On the origin of exponential growth in induced earthquakes in Groningen

The Groningen gas field shows exponential growth in earthquakes event counts around a magnitude M1 with a doubling time of 6-9 years since 2001. This behavior is identified with dimensionless curvature in land subsidence, which has been evolving at a constant rate over the last few decades {essentially uncorrelated to gas production.} We demonstrate our mechanism by a tabletop crack formation experiment. The observed skewed distribution of event magnitudes is matched by that of maxima of event clusters with a normal distribution. It predicts about one event $<$\,M5 per day in 2025, pointing to increasing stress to human living conditions.Comment: 12 pages, 7 figures, to appear in Earthquakes and Structure

Numerical Integration of Nonlinear Wave Equations for General Relativity

A second-order numerical implementation is given for recently derived nonlinear wave equations for general relativity. The Gowdy T$^3$ cosmology is used as a test bed for studying the accuracy and convergence of simulations of one-dimensional nonlinear waves. The complete freedom in space-time slicing in the present formulation is exploited to compute in the Gowdy line-element. Second-order convergence is found by direct comparison of the results with either analytical solutions for polarized waves, or solutions obtained from Gowdy's reduced wave equations for the more general unpolarized waves. Some directions for extensions are discussed.Comment: 19 pages (LaTex), 3 figures (ps

Uniqueness in MHD in divergence form: right nullvectors and well-posedness

Magnetohydrodynamics in divergence form describes a hyperbolic system of covariant and constraint-free equations. It comprises a linear combination of an algebraic constraint and Faraday's equations. Here, we study the problem of well-posedness, and identify a preferred linear combination in this divergence formulation. The limit of weak magnetic fields shows the slow magnetosonic and Alfven waves to bifurcate from the contact discontinuity (entropy waves), while the fast magnetosonic wave is a regular perturbation of the hydrodynamical sound speed. These results are further reported as a starting point for characteristic based shock capturing schemes for simulations with ultra-relativistic shocks in magnetized relativistic fluids.Comment: To appear in J Math Phy

Predicting sex from brain rhythms with deep learning

We have excellent skills to extract sex from visual assessment of human faces, but assessing sex from human brain rhythms seems impossible. Using deep convolutional neural networks, with unique potential to find subtle differences in apparent similar patterns, we explore if brain rhythms from either sex contain sex specific information. Here we show, in a ground truth scenario, that a deep neural net can predict sex from scalp electroencephalograms with an accuracy of >80% (p < 10-5), revealing that brain rhythms are sex specific. Further, we extracted sex-specific features from the deep net filter layers, showing that fast beta activity (20-25 Hz) and its spatial distribution is a main distinctive attribute. This demonstrates the ability of deep nets to detect features in spatiotemporal data unnoticed by visual assessment, and to assist in knowledge discovery. We anticipate that this approach may also be successfully applied to other specialties where spatiotemporal data is abundant, including neurology, cardiology and neuropsychology

Differential Forms and Wave Equations for General Relativity

Recently, Choquet-Bruhat and York and Abrahams, Anderson, Choquet-Bruhat, and York (AACY) have cast the 3+1 evolution equations of general relativity in gauge-covariant and causal ``first-order symmetric hyperbolic form,'' thereby cleanly separating physical from gauge degrees of freedom in the Cauchy problem for general relativity. A key ingredient in their construction is a certain wave equation which governs the light-speed propagation of the extrinsic curvature tensor. Along a similar line, we construct a related wave equation which, as the key equation in a system, describes vacuum general relativity. Whereas the approach of AACY is based on tensor-index methods, the present formulation is written solely in the language of differential forms. Our approach starts with Sparling's tetrad-dependent differential forms, and our wave equation governs the propagation of Sparling's 2-form, which in the ``time-gauge'' is built linearly from the ``extrinsic curvature 1-form.'' The tensor-index version of our wave equation describes the propagation of (what is essentially) the Arnowitt-Deser-Misner gravitational momentum.Comment: REVTeX, 26 pages, no figures, 1 macr

Development and process evaluation of a motor activity program for people with profound intellectual and multiple disabilities

Background The support of people with profound intellectual and multiple disabilities (PIMD) rarely focused on motor activity, which might have negative consequences for the quality of life of these people. Evidence-based motor activity programs that present individually tailored and structural motor activity for these people are, regretfully, lacking. This study developed such a program for these people and evaluated the implementation process. Methods The motor activity program is developed in accordance with the theoretical premises of the educational program and consists of four methodological steps in which the content is individually filled with: motor activity structurally embedded within the activities of daily living, and 3–5 motor activities aimed at a specific goal, which is evaluated. Program delivery consisted of a manual, explanation to the teams, and coaching of one contact person per participant (n = 9). Process evaluation included the delivered fidelity, dose, reach, and adaptations made during the program. In addition, mechanisms of impact and the influence of contextual factors were evaluated. Data collection included researcher logbooks, individual program content, and staff reports. Results The intended fidelity, dose, and reach were not obtained in most participants. Content has been made explicit for seven participants, but only in one participant all critical steps in implementation were performed as intended, though later in time. In three participants, previously offered motor activities were described within the weekly program, but without all activities having a clear link with the goal set. It is showed that the core elements of the program were affected with the conceived implementation plan. The time schedule, critical elements in implementation and program content were influenced by a lack of conditions such as professionals’ motivation and responsibility, methodical working, interdisciplinarity and continuity in staff. Conclusions The results suggest that the implementation might be improved in case more attention is paid to the organizational conditions and implementation structure. The findings led to substantial changes in the implementation strategy. This study underlines the importance of process evaluation prior to testing for effectiveness

Measurement of the ΔS=-ΔQ Amplitude from K_(e3)^0 Decay

We have measured the time distribution of the π^+e^-ν and π^-e^+ν modes from initial K^0's in a spark-chamber experiment performed at the Bevatron. From 1079 events between 0.2 and 7 K_S^0 lifetime, we find ReX=-0.069±0.036, ImX=+0.108_(-0.074)^(+0.092). This result is consistent with X=0 (relative probability = 0.25), but more than 4 standard deviations from the existing world average, +0.14 -0.13i

Physical-activity support for people with intellectual disabilities:A theory-informed qualitative study exploring the direct support professionals’ perspective

Purpose: The study aims to explore factors that influence (facilitate or impede) direct support professionals supporting people with intellectual disabilities in engaging in physical activity. Influencing factors will be synthesized into a conceptual model to set the stage for developing future interventions and policies to change direct support professional behavior. Method: Based on the Theoretical Domains Framework, semi-structured interviews were conducted with 25 direct support professionals of people with mild to profound intellectual disabilities. Influencing factors were analyzed using both inductive and deductive coding strategies. The theoretical sources of behavior (i.e., capability, opportunity, and motivation) were leading components in the development of a conceptual model. Results: Five influential factors facilitating or impeding physical-activity support were isolated that related to direct support professionals’ capability, eight to the opportunities afforded them, and 11 to their motivation. Another six inductively emerged, which related to the characteristics of people with intellectual disabilities and which then influenced the capability, opportunity, or motivation to engage in physical-activity support by direct support professionals. Conclusions: Although experiences differed, the conceptual model developed here provides theoretically based targets for a comprehensive approach to changing direct support professional behavior and thus promoting the support of physical activity in people with intellectual disabilities

Cathepsin-D in primary breast cancer: prognostic evaluation involving 2810 patients

There is controversy regarding the prognostic value of cathepsin-D in primary breast cancer. An increased level of cathepsin-D in tumour extracts has been found to be associated with a poor relapse-free and overall survival. Studies performed with immunohistochemistry or Western blotting have produced diverse results. We have analysed 2810 cytosolic extracts obtained from human primary breast tumours for cathepsin-D expression, and have correlated their levels with prognosis. The median follow-up of the patients still alive was 88 months. Patients with high cathepsin-D levels had a significantly worse relapse-free and overall survival, also in multivariate analysis (P < 0.0001). Adjuvant therapy which was associated with an improved prognosis in node-positive patients in univariate analysis, also significantly added to the multivariate models for relapse-free and overall survival. There were no statistically significant interactions between the levels of cathepsin-D and any of the classical prognostic factors in analysis for relapse-free survival, suggesting that the prognostic value of cathepsin-D is not different in the various subgroups of patients. Indeed, multivariate analyses in subgroups of node-negative and -positive patients, pre- and post-menopausal patients, and their combinations, showed that tumours with high cathepsin-D values had a significantly poor relapse-free survival, with relative hazard rates ranging from 1.3 to 1.5, compared with tumours with low cathepsin-D levels. The results presented here on 2810 patients confirm that high cytosolic cathepsin-D values are associated with poor prognosis in human primary breast cancer. © 1999 Cancer Research Campaig