Constraints on the mass and atmospheric composition and evolution of the low-density young planet DS Tuc A b

We performed a radial velocity (RV) monitoring of the 40 Myr old star DS Tuc A with HARPS at the ESO-3.6m to determine the planetary mass of its 8.14-days planet, first revealed by TESS. We also observed two planetary transits with HARPS and ESPRESSO at ESO-VLT, to measure the Rossiter-McLaughlin (RM) effect and characterise the planetary atmosphere. We measured the high-energy emission of the host with XMM observations to investigate models for atmospheric evaporation. We employed Gaussian Processes (GP) regression to model the high level of the stellar activity, which is more than 40 times larger than the expected RV planetary signal. We extracted the transmission spectrum of DS Tuc A b from the ESPRESSO data and searched for atmospheric elements/molecules either by single-line retrieval and by performing cross-correlation with a set of theoretical templates. Through a set of simulations, we evaluated different scenarios for the atmospheric photo-evaporation of the planet induced by the strong XUV stellar irradiation. While the stellar activity prevented us from obtaining a clear detection of the planetary signal from the RVs, we set a robust mass upper limit of 14.4 M_e for DS Tuc A b. We also confirm that the planetary system is almost (but not perfectly) aligned. The strong level of stellar activity hampers the detection of any atmospheric compounds, in line with other studies presented in the literature. The expected evolution of DS Tuc A b from our grid of models indicates that the planetary radius after the photo-evaporation phase will fall within the Fulton gap. The comparison of the available parameters of known young transiting planets with the distribution of their mature counterpart confirms that the former are characterised by a low density, with DS Tuc A b being one of the less dense.Comment: 24 pages, 19 figures, Accepted for publication on Astronomy and Astrophysic

Exploring the potential of using a text-based game to inform simulation models of risky migration decisions

Background: In this paper, we explore the potential of games to collect empirical data for informing agent-based simulation models of migration. To examine the usefulness of game-based approaches, we conducted a simple, yet carefully designed psychological experiment. Methods: In a preregistered study, we used a novel, immersive experimental setting to investigate the risky migration decisions made by migrants and non-migrants. Participants (284 migrants and 284 non-migrants) played a choice-based interactive fiction game—a fully text-based game where players progress by selecting from a list of possible actions—that involved making three risky migration decisions. In one condition, participants were shown a non-linear progress bar and explicit acknowledgements of the choices they made to promote perceived agency: the feeling that one’s actions have a non-trivial impact on the game. In the other condition, the progress bar was linear, and the explicit acknowledgements were omitted. Results: Our experimental manipulation was successful; participants in the former condition self-reported higher perceived agency than participants in the latter condition, as did migrants compared to non-migrants. Nevertheless, condition and migrant status did not meaningfully affect the risky migration decisions participants made in the game. Conclusion: These findings indicate that the results of generic studies on risky migration decisions conducted on non-migrants can potentially inform simulation models of migration. However, these findings were obtained from a single experiment, and thus warrant replication and further research before definitive conclusions can be drawn. Furthermore, a simple text-based game may be too superficial to allow deep insights into the idiosyncrasies of migration decision-making. This suggests a possible trade-off between clear interpretability of the results and the usefulness for informing simulation models of complex social processes, such as migration

ARES. III. Unveiling the Two Faces of KELT-7 b with HST WFC3*

We present the analysis of the hot-Jupiter KELT-7 b using transmission and emission spectroscopy from the Hubble Space Telescope, both taken with the Wide Field Camera 3. Our study uncovers a rich transmission spectrum that is consistent with a cloud-free atmosphere and suggests the presence of H_{2}O and H^{−}. In contrast, the extracted emission spectrum does not contain strong absorption features and, although it is not consistent with a simple blackbody, it can be explained by a varying temperature–pressure profile, collision induced absorption, and H^{-}. KELT-7 b had also been studied with other space-based instruments and we explore the effects of introducing these additional data sets. Further observations with Hubble, or the next generation of space-based telescopes, are needed to allow for the optical opacity source in transmission to be confirmed and for molecular features to be disentangled in emission

Acute escitalopram treatment inhibits REM sleep rebound and activation of MCH-expressing neurons in the lateral hypothalamus after long term selective REM sleep deprivation.

RATIONALE: Selective rapid eye movement sleep (REMS) deprivation using the platform-on-water ("flower pot") method causes sleep rebound with increased REMS, decreased REMS latency, and activation of the melanin-concentrating hormone (MCH) expressing neurons in the hypothalamus. MCH is implicated in the pathomechanism of depression regarding its influence on mood, feeding behavior, and REMS. OBJECTIVES: We investigated the effects of the most selective serotonin reuptake inhibitor escitalopram on sleep rebound following REMS deprivation and, in parallel, on the activation of MCH-containing neurons. METHODS: Escitalopram or vehicle (10 mg/kg, intraperitoneally) was administered to REMS-deprived (72 h) or home cage male Wistar rats. During the 3-h-long "rebound sleep", electroencephalography was recorded, followed by an MCH/Fos double immunohistochemistry. RESULTS: During REMS rebound, the time spent in REMS and the number of MCH/Fos double-labeled neurons in the lateral hypothalamus increased markedly, and REMS latency showed a significant decrease. All these effects of REMS deprivation were significantly attenuated by escitalopram treatment. Besides the REMS-suppressing effects, escitalopram caused an increase in amount of and decrease in latency of slow wave sleep during the rebound. CONCLUSIONS: These results show that despite the high REMS pressure caused by REMS deprivation procedure, escitalopram has the ability to suppress REMS rebound, as well as to diminish the activation of MCH-containing neurons, in parallel. Escitalopram caused a shift from REMS to slow wave sleep during the rebound. Furthermore, these data point to the potential connection between the serotonergic system and MCH in sleep regulation, which can be relevant in depression and in other mood disorders

Cascade of Neural Events Leading from Error Commission to Subsequent Awareness Revealed Using EEG Source Imaging

The goal of the present study was to shed light on the respective contributions of three important action monitoring brain regions (i.e. cingulate cortex, insula, and orbitofrontal cortex) during the conscious detection of response errors. To this end, fourteen healthy adults performed a speeded Go/Nogo task comprising Nogo trials of varying levels of difficulty, designed to elicit aware and unaware errors. Error awareness was indicated by participants with a second key press after the target key press. Meanwhile, electromyogram (EMG) from the response hand was recorded in addition to high-density scalp electroencephalogram (EEG). In the EMG-locked grand averages, aware errors clearly elicited an error-related negativity (ERN) reflecting error detection, and a later error positivity (Pe) reflecting conscious error awareness. However, no Pe was recorded after unaware errors or hits. These results are in line with previous studies suggesting that error awareness is associated with generation of the Pe. Source localisation results confirmed that the posterior cingulate motor area was the main generator of the ERN. However, inverse solution results also point to the involvement of the left posterior insula during the time interval of the Pe, and hence error awareness. Moreover, consecutive to this insular activity, the right orbitofrontal cortex (OFC) was activated in response to aware and unaware errors but not in response to hits, consistent with the implication of this area in the evaluation of the value of an error. These results reveal a precise sequence of activations in these three non-overlapping brain regions following error commission, enabling a progressive differentiation between aware and unaware errors as a function of time elapsed, thanks to the involvement first of interoceptive or proprioceptive processes (left insula), later leading to the detection of a breach in the prepotent response mode (right OFC)

Circuit-based interrogation of sleep control.

Sleep is a fundamental biological process observed widely in the animal kingdom, but the neural circuits generating sleep remain poorly understood. Understanding the brain mechanisms controlling sleep requires the identification of key neurons in the control circuits and mapping of their synaptic connections. Technical innovations over the past decade have greatly facilitated dissection of the sleep circuits. This has set the stage for understanding how a variety of environmental and physiological factors influence sleep. The ability to initiate and terminate sleep on command will also help us to elucidate its functions within and beyond the brain

Correlational structure of ‘frontal’ tests and intelligence tests indicates two components with asymmetrical neurostructural correlates in old age

AbstractBoth general fluid intelligence (gf) and performance on some ‘frontal tests’ of cognition decline with age. Both types of ability are at least partially dependent on the integrity of the frontal lobes, which also deteriorate with age. Overlap between these two methods of assessing complex cognition in older age remains unclear. Such overlap could be investigated using inter-test correlations alone, as in previous studies, but this would be enhanced by ascertaining whether frontal test performance and gf share neurobiological variance. To this end, we examined relationships between gf and 6 frontal tests (Tower, Self-Ordered Pointing, Simon, Moral Dilemmas, Reversal Learning and Faux Pas tests) in 90 healthy males, aged ~73years. We interpreted their correlational structure using principal component analysis, and in relation to MRI-derived regional frontal lobe volumes (relative to maximal healthy brain size). gf correlated significantly and positively (.24≤r≤.53) with the majority of frontal test scores. Some frontal test scores also exhibited shared variance after controlling for gf. Principal component analysis of test scores identified units of gf-common and gf-independent variance. The former was associated with variance in the left dorsolateral (DL) and anterior cingulate (AC) regions, and the latter with variance in the right DL and AC regions. Thus, we identify two biologically-meaningful components of variance in complex cognitive performance in older age and suggest that age-related changes to DL and AC have the greatest cognitive impact

Mean rating difference scores are poor measures of discernment: the role of response criteria

Many interventions aim to protect people from misinformation. Here, we review common measures used to assess their efficacy. Some measures only assess the target behavior (e.g., ability to spot misinformation) and therefore cannot determine whether interventions have overly general effects (e.g., erroneously identifying accurate information as misinformation). Better measures assess discernment, the ability to discriminate target from non-target content. Discernment can determine whether interventions are overly general but is often measured by comparing differences in mean ratings between target and non-target content. We show how this measure is confounded by the configuration of response criteria, leading researchers to incorrectly conclude that an intervention improves discernment. We recommend using measures from signal detection theory, such as the area under the receiver operating characteristic curve, to assess discernment