Longitudinal assessments of balance and jump-landing performance before and after anterior cruciate ligament injuries in collegiate athletes

The purpose was to quantify the effect of an anterior cruciate ligament (ACL) injury on balance and jump-landing performance and bilateral asymmetries. Among 500 collegiate athletes who performed a reaching test and a double-leg counter-movement jump-landing test at baseline, 8 male and 6 female athletes suffered ACL injuries. In the follow-up, they performed the reaching test 3 and 6 months after ACL reconstruction (ACLR) and the jump-landing test 6 months after ACLR. Less reaching distances for the injured leg and increased reaching distance asymmetries were observed 3 and 6 months after ACLR compared to baseline. Less peak jumping and landing forces for the injured leg and increased jumping and landing force asymmetries were found 6 months after ACLR compared to baseline. The decreased performance of the injured leg and increased asymmetries may contribute to the high ACL re-injury rates. Baseline assessments would be useful for establishing an individual's pre-injury performance.

The Effect of Increased Gait Speed on Asymmetry and Variability in Children With Cerebral Palsy

Gait of children and adolescents with cerebral palsy (CP) is often reported to be more asymmetric and variable than gait of typically developing (TD) peers. As this may lead to less stable and less efficient gait, a relevant clinical question is how asymmetry may be improved and variability reduced in this population. The main objective of the current study was to investigate whether higher walking speed would affect gait symmetry and gait variability in children and adolescents with CP. Data from clinical gait analyses of 43 children and adolescents (29 males and 14 females) with unilateral (n = 28) or bilateral (n = 15) CP were included. Mean age was 11.3 ± 3.4 years, with level I (n = 26) or level II (n = 17) according to the Gross Motor Function Classification System (GMFCS). Corresponding data from 20 TD peers, matched in age and gender, were included as reference. Step time, step length, single support, and stance phase were studied at two different gait speeds: preferred and fast walking speed. Symmetry index and coefficient of variation were used as measures of asymmetry and variability, respectively. Results indicated that all participants managed to increase gait speed when instructed to do so. Overall, increased speed did not result in a more asymmetrical or variable gait, except for an increase in step length asymmetry and a difference in response between GMFCS levels I and II in variability. This implies that manipulation of gait speed may be useful clinically without necessarily making gait more unstable. However, some increase in step length asymmetry may be inevitable when gait speed is increased in people with CP.

Beneficial Effect of Foot Plantar Stimulation in Gait Parameters in Individuals with Parkinson's Disease

New treatments based on peripheral stimulation of the sensory-motor system have shown to be promising in rehabilitation strategies for patients with neurological disorders, including Parkinson's disease (PD), especially in regards to reducing gait impairment, and hence, the incidence of falls. The aim of this study was to evaluate the change in several gait parameters measured by sensor inertial measurement in PD patients after acute plantar stimulation, under the distal phalanx of the big toe, and underneath the head of the first metatarsal joint of both feet, using a 3D printing insole. In order to assess whether the effects are selective for PD patients, we compared the effect of the treatment in a control group (age-matched) consisting of patients with other neurological disorders which also displayed gait and balance impairment, and a similar cognitive function, depressive symptoms, body mass index, and comorbidity burden observed in the PD group. Plantar foot stimulation in PD patients eliminated the significant (p < 0.05) alterations existing in stride asymmetry and in stride variability. When comparing the effects of post-plantar stimulation with the respective basal level, considered as 100% in both groups, we observed a significant (p = 0.019, Mann-Whitney test) increase in stride length compared to basal in the PD group and control group. No significant effects of foot plantar stimulation were observed in any of the gait parameters in the control group. Plantar foot stimulation has a positive effect on the step and stride length, and has a positive effect on walking stability, measured by the increase in stride length. No significant effect was observed on bradykinesia because it did not improve walking velocity. These findings indicate that foot plantar stimulation using a 3D printing insole seems to generate a more stable walking pattern in PD patients, with an interesting applicability, and a low-cost, for reducing gait impairment in PD patients.

A Comprehensive Analysis of Histopathologic Examination Results of Tonsillectomy Specimens

Objective

This study aims to review the histopathologic results of tonsillectomy specimens, determine the rates of the tonsillectomy indications, and investigate the characteristics of asymmetric hypertrophy.

Materials and Methods

Medical records of 484 patients who underwent tonsillectomy were reviewed retrospectively. Descriptive data of adult and pediatric patients were presented as percentage. Comparisons between asymmetric and symmetric hypertrophy groups were performed to determine the features of asymmetric hypertrophy.

Results

The mean age of 484 patients who underwent tonsillectomy was 13 years (range: 3-69 years). While 372 (76.85%) patients were operated for infection, 100 (20.66%) were operated for tonsillar hypertrophy, 1 (0.21%) for a suspicion of malignancy, and 11 (2.27%) for other various reasons. Asymmetric hypertrophy was seen in 25 (5.16%) patients, whereas symmetric hypertrophy was seen in 75 (15.49%) patients. Malignancy was detected in three (0.61%) adult patients with asymmetric hypertrophy. Tonsillar tuberculosis was observed in one foreign patient with asymmetric hypertrophy. The presence of malignancy was higher in the asymmetric hypertrophy group (three patients [12%]) compared with the symmetric hypertrophy group (none) (p=0.002; X²=9.27). Median maximum specimen diameter was 3 cm (range: 1.15-5.5 cm) in the asymmetric hypertrophy group and 2.4 cm (range: 1.25-4.8 cm) in the symmetric hypertrophy group (p=0.08). The Friedman grade was significantly (p<0.001), positively, and strongly (r=0.885) correlated with the maximum specimen diameter.

Conclusion

Routine histopathologic examination of the tonsillectomy specimens might not be necessary for all patients, but it is recommended for the patients with a real asymmetry.

Distinct chromophore-protein environments enable asymmetric activation of a bacteriophytochrome-activated diguanylate cyclase

Sensing of red and far-red light by bacteriophytochromes involves intricate interactions between their bilin chromophore and the protein environment. The light-triggered rearrangements of the cofactor configuration and eventually the protein conformation enable bacteriophytochromes to interact with various protein effector domains for biological modulation of diverse physiological functions. Excitation of the holoproteins by red or far-red light promotes the photoconversion to their far-red light-absorbing Pfr state or the red light-absorbing Pr state, respectively. Because prototypical bacteriophytochromes have a parallel dimer architecture, it is generally assumed that symmetric activation with two Pfr state protomers constitutes the signaling-active species. However, the bacteriophytochrome from Idiomarina species A28L (IsPadC) has recently been reported to enable long-range signal transduction also in asymmetric dimers containing only one Pfr protomer. By combining crystallography, hydrogen-deuterium exchange coupled to MS, and vibrational spectroscopy, we show here that Pfr of IsPadC is in equilibrium with an intermediate "Pfr-like" state that combines features of Pfr and Meta-R states observed in other bacteriophytochromes. We also show that structural rearrangements in the N-terminal segment (NTS) can stabilize this Pfr-like state and that the PHY-tongue conformation of IsPadC is partially uncoupled from the initial changes in the NTS. This uncoupling enables structural asymmetry of the overall homodimeric assembly and allows signal transduction to the covalently linked physiological diguanylate cyclase output module in which asymmetry might play a role in the enzyme-catalyzed reaction. The functional differences to other phytochrome systems identified here highlight opportunities for using additional red-light sensors in artificial sensor-effector systems.

Changes in Morphometric Traits of Ground Beetles Along Urbanization Gradients

Urbanization has a significant impact on abiotic and biotic factors in nature. We examined the morphometric characters of four carabid species (Abax parallelepipedus, Carabus scheidleri, Carabus violaceus, and Pterostichus oblongopunctatus) along urbanization gradients in and around the cities of Vienna (Austria) and Debrecen (Hungary). We found significant differences among urban, suburban, and rural areas in the parameters of antennomers, the maxillary palpus, the labial palpus, and the length of the tibia and the elytra of the carabids studied. We also found significant differences between males and females based on the parameters of antennomers, the maxillary palpus, the labial palpus, the femur, and the elytra. An interaction between urbanization and sex was found in the case of antennomers, the maxillary palpus, the labial palpus, the femur, and the elytra. Our findings suggested that in the cases of species from Carabini tribus the parameters of antennomers, the maxillary palpus, and the elytra could be useful for assessing the effects of urbanization because these morphometric characters responded sensitively to the environmental stress, whereas the most useful parameters are those of antennomers and the tibia for the species of Pterostichini tribus. Our findings also revealed that females are more sensitive to environmental stress than males.

The Effect of Optical Flow Motion Direction on Vection Strength

In some phenomena of visual perception, the motion direction of visual stimuli can affect perception. In particular, asymmetries between oblique directions and cardinal (horizontal and vertical) directions have been reported and are known as oblique effects (e.g., contrast sensitivity and motion threshold). In this study, we investigated how vection strength depends on motion direction. Participants observed random-dot optical flow in a circular field and rated the perceived vection strength. Dot movement was systematically controlled using the following angles: 0° (up), 30°, 45°, 60°, 90°, 120°, 135°, 150°, and 180° (down). We found that vection strength depended on motion direction and was weaker in the oblique directions than cardinal directions. Thus, the effect of motion direction on vection strength was variable, as seen in the shape of the oblique effect.

Patient-Reported Measurement of Breast Asymmetry Using Archimedes' Principle in Breast Reduction Mammaplasty: A Retrospective Study

Introduction Breast hypertrophy is a common condition that is often treated with breast reduction surgery. A large percentage of breast hypertrophy patients have notable asymmetry between breasts. Methods The purpose of this study was to investigate a method of measuring breast asymmetry, one that allows patients to determine the asymmetry of their own breasts at home with ease, and to assess its accuracy and role in a surgical practice. A retrospective chart review was conducted, wherein self-measurements of breast asymmetry using a variation of Bouman's technique were compared with the recorded intra-operative resected tissue mass. Results In total, 47 patients with asymmetry were included in the study. The difference between patient-reported measurements and resected breast tissue mass varied from 0 grams to 240 grams. Of the 47 patients, 38% were able to measure their breast difference within a remarkable 10 grams as compared to the resected breast tissue, of which four patients were accurate to less than one gram. The majority (70%) of patients accurately measured their asymmetry within 50 grams, which was determined to be a clinically significant amount based on a survey of plastic surgeons performed for the study. Conclusion The breast measurement technique presented in this study appears to be effective and accurate for most patients with suspected asymmetry undergoing reduction mammaplasty that stands to reduce pre-operative planning time. Patient-reported breast measurement may emerge as a valuable tool in clinical and research pursuits; however, further research on this topic is indicated at this time.

Asymmetric Graves' Orbitopathy

Graves' Orbitopathy (GO) is an autoimmune orbital disorder usually presenting as a sequala of autoimmune thyroid disease. The presence of GO is associated with increased psychological burden and, in severe cases may cause blindness. While most patients with GO present with bilateral disease, asymmetric or unilateral GO may affect a significant proportion of patients diagnosed with GO. Older age, male sex, active and severe disease correlate with asymmetric disease. However, the exact mechanisms causing asymmetry remain elusive. Herein, we review the literature on asymmetric GO and highlight its differences compared with bilateral GO.

Atrophic Corpus Callosum Associated with Altered Functional Asymmetry in Major Depressive Disorder

PURPOSE

Impairments in intra- and inter-hemispheric information transfer circuits have been reported in patients with major depressive disorder (MDD). However, the specific anomalous connection (intra- and/or inter-hemispheric) and hemisphere (left and/or right) in which this connection plays a more dominant role in the pathogenic mechanism underlying MDD are still poorly understood.

PATIENTS AND METHODS

Structural magnetic resonance imaging and resting-state functional magnetic resonance imaging were performed in 33 patients with MDD and 33 healthy controls. The intra- and inter-hemispheric functional connectivity (FC) strength in the default mode network areas and volume of the callosal subregions were computed using independent samples t-tests. The partial correlations between the volumes and FCs were also computed.

RESULTS

The patients with MDD had smaller volumes in the genu of the corpus callosum than the controls. The intrahemispheric FCs of the bilateral posterior cingulate gyrus, left precuneus, left medial superior frontal gyrus, left medial orbitofrontal gyrus, left angular gyrus and left middle temporal gyrus, and interhemispheric FCs of the bilateral posterior cingulate gyrus in the patients with MDD were lower than those in the controls. Moreover, the intrahemispheric FCs of the precuneus and interhemispheric FCs of middle frontal gyrus, orbital middle frontal gyrus, and anterior cingulate gyrus in the patients with MDD showed right-lateralized asymmetry, which were opposite from the asymmetry patterns observed in the controls. The functional asymmetry of the anterior cingulate gyrus was correlated with the volume of the genu of the corpus callosum and disease duration.

CONCLUSION

These findings provide robust evidence that intra- and inter-hemispheric disconnections are involved in MDD, and that functional disruptions in the left hemisphere may be more relevant to the pathophysiology of MDD. Furthermore, imbalanced interhemispheric exchanges may contribute to the anatomical deficits in the corpus callosum in patients with MDD.

Hemispheric Asymmetry of White Matter Hyperintensity in Association With Lacunar Infarction

Background

White matter hyperintensities (WMHs) are commonly asymmetric between hemispheres but for unknown reasons. We investigated asymmetric WMHs associated with lacunar infarcts.

Methods and Results

A total of 267 consecutive patients with small first‐ever supratentorial infarcts (≤20 mm) were included. None had a relevant vascular stenosis. WMH asymmetry was measured based on the hemispheric difference of a modified Scheltens scale score (≥3 defined as asymmetric). We analyzed the association of the hemispheric WMH asymmetry with old silent lacunar infarcts or acute lacunar infarcts. We compared lesion frequency maps between groups and generated t‐statistics maps. The mean age of patients was 64 years, and 63% were men. Asymmetric WMH was more than 3‐fold as frequent (P<0.001) in the group with old silent lacunar infarcts (42%, 43/102) than in the group without old silent lacunar infarcts (15%, 24/165). In patients with left hemispheric dominance of WMHs, an acute lacunar infarct was more likely to be located in the left (versus right) hemisphere (74% versus 26%, P<0.001). In patients with right hemispheric dominance of WMHs, an acute lacunar infarct was more likely to be located on the right (versus left) hemisphere (81% versus 19%, P<0.001). Mapping studies showed that the side of hemispheric dominance of WMHs was associated with acute and silent lacunes on the same side.

Conclusions

These are the first data to show that asymmetric WMHs are associated with both old silent lacunar infarcts and acute lacunar infarcts ipsilateral to the greatest WMH burden. This suggests that the hemisphere with relatively large WMHs is more vulnerable to ischemia.

Asymmetric Unilateral Vestibular Perception in Adolescents With Idiopathic Scoliosis

The cause of Adolescent Idiopathic Scoliosis (AIS) remains unclear, but one proposed cause of AIS is asymmetric vestibular function and the related descending drive to the spine musculature. The objective of this study was to determine if asymmetric vestibular function is present in individuals with AIS. Ten individuals with AIS (8F, 2M) and 10 healthy age- and sex-matched controls were exposed to 10s-long virtual rotations induced by monaural or binaural electrical vestibular stimulation (EVS), and 10s-long real rotations delivered by a rotating chair. Using a forced-choice paradigm, participants indicated their perceived rotation direction (right or left) to stimuli of varying intensity. A Bayesian adaptive algorithm adjusted the stimulus intensity and direction to identify a stimulus level, which we called the direction recognition threshold, at which participants correctly identified the rotation direction 69% of the time. For unilateral vestibular stimuli (monaural EVS), the direction recognition thresholds were more asymmetric in all participants with AIS compared to control participants [(0.22-1.00 mA) vs. (0.01-0.21 mA); p < 0.001]. For bilateral vestibular stimuli, however, the direction recognition thresholds did not differ between groups for either the real or virtual rotations (multiple p > 0.05). Previous reports of semicircular canal orientation asymmetry in individuals with AIS could not explain the magnitude of the vestibular function asymmetry we observed, suggesting a functional cause to the observed vestibular asymmetry. Thus, the present results suggest that a unilateral vestibular dysfunction is linked to AIS, potentially revealing a new path for the screening and monitoring of scoliosis in adolescents.

Gait Asymmetry Post-Stroke: Determining Valid and Reliable Methods Using a Single Accelerometer Located on the Trunk

Asymmetry is a cardinal symptom of gait post-stroke that is targeted during rehabilitation. Technological developments have allowed accelerometers to be a feasible tool to provide digital gait variables. Many acceleration-derived variables are proposed to measure gait asymmetry. Despite a need for accurate calculation, no consensus exists for what is the most valid and reliable variable. Using an instrumented walkway (GaitRite) as the reference standard, this study compared the validity and reliability of multiple acceleration-derived asymmetry variables. Twenty-five post-stroke participants performed repeated walks over GaitRite whilst wearing a tri-axial accelerometer (Axivity AX3) on their lower back, on two occasions, one week apart. Harmonic ratio, autocorrelation, gait symmetry index, phase plots, acceleration, and jerk root mean square were calculated from the acceleration signals. Test–retest reliability was calculated, and concurrent validity was estimated by comparison with GaitRite. The strongest concurrent validity was obtained from step regularity from the vertical signal, which also recorded excellent test–retest reliability (Spearman’s rank correlation coefficients (rho) = 0.87 and Intraclass correlation coefficient (ICC₂₁) = 0.98, respectively). Future research should test the responsiveness of this and other step asymmetry variables to quantify change during recovery and the effect of rehabilitative interventions for consideration as digital biomarkers to quantify gait asymmetry.

Progress in the Synthesis of Bifunctionalized Polyhedral Oligomeric Silsesquioxane

Polyhedral oligomeric silsesquioxane (POSS) has been considered as one of the most promising nanofillers in academic and industrial research due to its unique multifunctional nanostructure, easy functionalization, hybrid nature, and high processability. The progress of POSS has been extensive, particularly applications based on single- or multiple-armed POSS. In polymer hybrids, in order to enhance the properties, bifunctional POSS has been incorporated into the backbone chain of the polymer. This review summarizes recent developments in the synthesis, modification, and application of bifunctional POSS-containing composite materials. This includes amino-POSS, hydroxyl-POSS, aromatic ring-POSS, ether-POSS, and vinyl groups-POSS and their applications, exemplified by polyurethanes (PUs) and polyimides (PIs). In addition, the review highlights the enhancement of thermal, mechanical, and optical properties of the composites.

In-Water and On-Land Swimmers' Symmetry and Force Production

Although performance and biomechanical evaluations are becoming more swimming-specific, dryland testing permits monitoring of a larger number of performance-related variables. However, as the degree of comparability of measurements conducted in-water and on land conditions is unclear, we aimed to assess the differences between force production in these two different conditions. Twelve elite swimmers performed a 30 s tethered swimming test and four isokinetic tests (shoulder and knee extension at 90 and 300°/s) to assess peak force, peak and average torque, and power symmetry index. We observed contralateral symmetry in all the tests performed, e.g., for 30 s tethered swimming and peak torque shoulder extension at 90°/s: 178 ± 50 vs. 183 ± 56 N (p = 0.38) and 95 ± 37 vs. 94 ± 35 N × m (p = 0.52). Moderate to very large direct relationships were evident between dryland testing and swimming force production (r = 0.62 to 0.96; p < 0.05). Swimmers maintained similar symmetry index values independently of the testing conditions (r = −0.06 to −0.41 and 0.04 to 0.44; p = 0.18–0.88). Asymmetries in water seems to be more related to technical constraints than muscular imbalances, but swimmers that displayed higher propulsive forces were the ones with greater force values on land. Thus, tethered swimming and isokinetic evaluations are useful for assessing muscular imbalances regarding propulsive force production and technical asymmetries.

Shell-Exchange Behavior in a Hermit-Crab-Like Tanaidacean (Crustacea: Malacostraca)

This study describes shell-exchange behavior in the hermit-crab-like tanaidacean Macrolabrum sp. (Pagurapseudidae: Pagurapseudinae) under captive conditions. I observed one shell exchange by Macrolabrum sp., the behavioral sequence of which was as follows: a shell-carrying tanaidacean 1) grasped the edge of the aperture of an empty gastropod shell with its right cheliped; 2) inspected the condition inside the shell four times by inserting the anterior portion of its body into the shell; and 3) moved into the shell, posterior end (pleotelson) first. The elapsed time from the initial grasping of the empty shell to completing the move into it was 2 min 20 sec. In contrast to a Pagurapseudes tanaidacean and hermit crabs, the individual of Macrolabrum sp. did not examine the external surface of the shell during the single shell exchange observed.

Distinct Frequency Specialization for Detecting Dark Transients in Humans and Tree Shrews

Despite well-known privileged perception of dark over light stimuli, it is unknown to what extent this dark dominance is maintained when visual transients occur in rapid succession, for example, during perception of moving stimuli. Here, we address this question using dark and light transients presented at different flicker frequencies. Although both human participants and tree shrews exhibited dark dominance for temporally modulated transients, these occurred at different flicker frequencies, namely, at 11 Hz in humans and 40 Hz and higher in tree shrews. Tree shrew V1 neuronal activity confirmed that differences between light and dark flicker were maximal at 40 Hz, corresponding closely to behavioral findings. These findings suggest large differences in flicker perception between humans and tree shrews, which may be related to the lifestyle of these species. A specialization for detecting dark transients at high temporal frequencies may thus be adaptive for tree shrews, which are particularly fast-moving small mammals.

Effects of Additional Load on the Occurrence of Bilateral Deficit in Counter-Movement and Squat Jumps

Purpose: A vertical jump (VJ) is a common task performed in several sports, with the height achieved correlated to skilled performance. Loaded VJs are often used in the training of recreational and professional athletes. The bilateral deficit (BLD), which refers to the difference between the heights achieved by a bilateral jump and the sum of two unilateral jumps, has not been reported for loaded jumps and the findings for unloaded jumps are inconclusive. The purpose of this study was threefold: (a) to quantify and compare BLD in countermovement (CMJ) and squat jumps (SJ), (b) to explore the effects of an additional 10% of body weight (BW) load on the BLD in both CMJ and SJ, and (c) examine the relationship between magnitude of BLD and jump performance in both jumps and conditions. Methods: Forty participants (22 for CMJ and 18 for SJ) performed a bilateral jump and unilateral jumps on each leg with and without an added load equivalent to 10% of each participant's bodyweight. Results: BLD was evident in all conditions, with CMJ BLD values nearly double those for the SJ. The extra load did not affect the magnitude of BLD. BLD had a significant correlation with unilateral jump height, expect for the 110%BW SJ. Conclusions: BLD is present in SJs and CMJs at both loaded and unloaded conditions. The SJs have about half of the BLD observed in CMJs regardless of additional load. Participants who had higher single leg jumps seemed to also have higher BLDs, but there was no evidence of association between the bilateral jump height and BLD.

A universal transportin protein drives stochastic choice of olfactory neurons via specific nuclear import of a sox-2-activating factor

Stochastic neuronal cell fate choice involving notch-independent mechanisms is a poorly understood biological process. The Caenorhabditis elegans AWC olfactory neuron pair asymmetrically differentiates into the default AWC^OFF and induced AWC^ON subtypes in a stochastic manner. Stochastic choice of the AWC^ON subtype is established using gap junctions and SLO BK potassium channels to repress a calcium-activated protein kinase pathway. However, it is unknown how the potassium channel-repressed calcium signaling is translated into the induction of the AWC^ON subtype. Here, we identify a detailed working mechanism of how the homeodomain-like transcription factor NSY-7, previously described as a repressor in the maintenance of AWC asymmetry, couples SLO BK potassium channels to transactivation of sox-2 expression for the induction of the AWC^ON subtype through the identification of a unique imb-2 (transportin 1) allele. imb-2 loss-of-function mutants are not viable; however, we identify a viable imb-2 allele from an unbiased forward genetic screen that reveals a specific role of imb-2 in AWC olfactory neuron asymmetry. IMB-2 specifically drives nuclear import of NSY-7 within AWC neurons to transactivate the expression of the high mobility group (HMG)-box transcription factor SOX-2 for the specification of the AWC^ON subtype. This study provides mechanistic insight into how NSY-7 couples SLO BK potassium channels to transactivation of sox-2 expression for the induction of the AWC^ON subtype. Our findings also provide structure-function insight into a conserved amino acid residue of transportins in brain development and suggest its dysfunction may lead to human neurological disorders.

Time as a consequence of internal coherence

Time has been an elusive concept to grasp. Although we do not yet understand it properly, there have been advances made in regard to how we can explain it. One such advance is the Page-Wootters mechanism. In this mechanism, time is seen as an inaccessible coordinate and the apparent passage of time arises as a consequence of correlations between the subsystems of a global state. Here we propose a measure that captures the relational character of the mechanism, showing that the internal coherence is the necessary ingredient for the emergence of time in the Page-Wootters model. Also, we connect it to results in quantum thermodynamics, showing that it is directly related to the extractable work from quantum coherence.

Age-specific modifications in healthy adults' knee joint position sense

Aim: Right-handed young adults perform target-matching tasks more accurately with the non-dominant (ND) compared to the dominant (D) limb, but it is unclear if age affects this disparity. We determined if age affects target-matching asymmetry in right-side dominant healthy adults. Method: Young (n = 12, age: 23.6 y, 6 females) and older (n = 12; age: 75.1 y, 7 females) adults performed a passive joint position-matching task with the D and ND leg in a randomized order. Result: Age affected absolute, constant, and variable knee JPS errors but, contrary to expectations, it did not affect target-matching asymmetries between the D and ND knees. However, older participants tended to underestimate while young subjects overestimated the target angles. Moreover, older as compared to young subjects performed the target-matching task with higher variability. Conclusion: Altogether, age seems to affect passive knee target-matching behaviour in right-side dominant healthy adults. The present data indicate that healthy aging produces age-specific modifications in passive joint position sense.

The ontogeny of the lateral line system in Telmatobius atacamensis (Anura, Telmatobiidae)

The lateral line system in anurans is functional during aquatic stages and therefore could provide characters related to larval morphological variation. However, few studies have addressed its components in an integrated overview, and little is known about its ontogenetic variation. This study describes the postembryonic trajectory of the lateral system in Telmatobius atacamensis up to its metamorphic regression. This includes structure, number, topography, and innervation of neuromasts, to contribute new and complete information about its larval organization and its temporal sequence of regression. The arrangement and innervation of lateral lines in T. atacamensis resembles those described for other Type IV tadpoles. Its distinctive features are the orientation of the neuromast stitches in the lateral lines, the presence of supraotic neuromasts, and the first-described case of asymmetry of the ventral trunk line. The temporal sequence of regression during metamorphosis differs between the lateral lines and the lateral line nerves, which remain myelinated into postmetamorphic stages. This asynchronous pattern between different components of the system has also been described for Pseudis paradoxa, which shares with T. atacamensis a remarkably long larval period. This long larval period and gradual metamorphosis could also be related to the constitutive metamorphic regression of the system, in spite of the aquatic lifestyle of these frogs.

Association between asymmetry in lower extremity lean mass and functional mobility in older adults living in the community: Results from the Korean Frailty and Aging Cohort Study

The asymmetry in lower extremity strength is known to be related to the functional mobility in older adults living in the community. However, little is known about the association between lower extremity lean mass asymmetry and functional mobility in this patient group. Hence, this study aimed to determine whether asymmetry in lower extremity muscle mass has a significant relationship with functional mobility in older adults living in the community.This cross-sectional study analyzed the pre-existing data from the Korean Frailty and Aging Cohort Study. A total of 435 older people (aged 70-84 years) were divided into the following groups according to their Limb Asymmetry Index (LAsI): low, intermediate, and high asymmetric groups. LAsI is calculated using lower extremity lean mass, and comparisons between groups were conducted. The participants were also further divided into better and worse mobility groups based on their physical performance test results (Timed Up and Go and Short Physical Performance Battery), and comparisons between groups were conducted. Comparisons between fallers and non-fallers were also conducted. In addition, this study investigated the factors that had a significant effect on gait speed and fall experience within the past year among older adults living in the community.The LAsI was significantly associated with gait speed in older adults living in the community. Older adults in the highest tertile of the LAsI had a slower gait speed than those in the lowest tertile of the LAsI. However, no significant difference was observed in the LAsI between the better mobility group and worse mobility group. Moreover, the LAsI was not a significant predictor of falls.Asymmetry in lower extremity lean mass was significantly associated with gait speed in older adults living in the community.

Statistical Parametric Mapping as a Measure of Differences Between Limbs: Applications to Clinical Populations

In healthy individuals, symmetrical lower-extremity movement is often assumed and calculated using discrete points during various tasks. However, measuring overall movement patterns using methods such as statistical parametric mapping (SPM) may allow for better interpretation of human movement. This study demonstrated the ability of SPM to assess interlimb differences in lower-extremity movement during 2 example tasks: running and landing. Three-dimensional motion analysis was used to determine sagittal and frontal plane lower-extremity joint angles in (1) young and older individuals during running and (2) patients with anterior cruciate ligament reconstruction and uninjured control athletes during landing. Interlimb differences within each group were compared using SPM and paired t tests on peak discrete angles. No differences between limbs were found between young and older runners using SPM. Peak ankle eversion and plantar flexion angles differed between limbs in young and older runners. Sagittal plane hip angle varied between limbs in uninjured control athletes. Frontal plane ankle angle and sagittal plane knee and hip angles differed between limbs in patients with anterior cruciate ligament reconstruction using SPM and discrete analysis. These data suggest that SPM can be useful to determine clinically meaningful interlimb differences during running and landing in multiple populations.

How Grammar Introduces Asymmetry Into Cognitive Structures: Compositional Semantics, Metaphors, and Schematological Hybrids

This paper presents a preliminary and tentative formulation of a novel empirical generalization governing the relationship between grammar and cognition across a variety of independent domains. Its point of departure is an abstract distinction between two kinds of cognitive structures: symmetric and asymmetric. While in principle any feature whatsoever has the potential for introducing asymmetry, this paper focuses on one specific feature, namely thematic-role assignment. Our main empirical finding concerns the role of language, or, more specifically, grammar, in effecting and maintaining the distinction between symmetric and asymmetric cognitive structures. Specifically, whereas symmetric structures devoid of thematic-role assignment more commonly occur in a non-grammatical and usually also non-verbal medium, asymmetric structures involving thematic-role assignment are more likely to be associated with a grammatical medium. Our work draws together three independent strands of empirical research associated with three diverse phenomenological domains: compositional semantics, metaphors and schematological hybrids. These three domains instantiate conceptual combinations, bringing together two or more subordinate entities into a single superordinate entity. For compositional semantics this consists of a juxtaposition of constituent signs to form a single more complex sign; for metaphors this entails the bringing together of two different concepts in order to produce a comparison; while for schematological hybrids this involves the combination of different entities to form a single new hybrid entity. Our empirical results reveal a remarkable parallelism between the above three domains. Within each domain, symmetric structures tend to be associated with a non-verbal or otherwise non-grammatical medium, while asymmetric structures are more frequently associated with a grammatical medium. Thus, within each domain, grammar introduces asymmetry. More specifically, we find that in all three domains, the asymmetry in question is one that involves the assignment of thematic roles. To capture this effect, we posit two distinct levels, or tiers, of cognition: non-grammatical cognition, more commonly associated with symmetric structures, and grammatical cognition more conducive to asymmetric structures. Within each of the three phenomenological domains, we find the distinction between non-grammatical and grammatical cognition to be manifest in three independent realms, phylogeny, ontogeny, and the architecture of human cognition. Thus, grammar constitutes the driving force behind the transition from symmetric to asymmetric cognitive structures.