The newly formed generative cell of the pollen grain of the African blood lily is spheroidal after its detachment from the pollen wall. Plastids are almost always excluded from the generative cell, while dictyosomes, mitochondria, ribosomes, endoplasmic reticulum, and microtubules are present throughout development of the cell. During the time that the generative cell is spheroidal, microtubule...

Pollen morphology and the degree of pollen variability within nine species and two varieties of Oxalis species from Buenos Aires Province (Argentina) were studied using light microscopy (LM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Oxalis pollen grain is generally 3-colpate and the shape is prolate spheroidal, oblate spheroidal or spheroidal. The exine is ...

This paper deals with a dynamical system that generalizes the Kepler-Coulomb system and the Hartmann system. It is shown that the Schrödinger equation for this generalized KeplerCoulomb system can be separated in prolate spheroidal coordinates. The coefficients of the interbasis expansions between three bases (spherical, parabolic and spheroidal) are studied in detail. It is found that the coef...

A study of almost 1000 outpatients at a London eye hospital showed the presence of asymptomatic yellowish, spheroidal deposits in the peripheral cornea or conjunctiva, or both, in about 6 per cent, with a preponderance of males and older subjects among those affected. This prevalence is less than is observed in people in countries exposed to higher levels of sunlight. Histological study of the ...

ABSTRACT Feedback from active galactic nuclei (AGNs) has become established as a fundamental process in the evolution of most massive galaxies. Its impact on Milky Way (MW)-mass systems, however, remains comparatively unexplored. In this work, we use auriga simulations to probe AGN feedback dynamical and structural properties galaxies, focusing bar, bulge, disc. We analyse three galaxies – two ...

In this paper, we introduce the production of ductile iron crankshaft of the engine status quo and development. Ductile iron crankshaft discussed smelting process, alloying and manufacturing process mode. This paper focuses on the application of isothermal hardened spheroidal graphite cast iron in the crankshaft, especially its application in the power of the engine crankshaft. We also introduc...

We investigate the self-locomotion of an elongated microswimmer by virtue of unidirectional tangential surface treadmilling. We show that the propulsion could be almost frictionless, as the microswimmer is propelled forward with the speed of the backward surface motion, i.e. it moves through an almost quiescent fluid. We investigate this swimming technique using the special spheroidal coordinat...

Below a threshold energy, gas in the constant density core of a triaxial galaxy can find no simple non-intersecting periodic orbit to act as an attractor for its trajectory (El-Zant et al. 2003). If a disc of gas arriving from further out in the galaxy dissipates sufficient energy to fall below this threshold, it will thereafter collapse into the very centre. Such a mechanism may be relevant to...

BACKGROUND AND AIMS Marcgraviaceae are a rather small family of seven genera and approx. 130 neotropical species. This study aims to present a detailed palynological survey of the family in order to comment on the intrafamily relationships and possible correlations with pollinators. METHODS In total, 119 specimens representing 67 species and all genera are observed using light microscopy and ...

We study a system comprising a spheroidal particle with permittivity epsilon 2 and conductivity sigma 2 immersed in a host medium with permittivity epsilon 1 and conductivity sigma 1 in the ac external electric field with a strength Epsilon 0 and frequency omega. We determined conditions when orientation of a spheroidal particle with a finite electric conductivity at t --> infinity coincides wi...