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2. Analysis of nonuniform beams on elastic foundations using recursive differentation method

Creator:
Taha Hassan, Mohamed and Abo Hadima, Samir
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
critical load, natural frequency, recursive differentiation method, and beams on elastic foundation
Language:
English
Description:
Analytical solutions for static an dynamic stability parameters (Pcr and ωn) of an axially loaded nonuniform beam resting on a two parameter foundation are obtained using the recursive differentiation method (RDM) along with automatic differentiation. The analysis includes all cases of beam end conditions and indicates that the foundation stiffness influence is noticeable on both the critical load Per and natural frequency ωn in the case of slender beams. Also, it is found that the effect of the end conditions decreases as the slenderness parameter of the beam increases. In addition, the analysis concludes that neither the critical load nor the natural frequency corresponding to the first mode is always the smallest one in the case of beams of elastic foundations. The obtained solutions are verified and used to investigate the significance of different parameters on the critical loads and natural frequencies., Obsahuje seznam literatury a názvosloví, and V názvu článku je překlep ve slově differentation - správně differentiation (= chybí druhé i)
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. Public health importance of Brachiola algerae (Microsporidia) - an emerging pathogen of humans

Creator:
Visvesvara, Govinda S., Moura, Hercules, Leitch, Gordon J., Schwartz, David A., and Xiao, Lihua X.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Microsporidia, Brachiola algerae, cell culture, genotype, immunolbot, PCR products, and sequencing
Language:
English
Description:
Brachiola algerae (Vavra et Undeen, 1970), a parasite of Anopheles mosquitoes, has also been isolated from a human cornea, a cutaneous nodule and deep muscle tissue. All three human isolates of B. algerae are morphologically, serologically, and genetically similar to the mosquito-derived isolates including the original isolate of Vavra and Undeen. All of these isolates grew well in mammalian cell cultures at 37°C and produced spores. Transmission electron microscopy revealed that all developmental stages including meronts, sporoblasts and spores were diplokaryotic and developed in direct contact with the host cell cytoplasm, a feature characteristic of the genus Brachiola. Spores of all isolates reacted well, in the immunofluorescence assay, with the rabbit anti-B. algerae serum. In the immunoblot assay, although the overall banding patterns of the human and mosquito isolates were similar, minor differences could be discerned. Sequencing of the PCR products of the amplified SSU rRNA gene revealed the existence of two distinct genotypes; the original mosquito (Undeen) isolate belonged to genotype 1 and the isolate from cornea and that from the deep muscle biopsy to genotype 2, whereas the isolates from a mosquito and one of the other two human isolates (one from skin abscess) had both genotypes, 1 and 2. It is known that spores of mosquito-derived B. algerae can not only proliferate in mammalian cell cultures at 37°C but also can infect mice when injected into footpads or deposited on the corneal surface. These observations indicate that the spores have potential to be a risk factor for humans, especially those with immunodeficiency.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public