Curriculum Restructuring at Lynchburg College: Effects of Realignment to State-Mandated Competencies and Implications for K-6 Math and Science Teacher Preparation

Because Lynchburg College offers a four-year program to attain teacher licensure, current restructuring efforts have been aimed at targeting the professional studies requirements across a program of courses that are efficiently integrated. Math and science methods courses will be combined into a workshop course. A new general studies program has been approved which requires eight hours of lab sciences and three hours of math. A General Science course has been approved which will be geared towards pre-service teachers. The professional core requires an additional eight hours of lab sciences, totaling 16 hours in science, and six hours of math, geared towards the needs of pre-service teachers. While recommended teaching practices are stressed, these may be de-emphasized by the student teaching capstone experience. This is due to the current pressure in public schools to address content-loaded Standards of Learning. From this perspective, standards-based education may prove to be an impediment to reform efforts in science education that stress process skills and the messy, time-consuming nature of learning

Crystal structure of Pseudomonas aeruginosa apo-azurin at 1.85 Å resolution

AbstractThe 3D structure of apo-azurin from Pseudomonas aeruginosa has been determined at 1.85 Å resolution. The crystal structure is composed of two different molecular forms of apo-azurin arranged as hetero-dimers in the tetramer of the asymmetric unit. Form 1 closely resembles the holo-protein lacking copper. Form 2 shows differences in the metal binding site region induced by the incorporation of a solvent molecule into this site. The positions of the copper ligands His46 and His117 are shifted by 0.6 Å and 1.6 Å. The His117 side chain adopts a position at the surface of the protein, thereby facilitating access to the copper site. The presence of two different molecular forms of apo-azurin in the crystal lattice may reflect an equilibrium between the two forms in solution. 1H-NMR spectra or apo-azurin recorded as a function or pH show that at high pH the line broadening of His35, His46 and His117 resonances is consistent with an interconversion between forms 1 and 2. At low pH, no broadening is observed. This may indicate that here the interconversion is fast on the NMR timescale

Manufacturing of nanostructures with high aspect ratios using soft UV-nanoimprint lithography with bi- and trilayer resist systems

In this contribution we introduce new multilayer (bilayer and trilayer) resist systems for the generation of nanostructures with high aspect ratios of up to 14:1 on 4-in. full wafer scale. The bilayer stack consists of a bottom resist layer (lift off polymer LOR1A) and an UV-curable top resist layer (UV-NIL resist mr-NIL210 200 nm). The top resist is structured by UV-nanoimprint lithography with a soft polydimethysiloxane (PDMS) stamp (soft UV-NIL). After removal of the residual layer a wet chemical development is performed to achieve an isotropic undercut underneath the nanostructures in the top layer. This undercut is mandatory in order to perform a reliable and precise lift-off. The bilayer system is applicable on both silicon and fused silica. For a higher variety and combination of different resists, a trilayer system is investigated. A layer stack with new materials for bottom and top layer is presented. An intermediate layer made of silicon oxide by low temperature ICP-PECVD is added between a tailor-made top resist (mr-NIL213FC 200 nm) and an organic transfer layer (UL1). The intermediate layer serves as hard mask in order to etch the bottom layer isotropically utilizing a plasma etch process and thus replacing the wet-chemical development step. Subsequently, a thin metal layer is deposited onto the structured resist stack by electron beam evaporation. After lift-off, a nanostructured metal mask remains on the substrate providing a high selectivity during the following plasma etch step. A cryogenic ICPRIE etch process creates high aspect ratio nanostructures within the substrate. An aspect ratio of 14:1 was achieved

A study of imprint and etching behavior on fused silica of a new tailored resist mr-NIL213FC for soft UV-NIL

A new type of a specifically tailored resist for Soft Nanoimprint Lithography (Soft UV-NIL) namely mr-NIL213FC has been developed. It aims for a significant improvement of its etch-resistance with regard to underlying oxide substrates such as glass. This work demonstrates the first study of its imprint performance and etching behavior against fused silica wafers. First of all, the resist shows full compatibility with automated Soft UV-NIL using PDMS-based soft stamps and at ambient (oxygen containing) conditions for both step-and-repeat and full-wafer approaches. Moreover, the selectivity of the resist to the underlying fused silica substrate, in a high power and high etch rate condition, has reached to over 0.6, which is a significant step-up among most products in this context. The improved resistance of the resist facilitates direct etching processes for high resolution and high structure fidelity

YAP and β-catenin co-operate to drive oncogenesis in basal breast cancer

Targeting cancer stem cells (CSCs) can serve as an effective approach toward limiting resistance to therapies and the development of metastases in many forms of cancer. While basal breast cancers encompass cells with CSC features, rational therapies remain poorly established. Here, we show that receptor tyrosine kinase Met signalling promotes the activity of the Hippo component YAP in basal breast cancer. Further analysis revealed enhanced YAP activity within the CSC population. Using both genetic and pharmaceutical approaches, we show that interfering with YAP activity delays basal cancer formation, prevents luminal to basal trans-differentiation and reduces CSC survival. Gene expression analysis of YAP knock-out mammary glands revealed a strong decrease in β-catenin target genes in basal breast cancer, suggesting that YAP is required for nuclear β-catenin activity. Mechanistically, we find that nuclear YAP interacts and overlaps with β-catenin and TEAD4 at common gene regulatory elements. Analysis of proteomic data from primary breast cancer patients identified a significant upregulation of the YAP activity signature in basal compared to other breast cancers, suggesting that YAP activity is limited to basal types. Our findings demonstrate that in basal breast cancers, β-catenin activity is dependent on YAP signalling and controls the CSC program. These findings suggest that targeting the YAP/TEAD4/β-catenin complex offers a potential therapeutic strategy for eradicating CSCs in basal (triple-negative) breast cancers

Atmospheric greenhouse gases retrieved from SCIAMACHY: comparison to ground-based FTS measurements and model results

SCIAMACHY onboard ENVISAT (launched in 2002) enables the retrieval of global long-term column-averaged dry air mole fractions of the two most important anthropogenic greenhouse gases carbon dioxide and methane (denoted XCO_2 and XCH_4). In order to assess the quality of the greenhouse gas data obtained with the recently introduced v2 of the scientific retrieval algorithm WFM-DOAS, we present validations with ground-based Fourier Transform Spectrometer (FTS) measurements and comparisons with model results at eight Total Carbon Column Observing Network (TCCON) sites providing realistic error estimates of the satellite data. Such validation is a prerequisite to assess the suitability of data sets for their use in inverse modelling. It is shown that there are generally no significant differences between the carbon dioxide annual increases of SCIAMACHY and the assimilation system CarbonTracker (2.00 ± 0.16 ppm yr^(−1) compared to 1.94 ± 0.03 ppm yr−1 on global average). The XCO_2 seasonal cycle amplitudes derived from SCIAMACHY are typically larger than those from TCCON which are in turn larger than those from CarbonTracker. The absolute values of the northern hemispheric TCCON seasonal cycle amplitudes are closer to SCIAMACHY than to CarbonTracker and the corresponding differences are not significant when compared with SCIAMACHY, whereas they can be significant for a subset of the analysed TCCON sites when compared with CarbonTracker. At Darwin we find discrepancies of the seasonal cycle derived from SCIAMACHY compared to the other data sets which can probably be ascribed to occurrences of undetected thin clouds. Based on the comparison with the reference data, we conclude that the carbon dioxide data set can be characterised by a regional relative precision (mean standard deviation of the differences) of about 2.2 ppm and a relative accuracy (standard deviation of the mean differences) of 1.1–1.2 ppm for monthly average composites within a radius of 500 km. For methane, prior to November 2005, the regional relative precision amounts to 12 ppb and the relative accuracy is about 3 ppb for monthly composite averages within the same radius. The loss of some spectral detector pixels results in a degradation of performance thereafter in the spectral range currently used for the methane column retrieval. This leads to larger scatter and lower XCH_4 values are retrieved in the tropics for the subsequent time period degrading the relative accuracy. As a result, the overall relative precision is estimated to be 17 ppb and the relative accuracy is in the range of about 10–20 ppb for monthly averages within a radius of 500 km. The derived estimates show that the SCIAMACHY XCH_4 data set before November 2005 is suitable for regional source/sink determination and regional-scale flux uncertainty reduction via inverse modelling worldwide. In addition, the XCO2 monthly data potentially provide valuable information in continental regions, where there is sparse sampling by surface flask measurements

Methane observations from the Greenhouse Gases Observing SATellite: Comparison to ground‐based TCCON data and model calculations

We report new short-wave infrared (SWIR) column retrievals of atmospheric methane (X_(CH4)) from the Japanese Greenhouse Gases Observing SATellite (GOSAT) and compare observed spatial and temporal variations with correlative ground-based measurements from the Total Carbon Column Observing Network (TCCON) and with the global 3-D GEOS-Chem chemistry transport model. GOSAT X_(CH4) retrievals are compared with daily TCCON observations at six sites between April 2009 and July 2010 (Bialystok, Park Falls, Lamont, Orleans, Darwin and Wollongong). GOSAT reproduces the site-dependent seasonal cycles as observed by TCCON with correlations typically between 0.5 and 0.7 with an estimated single-sounding precision between 0.4–0.8%. We find a latitudinal-dependent difference between the X_(CH4) retrievals from GOSAT and TCCON which ranges from 17.9 ppb at the most northerly site (Bialystok) to −14.6 ppb at the site with the lowest latitude (Darwin). We estimate that the mean smoothing error difference included in the GOSAT to TCCON comparisons can account for 15.7 to 17.4 ppb for the northerly sites and for 1.1 ppb at the lowest latitude site. The GOSAT X_(CH4) retrievals agree well with the GEOS-Chem model on annual (August 2009 – July 2010) and monthly timescales, capturing over 80% of the zonal variability. Differences between model and observed X_(CH4) are found over key source regions such as Southeast Asia and central Africa which will be further investigated using a formal inverse model analysis

Three-dimensional Structure of L-2-Haloacid Dehalogenase from Xanthobacter autotrophicus GJ10 Complexed with the Substrate-analogue Formate

The L-2-haloacid dehalogenase from the 1,2-dichloroethane degrading bacterium Xanthobacter autotrophicus GJ10 catalyzes the hydrolytic dehalogenation of small L-2-haloalkanoic acids to yield the corresponding D-2-hydroxyalkanoic acids. Its crystal structure was solved by the method of multiple isomorphous replacement with incorporation of anomalous scattering information and solvent flattening, and was refined at 1.95-Å resolution to an R factor of 21.3%. The three-dimensional structure is similar to that of the homologous L-2-haloacid dehalogenase from Pseudomonas sp. YL (1), but the X. autotrophicus enzyme has an extra dimerization domain, an active site cavity that is completely shielded from the solvent, and a different orientation of several catalytically important amino acid residues. Moreover, under the conditions used, a formate ion is bound in the active site. The position of this substrate-analogue provides valuable information on the reaction mechanism and explains the limited substrate specificity of the Xanthobacter L-2-haloacid dehalogenase.

Imaging Molecular Structure through Femtosecond Photoelectron Diffraction on Aligned and Oriented Gas-Phase Molecules

This paper gives an account of our progress towards performing femtosecond time-resolved photoelectron diffraction on gas-phase molecules in a pump-probe setup combining optical lasers and an X-ray Free-Electron Laser. We present results of two experiments aimed at measuring photoelectron angular distributions of laser-aligned 1-ethynyl-4-fluorobenzene (C8H5F) and dissociating, laseraligned 1,4-dibromobenzene (C6H4Br2) molecules and discuss them in the larger context of photoelectron diffraction on gas-phase molecules. We also show how the strong nanosecond laser pulse used for adiabatically laser-aligning the molecules influences the measured electron and ion spectra and angular distributions, and discuss how this may affect the outcome of future time-resolved photoelectron diffraction experiments.Comment: 24 pages, 10 figures, Faraday Discussions 17