Stacking and Registry Effects in Layered Materials: The Case of Hexagonal Boron Nitride

The interlayer sliding energy landscape of hexagonal boron nitride (h-BN) is investigated via a van der Waals corrected density functional theory approach. It is found that the main role of the van der Waals forces is to "anchor" the layers at a fixed distance, whereas the electrostatic forces dictate the optimal stacking mode and the interlayer sliding energy. A nearly free-sliding path is identified, along which bandgap modulations of ~0.6 eV are obtained. We propose a simple geometrical model that quantifies the registry matching between the layers and captures the essence of the corrugated h-BN interlayer energy landscape. The simplicity of this phenomenological model opens the way to the modeling of complex layered structures, such as carbon and boron nitride nanotubes.Comment: 4 Pages, 3 Figure

Do Investors Care About Biodiversity?

This paper introduces a new proprietary measure of a firm's negative impact on biodiversity, the corporate biodiversity footprint, and studies whether it is priced in the cross-section of stock returns. Using an international sample of firms, we find no evidence that the biodiversity footprint explains these returns, on average. However, event-study evidence shows that, following the UN Biodiversity Conference (COP15), which raised awareness of biodiversity issues, however, firms with larger corporate biodiversity footprints lost value. This response is consistent with investors revising their valuation of these firms downward upon the prospect that regulations to preserve biodiversity will become more stringent

Probing the faint end Luminosity Function of Lyman Alpha Emitters at 3<z<7 behind 17 MUSE lensing clusters

We present a study of the galaxy Lyman-alpha luminosity function (LF) using a sample of 17 lensing clusters observed by the MUSE/VLT. Magnification from strong gravitational lensing by clusters of galaxies and MUSE apabilities allow us to blindly detect LAEs without any photometric pre-selection, reaching the faint luminosity regime. 600 lensed LAEs were selected behind these clusters in the redshift range 2.9<$z$< 6.7, covering four orders of magnitude in magnification-corrected Lyman-alpha luminosity (39.0<log$L$< 43.0). The method used in this work ($V_{\text{max}}$) follows the recipes originally developed by arXiv:1905.13696(N) (DLV19) with some improvements to better account for the effects of lensing when computing the effective volume. The total co-moving volume at 2.9<$z$<6.7 is $\sim$50 $10^{3}Mpc^{3}$. Our LF points in the bright end (log L)>42 are consistent with those obtained from blank field observations. In the faint luminosity regime, the density of sources is well described by a steep slope, $\alpha\sim-2$ for the global redshift range. Up to log(L)$\sim$41, the steepening of the faint end slope with redshift, suggested by the earlier work of DLV19 is observed, but the uncertainties remain large. A significant flattening is observed towards the faintest end, for the highest redshift bins (log$L$<41). Using face values, the steep slope at the faint-end causes the SFRD to dramatically increase with redshift, implying that LAEs could play a major role in the process of cosmic reionization. The flattening observed towards the faint end for the highest redshift bins still needs further investigation. This turnover is similar to the one observed for the UV LF at $z\geq6$ in lensing clusters, with the same conclusions regarding the reliability of current results (e.g.arXiv:1803.09747(N); arXiv:2205.11526(N)).Comment: 20 pages, 15 figures, 6 tables. Accepted for publication in A\&

The Montreal model: an integrative biomedical-psychedelic approach to ketamine for severe treatment-resistant depression

BackgroundSubanesthetic ketamine has accumulated meta-analytic evidence for rapid antidepressant effects in treatment-resistant depression (TRD), resulting in both excitement and debate. Many unanswered questions surround ketamine’s mechanisms of action and its integration into real-world psychiatric care, resulting in diverse utilizations that variously resemble electroconvulsive therapy, conventional antidepressants, or serotonergic psychedelics. There is thus an unmet need for clinical approaches to ketamine that are tailored to its unique therapeutic properties.MethodsThis article presents the Montreal model, a comprehensive biopsychosocial approach to ketamine for severe TRD refined over 6 years in public healthcare settings. To contextualize its development, we review the evidence for ketamine as a biomedical and as a psychedelic treatment of depression, emphasizing each perspectives’ strengths, weaknesses, and distinct methods of utilization. We then describe the key clinical experiences and research findings that shaped the model’s various components, which are presented in detail.ResultsThe Montreal model, as implemented in a recent randomized clinical trial, aims to synergistically pair ketamine infusions with conventional and psychedelic biopsychosocial care. Ketamine is broadly conceptualized as a brief intervention that can produce windows of opportunity for enhanced psychiatric care, as well as powerful occasions for psychological growth. The model combines structured psychiatric care and concomitant psychotherapy with six ketamine infusions, administered with psychedelic-inspired nonpharmacological adjuncts including rolling preparative and integrative psychological support.DiscussionOur integrative model aims to bridge the biomedical-psychedelic divide to offer a feasible, flexible, and standardized approach to ketamine for TRD. Our learnings from developing and implementing this psychedelic-inspired model for severe, real-world patients in two academic hospitals may offer valuable insights for the ongoing roll-out of a range of psychedelic therapies. Further research is needed to assess the Montreal model’s effectiveness and hypothesized psychological mechanisms

Emergence of neuronal diversity from patterning of telencephalic progenitors.

During central nervous system (CNS) development, hundreds of distinct neuronal subtypes are generated from a single layer of multipotent neuroepithelial progenitor cells. Within the rostral CNS, initial regionalization of the telencephalon marks the territories where the cerebral cortex and the basal ganglia originate. Subsequent refinement of the primary structures determines the formation of domains of differential gene expression, where distinct fate-restricted progenitors are located. To understand how diversification of neural progenitors and neurons is achieved in the telencephalon, it is important to address early and late patterning events in this context. In particular, important questions include: How does the telencephalon become specified and regionalized along the major spatial axes? Within each region, are the differences in neuronal subtypes established at the progenitor level or at the postmitotic stage? If distinct progenitors exist that are committed to subtype-specific neuronal lineages, how does the diversification emerge? What is the contribution of positional and temporal cues and how is this information integrated into the intrinsic programs of cell identity? WIREs For further resources related to this article, please visit the WIREs website.This work was supported by Medical Research Council (MRC) grants G0700758 and MR/K018329/1 and Doctoral Training Award (LH); RA is supported by an MRC postdoctoral fellowship.This is the accepted manuscript. The final version is available from Wiley at http://onlinelibrary.wiley.com/doi/10.1002/wdev.174/abstract

No English title available

Cette thèse traite de l’influence de l’horizon d’investissement des actionnaires sur les décisions des entreprises et sur leur performance. Elle est composée de quatre articles. Le premier article effectue une revue de la littérature et identifie des lacunes que les trois autres articles empiriques cherchent à combler. Le second article est consacré à l’effet de l’horizon d’investissement des actionnaires sur la satisfaction des employés. La satisfaction des employés est un actif intangible qui, bien que créateur de valeur sur le long-terme, est mal valorisé par le marché à court-terme. Pour cette raison, les investisseurs de long-terme et de court-terme pourraient ne pas avoir le même intérêt à ce que les entreprises dans lesquelles ils investissent satisfassent leurs employés. L’article documente un effet positif des investisseurs de long-terme sur la satisfaction des employés et établit la causalité de différentes façons. Ce résultat indique que la structure de l’actionnariat est un déterminant important de mise en place de politiques RSE créatrices de valeur à long-terme. Le troisième article étudie l’impact de l’horizon d’investissement des actionnaires sur la performance des banques pendant la crise. Les résultats de l’analyse empirique montrent qu’une plus grande présence d’actionnaires de court-terme est associée à une plus forte chute du cours de bourse pendant la crise. Cette association s’explique partiellement par une prise de risques plus grande, avant crise, des banques dans lesquelles les actionnaires de court-terme étaient plus présents. Elle s’explique également par le comportement des actionnaires de court-terme pendant la crise. Ces derniers ont vendu massivement leurs actions, générant une pression à la vente plus forte des actions des banques par l’ensemble des investisseurs institutionnels. Ces résultats ont une implication pour la réglementation des fonds propres bancaires, ils suggèrent que l’effet protecteur des fonds propres pour les banques varie en fonction de l’horizon d’investissement des détenteurs de ces fonds. Le dernier article se concentre sur l’effet disciplinaire des investisseurs de long-terme. Il montre que l’effet disciplinaire des investisseurs de long-terme sur le surinvestissement d’une entreprise dépend de la durée pendant laquelle ces investisseurs ont effectivement détenu les actions de l’entreprise. Les résultats de l’analyse empirique soutiennent l’idée que, pour constituer une base actionnariale qui génère plus de valeur, attirer des investisseurs de long-terme n’est pas suffisant, les entreprises devraient également inciter leurs actionnaires à détenir leurs actions plus longtemps.No English summary available

The effect of cultural distance between an analyst and a CEO on analysts’ earnings forecast performance

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CEO exposure to abnormally hot temperature and corporate carbon emissions

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Investor rewards to environmental responsibility: Evidence from the COVID-19 crisis

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