Uniform semiglobal practical asymptotic stability for non-autonomous cascaded systems and applications

It is due to the modularity of the analysis that results for cascaded systems have proved their utility in numerous control applications as well as in the development of general control techniques based on ``adding integrators''. Nevertheless, the standing assumptions in most of the present literature on cascaded systems is that, when decoupled, the subsystems constituting the cascade are uniformly globally asymptotically stable (UGAS). Hence existing results fail in the more general case when the subsystems are uniformly semiglobally practically asymptotically stable (USPAS). This situation is often encountered in control practice, e.g., in control of physical systems with external perturbations, measurement noise, unmodelled dynamics, etc. This paper generalizes previous results for cascades by establishing that, under a uniform boundedness condition, the cascade of two USPAS systems remains USPAS. An analogous result can be derived for USAS systems in cascade. Furthermore, we show the utility of our results in the PID control of mechanical systems considering the dynamics of the DC motors.Comment: 16 pages. Modifications 1st Feb. 2006: additional requirement that links the parameter-dependency of the lower and upper bounds on the Lyapunov function, stronger condition of uniform boundedness of solutions, modification and simplification of the proofs accordingl

Arrhythmogenic right ventricular cardiomyopathy associated with severe left ventricular involvement in a cat.

An 8-year-old, 4 kg, intact female, domestic shorthaired cat was referred for tachypnea and pleural effusion. A 24-h Holter recording showed numerous polymorphic ventricular premature complexes with left and right bundle branch block morphology. Echocardiographic examination revealed right atrial and ventricular dilation. The right ventricular free wall was thin and aneurysmal. The cat died 10 days after initiation of antiarrhythmic therapy. Gross and histopathological findings were consistent with arrhythmogenic right ventricular cardiomyopathy (ARVC) associated with severe left ventricular involvement

The Genetic and Environmental Effects on Diabetes in Humans and Animals: An Overview

Despite intense scrutiny the precise etiology of diabetes mellitus remains unclear. There appear to be two major forms of diabetes: juvenile-onset or insulin-dependent diabetes, and late-onset or insulin-independent diabetes; the late-onset form, in itself, may be etiologically heterogeneous. Either form may occur at any age, with a clear distinction between the two often being difficult to make. Juvenile-onset diabetes, representing 5% to 10% of all cases, is characterized by abrupt onset, clinical manifestation of hyperglycemia and ketoacidosis, and generally by a requirement for exogenous insulin; in maturity-onset diabetes plasma levels of insulin are usually normal or elevated and the abnormality in glucose metabolism results from a decrease in the number of insulin receptors rather than a deficiency of the hormone itself

Eigenvector Centrality Distribution for Characterization of Protein Allosteric Pathways

Determining the principal energy pathways for allosteric communication in biomolecules, that occur as a result of thermal motion, remains challenging due to the intrinsic complexity of the systems involved. Graph theory provides an approach for making sense of such complexity, where allosteric proteins can be represented as networks of amino acids. In this work, we establish the eigenvector centrality metric in terms of the mutual information, as a mean of elucidating the allosteric mechanism that regulates the enzymatic activity of proteins. Moreover, we propose a strategy to characterize the range of the physical interactions that underlie the allosteric process. In particular, the well known enzyme, imidazol glycerol phosphate synthase (IGPS), is utilized to test the proposed methodology. The eigenvector centrality measurement successfully describes the allosteric pathways of IGPS, and allows to pinpoint key amino acids in terms of their relevance in the momentum transfer process. The resulting insight can be utilized for refining the control of IGPS activity, widening the scope for its engineering. Furthermore, we propose a new centrality metric quantifying the relevance of the surroundings of each residue. In addition, the proposed technique is validated against experimental solution NMR measurements yielding fully consistent results. Overall, the methodologies proposed in the present work constitute a powerful and cost effective strategy to gain insight on the allosteric mechanism of proteins

Cardiac biomarkers in clinical practice of dog and cat - a review

A biomarker is an indicator of a normal or pathologic process, or a pharmacologic response to a therapeutic intervention. Nowadays, in veteriary cardiology, the most used biomarkers for assessing the pathological status of the cardio-vascular system, are B-type natriuretic peptide and cardiac troponins. These biomarkers have been very well studied in cardiac pathology in order to assess their diagnostic potential. The aim of the present paper was to discuss the structure, metabolism, function, applicability, reference values and variations in different diseases and to review some practical aspects of the two cardiac biomarkers, used nowadays in small animal cardiology

On high-speed turning of a third-generation gamma titanium aluminide

Gamma titanium aluminides are heat-resistant intermetallic alloys predestined to be employed in components suffering from high mechanical stresses and thermal loads. These materials are regarded as difficult to cut, so this makes process adaptation essential in order to obtain high-quality and defect-free surfaces suitable for aerospace and automotive parts. In this paper, an innovative approach for longitudinal external high-speed turning of a third-generation Ti-45Al-8Nb- 0.2C-0.2B gamma titanium aluminide is presented. The experimental campaign has been executed with different process parameters, tool geometries and lubrication conditions. The results are discussed in terms of surface roughness/integrity, chip morphology, cutting forces and tool wear. Experimental evidence showed that, due to the high cutting speed, the high temperatures reached in the shear zone improve chip formation, so a crack-free surface can be obtained. Furthermore, the use of a cryogenic lubrication system has been identified in order to reduce the huge tool wear, which represents the main drawback when machining gamma titanium aluminides under the chosen process condition

Plasma disposition, concentration in the hair, and anthelmintic efficacy of eprinomectin after topical administration in donkeys

Objective-To investigate plasma disposition, concentration in the hair, and anthelmintic efficacy of eprinomectin after topical administration in donkeys. Animals-12 donkeys naturally infected with strongyle nematodes. Procedures-The pour-on formulation of eprinomectin approved for use in cattle was administered topically to donkeys at a dosage of 0.5 mg/kg. Heparinized blood samples and hair samples were collected at various times between 1 hour and 40 days after administration. Samples were analyzed via high-performance liquid chromatography with fluorescence detection. Fecal strongyle egg counts were performed by use of a modified McMaster technique before and at weekly intervals for 8 weeks after treatment. Results-Plasma concentration and systemic availability of eprinomectin were relatively higher in donkeys, compared with values reported for other animal species. Concerning the anthelmintic efficacy against strongyle nematodes, eprinomectin was completely effective (100%) on days 7 and 14 and highly effective (> 99%) until the end of the study at 56 days after treatment. No abnormal clinical signs or adverse reactions were observed for any donkeys after treatment. Conclusions and Clinical Relevance-Eprinomectin had excellent safety. The relatively high plasma concentration after topical administration could result in use of eprinomectin for the control and treatment of parasitic diseases in donkeys

Efficacy evaluation of an oral powder supplement enriched with eicosapentaenoic acid in cancer patients

Introducción: El efecto beneficioso del ácido eicosapentaenoico en pacientes con cáncer está ampliamente descrito sobre todo en lo que respecta a su rol en la caquexia tumoral. Objetivo: Evaluar la eficacia de la administración de un nuevo suplemento oral en polvo con adición de este componente frente a un suplemento líquido estándar en un grupo de pacientes oncológicos. Pacientes y métodos: 61 adultos mayores de 18 años de ambos sexos con cáncer, fueron aleatorizados en dos grupos para recibir durante un mes 600 kcal extras añadidas a su alimentación; uno a través de un suplemento oral en polvo con 1,5 g de ácido eicosapentaenoico/día (RSI) y el otro con un producto líquido estándar (RE). Tanto al inicio como al final del estudio se realizaron las siguientes medidas: valoración global subjetiva generada por el paciente (VGS-gp), parámetros antropométricos (Pliegues, circunferencia del brazo y bioimpedancia), dietéticos (registro alimentario de 72 horas), bioquímicos e inflamatorios (bioquímica básica, citoquinas, prealbúmina y PCR). La calidad de vida fue valorada mediante el cuestionario SF-36. Así mismo se emplearon escalas de percepción sensorial, tolerancia de los productos y motivación y saciedad al comer durante el estudio. Resultados: Finalizaron el estudio 40 pacientes. Tras la intervención ambos grupos mantuvieron sus parámetros antropométricos y aumentaron significativamente la prealbúmina (RSI 16,11 ± 5,66 mg/dl vs 19.81 ± 6.75 mg/dl p < 0,05 y RE 16.55 ± 6.13 mg/dl vs 19.03 ± 5.47 mg/dl p < 0,05). El grupo RSI disminuyó significativamente los valores de interferón gamma (INF- ) (0,99 ± 0,95 vs 0,65 ± 0,92 pg/ml, p < 0,05). Sin embargo, el grupo RE los aumentó al final del estudio (1,62 ± 1,27 vs 2,2 ± 3,19 pg/ml, p < 0,05). No se encontraron diferencias significativas en la sensación de hambre, apetito, saciedad y capacidad de ingesta tras la intervención en ambos grupos. Las puntuaciones del SF-36 mejoraron en ambos grupos. Conclusión: La suplementación durante un mes de un producto en polvo enriquecido con 1,5 g de EPA en una población de pacientes con cáncer, modula positivamente ciertos parámetros inflamatorios. Este producto podría ser una opción nueva a tener en cuenta que podría sumarse a las estrategias de intervención para el tratamiento nutricional del paciente oncológico.Background and objectives: The beneficial effect of eicosapentaenoic acid in cancer patients is widely described especially in relation to its role in tumour cachexia. The aim of the study was to evaluate the efficacy of administration of a new oral powder supplement enriched with eicosapentaenoic acid compared to a standard liquid supplement in cancer patients. Patients and methods: A total of 61cancer patients, aged more than 18 years, were randomized to receive during a month a bonus of 600 kcal/ day to their regular diet with an oral powder supplement enriched with eicosapentaenoic acid (1.5 g) (RSI) or with a standard liquid supplement (RE). The following data were collected at baseline and after one month: the Patient-Generated Subjective Global Assessment (pg-SGA), anthropometric measurements (skin folds, circumferences and bioimpedance), dietary parameters (3-day food record), biochemical and inflammatory parameters (basic biochemistry, cytokines, prealbumin and Reactive C Protein). Quality of life was evaluated using the SF-36 questionnaire. At the end, scales were used to asses sensory perception, tolerance and satiety induced by the products and motivation to eat. Results: 40 patients completed the study. After intervention, anthropometric parameters do not change and prealbumin values increased significantly in both groups (RSI 16.11 ± 5.66 mg/dl vs. 19.81 ± 6.75 mg/dl p < 0.05 and RE 6.13 ± 16.55 mg/dl vs. 19.03 ± 5.47 mg / dl p < 0.05). RSI group significantly decreased interferon gamma (INF- ) values (0.99 ± 0.95 vs. 0.65 ± 0.92 pg/ml, p < 0.05). In contrast, RE group increased INF- after intervention (1.62 ± 1 27 vs. 2.2 ± 3.19 pg/ml, p < 0.05). There were no significant differences in hunger, appetite, satiety and intake capacity in both groups. The SF-36 scores improved in both groups. Conclusions: Supplementation based on an oral powder formula enriched with 1.5g EPA during one month in cancer patients improved certain inflammatory parameters. This product may be a novel and valuable option to be added to the nutritional intervention strategies used for cancer patients.Este estudio fue financiado por Nestlé Health Care Nutrition SA pero no tuvo intervención en el desarrollo del diseño del estudio, la recolección de los datos, el análisis estadístico, la interpretación de los resultados, la redacción ni publicación de este artícul