Segmentation of Fault Networks Determined from Spatial Clustering of Earthquakes

We present a new method of data clustering applied to earthquake catalogs, with the goal of reconstructing the seismically active part of fault networks. We first use an original method to separate clustered events from uncorrelated seismicity using the distribution of volumes of tetrahedra defined by closest neighbor events in the original and randomized seismic catalogs. The spatial disorder of the complex geometry of fault networks is then taken into account by defining faults as probabilistic anisotropic kernels, whose structures are motivated by properties of discontinuous tectonic deformation and previous empirical observations of the geometry of faults and of earthquake clusters at many spatial and temporal scales. Combining this a priori knowledge with information theoretical arguments, we propose the Gaussian mixture approach implemented in an Expectation-Maximization (EM) procedure. A cross-validation scheme is then used and allows the determination of the number of kernels that should be used to provide an optimal data clustering of the catalog. This three-steps approach is applied to a high quality relocated catalog of the seismicity following the 1986 Mount Lewis ($M_l=5.7$) event in California and reveals that events cluster along planar patches of about 2 km$^2$, i.e. comparable to the size of the main event. The finite thickness of those clusters (about 290 m) suggests that events do not occur on well-defined euclidean fault core surfaces, but rather that the damage zone surrounding faults may be seismically active at depth. Finally, we propose a connection between our methodology and multi-scale spatial analysis, based on the derivation of spatial fractal dimension of about 1.8 for the set of hypocenters in the Mnt Lewis area, consistent with recent observations on relocated catalogs

Underreported Threat of Multidrug-Resistant Tuberculosis in Africa

Identification of population-based factors should influence regional and national policy

The effect of an integrated multisector model for achieving the Millennium Development Goals and improving child survival in rural sub-Saharan Africa: a non-randomised controlled assessment

Background Simultaneously addressing multiple Millennium Development Goals (MDGs) has the potential to complement essential health interventions to accelerate gains in child survival. The Millennium Villages project is an integrated multisector approach to rural development operating across diverse sub-Saharan African sites. Our aim was to assess the effects of the project on MDG-related outcomes including child mortality 3 years after implementation and compare these changes to local and national reference data

Beginning teachers moving toward effective elementary science teaching

We use a 10-year program of research centered on iterations of one elementary science methods course as a vehicle for exploring three important and interrelated goals for the learning of beginning elementary teachers. These include learning about inquiry-oriented science teaching, using science curriculum materials effectively, and anticipating and working with students' ideas in instruction. For each goal we discuss how the literature informs our thinking, describe relevant aspects of our design of the course, and present findings of our research with regard to preservice teachers' experiences in and learning from aspects of the course. For each goal, we also highlight examples from our longitudinal work following the preservice teachers into their early years as elementary teachers, to provide a glimpse of teachers' trajectories related to each of the themes. We close with a discussion of implications for research and practice in elementary science teacher education. © 2009 Wiley Periodicals, Inc. Sci Ed 93: 745–770, 2009Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63063/1/20311_ftp.pd