1,759 research outputs found
The hepta-β-glucoside elicitor-binding proteins from legumes represent a putative receptor family
The ability of legumes to recognize and respond to β-glucan elicitors by synthesizing phytoalexins is consistent with the existence of a membrane-bound β-glucan-binding site. Related proteins of approximately 75 kDa and the corresponding mRNAs were detected in various species of legumes which respond to beta-glucans. The cDNAs for the beta-glucan-binding proteins of bean and soybean were cloned. The deduced 75-kDa proteins are predominantly hydrophilic and constitute a unique class of glucan-binding proteins with no currently recognizable functional domains. Heterologous expression of the soybean beta-glucan-binding protein in tomato cells resulted in the generation of a high-affinity binding site for the elicitor-active hepta-β-glucoside conjugate (K-d = 4.5 nM). Ligand competition experiments with the recombinant binding sites demonstrated similar ligand specificities when compared with soybean. In both soybean and transgenic tomato, membrane-bound, active forms of the glucan-binding proteins coexist with immunologically detectable, soluble but inactive forms of the proteins. Reconstitution of a soluble protein fraction into lipid vesicles regained beta-glucoside-binding activity but with lower affinity (K-d = 130 nM). We conclude that the beta-glucan elicitor receptors of legumes are composed of the 75 kDa glucan-binding proteins as the critical components for ligand-recognition, and of an as yet unknown membrane anchor constituting the plasma membrane-associated receptor complex
Study of the system of middle atmosphere-ionosphere using remote-sensing data
In the present investigation, the methods of statistical spectral analysis are employed for a study of the quasi-periodic changes of state parameters of the middle atmosphere and the ionosphere, taking into account oscillations with periods of several days. The considered oscillations are typical for planetary waves. The theory and empirical findings regarding transient planetary waves are utilized as a basis for the concepts employed in the data analysis and for the interpretation of the results. The results of the investigation show a presence of coherent variations in the time series of radiation density measurements and other state parameters for the middle atmosphere and the ionosphere. The existence of presumably dynamic coupling processes can be recognized in oscillations with periods of about 16 or 5 days
Analysis of runoff for the Baltic basin with an integrated Atmospheric-Ocean-Hydrology Model
A fully integrated Atmospheric-Ocean-Hydrology Model (BALTIMOS = Baltic Integrated Model System) has been developed using existing model components. Experiment and model design has been adapted to the Baltic basin with a catchment area of approximately 1 750 000 km<sup>2</sup>. A comprehensive model validation has been completed using large meteorological and hydrological measurement database. Comparing the calculated runoff from the integrated and non-integrated model system with measurements for three different representative subbasins and the entire Baltic basin, the effect of the integrated model is described. The results display a good agreement between measured and calculated runoff. The effect of the integrated model is rather negligible looking at computed mean values: There is no significant difference between mean monthly runoff of the integrated and non-integrated model during the year with the exception of spring. There is a delay of one month with regard to peak runoff for the non-integrated model in spring caused by different interactive processes during the melting period
Kinetic energy budgets in areas of intense convection
A kinetic energy budget analysis of the AVE-SESAME 1 period which coincided with the deadly Red River Valley tornado outbreak is presented. Horizontal flux convergence was found to be the major kinetic energy source to the region, while cross contour destruction was the major sink. Kinetic energy transformations were dominated by processes related to strong jet intrusion into the severe storm area. A kinetic energy budget of the AVE 6 period also is presented. The effects of inherent rawinsonde data errors on widely used basic kinematic parameters, including velocity divergence, vorticity advection, and kinematic vertical motion are described. In addition, an error analysis was performed in terms of the kinetic energy budget equation. Results obtained from downward integration of the continuity equation to obtain kinematic values of vertical motion are described. This alternate procedure shows promising results in severe storm situations
The nucleotide sequences of two tryptophane-tRNAs from brewer's yeast
The study entitled “Observance of PMC and Its Relation to the Presence of Three Levels of Politeness” investigates politeness realizations according to Principles of Mutual Consideration (PMC) between two different cultures and its relation to the presence of three levels of politeness: pre-event, on-the-spot, and post-event politeness as proposed by Aziz (2000). PMC works as a cause and effect logic wgich consists of four sub-principles: i.e. harm and favor potential, shared-feeling, prima-facie, and continuity principles. The main data of the study were retrieved from www.rcti.tv on 26th April, 2010 which contained the opening-part of an interview script between an Indonesian Journalist and the President of the Unites States. Using the PMC framework, the study found that there is balanced-order in observing PMC’s sub-principles. This is due to the fact that both the interviewer and the interviewee had the intention to favour one another. This was realized in their complete observance of four PMC’s sub-principles. The study concluded that the observance of PMC together with its three levels of politeness is mainly motivated to balance and create harmony.Keywords: Principle of Mutual Consideration (PMC), Three Levels of Politeness
Evaluation of Risk Management Methods for Satsuma Mandarin
Simulation of production budgets were used to compare net discounted returns and the distribution of returns under alternative risk-mitigation scenarios. Results indicate that the combination of freeze protection and crop insurance increases expected net discounted 20-year returns while decreasing the downside risk. Break-even prices ranged from .289 per pound. Crop insurance returns were constant across price.Satsuma oranges, freeze protection, crop insurance, production budget, simulation, Crop Production/Industries, Farm Management, Risk and Uncertainty, C63, D81, Q12,
Metabolomics-coupled functional pharmacology of chlorophyll compounds isolated from the leaves of Ficus Exasperata Vahl (Moraceae) provides novel pathways on myometrial activity
New chlorophyll derivatives (pheophytins along with pheophorbide derivatives) were isolated from the leaves of Ficus exasperata and were found to have varying effects on uterine contractility. The current study was therefore aimed at the utilization of mass spectrometry and nuclear magnetic resonance spectroscopy coupled with isolated uterine tissue assay as a platform to assist in the determination of the mechanism of activity of the isolated chlorophyll compounds from the plant F exasperata. The pheophytin and pheophorbide compounds (200 µg/mL) were added to the isolated uterine tissues. Mice uteri, treated with the pheophytin compounds, and the physiological buffer in which the uterine tissues were immersed, were rapidly collected and analyzed using high-resolution Fourier transform mass spectrometry and proton (1H) nuclear magnetic resonance for bioinformatics study. Resulting data were analyzed via pairwise chemometric comparison models, with P < .05 considered statistically significant. Primary signaling pathways found to be correlated with the pheophytins in this study included cyclic adenosine monophosphate, dopamine, extracellular signal-regulated kinases 1/2, and glutamate pathways
Toward understanding myometrial regulation : metabolomic investigation reveals new pathways of oxytocin and ritodrine activity on the myometrium
In recent times, additional pathways involved in the regulation of the myometrium have been suggested. This also holds true for the effect of drugs such as oxytocin (OT) and β-adrenergic agonists on the myometrium. Knowledge of these additional pathways will certainly prove useful in designing better therapies for pathologies of the myometrium. This study was therefore aimed at investigating the possibility of other pathways involved in the activities of both OT and ritodrine (RIT; a β-adrenergic agonist) in the myometrium by utilizing metabolomics and bioinformatics. High-resolution Fourier transform mass spectrometry (HRFTMS) and nuclear magnetic resonance (NMR) spectroscopy coupled with functional uterine assays were used for an innovative assessment. In vitro pharmacological assay of OT (1 nmol/L) and RIT (0.1 nmol/L) on isolated mice uteri mounted in 3 mL organ baths was performed. Mice uteri, treated with OT or RIT, as well as the physiological buffer in which the uterine tissues were immersed, were rapidly collected and analyzed using HRFTMS, proton ((1)H)-NMR, and bioinformatics. Resulting data were analyzed via pairwise chemometric comparison models, with P ≤ .05 considered statistically significant. In addition to previously known metabolites, nicotinamide adenine dinucleotide, γ-aminobutyric acid, and sphingosine were significantly associated with the activity of OT, whereas the activity of RIT was associated with a downstream involvement of prostaglandin F1 and phosphatidylinositol signaling. These findings add evidence to the reports on additional regulation of myometrial activity by these drugs and suggest newer pathways for therapeutic manipulation
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