Responsiveness of bovine cumulus-oocyte-complexes (COC) to porcine and recombinant human FSH, and the effect of COC quality on gonadotropin receptor and Cx43 marker gene mRNAs during maturation in vitro

Substantially less development to the blastocyst stage occurs in vitro than in vivo and this may be due to deficiencies in oocyte competence. Although a large proportion of bovine oocytes undergo spontaneous nuclear maturation, less is known about requirements for proper cytoplasmic maturation. Commonly, supraphysiological concentrations of FSH and LH are added to maturation media to improve cumulus expansion, fertilization and embryonic development. Therefore, various concentrations of porcine FSH (pFSH) and recombinant human FSH (rhFSH) were investigated for their effect on bovine cumulus expansion in vitro. Expression of FSHr, LHr and Cx43 mRNAs was determined in cumulus-oocyte complexes to determine whether they would be useful markers of oocyte competence. In serum-free media, only 1000 ng/ml pFSH induced marked cumulus expansion, but the effect of 100 ng/ml pFSH was amplified in the presence of 10% serum. In contrast, cumulus expansion occurred with 1 ng/ml rhFSH in the absence of serum. FSHr mRNA was highest at 0–6 h of maturation, then abundance decreased. Similarly, Cx43 mRNA expression was highest from 0–6 h but decreased by 24 h of maturation. However, the relative abundance of LHr mRNA did not change from 6–24 h of maturation. Decreased levels of FSHr, LHr and Cx43 mRNAs were detected in COCs of poorer quality. In conclusion, expansion of bovine cumulus occurred at low doses of rhFSH in serum-free media. In summary, FSHr, LHr and Cx43 mRNA abundance reflects COC quality and FSHr and Cx43 mRNA expression changes during in vitro maturation; these genes may be useful markers of oocyte developmental competence

Modelling the temperature, maturity and moisture content in a drying concrete block

In this paper we continue work from a previous Study Group in developing a model for the maturation of concrete. The model requires equations describing the temperature, moisture content and maturity (or amount of cement that has reacted with the water). Non-dimensionalisation is used to simplify the model and provide simple analytical solutions which are valid for early time maturation. A numerical scheme is also developed and simulations carried out for maturation over one day and then two months. For the longer simulation we also investigate the effect of building the block in a single pour or two stages

Transient domain formation in membrane-bound organelles undergoing maturation

The membrane components of cellular organelles have been shown to segregate into domains as the result of biochemical maturation. We propose that the dynamical competition between maturation and lateral segregation of membrane components regulates domain formation. We study a two- component fluid membrane in which enzymatic reaction irreversibly converts one component into another, and phase separation triggers the formation of transient membrane domains. The maximum domains size is shown to depend on the maturation rate as a power-law similar to the one observed for domain growth with time in the absence of maturation, despite this time dependence not being verified in the case of irreversible maturation. This control of domain size by enzymatic activity could play a critical role in intra-organelle dynamics.Comment: 7 pages, 6 figure

Critical Steps of Plasmodium falciparum Ookinete Maturation

The egress and fertilization of Plasmodium gametes and development of a motile ookinete are the first crucial steps that mediate the successful transmission of the malaria parasites from humans to the Anopheles vector. However, limited information exists about the cell biology and regulation of this process. Technical impediments in the establishment of in vitro conditions for ookinete maturation in Plasmodium falciparum and other human malaria parasites further constrain a detailed characterization of ookinete maturation. Here, using fluorescence microscopy and immunolabeling, we compared P. falciparum ookinete maturation in Anopheles coluzzii mosquitoes in vivo and in cell culture in vitro. Our results identified two critical steps in ookinete maturation that are regulated by distinct mosquito factors, thereby highlighting the role of the mosquito environment in the transmission efficiency of malaria parasites

Control of RelB during dendritic cell activation integrates canonical and noncanonical NF-κB pathways.

The NF-κB protein RelB controls dendritic cell (DC) maturation and may be targeted therapeutically to manipulate T cell responses in disease. Here we report that RelB promoted DC activation not as the expected RelB-p52 effector of the noncanonical NF-κB pathway, but as a RelB-p50 dimer regulated by canonical IκBs, IκBα and IκBɛ. IκB control of RelB minimized spontaneous maturation but enabled rapid pathogen-responsive maturation. Computational modeling of the NF-κB signaling module identified control points of this unexpected cell type-specific regulation. Fibroblasts that we engineered accordingly showed DC-like RelB control. Canonical pathway control of RelB regulated pathogen-responsive gene expression programs. This work illustrates the potential utility of systems analyses in guiding the development of combination therapeutics for modulating DC-dependent T cell responses

A Smart Approach to Harvest Date Forecasting

The concept of grape ripeness depends not only on the degree of enrichment of the chemical compounds in the grape and the volume of the berries, but also on the possible production purposes. The different types of maturation in individual cases are not sufficient for the decision on the harvest date. Taken together, however, they define oenological maturation times and help to harvest them. However, there are no consistent studies that correlate the chemical parameters obtained from must analysis and oenological maturation due to the nonlinearity of these two types of variables. Therefore, this work seeks to create a self-explanatory model that allows for the prediction of ideal harvest time, based on eneological parameters related to practices in new developments in knowledge acquisition and management in relational databases

Abscission study during citrus fruit maturation in Corsica: unfavorable environmental conditions for fruit shedding

Citrus fruit development and ripening are complex processes involving physiological and biochemical changes that are under hormonal, nutritional and environmental control. One of the most evident phenomena in late maturation is shedding of ripe fruit. A previous study on sweet orange abscission supposed that fruit shedding was related to the increase of sugars content of pulp juice. To investigate this potential relationship between fruit abscission and internal maturity parameters we investigated the fruit maturity process of 10 mandarin x clementine hybrids and 9 commercial sweet orange varieties with different maturity time. Morphological and biochemical analyses (acidity, total soluble solids, fruit weight thickness of the flavedo, thickness of the peduncle and external color) were carried out on fruit sets of the different varieties during the maturation process, from December to June. The abscission initiation was evaluated by measuring the force required to detach the fruit of the peduncle. Analysis showed that under our local conditions, abscission was generally not expressed even though fruit maturation was evolving. Therefore, we suppose that even though the local conditions have an important effect, abscission of citrus fruit also results from environmental-genotype interactions. Moreover, evolution of abscission and fruit parameters are not correlated, suggesting the independence in the processing of maturation and abscission. (Résumé d'auteur

Nitrogen removal in maturation WSP ponds via biological uptake and sedimentation of dead biomass

In this work a set of experiments was undertaken in a pilot-scale WSP system to determine the importance of organic nitrogen sedimentation on ammonium and total nitrogen removals in maturation ponds and its seasonal variation under British weather conditions. Two maturation ponds in series (M1 and M2) were monitored seasonally from September 2004 to May 2007. The nitrogen content in collected sediment samples varied from 4.17 to 6.78 percent (dry weight) and calculated nitrogen sedimentation rates ranged from 291 to 2,868 g N/ha d in M1 and from 273 to 2,077 g N/ha d in M2. The increment of chlorophyll-a in M1 and M2 maturation pond effluents had a very good correlation with the corresponding increment of VSS (algal biomass) and suspended organic nitrogen; therefore, the occurrence of biological (algal) nitrogen uptake was confirmed. After sedimentation of the dead algal biomass, it was clear that algal-cell nitrogen was recycled from the sludge layer into the pond water column. An important portion (51% in M1 and 39% in M2) of the nitrogen taken up by the in-pond algae was finally accumulated as sludge after anaerobic digestion. Biological (mainly algal) uptake of inorganic nitrogen species and further sedimentation of dead biomass is one of the major mechanisms controlling ammonium and nitrogen removal in maturation WSP, particularly when environmental and operational conditions are favourable for algal growth

Early maturation processes in coal. Part 1: Pyrolysis mass balances and structural evolution of coalified wood from the Morwell Brown Coal seam

In this work, we develop a theoretical approach to evaluate maturation process of kerogen-like material, involving molecular dynamic reactive modeling with a reactive force field to simulate the thermal stress. The Morwell coal has been selected to study the thermal evolution of terrestrial organic matter. To achieve this, a structural model is first constructed based on models from the literature and analytical characterization of our samples by modern 1-and 2-D NMR, FTIR, and elemental analysis. Then, artificial maturation of the Morwell coal is performed at low conversions in order to obtain, quantitative and qualitative, detailed evidences of structural evolution of the kerogen upon maturation. The observed chemical changes are a defunctionalization of the carboxyl, carbonyl and methoxy functional groups coupling with an increase of cross linking in the residual mature kerogen. Gaseous and liquids hydrocarbons, essentially CH4, C4H8 and C14+ liquid hydrocarbons, are generated in low amount, merely by cleavage of the lignin side chain