Exploring the movement dynamics of deception

Both the science and the everyday practice of detecting a lie rest on the same assumption: hidden cognitive states that the liar would like to remain hidden nevertheless influence observable behavior. This assumption has good evidence. The insights of professional interrogators, anecdotal evidence, and body language textbooks have all built up a sizeable catalog of non-verbal cues that have been claimed to distinguish deceptive and truthful behavior. Typically, these cues are discrete, individual behaviors—a hand touching a mouth, the rise of a brow—that distinguish lies from truths solely in terms of their frequency or duration. Research to date has failed to establish any of these non-verbal cues as a reliable marker of deception. Here we argue that perhaps this is because simple tallies of behavior can miss out on the rich but subtle organization of behavior as it unfolds over time. Research in cognitive science from a dynamical systems perspective has shown that behavior is structured across multiple timescales, with more or less regularity and structure. Using tools that are sensitive to these dynamics, we analyzed body motion data from an experiment that put participants in a realistic situation of choosing, or not, to lie to an experimenter. Our analyses indicate that when being deceptive, continuous fluctuations of movement in the upper face, and somewhat in the arms, are characterized by dynamical properties of less stability, but greater complexity. For the upper face, these distinctions are present despite no apparent differences in the overall amount of movement between deception and truth. We suggest that these unique dynamical signatures of motion are indicative of both the cognitive demands inherent to deception and the need to respond adaptively in a social context

IDA: An implicit, parallelizable method for calculating drainage area

Models of landscape evolution or hydrological processes typically depend on the accurate determination of upslope drainage area from digital elevation data, but such calculations can be very computationally demanding when applied to high-resolution topographic data. To overcome this limitation, we propose calculating drainage area in an implicit, iterative manner using linear solvers. The basis of this method is a recasting of the flow routing problem as a sparse system of linear equations, which can be solved using established computational techniques. This approach is highly parallelizable, enabling data to be spread over multiple computer processors. Good scalability is exhibited, rendering it suitable for contemporary high-performance computing architectures with many processors, such as graphics processing units (GPUs). In addition, the iterative nature of the computational algorithms we use to solve the linear system creates the possibility of accelerating the solution by providing an initial guess, making the method well suited to iterative calculations such as numerical landscape evolution models. We compare this method with a previously proposed parallel drainage area algorithm and present several examples illustrating its advantages, including a continent-scale flow routing calculation at 3 arc sec resolution, improvements to models of fluvial sediment yield, and acceleration of drainage area calculations in a landscape evolution model. We additionally describe a modification that allows the method to be used for parallel basin delineation.National Science Foundation (U.S.). Geomorphology and Land-Use Dynamics Program (Award EAR-0951672

Containers for Portable, Productive, and Performant Scientific Computing

Containers are an emerging technology that holds promise for improving productivity and code portability in scientific computing. The authors examine Linux container technology for the distribution of a nontrivial scientific computing software stack and its execution on a spectrum of platforms from laptop computers through high-performance computing systems. For Python code run on large parallel computers, the runtime is reduced inside a container due to faster library imports. The software distribution approach and data that the authors present will help developers and users decide on whether container technology is appropriate for them. The article also provides guidance for vendors of HPC systems that rely on proprietary libraries for performance on what they can do to make containers work seamlessly and without performance penalty

Character Strengths and Deep Connections Following Hurricanes Katrina and Rita: Spiritual and Secular Pathways to Resistance Among Volunteers

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/100170/1/jssr12043.pd

Wavelet phase analysis of two velocity components to infer the structure of interscale transfers in a turbulent boundary-layer

Scale-dependent phase analysis of velocity time series measured in a zero pressure gradient boundary layer shows that phase coupling between longitudinal and vertical velocity components is strong at both large and small scales, but minimal in the middle of the inertial regime. The same general pattern is observed at all vertical positions studied, but there is stronger phase coherence as the vertical coordinate, y, increases. The phase difference histograms evolve from a unimodal shape at small scales to the development of significant bimodality at the integral scale and above. The asymmetry in the off-diagonal couplings changes sign at the midpoint of the inertial regime, with the small scale relation consistent with intense ejections followed by a more prolonged sweep motion. These results may be interpreted in a manner that is consistent with the action of low speed streaks and hairpin vortices near the wall, with large scale motions further from the wall, the effect of which penetrates to smaller scales. Hence, a measure of phase coupling, when combined with a scale-by-scale decomposition of perpendicular velocity components, is a useful tool for investigating boundary-layer structure and inferring process from single-point measurements

Evolutionary Events in a Mathematical Sciences Research Collaboration Network

This study examines long-term trends and shifting behavior in the collaboration network of mathematics literature, using a subset of data from Mathematical Reviews spanning 1985-2009. Rather than modeling the network cumulatively, this study traces the evolution of the "here and now" using fixed-duration sliding windows. The analysis uses a suite of common network diagnostics, including the distributions of degrees, distances, and clustering, to track network structure. Several random models that call these diagnostics as parameters help tease them apart as factors from the values of others. Some behaviors are consistent over the entire interval, but most diagnostics indicate that the network's structural evolution is dominated by occasional dramatic shifts in otherwise steady trends. These behaviors are not distributed evenly across the network; stark differences in evolution can be observed between two major subnetworks, loosely thought of as "pure" and "applied", which approximately partition the aggregate. The paper characterizes two major events along the mathematics network trajectory and discusses possible explanatory factors.Comment: 30 pages, 14 figures, 1 table; supporting information: 5 pages, 5 figures; published in Scientometric

Age and growth rate estimations of the commercially fished gastropod Buccinum undatum

Calculating age and growth rate for the commercially important whelk, Buccinum undatum in the aid of fishery management has historically been undertaken using growth rings on the organic operculum. This is difficult due to their poor readability and confusion between two different sets of growth lines present. Recent work presented the calcium carbonate statolith as an alternative for age determination of B. undatum. Here we compare the use of statoliths and opercula, comparing their readability and creating growth curves for three distinct populations across the United Kingdom. Using these data, we also test the most appropriate growth equation to model this species. Lastly, we use oxygen isotope analysis of the shells to assign accurate ages to several individuals from each site. These data were used to test the accuracy of statolith and operculum ages. Statoliths, whilst more time consuming to process have improved clarity and accuracy compared with the opercula. This improved readability has highlighted that a Gompertz growth function should be used for populations of this species, when in past studies, von Bertalanffy is often used. Statoliths are a viable improvement to opercula when assessing B. undatum in the context of fishery monitoring and management

Age and growth rate estimations of the commercially fished gastropod Buccinum undatum

Calculating age and growth rate for the commercially important whelk, Buccinum undatum in the aid of fishery management has historically been undertaken using growth rings on the organic operculum. This is difficult due to their poor readability and confusion between two different sets of growth lines present. Recent work presented the calcium carbonate statolith as an alternative for age determination of B. undatum. Here we compare the use of statoliths and opercula, comparing their readability and creating growth curves for three distinct populations across the United Kingdom. Using these data, we also test the most appropriate growth equation to model this species. Lastly, we use oxygen isotope analysis of the shells to assign accurate ages to several individuals from each site. These data were used to test the accuracy of statolith and operculum ages. Statoliths, whilst more time consuming to process have improved clarity and accuracy compared with the opercula. This improved readability has highlighted that a Gompertz growth function should be used for populations of this species, when in past studies, von Bertalanffy is often used. Statoliths are a viable improvement to opercula when assessing B. undatum in the context of fishery monitoring and management

Hubble Space Telescope Imaging of Brightest Cluster Galaxies

We used the HST WFPC2 to obtain I-band images of the centers of 81 brightest cluster galaxies (BCGs), drawn from a volume-limited sample of nearby BCGs. The images show a rich variety of morphological features, including multiple or double nuclei, dust, stellar disks, point source nuclei, and central surface brightness depressions. High resolution surface brightness profiles could be inferred for 60 galaxies. Of those, 88% have well-resolved cores. Twelve percent of the BCG sample lacks a well-resolved core; all but one of these BCGs have ``power-law'' profiles. Some of these galaxies have higher luminosities than any power-law galaxy identified by Faber et al. (1997), and have physical upper limits on the break radius well below the values observed for core galaxies of the same luminosity. These results support the idea that the central structure of early-type galaxies is bimodal in its physical properties, but also suggest that there exist high luminosity galaxies with power-law profiles (or unusually small cores). The BCGs in the latter category tend to fall at the low end of the BCG luminosity function and tend to have low values of the quantity alpha (the logarithmic slope of the metric luminosity as a function of radius, at 10 kpc). Since theoretical calculations have shown that the luminosities and alpha values of BCGs grow with time as a result of accretion, this suggests a scenario in which elliptical galaxies evolve from power-law profiles to core profiles through accretion and merging. This is consistent with theoretical scenarios that invoke the formation of massive black hole binaries during merger events (Abridged).Comment: Accepted for publication in AJ. Postscript file with high resolution figures (1 and 3) is available at http://spider.ipac.caltech.edu/staff/seppo/bcgfig