The distribution of agglutinins and lytic activity against Trypanosoma rangeli and erythrocytes in Rhodnius prolixus and Triatoma infestans tissue extracts and haemolymph

Haemolymph, heads, salivary glands, crops, midguts, hindguts, and Malpighian tubules from Rhodnius prolixus and Triatoma infestans were extracted in phosphate or Tris buffer saline with calcium, and tested for agglutination and lytic activities by microtitration against both vertebrateerythrocytes and cultured epimatigote forms of Trypanosoma rangeli. Haemagglutination activity against rabbit erythrocytes was found in the crop, midgut and hindgut extracts of T. infestans but only in the haemolymph of R. prolixus. Higher titres of parasite agglutinins were found in R. prolixus haemolymph than T. infestans, whilst the converse occurred for the tissue extracts. In addition, the extracts of T. infestans salivary glands, but not those of R. prolixus, showed a trypanolytic activity that was heat-inactivated and was not abolished by pre-incubation with any of the sugars or glycoproteins tested. T. infestans, which is refractory to infection by T. rangeli, thus appears to contain a much wider distribution of agglutinating and trypanolytic factors in its tissues than the more susceptible species, R. prolixus

On the behaviour of zeros of Jacobi polynomials

Denote by x(n,k)(alpha, beta) and x(n,k) (lambda) = x(n,k) (lambda - 1/2, lambda - 1/2) the zeros, in decreasing order, of the Jacobi polynomial P-n((alpha, beta))(x) and of the ultraspherical (Gegenbauer) polynomial C-n(lambda)(x), respectively. The monotonicity of x(n,k)(alpha, beta) as functions of a and beta, alpha, beta > - 1, is investigated. Necessary conditions such that the zeros of P-n((a, b)) (x) are smaller (greater) than the zeros of P-n((alpha, beta))(x) are provided. A. Markov proved that x(n,k) (a, b) < x(n,k)(α, β) (x(n,k)(a, b) > x(n,k)(alpha, beta)) for every n is an element of N and each k, 1 less than or equal to k less than or equal to n if a > alpha and b < β (a < alpha and b > beta). We prove the converse statement of Markov's theorem. The question of how large the function could be such that the products f(n)(lambda) x(n,k)(lambda), k = 1,..., [n/2] are increasing functions of lambda, for lambda > - 1/2, is also discussed. Elbert and Siafarikas proved that f(n)(lambda) = (lambda + (2n(2) + 1)/ (4n + 2))(1/2) obeys this property. We establish the sharpness of their result. (C) 2002 Elsevier B.V. (USA).

Ferroelectric and piezoelectric properties of bismuth titanate thin films grown on different bottom electrodes by soft chemical solution and microwave annealing

Bismuth titanate (Bi4Ti3O12, BIT) films were evaluated for use as lead-free piezoelectric thin films in micro-electromechanical systems. The films were grown by the polymeric precursor method on LaNiO3/SiO2/Si (1 0 0) (LNO), RuO2/SiO2/Si (1 0 0) (RuO2) and Pt/Ti/SiO2/Si (1 0 0) (Pt) bottom electrodes in a microwave furnace at 700 degrees C for 10 min. The domain structure was investigated by piezoresponse force microscopy (PFM). Although the converse piezoelectric coefficient, d(33), regardless of bottom electrode is around (similar to 40 pm/V), those over RuO2 and LNO exhibit better ferroelectric properties, higher remanent polarization (15 and 10 mu C/cm(2)), lower drive voltages (2.6 and 1.3 V) and are fatigue-free. The experimental results demonstrated that the combination of the polymeric precursor method assisted with a microwave furnace is a promising technique to obtain films with good qualities for applications in ferroelectric and piezoelectric devices. (c) 2006 Elsevier Ltd. All rights reserved.

New optimality conditions for nonsmooth control problems

This work considers nonsmooth optimal control problems and provides two new sufficient conditions of optimality. The first condition involves the Lagrange multipliers while the second does not. We show that under the first new condition all processes satisfying the Pontryagin Maximum Principle (called MP-processes) are optimal. Conversely, we prove that optimal control problems in which every MP-process is optimal necessarily obey our first optimality condition. The second condition is more natural, but it is only applicable to normal problems and the converse holds just for smooth problems. Nevertheless, it is proved that for the class of normal smooth optimal control problems the two conditions are equivalent. Some examples illustrating the features of these sufficient concepts are presented. © 2012 Springer Science+Business Media New York.

Avaliação do tempo e métodos de aquecimento de toras de Eucalyptus grandis Hill ex-Maiden e sua influência no rendimento em laminação e na qualidade das lâminas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A característica de Euler

Pós-graduação em Matemática em Rede Nacional - IBILCE

Análise de estabilidade de sistemas dinâmicos descontínuos e aplicações

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

C-l-contact and C-l-right equivalences of real semi-quasihomogeneous C-l function germs

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

C^l-contact and C^l-right equivalences of real semi-quasihomogeneous C^l-function germs

In this paper we investigate the C ` versions of contact and right equivalences of real semi-quasihomogeneous C ` function germs, 1 ≤ ` ≤ ∞. The C ` -right equivalence implies C ` -contact equivalence for any 1 ≤ ` ≤ ∞ and in this work we show, up to certain conditions, that for semi-quasihomogeneous C ` function germs the converse is also true. As a consequence, we recover some known results about C∞-right and C∞-contact equivalences of C∞ function germs. We note that we are considering semi-quasihomogeneous function germs with no additional hypothesis of isolated singularity at zero.

Some Results in Stability Analysis of Hybrid Dynamical Systems

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)