1,410 research outputs found
Improving the Collective Efficacy of Teachers: Transforming Schools Through Collaborative Learning
Abstract
Urban secondary schools situated in high-risk neighborhoods experience a myriad of challenges that have the potential to thwart community well-being and student success. School leaders are increasingly aware of the connection between the stressors experienced in such communities, and the effects they have on teacher efficacy and student achievement. The prevalent gap in the goals, standards, and expectations that the administrative team leading this Organizational Improvement Plan (OIP) seeks to address, and those that currently exist within the school community require attention and a methodology for positive change. It is for this reason, that the school leader recognizes the need to address teachers’ sense of collective efficacy in such challenging circumstances, as a conduit to student achievement. The problem of practice that will be addressed in this Organizational Improvement Plan (OIP), is how the collective efficacy of educators working in vulnerable communities can be elevated through transformational leadership.
In order for the organization to experience improvement, I, as one of the school leaders in my role as a vice-principal, must address how transformational leadership can encourage collective teacher efficacy. This problem of practice explores the utility of Bolman and Deal’s Four Frame Model (2013, 2017), identifying the challenges and opportunities for elevating collective efficacy. This proposal outlines an OIP that is framed by Kenneth Leithwood’s (2000; 2012) transformational model of leadership with a focus on value-laden and emotionally responsive leadership theories, while employing a parallel and collaborative approach to implementing change. Additionally, Cawsey, Deszca and Ingols’s, Change Path Model (2015), and Duck’s (2001) Five Stage Change Curve, and Moen and Norman (2009) updated version of Shewhart and Deming’s(1939), Plan Do Study Act, are drawn upon as a means of resolving issues of organizational improvement, as it relates to teacher efficacy and student achievement
Low-energy excitations of a linearly Jahn-Teller coupled orbital quintet
The low-energy spectra of the single-mode h x (G+H) linear Jahn-Teller model
is studied by means of exact diagonalization. Both eigenenergies and
photoemission spectral intensities are computed. These spectra are useful to
understand the vibronic dynamics of icosahedral clusters with partly filled
orbital quintet molecular shells, for example C60 positive ions.Comment: 14 pages revte
Condensate Fraction of a Fermi Gas in the BCS-BEC Crossover
We investigate the Bose-Einstein condensation of Fermionic pairs in a uniform
two-component Fermi gas obtaining an explicit formula for the condensate
density as a function of the chemical potential and the energy gap. We analyze
the condensate fraction in the crossover from the Bardeen-Cooper-Schrieffer
(BCS) state of weakly-interacting Cooper pairs to the Bose-Einstein Condensate
(BEC) of molecular dimers. By using the local density approximation we study
confined Fermi vapors of alkali-metal atoms for which there is experimental
evidence of condensation also on the BCS side of the Feshbach resonance. Our
theoretical results are in agreement with these experimental data and give the
behavior of the condensate on both sides of the Feshbach resonance at zero
temperature.Comment: 5 pages, 2 figure
Static friction on the fly: velocity depinning transitions of lubricants in motion
The dragging velocity of a model solid lubricant confined between sliding
periodic substrates exhibits a phase transition between two regimes,
respectively with quantized and with continuous lubricant center-of-mass
velocity. The transition, occurring for increasing external driving force F_ext
acting on the lubricant, displays a large hysteresis, and has the features of
depinning transitions in static friction, only taking place on the fly.
Although different in nature, this phenomenon appears isomorphic to a static
Aubry depinning transition in a Frenkel-Kontorova model, the role of particles
now taken by the moving kinks of the lubricant-substrate interface. We suggest
a possible realization in 2D optical lattice experiments.Comment: 5 pages, 4 figures, revtex, in print in Phys. Rev. Let
Exact zero-point energy shift in the , many modes dynamic Jahn-Teller systems at strong coupling
We find the exact semiclassical (strong coupling) zero-point energy shifts
applicable to the and dynamic Jahn-Teller
problems, for an arbitrary number of discrete vibrational modes
simultaneously coupled to one single electronic level. We also obtain an
analytical formula for the frequency of the resulting normal modes, which has
an attractive and apparently general Slater-Koster form. The limits of validity
of this approach are assessed by comparison with O'Brien's previous
effective-mode approach, and with accurate numerical diagonalizations.
Numerical values obtained for with and coupling
constants appropriate to C are used for this purpose, and are
discussed in the context of fullerene.Comment: 20 pages, 4 ps figure
The Phase Diagram of Correlated Electrons in a Lattice of Berry Molecules
A model for correlated electrons in a lattice with local additional spin--1
degrees of freedom inducing constrained hopping, is studied both in the low
density limit and at quarter filling. We show that in both 1D and 2D two
particles form a bound state even in presence of a repulsive U<U_c. A picture
of a dilute Bose gas, leading to off-diagonal long range order (LRO) in 2D
(quasi-LRO in 1D), is supported by quantitative calculations in 1D which allow
for a determination of the phase diagram.Comment: 7 pages + 2 ps figures, published versio
Electron-vibration coupling constants in positively charged fullerene
Recent experiments have shown that C60 can be positively field-doped. In that
state, fullerene exhibits a higher resistivity and a higher superconducting
temperature than the corresponding negatively doped state. A strong
intramolecular hole-phonon coupling, connected with the Jahn-Teller effect of
the isolated positive ion, is expected to be important for both properties, but
the actual coupling strengths are so far unknown. Based on density functional
calculations, we determine the linear couplings of the two a_g, six g_g, and
eight h_g vibrational modes to the H_u HOMO level of the C60 molecule. The
couplings predict a D_5 distortion, and an H_u vibronic ground state for C60^+.
They are also used to generate the dimensionless coupling constant
which controls the superconductivity and the phonon contribution to the
electrical resistivity in the crystalline phase. We find that is 1.4
times larger in positively-charged C60 than in the negatively-doped case. These
results are discussed in the context of the available transport data and
superconducting temperatures. The role of higher orbital degeneracy in
superconductivity is also addressed.Comment: 22 pages - 3 figures. This revision includes few punctuation
corrections from proofreadin
Interplay of Orbital Degeneracy and Superconductivity in a Molecular Conductor
We study electron propagation in a molecular lattice model. Each molecular
site involves doubly degenerate electronic states coupled to doubly degenerate
molecular vibration, leading to a so--called E-e type of Jahn-Teller
Hamiltonian. For weak electron-phonon coupling and in the anti-adiabatic limit
we find that the orbital degeneracy induces an intersite pairing mechanism
which is absent in the standard non-degenerate polaronic model. In this limit
we analyse the model in the presence of an additional on-site repulsion and we
determine, within BCS mean field theory, the region of stability of
superconductivity. In one dimension, where powerful analytical techniques are
available, we are able to calculate the phase diagram of the model both for
weak and for strong electron-phonon coupling.Comment: 11 pages, REVTEX style, 3 compressed figures adde
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