23,105 research outputs found
Asymmetric Policy Interaction among Subnational Governments: Do States Play Welfare Games?
This paper explores the possibility that states respond asymmetrically to increases versus decreases in their neighboring statesâ welfare benefit levels. We present a theoretical model suggesting that states respond more to decreases than to increases in their neighborsâ benefit levels. To test this proposition empirically, we use a panel of annual state-level data from 1983 to 1994 for each of the contiguous United States and the District of Columbia, and we observe changes in state demographic and economic characteristics as well as changes in state welfare benefits. We find substantial empirical evidence that uniformly supports our argument. State responses to neighbor benefit decreases tend to be at least twice as large as their responses to neighbor benefit increases. Our empirical results are robust to modeling neighbor benefits as endogenous. Our results, therefore, have substantial implications for public policy in the wake of the increased decentralization of welfare policy associated with the welfare reforms of 1996.
The geography of strain: organizational resilience as a function of intergroup relations
Organizational resilience is an organizationâs ability to absorb strain and preserve or
improve functioning, despite the presence of adversity. In existing scholarship there is
the implicit assumption that organizations experience and respond holistically to acute
forms of adversity. We challenge this assumption by theorizing about how adversity can
create differential strain, affecting parts of an organization rather than the whole. We
argue that relations among those parts fundamentally shape organizational resilience.
We develop a theoretical model that maps how the differentiated emergence of strain in
focal parts of an organization triggers the movements of adjoining parts to provide or
withhold resources necessary for the focal parts to adapt effectively. Drawing on core
principles of theories about intergroup relations, we theorize about three specific
pathwaysâintegration, disavowal, and reclamationâby which responses of adjoining
parts to focal part strain shape organizational resilience. We further theorize about
influences on whether and when adjoining parts are likely to select different pathways.
The resulting theory reveals how the social processes among parts of organizations
influence member responses to adversity and, ultimately, organizational resilience. We
conclude by noting the implications for organizational resilience theory, research, and
practice.Accepted manuscrip
Science Leadership: Impact of the New Science Coordinators Academy
This article discusses the impact of the New Science Coordinators Academy (NSCA) on two cohorts of participants. The NSCA is one of four components of the Virginia Initiative for Science Teaching and Achievement (VISTA), a United States Department of Education (USED) science education reform grant. The NSCA is designed to support new school district science coordinators (with less than five years of experience) and to continue building the state science education infrastructure. Research in education leadership traditionally focuses on teacher leaders, principals, and district office personnel. Interestingly, research on district office personnel rarely distinguishes between the different roles of district personnel. This article seeks to inform the field by sharing the impact of an academy designed for new science coordinators on their learning, and to begin to understand their role and impact in their district. The five-day Academy engaged participants in a variety of experiences designed to facilitate the following: 1) build leadership skills; 2) build a common understanding and vision for hands-on science, inquiry, problem-based learning, and nature of science in the science classroom; 3) investigate data to improve student learning goals; 4) and, develop a science strategic plan. The data indicate that the NSCA was successful at meeting its goals to support the participants and to build a common language among these new coordinators. Initial data also support the variety of responsibilities of these participants and the positive impact of the Academy on their district work
Design and performance of a high-pressure-ratio, highly loaded axial-flow transonic compressor space
A 50-cm-diam. axial-flow transonic compressor stage with multiple-circular-arc blades was designed and tested. At design speed, a rotor peak efficiency of 0.85 occurred at an equivalent weight flow of 29.3 kg/sec. Stage peak efficiency was 0.79 at 28.6 kg/sec. Stage total pressure ratio at peak efficiency was 1.84. The stall margin at design speed was 5 percent. Rotor and stator losses were higher than predicted. The stator choked at design flow
Viscous dark fluid universe
We investigate the cosmological perturbation dynamics for a universe
consisting of pressureless baryonic matter and a viscous fluid, the latter
representing a unified model of the dark sector. In the homogeneous and
isotropic background the \textit{total} energy density of this mixture behaves
as a generalized Chaplygin gas. The perturbations of this energy density are
intrinsically non-adiabatic and source relative entropy perturbations. The
resulting baryonic matter power spectrum is shown to be compatible with the
2dFGRS and SDSS (DR7) data. A joint statistical analysis, using also
Hubble-function and supernovae Ia data, shows that, different from other
studies, there exists a maximum in the probability distribution for a negative
present value of the deceleration parameter. Moreover,
while previous descriptions on the basis of generalized Chaplygin gas models
were incompatible with the matter power spectrum data since they required a
much too large amount of pressureless matter, the unified model presented here
favors a matter content that is of the order of the baryonic matter abundance
suggested by big-bang nucleosynthesis.Comment: 19 pages, 6 figure
Measuring the Higgs Branching Fraction into two Photons at Future Linear \ee Colliders
We examine the prospects for measuring the \gaga branching fraction of a
Standard Model-like Higgs boson with a mass of 120 GeV at the future TESLA
linear \ee collider, assuming an integrated luminosity of 1 ab and
center-of-mass energies of 350 GeV and 500 GeV. The Higgs boson is produced in
association with a fermion pair via the Higgsstrahlung process \ee ,
with \qq or \nn, or the WW fusion reaction . A relative uncertainty on BF(\hgg) of~16% can be achieved in
unpolarized \ee collisions at =~500 GeV, while for =~350
GeV the expected precision is slightly poorer. With appropriate initial state
polarizations BF(\hgg)/BF(\hgg) can be improved to 10%. If this
measurement is combined with the expected error for the total Higgs width, a
precision of 10% on the \gaga Higgs boson partial width appears feasible.Comment: 14 pages, 5 figure
The Perils of Clumpfind: The Mass Spectrum of Sub-structures in Molecular Clouds
We study the mass spectrum of sub-structures in the Perseus Molecular Cloud
Complex traced by 13CO (1-0), finding that for the
standard Clumpfind parameters. This result does not agree with the classical
. To understand this discrepancy we study the robustness
of the mass spectrum derived using the Clumpfind algorithm. Both 2D and 3D
Clumpfind versions are tested, using 850 m dust emission and 13CO
spectral-line observations of Perseus, respectively. The effect of varying
threshold is not important, but varying stepsize produces a different effect
for 2D and 3D cases. In the 2D case, where emission is relatively isolated
(associated with only the densest peaks in the cloud), the mass spectrum
variability is negligible compared to the mass function fit uncertainties. In
the 3D case, however, where the 13CO emission traces the bulk of the molecular
cloud, the number of clumps and the derived mass spectrum are highly correlated
with the stepsize used. The distinction between "2D" and "3D" here is more
importantly also a distinction between "sparse" and "crowded" emission. In any
"crowded" case, Clumpfind should not be used blindly to derive mass functions.
Clumpfind's output in the "crowded" case can still offer a statistical
description of emission useful in inter-comparisons, but the clump-list should
not be treated as a robust region decomposition suitable to generate a
physically-meaningful mass function. We conclude that the 13CO mass spectrum
depends on the observations resolution, due to the hierarchical structure of
MC.Comment: 5 pages, 3 figures. Accepted for publication in ApJ Letter
Coal-shale interface detection system
A coal-shale interface detection system for use with coal cutting equipment consists of a reciprocating hammer on which an accelerometer is mounted to measure the impact of the hammer as it penetrates the ceiling or floor surface of a mine. A pair of reflectometers simultaneously view the same surface. The outputs of the accelerometer and reflectometers are detected and jointly registered to determine when an interface between coal and shale is being cut through
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A New Framework for Condominium Structural Safety Reforms
Forty years after the widespread popularization of residential condominium ownership in the United States, millions of Americans now live in aging, densely occupied structures that are subject to little (if any) ongoing regulation of structural safety. Most structural safety requirements are imposed and enforced at the time of initial construction, thus relegating questions of how to maintain a buildingâs structural integrity to individual owners and the mechanisms of condominium governance. However, reliance on voluntary action by unit owners too often falters because the divided ownership characteristic of the condominium form deters associations from investing in preventive maintenance. Postponement of critical repairs is especially likely when structural safety risks are neither visibly apparent nor easily understood without structural engineering expertise. But tragically, the failure to address structural deterioration can be a deadly mistake, as demonstrated by the 2021 collapse of Champlain Towers South in Surfside, Florida.
This Article tackles the problem of structural deterioration in the large and growing stock of aging residential condominiums. It argues that building codes should be reformed to mandate periodic structural safety certifications, while also recognizing that regulation alone may be insufficient to ensure completion of expensive structural repairs when individual owners are unwilling or unable to pay for them. After explaining how property lawâs prioritization of liens impedes condominium associations from developing innovative strategies for financing critical structural repairs, the Article proposes reforms that would incentivize the development of a debt market to enable associations to finance those repairs while allowing cash-strapped owners to remain in their homes
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