Experimental Evidence for a Structural-Dynamical Transition in Trajectory Space

Among the key insights into the glass transition has been the identification of a non-equilibrium phase transition in trajectory space which reveals phase coexistence between the normal supercooled liquid (active phase) and a glassy state (inactive phase). Here we present evidence that such a transition occurs in experiment. In colloidal hard spheres we find a non-Gaussian distribution of trajectories leaning towards those rich in locally favoured structures (LFS), associated with the emergence of slow dynamics. This we interpret as evidence for an non-equilibrium transition to an inactive LFS-rich phase. Reweighting trajectories reveals a first-order phase transition in trajectory space between a normal liquid and a LFS-rich phase. We further find evidence of a purely dynamical transition in trajectory space.Comment: 5 page

The Impact of Migration on Productivity:Evidence from the United Kingdom

The UK saw a sharp rise in work-related migration, particularly from the EU, in the 2000s and 2010s, with profound impacts on the labour market. We investigate the relationship between migration and productivity in Great Britain between 2002 and 2018, using an instrumental variable approach which follows the commonly used shift-share methodology. Our results, which are robust to a variety of tests, suggest that immigration has a positive and significant impact (in both the statistical sense and more broadly) on productivity, as measured by GVA per job at the Travel-to-Work-Area level. We indeed find that a 1 p.p. increase in the share of migrants is associated with a 0.84 % increase in productivity in 2SLS estimates. We discuss the implications for post-Brexit immigration policy.</p

Two Empirical Essays in Labour Economics

This thesis includes two essays which empirically deal with topics in labour economics. Both chapters are co-authored with Luca Nunziata and Lorenzo Rocco, and employ data from Swiss Census, a rich dataset providing a large set of information, at individual level, on the whole population of residents in Switzerland. In the first chapter we explore the link between the propensity to engage in entrepreneurship and language, at individual level. We focus on one structural feature of languages’ grammar: the way time is encoded and, in particular, how languages differ in the syntactic expression of future events, i.e. whether they require or not the use of an explicit future marker. The heterogeneity across languages, along this dimension, may indeed affect cognitive domain and the way individuals perceive time, potentially leading to a difference in economic behaviours, especially those involving intertemporal choices. Starting from Chen (2013) linguistic-investment hypothesis, which relates the way languages’ grammar prescribes to mark future events and intertemporal decision (savings, healthy behaviours), we use data from 2000 Swiss Census in order to investigate the relationship between language and propensity to be entrepreneur. Our baseline estimates rely on the pooled populations of natives, first and second generation immigrants. The empirical strategy employes several techniques which aim at disentangling the individual effect of language future reference from regional and cultural effects nested in linguistic affiliation. We find that, in line with the theoretical hypothesis, futureless languages speakers (Weak Future Refence) are more likely to be entrepreneur with respect to Strong Future Reference languages speakers. In the second cahpter we analyse the impact of immigration on three labour market outcomes among native workers: the decision to be entrepreneur, the transition to high skilled occupations and the displacement from the professional sector of specialization embodied by their vocational education or training. We employ data from four waves of the complete Swiss Population Census covering the period 1970-2000 to build a panel dataset at the district level and adopt a quasi-experimental setting to deal with endogeneity of migration inflows. Our estimates show that an increase in immigration positively affects the share of native entrepreneurs, including low skilled, and leads to a higher regional share of natives in high skilled occupations. As regards sector displacement, native workers tend to move from their sector of specialization as a response to an increase in immigration, although they tend to stay within their macro-professional sector of origin, and move less across macrosectors. Finally, we find that foreign-born inflows are correlated to natives movements to occupations with a higher degree of cognitive, communicational and analytical skills

Immigrant inventors and diversity in the age of mass migration

A possible unintended but damaging consequence of anti-immigrant rhetoric, and the policies it inspires, is that they may put high-skilled immigrants off more than low-skilled ones at times when countries and businesses intensify their competition for global talent. We investigate this argument following the location choices of thousands of immigrant inventors across US counties during the Age of Mass Migration. To do so we combine a unique USPTO historical patent dataset with Census data and exploit exogenous variation in both immigration flows and diversity induced by former settlements, WWI and the 1920s Immigration Acts. We find that co-ethnic networks play an important role in attracting immigrant inventors. However, we also find that immigrant diversity acts as an additional significant pull factor. This is mainly due to externalities that foster immigrant inventors’ innovativeness. These findings are relevant for todays advanced economies that have become major receivers of migrant flows and, in a long-term perspective, have started thinking about immigration in terms of not only level but also composition

Notch Signaling Regulates Immune Responses in Atherosclerosis

Atherosclerosis is a chronic autoimmune inflammatory disease that can cause coronary artery disease, stroke, peripheral artery disease, depending on which arteries are affected. At the beginning of atherosclerosis plasma lipoproteins accumulate in the sub-endothelial space. In response, monocytes migrate from the circulation through the endothelium into the intima where they differentiate into macrophages. These early events trigger a complex immune response that eventually involves many cellular subtypes of both innate and adaptive immunity. The Notch signaling pathway is an evolutionary conserved cell signaling system that mediates cell-to-cell communication. Recent studies have revealed that Notch modulate atherosclerosis by controlling macrophages polarization into M1 or M2 subtypes. Furthermore, it is known that Notch signaling controls differentiation and activity of T-helper and cytotoxic T-cells in inflammatory diseases. In this review, we will discuss the role of Notch in modulating immunity in the context of atherosclerosis and whether targeting Notch may represent a therapeutic strategy

Energy Monitoring And Benchmarking In Wastewater Treatment Plants Using The ENERWATER Approach

One of the higher costs of wastewater services is the energy consumption. The total electricity consumption in wastewater treatment plants (WWTPs) corresponds to about 1% of the total electricity consumption per year of a country (Cao et al., 2011). In order to compare WWTPs having different processes and scheme configurations, the most useful methodology is energy efficiency measurement using benchmarking procedures (Parena et al., 2002). However, the available audit methodologies do not support well the decisions of the water utilities in order to best target their actions to improve the energy efficiency. Traditionally, energy consumption of a WWTP has been simplistically reported using global KPIs such as kWh/m3 (Mizuta and Shimada, 2010) or kWh/PE (Krampe, 2013; Balmer, 2000). As WWTPs are composed by several stages, each one with a different function, the use of specific KPIs for each treatment stage or function is more appropriate (Longo et al., 2016). A standard methodology is required in order to carry out the energy audit in WWTPs (Tao et al., 2009). Horizon2020 ENERWATER project (www.enerwater.eu ) deals, inter alia, with development of a standard methodology for continuously assessing, labelling and improving the overall performance of WWTPs. The objective of this study is to illustrate the application of the ENERWATER methodology to three real wastewater treatment plants (WWTPs). The ENERWATER methodology considers two approaches for the determination of energy consumption in WWTPs, namely Rapid Audit and Decision Support. The Rapid Audit allows for a quick estimation of the water treatment energy index (WTEI) based on existing information such as historical data pertaining to energy use records along with influent and effluent quality values. The Decision Support requires intensive monitoring across a WWTP of energy usage and water quality parameters that provides an accurate and detailed calculation of WTEI for each stage as well as its overall value for the plant. For the sake of brevity only the results of the Rapid Audit methodology will be presented here

Retrieval of phase relation and emission profile of quantum cascade laser frequency combs

The major development recently undergone by quantum cascade lasers has effectively extended frequency comb emission to longer-wavelength spectral regions, i.e. the mid and far infrared. Unlike classical pulsed frequency combs, their mode-locking mechanism relies on four-wave mixing nonlinear processes, with a temporal intensity profile different from conventional short-pulses trains. Measuring the absolute phase pattern of the modes in these combs enables a thorough characterization of the onset of mode-locking in absence of short-pulses emission, as well as of the coherence properties. Here, by combining dual-comb multi-heterodyne detection with Fourier-transform analysis, we show how to simultaneously acquire and monitor over a wide range of timescales the phase pattern of a generic frequency comb. The technique is applied to characterize a mid-infrared and a terahertz quantum cascade laser frequency comb, conclusively proving the high degree of coherence and the remarkable long-term stability of these sources. Moreover, the technique allows also the reconstruction of electric field, intensity profile and instantaneous frequency of the emission.Comment: 20 pages. Submitted to Nature Photonic

Impact-based flash-flood forecasting system: Sensitivity to high resolution numerical weather prediction systems and soil moisture

In recent years, continuous improvements have been made in weather forecasting and flood prediction with great benefit from Early Warning Systems (EWSs). Despite the continuous quest for innovation from the scientific and user communities, EWSs remain based mostly on hazard forecast, and the information on possible consequences and potential impacts is generally missing. In this work, a methodology for quantitative real-time impact assessment for flash floods is presented. The methodology uses a multi-model ensemble approach and considers soil moisture uncertainty. Moreover, the flood forecasting chain, which normally provides only the discharge probability of exceeding a given threshold, is extended to include a fully 2D hydraulic model and a damage estimation model to quantitatively assess impacts in terms of economic losses and the people involved. The procedure was tested on recent flood events occurring in Genoa in northwestern Italy. This paper discusses the potential challenges and opportunities offered by this approach in the decision-making workflow in an operational context

Magneto-optical probe for investigation of multiphase fe oxide nanosystems

In iron oxide nanoparticles the transformation of the metastable magnetite phase to maghemite, through the oxidation of iron, often represents a major drawback for correct interpretation of their physical properties and their effective use in several applicative areas. To solve this issue we propose an innovative method for identifying the chemical composition of complex ferrite nanostructures based on magneto-optical (MO) spectroscopy. Spherical iron oxide nanoparticles with increasing size are investigated by magnetic circular dichroism (MCD) in the nUV-vis-nIR range (350-1000 nm). Particular attention is dedicated to the time evolution of the MO response, which is ascribable to the oxidation process of the nanomaterial. The measured MCD spectra show a complex line shape due to the overlap of several MO transitions. Deconvolution analysis of MCD hysteresis loops allows the interpretation of this complex response as the combination of two distinct contributions, originating from magnetite and maghemite domains in the nanoparticles. We consider this method a viable complement to conventional techniques for the discrimination of the two magnetic phases in nanostructured materials

The Use of Music and Brain Stimulation in Clinical Settings: Frontiers and Novel Approaches for Rehabilitation in Pathological Aging

Aging is a phase of life characterized by the increasing risk of occurring neurodegenerative pathologies, as well as stroke and physical decline. Patients in such clinical conditions are known to benefit from programs able to promote the improvement of associated cognitive, functional, and behavioral disorders. In recent times, growing empirical evidence showed the efficacy of active and passive music-based interventions to be the highest when used for healing these diseases. Additionally, very latest research found the combination of electrical neurostimulation with music to have potential utility for clinical older adult populations, as it may amplify the impulse to neuroplasticity and, by consequence, the rehabilitation gains. Reiterating of active music making induces changes in multiple brain regions bringing to the enhancement of cognitive and sensorimotor skills, while merely listening to pleasurable music stimulates dopaminergic regions of the brain improving cognition, motivation, and mood in a variety of neurological diseases. The versatility of music-based interventions in combination with new technologies allows an effective application of innovative therapeutic techniques. Moreover, their easy implementation in healthcare settings and their positive effects on both recovery and patients’ quality of life makes the integration of music-based interventions with conventional rehabilitation approaches highly desirable