Directed Test Suite Augmentation

As software evolves, engineers use regression testing to evaluate its fitness for release. Such testing typically begins with existing test cases, and many techniques have been proposed for reusing these cost-effectively. After reusing test cases, however, it is also important to consider code or behavior that has not been exercised by existing test cases and generate new test cases to validate these. This process is known as test suite augmentation. In this paper we present a directed test suite augmentation technique, that utilizes results from reuse of existing test cases together with an incremental concolic testing algorithm to augment test suites so that they are coverage-adequate for a modified program. We present results of an empirical study examining the effectiveness of our approach.

Using Genetics to Assess Differentiation Among Raccoons in an Area with Variable Rabies Status in Alabama

The western spread of raccoon rabies in Alabama has been slow and even appears to regress eastward periodically. While the disease has been present in the state for over 30 years, areas in northwest Alabama are devoid of raccoon rabies. This variation resulting in an enzootic area of raccoon rabies primarily in southeastern Alabama may be due to landscape features that hinder the movement of raccoons (i.e., gene flow) among different locations. We used 11 raccoon-specific microsatellite markers to obtain individual genotypes to examine gene flow among areas that were rabies free, enzootic with rabies, or had only sporadic reports of the disease. Samples from 70 individuals were collected from 5 sampling localities in 3 counties. The landscape feature data were collected from geographic information system (GIS) data. We inferred gene flow by estimating FST and by using Bayesian tests to identify genetic clusters. Estimates of pairwise FST indicated genetic differentiation and restricted gene flow between some sites, and an uneven distribution of genetic clusters was observed. Of the landscape features examined (i.e., land cover, elevation, slope, roads, and hydrology), only land cover had an association with genetic differentiation, suggesting this landscape variable may affect gene flow among raccoon populations and thus the spread of raccoon variant of rabies in Alabama.

Differentiation in the Content-Area Classroom for English Language Learners

This paper explores the idea of using differentiation strategies in the content-area classroom to improve reading skills and comprehension. In particular, this thesis explores methods and strategies that can be used in the classroom to help address the individual needs of English language learners (ELLs). A broad range of experts in curriculum, differentiation, and English language acquisition were consulted in the development of this review, which synthesizes the research on ELLs’ needs, differentiation, and differentiation strategies for ELL readers. The models for best teaching practices are then placed within a ninth grade language arts unit.

Rhodium-Catalyzed Hydroboration: Directed Asymmetric Desymmetrization

Rhodium-catalyzed asymmetric hydroboration in conjunction with directing groups can be used control relative and absolute stereochemistry. Hydroboration has the potential to create new C–C, C–O, and C–N bonds from an intermediate C–B bond with retention of stereochemistry. Desymmetrization resulting in the loss of one or more symmetry elements can give rise to molecular chirality, i.e., the conversion of a prochiral molecule to one that is chiral. Unsaturated amides and esters hold the potential for two-point binding to the rhodium catalyst and have been shown to direct the regiochemistry and impact stereochemistry in asymmetric hydroborations of acyclic β,γ-unsaturated substrates. In the present study, the pendant amide functionality directs the hydroboration cis in the cyclic substrates studied; the corresponding ester substrates do so to a lesser extent. The enantioselectivity is determined by regioselective addition to the re or si site of the rhodium-complexed alkene. The effect of catalyst, ligand and borane on the observed diastereoselectivity and enantioselectivity for a variety of cyclopentenyl ester and amide substrates is discussed.