International Baccalaureate Mathematics, Advanced Placement Mathematics, and Dual Credit Mathematics Courses – An In Depth Look

Every year in the United States, many students who believe they are fully prepared for college find out that they have to take remedial math courses before they can take any credit bearing math courses toward their degree. A student can avoid this situation by taking an early college program in high school and potentially earning a college math credit. The purpose of this research project was to take an in depth look at three such programs. The names of these programs are the International Baccalaureate program, the Advanced Placement program, and Dual Credit programs. This research project looked into the histories of these programs, what is being taught in the mathematics classes of these programs, and what research says about these programs

Analysis of the proteins synthesized in ultraviolet light-irradiated Escherichia coli following infection with the bacteriophages λ drif d 18 and λ dfus -3

The presence of EF-Tu, RNA polymerase subunit α, and EF-G on the λ dfus -3 genome and EF-Tu, ribosomal proteins L7/L12, and RNA polymerase subunit β on the λ drif d 18 genome has been confirmed using a two-dimensional gel electrophoresis technique sensitive to changes in isoelectric point and molecular weight. In this system two EF-Tu gene products could not be resolved. Following infection of ultraviolet light-irradiated Escherichia coli with either λ dfus -3 or λ drif d 18, the EF-Tu gene, tufA , near 65 minutes on the genetic map is expressed as 3–4 copies per EF-G molecule. The EF-Tu gene, tufB , near 79 minutes on the genetic map, is expressed at about one-third of this rate. α is expressed as 1 copy per EF-G molecule, β as 0.14 per EF-G molecule and L7/L12 as 2.5 per EF-G. These figures compare well with the relative amounts found in exponentially-growing cells, in which the ratio of EF-Tu to EF-G is approximately 5. Almost 90% of the total number of proteins (calculated on a molecular weight basis) which theoretically can be encoded on the λ drif d 18 have been identified on the two-dimensional gel.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47541/1/438_2004_Article_BF00341733.pd

Regulation of the expression of tufA and tufB, the 2 genes coding for the elongation factor EF-Tu in eschericia coli

Microbial Biotechnolog

A study of a mutant elongation factor properties of E. coli HAK88 and its mutant elongation factor Tu

The E. coli chromosome contains two genes for elongation factor Tu, tufA (near the fusidic acid resistance marker) and tufB (near the rifampicin resistance marker). It has been discovered that the mutant E. coli K12 strain HAK88 bears a mutation in the tufB gene, which leads to the synthesis of a protein of increased acidity. To determine whether the mutation has altered the protein's function in peptide chain elongation, we have compared the reactivities of normal tufA EF-Tu and mutant tufB EF-Tu (purified together from HAK88) with the components of the AA-tRNA binding cycle. Normal tufA EF-Tu and mutant tufB EF-Tu are indistinguishable in their affinities for GDP, EF-Ts, and phe-tRNA, and differ only slightly in their affinities for ribosomes. Coupled with the results of a separate study showing the similarity of the normal tufA and tufB gene products, these experiments demonstrate that the mutation has not altered the function of tufB EF-Tu in peptide chain elongation. Contrary to the original report (Kuwano et al., 1974; J. Mol. Biol. 86 , 689–698) the HAK88 strains we have examined no longer possess a temperature-sensitive EF-Ts. The growth rates of HAK88 strains resemble the parent HAK8 strain in their lack of tRNA dependence but unlike HAK8 show varying degrees of temperature sensitivity. We conclude that HAK88 contains a physically altered but functionally intact tufB EF-Tu. The mutation in tufB should be valuable for studying in vivo the control of expression of the genes for EF-Tu.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47543/1/438_2004_Article_BF00401747.pd

A Computational Study of Elongation Factor G (EFG) Duplicated Genes: Diverged Nature Underlying the Innovation on the Same Structural Template

BACKGROUND: Elongation factor G (EFG) is a core translational protein that catalyzes the elongation and recycling phases of translation. A more complex picture of EFG's evolution and function than previously accepted is emerging from analyzes of heterogeneous EFG family members. Whereas the gene duplication is postulated to be a prominent factor creating functional novelty, the striking divergence between EFG paralogs can be interpreted in terms of innovation in gene function. METHODOLOGY/PRINCIPAL FINDINGS: We present a computational study of the EFG protein family to cover the role of gene duplication in the evolution of protein function. Using phylogenetic methods, genome context conservation and insertion/deletion (indel) analysis we demonstrate that the EFG gene copies form four subfamilies: EFG I, spdEFG1, spdEFG2, and EFG II. These ancient gene families differ by their indispensability, degree of divergence and number of indels. We show the distribution of EFG subfamilies and describe evidences for lateral gene transfer and recent duplications. Extended studies of the EFG II subfamily concern its diverged nature. Remarkably, EFG II appears to be a widely distributed and a much-diversified subfamily whose subdivisions correlate with phylum or class borders. The EFG II subfamily specific characteristics are low conservation of the GTPase domain, domains II and III; absence of the trGTPase specific G2 consensus motif "RGITI"; and twelve conserved positions common to the whole subfamily. The EFG II specific functional changes could be related to changes in the properties of nucleotide binding and hydrolysis and strengthened ionic interactions between EFG II and the ribosome, particularly between parts of the decoding site and loop I of domain IV. CONCLUSIONS/SIGNIFICANCE: Our work, for the first time, comprehensively identifies and describes EFG subfamilies and improves our understanding of the function and evolution of EFG duplicated genes

Faith and Banishment : the Artistic Credo of Katherine Anne Porter

In 1932 Katherine Anne Porter wrote to her brother from Paris, where she was living happily, about walking along the Quay and buying old maps of the New World: I have already a French map of America made in 1631, and a French map of Virginia dated 1640. They are beautiful and inaccurate and I mean to have a lot of them. (Letters of Katherine Anne Porter, 78) The image of the old, absolute map floated right off the page as I read; it seemed to serve as the perfect metaphor for something in Porter\u27s fiction that I had not yet been able to describe metaphorically: the determined and inspired impulse to create order that mediates the fearful space between the reality of New Worlds and the perception of the individual. The role of the artist, as defined in Porter\u27s fiction and nonfiction, is akin to that of the map maker who, working from her unique vantage point and from the vision of those preceding her, re-draws the boundaries, reshapes the landscape of individual consciousness. Each generation of artists, she believed, must not intentionally speak for a new age of understanding or the latest ultimate truths. Rather, the artist stands alone, necessarily a voice of dissent, creating a self-defined order in the context of communal pressure and the stream of time. Her writing articulates a steadfast sense of her mission as an artist and it is this mission I want to explain. Her letters and essays discuss it in straightforward terms, while the artistic ramifications of her credo are given the movement of narrative in the mythical initiations from innocence to experience which so often form the nexus of her stories