Thoracoschisis: case report and review of the literature

Introduction: Thoracoschisis is a rare congenital malformation characterized by herniation of intraabdominal contents through a thoracic wall defect. There have been six previously reported cases. We describe our novel approach incorporating closure of the chest wall defect with temporary abdominal wall expansion utilizing a silastic pouch.Case report: A male child born at 29 weeks’ gestation was transferred to our institution for the management of a right anterior chest wall defect with herniation of intraabdominal contents through this defect. The patient was taken to the operating room for reduction of the herniated viscera from the right chest wall defect into the abdomen utilizing a spring-loaded silastic pouch to cover the abdominal viscera.Discussion: The cause of thoracoschisis is unclear. Multiple mechanisms have been proposed for the development of thoracoschisis, including amnionic rupture, vascular injury, and embryologic maldevelopment. In previously reported cases, a majority of patients had associated limb abnormalities. It has been proposed that this association between extremity agenesis/deformity  and chest wall defects is related to the limb–body wall complex. In addition, most of the cases reported also had an accompanying diaphragmatic defect, allowing the abdominal viscera to enter the chest and then herniate through the thoracic defect.Conclusion: Overall, thoracoschisis is a very rare congenital abnormality characterized by a chest wall defect with herniation of intra-abdominal organs through this defect. Previously, only six cases have been reported, most of which had an associated limb anomaly or diaphragmatic hernia.Keywords: gastroschisis, limb–body wall complex, thoracoabdominal schisis, thoracoschisi

Geologic and geotechnical assessment RFETS Building 371, Rocky Flats, Colorado

This report describes the review and evaluation of the geological, geotechnical and geophysical data supporting the design basis analysis for the Rocky Flats Environmental Test Site (RFETS) Building 371. The primary purpose of the geologic and geotechnical reviews and assessments described herein are to assess the adequacy of the crustal and near surface rock and soil model used in the seismic analysis of Building 371. This review was requested by the RFETS Seismic Evaluation Program. The purpose was to determine the adequacy of data to support the design basis for Building 371, with respect to seismic loading. The objectives required to meet this goal were to: (1) review techniques used to gather data (2) review analysis and interpretations of the data; and (3) make recommendations to gather additional data if required. Where there were questions or inadequacies in data or interpretation, recommendations were made for new data that will support the design basis analysis and operation of Building 371. In addition, recommendations are provided for a geologic and geophysical assessment for a new facility at the Rocky Flats Site

Simulation-based optimal Bayesian experimental design for nonlinear systems

The optimal selection of experimental conditions is essential to maximizing the value of data for inference and prediction, particularly in situations where experiments are time-consuming and expensive to conduct. We propose a general mathematical framework and an algorithmic approach for optimal experimental design with nonlinear simulation-based models; in particular, we focus on finding sets of experiments that provide the most information about targeted sets of parameters. Our framework employs a Bayesian statistical setting, which provides a foundation for inference from noisy, indirect, and incomplete data, and a natural mechanism for incorporating heterogeneous sources of information. An objective function is constructed from information theoretic measures, reflecting expected information gain from proposed combinations of experiments. Polynomial chaos approximations and a two-stage Monte Carlo sampling method are used to evaluate the expected information gain. Stochastic approximation algorithms are then used to make optimization feasible in computationally intensive and high-dimensional settings. These algorithms are demonstrated on model problems and on nonlinear parameter estimation problems arising in detailed combustion kinetics.Comment: Preprint 53 pages, 17 figures (54 small figures). v1 submitted to the Journal of Computational Physics on August 4, 2011; v2 submitted on August 12, 2012. v2 changes: (a) addition of Appendix B and Figure 17 to address the bias in the expected utility estimator; (b) minor language edits; v3 submitted on November 30, 2012. v3 changes: minor edit

Petrology and Geochemistry of Neoproterozoic Arc Plutons Beneath the Atlantic Coastal Plain, SRS, SC

In this report is presented first a brief review of the regional geologic setting of the Savannah River Site, descriptions of the plutonic rock units sampled here, whole rock geochemical data on the plutonic igneous rocks, and finally, a discussion of how the crystalline basement rocks of the Savannah River Site formed and how they may correlate with other terranes exposed in the Piedmont of the Carolinas, Georgia, and Virginia

Global random optimization by simultaneous perturbation stochastic approximation

Abstract—We examine the theoretical and numerical global convergence properties of a certain “gradient free ” stochastic approximation algorithm called the “simultaneous perturbation stochastic approximation (SPSA)” that has performed well in complex optimization problems. We establish two theorems on the global convergence of SPSA, the first involving the wellknown method of injected noise. The second theorem establishes conditions under which “basic ” SPSA without injected noise can achieve convergence in probability to a global optimum, a result with important practical benefits. Index Terms—Global convergence, simulated annealing, simultaneous perturbation stochastic approximation (SPSA), stochastic approximation (SA), stochastic optimization. I

Weak convergence and the exponential rate of concentration for posterior density functions

Consider a Bayesian analysis of a parameter vector, [theta], based on n i.i.d. multivariate measurements. We establish weak convergence of a sequence of parameter values that arises in applying the mean value theorem for integrals to the marginal densities of the sequence of observed vectors. We apply this weak convergence theorem to obtain a finite-sample result characterizing the rate of change of the shape of the posterior density as the number of observations increases.Bayesian exponential family rate of convergence posterior density

Conditions for the insensitivity of the Bayesian posterior distribution to the choice of prior distribution

We present four theorems that establish conditions under which the Bayesian posterior distribution is insensitive to the choice of prior distribution. Both finite-sample and asymptotic results are included.Bayesian posterior robustness stable estimation weak consistency small-sample large-sample