Can oil prices forecast exchange rates?

This paper investigates whether oil prices have a reliable and stable out-of-sample relationship with the Canadian/U.S. dollar nominal exchange rate. Despite state-of-the-art methodologies, the authors find little systematic relation between oil prices and the exchange rate at the monthly and quarterly frequencies. In contrast, the main contribution is to show the existence of a very short-term relationship at the daily frequency, which is rather robust and holds no matter whether the authors use contemporaneous (realized) or lagged oil prices in their regression. However, in the latter case the predictive ability is ephemeral, mostly appearing after instabilities have been appropriately taken into account.Foreign exchange rates ; Economic forecasting

Essays on Asymmetric Labor-Market Fluctuations and Economic Growth

<p>This dissertation consists of three essays. In the first essay, ``The Asymmetric Cyclical Behavior of the U.S. Labor Market,'' I develop a search-and-matching model with endogenous job destruction and heterogeneous workers (in skill/productivity) that accounts for the asymmetry exhibited by cyclical fluctuations in the U.S. labor market and output while also generating (i) realistic volatility in unemployment and job-finding rates and (ii) preserving a downward-sloping Beveridge curve. The model delivers stark predictions for the time series of skill-specific unemployment rates that hold in the Current Population Survey (CPS) micro data once I sort workers by age and education. A general implication of the analysis is that the responsiveness of unemployment to stimulus policies increases substantially during recessions.</p><p>In the second essay, ``Volatility and Slow Technology Diffusion: The Case of Information Technologies,'' I address the following question: does business cycle volatility affect the rate at which new technologies are adopted? The answer to this question provides new insights on the link between volatility, total factor productivity (TFP), long-run economic</p><p>growth, and cross-country differences in incomes per capita. The paper presents novel cross-country evidence on the link between volatility and time adoption lags. I find a highly statistically and economically significant negative relationship between volatility and the diffusion of three major information and communication technologies (ICT's)---personal computers, internet and cell phones. Countries with more volatile growth rates of real GDP per capita have higher time adoption lags. This negative relationship is rather robust and persists after controlling for cross-country differences in average growth rates of real GDP per capita. I also offer a simple stochastic model of technology adoption in which I derive in closed form the theoretical mapping between time adoption lags, growth, and volatility. In the model as in the data, there is a positive link between volatility and time adoption lags: the interaction of uncertainty with sunk costs of adoption generates a real option value of inaction which delays the adoption of new technologies with the consequent adverse effect on long-run economic growth.</p><p>In the third essay, ``Commodity Prices, Long-Run Growth and Fiscal Vulnerability'' (coauthored with Pietro Peretto), we study the short- and long-run effects of commodity price changes and how fiscal policy interacts with the amplification and propagation of external shocks to these prices. To this aim, we develop a Schumpeterian small open economy (SOE) model of endogenous growth that does not exhibit the scale effect. Because of the sterilization of the scale effect, commodity prices have level effects on economic activity but no steady-state growth effects. A general implication of our analysis is that the economy dynamic response to commodity price changes depends both on the structure of the tax code in place and on the policy response necessary to balance the government budget. We show that asset income taxation has negative steady-state growth effects. Furthermore, a positive tax rate on asset income acts as an automatic amplifier of external shocks to commodity prices and makes the effects of these shocks more persistent. Ultimately, our analysis provides insights on how to design welfare-enhancing tax policies for commodity-exporting countries.</p>Dissertatio

Metabolic syndrome and nephrolithiasis: can we hypotize a common background?

Metabolic syndrome and nephrolithiasis are quite common disorders presenting similar epidemiological characteristics. Belonging to genetic, environmental and hormonal interaction, they have high incidence and prevalence in the adult population of industrialised countries and are characterised by a high level of morbidity and mortality if not adequately identified and treated. Despite metabolic syndrome is considered a fundamental risk factor for chronic kidney diseases, is not actually known whether it is associated with nephrolithiasis beyond the effect of its individual components, in particular obesity, glucose intolerance, and hypertension. In this paper, the possible pathogenetic links between metabolic syndrome and nephrolithiasis will be presented and discussed

The Intention to Purchase Recycled Products: Towards an Integrative Theoretical Framework

The growing interest of the scientific literature regarding purchase behavior, circular economy and new business models has generated the need, as well as the opportunity, for a comprehensive review and categorization of the state of the existing research carried out so far. The present study aims at reconciling the wide but fragmented literature dealing with the purchase intention of recycled products. An integrative theoretical framework, able to combine several constructs, perspectives, and theories discussed to date on the topic, is proposed. Such framework represents a further step toward a comprehensive understanding of behavioral theories and constructs, which need to be understood to design effective business models for the circular economy. This effort could be highly valuable both for scholars interested in the topic—as the integrative framework could assist them in theorizing additional effects—and for firms’ managers—who can understand, more in depth, the drivers of the consumers’ purchasing process and act accordingly

Super-crystals in composite ferroelectrics

As atoms and molecules condense to form solids, a crystalline state can emerge with its highly ordered geometry and subnanometric lattice constant. In some physical systems, such as ferroelectric perovskites, a perfect crystalline structure forms even when the condensing substances are non-stoichiometric. The resulting solids have compositional disorder and complex macroscopic properties, such as giant susceptibilities and non-ergodicity. Here, we observe the spontaneous formation of a cubic structure in composite ferroelectric potassium– lithium–tantalate–niobate with micrometric lattice constant, 104 times larger than that of the underlying perovskite lattice. The 3D effect is observed in specifically designed samples in which the substitutional mixture varies periodically along one specific crystal axis. Laser propagation indicates a coherent polarization super-crystal that produces an optical X-ray diffractometry, an ordered mesoscopic state of matter with important implications for critical phenomena and applications in miniaturized 3D optical technologies

deCLUTTER²⁺ – a pipeline to analyze calcium traces in a stem cell model for ventral midbrain patterned astrocytes

Astrocytes are the most populous cell type of the human central nervous system and are essential for physiological brain function. Increasing evidence suggests multiple roles for astrocytes in Parkinson’s disease, nudging a shift in the research focus, which historically pivoted around ventral midbrain dopaminergic neurons (vmDANs). Studying human astrocytes and other cell types in vivo remains challenging. However, in vitro-reprogrammed human stem cell-based models provide a promising alternative. Here, we describe a novel protocol for astrocyte differentiation from human stem cell-derived vmDAN-generating progenitors. This protocol simulates the regionalization, gliogenic switch, radial migration and final differentiation that occur in the developing human brain. We characterized the morphological, molecular and functional features of these ventral midbrain patterned astrocytes with a broad palette of techniques and identified novel candidate midbrain-astrocyte specific markers. In addition, we developed a new pipeline for calcium imaging data analysis called deCLUTTER2+ (deconvolution of Ca2+ fluorescent patterns) that can be used to discover spontaneous or cue-dependent patterns of Ca2+ transients. Altogether, our protocol enables the characterization of the functional properties of human ventral midbrain patterned astrocytes under physiological conditions and in disease.</p

Manipulating Light with Tunable Nanoantennas and Metasurfaces

The extensive progress in nanofabrication techniques enabled innovative methods for molding light at the nanoscale. Subwavelength structured optical elements and, in general, metasurfaces and metamaterials achieved promising results in several research areas, such as holography, microscopy, sensing and nonlinear optics. Still, a demanding challenge is represented by the development of innovative devices with reconfigurable optical properties. Here, we review recent achievements in the field of tunable metasurface. After a brief general introduction about metasurfaces, we will discuss two different mechanisms to implement tunable properties of optical elements at the nanoscale. In particular, we will first focus on phase-transition materials, such as vanadium dioxide, to tune and control the resonances of dipole nanoantennas in the near-infrared region. Finally, we will present a platform based on an AlGaAs metasurface embedded in a liquid crystal matrix that allows the modulation of the generated second harmonic signal

Psychostimulant effect of the synthetic cannabinoid JWH-018 and AKB48: Behavioral, neurochemical, and dopamine transporter scan imaging studies in mice

JWH-018 and AKB48 are two synthetic cannabinoids (SCBs) belonging to different structural classes and illegally marketed as incense, herbal preparations, or chemical supply for theirs psychoactive cannabis-like effects. Clinical reports from emergency room reported psychomotor agitation as one of the most frequent effects in people assuming SCBs. This study aimed to investigate the psychostimulant properties of JWH-018 and AKB48 in male CD-1 mice and to compare their behavioral and biochemical effects with those caused by cocaine and amphetamine. In vivo studies showed that JWH-018 and AKB48, as cocaine and amphetamine, facilitated spontaneous locomotion in mice. These effects were prevented by CB1 receptor blockade and dopamine (DA) D1/5 and D2/3 receptors inhibition. SPECT-CT studies on dopamine transporter (DAT) revealed that, as cocaine and amphetamine, JWH-018 and AKB48 decreased the [123I]-FP-CIT binding in the mouse striatum. Conversely, in vitro competition binding studies revealed that, unlike cocaine and amphetamine, JWH-018 and AKB48 did not bind to mouse or human DAT. Moreover, microdialysis studies showed that the systemic administration of JWH-018, AKB48, cocaine, and amphetamine stimulated DA release in the nucleus accumbens (NAc) shell of freely moving mice. Finally, unlike amphetamine and cocaine, JWH-018 and AKB48 did not induce any changes on spontaneous [3H]-DA efflux from murine striatal synaptosomes. The present results suggest that SCBs facilitate striatal DA release possibly with different mechanisms than cocaine and amphetamine. Furthermore, they demonstrate, for the first time, that JWH-018 and AKB48 induce a psychostimulant effect in mice possibly by increasing NAc DA release. These data, according to clinical reports, outline the potential psychostimulant action of SCBs highlighting their possible danger to human health

Multi-centre and multi-vendor reproducibility of a standardized protocol for quantitative susceptibility Mapping of the human brain at 3T

: Quantitative Susceptibility Mapping (QSM) is an MRI-based technique allowing the non-invasive quantification of iron content and myelination in the brain. The RIN - Neuroimaging Network established an optimized and harmonized protocol for QSM across ten sites with 3T MRI systems from three different vendors to enable multicentric studies. The assessment of the reproducibility of this protocol is crucial to establish susceptibility as a quantitative biomarker. In this work, we evaluated cross-vendor reproducibility in a group of six traveling brains. Then, we recruited fifty-one volunteers and measured the variability of QSM values in a cohort of healthy subjects scanned at different sites, simulating a multicentric study. Both voxelwise and Region of Interest (ROI)-based analysis on cortical and subcortical gray matter were performed. The traveling brain study yielded high structural similarity (∼0.8) and excellent reproducibility comparing maps acquired on scanners from two different vendors. Depending on the ROI, we reported a quantification error ranging from 0.001 to 0.017&nbsp;ppm for the traveling brains. In the cohort of fifty-one healthy subjects scanned at nine different sites, the ROI-dependent variability of susceptibility values, of the order of 0.005-0.025&nbsp;ppm, was comparable to the result of the traveling brain experiment. The harmonized QSM protocol of the RIN - Neuroimaging Network provides a reliable quantification of susceptibility in both cortical and subcortical gray matter regions and it is ready for multicentric and longitudinal clinical studies in neurological and pychiatric diseases

Manipulating Light with Tunable Nanoantennas and Metasurfaces

The extensive progress in nanofabrication techniques enabled innovative methods for molding light at the nanoscale. Subwavelength structured optical elements and, in general, metasurfaces and metamaterials achieved promising results in several research areas, such as holography, microscopy, sensing and nonlinear optics. Still, a demanding challenge is represented by the development of innovative devices with reconfigurable optical properties. Here, we review recent achievements in the field of tunable metasurface. After a brief general introduction about metasurfaces, we will discuss two different mechanisms to implement tunable properties of optical elements at the nanoscale. In particular, we will first focus on phase-transition materials, such as vanadium dioxide, to tune and control the resonances of dipole nanoantennas in the near-infrared region. Finally, we will present a platform based on an AlGaAs metasurface embedded in a liquid crystal matrix that allows the modulation of the generated second harmonic signal