Supporting Educator Professional Growth In Times Of Change

This action research cross-case comparison study is set at an independent school in Maine which serves approximately 1,600 students in grades 6-12. Recently, the administrative team of the school articulated an academic strategic plan focused on increasing student achievement as measured by standardized test scores. The changes created a challenge because administrators raised expectations and accountability of staff members with respect to professional performance. The current climate in the institution presents an opportunity to provide a sense of direction and support for faculty through thoughtful leadership and professional development (PD) programming to support their progress on meeting the goals set by the administration. This study documented the needs of the school’s teachers and provided a plan for supporting these educators throughout the ongoing process of professional growth amidst change. Nine participants were interviewed and the resulting data were categorized using Drago-Severson’s Four Pillars of Professional Development Practice. Results were considered within the context of turbulent change as suggested by Gross’ turbulence theory. In the interviews, teachers shared a desire for professional development which was authentic and mutually supported through the reflection of their peers. The implications of this study are that professional development providers and administrators of schools with a great deal of teacher and leadership autonomy would be well served to understand and support the professional goals of the individuals among their faculty

Quantifying Optimal Growth Policy

The optimal mix of growth policies is determined within a comprehensive endogenous growth model. The analysis captures important elements of the tax-transfer system and accounts for transitional dynamics. Currently, for calculating corporate taxable income US firms are allowed to deduct approximately all of their capital and R&D costs from sales revenue. Our analysis suggests that this policy leads to severe underinvestment in both R&D and physical capital. We find that firms should be allowed to deduct between 2-2.5 times their R&D costs and about 1.5-1.7 times their capital costs. Implementing the optimal policy mix is likely to entail huge welfare gains.economic growth, endogenous technical change, optimal growth policy, tax-transfer system, transitional dynamics

Memory Effects in Turbulent Dynamo: Generation and Propagation of Large Scale Magnetic Field

We are concerned with large scale magnetic field dynamo generation and propagation of magnetic fronts in turbulent electrically conducting fluids. An effective equation for the large scale magnetic field is developed here that takes into account the finite correlation times of the turbulent flow. This equation involves the memory integrals corresponding to the dynamo source term describing the alpha-effect and turbulent transport of magnetic field. We find that the memory effects can drastically change the dynamo growth rate, in particular, non-local turbulent transport might increase the growth rate several times compared to the conventional gradient transport expression. Moreover, the integral turbulent transport term leads to a large decrease of the speed of magnetic front propagation.Comment: 13 pages, 2 figure

Quantifying Optimal Growth Policy

The optimal mix of growth policies is derived within a comprehensive endogenous growth model. The analysis captures important elements of the tax-transfer system and takes into account transitional dynamics. Currently, for calculating corporate taxable income US firms are allowed to deduct approximately all of their capital and R&D costs from sales revenue. Our analysis suggests that this policy leads to severe underinvestment in both R&D and physical capital. We find that firms should be allowed to deduct between 2-2.5 times their R&D costs and about 1.5-1.7 times their capital costs. Implementing the optimal policy mix is likely to entail huge welfare gains.economic growth, endogenous technical change, optimal growth policy, tax-transfer system, transitional dynamics

Photochemical hazes in sub-Neptunian atmospheres with focus on GJ 1214 b

We study the properties of photochemical hazes in super-Earths/mini-Neptunes atmospheres with particular focus on GJ1214b. We evaluate photochemical haze properties at different metallicities between solar and 10000$\times$solar. Within the four orders of magnitude change in metallicity, we find that the haze precursor mass fluxes change only by a factor of $\sim$3. This small diversity occurs with a non-monotonic manner among the different metallicity cases, reflecting the interaction of the main atmospheric gases with the radiation field. Comparison with relative haze yields at different metallicities from laboratory experiments reveals a qualitative similarity with our theoretical calculations and highlights the contributions of different gas precursors. Our haze simulations demonstrate that higher metallicity results into smaller average particle sizes. Metallicities at and above 100$\times$solar with haze formation yields of $\sim$10$\%$ provide enough haze opacity to satisfy transit observation at visible wavelengths and obscure sufficiently the H$_2$O molecular absorption features between 1.1 $\mu$m and 1.7 $\mu$m. However, only the highest metallicity case considered (10000$\times$solar) brings the simulated spectra into closer agreement with transit depths at 3.6 $\mu$m and 4.5 $\mu$m indicating a high contribution of CO/CO$_2$ in GJ1214b's atmosphere. We also evaluate the impact of aggregate growth in our simulations, in contrast to spherical growth, and find that the two growth modes provide similar transit signatures (for D$_f$=2), but with different particle size distributions. Finally, we conclude that the simulated haze particles should have major implications for the atmospheric thermal structure and for the properties of condensation clouds

Demographic Change, Human Capital and Endogenous Growth

This paper employs a large scale overlapping generations (OLG) model with endogenous education to evaluate the quantitative role of human capital adjustments for the economic consequences of demographic change. We find that endogenous human capital formation is an important adjustment mechanism which substantially mitigates the macroeconomic impact of demographic change. Welfare gains from demographic change for newborn households are approximately three times higher when households endogenously adjust their education. Low ability agents experience higher welfare gains. Endogenous growth through human capital formation is found to increase the long-run growth rate in the economy by 0.2-0.4 percentage points.

Rejuvenation and Memory in model Spin Glasses in 3 and 4 dimensions

We numerically study aging for the Edwards-Anderson Model in 3 and 4 dimensions using different temperature-change protocols. In D=3, time scales a thousand times larger than in previous work are reached with the SUE machine. Deviations from cumulative aging are observed in the non monotonic time behavior of the coherence length. Memory and rejuvenation effects are found in a temperature-cycle protocol, revealed by vanishing effective waiting times. Similar effects are reported for the D=3$site-diluted ferromagnetic Ising model (without chaos). However, rejuvenation is reduced if off-equilibrium corrections to the fluctuation-dissipation theorem are considered. Memory and rejuvenation are quantitatively describable in terms of the growth regime of the spin-glass coherence length.Comment: Extended protocols. Accepted in Phys. Rev. B. 10 postscript figure

The Rational Locator: Why Travel Times Have Remained Stable

This paper evaluates household travel surveys for the Washington metropolitan region conducted in 1968 and 1988, and shows that commuting times remain stable or decline over the twenty year period despite an increase in average travel distance, after controlling for trip purpose and mode of travel. The average automobile work-to-home time of 32.5 minutes in both 1968 and 1988 is, moreover, very consistent with a 1957 survey showing an average time of 33.5 minutes in metropolitan Washington. Average trip speeds increased by more than 20 percent, countering the effect of increased travel distance. This change was observed during a period of rapid suburban growth in the region. With the changing distributional composition of trip origins and destinations, overall travel times have remained relatively constant. The hypothesis that jobs and housing mutually co-locate to optimize travel times is lent further support by these data. .

Interfaces with a single growth inhomogeneity and anchored boundaries

The dynamics of a one dimensional growth model involving attachment and detachment of particles is studied in the presence of a localized growth inhomogeneity along with anchored boundary conditions. At large times, the latter enforce an equilibrium stationary regime which allows for an exact calculation of roughening exponents. The stochastic evolution is related to a spin Hamiltonian whose spectrum gap embodies the dynamic scaling exponent of late stages. For vanishing gaps the interface can exhibit a slow morphological transition followed by a change of scaling regimes which are studied numerically. Instead, a faceting dynamics arises for gapful situations.Comment: REVTeX, 11 pages, 9 Postscript figure