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Uptake Ability (uptake + ability)
Selected AbstractsCan intra-specific genetic variation in arbuscular mycorrhizal fungi (Glomus etunicatum) affect a mesophyll-feeding herbivore (Tupiocoris notatus Distant)?ECOLOGICAL ENTOMOLOGY, Issue 4 2007STUART C. WOOLEY Abstract 1.,Arbuscular mycorrhizal fungal (AMF) infection can have negative, positive or neutral effects on insect herbivore populations, but patterns are difficult to predict. 2.,Intra-specific genetic variation in nutrient uptake ability between fungal isolates may also have indirect effects on insect herbivores due to changes in plant quality. In preliminary studies mirid (Tupiocoris notatus) populations were significantly reduced on tobacco (Nicotiana rustica) colonised by AMF but it was unknown if same-species fungal isolates differed in their effect. 3.,An experiment was performed as a first test of the effect of intra-specific genetic variation in the mycorrhizal fungus Glomus etunicatum on mirid nymphal population structure, dynamics, and growth rate. 4.,Mirid nymphal populations were lower on mycorrhizal fungal-infected plants. Population size, however, did not differ between the mycorrhizal isolates. While no statistical difference in population between isolates was found, one isolate consistently had 1.7,2.4 times lower mirid populations compared with the controls, indicating that the magnitude of effect is different between mycorrhizal isolates. 5.,The significantly negative effect of AMF on mirid populations likely resulted from AMF-induced changes in plant quality (e.g. increased defence). This study lends further support to recent demonstrations that below-ground symbionts significantly influence above-ground processes. In addition, mycorrhizal fungi can affect insect population structure, which may have consequences for future herbivory. [source] Occurrence of yeasts in municipal wastes and their behaviour in presence of cadmium, copper and zincJOURNAL OF BASIC MICROBIOLOGY, Issue 3 2003Luz Balsalobre Seven yeasts strains have been isolated from sewage sludge. Also six samples of compost with different sieving, composting times and origins, have been analysed. Apparently, composting processes negatively affect the viability of yeasts, as none could be isolated from the compost samples. The margins of tolerance of the yeasts to Cd, Cu and Zn have been determined. The physiological response to metals was similar in all the species studied, and in general, kinetic parameters (, and lag) were affected. Metal uptake ability was also studied and inter- and intra-specific heterogeneity was detected, thus indicating that both the tolerance to metals and the capacity of the uptake were dependent on ionic metal and yeast species. The effect of the presence of multi-metal ions on the uptake capacity of each individual metal was assayed for two selected yeasts, Pichia guilliermondii and Torulaspora delbrueckii. The uptake of each individual metal varied with the combination assayed, and when both strains were compared different results were also found. [source] Chitosan scaffolds for in vitro buffalo embryonic stem-like cell culture: An approach to tissue engineeringJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2007Wah W. Thein-Han Abstract Three-dimensional (3D) porous chitosan scaffolds are attractive candidates for tissue engineering applications. Chitosan scaffolds of 70, 88, and 95% degree of deacetylation (% DD) with the same molecular weight were developed and their properties with buffalo embryonic stem-like (ES-like) cells were investigated in vitro. Scaffolds were fabricated by freezing and lyophilization. They showed open pore structure with interconnecting pores under scanning electron microscopy (SEM). Higher % DD chitosan scaffolds had greater mechanical strength, slower degradation rate, lower water uptake ability, but similar water retention ability, when compared to lower % DD chitosan. As a strategy to tissue engineering, buffalo ES-like cells were cultured on scaffolds for 28 days. It appeared that chitosan was cytocompatible and cells proliferated well on 88 and 95% DD scaffolds. In addition, the buffalo ES-like cells maintained their pluripotency during the culture period. Furthermore, the SEM and histological study showed that the polygonal buffalo ES-like cells proliferated well and attached to the pores. This study proved that 3D biodegradable highly deacetylated chitosan scaffolds are promising candidates for ES-like cell based tissue engineering and this chitosan scaffold and ES cell based system can be used as in vitro model for subsequent clinical applications. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007 [source] Steam reactivation of a spent sorbent for enhanced SO2 capture in FBCAICHE JOURNAL, Issue 12 2006Fabio Montagnaro Abstract The regeneration by steam hydration of the sulfur capture ability of spent sorbent particles from Fluidized Bed Combustion (FBC) is addressed. The process is characterized in terms of effectiveness of sorbent reactivation, hydration degree, particle sulfation pattern, development of accessible porosity, and extent of particle attrition and fragmentation. Steam reactivation experiments were carried out in a lab-scale atmospheric FBC at 250°C for 10, 30, and 180 min with 0.05 MPa steam partial pressure. The effectiveness of sorbent reactivation was assessed by reinjecting the reactivated material into the FB reactor operated at 850°C under simulated desulfurization conditions and following the degree of calcium conversion and the attrition rate along with resulfation. The experimental results indicated that steam reactivation is effective in renewing the SO2 uptake ability of the exhausted sorbent particles. The regeneration mechanism based on the swelling upon hydration of the unreacted core, the generation of fissures and cracks, and the consequent development of accessible porosity is confirmed for the limestone under scrutiny. In addition to this, a remarkable result was that steam hydration induces, for the sorbent under investigation, a pronounced sulfur redistribution throughout the particle cross-section, which provides another pathway to the enhancement of the sulfur capture ability of the reactivated sorbent. © 2006 American Institute of Chemical Engineers AIChE J, 2006 [source] | ||||||||||