Investigation of the reactivity of organic materials in liquid oxygen

Measurements of impact-ignition sensitivity and studies of the relative reactivity of t-butoxy and t-butyl peroxy radicals toward a variety of organic compounds reveal improved methods of selection of materials for safe use in a liquid oxygen environment

Divergence, convergence, and the ancestry of feral populations in the domestic rock pigeon

ManuscriptDomestic pigeons are spectacularly diverse and exhibit variation in more traits than any other bird species [1]. In The Origin of Species, Charles Darwin repeatedly calls attention to the striking variation among domestic pigeon breeds - generated by thousands of years of artificial selection on a single species by human breeders - as a model for the process of natural divergence among wild populations and species [2]. Darwin proposed a morphology-based classification of domestic pigeon breeds [3], but the relationships among major groups of breeds and their geographic origins remain poorly understood [4, 5]. We used a large, geographically diverse sample of 361 individuals from 70 domestic pigeon breeds and two free-living populations to determine genetic relationships within this species. We found unexpected relationships among phenotypically divergent breeds that imply convergent evolution of derived traits in several breed groups. Our findings also illuminate the geographic origins of breed groups in India and the Middle East, and suggest that racing breeds have made substantial contributions to feral pigeon populations

Investigation of reactivity of launch vehicle materials with liquid oxygen Quarterly report, 23 Jul. - 22 Oct. 1968

Reactivity of launch vehicle organic materials with liquid oxyge

Investigation of Reactivity of Launch Vehicle Materials with Liquid Oxygen

Impact sensitivity and ignition mechanism of organic compounds in liquid oxygen correlated with chemical and physical propertie

Meta‐analysis of gene‐environment interaction exploiting gene‐environment independence across multiple case‐control studies

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138916/1/sim7398_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138916/2/sim7398.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138916/3/sim7398-sup-001-sup.pd

The Role of Environmental Heterogeneity in Meta‐Analysis of Gene–Environment Interactions With Quantitative Traits

With challenges in data harmonization and environmental heterogeneity across various data sources, meta‐analysis of gene–environment interaction studies can often involve subtle statistical issues. In this paper, we study the effect of environmental covariate heterogeneity (within and between cohorts) on two approaches for fixed‐effect meta‐analysis: the standard inverse‐variance weighted meta‐analysis and a meta‐regression approach. Akin to the results in Simmonds and Higgins ( ), we obtain analytic efficiency results for both methods under certain assumptions. The relative efficiency of the two methods depends on the ratio of within versus between cohort variability of the environmental covariate. We propose to use an adaptively weighted estimator (AWE), between meta‐analysis and meta‐regression, for the interaction parameter. The AWE retains full efficiency of the joint analysis using individual level data under certain natural assumptions. Lin and Zeng (2010a, b) showed that a multivariate inverse‐variance weighted estimator retains full efficiency as joint analysis using individual level data, if the estimates with full covariance matrices for all the common parameters are pooled across all studies. We show consistency of our work with Lin and Zeng (2010a, b). Without sacrificing much efficiency, the AWE uses only univariate summary statistics from each study, and bypasses issues with sharing individual level data or full covariance matrices across studies. We compare the performance of the methods both analytically and numerically. The methods are illustrated through meta‐analysis of interaction between Single Nucleotide Polymorphisms in FTO gene and body mass index on high‐density lipoprotein cholesterol data from a set of eight studies of type 2 diabetes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/107543/1/gepi21810.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/107543/2/gepi21810-sup-0001-appendix.pd

Classifying Organizations for Food System Ontologies using Natural Language Processing

Our research explores the use of natural language processing (NLP) methods to automatically classify entities for the purpose of knowledge graph population and integration with food system ontologies. We have created NLP models that can automatically classify organizations with respect to categories associated with environmental issues as well as Standard Industrial Classification (SIC) codes, which are used by the U.S. government to characterize business activities. As input, the NLP models are provided with text snippets retrieved by the Google search engine for each organization, which serves as a textual description of the organization that is used for learning. Our experimental results show that NLP models can achieve reasonably good performance for these two classification tasks, and they rely on a general framework that could be applied to many other classification problems as well. We believe that NLP models represent a promising approach for automatically harvesting information to populate knowledge graphs and aligning the information with existing ontologies through shared categories and concepts.Comment: Presented at IFOW 2023 Integrated Food Ontology Workshop at the Formal Ontology in Information Systems Conference (FOIS) 2023 in Sherbrooke, Quebec, Canada July 17-20th, 202

Logging planning and layout costs for thinning : experience from the Willamette Young Stand Project

Logging planning and layout costs were examined for commercial thinning of 40- to 50-yr-old stands of Douglas-fir on the Willamette National Forest in the Cascade Mountains of Oregon. The study consisted of four replications of three silvicultural treatments. Thinning involved three types of logging systems: mechanized cut-to-length (a combination of single-grip harvester and forwarder), tractor, and skyline. Data for the study came from two sources: activities completed by the Forest Service in preparing sales for bid, and the layout completed by the logging contractor after a contract was awarded. Planning and layout costs showed no consistent relationship to type of silvicultural treatment. Logging contractor layout costs showed a relationship to type of logging system: the mechanized system had the lowest layout cost, followed by the tractor systems, with the skyline systems having the highest costs