scholarly journals Dxa as a Tool for the Assessment of Morphological Asymmetry in Athletes

Author(s):  
Magdalena Krzykaa
Author(s):  
Patrizia Bisiacchi ◽  
Elisa Cainelli

AbstractAsymmetry characterizes the brain in both structure and function. Anatomical asymmetries explain only a fraction of functional variability in lateralization, with structural and functional asymmetries developing at different periods of life and in different ways. In this work, we perform a scoping review of the cerebral asymmetries in the first brain development phases. We included all English-written studies providing direct evidence of hemispheric asymmetries in full-term neonates, foetuses, and premature infants, both at term post-conception and before. The final analysis included 57 studies. The reviewed literature shows large variability in the used techniques and methodological procedures. Most structural studies investigated the temporal lobe, showing a temporal planum more pronounced on the left than on the right (although not all data agree), a morphological asymmetry already present from the 29th week of gestation. Other brain structures have been poorly investigated, and the results are even more discordant. Unlike data on structural asymmetries, functional data agree with each other, identifying a leftward dominance for speech stimuli and an overall dominance of the right hemisphere in all other functional conditions. This generalized dominance of the right hemisphere for all conditions (except linguistic stimuli) is in line with theories stating that the right hemisphere develops earlier and that its development is less subject to external influences because it sustains functions necessary to survive.


2018 ◽  
Vol Volume 11 ◽  
pp. 621-628 ◽  
Author(s):  
Daisy Kopera ◽  
Zrinka Ivezic-Schoenfeld ◽  
Ira G. Federspiel ◽  
Doris Grablowitz ◽  
Benjamin Gehl ◽  
...  

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e6098 ◽  
Author(s):  
Jiri Neustupa ◽  
Jan Stastny

Green microalgae of theMicrasteriaslineage are unicellular microorganisms with modular morphology consisting of successively differentiated lobes. Due to their morphological diversity and peculiar morphogenesis, these species are important model systems for studies of cytomorphogenesis and cellular plasticity. Interestingly, the phylogenetic structure of theMicrasteriaslineage and most other Desmidiales is poorly related to the traditional morphological characters used for delimitation of taxa. In this study, we focused on symmetry breaking between adjacent cellular lobes in relation to phylogeny of the studied species. While pronounced morphological asymmetry between the adjacent lobes is typical for some species, others have been characterized by the almost identical morphologies of these structures. We asked whether there is any detectable average shape asymmetry between the pairs of lobes and terminal lobules in 19Micrasteriasspecies representing all major clades of this desmidiacean lineage. Then, we evaluated whether the asymmetric patterns among species are phylogenetically structured. The analyses showed that the phylogeny was in fact strongly related to the patterns of morphological asymmetry between the adjacent cellular lobes. Thus, evolution of the asymmetric development between the adjacent lobes proved to be the key event differentiating cellular shape patterns ofMicrasterias. Conversely, the phylogeny was only weakly related to asymmetry between the pairs of terminal lobules. The subsequent analyses of the phylogenetic morphological integration showed that individual hierarchical levels of cellular morphology were only weakly coordinated with regard to asymmetric variation among species. This finding indicates that evolutionary differentiation of morphogenetic processes leading to symmetry breaking may be relatively independent at different branching levels. Such modularity is probably the key to the evolvability of cellular shapes, leading to the extraordinary morphological diversity of these intriguing microalgae.


1998 ◽  
Vol 201 (5) ◽  
pp. 717-730 ◽  
Author(s):  
P J Fonseca ◽  
H-C Bennet Clark

The type 1 echeme of the song of the small European cicada Tympanistalna gastrica consists of a pair of loud IN-OUT pulses followed by a train of soft IN-OUT pulses. In all nine insects investigated, the right and left tymbals buckled inwards and outwards alternately, but the echeme started with the buckling of the right tymbal. Both the inward and the outward buckling movements produced single discrete sound pulses. <P> The loud IN pulses were produced with the tymbal tensor muscle relaxed. They were approximately 10 dB louder than the loud OUT pulses and than the soft IN and OUT pulses. The period between the right loud IN and OUT pulses (3.75+/-0.31 ms) (mean +/- s.d.) was significantly shorter than between the left loud IN and OUT pulses (4.09+/-0.28 ms). The period between the loud IN and OUT pulses was significantly shorter than the period between the soft IN and OUT pulses, which was similar on both sides (mean for the right tymbal 5.54+/-0.20 ms, mean for the left tymbal 5.30+/-0.51 ms). <P> Measured at the tymbal, the power spectrum of the right loud IN pulses showed major components between 4 and 8 kHz as well as around 11.7 kHz. That of the left loud IN pulse had approximately 10 dB less power at 4 kHz and similar power at 7-8 kHz, with a further louder peak at around 10.8 kHz. The loud OUT pulses and all subsequent IN and OUT soft pulses showed very little power at 4 and 8 kHz, but all showed a spectral peak at approximately 13 kHz. The soft OUT pulses had similar pulse envelopes to the preceding IN pulses, which they closely mirrored. <P> Measured at the fourth abdominal sternite, only the right loud IN pulse produced peak power at 4 kHz. The transfer function between the tymbal sound and that at sternite 4 was maximal at 4 kHz for the right loud IN pulse and showed a peak at this frequency for both loud and soft IN and OUT pulses. The 4 kHz components of all pulses, and particularly that of the right loud IN pulse, which has the loudest 4 kHz component, excited sympathetic sound radiation from the abdominal sternite region. <P> Measured at the tympanal opercula, both loud IN pulses produced peaks at 7-8 kHz of similar power. The transfer functions between the tymbal sound and that at the tympanal opercula showed peaks of power at this frequency range for both loud and soft IN and OUT pulses, suggesting that this component excites sympathetic radiation via the tympana. <P> Components of the sound pulses produced by one tymbal are also transmitted via the contralateral tymbal. The pulses transmitted during both loud IN pulses had ragged envelopes, but the soft IN pulses and all OUT pulses were transmitted as clean coherent pulses with slow build-up and slow decay, suggesting that the ipsilateral tymbal excited a sympathetic resonance in the contralateral one. <P> The tymbals of T. gastrica have two unusual features. At the dorsal end of rib 2, there is a horizontal bar that extends anteriorly over rib 3 and posteriorly over rib 1 to the dorsal end of the tymbal plate. This bar appears to couple the three ribs so that they buckle in unison. The resilin sheet at the ventral ends of ribs 1, 2 and 3 was significantly wider, dorso-ventrally, in the right tymbal than in the left in eight insects that were measured (mean right-to-left ratio, 1.37). <P> The asymmetry between the right and left loud IN pulses correlates with the morphological asymmetry of the tymbals. The complexities of the song in T. gastrica appear to result from the preferential excitation of sound radiation from the abdomen surface or via the tympana by components of the distinct pulses produced by the asymmetrical tymbals and from the tymbals themselves. <P> Moribund or fatigued insects were successively unable to produce the right loud pulse and then the left loud pulse. The complex song may in this way act as an honest signal of male fitness.


Author(s):  
Juhn A. Wada ◽  
Alan E. Davis

SUMMARY:Morphological speech zone asymmetry in man cannot be due to environmental or developmental factors after birth. The functional implication of such a finding is not yet clear. Morphological asymmetry of the human brain is paralleled by electrophysiological evidence of cerebral hemispheric asymmetries. The results of our analysis of 50 infants suggest that clear occipital-temporal coherency asymmetry similar, but not identical to the adult pattern, also exists at or near birth. These asymmetries are generated by stimuli with no verbal content and in infants who presumably have no or an undeveloped capability for language. It is suggested that language is only a part of much more fundamental asymmetries which include the processing of auditory and visual information. Our results, and those of others, are consistent with the assumption that the left hemisphere is more able to relate stimuli to past experience, either short or long-term, while the right hemisphere is more able to process stimuli which are not easily identifiable or referable. These capabilities would not be based on language, and hence would be expected to develop independently and possibly before speech. The demonstration that reversing electrophysiological asymmetries can be generated with non-speech stimuli in the visual and auditory modalities, and in neonates, supports such an assumption.


1982 ◽  
Vol 243 (4) ◽  
pp. E325-E331 ◽  
Author(s):  
A. L. Goodman ◽  
M. J. Koering ◽  
W. E. Nixon ◽  
R. F. Williams ◽  
G. D. Hodgen

Previous work demonstrated that asymmetrical ovarian activity accompanies morphological asymmetry during the ovarian cycle in rhesus and cynomolgus macaques. This study was designed to determine whether functional ovarian asymmetry could be used to detect the upcoming dominant follicle (DF) even before it was grossly visible. Revealing a latent DF in this manner would permit a better estimate of the time when dominance of the follicle selected to ovulate is attained. To accomplish this, rhesus monkeys were luteectomized at midluteal phase to synchronize subsequent follicle growth, and 4 or 8 days later either the ipsilateral or contralateral ovary was removed. Unilateral ablation at day 4 (when no DF is grossly apparent) of either ovary produced symmetrical responses: the interval from luteectomy (CLX) to the next luteinizing hormone (LH) surge was extended by about 4 days in both groups (P less than 0.01), i.e., from about 12.5 days to 16.7 +/- 1.6 and 17.0 +/- 1.5 days (mean +/- SE). In contrast, hemiovariectomy at day 8 produced markedly divergent asymmetrical responses. Removal of the ipsilateral ovary 8 days after CLX did not affect the timing of the next LH surge (13.2 +/- 0.6 days), which ordinarily occurs about 12.5 days after CLX alone. However, ablation of the contralateral ovary (bearing the next DF) on day 8 extended the interval from CLX to the next LH surge from about 12.5 to 26.6 +/- 1.3 days. These findings indicate that, during the normal ovarian cycle when menses occurs 2--4 days after luteolysis, the follicle destined to ovulate becomes dominant between the 2nd and 6th day and that attainment of dominance signals the completion of a follicle selection process that begins or resumes promptly after luteolysis.


2012 ◽  
Vol 8 (4) ◽  
pp. 551-553 ◽  
Author(s):  
Michael J. Angilletta ◽  
Robbie S. Wilson

Animals commonly use their limbs as signals and weapons during territorial aggression. Asymmetries of limb performance that do not relate to asymmetries of limb size (cryptic asymmetry) could substantially affect disputes, but this phenomenon has not been considered beyond primates. We investigated cryptic asymmetry in male crayfish ( Cherax dispar ), which commonly use unreliable signals of strength during aggression. Although the strength of a chela can vary by an order of magnitude for a given size, we found repeatable asymmetries of strength that were only weakly related to asymmetries of size. Size-adjusted strength of chelae and the asymmetry of strength between chelae were highly repeatable between environmental conditions, suggesting that asymmetries of strength stemmed from variation in capacity rather than motivation. Cryptic asymmetry adds another dimension of uncertainty during conflict between animals, which could influence the evolution of unreliable signals and morphological asymmetry.


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