212 research outputs found

    This is What Democracy Looks Like: Some Thoughts on Democratic Schools

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    Curriculum Integration and The Disciplines of Knowledge

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    At a conference on curriculum integration, a speaker who admitted that he had only recently been introduced to the concept said, From a quick look at various readings, it seems that the disciplines of knowledge are the enemy of curriculum integration. Unwittingly or not, he had gone straight to the heart of perhaps the most contentious issue in current conversations about curriculum integration. Simply put, the issue is this: If we move away from the subject-centered approach to curriculum organization, will the disciplines of knowledge be abandoned or lost in the shuffle

    Long-Term Effects of Community Service Programs

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    The need to develop connections between life in the school and that in the community is a recurring theme in educational literature. Of the many means for doing this, one of the more prominent is experiential learning or planned opportunities for learning outside the classroom (Hamilton 1980). Within the experiential learning concept, one variation which has received a good deal of attention is youth participation programs or community service projects (Olsen 1946; National Society for the Study of Education 1953; Harnack 1974; Coleman 1974; National Commission on Resources for Youth 1974). Such programs involve the active engagement of youth in attempts to improve local communities, and while these programs may be carried out under the auspices of any community agency, the focus here is on those sponsored by the school. Specific projects might include conducting surveys of community attitudes, making recommendations for solving environmental problems, and helping older persons and the like

    Evaluation of West Virginia's Mountain Health Choices: Implementation, Challenges, and Recommendations

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    Assesses the implementation of the enhanced Medicaid program for low-income families that rewards personal responsibility. Examines enrollment, education and outreach, services and benefit structure, provider understanding and participation, and outcomes

    Cascading Effects of Hunting Disturbance on Northern Bobwhite Behavior, Physiology, and Survival

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    The northern bobwhite (Colinus virginianus; hereafter, bobwhite) is an important gamebird across the United States and has been in decline for several decades. As a commonly hunted prey species, the bobwhite provides an ideal study species to investigate the use of proactive and reactive antipredator behaviors in response to hunting pressure. We designed an experiment to understand how late-season hunting affects bobwhite demographics using fecal glucocorticoid (fGCM) concentrations, foraging and movement behaviors, survival, and breeding season metrics. Our results show that bobwhite responded to increased interactions with a shotgun through proactive responses. After one encounter with a discharged shotgun, bobwhite began foraging farther from supplemental feed where the risk of encountering a hunting party was the greatest (β = 0.21, 95% Bayesian credible interval [CrI]: 0.06–0.36). Bobwhite responded to increased hunting pressure, particularly late-season hunting pressure, via reactive responses through increased fecal glucocorticoid metabolite (fGCM) concentrations (β = 2.18, 95% CrI: 0.21–4.15), resulting in decreased survivorship in non-harvested individuals (β = -0.42, 95% CrI: -0.77 to -0.07) and decreased fecundity (β = -0.17, 95% CI: -0.31–0.09). These results can help inform hunting season regulations and management decisions aiding in bobwhite recovery

    Three Bosons in One Dimension with Short Range Interactions I: Zero Range Potentials

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    We consider the three-boson problem with δ\delta-function interactions in one spatial dimension. Three different approaches are used to calculate the phase shifts, which we interpret in the context of the effective range expansion, for the scattering of one free particle a off of a bound pair. We first follow a procedure outlined by McGuire in order to obtain an analytic expression for the desired S-matrix element. This result is then compared to a variational calculation in the adiabatic hyperspherical representation, and to a numerical solution to the momentum space Faddeev equations. We find excellent agreement with the exact phase shifts, and comment on some of the important features in the scattering and bound-state sectors. In particular, we find that the 1+2 scattering length is divergent, marking the presence of a zero-energy resonance which appears as a feature when the pair-wise interactions are short-range. Finally, we consider the introduction of a three-body interaction, and comment on the cutoff dependence of the coupling.Comment: 9 figures, 2 table

    Forward analysis of π\piN scattering with an expansion method

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    The π\piN forward scattering data are analyzed using an expansion method, where the invariant amplitudes are represented by expansions satisfying the forward dispersion relations. The experimental errors of the data are taken into account through the covariance matrix of the coefficients of the expansions in a careful error analysis. From the results, some coefficients, cn0±c_{n0}^\pm, of the subthreshold expansions have been calculated with proper error bars.Comment: 5 pages, 4 figures. v2: Added some references. v3: Corrected hyphenatio

    Low Energy Theorems For Nucleon-Nucleon Scattering

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    Low energy theorems are derived for the coefficients of the effective range expansion in s-wave nucleon-nucleon scattering valid to leading order in an expansion in which both mπm_\pi and 1/a1/a (where aa is the scattering length) are treated as small mass scales. Comparisons with phase shift data, however, reveal a pattern of gross violations of the theorems for all coefficients in both the 1S0^1S_0 and 3S1^3S_1 channels. Analogous theorems are developed for the energy dependence ϵ\epsilon parameter which describes 3S13D1^3S_1 - ^3D_1 mixing. These theorems are also violated. These failures strongly suggest that the physical value of mπm_\pi is too large for the chiral expansion to be valid in this context. Comparisons of mπm_\pi with phenomenological scales known to arise in the two-nucleon problem support this conjecture.Comment: 12 pages, 1 figure, 1 table; appendix added to discuss behavior in chiral limit; minor revisions including revised figure reference to recent work adde

    The Long and Short of Nuclear Effective Field Theory Expansions

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    Nonperturbative effective field theory calculations for NN scattering seem to break down at rather low momenta. By examining several toy models, we clarify how effective field theory expansions can in general be used to properly separate long- and short-range effects. We find that one-pion exchange has a large effect on the scattering phase shift near poles in the amplitude, but otherwise can be treated perturbatively. Analysis of a toy model that reproduces 1S0 NN scattering data rather well suggests that failures of effective field theories for momenta above the pion mass can be due to short-range physics rather than the treatment of pion exchange. We discuss the implications this has for extending the applicability of effective field theories.Comment: 22 pages, 9 figures, references corrected, minor modification

    Semileptonic decays of light quarks beyond the Standard Model

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    We describe non-standard contributions to semileptonic processes in a model independent way in terms of an SU(2)_L X U(1)_Y invariant effective lagrangian at the weak scale, from which we derive the low-energy effective lagrangian governing muon and beta decays. We find that the deviation from Cabibbo universality, \Delta_CKM = |V_ud|^2 + |V_us|^2 + |V_ub|^2 - 1, receives contributions from four effective operators. The phenomenological bound of \Delta_CKM = -1E-4 +- 6E-4 provides strong constraints on all four operators, corresponding to an effective scale greater than 11 TeV (90% CL). Depending on the operator, this constraint is at the same level or better then the Z pole observables. Conversely, precision electroweak constraints alone would allow universality violations as large as \Delta_CKM = -0.01 (90% CL). An observed nonzero \Delta_CKM at this level could be explained in terms of a single four-fermion operator which is relatively poorly constrained by electroweak precision measurements.Comment: 23 pages, 1 table and 5 eps figure
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