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10 pages, 3013 KiB

Open AccessArticle

A Method for Calculating the Sign and Degree of Chirality of Supercoiled Protein Structures

by Aleksey Lutsenko, Alla Sidorova, Denis Shpigun, Ekaterina Belova and Vsevolod Tverdislov

Symmetry 2023, 15(11), 2051; https://doi.org/10.3390/sym15112051 - 12 Nov 2023

Viewed by 1171

Abstract

Chirality plays an important role in studies of natural protein structures. Therefore, much attention is paid to solving the problems associated with the development of criteria and methods for assessing the chirality of biomolecules. In this paper, a new method for calculating the [...] Read more.

Chirality plays an important role in studies of natural protein structures. Therefore, much attention is paid to solving the problems associated with the development of criteria and methods for assessing the chirality of biomolecules. In this paper, a new method for calculating the sign and degree of chirality of superhelices is proposed. The method makes it possible to characterize the chirality sign and to quantify coiled-coils and collagen superhelices. The degree of chirality is understood as a value indicating the intensity of twisting of individual helices around the axis of the superhelix. The calculation requires information about the relative spatial arrangement of the alpha carbon of the amino acid residues of the helices that make up the superhelix. The use of a small amount of raw data makes the method easy to apply, and the validity of the results of this study is confirmed through the analysis of real protein structures. Full article

(This article belongs to the Special Issue Biology and Symmetry/Asymmetry：Feature Papers 2022)

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23 pages, 2546 KiB

Open AccessArticle

Multiple Axes of Visual Symmetry: Detection and Aesthetic Preference

by Maria Pombo, Hassan Aleem and Norberto M. Grzywacz

Symmetry 2023, 15(8), 1568; https://doi.org/10.3390/sym15081568 - 11 Aug 2023

Cited by 1 | Viewed by 1492

Abstract

Little is known about the detection of and preference for multiple simultaneous parallel axes of symmetry. Neuroscientists have suggested that the detection of symmetry occurs in extrastriate brain areas with large receptive fields. Such large receptive fields may potentially hinder the simultaneous detection [...] Read more.

Little is known about the detection of and preference for multiple simultaneous parallel axes of symmetry. Neuroscientists have suggested that the detection of symmetry occurs in extrastriate brain areas with large receptive fields. Such large receptive fields may potentially hinder the simultaneous detection of more than one axis of symmetry. In contrast, psychophysicists have found that symmetry detection occurs within small spatial windows, allowing for the concurrent detection of multiple axes of symmetry. Using psychophysical and computational methods, we aim to test whether multiple axes of symmetry can be detected in parallel and to understand the role of multiple axes of symmetry on aesthetic valence. Experiment 1 provides evidence that multiple axes of symmetry cannot be detected simultaneously. However, with relatively long temporal integration, people can detect them. Experiment 2 suggests that multiple axes of symmetry tend to increase preference. However, the preference for symmetry is not universal because, although most people prefer symmetry, others prefer complex images without axes of symmetry. We present and test a computational model that explains the results of these experiments. Full article

(This article belongs to the Special Issue Biology and Symmetry/Asymmetry：Feature Papers 2022)

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14 pages, 780 KiB

Open AccessArticle

Influence of Box Height on Inter-Limb Asymmetry and Box Jump Performance

by Marcel Lopes dos Santos, Ricardo Berton, JoCarol Shields, Chris Bishop, Taylor Dinyer-McNeely, Olivia Anderson and Jay Dawes

Symmetry 2023, 15(7), 1359; https://doi.org/10.3390/sym15071359 - 4 Jul 2023

Viewed by 2637

Abstract

Box jumps are often included in training programs as an introductory exercise to novice athletes and untrained individuals and are an efficient option of lower-body explosiveness training. However, it is unclear whether the use of boxes of differing heights affect the inter-limb asymmetry [...] Read more.

Box jumps are often included in training programs as an introductory exercise to novice athletes and untrained individuals and are an efficient option of lower-body explosiveness training. However, it is unclear whether the use of boxes of differing heights affect the inter-limb asymmetry during this exercise. The purpose of this study is to investigate the effect of box height in inter-limb asymmetry during box jumps. Recreationally active young males (n = 14) and females (n = 16) performed three jumps at boxes that corresponded to approximately 0, 20, 40, 60, and 80% of their individual countermovement jumps. The selected performance variables were peak force (PF), peak power (PP), rate of force development (RFD), and time to take-off (TToff). The intraclass correlation coefficients ranged from 0.76 to 0.99, and the coefficient of variation ranged from 4.03 to 16.52%. A series of one-way repeated measures ANOVA tests were used to test for significant differences of the performance variables and inter-limb asymmetries. The females’ PF at 80% was significantly higher from 0% (p < 0.05). No significant differences were observed for inter-limb asymmetry across box heights (p ≥ 0.25). This study shows that the box height does not affect the overall intra-session inter-limb asymmetries in recreationally active individuals. Full article

(This article belongs to the Special Issue Biology and Symmetry/Asymmetry：Feature Papers 2022)

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10 pages, 1246 KiB

Open AccessArticle

Mechanical Asymmetries during Treadmill Running: Effects of Running Velocity and Hypoxic Exposure

by Chris Chow Li Tee, Mee Chee Chong, Viswanath Sundar, Chuen Leang Chok, Wee Kian Yeo and Olivier Girard

Symmetry 2023, 15(7), 1303; https://doi.org/10.3390/sym15071303 - 23 Jun 2023

Cited by 1 | Viewed by 1726

Abstract

Studies evaluating mechanical asymmetry across a range of running velocities during treadmill runs have yielded inconsistent findings, while the impact of additional hypoxic exposure has never been investigated. The aim of this study was to characterize the effects of manipulating running velocity and [...] Read more.

Studies evaluating mechanical asymmetry across a range of running velocities during treadmill runs have yielded inconsistent findings, while the impact of additional hypoxic exposure has never been investigated. The aim of this study was to characterize the effects of manipulating running velocity and hypoxic exposure on gait asymmetry during treadmill running. Eleven trained individuals performed seven runs at different velocities (8, 10, 12, 14, 16, 18, and 20 km·h⁻¹) in a randomized order, each lasting 45 s. The running took place on an instrumented treadmill for normoxia (FiO₂ = 20.9%), moderate hypoxia (FiO₂ = 16.1%), high hypoxia (FiO₂ = 14.1%), and severe hypoxia (FiO₂ = 13.0%). Vertical and antero-posterior ground reaction force recordings over 20 consecutive steps (i.e., after running ∼25 s) allowed the measurement of running mechanics. Lower-limb asymmetry was assessed from the ‘symmetry angle’ (SA) score. Two-way repeated-measures ANOVA (seven velocities × four conditions) was used. There was no significant difference in SA scores for any of the biomechanical variables for velocity (except contact time and braking phase duration; p = 0.003 and p = 0.002, respectively), condition, or interaction. Mean SA scores varied between ∼1% and 2% for contact time (1.5 ± 0.8%), flight time (1.6 ± 0.6%), step length (0.8 ± 0.2%), peak vertical force (1.2 ± 0.5%), and mean vertical loading rate (2.1 ± 1.0%). Mean SA scores ranged from ∼2% to 5% for duration of braking (1.6 ± 0.7%) and push-off phases (1.9 ± 0.6%), as well as peak braking (5.0 ± 1.9%) and push-off forces (4.8 ± 1.7%). In conclusion, the trained runners exhibited relatively even strides, with mechanical asymmetries remaining low-to-moderate across a range of submaximal, constant running velocities (ranging from 8 to 20 km·h⁻¹) and varying levels of hypoxia severity (between normoxia and severe hypoxia). Full article

(This article belongs to the Special Issue Biology and Symmetry/Asymmetry：Feature Papers 2022)

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35 pages, 4878 KiB

Open AccessFeature PaperArticle

Leaf Shape and Self-Mulching by Trees: A Hypothesis

by John H. Graham and Rachel Christopher

Symmetry 2023, 15(6), 1198; https://doi.org/10.3390/sym15061198 - 2 Jun 2023

Viewed by 2911

Abstract

The simple leaves of deciduous forest trees in temperate zones have more irregular and asymmetric shapes than comparable non-deciduous leaves of trees in the tropics and subtropics. These shapes manifest as the irregular lobes and sinuses of temperate species of Quercus and Acer [...] Read more.

The simple leaves of deciduous forest trees in temperate zones have more irregular and asymmetric shapes than comparable non-deciduous leaves of trees in the tropics and subtropics. These shapes manifest as the irregular lobes and sinuses of temperate species of Quercus and Acer, as well as the greater bilateral asymmetry of Ulmaceae and Betulaceae, the serrated margins of many species, and the greater frequency of compound leaves generally (Fraxinus and Carya). These modifications may contribute to an early transition from laminar to turbulent flow, thus reducing the lateral movement of leaves when they drop during the onset of either winter or the dry season, or when they are simply shed for replacement. Such leaves are more likely to drop over the critical root zone than large, thin, broadly elliptic, and symmetric leaves. Here, we evaluate evidence for and against self-mulching as an explanation for differences in leaf shape between temperate and tropical forests. We suggest that the main evolutionary trade-offs are between competition for (1) light among tropical trees and temperate subcanopy trees, and (2) competition for water and soil nutrients among temperate canopy trees. Full article

(This article belongs to the Special Issue Biology and Symmetry/Asymmetry：Feature Papers 2022)

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12 pages, 1419 KiB

Open AccessFeature PaperArticle

Sexual Dimorphic Rightward Lateralization of Cerebral Sulcal Infolding in Cynomolgus Monkeys (Macaca fascicularis)

by Kazuhiko Sawada and Shigeyoshi Saito

Symmetry 2023, 15(6), 1164; https://doi.org/10.3390/sym15061164 - 28 May 2023

Viewed by 1832

Abstract

Cerebral sulcal infolding exhibits unique species-related lateralization patterns. The present investigation aimed to characterize the asymmetric patterns of sulcal infolding in cynomolgus monkeys and their sexual dimorphism. Three-dimensional magnetic resonance (MR) images were acquired at 7-Tesla from the fixed brains of adult male [...] Read more.

Cerebral sulcal infolding exhibits unique species-related lateralization patterns. The present investigation aimed to characterize the asymmetric patterns of sulcal infolding in cynomolgus monkeys and their sexual dimorphism. Three-dimensional magnetic resonance (MR) images were acquired at 7-Tesla from the fixed brains of adult male (n = 5) and female (n = 5) monkeys. The gyrification index (GI) was estimated on MR images throughout the cerebral cortex (global-GI) or in the representative primary sulci (sulcal-GI). The global-GI did not differ between the sexes when the ipsilateral sides were compared. Although there was no sex difference in the sulcal-GI of the ipsilateral sides of any primary sulci, a significant right bias of the sulcal-GI was noted in the inferior rams of the arcuate sulcus and circular sulcus in males but not in females. Secondary sulcal emergence was examined to assess sulcal infolding asymmetry at the individual and population levels. Nonbiased asymmetric emergence was noted in the posterior supraprincipal dimple in both sexes and the rostral sulcus in females. Notably, the emergence of the superior postcentral dimple was significantly right-lateralized in females. The findings revealed right-biased sulcal infolding in male and female cynomolgus monkeys, although the lateralized cortical regions differed between the sexes. Full article

(This article belongs to the Special Issue Biology and Symmetry/Asymmetry：Feature Papers 2022)

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14 pages, 1596 KiB

Open AccessFeature PaperArticle

Facial Asymmetry of Italian Children: A Cross-Sectional Analysis of Three-Dimensional Stereophotogrammetric Reference Values

by Annalisa Cappella, Riccardo Solazzo, Joshua Yang, Noha Mohamed Hassan, Claudia Dolci, Daniele Gibelli, Gianluca Tartaglia and Chiarella Sforza

Symmetry 2023, 15(4), 792; https://doi.org/10.3390/sym15040792 - 24 Mar 2023

Cited by 1 | Viewed by 2065

Abstract

Reference data on the asymmetry of facial thirds of children is still scarce, although it can offer meaningful comparative information for clinical studies. This study aims to provide reference data on the facial asymmetry of Italian children using a 3D analysis of facial [...] Read more.

Reference data on the asymmetry of facial thirds of children is still scarce, although it can offer meaningful comparative information for clinical studies. This study aims to provide reference data on the facial asymmetry of Italian children using a 3D analysis of facial thirds divided according to the trigeminal nerve distribution (upper, middle, and lower). A 3D surface-based approach was conducted on the digital models of the faces of 135 children (74 M, 61 F), acquired by stereophotogrammetry. In addition to sex, two different age classes were analyzed (4–8 years and 9–12 years). For each facial third, the asymmetry was expressed as root-mean-square distance (RMS) by calculating the point-to-point distances between the original and the reflected 3D models. A 3-way ANOVA test verified significant differences between the two sexes, the two age classes, and the three facial thirds (p-value < 0.05), and also their interaction. Significant differences were found between the sexes (females were more symmetric, p = 0.005) and the two age groups (younger were more symmetric p < 0.001). According to Tukey’s HSD post-hoc test, among the thirds, the middle one proved to be significantly more symmetrical (p < 0.001). No significant interaction impacting the asymmetry was found when the main factors were considered in any combination. Reference data on the “normal” facial asymmetry of Italian children was provided for further clinical purposes. Normal children have low average RMS values (0.30–0.51 mm) and younger, in particular females, proved more symmetrical than older children, while among the facial surfaces, the middle proved most symmetrical in both sexes, although with little clinical relevance. Since there is no consensus on the amount of symmetry deemed clinically acceptable, further studies on larger randomized samples are auspicial. Full article

(This article belongs to the Special Issue Biology and Symmetry/Asymmetry：Feature Papers 2022)

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9 pages, 853 KiB

Open AccessFeature PaperArticle

Passive Grouping Enhances Proto-Arithmetic Calculation for Leftward Correct Responses

by Maria Loconsole, Lucia Regolin and Rosa Rugani

Symmetry 2023, 15(3), 719; https://doi.org/10.3390/sym15030719 - 14 Mar 2023

Viewed by 1596

Abstract

Baby chicks and other animals including human infants master simple arithmetic. They discriminate 2 vs. 3 (1 + 1 vs. 1 + 1 + 1) but fail with 3 vs. 4 (1 + 1 + 1 vs. 1 + 1 + 1 + [...] Read more.

Baby chicks and other animals including human infants master simple arithmetic. They discriminate 2 vs. 3 (1 + 1 vs. 1 + 1 + 1) but fail with 3 vs. 4 (1 + 1 + 1 vs. 1 + 1 + 1 + 1). Performance is restored when elements are grouped as 2 + 1 vs. 2 + 2. Here, we address whether grouping could lead to asymmetric response bias. We recoded behavioural data from a previous study, in which separate groups of four-day-old domestic chicks underwent an arithmetic task: when the objects were presented one-by-one (1 + 1 + 1 vs. 1 + 1 + 1 + 1), chicks failed in locating the larger group irrespective of its position and did not show any side bias; Experiment 1. When the objects were presented as grouped (2 + 1 vs. 2 + 2), chicks succeeded, performing better when the larger set was on their left; Experiment 2. A similar leftward bias was also observed with harder discriminations (4 vs. 5: 3 + 1 vs. 3 + 2), with baby chicks succeeding in the task only when the larger set was on the left (Experiments 3 and 4). A previous study showed a rightward bias, with tasks enhancing individual processing. Despite a similar effect in boosting proto-arithmetic calculations, individual processing (eliciting a right bias) and grouping (eliciting a left bias) seem to depend on distinct cognitive mechanisms. Full article

(This article belongs to the Special Issue Biology and Symmetry/Asymmetry：Feature Papers 2022)

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17 pages, 3212 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Classification of Blood Rheological Models through an Idealized Symmetrical Bifurcation

by Konstantinos Tzirakis, Yiannis Kamarianakis, Nikolaos Kontopodis and Christos V. Ioannou

Symmetry 2023, 15(3), 630; https://doi.org/10.3390/sym15030630 - 2 Mar 2023

Cited by 9 | Viewed by 3578

Abstract

The assumed rheological behavior of blood influences the hemodynamic characteristics of numerical blood flow simulations. Until now, alternative rheological specifications have been utilized, with uncertain implications for the results obtained. This work aims to group sixteen blood rheological models in homogeneous clusters, by [...] Read more.

The assumed rheological behavior of blood influences the hemodynamic characteristics of numerical blood flow simulations. Until now, alternative rheological specifications have been utilized, with uncertain implications for the results obtained. This work aims to group sixteen blood rheological models in homogeneous clusters, by exploiting data generated from numerical simulations on an idealized symmetrical arterial bifurcation. Blood flow is assumed to be pulsatile and is simulated using a commercial finite volume solver. An appropriate mesh convergence study is performed, and all results are collected at three different time instants throughout the cardiac cycle: at peak systole, early diastole, and late diastole. Six hemodynamic variables are computed: the time average wall shear stress, oscillatory shear index, relative residence time, global and local non-Newtonian importance factor, and non-Newtonian effect factor. The resulting data are analyzed using hierarchical agglomerative clustering algorithms, which constitute typical unsupervised classification methods. Interestingly, the rheological models can be partitioned into three homogeneous groups, whereas three specifications appear as outliers which do not belong in any partition. Our findings suggest that models which are defined in a similar manner from a mathematical perspective may behave substantially differently in terms of the data they produce. On the other hand, models characterized by different mathematical formulations may belong to the same statistical group (cluster) and can thus be considered interchangeably. Full article

(This article belongs to the Special Issue Biology and Symmetry/Asymmetry：Feature Papers 2022)

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Graphical abstract

10 pages, 2168 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

A Study on the Intersection of Ground Reaction Forces during Overground Walking in Down Syndrome: Effects of the Pathology and Left–Right Asymmetry

by Johanna Vielemeyer, Cristina Sole, Manuela Galli, Matteo Zago, Roy Müller and Claudia Condoluci

Symmetry 2023, 15(2), 544; https://doi.org/10.3390/sym15020544 - 17 Feb 2023

Cited by 4 | Viewed by 4074

Abstract

Motor dysfunctions in patients with Down Syndrome (DS) result in poor locomotion and an altered gait phenotype, characterized by compromised stability management and frequent bilateral asymmetries. Directing ground reaction forces to a point above the center of mass, referred to as the virtual [...] Read more.

Motor dysfunctions in patients with Down Syndrome (DS) result in poor locomotion and an altered gait phenotype, characterized by compromised stability management and frequent bilateral asymmetries. Directing ground reaction forces to a point above the center of mass, referred to as the virtual pivot point (VPP), is one means of maintaining stability during walking. This cross-sectional observational study compared the dynamic gait function of 33 individuals with DS (mean age: 17.7 ± 6.4 years, 13 females) to a group of 36 healthy controls (mean age: 15.5 ± 6.1 years, 15 females), using the concept of the VPP. Results showed that the VPP was located more anteriorly in individuals with DS compared to healthy controls, with no differences in the variability (R²) or symmetry of VPP coordinates. This anterior VPP position is likely due to the larger hip moments observed in patients with DS during the propulsive phase of stance. High R² values in DS suggest that the VPP is strongly related to dynamic stability during walking. Full article

(This article belongs to the Special Issue Biology and Symmetry/Asymmetry：Feature Papers 2022)

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9 pages, 986 KiB

Open AccessArticle

Experimental Evidence Questions the Relationship between Stress and Fluctuating Asymmetry in Plants

by Dmitry E. Gavrikov, Vitali Zverev, Maksim A. Rachenko, Aleksey A. Pristavka and Mikhail V. Kozlov

Symmetry 2023, 15(2), 339; https://doi.org/10.3390/sym15020339 - 25 Jan 2023

Cited by 3 | Viewed by 1987

Abstract

The eco-evolutionary theory of developmental instability predicts that small, non-directional deviations from perfect symmetry in morphological traits (termed fluctuating asymmetry, FA) emerge when an individual is unable to buffer environmental or genetic stress during its development. Consequently, FA is widely used as an [...] Read more.

The eco-evolutionary theory of developmental instability predicts that small, non-directional deviations from perfect symmetry in morphological traits (termed fluctuating asymmetry, FA) emerge when an individual is unable to buffer environmental or genetic stress during its development. Consequently, FA is widely used as an index of stress. The goal of the present study was to experimentally test a seemingly trivial prediction derived from the theory of developmental instability—and from previous observational studies—that significant growth retardation (which indicates stress) in plants is accompanied by an increase in FA of their leaves. We induced stress, evidenced by a significant decrease in biomass relative to control, in cucumber (Cucumis sativus), sweet pepper (Capsicum annuum), and common bean (Phaseolus vulgaris) by applying water solutions of copper and nickel to the soil in which plants were grown. Repeated blind measurements of plant leaves revealed that leaf FA did not differ between stressed and control plants. This finding, once again, demonstrated that FA cannot be seen as a universal indicator of environmental stress. We recommend that the use of FA as a stress index is discontinued until the scope of the developmental instability theory is clarified and its applicability limits are identified. Full article

(This article belongs to the Special Issue Biology and Symmetry/Asymmetry：Feature Papers 2022)

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13 pages, 1414 KiB

Open AccessFeature PaperArticle

Analyzing Turning Behavior after Repeated Lithium, Ketamine, or NaCl Injection and Chronic Stress Exposure in Mice

by Annakarina Mundorf, Hiroshi Matsui, Sebastian Ocklenburg and Nadja Freund

Symmetry 2022, 14(11), 2352; https://doi.org/10.3390/sym14112352 - 8 Nov 2022

Cited by 3 | Viewed by 2371

Abstract

A single chronic stress is often considered a potential reinforcer in psychiatric disorders. Lithium and ketamine both seem to ameliorate the consequences of stress. Here, male mice were either injected with lithium carbonate (LiCl), ketamine hydrochloride (KET), or sodium chloride (NaCl; controls) over [...] Read more.

A single chronic stress is often considered a potential reinforcer in psychiatric disorders. Lithium and ketamine both seem to ameliorate the consequences of stress. Here, male mice were either injected with lithium carbonate (LiCl), ketamine hydrochloride (KET), or sodium chloride (NaCl; controls) over nine consecutive days. Treatment was followed by 2 h of restraint stress over the first seven days. On the 9th day, 2 h after injection, all animals were tested in the open field, and novel object tests and behavior were analyzed using the toolbox ‘DeepLabCut’. To exclude an effect of generally altered locomotion activity on turning behavior, further parameters were assessed. Treatment before chronic stress exposure did not influence the total number of turns, nor the direction of turning behavior in the open field and the novel object test. Additionally, general locomotion did not differ. However, mice treated with LiCl showed a stronger turning bias (i.e., larger absolute lateralization quotients) in the novel object test when compared to mice treated with KET. This study underlines the potential of investigating turning behavior as a sensitive and reliable marker of stress reaction. Additionally, analyzing behavioral asymmetries in the context of psychopharmacological treatment can render new insights. Full article

(This article belongs to the Special Issue Biology and Symmetry/Asymmetry：Feature Papers 2022)

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15 pages, 1952 KiB

Open AccessArticle

Holistic Symmetry Assessment Using Pedobarography after Treatment of Pertrochanteric Fractures in Elderly Patients

by Karolina Gawronska and Jacek Lorkowski

Symmetry 2022, 14(9), 1798; https://doi.org/10.3390/sym14091798 - 30 Aug 2022

Viewed by 1559

Abstract

Pertrochanteric fractures (PFs) are life threatening due to the prolonged immobilization of the elderly patient that affects, indirectly, the function of most organs. PFs may have an impact on the symmetry of the human body and contribute to poor global alignment. The aim [...] Read more.

Pertrochanteric fractures (PFs) are life threatening due to the prolonged immobilization of the elderly patient that affects, indirectly, the function of most organs. PFs may have an impact on the symmetry of the human body and contribute to poor global alignment. The aim of the study is to evaluate the functional, pedobarographic and radiological outcomes in a group of subjects with PFs treated with either a dynamic hip screw (DHS) or an intramedullary gamma nail fixation. A study group of 40 patients, admitted to hospital for pertrochanteric fractures between 2015 and 2019, at a mean age of 74.87 (range 65–99), were enrolled. A control group included 20 subjects free from significant disorders of the musculoskeletal system and any other disorders that might induce a compensatory abnormal gait pattern. Functional results were assessed by the Harris Hip Score, and the plantar pressure distribution and arch index were measured with a pedobarographic examination. Radiographic parameters were assessed based on the preoperative and postoperative standing AP pelvic radiographs and axial projection of the hip. The obtained results were evaluated at 9-month follow-up. The obtained results showed no significant difference between both study groups within the scope of the variables under study. To sum up, surgical treatment, either with DHS or intramedullary gamma nail fixation, and rehabilitation treatment support the symmetry of the musculoskeletal system. However, the full return of symmetry was not achieved at 9-month follow-up compared to the control group. Full article

(This article belongs to the Special Issue Biology and Symmetry/Asymmetry：Feature Papers 2022)

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8 pages, 775 KiB

Open AccessArticle

Differential Ageing of the Brain Hemispheres: Evidence from a Longitudinal Study of Hand Preferences in Common Marmosets

by Lesley J. Rogers

Symmetry 2021, 13(12), 2349; https://doi.org/10.3390/sym13122349 - 7 Dec 2021

Cited by 5 | Viewed by 2529

Abstract

This paper is concerned with decreasing asymmetry of motor control in ageing. It discusses age-related changes in humans and reports a longitudinal study of hand preferences in common marmosets. An annual assessment of hand preference for holding food was recorded throughout the lifespan [...] Read more.

This paper is concerned with decreasing asymmetry of motor control in ageing. It discusses age-related changes in humans and reports a longitudinal study of hand preferences in common marmosets. An annual assessment of hand preference for holding food was recorded throughout the lifespan of 19 marmosets that lived for at least 9 years, and half of those lived for at least 11 years. Those with a left-hand preference showed a gradual reduction in the strength of their hand preference throughout adult life. No significant change in the strength of hand preference was found in right-handed marmosets. Hence, ageing has a specific effect on motor control by the right hemisphere. Full article

(This article belongs to the Special Issue Biology and Symmetry/Asymmetry：Feature Papers 2022)

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12 pages, 1840 KiB

Open AccessArticle

An Assessment of the Hopping Strategy and Inter-Limb Asymmetry during the Triple Hop Test: A Test–Retest Pilot Study

by Kyle Davey, Paul Read, Joseph Coyne, Paul Jarvis, Anthony Turner, Jon Brazier, Nejc Šarabon, Matthew J. Jordan and Chris Bishop

Symmetry 2021, 13(10), 1890; https://doi.org/10.3390/sym13101890 - 7 Oct 2021

Cited by 7 | Viewed by 3392

Abstract

The aims of the present study are to: (1) determine within- and between-session reliability of multiple metrics obtained during the triple hop test; and (2) determine any systematic bias in both the test and inter-limb asymmetry scores for these metrics. Thirteen male young [...] Read more.

The aims of the present study are to: (1) determine within- and between-session reliability of multiple metrics obtained during the triple hop test; and (2) determine any systematic bias in both the test and inter-limb asymmetry scores for these metrics. Thirteen male young American football athletes performed three trials of a triple hop test on each leg on two separate occasions. In addition to the total distance hopped, manual detection of touch down and toe-off were calculated via video analysis, enabling flight time (for each hop), ground contact time (GCT), reactive strength index (RSI), and leg stiffness (between hops) to be calculated. Results showed all coefficient of variation (CV) values were ≤ 10.67% and intraclass correlation coefficients (ICC) ranged from moderate to excellent (0.53–0.95) in both test sessions. Intrarater reliability showed excellent reliability for all metrics (CV ≤ 3.60%, ICC ≥ 0.97). No systematic bias was evident between test sessions for raw test scores (g = −0.34 to 0.32) or the magnitude of asymmetry (g = −0.19 to 0.43). However, ‘real’ changes in asymmetry (i.e., greater than the CV in session 1) were evident on an individual level for all metrics. For the direction of asymmetry, kappa coefficients revealed poor-to-fair levels of agreement between test sessions for all metrics (K = −0.10 to 0.39), with the exception of the first hop (K = 0.69). These data show that, given the inherent limitations of distance jumped in the triple hop test, practitioners can confidently gather a range of reliable data when computed manually, provided sufficient test familiarization is conducted. In addition, although the magnitude of asymmetry appears to show only small changes between test sessions, limb dominance does appear to fluctuate between test sessions, highlighting the value of also monitoring the direction of the imbalance. Full article

(This article belongs to the Special Issue Biology and Symmetry/Asymmetry：Feature Papers 2022)

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Review

Jump to: Research

21 pages, 3386 KiB

Open AccessFeature PaperReview

The Symmetric Active Site of Enantiospecific Enzymes

by Elena Rosini, Loredano Pollegioni and Gianluca Molla

Symmetry 2023, 15(5), 1017; https://doi.org/10.3390/sym15051017 - 2 May 2023

Cited by 1 | Viewed by 2683

Abstract

Biomolecules are frequently chiral compounds, existing in enantiomeric forms. Amino acids represent a meaningful example of chiral biological molecules. Both L- and D-amino acids play key roles in the biochemical structure and metabolic processes of living organisms, from bacteria to mammals. In this [...] Read more.

Biomolecules are frequently chiral compounds, existing in enantiomeric forms. Amino acids represent a meaningful example of chiral biological molecules. Both L- and D-amino acids play key roles in the biochemical structure and metabolic processes of living organisms, from bacteria to mammals. In this review, we explore the enantiospecific interaction between proteins and chiral amino acids, introducing theoretical models and describing the molecular basis of the ability of some of the most important enzymes involved in the metabolism of amino acids (i.e., amino acid oxidases, dehydrogenases, and aminotransferases) to discriminate the opposite enantiomers. Our analysis showcases the power of natural evolution in shaping biological processes. Accordingly, the importance of amino acids spurred nature to evolve strictly enantioselective enzymes both through divergent evolution, starting from a common ancestral protein, or through convergent evolution, starting from different scaffolds: intriguingly, the active sites of these enzymes are frequently related by a mirror symmetry. Full article

(This article belongs to the Special Issue Biology and Symmetry/Asymmetry：Feature Papers 2022)

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10 pages, 950 KiB

Open AccessReview

Brain Asymmetry: Towards an Asymmetrical Neurovisceral Integration

by Manuel Ramírez-Sánchez, Isabel Prieto, Ana Belén Segarra, Inmaculada Banegas, Magdalena Martínez-Cañamero, Germán Domínguez-Vías and Marc de Gasparo

Symmetry 2021, 13(12), 2409; https://doi.org/10.3390/sym13122409 - 13 Dec 2021

Cited by 6 | Viewed by 3276

Abstract

Despite the ancestral evidence of an asymmetry in motor predominance, going through the inspiring discoveries of Broca and Wernicke on the localization of language processing, continuing with the subsequent noise coinciding with the study of brain function in commissurotomized patients—and the subsequent avalanche [...] Read more.

Despite the ancestral evidence of an asymmetry in motor predominance, going through the inspiring discoveries of Broca and Wernicke on the localization of language processing, continuing with the subsequent noise coinciding with the study of brain function in commissurotomized patients—and the subsequent avalanche of data on the asymmetric distribution of multiple types of neurotransmitters in physiological and pathological conditions—even today, the functional significance of brain asymmetry is still unknown. Currently, multiple evidence suggests that functional asymmetries must have a neurochemical substrate and that brain asymmetry is not a static concept but rather a dynamic one, with intra- and inter-hemispheric interactions between its various processes, and that it is modifiable depending on changing endogenous and environmental conditions. Furthermore, based on the concept of neurovisceral integration in the overall functioning of an organism, some evidence has emerged suggesting that this integration could be organized asymmetrically, using the autonomic nervous system as a bidirectional communication pathway, whose performance would also be asymmetric. However, the functional significance of this distribution, as well as the evolutionary advantage of an asymmetric nervous organization, is still unknown. Full article

(This article belongs to the Special Issue Biology and Symmetry/Asymmetry：Feature Papers 2022)

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Symmetric and Asymmetric Synapses Driving Neurodegenerative Disorders

by Daniel Romaus-Sanjurjo, Antía Custodia, Marta Aramburu-Núñez, Adrián Posado-Fernández, Laura Vázquez-Vázquez, Javier Camino-Castiñeiras, Yago Leira, Juan Manuel Pías-Peleteiro, José Manuel Aldrey, Alberto Ouro and Tomás Sobrino

Symmetry 2021, 13(12), 2333; https://doi.org/10.3390/sym13122333 - 5 Dec 2021

Cited by 4 | Viewed by 7582

Abstract

In 1959, E. G. Gray described two different types of synapses in the brain for the first time: symmetric and asymmetric. Later on, symmetric synapses were associated with inhibitory terminals, and asymmetric synapses to excitatory signaling. The balance between these two systems is [...] Read more.

In 1959, E. G. Gray described two different types of synapses in the brain for the first time: symmetric and asymmetric. Later on, symmetric synapses were associated with inhibitory terminals, and asymmetric synapses to excitatory signaling. The balance between these two systems is critical to maintain a correct brain function. Likewise, the modulation of both types of synapses is also important to maintain a healthy equilibrium. Cerebral circuitry responds differently depending on the type of damage and the timeline of the injury. For example, promoting symmetric signaling following ischemic damage is beneficial only during the acute phase; afterwards, it further increases the initial damage. Synapses can be also altered by players not directly related to them; the chronic and long-term neurodegeneration mediated by tau proteins primarily targets asymmetric synapses by decreasing neuronal plasticity and functionality. Dopamine represents the main modulating system within the central nervous system. Indeed, the death of midbrain dopaminergic neurons impairs locomotion, underlying the devastating Parkinson’s disease. Herein, we will review studies on symmetric and asymmetric synapses plasticity after three different stressors: symmetric signaling under acute damage—ischemic stroke; asymmetric signaling under chronic and long-term neurodegeneration—Alzheimer’s disease; symmetric and asymmetric synapses without modulation—Parkinson’s disease. Full article

(This article belongs to the Special Issue Biology and Symmetry/Asymmetry：Feature Papers 2022)

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