Growth temperature alters temperature dependence of the photosynthetic rate (temperature acclimation). In many species, the optimal temperature that maximizes the photosynthetic rate increases with increasing growth temperature. In this minireview, mechanisms involved in changes in the photosynthesis-temperature curve are discussed. Based on the biochemical model of photosynthesis, change in the photosynthesis-temperature curve is attributable to four factors: intercellular CO2 concentration, activation energy of the maximum rate of RuBP (ribulose-1,5-bisphosphate) carboxylation (Vc max), activation energy of the rate of RuBP regeneration (Jmax), and the ratio of Jmax to Vc max. In the survey, every species increased the activation energy of Vc max with increasing growth temperature. Other factors changed with growth temperature, but their responses were different among species. Among these factors, activation energy of Vc max may be the most important for the shift of optimal temperature of photosynthesis at ambient CO2 concentrations. Physiological and biochemical causes for the change in these parameters are discussed.
Abstract-In this note, robust stabilization and tracking performance of operator based nonlinear feedback control systems are studied by using robust right coprime factorization. Specifically, a new condition of robust right coprime factorization of nonlinear systems with unknown bounded perturbations is derived. Using the new condition, a broader class of nonlinear plants can be controlled robustly. When the spaces of the nonlinear plant output and the reference input are different, a space change filter is designed, and in this case this note considers tracking controller design using the exponential iteration theorem.
There are large inter- and intraspecific differences in the temperature dependence of photosynthesis, but the physiological cause of the variation is poorly understood. Here, the temperature dependence of photosynthesis was examined in three ecotypes of Plantago asiatica transplanted from different latitudes, where the mean annual temperature varies between 7.5 and 16.8 degrees C. Plants were raised at 15 or 30 degrees C, and the CO(2) response of photosynthetic rates was determined at various temperatures. When plants were grown at 30 degrees C, no difference was found in the temperature dependence of photosynthesis among ecotypes. When plants were grown at 15 degrees C, ecotypes from a higher latitude maintained a relatively higher photosynthetic rate at low measurement temperatures. This difference was caused by a difference in the balance between the capacities of two processes, ribulose-1,5-bisphosphate regeneration (J(max)) and carboxylation (V(cmax)), which altered the limiting step of photosynthesis at low temperatures. The organization of photosynthetic proteins also varied among ecotypes. The ecotype from the highest latitude increased the J(max) : V(cmax) ratio with decreasing growth temperature, while that from the lowest latitude did not. It is concluded that nitrogen partitioning in the photosynthetic apparatus and its response to growth temperature were different among ecotypes, which caused an intraspecific variation in temperature dependence of photosynthesis.
This paper deals with a plant output tracking design problem of perturbed nonlinear plants by using robust right coprime factorization approach. One of the interesting control system design schemes, which was given by G. Chen and Z. Han, uses robustness of the right coprime factorization for robust stability of the closed-loop system with perturbation. Unfortunately, the robust right coprime factorization cannot easily improve the tracking performance of the control system except for simple cases. I n this paper, nonlinear operatorbased design method for nonlinear plant output to track a reference input is given. Examples are presented to support the theoretical analysis.
We report the fabrication of BiFeO3/BiCrO3(111) artificial superlattices with 1/1 stacking in a layer-by-layer growth mode on atomically flat SrTiO3(111) surfaces. While BiFeO3 and BiCrO3 are antiferromagnets having Fe–O–Fe and Cr–O–Cr bonds, these superlattices contain Fe–O–Cr bonds, in which ferromagnetic interaction is expected. Magnetization measurements at 300 K revealed that the magnetic moment per transition metal ion was 1.7 µB, suggesting ferromagnetic spin order. Ferroelectric behavior at room temperature was confirmed by an analysis using a scanning non-linear dielectric microscope.
The lateral resolution of a scanning nonlinear dielectric microscope (SNDM) depends on
the tip radius. The contact-type SNDM has problems associated with tip abrasion
and tip deformation. Thus, the use of an electro-conductive carbon nanotube
(CNT) probe tip is expected to lead to improvements in resolution and durability.
In the present paper, we employ a contact-type SNDM with a CNT probe
to measure the ferroelectric domain wall of stoichiometric lithium tantalate
(LiTaO3), and similar SNDM measurements are performed with a platinum-coated probe for
comparison. In addition, we observe the charge distribution accumulated in a
floating gate (FG) type flash memory and the dopant profile of an n-channel
metal–oxide–semiconductor field-effect transistor (MOSFET), respectively. By comparing
the SNDM images obtained with the two probes, we demonstrate that the lateral resolution
of the CNT probe is better than that of the conventional metal-coated probe.
A novel late-stage solubilization of peptides using hydrazides is described. A solubilizing tag was attached through a selective N-alkylation at a hydrazide moiety with the aid of a 2picoline−borane complex in 50% acetic acid−hexafluoro-2propanol. The tag, which tolerates ligation and desulfurization conditions, can be detached by a Cu-mediated selective oxidative hydrolysis of the N-alkyl hydrazide. This new method was validated through the synthesis of HIV-1 protease.
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