232 research outputs found
An Application of Evolutionary Game Theory to Social Dilemmas: The Traveler's Dilemma and the Minimum Effort Coordination Game
The Traveler's Dilemma game and the Minimum Effort Coordination game are two social dilemmas that have attracted considerable attention due to the fact that the predictions of classical game theory are at odds with the results found when the games are studied experimentally. Moreover, a direct application of deterministic evolutionary game theory, as embodied in the replicator dynamics, to these games does not explain the observed behavior. In this work, we formulate natural variants of these two games as smoothed continuous-strategy games. We study the evolutionary dynamics of these continuous-strategy games, both analytically and through agent-based simulations, and show that the behavior predicted theoretically is in accord with that observed experimentally. Thus, these variants of the Traveler's Dilemma and the Minimum Effort Coordination games provide a simple resolution of the paradoxical behavior associated with the original games
A Viennese in London: English Reception
In a culture conducive to refining his compositions, Haydn was able to find success through his patrons and musical techniques. London was the largest musical city at the time, where advertising played a key role in the attendance at concerts. Haydn attended performances there which educated him on Londonâs music. His patrons (such as violinist Johann Peter Salomon and author Charles Burney) were immensely helpful in his growing musical career in London. Haydnâs shift in compositional style accordingly reflected his stay in London. He combined the music he heard in the city with his own musical language to create his new style. Through studying Londonâs concert life and Haydnâs interaction with it, one can understand why Haydnâs style changed while within a new city
Discriminating early-stage diabetic retinopathy with subjective and objective perimetry
Introduction: To prevent progression of early-stage diabetic retinopathy, we need functional tests that can distinguish multiple levels of neural damage before classical vasculopathy. To that end, we compared multifocal pupillographic objective perimetry (mfPOP), and two types of subjective automated perimetry (SAP), in persons with type 2 diabetes (PwT2D) with either no retinopathy (noDR) or mild to-moderate non-proliferative retinopathy (mmDR). Methods: Both eyes were assessed by two mfPOP test methods that present stimuli within either the central ±15° (OFA15) or ±30° (OFA30), each producing per-region sensitivities and response delays. The SAP tests were 24-2 Short Wavelength Automated Perimetry and 24-2 Matrix perimetry. Results: Five of eight mfPOP global indices were significantly different between noDR and mmDR eyes, but none of the equivalent measures differed for SAP. Per-region mfPOP identified significant hypersensitivity and longer delays in the peripheral visual field, verifying earlier findings. Diagnostic power for discrimination of noDR vs. mmDR, and normal controls vs. PwT2D, was much higher for mfPOP than SAP. The mfPOP per-region delays provided the best discrimination. The presence of localized rather than global changes in delay ruled out iris neuropathy as a major factor. Discussion: mfPOP response delays may provide new surrogate endpoints for studies of interventions for early-stage diabetic eye damage.</p
GiA Roots: Software for the high throughput analysis of plant root system architecture
Background: Characterizing root system architecture (RSA) is essential to understanding the development and function of vascular plants. Identifying RSA-associated genes also represents an underexplored opportunity for crop improvement. Software tools are needed to accelerate the pace at which quantitative traits of RSA are estimated from images of root networks.Results: We have developed GiA Roots (General Image Analysis of Roots), a semi-automated software tool designed specifically for the high-throughput analysis of root system images. GiA Roots includes user-assisted algorithms to distinguish root from background and a fully automated pipeline that extracts dozens of root system phenotypes. Quantitative information on each phenotype, along with intermediate steps for full reproducibility, is returned to the end-user for downstream analysis. GiA Roots has a GUI front end and a command-line interface for interweaving the software into large-scale workflows. GiA Roots can also be extended to estimate novel phenotypes specified by the end-user.Conclusions: We demonstrate the use of GiA Roots on a set of 2393 images of rice roots representing 12 genotypes from the species Oryza sativa. We validate trait measurements against prior analyses of this image set that demonstrated that RSA traits are likely heritable and associated with genotypic differences. Moreover, we demonstrate that GiA Roots is extensible and an end-user can add functionality so that GiA Roots can estimate novel RSA traits. In summary, we show that the software can function as an efficient tool as part of a workflow to move from large numbers of root images to downstream analysis
Characterization and optimization of heroin hapten-BSA conjugates: method development for the synthesis of reproducible hapten-based vaccines
A potential new treatment for drug addiction is immunization with vaccines that induce antibodies that can abrogate the addictive effects of the drug of abuse. One of the challenges in the development of a vaccine against drugs of abuse is the availability of an optimum procedure that gives reproducible and high yielding hapten-protein conjugates. In this study, a heroin/morphine surrogate hapten (MorHap) was coupled to bovine serum albumin (BSA) using maleimide-thiol chemistry. MorHap-BSA conjugates with 3, 5, 10, 15, 22, 28, and 34 haptens were obtained using different linker and hapten ratios. Using this optimized procedure, MorHap-BSA conjugates were synthesized with highly reproducible results and in high yields. The number of haptens attached to BSA was compared by 2,4,6-trinitrobenzenesulfonic acid (TNBS) assay, modified Ellmanâs test and matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Among the three methods, MALDI-TOF MS discriminated subtle differences in hapten density. The effect of hapten density on enzyme-linked immunosorbent assay (ELISA) performance was evaluated with seven MorHap-BSA conjugates of varying hapten densities, which were used as coating antigens. The highest antibody binding was obtained with MorHap-BSA conjugates containing 3â5 haptens. This is the first report that rigorously analyzes, optimizes and characterizes the conjugation of haptens to proteins that can be used for vaccines against drugs of abuse. The effect of hapten density on the ELISA detection of antibodies against haptens demonstrates the importance of careful characterization of the hapten density by the analytical techniques described. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00216-014-8035-x) contains supplementary material, which is available to authorized users
5D Attractors with Higher Derivatives
We analyze higher derivative corrections to attractor geometries in five
dimensions. We find corrected AdS_3xS^2 geometries by solving the equations of
motion coming from a recently constructed four-derivative supergravity action
in five dimensions. The result allows us to explicitly verify a previous
anomaly based derivation of the AdS_3 central charges of this theory. Also, by
dimensional reduction we compare our results with those of the 4D higher
derivative attractor, and find complete agreement.Comment: 18 pages, harvma
ConceptFusion: Open-set Multimodal 3D Mapping
Building 3D maps of the environment is central to robot navigation, planning,
and interaction with objects in a scene. Most existing approaches that
integrate semantic concepts with 3D maps largely remain confined to the
closed-set setting: they can only reason about a finite set of concepts,
pre-defined at training time. Further, these maps can only be queried using
class labels, or in recent work, using text prompts.
We address both these issues with ConceptFusion, a scene representation that
is (1) fundamentally open-set, enabling reasoning beyond a closed set of
concepts and (ii) inherently multimodal, enabling a diverse range of possible
queries to the 3D map, from language, to images, to audio, to 3D geometry, all
working in concert. ConceptFusion leverages the open-set capabilities of
today's foundation models pre-trained on internet-scale data to reason about
concepts across modalities such as natural language, images, and audio. We
demonstrate that pixel-aligned open-set features can be fused into 3D maps via
traditional SLAM and multi-view fusion approaches. This enables effective
zero-shot spatial reasoning, not needing any additional training or finetuning,
and retains long-tailed concepts better than supervised approaches,
outperforming them by more than 40% margin on 3D IoU. We extensively evaluate
ConceptFusion on a number of real-world datasets, simulated home environments,
a real-world tabletop manipulation task, and an autonomous driving platform. We
showcase new avenues for blending foundation models with 3D open-set multimodal
mapping.
For more information, visit our project page https://concept-fusion.github.io
or watch our 5-minute explainer video
https://www.youtube.com/watch?v=rkXgws8fiD
- âŠ