was significantly more prevalent among breast cancer cases compared with controls (P=4 × 10−9), and one discriminative ATM haplotype was significantly more prevalent among breast cancer cases (33.3%) compared with controls (3.8%), (P⩽10−10). There was no significant difference in the SNP and haplotype distribution between asymptomatic high-risk and symptomatic women as a function of disease status. We conclude that a specific ATM SNP and a specific haplotype are associated with increased breast cancer risk in high-risk non-Ashkenazi Jews

Benchmark study of undrained triaxial testing of Opalinus Clay shale: Results and implications for robust testing

Triaxial testing of argillaceous rocks and shales is significantly more challenging than conventional rock mechanical testing. The challenges are mainly related to the very low permeability of these geomaterials, and their sensitivity to exposure of atmosphere and brines, which induces variations of water content, suction and effective stress. There are currently no international standards to guide service laboratories for robust testing procedures for shales. A benchmark study of undrained triaxial testing was therefore initiated with three leading service laboratories in shale testing, performing 13 tests and using two different methods of establishing sample saturation prior to deformation. Both methods paid particular attention to minimize volume expansion of the specimens during saturation, and the loading rate during the shear phase in all tests was selected based on intrinsic sample properties and drainage configurations to ensure pore fluid pressure equilibration across the specimen. Opalinus Clay shale core material from the Mont Terri underground research laboratory was used for testing specimens, and intervals on cores were pre-selected on the basis of computer tomography to minimize material heterogeneity. A detailed diagnostic analysis of all tests was performed, and a comparison of the testing results is presented. Good reproducibility of the effective stress paths was achieved by the different laboratories for tests at identical or near-identical initial effective stress conditions. In particular, the test results over a larger range of effective stresses indicate very similar evolution of the fluid pressure during testing and a consistent picture for the derivation of global material properties. On the example of Opalinus Clay, the study demonstrates that robust triaxial testing results can be achieved for shales if some key challenges are adequately addressed.publishedVersio

Benchmark study of undrained triaxial testing of Opalinus Clay shale: Results and implications for robust testing

Triaxial testing of argillaceous rocks and shales is significantly more challenging than conventional rock mechanical testing. The challenges are mainly related to the very low permeability of these geomaterials, and their sensitivity to exposure of atmosphere and brines, which induces variations of water content, suction and effective stress. There are currently no international standards to guide service laboratories for robust testing procedures for shales. A benchmark study of undrained triaxial testing was therefore initiated with three leading service laboratories in shale testing, performing 13 tests and using two different methods of establishing sample saturation prior to deformation. Both methods paid particular attention to minimize volume expansion of the specimens during saturation, and the loading rate during the shear phase in all tests was selected based on intrinsic sample properties and drainage configurations to ensure pore fluid pressure equilibration across the specimen. Opalinus Clay shale core material from the Mont Terri underground research laboratory was used for testing specimens, and intervals on cores were pre-selected on the basis of computer tomography to minimize material heterogeneity. A detailed diagnostic analysis of all tests was performed, and a comparison of the testing results is presented. Good reproducibility of the effective stress paths was achieved by the different laboratories for tests at identical or near-identical initial effective stress conditions. In particular, the test results over a larger range of effective stresses indicate very similar evolution of the fluid pressure during testing and a consistent picture for the derivation of global material properties. On the example of Opalinus Clay, the study demonstrates that robust triaxial testing results can be achieved for shales if some key challenges are adequately addressed

Benchmark study of undrained triaxial testing of Opalinus Clay shale: Results and implications for robust testing

Triaxial testing of argillaceous rocks and shales is significantly more challenging than conventional rock mechanical testing. The challenges are mainly related to the very low permeability of these geomaterials, and their sensitivity to exposure of atmosphere and brines, which induces variations of water content, suction and effective stress. There are currently no international standards to guide service laboratories for robust testing procedures for shales. A benchmark study of undrained triaxial testing was therefore initiated with three leading service laboratories in shale testing, performing 13 tests and using two different methods of establishing sample saturation prior to deformation. Both methods paid particular attention to minimize volume expansion of the specimens during saturation, and the loading rate during the shear phase in all tests was selected based on intrinsic sample properties and drainage configurations to ensure pore fluid pressure equilibration across the specimen. Opalinus Clay shale core material from the Mont Terri underground research laboratory was used for testing specimens, and intervals on cores were pre-selected on the basis of computer tomography to minimize material heterogeneity. A detailed diagnostic analysis of all tests was performed, and a comparison of the testing results is presented. Good reproducibility of the effective stress paths was achieved by the different laboratories for tests at identical or near-identical initial effective stress conditions. In particular, the test results over a larger range of effective stresses indicate very similar evolution of the fluid pressure during testing and a consistent picture for the derivation of global material properties. On the example of Opalinus Clay, the study demonstrates that robust triaxial testing results can be achieved for shales if some key challenges are adequately addressed