Bayesian Restricted Likelihood Methods: Conditioning on Insufficient Statistics in Bayesian Regression

Bayesian methods have proven themselves to be successful across a wide range of scientific problems and have many well-documented advantages over competing methods. However, these methods run into difficulties for two major and prevalent classes of problems: handling data sets with outliers and dealing with model misspecification. We outline the drawbacks of previous solutions to both of these problems and propose a new method as an alternative. When working with the new method, the data is summarized through a set of insufficient statistics, targeting inferential quantities of interest, and the prior distribution is updated with the summary statistics rather than the complete data. By careful choice of conditioning statistics, we retain the main benefits of Bayesian methods while reducing the sensitivity of the analysis to features of the data not captured by the conditioning statistics. For reducing sensitivity to outliers, classical robust estimators (e.g., M-estimators) are natural choices for conditioning statistics. A major contribution of this work is the development of a data augmented Markov chain Monte Carlo (MCMC) algorithm for the linear model and a large class of summary statistics. We demonstrate the method on simulated and real data sets containing outliers and subject to model misspecification. Success is manifested in better predictive performance for data points of interest as compared to competing methods

Routine characterization and interpretation of complex alkali feldspar intergrowths

Almost all alkali feldspar crystals contain a rich inventory of exsolution, twin, and domain microtextures that form subsequent to crystal growth and provide a record of the thermal history of the crystal and often of its involvement in replacement reactions, sometimes multiple. Microtextures strongly influence the subsequent behavior of feldspars at low temperatures during diagenesis and weathering. They are central to the retention or exchange of trace elements and of radiogenic and stable isotopes. This review is aimed at petrologists and geochemists who wish to use alkali feldspar microtextures to solve geological problems or who need to understand how microtextures influence a particular process. We suggest a systematic approach that employs methods available in most well founded laboratories. The crystallographic relationships of complex feldspar intergrowths were established by the 1970s, mainly using single-crystal X-ray diffraction, but such methods give limited information on the spatial relationships of the different elements of the microtexture, or of the mode and chronology of their formation, which require the use of microscopy. We suggest a combination of techniques with a range of spatial resolution and strongly recommend the use of orientated sections. Sections cut parallel to the perfect (001) and (010) cleavages are the easiest to locate and most informative. Techniques described are light microscopy; scanning electron microscopy using both backscattered and secondary electrons, including the use of surfaces etched in the laboratory; electron-probe microanalysis and analysis by energy-dispersive spectrometry in a scanning electron microscope; transmission electron microscopy. We discuss the use of cathodoluminescence as an auxiliary technique, but do not recommend electron-backscattered diffraction for feldspar work. We review recent publications that provide examples of the need for great care and attention to pre-existing work in microtextural studies, and suggest several topics for future work

Integrating research, surveillance, and practice in environmental public health tracking.

The Centers for Disease Control and Prevention in the U.S. Department of Health and Human Services is working with selected state and local health departments, academic centers, and others to develop an environmental public health tracking initiative to improve geographic and temporal surveillance of environmental hazards, exposures, and related health outcomes. The objective is to support policy strategies and interventions for disease prevention by communities and environmental health agencies at the federal, state, and local levels. The first 3 years of the initiative focused on supporting states and cities in developing capacity, information technology infrastructure, and pilot projects to demonstrate electronic linkage of environmental hazard or exposure data and disease data. The next phase requires implementation across states. This transition could provide opportunities to further integrate research, surveillance, and practice through attention to four areas. The first is to develop a shared and transparent knowledge base that draws on environmental health research and substantiates decisions about what to track and the interpretation of results. The second is to identify and address information needs of policy and stakeholder audiences in environmental health. The third is to adopt mechanisms for coordination, decision making, and governance that can incorporate and support the major entities involved. The fourth is to promote disease prevention by systematically identifying and addressing population-level environmental determinants of health and disease

The Pitfalls of Constructing Yield Maps

Crop Production/Industries,

Weighted feature selection criteria for visual servoing of a telerobot

Because of the continually changing environment of a space station, visual feedback is a vital element of a telerobotic system. A real time visual servoing system would allow a telerobot to track and manipulate randomly moving objects. Methodologies for the automatic selection of image features to be used to visually control the relative position between an eye-in-hand telerobot and a known object are devised. A weighted criteria function with both image recognition and control components is used to select the combination of image features which provides the best control. Simulation and experimental results of a PUMA robot arm visually tracking a randomly moving carburetor gasket with a visual update time of 70 milliseconds are discussed

Government Policy in Support of Domestic Agriculture: Costs and Benefits, The United States

Agricultural and Food Policy,

Implications of Constraints on Mass Parameters in the Higgs Sector of the Nonlinear Supersymmetric SU(5) Model

The Higgs sector of the minimal nonlinear supersymmetric SU(5) model contains three mass parameters. Although these mass parameters are essentially free at the electroweak scale, they might have particular values if they evolve from a particular constraints at the GUT scale through the RG equations. By assuming a number of simple constraints on these mass parameters at the GUT scale, we obtain their values at the electroweak scale through the RG equations in order to investigate the phenomenological implications. Some of them are found to be consistent with the present experimental data.Comment: 23 pages, 10 figure

Mandibular ramus morphology and species identification in Australopithecus sediba.

The site of Malapa, South Africa, has produced fossil evidence from multiple individuals of Australopithecus sediba including the partial skeletons designated as MH1 (holotype) and MH2 (paratype). A recent article in this Journal presented the hypothesis that MH1 and MH2 are not one species but instead represent two different genera: Australopithecus and Homo, respectively. Here we briefly evaluate this claim. We review the evidence from across the skeleton that demonstrates that MH1 and MH2 represent a single species, and we highlight other fossil samples that show the same pattern of mandibular ramus variation as observed in MH1 and MH2. The evidence shows that there is no reason to separate MH1 and MH2 into different species or genera based upon mandibular ramus morphology. This case illustrates how misleading small fragments of anatomy can be, why researchers should not use such fragments particularly for species and genus-level diagnoses, and why it is essential to use all available evidence.Significance:This study shows that the mandibular variation that is present in fossils from Malapa attributed to Australopithecus sediba has parallels in both Australopithecus africanus and in Homo. This helps to demonstrate that mandibular form is not sufficient to provide evidence of species diagnosis, but also that the development and adaptations to diet in Au. sediba were overlapping with those present in other related species of hominins