Little is known regarding to impact of simulated shading conditions on cotton yield and fiber quality at different fruiting positions. In this 2-year study, our field experiments investigated the effects of shading percentage on the cotton yield, fiber properties, photosynthesis, and carbohydrate concentrations in boll's subtending leaves during various growing stages at different fruiting positions (FP). Net photosynthetic rate and effective quantum yield of PSII photochemistry decreased in response to shading on both FP1 and FP3 of the 7th sympodial branches, respectively. Shading also reduced sucrose and starch contents of leaves at each fruiting position. Shading decreased the number and mass of cotton bolls, the fiber strength and micronaire, while the fiber length increased at both fruiting positions. Our results suggested that shading resulted in the reduction of the cotton yield and fiber quality, which are mainly associated with the changes in boll number and alteration of photosynthesis and carbohydrate concentrations during the boll development., B. L. Chen, H. K. Yang, Y. N. Ma, J. R. Liu, F. J. Lv, J. Chen, Y. L. Meng, Y. H. Wang, Z. G. Zhou., and Obsahuje bibliografii
In the mammalian autonomic nervous system, tonic and phasic neurons can be differentiated on firing patterns in response to long depolarizing current pulse. However, the similar firing patterns in the somatic primary sensory neurons and their functional significance are not well investigated. Here, we identified two types of neurons innervating somatic sensory in rat dorsal root ganglia (DRG). Tonic neurons fire action potentials (APs) in an intensity-dependent manner, whereas phasic neurons typically generate only one AP firing at the onset of stimulation regardless of intensity. Combining retrograde labeling of somatic DRG neurons with fluorescent tracer DiI, we further find that these neurons demonstrate distinct changes under inflammatory pain states induced by complete Freund’s adjuvant (CFA) or bee venom toxin melittin. In tonic neurons, CFA and melittin treatments significantly decrease rheobase and AP durations (depolarization and repolarization), enhance amplitudes of overshoot and afterhyperpolarization (AHP), and increase the number of evoked action potentials. In phasic neurons, however, the same inflammation treatments cause fewer changes in these electrophysiological parameters except for the increased overshoot and decreased AP durations. In the present study, we find that tonic neurons are more hyperexcitable than phasic neurons after peripheral noxious inflammatory stimulation. The results indicate the distinct contributions of two types of DRG neurons in inflammatory pain., Y.-Q. Yu, X.-F. Chen, Y. Yang, F. Yang, J. Chen., and Obsahuje bibliografii
Erythropoietin (EPO), known for its role in erythroid differentiation, has been suggested to have a direct protective role against a variety of neurotoxic insults. In the present study, we investigated the expression of EPO receptor (EPOR) and the number of EPORpositive cells in three encephalic regions (ventral mesencephalon, striatum, cortex) following lesion induced by 1-methyl-4-phenyl- 1,2,3,6-tetrahydropyridine (MPTP). C57BL/6 mice underwent intraperitoneal injection of MPTP at 24 h intervals for 5 days, and their brains were examined 1, 2, 4, 7, 14 or 21 days after the last injection. Western blot and immunohistochemistry analysis revealed that EPOR was dramatically up-regulated in the ventral mesencephalon, 4 days after MPTP insult until the day 21. In contrast, there was a baseline level of EPOR in the striatum and cortex. At subsequent time points after MPTP injury, the levels of EPOR in the two regions were not statistically different compared with those in normal animals. These results suggest that the regional specific up-regulation of EPOR at an early stage after MPTP stimulus may represent a pro-survival mechanism against neurotoxin injury in Parkinsonian model., Y. Wu ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Net photosynthetic rate (PN) of leaves grown under free-air CO2 enriched condition (FACE, about 200 µmol mol-1 above ambient air) was significantly lower than PN of leaves grown at ambient CO2 concentration (AC) when measured at CO2 concentration of 580 µmol mol-1. This difference was found in rice plants grown at normal nitrogen supply (25 g m-2; NN-plants) but not in plants grown at low nitrogen supply (15 g m-2; LN-plants). Namely, photosynthetic acclimation to FACE was observed in NN-plants but not in LN-plants. Different from the above results measured in a period of continuous sunny days, such photosynthetic acclimation occurred in NN-plants, however, it was also observed in LN-plants when PN was measured before noon of the first sunny day after rain. Hence strong competition for the assimilatory power between nitrogen (N) and carbon (C) assimilations induced by an excessive N supply may lead to the photosynthetic acclimation to FACE in NN-plants. The hypothesis is supported by the following facts: FACE induced significant decrease in both apparent photosynthetic quantum yield (Φc) and ribulose-1,5-bisphosphate (RuBP) content in NN-plants but not in LN-plants. and Z.-H. Yong ... [et al.].
Net photosynthetic rate (PN) measured at the same CO2 concentration, the maximum in vivo carboxylation rate, and contents of ribulose-1,5-bisphosphate (RuBP) carboxylase/oxygenase (RuBPCO) and RuBPCO activase were significantly decreased, but the maximum in vivo electron transport rate and RuBP content had no significant change in CO2-enriched [EC, about 200 µmol mol-1 above the ambient CO2 concentration (AC)] wheat leaves compared with those in AC grown wheat leaves. Hence photosynthetic acclimation in wheat leaves to EC is largely due to RuBP carboxylation limitation. and D.-Y. Zhang ... [et al.].
Since 2002, Silver buffaloberry (Shepherdia argentea) has been introduced from North America in order to improve the fragile ecological environment in western China. To elucidate the
salt-resistance mechanism of S. argentea, we conducted a test with two-year-old seedlings subjected to 0, 200, 400, and 600 mM NaCl solutions for 30 d. The results showed that significant salt-induced suppression of plant fresh mass (FM) and stem height of S. argentea seedlings occurred only at the highest salinity level (600 mM). Leaf number, plant dry mass (DM), and chlorophyll (Chl) content declined markedly at both 400 and 600 mM. Leaf area (LA) and leaf water potential (Ψw) continuously declined with the increase of salinity. There was also a progressive and evident decrease in net photosynthetic rate (PN), transpiration rate (E), and stomatal conductance (gs) with the increase of salinity and time. The correlation analysis indicated that PN was positively correlated with gs at all salinity levels while correlated with intercellular CO2 concentration (Ci) only at moderate salinity levels (<600 mM). Based on the initial slope of the PN/Ci curves, the estimated carboxylation efficiency (CE) was strongly inhibited at 600 mM. We confirm that S. argentea is highly tolerant to salinity. Moreover, our results show that at moderate salinity levels, salt-induced inhibition of photosynthesis is mainly attributed to the stomatal efficient closure predetermined by a low water potential in leaves; while at the high salinity levels, the inhibition is mainly due to the suppression of chloroplast capacity to fix CO2 caused by the serious decline in both CE and Chl contents. and J. Qin ... [et al.].
learning machine (ELM), as a new learning mechanism for single hidden layer feedforward neural networks (SLFNs), has shown its advantages, such as fast computation speed and good generalization performance. However, the weak robustness of ELM is an unavoidable defect for image classification. To address the problem, we propose a novel ensemble method which combines rotation forest and selective ensemble model in this paper. Firstly, ELM and rotation forest are integrated to construct an ensemble classifier (RF-ELM), which combines the advantages of both rotation forest and ELM. The purpose of rotation forest here is to enhance the diversity of each base classifier which can improve the performance generalization. Then several ELMs are removed from the ensemble pool by using genetic algorithm (GA) based selective ensemble model to further enhance the robustness. Finally, the remaining ELMs are grouped as a selected ensemble classifier (RFSEN-ELM) for image classification. The performance is analyzed and compared with several existing methods on benchmark datasets and the experimental results demonstrate that the proposed algorithm substantially improves the accuracy and robustness of classification at an acceptable level of training cost.
To investigate how bisulfite promotes photosynthesis, a pot experiment was conducted with rice (Oryza sativa L.) plants to determine Rubisco activity and content, and Rubisco activase (RCA) gene expression after spraying NaHSO3 on rice leaves. The NaHSO3 treatment promoted significantly net photosynthetic rate (PN), carboxylation efficiency, maximum carboxylation rate, ribulose-1,5-bisphosphate regeneration rate, initial Rubisco activity, and RCA protein and mRNA concentrations. Therefore, the NaHSO3 enhancement of PN could be directly attributed to induction of RCA gene expression both at the transcription and translation levels. Thus, the increased RCA regulated the initial Rubisco activity in vivo., Y. Chen, J.-H. Jin, Q.-S. Jiang, C.-L. Yu, J. Chen, L.-G Xu, D.-A. Jiang., and Obsahuje bibliografii