Excitation-inhibition (E:I) imbalance is theorized as an important pathophysiological mechanism in autism. Autism affects males more frequently than females and sex-related mechanisms (e.g., X-linked genes, androgen hormones) can influence E:I balance. This suggests that E:I imbalance may affect autism differently in males versus females. With a combination of in-silico modeling and in-vivo chemogenetic manipulations in mice, we first show that a time-series metric estimated from fMRI BOLD signal, the Hurst exponent (H), can be an index for underlying change in the synaptic E:I ratio. In autism we find that H is reduced, indicating increased excitation, in the medial prefrontal cortex (MPFC) of autistic males but not females. Increasingly intact MPFC H is also associated with heightened ability to behaviorally camouflage social-communicative difficulties, but only in autistic females. This work suggests that H in BOLD can index synaptic E:I ratio and that E:I imbalance affects autistic males and females differently.

I mpaired fetal brain development during the third trimester has been increasingly reported as a contributing factor to brain injury and neurodevelopmental disabilities in survivors of complex congenital heart disease (CHD) (1,2). Available evidence suggests that alterations in fetal oxygen delivery may contribute to aberrant brain growth in this high-risk fetal population and raises the possibility of maternal hyperoxygenation as a potential fetal therapy for certain types of CHD (3-5). The role of maternal oxygen administration, or maternal hyperoxia (HO), to improve fetal outcomes has been studied primarily in pregnancies complicated by fetal growth restriction, presumably to support declining placental function. Most of these studies focused on the redistribution of placental and cerebral blood flow during HO as measured at Doppler US, however, the potential impact of this therapy remains unclear (6-9).Recent advances in fetal MRI allow for more sophisticated and quantitative analyses of fetal hemodynamics and oxygenation, including phase-contrast MRI, T2 mapping, and blood oxygenation level-dependent (BOLD) functional MRI (10,11).The fetal response to maternal HO has been reported in the healthy fetus by using BOLD functional MRI, which demonstrated negligible changes in fetal brain oxygenation even in the setting of increased placental oxygenation (8). In fetuses with CHD, T2* mapping has been studied to estimate fetal cerebral tissue oxygenation. These studies have revealed significant decreases in blood oxygenation and oxygen consumption of the fetal brain in CHD compared with healthy control fetuses (12), which was associated with impaired brain growth (4). In light of these findings, it has been proposed that administration of

Abstract. Data broadcasting services are required to provide user interactivity through connecting additional contents such as object information to audiovisual contents. H.264/AVC-based metadata authoring tools include functions which identify and track position and motion of objects. In this work, we propose a method for tracking the target object by using partially decoded texture data and motion vectors extracted directly from H.264/AVC bitstream. This method achieves low computational complexity and high performance through the dissimilarity energy minimization algorithm which tracks feature points adaptively according to these characteristics. The experiment has shown that the proposed method had high performance with fast processing time.

Abstract. Fetal motion manifests as signal degradation and image artifact in the acquired time series of blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) studies. We present a robust preprocessing pipeline to specifically address fetal and placental motion-induced artifacts in stimulus-based fMRI with slowly cycled block design in the living fetus. In the proposed pipeline, motion correction is optimized to the experimental paradigm, and it is performed separately in each phase as well as in each region of interest (ROI), recognizing that each phase and organ experiences different types of motion. To obtain the averaged BOLD signals for each ROI, both misaligned volumes and noisy voxels are automatically detected and excluded, and the missing data are then imputed by statistical estimation based on local polynomial smoothing. Our experimental results demonstrate that the proposed pipeline was effective in mitigating the motion-induced artifacts in stimulus-based fMRI data of the fetal brain and placenta.