In the stage 4 chick blastoderm, an area located 0.6 mm posterior to Hensen's node, the post-nodal piece (PNP), consists of an undifferentiated population of cells, since the explants when cultivated in vitro in a variety of media do not develop into any histologically identifiable structures. However, addition of a specific low molecular weight RNA isolated from the 16-day-old chick embryonic heart promotes the appearance of a distinct mode of morphological and biochemical changes that is similar to that of embryonic cardiogenic process. The RNA-induced changes in the PNP also include a marked increase in acetylcholinesterase activity. The increase in enzymatic activity can be measured biochemically, as well as visualized histochemically. 相似文献
This study evaluated the effects of microbial-enriched compost tea (CT) on the conidial germination of Golovinomyces cichoracearum DC. and development of powdery mildew on melons in a time-dependent manner. In vitro conidial germination was significantly reduced by 94?% and 85?% upon treatment with Daconil? (fungicide) or microbial-enriched CT, respectively, 96?h after incubation (hai). Morphological analysis under light microscopy demonstrated that conidia co-incubated with microbial-enriched CT at 48?hai appeared ruptured, which contributed to higher inhibition of conidial germination, increased cell permeability and leakage of cellular contents. These observations may be explained by antibiosis. Moreover, different application time of microbial-enriched CT on melons significantly affected disease development. There was a delay in disease development by 12?days in plants treated with Daconil?, microbial-enriched CT applied 24?h after inoculation and microbial-enriched CT applied simultaneously with inoculation when compared to the control treatment. Curative application of microbial-enriched CT (24?h after inoculation) delayed the onset of disease, and the efficiency of inhibition was comparable to a fungicidal spray (Daconil?). Hence, microbial-enriched CT may be used to inhibit the development of powdery mildew on melons, thus reducing the dependency on chemical fertilisers. 相似文献
Neurochemical Research - Neurotransmitter:sodium symporters are highly expressed in the human brain and catalyze the uptake of substrate through the plasma membrane by using the electrochemical... 相似文献
The fluctuation in temperature adversely affects grain development when the climate changes intermittently. This study investigated the effect of high day/night temperatures (34/30 °C, 38/34 °C and 42/38 °C) for two stress durations (24 h and 48 h) on Triticum aestivum. To ascertain the role of plant growth regulator (PGR) in alleviating the deleterious effects of high temperature stress, the combination of various PGRs (e.g., methyl jasmonate, salicylic acid, ascorbic acid, calcium chloride and indole acetic acid) were foliar sprayed twice; one week prior to commencement of anthesis stage and immediately after the exposure to high temperature stress. In general, the high temperature reduces plant growth, grain setting, and 100-grain weight. High temperature stress causes deterioration of plant photosynthetic machinery through a significant decline in energy dissipation, linear electron flow (LEF) and quantum yield of photosystem II (Phi2) which led to plant death. An increase in the antioxidant enzymes activity (SOD, APX, and CAT) was observed at 38/34 °C, while their activity declined sharply at 42/38 °C. Grain setting and filling were completely inhibited in plants exposed to 42/38 °C even when treated with different combinations of PGRs. Salicylic acid along with methyl jasmonate was the most effective PGR combination resulting in significant improvements in Phi2, NPQt, SOD, grain filling and grain protein content under high temperature stress. A strong correlation was observed between LEF and chlorophyll contents against the number of grains per spike and 100-grain weight. In summary, acute day and night temperature stress adversely affected wheat morphological, physiological, and yield traits, while foliar application of PGRs was partially effective in mitigating these harmful changes.
Invasive species are capable of causing considerable damage to natural ecosystems, agriculture and economies throughout the World. Samsum ant, Brachyponera (Pachycondyla) sennaarensis has been a reason for medical implication and social nuisance through its poisonous and severely painful sting causing anaphylactic shock in many cases. We surveyed for the presence of the samsum ant in various provinces of Saudi Arabia. B. sennaarensis was the abundant Ponerinae species in human settlements. In the Eastern provinces, however, few samples were collected, and none were found in the Northern and Western provinces. Infestations of B. sennaarensis were particularly severe in the spring and summer seasons, when the ants make nests in moist areas and in cracks in cemented structures, whereas the extent of infestation reduced in winter seasons. 相似文献
Molecular and Cellular Biochemistry - Vitiligo is autoimmune, acquired, idiopathic, chronic, and progressive de/hypopigmentary cutaneous condition that targets the cell-producing pigment called... 相似文献
We report on an improved method to interpret single molecule dissociation measurements using atomic force microscopy. We describe an easy to use methodology to reject nonspecific binding events, as well as estimating the number of multiple binding events. The method takes nonlinearities in the force profiles into account that result from the deformation of the used polymeric linkers. This new method is applied to a relevant enzyme-inhibitor system, latent matrix metalloprotease 9 (ProMMP-9, a gelatinase), and its inhibitor, tissue inhibitor of metalloproteases 1 (TIMP 1), which are important players in cancer metastasis. Our method provides a measured kinetic off-rate of 0.010 ± 0.003 s(-1) for the dissociation of ProMMP9 and TIMP1, which is consistent with values measured by ensemble methods. 相似文献
In this investigation, peristaltic flow of Walter’s B fluid in a uniform inclined tube is discussed. The formulation of the
problem is made in a cylindrical coordinate system. The analytical solutions have been calculated by using a regular perturbation
method by taking δ as the perturbation parameter. The expressions for pressure rise and friction forces were calculated using numerical integration.
The graphical results are presented to discuss the various physical quantities of the Walter’s B fluid parameter α, amplitude ratio φ, angle of inclination β and wave length δ. 相似文献