sigmoid curve
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2022 ◽  
Vol 8 (1) ◽  
pp. 473-494
Author(s):  
Bruce Hayes

In this review, I assess a variety of constraint-based formal frameworks that can treat variable phenomena, such as well-formedness intuitions, outputs in free variation, and lexical frequency-matching. The idea behind this assessment is that data in gradient linguistics fall into natural mathematical patterns, which I call quantitative signatures. The key signatures treated here are the sigmoid curve, going from zero to one probability, and the wug-shaped curve, which combines two or more sigmoids. I argue that these signatures appear repeatedly in linguistics, and I adduce examples from phonology, syntax, semantics, sociolinguistics, phonetics, and language change. I suggest that the ability to generate these signatures is a trait that can help us choose between rival frameworks.


Author(s):  
Nenden Senina Rindaha ◽  
Sulina Yanti Wibawa ◽  
Yuyun Widaningsih ◽  
Rachmawati A. Muhiddin

Chronic Kidney Disease (CKD) is defined as a renal failure that has lasted for more than three months. Hemodialysis is thetype of kidney replacement therapy that is mostly used, and blood gas analysis can be used to identify this condition. Thisstudy is to compare the blood gas analysis on pre-and post-dialysis in patients with CKD using pH, PaCO , PaO , HCO , SO , 2 2 3 2and BE as markers of improvement in the patients'condition. The population was all patients diagnosed with CKD andhemodialysis at Wahidin Sudirohusodo Hospital, and eligible according to the criteria in this study. The sample size wasdetermined using Federer's calculation, and the statistical analysis using paired T-test and Wilcoxon signed-rank test withα=0.05. Subjects were 34 patients, consisting of 18 females (52.9%) and 16 males (47.1%). Hemodialysis had the mostsignificant impact on the PaO and SaO variables. Relation between PaO and SaO was illustrated in a sigmoid curve. 2 2 2 2Oxygen-bound hemoglobin increased after the first molecule was bound. An almost full PaO pressure will cause a slight 2increase in SaO . Whereas at <90% saturation, a slight decrease in PaO will cause a large decrease in SaO . PaO and SaO 2 2 2 2 2determine cardiac efficiency and the markers for assessing the metabolic conditions of the lungs and heart that correlatewith oxygen. Chronic kidney disease patients experienced improved conditions after undergoing hemodialysis withincreased blood gas values, especially in PaO and SaO .


2021 ◽  
pp. 1-20
Author(s):  
Leslie A. Lewis ◽  
Carl M. Urban ◽  
Sami A. Hashim

Background: The study involved a female patient diagnosed with late-stage dementia, with chronic daytime somnolence (CDS) as a prominent symptom. Objective: To explore whether her dementia resulted from Type 3 diabetes, and whether it could be reversed through ketosis therapy. Methods: A ketogenic diet (KD) generating low-dose 100 μM Blood Ketone Levels (BKL) enhanced by a brief Ketone Mono Ester (KME) regimen with high-dose 2–4 mM BKLs was used. Results: Three sets of data describe relief (assessed by % days awake) from CDS: 1) incremental, slow, time-dependent KD plus KME-induced sigmoid curve responses which resulted in partial wakefulness (0–40% in 255 days) and complete wakefulness (40–85% in 50 days); 2) both levels of wakefulness were shown to be permanent; 3) initial permanent relief from CDS with low-dose ketosis from 6.7% to 40% took 87 days. Subsequent low-dose recovery from illness-induced CDS (6.9% to 40%) took 10 days. We deduce that the first restoration involved permanent repair, and the second energized the repaired circuits. Conclusion: The results suggest a role for ketosis in the elimination of CDS with the permanent functional restoration of the awake neural circuits of the Sleep-Wake cycle. We discuss whether available evidence supports ketosis-induced bioenergetics alone or whether other mechanisms of functional renewal were the basis for the elimination of CDS. Given evidence for permanent repair, two direct links between ketosis and neurogenesis in the adult mammalian brain are discussed: Ketosis-induced 1) brain-derived neurotrophic factor, resulting in neural progenitor/stem cell proliferation, and 2) mitochondrial bioenergetics-induced stem cell biogenesis.


Crustaceana ◽  
2021 ◽  
Vol 94 (8) ◽  
pp. 981-992
Author(s):  
Sergio G. Castillo-Vargasmachuca ◽  
E. Alberto Aragón-Noriega ◽  
Jesús T. Ponce-Palafox ◽  
Guillermo Rodríguez-Domínguez ◽  
Raúl Claro De los Santos

Abstract In the present study, weight-at-age data of reared Pacific white shrimp, Penaeus vannamei Boone, 1931, were analysed under four different assumptions of variance (observed, constant, depensatory, and compensatory variance) in order to analyse the robustness for selecting the right standard deviation structure to parametrize the Von Bertalanffy, Logistic and Gompertz models. Selection of the best model and variance criteria were obtained based on the Bayesian information criterion (BIC). According to the results of the BIC, the observed variance in the present study proved to constitute the best way to parametrize the three above-listed growth models, and the Von Bertalanffy model appeared to be the best to represent the growth curve found. This is an asymptotic sigmoid curve with an inflection point. Based on these results, using the observed error structure to calculate the growth parameters in multi-model inference analyses is recommended.


Author(s):  
H. Bendada ◽  
A. Guendouz ◽  
R. Benniou ◽  
N. Louahdi

Background: Barley (Hordeum vulgare L.) is one of the more important cultivated crops in the Mediterranean region, where drought and high temperatures during the grain filling stage are the main abiotic stresses limiting its production. The aim of this study is to evaluate the effects of the spike type on the grain yield, thousand kernels weight and some grain filling parameters.Methods: The present study was conducted on the experimental site of station ITGC in Setif, Algeria, eight Barley genotypes were tested during two cropping seasons (2017/2018 and 2018/2019) in a randomized block design with 3 replications.Result: The results proved significant effect of genotypes and spike types on the grain filling parameters, but no significant effect of spike type on the thousand kernels weight during the both cropping seasons. In addition, the spike type registered significant effect just during the second cropping season. Among the genotypes with 6 rows spike type the local genotype Fouarra have high grain yield (97.79 Q/ha) with a deviation of 37.57% from the total mean of the genotypes with 6 row spike type. Many studies proved that in 6-row barleys, the magnitude of contribution of grain number in grain yield was higher than contribution of grain weight. The grain growth of genotypes studied follows a sigmoid curve, during the first season (2017-2018) the duration of grain filling ranged between 24 days for Saida 183 and 28 days for Rihane 03, for the group of genotypes with 6 rows. In addition, the duration of grain filling for the 2 row genotypes varied from 24 days for G4 to 28 days for genotype G2. During the second season (2018-2019) and for the genotypes with 6 rows, the duration of the grain filling varied from 21 days for the Saida 183 and 26 days for the genotype Fouarra, for the genotypes with 2 rows the duration of grain filling ranged from 21 days for the genotype G2 to 26 days for the genotype G3. The correlation analysis between the grain filling parameters, GY and TKW demonstrate a significant and positive correlation between TKW and MGW and GFR (r = 0.82* and r = 0.84*, respectively). Overall, the genotype variation in grain filling velocity and duration was responsible for the difference in grain yield and the improvement in grain yield was achieved by the increasing in velocity or duration of grain filling.


OENO One ◽  
2021 ◽  
Vol 55 (1) ◽  
pp. 119-131
Author(s):  
George Letchov ◽  
Venelin Roychev ◽  
Neli Keranova

The process related to the changes in dimensions and mass of grape berry passes through two growth phases separated by a lag phase, and can be described by a double sigmoid curve. The onset of the growth phases and their duration are important factors for understanding the growth processes in grape berries. A new method for their quantitative determination was developed in the present study. In this method, the phase transition dates correspond to the times at which the rate of change of the curvature of the logistic (sigmoid) curve reaches an extreme value. The method was tested on three seedless grape varieties, Sultanina, Ruby Seedless and Rusalka 3, and the changes in grape berry dimensions and mass were tracked from anthesis to harvest. For each of the varieties, a double logistic model of change in berry length, width and mass from anthesis to harvest was developed and the metrics of growth - beginning, stabilisation and end of growth - for each of the two phases were determined. It was found that the metrics in mass and berry dimensions do not match and shift relative to each other over time. A comparison of growth metrics with phenological metrics, such as anthesis, veraison and ripening, showed that phenophases cannot be used as a time scale to record the acceleration of growth processes, as they shifted in time with growth metrics. An exception was veraison, which coincided with the beginning of the accelerated growth of grapes during the second growth phase, following the lag phase. The time scale presented in the current research is a new tool for monitoring growth processes and could help clarify the links between visible changes in the grape berries and the ongoing processes within them. The developed method can also be used for the analysis of various growth processes that follow the logistic law.


Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7197
Author(s):  
Bing Lu ◽  
Hongwen He ◽  
Huilong Yu ◽  
Hong Wang ◽  
Guofa Li ◽  
...  

The traditional potential field-based path planning is likely to generate unexpected path by strictly following the minimum potential field, especially in the driving scenarios with multiple obstacles closely distributed. A hybrid path planning is proposed to avoid the unsatisfying path generation and to improve the performance of autonomous driving by combining the potential field with the sigmoid curve. The repulsive and attractive potential fields are redesigned by considering the safety and the feasibility. Based on the objective of the shortest path generation, the optimized trajectory is obtained to improve the vehicle stability and driving safety by considering the constraints of collision avoidance and vehicle dynamics. The effectiveness is examined by simulations in multiobstacle dynamic and static scenarios. The simulation results indicate that the proposed method shows better performance on vehicle stability and ride comfortability than that of the traditional potential field-based method in all the examined scenarios during the autonomous driving.


2020 ◽  
Vol 15 (3) ◽  
Author(s):  
Adam J. Regalski ◽  
Lee H. Wurm

Abstract In this study we examined uses of the number 3017 as a neologism by members of an online forum. 3017 has a number of factors working against its success as a neologism, but its use grew dramatically over the course of six years. Statistical analyses showed that the growth data were very well modeled by both a quadratic and a sigmoid curve. The form was used primarily as an adjective and to a lesser extent as a noun over the first 500 days, before verbal forms came to dominate. To understand the structure of the 3017 concept in the mental lexicons of users, we examine attempts to define the term, and disagreements and negotiations about what the term does and does not include. Finally, we include examples of users’ creativity and productivity with the form, including readily-understood jokes.


2020 ◽  
Vol 48 (5) ◽  
pp. 768-778
Author(s):  
José A. Félix-Ortiz ◽  
E. Alberto Aragón-Noriega ◽  
Nicolás Castañeda-Lomas ◽  
Guillermo Rodríguez-Domínguez ◽  
Wenceslao Valenzuela-Quiñónez ◽  
...  

Length-frequency data of juveniles and sub-adults of Penaeus californiensis were analyzed, collected from January 2002 to January 2003 in the Agiabampo lagoon system and adjacent marine coastal zone. Six models were parameterized with four criteria, in addition to a mixed criterion (fat-tail and depensatory), to estimate the parameters that best fit the growth curve. The model that best fit was the Johnson model with the mixed criterion in females and males: k = 6.02 (5.93-6.12); L∞ = 188.8 (186.3-191.8); t0 = 0.0221 (0.0207-0.0234); and: k = 8.98 (8.85-9.12); L∞ =153.3 (151.7-155.0); t0 = 0.0386 (0.0378-0.0394), respectively. The conclusion is that: 1) the mixture approach found in this study as best leads to the application of a very high-performance objective function to analyze individual length-at-age variability, 2) shows that the best model to describe the growth trajectory of P. californiensis in marine and estuarine environments is a sigmoid curve with an inflection point near to cero age (Johnson model).


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