14,522 research outputs found

    Essays on monetary policy and financial stability

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    Doutoramento em EconomiaBy focusing on the relationship between financial stability and monetary policy for the cases of Chile, Colombia, Japan, Portugal and the UK, this thesis aims to add to the existing literature on the fundamental issue of the relationship between financial stability and monetary policy, a traditional topic that gained importance in the aftermath of the GFC as Central Banks lowered policy rates in an effort to rescue their economies. As the zero-lower bound loomed and the reach of traditional monetary policy narrowed, policy makers realised that alternative frameworks were needed and hence, macroprudential policy measures aimed at targeting the financial system as a whole were introduced. The second chapter looks at the relationship between monetary policy and financial stability, which has gained importance in recent years as Central Bank policy rates neared the zero-lower bound. We use an SVAR model to study the impact of monetary policy shocks on three proxies for financial stability as well as a proxy for economic growth. Monetary policy is represented by policy rates for the EMEs and shadow rates for the AEs in our chapter. Our main results show that monetary policy may be used to correct asset mispricing, to control fluctuations in the real business cycle and also to tame credit cycles in the majority of cases. Our results also show that for the majority of cases, in line with theory, local currencies appreciate following a positive monetary policy shock. Monetary policy intervention may indeed be successful in contributing to or achieving financial stability. However, the results show that monetary policy may not have the ability to maintain or re-establish financial stability in all cases. Alternative policy choices such as macroprudential policy tool frameworks which are aimed at targeting the financial system as a whole may be implemented as a means of fortifying the economy. The third chapter looks at the institutional setting of the countries in question, the independence of the Central Bank, the political environment and the impact of these factors on financial Abstract stability. I substantiate the literature review discussion with a brief empirical analysis of the effect of Central Bank Independence on credit growth using an existing database created by Romelli (2018). The empirical results show that there is a positive relationship between credit growth and the level of Central Bank Independence (CBI) due to the positive and statistically significant coefficient on the interaction term between growth in domestic credit to the private sector and the level of CBI. When considering domestic credit by deposit money banks and other financial institutions, the interaction term is positive and statistically significant for the case of the UK for the third regression equation. A number of robustness checks show that the coefficient is positive and statistically significant for a number of cases when implementing a variety of estimation methods. Fluctuations in credit growth are larger for higher levels of CBI and hence, in periods of financial instability or ultimately financial crises, CBI would be reined back in an effort to re-establish financial stability. Based on the empirical results, and in an effort to slow down surging credit supply and to maintain financial stability, policy makers and governmental authorities should attempt to decrease the level of CBI when the economy shows signs of overheating and credit supply continues to increase. The fourth chapter looks at the interaction between macroprudential policy and financial stability. The unexpected interconnectedness of the global economy and the economic blight that occurred as a result of this, recapitulated the need to implement an alternative policy framework aimed at targeting the financial system as a whole and hence, targeting the maintenance of financial stability. In this chapter, an index of domestic macroprudential policy tools is constructed and the effectiveness of these tools in controlling credit growth, managing GDP growth and stabilising inflation growth is studied using a dynamic panel data model for the period between 2000 and 2017. The empirical analysis includes two panels namely an EU panel of 27 countries and a Latin American panel of 7 countries, the chapter also looks at a case study of Japan, Portugal and the UK. Our main results find that a tighter macroprudential policy tool stance leads to a decrease in both credit growth and GDP growth while, a tighter macroprudential policy tool stance results in higher inflation in the majority of cases. Further, we find that capital openness plays a more important role in the case of Latin America, this may be due to the region’s dependence on foreign capital flows and exchange rate movements. Lastly, we find that, in times of higher perceived market volatility, GDP growth tends to be higher and inflation growth tends to be lower in the EU. In the other cases, higher levels of perceived market volatility result in higher inflation, higher credit growth and lower GDP Abstract growth. This is in line with expectations as an increase in perceived market volatility is met with an increased flow of assets into safer markets such as the EU. This thesis establishes a relationship between financial stability and monetary policy by studying the response of Chile, Colombia, Japan, Portugal and the UK in the aftermath of the GFC as Central Banks lowered policy rates in an effort to rescue their economies. In short, the results of the work conducted in this thesis may be summarised as follows. Our results show that monetary policy contributes to the achievement of financial stability. Still, monetary policy alone is not sufficient and should be reinforced by less traditional policy choices such as macroprudential policy tools. Secondly, we find that the level of CBI should be reined in in times of surging credit supply in an effort to maintain financial stability. Finally, we conclude that macroprudential policy tools play an important role in the achievement of financial stability. These tools should complement traditional monetary policy frameworks and should be adapted for each region.info:eu-repo/semantics/publishedVersio

    Aero-thermal analysis of a laminar separation bubble subjected to varying free-stream turbulence: Large Eddy Simulation

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    A quantitative analysis illustrating salient features of a Laminar Separation Bubble (LSB), its transition forming coherent structures, and associated heat transfer has been performed on a flat plate for varying free stream turbulence (fst) between 1.2% to 10.3%. A well-resolved Large Eddy Simulation (LES) developed in-house is used for the purpose. Flow separation has been induced by imposing an adverse pressure gradient on the upper boundary of a Cartesian domain. Isotropic perturbations are introduced at the inlet to mimic grid turbulence. With an increase of fst, an upstream shift in the mean reattachment point has been observed while the onset of separation remains almost invariant, shrinking the bubble length significantly. The transition of the shear layer is triggered by the Kelvin-Helmholtz (K-H) instability for fst of less than 3.3%, while Klebanoff modes (Kmodes) dictate the flow transition at fst greater than 6.5%. Further, a mixed mode, i.e., both K-H and K-modes, contribute to the flow transition at a moderate level of fst, lying between 3.3% and 6.5%. Thus, the roll-up of the shear layer appears in the second half of the bubble shedding large-scale vortices that keep their identity far downstream at low fst levels. On the contrary, the streamwise streaks via K-modes prior to the separation are found to interact with the LSB, resulting in an earlier breakdown of the shear layer with abundant small-scale vortices downstream at the moderate to high fst levels. However, higher surface-normal heat flux is associated with large-scale energetic coherent vortices

    A Design Science Research Approach to Smart and Collaborative Urban Supply Networks

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    Urban supply networks are facing increasing demands and challenges and thus constitute a relevant field for research and practical development. Supply chain management holds enormous potential and relevance for society and everyday life as the flow of goods and information are important economic functions. Being a heterogeneous field, the literature base of supply chain management research is difficult to manage and navigate. Disruptive digital technologies and the implementation of cross-network information analysis and sharing drive the need for new organisational and technological approaches. Practical issues are manifold and include mega trends such as digital transformation, urbanisation, and environmental awareness. A promising approach to solving these problems is the realisation of smart and collaborative supply networks. The growth of artificial intelligence applications in recent years has led to a wide range of applications in a variety of domains. However, the potential of artificial intelligence utilisation in supply chain management has not yet been fully exploited. Similarly, value creation increasingly takes place in networked value creation cycles that have become continuously more collaborative, complex, and dynamic as interactions in business processes involving information technologies have become more intense. Following a design science research approach this cumulative thesis comprises the development and discussion of four artefacts for the analysis and advancement of smart and collaborative urban supply networks. This thesis aims to highlight the potential of artificial intelligence-based supply networks, to advance data-driven inter-organisational collaboration, and to improve last mile supply network sustainability. Based on thorough machine learning and systematic literature reviews, reference and system dynamics modelling, simulation, and qualitative empirical research, the artefacts provide a valuable contribution to research and practice

    Complement mediated synapse elimination in schizophrenia

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    Schizophrenia (SCZ) is a devastating psychiatric disorder with a typically age of onset in late adolescence. The heritability is estimated to be in between 60-80% and large-scale genome-wide studies have revealed a prominent polygenic component to SCZ risk and identified more than three-hundred common risk variants. Despite a better understanding of which genetic risk variants that increases SCZ risk, it has been challenging to map out the pathophysiology of the disorder. This has stalled the development of target drugs and current treatment options display moderate efficacy and are prone to produce side-effects. SCZ is generally considered a neurodevelopmental disorder and it was proposed more than forty years ago that physiological removal of less active synapses in adolescence, i.e., synaptic pruning, is increased in SCZ and hereby causes the core symptoms of the disorder. This theory has then been supported by post-mortem brain tissue and imaging studies displaying decreased synapse density in SCZ. More recently, it was then shown that the most strongly associated risk loci can largely be explained by copy numbers of a gene coding for the complement factor 4A (C4A). As microglia prune synapses with the help of complement signalling, we therefore decided to use a recently developed human 2D in vitro assay to assess microglial uptake of synaptic structures in models based on cells from individuals with SCZ and healthy controls (study I). We observed excessive uptake of synaptic structures in SCZ models and by mixing synapses from healthy controls with microglia from SCZ patients, and vice versa, we showed the contribution of microglial and neuronal factors contributing to this excessive uptake of synaptic structures. We then developed an in vitro assay to study neuronal complement deposition dependent on copy numbers of C4A in the neuronal lines. Complement 3 (C3) deposition increased by C4A copy numbers but was independent of C4B copy numbers (also unrelated to SCZ risk). Similar C4A copy numbers correlated with the extent of microglial uptake of synapses. Microglial uptake of synaptic structures could also be inhibited by the tetracycline minocycline that also decreased risk of developing SCZ in an electronic health record cohort. In study II, we cerebrospinal fluid (CSF) from first-episode psychosis patients to measure protein levels of C4A. In two independent cohorts, we observed elevated C4A levels (although not C4B levels) in first-episode patients that later were to develop SCZ and could show correlations with markers of synapse density. However, elevated C4A levels could not fully be explained by more copy numbers of C4A in individuals with SCZ and in vitro experiments revealed that SCZ-associated cytokines can induce C4A mRNA expression while also correlating with C4A in patient-derived CSF. In study III, we set-up a 3D brain organoid models to more fully comprehensively capture processes in the developing human brain and then also included innately developing microglia. We display synaptic pruning within these models and use single cell RNA sequencing to validate them. In conclusion, this thesis uses patient-derived cellular modelling to uncover a disease mechanism in SCZ that link genetic risk variants with bona fide protein changes in living patients

    A Visual Modeling Method for Spatiotemporal and Multidimensional Features in Epidemiological Analysis: Applied COVID-19 Aggregated Datasets

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    The visual modeling method enables flexible interactions with rich graphical depictions of data and supports the exploration of the complexities of epidemiological analysis. However, most epidemiology visualizations do not support the combined analysis of objective factors that might influence the transmission situation, resulting in a lack of quantitative and qualitative evidence. To address this issue, we have developed a portrait-based visual modeling method called +msRNAer. This method considers the spatiotemporal features of virus transmission patterns and the multidimensional features of objective risk factors in communities, enabling portrait-based exploration and comparison in epidemiological analysis. We applied +msRNAer to aggregate COVID-19-related datasets in New South Wales, Australia, which combined COVID-19 case number trends, geo-information, intervention events, and expert-supervised risk factors extracted from LGA-based censuses. We perfected the +msRNAer workflow with collaborative views and evaluated its feasibility, effectiveness, and usefulness through one user study and three subject-driven case studies. Positive feedback from experts indicates that +msRNAer provides a general understanding of analyzing comprehension that not only compares relationships between cases in time-varying and risk factors through portraits but also supports navigation in fundamental geographical, timeline, and other factor comparisons. By adopting interactions, experts discovered functional and practical implications for potential patterns of long-standing community factors against the vulnerability faced by the pandemic. Experts confirmed that +msRNAer is expected to deliver visual modeling benefits with spatiotemporal and multidimensional features in other epidemiological analysis scenarios

    Anuário científico da Escola Superior de Tecnologia da Saúde de Lisboa - 2021

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    É com grande prazer que apresentamos a mais recente edição (a 11.ª) do Anuário Científico da Escola Superior de Tecnologia da Saúde de Lisboa. Como instituição de ensino superior, temos o compromisso de promover e incentivar a pesquisa científica em todas as áreas do conhecimento que contemplam a nossa missão. Esta publicação tem como objetivo divulgar toda a produção científica desenvolvida pelos Professores, Investigadores, Estudantes e Pessoal não Docente da ESTeSL durante 2021. Este Anuário é, assim, o reflexo do trabalho árduo e dedicado da nossa comunidade, que se empenhou na produção de conteúdo científico de elevada qualidade e partilhada com a Sociedade na forma de livros, capítulos de livros, artigos publicados em revistas nacionais e internacionais, resumos de comunicações orais e pósteres, bem como resultado dos trabalhos de 1º e 2º ciclo. Com isto, o conteúdo desta publicação abrange uma ampla variedade de tópicos, desde temas mais fundamentais até estudos de aplicação prática em contextos específicos de Saúde, refletindo desta forma a pluralidade e diversidade de áreas que definem, e tornam única, a ESTeSL. Acreditamos que a investigação e pesquisa científica é um eixo fundamental para o desenvolvimento da sociedade e é por isso que incentivamos os nossos estudantes a envolverem-se em atividades de pesquisa e prática baseada na evidência desde o início dos seus estudos na ESTeSL. Esta publicação é um exemplo do sucesso desses esforços, sendo a maior de sempre, o que faz com que estejamos muito orgulhosos em partilhar os resultados e descobertas dos nossos investigadores com a comunidade científica e o público em geral. Esperamos que este Anuário inspire e motive outros estudantes, profissionais de saúde, professores e outros colaboradores a continuarem a explorar novas ideias e contribuir para o avanço da ciência e da tecnologia no corpo de conhecimento próprio das áreas que compõe a ESTeSL. Agradecemos a todos os envolvidos na produção deste anuário e desejamos uma leitura inspiradora e agradável.info:eu-repo/semantics/publishedVersio

    Bridging technology and educational psychology: an exploration of individual differences in technology-assisted language learning within an Algerian EFL setting

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    The implementation of technology in language learning and teaching has a great influence onthe teaching and learning process as a whole and its impact on the learners’ psychological state seems of paramount significance, since it could be either an aid or a barrier to students’ academic performance. This thesis therefore explores individual learner differences in technology-assisted language learning (TALL) and when using educational technologies in higher education within an Algerian English as a Foreign Language (EFL) setting. Although I initially intended to investigate the relationship between TALL and certain affective variables mainly motivation, anxiety, self-confidence, and learning styles inside the classroom, the collection and analysis of data shifted my focus to a holistic view of individual learner differences in TALL environments and when using educational technologies within and beyond the classroom. In an attempt to bridge technology and educational psychology, this ethnographic case study considers the nature of the impact of technology integration in language teaching and learning on the psychology of individual language learners inside and outside the classroom. The study considers the reality constructed by participants and reveals multiple and distinctive views about the relationship between the use of educational technologies in higher education and individual learner differences. It took place in a university in the north-west of Algeria and involved 27 main and secondary student and teacher participants. It consisted of focus-group discussions, follow-up discussions, teachers’ interviews, learners’ diaries, observation, and field notes. It was initially conducted within the classroom but gradually expanded to other settings outside the classroom depending on the availability of participants, their actions, and activities. The study indicates that the impact of technology integration in EFL learning on individual learner differences is both complex and dynamic. It is complex in the sense that it is shown in multiple aspects and reflected on the students and their differences. In addition to various positive and different negative influences of different technology uses and the different psychological reactions among students to the same technology scenario, the study reveals the unrecognised different manifestations of similar psychological traits in the same ELT technology scenario. It is also dynamic since it is characterised by constant change according to contextual approaches to and practical realities of technology integration in language teaching and learning in the setting, including discrepancies between students’ attitudes and teacher’ actions, mismatches between technological experiences inside and outside the classroom, local concerns and generalised beliefs about TALL in the context, and the rapid and unplanned shift to online educational delivery during the Covid-19 pandemic situation. The study may therefore be of interest, not only to Algerian teachers and students, but also to academics and institutions in other contexts through considering the complex and dynamic impact of TALL and technology integration at higher education on individual differences, and to academics in similar low-resource contexts by undertaking a context approach to technology integration

    A direct-laser-written heart-on-a-chip platform for generation and stimulation of engineered heart tissues

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    In this dissertation, we first develop a versatile microfluidic heart-on-a-chip model to generate 3D-engineered human cardiac microtissues in highly-controlled microenvironments. The platform, which is enabled by direct laser writing (DLW), has tailor-made attachment sites for cardiac microtissues and comes with integrated strain actuators and force sensors. Application of external pressure waves to the platform results in controllable time-dependent forces on the microtissues. Conversely, oscillatory forces generated by the microtissues are transduced into measurable electrical outputs. After characterization of the responsivity of the transducers, we demonstrate the capabilities of this platform by studying the response of cardiac microtissues to prescribed mechanical loading and pacing. Next, we tune the geometry and mechanical properties of the platform to enable parametric studies on engineered heart tissues. We explore two geometries: a rectangular seeding well with two attachment sites, and a stadium-like seeding well with six attachment sites. The attachment sites are placed symmetrically in the longitudinal direction. The former geometry promotes uniaxial contraction of the tissues; the latter additionally induces diagonal fiber alignment. We systematically increase the length for both configurations and observe a positive correlation between fiber alignment at the center of the microtissues and tissue length. However, progressive thinning and “necking” is also observed, leading to the failure of longer tissues over time. We use the DLW technique to improve the platform, softening the mechanical environment and optimizing the attachment sites for generation of stable microtissues at each length and geometry. Furthermore, electrical pacing is incorporated into the platform to evaluate the functional dynamics of stable microtissues over the entire range of physiological heart rates. Here, we typically observe a decrease in active force and contraction duration as a function of frequency. Lastly, we use a more traditional ?TUG platform to demonstrate the effects of subthreshold electrical pacing on the rhythm of the spontaneously contracting cardiac microtissues. Here, we observe periodic M:N patterns, in which there are ? cycles of stimulation for every ? tissue contractions. Using electric field amplitude, pacing frequency, and homeostatic beating frequencies of the tissues, we provide an empirical map for predicting the emergence of these rhythms

    Identifying and responding to people with mild learning disabilities in the probation service

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    It has long been recognised that, like many other individuals, people with learningdisabilities find their way into the criminal justice system. This fact is not disputed. Whathas been disputed, however, is the extent to which those with learning disabilities arerepresented within the various agencies of the criminal justice system and the ways inwhich the criminal justice system (and society) should address this. Recently, social andlegislative confusion over the best way to deal with offenders with learning disabilities andmental health problems has meant that the waters have become even more muddied.Despite current government uncertainty concerning the best way to support offenders withlearning disabilities, the probation service is likely to continue to play a key role in thesupervision of such offenders. The three studies contained herein aim to clarify the extentto which those with learning disabilities are represented in the probation service, toexamine the effectiveness of probation for them and to explore some of the ways in whichprobation could be adapted to fit their needs.Study 1 and study 2 showed that around 10% of offenders on probation in Kent appearedto have an IQ below 75, putting them in the bottom 5% of the general population. Study 3was designed to assess some of the support needs of those with learning disabilities in theprobation service, finding that many of the materials used by the probation service arelikely to be too complex for those with learning disabilities to use effectively. To addressthis, a model for service provision is tentatively suggested. This is based on the findings ofthe three studies and a pragmatic assessment of what the probation service is likely to becapable of achieving in the near future
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