Of mice and men: Sparse statistical modeling in cardiovascular genomics

In high-throughput genomics, large-scale designed experiments are becoming common, and analysis approaches based on highly multivariate regression and anova concepts are key tools. Shrinkage models of one form or another can provide comprehensive approaches to the problems of simultaneous inference that involve implicit multiple comparisons over the many, many parameters representing effects of design factors and covariates. We use such approaches here in a study of cardiovascular genomics. The primary experimental context concerns a carefully designed, and rich, gene expression study focused on gene-environment interactions, with the goals of identifying genes implicated in connection with disease states and known risk factors, and in generating expression signatures as proxies for such risk factors. A coupled exploratory analysis investigates cross-species extrapolation of gene expression signatures--how these mouse-model signatures translate to humans. The latter involves exploration of sparse latent factor analysis of human observational data and of how it relates to projected risk signatures derived in the animal models. The study also highlights a range of applied statistical and genomic data analysis issues, including model specification, computational questions and model-based correction of experimental artifacts in DNA microarray data.Comment: Published at http://dx.doi.org/10.1214/07-AOAS110 in the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

Irrigation Technology Adoption in the Texas High Plains: A Real Options Approach

Water scarcity has been a significant issue for several decades in the Texas High Plains, with agriculture identified as the main activity contributing to this scarcity. To address this issue, much effort has been devoted to developing and encouraging adoption of sophisticated irrigation systems with high levels of water application efficiency, such as the low energy precision application (LEPA) system, subsurface drip irrigation (SDI), and variable rate irrigation (VRI). In this study, the economic feasibility of these irrigation systems is evaluated in cotton farming in the Texas High Plains using a real options approach. Results find that only the LEPA system is profitable under current conditions. The VRI system is profitable with high cotton prices (above $0.72/lb), while SDI is not profitable under any conditions explored.Resource /Energy Economics and Policy,

EFFECT OF REVENUE INSURANCE ON ENTRY AND EXIT DECISIONS IN TABLE GRAPE PRODUCTION: A REAL OPTION APPROACH

This study determines the entry and exit thresholds of table grape farming with irreversible investment under uncertainty. Real option approach is adopted to consider the investment and management flexibility. Also revenue insurance is introduced to consider the effect of the risk management programs on the entry and exit thresholds. Results show that revenue insurance increases the entry and exit thresholds by 1% and 4%, respectively, thus discouraging new investment and current farming, as long as the revenue guarantee is less than the exit threshold. Revenue insurance increases the entry threshold by 3% and decreases the exit threshold by 13% as long as the revenue guarantee is greater than the exit threshold. In this case, revenue insurance discourages the investment and encourages the current farmer to stay in farming, further. However, the decrease in the subsidy rate results in the increase in both entry and exit thresholds. Thus, the premium subsidy levels should be carefully considered if the policy objective is to encourage growers to shift to higher-value crops.Risk and Uncertainty,

Performance assessment of urban precinct design: a scoping study

Executive Summary: Significant advances have been made over the past decade in the development of scientifically and industry accepted tools for the performance assessment of buildings in terms of energy, carbon, water, indoor environment quality etc. For resilient, sustainable low carbon urban development to be realised in the 21st century, however, will require several radical transitions in design performance beyond the scale of individual buildings. One of these involves the creation and application of leading edge tools (not widely available to built environment professions and practitioners) capable of being applied to an assessment of performance across all stages of development at a precinct scale (neighbourhood, community and district) in either greenfield, brownfield or greyfield settings. A core aspect here is the development of a new way of modelling precincts, referred to as Precinct Information Modelling (PIM) that provides for transparent sharing and linking of precinct object information across the development life cycle together with consistent, accurate and reliable access to reference data, including that associated with the urban context of the precinct. Neighbourhoods are the ‘building blocks’ of our cities and represent the scale at which urban design needs to make its contribution to city performance: as productive, liveable, environmentally sustainable and socially inclusive places (COAG 2009). Neighbourhood design constitutes a major area for innovation as part of an urban design protocol established by the federal government (Department of Infrastructure and Transport 2011, see Figure 1). The ability to efficiently and effectively assess urban design performance at a neighbourhood level is in its infancy. This study was undertaken by Swinburne University of Technology, University of New South Wales, CSIRO and buildingSMART Australasia on behalf of the CRC for Low Carbon Living

SB 213 - Campaign Contributions Reporting

The Act amends Georgia’s campaign contributions reporting requirements for public officials. Specifically, the Act amends the dates that campaign contributions must be filed by public officials during nonelection years from January 31, before the start of the legislative session, to June 30, after the end of the legislative session. The Act also amends an election year reporting date from March 31 to April 30. Furthermore, the Act requires that any person or independent committee that contributes to, accepts contributions for, or makes expenditures on behalf of candidates to file a December 31 campaign contribution disclosure repor