Asymmetry In Response Research Articles

Positive asymmetric responses indicate larger carbon sink with increase in precipitation variability in global terrestrial ecosystems

<p>Climate changes have caused high inter-annual variability in precipitation. However, how the terrestrial ecosystem responds to precipitation variability remains unclear. Using global remote sensing data and a meta-analysis by synthesizing 800 pairwise observations of experimental manipulations worldwide, we quantified the responses of the terrestrial ecosystem net carbon productivity (NEP) to precipitation variability. The results indicate that NEP displays a positive asymmetry in response to precipitation change, e.g., the magnitude of the increase in NEP (33.4%) under water-addition treatments is larger than that of the decline in NEP (-24.62%) under water-reduction treatments. The positive asymmetry of NEP in arid regions (< 500 mm) is larger than that in humid regions (> 500 mm). The former is mainly due to the positive asymmetry in vegetation productivity, while the latter results from the respiration process, i.e., the decrease in soil respiration in water-reduction treatments is stronger than in water-addition treatments. Furthermore, land models reproduce a positive NEP asymmetry in response to precipitation change, but display poor performance in ecosystem respiration (ER) responses owing to uncertainties in simulating soil water content (SWC). The positive asymmetry of NEP in this study implies that the increase in precipitation variability (except extreme anomalies) is conducive to high carbon sink in the global terrestrial ecosystem. Meanwhile, the performance of the models when simulating SWC in response to precipitation in humid regions needs to be further improved to better predict the carbon sink in the terrestrial ecosystem.</p>

Functional Near‐Infrared Spectroscopy‐Based Computer‐Aided Diagnosis of Major Depressive Disorder Using Convolutional Neural Network with a New Channel Embedding Layer Considering Inter‐Hemispheric Asymmetry in Prefrontal Hemodynamic Responses

Background. Functional near‐infrared spectroscopy (fNIRS) is being extensively explored as a potential primary screening tool for major depressive disorder (MDD) because of its portability, cost‐effectiveness, and low susceptibility to motion artifacts. However, the fNIRS‐based computer‐aided diagnosis (CAD) of MDD using deep learning methods has rarely been studied. In this study, we propose a novel deep learning framework based on a convolutional neural network (CNN) for the fNIRS‐based CAD of MDD with high accuracy. Materials and Methods. The fNIRS data of participants—48 patients with MDD and 68 healthy controls (HCs)—were obtained while they performed a Stroop task. The hemodynamic responses calculated from the preprocessed fNIRS data were used as inputs to the proposed CNN model with an ensemble CNN architecture, comprising three 1D depth‐wise convolutional layers specifically designed to reflect interhemispheric asymmetry in hemodynamic responses between patients with MDD and HCs, which is known to be a distinct characteristic in previous MDD studies. The performance of the proposed model was evaluated using a leave‐one‐subject‐out cross‐validation strategy and compared with those of conventional machine learning and CNN models. Results. The proposed model exhibited a high accuracy, sensitivity, and specificity of 84.48%, 83.33%, and 85.29%, respectively. The accuracies of conventional machine learning algorithms—shrinkage linear discriminator analysis, regularized support vector machine, EEGNet, and ShallowConvNet—were 73.28%, 74.14%, 62.93%, and 62.07%, respectively. Conclusions. In conclusion, the proposed deep learning model can differentiate between the patients with MDD and HCs more accurately than the conventional models, demonstrating its applicability in fNIRS‐based CAD systems.

Age-related differences in the interhemispheric asymmetry of local cortical responses to abstract and concrete verbs in children: a magnetic mismatch negativity study

BACKGROUND: The development of brain neural networks that support lexico-semantic processing in children remains a poorly understood topic in neuroscience. Meanwhile, investigations in adults have provided ample evidence regarding the brain circuits underpinning the processing of abstract and concrete semantics. These studies have shown that interhemispheric asymmetry in neural responses across modal and amodal cortical areas might be an important marker that helps in distinguishing these two types of semantics, with more left-lateralized activity patterns for abstract than concrete word comprehension. However, little is known about such distinctions in children; thus, addressing this gap was the goal of this study. AIM: This study aimed to investigate age-related differences in the lateralization of neural response patterns associated with the processing of abstract and concrete semantics in children. METHODS: This study employed magnetoencephalography and a mismatch negativity (MMN) paradigm in a group of 41 healthy children aged 5–13 years. The participants were passively exposed to the auditory series of abstract and concrete Russian verbs presented outside the focus of attention. Spatiotemporal patterns of the dynamics of neuromagnetic sources activity were reconstructed using minimum-norm estimate within predefined regions of interest: primary auditory cortex, primary motor cortex, and inferior frontal gyrus of both hemispheres. The magnitudes of MMN responses were further compared statistically between the two hemispheres within two age groups: younger (aged 5–9 years) and older (aged 10–13 years) children. RESULTS: Regionally specific differences were found in the lateralization of event-related MMN responses to concrete compared with abstract words in motor and inferior frontal cortical areas (paired permutation tests, p 0.05). Moreover, in the younger group (aged 5–9 years), responses to the abstract and pseudoword stimulus were left-lateralized, and this effect was most pronounced in the inferior frontal regions (45 and 47 Brodmann fields) of the left hemisphere. In the older group (aged 10–13 years), no pronounced left-lateralized response was observed in these areas. However, for the concrete hand action verb stimulus, different patterns of the interhemispheric asymmetry of the hand motor area responses were observed: the response in the younger group was right-lateralized, whereas in the older group, the response was bilateral. CONCLUSION: The present area- and hemisphere-specific dynamics of neuromagnetic responses in the motor cortex and Broca’s area might correlate with the age-related changes in neurocognitive strategies for the comprehension of abstract and concrete language.

Mathematical modeling of corneal hysteresis

Mathematical modeling of the deformation of the eyeball under the external pressure applied to the cornea in a bounded area and gradually increasing and then decreasing according to a given law is performed. This relationship corresponds to the change in applied pressure in the ocular response analyzer (ORA) used in clinic. An approach pre-viously developed by the authors is applied, based on representing the cornea as a soft two-dimensional surface and the scleral region as a zero-dimensional element. Since the process under consideration occurs very quickly (lasting several tens of milliseconds), it cannot be considered as purely elastic. The Voigt viscoelasticity of the cornea is taken into account, the smallness of the strain relaxation time allowing us to consider the solu-tion as a correction to a similar purely elastic problem considered at the previous stage of research. The behavior of two parameters characterizing the asymmetry of the system's response to a symmetrical action is studied. These are the delay time of the moment of maximum flattening of the cornea in the apical region during unloading compared to the moment of its flattening during loading and the difference in external pressures at which these flattenings are reached (corneal hysteresis). Their values obtained from the simula-tion are of the same order as the same values determined experimentally. It is shown that hysteresis increases with increasing strain relaxation time and with increasing maximum external pressure.

Editorial: The asymmetry of real estate market responses

Editorial: The asymmetry of real estate market responses

Creep behavior of titanium alloy used in deep-sea pressure shell considering tensile/compressive asymmetry: Experiments and numerical modeling

Titanium alloy pressure shell of deep-sea submersible suffers from room-temperature creep problem, which can affect the safety of the structure. There is currently a lack of research on the tensile/compressive asymmetry of the creep response of titanium alloy structures at room temperature. In this paper, room-temperature creep behavior and mechanism of titanium alloy were investigated by creep test of twisting of titanium alloy square plate. Taking cylindrical pressure shell with geometrical imperfection and multi-sphere pressure shell as examples, the creep mechanical behavior of titanium alloy pressure shells under complex stress states were investigated by numerical simulation. It is found that only under tensile stress can slip bands move across phase boundaries, resulting in tensile/compressive asymmetry in creep behavior. The proposed DTC model can accurately describe the room-temperature creep behavior of titanium alloy structures. For cylindrical pressure shell with geometrical imperfection, creep deformation results in a 121 % increase in the magnitude of geometrical imperfection. The results obtained with the tensile model towards the conservative side. For multi-sphere pressure shell, the evolution of physical quantities cannot be accurately described without considering the tensile/compressive asymmetry in creep properties. The range of relative error when using traditional models is between 5% and 33%.

Venous malformation as a rare cause of sciatic neuropathy

Sciatic neuropathy is rare and difficult to diagnose in pediatrics and often associated with difficult to control neuropathic pain. The most common causes of sciatic nerve damage in children include trauma and iatrogenic lesions, less often the cause is tumor and vascular formations, among which intraneural venous malformations are the rarest. We present a clinical case of a 13-year boy suffered from right sciatic pain neuropathy with unexpressed neuropathic pain syndrome, asymmetry of the feet, scant impairment of motor and sensory function of the limb for five years, which changed the gait. Neurophysiological testing showed possible location of the process, an asymmetry of sensory and motor responses when testing the nerves of the legs, and abnormal EMG in sciatic-innervated muscles. The magnetic resonance imaging (MRI) showed focal enlargement of the right sciatic nerve in the pelvic region with enhancement upon administration of contrast. Due to the presence of pain in the limb and its forced position — bent at the knee joint, surgical treatment — endoneural neurolysis in combination with targeted therapy by immunosuppressant, was chosen as a therapeutic strategy. The histological study of the intraneural formation confirmed the presence of a venous malformation (VM) in the form of heterogeneous thick– and thin-walled vascular cavities by the presence of fibrosis and lymphocytic infiltration. The result of the treatment was the relief of neuropathic pain syndrome and the recovering of the child gait.

Analysis of Error Sources in the Lissajous Scanning Trajectory Based on Two-Dimensional MEMS Mirrors

Deviations or distortions in the trajectoy of MEMS-based Lissajous scanning imaging platforms might be detrimental to imaging quality. These deviations often arise from differences in MEMS mirror frequency response characteristics and asymmetry in parameters within the measurement and control circuit. This study concentrated on the measurement and control circuit unit as it identified and analyzed four error sources: the MEMS mirror frequency response error, the AD acquisition synchronization error, the drive source error, and the cross-coupling error between the MEMS mirror axes. This study constructed a Lissajous trajectory test platform based on oscilloscopes and a position sensitive detector. Consequently, its experimental results guided the error processing methods to access the feasibility of the compensation methods by combining measured trajectories. Overall, regarding MEMS-based Lissajous scanning platforms for biomedical imaging, this study could provide quantitative numerical references for error analysis, image reconstruction, and aberration correction.

Manipulating the Fourier spectra of stimuli comprising a two-frame kinematogram to study early visual motion-detecting mechanisms: Perception versus short latency ocular-following responses.

Two-frame kinematograms have been extensively used to study motion perception in human vision. Measurements of the direction-discrimination performance limits (Dmax) have been the primary subject of such studies, whereas surprisingly little research has asked how the variability in the spatial frequency content of individual frames affects motion processing. Here, we used two-frame one-dimensional vertical pink noise kinematograms, in which images in both frames were bandpass filtered, with the central spatial frequency of the filter manipulated independently for each image. To avoid spatial aliasing, there was no actual leftward-rightward shift of the image: instead, the phases of all Fourier components of the second image were shifted by ±¼ wavelength with respect to those of the first. We recorded ocular-following responses (OFRs) and perceptual direction discrimination in human subjects. OFRs were in the direction of the Fourier components' shift and showed a smooth decline in amplitude, well fit by Gaussian functions, as the difference between the central spatial frequencies of the first and second images increased. In sharp contrast, 100% correct perceptual direction-discrimination performance was observed when the difference between the central spatial frequencies of the first and second images was small, deteriorating rapidly to chance when increased further. Perceptual dependencies moved closer to the OFR ones when subjects were allowed to grade the strength of perceived motion. Response asymmetries common for perceptual judgments and the OFRs suggest that they rely on the same early visual processing mechanisms. The OFR data were quantitatively well described by a model which combined two factors: (1) an excitatory drive determined by a power law sum of stimulus Fourier components' contributions, scaled by (2) a contrast normalization mechanism. Thus, in addition to traditional studies relying on perceptual reports, the OFRs represent a valuable behavioral tool for studying early motion processing on a fine scale.

Asymmetric response of gross primary productivity to precipitation changes over China’s karst areas

China’s karst areas play an important role in regulating the global carbon dynamic and mitigating atmospheric CO2 concentration. Yet, extreme drought events have occurred frequently in recent years over China’s karst areas, which have a negative effect on the gross primary productivity (GPP) in the region. It is unclear whether gross primary productivity gains in the wet years can compensate for its losses in the dry years over the karst areas. In this study, we selected the asymmetry indices to assess the potential asymmetric response of gross primary productivity to the change in precipitation over China’s karst areas during the 2003 to 2018 period, using the gross primary productivity and precipitation dataset. Our results show that the gross primary productivity exhibits a positive asymmetry in response to precipitation changes, namely, the gains caused by increased precipitation in the wet years overcompensate the losses caused by decreased precipitation in the dry years. In addition, the gross primary productivity asymmetry shows an increasing trend over the study period despite extreme drought events occurring frequently, which is due to the response of gross primary productivity to drought has significantly decreased over the study period. For each biome, grasslands show the highest positive gross primary productivity asymmetry, indicating that the grassland biomes have a stronger capacity to utilize the increased precipitation during the wet years to increase gross primary productivity compared to other biomes. Furthermore, the gross primary productivity asymmetry over China’s karst areas can be effected by the precipitation asymmetry as well as mean annual precipitation. Our results will contribute to our knowledge of the response of gross primary productivity to precipitation changes in the karst areas of China.

Wholesale price rigidities and exchange rate pass-through: Evidence from daily data of agricultural products

We provide insights into the extent of rigidities and the exchange rate pass-through (ERPT) of wholesale food prices at the regional level in a small open emerging economy. Notably, we utilize a novel and extensive micro-database of wholesale prices in markets within the principal and intermediate Colombian cities. The granularity of the data provides the advantage of assessing whether temporal and spatial aggregation procedures conceal transmission channels from the exchange rate to wholesale agricultural prices. Our initial exploratory analysis of wholesale pricing characteristics suggests that the Colombian food sector demonstrates moderate price rigidity, with fewer price asymmetries in response to positive and negative exchange rate fluctuations. Furthermore, cross-section results indicate a lifelong ERPT of 27% in our preferred model specification. Moreover, outcomes from a non-linear autoregressive distributed lag (NARDL) analysis show cointegration between the exchange rate and wholesale prices in 81% of the cases, complete exchange rate pass-through (with notable heterogeneity across products), and less prevalence of price asymmetries.

Asymmetries in responses to group-based relative deprivation: The moderating effects of group status on endorsement of right-wing ideology

Feelings of group-based relative deprivation (GRD) motivate collective responses to defend the ingroup. As such, there may be status-based asymmetries in the associations GRD has with ideologies that perpetuate inequality—namely, right-wing authoritarianism (RWA) and social dominance orientation (SDO). Study 1 examined this hypothesis using a national sample of adults ( N = 41,007) and revealed that the correlations GRD had with RWA and SDO were positive among members of a high-status group but negative among members of low-status groups. Study 2 examined these associations longitudinally ( N = 22,083) across eight annual assessments. Although a traditional cross-lagged panel analysis identified status-based asymmetries in the longitudinal associations between our variables of interest, analyses partitioning between-person stability from within-person change found no evidence that GRD leads to differences in RWA or SDO (or vice versa). The theoretical and practical implications of these results are discussed.

Nuances in intensity deviant asymmetric responses as a biomarker for tinnitus.

We attempted to replicate a potential tinnitus biomarker in humans based on the Sensory Precision Integrative Model of Tinnitus called the Intensity Mismatch Asymmetry. A few advances on the design were also included, including tighter matching of participants for gender, and a control stimulus frequency of 1 kHz to investigate whether any differences between control and tinnitus groups are specific to the tinnitus frequency or domain-general. The expectation was that there would be asymmetry in the MMN responses between tinnitus and control groups at the tinnitus frequency, but not at the control frequency, where the tinnitus group would have larger, more negative responses to upward deviants than downward deviants, and the control group would have the opposite pattern or lack of a deviant direction effect. However, no significant group differences were found. There was a striking difference in response amplitude to control frequency stimuli compared to tinnitus frequency stimuli, which could be an intrinsic quality of responses to these frequencies or could reflect high frequency hearing loss in the sample. Additionally, the upward deviants elicited stronger MMN responses in both groups at tinnitus frequency, but not at the control frequency. Factors contributing to these discrepant results at the tinnitus frequency could include hyperacusis, attention, and wider contextual effects of other frequencies used in the experiment (i.e. the control frequency in other blocks).

Walking speed differentially affects lower extremity biomechanics in individuals with anterior cruciate ligament reconstruction compared to uninjured controls

BackgroundWalking biomechanics are commonly affected after anterior cruciate ligament reconstruction and differ compared to uninjured controls. Manipulating task difficulty has been shown to affect the magnitude of walking impairments in those early after knee surgery but it is unclear if patients in later phases post-op are similarly affected by differing task demands. Here, we evaluated the effects of manipulating walking speed on between-limb differences in ground reaction force and knee biomechanics in those with and without anterior cruciate ligament reconstruction. MethodsWe recruited 28 individuals with anterior cruciate ligament reconstruction and 20 uninjured control participants to undergo walking assessments at three speeds (self-selected, 120%, and 80% self-selected speed). Main outcomes included sagittal plane knee moments, angles, excursions, and ground reaction forces (vertical and anterior-posterior). FindingsWe observed walking speed differentially impacted force and knee-outcomes in those with anterior cruciate ligament reconstruction. Between-limb differences increased at fast and decreased at slow speeds in those with anterior cruciate ligament reconstruction while uninjured participants maintained between-limb differences regardless of speed (partial η2 = 0.13–0.33, p < 0.05). Anterior cruciate ligament reconstruction patients underloaded the surgical limb relative to both the contralateral, and uninjured controls in GRFs and sagittal plane knee moments (partial η2 range = 0.13–0.25, p < 0.05). InterpretationOverall, our findings highlight the persistence of walking impairments in those with anterior cruciate ligament reconstruction despite completing formal rehabilitation. Further research should consider determining if those displaying larger changes in gait asymmetries in response to fast walking also exhibit poorer strength and/or joint health outcomes.

Spatial Auditory Masking Affects the Interhemispheric Asymmetry of Evoked Responses

Interhemispheric asymmetry of electrical brain activity was investigated in the conditions of spatial auditory masking. Moving test signals were presented either in silence or against the background of stationary maskers of various spatial positions. The spatial properties of the stimuli were defined by interaural level differences (ILD). Onset-energy responses (ON-responses), motion-onset responses (MOR) and OFF-responses were analyzed. To compute the topograms and to analyze asymmetry, the amplitudes of each component were averaged over the symmetric electrode clusters in the left and right hemispheres. The ON-responses showed a contralateral dominance of the N1 component in silence, and the degree of contralateral bias increased in masking conditions. Interhemispheric asymmetry of the P2 component was absent in silence. However, the P2 amplitude was higher in the right hemisphere in all combinations of masker and signal. The asymmetry of both deflections was maximal when the masker and the initial portion of the signal were separated by 180 degrees. On the contrary, the interhemispheric asymmetry of the motion-onset response was found only in silence: the cN1 deflection was biased to the side contralateral to the signal. The topography of the OFF-response was symmetrical under all experimental conditions.

Drivers of WACR-Repo Rate Spread: An Empirical Analysis of India

The spread between the policy rate and operating target rate of the Reserve Bank of India (RBI) has consequences on the transmission of monetary policy signals. Using weekly data from 2011 to 2020 (504 observations), the study employs variants of General Auto Regressive Conditional Heteroskedastic model to comprehensively analyse the factors that drive this spread. Besides the factors retrieved from the literature, this study also gauges the impact of COVID-19 on the spread and its volatility. The results indicate that the spread is significantly impacted by its lag, volume of transactions in the counterpart markets, distribution pattern of the liquidity by the central bank, foreign market intervention, liquidity adjustment facility (LAF), currency in circulation and reserve requirement while market expectations and government cash balances are found to be non-significant. Besides, announcement effect of COVID and changes in key rates are found to be significant. The results of Exponential GARCH do not find significant asymmetry in response to positive and negative shocks on the spread. Volatility in the spread is comparatively more responsive to its lags than to the market shocks.

Interhemispheric Asymmetry of the Thermospheric Neutral Density Response to the 7–9 September 2017 Geomagnetic Storms

AbstractThe thermospheric neutral density response to the 7–9 September 2017 storms is investigated based on the Swarm satellite observations and the thermosphere‐ionosphere‐electrodynamic general circulation model (TIEGCM) simulation. The Swarm data depicted a prominent interhemispheric asymmetry (IHA) in the afternoon sector during the second storm, a feature that was yet explained. Driven by realistic high‐latitude electric potential and electron precipitation patterns, the TIEGCM is able to reproduce the observed storm‐time neutral density response. The TIEGCM simulation reveals that the differences in the traveling atmospheric disturbances (TADs) is largely responsible for the observed IHA in the neutral mass density response at low and middle latitudes, whereas the difference in mean molecular mass between the two hemispheres may contribute to the IHA in neutral density at higher latitudes. The IHAs in TADs and mean molecular mass are attributed to the IHA in Joule heating dissipation on the night and dawn sides.

Ideological values are parametrically associated with empathy neural response to vicarious suffering.

Several studies in political psychology reported higher levels of empathy among political leftists (i.e. liberals) as compared to political rightists (i.e. conservatives). Yet, all those studies lean on self-reports, which are often limited by subjective bias and conformity to social norms. Here, we tested this putative asymmetry using neuroimaging: we recorded oscillatory neural activity using magnetoencephalography while 55 participants completed a well-validated neuroimaging paradigm for empathy to vicarious suffering. The findings revealed a typical rhythmic alpha-band 'empathy response' in the temporal-parietal junction. This neural empathy response was significantly stronger in the leftist than in the rightist group. In addition to this dichotomous division, the neural response was parametrically associated with both self-reported political inclination and right-wing ideological values. This is the first study to reveal an asymmetry in the neural empathy response as a function of political ideology. The findings reported in this study are in line with the current literature in political psychology and provide a novel neural perspective to support the ideological asymmetry in empathy. This study opens new vistas for addressing questions in political psychology by using neuroimaging.

Changes of dorsoventral asymmetry and anoxygenic photosynthesis in response of Chelidonium majus leaves to the SiO&lt;sub&gt;2&lt;/sub&gt; nanoparticle treatment

Changes of dorsoventral asymmetry and anoxygenic photosynthesis in response of Chelidonium majus leaves to the SiO&lt;sub&gt;2&lt;/sub&gt; nanoparticle treatment

Brain Lateralization for Language, Vocabulary Development and Handedness at 18 Months

Is hemisphere lateralization for speech processing linked to handedness? To answer this question, we compared hemisphere lateralization for speech processing and handedness in 18-month-old infants, the age at which infants start to produce words and reach a stable pattern of handedness. To assess hemisphere lateralization for speech perception, we coupled event-related potential (ERP) recordings with a syllable-discrimination paradigm and measured response differences to a change in phoneme or voice (different speaker) in the left and right clusters of electrodes. To assess handedness, we gave a 15-item grasping test to infants. We also evaluated infants’ range of vocabulary to assess whether it was associated with direction and degree of handedness and language brain asymmetries. Brain signals in response to a change in phoneme and voice were left- and right-lateralized, respectively, indicating functional brain lateralization for speech processing in infants. Handedness and brain asymmetry for speech processing were not related. In addition, there were no interactions between the range of vocabulary and asymmetry in brain responses, even for a phoneme change. Together, a high degree of right-handedness and greater vocabulary range were associated with an increase in ERP amplitudes in voice condition, irrespective of hemisphere side, suggesting that they influence discrimination during voice processing.