Decrease In Path Length Research Articles

Path planning of PRM based on artificial potential field in radiation environments

The radiation environment in nuclear facility work sites is complex. To ensure the safety of personnel working in these environments, it is essential to develop an optimal path planning method based on the criterion of personnel radiation dose. In this paper an improved probabilistic roadmap algorithm (APF-PRM) is proposed based on the combination of artificial potential fields (APF) and probabilistic roadmap algorithm (PRM) for path planning in complex static radiation environments. The entire two-dimensional dose field model of the radiation environment is constructed using bilinear interpolation based on simulation data from Geant4. Using this dose field model and the personnel radiation dose calculation model, the new algorithm is integrated with the A* algorithm to perform path planning in the radiation environment. To assess the performance of the APF-PRM algorithm, a comparison with other algorithms is made in four cases. In the first case, the computation speed of APF-PRM algorithm is significantly faster than that of the conventional A* algorithm in the same environment. In case 2, a reduction of 16.25% in cumulative personnel radiation dose is observed when compared with the traditional PRM algorithm, and the results from multiple repetitions of the experiment display higher stability. In case 3 a comparison between the APF-PRM algorithm and the Voronoi diagram is made, revealing a 36.92% reduction in cumulative dose, along with a 16.49% decrease in path length. In case 4, the four algorithms, A*, APF-PRM, PRM, and Voronoi, are comprehensively compared under the same circumstances, and the parameters of the APF-PRM algorithm that meets the requirements of minimum dose and optimal path are found.

Synergy between vegetation patterns and sedimentation has a temporal effect on water erosion in a slope‐gully system

AbstractMultiple soil and water conservation measures applied together perform better at reducing runoff and sedimentation than individual measures, which can be attributed to their synergistic effects on water erosion. However, whether these synergistic effects are always effective at reducing water erosion remains unclear. In this study, a series of physical models representing a slope‐gully system were tested to quantify the trend of synergistic effects of multi‐measure over time through simulated rainfall. The tested scenarios included four vegetation patterns on the slope—Pattern A: no grass, Pattern B: grass on the up‐slope, Pattern C: grass on the middle‐slope and Pattern D: grass on the down‐slope—and five levels of runoff path length decrease (RPLD) in the gully caused by sedimentation of a check dam (0, 1, 2, 3 and 4 m). Synergistic effects on runoff and sediment yields were influenced by vegetation patterns and RPLDs. Under the same vegetation patterns, synergistic effects increased with increase of RPLD. Under the same RPLD, the mean value of synergistic effects on runoff was in the following order: Pattern D (0.10%) > Pattern C (0.09%) > Pattern B (0.06%), and synergistic effects on sediment yields had a similar order: Pattern D (0.60%) > Pattern C (0.42%) > Pattern B (0.22%). Under Pattern B, based on the Mann–Kendall trend test, the synergistic effects on the runoff yields decreased over time. Contrastingly, under Patterns C and D, the synergistic effects on the runoff yields increased over time. The results show that the synergistic effect has time effect, and its change trend is related to vegetation patterns. Additionally, the results suggest that the middle‐ and lower‐slopes should be prioritized when restoring vegetation as the synergistic effects on runoff tend to increase when these have good vegetation cover.

Synergistic effects of vegetation restoration and check dams on water erosion in a slope‐gully system

AbstractRestoring vegetation and constructing check dams are important measures for controlling water erosion in slope‐gully systems. However, percolation through the dam body could lead to shortened runoff paths in the gully. Moreover, the synergistic effects of vegetation patterns and siltation‐induced runoff path length decrease (RPLD) in slope‐gully systems on reducing water erosion remain unclear. In this study, 20 physical models of slope‐gully systems were constructed to quantitatively evaluate the synergistic effect of these measures under simulated rainfall. The models included four slope vegetation patterns (no vegetation, up‐slope, middle‐slope, and down‐slope) and five levels of RPLD in the gully (0, 1, 2, 3, and 4 m). Owing to synergistic effects, combined measures led to a more considerable reduction in soil and water loss than a single measure. Furthermore, the synergistic effect was related to vegetation patterns and shorter siltation‐induced runoff paths. The mean synergistic effect produced the following runoff yield order: down‐slope (2.84%) > middle‐slope (2.81%) > up‐slope (1.78%); and 4 m (3.18%) > 3 m (2.66%) > 2 m (2.29%) > 1 m (1.78%). The sediment yields were in the following order: down‐slope (18.15%) > middle‐slope (12.63%) > up‐slope (6.67%), and 4 m (14.56%) > 3 m (12.82%) > 2 m (11.73%) > 1 m (10.82%). These results suggest that revegetation of the lower parts of the slope, along with check dams, will be more effective for controlling soil erosion. Such synergistic effects should be considered in future soil erosion modeling.

Brain network deficits in breast cancer patients after early neoadjuvant chemotherapy: A longitudinal MRI study.

Breast cancer (BC) patients who undergo chemotherapy are likely to develop chemotherapy-related cognitive impairment (CRCI). Recent studies of BC patients after chemotherapy have used graph theory to investigate the topological properties of the brain functional connectome. However, little is known about structural morphological networks in BC patients after early neoadjuvant chemotherapy (NAC). Brain morphological network organization in 47 female participants with BC was investigated before and after NAC. Topological properties of brain networks were ascertained based on morphological similarities in regional gray matter using a graph theory approach based on 3D T1-weighted MRI data. Nonparametric permutation testing was used to assess longitudinal-group differences in topological metrics. Compared with BC patients before NAC, BC patients after early NAC showed significantly increased global efficiency (p=.048), decreased path length (p=.033), and abnormal nodal properties and connectivity, mainly located in the central executive network (CEN). The change in the network efficiency of the right caudate was negatively correlated with the change in the Self-Rating Anxiety Scale score (r=-.435, p=.008), and the change in the nodal degree of the left superior frontal gyrus (dorsolateral part) was positively correlated with the change in the Functional Assessment of Cancer Therapy score (r=.547, p=.002). BC participants showed randomization in global properties and dysconnectivity in the CEN after early NAC. NAC may disrupt the cognitive balance of the brain morphological network in individuals with BC.

Impact of changes in river network structure on hydrological connectivity of watersheds

River network connectivity is a key factor affecting watershed ecosystems and an important criterion for evaluating the health of river. The river network structure of the basin has changed dramatically in recent years due to human activity, but the response of connectivity to changes in physical structure is still poorly understood. In this paper, a dynamic index (connectivity index) based on daily-scale flow and probability density function is proposed to characterize the connectivity capacity of river networks. The Haihe River basin in China is selected as the study area, and a graphic model is constructed to assess the evolutionary structure of the river network. The 54 sections were classified into Low human impact (LHI) and High human impact (HHI), and the trends and causes of connectivity changes of the sections with the evolution of the network were analyzed. The results reveal that the river network degree and clustering coefficient keep increasing, the path length decreases and becomes more dense downstream, and the river network gradually evolves into a “small-world” network. The “small-world” characteristics improve the potential efficiency and specific functionality of the river network, but make the physical structure mismatch with the hydraulic gradient, and the network flow disperses severely, leading to a significant decrease in connectivity (HHI connectivity index is lower than LHI 52.1%). Moreover, the structural changes enhance the spatial and temporal differences in hydrological connectivity, which further restricts the function of the river system. “Small-world” and connectivity indicators (duration, start time, and intermittency) show strong correlations. Therefore, physical structure is an important factor influencing connectivity capacity of river networks. The planning and management of the watershed should consider the changes in hydrological connectivity caused by the structural modifications of the river network.

Grass coverage and the runoff path length decreased by sedimentation have synergistic effects on runoff and sediment yields in a slope-gully system, revealed by rainfall simulation experiments

Slope-gully systems on the Loess Plateau, China cause severe soil erosion. Planting vegetation and the construction of check dams are the most effective measures utilized for the mitigation of soil erosion in this region. Among them, due to the sedimentation behind the dam, the erosion basis was lifted, resulting in a decrease of the runoff path length (Runoff Path Length Decrease; RPLD) of the slope-gully system. However, the synergistic effects of vegetation and check dams to reduce the runoff and sediment yields of the slope-gully system has not been addressed often. In the present study, 10 physical models of slope-gully systems, including grass coverage on a slope (0% and 33%) and the RPLD (0, 1, 2, 3, and 4 m), were constructed to evaluate the synergistic effects of these measures. The results indicated that grass coverage reduced runoff and sediment yields by 42.63% and 25.66%, respectively. The combination of grass coverage and RPLD could control water erosion of slope-gully systems more effectively than the independent measures. With increasing RPLD, the runoff and sediment yield reduced significantly. Grass coverage and RPLD exhibited a synergistic effect on the erosion caused by water, which increased with RPLD as follows: 4 m (19.83%) > 3 m (18.68%) > 2 m (17.39%) > 1 m (16.70%). These results demonstrate that grass coverage on slopes and the RPLD synergistically influence hydrological processes. The synergistic effects not only should be incorporated to develop soil and water conservation regulations, but also should be considered in soil erosion models.

Decreasing Shortest Path Length of the Sensorimotor Network Induces Frontal Glioma-Related Epilepsy.

BackgroundGlioma-related epilepsy (GRE) is a common symptom in patients with prefrontal glioma. Epilepsy onset is associated with functional network alterations. This study investigated alterations of functional networks in patients with prefrontal glioma and GRE.MethodsSixty-five patients with prefrontal lobe gliomas were retrospectively assessed and classified into GRE and non-GRE groups. Additionally, 25 healthy participants were enrolled after matching for general information. Imaging data were acquired within 72 h in pre-operation. The sensorimotor network was used to delineate alterations in functional connectivity (FC) and topological properties. One-way analysis of variance and post-hoc analysis with Bonferroni correction were used to calculate differences of FC and topological properties.ResultsAll significant alterations were solely found in the sensorimotor network. Irrespective of gliomas located in the left or right prefrontal lobes, the edge between medial Brodmann area 6 and caudal ventrolateral Brodmann area 6 decreased FC in the GRE group compared with the non-GRE group [p < 0.0001 (left glioma), p = 0.0002 (right glioma)]. Moreover, the shortest path length decrease was found in the GRE group compared with the non-GRE group [p = 0.0292 (left glioma) and p = 0.0129 (right glioma)].ConclusionsThe reduction of FC between the medial BA 6 (supplementary motor area) and caudal ventrolateral BA 6 in the ipsilateral hemisphere and the shortening of the path length of the sensorimotor network were characteristics alterations in patients with GRE onset. These findings fill in the gap which is the relationship between GRE onset and the alterations of functional networks in patients with prefrontal glioma.Significance StatementGlioma related epilepsy is the most common symptom of prefrontal glioma. It is important to identify characteristic alterations in functional networks in patients with GRE. We found that all significant alterations occurred in the sensorimotor network. Moreover, a decreased FC in the supplementary motor area and a shortening of the path’s length are additional characteristics of glioma-related epilepsy. We believe that our findings indicate new directions of research that will contribute to future investigations of glioma-related epilepsy onset.

A preliminary study of the effects of mindfulness‐based cognitive therapy on structural brain networks in mood‐dysregulated youth with a familial risk for bipolar disorder

Mindfulness-based cognitive therapy for children (MBCT-C), as a psychotherapeutic intervention, has been shown to be effective for treating mood dysregulation (MD). While previous neuroimaging studies of MD have reported both pre-treatment structural and functional alterations, the effects of MBCT-C on brain morphological network organisation has not been investigated. We investigated brain morphological network organisation in 10 mood-dysregulated youth with familial risk for bipolar disorder and 15 matched healthy comparison youth (HC). Effects of 12 weeks of MBCT-C were examined in the mood-dysregulated youth. Topological properties of brain networks used for analyses were constructed based on morphological similarities in regional grey matter using a graph-theory approach using MRI data. At baseline, compared with the HC group, the mood-dysregulated group exhibited increased global efficiency (Eglob ), decreased path length (Lp ), and abnormal nodal properties, mainly in the limbic system. Right temporal pole alterations at baseline predicted change in Child and Adolescent Mindfulness Measure scores after treatment. The mood-dysregulated group showed significant decreases in both the Eglob and Lp metrics after MBCT-C, suggesting an improved capacity for optimal information processing. Changes in Lp were correlated with changes in Emotion Regulation Checklist scores. Our results show significant topological alterations in the mood-dysregulated group as compared to controls at baseline. After MBCT-C, disrupted topological properties in the mood-dysregulated group were significantly reduced. MBCT-C may facilitate clinically meaningful changes in the brain structural network in mood-dysregulated individuals.

The effect of shoe cushioning on gait and balance in females with multiple sclerosis.

Gait and balance deficits are significant concerns for people with multiple sclerosis (MS). Shoe cushioning can influence mobility and balance, but its effect on walking and balance remains unknown in MS. This study aimed to determine how shoe cushioning affects gait and balance in females with MS (FwMS). We hypothesized that extra cushioning would improve gait but reduce balance performance. FwMS performed gait (n = 18) and balance (n = 17) assessments instrumented using inertial sensors in two different shoe conditions: a standard-cushioned and an extra-cushioned shoe. Care was taken to ensure minimal differences between shoe types other than midsole cushioning, but shoe construction was not identical between conditions. Spatiotemporal gait parameters were assessed during a 2-min walk test, while postural sway measures were evaluated using the modified Clinical Test of Sensory Interaction and Balance. In the extra-cushioned shoe, FwMS spent less time in the double support and stance phase with more time in the single support and swing phase. No differences in stride length, gait speed, or elevation at midswing were observed between shoe conditions. Decreased path length, RMS sway, and sway velocity were observed in the extra-cushioned shoe. No differences were observed in the gait cycle's spatial composition between shoe conditions, but FwMS demonstrated improvements in the gait cycle's temporal parameters and postural sway in the extra-cushioned shoe. This may suggest a less cautious walking strategy and improved balance when wearing a shoe with extra cushioning.

Disrupted brain gray matter networks in drug-naïve participants with essential tremor.

To use structural magnetic resonance imaging and graph theory approaches to investigate the topological organization of the brain morphological network based on gray matter in essential tremor, and its potential relation to disease severity. In this prospective study conducted from November 2018 to November 2019, 36 participants with essential tremor and 37 matched healthy controls underwent magnetic resonance imaging. Brain networks based on the morphological similarity of gray matter across regions were analyzed using graph theory. Nonparametric permutation testing was used to assess group differences in topological metrics. Support vector machine was applied to the gray matter morphological matrices to classify participants with essential tremor vs. healthy controls. Compared with healthy controls, participants with essential tremor showed increased global efficiency (p < 0.01) and decreased path length (p < 0.01); abnormal nodal properties in frontal, parietal, and cerebellar lobes; and disconnectivity in cerebello-thalamo-cortical network. The abnormal brain nodal centralities (left superior cerebellum gyrus; right caudate nucleus) correlated with clinical measures, both motor (Fahn-Tolosa-Marìn tremor rating, p = 0.017, r = - 0.41) and nonmotor (Hamilton depression scale, p = 0.040, r = - 0.36; Hamilton anxiety scale, p = 0.008, r = - 0.436). Gray matter morphological matrices classified individuals with high accuracy of 80.0%. Participants with essential tremor showed randomization in global properties and dysconnectivity in the cerebello-thalamo-cortical network. Participants with essential tremor could be distinguished from healthy controls by gray matter morphological matrices.

Aberrant brain network topology in the frontoparietal-limbic circuit in bipolar disorder: a graph-theory study.

Characterizing the properties of brain networks across mood states seen in bipolar disorder (BP) can provide a deeper insight into the mechanisms involved in this type of affective disorder. In this study, graph theoretical methods were used to examine global, modular and nodal brain network topology in the resting state using functional magnetic resonance imaging data acquired from 95 participants, including those with bipolar depression (BPD; n = 30) and bipolar mania (BPM; n = 39) and healthy control (HC) subjects (n = 26). The threshold value of the individual subjects' connectivity matrix varied from 0.15 to 0.30 with steps of 0.01. We found that: (1) at the global level, BP patients showed a significantly increased global efficiency and synchronization and a decreased path length; (2) at the nodal level, BP patients showed impaired nodal parameters, predominantly within the frontoparietal and limbic sub-network; (3) at the module level, BP patients were characterized by denser FCs (edges) between Module III (the front-parietal system) and Module V (limbic/paralimbic systems); (4) at the nodal level, the BPD and BPM groups showed state-specific differences in the orbital part of the left superior-frontal gyrus, right putamen, right parahippocampal gyrus and left fusiform gyrus. These results revealed abnormalities in topological organization in the whole brain, especially in the frontoparietal-limbic circuit in both BPD and BPM. These deficits may reflect the pathophysiological processes occurring in BP. In addition, state-specific regional nodal alterations in BP could potentially provide biomarkers of conversion across different mood states.

Моделирование блока восстановления тактовой частоты и данных на основе схемы фазовой автоподстройки частоты

In many VLSIs, full amplitude CMOS drivers are used for information transfer via unterminated line. What is more, path length decreases carrying capacity of such interconnection in a greater degree than CMOS drivers’ performance. Because transmit channel considerably garbles transferred information, prevailing solution to this problem are clock data recovery blocks the role of which is to retrieve data along with recovering clock signal. In this work, the process of constructing a clock signal and data recovery unit based on a single-loop phase-locked-frequency scheme that does not require a reference periodic signal is considered. The development of its behavioral model was carried out in the Verilog-AMS hardware description language, and the block modeling at the transistor level was carried out in the 90 nm CMOS technology. In this case, the recovery time was 4.8 microseconds, and the «jitter» indicator of clock signal recovery unit was 7.6 ps. The obtained values of developed clock signal and data recovery unit’s output parameters are up to the best foreign analogues.

Sleep/Wake Regularity Associated with Default Mode Network Structure among Healthy Adolescents and Young Adults

Sleep deprivation and disorders are linked to reduced DMN connectivity. Less is known about how naturalistic sleep patterns – specifically sleep irregularity - relate to the DMN, particularly among adolescents and young adults. Additionally, no studies have utilized graph theory analysis to clarify whether sleep-related decreases in connectivity reflect global or local DMN changes. Twenty-five healthy adolescents and young adults (age range = 12–22; mean = 18.08; SD = 2.64, 56% female) completed 7 days of actigraphy and resting-state fMRI. Sleep regularity was captured by the Sleep Regularity Index (SRI) and the relationship between the SRI and DMN was examined using graph theory analysis. Analogous analyses explored relationships between the SRI and additional resting-state networks. Greater sleep regularity related to decreased path length (increased network connectivity) in DMN regions, particularly the right and left lateral parietal lobule, and the Language Network, including the left inferior frontal gyrus and the left posterior superior frontal gyrus. Findings were robust to covariates including sex and age. Sleep and DMN function may be tightly linked during adolescence and young adulthood, and reduced DMN connectivity may reflect local changes within the network. Future studies should assess how this relationship impacts cognitive development and neuropsychiatric outcomes in this age group.

Effects of tDCS on Brain Functional Network of Patients After Stroke

Transcranial direct current stimulation (tDCS) is an emerging brain intervention technique. However, the effects of tDCS on stroke patients are unclear. In this study, Granger Causality (GC) is used to construct brain functional networks of the tDCS group (9 cases) and the sham tDCS group (11 cases). Some parameters of brain functional networks are analyzed comparatively, such as degree, clustering coefficient, betweenness centrality, characteristic path length, and efficiency. In tDCS group, the results show that the distribution of degree changes greatly in left prefrontal lobe and left temporal lobe regions, the distribution of betweenness centrality transfers, characteristic path length decreases, clustering coefficient and efficiency increase significantly ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$p&lt; 0.05$ </tex-math></inline-formula> ) after stimulation. However, there is no significant difference in sham tDCS group. In this study, the positive effects of tDCS on the therapeutic of stroke are clarified and the evidence for the effects of tDCS on stroke is provided.

Can Haptic Simulators Distinguish Expert Performance? A Case Study in Central Venous Catheterization in Surgical Education.

High-tech simulators are gaining popularity in surgical training programs because of their potential for improving clinical outcomes. However, most simulators are static in nature and only represent a single anatomical patient configuration. The Dynamic Haptic Robotic Training (DHRT) system was developed to simulate these diverse patient anatomies during Central Venous Catheterization (CVC) training. This article explores the use of the DHRT system to evaluate objective metrics for CVC insertion by comparing the performance of experts and novices. Eleven expert surgeons and 13 first-year surgical residents (novices) performed multiple needle insertion trials on the DHRT system. Differences between expert and novice performance on the following five metrics were assessed using a multivariate analysis of variance: path length, standard deviation of deviations (SDoD), average velocity, distance to the center of the vessel, and time to complete (TtC) the needle insertion. A regression analysis was performed to identify if expertise could be predicted using these metrics. Then, a curve fit was conducted to identify whether learning curves were present for experts or novices on any of these five metrics. Time to complete the insertion and SDoD of the needle tip from an ideal path were significantly different between experts and novices. Learning curves were not present for experts but indicated a significant decrease in path length and TtC for novices. The DHRT system was able to identify significant differences in TtC and SDoD between experts and novices during CVC needle insertion procedures. In addition, novices were shown to improve their skills through DHRT training.

Six-week Pilates Program Improves Postural Stability, Balance, And Isometric Back Strength In College-aged Athletes

Pilates training engages core musculature and utilizes controlled repetitions of various movements to improve muscular strength and endurance, flexibility, balance, and posture. Although a growing body of research identifies the benefits of Pilates training for middle-aged and older adults, little emphasis has been placed on evaluating athletic populations. PURPOSE: To determine the effects of a short-term Pilates training program on postural stability, balance and core isometric back strength in NCAA DIII and competitive club sport athletes. METHODS: The experimental group of 16 off-season college-aged female athletes participated in a supervised Pilates training program, which took place two times each week for six weeks. The 30-minute Pilates sessions consisted of body weight training that progressed to the incorporation of dumbbells. Pre- and post-test measurements were taken in three functional tests, which included Force Plate Tandem Balance (FPTB), Limits of Postural Stability (LPS), and Biering-Sorensen Back Extension (BSBE). A control group of 10 college students, who maintained their normal physical activities, but were not involved in the Pilates training program, completed pre- and post-testing for comparison. RESULTS: There were no significant differences between the experimental and control groups at baseline testing. The control group did not show any significant changes between pre- and post-test measurements. The experimental group decreased path length in the FPTB assessment (39.8 inches vs. 36.5 inches, p<0.05). The experimental group also exhibited significant improvement in postural control score on the LPS assessment (37.1 vs. 47.4, p<0.001). Finally, there was a significant increase in seconds held during the BSBE assessment among the experimental group (172.4 seconds vs. 187.7 seconds, p<0.05). CONCLUSION: A six-week progressive Pilates program contributed to significant decreases in single-foot sway, increases in postural stability, and increases in isometric back strength in female college- aged athletes.

22-Effect of spatial smoothing on graph analysis of fMRI data

Introduction Smoothing is used to increase SNR. Here we examine it’s effect of smoothing on graph analysis of fMRI data. Methods We used fMRI data of 30 subjects from HCP (Human Connectome Project; 3T; motor task). We preprocessed the data using realign and unwarp, spatial normalization, filtering and smoothing with FWHM = {none, 3, 5, 8 and 11} mm, parcellated according AAL atlas, used mean and first eigenvector as representative signal. Finally, we performed graph analysis using average node strength, characteristic path length, lambda, efficiency, clustering coefficient, and gamma. Results Increase of FWHM is related to increase of clustering coefficient, node strength and efficiency, and to decrease of path length. Gamma and lambda are relatively not influenced by size of FMWH kernel. With low FHWM or no smoothing and using mean is the node strength higher and path length shorter. Discussion Increase of FWHM increases correlations in the network, i.e. weights in graph. Therefore node strength increases and characteristic path length decreases. Clustering coefficient also reflects increasing weights between neighboring nodes. Increase of correlation coefficients with higher FWHM is more prominent when using first eigenvector as representative signal. We recommend to smooth fMRI data consistently across study.

Disrupted Brain Network in Children with Autism Spectrum Disorder

Alterations in brain connectivity have been extensively reported in autism spectrum disorder (ASD), while their effects on the topology of brain network are still unclear. This study investigated whether and how the brain networks in children with ASD were abnormally organized with resting state EEG. Temporal synchronization analysis was first applied to capture the aberrant brain connectivity. Then brain network topology was characterized by three graph analysis methods including the commonly-used weighted and binary graph, as well as minimum spanning tree (MST). Whole brain connectivity in ASD group was found to be significantly reduced in theta and alpha band compared to typically development children (TD). Weighted graph found significantly decreased path length together with marginally significantly decreased clustering coefficient in ASD in alpha band, indicating a loss of small-world architecture to a random network. Such abnormal network topology was also demonstrated in the binary graph. In MST analysis, children with ASD showed a significant lower leaf fractions with a decrease trend of tree hierarchy in the alpha band, suggesting a shift towards line-like decentralized organization in ASD. The altered brain network may offer an insight into the underlying pathology of ASD and possibly serve as a biomarker that may aid in diagnosis of ASD.

Association between resting-state brain network topological organization and creative ability: Evidence from a multiple linear regression model

Previous studies have indicated a tight linkage between resting-state functional connectivity of the human brain and creative ability. This study aimed to further investigate the association between the topological organization of resting-state brain networks and creativity. Therefore, we acquired resting-state fMRI data from 22 high-creativity participants and 22 low-creativity participants (as determined by their Torrance Tests of Creative Thinking scores). We then constructed functional brain networks for each participant and assessed group differences in network topological properties before exploring the relationships between respective network topological properties and creative ability. We identified an optimized organization of intrinsic brain networks in both groups. However, compared with low-creativity participants, high-creativity participants exhibited increased global efficiency and substantially decreased path length, suggesting increased efficiency of information transmission across brain networks in creative individuals. Using a multiple linear regression model, we further demonstrated that regional functional integration properties (i.e., the betweenness centrality and global efficiency) of brain networks, particularly the default mode network (DMN) and sensorimotor network (SMN), significantly predicted the individual differences in creative ability. Furthermore, the associations between network regional properties and creative performance were creativity-level dependent, where the difference in the resource control component may be important in explaining individual difference in creative performance. These findings provide novel insights into the neural substrate of creativity and may facilitate objective identification of creative ability.

GP.04 Network connectivity following a single unprovoked seizure using 7 Tesla resting-state fMRI

Background: Predicting epilepsy following a first seizure is difficult. Network abnormalities are observed in patients with epilepsy using resting-state functional MRI (rs-fMRI), which worsen with duration of epilepsy. We use rs-fMRI to identify network abnormalities in patients after a first seizure that can be used as a biomarker to predict development of epilepsy. Methods: Patients after a single, unprovoked seizure and age/sex matched healthy controls underwent 7 Tesla structural and resting-state functional MRI. Data were analyzed using graph theory measures. Patients were followed for development of epilepsy. Results: Nine patients and nine control subjects were analyzed. There were no differences in baseline characteristics. No patients developed epilepsy (average follow-up 3 months). No differences between groups occurred on a whole-brain network level. At a 20% threshold, significant differences occurred in the default mode network (DMN). Patients demonstrated an increased local efficiency (p=0.02) and clustering coefficient (p=0.04), and decreased path length (p=0.02) and betweenness centrality (p=0.02). Conclusions: No whole-brain network changes occur after a single unprovoked seizure. No patient has developed epilepsy suggesting this group does not have network alterations after a single seizure. In the DMN, the alterations noted indicate increased segregation of network function.