Deactivation of human neutrophil chemotaxis by chemoattractants: effect on receptors for the chemotactic factor f-Met-Leu-Phe

Normal human peripheral blood PMN were exposed to varying concentrations of partially purified chemotactic complement fragments (C5fr) and a chemotactic peptide N-formyl methionylleucylphenylalanine (f-Met-Leu-Phe). This exposure resulted in a decreased chemotactic response termed deactivation of chemotaxis. Deactivation was found to be nonpreferential for the deactivating stimulus when high concentrations of either f-Met-Leu-Phe (10(-6) M) or C5fr (20 micrograms/ml) were used. When PMN were incubated with lower concentrations of C5fr (10 micrograms/ml), there was preferential deactivation towards C5fr. Similarly, preferential deactivation of chemotaxis was observed when PMN were incubated with 10(-6) M f-Met-Leu-Phe, but this was transient and cells were nonpreferentially deactivated 60 min after the initial exposure to f-Met-Leu-Phe. The availability of receptors for tritiated f-Met-Leu-Phe was examined by Scatchard analyses and measurement of reversible f-Met-Leu-[3H]Phe binding to C5fr and f-Met-Leu-Phe-deactivated PMN. When PMN f-Met-Leu-Phe receptors were studied immediately after exposure to concentrations of C5fr causing either preferential or nonpreferential deactivation, there was increased receptor availability compared with control PMN. In contrast, PMN deactivated with high concentrations of f-Met-Leu-Phe 10(-6) M) had a transient decrease in the number of receptors followed 1 hr later by an increase in the number of receptors. This was similar to the functional correlate of preferential deactivation of chemotaxis immediately after incubation with f-Met-Leu-Phe followed by nonpreferential deactivation in these same PMN. The data indicate that preferential deactivation of chemotaxis may be associated with a preferential decrease (down-regulation) of chemoattractant receptors and that nonpreferential deactivation is associated with an increase in chemoattractant receptors.     

Connections between finger print patterns and the form of terminal phalanges

The present paper resumes the theme taken up by Bonnevie in her studies of the embryonic development of dermatoglyphic systems. Relicts of the embryonic finger balls remain in later life (Fleischhacker) and influence the symmetry relationships of the terminal phalanges. Attention was, therefore, focussed on the connection between the asymmetry of terminal phalanges and that of the patterns. All loops and whorls with a different ridge count on the radial and on the ulnar side are asymmetrical. In order to determine the asymmetry of the terminal phalanges, casts were made of the fingers of 200 schoolchildren. Then, contour drawings were laid into various planes using the phalangograph (constructed on the same lines as the perigraph), and the plane of intersection of the two sides of the symmetry axis was determined planimetrically. A high correlation of r = 0·954 was established between the degree of asymmetry of the patterns and that of the terminal phalanges (cf. Figure 3).     

Facial symmetry in young girls and boys from a slum and a control area of Ankara,Turkey

Deviations from perfect symmetry in paired traits of otherwise bilateral symmetrical organisms are thought to reflect developmental quality, especially the ability to resist environmental perturbations early in ontogeny. It is well established that poor environmental conditions increase developmental instability (DI) as reflected by measurements of fluctuating asymmetry. In humans, there is evidence that DI relates to numerous fitness components, and studies have found that perceptions of facial attractiveness for example are positively correlated with measurements of facial symmetry. Here we report the data on measurements of facial symmetry of 503 Turkish senior year high school students aged 17 to 18 years, of whom 133 males and 117 females were recruited from a slum district of ?entepe in Ankara (Group 1), and 131 males and 122 females from three high schools in wealthy central urban areas (Group 2). Digital images were used to assess the degree of facial asymmetry as measured from seven paired traits and calculated as a composite score. Facial asymmetry of participants in Group 1 (slum district) was significantly higher than that of participants in Group 2 (urban areas). Moreover, males in Group 1 were found to have higher facial asymmetry than females, while no sex difference was observed in Group 2. We conclude that poor living conditions have an influence on DI in humans, which manifests itself in the form of facial asymmetry, and that this might be particularly true for males.     

Lower limb kinematics in individuals with chronic low back pain during walking

Several investigators have suggested the presence of a link between Chronic Low Back Pain (CLBP) and lower limbs kinematics that can contribute to functional limitations and disability. Moreover, CLBP has been connected to postural and structural asymmetry. Understanding the movement pattern of lower extremities and its asymmetry during walking can provide a basis for examination and rehabilitation in people with CLBP. The present study focuses on lower limbs kinematics in individuals with CLBP during walking. Three-dimensional movements of the pelvic, hip, knee and ankle joints were tracked using a seven-camera Qualysis motion capture system. Functional dada analysis (FDA) was applied for the statistical analysis of pelvic and lower limbs motion patterns in 40 participants (20 CLBP and 20 controls). The CLBP group showed significantly different hip motion pattern in the transvers plane, altered knee and ankle motion pattern in the sagittal plane on the dominant side and different hip motion pattern in the transvers and frontal planes on the non-dominant side in comparison with the control group over the stance phase. In terms of symmetry, in the CLBP group, hip and knee moved through a significantly different motion patterns in the transvers plane on the dominant side in comparison with the non-dominant side. In the control group, knee moved through a significantly different motion pattern in the transvers plane on the dominant side in comparison with the non-dominant side. In conclusion, low back pain lead to altered movement patterns of the main joints of lower limbs especially on the dominant side during stance phase. Therefore, care should be taken to examine dominant lower limb movement pattern in CLBP to make a better clinical decision.     

Lopsided Fish in the Snake River Basin — Fluctuating Asymmetry as a way of Assessing Impact of Hatchery Supplementation in Chinook Salmon, Oncorhynchus tshawytscha

The use of developmental instability (an individual's failure to produce a consistent phenotype in a given environment) was evaluated to detect the effects of outplanting hatchery fish on wild salmon. Juvenile chinook salmon were collected in 1989, 1990, and 1991 from five drainages in the Snake River Basin. In each drainage we attempted to collect fish from streams with no hatchery supplementation (wild), naturally spawning fish from streams with hatchery supplementation (natural), and fish collected at a hatchery. Forty fish were collected per site and the number of elements in bilateral characters were counted on each side of the fish. Indices of fluctuating asymmetry (FA), a measure of minor, random deviations in perfect symmetry of bilateral counts, were calculated as an estimator of developmental instability. Analysis of character counts from seven paired characters revealed normal distributions. Only one of the characters displayed counts that were statistically larger on one side than the other, indicating that directional asymmetry (DA) or antisymmetry was not a major bias of FA. However, the means of all individual characters revealed a non-statistically significant left side bias. We analyzed our data using two indices of FA (FA1 and FA5) with different levels of sensitivity to DA. Differences in both FA indices were found among years, with collection sites in 1989 having significantly larger FA values than in 1991 (FA p < 0.01). Levels of FA among wild, natural, and hatchery fish were comparatively small (FA1 p = 0.17). This suggests developmental conditions were different in the first year of the study than in the last. The cause of these differences may be linked to either genetic or environmental variation or to gene—environment interactions, but the general population declines of salmon that occurred during this time obscures more specific conclusions.     

Resonant frequencies of arms and legs identify different walking patterns

The present study is aimed at investigating changes in the coordination of arm and leg movements in young healthy subjects. It was hypothesized that with changes in walking velocity there is a change in frequency and phase coupling between the arms and the legs. In addition, it was hypothesized that the preferred frequencies of the different coordination patterns can be predicted on the basis of the resonant frequencies of arms and legs with a simple pendulum model. The kinematics of arms and legs during treadmill walking in seven healthy subjects were recorded with accelerometers in the sagittal plane at a wide range of different velocities (i.e., 0.3-1. 3m/s). Power spectral analyses revealed a statistically significant change in the frequency relation between arms and legs, i.e., within the velocity range 0.3-0.7m/s arm movement frequencies were dominantly synchronized with the step frequency, whereas from 0.8m/s onwards arm frequencies were locked onto stride frequency. Significant effects of walking speed on mean relative phase between leg and arm movements were found. All limb pairs showed a significantly more stable coordination pattern from 0.8 to 1.0m/s onwards. Results from the pendulum modelling demonstrated that for most subjects at low-velocity preferred movement frequencies of the arms are predicted by the resonant frequencies of individual arms (about 0.98Hz), whereas at higher velocities these are predicted on the basis of the resonant frequencies of the individual legs (about 0.85Hz). The results support the above-mentioned hypotheses, and suggest that different patterns of coordination, as shown by changes in frequency coupling and phase relations, can exist within the human walking mode.     

Identifying gait asymmetry using gyroscopes--a cross-correlation and Normalized Symmetry Index approach

Injury to a lower limb may disrupt natural walking and cause asymmetrical gait, therefore assessing the gait asymmetry has become one of the important procedures in gait analysis. This paper proposes the use of wireless gyroscopes as a new instrument to determine gait asymmetry. It also introduces two novel approaches: normalized cross-correlations (Cc(norm)) and Normalized Symmetry Index (SI(norm)). Cc(norm) evaluates the waveform patterns generated by the lower limb in each gait cycle. SI(norm) provides indications on the timing and magnitude of the bilateral differences between the limbs while addressing the drawbacks of the conventional methods. One-way ANOVA test reveals that Cc(norm) can be considered as single value indicator that determines the gait asymmetry (p<0.01). The experiment results showed that SI(norm) in asymmetrical gait were different from normal gait. SI(norm) in asymmetrical gait were found to be approximately 20% greater than SI(norm) in normal gait during pre-swing and initial swing.     

Central pattern generators for bipedal locomotion

Golubitsky, Stewart, Buono and Collins proposed two models for the achitecture of central pattern generators (CPGs): one for bipeds (which we call leg) and one for quadrupeds (which we call quad). In this paper we use symmetry techniques to classify the possible spatiotemporal symmetries of periodic solutions that can exist in leg (there are 10 nontrivial types) and we explore the possibility that coordinated arm/leg rhythms can be understood, on the CPG level, by a small breaking of the symmetry in quad, which leads to a third CPG architecture arm. Rhythms produced by leg correspond to the bipedal gaits of walk, run, two-legged hop, two-legged jump, skip, gallop, asymmetric hop, and one-legged hop. We show that breaking the symmetry between fore and hind limbs in quad, which yields the CPG arm, leads to periodic solution types whose associated leg rhythms correspond to seven of the eight leg gaits found in leg; the missing biped gait is the asymmetric hop. However, when arm/leg coordination rhythms are considered, we find the correct rhythms only for the biped gaits of two-legged hop, run, and gallop. In particular, the biped gait walk, along with its arm rhythms, cannot be obtained by a small breaking of symmetry of any quadruped gait supported by quad.     

Starlings can categorize symmetry differences in dot displays

Fluctuating asymmetry is an estimate of developmental stability and, in some cases, the asymmetry of morphological traits can reflect aspects of individual fitness. As asymmetry can be a marker for fitness, it has been proposed that organisms could use morphological asymmetry as a direct visual cue during inter- and intraspecific encounters. Despite some experimental evidence to support this prediction, the perceptual abilities of animals to detect and respond to symmetry differences have been largely overlooked. Studying the ability of animals to perceive symmetry and factors that affect this ability are crucial to assessing whether fluctuating asymmetry could be used as a visual cue in nature. In this study, we investigated the ability of wild-caught European starlings Sturnus vulgaris to learn to discriminate symmetry from asymmetry in random dot patterns through operant learning experiments. The birds did not possess a spontaneous preference for either symmetry or asymmetry. The birds learned a symmetry preference, although the learning process took longer than that previously reported for pigeons Columba livia and was more error prone. After being trained to discriminate symmetry differences in random dot patterns, birds successfully transferred their symmetry discrimination abilities to a set of novel stimuli that they had not previously seen. This indicates that starlings can form a mental categorization of visual stimuli on the basis of a somewhat generalized symmetry phenomenon. We discuss these findings in relation to the probability that birds use fluctuating asymmetry as a visual cue.     

Asymmetry of Mouth-Opening of a Small Herbivorous Cichlid Fish Telmatochromis temporalis in Lake Tanganyika

Direction of mouth-opening of a small herbivorous Tanganyikan cichlid, Telmatochromis temporalis, was studied. Each sample fish opened its mouth either rightward or leftward in some degree. The directions of mouth-opening were independent of the body curve directions, and the asymmetry will be due to asymmetric mouth morph individually specific. The degree of the mouth asymmetry was not related to body size, suggesting the asymmetry being not acquired characters. No fish opened the mouth in lateral symmetry, indicating that the asymmetry is different from "fluctuating asymmetry". This fish took algae on rock surface usually using right or left side of its mouth. However, strong relations between directions of mouth-openings and frequencies of mouth side used in foraging were not found, and the biological role of the asymmetry, if any, is not clear now.     

Similar responses of insect herbivores to leaf fluctuating asymmetry

Fluctuating asymmetry (FA) represents small, random variation from symmetry and it has been used as an indicator of plant quality and susceptibility to herbivory. In this study, the effects of FA on the responses of distinct herbivore species belonging to several guilds were examined along an environmental gradient in south Florida. This approach was chosen because it relies on a multi-species approach to the study of fluctuating asymmetry and patterns of herbivory between and within plants along an environmental gradient of salinity and plant stress. To examine differences in FA between and within plant communities, seven plant species were investigated. Four of these plants were coastal species and three species occurred in upland communities. Levels of FA were assessed before herbivory and plants were followed for the whole herbivory season in 2006. Coastal plants exhibited significantly higher salt concentration, higher percentage of asymmetric leaves and higher asymmetry levels than upland plants. Herbivore abundance varied widely amongst the seven species studied, but quantitative syntheses of our results indicated significant and positive responses of insect herbivores to leaf asymmetry: insects were 25.11% more abundant on more asymmetric plants and stronger effects of asymmetry were observed for leaf miners compared to gall-formers. As demonstrated by other recent studies, FA might be used as a reliable stress indicator, leading to similar responses of insect herbivores to variation in leaf symmetry.     

Flower Symmetry Preferences in Honeybees and their Crab Spider Predators

Flowers exhibit symmetrical patterns, and innate preferences for symmetry in pollinators like honeybees are documented. Most previous studies of symmetry preferences in honeybees, Apis mellifera, tested levels of asymmetry using artificial flowers or stimuli. Here we investigated the effect of flower asymmetry on flower preferences of honeybees in a novel approach using real flowers, incorporating their spectral properties and how the receivers process the visual signals. Importantly, we also tested the response of an ‘eavesdropping’ predator, the crab spider Thomisus spectabilis, that also utilizes the same flower to prey on honeybees. Flowers (Chrysanthemum frutescens) were manipulated to contain asymmetrical and symmetrical patterns, excluding olfactory cues. Both crab spiders and honeybees exhibited a significant preference for symmetrical flowers. Moreover, honeybees exhibited a significant preference for radial symmetry over bilateral symmetry, but no corresponding effect was recorded in crab spiders. Further analyses demonstrated that flower reflectance and orientation of the axis of symmetry did not affect crab spider decisions. Field observations on T. spectabilis revealed that the natural variation in C. frutescens symmetry had no effect on the choice of crab spiders. This indicates that spiders and honeybees may use other flower characteristics, for example, olfactory cues, together with flower symmetry, to make their foraging decisions.     

Relative contribution of arms and legs in humans to propulsion in 25-m sprint front-crawl swimming

Eight male subjects were asked to swim 25 m at maximal velocity while the use of the arm(s) and legs was alternately restricted. Four situations were examined using one arm (1A), two arms (2A), one arm and two legs (1A2L) and both arms and legs (2A2L, normal swim) for propulsion. A significant mean increase of 10% on maximal velocity was obtained in 1A2L and 2A2L compared to 1A and 2A. A non-significant 4% effect was obtained in 1A. This study focused on the actual contribution of leg kick in the 10% gain in maximal velocity. It was clear that the underwater trajectory of the wrist was modified by the action of the legs (most comparisons P < 0.001). Therefore it was thought that the legs enhanced the generated propulsive force by improving the propulsive action of the arm. The arm action was quantified by selecting typical phases from the filmed trajectory of the wrist, namely forward (F), downwards (D) and backwards (B). Although there was a tendency for individual changes in kinematic parameters (F, D and B) to occur with individual changes in velocity when 2A was compared to 2A2L, no relationship was found between the relative changes in F, D and B and relative changes in velocity. This was illustrated by describing the responses of three individuals who could represent three patterns of contribution by legs and arms to propulsion in high speed swimming.     

A method for quantifying rotational symmetry

Here, a new approach for quantifying rotational symmetry based on vector analysis was described and compared with information obtained from a geometric morphometric analysis and a technique based on distance alone. A new method was developed that generates a polygon from the length and angle data of a structure and then quantifies the minimum change necessary to convert that polygon into a regular polygon. This technique yielded an asymmetry score (s) that can range from 0 (perfect symmetry) to 1 (complete asymmetry). Using digital images of Geranium robertianum flowers, this new method was compared with a technique based on lengths alone and with established geometric morphometric methods used to quantify shape variation. Asymmetry scores (s) more clearly described variation in symmetry and were more consistent with a visual assessment of the images than either comparative technique. This procedure is the first to quantify the asymmetry of radial structures accurately, uses easily obtainable measures to calculate the asymmetry score and allows comparisons among individuals and species, even when the comparisons involve structures with different patterns of symmetry. This technique enables the rigorous analysis of polysymmetric structures and provides a foundation for a better understanding of symmetry in nature.     

Take a breath and take the turn: how breathing meets turns in spontaneous dialogue

Physiological rhythms are sensitive to social interactions and could contribute to defining social rhythms. Nevertheless, our knowledge of the implications of breathing in conversational turn exchanges remains limited. In this paper, we addressed the idea that breathing may contribute to timing and coordination between dialogue partners. The relationships between turns and breathing were analysed in unconstrained face-to-face conversations involving female speakers. No overall relationship between breathing and turn-taking rates was observed, as breathing rate was specific to the subjects'' activity in dialogue (listening versus taking the turn versus holding the turn). A general inter-personal coordination of breathing over the whole conversation was not evident. However, specific coordinative patterns were observed in shorter time-windows when participants engaged in taking turns. The type of turn-taking had an effect on the respective coordination in breathing. Most of the smooth and interrupted turns were taken just after an inhalation, with specific profiles of alignment to partner breathing. Unsuccessful attempts to take the turn were initiated late in the exhalation phase and with no clear inter-personal coordination. Finally, breathing profiles at turn-taking were different than those at turn-holding. The results support the idea that breathing is actively involved in turn-taking and turn-holding.     

汉族湘语族群的7项不对称行为特征

在湖南省娄底地区调查了汉族湘语族群507例(男269例、女238例)高中学生的7项不对称行为特征(扣手、利手、叠臂、叠腿、利足、起步类型和优势眼)。研究结果显示:1)湘语族群叠臂与起步类型L型率高于R型率, 其余5项均R型率高于L型率。2)湘语族群利手、叠臂、利足出现率存在性别间差异, 其余4项出现率均不存在性别间差异。3)在已发表的资料中, 湘语族群扣手和起步类型右型率中等偏高, 利手右型率处于中等水平, 叠臂和叠腿右型率低,利足和优势眼右型率高。4)主成分分析结果显示, 汉族各族群不对称行为特征有一定的共性, 相对接近于中国北亚类型族群, 而与南亚类型族群差距较大。中国族群间不对称行为特征的差异, 主要反映在叠臂率差异、利足率差异。     

Functional foot symmetry and its relation to lower extremity physical performance in older adults: the Framingham Foot Study

BackgroundWhile many studies use gait symmetry as a marker of healthy gait, the evidence that gait symmetry exists is limited. Because gait symmetry is thought to arise through laterality (i.e., limb preference) and affects gait retraining efforts, it is important to understand if symmetry exists during gait in older adults. Therefore, the purpose of this study was to evaluate foot and gait symmetry in the population-based Framingham Foot Study as well as to determine the effects of vertical force symmetry on physical performance measures.MethodsMembers of the Framingham Foot Study were included in this analysis (N=1333). Foot function and force data were collected using the Tekscan Matscan during self-selected gait, with symmetry evaluated using the symmetry index. The short physical performance battery (SPPB) measures of balance, chair stands and gait speed assessed lower extremity physical function. Participants were evaluated using quartiles of gait speed and foot symmetry to determine the effects of symmetry on lower extremity physical function.ResultsIndividuals with faster gait speed displayed greater foot function asymmetry; individuals with ?3.0% to ?9.5% asymmetry in foot function performed better on the short physical performance battery (SPPB). Further, with aging, the degree of asymmetry was reduced.ConclusionsWhile this research suggests that a moderate degree of foot asymmetry is associated with better lower extremity function, the causes of vertical force asymmetry are unknown. Future studies should evaluate the causes of foot asymmetry and should track the changes in symmetry that occur with aging.     

The activity pattern of shoulder muscles in subjects with and without subacromial impingement

Altered shoulder muscle activity is frequently believed to be a pathogenetic factor of subacromial impingement (SI) and therapeutic interventions have been directed towards restoring normal motor patterns. Still, there is a lack of scientific evidence regarding the changes in muscle activity in patients with SI. The aim of the study was to determine and compare the activity pattern of the shoulder muscles in subjects with and without SI. Twenty-one subjects with SI and 20 healthy controls were included. Electromyography (EMG) was assessed from eight shoulder muscles from both shoulders during motion. In the symptomatic shoulder, there was a significantly greater EMG activity during abduction in the supraspinatus and latissimus muscles and less activity in serratus anterior compared to the healthy subjects. During external rotation, there was significantly less activity of the infraspinatus and serratus anterior muscles on the symptomatic side compared to the healthy subjects. On the asymptomatic side, the groups showed different muscle activity during external rotation. Our findings of an altered shoulder muscle activity pattern on both the symptomatic and asymptomatic side in patients indicate that the different motor patterns might be a pathogenetic factor of SI, perhaps due to inappropriate neuromuscular strategies affecting both shoulders.     

Voluntary induced alterations in regional ventilation in normal humans

We tested the hypothesis that voluntary changes of thoraco-abdominal shape can influence regional ventilation via altering regional pleural pressure swings (Ppl). Regional ventilation was measured simultaneously with regional Ppl during tidal volume breathing maneuvers in five normal subjects while they were performing one of three thoracoabdominal patterns of breathing: normal, preferential intercostal (IC), or preferential diaphragmatic (DIA). In every subject, the lower lung region's 133Xe washout rate was faster than the upper region's, regardless of the pattern of thoracoabdominal breathing adopted. Although IC breathing tended to make regional ventilation more homogeneous, DIA breathing tended to augment regional ventilation inhomogenities. On the average, the Ppl values were greatest in the lower lung region, regardless of the thoracoabdominal pattern adopted; however, IC breathing reduced and DIA breathing increased regional Ppl inhomogenities. When the ratios of the Ppl (lower/upper) were plotted vs. the ratios of the regional 133Xe washout decay constants (lower/upper), a significant positive correlation was found. These data suggest that a causal relation between regional tidal Ppl and regional ventilation exist, thus supporting the concept that thoracoabdominal shape changes can influence regional ventilation.