Albion College

About: Albion College is a education organization based out in Albion, Michigan, United States. It is known for research contribution in the topics: Population & Higher education. The organization has 485 authors who have published 754 publications receiving 20907 citations.

Survey Data Harmonization and the Quality of Data Documentation in Cross-national Surveys

Abstract: Many social phenomena bare the imprint of regional and global social, economic, and political processes, and therefore should be studied in a comparative framework. However, inequalities in survey coverage across various regions and the lack of uniform data collection and documentation standards in cross-national survey projects pose a serious limitation to comparative research. While previous efforts to advance cross-national research usually produce a new dataset, we argue that the answer to these problems is actually better integration of existing data. This paper focuses on the assessment of the quality of data documentation, an important, although often neglected, element of any data analysis that is especially crucial for data harmonization projects. We assessed the quality of surveys based on information provided in survey documentation: questionnaire pre-testing, translation method, sampling, presence of fieldwork control, as well as unit and item non-response. Finally, we discuss incorporating documentation measures into substantive analyses, as well as the potential for standardization of survey documentation and the survey process itself.

Integration specificity of the hobo element of Drosophila melanogaster is dependent on sequences flanking the integration site.

Abstract: We analyzed the integration specificity of the hobo transposable element of Drosophila melanogaster. Our results indicate that hobo is similar to other transposable elements in that it can integrate into a large number of sites, but that some sites are preferred over others, with a few sites acting as integration hot spots. A comparison of DNA sequences from 112 hobo integration sites identified a consensus sequence of NTNNNNAC, but this consensus was insufficient to account for the observed integration specificity. To begin to define the parameters affecting hobo integration preferences, we analyzed sequences flanking a donor hobo element, as well as sequences flanking a hobo integration hot spot for their relative influence on hobo integration specificity. We demonstrate experimentally that sequences flanking a hobo donor element do not influence subsequent integration site preference, whereas, sequences contained within 31 base pairs flanking an integration hot spot have a significant effect on the frequency of integration into that site. However, sequence analysis of the DNA flanking several hot spots failed to identify any common sequence motif shared by these sites. This lack of primary sequence information suggests that higher order DNA structural characteristics of the DNA and/or chromatin may influence integration site selection by the hobo element.

Navigation Planning Using Quadtrees

Abstract: An algorithm is presented for planning a 2-D collision-free path for a mobile robot in an unstructured work environment. The algorithm assumes the existence of a pixel map of all or part of the environment, where each pixel is either on (implying blocked) or off (implying clear). The goal is to compute a "reasonable path" between two points in a minimal amount of time, and this is achieved through a "compressed" representation of the pixel map using a modified quadtree data structure and a procedure for smoothing the resulting path. The algorithm has been coded in the C programming language to facilitate portability, and the results of tests made on "realistic" indoor environments are presented. A discussion on how the environmental maps were obtained is also included.