3,641 research outputs found
Teacher Sense-Making: A Case Study Of The Implementation Of The Giffin Model
This study sought to shed light on teachers’ thinking as they implemented an educational intervention. Specifically, this study looked at teachers’ attitudes and beliefs about teaching and learning, their interpretations of a policy’s attributes, and how those views impacted implementation quality. The findings from this study describe how factors related to the implementation of a program interact with teachers’ knowledge and philosophies of teaching. This interaction was shown to be related to the success of implementation in these schools. Based on its findings, this study recommends that further investigation into the role of teacher sense-making and its impact on implementation using the framework proposed in this paper. Further efforts should be made to improve the survey for this purpose. The effectiveness of a program is mediated by the quality of implementation, which this research shows is related to perceptions of a program. As schools grapple with implementing programs, principals and other leaders of implementation should pay close attention the factors related to implementation that are described in this paper
Black Male Student-Athletes and Racial Inequities in NCAA Division I College Sports
The purpose of this report is to make transparent racial inequities in NCAA Division I college sports. Specifically, the authors offer a four-year analysis of Black men's representation on football and basketball teams versus their representation in the undergraduate student body on each campus. The report concludes with recommendations for the NCAA and commissioners of the six major sports conferences, college and university leaders, coaches and athletics directors, journalists, and Black male student-athletes and their families
Thermodynamic Entropy And The Accessible States of Some Simple Systems
Comparison of the thermodynamic entropy with Boltzmann's principle shows that
under conditions of constant volume the total number of arrangements in simple
thermodynamic systems with temperature-independent heat capacities is TC/k. A
physical interpretation of this function is given for three such systems; an
ideal monatomic gas, an ideal gas of diatomic molecules with rotational motion,
and a solid in the Dulong-Petit limit of high temperature. T1/2 emerges as a
natural measure of the number of accessible states for a single particle in one
dimension. Extension to N particles in three dimensions leads to TC/k as the
total number of possible arrangements or microstates. The different microstates
of the system are thus shown a posteriori to be equally probable, with
probability T-C/k, which implies that for the purposes of counting states the
particles of the gas are distinguishable. The most probable energy state of the
system is determined by the degeneracy of the microstates.Comment: 9 pages, 1 figur
On a Supernumerary Median Ocellus in Melanoplus Femur-Rubrum
Volume: 19 ; Start Page: 92 ; End Page: 9
Distinguishing Solar Flare Types by Differences in Reconnection Regions
Observations show that magnetic reconnection and its slow shocks occur in
solar flares. The basic magnetic structures are similar for long duration event
(LDE) flares and faster compact impulsive (CI) flares, but the former require
less non-thermal electrons than the latter. Slow shocks can produce the
required non-thermal electron spectrum for CI flares by Fermi acceleration if
electrons are injected with large enough energies to resonate with scattering
waves. The dissipation region may provide the injection electrons, so the
overall number of non-thermal electrons reaching the footpoints would depend on
the size of the dissipation region and its distance from the chromosphere. In
this picture, the LDE flares have converging inflows toward a dissipation
region that spans a smaller overall length fraction than for CI flares. Bright
loop-top X-ray spots in some CI flares can be attributed to particle trapping
at fast shocks in the downstream flow, the presence of which is determined by
the angle of the inflow field and velocity to the slow shocks.Comment: 15 pages TeX and 2 .eps figures, accepted to Ap.J.Let
Reconnecting Magnetic Flux Tubes as a Source of In Situ Acceleration in Extragalactic Radio Sources
Many extended extragalactic radio sources require a local {\it in situ\/}
acceleration mechanism for electrons, in part because the synchrotron lifetimes
are shorter than the bulk travel time across the emitting regions. If the
magnetic field in these sources is localized in flux tubes, reconnection may
occur between regions of plasma \be (ratio of particle to magnetic pressure)
, even though averaged over the plasma volume may be \gsim 1.
Reconnection in low regions is most favorable to acceleration from
reconnection shocks. The reconnection X-point regions may provide the injection
electrons for their subsequent non-thermal shock acceleration to distributions
reasonably consistent with observed spectra. Flux tube reconnection might
therefore be able to provide acceleration required by large scale
jets and lobes.Comment: 14 pages, plain TeX, accepted to Ap.J.Let
Molecular gyroscopes and biological effects of weak ELF magnetic fields
Extremely-low-frequency magnetic fields are known to affect biological
systems. In many cases, biological effects display `windows' in biologically
effective parameters of the magnetic fields: most dramatic is the fact that
relatively intense magnetic fields sometimes do not cause appreciable effect,
while smaller fields of the order of 10--100 T do. Linear resonant
physical processes do not explain frequency windows in this case. Amplitude
window phenomena suggest a nonlinear physical mechanism. Such a nonlinear
mechanism has been proposed recently to explain those `windows'. It considers
quantum-interference effects on protein-bound substrate ions. Magnetic fields
cause an interference of ion quantum states and change the probability of
ion-protein dissociation. This ion-interference mechanism predicts specific
magnetic-field frequency and amplitude windows within which biological effects
occur. It agrees with a lot of experiments. However, according to the
mechanism, the lifetime of ion quantum states within a protein
cavity should be of unrealistic value, more than 0.01 s for frequency band
10--100 Hz. In this paper, a biophysical mechanism has been proposed that (i)
retains the attractive features of the ion interference mechanism and (ii) uses
the principles of gyroscopic motion and removes the necessity to postulate
large lifetimes. The mechanism considers dynamics of the density matrix of the
molecular groups, which are attached to the walls of protein cavities by two
covalent bonds, i.e., molecular gyroscopes. Numerical computations have shown
almost free rotations of the molecular gyros. The relaxation time due to van
der Waals forces was about 0.01 s for the cavity size of 28 angstr\"{o}ms.Comment: 10 pages, 7 figure
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