Synthesis of mutual intensity distributions using the fractional Fourier transform

Cataloged from PDF version of article.Our aim in this paper is to obtain the best synthesis of a desired mutual intensity dis~but~on, by filtering in fractional Fourier domains. More specifically, we find the optimal fractional-domain filter that transforms a given (source) mutual intensity distribution into the desired one as closely as possible (in the minimum mean-square error sense). It is observed that, in some cases, closer approximations to the desired profile can be obtained by filtering in fractional Fourier domains, in comparison to filtering in the ordinary space or frequency domains

Two new convolutions for the fractional Fourier transform

In this paper we introduce two novel convolutions for the fractional Fourier transforms (FRFT), and prove natural algebraic properties of the corresponding multiplications such as commutativity, associativity and distributivity, which may be useful in signal processing and other types of applications. We analyze a consequent comparison with other known convolutions, and establish a necessary and sufficient conditions for the solvability of associated convolution equations of both the first and second kind in L^1(R) and L^2(R) spaces. An example satisfying the sufficient and necessary condition for the solvability of the equations is given at the end of the paper

The immunopathology of human schistosomiasis-III: immunoglobulin isotype profiles and response to praziquantel

Immunoglobulin (Ig) isotype (IgG, IgG1, IgG2, IgG3, IgG4, IgM, IgD and IgE) levels were investigated, both pre- and post-treatment with praziquantel (PZQ), in 43 adults and children chronically infected with Schistosoma mansoni , by means of a two-site, isotype-specific immunoenzymometric assay. The patients were classified as responders (R) or non-responders (NR) on the basis of their circumoval precipitin test (COPT) results 12 months after treatment. In comparison with controls, pre-treatment R children showed significantly higher levels of IgG, IgG1, IgG4 (p<0.001) and IgE (p<0.01), and diminished IgG2 (p<0.05), while NR children showed significantly elevated levels only of IgE (p<0.05). Twelve months after therapy, R children maintained significantly lower levels of IgG2, but showed significantly decreased levels of IgG, IgG1, IgG4, and IgE, while the Ig isotype profile of NR children was unaltered. Adult R and NR showed similar isotype profiles before chemotherapy, with the exception of significantly elevated IgM levels in R. Twelve months after therapy, R adults showed significantly decreased levels of IgG, IgG1, and IgG4, while NR adults showed only diminshed IgG4 levels. These results reveal different Ig isotype profiles in untreated adults and children chronically infected with S. mansoni. The results further show that the pre-treatment Ig isotype profile may be significantly modified after an effective R to chemotherapy, accounted for by down regulation of the IgG1 isotype in association with negative seroconversion of the COPT in R patients. The COPT reaction has been associated with the highly specific egg glycoprotein antigen w1, which shows a significant reduction in reactivity six months after treatment. IgG1 may thus play a main role in the response against the w1 antigen

Design of dynamically adjustable anamorphic fractional Fourier transformer

Cataloged from PDF version of article.We form optical systems by using only free space portions and cylindrical lenses, and consider these systems as anamorphic fractional Fourier transformers. We dynamically adjust the transform order, scale factor and field curvature of both orthogonal dimensions of anamorphic fractional Fourier transformation by just changing the focal lengths of cylindrical lenses used in the proposed setups. Here, we also consider two approaches for implementing cylindrical lenses with dynamically adjustable focal lengths. There may also be some other methods to obtain cylindrical lenses having adjustable focal lengths which can successfully be used in these proposed setups

Cloning, characterization, and functional expression of Taenia solium calreticulin

Calreticulin is an endoplasmic reticulum protein involved in the homeostasis of intracellular Call and other physiological processes. A complementary DNA clone containing the complete coding sequence of Taenia solium calreticulin (TsCRT) was isolated and characterized. Recombinant TsCRT was expressed in bacteria as a 50-kDa protein that specifically bound calcium when tested in a radioassay. The deduced amino acid sequence has 47-50% identity with other reported calreticulins. Poor recognition of TsCRT by human and pig sera with confirmed cysticercosis discourages its use for diagnosis of the disease. However. further characterization and localization studies could provide insights into the role of TsCRT in T. solium physiology and host-parasite interactions

Lack of postmortem digestion of tapeworms in golden hamsters experimentally infected with Taenia solium

Taenia solium causes human neurocysticercosis, a public health problem in Mexico and other developing countries. Surprisingly, tapeworm carriers are very rarely found and in necropsy studies practically no tapeworms have been reported. In this paper we analyze the possibility that, after the death of the host, tapeworms could easily be destroyed in the intestine. Our experiments, performed in the hamster model, suggest that the absence of tapeworms in human intestine during necropsy is not due to postmortem digestion. (c) 2006 Elsevier B.V. All rights reserved