The Influences of Hearing and Vision on Egocentric Distance and Room Size Perception under Rich-Cue Conditions

Artistic renditions are mediated by the performance rooms in which they are staged. The perceived egocentric distance to the artists and the perceived room size are relevant features in this regard. The influences of both the presence and the properties of acoustic and visual environments on these features were investigated. Recordings of music and a speech performance were integrated into direct renderings of six rooms by applying dynamic binaural synthesis and chroma-key compositing. By the use of a linearized extraaural headset and a semi-panoramic stereoscopic projection, the auralized, visualized, and auralized-visualized spatial scenes were presented to test participants who were asked to estimate the egocentric distance and the room size. The mean estimates differed between the acoustic and the visual as well as between the acoustic-visual and the combined single-domain conditions. Geometric estimations in performance rooms relied upon nine-tenths on the visual, and one-tenth on the acoustic properties of the virtualized spatial scenes, but negligibly on their interaction. Structural and material properties of rooms may also influence auditory-visual distance perception

Essays on firm heterogeneity and its implications for macroeconomic policy

Defence date: 13 May 2024Examining Board: Prof. Ramon Marimon (Universitat Pompeu Fabra; BSE; European University Institute, supervisor); Prof. Russell Cooper (European University Institute, co-supervisor); Dr. Julian di Giovanni (Federal Reserve Bank of New York and Columbia University); Dr. Ernesto Pastén (Central Bank of Chile; Toulouse School of Economics)This thesis contains three independent essays studying the role of firm heterogeneity in the transmission of macroeconomic shocks and policies to the economy. In the first chapter, written jointly with Johannes Fischer, we analyse the effect of monetary policy on mergers and acquisitions (M&A) activity in the U.S. We provide causal evidence that contractionary monetary policy reduces aggregate M&A activity. In the cross-section of U.S. publicly listed companies, we show that this effect is particularly pronounced among financially constrained firms, leading to a change in the composition of firms conducting M&A in response to monetary contractions. As a result of this selection effect, contractionary monetary policy increases the quality of M&A deals taking place since fewer financially constrained firms engage in M&A. Finally, we provide evidence that following a monetary tightening, acquirers match with relatively smaller and younger target firms. The profitability of targets firms, relative to acquiring firms, does not change. In the second chapter, written jointly with Russell Cooper and Leonardo Indraccolo, we study the effects of Covid-19 on manufacturing output, employment and productivity across a set of European countries. Using a quantitative firm dynamics model with endogenous entry and exit, we estimate the key parameters of adjustment costs and market power to match the country-specific responsiveness of firms to exogenous shocks. We then use the estimated model to simulate the effects of the Covid-19 shock, with and without policy support measures. As seen through counterfactual exercises, the main impact of the policy interventions, treated here as work-sharing schemes targeted to low profitability firms and “no-firing" obligations, was to mitigate the drop in aggregate employment by keeping firms in business. We calculate that the aggregate drop in employment would have been between 1.0 and 1.9 percentage points higher across countries without policy support. We do not find evidence of adverse productivity effects from these interventions. Building on these counterfactuals, we, furthermore, establish the importance of targeted subsidies and the sensitivity of employment responses to firm beliefs. In the third chapter, I study the implications of public procurement for the transmission of monetary policy to asset prices and firm-level investment. I document that, among publicly listed U.S. companies, contracting with the government dampens the response of both stock returns and physical investment to monetary policy shocks. I provide novel evidence suggesting that federal procurement is less responsive to monetary policy shocks than private sector demand, providing an additional channel of insurance to government contractors against the adverse effects of monetary policy on final demand. I find only limited evidence for a weaker credit channel among government contractors.-- 1. Monetary Policy and Mergers and Acquisitions -- 2. Covid and Productivity in Europe: A Responsiveness Perspective -- 3. Monetary Policy and Public Procurement -- References -- A. Appendix to Chapter 1 -- B. Appendix to Chapter 2 -- C. Appendix to Chapter

Compensation claims in pediatric orthopedics in Norway between 2012 and 2018: a nationwide study of 487 patients

publishedVersionpublishedVersio

Reinforcement magnitudes modulate subthalamic beta band activity in patients with Parkinson's disease

We set out to investigate whether beta oscillations in the human basal ganglia are modulated during reinforcement learning. Based on previous research, we assumed that beta activity might either reflect the magnitudes of individuals' received reinforcements (reinforcement hypothesis), their reinforcement prediction errors (dopamine hypothesis) or their tendencies to repeat versus adapt responses based upon reinforcements (status-quo hypothesis). We tested these hypotheses by recording local field potentials (LFPs) from the subthalamic nuclei of 19 Parkinson's disease patients engaged in a reinforcement-learning paradigm. We then correlated patients' reinforcement magnitudes, reinforcement prediction errors and response repetition tendencies with task-related power changes in their LFP oscillations. During feedback presentation, activity in the frequency range of 14 to 27 Hz (beta spectrum) correlated positively with reinforcement magnitudes. During responding, alpha and low beta activity (6 to 18 Hz) was negatively correlated with previous reinforcement magnitudes. Reinforcement prediction errors and response repetition tendencies did not correlate significantly with LFP oscillations. These results suggest that alpha and beta oscillations during reinforcement learning reflect patients' observed reinforcement magnitudes, rather than their reinforcement prediction errors or their tendencies to repeat versus adapt their responses, arguing both against an involvement of phasic dopamine and against applicability of the status-quo theory

The Crystal and Mesophase Structure of Hexakis(alkylsulfono)- benzene Homologues by X-Ray Diffractometry

A powder X-ray diffractometer study of hexakis(tridecylsulfono)benzene (HASB13) has been carried out over the temperature range 20 to above 80 °C. In this range three phase transitions are observed by sharp discontinuities in the diffraction pattern indicating a solid-solid, solidmesophase, and mesophase-liquid transition. The mesomorphic phase is identified as a hexagonal columnar discotic mesophase, Dhd, with intercolumnar spacing of 25.7 Å and average stacking distance of 4.9 Å. Both distances are independent of temperature but there appears to be a gradual increase in the stacking disorder as the temperature is increased. The magnitude of the intercolumnar distance suggests a considerable degree of side chain disorder. A detailed X-ray diffraction study was also performed at room temperature on a single crystal of hexakis(propylsulfono) benzene (HASB3), which is not mesogenic. The results provide detailed information on the structure of HASB 3 which is used in the interpretation of HASB 13 results

Tuning the optical properties of 2D monolayer silver-bismuth bromide double perovskite by halide substitution

: Silver-bismuth double perovskites are promising replacement materials for lead-based ones in photovoltaic (PV) devices due to the lower toxicity and enhanced stability to environmental factors. In addition, they might even be more suitable for indoor PV, due to the size of their bandgap better matching white LEDs emission. Unfortunately, their optoelectronic performance does not reach that of the lead-based counterparts, because of the indirect nature of the band gap and the high exciton binding energy. One strategy to improve the electronic properties is the dimensional reduction from the 3D to the 2D perovskite structure, which features a direct band gap, as it has been reported for 2D monolayer derivates of Cs2AgBiBr6obtained by substituting Cs+cations with bulky alkylammonium cations. However, a similar dimensional reduction also brings to a band gap opening, limiting light absorption in the visible. In this work, we report on the achievement of a bathochromic shift in the absorption features of a butylammonium-based silver-bismuth bromide monolayer double perovskite through doping with iodide and study the optical properties and stability of the resulting thin films in environmental conditions. These species might constitute the starting point to design future sustainable materials to implement as active components in indoor photovoltaic devices used to power the IoT