9,225 research outputs found

    The perception of new principal support as described by experienced principals of the Baldwin Park Unified School District

    Get PDF
    The role of the principal has progressed from manager and authoritarian to educational leader. Principals are expected to assume principal duties and function at an exceptional level, creating change and elevating student achievement, regardless of their experience. The review of the literature reveals that a principal needs to be skilled in organizational leadership and to produce high-performing students while facing numerous obstacles such as funding cuts and shortages of qualified staff. They are expected to communicate effectively and maintain trust and confidence of faculty, staff, parents, students, and district administrators. The purpose of this study was to describe new elementary school principal support as perceived by experienced elementary school principals of the Baldwin Park Unified School District in order to recommend a plan of support for future new elementary school principals in the Baldwin Park Unified School District. This study was qualitative in approach. Nine experienced principals were interviewed and asked the following research questions: (a) What is your perception of the support you received, intended to assist you lead your school, during your first 2 years as a principal? (b) What actions, strategies, guidance, and coaching effectively assisted you during your first 2 years as a principal? (c) What actions, strategies, guidance, and coaching hindered you during your first 2 years as a principal? (d) What additional support do you perceive would have assisted you to be more effective during your first 2 years as a principal? (e) What recommendations do you have to increase support for future new principals in the Baldwin Park Unified School District? The study results revealed that experienced elementary principals recommended that all new principals be assigned a support provider (mentor) for their first 2 years as a site principal. They also recommended that the relationship be non-threatening, trusting, and confidential. The study concluded that the principal\u27s leadership has a great impact on a student\u27s achievement and success. It is the responsibility of the district to take a proactive role in meeting new principals\u27 needs and supporting them through their initial 2 years as a principal

    Observations of the X-ray Nova GRO~J0422+32: II: Optical Spectra Approaching Quiescence

    Full text link
    We present results obtained from a series of 5~\AA\ resolution spectra of the X-ray Nova GRO~J0422+32 obtained in 1993~October, when the system was approximately 2 magnitudes above quiescence, with R∌19{\rm R \sim 19}. The data were obtained in an effort to measure the orbital radial velocity curve of the secondary, but detection of the narrow photospheric absorption lines needed to do this proved elusive. Instead we found wide absorption bands reminiscent of M~star photospheric features. The parameters determined by fitting accretion disk line profiles (Smak profiles) to the Hα\alpha line are similar to those found in several strong black-hole candidates. Measurements of the velocity of the Hα\alpha line are consistent with an orbital period of 5.1~hours and a velocity semi-amplitude of the primary of 34±634 \pm 6~\kms. These measurements, when combined with measurements of the velocity semi-amplitude of the secondary made by others, indicate that the mass ratio q∌0.09q \sim 0.09. If the secondary follows the empirical mass-radius relation found for CVs, the low qq implies a primary mass of Mx∌5.6M_x \sim 5.6\mo, and a rather low (face-on) inclination. The Hα\alpha EW is found to be modulated on the orbital period with a phasing that implies a partial eclipse of the disk by the secondary, but simultaneous R~band photometry shows no evidence for such an eclipse.Comment: Accepted for ApJ, plain latex, 5 figures available as self-extracting uuendoced, compressed, tarfiles (from uufiles

    The Foundations of Latino Voter Partisanship: Evidence from the 2000 Election

    Get PDF
    Traditionally, the Latino electorate has been considered to be Democratic in partisan affiliation. However, during the 2000 presidential election there were many efforts made by the Republican Party to court Latino voters, suggesting that perhaps Latino voters may be becoming more Republican in orientation. Using a telephone survey of Latino likely voters conducted in the 2000 election, we examine three different sets of correlates of Latino voter partisanship: social and demographic, issue and ideological, and economic. We find that Latino voter partisanship is strongly structured by social and demographic, as well as issue and ideological, factors. We also find that while it is unlikely that changes in economic factors or abortion attitudes will significantly change which parties the different Latino nation-origin groups identify with, it is possible that changes in ideological positions regarding the role of government in providing social services could result in significant changes in Latino party identification

    RJK Observations of the Optical Afterglow of GRB 991216

    Get PDF
    We present near-infrared and optical observations of the afterglow to the Gamma-Ray Burst (GRB) 991216 obtained with the F. L. Whipple Observatory 1.2-m telescope and the University of Hawaii 2.2-m telescope. The observations range from 15 hours to 3.8 days after the burst. The temporal behavior of the data is well described by a single power-law decay with index -1.36 +/-0.04, independent of wavelength. The optical spectral energy distribution, corrected for significant Galactic reddening of E(B-V)=0.626, is well fitted by a single power-law with index -0.58 +/- 0.08. Combining the IR/optical observations with a Chandra X-ray measurement gives a spectral index of -0.8 +/- 0.1 in the synchrotron cooling regime. A comparison between the spectral and temporal power-law indices suggest that a jet is a better match to the observations than a simple spherical shock.Comment: Accepted to the Astrophysical Journal, 12 pages, 4 postscript figure

    The Discovery of a Spatially-Resolved Supernova Remnant in M31 with Chandra

    Get PDF
    Chandra observations of M31 allow the first spatially resolved X-ray image of a supernova remnant (SNR) in an external spiral galaxy. CXOM31 J004327.7+411829 is a slightly elongated ring-shaped object with a diameter of ~11'' (42 pc). In addition, the X-ray image hints that the chemical composition of the SNR is spatial dependent. The X-ray spectrum of the SNR can be well fitted with a Raymond-Smith model or a non-equilibrium ionization model. Depending on the spectral model, the 0.3-7 keV luminosity is between 3.2x10^36 erg/s and 4.5x10^37 erg/s. The age of the SNR is estimated to be 3210-22300 years and the number density of ambient gas is ~0.003-0.3 cm^-3. This suggests that the local interstellar medium around the SNR is low.Comment: 5 pages, 3 figures; accepted for publication in ApJ

    Cosmological Parameters from the Comparison of the 2MASS Gravity Field with Peculiar Velocity Surveys

    Full text link
    We compare the peculiar velocity field within 65 h−1h^{-1} Mpc predicted from 2MASS photometry and public redshift data to three independent peculiar velocity surveys based on type Ia supernovae, surface brightness fluctuations in ellipticals, and Tully-Fisher distances to spirals. The three peculiar velocity samples are each in good agreement with the predicted velocities and produce consistent results for \beta_{K}=\Omega\sbr{m}^{0.6}/b_{K}. Taken together the best fit ÎČK=0.49±0.04\beta_{K} = 0.49 \pm 0.04. We explore the effects of morphology on the determination of ÎČ\beta by splitting the 2MASS sample into E+S0 and S+Irr density fields and find both samples are equally good tracers of the underlying dark matter distribution, but that early-types are more clustered by a relative factor b\sbr{E}/b\sbr{S} \sim 1.6. The density fluctuations of 2MASS galaxies in 8h−18 h^{-1} Mpc spheres in the local volume is found to be \sigma\sbr{8,K} = 0.9. From this result and our value of ÎČK\beta_{K}, we find \sigma_8 (\Omega\sbr{m}/0.3)^{0.6} = 0.91\pm0.12. This is in excellent agreement with results from the IRAS redshift surveys, as well as other cosmological probes. Combining the 2MASS and IRAS peculiar velocity results yields \sigma_8 (\Omega\sbr{m}^/0.3)^{0.6} = 0.85\pm0.05.Comment: 11 pages, ApJ accepte

    Design and fabrication of chemically robust three-dimensional microfluidic valves

    Get PDF
    A current problem in microfluidics is that poly(dimethylsiloxane) (PDMS), used to fabricate many microfluidic devices, is not compatible with most organic solvents. Fluorinated compounds are more chemically robust than PDMS but, historically, it has been nearly impossible to construct valves out of them by multilayer soft lithography (MSL) due to the difficulty of bonding layers made of non-stick fluoropolymers necessary to create traditional microfluidic valves. With our new three-dimensional (3D) valve design we can fabricate microfluidic devices from fluorinated compounds in a single monolithic layer that is resistant to most organic solvents with minimal swelling. This paper describes the design and development of 3D microfluidic valves by molding of a perfluoropolyether, termed Sifel, onto printed wax molds. The fabrication of Sifel-based microfluidic devices using this technique has great potential in chemical synthesis and analysis

    The DDO IVC Distance Project: Survey Description and the Distance to G139.6+47.6

    Get PDF
    We present a detailed analysis of the distance determination for one intermediate Velocity Cloud (IVC G139.6+47.6) from the ongoing DDO IVC Distance Project. Stars along the line of sight to G139.6+47.6 are examined for the presence of sodium absorption attributable to the cloud, and the distance bracket is established by astrometric and spectroscopic parallax measurements of demonstrated foreground and background stars. We detail our strategy regarding target selection, observational setup, and analysis of the data, including a discussion of wavelength calibration and sky subtraction uncertainties. We find a distance estimate of 129 (+/- 10) pc for the lower limit and 257 (+211-33) pc for the upper limit. Given the high number of stars showing absorption due to this IVC, we also discuss the small-scale covering factor of the cloud and the likely significance of non-detections for subsequent observations of this and other similar IVC's. Distance measurements of the remaining targets in the DDO IVC project will be detailed in a companion paper.Comment: 10 pages, 6 figures, LaTe

    Withania somnifera Root Extract Inhibits Mammary Cancer Metastasis and Epithelial to Mesenchymal Transition

    Get PDF
    Though clinicians can predict which patients are at risk for developing metastases, traditional therapies often prove ineffective and metastatic disease is the primary cause of cancer patient death; therefore, there is a need to develop anti-metastatic therapies that can be administered over long durations to specifically inhibit the motility of cancer cells. Withania somnifera root extracts (WRE) have anti-proliferative activity and the active component, Withaferin A, inhibits the pro-metastatic protein, vimentin. Vimentin is an intermediate filament protein and is part of the epithelial to mesenchymal transition (EMT) program to promote metastasis. Here, we determined whether WRE standardized to Withaferin A (sWRE) possesses anti-metastatic activity and whether it inhibits cancer motility via inhibition of vimentin and the EMT program. Several formulations of sWRE were created to enrich for Withaferin A and a stock solution of sWRE in EtOH could recover over 90% of the Withaferin A found in the original extract powder. This sWRE formulation inhibited breast cancer cell motility and invasion at concentrations less than 1ÎŒM while having negligible cytotoxicity at this dose. sWRE treatment disrupted vimentin morphology in cell lines, confirming its vimentin inhibitory activity. To determine if sWRE inhibited EMT, TGF-ÎČ was used to induce EMT in MCF10A human mammary epithelial cells. In this case, sWRE prevented EMT induction and inhibited 3-D spheroid invasion. These studies were taken into a human xenograft and mouse mammary carcinoma model. In both models, sWRE and Withaferin A showed dose-dependent inhibition of tumor growth and metastatic lung nodule formation with minimal systemic toxicity. Taken together, these data support the hypothesis that low concentrations of sWRE inhibit cancer metastasis potentially through EMT inhibition. Moreover, these doses of sWRE have nearly no toxicity in normal mouse organs, suggesting the potential for clinical use of orally administered WRE capsules. © 2013 Yang et al
    • 

    corecore