49 research outputs found
Performance Factors in Associative Learning: Assessment of the Sometimes Competing Retrieval Model
Previous simulations revealed that the sometimes competing retrieval model (SOCR; Stout & Miller, 2007), which assumes local error reduction, can explain many cue interaction phenomena that elude traditional associative theories based on total error reduction. Here we applied SOCR to a new set of Pavlovian phenomena. Simulations used a single set of fixed parameters to simulate each basic effect (e.g., blocking) and, for specific experiments using different procedures, used fitted parameters discovered through hillclimbing. In Simulation 1, SOCR was successfully applied to basic acquisition, including the âovertraining effect,â which is context dependent. In Simulation 2, we applied SOCR to basic extinction and renewal. SOCR anticipated these effects with both fixed parameters and best fitting parameters, although the renewal effects were weaker than those observed in some experiments. In Simulation 3a, feature negative training was simulated, including the often observed transition from second-order conditioning to conditioned inhibition. In Simulation 3b, SOCR predicted the observation that conditioned inhibition after feature-negative and differential conditioning depends on intertrial interval. In Simulation 3c, SOCR successfully predicted failure of conditioned inhibition to extinguish with presentations of the inhibitor alone under most circumstances. In Simulation 4, cue competition, including blocking (4a), recovery from relative validity (4b), and unblocking (4c), were simulated. In Simulation 5, SOCR correctly predicted that inhibitors gain more behavioral control than excitors when they are trained in compound. Simulation 6 demonstrated that SOCR explains the slower acquisition observed following CS-weak shock pairings
Enhancing Big Ideas Through Regional Planning: Cross-Jurisdictional \u27Value Added\u27 in Washington State
This paper argues that enhancing multi-jurisdictional planning - i.e. regionalism in various forms -- should be at the center of how we ameliorate most of our major developmental challenges. Put another way, efforts to improve the planning professionâs contribution to concerns like âclimate action,â âeconomic development,â âsocial equity,â âlocal government capacity,â and so on, all require more attention to stronger regional planning processes. The paper is divided into three sections. In the first section, we develop the over-arching theme that experiments in regionalism longer refer to significant institutional-structural reforms - in particular, to consolidation or centralization of planning authority -- but instead to far less threatening, more politically viable, and also less ambitious efforts to build incremental, horizontal collaborations that frequently lack much formal authority because they rely heavily on voluntary reciprocity. We then turn to a lengthy discussion of five different regional planning experiences in Washington State: (1) efforts by the Yakima Council of Governments to making homelessness a âcross-cuttingâ regional issue; (2)Walla Wallaâs efforts to strengthen regional watershed planning; (3) a discussion of the strengths and weaknesses of the Columbia River Gorge Commission; (4) a critical reflection on the importance of tribes in regional planning and possible future dynamics in the Whatcom-La Connor-Swinomish area; and (5) a discussion of recent efforts in the Olympia-Thurston County to coordinate local climate action through enhanced regional collaborations. The final section of the paper recapitulates the main ideas and offers preliminary suggestions as we move forward
Uncertainty-Informed Deep Learning Models Enable High-Confidence Predictions for Digital Histopathology
A model's ability to express its own predictive uncertainty is an essential
attribute for maintaining clinical user confidence as computational biomarkers
are deployed into real-world medical settings. In the domain of cancer digital
histopathology, we describe a novel, clinically-oriented approach to
uncertainty quantification (UQ) for whole-slide images, estimating uncertainty
using dropout and calculating thresholds on training data to establish cutoffs
for low- and high-confidence predictions. We train models to identify lung
adenocarcinoma vs. squamous cell carcinoma and show that high-confidence
predictions outperform predictions without UQ, in both cross-validation and
testing on two large external datasets spanning multiple institutions. Our
testing strategy closely approximates real-world application, with predictions
generated on unsupervised, unannotated slides using predetermined thresholds.
Furthermore, we show that UQ thresholding remains reliable in the setting of
domain shift, with accurate high-confidence predictions of adenocarcinoma vs.
squamous cell carcinoma for out-of-distribution, non-lung cancer cohorts
The Atacama Cosmology Telescope: A Measurement of the DR6 CMB Lensing Power Spectrum and its Implications for Structure Growth
We present new measurements of cosmic microwave background (CMB) lensing over
sq. deg. of the sky. These lensing measurements are derived from the
Atacama Cosmology Telescope (ACT) Data Release 6 (DR6) CMB dataset, which
consists of five seasons of ACT CMB temperature and polarization observations.
We determine the amplitude of the CMB lensing power spectrum at
precision ( significance) using a novel pipeline that minimizes
sensitivity to foregrounds and to noise properties. To ensure our results are
robust, we analyze an extensive set of null tests, consistency tests, and
systematic error estimates and employ a blinded analysis framework. The
baseline spectrum is well fit by a lensing amplitude of
relative to the Planck 2018 CMB power spectra
best-fit CDM model and relative to
the best-fit model. From our lensing power
spectrum measurement, we derive constraints on the parameter combination
of
from ACT DR6 CMB lensing alone and
when combining ACT DR6 and Planck NPIPE
CMB lensing power spectra. These results are in excellent agreement with
CDM model constraints from Planck or
CMB power spectrum measurements. Our lensing measurements from redshifts
-- are thus fully consistent with CDM structure growth
predictions based on CMB anisotropies probing primarily . We find no
evidence for a suppression of the amplitude of cosmic structure at low
redshiftsComment: 45+21 pages, 50 figures. Prepared for submission to ApJ. Also see
companion papers Madhavacheril et al and MacCrann et a
The Atacama Cosmology Telescope: High-resolution component-separated maps across one-third of the sky
Observations of the millimeter sky contain valuable information on a number
of signals, including the blackbody cosmic microwave background (CMB), Galactic
emissions, and the Compton- distortion due to the thermal Sunyaev-Zel'dovich
(tSZ) effect. Extracting new insight into cosmological and astrophysical
questions often requires combining multi-wavelength observations to spectrally
isolate one component. In this work, we present a new arcminute-resolution
Compton- map, which traces out the line-of-sight-integrated electron
pressure, as well as maps of the CMB in intensity and E-mode polarization,
across a third of the sky (around 13,000 sq.~deg.). We produce these through a
joint analysis of data from the Atacama Cosmology Telescope (ACT) Data Release
4 and 6 at frequencies of roughly 93, 148, and 225 GHz, together with data from
the \textit{Planck} satellite at frequencies between 30 GHz and 545 GHz. We
present detailed verification of an internal linear combination pipeline
implemented in a needlet frame that allows us to efficiently suppress Galactic
contamination and account for spatial variations in the ACT instrument noise.
These maps provide a significant advance, in noise levels and resolution, over
the existing \textit{Planck} component-separated maps and will enable a host of
science goals including studies of cluster and galaxy astrophysics, inferences
of the cosmic velocity field, primordial non-Gaussianity searches, and
gravitational lensing reconstruction of the CMB.Comment: The Compton-y map and associated products will be made publicly
available upon publication of the paper. The CMB T and E mode maps will be
made available when the DR6 maps are made publi
The Atacama Cosmology Telescope: DR6 Gravitational Lensing Map and Cosmological Parameters
We present cosmological constraints from a gravitational lensing mass map
covering 9400 sq. deg. reconstructed from CMB measurements made by the Atacama
Cosmology Telescope (ACT) from 2017 to 2021. In combination with BAO
measurements (from SDSS and 6dF), we obtain the amplitude of matter
fluctuations at 1.8% precision,
and the Hubble
constant at
1.6% precision. A joint constraint with CMB lensing measured by the Planck
satellite yields even more precise values: ,
and . These measurements agree
well with CDM-model extrapolations from the CMB anisotropies measured
by Planck. To compare these constraints to those from the KiDS, DES, and HSC
galaxy surveys, we revisit those data sets with a uniform set of assumptions,
and find from all three surveys are lower than that from ACT+Planck
lensing by varying levels ranging from 1.7-2.1. These results motivate
further measurements and comparison, not just between the CMB anisotropies and
galaxy lensing, but also between CMB lensing probing on
mostly-linear scales and galaxy lensing at on smaller scales. We
combine our CMB lensing measurements with CMB anisotropies to constrain
extensions of CDM, limiting the sum of the neutrino masses to eV (95% c.l.), for example. Our results provide independent
confirmation that the universe is spatially flat, conforms with general
relativity, and is described remarkably well by the CDM model, while
paving a promising path for neutrino physics with gravitational lensing from
upcoming ground-based CMB surveys.Comment: 30 pages, 16 figures, prepared for submission to ApJ. Cosmological
likelihood data is here:
https://lambda.gsfc.nasa.gov/product/act/actadv_prod_table.html ; likelihood
software is here: https://github.com/ACTCollaboration/act_dr6_lenslike . Also
see companion papers Qu et al and MacCrann et al. Mass maps will be released
when papers are publishe
AI is a viable alternative to high throughput screening: a 318-target study
: High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNetÂź convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNetÂź model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery
The Atacama Cosmology Telescope: A measurement of the DR6 CMB lensing power spectrum and its implications for structure growth
We present new measurements of cosmic microwave background (CMB) lensing over 9400 deg2 of the sky. These lensing measurements are derived from the Atacama Cosmology Telescope (ACT) Data Release 6 (DR6) CMB data set, which consists of five seasons of ACT CMB temperature and polarization observations. We determine the amplitude of the CMB lensing power spectrum at 2.3% precision (43Ï significance) using a novel pipeline that minimizes sensitivity to foregrounds and to noise properties. To ensure that our results are robust, we analyze an extensive set of null tests, consistency tests, and systematic error estimates and employ a blinded analysis framework. Our CMB lensing power spectrum measurement provides constraints on the amplitude of cosmic structure that do not depend on Planck or galaxy survey data, thus giving independent information about large-scale structure growth and potential tensions in structure measurements. The baseline spectrum is well fit by a lensing amplitude of A lens = 1.013 ± 0.023 relative to the Planck 2018 CMB power spectra best-fit ÎCDM model and A lens = 1.005 ± 0.023 relative to the ACT DR4 + WMAP best-fit model. From our lensing power spectrum measurement, we derive constraints on the parameter combination S8CMBLâĄÏ8Ωm/0.30.25 of S8CMBL=0.818±0.022 from ACT DR6 CMB lensing alone and S8CMBL=0.813±0.018 when combining ACT DR6 and Planck NPIPE CMB lensing power spectra. These results are in excellent agreement with ÎCDM model constraints from Planck or ACT DR4 + WMAP CMB power spectrum measurements. Our lensing measurements from redshifts z ⌠0.5â5 are thus fully consistent with ÎCDM structure growth predictions based on CMB anisotropies probing primarily z ⌠1100. We find no evidence for a suppression of the amplitude of cosmic structure at low redshifts
The Atacama Cosmology Telescope: DR6 gravitational lensing map and cosmological parameters
We present cosmological constraints from a gravitational lensing mass map covering 9400 deg2 reconstructed from measurements of the cosmic microwave background (CMB) made by the Atacama Cosmology Telescope (ACT) from 2017 to 2021. In combination with measurements of baryon acoustic oscillations and big bang nucleosynthesis, we obtain the clustering amplitude Ï 8 = 0.819 ± 0.015 at 1.8% precision, S8âĄÏ8(Ωm/0.3)0.5=0.840±0.028 , and the Hubble constant H 0 = (68.3 ± 1.1) km sâ1 Mpcâ1 at 1.6% precision. A joint constraint with Planck CMB lensing yields Ï 8 = 0.812 ± 0.013, S8âĄÏ8(Ωm/0.3)0.5=0.831±0.023 , and H 0 = (68.1 ± 1.0) km sâ1 Mpcâ1. These measurements agree with ÎCDM extrapolations from the CMB anisotropies measured by Planck. We revisit constraints from the KiDS, DES, and HSC galaxy surveys with a uniform set of assumptions and find that S 8 from all three are lower than that from ACT+Planck lensing by levels ranging from 1.7Ï to 2.1Ï. This motivates further measurements and comparison, not just between the CMB anisotropies and galaxy lensing but also between CMB lensing probing z ⌠0.5â5 on mostly linear scales and galaxy lensing at z ⌠0.5 on smaller scales. We combine with CMB anisotropies to constrain extensions of ÎCDM, limiting neutrino masses to âm Îœ < 0.13 eV (95% c.l.), for example. We describe the mass map and related data products that will enable a wide array of cross-correlation science. Our results provide independent confirmation that the universe is spatially flat, conforms with general relativity, and is described remarkably well by the ÎCDM model, while paving a promising path for neutrino physics with lensing from upcoming ground-based CMB surveys