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Predictive power of the term structure
No full textEmpirical thesis.Includes bibliographical references.1. Abstract -- 2. Introduction -- 3. Forecasting the term Structure of interest rates near the zero bound - a new era? -- 4. Factors of the term structure of sovereign yield spreads -- 5. Exchange rates and unobservable fundamentals : a new approach to out-of-sample forecasting -- 6. Thesis summary and conclusions.This PhD thesis analyzes the predictive power entailed in the term structure of interest rates and interest rate differentials. It consists of three key chapters based on three research papers.The first research paper titled ’Forecasting the Term Structure of Interest Rates near the Zero Bound - a New Era?’ investigates the forecasting performance of popular dynamic factor models of the yield curve after the global financial crisis (GFC). This time period is characterized by a low and nonvolatile interest rate environment in most major economies with short rates close to the zero bound. We focus on two popular factor models which exploit the information contained in the cross-section of the term structure – the dynamic Nelson-Siegel model and regressions on principal components – to show that subsequent to the GFC both models are significantly outperformed by a random walk no-change forecast. Especially for short and medium term yields, the random walk is up to ten times more accurate. Interestingly, these results are not picked up by traditional global forecast evaluation metrics. We further show that combining forecasts mitigates model uncertainty and improves the disappointing forecasting accuracy especially after the GFC.The research work ’Factors of the Term Structure of Sovereign Yield Spreads’ investigates the term structure of sovereign yield spreads for five advanced economies against the US and provides novel insights into the key drivers of the spread term structure. We show that the spread term structure dynamics are driven by three latent factors which can be labeled as spread level, slope and curvature, similar to common interpretations found in the yield curve literature. We further show that these estimated spread factors have predictive power for exchange rate movements and excess returns above the predictability of an uncovered interest rate parity approach. As the yield curve contains information about expected future economic conditions, we conjecture that these yield spread factors reflect expected macroeconomic differentials which in turn drive exchange rates. Using the information content of yield spread curves may thus be a promising approach to improve the forecasting accuracy of exchange rate models.The third research paper titled ’Exchange Rates and Unobservable Fundamentals : A New Approach to Out-of Sample Forecasting’ builds on the key findings of the previous paper and suggests applying the empirical sovereign yield spread level and slope to forecast exchange rates out-of-sample. Traditional exchange rate models are usually based on differences in observable macroeconomic fundamentals such as output and inflation. However, while being well grounded in economic theory, these fundamental models have a rather poor out-of sample forecasting record. This empirical failure may be a result of the overly restrictive choice of macroeconomic fundamentals. We thus apply the empirical sovereign yield spread level and slope as unobservable proxies of the market’s expectations for current and future fundamentals. Our approach outperforms traditional exchange rate models in forecasting accuracy and profitability for all applied forecasting evaluation metrics. It is also superior to a random walk in terms of direction of change forecasts and profitability of the forecasts.Mode of access: World wide web1 online resource (vii, 188 pages) graphs, table
Autonomous control system with drag meaurement capaility for a wind tunnel model vehicle
No full textEmpirical thesis.Bibliography: pages 91-92.1. Introduction -- 2. Literature review -- 3. Development of an advanced control system algorithm -- 4. Specific criteria based sensor analysis -- 5. Implementation of the control system -- 6. Interfacing with the control system -- 7. Conclusions -- Appendices -- Bibliography.In order to understand the aerodynamics of a model, wind tunnel testing is crucial and in wind tunnel testing there needs to be an accurate correlation between the environment inside the tunnel and the environment on the road. In the automotive industry, to make the test environment more realistic, a model vehicle being analyzed is now placed on a rolling road to simulate a moving ground. Inside wind tunnels as such, these models are supported by structures such as struts so that it can be held in place and a system of balance connected to these struts is used to measure the aerodynamic forces such as drag. These structures, however, interfere with wind tunnel results and it is standard practice to correct wind tunnel results for a model with and without presence of support structures. In order to make the wind tunnel test environment more realistic and results more accurate thus enabling us to understand the complete aerodynamics of a model, an advanced alternative is proposed and researched in this project. This project is about the development of an autonomous control system that can maintain a model vehicle's position inside a wind tunnel over a moving ground with high degree of accuracy and measure the drag the vehicle is experiencing. This thesis reviews existing technology in the field of wind tunnel testing and autonomous driving and discusses the development of an advanced mathematical algorithm for the aimed control system.Mode of access: World wide web.1 online resource (xiii, 92 pages illustrations (some colour)
Spectroscopic aperture biases in inside-out evolving early-type galaxies from CALIFA
No full textIntegral field spectroscopy (IFS) studies based on CALIFA survey data have recently revealed ongoing low-level star formation (SF) in the periphery of a small fraction (~10%) of local early-type galaxies (ETGs), witnessing a still ongoing inside-out galaxy growth process. A distinctive property of the nebular component in these ETGs, classified i+, is a structure with two radial zones, the inner of which displays LINER emission with a Hα equivalent width EW(Hα) ≃ 1 Å, the outer (3 Å < EW(Hα) ≲ 20 Å) Hɪɪ-region characteristics. Using CALIFA IFS data, we empirically demonstrate that the confinement of nebular emission to the galaxy periphery leads to a strong aperture (or, correspondingly, redshift) bias in spectroscopic single-fiber studies of type i+ ETGs: at low redshift (z ≲ 0.45), SDSS spectroscopy is restricted to the inner (SF-devoid LINER) zone, which causes the galaxies to be erroneously classified as "retired", that is, systems entirely lacking SF, and whose faint nebular emissionis solely powered by the post-AGB stellar component. The SDSS aperture progressively encompasses the outer SF zone only at higher z, at which the galaxies are unambiguously classified as "composite SF/LINER". We also empirically demonstrate that the principal effect of a decreasing spectroscopic aperture on the classification of i+ ETGs through standard [Nɪɪ]/Hα vs. [Oɪɪɪ]/Hβ emission-line (BPT) ratios consists of a monotonic shift upward and to the right precisely along the upper right wing of the "seagull" distribution on the BPT plane, that is, along the pathway connecting composite SF/Hɪɪ galaxies with AGN/LINERs. Motivated by these observational insights, we also investigate theoretically observational biases in aperture-limited studies of inside-out growing galaxies as a function of z. To this end, we devise a simple 1D model that involves an outward-propagating exponentially decreasing SF process since z ~ 10 and reproduces the radial extent and two-zone EW(Hα) distribution of local i+ ETGs. By simulating the 3″ spectroscopic SDSS aperture in this model, we find that SDSS studies at z ≲ 1 are progressively restricted to the inner (SF-devoid LINER) zone and miss an increasingly larger portion of the Hα-emitting periphery. This leads to the incorrect spectroscopic classification of these inside-out assembling galaxies as retired ETG/LINERs and also to a severe underestimation of their total star formation rate (SFR) in a manner inversely related to z. More specifically, the SFR inferred from the Hα luminosity registered within the SDSS fiber is reduced by 50% at z ~ 0.86, reaching only 0.1% of its integral value at z = 0.1. We argue that the aperture-driven biases described above pertain to any morphological analog of i+ ETGs (e.g., SF-quiescent bulges within star-forming disks), regardless of whether it is viewed from the perspective of inside-out growth or inside-out SF quenching, and might be of considerable relevance to galaxy taxonomy and studies of the cosmic SFR density as a function of z.6 page(s
Action observation and imitation in autism spectrum disorders : an ALE meta-analysis of fMRI studies
No full textPrevious studies have shown that the mirror neuron system (MNS) plays an important role in action understanding. However, whether and how the MNS activity is different in individuals with autism spectrum disorders (ASD) and typically developed (TD) individuals are still unclear. The current study used activation likelihood estimation to conduct a meta-analysis of functional magnetic resonance imaging studies that investigated action observation and imitation in ASD and TD individuals. Thirteen studies were selected, and the contrasts focused on the brain effects in ASD and TD participants and the differences between the two groups. The results showed that compared with TD individuals, ASD individuals exhibited stronger effects in the anterior inferior parietal lobule, a part of the putative human MNS. In addition, the ASD group demonstrated altered effects in the occipital cortex, dorsolateral prefrontal cortex, cingulate cortex, and insula. These results suggest that ASD individuals demonstrate dysfunction of the MNS during action observation and imitation. Furthermore, brain regions involved in visual processing, executive function, and social cognitive function might also show dysfunction during action task performance.10 page(s
Perceived speed of compound stimuli is moderated by component contrast, not overall pattern contrast
No full textThe perception of speed is susceptible to manipulations of image contrast, both for simple sine wave and more complex stimuli, such that low-contrast patterns generally appear slower than their high-contrast equivalents. It is not known whether the crucial factor is the contrast of the underlying Fourier components or the contrast of the overall complex pattern. Here, two experiments investigate this issue using compound gratings, comprising two vertical sine wave stimuli with equal contrast, but a 3:1 spatial frequency ratio. Component gratings were summed in “peaks add” and in “peaks subtract” phase, creating conditions with either (a) identical component contrasts, despite differences in overall pattern contrast or (b) differences in component contrasts despite identical overall pattern contrast. Experiment 1 demonstrated that the perceived speed is determined by the contrast of the components regardless of relative phase and hence of overall pattern contrast. Experiment 2 replicated this result while eliminating potential explanations based on differences in spatial frequency content. Along with previous compound grating and plaid studies, the data support a two-stage velocity estimation process involving the derivation of separate speed signals for each Fourier component, followed by integration of these signals across spatial scales.15 page(s
A case of retroperitoneal metastases that occur 14 years after surgery
No full textEndometrial Stromal Sarcomas are rare malignant tumours of the uterus. We report the case of incidental finding of Low-Grade Endometrial Stromal Sarcoma (LGESS) that metastasized to the retroperitoneum 14 years after the original surgery in a 72-year-old woman. The patient underwent a laparotomy and excision of all tumour nodules. Considering the common recurrence of and slow growing nature of LGESS, appropriate treatment options like surgical excision and life-long follow up should be considered.3 page(s
Case studies on corporations and global health governance : impacts, influence and accountability
No full textA collection of case studies providing interdisciplinary empirical analysis of the impact of corporations on global health and global health governance across a broad range of industrial sectors and issue areas.1.Introduction / Ross MacKenzie -- I.Impacts of Corporations on Global Health -- 2.Governing through Production: A Public-Private Partnership's Impacts and Dissolution in Lesotho's Garment Industry / Nora J. Kenworthy -- 3.Medicalisation and Commodification of Smoking Cessation: The Role of Industry Actors in Shaping Health Policy / Benjamin Hawkins -- 4.The Influence of the Food Industry on Public Health Governance: Insights from Mexico and the United States / Cecile Knai -- 5.Examples of Failures to Regulate Mining and Smelting Emissions and Their Consequent Effects on Human Health Outcomes / Steven George -- II.Corporate Influence of Global Health Governance -- 6.Informal Channels of Corporate Influence on Global Health Policymaking: A Mapping of Strategies across Four Industries / Suerie Moon -- 7.How Corporations Shape Our Understanding of Problems with Gambling and Their Solutions / Rebecca Cassidy -- 8.Corporate Manipulation of Global Health Policy: A Case Study of Asbestos / John Calvert -- 9.The Entrenchment of the Public-Private Partnership Paradigm / Michael Stevenson -- 10.Trade and Investment Agreements: The Empowerment of Pharmaceutical and Tobacco Corporations / Ronald Labonte -- 11.Health Policy, Corporate Influence and Multi-Level Governance: The Case of Alcohol Policy in the European Union / Benjamin Hawkins -- 12.Tobacco Industry Strategies to Influence Global Governance / Kelley Lee -- III.Holding Corporations to Account -- 13.A Proposed Approach to Systematically Identify and Monitor the Corporate Political Activity of the Food Industry with Respect to Public Health Using Publicly Available Information / Gary Sacks -- 14.Regulating Baby Food Marketing: Civil Society versus Private Sector Influence / Tracey Wagner-Rizvi -- Contents note continued: 15.Epidemiology in the Struggle over Contamination of the Ecuadorian Amazon: Communities, Controversy and Chevron / Ben Brisbois -- 16.Citizens United, Public Health and Democracy: The Supreme Court Ruling, Its Implications and Proposed Action / William H. Wiist -- 17.Conclusion / Kelley Lee.269 page(s
Three-dimensional controlled growth of monodisperse sub-50 nm heterogeneous nanocrystals
No full textThe ultimate frontier in nanomaterials engineering is to realize their composition control with atomic scale precision to enable fabrication of nanoparticles with desirable size, shape and surface properties. Such control becomes even more useful when growing hybrid nanocrystals designed to integrate multiple functionalities. Here we report achieving such degree of control in a family of rare-earth-doped nanomaterials. We experimentally verify the co-existence and different roles of oleate anions (OA⁻) and molecules (OAH) in the crystal formation. We identify that the control over the ratio of OA⁻ to OAH can be used to directionally inhibit, promote or etch the crystallographic facets of the nanoparticles. This control enables selective grafting of shells with complex morphologies grown over nanocrystal cores, thus allowing the fabrication of a diverse library of monodisperse sub-50 nm nanoparticles. With such programmable additive and subtractive engineering a variety of three-dimensional shapes can be implemented using a bottom–up scalable approach.8 page(s
Localised magmatic constraints on continental back-arc volcanism in southern Mendoza, Argentina : the Santa Maria Volcano
No full textThe Payún Matrú Volcanic Field constitutes part of the continental back-arc in Argentina. This volcanic field has been the focus of several regional investigations; however, geochemical analysis of recent volcanoes (<8 ka) at the scale of an individual volcano has not been conducted. We present a morphological description for the Santa Maria Volcano in addition to results from major and trace element analysis and ²³⁸U-²³⁰Th-²²⁶Ra disequilibria. The trace element evidence suggests that the Santa Maria magmatic source has a composition similar to that of the local intraplate end member (resembling an ocean island basalt-like source), with a slight contribution from subduction-related material. The U-series analyses suggest a high ²²⁶Ra excess over ²³⁰Th for this volcano, which is not derived from a shallow process such as hydrothermal alteration or upper crustal contamination. Furthermore, intermediate-depth processes such as fractional crystallisation have been inferred for the Santa Maria Volcano, but they are not capable of producing the ²²⁶Ra excess measured. The ²²⁶Ra excess is explained by deep processes like partial melting of mantle lithologies with some influence from subducted Chilean trench sediments. Due to the short half-life of ²²⁶Ra (1600 years), we infer that fast magma ascent rates are required to preserve the high ²²⁶Ra excess.13 page(s
