Dynamic Architecture Research Articles

Self-organizing nervous systems for robot swarms.

We present the self-organizing nervous system (SoNS), a robot swarm architecture based on self-organized hierarchy. The SoNS approach enables robots to autonomously establish, maintain, and reconfigure dynamic multilevel system architectures. For example, a robot swarm consisting of n independent robots could transform into a single n-robot SoNS and then into several independent smaller SoNSs, where each SoNS uses a temporary and dynamic hierarchy. Leveraging the SoNS approach, we showed that sensing, actuation, and decision-making can be coordinated in a locally centralized way without sacrificing the benefits of scalability, flexibility, and fault tolerance, for which swarm robotics is usually studied. In several proof-of-concept robot missions-including binary decision-making and search and rescue-we demonstrated that the capabilities of the SoNS approach greatly advance the state of the art in swarm robotics. The missions were conducted with a real heterogeneous aerial-ground robot swarm, using a custom-developed quadrotor platform. We also demonstrated the scalability of the SoNS approach in swarms of up to 250 robots in a physics-based simulator and demonstrated several types of system fault tolerance in simulation and reality.

Chromatin structure and 3D architecture define the differential functions of PU.1 regulatory elements in blood cell lineages

The precise spatiotemporal expression of the hematopoietic ETS transcription factor PU.1, a key determinant of hematopoietic cell fates, is tightly regulated at the chromatin level. However, how chromatin signatures are linked to this dynamic expression pattern across different blood cell lineages remains uncharacterized. Here, we performed an in-depth analysis of the relationships between gene expression, chromatin structure, 3D architecture, and trans-acting factors at PU.1 cis-regulatory elements (PCREs). By identifying phylogenetically conserved DNA elements within chromatin-accessible regions in primary human blood lineages, we discovered multiple novel candidate PCREs within the upstream region of the human PU.1 locus. A subset of these elements localizes within an 8-kb-wide cluster exhibiting enhancer features, including open chromatin, demethylated DNA, enriched enhancer histone marks, present enhancer RNAs, and PU.1 occupation, presumably mediating PU.1 autoregulation. Importantly, we revealed the presence of a common 35-kb-wide CTCF-flanked insulated neighborhood that contains the PCRE cluster (PCREC), forming a chromatin territory for lineage-specific and PCRE-mediated chromatin interactions. These include functional PCRE-promoter interactions in myeloid and B cells that are absent in erythroid and T cells. By correlating chromatin structure and 3D architecture with PU.1 expression in various lineages, we were able to attribute enhancer versus silencer functions to individual elements. Our findings provide mechanistic insights into the interplay between dynamic chromatin structure and 3D architecture in the chromatin regulation of PU.1 expression. This study lays crucial groundwork for additional experimental studies that validate and dissect the role of PCREs in epigenetic regulation of normal and malignant hematopoiesis.

PIM-1L Kinase Binds to and Inactivates SRPK1: A Biochemical and Molecular Dynamics Study.

SR/RS dipeptide repeats vary in both length and position, and are phosphorylated by SR protein kinases (SRPKs). PIM-1L, the long isoform of PIM-1 kinase, the splicing of which has been implicated in acute myeloid leukemia, contains a domain that consists largely of repeating SR/RS and SH/HS dipeptides (SR/SH-rich). In order to extend our knowledge on the specificity and cellular functions of SRPK1, here we investigate whether PIM-1L could act as substrate of SRPK1 by a combination of biochemical and computational approaches. Our biochemical data showed that the SR/SH-rich domain of PIM-1L was able to associate with SRPK1, yet it could not act as a substrate but, instead, inactivated the kinase. In line with our biochemical data, molecular modeling followed by a microsecond-scale all-atom molecular dynamics (MD) simulation suggests that the SR/SH-rich domain acts as a pseudo-docking peptide that binds to the same acidic docking-groove used in other SRPK1 interactions and induces inactive SRPK1 conformations. Comparative community network analysis of the MD trajectories, unraveled the dynamic architecture of apo SRPK1 and notable alterations of allosteric communications upon PIM-1L peptide binding. This analysis also allowed us to identify key SRPK1 residues, including unique ones, with a pivotal role in mediating allosteric signal propagation within the kinase core. Interestingly, most of the identified amino acids correspond to cancer-associated amino acid changes, validating our results. In total, this work provides insights not only on the details of SRPK1 inhibition by the PIM-1L SR/SH-domain, but also contributes to an in-depth understanding of SRPK1 regulation.

Dynamic protein assembly and architecture of the large solitary membraneless organelle during germline development in the wasp Nasonia vitripennis.

Throughout metazoa, germ cells assemble RNA-protein organelles (germ granules). In Drosophila ovaries, perinuclear nuage forms in the nurse cells, while compositionally similar polar granules form in the oocyte. A similar system appears to exist in the distantly related (∼350 million years) wasp Nasonia, with some surprising divergences. Nuage is similarly formed in Nasonia, except that anterior nurse cells accumulate significantly more nuage, in association with high levels of DNA double-strand breaks, suggesting that increased transposon activity in anterior is silenced by high nuage levels. In the oocyte, the germ plasm forms a single granule that is 40 times larger than a homologous Drosophila polar granule. While conserved germ granule proteins are recruited to the oosome, they show unusual localization: Tudor protein forms a shell encapsulating the embryonic oosome, while small Oskar/Vasa/Aubergine granules coalesce interiorly. Wasp Vasa itself is unusual since it has an alternative splice form that includes a novel nucleoporin-like phenylalanine-glycine repeat domain. Our work is consistent with the high degree of evolutionary plasticity of membraneless organelles and describes new experimental model and resources to study biomolecular condensates.

The dual Ras Association (RA) Domains of Drosophila Canoe have differential roles in linking cell junctions to the cytoskeleton during morphogenesis.

During development cells must change shape and move without disrupting dynamic tissue architecture. This requires robust linkage of cell-cell adherens junctions to the force-generating actomyosin cytoskeleton. Drosophila Canoe and mammalian Afadin play key roles. One central task for the field is defining mechanisms by which upstream inputs from Ras-family GTPases regulate Canoe/Afadin. They are unusual in sharing two tandem Ras-association (RA) domains, which, when deleted, virtually eliminate Canoe function. Work in vitro suggested RA1 and RA2 differ in GTPase affinity, but their individual functions in vivo remain unknown. Combining bioinformatic and biochemical approaches, we find that both RA1 and RA2 bind to active Rap1 with similar affinities, and their conserved N-terminal extensions enhance binding. We created Drosophila canoe mutants to test RA1 and RA2 function in vivo. Despite their similar affinities for Rap1, RA1 and RA2 play strikingly different roles. Deleting RA1 virtually eliminates Canoe function, while mutants lacking RA2 are viable and fertile but have defects in junctional reinforcement in embryos and during pupal eye development. These data significantly expand our understanding of regulation of adherens junction:cytoskeletal linkage.

Spatiotemporal lineage tracing reveals the dynamic spatial architecture of tumor growth and metastasis.

Tumor progression is driven by dynamic interactions between cancer cells and their surrounding microenvironment. Investigating the spatiotemporal evolution of tumors can provide crucial insights into how intrinsic changes within cancer cells and extrinsic alterations in the microenvironment cooperate to drive different stages of tumor progression. Here, we integrate high-resolution spatial transcriptomics and evolving lineage tracing technologies to elucidate how tumor expansion, plasticity, and metastasis co-evolve with microenvironmental remodeling in a Kras;p53 -driven mouse model of lung adenocarcinoma. We find that rapid tumor expansion contributes to a hypoxic, immunosuppressive, and fibrotic microenvironment that is associated with the emergence of pro-metastatic cancer cell states. Furthermore, metastases arise from spatially-confined subclones of primary tumors and remodel the distant metastatic niche into a fibrotic, collagen-rich microenvironment. Together, we present a comprehensive dataset integrating spatial assays and lineage tracing to elucidate how sequential changes in cancer cell state and microenvironmental structures cooperate to promote tumor progression.

6432 Enriching Testicular Organoid Aggregates to Promote Germ Cell Homing

Abstract Disclosure: A. Patel: None. O.O. Printy: None. C. Joswiak: None. M.M. Laronda: None. The long-term effects of life-saving chemotherapy treatments, such as an increased risk of infertility, are of concern to the growing number of childhood cancer survivors. De novo testicular morphogenesis seeks to generate testicular organoids that are structurally and functionally similar to the native testis. These organoids serve as a tool for investigating patient-specific models for restoring spermatogenesis for prepubertal cancer patients. Our lab has previously developed testicular organoids containing tubule-like structures (TLS) resembling the native seminiferous tubules as assessed by immunohistochemistry of testicular cell-type markers for Leydig cells (HSD3B2), peritubular myoid cells (ACTA1), Sertoli cells (SOX9), germ cells (DDX4), and spermatogonial stem cells (SSCs) (SALL4). Internal architecture demonstrated semi-continuous ring-like structures composed of ACTA1-positive cells encapsulating a population of SOX9-positive cells with HSD3B2-positive cells clustering near the periphery of the organoids. However, organoids lacked native germ cell populations. We hypothesized that murine testicular organoids would merge to form elongated TLS, within which exogenous SSCs would home to existing Sertoli cell niches, when cultured within structures designed from the appropriate dimensions and materials. Organoids were generated from testicular tissue isolated from 5 days-post-partum (dpp) CD1 mice using cell-seeding densities and microenvironmental conditions previously established by our lab. To promote aggregate formation, 48-hour-old organoids were transferred to trough-shaped structures formed from 2% agarose using 3D printed silicone molds. Separately, SSCs were isolated from 5 dpp tdTomato+ mice via magnetic-activated cell sorting of THY1+ cells. Organoids and aggregates were enriched with SSCs by three methods: (1) enrichment of cell suspension during organoid formation, (2) enrichment of culture during aggregate formation, and (3) injection of SSCs into aggregate using 20 µm glass pipette. Organoids transferred to agarose troughs on day 2 of culture merged to form aggregates by day 5 and continued to display dynamic architecture, shortening in length and increasing in width over time. Aggregates were more elongated in shape when cultured in narrow troughs less than 700µm in width. Observations thus far indicate that attempts to inject aggregates resulted in penetrance and inclusion of the SSC suspension; additionally, tdTomato+ cells were visualized within injected aggregates on day 17 of culture. Research is ongoing to define where exogenous SSCs take up residence, how long they survive, and if they proliferate over time within the testicular aggregates. This research expands upon foundational work establishing testicular organoids as an approach to in vitro spermatogenesis with clinical applications in fertility restoration. Presentation: 6/2/2024

6432 Enriching Testicular Organoid Aggregates to Promote Germ Cell Homing

Abstract Disclosure: A. Patel: None. O.O. Printy: None. C. Joswiak: None. M.M. Laronda: None. The long-term effects of life-saving chemotherapy treatments, such as an increased risk of infertility, are of concern to the growing number of childhood cancer survivors. De novo testicular morphogenesis seeks to generate testicular organoids that are structurally and functionally similar to the native testis. These organoids serve as a tool for investigating patient-specific models for restoring spermatogenesis for prepubertal cancer patients. Our lab has previously developed testicular organoids containing tubule-like structures (TLS) resembling the native seminiferous tubules as assessed by immunohistochemistry of testicular cell-type markers for Leydig cells (HSD3B2), peritubular myoid cells (ACTA1), Sertoli cells (SOX9), germ cells (DDX4), and spermatogonial stem cells (SSCs) (SALL4). Internal architecture demonstrated semi-continuous ring-like structures composed of ACTA1-positive cells encapsulating a population of SOX9-positive cells with HSD3B2-positive cells clustering near the periphery of the organoids. However, organoids lacked native germ cell populations. We hypothesized that murine testicular organoids would merge to form elongated TLS, within which exogenous SSCs would home to existing Sertoli cell niches, when cultured within structures designed from the appropriate dimensions and materials. Organoids were generated from testicular tissue isolated from 5 days-post-partum (dpp) CD1 mice using cell-seeding densities and microenvironmental conditions previously established by our lab. To promote aggregate formation, 48-hour-old organoids were transferred to trough-shaped structures formed from 2% agarose using 3D printed silicone molds. Separately, SSCs were isolated from 5 dpp tdTomato+ mice via magnetic-activated cell sorting of THY1+ cells. Organoids and aggregates were enriched with SSCs by three methods: (1) enrichment of cell suspension during organoid formation, (2) enrichment of culture during aggregate formation, and (3) injection of SSCs into aggregate using 20 µm glass pipette. Organoids transferred to agarose troughs on day 2 of culture merged to form aggregates by day 5 and continued to display dynamic architecture, shortening in length and increasing in width over time. Aggregates were more elongated in shape when cultured in narrow troughs less than 700µm in width. Observations thus far indicate that attempts to inject aggregates resulted in penetrance and inclusion of the SSC suspension; additionally, tdTomato+ cells were visualized within injected aggregates on day 17 of culture. Research is ongoing to define where exogenous SSCs take up residence, how long they survive, and if they proliferate over time within the testicular aggregates. This research expands upon foundational work establishing testicular organoids as an approach to in vitro spermatogenesis with clinical applications in fertility restoration. Presentation: 6/2/2024

Magnetic, conductive nanoparticles as building blocks for steerable micropillar-structured anodic biofilms

In bioelectrochemical systems (BES), biofilm formation and architecture are of crucial importance, especially for flow-through applications. The interface between electroactive microorganisms and the electrode surface plays an important and often limiting role, as the available surface area influences current generation, especially for poor biofilm forming organisms. To overcome the limitation of the available electrode surface, nanoparticles (NPs) with a magnetic iron core and a conductive, hydrophobic carbon shell were used as building blocks to form conductive, magnetic micropillars on the anode surface. The formation of this dynamic three-dimensional electrode architecture was monitored and quantified in situ using optical coherence tomography (OCT) in conjunction with microfluidic BES systems. By cyclic voltammetry the assembled three-dimensional anode extensions were found to be electrically conductive and increased the available electroactive surface area. The NPs were used as controllable carriers for the electroactive model organisms Shewanella oneidensis and Geobacter sulfurreducens, resulting in a 5-fold increase in steady-state current density for S. oneidensis, which could be increased 22-fold when combined with Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) aggregates. In the case of G. sulfurreducens, the steady-state current density was not increased, but was achieved four times faster. The study presents a controllable, scalable and easy-to-use method to increase the electrode surface area in existing BES by applying a magnetic field and adding conductive magnetic NPs. These findings can most likely also be transferred to other electroactive microorganisms.

Dynamic MIMO Architecture Design for Near-Field Communications

Dynamic MIMO Architecture Design for Near-Field Communications

Deep learning segmentation model for quantification of infarct size in pigs with myocardial ischemia/reperfusion.

Infarct size (IS) is the most robust end point for evaluating the success of preclinical studies on cardioprotection. The gold standard for IS quantification in ischemia/reperfusion (I/R) experiments is triphenyl tetrazolium chloride (TTC) staining, typically done manually. This study aimed to determine if automation through deep learning segmentation is a time-saving and valid alternative to standard IS quantification. High-resolution images from TTC-stained, macroscopic heart slices were retrospectively collected from pig experiments (n = 390) with I/R without/with cardioprotection to cover a wide IS range. Existing IS data from pig experiments, quantified using a standard method of manual and subsequent digital labeling of film-scan annotations, were used as reference. To automate the evaluation process with the aim to be more objective and save time, a deep learning pipeline was implemented; the collected images (n = 3869) were pre-processed by cropping and labeled (image annotations). To ensure their usability as training data for a deep learning segmentation model, IS was quantified from image annotations and compared to IS quantified using the existing film-scan annotations. A supervised deep learning segmentation model based on dynamic U-Net architecture was developed and trained. The evaluation of the trained model was performed by fivefold cross-validation (n = 220 experiments) and testing on an independent test set (n = 170 experiments). Performance metrics (Dice similarity coefficient [DSC], pixel accuracy [ACC], average precision [mAP]) were calculated. IS was then quantified from predictions and compared to IS quantified from image annotations (linear regression, Pearson's r; analysis of covariance; Bland-Altman plots). Performance metrics near 1 indicated a strong model performance on cross-validated data (DSC: 0.90, ACC: 0.98, mAP: 0.90) and on the test set data (DSC: 0.89, ACC: 0.98, mAP: 0.93). IS quantified from predictions correlated well with IS quantified from image annotations in all data sets (cross-validation: r = 0.98; test data set: r = 0.95) and analysis of covariance identified no significant differences. The model reduced the IS quantification time per experiment from approximately 90min to 20s. The model was further tested on a preliminary test set from experiments in isolated, saline-perfused rat hearts with regional I/Rwithout/with cardioprotection (n = 27). There was also no significant difference in IS between image annotations and predictions, but the performance on the test set data from rat hearts was lower (DSC: 0.66, ACC: 0.91, mAP: 0.65). IS quantification using a deep learning segmentation model is a valid and time-efficient alternative to manual and subsequent digital labeling.

Living Walls

In her acclaimed science fiction trilogy Xenogenesis, Octavia E. Butler presents a narrative of interspecies coexistence involving humans and the alien Oankali. This coexistence is facilitated by living entities known as Lo, which serve as dynamic architectures mediating positive, mutualistic interactions between the two species. These entities offer a valuable framework for analysing architectures that seek to integrate the other. In this article, we propose to extend existing debates on interspecies co-design practices and link them to the concept of xenoarchitecture. Furthermore, we propose the Interspecies Interaction Protocols (IIP) to regulate human/other-than-human interactions in built environments. To demonstrate that xenoarchitecture’s interspecies mediating vision can be applied to non-fictional real-world architecture, we project ideas from Butler’s onto three unusual examples of buildings that achieve this human/other-than-human mediation: the library at the National Palace of Mafra and Coimbra University’s Joanina Library, both located in Portugal, and the Karni Mata temple, located in Rajasthan, India. These case studies illustrate positive IIPs that facilitate mutualistic coexistence between humans and two other species, bats and rats.

Dynamic chromatin architecture identifies new autoimmune-associated enhancers for IL2 and novel genes regulating CD4+ T cell activation.

Genome-wide association studies (GWAS) have identified hundreds of genetic signals associated with autoimmune disease. The majority of these signals are located in non-coding regions and likely impact cis-regulatory elements (cRE). Because cRE function is dynamic across cell types and states, profiling the epigenetic status of cRE across physiological processes is necessary to characterize the molecular mechanisms by which autoimmune variants contribute to disease risk. We localized risk variants from 15 autoimmune GWAS to cRE active during TCR-CD28 co-stimulation of naïve human CD4+ T cells. To characterize how dynamic changes in gene expression correlate with cRE activity, we measured transcript levels, chromatin accessibility, and promoter-cRE contacts across three phases of naive CD4+ T cell activation using RNA-seq, ATAC-seq, and HiC. We identified ~1200 protein-coding genes physically connected to accessible disease-associated variants at 423 GWAS signals, at least one-third of which are dynamically regulated by activation. From these maps, we functionally validated a novel stretch of evolutionarily conserved intergenic enhancers whose activity is required for activation-induced IL2 gene expression in human and mouse, and is influenced by autoimmune-associated genetic variation. The set of genes implicated by this approach are enriched for genes controlling CD4+ T cell function and genes involved in human inborn errors of immunity, and we pharmacologically validated eight implicated genes as novel regulators of T cell activation. These studies directly show how autoimmune variants and the genes they regulate influence processes involved in CD4+ T cell proliferation and activation.

Dynamic chromatin architecture identifies new autoimmune-associated enhancers for IL2 and novel genes regulating CD4+ T cell activation

Dynamic chromatin architecture identifies new autoimmune-associated enhancers for IL2 and novel genes regulating CD4+ T cell activation

Towards Double-Layer Dynamic Heterogeneous Redundancy Architecture for Reliable Railway Passenger Service System

Researchers have proposed the dynamic heterogeneous redundancy (DHR) architecture, which integrates dynamic, heterogeneous, redundant, and closed-loop feedback elements into the system, to fortify the reliability of the railway passenger service system (RPSS). However, there are at least two weaknesses with the common DHR architectures: (1) they need system nodes with enough computing and storage resources; (2) they have hardly considered the reliability of DHR architecture. To this end, this paper proposes a double-layer DHR (DDHR) architecture to ensure the reliability of RPSS. This architecture introduces a set of algorithms, which are optimized co-computation and ruling weight optimization algorithms for the data processing flow of the DDHR architecture. This set improves the reliability of the DDHR architecture. For the evaluation of the reliability of DDHR architecture, this paper also proposes two metrics: (1) Dynamic available similarity metric. This metric does not rely on the overall similarity of the double-layer redundant executor sets but evaluates the similarity of their performance under the specified interaction paths within a single scheduling cycle. The smaller its similarity, the higher its reliability. (2) Scheduling cycle under dual-layer similarity threshold. This metric evaluates the reliability of the RPSS under actual conditions by setting the schedulable similarity thresholds between the same and different layers of the dual-layer redundant executives in the scheduling process. Finally, analog simulation experiments and prototype system building experiments are carried out, whose numerical experimental results show that the DDHR architecture outperforms the traditional DHR architecture in terms of reliability and performance under different redundancy and dynamically available similarity thresholds, while the algorithmic complexity and multi-tasking concurrency performance are slightly weaker than that of the DHR architecture, but can be applied to the main operations of the RPSS in general.

Spatiotemporal transcriptomic mapping of regenerative inflammation in skeletal muscle reveals a dynamic multilayered tissue architecture.

Tissue regeneration is orchestrated by macrophages that clear damaged cells and promote regenerative inflammation. How macrophages spatially adapt and diversify their functions to support the architectural requirements of actively regenerating tissue remains unknown. In this study, we reconstructed the dynamic trajectories of myeloid cells isolated from acutely injured and early stage dystrophic muscles. We identified divergent subsets of monocytes/macrophages and DCs and validated markers (e.g., glycoprotein NMB [GPNMB]) and transcriptional regulators associated with defined functional states. In dystrophic muscle, specialized repair-associated subsets exhibited distinct macrophage diversity and reduced DC heterogeneity. Integrating spatial transcriptomics analyses with immunofluorescence uncovered the ordered distribution of subpopulations and multilayered regenerative inflammation zones (RIZs) where distinct macrophage subsets are organized in functional zones around damaged myofibers supporting all phases of regeneration. Importantly, intermittent glucocorticoid treatment disrupted the RIZs. Our findings suggest that macrophage subtypes mediated the development of the highly ordered architecture of regenerative tissues, unveiling the principles of the structured yet dynamic nature of regenerative inflammation supporting effective tissue repair.

Evaluating Wind Speed Forecasting Models: A Comparative Study of CNN, DAN2, Random Forest and XGBOOST in Diverse South African Weather Conditions

The main source of electricity worldwide stems from fossil fuels, contributing to air pollution, global warming, and associated adverse effects. This study explores wind energy as a potential alternative. Nevertheless, the variable nature of wind introduces uncertainty in its reliability. Thus, it is necessary to identify an appropriate machine learning model capable of reliably forecasting wind speed under various environmental conditions. This research compares the effectiveness of Dynamic Architecture for Artificial Neural Networks (DAN2), convolutional neural networks (CNN), random forest and XGBOOST in predicting wind speed across three locations in South Africa, characterised by different weather patterns. The forecasts from the four models were then combined using quantile regression averaging models, generalised additive quantile regression (GAQR) and quantile regression neural networks (QRNN). Empirical results show that CNN outperforms DAN2 in accurately forecasting wind speed under different weather conditions. This superiority is likely due to the inherent architectural attributes of CNNs, including feature extraction capabilities, spatial hierarchy learning, and resilience to spatial variability. The results from the combined forecasts were comparable with those from the QRNN, which was slightly better than those from the GAQR model. However, the combined forecasts were more accurate than the individual models. These results could be useful to decision-makers in the energy sector.

An 8-bit successive-approximation register analog-to-digital converter operating at 125 kS/s with enhanced comparator in 180 nm CMOS technology

Data converters are necessary for the conversion process of analog and digital signals. Successive approximation register (SAR) analog-to-digital converters (ADC) can achieve high levels of accuracy while consuming relatively low amounts of power and operating at relatively high speeds. This paper describes a design of 8-bit 125 kS/s SAR ADC with a proposed high-speed comparator design based on dynamic latch architecture. The proposed design of the comparator enhances the performance compared to a conventional dynamic comparator by adding two parallel clocked input complementary metal-oxide semiconductor (CMOS) transistors which reduce the parasitic resistance in the latch ground path and serve to minimize the latch delay time. The design of each sub-system for the ADC is explained thoroughly, which contains a sample and hold circuit, successive approximation register, charge redistribution types digital-to-analog converter, and the new proposed comparator. The proposed design is implemented using 180 nm CMOS technology with a power supply of 1.2 V. The average inaccuracy in differential non-linearity (DNL) is +0.6/−0.8 LSB (least significant bit), and integral non-linearity (INL) is +0.4/−0.7 LSB. The proposed design exhibits a delay time of 157 ps at 1 MHz clock frequency.

How are segmentation and binding computed and represented in the brain?

A programmatically described solution to the segmentation problem is taken as opportunity to dicuss the neural architecture problem of vision. At the center of this problem is the formation of holistic entities (the Gestalt phenomenon) out of masses of neurons (the binding problem). As formulated in the Dynamic Net Architecture (DNA), neurons can become part of a (short-term) stable state only if supported inside a coherent network ('net'). Integration into nets is the basis for global treatment of structures, such as recognition as rigid body or projection to an invariant model.

Brain dynamics supported by a hierarchy of complex correlation patterns defining a robust functional architecture

Functional magnetic resonance imaging (fMRI) provides insights into cognitive processes with significant clinical potential. However, delays in brain region communication and dynamic variations are often overlooked in functional network studies. We demonstrate that networks extracted from fMRI cross-correlation matrices, considering time lags between signals, show remarkable reliability when focusing on statistical distributions of network properties. This reveals a robust brain functional connectivity pattern, featuring a sparse backbone of strong 0-lag correlations and weaker links capturing coordination at various time delays. This dynamic yet stable network architecture is consistent across rats, marmosets, and humans, as well as in electroencephalogram (EEG) data, indicating potential universality in brain dynamics. Second-order properties of the dynamic functional network reveal a remarkably stable hierarchy of functional correlations in both group-level comparisons and test-retest analyses. Validation using alcohol use disorder fMRI data uncovers broader shifts in network properties than previously reported, demonstrating the potential of this method for identifying disease biomarkers.