Oxytalan fibres in marsupial periodontal ligaments

Thesis (M.D.S.) from the Department of Dental Health, University of Adelaide, 197

Comprehension Instruction for Elementary Learners: A Content Analysis of Professional Literacy Texts

This study examined how reading comprehension was addressed in literacy texts used with preservice teachers at five universities in the southwestern United States. Universities were selected based on the highest number of graduates receiving their initial Early Childhood through 4th grade (EC-4) teaching certificates. An introductory Reading course was selected from each university. A total of 11 required textbooks were examined for definitions of reading comprehension, the presence of reading instructional incidents (RIIs), and reading comprehension instructional incidents (RCIIs). Overall, more RIIs (reading instruction) than RCIIs (reading instruction related to comprehension) were found

Development of Literacy Beliefs and Practices: Preservice Teachers with Reading Specializations in a Field-Based Program

This manuscript documents a year-long descriptive case study of preservice teachers specializing in reading. The objectives of this study were to (a) better understand the development of literacy beliefs and change processes in preservice teachers with reading specializations engaged in the final year of their field-based teacher education program, and (b) ascertain factors influencing their change processes during the final year of preparation. The results highlight the shifts these preservice teachers made concerning their beliefs about literacy instruction and the factors that served as catalysts for those changes

Standardization and performance evaluation of mononuclear cell cytokine secretion assays in a multicenter study

BACKGROUND: Cryopreservation of peripheral blood mononuclear cells has been used to preserve and standardize immunologic measurements for multicenter studies, however, effects of cryopreservation on cytokine responses are incompletely understood. In designing immunologic studies for a new multicenter birth cohort study of childhood asthma, we performed a series of experiments to determine the effects of two different methods of cryopreservation on the cytokine responses of cord and peripheral blood mononuclear cells. RESULTS: Paired samples of PBMC were processed freshly, or after cryopreservation in a Nalgene container (NC) or a controlled-rate freezer (CRF). Although there were some differences between the methods, cryopreservation inhibited PHA-induced IL-10 secretion and Der f 1-induced IL-2 secretion, and augmented PHA-induced IL-2 secretion and spontaneous secretion of TNF-α. In separate experiments, NC cryopreservation inhibited secretion of several cytokines (IL-13, IL-10, IFN-γ, TNF-α) by PHA-stimulated cord blood mononuclear cells. With the exception of PHA-induced IL-13, results from fresh and cryopreserved cord blood samples were not significantly correlated. Finally, in reproducibility studies involving processing of identical cell samples in up to 4 separate laboratories, variances in cytokine responses of fresh cells stimulated at separate sites did not exceed those in cryopreserved cells stimulated at a central site. CONCLUSION: Collectively, these studies indicate that cryopreservation can affect mononuclear cell cytokine response profiles, and that IL-10 secretion and antigen-induced responses may be especially vulnerable. These studies also demonstrate that mononuclear cell responses can be standardized for performance in a small number of laboratories for multicenter studies, and underscore the importance of measuring reproducibility and of testing whether cryopreservation techniques alter specific immunologic outcomes

Analysis of americium-beryllium neutron source composition using the FRAM code

The FRAM code was originally developed to analyze high-resolution gamma spectra from plutonium items. Its capabilities have since been expanded to include analysis of uranium spectra. The flexibility of the software also enables a capable spectroscopist to use FRAM to analyze spectra in which neither plutonium nor uranium is present in significant amounts. This paper documents the use of FRAM to determine the {sup 239}Pu/{sup 241}Am, {sup 243}Am/{sup 241}Am, {sup 237}Np/{sup 241}Am, and {sup 239}Np/{sup 241}Am ratios in americium-beryllium neutron sources. The effective specific power of each neutron source was calculated from the ratios determined by FRAM in order to determine the americium mass of each of these neutron sources using calorimetric assay. We will also discuss the use of FRAM for the general case of isotopic analysis of nonplutonium, nonuranium items

Ring-Closing Metathesis of Olefinic Peptides: Design, Synthesis, and Structural Characterization of Macrocyclic Helical Peptides

Heptapeptides containing residues with terminal olefin-derivatized side chains (3 and 4) have been treated with ruthenium alkylidene 1 and undergone facile ring-closing olefin metathesis (RCM) to give 21- and 23-membered macrocyclic peptides (5 and 6). The primary structures of peptides 3 and 4 were based upon a previously studied heptapeptide (2), which was shown to adopt a predominantly 3_(10)-helical conformation in CDCl_3 solution and an α-helical conformation in the solid state. Circular dichroism, IR, and solution-phase ^1H NMR studies strongly suggested that acyclic precursors 3 and 4 and the fully saturated macrocyclic products 7 and 8 also adopted helical conformations in apolar organic solvents. Single-crystal X-ray diffraction of cyclic peptide 8 showed it to exist as a right-handed 3_(10)-helix up to the fifth residue. Solution-phase NMR structures of both acyclic peptide 4 and cyclic peptide 8 in CD_2Cl_2 indicated that the acyclic diene assumes a loosely 3_(10)-helical conformation, which is considerably rigidified upon macrocyclization. The relative ease of introducing carbon−carbon bonds into peptide secondary structures by RCM and the predicted metabolic stability of these bonds renders olefin metathesis an exceptional methodology for the synthesis of rigidified peptide architectures