Search results for "TRIF"
showing 10 items of 1419 documents
Relationship between N-cycling communities and ecosystem functioning in a 50-year-old fertilization experiment.
2009
The relative importance of size and composition of microbial communities in ecosystem functioning is poorly understood. Here, we investigated how community composition and size of selected functional guilds in the nitrogen cycle correlated with agroecosystem functioning, which was defined as microbial process rates, total crop yield and nitrogen content in the crop. Soil was sampled from a 50-year fertilizer trial and the treatments comprised unfertilized bare fallow, unfertilized with crop, and plots with crop fertilized with calcium nitrate, ammonium sulfate, solid cattle manure or sewage sludge. The size of the functional guilds and the total bacterial community were greatly affected by …
Hydrolysis and microbial community analyses in two-stage anaerobic digestion of energy crops
2007
Aims: The roles of the diverse populations of micro-organisms responsible for biodegradation of organic matter to form methane and carbon dioxide are rudimentarily understood. To expand the knowledge on links between microbial communities and the rate limiting, hydrolytic stage of two-stage biogas production from energy crops, this study was performed. Methods and Results: The process performance. and microbial communities (as determined by fluorescence in situ hybridization) in two separate two-stage batch digestions of sugar beets and grass/clover were studied. The microbial populations developed in the hydrolytic stage of anaerobic digestion of beets and grass/clover showed very few simi…
Two-Stage Anaerobic Digestion of Energy Crops: Methane Production, Nitrogen Mineralisation and Heavy Metal Mobilisation
2006
Energy crops (willow, sugar beet and grass silage) were digested in pilot scale two-stage anaerobic digesters. The specific methane yields obtained were 0.16, 0.38 and 0.39 m3 kg(-1) added volatile solids (VSadded) for willow, sugar beet and grass, respectively, corresponding to yearly gross energy yields of 15, 53 and 26 megawatt-hours (MWh) per hectare. With grass and sugar beets as substrate, 84-85% of the harvestable methane was obtained within 30 days. In pilot scale two-stage digestion of willow and sugar beet, 56 and 85% of the laboratory scale methane yields were obtained, but digestion of grass in two-stage reactors yielded 5% more methane than digestion in laboratory scale complet…
Investigating the cryopreservation of nodal explants of Lithodora rosmarinifolia (Ten.) Johnst., a rare, endemic Mediterranean species
2012
In this study, we investigated the possibility of using the droplet-vitrification technique for cryopreserving nodal segments of in vitro plantlets of the endangered plant species Lithodora rosmarinifolia. Among the three vitrification solutions tested, only solutions B1, containing (w/v) 50 % glycerol and 50 % sucrose, and B3, containing 40 % glycerol and 40 % sucrose, were able to induce cryotolerance in nodal explants, resulting in intermediate survival and recovery after cryopreservation. A three-step vitrification protocol, including an additional dehydration treatment with half-strength vitrification solution for 30 min before the treatment with full-strength vitrification solution, d…
Vitrification of Immature Porcine Oocytes: Effects of Lipid Droplets, Temperature, Cytoskeleton, and Addition and Removal of Cryoprotectant
1998
Three experiments were conducted to investigate the effects of single-step and stepwise exposure to and removal of cryoprotectant, of temperature, and of a cytoskeletal relaxant on the development of germinal vesicle porcine oocytes to the M-II stage. In experiment I, noncooled cumulus-oocyte complexes (COCs) were treated using single-step/stepwise exposure to ethylene glycol (EG) and removal at 23 or 42 degrees C. Stepwise exposure to EG and dilution at 42 degrees C were found to have a positive effect on the COC developmental rate. In experiment II, also without cooling, COCs were treated with Cytochalasin B at 42 degrees C using single-step and stepwise protocols of exposure to and remov…
Vitrification of human mature oocytes in clinical practice.
2009
Oocyte cryopreservation has long been the focus of unsuccessful efforts to perfect its clinical application. Lately, vitrification has been shown to provide high degrees of success by different research groups. This review attempts to address the efficiency of oocyte vitrification in clinical practice through an analysis of reports of IVF cycles in which embryo transfers have been conducted with vitrified metaphase-II human oocytes.
Cryopreservation of Limonium serotinum apical meristems from in vitro plantlets using droplet-vitrification
2011
Abstract In this study in vitro shoot tips of a Sicilian genotype of Limonium serotinum were successfully cryopreserved using the droplet-vitrification technique. Growth recovery of cryopreserved shoot tips was possible only when samples were pretreated for 16 h in liquid medium with 0.3 M sucrose, then for 5 h in liquid medium with 0.7 M sucrose before performing the cryopreservation protocol. Optimal conditions included treatment for 20 min in a loading solution containing 1.9 M glycerol + 0.5 M sucrose, treatment with vitrification solution B5 (glycerol 40.0%, sucrose 40.0%, w/v) for 60 and 90 min or vitrification solution A9 (glycerol 30.0%, dimethylsulfoxide 20.0%, ethylene glycol 20.0…
Comparing encapsulation-dehydration and droplet-vitrification for cryopreservation of sugarcane (Saccharum spp.) shoot tips
2011
Abstract In this study, in vitro shoot tips of two sugarcane clones were successfully cryopreserved using encapsulation-dehydration and droplet-vitrification with two vitrification solutions, PVS2 and PVS3. For both clones, encapsulation-dehydration induced significantly higher recovery, reaching 60% for clone H70-144 and 53% for clone CP68-1026, compared with droplet-vitrification in which recovery was 33–37% for clone H70-144 and 20–27% for clone CP68-1026. Optimal conditions included preculture of encapsulated shoot apices for 24 h in liquid medium with 0.75 M sucrose and dehydration with silica gel to 20% moisture content (fresh weight basis) before direct immersion in liquid nitrogen. …
Neonatal Outcomes and Long-Term Follow-Up of Children Born from Frozen Embryo, a Narrative Review of Latest Research Findings
2022
In recent years, the growing use of ART (assisted reproductive techniques) has led to a progressive improvement of protocols; embryo freezing is certainly one of the most important innovations. This technique is selectively offered as a tailored approach to reduce the incidence of multiple pregnancies and, most importantly, to lower the risk of developing ovarian hyperstimulation syndrome when used in conjunction with an ovulation-triggering GnRH antagonist. The increase in transfer cycles with frozen embryos made it possible to study the effects of the technique in children thus conceived. Particularly noteworthy is the increase in macrosomal and LGA (large for gestational age) newborns, i…
Ultrastructure, fractionation and biochemical analysis of Cryptosporidium parvum sporozoites.
1999
Abstract Sporozoites of the apicomplexan parasite Cryptosporidium parvum were subjected to cell disruption and subcellular fractionation using a sucrose density step gradient. With this procedure, highly enriched preparations of the parasite membrane, the micronemes, dense granules and amylopectin granules were produced. No separate fraction containing rhoptries was obtained, however this organelle was found in defined fractions of the gradient, still associated with the apical tip of the sporozoites. Using negative staining, the internal structure of the micronemes was revealed by transmission electron microscopy. Micronemes and dense granules showed characteristic protein compositions by …