Morphological Asymmetry Research Articles

Progressive decline in old pole gene expression signal enhances phenotypic heterogeneity in bacteria.

Cell growth and gene expression are heterogeneous processes at the single-cell level, leading to the emergence of multiple physiological states within bacterial populations. Aging is a known deterministic driver of growth asymmetry; however, its role in gene expression heterogeneity remains elusive. Here, we show that aging mother cells undergo a progressive decline in old pole activity, generating asymmetry in protein partitioning, gene expression, and cell morphology. We demonstrate that mother cells, when compared to their daughters, exhibit lower product inheritance and gene expression rates independently of promoter dynamics. The declining activity of maternal old poles generates gene expression gradients that manifest as mother-daughter asymmetry upon division, showing that asymmetry is progressively built over time within the maternal intracellular environment. Moreover, old pole aging correlates with a gradual increase in cell length, leading to morphological asymmetry. These findings provide further evidence for aging as a mechanism to enhance phenotypic heterogeneity in bacterial populations, with possible consequences for stress response and survival.

Rapid Assessment of Morphological Asymmetries Using 3D Body Scanner and Bioelectrical Impedance Technologies in Sports: A Case of Comparative Analysis Among Age Groups in Judo

(1) Background: The advancement of technologies has made morphological assessment rapid and reliable. A combination of 3D body scanning (3D-BS) and bioelectrical impedance (BIA) could be essential in monitoring the morphological status of athletes and the general population and their symmetries for coaches, researchers and medical professionals. (2) Methods: The current study presents the use of Inbody-720 BIA and 3D-BS NX-16 for analyzing the asymmetry profile of an athlete in 2 min on a sample of 106 male judo competitors from the following age categories: older boys—U14 (N = 24), younger cadets—U16 (N = 31), cadets—U18 (N = 17), juniors—U21 (N = 19) and seniors (N = 15). Variables observed were arm lean mass, upper arm, elbow, forearm and wrist girth, leg lean mass, thigh length, thigh, knee and calf girth. The paired sample t-test, asymmetry index (AI) and Kruskal–Wallis analysis were used at p ≤ 0.05; (3) Results: Morphological asymmetries were detected in all age categories: seniors—three, U21—four, U18—three, U16—five and U14—four. The most common asymmetrical variable in all categories was the forearm girth, while thigh length, knee girth and upper arm girth presented symmetrical variables in all age categories. AI showed that the size of the asymmetries did not differentiate between the age groups. (4) Conclusions: The current study demonstrated great potential for combining BIA and 3D-BS for rapid asymmetry detection that would allow for monitoring and quick adjustments to the training process in youth to senior age categories.

Navicular Drop Height Asymmetry as an Intrinsic Risk Factor for Lower Limb Injury in Male Recreational Athletes

Morphological and functional asymmetry of the lower limbs is a well-recognized factor contributing to musculoskeletal injuries among athletes across different levels. However, limited research exists on evaluating foot mobility asymmetry as a potential predictor of such injuries. This study aimed to (1) assess the frequency of foot mobility asymmetries among amateur athletes, (2) investigate the predictive value of foot mobility asymmetry (measured via navicular height drop) for injury risk, and (3) explore the relationship between foot type and injury occurrence. A cross-sectional sampling method was employed to select 45 physically active male amateur athletes (runners and team sports practitioners) from a university. Injury history was retrospectively recorded, and a modified navicular drop test was conducted to classify foot arch height. The predictive power of navicular height drop asymmetry was analyzed using ROC curves, and the relationship between foot type (neutral and defective combinations—pronated or supinated) and injury occurrence was examined using chi-square tests for independence. Multiple logistic regression was applied to calculate injury risk odds ratios across different foot type subgroups. The results revealed a significant frequency (51.1%) of participants with at least one defective foot, including 31.1% with one neutral and one defective foot and 20% with both feet defective. Navicular height drop asymmetry emerged as a valuable predictor of injuries, with a 36% asymmetry identified as the cut-off for increased injury risk (AUC = 0.832, 95% CI: 0.691–0.973, p < 0.001). A significant relationship was found between foot type and injury occurrence. Only one out of 22 participants with neutral feet (4.55%) experienced an injury, compared to 9 out of 14 (64.29%) with one neutral and one defective foot and 5 out of 9 (55.56%) with both feet defective. These differences were statistically significant (χ2 = 16.24, p < 0.001, Cramer’s V = 0.60). The odds ratio for injury risk was 37.8 (p = 0.016) for those with asymmetry (one neutral and one defective foot) and 26.3 (p = 0.102) for those with both feet defective, compared to participants with both feet neutral. In clinical practice, these findings suggest that routine screenings for physically active individuals should incorporate foot mobility asymmetry assessment. However, it is essential to integrate this factor with other risk indicators. For individuals exhibiting high asymmetry, general foot defect correction programs may be beneficial, but injury prevention strategies should adopt a more comprehensive approach, focusing on overall fitness and tailored interventions for high-risk individuals.

Comparing the three-dimensional morphological asymmetries in the ejecta of Kepler and Tycho in X-rays

Aims. Recent simulations have shown that asymmetries in the ejecta distribution of supernova remnants (SNRs) may be a reflection of asymmetries left over from the initial supernova explosion. Thus, SNR studies provide a vital means for testing and constraining model predictions in relation to the distribution of heavy elements, which are key to improving our understanding of the explosion mechanisms in Type Ia supernovae. Methods. The use of a novel blind source separation method applied to the megasecond X-ray observations of the historic Kepler and Tycho supernova remnants has revealed maps of the ejecta distribution. These maps are endowed with an unprecedented level of detail and clear separations from the continuum emission. Our method also provides a three-dimensional (3D) view of the ejecta by individually disentangling red- and blueshifted spectral components associated with images of the Si, S, Ar, Ca, and Fe emission. This approach provides insights into the morphology of the ejecta distribution in those two remnants. Results. Those mappings have allowed us to thoroughly investigate the asymmetries in the intermediate-mass elements and Fe distribution in two Type Ia supernova remnants. We also compared the results with the core-collapse Cassiopeia A remnant, which we had studied previously. The images obtained confirm, as expected for Type Ia SNRs, that the Fe distribution is mostly closer to the core than that of intermediate-mass elements. They also highlight peculiar features in the ejecta distribution, such as the Fe-rich southeastern knot in Tycho.

UV‐Triggered Optical Asymmetry Modification of Gold Nanorods Helical Assemblies in a Cholesteric Liquid Crystal Host

AbstractThe creation and modulation of chirality innanomaterials is a well‐established and widely applied concept. Nevertheless, the direct approach of dynamically tuning their morphological asymmetry at thenanoscale to reveal their optical asymmetry variations is yet less well‐implemented. The helical templating of nanomaterials within a cholesteric liquidcrystal (CLC) host and the exploitation of their optical asymmetry change inconjunction with the host represent a means of circumventing technological limitations. In this study, a blending approach is employed to investigate the helical assemblies of gold nanorods (Au NRs) within a photo‐tunable CLC host, followed by their morphological asymmetry modulation through the use of UV irradiation. The results demonstrated that the optical asymmetry of the Au NR shelical assemblies increased in response to a reduction in pitch and the distance between the Au NRs, regardless of the azimuthal variations.Furthermore, the Au NRs blended with CLCs exhibited excellent and stable reflective properties comparable to those of conventional CLCs. Additionally,they can modulate the light flux of incident light at NIR wavelengths. The integrated modulation of reflection and transmission by Au NRs helical assemblies and CLC hosts represents a promising avenue for future research inthe field of multi‐level information encryption.

The “Twin Peaks” method of automated Spike-Wave detection: A two-step, two-criteria Matlab application

BackgroundThere are many automated spike-wave discharge detectors, but the known weaknesses of otherwise good methods and the varying working conditions of different research groups (mainly the access to hardware and software) invite further exploration into alternative approaches. New methodThe algorithm combines two criteria, one in the time-domain and one in the frequency-domain, exploiting morphological asymmetry and the presence of harmonics, respectively. The time-domain criterion is additionally adjusted by normal modelling between the first and second iterations. ResultsWe report specificity, sensitivity and accuracy values for 20 recordings from 17 mature, male WAG/Rij rats. In addition, performance was preliminary tested with different hormones, pharmacological injections and species (mice) in a smaller sample. Accuracy and specificity were consistently above 91 %. The number of automatically detected spike-wave discharges was strongly correlated with the numbers derived from visual inspection. Sensitivity varied more strongly than specificity, but high values were observed in both rats and mice. Comparison with existing methodsThe algorithm avoids low-voltage movement artifacts, displays a lower false positive rate than many predecessors and appears to work across species, i.e. while designed initially with data from the WAG/Rij rat, the algorithm can pick up seizure activity in the mouse of considerably lower inter-spike frequency. Weaknesses of the proposed method include a lower sensitivity than several predecessors. ConclusionThe algorithm excels in being a selective and flexible (based on e.g. its performance across rats and mice) spike-wave discharge detector. Future work could attempt to increase the sensitivity of this approach.

Development of Upper-Extremity Morphological Asymmetries in Male and Female Elite Youth Tennis Players: A Longitudinal Study.

This 2-year longitudinal study examined the development of upper-extremity bone mineral density (BMD), bone mineral content (BMC), and lean mass (LM) asymmetry magnitudes in male and female youth tennis players. Dominant and nondominant upper-extremity BMD, BMC, and LM values of 49 male and 31 female players were measured yearly using dual X-ray absorptiometry. From these values, asymmetry magnitudes were calculated and expressed as a percentage. Maturity offset was estimated using anthropometric measurements. Linear mixed effect models examined the development of BMD, BMC, and LM asymmetry magnitudes according to players' maturity offset, sex, and training volume. Adjusted for sex and training volume, a 1-year increment in maturity offset was associated with a significant increase in BMD (1.3% [2.2%]; P < .001) and BMC (0.6% [2.4%]; P = .011) asymmetry magnitudes. Male players displayed significantly higher LM asymmetry magnitudes (Δ3.2% [8.4%]; P = .002) compared with their female counterparts. Training volume was not significantly associated with asymmetry magnitude development. In contrast to LM, male and female youth tennis players' upper-extremity bones are still responsive to mechanical loading with a significant increase in BMD and BMC asymmetry magnitudes according to maturity offset.

Bimodal orientation distribution and head-tail asymmetry of a sample of filamentary molecular clouds

ABSTRACT The morphology of molecular clouds is crucial for understanding their origin and evolution. In this work, we investigate the morphology of the filamentary molecular clouds (filaments for short) using a portion of the 12CO(J = 1 − 0) data from the Milky Way Imaging Scroll Painting project. The data cover an area spanning 104.75° &amp;lt; l &amp;lt; 150.25°, |b| &amp;lt; 5.25° in Galactic coordinates, with VLSR ranging from −95 to 25 kms−1. Our primary focus is on the orientation and morphological asymmetry of the filaments. To achieve this, we apply several criteria on the data to create a sample of filaments with well-defined straight shape, and we use elliptical fitting to obtain the orientation of each filament, with an estimated error of ∼1.6° for the orientation. We find that the filament orientation with respect to the Galactic plane exhibits a bimodal distribution, a double-Gaussian fitting of which has two centres located at −38.1° and 42.0°, with 1σ of the two Gaussian functions being 35.4° and 27.4°. We do not find significant correlation between the orientation and other parameters, including the Galactic coordinates, radial velocity, velocity width, and physical scale. A considerable fraction of filaments (≳40 per cent) display head-tail asymmetry, which suggests that mass concentration tends to occur at one end of the filaments.

Relationships of lower extremity and trunk asymmetries in elite soccer players.

In light of previous research highlighting the prevalence of asymmetries in soccer players and possible links to injury risks, there is a crucial gap in the biomechanical understanding of complex relationships between lower extremity and trunk asymmetries in elite soccer players. The purpose of this study was to investigate the level, relationships, and differences among twelve different parameters of strength, morphological, and neuromuscular asymmetries in elite soccer players. Methods: Elite male soccer players (n = 25, age 21.7 ± 3.9years) were tested in the following tests: bilateral fluid distribution, hip flexor range of motion, postural stability, isokinetic strength of knee extensors and flexors, isometric lateral trunk rotation strength, eccentric strength of knee flexors, isometric bilateral strength of hip adductors, and vertical ground reaction force in counter-movement jump-free arms, counter-movement jump, squat jump, and drop jump tests. One-way ANOVA, Pearson's coefficient (r), and partial eta squared (η p 2) were used for data analysis. Results: Significant differences in asymmetries were found in elite soccer players (F11,299 = 11.01, p < .01). The magnitude of asymmetry over 10% was in postural stability and drop jump parameters. The lowest magnitudes of asymmetries were in the fluid distribution of the lower limbs and the vertical ground reaction force during the take-off phase in squat jumps. The highest asymmetries between the dominant and non-dominant sides were found in postural stability and drop jump. A total of eleven significant correlations (p < 0.05, r = 0.41-0.63, R2 = 0.17-0.40) were detected between the analyzed asymmetries in elite soccer players. The lateral trunk rotation asymmetries were significantly correlated to vertical ground reaction force asymmetries and knee extensors. Conclusion: Long-term exposure in elite soccer leads to unilateral biomechanical loading that induces abnormal strength and morphological adaptations in favor of the dominant side while linking lower limb and trunk strength asymmetries. By unraveling these complex relationships, we strive to contribute novel methods that could inform targeted training regimens and injury prevention strategies in the elite soccer community. The data should encourage future researchers and coaches to monitor and develop trunk strength linked to lower body kinematics.

Occurrence Probability of Magnetic Field Disturbances Measured With Swarm: Mapping the Dynamic Magnetosphere‐Ionosphere Coupling

AbstractThe exchange of kinetic and electromagnetic energy by precipitation and/or outflow and through field‐aligned currents are two aspects of the ionosphere‐magnetosphere coupling. A thorough investigation of these processes is required to better understand magnetospheric dynamics. Building on our previous study using the Defense Meteorological Satellite Program spectrometer data, here we use Swarm vector field magnetometer data to describe the auroral zone morphology in terms of east‐west magnetic field perturbations. We define a threshold for detecting magnetic fluctuations based on the power spectral density of ΔBEW, and derive the disturbed magnetic field occurrence probability (dBOP) at low [0.1–1 Hz] and high [2.5–5 Hz] frequencies. High‐frequency distributions of dBOP reveal a dayside‐nightside asymmetry, whereas low‐frequency dBOP exhibits a persistent morphological asymmetry between the dawn‐to‐noon and the dusk‐to‐midnight sectors, peaking at dawn. Notably, weak solar wind conditions are associated with an increase in the dBOP asymmetric patterns. At low frequency in particular, while the dBOP seems to be primarily constant at dawn, the dusk dBOP decreases during quiet times, inducing a relatively larger dawn‐dusk asymmetry in such conditions. Furthermore, based on a comparison analysis between low‐frequency dBOP and auroral electron precipitation occurrence probability, we suggest that both types of distribution offer a more comprehensive understanding of the large‐scale auroral zone when considered concurrently. Our interpretation is that the dBOP at low frequencies reflects a quasi‐steady state circulation of energy, while the high‐frequency dBOP reflects the regions of rapid changes in the magnetosphere. The dBOP is therefore a crucial source of information regarding the magnetosphere‐ionosphere coupling.

Morphoelastic models discriminate between different mechanisms of left-right asymmetric stomach morphogenesis

The mechanisms by which the vertebrate stomach undergoes its evolutionarily conserved leftward bending remain incompletely understood. Although the left and right sides of the organ are known to possess different gene expression patterns and undergo distinct morphogenetic events, the physical mechanisms by which these differences generate morphological asymmetry remain unclear. Here, we develop a continuum model of asymmetric stomach morphogenesis. Using a morphoelastic framework, we investigate the morphogenetic implications of a variety of hypothetical, tissue-level growth differences between the left and right sides of a simplified tubular organ. Simulations reveal that, of the various differential growth mechanisms tested, only one category is consistent with the leftward stomach curvature observed in wild-type embryos: equal left and right volumetric growth rates, coupled with transversely isotropic tissue thinning on the left side. Simulating this mechanism in a defined region of the model over a longer period of growth leads to mature stomach-like curvatures.

Three-dimensional analysis of mandibular morphology asymmetry and temporomandibular joint position in patients with unilateral Brodie bite.

Previous studies have shown unilateral posterior crossbite is associated with mandibular asymmetry in morphology and position. However, it remains unclear whether unilateral Brodie bite plays a similar role in mandibular development. Therefore, this study aims to investigate the morphological and positional symmetry of mandibles in patients with unilateral Brodie bite by three-dimensional anaylsis. Fourteen patients with unilateral Brodie bite (mean age 18.43 ± 4.24 years) and fourteen sex- and age-matched patients with normal occlusion (mean age 18.07 ± 5.48 years) underwent cone-beam computed tomography (CBCT) scans. 3D surface mesh models of their mandibles were established using Mimics Research 19.0. The surface matching percentage was compared between the original and mirrored mandible by Geomagic Control X software. Furthermore, the dimension and position of the temporomandibular joint (TMJ) were determined for both groups using InVivoDental 5.0. For surface-to-surface deviation analysis, the percentage of mismatch in patients with unilateral Brodie bite was significantly higher than the control group at ±0.50 mm, ±0.75 mm, and ±1.00 mm tolerance (P < .001). In patients with unilateral Brodie syndrome, the condyles on the scissors-bite side showed a significantly more anterior position (P = .03), greater medial inclination (P < .01), and larger posterior TMJ space (P = .01) than the non-scissors-bite side. Patients with unilateral Brodie bite exhibit a more asymmetrical mandibular morphology, with a greater anterior condylar position and posterior joint space on the scissors-bite side, indicating that early diagnosis and treatment may be necessary for patients with unilateral Brodie bite.

The neglected floral polymorphism: mirror-image flowers emerge from the shadow of heterostyly

Abstract Morphological asymmetries in plants and animals raise intriguing questions concerning their function and how they have evolved. One of the most conspicuous asymmetries in plants involves mirror-image flowers (enantiostyly) in which styles are deflected to either the left or right sides (L or R, respectively) of the flower. Species with this floral polymorphism often possess two types of stamens (heteranthery): centrally located feeding anthers and a pollinating anther orientated in the opposite direction to the style (reciprocal enantiostyly). However, some species lack heteranthery and sex-organ reciprocity can be partial or absent (non-reciprocal enantiostyly). Many enantiostylous species have nectarless flowers and are ‘buzz-pollinated’ by pollen-collecting bees. In contrast to other stylar polymorphisms such as heterostyly, enantiostyly exists as either monomorphic or dimorphic conditions, with L and R flowers on the same plant in the former, and genetically determined floral morphs with either L or R flowers in the latter. Enantiostyly has been reliably reported from 11 angiosperm families, but in only two is there convincing evidence that dimorphic enantiostyly occurs. Various hypotheses concerning developmental or selective constraints attempt to explain the rarity of this genetic polymorphism. Experimental studies on the function of enantiostyly indicate that the reciprocity of stigmas and pollinating anthers promotes pollinator-mediated cross-pollination and limits geitonogamous selfing. Insufficient or inferior pollinator service can result in the evolutionary breakdown of enantiostyly, including reduced stigma–anther separation, increased selfing, and dissolution of heteranthery. In this article we review recent advances and knowledge gaps in understanding these curious asymmetries and discuss why they have received less attention than heterostyly.

A multiscale characterization of cortical shape asymmetries in early psychosis.

Psychosis has often been linked to abnormal cortical asymmetry, but prior results have been inconsistent. Here, we applied a novel spectral shape analysis to characterize cortical shape asymmetries in patients with early psychosis across different spatial scales. We used the Human Connectome Project for Early Psychosis dataset (aged 16-35), comprising 56 healthy controls (37 males, 19 females) and 112 patients with early psychosis (68 males, 44 females). We quantified shape variations of each hemisphere over different spatial frequencies and applied a general linear model to compare differences between healthy controls and patients with early psychosis. We further used canonical correlation analysis to examine associations between shape asymmetries and clinical symptoms. Cortical shape asymmetries, spanning wavelengths from about 22 to 75 mm, were significantly different between healthy controls and patients with early psychosis (Cohen's d = 0.28-0.51), with patients showing greater asymmetry in cortical shape than controls. A single canonical mode linked the asymmetry measures to symptoms (canonical correlation analysis r = 0.45), such that higher cortical asymmetry was correlated with more severe excitement symptoms and less severe emotional distress. Significant group differences in the asymmetries of traditional morphological measures of cortical thickness, surface area, and gyrification, at either global or regional levels, were not identified. Cortical shape asymmetries are more sensitive than other morphological asymmetries in capturing abnormalities in patients with early psychosis. These abnormalities are expressed at coarse spatial scales and are correlated with specific symptom domains.

Morphological and metabolic asymmetries of the thalamic subregions in temporal lobe epilepsy predict cognitive functions

Both morphological and metabolic imaging were used to determine how asymmetrical changes of thalamic subregions are involved in cognition in temporal lobe epilepsy (TLE). We retrospectively recruited 24 left-TLE and 15 right-TLE patients. Six thalamic subnuclei were segmented by magnetic resonance imaging, and then co-registered onto Positron emission tomography images. We calculated the asymmetrical indexes of the volumes and normalized standard uptake value ratio (SUVR) of the entire and individual thalamic subnuclei. The SUVR of ipsilateral subnuclei were extensively and prominently decreased compared with the volume loss. The posterior and medial subnuclei had persistently lower SUVR in both TLE cases. Processing speed is the cognitive function most related to the metabolic asymmetry. It negatively correlated with the metabolic asymmetrical indexes of subregions in left-TLE, while positively correlated with the subnuclei volume asymmetrical indexes in right-TLE. Epilepsy duration negatively correlated with the volume asymmetry of most thalamic subregions in left-TLE and the SUVR asymmetry of ventral and intralaminar subnuclei in right-TLE. Preserved metabolic activity of contralateral thalamic subregions is the key to maintain the processing speed in both TLEs. R-TLE had relatively preserved volume of the ipsilateral thalamic volume, while L-TLE had relatively decline of volume and metabolism in posterior subnucleus.

Characterization of dynamic patterns of human fetal to neonatal brain asymmetry with deformation-based morphometry.

Despite established knowledge on the morphological and functional asymmetries in the human brain, the understanding of how brain asymmetry patterns change during late fetal to neonatal life remains incomplete. The goal of this study was to characterize the dynamic patterns of inter-hemispheric brain asymmetry over this critically important developmental stage using longitudinally acquired MRI scans. Super-resolution reconstructed T2-weighted MRI of 20 neurotypically developing participants were used, and for each participant fetal and neonatal MRI was acquired. To quantify brain morphological changes, deformation-based morphometry (DBM) on the longitudinal MRI scans was utilized. Two registration frameworks were evaluated and used in our study: (A) fetal to neonatal image registration and (B) registration through a mid-time template. Developmental changes of cerebral asymmetry were characterized as (A) the inter-hemispheric differences of the Jacobian determinant (JD) of fetal to neonatal morphometry change and the (B) time-dependent change of the JD capturing left-right differences at fetal or neonatal time points. Left-right and fetal-neonatal differences were statistically tested using multivariate linear models, corrected for participants' age and sex and using threshold-free cluster enhancement. Fetal to neonatal morphometry changes demonstrated asymmetry in the temporal pole, and left-right asymmetry differences between fetal and neonatal timepoints revealed temporal changes in the temporal pole, likely to go from right dominant in fetal to a bilateral morphology in neonatal timepoint. Furthermore, the analysis revealed right-dominant subcortical gray matter in neonates and three clusters of increased JD values in the left hemisphere from fetal to neonatal timepoints. While these findings provide evidence that morphological asymmetry gradually emerges during development, discrepancies between registration frameworks require careful considerations when using DBM for longitudinal data of early brain development.

Condition, Reproductive Fitness, and Fluctuating Asymmetry in Brook Stickleback: Responses to Anthropogenic Runoff

Multiple indicators have been used to assess the degree of exposure of fish to anthropogenic chemicals in their stream habitats. We hypothesized that brook stickleback (Culaea inconstans) in a headwater stream receiving urban and agricultural runoff (South Fork Whitewater River, SFWR) would exhibit poorer condition, reduced reproductive fitness, and a greater left side to right side morphological asymmetry (i.e., fluctuating asymmetry or FA) than fish from a nearby headwater stream with a forested drainage basin (Garvin Brook). Male and female fish were collected from both streams just prior to spawning in 2013–2015. In 2013 and 2014, fish were assessed for overall condition (Fulton’s K), internal measures of condition (hepatosomatic index, HSI) and reproductive fitness (gonadosomatic index [GSI], total oocyte count, and oocyte mass). In 2015, measurements of head length, jaw length, eye diameter, pectoral fin length, and pelvic fin length were made on both sides of each fish for assessing degree of FA. We observed declining condition with fish size, increased liver size, and reduced oocyte counts and oocyte size in female brook stickleback in SFWR relative to those from Garvin Brook. SFWR females had significantly higher FA than Garvin females for all structures assessed, except pelvic fin length. FA also was slightly higher for all structures in SFWR males compared to Garvin males, but differences were not significant. A composite FA index combining all measurements from an individual fish into a single value displayed highly significant differences for female fish (SFWR FA &gt;&gt; Garvin FA), but not for male fish (SFWR FA = Garvin FA). Exposure of brook stickleback to reduced water quality in SFWR during early development appears to increase morphological asymmetry in female (but not male) fish, and continuing exposure to compromised water quality throughout life impacts both general condition and reproductive fitness of stickleback, especially older female fish, in SFWR.

Direct Observation of Seeded Conformational Conversion of hIAPP In Silico Reveals the Mechanisms for Morphological Dependence and Asymmetry of Fibril Growth.

Rapid growth of amyloid fibrils via a seeded conformational conversion of monomers is a critical step of fibrillization and important for disease transmission and progression. Amyloid fibrils often display diverse morphologies with distinct populations, and yet the molecular mechanisms of fibril elongation and their corresponding morphological dependence remain poorly understood. Here, we computationally investigated the single-molecular growth of two experimentally resolved human islet amyloid polypeptide fibrils of different morphologies. In both cases, the incorporation of monomers into preformed fibrils was observed. The conformational conversion dynamics was characterized by a small number of fibril growth intermediates. Fibril morphology affected monomer binding at fibril elongation and lateral surfaces as well as the seeded conformational conversion dynamics at the fibril ends, resulting in different fibril elongation rates and populations. We also observed an asymmetric fibril growth as in our prior experiments, attributing to differences of two fibril ends in terms of their local surface curvatures and exposed hydrogen-bond donors and acceptors. Together, our mechanistic findings afforded a theoretical basis for delineating different amyloid strains-entailed divergent disease progression.

Effect of two larval diets on the reproductive parameters of the housefly, Musca domestica L. (Diptera, Muscidae)

Abstract Deep understanding of the optimal reproductive and biological parameters is necessary to obtain the maximum egg production in captive rearing of Musca domestica, the common housefly. The effect of larval diet is explored in this study, using two different media: poultry manure and an artificial medium based on cereals mixed with meat. The preimaginal mortality and development time, with other reproductive parameters that indirectly affect adult fecundity as: ovary and wing size, fluctuating asymmetry, and cuticular hydrocarbon composition, were analysed. The results show that poultry manure was related with better efficacy values, lower larval mortality rate, and a sex-dependent effect in fecundity. Asymmetry fluctuation and different hydrocarbon composition was detected in females. The females from larvae that grew on manure presented bigger ovaries and oocytes, but a smaller number of ovarioles per ovary. Their morphological asymmetry was also lower; and the cuticular hydrocarbon composition was distinct from the rest of the adults, with more alkanes and less alkenes than males or females related with the artificial diet. As conclusion, the effect of larval substrate on the survival and fecundity parameters is evident. The implications for the mass production of the house fly as animal feed are also indicated.

Analysis of the Anatomical Variations in Sylvian Fissure Using MRI

Abstract Background The most common surgical approach in neurosurgery to diagnose and treat tumors and aneurysms is the transylvian-pterional approach. The classification of Sylvian fissure (SF) was proposed based on pure anatomical observations by Yasargil. The SF is the most identifiable feature of the superolateral brain surface, which divides the parietal and frontal lobes from the temporal lobe which lies below. Aim The aim was to identify the anatomical variations in SF (bilaterally) in the normal population and to identify its morphological asymmetry. Setting and Design This was a retrospective, observational descriptive record-based study which was done to identify the anatomical variations and morphological asymmetry in SF (bilaterally) in the normal healthy population using a 1.5-T magnetic resonance imaging (MRI) system. Materials and Methods The SF was classified into five types. The categorization of the SF was done by MRI, either using T1-weighted images in three planes. Statistical Analysis Percentage and frequency using SPSS 23.0. Results In this study, we found that type 4 was most common in the general population of 100 patients. We found type 1 was most common in age groups above 50 up to 60 years of age. Types 2 and 4 SF were found in all age groups. Bilateral presentation of the SF can be considered as symmetric in 85% of the general population and asymmetric in 15% of the population considered in this study. Conclusion Classification of the SF types on MRI was shown to be reliable and practicable. Sound knowledge of SF anatomy before neurosurgery can help reduce procedure-related morbidity, ischemic lesions, or edema.