576 research outputs found
Philanthropy and Outcomes: Dilemmas in the Quest for Accountability
Grantees report that never before have grant negotiations with foundation staffs been so focused on specifying outcomes. Some foundations have employed consultants to work with their staffs so that inputs, operational processes, and intended intermediate and long-term outcomes and impacts are specified and differentiated. A number have added evaluation departments to their organizational structure. Small and medium sized foundations, which have previously given exclusively to direct services, are now asking for and funding evaluations, so that they may know with objectivity and rigor if the projected outcomes are achieved. We do not recommend a moratorium on all outcome and impact assessments. In some settings, formal impact evaluation is what is called for. What we are arguing for is a strategic rethinking of when to utilize the tools of formal outcome and impact research
The Winner Doesn’t Take It All: Analyzing Audience Responses to an Inspirational Sports Narrative
Applying a dual-process rationale, this study explored the cognitive and affective mechanisms involved in the processing of hedonic versus eudaimonic film clips and their putatively distinct inspirational effects. The two types of narratives were operationalized in terms of complete and incomplete goal satisfaction in the film endings. Participants either watched the final boxing match from Rocky, where the protagonist loses the fight, but achieves self-mastery and finds love (eudaimonic narrative) or from Rocky II, where he wins against his opponent (hedonic narrative). A combination of continuous measures of how pleasant participants felt (slider ratings) and psychophysiological measures (heart rate, galvanic skin response [GSR], pulse volume amplitude [PVA]) indicating cognitive load and arousal was used to track the audience responses while watching a compilation of the same intro and the different fight versions. Results revealed that arousal was more strongly associated with participants’ affective scores during the hedonic (winning) version than during the eudaimonic (losing) one. Furthermore, participants experience more positive affect and arousal after watching the protagonist win the match compared to those that watched him lose. Lastly, participants in the eudaimonic condition were more likely to be inspired to exercise afterward. Implications of our results are discussed
Locally Optimally-emitting Clouds and the Narrow Emission Lines in Seyfert Galaxies
The narrow emission line spectra of active galactic nuclei are not accurately
described by simple photoionization models of single clouds. Recent Hubble
Space Telescope images of Seyfert 2 galaxies show that these objects are rich
with ionization cones, knots, filaments, and strands of ionized gas. Here we
extend to the narrow line region the ``locally optimally emitting cloud'' (LOC)
model, in which the observed spectra are predominantly determined by powerful
selection effects. We present a large grid of photoionization models covering a
wide range of physical conditions and show the optimal conditions for producing
many of the strongest emission lines. We show that the integrated narrow line
spectrum can be predicted by an integration of an ensemble of clouds, and we
present these results in the form of diagnostic line ratio diagrams making
comparisons with observations. We also predict key diagnostic line ratios as a
function of distance from the ionizing source, and compare these to
observations. The predicted radial dependence of the [O III]/[O II] ratio may
be matched to the observed one in NGC4151, if the narrow line clouds see a more
intense continuum than we see. The LOC scenario when coupled with a simple
Keplerian gravitational velocity field will quite naturally predict the
observed line width versus critical density relationship. The influence of dust
within the ionized portion of the clouds is discussed and we show that the more
neutral gas is likely to be dusty, although a high ionization dust-free region
is most likely present too. This argues for a variety of NLR cloud origins.Comment: 29 pages plus 16 figures, accepted for publication in Ap
Classification and analysis of emission-line galaxies using mean field independent component analysis
We present an analysis of the optical spectra of narrow emission-line
galaxies, based on mean field independent component analysis (MFICA). Samples
of galaxies were drawn from the Sloan Digital Sky Survey (SDSS) and used to
generate compact sets of `continuum' and `emission-line' component spectra.
These components can be linearly combined to reconstruct the observed spectra
of a wider sample of galaxies. Only 10 components - five continuum and five
emission line - are required to produce accurate reconstructions of essentially
all narrow emission-line galaxies; the median absolute deviations of the
reconstructed emission-line fluxes, given the signal-to-noise ratio (S/N) of
the observed spectra, are 1.2-1.8 sigma for the strong lines. After applying
the MFICA components to a large sample of SDSS galaxies we identify the regions
of parameter space that correspond to pure star formation and pure active
galactic nucleus (AGN) emission-line spectra, and produce high S/N
reconstructions of these spectra.
The physical properties of the pure star formation and pure AGN spectra are
investigated by means of a series of photoionization models, exploiting the
faint emission lines that can be measured in the reconstructions. We are able
to recreate the emission line strengths of the most extreme AGN case by
assuming the central engine illuminates a large number of individual clouds
with radial distance and density distributions, f(r) ~ r^gamma and g(n) ~
n^beta, respectively. The best fit is obtained with gamma = -0.75 and beta =
-1.4. From the reconstructed star formation spectra we are able to estimate the
starburst ages. These preliminary investigations serve to demonstrate the
success of the MFICA-based technique in identifying distinct emission sources,
and its potential as a tool for the detailed analysis of the physical
properties of galaxies in large-scale surveys.Comment: MNRAS accepted. 29 pages, 24 figures, 3 table
Interpreting the Ionization Sequence in AGN Emission-Line Spectra
We investigate the physical cause of the great range in the ionization level
seen in the spectra of narrow lined active galactic nuclei (AGN). Mean field
independent component analysis identifies examples of individual SDSS galaxies
whose spectra are not dominated by emission due to star formation (SF), which
we designate as AGN. We assembled high S/N ratio composite spectra of a
sequence of these AGN defined by the ionization level of their narrow-line
regions (NLR), extending down to very low-ionization cases. We used a local
optimally emitting cloud (LOC) model to fit emission-line ratios in this AGN
sequence. These included the weak lines that can be measured only in the
co-added spectra, providing consistency checks on strong line diagnostics.
After integrating over a wide range of radii and densities our models indicate
that the radial extent of the NLR is the major parameter in determining the
position of high to moderate ionization AGN along our sequence, providing a
physical interpretation for their systematic variation. Higher ionization AGN
contain optimally emitting clouds that are more concentrated towards the
central continuum source than in lower ionization AGN. Our LOC models indicate
that for the objects that lie on our AGN sequence, the ionizing luminosity is
anticorrelated with the NLR ionization level, and hence anticorrelated with the
radial concentration and physical extent of the NLR. A possible interpretation
that deserves further exploration is that the ionization sequence might be an
age sequence where low ionization objects are older and have systematically
cleared out their central regions by radiation pressure. We consider that our
AGN sequence instead represents a mixing curve of SF and AGN spectra, but argue
that while many galaxies do have this type of composite spectra, our AGN
sequence appears to be a special set of objects with negligible SF excitation.Comment: 57 pages; 18 figures, accepted by MNRA
Two-Component Structure of the Hbeta Broad-Line Region in Quasars. I. Evidence from Spectral Principal Component Analysis
We report on a spectral principal component analysis (SPCA) of a sample of
816 quasars, selected to have small Fe II velocity shifts with spectral
coverage in the rest wavelength range 3500--5500 \AA. The sample is explicitly
designed to mitigate spurious effects on SPCA induced by Fe II velocity shifts.
We improve the algorithm of SPCA in the literature and introduce a new
quantity, \emph{the fractional-contribution spectrum}, that effectively
identifies the emission features encoded in each eigenspectrum. The first
eigenspectrum clearly records the power-law continuum and very broad Balmer
emission lines. Narrow emission lines dominate the second eigenspectrum. The
third eigenspectrum represents the Fe II emission and a component of the Balmer
lines with kinematically similar intermediate velocity widths. Correlations
between the weights of the eigenspectra and parametric measurements of line
strength and continuum slope confirm the above interpretation for the
eigenspectra. Monte Carlo simulations demonstrate the validity of our method to
recognize cross talk in SPCA and firmly rule out a single-component model for
broad Hbeta. We also present the results of SPCA for four other samples that
contain quasars in bins of larger Fe II velocity shift; similar eigenspectra
are obtained. We propose that the Hbeta-emitting region has two kinematically
distinct components: one with very large velocities whose strength correlates
with the continuum shape, and another with more modest, intermediate velocities
that is closely coupled to the gas that gives rise to Fe II emission.Comment: 22 pages, 17 figures, accepted for publication in The Astrophysical
Journa
The elusive search for an effective repellent against voles: an assessment of anthraquinone for citrus crops
Vole (Cricetidae) girdling of tree trunks is a common form of damage experienced by tree and vine growers throughout much of the Northern Hemisphere. Management programs that effectively incorporate chemical repellents and vegetation management would be of substantial assistance to growers that experience such damage. Anthraquinone has proven effective as a repellent against voles in lab trials, yet controlled field tests of combined anthraquinone and vegetation management programs are lacking. Therefore, we established a mesocosm-based study in central California, USA, to test the efficacy of anthraquinone and vegetation management for reducing girdling damage caused by California voles Microtus californicus to Clementine citrus trees Citrus clementine under semi-field conditions. We observed a 90–100% reduction in girdling damage for trees following a single application of anthraquinone during two trials in summer and spring, respectively. Removal of vegetation around the base of trees further reduced damage during the summer sampling period, with no girdling observed on anthraquinone-treated trees that were surrounded by bare soil. We did not observe this same relationship during spring, and we observed no relationship between vegetation management in the absence of anthraquinone treatments in either seasonal trial, suggesting that vegetation management had a lesser impact on vole girdling than anthraquinone applications. We observed no decrease in efficacy of anthraquinone across the duration of both sampling periods (5–6 weeks), indicating substantial longevity for anthraquinone. Anthraquinone appears to have substantial utility for minimizing vole girdling damage. Field testing is warranted for additional mammalian species to determine potential uses for other taxa
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