11,915 research outputs found
Indianapolis-Marion County City-County Council: A Study of Council Effectiveness
The purpose of this research is to measure and assess the effectiveness of the Indianapolis-Marion County City-County Council. Given that effectiveness may be defined in a number of ways, the research conducted includes many types of information that can provide a well-rounded assessment of the council
Black Hole Motion as Catalyst of Orbital Resonances
The motion of a black hole about the centre of gravity of its host galaxy
induces a strong response from the surrounding stellar population. We treat the
case of a harmonic potential analytically and show that half of the stars on
circular orbits in that potential shift to an orbit of lower energy, while the
other half receive a positive boost and recede to a larger radius. The black
hole itself remains on an orbit of fixed amplitude and merely acts as a
catalyst for the evolution of the stellar energy distribution function f(E). We
show that this effect is operative out to a radius of approx 3 to 4 times the
hole's influence radius, R_bh. We use numerical integration to explore more
fully the response of a stellar distribution to black hole motion. We consider
orbits in a logarithmic potential and compare the response of stars on circular
orbits, to the situation of a `warm' and `hot' (isotropic) stellar velocity
field. While features seen in density maps are now wiped out, the kinematic
signature of black hole motion still imprints the stellar line-of-sight mean
velocity to a magnitude ~18% the local root mean-square velocity dispersion
sigma.Comment: revised version, typos fixed, added references, 20 pages MN styl
What Makes an Organization Public? Managers’ Perceptions in the Mental Health and Substance Abuse Treatment System
The question “What makes an organization public?” is a leading point of scholarly inquiry in the field of public administration. This study supplements existing theory on publicness by further exploring the primary influences on an organization’s publicness—influences identified by analyzing data from in-depth interviews with senior-level managers of mental health and substance abuse treatment facilities. Results from a grounded theoretical analysis of these managers’ perceptions provide support for a conceptual framework of organizational publicness in which political authority, horizontal engagement, and public engagement are associated with higher levels of publicness. Better understanding of the prism through which senior managers conceptualize publicness may enhance managerial awareness of the most salient structural and institutional mechanisms that empower treatment facilities to effectively support individuals suffering from mental health disorders such as substance abuse, emotional distress, and depression
Experimental characterization of the stagnation layer between two obliquely merging supersonic plasma jets
We present spatially resolved measurements characterizing the stagnation
layer between two obliquely merging supersonic plasma jets. Intra-jet
collisionality is very high (mm), but the inter-jet ion-ion
mean free paths are on the same order as the stagnation layer thickness (a few
cm). Fast-framing camera images show a double-peaked emission profile
transverse to the stagnation layer, with the central emission dip consistent
with a density dip observed in the interferometer data. We demonstrate that our
observations are consistent with collisional oblique shocks.Comment: 5 pages, 7 figure
Cusp Disruption in Minor Mergers
We present 0.55 x 10^6 particle simulations of the accretion of high-density
dwarf galaxies by low-density giant galaxies, using models that contain both
power-law central density cusps and point masses representing supermassive
black holes. The cusp of the dwarf galaxy is disrupted during the merger,
producing a remnant with a central density that is only slightly higher than
that of the giant galaxy initially. Removing the black hole from the giant
galaxy allows the dwarf galaxy to remain intact and leads to a remnant with a
high central density, contrary to what is observed. Our results support the
hypothesis that the persistence of low-density cores in giant galaxies is a
consequence of supermassive black holes.Comment: 5 pages, 2 postscript figures, uses emulateapj.sty. Accepted for
publication in The Astrophysical Journal Letter
Do Personnel with Lived Experience Cultivate Public Values? Insights and Lessons from Mental Health Care Managers
Health care organizations charged with addressing public problems sometimes employ persons with relevant lived experience in meaningful organizational roles. Because of their prior experience living with the challenges their facilities are charged with addressing, these individuals have intimate knowledge of the subject matter that professional training and education cannot replicate. Mental health treatment facilities in particular have demonstrated a growing trend toward incorporating staff members with lived experience. This study conducted semi-structured interviews with senior-level managers of organizations in this field to gain insight into the public values associated with this practice. Findings reveal that several public values, including dialogue, social cohesion, sustainability, productivity, and altruism, are cultivated when treatment facilities incorporate staff members with lived experience into service delivery. This study concludes with lessons for mental health care managers seeking to innovatively address mental illness
Social Equity and COVID-19: The Case of African Americans
Emerging statistics demonstrate that COVID-19 disproportionately affects African Americans. The effects of COVID-19 for this population are inextricably linked to areas of systemic oppression and disenfranchisement, which are further exacerbated by COVID-19: (1) healthcare inequality; (2) segregation, overall health, and food insecurity; (3) underrepresentation in government and the medical profession; and (4) inequalities in participatory democracy and public engagement. Following a discussion of these issues, this article shares early and preliminary lessons and strategies on how public administration scholars and practitioners can lead in crafting equitable responses to this global pandemic to uplift the African American community
A center for commercial development of space: Real-time satellite mapping. Remote sensing-based agricultural information expert system
The research project results in a powerful yet user friendly CROPCAST expert system for use by a client to determine the crop yield production of a certain crop field. The study is based on the facts that heuristic assessment and decision making in agriculture are significant and dominate much of agribusiness. Transfer of the expert knowledge concerning remote sensing based crop yield production into a specific expert system is the key program in this study. A knowledge base consisting of a root frame, CROP-YIELD-FORECAST, and four subframes, namely, SATELLITE, PLANT-PHYSIOLOGY, GROUND, and MODEL were developed to accommodate the production rules obtained from the domain expert. The expert system shell Personal Consultant Plus version 4.0. was used for this purpose. An external geographic program was integrated to the system. This project is the first part of a completely built expert system. The study reveals that much effort was given to the development of the rules. Such effort is inevitable if workable, efficient, and accurate rules are desired. Furthermore, abundant help statements and graphics were included. Internal and external display routines add to the visual capability of the system. The work results in a useful tool for the client for making decisions on crop yield production
Long-Term Evolution of Massive Black Hole Binaries. III. Binary Evolution in Collisional Nuclei
[Abridged] In galactic nuclei with sufficiently short relaxation times,
binary supermassive black holes can evolve beyond their stalling radii via
continued interaction with stars. We study this "collisional" evolutionary
regime using both fully self-consistent N-body integrations and approximate
Fokker-Planck models. The N-body integrations employ particle numbers up to
0.26M and a direct-summation potential solver; close interactions involving the
binary are treated using a new implementation of the Mikkola-Aarseth chain
regularization algorithm. Even at these large values of N, two-body scattering
occurs at high enough rates in the simulations that they can not be simply
scaled to the large-N regime of real galaxies. The Fokker-Planck model is used
to bridge this gap; it includes, for the first time, binary-induced changes in
the stellar density and potential. The Fokker-Planck model is shown to
accurately reproduce the results of the N-body integrations, and is then
extended to the much larger N regime of real galaxies. Analytic expressions are
derived that accurately reproduce the time dependence of the binary semi-major
axis as predicted by the Fokker-Planck model. Gravitational wave coalescence is
shown to occur in <10 Gyr in nuclei with velocity dispersions below about 80
km/s. Formation of a core results from a competition between ejection of stars
by the binary and re-supply of depleted orbits via two-body scattering. Mass
deficits as large as ~4 times the binary mass are produced before coalescence.
After the two black holes coalesce, a Bahcall-Wolf cusp appears around the
single hole in one relaxation time, resulting in a nuclear density profile
consisting of a flat core with an inner, compact cluster, similar to what is
observed at the centers of low-luminosity spheroids.Comment: 21 page
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