469 research outputs found
Payoff levels, loss avoidance, and equilibrium selection in the Stag Hunt: an experimental study
Game theorists typically assume that changing a gameâs payoff levelsâby adding the same constant to, or subtracting it from, all payoffsâshould not affect behavior. While this invariance is an implication of the theory when payoffs mirror expected utilities, it is an empirical question when the âpayoffsâ are actually money amounts. In particular, if individuals treat monetary gains and losses differently, then payoffâlevel changes may matter when they result in positive payoffs becoming negative, or vice versa. We report the results of a humanâsubjects experiment designed to test for two types of loss avoidance: certainâloss avoidance (avoiding a strategy leading to a sure loss, in favor of an alternative that might lead to a gain) and possibleâloss avoidance (avoiding a strategy leading to a possible loss, in favor of an alternative that leads to a sure gain). Subjects in the experiment play three versions of Stag Hunt, which are identical up to the level of payoffs, under a variety of treatments. We find differences in behavior across the three versions of Stag Hunt; these differences are hard to detect in the first round of play, but grow over time. When significant, the differences we find are in the direction predicted by certainâ and possibleâloss avoidance. Our results carry implications for games with multiple equilibria, and for theories that attempt to select among equilibria in such games
Shedding Light on the Compton-thick Active Galactic Nucleus in the Ultra-luminous Infrared Galaxy UGC 5101 with Broadband X-ray Spectroscopy
We report the broadband X-ray spectra of the ultra-luminous infrared galaxy
(ULIRG) UGC 5101 in the 0.25-100 keV band observed with Swift/Burst Alert
Telescope (BAT), NuSTAR, Suzaku, XMM-Newton, and Chandra. A Compton-thick AGN
obscured with a hydrogen column density of cm
is detected above 10 keV. A spectral fit with a numerical torus model favors a
large half opening angle of the torus, degrees, suggesting that the
covering fraction of material heavily obscuring the X-ray source is moderate.
The intrinsic 2-10 keV luminosity is determined to be erg s, which is 2.5 times larger than the previous
estimate using only data below 10 keV with a simple spectral model. We find
that UGC 5101 shows the ratio between the [O IV] 26 m line and 2-10 keV
luminosities similar to those of normal Seyfert galaxies, along with other
ULIRGs observed with NuSTAR, indicating that a significant portion of local
ULIRGs are not really "X-ray faint" with respect to the flux of forbidden lines
originating from the narrow line region (NLR). We propose a possible scenario
that (1) the AGN in UGC 5101 is surrounded not only by Compton-thick matter
located close to the equatorial plane but also by Compton-thin ( cm) matter in the torus-hole region and (2) it is
accreting at a high Eddington rate with a steep UV to X-ray spectral energy
distribution. Nevertheless, we argue that AGNs in many ULIRGs do not look
extraordinary (i.e., extremely X-ray faint), as suggested by recent works,
compared with normal Seyferts.Comment: 11 pages, 7 figures, accepted for publication in Ap
On geometric independency trees for points in the plane
AbstractA plane spanning tree is a tree drawn in the plane so that its edges are closed straight-line segments and no two edges intersect internally, and no three of its vertices are collinear. In this paper, we present several results on a plane spanning tree T such that the graph obtained from T by adding a line segment between any two end-vertices of T is self-intersecting
Automated classification of heat sources detected using SWIR remote sensing
Abstract The potential of shortwave infrared (SWIR) remote sensing to detect hotspots has been investigated using satellite data for decades. The hotspots detected by satellite SWIR sensors include very high-temperature heat sources such as wildfires, volcanoes, industrial activity, or open burning. This study proposes an automated classification method of heat source detected utilizing Landsat 8 and Sentinel-2 data. We created training data of heat sources via visual inspection of hotspots detected by Landsat 8. A scheme to classify heat sources for daytime data was developed by combining classification methods based on a Convolutional Neural Network (CNN) algorithm utilizing spatial features and a decision tree algorithm based on thematic land-cover information and our time series detection record. Validation work using 10,959 classification results corresponding to hotspots acquired from May 2017 to July 2019 indicated that the two classification results were in 79.7% agreement. For hotspots where the two classification schemes agreed, the classification was 97.9% accurate. Even when the results of the two classification schemes conflicted, either was correct in 73% of the samples. To improve the accuracy, the heat source category was re-allocated to the most probable category corresponding to the combination of the results from the two methods. Integrating the two approaches achieved an overall accuracy of 92.8%. In contrast, the overall accuracy for heat source classification during nighttime reached 79.3% because only the decision tree-based classification was applicable to limited available data. Comparison with the Visible Infrared Imaging Radiometer Suite (VIIRS) fire product revealed that, despite the limited data acquisition frequency of Landsat 8, regional tendencies in hotspot occurrence were qualitatively appropriate for an annual period on a global scale
Optimization of WAVE2 complexâinduced actin polymerization by membrane-bound IRSp53, PIP3, and Rac
WAVE2 activates the actin-related protein (Arp) 2/3 complex for Rac-induced actin polymerization during lamellipodium formation and exists as a large WAVE2 protein complex with Sra1/PIR121, Nap1, Abi1, and HSPC300. IRSp53 binds to both Rac and Cdc42 and is proposed to link Rac to WAVE2. We found that the knockdown of IRSp53 by RNA interference decreased lamellipodium formation without a decrease in the amount of WAVE2 complex. Localization of WAVE2 at the cell periphery was retained in IRSp53 knockdown cells. Moreover, activated Cdc42 but not Rac weakened the association between WAVE2 and IRSp53. When we measured Arp2/3 activation in vitro, the WAVE2 complex isolated from the membrane fraction of cells was fully active in an IRSp53-dependent manner but WAVE2 isolated from the cytosol was not. Purified WAVE2 and purified WAVE2 complex were activated by IRSp53 in a Rac-dependent manner with PIP3-containing liposomes. Therefore, IRSp53 optimizes the activity of the WAVE2 complex in the presence of activated Rac and PIP3
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Genome Wide Association Study of Age at Menarche in the Japanese Population
Age at menarche (AAM) is a complex trait involving both genetic and environmental factors. To identify the genetic factors associated with AAM, we conducted a large-scale meta-analysis of genome-wide association studies using more than 15,000 Japanese female samples. Here, we identified an association between SNP (single nucleotide polymorphism) rs364663 at the LIN28B locus and AAM, with a P-value of 5.49Ă10â7 and an effect size of 0.089 (year). We also evaluated 33 SNPs that were previously reported to be associated with AAM in women of European ancestry. Among them, two SNPs rs4452860 and rs7028916 in TMEM38B indicated significant association with AAM in the same directions as reported in previous studies (P = 0.0013 with an effect size of 0.051) even after Bonferroni correction for the 33 SNPs. In addition, six loci in or near CCDC85A, LOC100421670, CA10, ZNF483, ARNTL, and RXRG exhibited suggestive association with AAM (P<0.05). Our findings elucidated the impact of genetic variations on AAM in the Japanese population
Spin-splitting band dispersions of the heavy elements on Si(111)-(1Ă1) surface
éæȹ性ćŠć€§ćŠéąèȘç¶ç§ćŠç 究ç§ăWe have carried out the first-principles fully relativistic electronic structure calculations for the surfaces, R/Si(111) (R = Pb and Bi). The band dispersions of the surface states in the bulk band gap shows the large spin splitting, associated with the spin-orbit interaction on the atoms of the overlayer. Besides the usual Rashba effect around the center of the surface Brillouin zone, the vortical spin polarizations were obtained around the M Ì points. At the KÌ, associated with the symmetry, the complete out-of-plane spin polarization was obtained for the surface states. © 2010 IOP Publishing Ltd
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