Integration across time determines path deviation discrimination for moving objects.

YesBackground: Human vision is vital in determining our interaction with the outside world. In this study we characterize our ability to judge changes in the direction of motion of objects-a common task which can allow us either to intercept moving objects, or else avoid them if they pose a threat. Methodology/Principal Findings: Observers were presented with objects which moved across a computer monitor on a linear path until the midline, at which point they changed their direction of motion, and observers were required to judge the direction of change. In keeping with the variety of objects we encounter in the real world, we varied characteristics of the moving stimuli such as velocity, extent of motion path and the object size. Furthermore, we compared performance for moving objects with the ability of observers to detect a deviation in a line which formed the static trace of the motion path, since it has been suggested that a form of static memory trace may form the basis for these types of judgment. The static line judgments were well described by a 'scale invariant' model in which any two stimuli which possess the same two-dimensional geometry (length/width) result in the same level of performance. Performance for the moving objects was entirely different. Irrespective of the path length, object size or velocity of motion, path deviation thresholds depended simply upon the duration of the motion path in seconds. Conclusions/Significance: Human vision has long been known to integrate information across space in order to solve spatial tasks such as judgment of orientation or position. Here we demonstrate an intriguing mechanism which integrates direction information across time in order to optimize the judgment of path deviation for moving objects.Wellcome Trust, Leverhulme Trust, NI

Safety and efficacy of global intracoronary administration of cardiosphere-derived cells or conditioned medium immediately after coronary reperfusion in rats

Objective: Cardiosphere-derived cells (CDCs) have been shown to reduce infarct size after myocardial infarction (MI). In the present study we investigated the safety and efficacy of global intracoronary administration (GIA) of CDCs or CDC-conditioned medium (CM) immediately after reperfusion in a rat model of ischemia-reperfusion. Methods: CDCs were grown from myocardial biopsies obtained from male Wistar Kyoto rats (WKY). Female WKY rats underwent MI for 45minutes, followed by reperfusion for 1hour. Infarcted rats were randomized to receive GIA of CDCs (CDC group), CM (CM group) or vehicle (control group) immediately after the onset of reperfusion. Cell retention was quantified by PCR for the male specific SRY gene; area at risk (AR) and no reflow area (NR) were measured by histopathology. Cardiac function was evaluated by echocardiography at 1 and 2 months post-MI. Results: Cell retention at 1hour after GIA was 25.1% ±5.1. The myocardial AR and NR (measured at 1 hour post-reperfusion) were similar between groups [AR: 28.8% ±7.4 of LV mass in control vs 27.2% ±8 in CM vs 27% ±7 in CDCs group. NR: 7.0% ±3.3 in control vs 7.3% ±3.8 in CM vs 7.1% ±3.6 in CDCs]. One and 2 months post-MI, systolic function and LV volumes did not differ between control and CM groups. Conclusion: Intracoronary administration of CDCs during the acute phase of MI, at the beginning of reperfusion, does not aggravate microvascular obstruction and results in high cell retention. Delivery of CM in the acute phase of MI did not confer long-term cardiac functional benefits. © 2019 Hellenic Society of Cardiolog

Skeletal muscle microcirculatory abnormalities are associated with exercise intolerance, ventilatory inefficiency, and impaired autonomic control in heart failure

Background: Several skeletal muscle abnormalities have been identified in patients with chronic heart failure (CHF), including endothelial dysfunction. We hypothesized that skeletal muscle microcirculation, assessed by near-infrared spectroscopy (NIRS), is impaired in CHF patients and is associated with disease severity. Methods: Eighty-three stable patients with mildmoderate CHF (72 males, mean age 54 ± 14 years, body mass index 26.7 ± 3.4 kg/m 2) and 8 healthy subjects, matched for age, gender and body mass index, underwent NIRS with the vascular occlusion technique and cardiopulmonary exercise testing (CPET) evaluation on the same day. Tissue oxygen saturation (StO 2, %), defined as the percentage of hemoglobin saturation in the microvasculature compartments, was measured in the thenar muscle by NIRS before, during and after 3-minute occlusion of the brachial artery. Measurements included StO 2, oxygen consumption rate (OCR, %/min) and reperfusion rate (RR, %/min). All subjects underwent a symptom-limited CPET on a cycle ergometer. Measurements included VO 2 at peak exercise (VO 2peak, ml/kg/min) and anaerobic threshold (VO 2AT, ml/kg/min), VE/VCO 2 slope, chronotropic reserve (CR, %) and heart rate recovery (HRR 1, bpm). Results: CHF patients had significantly lower StO 2 (75 ± 8.2 vs 80.3 ± 6, p < 0.05), lower OCR (32.3 ± 10.4 vs 37.7 ± 5.5, p < 0.05) and lower RR (10 ± 2.8 vs 15.7 ± 6.3, p < 0.05) compared with healthy controls. CHF patients with RR <9.5 had a significantly greater VO 2peak (p < 0.001), VO 2AT (p < 0.01), CR (p = 0.01) and HRR 1 (p = 0.01), and lower VE/VCO 2 slope (p = 0.001), compared to those with RR <9.5. In a multivariate analysis, RR was identified as an independent predictor of VO 2peak, VE/VCO 2 slope and HRR 1. Conclusions: Peripheral muscle microcirculation, as assessed by NIRS, is significantly impaired in CHF patients and is associated with disease severity. © 2011 International Society for Heart and Lung Transplantation. All rights reserved

Exercise training improves characteristics of exercise oscillatory ventilation in chronic heart failure

Background Exercise oscillatory ventilation in chronic heart failure has been suggested as a factor related to adverse cardiac events, aggravated prognosis and higher mortality. Exercise training is well known to affect exercise capacity and mechanisms of pathophysiology beneficially in chronic heart failure. Little is known, however, about the exercise training effects on characteristics of exercise oscillatory ventilation in chronic heart failure patients. Design and methods Twenty (out of 38) stable chronic heart failure patients exhibited exercise oscillatory ventilation (age 54 ± 11 years, peak oxygen uptake 15.0 ± 5.0 ml/kg per minute). Patients attended 36 sessions of high intensity interval exercise. All patients underwent cardiopulmonary exercise testing before and after the programme. Assessment of exercise oscillatory ventilation was based on the amplitude of cyclic fluctuations in breathing during rest and exercise. All values are mean ± SD. Results Exercise training reduced (P < 0.05) the percentage of exercise oscillatory ventilation duration (79.0 ± 13.0 to 50.0 ± 25.0%), while average amplitude (5.2 ± 2.0 to 4.9 ± 1.6 L/minute) and length (44.0 ± 10.9 to 41.0 ± 6.7 seconds) did not change (P > 0.05). Exercise oscillatory ventilation patients also increased exercise capacity (P < 0.05). Conclusions A rehabilitation programme based on high intensity interval training improved exercise oscillatory ventilation observed in chronic heart failure patients, as well as cardiopulmonary efficiency and functional capacity. © European Society of Cardiology 2017

Salutary effects of the Pulvad, a novel implantable counterpulsation assist device, on cardiac mechanoenergetics

The Pressure Unloading Left Ventricular Assist Vevice (PULVAD) is a novel implantable counterpulsation LVAD, designed to provide ventricular unloading with augmentation of LV performance and retention of pulsatility. We assessed the effects of the PULVAD on hemodynamics and LV mechanoenergetics in seven farm pigs with acute ischemic heart failure. The PULVAD was implanted in the thorax and was connected to the ascending aorta. The PULVAD was pneumatically driven by a standard intra-aortic balloon pump console and was electrocardiogram-synchronized to provide LV pressure unloading along with diastolic aortic pressure augmentation. Hemodynamics, indices of LV mechanoenergetics, and coronary blood flow were measured without and after brief PULVAD support. PULVAD support decreased LV afterload and improved LV mechanical performance (increased ejection fraction, stroke volume, cardiac output and maximum elastance). The PULVAD concurrently reduced LV energy consumption (decreased stroke work and pressure-volume area) and optimized LV energetic performance (improved the ratio of stroke work to pressure-volume area). PULVAD support increased mean coronary blood flow, through dramatic augmentation of diastolic blood flow. In conclusion, the PULVAD unloads the failing LV, optimizes LV mechanoenergetics, and augments coronary blood flow. These salutary effects of short-term PULVAD support provide the foundation for long-term testing. © 2018 by the ASAIO

Typologie des zones rurales périurbaines et analyse de leur diversité : application à un ensemble de régions européennes - Projet NEWRUR - Rapport de recherche D 2.4

[Departement_IRSTEA]GT [TR1_IRSTEA]31 - RURAMEN / EDENNEWRUR first work-package results were a preliminary detection of periurban rural zones, notably based on population density of rural areas close to main urban zones, that led to select, in each country, NUTS 2 regions particularly faced with periurbanisation. NEWRUR second work-package aims are to characterise rural periurban zones more deeply, to precise their location and to express their diversity through typologies. Main issues of NEWRUR second work-package are first establishing in each selected region a periurbanisation gradient, that ranks rural areas on a scale of spatial and functional integration into urban-dominated systems. The periurbanisation gradient shows the diversity of rural periurban zones in terms of periurbanisation trends intensity. These issues are set out in D 2.2 research report. The diversity illustrated through periurbanisation gradients has then been integrated into more general analyses of diversity factors prevailing in rural periurban zones. Results of these analyses and their issues in terms of typologies of rural periurban zones are presented in this D 2.4 research report.In parallel with those taken into account in the periurbanisation gradients, the main diversity factors of rural periurban zones have been illustrated through many statistical indicators, that concern as much demography, employment or economic activities as land uses or way of life of inhabitants. Finally, the typologies based on these indicators show different kinds of combination of these factors and make it possible to prioritize some factors: they reveal other differentiations that those expressed through the periurbanisation gradients.La première phase de ce travail de recherche avait permis d'établir un premier repérage des zones rurales périurbaines, basé notamment sur des critères de densité de population des espaces ruraux proches des grandes agglomérations urbaines, et de sélectionner dans chaque pays des régions NUTS 2 particulièrement concernées par la périurbanisation. La seconde phase vise à caractériser de manière plus complète ces zones périurbaines de façon à affiner le repérage de celles-ci et à en exprimer la diversité en établissant des typologies.Les résultats de cette seconde phase de la recherche sont d'abord la mise en évidence dans les régions étudiées de gradients de périurbanisation, permettant de situer les zones rurales sur une échelle croissante d'intégration spatiale et fonctionnelle dans des systèmes à dominante urbaine et donc d'apprécier la diversité des zones rurales périurbaines en termes d'intensité des processus de périurbanisation. Ces résultats sont consignés dans le rapport de recherche D 2.2. La diversité des zones rurales périurbaines attestée par le gradient de périurbanisation a été ensuite replacée dans des analyses plus générales des facteurs de diversité des zones périurbaines. Les résultats de ces analyses et les typologies des zones périurbaines qu'elles ont permis d'établir sont présentés dans ce rapport D 2.4. Parallèlement à ceux pris en compte dans les gradients de périurbanisation, les facteurs de diversité essentiels des zones rurales périurbaines ont été illustrés par de nombreux indicateurs statistiques, concernant aussi bien la démographie ou les emplois et les activités économiques exercées que les modes d'occupation de l'espace ou les conditions de vie des habitants. En définitive, les typologies établies permettent de situer les façons dont se combinent les divers facteurs étudiés et de les hiérarchiser, en faisant apparaître d'autres différenciations que celles traduites par les gradients de périurbanisation

Bone mass loss in chronic heart failure is associated with secondary hyperparathyroidism and has prognostic significance

Aims: Chronic heart failure (CHF) is associated with increased risk of osteoporosis. We investigated the relationship between severity of CHF and bone loss, underlying pathophysiological mechanisms, and the prognostic significance of bone mass changes in heart failure. Methods and results: Total body (TB) and femoral (F) bone mineral density (BMD), and T- and Z-scores in the femur were measured in 60 men with CHF (56 ± 11 years) and 13 age-matched men free from CHF. The composite study endpoint was death, implantation of a left ventricular assist device (LVAD), or inotrope dependency during a median 2-year follow-up. Parathyroid hormone (PTH) and vitamin D were measured in all subjects. TBBMD, FBMD, T-score, and Z-score were significantly lower in men with CHF. Their PTH levels were also significantly increased (111 ± 59 vs. 39 ± 14; P < 0.001). Patients in New York Heart Association classes IIIIV compared with those in classes III demonstrated significantly lower TBBMD, FBMD, T-score, and Z-score, and higher PTH (136 ± 69 vs. 86 ± 31; P = 0.001). Increased PTH levels were correlated with reduced TBBMD (P = 0.003), FBMD (P = 0.002), and femur T-score (P = 0.001), reduced cardiac index (P = 0.01) and VO 2 peak (P < 0.0001), and increased wedge pressure (P = 0.001). Low TBBMD [hazard ratio (HR) 0.003, 95% confidence interval (CI) 0.00-0.58; P = 0.03] and Z-score (HR 0.56, 95% CI 0.35-0.90; P = 0.017) were associated with adverse outcome. Conclusions: Secondary hyperparathyroidism and reduction in bone density occur in CHF patients and are associated with disease severity. Increased bone mass loss in CHF has prognostic significance. © The Author 2012