1,794 research outputs found

    Anatomical pathways for auditory memory II: information from rostral superior temporal gyrus to dorsolateral temporal pole and medial temporal cortex

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    Auditory recognition memory in non-human primates differs from recognition memory in other sensory systems. Monkeys learn the rule for visual and tactile delayed matching-to-sample within a few sessions, and then show one-trial recognition memory lasting 10–20 min. In contrast, monkeys require hundreds of sessions to master the rule for auditory recognition, and then show retention lasting no longer than 30–40 s. Moreover, unlike the severe effects of rhinal lesions on visual memory, such lesions have no effect on the monkeys' auditory memory performance. The anatomical pathways for auditory memory may differ from those in vision. Long-term visual recognition memory requires anatomical connections from the visual association area TE with areas 35 and 36 of the perirhinal cortex (PRC). We examined whether there is a similar anatomical route for auditory processing, or that poor auditory recognition memory may reflect the lack of such a pathway. Our hypothesis is that an auditory pathway for recognition memory originates in the higher order processing areas of the rostral superior temporal gyrus (rSTG), and then connects via the dorsolateral temporal pole to access the rhinal cortex of the medial temporal lobe. To test this, we placed retrograde (3% FB and 2% DY) and anterograde (10% BDA 10,000 mW) tracer injections in rSTG and the dorsolateral area 38DL of the temporal pole. Results showed that area 38DL receives dense projections from auditory association areas Ts1, TAa, TPO of the rSTG, from the rostral parabelt and, to a lesser extent, from areas Ts2-3 and PGa. In turn, area 38DL projects densely to area 35 of PRC, entorhinal cortex (EC), and to areas TH/TF of the posterior parahippocampal cortex. Significantly, this projection avoids most of area 36r/c of PRC. This anatomical arrangement may contribute to our understanding of the poor auditory memory of rhesus monkeys

    Rectification from Radially-Distorted Scales

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    This paper introduces the first minimal solvers that jointly estimate lens distortion and affine rectification from repetitions of rigidly transformed coplanar local features. The proposed solvers incorporate lens distortion into the camera model and extend accurate rectification to wide-angle images that contain nearly any type of coplanar repeated content. We demonstrate a principled approach to generating stable minimal solvers by the Grobner basis method, which is accomplished by sampling feasible monomial bases to maximize numerical stability. Synthetic and real-image experiments confirm that the solvers give accurate rectifications from noisy measurements when used in a RANSAC-based estimator. The proposed solvers demonstrate superior robustness to noise compared to the state-of-the-art. The solvers work on scenes without straight lines and, in general, relax the strong assumptions on scene content made by the state-of-the-art. Accurate rectifications on imagery that was taken with narrow focal length to near fish-eye lenses demonstrate the wide applicability of the proposed method. The method is fully automated, and the code is publicly available at https://github.com/prittjam/repeats.Comment: pre-prin

    2-year outcomes for transcatheter repair in patients with functional mitral regurgitation from the CLASP study

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    Background: Transcatheter mitral valve repair has emerged as a favourable option in patient care for treating functional mitral regurgitation (FMR) with a need for longer term data. We herein report two-year outcomes from the FMR group of the multicentre, prospective, single arm CLASP study with the PASCAL transcatheter valve repair system. Methods: Patients with symptomatic, clinically significant FMR ≥3+ as evaluated by the core laboratory and deemed candidates for transcatheter repair by the local heart team were eligible for the study. Follow-up was conducted at 30 days, one year, and two years with echocardiographic outcomes evaluated by the core laboratory at all timepoints and major adverse events (MAEs) evaluated by an independent clinical events committee to one year (site-reported thereafter). Results: Eighty-five FMR patients were treated with mean age 72 years, 55% male, 65% in NYHA Class III-IVa, 37% LVEF, and 100% MR grade ≥3+. Successful implantation was achieved in 96% of patients. MAEs included one cardiovascular mortality (1.2%) and one conversion tomitral valve replacement surgery (1.2%) at 30 days, and two reinterventions between 30 days and two years. Kaplan-Meier (KM) estimates for survival were 88% at one year and 72% at two years. Freedom from heart failure (HF) rehospitalization KM estimates were 81% at one year and 78% for two years. The reduction in annualized HF hospitalization rate was 81% at two years (p\u3c0.001). MR ≤1+ was achieved in 73% of patients at 30 days, 75% at one year, and 84% at two years; MR ≤2+ was achieved in 96% of patients at 30 days, 100% at one year, and 95% two years (all p\u3c0.001). Mean LVEDV of 199 mL at baseline decreased by 9 mL at 30 days (p=0.039), 29 mL at one year (p\u3c0.001), and 31 mL at two years (p\u3c0.001). NYHA class I/II was achieved in 87% of patients at 30 days, 86% at one year, and 88% at two years (all p\u3c0.001). Six-minute walk distance (6MWD) improved by 22 m at 30 days (p=0.004) and 40 m at one year (p=0.003). Kansas City Cardiomyopathy Questionnaire (KCCQ) score improved by 16 points at 30 days and one year (all p\u3c0.001). Conclusions: In the CLASP study, the PASCAL transcatheter valve repair system demonstrated sustained favourable outcomes at two years in patients with FMR. Results showed a high survival rate of 72% and freedom from HF rehospitalization of 78% at two years. An 81% reduction in annualized HF hospitalization rate was observed. At two years, sustained MR reduction of MR ≤2+ was achieved in 95% andMR ≤1+ in 84% of patients, with evidence of left ventricular reverse remodelling. Improvements in functional status were significant and sustained at two years. The CLASP IIF randomized pivotal trial is ongoing

    Exogenous spatial precuing reliably modulates object processing but not object substitution masking

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    Object substitution masking (OSM) is used in behavioral and imaging studies to investigate processes associated with the formation of a conscious percept. Reportedly, OSM occurs only when visual attention is diffusely spread over a search display or focused away from the target location. Indeed, the presumed role of spatial attention is central to theoretical accounts of OSM and of visual processing more generally (Di Lollo, Enns, & Rensink, Journal of Experimental Psychology: General 129:481–507, 2000). We report a series of five experiments in which valid spatial precuing is shown to enhance the ability of participants to accurately report a target but, in most cases, without affecting OSM. In only one experiment (Experiment 5) was a significant effect of precuing observed on masking. This is in contrast to the reliable effect shown across all five experiments in which precuing improved overall performance. The results are convergent with recent findings from Argyropoulos, Gellatly, and Pilling (Journal of Experimental Psychology: Human Perception and Performance 39:646–661, 2013), which show that OSM is independent of the number of distractor items in a display. Our results demonstrate that OSM can operate independently of focal attention. Previous claims of the strong interrelationship between OSM and spatial attention are likely to have arisen from ceiling or floor artifacts that restricted measurable performance

    Gold as a Tool for Hedging Financial Risks

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    The article discusses gold as a protective asset, which claims to be a high-efficiency tool for hedging financial risks. In the introductory part the general characteristics of hedging as a method of full or partial risk elimination is given, and the main known types of risk hedging typical for a financial asset portfolio holder are considered. Further, dynamics of the world prices for gold is analyzed in a historical retrospective, whereby the conclusion is drawn on a tendency of this asset to grow during the periods of financial instability, and also if new financial assets appear. In the final part of the article the assessment of gold as a tool for hedging financial risks is given

    The macroeconomics of a financial Dutch disease

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    We describe the medium-run macroeconomic effects and long-run development consequences of a financial Dutch disease that may take place in a small developing country with abundant natural resources. The first move is in financial markets. An initial surge in foreign direct investment targeting natural resources sets in motion a perverse cycle between exchange rate appreciation and mounting short- and medium-term capital flows. Such a spiral easily leads to exchange rate volatility, capital reversals, and sharp macroeconomic instability. In the long run, macroeconomic instability and overdependence on natural resource exports dampen the development of nontraditional tradable goods sectors and curtail labor productivity dynamics. We advise the introduction of constraints to short- and medium-term capital flows to tame exchange rate/capital flows boom-and-bust cycles. We support the implementation of a developmentalist monetary policy targeting competitive nominal and real exchange rates in order to encourage product and export diversification

    Issues of geologically-focused situational awareness in robotic planetary missions: lessons from an analogue mission at Mistastin Lake impact structure, Labrador, Canada

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    Remote robotic data provides different information than that obtained from immersion in the field. This significantly affects the geological situational awareness experienced by members of a mission control science team. In order to optimize science return from planetary robotic missions, these limitations must be understood and their effects mitigated to fully leverage the field experience of scientists at mission control. Results from a 13-day analogue deployment at the Mistastin Lake impact structure in Labrador, Canada suggest that scale, relief, geological detail, and time are intertwined issues that impact the mission control science team‟s effectiveness in interpreting the geology of an area. These issues are evaluated and several mitigation options are suggested. Scale was found to be difficult to interpret without the reference of known objects, even when numerical scale data were available. For this reason, embedding intuitive scale-indicating features into image data is recommended. Since relief is not conveyed in 2D images, both 3D data and observations from multiple angles are required. Furthermore, the 3D data must be observed in animation or as anaglyphs, since without such assistance much of the relief information in 3D data is not communicated. Geological detail may also be missed due to the time required to collect, analyze, and request data. We also suggest that these issues can be addressed, in part, by an improved understanding of the operational time costs and benefits of scientific data collection. Robotic activities operate on inherently slow time-scales. This fact needs to be embraced and accommodated. Instead of focusing too quickly on the details of a target of interest, thereby potentially minimizing science return, time should be allocated at first to more broad data collection at that target, including preliminary surveys, multiple observations from various vantage points, and progressively smaller scale of focus. This operational model more closely follows techniques employed by field geologists and is fundamental to the geologic interpretation of an area. Even so, an operational time cost/benefit analyses should be carefully considered in each situation, to determine when such comprehensive data collection would maximize the science return. Finally, it should be recognized that analogue deployments cannot faithfully model the time scales of robotic planetary missions. Analogue missions are limited by the difficulty and expense of fieldwork. Thus, analogue deployments should focus on smaller aspects of robotic missions and test components in a modular way (e.g., dropping communications constraints, limiting mission scope, focusing on a specific problem, spreading the mission over several field seasons, etc.)
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