295 research outputs found
AI Hyperrealism: Why AI Faces Are Perceived as More Real Than Human Ones
Recent evidence shows that AI-generated faces are now indistinguishable from human faces. However, algorithms are trained disproportionately on White faces, and thus White AI faces may appear especially realistic. In Experiment 1 (N = 124 adults), alongside our reanalysis of previously published data, we showed that White AI faces are judged as human more often than actual human faces-a phenomenon we term AI hyperrealism. Paradoxically, people who made the most errors in this task were the most confident (a Dunning-Kruger effect). In Experiment 2 (N = 610 adults), we used face-space theory and participant qualitative reports to identify key facial attributes that distinguish AI from human faces but were misinterpreted by participants, leading to AI hyperrealism. However, the attributes permitted high accuracy using machine learning. These findings illustrate how psychological theory can inform understanding of AI outputs and provide direction for debiasing AI algorithms, thereby promoting the ethical use of AI
AI Hyperrealism : Why AI Faces Are Perceived as More Real Than Human Ones
Acknowledgment We thank Sophie J. Nightingale and Hany Farid for providing open access to their stimuli and data. Funding This research is supported by the Australian Government through the Australian Research Council’s Discovery Projects funding scheme (Project No. DP220101026), a TRANSFORM Career Development Fellowship to A. Dawel from the Australian National University College of Health and Medicine, and an Experimental Psychology Society Small Grant to C. A. M. Sutherland. The funders had no role in developing or conducting this research.Peer reviewe
Faint galaxy population in clusters: X-ray emission, cD halos and projection effects
We analyze samples of nearby clusters taken from the Abell catalog and the
X-ray Sample of Bright Clusters(De Grandi et al 1999) including a wide range of
X-ray luminosities.Using the usually adopted background subtraction procedures,
we find that galaxies in clusters selected by means of their X-ray emission
show a flat luminosity function (faint end slope )
consistent with that derived for galaxies in the field and groups. By contrast,
the sample of Abell clusters that do not have an X-ray counterpart shows a
galaxy luminosity function with a steep faint end (). We
investigate the possibility that cD halos could be formed by the disruption of
galaxies in rich relaxed clusters that show an apparently flat faint end galaxy
luminosity function (Lopez-Cruz et al 1997).
We find that clusters dominated by a central cD galaxy (Bautz-Morgan classes
I and II) show the same systematic trend: X-ray selected clusters have flatter
faint end slopes than those clusters with no detected X-ray emission. Thus, it
is likely the X-ray selection and not the cluster domination by central
galaxies what correlates with background decontamination estimates of the
galaxy luminosity function. Moreover, no significant correlation between X-ray
luminosity and the galaxy LF faint end slope is found. These results do not
support a scenario where flat faint end slopes are a consequence of cD
formation via the disruption of faint galaxies. We argue that the clusters
without X-ray emission are strongly affected by projection effects which give
rise to spurious faint end slopes estimated using background subtraction
procedures (Valotto et al 2001).Comment: Accepted for publication in ApJ (vol. 601
Individualization as driving force of clustering phenomena in humans
One of the most intriguing dynamics in biological systems is the emergence of
clustering, the self-organization into separated agglomerations of individuals.
Several theories have been developed to explain clustering in, for instance,
multi-cellular organisms, ant colonies, bee hives, flocks of birds, schools of
fish, and animal herds. A persistent puzzle, however, is clustering of opinions
in human populations. The puzzle is particularly pressing if opinions vary
continuously, such as the degree to which citizens are in favor of or against a
vaccination program. Existing opinion formation models suggest that
"monoculture" is unavoidable in the long run, unless subsets of the population
are perfectly separated from each other. Yet, social diversity is a robust
empirical phenomenon, although perfect separation is hardly possible in an
increasingly connected world. Considering randomness did not overcome the
theoretical shortcomings so far. Small perturbations of individual opinions
trigger social influence cascades that inevitably lead to monoculture, while
larger noise disrupts opinion clusters and results in rampant individualism
without any social structure. Our solution of the puzzle builds on recent
empirical research, combining the integrative tendencies of social influence
with the disintegrative effects of individualization. A key element of the new
computational model is an adaptive kind of noise. We conduct simulation
experiments to demonstrate that with this kind of noise, a third phase besides
individualism and monoculture becomes possible, characterized by the formation
of metastable clusters with diversity between and consensus within clusters.
When clusters are small, individualization tendencies are too weak to prohibit
a fusion of clusters. When clusters grow too large, however, individualization
increases in strength, which promotes their splitting.Comment: 12 pages, 4 figure
Toward a Generalizable Framework of Disturbance Ecology Through Crowdsourced Science
© 2021 Graham, Averill, Bond-Lamberty, Knelman, Krause, Peralta, Shade, Smith, Cheng, Fanin, Freund, Garcia, Gibbons, Van Goethem, Guebila, Kemppinen, Nowicki, Pausas, Reed, Rocca, Sengupta, Sihi, Simonin, Słowiński, Spawn, Sutherland, Tonkin, Wisnoski, Zipper and Contributor Consortium.Disturbances fundamentally alter ecosystem functions, yet predicting their impacts remains a key scientific challenge. While the study of disturbances is ubiquitous across many ecological disciplines, there is no agreed-upon, cross-disciplinary foundation for discussing or quantifying the complexity of disturbances, and no consistent terminology or methodologies exist. This inconsistency presents an increasingly urgent challenge due to accelerating global change and the threat of interacting disturbances that can destabilize ecosystem responses. By harvesting the expertise of an interdisciplinary cohort of contributors spanning 42 institutions across 15 countries, we identified an essential limitation in disturbance ecology: the word ‘disturbance’ is used interchangeably to refer to both the events that cause, and the consequences of, ecological change, despite fundamental distinctions between the two meanings. In response, we developed a generalizable framework of ecosystem disturbances, providing a well-defined lexicon for understanding disturbances across perspectives and scales. The framework results from ideas that resonate across multiple scientific disciplines and provides a baseline standard to compare disturbances across fields. This framework can be supplemented by discipline-specific variables to provide maximum benefit to both inter- and intra-disciplinary research. To support future syntheses and meta-analyses of disturbance research, we also encourage researchers to be explicit in how they define disturbance drivers and impacts, and we recommend minimum reporting standards that are applicable regardless of scale. Finally, we discuss the primary factors we considered when developing a baseline framework and propose four future directions to advance our interdisciplinary understanding of disturbances and their social-ecological impacts: integrating across ecological scales, understanding disturbance interactions, establishing baselines and trajectories, and developing process-based models and ecological forecasting initiatives. Our experience through this process motivates us to encourage the wider scientific community to continue to explore new approaches for leveraging Open Science principles in generating creative and multidisciplinary ideas.This research was supported by the U.S. Department of Energy (DOE), Office of Biological and Environmental Research (BER), as part of Subsurface Biogeochemical Research Program’s Scientific Focus Area (SFA) at the Pacific Northwest National Laboratory (PNNL). PNNL is operated for DOE by Battelle under contract DE-AC06-76RLO 1830
Do clusters contain a large population of dwarf galaxies?
We analyze systematic effects in the determination of the galaxy luminosity
function in clusters using a deep mock catalogue constructed from a numerical
simulation of a hierarchical universe. The results indicate a strong tendency
to derive a rising faint end (\alpha \lsim -1.5) in clusters selected in two
dimensions, using a galaxy catalogue constructed with a universal flat
luminosity function with . This is due to the projection
effects inherent in catalogues of clusters constructed using 2 dimensional
data. Many of the clusters found in 2d have no significant 3d counterparts, and
most suffer from massive background contamination that cannot be corrected for
by subtracting random offset fields. The luminosity function of high surface
brightness galaxies in the field and within small groups follows a Schechter
function with a fairly flat faint end slope, with
to -1.2. On the contrary, observational studies of clusters
constructed using Abell, EDCC and APM catalogues are systematically found to
have steeper luminosity functions with to -2.0. This may be
attributed to projection effects rather than a dominant population of high
surface brightness dwarf galaxies (M\gsim M^*+2) in clusters. It should be
straighforward to confirm our results by measuring redshifts of these faint
cluster galaxies.Comment: 23 pages, 7 Postscript figures TeX, accepted for publication in the
Astrophysical Journal, e-mail:[email protected]
http://iate.oac.uncor.edu/cv.htm
Active Brownian Particles. From Individual to Collective Stochastic Dynamics
We review theoretical models of individual motility as well as collective
dynamics and pattern formation of active particles. We focus on simple models
of active dynamics with a particular emphasis on nonlinear and stochastic
dynamics of such self-propelled entities in the framework of statistical
mechanics. Examples of such active units in complex physico-chemical and
biological systems are chemically powered nano-rods, localized patterns in
reaction-diffusion system, motile cells or macroscopic animals. Based on the
description of individual motion of point-like active particles by stochastic
differential equations, we discuss different velocity-dependent friction
functions, the impact of various types of fluctuations and calculate
characteristic observables such as stationary velocity distributions or
diffusion coefficients. Finally, we consider not only the free and confined
individual active dynamics but also different types of interaction between
active particles. The resulting collective dynamical behavior of large
assemblies and aggregates of active units is discussed and an overview over
some recent results on spatiotemporal pattern formation in such systems is
given.Comment: 161 pages, Review, Eur Phys J Special-Topics, accepte
Organic residue analysis of Egyptian votive mummies and their research potential
YesVast numbers of votive mummies were produced in Egypt during the Late Pharaonic, Ptolemaic, and Roman
periods. Although millions remain in situ, many were removed and have ultimately entered museum
collections around the world. There they have often languished as uncomfortable reminders of antiquarian
practices with little information available to enhance their value as artefacts worthy of conservation or
display. A multi-disciplinary research project, based at the University of Manchester, is currently
redressing these issues. One recent aspect of this work has been the characterization of natural products
employed in the mummification of votive bundles. Using gas chromatography–mass spectrometry and the
well-established biomarker approach, analysis of 24 samples from 17 mummy bundles has demonstrated
the presence of oils/fats, natural waxes, petroleum products, resinous exudates, and essential oils. These
results confirm the range of organic materials employed in embalming and augment our understanding of
the treatment of votives. In this first systematic initiative of its kind, initial findings point to possible trends in
body treatment practices in relation to chronology, geography, and changes in ideology which will be
investigated as the study progresses. Detailed knowledge of the substances used on individual bundles
has also served to enhance their value as display items and aid in their conservation.RCB is supported by a PhD studentship from the Art and Humanities Research Council (43019R00209). L.M. and S.A.W. are supported by a Leverhulme Trust Research Project Award (RPG-2013-143)
NFV, an HIV-1 protease inhibitor, induces growth arrest, reduced Akt signalling, apoptosis and docetaxel sensitisation in NSCLC cell lines
HIV-1 protease inhibitor (PI), nelfinavir (NFV) induced growth arrest and apoptosis of NCI-H460 and -H520, A549, EBC-1 and ABC-1 non-small-cell lung cancer (NSCLC) cells in association with upregulation of p21waf1, p27 kip1 and p53, and downregulation of Bcl-2 and matrix metalloproteinase (MMP)-2 proteins. We found that NFV blocked Akt signalling in these cells as measured by Akt kinase assay with glycogen synthase kinase-3α/β (GSK-3α/β) as a substrate. To explore the role of Akt signalling in NFV-mediated growth inhibition of NSCLC cells, we blocked this signal pathway by transfection of Akt small interfering RNA (siRNA) in these cells; transient transfection of Akt siRNA in NCI-H460 cells decreased the level of Bcl-2 protein and slowed their proliferation compared to the nonspecific siRNA-transfected cells. Conversely, forced-expression of Akt partially reversed NFV-mediated growth inhibition of these cells, suggesting that Akt may be a molecular target of NFV in NSCLC cells. Also, we found that inhibition of Akt signalling by NFV enhanced the ability of docetaxel to inhibit the growth of NCI-H460 and -H520 cells, as measured by MTT assay. Importantly, NFV slowed the proliferation and induced apoptosis of NCI-H460 cells present as tumour xenografts in nude mice without adverse systemic effects. Taken together, this family of compounds might be useful for the treatment of individuals with NSCLC
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