The microsporidium Vittaforma corneae (Shadduck, Meccoli, Davis et Font, 1990) develops within the target cell cytoplasm. In the present study, green monkey kidney (E6) cells infected at 30°C, 35°C or 37°C with V. corneae developed enlarged multinucleate structures of up to 200 µm in any horizontal dimension made up either of a single cell or of multiple fused cells. A number of epithelial cell types (SW-480, HT-29, Caco-2 and HCT-8) were infected with V. corneae but did not induce the same highly organized structures, suggesting that for the structure to develop, the host cell must be capable of continued mitosis, and not be differentiated or be detaching from the surface matrix. Live cell imaging of infected E6 cells revealed large, multinucleate infected cells characterized by a central focus from which radiated parasite stages and host cell mitochondria. Immunocytochemistry identifying γ and α tubulin suggested that a single centrally-located microtubule organizing centre governed the distribution of parasite stages and host cell organelles, with mitochondria and parasites being eventually transported towards the periphery of the structure. Whole cell patch clamp analysis of infected cells indicated an average five-fold increase in total membrane capacitance, consistent with an enlarged single cell. Scanning electron microscopy revealed cell-like protrusions around the periphery of the structure with the intervening space being made up of parasites and cell debris. Clearly in the case of V. corneae-infected E6 cells the parasite-host cell relationship involves subverting the host cell cytoskeleton and cell volume control, providing the parasite with the same protected niche as does a xenoma.
This paper deals with the utilizing of the Bayesian optimization algorithm (BOA) for the niultiobjective optimization of combinatorial problems. Three probabilistic models used in the Estimation Distribution Algorithms (EDA), such as UMDA, BMDA and BOA which allow one to search effectively on the promising areas of the combinatorial search space, are discussed. The main attention is focused on the incorporation of Pareto optimality concept into classical structure of the BOA algorithm. We have modified the standard algorithm BOA for one criterion optimization utilizing the known niching techniques to find the Pareto optimal set. The experiments are focused on tree classes of the combinatorial problems: artificial problem with known Pareto set, multiple 0/1 knapsack problém and the bisectioning of hypergraphs as well.
The effect of multiple matings on the readiness with which mating occurred, fecundity, egg viability and adult longevity in the aphidophagous ladybird beetle, Coelophora saucia (Mulsant) (Coleoptera: Coccinellidae), was investigated under laboratory conditions. The time to onset of mating after previous pairing was found to decrease with increase in the number of matings. Multiply mated females had a higher fecundity and egg viability than single mated females. The trends in the results were analyzed using both binomial regression and the Gompertz equation. The best fitting curve was that based on the binomial equation, which indicates that 95% of the maximum theoretical fecundity was attained after mating 11 times and 95% of the maximum theoretical egg viability after mating 3 times. Unlike previous studies on ladybirds, a slight but statistically significant increase in female longevity was observed with increase in number of matings indicating that the male ejaculate might provide a supply of nutrients.
In this paper, using a fixed point theorem on a convex cone, we consider the existence of positive solutions to the multipoint one-dimensional $p$-Laplacian boundary value problem with impulsive effects, and obtain multiplicity results for positive solutions.
Aging is a multifactorial process influenced by genetic factors, nutrition, and lifestyle. According to mitochondrial theory of aging, mitochondrial dysfunction is widely considered a major contributor to age-related processes. Mitochondria are both the main source and targets of detrimental reactions initiated in association with age-dependent deterioration of the cellular functions. Reactions leading to increased reactive oxygen species generation, mtDNA mutations, and oxidation of mitochondrial proteins result in subsequent induction of apoptotic events,
impaired oxidative phosphorylation capacity, mitochondrial dynamics, biogenesis and autophagy. This review summarizes the major changes of mitochondria related to aging, with emphasis on mitochondrial DNA mutations, the role of the reactive oxygen species, and structural and functional changes of mitochondria.
Many biological processes involve globular transport proteins belonging to a family called lipocalins. The prominent feature in lipocalin structure is their specific tertiary conformation forming eight-stranded beta barrel with capacity to bind various ligands inside. The importance of lipocalins is evident from the list of vital substances (Hydrophobic ligands including vitamin A, steroids, bilins, lipids, pheromones etc.) that these proteins transport and from their high expression levels in various tissues. Among wide spectrum of lipocalins, Major Urinary Proteins (Mup) and Odorant Binding Proteins (Obp) are well known for their capacity to bind and carry odorants / pheromones and have been studied to detail in various mammalian models including mice, rats, and hamsters. However, many lipocalins (also including Mups) have previously been described with respect to their protective function in mammalian organism where they transport potentially harmful molecules to a degradation site (e. g. lysozomes) or straight out of the body. As most of lipocalins share similar tertiary structure, their potential role in both transport and excretion processes may be additive or complementary. In addition to a role of lipocalins in chemical communication this review presents lipocalins from the point of view of the "toxic waste hypothesis". This hypothesis assumes that members of lipocalins that are linked to a metabolic degradation of their ligands were an ideal source for natural selection during evolution due to an ability of potential receivers to detect lipocalin ligands levels as a signal by other individuals.
This paper examines the significant phenomena of multiple wh-fronting (MWF) in Czech and wh-in-situ in Korean. It explores the general question of that kinds of syntactic mechanisms can give rise to the analysis of MWF in Czech as well as what licenses the formation of wh-questions in Korean. In particular, I focus on the question of where Czech wh-items can be projected within syntactic trees with respect to elitic placement in second position. For the question of what licenses the formation of wh-questions in Korean,. I propose the sentence-final markers (henceforth SFMs) to determine the scope of wh-operators, without any appparent wh-movement. Additionally, I argue that the non-overt movement of wh-items in Korean can be also supported by ambigous reading.
Semirings are modifications of unitary rings where the additive reduct does not form a group in general, but only a monoid. We characterize multiplicatively idempotent semirings and Boolean rings as semirings satisfying particular identities. Further, we work with varieties of enriched semirings. We show that the variety of enriched multiplicatively idempotent semirings differs from the join of the variety of enriched unitary Boolean rings and the variety of enriched bounded distributive lattices. We get a characterization of this join.
In this paper, we prove some multiplicity results for sign-changing solutions of an operator equation in an ordered Banach space. The methods to show the main results of the paper are to associate a fixed point index with a strict upper or lower solution. The results can be applied to a wide variety of boundary value problems to obtain multiplicity results for sign-changing solutions.