A dynamic code for economic object valuation in prefrontal cortex neurons.

Neuronal reward valuations provide the physiological basis for economic behaviour. Yet, how such valuations are converted to economic decisions remains unclear. Here we show that the dorsolateral prefrontal cortex (DLPFC) implements a flexible value code based on object-specific valuations by single neurons. As monkeys perform a reward-based foraging task, individual DLPFC neurons signal the value of specific choice objects derived from recent experience. These neuronal object values satisfy principles of competitive choice mechanisms, track performance fluctuations and follow predictions of a classical behavioural model (Herrnstein's matching law). Individual neurons dynamically encode both, the updating of object values from recently experienced rewards, and their subsequent conversion to object choices during decision-making. Decoding from unselected populations enables a read-out of motivational and decision variables not emphasized by individual neurons. These findings suggest a dynamic single-neuron and population value code in DLPFC that advances from reward experiences to economic object values and future choices.Wellcome Trust, Behavioural and Clinical Neuroscience Institute (BCNI) Cambridg

Measuring the flatness of focal plane for very large mosaic CCD camera

Large mosaic multiCCD camera is the key instrument for modern digital sky survey. DECam is an extremely red sensitive 520 Megapixel camera designed for the incoming Dark Energy Survey (DES). It is consist of sixty two 4k$\times$2k and twelve 2k x 2k 250-micron thick fully-depleted CCDs, with a focal plane of 44 cm in diameter and a field of view of 2.2 square degree. It will be attached to the Blanco 4-meter telescope at CTIO. The DES will cover 5000 square-degrees of the southern galactic cap in 5 color bands (g, r, i, z, Y) in 5 years starting from 2011. To achieve the science goal of constraining the Dark Energy evolution, stringent requirements are laid down for the design of DECam. Among them, the flatness of the focal plane needs to be controlled within a 60-micron envelope in order to achieve the specified PSF variation limit. It is very challenging to measure the flatness of the focal plane to such precision when it is placed in a high vacuum dewar at 173 K. We developed two image based techniques to measure the flatness of the focal plane. By imaging a regular grid of dots on the focal plane, the CCD offset along the optical axis is converted to the variation the grid spacings at different positions on the focal plane. After extracting the patterns and comparing the change in spacings, we can measure the flatness to high precision. In method 1, the regular dots are kept in high sub micron precision and cover the whole focal plane. In method 2, no high precision for the grid is required. Instead, we use a precise XY stage moves the pattern across the whole focal plane and comparing the variations of the spacing when it is imaged by different CCDs. Simulation and real measurements show that the two methods work very well for our purpose, and are in good agreement with the direct optical measurements.Comment: Presented at SPIE Conference,Ground-based and Airborne Instrumentation for Astronomy III, San Diego, 201

Influence of ractopamine supplementation on Salmonella in feeder pigs

The objective of the current study was to determine the effect of ractopamine supplementation on gut populations and fecal shedding of Salmonella in growing pigs

The Effects of Escalation of Respiratory Support and Prolonged Invasive Ventilation on Outcomes of Cardiac Surgical Patients: A Retrospective Cohort Study

Abstract Objectives: The aim of this study was to determine the effects of escalation of respiratory support and prolonged postoperative invasive ventilation on patient–centered outcomes, and identify perioperative factors associated with these two respiratory complications. Design: A retrospective cohort analysis of cardiac surgical patients admitted to cardiothoracic intensive care unit (ICU) between August 2015 and January 2018. Escalation of respiratory support was defined as ‘unplanned continuous positive airway pressure’, ‘non-invasive ventilation’ or ‘reintubation’ following surgery; prolonged invasive ventilation was defined as ‘invasive ventilation beyond the first 12 hours following surgery’. The primary endpoint was the composite of escalation of respiratory support and prolonged ventilation. Setting: Tertiary cardiothoracic ICU. Participants: A total of 2,098 patients were included and analyzed. Interventions: None. Measurements and Main Results: The composite of escalation of support or prolonged ventilation occurred in 509 patients (24.3%). Patients who met the composite had higher mortality (2.9% vs 0.1%; P<0.001) and longer median [interquartile range] length of ICU (2.1 [1.0–4.9] vs 0.9 [0.8–1.0] days; P<0.0001) and hospital (10.6 [8.0–16.0] vs 7.2 [6.2–10.0] days; P<0.0001) stay. Hypoxemia and anemia on admission to ICU were the only two factors independently associated with need for escalation of respiratory support or prolonged invasive ventilation. Conclusions: Escalation of respiratory support or prolonged invasive ventilation are frequently seen in cardiac surgery patients, and are highly associated with increased mortality and morbidity. Hypoxemia and anemia on admission to ICU are potentially modifiable factors associated with escalation of respiratory support or prolonged invasive ventilation.ACM is supported by a Clinical Research Career Development Fellowship from the Wellcome Trust (WT 2055214/Z/16/Z). VZ is supported by an Academic Clinical Fellowship from the National Institute for Health Research (ACF-2016-09-011)