The amount of mental effort we invest in a task is influenced by the reward we can expect if we perform that task well. However, some of the rewards that have the greatest potential for driving these ...efforts are partly determined by factors beyond one's control. In such cases, effort has more limited efficacy for obtaining rewards. According to the Expected Value of Control theory, people integrate information about the expected reward and efficacy of task performance to determine the expected value of control, and then adjust their control allocation (i.e., mental effort) accordingly. Here we test this theory's key behavioral and neural predictions. We show that participants invest more cognitive control when this control is more rewarding and more efficacious, and that these incentive components separately modulate EEG signatures of incentive evaluation and proactive control allocation. Our findings support the prediction that people combine expectations of reward and efficacy to determine how much effort to invest.
The Asteroid Terrestrial-impact Last Alert System (ATLAS) observes most of the sky every night in search of dangerous asteroids. Its data are also used to search for photometric variability, where ...sensitivity to variability is limited by photometric accuracy. Since each exposure spans 7 6 corner to corner, variations in atmospheric transparency in excess of 0.01 mag are common, and 0.01 mag photometry cannot be achieved by using a constant flat-field calibration image. We therefore have assembled an all-sky reference catalog of approximately one billion stars to m ∼ 19 from a variety of sources to calibrate each exposure's astrometry and photometry. Gaia DR2 is the source of astrometry for this ATLAS Refcat2. The sources of g, r, i, and z photometry include Pan-STARRS DR1, the ATLAS Pathfinder photometry project, ATLAS reflattened APASS data, SkyMapper DR1, APASS DR9, the Tycho-2 catalog, and the Yale Bright Star Catalog. We have attempted to make this catalog at least 99% complete to m < 19, including the brightest stars in the sky. We believe that the systematic errors are no larger than 5 mmag rms, although errors are as large as 20 mmag in small patches near the Galactic plane.
More than 1000 published experimental data of gas (O2 and CO2) and vapor (H2O) permeability in nanocomposites containing either spherical, elongated or platelet particles were collected, assorted and ...compared in order to decipher the role of particle shape on the reduction of the relative permeability of the nanocomposite. It is well known that inclusion of homogeneously dispersed and oriented impermeable fillers with high aspect ratio, such as platelets or elongated particles, should significantly increase the diffusion path of gas and vapors and yield to improve barrier properties. Results revealed that this expected impact was not systematically achieved, even for impermeable lamellar fillers that usually displayed the highest aspect ratio. More specifically, an unexpected increase of the permeability in the nanocomposite was often observed. To explain this deviation of the ‘ideal behavior’, this paper discusses extensively the impact of the nanoparticle shape on the nanocomposite permeability along with structural aspects, related to both the particle nature and size, and the nanocomposite processing routes. Deviations from expected results of enhanced barrier effect are also discussed in correlation with unexpected variations in gas selectivity for O2/CO2 pair. Lastly, this review aims at drawing meaningful conclusions on the structure/mass transfer relationships and giving directions for the development of the next generation of packaging materials with tailored mass transfer properties.
•More than 1000 experimental data of O2, CO2 and H2O permeability are presented.•Impact of nanoparticle shape on permeability is analyzed.•Expected impact of tortuosity on permeability is not systematically achieved.•Selective transport characteristics of nanocomposites is discussed.•Meaningful conclusions on the structure/mass transfer relationship are offered.
The aryl hydrocarbon receptor (AHR) recognizes xenobiotics as well as natural compounds such as tryptophan metabolites, dietary components and microbiota-derived factors, and it is important for ...maintenance of homeostasis at mucosal surfaces. AHR activation induces cytochrome P4501 (CYP1) enzymes, which oxygenate AHR ligands, leading to their metabolic clearance and detoxification. Thus, CYP1 enzymes have an important feedback role that curtails the duration of AHR signalling, but it remains unclear whether they also regulate AHR ligand availability in vivo. Here we show that dysregulated expression of Cyp1a1 in mice depletes the reservoir of natural AHR ligands, generating a quasi AHR-deficient state. Constitutive expression of Cyp1a1 throughout the body or restricted specifically to intestinal epithelial cells resulted in loss of AHR-dependent type 3 innate lymphoid cells and T helper 17 cells and increased susceptibility to enteric infection. The deleterious effects of excessive AHR ligand degradation on intestinal immune functions could be counter-balanced by increasing the intake of AHR ligands in the diet. Thus, our data indicate that intestinal epithelial cells serve as gatekeepers for the supply of AHR ligands to the host and emphasize the importance of feedback control in modulating AHR pathway activation.
Major depressive disorder (MDD) is characterized by alterations in brain function that are identifiable also during the brain's 'resting state'. One functional network that is disrupted in this ...disorder is the default mode network (DMN), a set of large-scale connected brain regions that oscillate with low-frequency fluctuations and are more active during rest relative to a goal-directed task. Recent studies support the idea that the DMN is not a unitary system, but rather is composed of smaller and distinct functional subsystems that interact with each other. The functional relevance of these subsystems in depression, however, is unclear.
Here, we investigated the functional connectivity of distinct DMN subsystems and their interplay in depression using resting-state functional magnetic resonance imaging.
We show that patients with MDD exhibit increased within-network connectivity in posterior, ventral and core DMN subsystems along with reduced interplay from the anterior to the ventral DMN subsystems.
These data suggest that MDD is characterized by alterations of subsystems within the DMN as well as of their interactions. Our findings highlight a critical role of DMN circuitry in the pathophysiology of MDD, thus suggesting these subsystems as potential therapeutic targets.
In a phase 3 trial, patients with moderately to severely active ulcerative colitis were randomly assigned to receive placebo or ozanimod, a selective sphingosine-1-phosphate receptor modulator. ...Clinical remission was significantly greater with ozanimod during the induction and maintenance periods. The incidence of infection was higher with ozanimod than with placebo during maintenance.
Infrared thermography has been successfully adopted in the field of flow diagnostics over the last decades. Detecting the laminar-turbulent boundary layer transition through variations in the ...convective heat transfer is one of the primary applications due to its impact on the aerodynamic performance. Recent developments in fast-response infrared cameras allow unsteady measurement of fast-moving surfaces and moving transition positions, which must consider the thermal responsiveness of the surface material. Experimental results on moving boundary layer transition positions are highly valuable in the design and optimization of airfoils or rotor blades in unsteady applications, for example regarding helicopter main rotors in forward flight. This review article summarizes recent developments in steady and unsteady infrared thermography, particularly focusing on the development of differential infrared thermography (DIT). The new methods have also led to advances in the analysis of unmoving boundary layer transition for static airfoil test cases which were previously difficult to analyze using single-image methods.
Bile acids are synthesized from cholesterol in the liver and subjected to multiple metabolic biotransformations in hepatocytes, including oxidation by cytochromes P450 (CYPs) and conjugation with ...taurine, glycine, glucuronic acid, and sulfate. Mice and rats can hydroxylate chenodeoxycholic acid (CDCA) at the 6β-position to form α-muricholic acid (MCA) and ursodeoxycholic acid (UDCA) to form β-MCA. However, MCA is not formed in humans to any appreciable degree and the mechanism for this species difference is not known. Comparison of several Cyp-null mouse lines revealed that α-MCA and β-MCA were not detected in the liver samples from Cyp2c-cluster null (Cyp2c-null) mice. Global bile acid analysis further revealed the absence of MCAs and their conjugated derivatives, and high concentrations of CDCA and UDCA in Cyp2c-null mouse cecum and feces. Analysis of recombinant CYPs revealed that α-MCA and β-MCA were produced by oxidation of CDCA and UDCA by Cyp2c70, respectively. CYP2C9-humanized mice have similar bile acid metabolites as the Cyp2c-null mice, indicating that human CYP2C9 does not oxidize CDCA and UDCA, thus explaining the species differences in production of MCA. Because humans do not produce MCA, they lack tauro-β-MCA, a farnesoid X receptor antagonist in mouse that modulates obesity, insulin resistance, and hepatosteatosis.
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