Stretch is known to result in an electrically less stable ventricular substrate, yet the reported effects of stretch on measured electrophysiological parameters have been inconsistent and even contradictory. The goal of this study was to evaluate the effects of acute mechanical stretch on cardiac electrical features thought to be key in generation of arrhythmia, namely restitution of action potential duration (APD), electrical memory, and onset of alternans. Microelectrodes were used to record intracellular potentials pre, during, and post-stretch from isolated right ventricular tissues from swine. In separate experiments, the effects of two levels of stretch were quantified. Pacing protocols employing explicit diastolic interval (DI) control and cycle length (CL) control were used to obtain measures of restitution of APD, memory, and alternans of APD. Stretching the tissue had varying effects on APD, restitution and memory. Stretch increased APD, restitution slopes and memory by as much as 24, 30 and 53 % in some cases, while it decreased these by up to 18, 37 and 81 % in others. During stretch, alternans of APD were observed in some cases, which occurred at slower rates of activation than before stretch. Histology of tissue samples showed localized changes in orientation of cells relative to the direction of stretch. Our results show that among individual trials, stretch altered the measured electrophysiological properties, sometimes markedly. However, when pooled together, these changes cancelled each other and the averages showed no statistically significant difference after stretch. A potential mechanism that explains this divergent and inconsistent response to stretch is the presence of local, micron level, variation in orientation of myocytes. Upon stretch, these divergent effects likely increase dispersion of repolarization diffusely and might thus be the reason behind the consistently observed increase in arrhythmic substrate after stretch.

This paper examines how and to what extent the District Six Museum has contributed the current redevelopment of the District Six site. Since its inception, the Museum has challenged accepted definitions of heritage and has transcended common museological practices through its initiative as an institution to go beyond nurturing the memory of one of the most iconic sites of forced removal in South Africa, but to also contribute to the site’s redevelopment. The Museum grew out of an organisation that was dedicated to protecting the empty wasteland that the District had become since it was announced a ‘white area’ by the apartheid government and bulldozed. The same group of people became passionate not only about protecting the site, and conducting “memory work” surrounding it but eventually contributing to a process of restitution and rebuilding the homes and lives of those whose houses where destroyed and communities were fragmented. This paper considers such an initiative, which began in a pre-democratic environment where the concept of heritage was ill-defined and cultural institutions often served apartheid agendas. This consideration will involve an examination of the way in which the District Six Museum developed; the Museum’s role and how this role has evolved and the District Six that has been re-imagined through the Museum and how this “idea” is contributing to re-development.

The diploma thesis deals primarily with the so-called first stage of the nationalization process in Czechoslovakia, which took place between 1945 - 1948, and the post-war confiscations of the same period, as well. The objective of the thesis is particularly to describe and analyze the then relevant legal regulations and place them adequately in the historical context. The content of the five thematic chapters is adapted to this topic. First, it attempts to define the basic concepts of nationalization, appropriation, socialization, expropriation and confiscation. Subsequently, it examines the basic historical roots of the concept of nationalization. It does so especially by comparing the approaches to proprietary rights through the prism of two dominant ideologies, namely liberalism and socialism. The core of the thesis consists of the nationalization and confiscation decrees themselves and the issues related. The National Institute of Administration was closely associated with this issue, as well. From the legislator's point of view, it was also necessary to distinguish which assets were to be confiscated and which, on the other hand, nationalized. The film industry first, followed by mines and large industrial enterprises, the food industry, banking and insurance companies were subject to...

Birks' unjust enrichment formula was intended to provide a common descriptive structure to all the instances where there was recovery. He did not, however, engage in an analysis of the various reasons why courts awarded restitution. My thesis seeks to fill this gap. I argue that without such an account Birks work is incomplete. According to Birks, for example, money and services both amounted to enrichments and so should be considered together. But there are some differences and similarities between money and services. In order to be able to group them together Birks needs to be able to say that the reasons for giving recovery in money and service cases are similar enough that they can be grouped together. The same goes for all the unjust factors. The point is, the generalisation that Birks sought to do, can only properly be done if one is attuned to the reasons why recovery is granted in each of those cases. If the reasons are similar then the generalisation makes sense. But if they are not then it does not make sense to so generalise. The argument of the thesis is that there three relevant principles to justifying unjust enrichment: the Property Principle, the Benefit-Burden Principle and the Autonomy Principle. The Property Principle states that one should not have property belonging to another. The Benefit-Burden Principle states that if one takes a benefit then one must bear the associated burdens; to put it more colloquially: you have to take the rough with the smooth. These first two principles provide reasons for considering a situation to be defective and the last principle provides a constraint for the operation of the first two. It is there to ensure that the imposition of liability will not unduly affect the autonomy of the defendant. Based on that the thesis proposes that the scope of the unjust enrichment formula be trimmed down to only cover defective transfers of money and other assets. For the other cases, a different analytical structure is needed. This is because the reasons for recovery in those cases are different.

<p>Instability in the propagation of nonlinear electro-chemical waves in the heart is responsible for life-threatening disease. This thesis describes an investigation of the effects of boundaries on cardiac wave propagation that arises from a site where an electrical stimulus is applied or from boundaries beyond which current does not flow. It is generally believed that the spatial scale for boundary effects is approximately equal to the passive length constant, lambda, of the tissue, the distance over which a a voltage pulse decays when it is below the threshold for wave generation. From the results of <em>in vitro</em> experiments with bullfrog cardiac tissue and through numerical simulations, I find that boundaries affect wave propagation over a much larger spatial scale and that the spatial variation in some cardiac restitution properties is correlated statistically with the onset of alternans, a possible precursor to fibrillation in the human heart.</p><p>An optical imaging system using novel illumination based on LEDs is used to determine the spatial dependence of action potential duration (APD) and the slope of the dynamic restitution curve S_DRC, which describes the relationship between steady-state APD and diastolic interval. For tissue with nearly identical cells, I find that APD is longest near the stimulus and shortest near the physical boundary with significant changes (~100 ms) over a distance of ~10lambda. S_DRC decreases with distance from the stimulus at a constant rate (~0.1-1.5 /mm) over the surface of the tissue. Simulations using a two-variable cardiac model confirm that spatial patterns of APD and S_DRC can be induced by boundaries.</p><p>Additional measurements with the simultaneous impalement of two microelectrodes are used to determine the spatial differences of other restitution properties. These studies indicate that APD and S_DRC, as well as the slopes of the constant-BCL and S1S2 restitution curves, vary in space and that the spatial differences and onset of alternans at rapid pacing are correlated. If similar correlations are evident in humans, such measurements may identify patients who are susceptible to arrhythmias and allow for early treatment.</p> / Dissertation

Mano pasirinktas tikslas buvo - išnagrinėti nuosavybės teisių į žemę atkūrimo proceso problematiką Kauno mieste. Šiam tikslui įgyvendinti, siekiau: išnagrinėti Lietuvos Respublikos teisės aktus įstatymus reglamentuojančius nuosavybės teisių į žemę atkūrimą Lietuvoje ir Kauno mieste, jų raidą; išnagrinėti administracinę atsakomybę už nuosavybės teisių į žemę atkūrimą Lietuvoje ir Kaune, Ištirti praktines problemas, kylančias taikant teisės aktus ir įstatymus, reglamentuojančius nuosavybės teisių į žemę atkūrimą bei ištirti nuosavybės teisių į žemę atkūrimo proceso administravimą Kaune. Siekiant įgyvendinti šiuos uždavinius šiame darbe buvo naudoti aprašomasis, atvejo analizės bei kokybinis tyrimo metodas pritaikant struktūruoto interviu, taip pat buvo atlikta išsami teisės aktų ir įstatymų, reglamentuojančių nuosavybės teisių atkūrimą į žemę, analizė. / My purpose was to inspect the process problematic of property restitution of land in Kaunas. Accordingly I was seeking: to explore all legislation which is coherent to my theme; to inspect the administrative responsibilities of institutions which are implementing the property restitution of land, also, I wanted to explore all the practical problems, which emerged due bad legislation, corruption or other matters and finally I wanted to inspect the process of property restitution of land in Kaunas. That I could obtain my goals, in had to inspect all legislation coherent to property restitution of Land in Lithuania, also I had to analyze all the rules of government institutions coherent to my theme, press articles and I had to do qualitative analysis using interview.

No description available.

The presented studies investigate dynamics of action potential duration (APD) tobetter understand the underlying mechanism for repolarization alternans.We recorded trans-membrane potentials (TMP) in canine endocardial muscle tissueusing standard glass microelectrode under the control of an explicit diastolic interval (DI)control pacing protocol, i.e. feedback protocol. During sequential sinusoidal DI activation,the trajectory of APD dynamics has multiple values of APD correspondent to the sameDI, i.e. restitution is a bi-modal relationship. Our results indicate that: 1) there is a delay,similar to hysteresis, of change in APD responding to change in DI, 2) and the timecourse of the delay is asymmetric for fast or slow pacing history. The alternans wasobserved during constant DI pacing, i.e. the DI preceding each APD was invariant orchanged within a limited range. This finding suggests that alternans of APD do not needthe oscillation of preceding DI, i.e. DI dependent restitution is not a necessary conditionfor the alternans. This result implies that DI independent component exists in themechanism of the alternans. Nonetheless, the amplitude of alternans was statisticallylarger during constant pacing cycle length (PCL) pacing than that during constant DIpacing, even though both PCL and DI pacing trials used similar average activation rate.These results also demonstrate the ability of the feedback protocol to analyze the memoryeffects and dissect different components in the mechanism of alternans.Two computational models, Luo-Rudy dynamics (LRD) and cardiac ventricle model(CVM) were used to study the hysteresis in restitution. By perturbing membrane current:L-type calcium current, rapid and slow potassium rectifier, and intracellular calciumtransfer rate in sarcoplasmic reticulum (SR) and using sinusoidal DI pacing sequence, weshowed that the asymmetric calcium current across the membrane and its interaction withcalcium buffer in SR during increasing and decreasing DI phase plays an important rolein the hysteresis. CVM was used to study the alternans during constant DI pacing.However CVM failed to replicate the alternans that occurred in the experiments. Thisresult implies that CVM lacks the electrophysiological kinetics related to alternans thatwas shown in our experiment.

Thesis (doctoral)--Technische Universität, Dresden, 2006. / Includes bibliographical references (p. 151-154).

Zugl.: Berlin, Humboldt-Univ., Diss., 2005