Strategies and Sources of Support for Beginning Teachers of Science and Mathematics

This study examines the support structures and strategies utilized by beginning mathematics and science teachers. The qualitative case study of 18 teachers (0–3 years of experience) includes teachers from rural, suburban and urban schools. Data collection consisted of one‐hour interviews. The findings indicate participants utilized formal and informal support structures within the school district (e.g., mentoring programs, talking to other new teachers) as well as those external to the school (e.g., professional organizations and conferences, talking to family and friends). We propose a model of beginning teachers' initiating access to support structures based on the realization that their ideal images of teaching do not match the realities of their classrooms. Implications are given for teacher educators, researchers, and school administrators.     

Assessing the role of chemical components in cellular responses to atmospheric particle matter (PM) through chemical fractionation of PM extracts

In order to further our understanding of the influence of chemical components and ultimately specific sources of atmospheric particulate matter (PM) on pro-inflammatory and other adverse cellular responses, we promulgate and apply a suite of chemical fractionation tools to aqueous aerosol extracts of PM samples for analysis in toxicity assays. We illustrate the approach with a study that used water extracts of quasi-ultrafine PM (PM_0.25) collected in the Los Angeles Basin. Filtered PM extracts were fractionated using Chelex, a weak anion exchanger diethylaminoethyl (DEAE), a strong anion exchanger (SAX), and a hydrophobic C18 resin, as well as by desferrioxamine (DFO) complexation that binds iron. The fractionated extracts were then analyzed using high-resolution sector field inductively coupled plasma mass spectrometry (SF-ICPMS) to determine elemental composition. Cellular responses to the fractionated extracts were probed in an in vitro rat alveolar macrophages model with measurement of reactive oxygen species (ROS) production and the cytokine tumor necrosis factor-α (TNF-α). The DFO treatment that chelates iron was very effective at reducing the cellular ROS activity but had only a small impact on the TNF-α production. In contrast, the hydrophobic C18 resin treatment had a small impact on the cellular ROS activity but significantly reduced the TNF-α production. The use of statistical methods to integrate the results across all treatments led to the conclusion that sufficient iron must be present to participate in the chemistry needed for ROS activity, but the amount of ROS activity is not proportional to the iron solution concentration. ROS activity was found to be most related to cationic mono- and divalent metals (i.e., Mn and Ni) and oxyanions (i.e., Mo and V). Although the TNF-α production was not significantly affected by the chelexation of iron, it was greatly impacted by the removal of organics with the C18 resin and all other metal removal methods, suggesting that iron is not a critical pathway leading to TNF-α production, but a wide range of soluble metals and organic compounds in particulate matter play a role. Although the results are specific to the Los Angeles Basin, where the samples used in the study were collected, the method employed in the study can be widely employed to study the role of components of particulate matter in in vitro or in vivo assays.     

Common Core State Standards in the Middle Grades: What's New in the Geometry Domain and How Can Teachers Support Student Learning?

The Common Core State Standards for Mathematics (CCSSM) is a primary focus of attention for many stakeholders' (e.g., teachers, district mathematics leaders, and curriculum developers) intent on improving mathematics education. This article reports on specific content shifts related to the geometry domain in the middle grades (6–8) mathematics curriculum. The methodology employed allows for comparisons of content across multiple standards documents. We report on some dramatic changes with regards to the geometry content taught in the middle grades. We found 52% of the middle grades geometry CCSSM learning expectations will be new to the respective grade level at which they are taught in at least six of the eight states analyzed in this study (57% in grade 6, 50% in grade 7, and 50% in grade 8). We also highlight three areas that represent “new” geometry content at the middle grades based on our analysis of CCSSM and pre‐CCSSM state standards.     

Discrimination of bacteria from Jamaican bauxite soils using laser-induced breakdown spectroscopy

Soil bacteria are sensitive to ecological change and can be assessed to gauge anthropogenic influences and ecosystem health. In recent years, there has been a significant increase in the focus on new technologies that can be applied to the evaluation of soil quality. Laser-induced breakdown spectroscopy (LIBS) is a promising technique that has been used for the investigation and characterization of explosives, solids, liquids, gases, biological and environmental samples. In this study, bacteria from un-mined and a chronosequence of reclaimed bauxite soils were isolated on Luria–Bertani agar media. Polymerase chain reaction amplification of the bacterial 16S rDNA, sequencing, and phylogenetic analysis were applied to each isolated soil bacteria from the sample sites resulting in the identification and classification of the organisms. Femtosecond LIBS performed on the isolated bacteria showed atomic and ionic emission lines in the spectrum containing inorganic elements such as sodium (Na), magnesium (Mg), potassium (K), zinc (Zn), and calcium (Ca). Principal component analysis and partial least squares regression analysis were performed on the acquired bacterial spectra demonstrating that LIBS has the potential to differentiate and discriminate among bacteria in the un-mined and reclaimed chronosequence of bauxite soils.     

Heat and light dual switching of a single-walled carbon nanotube/thermo-responsive helical polysaccharide complex: a new responsive system applicable to photodynamic therapy

A thermo- and light-responsive system consisting of single-walled carbon nanotube and helical polysaccharide modified with poly(N-isopropylacrylamide) side-chains has been developed through supramolecular polymer wrapping. Coagulation of the complex can be induced by the external stimuli, which leads to a catch-and-release action of a porphyrin derivative.     

Parallel tempering simulations of the 13-center Lennard-Jones dipole-dipole cluster (muD=0-->0.5 a.u.)

We investigate the thermodynamic behavior of the thirteen center uniform Lennard-Jones dipole-dipole cluster [(LJDD)(13)] for a wide range of dipole moment strengths. We find a relatively wide range of potential parameters where solid-solid coexistence manifests itself. Using structural characterization methods we determine the shape of the few isomers that contribute to the solid-solid coexistence region. The thermal distributions of the size of the net dipole moment are broad even at the coldest temperatures of the simulation where the (LJDD)(13) cluster is solid.     

Analysing the output from primary screening

From a perspective of process knowledge and enhancement, the analysis of the results of biological screening should not be limited to the outcome of specific projects, but additionally encompass a process centric view. Summarising outcomes across multiple projects is a powerful tool to gain a greater understanding of biological screening that will also enable optimisation of the strategy for specific projects or target classes. We have analysed a set of 73,651 compounds with reproducible (confirmed) results from 63 high-throughput screening (HTS) campaigns to reveal the underlying trends in the population of active compounds. We have focused on the overall physico-chemical profile of compound populations derived from biological screening since the in vivo activity of drug molecules is the result of physico-chemical and structural properties of the compound.     

Compact chip-scale filter based on curved waveguide Bragg gratings

We propose a method for miniaturization of filters based on curved waveguide Bragg gratings, so that long structures can be packed into a small area on a chip. This eliminates the stitching errors introduced in the fabrication process, which compromise the performance of long Bragg gratings. Our approach relies on cascading curved waveguide Bragg gratings with the same radius of curvature. An analytical model for the analysis of these devices was developed, and a filter based on this model was designed and fabricated in a silicon on insulator platform. The filter had a total length of 920μm, occupied an area of 190μm×114μm, and exhibited a stop band of 1.7nm at 1.55μm and an extinction ratio larger than 23dB.