In conjunction with recognition (sensing) and transport, the signaling properties of nitrate (
) in species that differ in evolutionary and taxonomic terms, from primitive prokaryotes to flowering ...plants, are examined. On the basis of a comparative physiological analysis, the authors make assumptions about some pathways of the phylogenetic formation of signaling cascades triggered by the indicated ion. It is possible that nitrate arose on Earth as early as the Catarchea during the anaerobic nature of the primary atmosphere. Then oxygenic photosynthesis appeared, creating the prerequisites for nitrification as the main source of
. The increasing gradient of nitrate levels in the medium contributed to the creation of polymorphism of its low- and high-affinity sensors and transporters. The system of sensing and signaling of nitrate from prokaryotes was inherited by eukaryotes and received further development from them. In flowering plants, the formation of new regulatory mechanisms is evident; they determine the possibility of fine tuning sensing and absorption of different doses of
with the participation of transporters of appropriate affinity. Depending on the organo-tissue localization of a given ion, the spectrum of its sensors expands, which determines the metabolic direction of the main functions of plants associated with nitrogen assimilation, photosynthesis, and growth and production processes.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Investigation is devoted to the optimization of light spectrum and intensity used for red mustard growing. Notably, most of the studies devoted to red mustard growing were conducted on micro-greens, ...which is not enough for the development of methods and recommendations for making the right choices about the irradiation parameters for full-cycle cultivation. In this study, we tested four models of LED with different ratios of blue, green red and far red radiation intensity: 12:20:63:5; 15:30:49:6; 30:1:68:1, in two values of photon flux density (PFD)—120 and 180 µmol m−2 s−1—to determine the most effective combination for red mustard growing. The study was conducted in a container-type climate chamber, where the red leaf mustard was cultivated in hydroponics. On the 30th day of cultivation, the plant’s morphological, biochemical and chlorophyll fluorescence parameters, and reflection coefficients were recorded. The results indicated that the PFD 120 µmol m−2 s−1 had a worse effect on both mustard leaf biomass accumulation and nitrate concentration (13–30% higher) in the plants. The best lighting option for growing red mustard was the blue–red spectrum, as the most efficient in terms of converting electricity into biomass (77 Wth/g). This light spectrum contributes to plant development with a larger leaf area (60%) and a fresh mass (54%) compared with the control, which has a maximum similarity in spectrum percentage to the sunlight spectrum. The presence of green and far red radiation with the blue–red light spectrum in various proportions at the same level of PFD had a negative effect on plant fresh mass, leaf surface area and photosynthetic activity. The obtained results could be useful for lighting parameters’ optimization when growing red mustard in urban farms.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
We show that if the equation mapping is 2-regular at a solution in some nonzero direction in the null space of its Jacobian (in which case this solution is critical; in particular, the local ...Lipschitzian error bound does not hold), then this direction defines a star-like domain with nonempty interior from which the iterates generated by a certain class of Newton-type methods necessarily converge to the solution in question. This is despite the solution being degenerate, and possibly non-isolated (so that there are other solutions nearby). In this sense, Newtonian iterates are attracted to the specific (critical) solution. Those results are related to the ones due to A. Griewank for the basic Newton method but are also applicable, for example, to some methods developed specially for tackling the case of potentially non-isolated solutions, including the Levenberg–Marquardt and the LP-Newton methods for equations, and the stabilized sequential quadratic programming for optimization.
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CEKLJ, DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, ODKLJ, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Excitation of atoms (molecules) of a rarefied gas by stationary broadband optical radiation in a thin cell with an inner thickness many times smaller than the transverse size is studied ...theoretically. The features of the optical pumping and transit-time relaxation of atomic particles in such cells open new possibilities for ultra-high-resolution spectroscopy. The conditions under which narrow high-contrast sub-Doppler fluorescence resonances arise at the central frequencies of spontaneous transitions from optically excited atomic (molecular) quantum levels are analyzed.
Free radical reactions play an important role in biological functions of living systems. The balance between oxidants and antioxidants is necessary for the normal homeostasis of cells and organisms. ...Experimental works demonstrate the role of oxidative stress that is caused by influenza virus as well as the toxic effects of some antiviral drugs. Therefore, antiviral drugs should be characterized by its pro- and antioxidant activity, because it can affect its therapeutic efficiency. The aim of the study was to quantify the antioxidant capacity and propose the mechanism of the antioxidant effect of the antiviral drug Umifenovir (Arbidol
). The kinetic chemiluminescence with the 2,2'-azobis (2-amidinopropane) dihydrochloride + luminol system was used to quantify the antioxidant capacity of Umifenovir relative to the standard compound Trolox. With computer simulation, the reaction scheme and rate constants were proposed. The antioxidant capacity of 0.9 μM Umifenovir (maximum concentration of Umifenovir in blood after oral administration of 200 mg) was as high as 1.65 ± 0.18 μM of Trolox. Thus, the total antioxidant capacity of Umifenovir is comparable to the antioxidant capacity of Trolox. Unlike Trolox, Umifenovir reacts with free radicals in two stages. For Trolox, the free radical scavenging rate constant was
= 2000 nM
min.
, for Umifenovir
= 300 nM
min.
,
= 4 nM
min.
. Slower kinetics of Umifenovir provides the prolonged antioxidant effect when compared to Trolox. This phenomenon can make a serious contribution to the compensation of oxidative stress that is caused by a viral disease and the therapeutic effect of the drug.
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In the Russian Federation an electricity demand management market is being formed, it is one of the tools that allows industrial consumers of electricity to receive financial rewards from the ...infrastructure of the electricity and capacity market. The paper considers the mechanism for managing the load of enterprises to ensure the system reliability of the unified energy system of Russia. The technical and economic possibilities of mechanisms for price-dependent reduction of consumption in the wholesale electricity market and load management (demand response) in the retail electricity market for consumers have been studied. The relationship between enterprise load management and the reduction in the price of electricity on the day-ahead market has been analyzed. The economic effect for electricity consumers from the introduction of a demand management mechanism in the electricity market has been determined. The directions of development of the load management mechanism to ensure system reliability in the unified power system of Russia have been described.
For many years, local Lipschitzian error bounds for systems of equations have been successfully used for the design and analysis of Newton-type methods. There are characterizations of those error ...bounds by means of first-order derivatives like a recent result by Izmailov, Kurennoy, and Solodov on critical solutions of nonlinear equations. We aim at extending this result in two directions which shall enable, to some extent, to include additional constraints and to consider mappings with reduced smoothness requirements. This leads to new necessary as well as sufficient conditions for the existence of error bounds.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
It has been previously demonstrated that in the case when a Lagrange multiplier associated to a given solution is not unique, Newton iterations e.g., those of sequential quadratic programming (SQP) ...have a tendency to converge to special multipliers, called critical multipliers (when such critical multipliers exist). This fact is of importance because critical multipliers violate the second-order sufficient optimality conditions, and this was shown to be the reason for slow convergence typically observed for problems with degenerate constraints (convergence to noncritical multipliers results in superlinear rate despite degeneracy). Some theoretical and numerical validation of this phenomenon can be found in Izmailov and Solodov (Comput Optim Appl 42:231–264, 2009; Math Program 117:271–304, 2009). However, previous studies concerned the basic forms of Newton iterations. The question remained whether the attraction phenomenon still persists for relevant modifications, as well as in professional implementations. In this paper, we answer this question in the affirmative by presenting numerical results for the well known MINOS and SNOPT software packages applied to a collection of degenerate problems. We also extend previous theoretical considerations to the linearly constrained Lagrangian methods and to the quasi-Newton SQP, on which MINOS and SNOPT are based. Experiments also show that in the stabilized version of SQP the attraction phenomenon still exists but appears less persistent.
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CEKLJ, DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, ODKLJ, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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