Basins of Attraction for Chimera States

Chimera states---curious symmetry-broken states in systems of identical coupled oscillators---typically occur only for certain initial conditions. Here we analyze their basins of attraction in a simple system comprised of two populations. Using perturbative analysis and numerical simulation we evaluate asymptotic states and associated destination maps, and demonstrate that basins form a complex twisting structure in phase space. Understanding the basins' precise nature may help in the development of control methods to switch between chimera patterns, with possible technological and neural system applications.Comment: Please see Ancillary files for the 4 supplementary videos including description (PDF

Evaluation of LANDSAT MSS vs TM simulated data for distinguishing hydrothermal alteration

The LANDSAT Follow-On (LFO) data was simulated to demonstrate the mineral exploration capability of this system for segregating different types of hydrothermal alteration and to compare this capability with that of the existing LANDSAT system. Multispectral data were acquired for several test sites with the Bendix 24-channel MSDS scanner. Contrast enhancements, band ratioing, and principal component transformations were used to process the simulated LFO data for analysis. For Red Mountain, Arizona, the LFO data allowed identification of silicified areas, not identifiable with LANDSAT 1 and 2 data. The improved LFO resolution allowed detection of small silicic outcrops and of a narrow silicified dike. For Cuprite - Ralston, Nevada, the LFO spectral bands allowed discrimination of argillic and opalized altered areas; these could not be spectrally discriminated using LANDSAT 1 and 2 data. Addition of data from the 1.3- and 2.2- micrometer regions allowed better discriminations of hydrothermal alteration types

A study of alteration associated with uranium occurrences in sandstone and its detection by remote sensing methods, volume 2

This document contains tabular and graphic data for volume 1

Tunable Oscillations in the Purkinje Neuron

In this paper, we study the dynamics of slow oscillations in Purkinje neurons in vitro, and derive a strong association with a forced parametric oscillator model. We demonstrate the precise rhythmicity of the oscillations in Purkinje neurons, as well as a dynamic tunability of this oscillation using a photo-switchable compound. We show that this slow oscillation can be induced in every Purkinje neuron, having periods ranging between 10-25 seconds. Starting from a Hodgkin-Huxley model, we also demonstrate that this oscillation can be externally modulated, and that the neurons will return to their intrinsic firing frequency after the forced oscillation is concluded. These results signify an additional functional role of tunable oscillations within the cerebellum, as well as a dynamic control of a time scale in the brain in the range of seconds.Comment: 12 pages, 5 figure

How groups react to disloyalty in the context of intergroup competition: Evaluations of group deserters and defectors

Groups strongly value loyalty, especially in the context of intergroup competition. However, research has yet to investigate how groups respond to members who leave the group or join a competing outgroup. Three studies investigated groups' reactions to defectors (Experiment 1) and deserting members (Experiments 2 and 3). Experiment 1 used a minimal group paradigm to demonstrate that defectors trigger a stronger derogation of ingroup deviants than outgroup deviants vis-à-vis normative members. Experiments 2 and 3 compared group members' responses to defection versus desertion from minimal and self-assigned groups, respectively. Experiment 3 also explored an explanation for the evaluations of disloyalty. Across studies, participants evaluated normative ingroup members more positively than defectors and deserters. Outgroup deserting and defecting members were evaluated similarly. Derogation of ingroup as compared to outgroup targets emerged only for defectors. In addition, Experiment 3 demonstrated that negativity toward the outgroup was related to stronger derogation of disloyal targets. Negative outgroup attitudes trigger stricter criteria for responding to disloyalty. Directions for future research are discussed

Matchmaker, Matchmaker, Make Me a Match: Migration of Populations via Marriages in the Past

The study of human mobility is both of fundamental importance and of great potential value. For example, it can be leveraged to facilitate efficient city planning and improve prevention strategies when faced with epidemics. The newfound wealth of rich sources of data---including banknote flows, mobile phone records, and transportation data---has led to an explosion of attempts to characterize modern human mobility. Unfortunately, the dearth of comparable historical data makes it much more difficult to study human mobility patterns from the past. In this paper, we present an analysis of long-term human migration, which is important for processes such as urbanization and the spread of ideas. We demonstrate that the data record from Korean family books (called "jokbo") can be used to estimate migration patterns via marriages from the past 750 years. We apply two generative models of long-term human mobility to quantify the relevance of geographical information to human marriage records in the data, and we find that the wide variety in the geographical distributions of the clans poses interesting challenges for the direct application of these models. Using the different geographical distributions of clans, we quantify the "ergodicity" of clans in terms of how widely and uniformly they have spread across Korea, and we compare these results to those obtained using surname data from the Czech Republic. To examine population flow in more detail, we also construct and examine a population-flow network between regions. Based on the correlation between ergodicity and migration in Korea, we identify two different types of migration patterns: diffusive and convective. We expect the analysis of diffusive versus convective effects in population flows to be widely applicable to the study of mobility and migration patterns across different cultures.Comment: 24 pages, 23 figures, 5 table

Conversations with Gatekeepers: An Exploratory Study of Agricultural Publication Editors\u27 Decisions to Publish Risk Coverage

The United States’ agriculture industry is impacted by numerous financial, human, legal, and production risks. These risks are frequently reported in mass media and agricultural publications. Farmers often use agricultural magazines to help them make production decisions and learn about new technology, which both involve some element of risk. Gatekeeping is the process of determining what information is included in media coverage in which editors serve as gatekeepers and make decisions regarding what topics to report. The purpose of this study was to discover how agricultural publication editors, in their role as gatekeepers, make decisions regarding coverage of risk related to agriculture and to explore the forces that influence this coverage. Researchers interviewed seven purposively selected editors of national or regional agricultural magazines. The findings indicated that the editors conceptualize risk in agriculture differently from how agricultural risks are reported in the mainstream media for the more general public; many emphasized the issues in terms of marketing or financial risk. Editors emphasized that they report on risk from an action angle, providing advice or information on how to mitigate the risk. The public’s perception of agriculture, advertisers, and personal topic preferences were cited as influencers of their risk coverage. When covering risk stories, agricultural publication editors prefer journalists who can write well and have an agricultural background or knowledge of the industry. Future research should be conducted to expand on the results from this exploratory study

Detection and mapping of hydrothermally altered rocks in the vicinity of the comstock lode, Virginia Range, Nevada, using enhanced LANDSAT images

The author has identified the following significant results. LANDSAT images enhanced by the band-ratioing method can be used for reconnaissance alteration mapping in moderately heavily vegetated semiarid terrain as well as in sparsely vegetated to semiarid terrain where the technique was originally developed. Significant vegetation cover in a scene, however, requires the use of MSS ratios 4/5, 4/6, and 6/7 rather than 4/5, 5/6, and 6/7, and requires careful interpretation of the results. Supplemental information suitable to vegetation identification and cover estimates, such as standard LANDSAT false-color composites and low altitude aerial photographs of selected areas is desirable

The detection of geothermal areas from Skylab thermal data

Skylab-4 X-5 thermal data of the geysers area was analyzed to determine the feasibility of using midday Skylab images to detect geothermal areas. The hottest ground areas indicated on the Skylab image corresponded to south-facing barren or sparsely vegetated slopes. A geothermal area approximately 15 by 30 m coincided with one of the hottest areas indicated by Skylab. This area could not be unambiguously distinguished from the other areas which are believed to be hotter than their surroundings as a result of their topography, and micrometeorological conditions. A simple modification of a previous thermal model was performed and the predicted temperatures for the hottest slopes using representative values was in general agreement with the observed data. It is concluded that data from a single midday Skylab pass cannot be used to locate geothermal areas