Von Willebrand factor (VWF) is a plasma glycoprotein that can bind collagen at a wound site as well as circulating platelets. VWF forms high molecular weight multimers (>20,000 kDa). VWF can also form VWF strings that appear to be attached to the endothelial surface and are capable of binding platelets. These strings are only observed in vitro and in vivo in the absence of the VWF-cleaving protease ADAMTS13. Deficiency in ADAMTS13 results in thrombotic thrombocytopenic purpura (TTP), a clotting disorder characterized by thrombocytopenia, microangiopathic hemolytic anemia, renal dysfunction, neurological dysfunction and fever. Patients suffering from TTP demonstrate VWF-and platelet-rich thrombi in the microvasculature of numerous organ systems, but most notably in the kidneys, heart, and brain. While VWF strings have not been directly connected to TTP, their presence in vivo was only identified with the ADAMTS13 knockout mouse (a model of TTP), suggesting a possible relationship. Recently we identified glycerol as an agent, similar to histamine, that triggers the formation of VWF strings in vitro. We found that glycerol and histamine trigger TTP in an ADAMTS13-deficient mouse model. In addition, we determined conditions in vitro that promote the formation of dense VWF networks. These networks of VWF can be greater than 70 μm thick and appear to be able to form fibers as long as several millimeters in length. These networks have not been previously identified and may underlie a possible mechanism by which VWF-rich thrombi form in TTP. These networks were formed solely from cultured endothelial cells, leading us to believe that endothelial cells alone are capable of producing more VWF than perhaps previously appreciated. These data suggest that secretion of VWF from the endothelium may play an important role in the pathophysiology of TTP.

The main objective of this thesis is to study the behavior of black objects in external fields, for example black holes and black strings in 4 and 5-dimensional spacetimes respectively. In particular, to analyze how external fields affect horizons and the internal structure of such objects, to study their properties, and tocunderstand how the spacetime fabric works. The thesis contains three chapters. In Chapters 1 and 2 we study the interior of 4-dimensional static, axisymmetric, electrically neutral and electrically charged distorted black holes. We analyze how external static and axisymmetric distortions affect the interior of such black holes. In particular, we study the behavior of the interior solution of an electrically neutral black hole near its horizon and singularity. The analysis shows that there exists a certain duality between the event horizon and the singularity. As a special example, we study the interior of a compactified 4-dimensional Schwarzschild black hole. In the case of an electrically charged black hole, a similar duality exists between its event and Cauchy horizons. The duality implies that the Cauchy horizon remains regular, provided the distortion is regular at the event horizon. Extension of the general theory of relativity to higher dimensional spacetimes brings a large variety of black objects whose boundary, the event horizon, may be of a complicated structure. One such object is a black string. In Chapter 3 we discuss the so-called Gregory-Laflamme instability of 5-dimensional black strings in a spacetime with one compact dimension and their topological phase transitions. Here we consider black strings with electric or magnetic charge. Linear static perturbations of these objects indicate the presence of a threshold unstable mode. An analysis of such mode shows that an electrically charged black string is less stable than a neutral one. The situation is opposite for a magnetically charged black string. An analysis of 5-dimensional extremal black string with electric charge shows a continuous spectrum of unstable threshold modes. The results presented in this thesis may have applications in the theory of classical 4-dimensional black holes and in the modern theoretical models of higher dimensions.

Τα τελευταία χρόνια, υπό την πίεση της ολοένα αυξανόμενης επιβάρυνσης του περιβάλλοντος από την χρήση ορυκτών καυσίμων και υπό τον φόβο των μεγάλων κλιματικών αλλαγών των οποίων ήδη γινόμαστε μάρτυρες, έχει γίνει πολύς λόγος για την χρήση οικολογικών και περιβαλλοντικά φιλικών ενεργειακών λύσεων. Έτσι, έχουν χυθεί τόνοι μελανιού και έχουν ξοδευθεί δισεκατομμύρια χρηματικές μονάδες στις έρευνες για την εύρεση νέων μορφών ανανεώσιμης ενέργειας και βελτιστοποίηση της απόδοσης των ήδη υπαρχόντων. Μία λοιπόν ευρέως διαδεδομένη ανανεώσιμη μορφή ενέργειας, η οποία έχει βρει πεδίο ανάπτυξης και στην χώρα μας (υπό τον φόβο δυστυχώς των προστίμων της Ευρωπαϊκής Ένωσης και όχι από την ανάπτυξη εγγενούς περιβαλλοντικής συνείδησης), είναι η τεχνολογία των φωτοβολταϊκών (ΦΒ). Πρόκειται για μία αρκετά γνωστή στους επιστήμονες και τις ερευνητικές ομάδες ανανεώσιμη πηγή ενέργειας, των οποίων οι προσπάθειες έχουν μειώσει το κόστος των ΦΒ σε τέτοια επίπεδα, ώστε να κρίνεται οικονομικά συμφέρουσα μία επένδυση σε αυτά, ακόμα και για κατόχους μικρών κεφαλαίων. Η μορφή της ενέργειας όμως που παράγεται από μία ΦΒ συστοιχία δεν είναι άμεσα εκμεταλλεύσιμη, καθώς η συνεχής τάση που αυτά παράγουν δεν είναι κατάλληλη ούτε για μεταφορά από το δημόσιο δίκτυο ηλεκτρισμού, ούτε για κατανάλωση από τα φορτία, τα οποία λειτουργούν υπό εναλλασσόμενη τάση. Επομένως, μία συστοιχία για να είναι κατάλληλη προς σύνδεση στο δίκτυο, πρέπει να συνοδεύεται από κατάλληλες διατάξεις, η οποίες επιτρέπουν την μετατροπή της ενέργειας σε κατάλληλη μορφή, αλλά και τον βέλτιστο έλεγχό της. Σκοπός λοιπόν της παρούσας εργασίας είναι η αναφορά στις κύριες δομές λειτουργίας και ελέγχου ΦΒ διασυνδεδεμένων στο δίκτυο, καθώς η περίπτωση αυτή είναι η πιο πολύπλοκη, λόγω της δυναμικής που εισάγει μία σύνδεση με το δίκτυο μεταφοράς. Η δε δομή της διαμορφώνεται ως ακολούθως: 1o Κεφάλαιο: Δομές Ηλεκτρονικών Ισχύος για την Διασύνδεση στο Δίκτυο ΦΒ Συστημάτων Γίνεται μία γενική αναφορά στις υπάρχουσες τεχνολογίες αντιστροφέων και επιχειρείται μία γενική ομαδοποίηση τους 2ο Κεφάλαιο: Ανασκόπηση μονοφασικών διασυνδεδεμένων αντιστροφέων για ΦΒ πλαίσια Παρουσιάζονται γενικές τοπολογίες μονοφασικών αντιστροφέων, ταξινομούνται και συγκρίνονται ως προς διάφορα χαρακτηριστικά. 3ο Κεφάλαιο: Σύγκριση τεχνικών ανίχνευσης μεγίστου σημείου λειτουργίας ΦΒ συστοιχίας Είναι άκρως απαραίτητη η λειτουργία των πλαισίων στο σημείο λειτουργίας που εγγυάται την μέγιστη παραγωγή ισχύος, έτσι ώστε να κρίνεται συμφέρουσα μία επένδυση σε αυτά. Εδώ λοιπόν εξετάζονται αρκετές τέτοιες τεχνικές που υπάρχουν διαθέσιμες. 4ο Κεφάλαιο: Διακυμάνσεις τάσης που εισάγονται σε επίπεδο διανομής από ΦΒ συστήματα Τα ΦΒ στοιχεία μετατρέπουν την ηλιακή ενέργεια σε ηλεκτρική. Επομένως, είναι άμεσα εξαρτώμενη η παραγωγή τους από τις καιρικές συνθήκες. Στο παρόν κεφάλαιο παρουσιάζονται μέθοδοι πρόβλεψης τέτοιων διακυμάνσεων στην ηλιακή ενέργεια, και άρα στην παραγόμενη τάση. 5ο Κεφάλαιο: Συστήματα αποθήκευσης Κάθε σύστημα παραγωγής ηλεκτρικής ενέργειας, για να θεωρείται ολοκληρωμένο, θα πρέπει να μπορεί να αποθηκεύει την περίσσεια ενέργειας που μπορεί να παρουσιάσει σε κάποιες χρονικές περιόδους, και να την αποδώσει όταν θα υπάρχει κάποια μεγάλη διακοπή παροχής ισχύος. Σε αυτό το κεφάλαιο παρουσιάζονται οι πιο γνωστές μέθοδοι αποθήκευσης. / During the last few years, under the pressure of the increased burden on the environment due to the use of fossil fuels and in fear of great climate changes which we all have already witnessed, the use of ecological and environmentally friendly energy solutions has already been widely discussed. Consequently ,billions have been spent and research has been conducted, in the development of new forms of renewable energy sources and in performance optimization of the existing ones. A widely used renewable energy source, which has been also develop in our country(under the fear of fines from the European Union and not because of the development of environmental conscience), is the technology of photovoltaic systems(PV). PV is a quite known to scientists and to research teams renewable energy source, which efforts have reduced the cost of PV in such levels, that an investment in those systems would be proved cost effective even for the owner of low capitals. The energy produced from a PV string is not directly exploited for use, since the produced dc voltage is not appropriate neither for distribution from the public electrical grid, nor for use from the loads,which operate under conditions of ac voltage.Consequently a photovoltaic string could be connected to the grid, only if it is equipped with appropriate devices, which allow the proper conversion and optimum control of energy. The purpose of this work is the reference of the main structures, for the operation and management of grid-integrated photovoltaic systems.In particular the paper can be summurised as follows: Chapter 1: Power-Electronic Structures for the Grid Integration of Photovoltaic Systems A general reference in the existing inverter technologies and a general categorisation of the latter is presented. Chapter 2: Re view of Single-Phase Grid-Connected Inverters for Photovoltaic Modules Single-plase inverter topologies are presented, categorized, compared and evaluated against different characteristics. Chapter 3: Comparison of Photovoltaic Array Maximum Power Point Tracking Techniques The functioning of photovoltaic arrays to the maximum power point is necessary, in order to be considered profitable an investment in photovoltaic systems. Many such techniques available, are being reviewed. Chapter 4: Voltage Fluctuations on Distribution Level Introduced by Phtovoltaic Systems Photovoltaic elements convert solar energy to electric, and consequently their electric generation is directly dependant on climatic conditions. The present analysis describes forecasting methods of fluctuations in solar irradiance which also results in fluctuations in the generated voltage. Chapter 5: Storage Systems Every electrical energy system, in order to be considered fully integrated, must store excessive energy produced during certain time periods, and support with it critical loads, during mains’ power interruption.This last chapter contains the most widespread storage techniques.

It is well known that ultrashort, high intensity pulses with peak powers exceedinga certain critical value (Pcr) undergo self-focusingleading to collapse and filamentation. During the initial stagesof propagation at low intensities the beamdynamics are dominated by diffraction and dispersion. During filamentation, self-focusing resulting from the nonlinear Kerr effect is balanced by higher order nonlinearities such as plasma induced defocusing and absorption.This work examines the role that linear processes combined with initial spatial and temporal conditioningplay in the generation and subsequent evolution of filaments within nonlinearbeams. It is demonstrated that, because of linear diffraction, initial spatial beam shaping can have a dramatic effect on the filament pattern, the number of filaments and the energy contained in each filament. These ideas are applicable to cases that arequite common, such as circularly apodized beams, and help to explain interestingbehavior observed in these types of beams. Finally, it is demonstrated thatwith appropriate preconditioning of multiple subcritical pulses, linear effects can be employed to accurately control when and where filamentation occurs during long distance propagation through conditional collapse of overlapping pulses.

Until recently, Schubert's sonata forms have been treated as the partially successful products of a classicist who often misunderstood his models. The development of sonata form in his early string quartets, though, raises serious questions about such a view. The quartets (ca. 1810 to 1816), constitute the composer's first concentrated work in large-scale instrumental music and include some of his earliest compositions in any genre. The first sonata-form movements all lack the most basic features of the structure, specifically a clearly delineated subordinate theme and subordinate key in the exposition. The evolution of Schubert's sonata form from 1810 to 1816 consists of an expansion to encompass such necessary tonal and thematic contrast. This process, however, does not lead to a close imitation of the Classical prototype but rather to a highly original reinterpretation of the form. By the end of 1814, many of the distinctive tendencies in his writing are already evident. These include (1) unusual modulatory strategies dependant upon tonal ambiguity and surprise, (2) the first signs of an intensely lyrical quality in the thematic material, (3) complementary, as opposed to derivative, thematic relationships, in which the musical discourse is divided between two contrasting motivic regions connected by underlying harmonic links and (4) a widespread allusiveness in his handling of harmony, which allows an initial harmonic event or "sensitive sonority" to become increasingly significant as the music proceeds. Ultimately Schubert's innovative approach to sonata form, while weakening the Classical attributes of clarity and conciseness, infuses a new atmosphere into the structure, making it the perfect vehicle for the expression of Romantic sentiment.

This study describes the integration of harmonic idiom and tonal design in Schoenberg's First Quartet, op. 7. Two general questions are answered: whether the composition should be judged by common-practice-period norms, and whether a coherent tonal structure is truly discernible. Chapter 1 first surveys the existing literature. It then describes a prime motivator of foreground chromaticism in the quartet—the chromatic surrounding of tonic and dominant pitches—and discusses two features of large-scale pitch organization applicable to Schoenberg's first-period music that contravene common-practice-period norms: tonal structure consisting of a pattern of keys, and systematic use of dual or even multiple tonics in place of monotonality. Examples illustrate three types of graphic representation of tonal duality to be used in the study. The next four chapters describe tonal process within and across the four "movements" of the quartet (Schoenberg's Parts I through IV). Chapter 2, which studies Part I, reveals systematic avoidance of V-I function in the opening key, D, tonal rivalries between D and each of its two semitone-related keys, and the beginning of a large-scale chromatic surrounding of the key of D. Chapter 3, on Part II of the quartet, demonstrates continuation of the rivalry between tonics D and Dt> by their use as competing secondary tonics within the Scherzo, and the harmonic progression VII-I replacing V-I at a crucial structural point. Chapter 4, on Part III of the quartet, describes tonal duality as it occurs in the Adagio, the furthering of the tonal plot in a section that engages in a "plagal" system of tonality, and the beginning of a large chromatic surrounding of A. Chapter 5 shows that Part IV eschews a simple relationship between the A-major tonic of the Rondo and the D-major tonic of the Coda by allowing the infiltration of elements of the Db-major collection. Chapter 6 summarizes the evidence contradicting a monotonal understanding of the composition and reviews evidence that the demonstrated multi-tonal coherence is part of the musical reality of the work.

No description available.

Traditionally manufacturing job shops either have a process layout or a product layout. The advantages of one type of layout tend to be a disadvantage for the other. Hybrid cellular constructs represents a novel fusion of process and product layouts. In this thesis, hybrid cellular constructs specifically Hybrid Flow Shops and Reoriented andamp; Reshaped Cells are clearly described in terms of their structure, key features, and modes of operation. An engineering procedure is illustrated by cases and particular manufacturing circumstances where each concept would be most useful are identified. This thesis then defines the lean practices that are compatible with the structure in question and identifies what practices are incompatible. It suggests how to modify lean practices to fit and at least obtain some benefits for the incompatible ones. Finally, a procedure for design of logistics management systems for assembly cells and lines is presented.

Nous présentons ici, l’analyse détaillée et l’étude de la stabilité de nouvelles solutions de type vortex dans le secteur bosonique de la théorie électrofaible. Les nouvelles solutions généralisent le plongement des solutions d’Abrikosov-Nielsen-Olesen dans la théorie électrofaible et reproduisent les résultats précédemment connus. Les vortex, génériquement porteurs d’un courant électrique, sont constitués d’un coeur massif de bosons chargés Wentouré d’une superposition non-linéaire de champs Z et Higgs. Au loin la solution est purement électromagnétique avec un potentiel de Biot et Savart. Les solutions sont génériques de la théorie et existent en particulier pour les valeurs expérimentales des constantes de couplage. Il est en particulier démontré que le courant dont l’échelle typique est le milliard d’Ampères peut être arbitrairement grand. Dans un second temps la stabilité linéaire des vortex supraconducteurs vis-à-vis des perturbations génériques est considérée. Le spectre de l’opérateur de fluctuations est étudié qualitativement. Lorsque des modes instables sont détectés, ils sont explicitement construits ainsi que leurs relations de dispersion. La plupart des modes instables sont supprimés par une périodisation du vortex. Il subsiste cependant un unique mode instable homogène. On peut espérer qu’un tel mode puisse être supprimé par des effets de courbure si une portionde vortex est refermée afin de former une boucle stabilisée par le courant électrique. / In this dissertation, we analyze in detail the properties of new string-like solutions of the bosonic sector of the electroweak theory. The new solutions are current carrying generalizations of embedded Abrikosov-Nielsen-Olesen vortices. We were also able to reproduce all previously known features of vortices in the electroweak theory. Generically vortices are current carrying. They are made of a compact conducting core of charged Wbosons surrounded by a nonlinear superposition of Z and Higgs field. Faraway from the core, the solution is described by purely electromagnetic Biot and Savart field. Solutions exist for generic parameter values including experimental values of the coupling constants. We show that the current whose typical scale is the billion of Ampères can be arbitrarily large.In the second part the linear stability with respect to generic perturbations is studied. The fluctuation spectrum is qualitatively investigated. When negative modes are detected, they are explicitly constructed and their dispersion relation is determined. Most of the unstable modes can be eliminated by imposing periodic boundary conditions along the vortex. However there remains a unique negative mode which is homogeneous. This mode can probably be eliminated by curvature effects if a small piece of vortex is bent into aloop, stabilized against contraction by the electric current.

O objetivo deste trabalho é apresentar hipóteses de destacados violoncelistas e professores de violoncelo sobre o processo de aprendizagem e o ensino da técnica e da interpretação do instrumento, com a finalidade de proporcionar importantes reflexões sobre o assunto, meios de pesquisa no instrumento, alem de ser uma iniciativa de pesquisa sobre e para o meio violoncelístico brasileiro. Fundamentalmente, este trabalho consiste na apreciação da literatura especifica sobre o instrumento, produzida, na maioria das vezes, por mestres consagrados. Isso foi complementado por entrevistas e por idéias transmitidas oralmente, por meio de aulas de violoncelo (talvez o mais importante por meio de transmissão de conhecimentos musicais), alem da experiência pessoal desta autora, em sua pratica docente. Resultou desta pesquisa uma grande quantidade de dados, divergentes e convergentes, sobre os inúmeros aspectos do estudo do violoncelo, tais como: maneiras de se pensar o estudo, relaxamento, postura, respiração, escolas de técnica de arco, vibrato, mão esquerda, construção a interpretação, assim como problemas referentes ao ensino e ao estudo do violoncelo no Brasil, bem como idéias para possíveis soluções. / The goal of this to present ideas and hypothesis of remarkable cellists and professors of the cello about the learning process and the teaching of technique and interpretation of the instrument, with the objective of generating important reflections about these issues, ways of researching on the instrument, as well as being a first step towards research about and for Brazilian cellists. The ideas presented have been reached by bibliographical research, interviews, transmitted orally through cello lessons (perhaps the most important way of transmitting musical know ledge), and also obtained by the personal experience of this author over her teaching practice. A great amount of data has resulted from this research, including convergent and divergent ideas dealing with the innumerable aspects of the process of cello study, such as: ways of developing cello study, relaxation with the instrument, posture, breathing, schools of bow technique, vibrato, the left hand, construction of interpretation, problems encountered by those teaching and learning cello in Brazil, as well as ideas for possible solutions to those problems.