Pullback and forward dynamics of nonautonomous Laplacian lattice systems on weighted spaces

<p style='text-indent:20px;'>A nonautonomous lattice system with discrete Laplacian operator is revisited in the weighted space of infinite sequences <inline-formula><tex-math id="M1">\begin{document}$ {{\ell_{\rho}^2}} $\end{document}</tex-math></inline-formula>. First the existence of a pullback attractor in <inline-formula><tex-math id="M2">\begin{document}$ {{\ell_{\rho}^2}} $\end{document}</tex-math></inline-formula> is established by utilizing the dense inclusion of <inline-formula><tex-math id="M3">\begin{document}$ \ell^2 \subset {{\ell_{\rho}^2}} $\end{document}</tex-math></inline-formula>. Moreover, the pullback attractor is shown to consist of a singleton trajectory when the lattice system is uniformly strictly contracting. Then forward dynamics is investigated in terms of the existence of a nonempty compact forward omega limit set. A general class of weights for the sequence space are adopted, instead of particular types of weights often used in the literature. The analysis presented in this work is more direct compare with previous studies.</p>

Non-structural protein P6 encoded by rice black-streaked dwarf virus is recruited to viral inclusion bodies by binding to the viroplasm matrix protein P9-1

Like other members of the family Reoviridae, rice black-streaked dwarf virus (RBSDV, genus Fijivirus) is thought to replicate and assemble within cytoplasmic viral inclusion bodies, commonly called viroplasms. RBSDV P9-1 is the key protein for the formation of viroplasms, but little is known about the other proteins of the viroplasm or the molecular interactions amongst its components. RBSDV non-structural proteins were screened for their association with P9-1 using a co-immunoprecipitation assay. Only P6 was found to directly interact with P9-1, an interaction that was confirmed by bimolecular fluorescence complementation assay in Spodoptera frugiperda (Sf9) cells. Immunoelectron microscopy showed that P6 and P9-1 co-localized in electron-dense inclusion bodies, indicating that P6 is a constituent of the viroplasm. In addition, non-structural protein P5 also localized to viroplasms and interacted with P6. In Sf9 cells, P6 was diffusely distributed throughout the cytoplasm when expressed alone, but localized to inclusions when co-expressed with P9-1, suggesting that P6 is recruited to viral inclusion bodies by binding to P9-1. P5 localized to the inclusions formed by P9-1 when co-expressed with P6 but did not when P6 was absent, suggesting that P5 is recruited to viroplasms by binding to P6. This study provides a model by which viral non-structural proteins are recruited to RBSDV viroplasms.

Ultrastructure of the digestive and protonephridial systems of the metacercaria of Euclinostomum multicaecum

The structure of the digestive tract of Euclinostomum multicaecum (Digenea: Euclinostomatidae) is unusual, comprising several main lateral caeca which extend posteriorly and further divide, giving rise to numerous smaller branches which are widely distributed throughout the fluke. These multicaeca presumably promote nutrient absorption during rapid and prolonged feeding directly following excystment. The caecal wall consists of a syncytial gastrodermal epithelium, bearing loop-like lamellae which extend into the lumen and enclose spherical inclusion bodies and presumably also, increase the absorptive surface area. There was no evidence of endo- or exocytosis, nor were lysosomes, phagosomes or residual bodies observed. The gut caeca are supported by a fibrous basal lamina and an underlying layer of muscle fibres, while parenchymal cells occupy much of the extracellular space. The protonephridial system resembles that observed in other digeneans consisting of flame cells and collecting ducts which join to form a bladder that opens externally through a single excretory pore. The syncytial epithelium of the collecting ducts is elevated by numerous lamellae while the basal lamina is highly infolded. The luminal contents of these ducts comprise bar-shaped crystalline structures, lipid droplets and electron-dense inclusion bodies. The excretory system is supported by a network of muscle fibres and parenchymal cells.

Structural Properties of the Female Accessory Gland in the Stable Fly, Stomoxys calcitrans

The accessory reproductive glands of the female stable fly are translucent structures that run parallel to the common oviduct when the ovipositor is extended. The only muscles found associated with the gland were those at either end of the long tube of simple cuboidal epithelial cells. The posterior region of each gland is connected to the anterior vagina by means of a valve of circular muscle. The myofibrils of the valve are separated into sarcomeres of irregular alignment with Z disks that appear as discontinuous rows of dense bodies. Transections through the Z disk region also revealed a perforated character which is common in muscles that have the ability to super contract. The sarcolemma of many cells have tubular invaginations that correspond to the T-system of tubules found in most muscles. Terminal axons with both synaptic vesicles and larger neurosecretory granules were found in close apposition to muscle fibers of the valve. Large vacuoles (with a mean of 26.36 μm and a SD = ± 2.09) were the most prominent structures in the cytoplasm of the glandular epithelium. The fine structure of these vacuoles showed a microvillar border and a central portion that contains clumps of secretory material in a granular matrix. Many vacuoles also contain dense inclusion bodies while other inclusion bodies were observed in apical membranous networks just beneath the cuticular intima. Such ultrastructural features suggest a largely merocrine type secretion for this gland.

Microprobe analysis of inclusion bodies related to two benzofuran derivatives

Two benzofuran derivatives, chlorpromazine and amiodarone, are known to produce inclusion bodies in human tissues. Prolonged high dose chlorpromazine therapy causes hyperpigmentation of the skin with electron-dense inclusion bodies present in dermal histiocytes and endothelial cells ultrastructurally. The nature of the deposits is not known although a drug-melanin complex has been hypothesized. Amiodarone may also cause cutaneous hyperpigmentation and lamellar lysosomal inclusion bodies have been demonstrated within the cells of multiple organ systems. These lamellar bodies are believed to be the product of an amiodarone-induced phospholipid storage disorder. We performed transmission electron microscopy (TEM) and energy dispersive x-ray microanalysis (EDXA) on tissue samples from patients treated with these drugs, attempting to detect the sulfur atom of chlorpromazine and the iodine atom of amiodarone within their respective inclusion bodies.A skin biopsy from a patient with hyperpigmentation due to prolonged chlorpromazine therapy was fixed in 4% glutaraldehyde and processed without osmium tetroxide or en bloc uranyl acetate for Epon embedding.

Fine structure of the thraustochytrid Ulkenia amoeboidea. I. Vegetative thallus and formation of the amoeboid stage

Development of the thraustochytrid Ulkenia amoeboidea was investigated at the ultrastructural level. The mature thallus possesses a lamellate wall, a nucleus with intranuclear vesicles and lamellae, several Golgi bodies, mitochondria, bundles of microfilaments, multivesicular bodies, dilated perinuclear continuum with filamentous material, endoplasmic reticulum, sagenogenetosomes, and two centrioles. Several unit membrane bounded, variously electron-dense inclusion bodies with electron-dense globular units are present. Wall scales are produced in Golgi cisternae which inflate to form vesicles. These vesicles deposit the wall material to the outside by exocytosis. An aggregate of unit membrane bounded electron-dense cisternae (paranuclear body) is found adpressed to the nucleus. A close association between the paranuclear body and the mitochondria, the former often producing finger-like projections in mitochondrial vicinity, is present. A protocentriole-like structure is seen near the nucleus of young thalli. At later stages, the ectoplasmic net elements disappear. Closely adpressed membrane arrays appear between the cell wall and plasmalemma. These are accumulated in bundles at various places in the cell and are later found in presumed autophagic vacuoles. Before the cell contents escape as an amoeboid mass, the cell wall becomes thinner owing to the peeling off of wall scales and the cell contents round up, with the plasmalemma becoming detached from the cell wall. Various vesicles are closely associated with the plasmalemma.

A membrane-bound plastid inclusion in the epidermis of leaves of Taraxacum officinale

Epidermal chloroplasts of Taraxacum officinale agg. contain large electron-dense inclusion bodies enclosed by a single membrane. These inclusion bodies were not observed in mesophyll chloroplasts. The origin and functional role of these structures is discussed.