Non-invasive hemodynamic monitoring techniques for detecting Preload responsiveness in critically ill patients

Volume expansion is the first-line treatment for acute circulatory failure in almost all cases. However, its inconsistent effectiveness and its side effects make it necessary to predict the effects before undertaking it. Several tests have been developed to detect this state of preload dependence, and we are interested in refining some of them and improve their use. The end expiratory occlusion (EEXPO) test consists in transiently stopping mechanical ventilation at end expiration to increase venous return and, thus, cardiac preload. In preload responder patients it is expected to increase cardiac output. We have gathered an amount of information from the existing literature, showing that its ability of detecting fluid responsiveness is very high, through a systematic review and meta-analysis. The effects of this test must be assessed on cardiac output, and several methods have already been described for this. Bioreactance is a completely non invasive technique to measure cardiac output, which has been demonstrated to be reliable in detecting preload responsiveness through a passive leg raising (PLR) maneuver. Nevertheless, its role in detecting a positive EEXPO test was never investigated. In the main study of this PhD project, we show that the current available commercial version of the bioreactance device is not suitable for this purpose, due to its very long averaging and refreshing times (24 and 4 seconds, respectively). However, when we used a research version of the device, which allowed us to reduce both intervals (8 and 1 second for averaging and refreshing times, respectively), bioreactance proved to be a reliable method to detect preload responsiveness through the EEXPO test. We have also described an original and reliable method for measuring the effects of both PLR and EEXPO tests, which consists of measuring the perfusion index (PI), the ratio between the pulsatile and the non-pulsatile portion of the pulse oxygen saturation signal. Although the signal could not be collected stably in all patients, changes in this index during passive leg raising were able to measure the effects of the PLR test and predict the response to volume expansion. Similarly, Pl measurements could identify a positive EEXPO test, even though their changes were of lower amplitude compared to those of a PLR test. Our results open up the possibility of measuring the effects of these tests of preload responsiveness using non-invasive tools. This could prompt their use outside the intensive care unit, such as in the emergency department, where tracking changes of cardiac output during the first hours of the management of acute circulatory failure could lead to a more rational use of fluid administration

Cainà: Islandscape and ‘islanderscope’ on screen

The establishment of Island Studies within the academe and the introduction of concepts such as ‘islandness’ and ‘islandscape’ have accompanied a general rethinking of the concept of insularity which encompasses the reflection over a cinematic representation of islands and islanders. The use of islands as cinematic landscapes and settings has reinforced cultural, mythical, and identity stereotypes associated with the island imagery built-up in literature, as well as the construction of the islander as a character exhibiting specific behavioural features. The film Cainà. L’isola e il continente (Gennaro Righelli, 1922) is emblematic insofar as it is the first feature film shot in Sardinia and its character is not just a symbol of feminine rebellion against a patriarchal society, but it also serves as an allegory of an unspoiled island, such as it was considered and depicted at that time. As islanders ourselves, we have wondered to what extent Cainà adheres to the stereotypes of islandness and insularity conventionally ascribed to islands and, in this specific case, to Sardinia. Our paper aims to examine the genesis of the Sardinian insular imagination through the lens of the cinematic construction of ‘islanderness’ and ‘islanderscope’, an assortment of agency representing islanders — and islands — on screen

Bleeding Pseudocyst of the Pancreatic Head. The role of Omentoplasty and Local Hemostasis

Treatment of bleeding psedoaneurysms and pseudocysts of the pancreas is controversial. Surgical treatment with pancreatic resection or trancystic arterial ligation is not always satisfactory since postoperative mortality rate is high, especially for lesions located in the pancreatic head and rebleeding is not unusual. Two patients with bleeding pseudoaneurysms (one post traumatic, one spontaneous) and one with a hemorrhagic pseudocyst of the pancreatic head were treated surgically with arterial suture and omentoplasty. Bleeding was controlled in all, without any postoperative mortality or morbidity. No rebleeding occurred with a follow up of 33, 26 and 12 months. Trancystic ligation of bleeding vessels with omentoplasty may be a useful approach, which should be compared to arterial embolization in the future

L’appropriation culturelle dans le secteur de la mode

Les cas de copies de dessins et modèles traditionnels par les entreprises du secteur de la mode sont nombreux et dénoncés médiatiquement à travers la notion d’appropriation culturelle. En droit, ce phénomène pose la question de la reconnaissance d’un rapport de propriété entre les expressions culturelles traditionnelles et les communautés qui les perpétuent. Si les motifs et coupes de vêtements traditionnels font partie du « patrimoine culturel immatériel », le lien juridique avec leurs communautés culturelles demeure artificiel. Pour pallier l’insuffisance de ce statut juridique, le droit d’auteur se présente à première vue comme un mode de régulation des échanges culturels pertinent, en raison de sa double nature patrimoniale et morale. Mais, une propriété culturelle collective peine à se concevoir dans notre système juridique. Les difficultés à étendre ce modèle à ce type de créations ainsi que les enjeux économiques et culturels qui sous-tendent la notion d’appropriation culturelle incitent à un décentrement du regard afin de réévaluer non seulement nos représentations symboliques, mais aussi nos rapports juridiques aux choses.The copying of traditional designs by firms of the global fashion industry is a frequent occurrence, that is often denounced through the notion of cultural appropriation. Legally speaking, this phenomenon raises the issue of recognizing an ownership relation between traditional cultural expressions and the communities that perpetuate them. If traditional clothing designs and patterns are part of the “intangible cultural heritage”, the legal link with their cultural communities remains artificial. To overcome the inadequacy of this legal status, copyright appears at first sight to be a relevant means of regulating cultural exchanges, due to its patrimonial and moral dual nature. But collective cultural property is hard to conceive of in our legal system. The difficulties of extending this model to this type of creation, as well as the economic and cultural stakes underlying the notion of cultural appropriation, invite us to reconsider not only our symbolic representations, but also our legal relationships with things that surround us

Funzioni a Variazione limitata e insiemi di Perimetro minimo

Questa Tesi si propone di trattare parte della teoria di tali Spazi BV, seguendo principalmente la presentazione di Evans e Gariepy, per poi arrivare nell’ultimo capitolo dimostrare un Teorema di esistenza di insiemi di perimetro minimo, date determinate condizioni al contorno. Per quest'ultimo risultato si fa riferimento a Giusti. Nel primo capitolo si introducono gli Spazi BV e viene data una definizione di insiemi di perimetro finito. Si dimostra il Teorema di Struttura che garantisce che le derivate in senso distribuzionale delle funzioni f in BV sono misure di Radon, per poi dare a BV una struttura di Spazio normato. Il capitolo si conclude con un confronto tra gli Spazi BV e gli Spazi di Sobolev. Il capitolo 2 inizia con la dimostrazione della semicontinuità inferiore della misura variazione. All'interno di questo capitolo si dimostra anche il Teorema di Anzellotti-Giaquinta, una generalizzazione del Teorema di Meyers-Serryn nello Spazio delle funzioni BV che permette di approssimare ogni funzione a variazione limitata tramite funzioni lisce. Il terzo capitolo è interamente dedicato allo studio del funzionale di "Traccia", utile per controllare il "comportamento al bordo" per funzioni con una certa regolarità fino alla frontiera dell'insieme in cui sono supportate. Nel quarto capitolo vengono generalizzate le disuguaglianze di Sobolev e Poincaré alle funzioni BV. Fatto ciò, vengono dimostrate la disuguaglianza isoperimetrica e una sua versione locale. Nel quinto ed ultimo capitolo infine si vuole dare un esempio di problema che è stato risolto grazie all'introduzione degli Spazi BV. Il problema è quello di mostrare l'esistenza e l'unicità di un insieme di perimetro minimo tra un insieme di insiemi che rispettino una stessa condizione al contorno. Per fare ciò si sfrutta un metodo diretto del calcolo delle variazioni che si avvale principalmente dei risultati di semicontinuità inferiore e di Compattezza mostrati nel capitolo 2

CT perfusion in patients with lung cancer: Squamous cell Carcinoma and Adenocarcinoma show a different Blood Flow

Objectives. To characterize tumour baseline blood flow (BF) in two lung cancer subtypes, adenocarcinoma (AC) and squamous cell carcinoma (SCC), also investigating those \u201cborderline\u201d cases whose perfusion value is closer to the group mean of the other histotype. Materials and Methods. 26 patients (age range 36-81 years) with primary Non-Small Cell Lung Cancer (NSCLC), subdivided into 19 AC and 7 SCC, were enrolled in this study and underwent a CT perfusion, at diagnosis. BF values were computed according to the maximum-slope method and unreliable values (e.g., arising from artefacts or vessels) were automatically removed. The one-tail Welch\u2019s t-test (p-value < 0.05) was employed for statistical assessment. Results. At diagnosis, mean BF values (in [mL/min/100g]) of AC group [(83.5 \ub1 29.4)] are significantly greater than those of SCC subtype [(57.0 \ub1 27.2)] (p-value = 0.02). However, two central SCCs undergoing artefacts from vena cava and pulmonary artery have an artificially increased mean BF. Conclusions. The different hemodynamic behaviour of AC and SCC should be considered as a biomarker supporting treatment planning to select the patients, mainly with AC, that would most benefit from antiangiogenic therapies. The significance of results was achieved by automatically detecting and excluding artefactual BF values

Gromov-hyperbolicity of strictly pseudoconvex domains and applications

The reason of interest for this thesis is to investigate bounded strictly pseudoconvex domains with C^2−smooth boundary, that is domains Ω ⊂ C^n which admit a strictly plurisubharmonic defining function of class C^2. Central part of the thesis is to show that bounded strictly pseudoconvex domains with C^2−smooth boundary, when endowed with the Kobayashi metric, are Gromov-hyperbolic. Chapter 4 is entirely devoted to the proof of this Theorem. Chapter 1, 2 and 3 introduce the terminology and the preliminary results needed to carry out the proof in Chapter 4. Chapter 1 deals in detail with the geometric structure of strictly pseudoconvex domains and the construction of the Carnot-Carathéodory metric on the boundary. In Chapter 2 we present the notion of Gromov-hyperbolicity. Such notion is a generalization of the ”classical” notion of hyperbolicity to general metric spaces. In Chapter 3 we introduce another notion of hyperbolicity, due to Kobayashi, for complex spaces. It is based on the definition of an intrinsic semi-distance function on any complex space, and such space is said to be Kobayashi-hyperbolic if such semi-distance function is an actual distance function. Notice that a Kobayashi-hyperbolic space is a metric space, hence it makes sense to investigate its Gromov-hyperbolicity. The domains of interest in this Thesis result to be Kobayashi-hyperbolic and Chapter 4, as previously mentioned, deals with the proof of their Gromov-hyperbolicity In the final part of the thesis we present a recent application of the results by Balogh and Bonk to the theory of functions with Bounded Mean Oscillation (BMO spaces, for short). In the setting of strictly pseudoconvex domains there are at least two notions of such spaces: BMO spaces defined via balls in the Kobayashi metric and dyadic BMO spaces. It was recently proved that such notions are equivalent. A key role in the proof of such equivalence is indeed played by the results presented by Balogh and Bonk

Incidencias psicoeducativas en contextos escolares desde la perspectiva de la complejidad: revisión sistemática

En los últimos años se ha observado una falta de orientación en las instituciones educativas para abordar el bajo rendimiento psicoeducativo, el cual es el resultado de múltiples variables. Por lo que, el presente trabajo tuvo como objetivo analizar las incidencias psicoeducativas en contextos escolares desde la perspectiva de la complejidad, a través de factores psicológicos y educativos que influyen en el proceso de enseñanza y aprendizaje. Se realizó una revisión sistemática de la literatura siguiendo el modelo PRISMA, en el cual se incluyeron publicaciones de Latinoamérica. La búsqueda se realizó en diferentes bases de datos, con una limitación temporal de los últimos 10 años. Se analizaron 33 estudios relacionados con las temáticas de esta investigación. Se encontró que las incidencias psicoeducativas ocurren debido a diferentes problemáticas, como el apoyo familiar, la influencia de los docentes, dificultades específicas de aprendizaje, la influencia del sueño, la alimentación y el estado emocional de los estudiantes. Estos factores están estrechamente relacionados con la complejidad, ya que los problemas escolares provienen de factores internos y externos que afectan de manera única a cada estudiante, sin seguir una trayectoria lineal. En relación con los programas psicoeducativos, la implementación de estrategias activas e innovadoras tiene un impacto positivo en el rendimiento de los estudiantes. Programas enfocados en fortalecer las habilidades cognitivas y ejecutivas, complementados con apoyo psicopedagógico, han demostrado mejoras significativas. En conclusión, hay que reconocer la complejidad de cada individuo y su relación con el entorno social para mejorar la calidad del aprendizaje.Licenciatura en Psicología Educativ

Image-processing assisted characterization of spray injection systems

The objective of this work is to investigate the spray characteristics of a fuel injection nozzle. The analysis is performed by means of a framework which exploits different image processing techniques to provide spray-related data to the operator. Innovative metrics are introduced to increase the accuracy and efficiency of the scheme. Experimental results show that it is possible to automatically get useful information about the spray distribution, asymmetries and key properties together with the capability to measure significant angles and other information to detect anomalies in the injection system