scholarly journals Morphometric Analyses of (Hidden) Directional Asymmetry in Leaf Blades

2018 ◽  
Vol 2 (4) ◽  
Author(s):  
Sergey Gennadevich Baranov
Keyword(s):  
Fluctuating Asymmetry ◽  
Leaf Blade ◽  
Permutation Test ◽  
Principal Component ◽  
Bilateral Symmetry ◽  
Procrustes Analysis ◽  
Directional Asymmetry ◽  
Asymmetry Factor ◽  
Shape Deviation ◽  
Data Set

The deviation from perfect bilateral symmetry is a phenomenon actively exploring in evolutionary and environmental studies. The bilateral variation presents on different ecosystem level. The methods applied vary depending on the task and the final goal of study. The present study demonstrates the statistically significant presence of components (traces) of directional asymmetry (DA), fluctuating asymmetry (FA) and antisymmetry (AS) in leaf blade of Betula pendula on low level of ecosystem such as tree and leaf blade. The Generalized Procrustes Analysis was applied for testing asymmetry of shape in all data set and subgroups. The category ‘population’ revealed no significant value of DA (factor ‘side’). In the levels ‘tree’ and ‘leaf blade’ the factor ‘side’ was statistically significant as well as fluctuating asymmetry (factor interaction ‘leaf × side’).The principal component analysis showed visually the difference in PC scores between antisymmetry matrices of the left and right halves of the leaf blade. Covariate analysis matrices demonstrated the shape deviation from strict symmetry. The metric traits showed directional asymmetry in t-test in the leaf blade and the low kurtosis values. Permutation test of kurtosis values in geometric morphometric approach showed deviation from normality that could verified as a weak presence AS traces. The discriminant analysis results showed that traces of DA differed at the subpopulation level, as three of 10 populations revealed not significant factor ‘side’. Descriptive statistics of the metric train showed a correspondence to the trace of directional asymmetry in the shape of leaf blade. Fluctuating asymmetry in its pure form, at three levels of ecosystem was met only in single population of ten that should be taken into account testing developmental stability of birch and possibly other woody plants.

scholarly journals Side Differences in the Skull of Sheep: An Assessment by Geometric Morphometrics

2020 ◽  
pp. 1-7
Author(s):  
P. M. Parés-Casanova ◽  
A. Tolić ◽  
R. Carnicero
Keyword(s):  
Fluctuating Asymmetry ◽  
Genetic Factors ◽  
Bilateral Symmetry ◽  
Directional Asymmetry ◽  
Two Dimensional ◽  
Geometric Morphometric ◽  
Dorsal Aspect ◽  
Morphometric Methods ◽  
Muscular Function ◽  
External Stimuli

Effects of perturbations during development can be due to environmental and/or genetic factors, resulting in increased developmental instability which in turn can be expressed as fluctuating asymmetry (FA), defined as the non-directional deviation (right-left differences) from bilateral symmetry. However, other asymmetry types can appear, such as and directional asymmetry (DA), characterized by a distribution skewed to one side (right or left) at the, which is originated as a response to external stimuli that affect differentially on both sides of the organism. In order to describe asymmetric patterns in the ovine skull, we studied 165 specimens from animals belonging to the sheep breed “Navarra” from North Spain, using geometric morphometric methods. On digital pictures, we analyzed two midline and 8 bilateral two-dimensional landmarks on skull dorsal aspect. Results showed that FA accounted for a reduced amount of total variation, while DA explained most of it. We suggest that the presence of side differences due to lateralized muscular function (mastication) is the most important factor in skull asymmetry. Obtained results should provide a basis for relating asymmetries to the mechanics of cranial skeletum in sheep.

scholarly journals About the asymmetry structure of the leaf blade Common plantain

2021 ◽  
Vol 262 ◽  
pp. 04004
Author(s):  
Sergey G. Baranov ◽  
Igor E. Zykov ◽  
Tatyana S. Biryukova ◽  
Lubov V. Fedorova ◽  
Alla M. Antsyshkina
Keyword(s):  
Fluctuating Asymmetry ◽  
Leaf Blade ◽  
Geographical Location ◽  
Climatic Conditions ◽  
Directional Asymmetry ◽  
Plantago Major ◽  
The Common ◽  
Axis Of Symmetry ◽  
The Asymmetry ◽  
High Precipitation

Using the method of geometric morphometrics the contour of the image of the leaf blade of the Common plantain (Plantago major) was aligned along the axis of symmetry to answer the question of whether the asymmetry and shape were influenced by environmental pollution by vehicles and climatic conditions. Procrustes distances showed that fluctuating asymmetry was higher in roadside populations in 2019. In the control populations, a mixture of two types of asymmetry, fluctuating and directional, was obtained. In 2020 with high precipitation (47% more than in 2019), asymmetry was represented by higher directional asymmetry (p <0.0001), although the overall asymmetry remained the same. The nonparametric Kruskal-Wallis test showed the influence on the shape only climatic environments of the year (p <0.001). The geographical location of the populations and the combined effect of the factors year and the place of leaves gathering did not affect the shape of the leaf blade. In 2020, no data were obtained on the excess of asymmetry in roadside populations compared to the control, therefore authors conclude about the weak bioindicative properties of the Common plantain in response to traffic pollution.

scholarly journals PRECISION OF MEASUREMENT AND DIRECTED ASYMMETRY IN LEAF PLATES OF BETULA PENDULA ROTH

2017 ◽  
Vol 12 (2) ◽  
pp. 14-21
Author(s):  
Сергей Баранов ◽  
Sergey Baranov ◽  
Татьяна Бибик ◽  
Tat'yana Bibik ◽  
Леонид Ильин ◽  
...  
Keyword(s):  
Fluctuating Asymmetry ◽  
Betula Pendula ◽  
Procrustes Analysis ◽  
Directional Asymmetry ◽  
Population Characteristic ◽  
Linear Features ◽  
Vladimir Region ◽  
Unit Of Measurement ◽  
Two Populations ◽  
Normal Variability

The directional asymmetry in the birch leaf plates was studied. For this purpose, ten randomly selected populations were used in the Vladimir region (Russia). The leaf plates were photographed twice, 5 pairs of bilateral-symmetric labels were used and Procrustes analysis of variance carried out. Directional asymmetry testing was carried out at three biosystemic levels (population, individual and leaf plate level). The totality of all populations did not show the presence of directional asymmetry. Biosystemic level – “tree” had a statistically significant directional asymmetry in 4 populations. At the level of “leaf plate” biosystem, directional asymmetry was found in 9 populations among 10. Thus, only one population had a fluctuating asymmetry at all biosystemic levels (p <0.0001). The directional asymmetry of the linear features was checked in the t-test and was statistically significant only in two populations. Thus, directional asymmetry is the usual kind of asymmetry, present in the form of birch leaf plates which are pendant under conditions of normal variability. The described fact related specifically to the leaf plate, as to the unit of measurement. Therefore, in determining the FA and HA of leaf plates, one must keep in mind the possible presence of directional asymmetry as a population characteristic.

Customer-Related Social Stressors

2015 ◽  
Vol 14 (4) ◽  
pp. 165-181 ◽  
Author(s):  
Sarah Dudenhöffer ◽  
Christian Dormann
Keyword(s):  
Service Providers ◽  
Principal Component ◽  
Well Being ◽  
Emotional Dissonance ◽  
Social Stressors ◽  
Data Set ◽  
Confirmatory Factor Analyses ◽  
Confirmatory Factor ◽  
Service Jobs ◽  
Single Data

Abstract. The purpose of this study was to replicate the dimensions of the customer-related social stressors (CSS) concept across service jobs, to investigate their consequences for service providers’ well-being, and to examine emotional dissonance as mediator. Data of 20 studies comprising of different service jobs (N = 4,199) were integrated into a single data set and meta-analyzed. Confirmatory factor analyses and explorative principal component analysis confirmed four CSS scales: disproportionate expectations, verbal aggression, ambiguous expectations, disliked customers. These CSS scales were associated with burnout and job satisfaction. Most of the effects were partially mediated by emotional dissonance. Further analyses revealed that differences among jobs exist with regard to the factor solution. However, associations between CSS and outcomes are mainly invariant across service jobs.

Spectroscopy-Based Mapping with Scanning Microwave Impedance Microscopy

2018 ◽  
Author(s):  
Peter De Wolf ◽  
Zhuangqun Huang ◽  
Bede Pittenger
Keyword(s):  
Single Point ◽  
Electrical Characterization ◽  
Principal Component ◽  
High Sensitivity ◽  
Data Cube ◽  
Nanometer Scale ◽  
Learning Approaches ◽  
Data Set ◽  
3D Data ◽  
Higher Dimensional

Abstract Methods are available to measure conductivity, charge, surface potential, carrier density, piezo-electric and other electrical properties with nanometer scale resolution. One of these methods, scanning microwave impedance microscopy (sMIM), has gained interest due to its capability to measure the full impedance (capacitance and resistive part) with high sensitivity and high spatial resolution. This paper introduces a novel data-cube approach that combines sMIM imaging and sMIM point spectroscopy, producing an integrated and complete 3D data set. This approach replaces the subjective approach of guessing locations of interest (for single point spectroscopy) with a big data approach resulting in higher dimensional data that can be sliced along any axis or plane and is conducive to principal component analysis or other machine learning approaches to data reduction. The data-cube approach is also applicable to other AFM-based electrical characterization modes.

THYMUS VARIABILITY IN WHITE RATS EXPOSED TO FORMALDEHYDE

2019 ◽  
pp. 105-116
Author(s):  
V.N. Voloshin ◽  
I.S. Voloshina ◽  
I.Yu. Vash
Keyword(s):  
White Male ◽  
Principal Component ◽  
Middle Part ◽  
Procrustes Analysis ◽  
Male Rats ◽  
Canonical Variables ◽  
Generalized Procrustes Analysis ◽  
White Rats ◽  
Main Component ◽  
Formaldehyde Inhalation

The aim of the paper is to study thymus variability in white rats, which were exposed to formaldehyde, and to compare these data with the indicators in control animals. Materials and Methods. The trial enrolled 72 white male rats, initial body weight 40–50 g. The animals were divided into 2 groups (36 rats in each). The first group consisted of control rats. Animals of the second group were exposed to formaldehyde inhalation, 2.766 mg/m3. To characterize the variability of the organ size, centroids were determined. The superposition of landmark configurations was performed using the generalized Procrustes analysis method, MorphoJ 1.06d program. The principal component analysis and canonical analysis of the obtained data were carried out. Results. One-Way ANOVA revealed a high level of intergroup differences in Procrust distance (F=1.34; p<0.0001). The significant effect of the duration of formaldehyde exposure on centroid size was established. The Kruskal-Wallis criterion was 19.778 (p=0.0014). The analysis of the principal components indicated that each of the first 10 components stands for more than 1 % of Procrustes coordinate variance. In this case, the first 7 components compatibly explain 91.398 % of thymus variability. The proportion of the first main component to the total variance of the Procrustes coordinates is 40.236 %. PC1 (-) shows changes in the thymus shape, mostly affecting the tops of its lobes, the middle part of the right boundary and the entire left thymus boundary. The scattering ellipses of the thymus ordinates in rats exposed to formaldehyde, in the first two canonical variables are located higher than those in the control animals. Conclusion. Formaldehyde inhalation leads to thymus changes in white rat. The most significant differences with control data are determined along the second canonical variable. Keywords: thymus, form, rat, formaldehyde, geometric morphometry. Цель. Изучение изменчивости формы тимуса белых крыс, находившихся в условиях влияния формальдегида, и сравнение этих данных с показателями, полученными у контрольных животных. Материалы и методы. Работа выполнена на 72 белых крысах-самцах с начальной массой тела 40–50 г. Животные были разделены на 2 серии (по 36 крыс). Первую серию составляли контрольные крысы. Животные второй серии подвергались ингаляционному воздействию формальдегида (ФА) в концентрации 2,766 мг/м3. Для характеристики изменчивости размеров органов определяли размер их центроидов. Процедуру суперимпозиции конфигураций ландмарок выполняли методом генерализованного прокрустова анализа с использованием программы MorphoJ 1.06d. Проводили анализ главных компонент и канонический анализ полученных данных. Результаты. Однофакторный дисперсионный анализ выявил высокий уровень межгрупповых различий по показателю прокрустовых расстояний (F=1,34; р<0,0001). Установлено значительное влияние продолжительности нахождения животных в условиях воздействия ФА на размер центроида. Критерий Краскела–Уоллиса составил 19,778 (р=0,0014). Анализ главных компонент указывал на то, что каждая из первых 10 компонент объясняет более 1 % дисперсии прокрустовых координат. При этом первые 7 компонент совместно объясняют 91,398 % изменчивости формы тимуса. Вклад первой главной компоненты в общую дисперсию прокрустовых координат составляет 40,236 %. РС1 (–) показывает изменения формы тимуса, в большей степени затрагивающие верхушки его долей, среднюю часть правого контура и весь левый контур тимуса. Эллипсы рассеивания ординат тимусов, принадлежащих крысам, подвергавшимся влиянию ФА, в пространстве первых двух канонических переменных расположены выше по отношению к таковым контрольных животных. Заключение. Ингаляционное воздействие формальдегида приводит к изменению формы тимуса белых крыс. Наибольшие различия с контрольными данными определяются вдоль второй канонической переменной. Ключевые слова: тимус, форма, крыса, формальдегид, геометрическая морфометрия.

QSAR Study of PARP Inhibitors by GA-MLR, GA-SVM and GA-ANN Approaches

2020 ◽  
Vol 16 (8) ◽  
pp. 1088-1105
Author(s):  
Nafiseh Vahedi ◽  
Majid Mohammadhosseini ◽  
Mehdi Nekoei
Keyword(s):  
Present Report ◽  
Principal Component ◽  
Parp Inhibitors ◽  
Support Vector ◽  
Ann Model ◽  
Statistical Parameters ◽  
Qsar Study ◽  
Data Set ◽  
Test Set ◽  
Non Linear

Background: The poly(ADP-ribose) polymerases (PARP) is a nuclear enzyme superfamily present in eukaryotes. Methods: In the present report, some efficient linear and non-linear methods including multiple linear regression (MLR), support vector machine (SVM) and artificial neural networks (ANN) were successfully used to develop and establish quantitative structure-activity relationship (QSAR) models capable of predicting pEC50 values of tetrahydropyridopyridazinone derivatives as effective PARP inhibitors. Principal component analysis (PCA) was used to a rational division of the whole data set and selection of the training and test sets. A genetic algorithm (GA) variable selection method was employed to select the optimal subset of descriptors that have the most significant contributions to the overall inhibitory activity from the large pool of calculated descriptors. Results: The accuracy and predictability of the proposed models were further confirmed using crossvalidation, validation through an external test set and Y-randomization (chance correlations) approaches. Moreover, an exhaustive statistical comparison was performed on the outputs of the proposed models. The results revealed that non-linear modeling approaches, including SVM and ANN could provide much more prediction capabilities. Conclusion: Among the constructed models and in terms of root mean square error of predictions (RMSEP), cross-validation coefficients (Q2 LOO and Q2 LGO), as well as R2 and F-statistical value for the training set, the predictive power of the GA-SVM approach was better. However, compared with MLR and SVM, the statistical parameters for the test set were more proper using the GA-ANN model.

Evaluation of the Aging Behavior of High Density Polyethylene in Thermal Oxidative Environment by Principal Component Analysis

2017 ◽  
Vol 727 ◽  
pp. 447-449 ◽  
Author(s):  
Jun Dai ◽  
Hua Yan ◽  
Jian Jian Yang ◽  
Jun Jun Guo
Keyword(s):  
Principal Component Analysis ◽  
Impact Strength ◽  
High Density Polyethylene ◽  
Tensile Modulus ◽  
Principal Component ◽  
Component Analysis ◽  
High Density ◽  
Aging Behavior ◽  
Data Set ◽  
The Impact

To evaluate the aging behavior of high density polyethylene (HDPE) under an artificial accelerated environment, principal component analysis (PCA) was used to establish a non-dimensional expression Z from a data set of multiple degradation parameters of HDPE. In this study, HDPE samples were exposed to the accelerated thermal oxidative environment for different time intervals up to 64 days. The results showed that the combined evaluating parameter Z was characterized by three-stage changes. The combined evaluating parameter Z increased quickly in the first 16 days of exposure and then leveled off. After 40 days, it began to increase again. Among the 10 degradation parameters, branching degree, carbonyl index and hydroxyl index are strongly associated. The tensile modulus is highly correlated with the impact strength. The tensile strength, tensile modulus and impact strength are negatively correlated with the crystallinity.

scholarly journals Fluctuating Asymmetry and Sexual Dimorphism in Human Facial Morphology: A Multi-Variate Study

Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 304
Author(s):  
Omid Ekrami ◽  
Peter Claes ◽  
Ellen Van Assche ◽  
Mark D. Shriver ◽  
Seth M. Weinberg ◽  
...  
Keyword(s):  
Fluctuating Asymmetry ◽  
Life History Traits ◽  
Principal Component ◽  
Underlying Mechanism ◽  
High Density ◽  
Direct Result ◽  
Facial Morphology ◽  
Strongly Correlated ◽  
Large Dataset ◽  
Genetic Quality

(1) Background: Fluctuating asymmetry is often used as an indicator of developmental instability, and is proposed as a signal of genetic quality. The display of prominent masculine phenotypic features, which are a direct result of high androgen levels, is also believed to be a sign of genetic quality, as these hormones may act as immunosuppressants. Fluctuating asymmetry and masculinity are therefore expected to covary. However, there is lack of strong evidence in the literature regarding this hypothesis. (2) Materials and methods: In this study, we examined a large dataset of high-density 3D facial scans of 1260 adults (630 males and 630 females). We mapped a high-density 3D facial mask onto the facial scans in order to obtain a high number of quasi-landmarks on the faces. Multi-dimensional measures of fluctuating asymmetry were extracted from the landmarks using Principal Component Analysis, and masculinity/femininity scores were obtained for each face using Partial Least Squares. The possible correlation between these two qualities was then examined using Pearson’s coefficient and Canonical Correlation Analysis. (3) Results: We found no correlation between fluctuating asymmetry and masculinity in men. However, a weak but significant correlation was found between average fluctuating asymmetry and masculinity in women, in which feminine faces had higher levels of fluctuating asymmetry on average. This correlation could possibly point to genetic quality as an underlying mechanism for both asymmetry and masculinity; however, it might also be driven by other fitness or life history traits, such as fertility. (4) Conclusions: Our results question the idea that fluctuating asymmetry and masculinity should be (more strongly) correlated in men, which is in line with the recent literature. Future studies should possibly focus more on the evolutionary relevance of the observed correlation in women.

Agreement and reliability of magnetic, angular rate, and gravity (MARG) sensors to assess multiple body segment’s external loads during off-road running

2021 ◽  
pp. 175433712199698
Author(s):  
Daniel Rojas-Valverde ◽  
José Pino-Ortega ◽  
Rafael Timón ◽  
Randall Gutiérrez-Vargas ◽  
Braulio Sánchez-Ureña ◽  
...  
Keyword(s):  
Vastus Lateralis ◽  
Angular Rate ◽  
Wearable Sensors ◽  
Intraclass Correlation ◽  
Principal Component ◽  
Test Reliability ◽  
Data Set ◽  
Body Segments ◽  
External Loads ◽  
Good Agreement

The extensive use of wearable sensors in sport medicine, exercise medicine, and health has increased the interest in their study. That is why it is necessary to test these technologies’ efficiency, effectiveness, agreement, and reliability in different settings. Consequently, the purpose of this article was to analyze the magnetic, angular rate, and gravity (MARG) sensor’s test-retest agreement and reliability when assessing multiple body segments’ external loads during off-road running. A total of 18 off-road runners (38.78 ± 10.38 years, 73.24 ± 12.6 kg, 172.17 ± 9.48 cm) ran two laps (1st and 2nd Lap) of a 12 km circuit wearing six MARG sensors. The sensors were attached to six different body segments: left (MPLeft) and right (MPRight) malleolus peroneus, left (VLLeft) and right (VLRight) vastus lateralis, lumbar (L1-L3), and thorax (T2-T4) using a special neoprene suit. After a principal component analysis (PCA) was performed, the total data set variance of all body segments was represented by 44.08%–70.64% for the 1st PCA factor considering two variables, Player LoadRT and Impacts, on L1-L3, respectively. These two variables were chosen among three total accelerometry-based external load indicators (ABELIs) to perform the agreement and reliability tests due to their relevance based on PCAs for each body segment. There were no significant differences between laps in the Player LoadRT or Impacts ( p > 0.05, trivial). The intraclass correlation and lineal correlation showed a substantial to almost perfect over-time test consistency assessed via reliability in both Player LoadRT and Impacts. Bias and t-test assessments showed good agreement between Laps. It can be concluded that MARGs sensors offer significant test re-test reliability and good agreement when assessing off-road kinematics in the six different body segments.

Sign in / Sign up

Export Citation Format

Share Document