scholarly journals Application of an Ovate Leaf Shape Model to Evaluate Leaf Bilateral Asymmetry and Calculate Lamina Centroid Location

2022 ◽  
Vol 12 ◽  
Author(s):  
Yirong Li ◽  
Yiwen Zheng ◽  
David A. Ratkowsky ◽  
Hailin Wei ◽  
Peijian Shi
Keyword(s):  
Leaf Shape ◽  
Absolute Deviation ◽  
Maximum Width ◽  
Shape Model ◽  
Bilateral Asymmetry ◽  
Leaf Petiole ◽  
Leaf Trait ◽  
Significant Difference ◽  
Mean Square Errors ◽  
Centroid Location

Leaf shape is an important leaf trait, with ovate leaves common in many floras. Recently, a new leaf shape model (referred to as the MLRF equation) derived from temperature-dependent bacterial growth was proposed and demonstrated to be valid in describing leaf boundaries of many species with ovate leaf shape. The MLRF model’s parameters can provide valuable information of leaf shape, including the ratio of lamina width to length and the lamina centroid location on the lamina length axis. However, the model wasn’t tested on a large sample of a single species, thereby limiting its overall evaluation for describing leaf boundaries, for evaluating lamina bilateral asymmetry and for calculating lamina centroid location. In this study, we further test the model using data from two Lauraceae species, Cinnamomum camphora and Machilus leptophylla, with >290 leaves for each species. The equation was found to be credible for describing those shapes, with all adjusted root-mean-square errors (RMSE) smaller than 0.05, indicating that the mean absolute deviation is smaller than 5% of the radius of an assumed circle whose area equals lamina area. It was also found that the larger the extent of lamina asymmetry, the larger the adjusted RMSE, with approximately 50% of unexplained variation by the model accounted for by the lamina asymmetry, implying that this model can help to quantify the leaf bilateral asymmetry in future studies. In addition, there was a significant difference between the two species in their centroid ratio, i.e., the distance from leaf petiole to the point on the lamina length axis associated with leaf maximum width to the leaf maximum length. It was found that a higher centroid ratio does not necessarily lead to a greater investment of mass to leaf petiole relative to lamina, which might depend on the petiole pattern.

scholarly journals An elliptical blade is not a true ellipse, but a superellipse–Evidence from two Michelia species

2021 ◽  
Author(s):  
Yuping Li ◽  
Karl J. Niklas ◽  
Johan Gielis ◽  
Ülo Niinemets ◽  
Julian Schrader ◽  
...  
Keyword(s):  
Leaf Shape ◽  
Mean Absolute Deviation ◽  
Mean Square ◽  
Ambient Light ◽  
Absolute Deviation ◽  
Nonlinear Fitting ◽  
Species Analysis ◽  
The Mean ◽  
Mean Square Errors ◽  
Developmental Condition

AbstractThe shape of leaf laminae exhibits considerable diversity and complexity that reflects adaptations to environmental factors such as ambient light and precipitation as well as phyletic legacy. Many leaves appear to be elliptical which may represent a ‘default’ developmental condition. However, whether their geometry truly conforms to the ellipse equation (EE), i.e., (x/a)2 + (y/b)2 = 1, remains conjectural. One alternative is described by the superellipse equation (SE), a generalized version of EE, i.e., |x/a|n +|y/b|n = 1. To test the efficacy of EE versus SE to describe leaf geometry, the leaf shapes of two Michelia species (i.e., M. cavaleriei var. platypetala, and M. maudiae), were investigated using 60 leaves from each species. Analysis shows that the majority of leaves (118 out of 120) had adjusted root-mean-square errors of < 0.05 for the nonlinear fitting of SE to leaf geometry, i.e., the mean absolute deviation from the polar point to leaf marginal points was smaller than 5% of the radius of a hypothesized circle with its area equaling leaf area. The estimates of n for the two species were ˂ 2, indicating that all sampled leaves conformed to SE and not to EE. This study confirms the existence of SE in leaves, linking this to its potential functional advantages, particularly the possible influence of leaf shape on hydraulic conductance.

Differential impact of liana colonization on the leaf functional traits of co-occurring deciduous and evergreen trees

2021 ◽  
Author(s):  
vivek pandi ◽  
Kanda Naveen Babu
Keyword(s):  
Functional Traits ◽  
Tree Species ◽  
Dry Matter Content ◽  
Differential Impact ◽  
Deciduous Species ◽  
Evergreen Species ◽  
Leaf Functional Traits ◽  
Leaf Trait ◽  
Host Trees ◽  
Significant Difference

Abstract The present study was carried out to analyse the leaf functional traits of co-occurring evergreen and deciduous tree species in a tropical dry scrub forest. This study also intended to check whether the species with contrasting leaf habits differ in their leaf trait plasticity, responding to the canopy-infestation by lianas. A total of 12 leaf functional traits were studied for eight tree species with contrasting leaf habits (evergreen and deciduous) and liana-colonization status (Liana+ and Liana−). In the liana-free environment (L−), evergreen trees had significantly higher specific leaf mass (LMA) and leaf dry matter content (LDMC) than the deciduous species. Whereas, the deciduous trees had higher specific leaf area (SLA) and mass-based leaf nitrogen concentration (Nmass). The leaf trait-pair relationship in the present study agreed to the well-established global trait-pair relationships (SLA Vs Nmass, Lth Vs SLA, Nmass Vs Lth, Nmass Vs LDMC, LDMC Vs SLA). There was no significant difference between L+ and L− individuals in any leaf functional traits studied in the deciduous species. However, evergreen species showed marked differences in the total chlorophyll content (Chlt), chlorophyll b (Chlb), SLA, and LMA between L+ and L− individuals of the same species. Deciduous species with the acquisitive strategy can have a competitive advantage over evergreen species in the exposed environment (L−) whereas, evergreen species with shade-tolerant properties were better acclimated to the shaded environments (L+). The result revealed the patterns of convergence and divergence in some of the leaf functional traits between evergreen and deciduous species. The results also showed the differential impact of liana colonization on the host trees with contrasting leaf habits. Therefore, liana colonization can significantly impact the C-fixation strategies of the host trees by altering their light environment. Further, the magnitude of such impact may vary among species of different leaf habits. The increased proliferation of lianas in the tropical forest canopies may pose a severe threat to the whole forest carbon assimilation rates.

scholarly journals Towards More Realistic Leaf Shapes in Functional-Structural Plant Models

Symmetry ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 278 ◽  
Author(s):  
Dominik Schmidt ◽  
Katrin Kahlen
Keyword(s):  
Fluctuating Asymmetry ◽  
Leaf Shape ◽  
Three Dimensional ◽  
Directional Asymmetry ◽  
The Novel ◽  
Shape Model ◽  
Plant Model ◽  
Virtual Plant ◽  
Perfect Symmetry

Fluctuating asymmetry in plant leaves is a widely used measure in geometric morphometrics for assessing random deviations from perfect symmetry. In this study, we considered the concept of fluctuating asymmetry to improve the prototype leaf shape of the functional-structural plant model L-Cucumber. The overall objective was to provide a realistic geometric representation of the leaves for the light sensitive plant reactions in the virtual plant model. Based on three-dimensional data from several hundred in situ digitized cucumber leaves comparisons of model leaves and measurements were conducted. Robust Bayesian comparison of groups was used to assess statistical differences between leaf halves while respecting fluctuating asymmetries. Results indicated almost no directional asymmetry in leaves comparing different distances from the prototype while detecting systematic deviations shared by both halves. This information was successfully included in an improved leaf prototype and implemented in the virtual plant model L-Cucumber. Comparative virtual plant simulations revealed a slight improvement in plant internode development against experimental data using the novel leaf shape. Further studies can now focus on analyses of stress on the 3D-deformation of the leaf and the development of a dynamic leaf shape model.

scholarly journals Do we have infraspecific taxa of Salvia multicaulis Vahl. (Lamiaceae) in Iran?

2017 ◽  
Vol 7 (4) ◽  
pp. 432-439 ◽  
Author(s):  
Seyed Mehdi Talebi ◽  
Reza Rezakhanlou ◽  
A V. Matsyura
Keyword(s):  
Leaf Shape ◽  
Morphological Characteristics ◽  
Leaf Length ◽  
Width Ratio ◽  
Petiole Length ◽  
Widespread Species ◽  
Basal Leaf ◽  
Leaf Petiole ◽  
Upgma Cluster Analysis ◽  
Length Width

<p><em>Salvia multicaulis</em> is a widespread species of Lamiaceae family in Iran. There are many discussions about its infraspecific variations. Although some varieties were definite for this species in various parts of the world, no infraspecific taxon was reported in Iran and all samples of this species were named as S. multicaulis. In this study, morphological characteristics of S. multicaulis populations, naturally growing in Iran, was examined. Twenty-two traits were examined in 94 individuals of this species to<br />identify their phenotypic difference. Most of the investigated features were showing a high degree of variability, but it was highly pronounced for some characteristics such as basal leaf shape, basal leaf width, basal leaf length/ width ratio and basal petiole length. Significant positive/negative correlations were observed between some morphological variables. Furthermore, significant negative correlations were found between the eastern distribution of populations with basal leaf petiole length and basal leaf length/ width ratio. Based on the UPGMA cluster analysis, populations were divided into two main branches. The first branch contained four populations, while the second branch was bigger and clustered in two sub-branches. In one of them,<br />three populations and in another one the rest populations arranged in two groups. CA joined plot confirmed that each of studied populations or group of populations had distinct morphological trait(s), which were useful in identification of them. Our findings supported population no. 13 had unique morphological traits such as the largest bracts and basal leaf petiole, highest flower number of each inflorescence cycle, widest and largest calyx. The conservation of the highly diverse populations of<br />Iranian S. multicaulis is recommended.</p>

scholarly journals A study on maxillary sinus dimensions by computed tomography in population of Tamil Nadu

2016 ◽  
Vol 05 (02) ◽  
pp. 091-096
Author(s):  
N Muthukumaravel ◽  
K.Y Manjunath
Keyword(s):  
Computed Tomography ◽  
Maxillary Sinus ◽  
Tamil Nadu ◽  
Maximum Width ◽  
Average Width ◽  
Computed Tomographic ◽  
Significant Difference ◽  
The Difference ◽  
The Right ◽  
Maxillary Sinuses

Abstract Background and aims: Maxillary sinuses are the largest of the paranasal sinuses known for variability in their dimensions. The maxillary sinus dimensions can be better ascertained in living by using computed tomography instead of plain radiography. This study was planned for highlighting the variations in the dimensions of the maxillary sinuses of population of Tamil Nadu region. The aims of the present study were to estimate dimensions of the maxillary sinuses on computed tomographic (CT) scan of the head of patients from Tamil Nadu and to compare the data gender wise and sidewise. Material and methods: Maximum width, height and depth of maxillary sinus of both sides were measured in CT - head images of 100 males and 100 females of 20-50 years of age in Tamil Nadu. Comparison of data between genders and sides by applying unpaired student "t" test was done. Results : The mean depth, height and width of both right and left maxillary sinuses were comparatively less in females than the males and the difference was found to be statistically significant ( P <.0001). On comparison between the sides of maxillary sinuses, the depth and the height of maxillary sinus did not show any significant difference in the measurements (p >.05), whereas the width of the left side (23.96 mm) was higher than that of the right side (23.69) and the difference was found to be statistically significant (P<.05). The combined average maxillary sinus dimensions (in mm) for both genders in the study population of Tamil Nadu are as follows: Right side depth: 33.71 ± 1.00; Left side depth : 33.65 ± 1.22; Right side height: 34.66 ± 2.71; Left side height: 34.74± 2.48; Right side width: 23.69 ± 0.78 and Left side width: 23.96 ± 0.86. Conclusion: The dimensions of maxillary sinuses in males were found to be larger than those of females and this difference was statistically significant. The average width of the maxillary sinuses on the left side is significantly more than that of right sided sinuses. Computed tomography measurements of maxillary sinuses may be useful in gender determination.

scholarly journals Pengaruh Perilaku Follower Investor pada Volatilitas Saham

2017 ◽  
pp. 44
Author(s):  
Made Dewi Ayu Untari
Keyword(s):  
Service Sector ◽  
Raw Materials ◽  
Stock Exchange ◽  
Sampling Technique ◽  
Total Sample ◽  
Absolute Deviation ◽  
Population Number ◽  
Cross Sectional ◽  
Industrial Sectors ◽  
Significant Difference

The purposes of this study are to obtain emperical evidence about the influence of followers investor’s behaviour to the stock volatility and analyze the difference offollowers investor’s betweenindustry sectors producing raw materials,manufacture industry and service industry in the Indonesia Stock Exchange (BEI), during the market crash happened in Indonesia. The population number are 507 companies, while the total sample of 247 companies. Sampling technique used purposive sampling. The analysis technique used was a cross-sectional absolute Deviation (CSADand test One Way ANOVA with Post Hoc Test and Least Significant Difference (LSD. Data shows that the behavior of follower investors has positive effect on the volatility of the current stock market crash occurs. Meanwhile, there was no difference in behavior between the follower investor industrial sectors producing raw materials, the manufacturing sector and the service sector when  the market crash.

scholarly journals Assessing the Impact of Satellite Revisit Rate on Estimation of Corn Phenological Transition Timing through Shape Model Fitting

2019 ◽  
Vol 11 (21) ◽  
pp. 2558 ◽  
Author(s):  
Emily Myers ◽  
John Kerekes ◽  
Craig Daughtry ◽  
Andrew Russ
Keyword(s):  
Time Series ◽  
Vegetation Index ◽  
Time Series Data ◽  
Model Fitting ◽  
Series Data ◽  
Sigmoid Function ◽  
Absolute Deviation ◽  
Shape Model ◽  
Area Index ◽  
The Impact

Agricultural monitoring is an important application of earth-observing satellite systems. In particular, image time-series data are often fit to functions called shape models that are used to derive phenological transition dates or predict yield. This paper aimed to investigate the impact of imaging frequency on model fitting and estimation of corn phenological transition timing. Images (PlanetScope 4-band surface reflectance) and in situ measurements (Soil Plant Analysis Development (SPAD) and leaf area index (LAI)) were collected over a corn field in the mid-Atlantic during the 2018 growing season. Correlation was performed between candidate vegetation indices and SPAD and LAI measurements. The Normalized Difference Vegetation Index (NDVI) was chosen for shape model fitting based on the ground truth correlation and initial fitting results. Plot-average NDVI time-series were cleaned and fit to an asymmetric double sigmoid function, from which the day of year (DOY) of six different function parameters were extracted. These points were related to ground-measured phenological stages. New time-series were then created by removing images from the original time-series, so that average temporal spacing between images ranged from 3 to 24 days. Fitting was performed on the resampled time-series, and phenological transition dates were recalculated. Average range of estimated dates increased by 1 day and average absolute deviation between dates estimated from original and resampled time-series data increased by 1/3 of a day for every day of increase in average revisit interval. In the context of this study, higher imaging frequency led to greater precision in estimates of shape model fitting parameters used to estimate corn phenological transition timing.

DEVELOPMENT OF OVATE AND LANCEOLATE LEAF SHAPE MODEL USING B-SPLINE GENERATIVE SHAPE METHOD

2016 ◽  
Vol 100 (11) ◽  
pp. 1909-1915
Author(s):  
Norazman Arbin ◽  
Mohammad Fazli Ramli ◽  
Mohd Syafarudy Abu ◽  
Latifah Md Amin
Keyword(s):  
Leaf Shape ◽  
Shape Model ◽  
B Spline ◽  
Lanceolate Leaf

Incidence rate and morphyology of cavum septum pellucidum in patients with treatment-resistant schizophrenia, major depression: A structural MRI study

2011 ◽  
Vol 26 (S2) ◽  
pp. 955-955 ◽  
Author(s):  
J. Sun ◽  
J.J. Maller ◽  
L. Guo ◽  
Z.J. Daskalakis ◽  
P.B. Fitzgerald
Keyword(s):  
Structural Mri ◽  
Septum Pellucidum ◽  
Treatment Resistant ◽  
Maximum Width ◽  
Cavum Septum Pellucidum ◽  
Significant Difference ◽  
Length Width ◽  
The Difference ◽  
Developmental Characteristics ◽  
Mri Study

IntroductionSeveral studies have independently suggested that schizophrenia patients are more likely to have an enlarged cavum septum pellucidum (CSP). However, neither finding has been consistently replicated.ObjectivesWe recruited the relatively homogeneity population: treatment resistant schizophrenia (TRS) and treatment resistant depression (TRD).To investigate whether CSP was present more frequently in TRS or TRD patients than controls and the difference of CSP morphological characteristic between groups.Methods1.5-Tesla MRI was used to evaluate the prevalence of CSP and morphology changes in 42 TRS, 45 TRD patients and 30 healthy controls. The CSP length, width and volume were measured using MRIcro and Analyze™ 8.1 software. A CSP equal to or greater than 6 mm in length was defined as big CSP.ResultsTRS Patients had a significantly higher prevalence (6%) of the big CSP than TRD patients (0%) or controls (3.3%) while no significant difference on the prevalence of all CSP (TRS: 64.3%, TRD: 48.9%, controls: 50.0%) or small CSP between groups. Compared with controls or TRD patients, the values of CSP maximum width in patients with TRS were significant lower and CSP length were higher. There was no significant difference in the CSP volume between groups.ConclusionsThe incidence in Big CSP in TRS patients was higher than that of TRS patients or controls. The small CSP may be a kind of normal variant. There were different CSP developmental characteristics between TRS and TRD patients based on the MRI study.

scholarly journals Teleneurorehabilitation program (virtual reality) for patients with balance disorders: descriptive study

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Marcos Maldonado-Díaz ◽  
Patricia Vargas ◽  
Ricardo Vasquez ◽  
Felipe Gonzalez-Seguel ◽  
Betel Rivero ◽  
...  
Keyword(s):  
Virtual Reality ◽  
Interobserver Reliability ◽  
Kappa Statistic ◽  
Descriptive Study ◽  
Second Phase ◽  
Maximum Width ◽  
Balance Disorders ◽  
Vestibular Diseases ◽  
Significant Difference ◽  
Level Of Agreement

Abstract Background Balance disorders are common in patients with neurological or vestibular diseases. Telerehabilitation program is a treatment to be as safe as conventional treatment. One of the most used methods to perform telerehabilitation is the incorporation of Virtual Reality. In general, rehabilitation programs train predictive postural control, so the patient does not always acquire the necessary autonomy to react to situations of instability. On the other hand, the objective and systematic supervision and measurement of these programs is limited, making it necessary to create clinical protocols with precise and measurable rehabilitation objectives. This study present the training selection methodology and clinical protocol for patients with balance disorders inserted in a Telerehabilitation Program based on Virtual Reality. Methods Descriptive study where physiotherapists were trained to use RehaMetrics®. To evaluate their level of agreement in the selection of the exercise clusters developed, the Interobserver Reliability was measured through the kappa statistic. Subsequently, the exercises were applied to a group of patients recruited with sedentary trunk control (Berg Balance Scale = 3 points in item 3), mild or normal cognitive level (Montreal Cognitive Assessment> 21 points), and prescribed for tele-rehabilitation by a doctor. Results The agreement among the expert physiotherapists irrespective of the cluster exceeds 80%, which indicates a very good strength of agreement, while the novices reached a level of agreement of 45%, which suggests a moderate strength of agreement. All clinical outcomes showed statistically significant differences between the median times, as did the Maximum Width Left Side (MWLS) (cm). The average number of minutes of training was 485.81 (SD 246.49 min), and the number of sessions performed during the 4 weeks of intervention was 17 (SD 7.15 sessions). Conclusions This analysis what had excellent interobserver reliability with trained physiotherapists. Regarding the second phase of the study, the results show a statistically significant difference between the initial and final evaluation of the clinical tests, which could result in better performance in aspects such as: balance, gait functionality, meter walked and cognition. Telerehabilitation Program based on Virtual Reality is an excellent alternative to provide continuity of treatment to patients with balance disorders.

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