A comprehensive tribal-level classification for the world's subfamilies of Hesperiidae, the skipper butterflies, is proposed for the first time. Phylogenetic relationships between tribes and subfamilies are inferred using DNA sequence data from three gene regions: 943 bp of cytochrome oxidase subunit I (COI) (in the mitochondrial genome), 739 bp of...
Water availability is a critical limiting element in semi-arid ecosystem productivity and presents particular challenges in Sahelian countries such as Senegal. The landscapes are characterized by the presence of two common semi-arid shrubs (Piliostigma reticulatum and Guiera senegalensis), both of which may be important hydraulic regulators in these water-limited ecosystems....
The purpose of this study was to investigate the knowledge base and instructional
practices of two highly qualified experienced secondary mathematics teachers within
the context of their classrooms during a unit in a geometry class. Data collected from
interviews, classroom observations, pre and post-observation questionnaires, and
detailed analyses of several...
Pyrenophora tritici-repentis, causal agent of tan spot of wheat, produces multiple
host-selective toxins (HSTs), including Ptr ToxA, encoded for by ToxA, Ptr ToxB,
encoded for by ToxB, and Ptr ToxC. Variable distribution of these three HSTs among
different isolates of P. tritici-repentis, both singularly and in all possible combinations,
defines...
This study co-investigated with students with hidden disabilities the phenomenon of disability identity. This qualitative study utilized phenomenology and strategies proposed by Paulo Freire in an effort to understand identity development specific to individuals with hidden disabilities. There were seven students from a medium-sized, public university who participated in the...
Development of efficient methods for the destruction of solid wastes and recovery of valuable resources is needed to support long-duration manned missions in space. In particular, these technologies are required for deployment in hypogravity and microgravity environments, such as at the lunar or Martian surfaces. Gradient Magnetically Assisted Fluidized Bed...
The miniaturization of energy, chemical and biological systems for distributed and portable applications, known as process intensification, is realized by the enhancement in heat and mass transfer performance within high surface-to-volume ratio microchannels. Fabrication of devices for process intensification is achieved in part by microlamination techniques. These techniques consist of...
Many Hymenoptera, with their painful stings and noxious chemical defenses, exhibit bright aposematic warning color patterns and are the most frequently mimicked group of organisms. Such aposematic color patterns are found in parasitic wasps of the Neotropical Compsobracon group (Braconidae). Many members of this group exhibit color patterns similar to...
The first asymmetric synthesis of (-)-7-epicylindrospermopsin via intramolecular nitrone cycloaddition is described. The synthesis utilized a convergent approach to prepare the cycloaddition precursor 176, which was assembled by condensation of hydroxylamine 175 with aldehyde 145. Hydroxylamine 175 was synthesized from ethylene glycol (166) in seven steps. Aldehyde 145 was completed...
The purpose of the study was to investigate students' learning of the function concept and the role of the graphing calculator in a College Algebra course. Differences between students with high symbolic manipulation skills. and students with low symbolic manipulation skills were also examined. On the basis of an algebraic...