Using Form and Function Analogy Object Boxes to Teach Human Body Systems

This study compares the use of form and function analogy object boxes to more traditional lecture and worksheet instruction during a 10th‐grade unit on human body systems. The study was conducted with two classes (N= 32) of mixed ability students at a high‐needs rural high school in central New York State. The study used a pretest/posttest design, in which the two classes alternated between conditions for the four systems (skeletal, digestive, immune, nervous). Both conditions involved students in quality instruction addressing the same concepts for the same amount of time. Additionally, all students participated in hands‐on labs. The experimental condition presented students with a set of objects analogous in form and function to parts of a human body system. Students matched objects with cards describing body system parts, mapped the analogies on a chart, generated alternative objects that could be used for the analogy, and finally, created new analogies for other body system parts. Students made significantly higher posttest and gain scores on material learned in the experimental condition, with a mean gain score average of 12.4 points out of 25, compared to 6.2 points in the control condition. Cohen's Effect Size was large, 1.36.     

Crystallization of Arthrobacter sp. strain 1C N-(1-D-carboxyethyl)-L-norvaline dehydrogenase and its complex with NAD+

The novel NAD+-linked opine dehydrogenase from a soil isolate Arthrobacter sp. strain 1C belongs to an enzyme superfamily whose members exhibit quite diverse substrate specificites. Crystals of this opine dehydrogenase, obtained in the presence or absence of co-factor and substrates, have been shown to diffract to beyond 1.8 ? resolution. X-ray precession photographs have established that the crystals belong to space group P21212, with cell parameters a = 104.9, b = 80.0, c = 45.5 ? and a single subunit in the asymmetric unit. The elucidation of the three-dimensional structure of this enzyme will provide a structural framework for this novel class of dehydrogenases to enable a comparison to be made with other enzyme families and also as the basis for mutagenesis experiments directed towards the production of natural and synthetic opine-type compounds containing two chiral centres.     

Flow-injection liposome immunoanalysis (FILIA) for alachlor

An automated Flow-Injection Liposome ImmunoAnalysis (FILIA) system has been modified from a previous design, using a specific environmental contaminant, the herbicide alachlor, as a model analyte. Signal amplification by means of fluorescent marker-loaded, analyte-tagged liposomes provides high sensitivity. The computer controlled system is composed of commercially available components, with the exception of the column packing material, which has to be prepared for each specific analyte to be determined. The use of such components means that the system is easily modified. The relationships between antibody concentration and assay speed and sensitivity are explored, and the possibilities of using the system for determination of multiple analytes is discussed.     

Preparation of enediyne-crosslinked networks and their reactivity under thermal and mechanical conditions

The COGEF technique (COnstrained Geometries simulating External Force) was used to investigate the effects of macroscopic forces on cyclic enediynes, which can undergo Bergman Cyclization (BC). Because the forces needed to activate BC were found to be less than the forces needed for chain scission in polymer backbones, the calculations suggest that enediynes are potentially useful mechanophores. Three enediynes studied computationally were synthesized. The thermal BC reactions for these compounds were studied by DSC and found to be consistent with the predicted thermal sensitivity based on known substituent effects. However, upon incorporation of the enediynes into a polymer matrix as crosslinks, no definitive mechanical activation was observed, and conclusions about the stress-sensitivity of enediynes were unable to be drawn. Model studies suggest that insufficient force was applied to the crosslinks for mechanical activation to be observable by DSC.     

Symbolic Drawings Reveal Changes in Preservice Teacher Mathematics Attitudes After a Mathematics Methods Course

A new method of analyzing mathematics attitudes through symbolic drawings, situated within the field of Jungian‐oriented analytical psychology, was applied to 52 preservice elementary teachers before and after a mathematics methods course. In this triangulation mixed methods design study, pretest images related to past mathematics experiences drawn by prospective teachers were 63.2% negative in tone, and listed associated emotions were 60.4% negative; on the posttest these changed significantly to 72.1% positive images, with 70.5% positive associated emotions. The qualitative analysis of images and preservice teacher interpretations of them indicate that mathematics anxiety decreased and motivation changed from extrinsic to intrinsic as a result of the course. Pretest images and interpretations focused primarily on grades, unhappiness, time and pressure, struggle, and lack of success. Posttest images and interpretations revealed (a) greater understanding of mathematical concepts through use of concrete materials; (b) greater engagement in mathematics through interesting activities and discourse with peers; and (c) a sense of accomplishment from teaching practicum lessons. Because the drawing exercise helped students connect with their previously unconscious images of mathematics, thereby helping to shift the mathematics anxiety complex toward a more positive affective state, it is recommended that these activities be part of mathematics methods courses.     

3R,4R-dihydroxy-L-proline: a potent and specific β-D-glucuronidase inhibitor

The title compound, a naturally-occurring amino acid found in virotoxins, competitively inhibits bovine β-D-glucuronidase but does not affect other glycosidases.     

High yield protection of alcohols, including tertiary and base sensitive alcohols, as benzhydryl ethers by heating with diphenyldiazomethane in the absence of any other reagent

A protecting group that can be introduced efficiently without the need for any acid or base catalysis and which is not prone to acid or base catalysed migration is a significant advantage for many syntheses. Benzhydryl [diphenylmethyl] ethers of sugar lactones are formed in high yield under neutral conditions when the corresponding alcohol is heated with diphenyldiazomethane in an inert solvent such as acetonitrile or toluene; this allows the easy protection of base sensitive and highly hindered tertiary alcohols in the absence of any other reagents.