Bioprocess and Biosystems Engineering - In this work, a fed-batch approach was adopted to overcome propionic acid lipase inactivation effects in the benzyl propionate direct esterification mediated... 相似文献
acta ethologica - Chemical pollution of aquatic environments has been increasing in recent times, causing great damage to the ecosystems and to the fishery sector. Pollutants can negatively alter... 相似文献
Amino Acids - It is known for almost 25 years that the corpora cardiaca (neurosecretory glands) of cicadas synthesize two isobaric peptides with hypertrehalosaemic activity denominated... 相似文献
Bacillus methylotrophicus M4-96 is a beneficial rhizobacterium that has been isolated from the rhizosphere of maize (Zea mays). In this study, we investigated its efficacy as a plant growth promoter for strawberry in vitro, as well as its ability to induce callose deposition in leaves to reduce the severity of Botrytis cinerea infection. Two methods of plant-bacterial interaction were used: inoculation near the root and emission of volatile compounds with no physical contact. Plant biomass increased under both treatments, but with developmental parameters of the plants differentially stimulated by each method. Root inoculation increased petiole number and root length, whereas bacterial volatiles increased petiole length and root number. A chemical analysis of the bacterial culture revealed the presence of indole acetic acid (0.21 μg L−1) and gibberellic acid (6.16 μg L−1). Acetoin was previously identified as the major volatile produced by the bacteria, and its application to strawberry explants increased their growth and development. Furthermore, when acetoin and both phytoregulators were added to the culture media, these positive effects were enhanced. The inoculation method also affected the size and quantity of callose deposits in the leaves. Treatment with volatiles increased callose deposition in the leaves by up to five-fold, which promoted a rapid defense reaction that inhibited the incidence of gray mold by reinforcing cell wall. Taken together, our results show that B. methylotrophicus M4-96 promotes growth and induces systemic resistance in strawberry plants.
Plant and Soil - We examined how legacies of afforestation affect soil food webs using the composition, structure, and diversity of soil nematode communities along a prairie restoration... 相似文献
ABSTRACT. We designed a system of solar-powered video cameras that transmitted images via telemetry to a monitor. This system allowed us to study the breeding behavior of the Bearded Vulture ( Gypaetus barbatus ) in the Pyrenees (northeastern Spain). From 2000 to 2004, 12 nests in seven territories were equipped with video cameras. To avoid disturbing the birds, equipment was installed 3–8 weeks before egg-laying. The acceptance rate was 75%. No decline in productivity was observed for nests monitored with video cameras compared to control nests. The cameras enabled us to document egg-laying, hatching asynchrony, the nestlings' diet, and the parents' breeding behavior from distances of 2–3 km, although technical problems temporarily interrupted the transmission of images. Video cameras can be used successfully to study the Bearded Vultures, and probably other cliff-nesting raptors, without reducing productivity. 相似文献
Hierarchies readily appear when rearing flounders through metamorphosis in space-limited conditions. In this experiment, subordinate fish were stressed, as suggested by their elevated cortisol level compared to dominant fish. Subordinate fish, although of smaller size than the dominant fish, showed no suppressed digestive capacity. By separating the two hierarchical groups into different tanks at low density, the cortisol level of the subordinate fish substantially decreased. The removal of the stressor also resulted in an increase in digestive function and improved coloration. Also, compensatory growth in length but not in weight was observed in the subordinate group, suggesting that the subordinate fish devoted their energy to increase their length. These results imply that the climax of flounder metamorphosis (i.e. the settlement stage) is a highly sensitive period, where social interactions may induce high levels of stress. However, Japanese flounder early juveniles prove to have a high recovery capacity from stress and show to allocate energy preferentially to growth in length. This seems to be an adaptation to diminish the probability of death by predation. 相似文献
Liver growth factor (LGF) is a mitogen for liver cells that shows biological activity in extrahepatic sites and may be useful for neuroregenerative therapies. The aim of this work was to investigate the effects of the intrastriatal (IS) infusion of LGF in the 6-hydroxydopamine rat model of Parkinson's disease. Tyrosine hydroxylase-positive innervation was significantly increased in the dopamine-denervated striatum of rats receiving intrastriatal LGF infusions (160 ng/day/rat x 15 days) as compared with a vehicle-infused group. There was no evidence of dopaminergic neurogenesis in the striatum or substantia nigra in any experimental group at the times studied. However, in those animals undergoing IS-LGF infusion for 48 hr, we found a significant increase in both microglial proliferation and in the number of microglial cells that acquired the ameboid morphology. This is characteristic of activated microglia/macrophages that has been reported to play an important role in dopamine terminal sprouting. In summary, our study shows that IS infusion of LGF stimulates the outgrowth of tyrosine hydroxylase-positive terminals in the striatum of 6-hydroxydopamine-treated rats. As apomorphine-induced rotational behavior was also reduced in these animals, we propose LGF as a novel factor that, when delivered to the striatum, may be useful in the treatment of Parkinson's disease. 相似文献