In this work, we introduce several novel approaches to feedback controller design, known collectively as the “Robust Bode” methods, which adapt classical control principles to a modern robust control (H∞) framework. These methods, based on specially modified Bode diagrams extend familiar frequency-domain controller design techniques to linear and nonlinear, single–input/single– output (SISO) and multi–input/multi–output (MIMO) systems with parametric and/or unstructured uncertainties. In particular, we introduce the Contoured Robust Controller Bode (CRCBode) plots which show contours (level-sets) of a robust metric on the Bode magnitude and phase plots of the controller. An iterative loop shaping design procedure is then employed in an attempt to eliminate all intersections of the controller frequency response with certain forbidden regions indicating that a robust stability and performance criteria is satisfied. For SISO systems a robust stability and performance criterion is derived using Nyquist arguments leading to the robust metric used in the construction of the CRCBode plots. For open-loop unstable systems and for non-minimum phase systems the Youla parametrization of all internally stabilizing controllers is used to develop an alternative Robust Bode method (QBode). The Youla parametrization requires the introduction of state-space methods for coprime factorization, and these methods lead naturally to an elegant connection between linear-quadratic Gaussian (LQG) optimal control theory and Robust Bode loop-shaping controller design. Finally, the Robust Bode approach is extended to MIMO systems. Utilizing a matrix norm based robustness metric on the MIMO CRCBode plots allows cross-coupling between all input/output channels to be immediately assessed and accounted for during the design process, making sequential MIMO loop-shaping controller design feasible.

Herpes Simplex Virus Type 1 (HSV-1) establishes latent infections in neurons in vivo and lytic infections in epithelial cells and fibroblasts. During latent infections, HSV-1 transcription is restricted and the genomes are not replicated. Latent HSV-1 genomes are chromatinized, such that digestion with micrococcal nuclease (MCN) releases DNA fragments with sizes characteristic of nucleosomal DNA. During lytic infections, in contrast, all HSV-1 genes are expressed, the genomes are replicated, and their digestion produces primarily heterogeneously sized fragments. However, as evaluated by ChIP assays, HSV-1 DNA interacts with histones during lytic infections, although in most cases only a small percentage of HSV-1 DNA co-immunoprecipitates with histones (or is cleaved to nucleosome sizes following MCN digestion). Therefore, although current models propose that chromatin regulates HSV-1 transcription, it remains unclear how the association of histones with only a small percentage of HSV-1 DNA can globally regulate viral transcription. Moreover, the physical properties of the complexes containing histones and HSV-1 DNA are unknown. My objective was therefore to evaluate the biophysical properties of the HSV-1 DNA-containing complexes during lytic infection. Differing from pervious studies, however, I used classical chromatin purification techniques. I show that most HSV-1 DNA is in unstable nucleoprotein complexes and, consequently, more accessible to MCN than DNA in cellular chromatin. This HSV-1 DNA is protected from MCN redigestion only after crosslinking, similar to unstable cellular nucleosomes. HSV-1 DNA is in such complexes throughout lytic infection. Using unrelated small-molecule inhibitors, I further show that inhibition of HSV-1 transcription is associated with a decrease in MCN accessibility of HSV-1 DNA. Roscovitine, a cyclin-dependent kinase inhibitor, prevents activation but not elongation of IE, E, and L HSV-1 transcription. Consistent with a functional association between accessibility and transcription, roscovitine only decreases the accessibility of DNA templates of which it also inhibits transcription, independent of specific promoter sequences. In summary, I show that most HSV-1 DNA is in unstable nucleosome-like complexes during lytic infection and that accessibility to HSV-1 DNA likely plays a key role in regulating HSV-1 transcription.

No description available.

The evolution of column instabilities that lead to break up of a microscale liquid jet is studied experimentally using shadowgraph technique. The jet formation is investigated over a range of Reynolds number, Pressure Ratio, and Ohnesorge number which are varied by the driving pressure, observation chamber pressure, and the jet liquid. Over the range of these parameters, the jet experiences different break up mechanisms as a result of different dominant instabilities. The present investigation discusses both break up mechanisms that are similar to the break up of macroscale jets and some new microscale break up phenomena.

Research Doctorate - Doctor of Philosophy (PhD) / This dissertation presents some new approaches to addressing the main issues encountered by practitioners in the implementation of linear model predictive control(MPC), namely, stability, feasibility, complexity and the size of the region of attraction. When stability guaranteeing techniques are applied nominal feasibility is also guaranteed. The most common technique for guaranteeing stability is to apply a special weighting to the terminal state of the MPC formulation and to constrain the state to a terminal region where certain properties hold. However, the combination of terminal state constraints and the complexity of the MPC algorithm result in regions of attraction that are relatively small. Small regions of attraction are a major problem for practitioners. The main approaches used to address this issue are either via the reduction of complexity or the enlargement of the terminal region. Although the ultimate goal is to enlarge the region of attraction, none of these techniques explicitly consider the upper bound of this region. Ideally the goal is to achieve the largest possible region of attraction which for constrained systems is the null controllable set. For the case of systems with a single unstable pole or a single non-minimum phase zero their null controllable sets are defined by simple bounds which can be thought of as implicit constraints. We show in this thesis that adding implicit constraints to MPC can produce maximally controllable systems, that is, systems whose region of attraction is the null controllable set. For higher dimensional open-loop unstable systems with more than one real unstable mode, the null controllable sets belong to a class of polytopes called zonotopes. In this thesis, the properties of these highly structured polytopes are used to implement a new variant of MPC, which we term reduced parameterisation MPC (RP MPC). The proposed new strategy dynamically determines a set of contractive positively invariant sets that require only a small number of parameters for the optimisation problem posed by MPC. The worst case complexity of the RP MPC strategy is polylogarithmic with respect to the prediction horizon. This outperforms the most efficient on-line implementations of MPC which have a worst case complexity that is linear in the horizon. Hence, the reduced complexity allows the resulting closed-loop system to have a region of attraction approaching the null controllable set and thus the goal of maximal controllability.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2002. / Härtill 6 uppsatser.

Diss. (sammanfattning)--Stockholm : Karol. inst., 2002. / Härtill 5 uppsatser.

Thesis (M.S.)--Medical College of Ohio, 2005. / In partial fulfillment of the requirements for the degree of Master of Science in Nursing. Major advisor: Jane C. Evans. Includes abstract. Document formatted into pages: vi, 53 p. Title from title page of PDF document. Title at ETD Web Site : Prodromal signs and symptoms of women with acute coronary syndrome . Bibliography: pages 48-52.

Objetivou-se verificar a relação entre a contagem de células somáticas do leite bovino ordenhado separadamente de quartos mamários com a qualidade físico-química do leite, em especial com o leite instável não ácido (LINA). Foram utilizadas 21 vacas das raças Holandês e Jersey, sendo selecionados a partir do teste do CMT os animais que apresentaram pelo menos um quarto mamário normal e os demais quartos com mastite subclínica. Realizou-se análise microbiológica, identificação dos agentes e, durante quatro dias consecutivos, as vacas foram ordenhadas com uma ordenhadeira especial de quartos individuais avaliando a produção, composição química, contagem de células somáticas (CCS) e análise física do leite. O principal agente isolado no leite foi o Corynebacterium sp. (27,38%). Ocorreu diminuição de 21,65% na produção de leite dos quartos com CCS acima de 750.000cél/mL. A instabilidade do leite não apresentou variação significativa dos quartos saudáveis em comparação com os quartos mastíticos. Dentre os componentes químicos do leite, o teor de lactose diminuiu à medida que ocorreu o aumento da CCS e não houve variação significativa nos teores de gordura, proteína bruta, sólidos totais e sólidos desengordurados. Houve variação significativa dos componentes do leite nas diferentes raças. Não houve relação entre a mastite subclínica e o LINA. / This study assessed the relationship between milk somatic cell count from different mammary quarters of cows with subclinical mastitis with physical and chemical milk quality, especially unestable non acid milk (UNAM). Twenty-one Holstein and Jersey cows were used which had at least one healthy quarter and the others with subclinical mastitis. Microbiological analysis was performed and the agents were identified. Cows were milked with a special milking machine which separate milk from each quarter for four consecutive days. Milk samples were collected to evaluate production, chemical composition, somatic cell count (SCC) and physical characteristics. The main agent identified in the milk was Corynebacterium sp. (27,38%). There was a decrease of 21,65% in quarter milk production of cows with SCC above 750.000cél/mL. Milk instability did not vary significantly from healthy quarters compared with mastitis. Among milk chemical components, lactose decreased as the SCC increased and there were no significant variation in levels of fat, protein, total solids and non-fat solids. There were significant variations in the components of milk in different breeds. There was no relationship between subclinical mastitis and UNAM.

INTRODUÇÃO: as fraturas transtrocanterianas do fêmur são muito frequentes nos idosos, e seu tratamento é eminentemente cirúrgico. Na grande maioria dos casos há a consolidação da fratura, mas os pacientes parecem não evoluir satisfatoriamente do ponto de vista clínico. O objetivo deste estudo é avaliar a qualidade da marcha de pacientes que foram submetidos ao tratamento cirúrgico por uma técnica de fratura transtrocanteriana instável. MATERIAL E MÉTODOS: participaram deste estudo 24 pacientes operados por fratura transtrocanteriana instável do fêmur com utilização do DHS. Os pacientes foram acompanhados prospectivamente, e foi avaliada a qualidade da marcha de pós-operatório e comparada com a de antes da cirurgia, segundo o escore de Robinson. RESULTADOS: no período pré-operatório, 14 pacientes (58,3%) eram do grupo I segundo o escore de marcha de Robinson; 4 (16,7%), do grupo II; 3 (12,5%), do grupo III; 1 (4,2%), do grupo IV; e 2 (8,3%), do grupo V. Todas as fraturas evoluíram para a consolidação, e a taxa de mortalidade foi de 25%. Todos os pacientes foram encaminhados para o mesmo protocolo de reabilitação, e após um período médio de 9,69 meses, 28,6% dos pacientes apresentavam-se no grupo I do escore de Robinson; 23,8%, no grupo II; 4,8%, no grupo III; 23,8%, no grupo IV; e 19% estavam no grupo V. Esses dados mostram que, apesar da alta taxa de consolidação das fraturas, não houve melhora sequer na manutenção da qualidade da marcha dos pacientes, sendo estatisticamente significante (p= 0,003). CONCLUSÕES: as fraturas transtrocanterianas instáveis do fêmur podem ser tratadas com o DHS, apresentando uma alta taxa de consolidação. Entretanto, parecem não evoluir bem do ponto de vista funcional. Esses achados deveriam ser confirmados por outros estudos com maior número de pacientes e avaliando outro tipo de implante. / INTRODUCTION: transtrochanteric fractures of the femur are very frequent in elderly patients, and its treatment is mainly surgical. In most cases the fracture can be consolidated, but patients seem not to have a satisfactory clinical evolution. The objective of this study is to evaluate gait quality of patients who have been submitted to surgical treatment with a technique of unstable transtrochanteric fracture. MATHERIAL AND METHODS: This study evaluated 24 patients who had been operated for unstable transtrochanteric fracture of the femur with the use of DHS. The patients were prospectively followed up, and the postoperative gait quality was evaluated and compared to preoperative gait using Robinson score. RESULTS: In preoperative period, 14 (58.3%) patients belonged to Group I according to Robinson score, 4 (16.7%) belonged to Group II, 3 (12.5%) belonged to Group III, 1 (4.2%) belonged to Group IV, and 2 (8.3%) belonged to Group V. All the fracture evolved to consolidation, and the mortality rate was 25%. All the patients were referred to the same rehabilitation protocol, and after an average period of 9.69 months, 28.6% were in Group I of Robinson score, 23.8% were in Group II, 4.8% in Group III, 23.8% in Group IV, and 19% in Group V. These data show that, despite the high rate of fracture consolidation, there was no improvement even in the maintenance of the patients’ gait quality, being it statistically significant (p= 0.003). CONCLUSIONS: Unstable transtrochanteric fractures of the femur can be treated with DHS, presenting a high consolidation rate. However, they seem not to evolve functionally. These findings should be confirmed by other studies with a higher number of patients who also use another type of implant.