An Interdisciplinary Approach to Science,Mathematics, and Reading: Learning as Children Learn

A project was designed to implement an integrated curriculum in mathematics, science, and reading by promoting the professional growth of K-4 in-service teachers through a 6-hour graduate course. The course adopts a view of teachers' knowledge acquisition based on constructivism, a perspective currently more accepted for elementary children than for teachers. The effectiveness of the project in the Ist year was evaluated in part by employing content examinations, portfolios, journals, questionnaires, and course assignments. The findings suggest implications for teacher educators, program administrators, teachers in K-4, and the children served by the educational system.     

A stereoselective intramolecular 1,3-dipolar nitrone cycloaddition for the synthesis of substituted chromanes

A stereoselective intramolecular 1,3-dipolar nitrone cycloaddition useful in the synthesis of chromanes is described. The reaction relies on the use of a chiral auxiliary on the nitrone partner. Key to the success of the reaction is the choice of auxiliary and the choice of Lewis acid catalyst. Utilizing an auxiliary with a pendant coordinating group, and Zn(OTf)(2) as the Lewis acid, diastereoselectivities up to 22:1 could be achieved.     

The structure of pacifigorgiol,an ichthyotoxic sesquiterpenoid from the pacific gorgonian coral pacifigorgiacf.adamsii

An ichthyotoxic sesquiterpenoid of unusual structure, pacifigorgiol, has been isolated from the Pacific gorgonian caora $\text{Pacifigorgia}$$\text{adamsii}$. The structure of pacifigorgiol, with relative stereochemistry only, has been defined by a combination of spectral and x-ray crystallographic techniques.     

Gender Differences in Toddlers’ Visual-Spatial Skills

The purpose of the present study was to determine whether there are visual-spatial gender differences in two-year-olds, to investigate the environmental and cognitive factors that contribute to two-year-olds’ visual-spatial skills, and to explore whether these factors differ for boys and girls. Children (N = 63; M_age = 28.17 months) were assessed on their visual-spatial skills and on measures related to visual-spatial skills: intelligence, quantitative reasoning, working memory, and home spatial activity engagement. Children’s mothers were assessed on mental rotation ability. Results found no difference between boys’ and girls’ visual-spatial skills at age two. Quantitative reasoning contributed the most to girls’ visual-spatial skills. No variables were predictive for the boys, though boys with higher spatial activity frequency had higher visual-spatial skills. The differential predictors have implications for the development and fostering of visual-spatial skills, particularly for girls, who may be at a disadvantage in this area when they are older.     

Characterization of new phenolic compounds from leaves of Olea europaea L. by high-resolution tandem mass spectrometry

A set of minor constituents of Olea europaea L. leaves have been identified and characterized by electrospray ionization tandem mass spectrometry (ESI-MS/MS) and high-resolution measurements (HRMS). Most of them are modified hydroxytyrosol species conjugated to a hexose unit. When possible, the structures of the new phenolic compounds present in Olea europaea L. have been confirmed by matching their MS/MS spectra with those of authentic standards isolated from other plants of the oleaceae family. The knowledge of the presence of new phenolic species in Olea europaea L. could provide tools for a full understanding of the secondary metabolism of this plant in relation to the biosynthesis of the phenolic species.     

Probing solute clustering in supercritical solutions using solvatochromic parameters

Kamlet and Taft polarity parameters are presented for three supercritical solutions containing solutes of different polarities at two concentrations. It is shown that the polarizability and hydrogen-bond-donating ability change significantly with pressure. In the lower pressure regime, naphthalene and salicylic acid cause a decrease in the polarity parameters compared with the pure fluid, whereas toluic acid causes an increase. These differences can be explained in terms of solute-solute and solute-indicator clustering. It is shown that there is, however, a direct correlation between the change in the hydrogen-bond-donating ability and polarizability for all solutes and all pressures and concentrations, which is thought to result from changes in the amount of solvent required to solvate the solute.     

Characterization of self-assembled monolayers from lithium dialkyldithiocarbamate salts

We report the formation of self-assembled monolayers (SAMs) onto gold substrates by exposure to lithium dialkyldithiocarbamate salts [(Li+(R2DTC-), where R = n-propyl, n-butyl, n-octyl, n-decyl, n-dodecyl, or n-octadecyl] in ethanol or methylene chloride. The crystallinity and composition of the monolayers were assessed by polarized modulation infrared reflection absorption spectroscopy (PM-IRRAS), wettability was characterized by contact angles of water and hexadecane, thickness was measured by spectroscopic ellipsometry, and barrier properties determined by electrochemical impedance spectroscopy. While the shorter R2DTC-s formed monolayers with liquid-like packing, monolayers prepared from the longest R2DTC- (where R = n-octadecyl) exhibit similar thickness, crystallinity, wettability, and capacitance as monolayers prepared from n-octadecanethiol. The hydrocarbon chains within the monolayers prepared from (C18)2DTC- are less canted on average than those prepared from n-octadecanethiol. Nonetheless, the (C18)2DTC- SAM exhibits an order of magnitude lower resistance against the penetration of redox probes, which is attributed to a higher density of pinhole defect sites.