response curve
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Plants ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 174
Author(s):  
Azumi Okamoto ◽  
Kohei Koyama ◽  
Narayan Bhusal

Understanding plant physiological responses to high temperature is an important concern pertaining to climate change. However, compared with terrestrial plants, information about aquatic plants remains limited. Since the degree of midday depression of photosynthesis under high temperature depends on soil water conditions, it is expected that emergent aquatic plants, for which soil water conditions are always saturated, will show different patterns compared with terrestrial plants. We investigated the diurnal course of the photosynthetic light-response curve and incident light intensity for a freshwater emergent plant, buckbean (Menyanthes trifoliata L.; Menyanthaceae) in a cool temperate region. The effect of midday depression was observed only on a very hot day, but not on a moderately hot day, in summer. The diurnal course of photosynthetic light-response curves on this hot day showed that latent morning reduction of photosynthetic capacity started at dawn, preceding the apparent depression around the midday, in agreement with results reported in terrestrial plants. We concluded that (1) midday depression of emergent plants occurs when the stress intensity exceeds the species’ tolerance, and (2) measurements of not only photosynthetic rate under field conditions but also diurnal course of photosynthetic light-response curve are necessary to quantify the effect of midday depression.


PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0261683
Author(s):  
Xuemei Ma ◽  
Qiang Liu ◽  
Zhidong Zhang ◽  
Zewen Zhang ◽  
Zeyu Zhou ◽  
...  

Accurately predicting the crown photosynthesis of trees is necessary for better understanding the C circle in terrestrial ecosystem. However, modeling crown for individual tree is still challenging with the complex crown structure and changeable environmental conditions. This study was conducted to explore model in modeling the photosynthesis light response curve of the tree crown of young Larix principis-rupprechtii Mayr. Plantation. The rectangular hyperbolic model (RHM), non-rectangular hyperbolic model (NRHM), exponential model (EM) and modified rectangular hyperbolic model (MRHM) were used to model the photosynthetic light response curves. The fitting accuracy of these models was tested by comparing determinants coefficients (R2), mean square errors (MSE) and Akaike information criterion (AIC). The results showed that the mean value of R2 of MRHM (R2 = 0.9687) was the highest, whereas MSE value (MSE = 0.0748) and AIC value (AIC = -39.21) were the lowest. The order of fitting accuracy of the four models for Pn-PAR response curve was as follows: MRHM > EM > NRHM > RHM. In addition, the light saturation point (LSP) obtained by MRHM was slightly lower than the observed values, whereas the maximum net photosynthetic rates (Pmax) modeled by the four models were close to the measured values. Therefore, MRHM was superior to other three models in describing the photosynthetic response curve, the accurate values were that the quantum efficiency (α), maximum net photosynthetic rate (Pmax), light saturation point (LSP), light compensation point (LCP) and respiration rate (Rd) were 0.06, 6.06 μmol·m-2s-1, 802.68 μmol·m-2s-1, 10.76 μmol·m-2s-1 and 0.60 μmol·m-2s-1. Moreover, the photosynthetic response parameters values among different layers were also significant. Our findings have critical implications for parameter calibration of photosynthetic models and thus robust prediction of photosynthetic response in forests.


Author(s):  
Andrea Signorini

Homeopathy is universally known as an opponent of allopathic Medicine, namely scientific medicine based on ponderal drugs and recognised mechanisms of receptor agonism and antagonism following the dose-response curve. Over time the difficulty to explain with arguments the action of homeopathic ultra-diluted remedies has led many homeopaths to distance themselves from any pharmacological knowledges. Nevertheless this position fortgets not only the modalities in which homeopathy was born and has grown, but a lot of modern changes of view in body-mind communication, cell communication, neuro-immune-endocrinology and bioelectromagnetism, that could give new reasons to treat as clinical homeopathic practice is teaching and to recognize the principle of similars as a modern pharmacological principle. These arguments, receptorial cell communication, bioelectromagnetism and body-mind unity are the bases of Homeopathy and of the Similia Principle and are all included in embryonic but sufficiently clear considerations in the fundamental book of Hahnemann, the Organon (parr. 11, 13, 15-18, 21, 22, 29-32, 63-70). Two kind of evidences confirm the pharmacological bases of SimiliaPriniciple, in vitro experiments and homeopathic pathogenetic trials on healthy volunteers, best known as provings. Even clinical homeopathic phenomena like initial aggravation and return of old symptoms confirm this pharmacological view of the Simila Principle.


2021 ◽  
Vol 14 (12) ◽  
pp. 1324
Author(s):  
Sanghyun Kim ◽  
Sohyun Hwang

High-throughput screening of drug response in cultured cell lines is essential for studying therapeutic mechanisms and identifying molecular variants associated with sensitivity to drugs. Assessment of drug response is typically performed by constructing a dose-response curve of viability and summarizing it to a representative, such as IC50. However, this is limited by its dependency on the assay duration and lack of reflections regarding actual cellular response phenotypes. To address these limitations, we consider how each response-phenotype contributes to the overall growth behavior and propose an alternative method of drug response screening that takes into account the cellular response phenotype. In conventional drug response screening methods, the ranking of sensitivity depends on either the metric used to construct the dose-response curve or the representative factor used to summarize the curve. This ambiguity in conventional assessment methods is due to the fact that assessment methods are not consistent with the underlying principles of population dynamics. Instead, the suggested phenotype metrics provide all phenotypic rates of change that shape overall growth behavior at a given dose and better response classification, including the phenotypic mechanism of overall growth inhibition. This alternative high-throughput drug-response screening would improve preclinical pharmacogenomic analysis and the understanding of a therapeutic mechanism of action.


Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3483
Author(s):  
Kexin Liu ◽  
Weimin Bao ◽  
Yufeng Hu ◽  
Yiqun Sun ◽  
Dongjing Li ◽  
...  

The ridge estimation-based dynamic system response curve (DSRC-R) method, which is an improvement of the dynamic system response curve (DSRC) method via the ridge estimation method, has illustrated its good robustness. However, the optimization criterion for the ridge coefficient in the DSRC-R method still needs further study. In view of this, a new optimization criterion called the balance and random degree criterion considering the sum of squares of flow errors (BSR) is proposed in this paper according to the properties of model-simulated residuals. In this criterion, two indexes, namely, the random degree of simulated residuals and the balance degree of simulated residuals, are introduced to describe the independence and the zero mean property of simulated residuals, respectively. Therefore, the BSR criterion is constructed by combining the sum of squares of flow errors with the two indexes. The BSR criterion, L-curve criterion and the minimum sum of squares of flow errors (MSSFE) criterion are tested on both synthetic cases and real-data cases. The results show that the BSR criterion is better than the L-curve criterion in minimizing the sum of squares of flow residuals and increasing the ridge coefficient optimization speed. Moreover, the BSR criterion has an advantage over the MSSFE criterion in making the estimated rainfall error more stable.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Yifei Chen ◽  
Rongfei Xia ◽  
Yongjian Feng

In order to solve the problem of existing diagnostic methods for chronic gastritis which are complex and traumatic, a novel noninvasive method for diagnosis of chronic gastric based on e-nose and deep convolutional neural network is proposed. Firstly, in order to collect samples, a respiratory gas sampling device was established and the response curve of respiratory gas is generated. Then, a deep convolutional neural network for the diagnosis of chronic gastritis is proposed to recognize and classify the respiratory gas response curve. The DCNN model attained good results with accuracy, sensitivity, and specificity of 85.00%, 90.00%, and 80.00%, respectively, for chronic gastric prediction. The proposed method provides a new way for the clinical auxiliary diagnoses of chronic gastric.


2021 ◽  
Vol 2132 (1) ◽  
pp. 012052
Author(s):  
Haoming Dong ◽  
Xiajie Jin ◽  
Keli Xing

Abstract This article takes K3VDT63 variable plunger pump original regulator as the research object, establishes its dynamic motion equation, uses matlab simulation software to establish its simulation model on the basis of this equation, and the dynamic characteristics of the simulation model under different physical parameters Experiment, and get the dynamic response curve and result of variable regulator constant power control under the influence of various factors.


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