Bounds on Correlation Functions of Quantum Rotators

We derive a McBryan-Spencer bound to the correlation function of a one-dimensional array of quantum rotators in the Villain approximation of the cosine interaction. We obtain the partition function of the system in the gas representation and establish a lower bound on the external charge correlation function. We also discuss the possible existence of a Kosterlitz-Thouless phase for the quantum rotator in the Villain approximation.Comment: Latex 7 page

Resistive switching in ZrO2 films: physical mechanism for filament formation and dissolution

Resistive switching devices, also called memristors, have attracted much attention due to their potential memory, logic and even neuromorphic applications. Multiple physical mechanisms underpin the non-volatile switching process and are ultimately believed to give rise to the formation and dissolution of a discrete conductive filament within the active layer. However, a detailed nanoscopic analysis that fully explains all the contributory events remains to be presented. Here, we present aspects of the switching events that are correlated back to tunable details of the device fabrication process. Transmission electron microscopy and atomically resolved electron energy loss spectroscopy (EELS) studies of electrically stressed devices will then be presented, with a view to understanding the driving forces behind filament formation and dissolution

A Cluster Expansion for Dipole Gases

We give a new proof of the well-known upper bound on the correlation function of a gas of non-overlapping dipoles of fixed length and discrete orientation working directly in the charge representation, instead of the more usual sine-Gordon representation.Comment: 8 pages, Late

O lugar das bibliotecas

A história das Bibliotecas Públicas em Portugal nas últimas décadas, é conhecida de todos. Há apenas 30 e poucos anos, no princípio da década de 80, o cenário era desolador. As bibliotecas da Fundação Calouste Gulbenkian, que durante décadas asseguraram o serviço de leitura pública em Portugal, estavam a viver os seus últimos dias e os bibliotecários eram pessoas envelhecidas pelo silêncio obscuro das salas. Nas bibliotecas itinerantes, o ar livre e a sensação de venda ambulante conferiam uma dinâmica diferente que deixou marcas nostálgicas em todos os que as utilizaram

Kinesio Taping versus Stretching global ativo na diminuição da dor lombar em grávidas

Projeto de Graduação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Licenciada em FisioterapiaA dor lombar é considerada um sintoma frequente e habitual entre as grávidas, principalmente nos últimos meses de gravidez, o que irá reduzir a sua qualidade de vida. Objetivo: estudar a eficácia da aplicação de kinesio taping (KT) e do método Stretching Global Ativo (SGA) no tratamento da dor lombar durante a gravidez. Metodologia: foram selecionadas 30 grávidas com dor lombar, divididas em três grupos, 10 no Grupo Controlo (GC) e 20 no Grupo Experimental (GE), subdivido na aplicação de KT (GEk) e na realização de exercícios de pelo método de SGA (GEs). Este estudo durou quatro semanas, com reavaliação após duas semanas. Para avaliar a intensidade da dor utilizou-se a Escala Visual Numérica e o Questionário Roland Morris para avaliar limitações funcionais. Resultados: observaram-se diferenças significativas entre o primeiro momento de aplicação terapêutica e no final de quatro semanas. No GE houve redução de dor e no GC um aumento da intensidade da dor e um maior número de grávidas com limitações funcionais. Verificou-se um efeito prolongado após duas semanas no GE, embora seja mais notório no GEk. Conclusão: o KT e o método de SGA são eficazes na diminuição da dor lombar durante a gravidez, embora a aplicação de KT tenha evidenciando um efeito duradouro. The low back pain is one of the most frequent and usual symptom between pregnant women, mainly in the last months of pregnancy, which will reduce their quality of life. Aim: study the effectiveness of the kinesio taping (KT) application and the Stretching Global Ativo (SGA) method in the treatment of low back pain during pregnancy. Methodology: were selected 30 pregnant women with low back pain, were divided into three groups, 10 in the Control Group (CG), and the others 20 take part to the Experimental Group (EG), subdivided into the KT application (GEk) and in the realization of exercises by the SGA method. This study lasted four weeks, with a reassessment after two weeks. To evaluate pain intensity we used the Visual Numeric Scale and the Roland Morris Questionnaire was applied in order to assess functional limitations. Results: Significant changes were observed between the first moment of therapeutic application and at the end of the four weeks. In the EG there was a reduction of the pain intensity and in the CG the pain and the functional limitations were increased. The effect was prolonged after two weeks in the EG, although it was more remarkable in the EG. Conclusion: the KT and the SGA method are effective in reducing low back pain during pregnancy, although the application of KT has showing a lasting effect

A novel simplified approach to radiofrequency catheter ablation of idiopathic ventricular outflow tract premature ventricular contractions : from substrate analysis to results

Summary: Premature ventricular contractions (PVCs) are a common finding in the general population. The most common site of PVCs, in patients without structural heart disease, is the right ventricular outflow tract (RVOT) and the left ventricular outflow tract (LVOT). The prognosis associated with frequent PVCs depends on the presence of structural heart disease, so that idiopathic PVCs have been considered benign. Recently however, evidence has emerged that a small percentage of those patients may present with polymorphic ventricular tachycardia or ventricular fibrillation or evolve to left ventricular dysfunction. Catheter ablation is indicated for frequent symptomatic PVCs refractory to medical therapy or in case of patient’s preference. Currently, catheter ablation is based on activation mapping, confirmed by pace mapping match of at least 11/12 ECG leads between the paced beat and the PVC morphology. The acute success rate ranges from 78% to 100% according to the series, and to the location of the PVCs. Remote magnetic navigation presents as a good option for PVC ablation offering a high success rate with better safety profile. Intraprocedural low PVC burden occurs in up to 30% to 48% of cases, resulting in either, cancelation of the ablation procedure in up to 11% of patients, or reduction of the success rate from 85% to 56% when ablation is attempted with pace mapping only. Recently non-invasive mapping systems based on the electrocardiogram analysis (ECGI) have been developed. These systems are capable of mapping an arrhythmia with just one beat, instead of the usual point by point acquisition, being especially useful in the case of rare arrhythmias. EGGI also constitutes a valuable noninvasive tool for studying the mechanisms of arrhythmias. With this system we were able to demonstrate the presence of an electrophysiological substrate in the RVOT of patients with PVCs and apparently normal hearts. It has been accepted for many years that in patients with idiopathic PVCs from the outflow tracts, the RVOT displays normal electroanatomical mapping features and electrophysiological properties. However, we have demonstrated that there is a substrate for idiopathic PVCs in the form of low voltage areas (LVAs) that are not detected by usual image methods including cardiac magnetic resonance (CMR). We described for the first time, the association between the presence of ST-segment elevation in V1-V2 at the 2nd intercostal space (ICS) with LVAs across the RVOT and have proposed it as a non-invasive electrocardiographic marker of LVAs. We also identified the presence of abnormal potentials in intracardiac electrograms at the ablation site during diastole, after the T wave of the surface ECG that became presystolic during the PVC and were called diastolic potentials (DPs). In Chapter V we describe in detail the study that validated those findings and evaluated the feasibility and efficacy of a proposed simplified substrate approach, for catheter ablation in patients with low intraprocedural PVC burden, defined as less than 2 PVCs/min in the first 5 minutes of the procedure. It consists of fast mapping of the RVOT in sinus rhythm looking for LVAs and DPs, identifying the area, and finally performing a restricted activation map of the PVCs at that area. Briefly, it was a prospective single-arm clinical trial at two centers and three groups were studied: a) patients with low intraprocedural PVC burden that underwent ablation with the novel simplified approach method (study group); b) patients with low intraprocedural PVC burden that underwent ablation using the standard activation mapping method between 2016 and 2018 (historical group); and c) patients without PVCs, subjected to catheter ablation of supraventricular tachycardias that agreed to have a voltage map of the RVOT in sinus rhythm performed (validation group). The calculated sample size was 38 patients in each group. The exclusion criteria were as follows: known structural heart disease, history of sustained ventricular arrhythmias, inability to perform CMR, previous ablation and standard 12-Lead ECG with evidence of conduction or electrical disease or abnormal QRS morphology were excluded. Patients in the study and validation groups, had an ECG performed at the 2nd ICS and the RVOT mapped in sinus rhythm to assess the presence of ST-segment elevation, and LVAS and DPs, respectively. The results were compared between both groups. The study group and the historical group were compared regarding the efficacy of the new simplified ablation method in terms of abolishment of the PVCs and improvement of procedure speed and success rate. When available, ECGI was performed in the study group to evaluate the accuracy of the method to identify the site of origin of the PVCs. The ECGI was performed with two systems, the Amycard (EP Solutions SA, Switzerland) and the VIVO (Catheter Precision, NJ USA). The prevalence of LVAs and DPs was significantly higher in the study group in comparison with the validation group, respectively, 71% vs 11%, p<0.0001 and 87% vs 8%, p<0.0001. The ST-segment elevation was a good predictor of LVAS with a sensitivity of 87%, specificity of 96%, positive predictor value of 93% and negative predictor value of 91%. The novel simplified approach abolished the PVCs in 90% of the patients as opposed to 47% of patients in the historical group, p<0.0001. Only 74% patients underwent ablation in the historical group versus 100% in the study group. In patients that underwent ablation, the procedure time was significantly lower in the study group when comparing to the historical group, 130 (100-164) vs 183 (160-203) min, p<0.0001 and the success rate was significantly higher, 90% vs 64%, p=0.013. The recurrence rate in patients with a successful ablation after a median follow-up time of 1060 (574-1807) days, was not significantly different between both groups, Log-Rank=0.125 ECGI before ablation was performed in 17 patients in the study group. In 6 patients the ECGI was performed just with the Amycard system, in two just with the VIVO system and in 9 patients both systems were used. We found a good agreement between the ECGI and the invasive mapping, with the predicted site of origin being in the same or contiguous segment of the ablation site in 14/15 patients (93%) with the Amycard system and in 100% of patients with the VIVO system. When both systems were used simultaneously, the agreement between them was 8/9 (90%). So, in conclusion, the proposed approach partially based on substrate mapping including searching for LVAs and DPs, proved to be feasible, faster, and more efficient than the previous approach based exclusively on activation mapping. ST-segment elevation at the 2nd ICS proved to be a good predictor of LVAs. ECGI was a valuable tool to noninvasively predict the site of origin the arrhythmia

Eficiência in vivo e in vitro, de três diluidores de sémen de coelho refrigerado

Dissertação de Mestrado, Engenharia Zootécnica, 12 de Junho de 2014, Universidade dos Açores.Diversos estudos têm sido realizados ao sémen, avaliando essencialmente a concentração de espermatozóides (SPZ), a sua mobilidade e morfologia. A viabilidade do sémen muitas vezes é testada através da mobilidade espermática, pois é sempre necessário uma boa motilidade dos SPZ para que o sémen consiga atingir o oócito e fecundar. O estado do acrossoma é um dos parâmetros importantes a analisar, pois este encontra-se relacionado com o processo de penetração do SPZ no oócito. Este trabalho teve como objetivo testar a eficiência in vitro e in vivo, de três diluidores de sémen de coelho refrigerado. Para a testagem dos meios de diluição in vitro utilizou-se a técnica de citometria de fluxo, com dois fluorocromos, sendo que para testar a viabilidade utilizou-se o Sybr-14/Pi e para testar a integridade do acrossoma utilizou-se o fluorocromo FITC-PSA/Pi. Para o teste aos diluidores in vivo, utilizou-se a técnica de inseminação artificial (IA), realizando a recolha de sémen e posteriormente diluir o sémen nos respetivos diluidores e inseminar as coelhas. Com base nos resultados obtidos pela análise por citometria de fluxo, no teste a viabilidade o diluidor Lactato de Ringer (LR), apresenta uma média superior ao meio Gema de Ovo (GO) e Leite Desnatado (LD), mas não apresentando diferenças significativas (P> 0.05). Para o teste a integridade do acrossoma, através dos resultados obtidos pela análise do citómetro de fluxo, pode-se verificar que o meio de diluição LR apresenta novamente, médias superiores aos outros meios, mas sem apresentar diferenças significativas (P> 0.05). Ao comparar a média dos meios de diluição testados in vivo, é possível verificar que os meio LR apresentam uma média superior de láparos nascidos vivos, sendo que é observado que existe uma diferença significativa (P≤ 0.05) com o meio GO

Some of the snags of interdisciplinarity: from life forms into form of life studies

In this paper I look at some central problems, which have been puzzling me in my PhD research, when applying an interdisciplinary approach to data. My thesis is about the reader’s identity construction in the English-language newspapers in Portugal, about the expatriates’ textual positions in these newspapers. The theoretical framework I refer to is part of the wider and heterogeneous field of critical language analysis – a combination of linguistic and social analysis. This differs from many other forms of linguistic analysis because it studies language as a social practice that mediates reality.F.C.H.S. e E.S.E. da Universidade do Algarve, British Council, Calouste Gulbenkian Foundation, Luso-American Foundation for Development, Embassy of the USA, Institute for Educational Innovation, Faro City Hall, Centre for Anglo-Portuguese Studies at Universidade Nova de Lisboa, Centre for Comparative Studies Program in Literary Theory at Faculdade de Letras de Lisboa, APEAA e Algarve Tourism Boar

Estudo comparativo do conceito de Mulligan e a aplicação de kinesio taping na epicondilite lateral

Introdução: A epicondilite lateral (EL) é uma das lesões mais comuns que afeta o membro superior, caracterizada pela dor lateral do cotovelo. Na literatura são descritas diferentes opções de tratamento para a EL mas sem existir consenso sobre a estratégia de intervenção com maior eficácia. A mobilização com movimento (MWM) e aplicação de kinesio taping (KT) tem apresentado bons resultados na melhoria da dor e funcionalidade e no aumento de força de preensão. No entanto, não existe estudos a comparar a efectividade das duas técnicas. Objetivo(s): Analisar e comparar os efeitos da técnica mobilização com movimento (MWM) em relação à aplicação de kinesio taping (KT), na dor, na força de preensão e na funcionalidade em indivíduos com EL. Métodos: Foram incluídos 39 participantes com EL, divididos em três grupos, um grupo de controlo (GC) e dois grupos experimentais, sendo um grupo submetido a uma das técnicas do conceito de Mulligan (GEM) e um grupo submetido a uma aplicação de KT (GEKT). Foram avaliadas a intensidade da dor através da Escala Visual Analógica (EVA), a força de preensão isométrica através de um dinamómetro digital e a funcionalidade através do questionário Patient-Rated Tennis Elbow Evaluation (PRTEE). Resultados: Observaram-se diferenças significativas entre o momento inicial e o momento final de intervenção em todos os grupos em estudo (p≤0,018). Ao analisar a EVA, a força de preensão e o questionário PRTEE, os grupos experimentais obtiveram melhores resultados relativamente ao GC (p<0,001). Comparando os dois grupos experimentais, o GEM apresentou melhores resultados na dor (p=0,012) e na funcionalidade (p=0,001). Conclusão: Ambas as técnicas estudadas promovem melhorias na sintomatologia em indivíduos com EL. Contudo, os resultados sugerem que a aplicação da técnica de Mulligan produz um maior efeito na diminuição da dor e no aumento da funcionalidade, comparativamente à aplicação de KT