Gaze-dependent topography in human posterior parietal cortex.

The brain must convert retinal coordinates into those required for directing an effector. One prominent theory holds that, through a combination of visual and motor/proprioceptive information, head-/body-centered representations are computed within the posterior parietal cortex (PPC). An alternative theory, supported by recent visual and saccade functional magnetic resonance imaging (fMRI) topographic mapping studies, suggests that PPC neurons provide a retinal/eye-centered coordinate system, in which the coding of a visual stimulus location and/or intended saccade endpoints should remain unaffected by changes in gaze position. To distinguish between a retinal/eye-centered and a head-/body-centered coordinate system, we measured how gaze direction affected the representation of visual space in the parietal cortex using fMRI. Subjects performed memory-guided saccades from a central starting point to locations “around the clock.” Starting points varied between left, central, and right gaze relative to the head-/body midline. We found that memory-guided saccadotopic maps throughout the PPC showed spatial reorganization with very subtle changes in starting gaze position, despite constant retinal input and eye movement metrics. Such a systematic shift is inconsistent with models arguing for a retinal/eye-centered coordinate system in the PPC, but it is consistent with head-/body-centered coordinate representations

Using Variable Natural Environment Brain-Computer Interface Stimuli for Real-time Humanoid Robot Navigation

This paper addresses the challenge of humanoid robot teleoperation in a natural indoor environment via a Brain-Computer Interface (BCI). We leverage deep Convolutional Neural Network (CNN) based image and signal understanding to facilitate both real-time bject detection and dry-Electroencephalography (EEG) based human cortical brain bio-signals decoding. We employ recent advances in dry-EEG technology to stream and collect the cortical waveforms from subjects while they fixate on variable Steady State Visual Evoked Potential (SSVEP) stimuli generated directly from the environment the robot is navigating. To these ends, we propose the use of novel variable BCI stimuli by utilising the real-time video streamed via the on-board robot camera as visual input for SSVEP, where the CNN detected natural scene objects are altered and flickered with differing frequencies (10Hz, 12Hz and 15Hz). These stimuli are not akin to traditional stimuli - as both the dimensions of the flicker regions and their on-screen position changes depending on the scene objects detected. On-screen object selection via such a dry-EEG enabled SSVEP methodology, facilitates the on-line decoding of human cortical brain signals, via a specialised secondary CNN, directly into teleoperation robot commands (approach object, move in a specific direction: right, left or back). This SSVEP decoding model is trained via a priori offline experimental data in which very similar visual input is present for all subjects. The resulting classification demonstrates high performance with mean accuracy of 85% for the real-time robot navigation experiment across multiple test subjects.Comment: Accepted as a full paper at the 2019 International Conference on Robotics and Automation (ICRA

Predictors of Improved Pain, Quality of Life, and Physical Function after Surgical Treatment of Lumbar Spinal Stenosis

Introduction: Degenerative lumbar stenosis is common in adults and is frequently managed by surgical intervention after non-operative measures fail to relieve pain. Limited evidence-based information regarding optimal selection of patients for surgery exists. Current reform in healthcare policy has sparked significant interest in comparative effectiveness research with the goal of optimizing treatment strategies for common conditions such as degenerative lumbar stenosis. The purpose of this study is to quantify the effectiveness of surgical treatment of lumbar stenosis and to identify patient predictors of greatest improvement using patient reported measures of pain, physical function and quality of life. Methods: A retrospective study evaluated 229 adult patients who underwent decompression with or without posterior lumbar fusion for treatment of lumbar stenosis over a two year time period. Patient reported outcomes were measured using the SF36 health survey. 146 patients had 6 month follow-up and 106 patients had one year follow-up. Variations in scores of the SF36 pain, mental component summary (MCS), and physical component summary (PCS) subscales were analyzed by multivariate linear regression analysis. Results: At 6-12 months post-surgery, patients reported an improvement of 8 points in average pain (32.3 to 40.4), physical function (28.6 to 36.9), and PCS (29.0 to 36.9) subscales of the SF36. There was a 6 point average improvement in MCS scores (41.8 to 48.10). Greater post-operative pain was significantly associated with smoking (p In regards to improvements in quality of life, older age (p Conclusion: In general, surgical treatment for lumbar stenosis improves patient pain, quality of life, and physical function as indicated by substantial improvement in all subscales of the SF36 health survey. Predictive factors associated with poor pain relief after surgery include smoking, diabetes, the presence of instrumentation, and re-operation within a 12 month time period. Higher MCS scores are seen in older patients and those with an increase in physical function post-operatively. Predictive factors for poor MCS scores include revision surgery and mental health diagnosis. No specific predictors of PCS score were identified, most likely due to the complicated nature of the patient population with lumbar spinal stenosis. Further work is necessary to determine the ideal surgical candidate

An imbalance between specialized pro-resolving lipid mediators and pro-inflammatory leukotrienes promotes instability of atherosclerotic plaques

Chronic unresolved inflammation plays a causal role in the development of advanced atherosclerosis, but the mechanisms that prevent resolution in atherosclerosis remain unclear. Here, we use targeted mass spectrometry to identify specialized pro-resolving lipid mediators (SPM) in histologically-defined stable and vulnerable regions of human carotid atherosclerotic plaques. The levels of SPMs, particularly resolvin D1 (RvD1), and the ratio of SPMs to pro-inflammatory leukotriene B4 (LTB₄), are significantly decreased in the vulnerable regions. SPMs are also decreased in advanced plaques of fat-fed Ldlr⁻/⁻ mice. Administration of RvD1 to these mice during plaque progression restores the RvD1:LTB₄ ratio to that of less advanced lesions and promotes plaque stability, including decreased lesional oxidative stress and necrosis, improved lesional efferocytosis, and thicker fibrous caps. These findings provide molecular support for the concept that defective inflammation resolution contributes to the formation of clinically dangerous plaques and offer a mechanistic rationale for SPM therapy to promote plaque stability

Cytological and transcript analyses reveal fat and lazy persister-like bacilli in tuberculous sputum

As nonreplicating tubercle bacilli are tolerant to the cidal action of antibiotics and resistant to multiple stresses, identification of this persister-like population of tubercle bacilli in sputum presents exciting and tractable new opportunities to investigate both responses to chemotherapy and the transmission of tuberculosis

Of “sluts” and “arseholes”: Antagonistic desire and the production of sexual vigilance

This article examines a contemporary antagonism in gendered safety discourses—the imperative to be free in public space against the obligation to be safe and “properly” feminine. We argue that this produces (and is produced by) contemporary rape culture, which might be contested through recourse to an agonistic ethic. Using qualitative interview data, we examine how participants contest victim-blaming discourses, while limiting how far they will accept the female body’s right to occupy public space. This article has significant implications for approaching social justice, in particular justice for women and their right to occupy public space

The DEEP Groth Strip Survey. I. The Sample

The Deep Extragalactic Exploratory Probe (DEEP) is a multi-phase research program dedicated to the study of the formation and evolution of galaxies and of large scale structure in the distant Universe. This paper describes the first five-year phase, denoted DEEP1. A series of ten DEEP1 papers will discuss a range of scientific topics (e.g., the study of photometric and spectral properties of a general distant galaxy survey, the evolution observed in galaxy populations of varied morphologies). The observational basis for these studies is the Groth Survey Strip field, a 127 square arcminute region which has been observed with the Hubble Space Telescope in both broad I-band and V-band optical filters and with the Low Resolution Imaging Spectrograph on the Keck Telescopes. Catalogs of photometric and structural parameters have been constructed for 11,547 galaxies and stars at magnitudes brighter than 29, and spectroscopy has been conducted for a magnitude-color weighted subsample of 818 objects. We evaluate three independent techniques for constructing an imaging catalog for the field from the HST data, and discuss the depth and sampling of the resultant catalogs. The selection of the spectroscopic subsample is discussed, and we describe the multifaceted approach taken to prioritizing objects of interest for a variety of scientific subprograms. A series of Monte Carlo simulations then demonstrates that the spectroscopic subsample can be adequately modeled as a simple function of magnitude and color cuts in the imaging catalog.Comment: ApJS accepted, 15 pages, 12 figures. Version with higher-quality figures available at http://astronomy.nmsu.edu/nicol