Optimal control theory based design of elasto-magnetic metamaterial

A method to design a new type of metamaterial is presented. A two-step strategy to define an optimal long-range force distribution embedded in an elastic support to control wave propagation is considered. The first step uses a linear quadratic regulator (LQR) to produce an optimal set of long-range interactions. In the second step, a least square passive approximation of the LQR optimal gains is determined. The paper investigates numerical solutions obtained by the previously described procedure. Finally, we discuss physical and engineering implications and practical use of the present study

Twin-waves propagation phenomena in magnetically-coupled structures

The use of magnetic dipoles embedding in an elastic support introduces long-range interaction forces. This is a completely new paradigm in structural mechanics, classically based on local short-range particle interaction. The features of long-range forces produce very new mechanical coupling effects. This paper examines the case in which two identical rod-like structures, each with a dipole distribution embedded, vibrate side by side. Waves generated in one of the rods propagate also in the second and vice versa creating a new effect we name twin-waves. The present investigation unveils the existence of an infinite number of propagation modes even in one-dimensional infinite structures, a new and unus al behaviour in classical waveguides. The physics behind this phenomenon is further investigated also by numerical simulations

Multivariate analysis about causes of growth delay in early weaned calves

The purpose of this trial was to check if early weaned calf growth delay is due to stress or inadequate feeding. In 4 successive years, assays of 120 days each were carried out, using in total 120 half-bred Zebu calves (2 months old) grazed on natural pasture. Sixty animals were controls fed on maternal milk (C), and other 60 made up the experimental group (E), which was submitted to early weaning and supplemented with balanced food. Weightings and blood extractions were made in days 0, 7, 14, 21, 28, 60, 90 and 120. Hematological and biochemical determinations (42 parameters) included stress and malnutrition indicators, which were evaluated by radio-immune-assay, chemoluminiscency, spectrophotometry, electrophoresis, and electronic particle recount. Such procedures generated more than 40,000 data, which were statistically processed by multivariate techniques, to eliminate the additive effect of random intervention probability (alpha error), characteristic from univariate methods that comprise numerous dependent variables. Variables that obtained significant differences for treatment and/or time effects in repeated measures univariate techniques, were selected for analysis of principal components. Four orthogonal supervariables, susceptible to stress, malnutrition and ontogeny, were created. Weight gains were 79.9 kg (666 g/animal/day) in C, and 61.6 kg (513 g/animal/day) in E. Variations of cortisol, aldosterone, fructosamine, glucose, sodium, potassium, leukocytes, gamma globulins and enzymes suggested absence of stress, examined under an ontogenic frame. On the other hand, decrease of protein, carbohydrate, lipid, and mineral nutritional indicators, revealed malnutrition in E. Selected principal components indicated that most of total variance was due to malnutrition and ontogeny, but not to stress. It is important to develop more appropriate balanced supplements for early weaned calves

Long-range retarded elastic metamaterials: wave-stopping, negative, and hypersonic or superluminal group velocity

This paper investigates new phenomena in elastic wave propagation in metamaterials, characterised by long-range interactions. The kind of waves borne in this context unveil wave-stopping, negative group velocity, instability and hypersonic or superluminal effects, both for instantaneous and for nonlocal retarded actions. Closed form results are presented and a universal propagation map synthesizes the expected properties of these materials. Perspectives in physics, engineering and social dynamics are discussed

Reference interval and physiological variations of plasma electrolytes in Rana Catesbeiana (Shaw, 1802, Amphibia: Ranidae)

To obtain plasma ionogram normal values, as well as sex, age, weight, climate, and breeding and feeding systems physiological variations, 302 samples of healthy Rana catesbeiana specimens from argentine northeastern (9-21 months old, 50-350 g liveweight, 50% each sex), were analyzed. Confidence intervals for sodium (116-121 meq/l), potasssium (3.42-3.81 meq/l), chloride (100-116 meq/l), calcium (7.98-8.61 mg/dl), inorganic phosphorous (8.31-9.36 mg/dl), iron (105-178 ug/dl) and magnesium (2.26-2.55 mg/dl), were obtained. Physiological variations due to sex were not verified. Weight and age advances correlated to potassium increase, and calcium and inorganic phosphorous decrease (p < 0.05). Magnesium, potassium, inorganic phosphorous and calcium values, were lower in winter than in remaining year seasons. Ionograma was significantly influenced by handling technique; in general, values were high when tanks floor had smaller surface covered by water, and vice versa. Plasma electrolytes were low in frogs maintained on viscera, intermediate when they fed on balanced pellets plus larvas or worms, and high when they fed "naturally" in a lagoon. Utility of ionogram to evaluate nutritional and sanitary states is emphasized, and its application as useful instrument to optimize the frog production is recommended

Evolución de parámetros hemáticos de terneros media sangre cebú en crecimiento

El propósito del trabajo fue obtener intervalos de confianza y detectar variaciones ontogénicas de algunos parámetros hemáticos de interés diagnóstico que pudiera ocurrir entre los 2 y 6 meses de vida del ternero media sangre cebú mantenido en lactación sobre pasturas naturales del nordeste argentino.-- En cada uno de cuatro años sucesivos, fueron estudiados 15 terneros clínicamente sanos de 60 - 75 días de edad y 60 - 90 kg de peso [n = 60].-- Las determinaciones hemáticas y bioquímicas fueron realizadas con técnicas usuales de laboratorio. Se efectuaron estadísticas descriptivas paramétricas y análisis de la variancia a una vía, estableciéndose un riesgo alfa del 5 por ciento.-- Al final del ensayo se verificaron aumentos significativos de cortisol, creatinfosfoquinasa, volumen corpuscular medio, hemoglobina corpuscular media, neutrófilos, eosinófilos, urea, proteínas totales, beta y gammaglobulinas, así como disminuciones significativas de aldosterona, fructosamina, glucosa, triglicéridos, colesterol total, fósforo inorgánico, fosfatasa alcalina, relación albúmina - globulinas, leucocitos totales y linfocitos

Evolución del peso e indicadores nutricionales del balance nitrogenado en sangre de vacas destetadas a los 60 y 90 días post – parto

indicadores bioquímicos del balance nitrogenado, así como su relación con la ganancia de peso, se dispuso de 30 vacas cruza cebú (x: 375 kg)divididas en lotes control C (en lactación, n = 15) y experimental E (destetadas a los 60 días post-parto, n = 15). Bajo un diseño de medidas repetidas se efectuaron pesajes y extracciones de sangre en los días 0, 7, 14, 21, 28, 60y 90. Al finalizar el estudio, en E se registraron valores significativamente más altos (p < 0,05) de proteínas totales (7,90 versus 7,25 g/dl en C), albúminas (3,15 versus 2,89 g/dl) y urea (0,38 versus 0,29 g/l). Los valores de globulinas alfa, beta y gamma, así como la relación albúmina / globulinas, también resultaron más elevados en E, pero las diferencias fueron no significativas. Las vacas destetadas registraron mayores ganancias diarias de peso que las vacas lactantes (339 versus 130 g/animal). Las diferencias entre Cy E comenzaron a ser significativas hacia los días 21 (valores bioquímicos) y28 (peso vivo). Las variaciones del peso revelaron alto grado de asociación lineal con los datos del laboratorio. La mejoría del peso y los parámetros séricos en E se atribuyen al cese del drenaje lácteo de sustancias nitrogenadas

Acuaporinas

Se efectúa una revisión bibliográfica sobre la estructura, localización anatómica, funciones y enfermedades humanas y animales asociadas a las acuaporinas (AQP). Estas proteínas son las mediadoras del pasaje de agua a través de las membranas celulares de animales, vegetales y microorganismos. En Medicina Veterinaria, los aumentos o disminuciones de su expresión podrían estar vinculados a varias enfermedades de los animales domésticos, de naturaleza hereditaria, congénita o adquirida, tales como edemas, cataratas, obesidad, diabetes insípida nefrogénica y otras. El conocimiento de la fisiopatología de las AQP seguramente se traducirá en el perfeccionamiento de los métodos de diagnóstico y en la especificidad de las medidas terapéuticas

Approach to some hematological variables of healthy captive “yaguareté” (Panthera onca) from Northeast Argentina

Samples of three healthy Panthera onca from a Northeast Argentina reserve were analyzed through spectrophotometry, electrophoresis, densitometry, and microscopy in order to obtain hematological and biochemical reference values. Means and standard deviation for hematocrit, hemoglobin, red and white blood cells, leukocyte differential count, total protein, albumin, globulins, glucose, total cholesterol, lipoproteins, calcium, inorganic phosphorus, urea, creatinine and some enzymatic activities, were obtained. Usefulness of studied parameters to evaluate sanitary and nutritional state on captive P. onca, is emphasized