Silvana L. D’AMICO¹, Patricia I. LEONARDI ^1,2*, Eduardo J. CÁCERES¹

BIOCELL, Vol.37, No.3, pp. 85-90, 2013, DOI:10.32604/biocell.2013.37.085

Abstract This is the first comprehensive ultrastructural study on dwarf males with external gametangia in the ge in the genus Oedogonium, from androspore germination to the liberation of mature male gametes. The ultrastructure of the process in O. macrandrium Wittrok is similar to that of Bulbochaete hiloensis (Nordstedt) Tiffany, butwith two remarkable differences. In O. macrandrium : 1) instead of a true transverse wall, only condensed mucilage appears between the gametes of each antheridial cell, and 2) the cell wall between the basal cell and the basal most antheridial cell has simple plasmodesmata similar to those present in the transverse walls… More >

JUAN CARLOS CAVICCHIA*, GUSTAVO GUEMBE, MABEL FÓSCOLO

BIOCELL, Vol.34, No.2, pp. 81-90, 2010, DOI:10.32604/biocell.2010.34.081

Abstract In a previous paper we described a pronounced increase of apoptotic nuclei in rat corpus luteum of pregnancy whose programmed chromatin degeneration was induced by the progesterone antagonist mifepristone. Those observations encouraged us to study the apoptotic nuclear membrane during pregnancy and after parturition and pup removal, by using a freeze-fracture technique which allows us to observe ‘en face’ the nuclear envelop and also permits nuclear pore counting. This study was complemented with the TUNEL assay (TdT-mediated dUTP nick-end labelling). Changes in nuclear pores during pregnancy begin with an intense reduction in number but still showing an even distribution on… More >

ELISA R. PARODI^1,2*, EDUARDO J. CÁCERES³, RENATO WESTERMEIER⁴, DIETER G. MÜLLER⁵

BIOCELL, Vol.34, No.1, pp. 45-52, 2010, DOI:10.32604/biocell.2010.34.045

Abstract The present paper deals with the ultrastructure of zoospores produced by the plasmodiophorid Maullinia ectocarpii, living in the marine algal host Ectocarpus siliculosus. The zoospores described here are very similar to secondary zoospores of Polymyxa graminis and Phagomyxa sp. (the latter an algal endoparasite, also). Our results indicate that M. ectocarpii produces two types of plasmodia, and suggest that is a species with a complete life cycle, as it is known for all the Plasmodiophormycota that have been studied. Sporogenic and sporangial plasmodia produce, respectively, primary zoospores with parallel flagella within thick walled resting sporangia, and secondary zoospores with opposite… More >

Bonomo MC, OG Martínez, ME Tanco, R Cardozo, Z Avilés

Phyton-International Journal of Experimental Botany, Vol.82, pp. 119-126, 2013, DOI:10.32604/phyton.2013.82.119

Abstract The tree fern Alsophila odonelliana is found from southern Bolivia to northwestern Argentina, in the Tucuman-Bolivian forests. Spore germination was tested in three sterile nutritive media: Dyer (D), Murashige and Skoog (MS) and Knudson (K). We also evaluated the effect on gametophyte development of the addition of two growth regulators, BAP and 2,4-D to the culture medium Dyer; 2,4-D was evaluated using two concentrations: 0.1 and 2.0 mg/L, and BAP using three concentrations, 0.01; 0.1 and 1.0 mg/L. We found no significant differences in the germination of spores among all three media. We noted that supplementing media with BAP affected… More >

Donghong He¹, Hang Ma^{2, *}

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.1, pp. 15-40, 2019, DOI:10.31614/cmes.2019.04327

Abstract To deal with the problems encountered in the large scale numerical simulation of three dimensional (3D) elastic solids with fluid-filled pores, a novel computational model with the corresponding iterative solution procedure is developed, by introducing Eshelby’s idea of eigenstrain and equivalent inclusion into the boundary integral equations (BIE). Moreover, by partitioning all the fluid-filled pores in the computing domain into the near- and the far-field groups according to the distances to the current pore and constructing the local Eshelby matrix over the near-field group, the convergence of iterative procedure is guaranteed so that the problem can be solved effectively and… More >

Lianhua Ma¹, Qingsheng Yang^{2, *}

CMES-Computer Modeling in Engineering & Sciences, Vol.114, No.2, pp. 239-259, 2018, DOI:10.3970/cmes.2018.114.239

Abstract Fluid-filled closed-cell porous media could exhibit distinctive features which are influenced by initial fluid pressures inside the cavities. Based on the equivalent far-field method, micromechanics-based solutions for the local elastic fields of porous media saturated with pressurized fluid are formulated in this paper. In the present micromechanics model, three configurations are introduced to characterize the different state the closed-cell porous media. The fluid-filled cavity is assumed to be a compressible elastic solid with a zero shear modulus, and the pressures in closed pores are represented by eigenstrains introduced in fluid domains. With the assumption of spheroidal fluid-filled pores, the local… More >