Zirkulierende inflammatorische Mediatoren spielen eine zentrale Rolle in der Induktion und Unterhaltung eines septischen Multiorganversagens (MOV). Tritt im Rahmen eines septischen MOV ein akutes Nierenversagen auf, so wird der Einsatz einer Nierenersatztherapie notwendig. Kontinuierliche Nierenersatztherapieverfahren (CRRT) haben sich hier bewährt. Der Einsatz von CRRT zur adjuvanten Therapie des septischen MOV ist in den neunziger Jahren aufgekommen. Grundlage bildet die Hypothese, dass durch die Reduktion von Spitzenpegeln pro- and anti-inflammatorischer Mediatoren im Blutplasma die Homöostase der Immunabwehr wiederhergestellt werden kann. Kommerziell erhältlichen Hämofilter weisen aufgrund ihrer Konstruktion nur eine geringe Clearanceleistung für inflammatorische Mediatoren auf. In Kooperation mit der Industrie (Gambro, Medical Research, Hechingen, Germany) entwickelten wir einen neuartigen, großporigen Hämofilter für den klinischen Einsatz. Der Hämofilter wurde konzipiert, um Moleküle in einer Größe von bis zu 60 kD aus dem Blut septischer Patienten zu eliminieren. In einer ersten Pilotstudie wurde der Hämofilter auf seine klinische Verwendbarkeit untersucht. Untersucht wurde die hämodynamische Verträglichkeit, der Verlust an Bluteiweißen und Gerinnungsfaktoren sowie die Effektivität der Mediatorelimination am Beispiel von Interleukin-6 (IL-6) und Tumornekrosefaktor-alpha (TNF-alpha). Wir konnten zeigen, dass die großporige Hämofiltrationstherapie ein sicheres und effizientes Nierenersatzverfahren darstellt. Es erwies sich als hämodynamisch verträglich. Der kumulative Eiweißverlust lag bei 8 g/Tag. Signifikante Verluste an essentiellen Gerinnungsfaktoren wurden nicht beobachtet. Es zeigte sich zudem eine signifikante Filtration von im Blut zirkulierendem IL-6. Die Clearancekapazität für TNF-alpha war jedoch gering. In Folgestudien konnten wir zeigen, dass die großporige Hämofiltration immunmodulatorische Eigenschaften ausübt. Sowohl die Phagozytose-Aktivität zirkulierender polymorphkerniger Leukozyten und Monozyten, als auch die Proliferationseigenschaften von T-Lymphozyten wurden günstig beeinflusst. Um den Verlust an Bluteiweißen durch den großporigen Hämofilter zu reduzieren, wurden verschiedene Nierenersatzstrategien experimentiert. Der diffusive Stofftransport scheint dem konvektiven Verfahren hinsichtlich der Mediatorelimination, bei deutlich günstigerem Effekt auf den Proteinhaushalt, gleichwertig zu sein. In wieweit die großporige Hämofiltration den Krankheitsverlauf septischer Patienten beeinflussen kann, ist Gegenstand aktueller Studien. / Inflammatory mediators play a pivotal role in the induction and maintenance of a septic syndrome. In the course of a septic multiorgan dysfunction syndrome, acute renal failure (ARF) often necessitates the use of renal replacement therapy. Continuous renal replacement therapy (CRRT) is the treatment of choice in this regard, and convection (hemofiltration) has become the most common used purification technique. Apart from representing a valuable renal replacement modality, CRRT also allows the elimination of inflammatory mediators. Since the early nineties CRRT has been used as an adjuvant treatment strategy in the septic multiorgan failure syndrome. It has been hypothesized that CRRT may re-institute the immunologic and hemostasilogic homeostasis by reducing the peak cytokine concentration in circulating blood. Commercially available hemofilters do not allow for a substantial elimination of inflammatory mediators. Their clearance capacity for septic mediators is poor. In cooperation with an industry company (Gambro, Medical Research, Hechingen, Germany), we developed a high cut-off hemofilter for clinical use in septic patients. The hemofilter was developed in order to allow the elimination of septic mediators in the molecular weight range up to 60 kilodaltons (kD). In a first pilot study the newly developed hemofilter was analyzed for clinical feasibility. We studied the hemodynamic impact, the transmembrane loss of plasma proteins and coagulation parameters as well as the efficacy in regard to mediator elimination. For mediator elimination Interleukin-6 (IL-6) and tumor-necrosis-factor-alpha (TNF-alpha) were chosen. We were able to show, that high cut-off hemofiltration is a safe and effective renal replacement procedure. Hemodynamically high cut-off hemofiltration was well tolerated. The cumulative transmembrane total plasma protein loss was around 8g/day. Coagulation parameters were not effected. We further demonstrated, that high cut-off hemofiltration is able to significantly eliminate substantial amounts of circulating IL-6. However, the elimination capacity for TNF-alpha was poor. We were also able to show, that high cut-off hemofiltration exerts immunomodulatory properties. The phagocytotic activity of polymorphnuclear leukocytes and monocytes as well as proliferative capacity of lymphocytes were positively influenced. In order to reduced transmembrane protein losses through the high cut-off hemofilter, a variety of different renal replacement strategies were tested. Diffusive purification techniques were comparable to convective techniques in regard to the mediator elimination capacity, but were associated with significantly lower transmembrane protein losses. Whether high cut-off hemofiltration can positively influence the course of critically ill septic patients is still under investigation.

<p>This paper aimed to investigate to what extent there is an age cut-off for teenage boys in the women’s shelters of Sweden and how a possible cut-off is described and maintained. This occurrence has not been investigated earlier to a large extent, which emphasizes the importance of this paper. A mixed strategy was used to cover both the frequency as well as the explanations to the age cut-off. The quantitative survey was sent to all women’s shelters in Sweden and the result showed that 56 % of the shelters had an age cut-off for teenage boys from 12 years of age and above. Qualitative interviews were conducted with six women’s shelters in Stockholm to examine how the notion teenage boys was constructed and used by the respondents to deny them refuge together with their mothers. The teenage boys were described as young men, aggressive and in the same time need of support, which all had the consequence that they could not stay at the shelters with collective housing. The age cut-off was neither discussed nor questioned by the members of the women’s shelters and was upheld by its legitimation. From a social constructive perspective the women’s shelters could be understood as institutionalized.</p>

Modern turbomachines are designed towards thinner, lighter and highly loaded blades. This gives rise to increased sensitivity to flow induced vibrations such as flutter, which leads to structure failure in a short period of time if not sufficiently damped. Although numerical tools are more and more reliable, flutter prediction still depends on a large degree on simplified models. In addition, the critical nature of flutter, resulting in poor well-documented real cases in the open literature, and the lack of experimental database typical of engine flows make its apprehension even more challenging.  In that context, the present thesis is dedicated to study flutter in recent turbines through aerodynamic analysis of subsonic or supersonic flows in response to a prescribed vibratory mode of the structure. The objective is to highlight some mechanisms potentially responsible for flutter in order to be in better position when designing blades. The strategy consists in leading both experimental and numerical investigations.  The experimental part is based on a worldwide unique annular turbine sector cascade employed for measuring the aeroelastic response by means of the aerodynamic influence coefficient technique. The cascade comprises seven low pressure gas turbine blades one of which can oscillate in a controlled way as a rigid body. Aeroelastic responses are measured at various mechanical and aerodynamic parameters: pure and combined modeshapes, reduced frequency, Mach number, incidence angle. In addition to turbulence level measurements, the database aims at assessing the influence of these parameters on the aerodynamic damping, at validating the linear combination principle and at providing input for numerical tools. The numerical part is based on unsteady computations linearized in the frequency domain and performed in the traveling wave mode. The focus is put on two industrial space turbines: 2D computations are performed on an integrally bladed disk, also called blisk; its very low viscous material damping results in complex motions with combined modes and extremely high reduced frequency. The blisk operates at low subsonic conditions without strong non-linearities. Although the blades have been predicted aeroelastically stable, an original methodology based on elementary decompositions of the blade motion is presented to identify the destabilizing movements. The results suggest that the so-called classical flutter is surprisingly prone to occur. Moreover, the aerodynamic damping has been found extremely sensitive to the interblade phase angle and cut-on/cut-off conditions. 3D computations are then performed on a supersonic turbine, which features shock waves and boundary layer separation. In contrast, the blade motion is of elementary nature, i.e. purely axial. The blades have been predicted aeroelastically unstable for backward traveling waves and stable for forward traveling waves. The low reduced frequencies allow quasi-steady analysis, which still account for flutter mechanisms: the shock wave motion establishes the boundary between stable and unstable configurations. / <p>QC 20111209</p>

This paper aimed to investigate to what extent there is an age cut-off for teenage boys in the women’s shelters of Sweden and how a possible cut-off is described and maintained. This occurrence has not been investigated earlier to a large extent, which emphasizes the importance of this paper. A mixed strategy was used to cover both the frequency as well as the explanations to the age cut-off. The quantitative survey was sent to all women’s shelters in Sweden and the result showed that 56 % of the shelters had an age cut-off for teenage boys from 12 years of age and above. Qualitative interviews were conducted with six women’s shelters in Stockholm to examine how the notion teenage boys was constructed and used by the respondents to deny them refuge together with their mothers. The teenage boys were described as young men, aggressive and in the same time need of support, which all had the consequence that they could not stay at the shelters with collective housing. The age cut-off was neither discussed nor questioned by the members of the women’s shelters and was upheld by its legitimation. From a social constructive perspective the women’s shelters could be understood as institutionalized.

In this thesis, we propose a novel architecture for hybrid radio frequency (RF)/free–space optics (FSO) wireless systems. Hybrid RF/FSO systems are attractive since the RF and FSO sub–systems are affected differently by weather and fading phenomena. We give a thorough introduction to the RF and FSO technology, respectively. The state of the art of hybrid RF/FSO systems is reviewed. We show that a hybrid system robust to different weather conditions is obtained by joint bit–interleaved coded modulation (BICM) of the bit streams transmitted over the RF and FSO sub–channels. An asymptotic performance analysis reveals that a properly designed convolutional code can exploit the diversity offered by the independent sub–channels. Furthermore, we develop code design and power assignment criteria and provide an efficient code search procedure. The cut–off rate of the proposed hybrid system is also derived and compared to that of hybrid systems with perfect channel state information at the transmitter. Simulation results show that hybrid RF/FSO systems with BICM outperform previously proposed hybrid systems employing a simple repetition code and selection diversity.

High-pass filtering that is one of the most efficient methods in removing long-period noise of accelerograms is investigated for its effect on nonlinear oscillator deformation response. Within this context, uncertainty in filter cut-off periods that would significantly modify the low-frequency content of accelerograms come into prominence for obtaining reliable long-period displacement response. Analog and digital ground-motion records from recently compiled Turkish strong-motion database are used and these records are high-pass filtered with a consistent methodology by randomly generated filter cut-offs that represent different filter cut-off decisions of the analysts. The uncertainty in inelastic spectral and residual displacements (SDIE and SDR, respectively) due to variations in filter cut-offs is examined to derive the usable period ranges where the effect of high-pass filtering is tolerable. Non-degrading, stiffness degrading and stiffness and strength degrading oscillator behavior are considered in these analyses. The level of nonlinear behavior in single degree of freedom (SDOF) response is described by varying the yield strength (R, normalized yield strength) and displacement ductility (&micro / ) levels. The usable period ranges that depend on magnitude, recording quality, level of inelasticity and level of degradation are determined for SDIE through robust probabilistic methodologies.

In this thesis, fluid characteristics and sampling efficiency of high molecular weight cut-off microdialysis are presented, with the aim of improving the understanding of microdialysis sampling mechanisms and its performance regarding extraction efficiency of biological fluid and biomarkers. Microdialysis is a well-established clinical sampling tool for monitoring small biomarkers such as lactate and glucose. In recent years, interest has raised in using high molecular weight cut-off microdialysis to sample macro molecules such as neuropeptides, cytokines and proteins. However, with the increase of the membrane pore size, high molecular weight cut-off microdialysis exhibits drawbacks such like unstable catheter performance, imbalanced fluid recovery, low and unstable molecule extraction efficiency, etc. But still, the fluid characteristics of high molecular weight cut-off microdialysis is rarely studied, and the clinical or in vitro molecule sampling efficiency from recent studies vary from each other and are difficult to compare.   Therefore, in this thesis three aspects of high molecular weight cut-off microdialysis have been explored. The first, the fluid characteristics of large pore microdialysis has been investigated, theoretically and experimentally. The results suggest that the experimental fluid recovery is in consistency with its theoretical formula. The second, the macromolecule transport behaviour has been visualized and semi-quantified, using an in vitro test system and fluorescence imaging. The third, two in vitro tests have been done to mimic in vivo cerebrospinal fluid sampling under pressurization, using native and differently surface modified catheters. As results, individual protein/peptide extraction efficiencies were achieved, using targeted mass spectrometry analysis. In summary, a theory system of the fluid characteristics of high molecular weight cut-off microdialysis has been built and testified; Macromolecular transport of microdialysis catheter has been visualized; In vivo biomolecules sampling has been simulated by well-defined in vitro studies; Individual biomolecular extraction efficiency has been shown; Different surface modifications of microdialysis catheter have been investigated. It was found that, improved sampling performance can be achieved, in terms of balanced fluid recovery and controlled protein extraction efficiency.

In the field of diagnostic test studies, the accuracy of a diagnostic test is essential in evaluating the performance of the test. The receiver operating characteristic (ROC) curve and the area under the curve (AUC) are widely used in such evaluation procedures. Meanwhile, the Youden index is also introduced into practice to measure the accuracy of the diagnostic test from another aspect. The Youden index maximizes the sum of sensitivity and specificity, assuring decent true positive and negative rates. It draws one's attention due to its merit of finding the optimal cut-off points of biomarkers. Similar to Partial ROC, a new index, called "Partial Youden index" can be defined as an extension of Youden's Index. It is more meaningful than regular Youden index since the regular one is just a special case of the Partial Youden Index. In this thesis, we focus on construction of generalized confidence intervals for the Partial Youden Index and its corresponding optimal cut-off points. Extensive simulation studies are conducted to evaluate the finite sample performances of the new intervals.

In this thesis, we propose a novel architecture for hybrid radio frequency (RF)/free–space optics (FSO) wireless systems. Hybrid RF/FSO systems are attractive since the RF and FSO sub–systems are affected differently by weather and fading phenomena. We give a thorough introduction to the RF and FSO technology, respectively. The state of the art of hybrid RF/FSO systems is reviewed. We show that a hybrid system robust to different weather conditions is obtained by joint bit–interleaved coded modulation (BICM) of the bit streams transmitted over the RF and FSO sub–channels. An asymptotic performance analysis reveals that a properly designed convolutional code can exploit the diversity offered by the independent sub–channels. Furthermore, we develop code design and power assignment criteria and provide an efficient code search procedure. The cut–off rate of the proposed hybrid system is also derived and compared to that of hybrid systems with perfect channel state information at the transmitter. Simulation results show that hybrid RF/FSO systems with BICM outperform previously proposed hybrid systems employing a simple repetition code and selection diversity.

The thesis is concerned in problem that can occure after a blackout. The South Bohemia region was chosen as the area of blackout impacts. The theoretical part of the work describes a critical infrastructure, whose part electrical energy is. It also learns about the electricity supply system in the Czech Republic and explains what is considered to be a blackout. The research is made in two levels. First there are processed baground researches of selected blackouts in the world and consequently the impacts of possible blackout in the South Bohemia are examined. The method of guided interview was used to make a questionnaire. The guided interviews were made with a few specialists. The questionnaire results are analysed and the possible consequences of blackout in the South Bohemia region are described. The main purpose of the work was ? The description of a blackout in the South Bohemia region?. The aim was fulfilled and a blackout in the South Bohemia region was described. The thesis worked with two hypothesis. The first one was ?A blackout strongly influences the population? a this hypothesis was proved by my research. The second hypothesis sounded ?Electrical energy is a strategical part of a critical infrastructure in the South Bohemia region?, and this hypothesis was also proved on basis of my results.