Wearing the Letter Jacket: Legitimate Participation in a Collaborative Science,Mathematics, Engineering,and Technology Education Reform Project

This study examines one NSF‐funded Collaborative for Excellence in Teacher Preparation and describes the complexities of such a science education reform effort. A theoretical model based in community, culture, and identity is used to address key questions: How did institutional ideologies, structures, policies, and practices influence the Collaborative's success? What unique problems were associated with the university and school partnership? How did K‐12 teachers' participation affect their development and the success of the Collaborative? Findings indicate that though K‐12 participants were deemed as “pedagogy experts” and shared the inquiry‐based culture espoused in the Collaborative, they felt both as project insiders and outsiders. This was due to issues of status between university faculty and K‐12 teachers; teachers' less‐than‐active role in the Collaborative; and the constraints and narrow focus that resulted from long‐established institutional, social, and political structures and that marginalized, delegitimized, excluded, and proved unattractive to teachers.     

HPLC quantification of 5‐hydroxyeicosatetraenoic acid in human lung cancer tissues

A simple and cost‐effective HPLC method was established for quantification of 5‐hydroxyeicosatetraenoic acid (5‐HETE) in human lung cancer tissues. 5‐HETE from 27 patients' lung cancer tissues were extracted by solid‐phase extraction and analyzed on a Waters Symmetry C₁₈ column (4.6 × 250 mm, 5 µm) with a mobile phase consisting of methanol, 10 mm ammonium acetate, and 1 m acetic acid (70:30:0.1, v:v:v) at a flow rate of 1.0 mL/min. The UV detection wavelength was set at 240 nm. The calibration curve was linear within the concentration range from 10 to 1000 ng/mL (r² > 0.999, n = 7), the limit of detection was 1.0 ng/mL and the limit of quantitation was 10.0 ng/mL for a 100 µL injection. The relative error (%) for intra‐day accuracy was from 93.14 to 112.50% and the RSD (%) for intra‐day precision was from 0.21 to 2.60% over the concentration range 10–1000 ng/mL. By applying this method, amounts of 5‐HETE were quantitated in human lung cancer tissues from 27 human subjects. The established HPLC method was validated to be a simple, reliable and cost‐effective procedure that can be applied to conduct translational characterization of 5‐HETE in human lung cancer tissues. Copyright © 2009 John Wiley & Sons, Ltd.     

Relaxation Limit for Aw-Rascle System

We study the relaxation limit for the Aw-Rascle system of traffic flow. For this we apply the theory of invariant regions and the compensated compactness method to get global existence of Cauchy problem for a particular Aw-Rascle system with source, where the source is the relaxation term, and we show the convergence of this solutions to the equilibrium state.     

Increasing mechanical resilience and enhanced electrical conductivity through the incorporation of CNF reinforcing additives in PA6 nanocomposites

Structural Chemistry - In pursuit of strong, tough, and functional advanced composite materials, a series of polymer nanocomposite blends were prepared from the engineering thermoplastic polyamide...     

Optical Spin Polarization of a Narrow-Linewidth Electron-Spin Qubit in a Chromophore/Stable-Radical System

Photoexcited organic chromophores appended to stable radicals can serve as qubit and/or qudit candidates for quantum information applications. 1,6,7,12-Tetra-(4-tert-butylphenoxy)-perylene-3,4 : 9,10-bis(dicarboximide) (tpPDI) linked to a partially deuterated α,γ-bisdiphenylene-β-phenylallyl radical (BDPA-d₁₆) was synthesized and characterized by time-resolved optical and electron paramagnetic resonance (EPR) spectroscopies. Photoexcitation of tpPDI-BDPA-d₁₆ results in ultrafast radical-enhanced intersystem crossing to produce a quartet state ( Q ) followed by formation of a spin-polarized doublet ground state ( D ₀). Pulse-EPR experiments confirmed the spin multiplicity of Q and yielded coherence times of T_m=2.1±0.1 μs and 2.8±0.2 μs for Q and D ₀, respectively. BDPA-d₁₆ eliminates the dominant ¹H hyperfine couplings, resulting in a single narrow line for both the Q and D ₀ states, which enhances the spectral resolution needed for good qubit addressability.     

Insight into diacetylene photopolymerization in Langmuir‐Blodgett films using simultaneous AFM and fluorescence microscopy imaging

A phase‐separated monolayer film comprised of a mixture of 10, 12‐pentacosadiynoic acid (PCDA) with perfluorotetradecanoic acid (PF; CF₃(CF₂)₁₂COOH) has been characterized using a microscope that is capable of simultaneous atomic force microscope (AFM) imaging and fluorescence imaging. Design criteria for this instrument are described, as well as its application to investigating the mixed film systems. The product of PCDA photopolymerization has two phases, a red phase with strong fluorescence and a blue phase with no fluorescence. With the help of the dual AFM‐fluorescence microscope, it was found that both the red and the blue phase polymers were produced in the same sample from photoillumination, and the relative quantities of the different phases were quantified. Further, the importance of intrinsic mechanical stress in the films is discussed in terms of its influence on selectivity towards the red polymer phase.