2,031 research outputs found
Towards New High-Order Operator Splitting Time-Integration Methods
Operator splitting (OS) methods represent a powerful strategy to solve
an extensive range of mathematical models in the form of
differential equations. They have a long and celebrated history,
having been successfully used for well over half a century to provide
efficient numerical solutions to challenging problems. In fact, OS methods are
often the only viable way to solve many problems in practice.
The simplest, and perhaps, most well-known OS methods are Lie--Trotter--Godunov and the Strang--Marchuk methods. They compute a numerical solution that is first-, and second-order accurate in time, respectively.
OS methods can be derived by imposing order conditions using the Campbell--Baker--Hausdorff formula. It follows that, by setting the appropriate order conditions, it is possible to derive OS methods of any desired order. An important observation regarding OS methods with order higher than two is that, according to the Sheng--Suzuki theorem, at least one of their defining coefficients must be negative.
Therefore, the time integration with OS methods of order higher than two has not been considered suitable to solve deterministic parabolic problems, because the necessary backward time integration would cause instabilities.
Throughout this thesis, we focus our attention on high-order (i.e., order higher than two) OS methods. We successfully assess the convergence properties of some higher-order OS methods on diffusion-reaction problems describing cardiac electrophysiology and on an advection-diffusion-reaction problem describing chemical combustion. Furthermore, we compare the efficiency performance of higher-order methods to second-order methods. For all the cases considered, we confirm an improved efficiency performance compared to methods of lower order.
Next, we observe how, when using OS and Runge--Kutta type methods to advance the time integration, we can construct a unique extended Butcher tableau with a similar structure to the ones describing Generalized Additive Runge--Kutta (GARK) methods. We define a combination of methods to be OS-GARK methods. We apply linear stability analysis to OS-GARK methods; this allows us to conveniently analyze the stability properties of any combination of OS and Runge--Kutta methods. Doing so, we are able to perform an eigenvalue analysis to understand and improve numerically unstable solutions
Efficacy of the Identity Project intervention in Italian multiethnic classrooms
openThis final dissertation aims to lay out the results of one of the implementations of the Identity Project in its Italian adaptation. It seeks to analyse the general efficacy of the project as carried out in some multicultural high school classes in the area of Padova, by looking into the variables of cultural identity exploration and resolution. A brief understanding of the theoretical background for the project will be provided, with reference to the concept of cultural identity and the theory by Erikson. The reasons for implementation will be made clear through an overview of the current situation of culturally diverse school classes in Italy, and the related governmental policies. Finally, the beneficial effects of the Identity Project will be presented, confirming the enhancement of identity exploration processes in the adolescents participating in the project.This final dissertation aims to lay out the results of one of the implementations of the Identity Project in its Italian adaptation. It seeks to analyse the general efficacy of the project as carried out in some multicultural high school classes in the area of Padova, by looking into the variables of cultural identity exploration and resolution. A brief understanding of the theoretical background for the project will be provided, with reference to the concept of cultural identity and the theory by Erikson. The reasons for implementation will be made clear through an overview of the current situation of culturally diverse school classes in Italy, and the related governmental policies. Finally, the beneficial effects of the Identity Project will be presented, confirming the enhancement of identity exploration processes in the adolescents participating in the project
TikTok use in municipal elections: from candidate-majors to influencer-politicians
TikTok is without any doubt the most successful social network among Gen Zers and, consequently, is increasingly becoming their preferred place to discuss, share opinions, rally around social issues, and express political alignments. Accordingly, both politicians and political parties around the world are joining the platform to connect with young voters: previous exploratory studies, however, have shown that most political actors struggle to adapt to the platform's affordances, appearing cringy, out of touch, or simply using TikTok as an «old medium», without utilizing it to enhance interaction with citizens. This article contributes to the emerging stream of literature looking at the political uses of this platform in electoral campaigns by studying its application in a local election, focusing on how Ada Colau, candidate mayor for the 2023 Barcelona Municipal elections, has integrated TikTok in her communication strategy. Applying an affordance-based multimodal content analysis of all the tiktoks posted during the campaign, the paper discloses that, although not fully exploiting the platform's affordances -in particular its participatory potential- the candidate optimally adapts to its vernaculars and cultural environment, constructing a highly recognizable personal style, which seems to borrow and implement the marketing techniques used by influencers and internet celebrities. Therefore, the study concludes that Ada Colau can be considered an example of a new category of celebrity politician, the «influencer-politician», suggesting that future research should dig deeper into this novel dynamic of hybridization and cross-pollination between politics and digital cultures.TikTok es la red social de mayor éxito entre la llamada Generación Z y se está convirtiendo en su lugar preferido para debatir, compartir opiniones sobre temas sociales y expresar su posicionamiento político. Por consecuente, los políticos quieren usar la plataforma para conectar con los jóvenes: sin embargo, estudios anteriores han demostrado que la mayoría de los actores políticos tienen dificultades para adaptarse a las posibilidades de la plataforma, pareciendo fuera de lugar o utilizando TikTok como un «viejo medio», sin aprovecharlo para mejorar la interacción con los ciudadanos. Este artículo contribuye a la corriente académica que estudia los usos políticos de esta plataforma en las campañas electorales analizando su aplicación en unas elecciones locales, centrándose en cómo Ada Colau, candidata a la alcaldía en las elecciones municipales de Barcelona 2023, ha integrado TikTok en su estrategia de comunicación. A través de un análisis de contenido multimodal basado en las affordances de los tiktoks publicados durante la campaña, se revela que, aunque no explote plenamente las affordances de la plataforma -en particular su potencial participativo-, la candidata se adapta de forma óptima a este entorno tecnológico y cultural, construyendo un estilo personal altamente reconocible, que parece replicar las técnicas de marketing utilizadas por los influencers y las Internet celebrities. El estudio concluye que Ada Colau puede considerarse un ejemplo de una nueva categoría de político, el «influencer-político», sugiriendo que futuras investigaciones profundicen en esta novedosa dinámica de hibridación y mutua polinización entre la política y las culturas digitales
Formation and removal of aldehydes as ozonation by-products in a pilot-scale water treatment plant.
This study investigated the effect of water treatment plant configurations on the formation and removal of aldehydes in a pilot water treatment plant located in Windsor, Ontario, Canada. The plant was operated in non-ozonation, pre-coagulation ozonation, and post-sedimentation ozonation treatment configurations, and ozone dose and flowrate through the anthracite/sand filters were studied to determine the effect on formation and removal of aldehydes in the pilot plant. It was found that formaldehyde, acetaldehyde, glyoxal, and methyl-glyoxal were the main aldehyde species formed as a result of ozonation, with formaldehyde usually being found to be formed at the highest concentrations. Aldehyde formation was found to increase as ozone dose was increased. For removal of aldehydes, it was found that aldehydes were removed marginally in anthracite/sand filtration, and an increase in temperature caused an increase in removal. It was found that low-molecular-mass aldehydes usually decreased, while high-molecular-mass aldehydes only slightly decreased or even increased in anthracite/sand filters, showing that glyoxal and methyl-glyoxal were more difficult to remove in anthracite/sand filtration. Aldehydes consistently showed complete removal in GAC contactors. Finally, at low flowrates through the anthracite/sand filters, there appeared to be a minimum level of aldehydes present in the anthracite/sand filters.Dept. of Civil and Environmental Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1996 .C41. Source: Masters Abstracts International, Volume: 37-01, page: 0356. Adviser: N. Biswas. Thesis (M.A.Sc.)--University of Windsor (Canada), 1996
Exclusionary populism and islamophobia : a comparative analysis of Italy and Spain
Exclusionary populism is well known for twisting real grievances of the citizens, by problematizing the gap between "us" and "them", capitalizing on identity lines, calling out as "others" those who do not share "pure people's" identity and culture. Especially after 9/11, Muslims have become the ideal-type of "other", making Islamophobia the primary populist anti-paradigm. This article contributes to the burgeoning literature on Islamophobic populism analyzing the presence of Islamophobia in the electoral discourse of Vox party in Spain and Lega in Italy. In addition, it makes a novel contribution by discussing and testing the existence of different models of Islamophobia, distinguishing between "banal Islamophobia" and "ontological Islamophobia". Applying clause-based semantic text analysis-including qualitative and quantitative variables-to thirty speeches by the two party leaders, Santiago Abascal and Matteo Salvini, during the last three elections (General, Regional and European), the paper concludes that, despite the similarities, the two politician display two different models of Islamophobia. Whereas Abascal displays a clear "ontological Islamophobia", depicting Muslims ontologically incompatible with Spanish civilization (defined precisely by its anti-Muslim history), the latter presents a mix of arguments that oscillate between "ontological" and "banal" Islamophobia
Primary cytomegalovirus infection in pregnancy: prognostic factors of symptomatic disease determinable within the twenty-second week of gestation
Background. L’infezione primaria da Citomegalovirus (CMV) in gravidanza può portare a infezione congenita in circa il 30% dei casi, di cui 15-20% possono sviluppare sintomi a lungo termine inclusi deficit uditivi e sequele neurologiche. Gravi anomalie cerebrali nello studio ecografico prenatale sono associate a peggiore prognosi, ma è più difficile stabilire gli esiti post-natali nei feti con anomalie ecografiche non gravi.
Obiettivi. Valutazione del potere predittivo di malattia sintomatica delle anomalie ecografiche non gravi, in associazione all’amniocentesi, determinabili entro la ventiduesima settimana di gestazione.
Metodi. Studio prospettico osservazionale di donne con infezione primaria in gravidanza tra il 2007 e 2015: le pazienti sono state sottoposte a studio ecografico e neurosografico della morfologia fetale ed isolamento virale su liquido amniotico tra 20 e 21 settimane di gestazione, ad almeno 6 settimane dal presunto contagio materno. I segni e i sintomi di malattia congenita sono stati valutati alla nascita e al follow up nei nati vivi e attraverso l’esame autoptico nei casi di interruzione di gravidanza.
Risultati. Lo studio ecografico prenatale di 306 gravidanze complicate da infezione primaria da CMV ha rilevato la presenza di anomalie cerebrali lievi e/o extracerebrali in 15 casi (4.9%). Tali reperti si sono dimostrati significativamente associati alla presenza di malattia sintomatica post-natale (OR= 18.5; 95% CI: 5.43-62.8, P<0.001), con alta specificità (97.6%) e valore predittivo negativo (95.6%) La contemporanea presenza di anomalie ecografiche e isolamento di DNA virale su liquido amniotico ha mostrato specificità e valore predittivo negativo pari a 99.7% e 95.7%, mentre la presenza di uno solo dei due reperti ha raggiunto una sensibilità di 94.7% e valore predittivo negativo di 99.6%.
Conclusioni. La valutazione del rischio di malattia sintomatica può essere realizzata prima della ventiduesima settimana con buona sensibilità e specificità, attraverso un dettagliato esame ecografico morfologico ed isolamento virale su liquido amniotico.Background. Primary maternal Cytomegalovirus (CMV) infection during pregnancy can lead to congenital infection in around 30% of newborns, with 15-20% of infected children developing long-term symptoms including hearing loss and neurological sequelae. Severe brain ultrasound anomalies are associated with poor prognosis, but post-natal outcomes of fetuses with mild ultrasound anomalies are difficult to establish.
Objective. The aim of the study was to evaluate the predictive value of mild ultrasound anomalies and viral load in amniotic fluid, performed before twenty-second week of gestation, in relation to the presence of symptomatic congenital disease.
Methods. This is a prospective observational study of pregnant women with primary CMV infection enrolled between 2007 and 2015: fetal ultrasound scan with detailed neurosonogram and viral isolation in amniotic fluid were performed in all pregnancies between 20 and 21 weeks of gestation, at least 6 weeks after maternal infection. Sign and symptoms of congenital infection were evaluated at birth and at neonatal follow up in live-borns, post-mortem examinations were carried out in second trimester aborted fetuses.
Results. Ultrasound fetal scan of 306 pregnant women with primary CMV infection detected the presence of mild cerebral and extracerebral anomalies in 15 cases (4.9%). These features was significantly associated with symptomatic congenital disease (OR= 18.5; 95%CI: 5.43-62.8, P<0.001) with high specificity (97.6%) and high negative predictive value (95.6%). The combined specificity and negative predictive value of ultrasound and viral isolation in amniotic fluid were 99.7% and 95.7%, respectively. The presence of one of this features alone reached sensibility of 94.7% and negative predictive value of 99.6%.
Conclusion. The evaluation of neonatal risk of symptomatic CMV congenital disease can be realized with a good sensibility and specificity through the combination of detailed ultrasound fetal scan and viral isolation within the twenty-second week of gestation
Slični političari, drukčiji mediji: medijski tretman seks-skandala u Italiji i SAD-u
The article analyzes the media treatment of two sex scandals: the “Stormy Daniels scandal”, which involved the current US President Donald Trump in 2018 and the “Ruby scandal”, which involved Silvio Berlusconi in 2010, while he was Italy’s Prime Minister. By combining both quantitative and qualitative methodologies the aim is to discover whether the media treatment is different, as we can expect since the two countries belong to two different media systems, or if, following the theory of Americanization of political communication, the Italian media will tend to emulate the American model. Furthermore, another aim of this study is to detect whether a shift towards a more Polarized Pluralist model can be identified in the USA, as some authors have started foreseeing. The results will show that both countries’ media behave coherently with the traditional feature of their media system, the Polarized Pluralist and the Liberal.Ovaj rad analizira medijski tretman dvaju seks-skandala: skandala „Stormy Daniels“ iz 2018. u koji je bio uključen sadašnji predsjednik SAD-a Donald Trump i skandala „Ruby“ u kojem je sudjelovao Silvio Berlusconi 2010. dok je bio talijanski premijer. U radu se koriste kvantitativne i kvalitativne metode, a cilj je otkriti je li medijski tretman navedenih događaja drukčiji, što očekujemo s obzirom na to da dvije zemlje pripadaju dvama različitim medijskim sustavima, te može li se očekivati, na tragu teorije amerikanizacije političke komunikacije, da bi talijanski mediji mogli biti skloni imitiranju američkog modela. Nadalje, drugi cilj ove studije jest otkriti može li se zaokret prema tzv. polariziranom pluralističkom (talijanskom) modelu pronaći u SAD-u, kako su pojedini autori počeli predviđati. Rezultati su pokazali da se mediji u obje zemlje drže svojih tradicionalnih načina tretiranja događaja koji zanimaju javnost
New Applications of Cardiopulmonary Exercise Testing and Training in Paediatric Heart Disease
Congenital heart defects (CHD) have an incidence of 4-8/1000 live births and encompass a broad spectrum of disorders. Due to advances in cardiac surgery and cardiology care, most children born with CHD are now surviving into adulthood and there are currently more adults affected than children. Exercise capacity is reduced across the spectrum of patients with CHD, both in natural history and after surgical and interventional treatment. The aim of this project was to better understand exercise limitations and safety/usefulness of training in young patients with heart disease across a broad spectrum of disorders and in particular we focused on left-to-right shunts, systemic right ventricular physiology, univentricular physiology with Fontan palliation and dilated cardiomyopathy. Future perspective include exploring new ways of engaging teenagers with univentricular palliation in systemic and respiratory muscle training. Furthermore, the collaboration with biomedical engineers will allow us to gain in depth understanding of univentricular physiology. Similarities exisit in the physiological changes observed during exercise and pregnancy and the final goal is to implement the model with these variables to achieve better clinical outcome in this growing population of young adults with complex lesions and limited exercise and child-bearing potential.
Exercise testing and training are becoming more and more relevant to guide therapy and management but also to assess the ability in daily activities that play an important role in many aspects of life that have not been addressed specifically until now. The increasing data available enable physicians to give adequate counseling regarding vocational or professional choices, suitable leisure activities and family planning according to the levels of activity considered safe and sustainable in the specific physiology. Further studies will warrant deeper understanding of issues that are specific to univentricular physiology and will help us to target interventions to improve quantity and quality of life
Número efetivo de candidatos e desenvolvimento regional em análises de financiamento de campanhas: uma proposta metodológica para comparar os efeitos da monetarização das campanhas eleitorais no Brasil
[ES]El trabajo presenta estudio empírico sobre el efecto de los recursos financieros en los resultados electorales. En Brasil, debido a que es un país de grandes extensiones y heterogeneidad económica, política y social en los distritos electorales, las comparaciones directas son difíciles. Se parte del princpio de que los recursos de campaña tienen pesos diferentes en función de los niveles de la competición politica y de la riqueza regional. Tenemos la intención de proponer un modelo que permite igualar las diferentes condiciones de campaña para evaluar los impactos de los recursos financieros en las disputas. Para ello, hemos utilizado los datos sobre las elecciones de 2010 para diputado federal.[EN]This paper is an empirical study to measure the impact of financial resources on election
campaigns. As Brazil is a large country with economically, politically and socially heterogeneous electoral districts, it is difficult to make direct comparisons regarding the impact of campaign financing on national elections. The study sets out by assuming that campaign resources have different effects depending on the levels of political competitiveness and local wealth. The aim
of the study is to propose a model that will allow different campaign situations to be put on the same level in order to conduct a comparative evaluation of the impacts that financial resources
make on elections. For this purpose, the data for the 2010 elections for Federal Deputy will be
used
Gender and personality in the stress process
This study examines the influence of gender and several personality characteristics in the stress process using a cross-sectional study of 443 university students from a mid-size public New England university, a New England Catholic college, and a mid-size private Florida university. Three models are tested to consider the direct, mediating, and moderating effects of gender and personality on the stress outcomes of drug/alcohol use; non-substance deviant behavior; and depressive symptomatology.
Model 1 tests the antecedent effects of gender and personality to determine their influence on stress outcomes. The main effect of gender explained the largest portion of variance for drug/alcohol use and deviance with men reporting higher prevalence in both outcomes. Self esteem is found to be negatively related to drug/alcohol use and sense of coherence and authoritarianism are negatively related to deviance. Gender is significantly related to depressive symptomatology with women suffering more with this outcome.
Model 2 uses hierarchical regression to test the mediating effects of personality and stressors in the gender-outcome relationship. For the three outcomes tested, gender emerged as the strongest predictor, and the addition of personality and stress variables failed to explain away the sex differences. Personality and stress explain a portion of the sex difference for depressive symptomatology, however the sex difference remained significant. Self esteem and extraversion are significant personality factors mediating between gender and alcohol/drug use; sense of coherence and extraversion are significant personality factors mediating between gender and deviant behavior; and self esteem, neuroticism, mastery, and sense of coherence are significant personality factors mediating between gender and depressive symptomatology. Life events stress is a significant mediating factor in all three outcomes and ongoing problems is a significant factor in alcohol/drug use and depressive symptomatology.
In Model 3 a significant interaction is found between gender and life events stress on alcohol/drug use, with men being effected more at higher levels of stress. The only significant personality-stress interaction is between masculinity and life events on alcohol/drug use with those high in masculinity being affected more at higher levels of stress. Two significant interactions were observed between personality variables and ongoing problems on depressive symptomatology. Those low in masculinity suffer more depressive symptoms as ongoing problems increase. There is a similar finding with the interaction between self esteem and ongoing problems on depressive symptomatology with those low in self esteem more greatly affected.
Because of the mostly premarital and preoccupational character of the sample, differences structured into early sex-role socialization and current structures in the world of young college students emerge as the best explanations for the gender differences found in this study
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