Anxiety and amygdala connectivity during movie-watching

Rodent and human studies have implicated an amygdala-prefrontal circuit during threat processing. One possibility is that while amygdala activity underlies core features of anxiety (e.g. detection of salient information), prefrontal cortices (i.e. dorsomedial prefrontal/anterior cingulate cortex) entrain its responsiveness. To date, this has been established in tightly controlled paradigms (predominantly using static face perception tasks) but has not been extended to more naturalistic settings. Consequently, using ‘movie fMRI’—in which participants watch ecologically-rich movie stimuli rather than constrained cognitive tasks—we sought to test whether individual differences in anxiety correlate with the degree of face-dependent amygdala-prefrontal coupling in two independent samples. Analyses suggested increased face-dependent superior parietal activation and decreased speech-dependent auditory cortex activation as a function of anxiety. However, we failed to find evidence for anxiety-dependent connectivity, neither in our stimulus-dependent or -independent analyses. Our findings suggest that work using experimentally constrained tasks may not replicate in more ecologically valid settings and, moreover, highlight the importance of testing the generalizability of neuroimaging findings outside of the original context

Uncertainty Quantification Visualization Tool to Simulate Porous Lithium-Ion Batteries

To maintain people’s fast-paced lifestyles, a more powerful and reliable rechargeable battery is critical. During the manufacturing process, electrode parameters such as cathode thickness, the porosity of the positive electrode and radius of negative active materials are subject to uncertainty. Such uncertainty may have a dramatic impact on the performance of the battery. To optimize its performance, it is critical to quantify uncertainty due to variation in electrode parameters and measure the response of the system through multiscale computer simulation. To achieve this goal, a porous lithium-ion battery uncertainty quantification and visualization tool has been created. This tool consists of three components: 1) a generator of uncertainty input; 2) an electrochemical system simulator; 3) a statistical analysis and visualization module. This project focuses on the first and the third components. First, the uncertainty input generator provides the option of selecting one of two statistical models for the input parameter distributions: Gaussian and lognormal. For Gaussian and lognormal distributions, sample points and weights are generated based on Gauss-Hermite quadrature formula. Each module provides a GUI, built using an open source, class-oriented environment, the Virtual Kinetics of Materials Lab [1]. Ensemble simulations are performed using the electrochemical system simulator that in turn uses the data distributions obtained from the uncertainty input generator. In the statistics analysis and visualization component, the simulation results are quantified graphically through error bar plots that visualize the impact of the uncertainties that were introduced into the system. The variation of power and energy densities as a function of current density of the battery electrode is presented, enabling the user to visualize the uncertainty propagation from the three electrode uncertainty inputs and its impact on the battery performance. [1] Alex Bartol; R. Edwin García; David R. Ely; Jon Guyer (2015), The Virtual Kinetics of Materials Laboratory, https://nanohub.org/resources/vkmllive. (DOI: 10.4231/D3B853J85)

Tailored stereotactic radiotherapy technique using deep inspiration breath-hold to reduce stomach dose for cardiac radioablation

PURPOSE: To provide a new insight on a novel safe cardiac radioablation using deep inspiration breath-hold (DIBH) to reduce gastrointestinal dose. MATERIALS AND METHODS: For treating incessant ventricular tachycardia (VT) originated from left ventricle inferior scar abutting the stomach, a target delineation and treatment planning for cardiac radioablation was performed. With four different computed tomography (CT) scan protocols-DIBH, full expiration breath-hold, four-dimensional (4D) CT without and with abdominal compression, the distances between the target and the stomach were compared. RESULTS: Among the protocols, the CT scan with DIBH showed largest distance between the target and the stomach and selected for the treatment planning. The prescribed dose was 25 Gy in a single fraction, and satisfactory dosimetric parameters were achieved with the DIBH. The patient was successfully treated with the DIBH, and experienced no acute toxicity. CONCLUSION: To gain the best benefit from cardiac radioablation, understanding the possible toxicity in the adjacent organs is crucial. By moving the heart with thoraco-diaphragmatic movement by DIBH, the target could be physically separated from the stomach

Parton Distributions in Light-Cone Gauge: Where Are the Final-State Interactions?

We show that the final-state interaction effects in the single target spin asymmetry discovered by Brodsky et al. can be reproduced by either a standard light-cone gauge definition of the parton distributions with a prescription of the light-cone singularities consistent with the light-cone gauge link, or a modified light-cone gauge definition with a gauge link involving the gauge potential at the spatial infinity.Comment: 9 pages, 2 figures, additional results are adde

Fossil AGN jets as ultra high energy particle accelerators

Remnants of AGN jets and their surrounding cocoons leave colossal magnetohydrodynamic (MHD) fossil structures storing total energies ~10^{60} erg. The original active galacic nucleus (AGN) may be dead but the fossil will retain its stable configuration resembling the reversed-field pinch (RFP) encountered in laboratory MHD experiments. In an RFP the longitudinal magnetic field changes direction at a critical distance from the axis, leading to magnetic re-connection there, and to slow decay of the large-scale RFP field. We show that this field decay induces large-scale electric fields which can accelerate cosmic rays with an E^{-2} power-law up to ultra-high energies with a cut-off depending on the fossil parameters. The cut-off is expected to be rigidity dependent, implying the observed composition would change from light to heavy close to the cut-off if one or two nearby AGN fossils dominate. Given that several percent of the universe's volume may house such slowly decaying structures, these fossils may even re-energize ultra-high energy cosmic rays from distant/old sources, offsetting the ``GZK-losses'' due to interactions with photons of the cosmic microwave background radiation and giving evidence of otherwise undetectable fossils. In this case the composition would remain light to the highest energies if distant sources or fossils dominated, but otherwise would be mixed. It is hoped the new generation of cosmic ray experiments such as the Pierre Auger Observatory and ultra-high energy neutrino telescopes such as ANITA and lunar Cherenkov experiments will clarify this.Comment: 11 pages, 6 figures, additional references and explanations. Accepted for publication in MNRA

Definitive evidence for fast electron transfer at pristine basal plane graphite from high-resolution electrochemical imaging

After all, it's active: High-resolution scanning electrochemical cell microscopy (SECCM) demonstrates that electron transfer at the basal plane of highly oriented pyrolytic graphite (HOPG) is fast. This finding requires radical revision of the current textbook model for HOPG electrochemistry

On the Fundamental Mass-Period Functions of Extrasolar Planets

Employing a catalog of 175 extrasolar planets (exoplanets) detected by the Doppler-shift method, we constructed the independent and coupled mass-period functions. It is the first time in this field that the selection effect is considered in the coupled mass-period functions. Our results are consistent with those in Tabachnik and Tremaine (2002) with the major differences that we obtain a flatter mass function but a steeper period function. Moreover, our coupled mass-period functions show that about 2.5 percent of stars would have a planet with mass between Earth Mass and Neptune Mass, and about 3 percent of stars would have a planet with mass between Neptune Mass and Jupiter Mass.Comment: Accepted by ApJ Supplement Series in Nov. 2009, Acknowledgment added in Dec. 2009, a Reference-Based Catalog of Exoplanets can be obtained electronically from Appendix A of the latex file or from the authors for further studies

MR Imaging Features of Obturator Internus Bursa of the Hip

The authors report two cases with distension of the obturator internus bursa identified on MR images, and describe the location and characteristic features of obturator internus bursitis; the "boomerang"-shaped fluid distension between the obturator internus tendon and the posterior grooved surface of the ischium