Factors Affecting the Retention of First-career and Second-career Science Teachers in Urban High Schools

The turnover of high school science teachers is an especially troubling problem in urban schools with economically disadvantaged students. Because high teacher turnover rates impede effective instruction, the persistence of teacher attrition is a serious concern. Using an online survey and interviews in a sequential mixed-methods approach, this study investigates the perceptions of high school science teachers regarding factors that contribute to their employment decisions. The study also compares first-career and second-career science teachers\u27 perceptions of retention and attrition factors and identifies conditions that urban school leaders can establish to support the retention of their science teachers. A purposeful sample of 138 science teachers from urban area New England public high schools with 50% or more Free and Reduced Price Lunch-eligible students participated in the survey. Twelve survey respondents were subsequently interviewed. In accord with extant research, this study\u27s results suggest that school leadership is essential to fostering teacher retention. The findings also reveal the importance of autonomy, professional community, and adequate resources to support science instruction. Although mentoring and induction programs receive low importance ratings in this study, career-changers view these programs as more important to their retention than do first-career science teachers. Second-career interviewees, in particular, voice the importance of being treated as professionals by school leaders. Future research may examine the characteristics of mentoring and induction programs that make them most responsive to the needs of first-career and second-career science teachers. Future studies may also investigate the aspects of school leadership and professional autonomy that are most effective in promoting science teacher retention

Dihadron Correlation in Jets Produced in Heavy-Ion Collisions

The difference between the structures of jets produced in heavy-ion and hadronic collisions can best be exhibited in the correlations between particles within those jets. We study the dihadron correlations in jets in the framework of parton recombination. Two types of triggers, $\pi^+$ and proton, are considered. It is shown that the recombination of thermal and shower partons makes the most important contribution to the spectra of the associated particles at intermediate $p_T$. In $pp$ collisions the only significant contribution arises from shower-shower recombination, which is negligible in heavy-ion collisions. Moments of the associated-particle distributions are calculated to provide simple summary of the jet structures for easy comparison with experiments.Comment: 24 pages in Latex + 5 figure

Jet Correlations of Identified Particles in PHENIX

Azimuthal two particle correlations at intermediate $p_{T}$ with one of the particles identified have been measured at PHENIX. Trigger ($2.5 < p_{T} < 4.0 GeV/c$) baryons and mesons show little significant difference in the number of associated particles ($1.7 < p_{T} < 2.5 GeV/c$) independent of centrality. For inclusive hadron triggers with $2.5 < p_{T} < 4.0 GeV/c$, associated fragmentation particles with $1.0 < p_{T} < 2.5 GeV/c$ show a higher baryon to meson ratio on the away side.Comment: talk given at Quark Matter 2004, 4 pages 4 figur

Electronic structure and energetics of tetragonal SrCuO 2 and its high-pressure superstructure phase

First-principles calculations have been used to investigate the electronic structure and energetics of the simple tetragonal SrCuO 2 ( P 4/ m m m ) and its high-pressure tetragonal superstructure ( P 4/ m m m ). Based on the calculations, the high-pressure phase is metastable as compared with the low pressure tetragonal phase, with an energy difference of 0.13 eV per SrCuO 2 formula unit. The energy barrier to the transition from the superstructure to the simple tetragonal structure is 0.24 eV at 7 GPa; thus, high temperatures are required to synthesize the latter. Among the possible structural configurations resulting from the partially occupied oxygen site in the superstructure phase, the most stable structure has a space group ##IMG## [http://ej.iop.org/images/0953-8984/23/46/465503/cm401032ieqn3.gif] {$P\bar {4}m 2$} , reduced from that of the simple tetragonal structure P 4/ m m m . The detailed analysis of the electronic band structures of the simple tetragonal and superstructure phases suggests that the out-of-plane buckling of the O atoms in the superstructure leads to significant decrease in the O p–Cu d orbital overlap, allowing the energy of the system to be lowered, which is necessary for the structural stability. An understanding of the electronic structure and energetics of the high-pressure superstructure phase and its relation to the simple tetragonal phase provides a basis for exploring the physical properties of the infinite layer, high- T C superconductor.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90783/1/0953-8984_23_46_465503.pd

B-meson production at forward and backward rapidity in p+p and Cu + Au collisions at √sNN=200 GeV

The fraction of J/psi mesons which come from B-meson decay, F-B -> J/psi is measured for J/psi rapidity 1.2 0 in p + p and Cu+Au collisions at root s(NN) = 200 GeV with the PHENIX detector. The extracted fraction is F-B -> J/psi = 0.025 +/- 0.006 (stat) +/- 0.010(syst) for p + p collisions. For Cu+Au collisions, F-B -> J/psi is 0.094 +/- 0.028(stat) +/- 0.037(syst) in the Au-going direction (-2.2 <y <-1.2) and 0.089 +/- 0.026(stat) +/- 0.040(syst) in the Cu-going direction (1.2 <y <2.2). The nuclear modification factor, R-CuAu,of B mesons in Cu+Au collisions is consistent with binary scaling of measured yields in p + p at both forward and backward rapidity.Peer reviewe

Cross section and transverse single-spin asymmetry of muons from open heavy-flavor decays in polarized p plus p collisions at root s=200 GeV

The cross section and transverse single-spin asymmetries of mu(-) and mu(+) from open heavy-flavor decays in polarized p + p collisions at pffisffiffi root s = 200 GeV were measured by the PHENIX experiment during 2012 at the Relativistic Heavy Ion Collider. Because heavy-flavor production is dominated by gluon-gluon interactions at ffiffiffi root s = 200 GeV, these measurements offer a unique opportunity to obtain information on the trigluon correlation functions. The measurements are performed at forward and backward rapidity (1.4 <vertical bar y vertical bar <2.0) over the transverse momentum range of 1.25 <p(T) <7 GeV/c for the cross section and 1.25 <p(T) <5 GeV/c for the asymmetry measurements. The obtained cross section is compared to a fixed-order-plus-next-to-leading-log perturbative-quantum-chromodynamics calculation. The asymmetry results are consistent with zero within uncertainties, and a model calculation based on twist-3 three-gluon correlations agrees with the data.Peer reviewe

Production of pi(0) and eta mesons in Cu plus Au collisions at root S-NN=200 GeV

Production of pi(0) and eta mesons has been measured at midrapidity in Cu+Au collisions at root S-NN = 200 GeV. Measurements were performed in pi(0) (eta) -> gamma gamma decay channel in the 1(2)-20 GeV/c transverse momentum range. A strong suppression is observed for pi(0) and eta meson production at high transverse momentum in central Cu+Au collisions relative to the p + p results scaled by the number of nucleon-nucleon collisions. In central collisions the suppression is similar to Au + Au with comparable nuclear overlap. The eta/pi(0) ratio measured as a function of transverse momentum is consistent with m(T)-scaling parametrization down to p(T) = 2 GeV/c, its asymptotic value is constant and consistent with Au + Au and p + p and does not show any significant dependence on collision centrality. Similar results were obtained in hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions as well as in e(+)e(-) collisions in a range of collision energies root S-NN = 3-1800 GeV. This suggests that the quark-gluon-plasma medium produced in Cu+Cu collisions either does not affect the jet fragmentation into light mesons or it affects the pi(0) and eta the same way.Peer reviewe