scholarly journals Parallel Distributed Networks Resolved at High Resolution Reveal Close Juxtaposition of Distinct Regions

2018 ◽  
Author(s):  
Rodrigo M. Braga ◽  
Koene R. A. Van Dijk ◽  
Jonathan R. Polimeni ◽  
Mark C. Eldaief ◽  
Randy L. Buckner
Keyword(s):  
High Resolution ◽  
Large Scale ◽  
Spatial Separation ◽  
Distributed Networks ◽  
Association Cortex ◽  
Default Network ◽  
Network Organization ◽  
Parahippocampal Cortex ◽  
The Individual ◽  
Insight Into

Examination of large-scale distributed networks within the individual reveals details of cortical network organization that are absent in group-averaged studies. One recent discovery is that a distributed transmodal network, often referred to as the ‘default network’, is comprised of two separate but closely interdigitated networks, only one of which is coupled to posterior parahippocampal cortex. Not all studies of individuals have identified the same networks and questions remain about the degree to which the two networks are separate, particularly within regions hypothesized to be interconnected hubs. Here we replicate the observation of network separation across analytical (seed-based connectivity and parcellation) and data projection (volume and surface) methods in 2 individuals each scanned 31 times. Additionally, 3 individuals were examined with high-resolution fMRI to gain further insight into the anatomical details. The two networks were identified with separate regions localized to adjacent portions of the cortical ribbon, sometimes inside the same sulcus. Midline regions previously implicated as hubs revealed near complete spatial separation of the two networks, displaying a complex spatial topography in the posterior cingulate and precuneus. The network coupled to parahippocampal cortex also revealed a separate region directly within the hippocampus at or near the subiculum. These collective results support that the default network is composed of at least two spatially juxtaposed networks. Fine spatial details and juxta-positions of the two networks can be identified within individuals at high resolution, providing insight into the network organization of association cortex and placing further constraints on interpretation of group-averaged neuroimaging data.

scholarly journals Parallel distributed networks resolved at high resolution reveal close juxtaposition of distinct regions

2019 ◽  
Vol 121 (4) ◽  
pp. 1513-1534 ◽  
Author(s):  
Rodrigo M. Braga ◽  
Koene R. A. Van Dijk ◽  
Jonathan R. Polimeni ◽  
Mark C. Eldaief ◽  
Randy L. Buckner
Keyword(s):  
High Resolution ◽  
Large Scale ◽  
Hippocampal Formation ◽  
Spatial Separation ◽  
Distributed Networks ◽  
Association Cortex ◽  
Default Network ◽  
Network Organization ◽  
Parahippocampal Cortex ◽  
Insight Into

Examination of large-scale distributed networks within the individual reveals details of cortical network organization that are absent in group-averaged studies. One recent discovery is that a distributed transmodal network, often referred to as the “default network,” comprises two closely interdigitated networks, only one of which is coupled to posterior parahippocampal cortex. Not all studies of individuals have identified the same networks, and questions remain about the degree to which the two networks are separate, particularly within regions hypothesized to be interconnected hubs. In this study we replicate the observation of network separation across analytical (seed-based connectivity and parcellation) and data projection (volume and surface) methods in two individuals each scanned 31 times. Additionally, three individuals were examined with high-resolution (7T; 1.35 mm) functional magnetic resonance imaging to gain further insight into the anatomical details. The two networks were identified with separate regions localized to adjacent portions of the cortical ribbon, sometimes inside the same sulcus. Midline regions previously implicated as hubs revealed near complete spatial separation of the two networks, displaying a complex spatial topography in the posterior cingulate and precuneus. The network coupled to parahippocampal cortex also revealed a separate region directly within the hippocampus, at or near the subiculum. These collective results support that the default network is composed of at least two spatially juxtaposed networks. Fine spatial details and juxtapositions of the two networks can be identified within individuals at high resolution, providing insight into the network organization of association cortex and placing further constraints on interpretation of group-averaged neuroimaging data. NEW & NOTEWORTHY Recent evidence has emerged that canonical large-scale networks such as the “default network” fractionate into parallel distributed networks when defined within individuals. This research uses high-resolution imaging to show that the networks possess juxtapositions sometimes evident inside the same sulcus and within regions that have been previously hypothesized to be network hubs. Distinct circumscribed regions of one network were also resolved in the hippocampal formation, at or near the parahippocampal cortex and subiculum.

scholarly journals Parallel distributed networks dissociate episodic and social functions within the individual

2020 ◽  
Vol 123 (3) ◽  
pp. 1144-1179 ◽  
Author(s):  
Lauren M. DiNicola ◽  
Rodrigo M. Braga ◽  
Randy L. Buckner
Keyword(s):  
Theory Of Mind ◽  
Large Scale ◽  
Distributed Networks ◽  
Association Cortex ◽  
Default Network ◽  
Multiple Forms ◽  
Social Functions ◽  
Temporoparietal Junction ◽  
Parahippocampal Cortex ◽  
The Individual

Association cortex is organized into large-scale distributed networks. One such network, the default network (DN), is linked to diverse forms of internal mentation, opening debate about whether shared or distinct anatomy supports multiple forms of cognition. Using within-individual analysis procedures that preserve idiosyncratic anatomical details, we probed whether multiple tasks from two domains, episodic projection and theory of mind (ToM), rely on the same or distinct networks. In an initial experiment (6 subjects, each scanned 4 times), we found evidence that episodic projection and ToM tasks activate separate regions distributed throughout the cortex, with adjacent regions in parietal, temporal, prefrontal, and midline zones. These distinctions were predicted by the hypothesis that the DN comprises two parallel, interdigitated networks. One network, linked to parahippocampal cortex (PHC), is preferentially recruited during episodic projection, including both remembering and imagining the future. A second juxtaposed network, which includes the temporoparietal junction (TPJ), is differentially engaged during multiple forms of ToM. In two prospectively acquired independent experiments, we replicated and triplicated the dissociation (each with 6 subjects scanned 4 times). Furthermore, the dissociation was found in all zones when analyzed independently, including robustly in midline regions previously described as hubs. The TPJ-linked network is interwoven with the PHC-linked network across the cortex, making clear why it is difficult to fully resolve the two networks in group-averaged or lower-resolution data. These results refine our understanding of the functional-anatomical organization of association cortex and raise fundamental questions about how specialization might arise in parallel, juxtaposed association networks. NEW & NOTEWORTHY Two distributed, interdigitated networks exist within the bounds of the canonical default network. Here we used repeated scanning of individuals, across three independent samples, to provide evidence that tasks requiring episodic projection or theory of mind differentially recruit the two networks across multiple cortical zones. The two distributed networks thus appear to preferentially subserve distinct functions.

scholarly journals Parallel Distributed Networks Dissociate Episodic and Social Functions Within the Individual

2019 ◽  
Author(s):  
Lauren M. DiNicola ◽  
Rodrigo M. Braga ◽  
Randy L. Buckner
Keyword(s):  
Large Scale ◽  
Distributed Networks ◽  
Association Cortex ◽  
Multiple Forms ◽  
Social Functions ◽  
Temporoparietal Junction ◽  
Cortical Organization ◽  
Functional Regions ◽  
Parahippocampal Cortex ◽  
The Individual

Association cortex is organized into large-scale distributed networks. One such network, the default network (DN), is linked to diverse forms of internal mentation, opening debate about whether shared anatomy supports multiple forms of cognition. Alternatively, subtle distinctions in cortical organization could remain to be resolved. Using within-individual analysis procedures that preserve idiosyncratic details of cortical anatomy, we probed whether multiple tasks from two domains - Episodic Projection and Theory of Mind (ToM) - rely upon the same or distinct networks. In an initial experiment (n=6, subjects scanned 4 times each), we found evidence that Episodic Projection and ToM tasks activate distinct functional regions distributed throughout cortex, with adjacent regions in parietal, temporal, prefrontal and midline zones. These distinctions were predicted by the hypothesis that the DN comprises two parallel, interdigitated networks. One network, linked to parahippocampal cortex (PHC), is preferentially recruited during Episodic Projection, including both remembering the past and imagining the future. A second juxtaposed network, which includes the temporoparietal junction (TPJ), is differentially engaged during multiple forms of ToM tasks. The TPJ-linked network is interwoven with the PHC-linked network in multiple zones, including the posterior and anterior midline, making clear why it is difficult to fully resolve the two networks in group-averaged or lower-resolution data. We replicated all aspects of this network dissociation in a second, prospectively acquired dataset (n=6). These results refine our understanding of the functional-anatomical organization of association cortex as well as raise questions about how functional specialization might arise in parallel, juxtaposed association networks.

scholarly journals Situating the Left-Lateralized Language Network in the Broader Organization of Multiple Specialized Large-Scale Distributed Networks

2019 ◽  
Author(s):  
Rodrigo M. Braga ◽  
Lauren M. DiNicola ◽  
Randy L. Buckner
Keyword(s):  
Large Scale ◽  
Temporal Cortex ◽  
Distributed Networks ◽  
Inferior Temporal Cortex ◽  
Association Cortex ◽  
Candidate Network ◽  
Motor Region ◽  
Classical Language ◽  
The Individual ◽  
Language Network

Using procedures optimized to explore network organization within the individual, the topography of a candidate language network was characterized and situated within the broader context of adjacent networks. The candidate network was first identified using functional connectivity and replicated across individuals, datasets, acquisition tasks, and analytic methods. In addition to classical language regions near to perisylvian cortex and temporal pole, additional regions were observed in dorsal posterior cingulate, midcingulate, anterior superior frontal and inferior temporal cortex. The candidate network was selectively activated when processing meaningful (as contrast to non-word) sentences, while spatially adjacent networks showed minimal or even decreased activity. Examined in relation to adjacent networks, the topography of the language network was found to parallel the motif of other association networks including the transmodal association networks linked to theory of mind and episodic remembering (often collectively called the default network). The several networks contained juxtaposed regions in multiple association zones. Outside of these juxtaposed higher-order networks, we further noted a distinct frontotemporal network situated between language regions and a frontal orofacial motor region and a temporal auditory region. A possibility is that these functionally-related sensorimotor regions might anchor specialization of neighboring association regions that develop into the language network. What is most striking is that the canonical language network appears to be just one of multiple similarly organized, differentially specialized distributed networks that populate the evolutionarily expanded zones of human association cortex.

scholarly journals Situating the left-lateralized language network in the broader organization of multiple specialized large-scale distributed networks

2020 ◽  
Vol 124 (5) ◽  
pp. 1415-1448 ◽  
Author(s):  
Rodrigo M. Braga ◽  
Lauren M. DiNicola ◽  
Hannah C. Becker ◽  
Randy L. Buckner
Keyword(s):  
Functional Connectivity ◽  
Large Scale ◽  
Distributed Networks ◽  
Task Demands ◽  
Association Cortex ◽  
Control Networks ◽  
Language Network

This research shows that a language network can be identified within individuals using functional connectivity. Organizational details reveal that the language network shares a common spatial motif with other association networks, including default and frontoparietal control networks. The language network is activated by language task demands, whereas closely juxtaposed networks are not, suggesting that similarly organized but differentially specialized distributed networks populate association cortex.

scholarly journals Detection and Differentiation of Two Koala Gammaherpesviruses by Use of High-Resolution Melt (HRM) Analysis Reveals Differences in Viral Prevalence and Clinical Associations in a Large Study of Free-Ranging Koalas

2019 ◽  
Vol 57 (3) ◽  
Author(s):  
P. K. Vaz ◽  
A. R. Legione ◽  
C. A. Hartley ◽  
J. M. Devlin
Keyword(s):  
High Resolution ◽  
Clinical Significance ◽  
Large Scale ◽  
Diagnostic Methods ◽  
High Resolution Melt ◽  
Phascolarctos Cinereus ◽  
Content Type ◽  
Island Populations ◽  
Chlamydia Pecorum ◽  
The Individual

ABSTRACTThe iconic koala (Phascolarctos cinereus) is host to two divergent gammaherpesviruses, phascolarctid gammaherpesviruses 1 and 2 (PhaHV-1 and -2), but the clinical significance of the individual viruses is unknown and current diagnostic methods are unsuitable for differentiating between the viruses in large-scale studies. To address this, we modified a pan-herpesvirus nested PCR to incorporate high-resolution melt analysis. We applied this assay in a molecular epidemiological study of 810 koalas from disparate populations across Victoria, Australia, including isolated island populations. Animal and clinical data recorded at sampling were analyzed and compared to infection status. Between populations, the prevalence of PhaHV-1 and -2 varied significantly, ranging from 1% to 55%. Adult and older animals were 5 to 13 times more likely to be positive for PhaHV-1 than juveniles (P< 0.001), whereas PhaHV-2 detection did not change with age, suggesting differences in how these two viruses are acquired over the life of the animal. PhaHV-1 detection was uniquely associated with the detection of koala retrovirus, particularly in females (P= 0.008). Both viruses were significantly associated (P< 0.05) with the presence of genital tract abnormalities (uterine/ovarian cysts and testicular malformation), reduced fertility in females, urinary incontinence, and detection ofChlamydia pecorum, although the strength of these associations varied by sex and virus. Understanding the clinical significance of these viruses and how they interact with other pathogens will inform future management of threatened koala populations.

scholarly journals Rapid, Large-Scale Wastewater Surveillance and Automated Reporting System Enable Early Detection of Nearly 85% of COVID-19 Cases on a University Campus

mSystems ◽  
2021 ◽  
Author(s):  
Smruthi Karthikeyan ◽  
Andrew Nguyen ◽  
Daniel McDonald ◽  
Yijian Zong ◽  
Nancy Ronquillo ◽  
...  
Keyword(s):  
High Resolution ◽  
Early Detection ◽  
Large Scale ◽  
Reporting System ◽  
Spatial Sampling ◽  
Campus Community ◽  
University Campus ◽  
University Campuses ◽  
Insight Into

Wastewater-based epidemiology can be particularly valuable at university campuses where high-resolution spatial sampling in a well-controlled context could not only provide insight into what affects campus community as well as how those inferences can be extended to a broader city/county context. In the present study, a large-scale wastewater surveillance was successfully implemented on a large university campus enabling early detection of 85% of COVID-19 cases thereby averting potential outbreaks.

Simulating the emission and transport of gases on 100-meter resolution in a 100-kilometer domain.

2021 ◽  
Author(s):  
Marco de Bruine ◽  
Fredrik Jansson ◽  
Bart van Stratum ◽  
Pieter Rijsdijk ◽  
Sander Houweling
Keyword(s):  
Boundary Layer ◽  
High Resolution ◽  
The Netherlands ◽  
Large Scale ◽  
Satellite Monitoring ◽  
Free Atmosphere ◽  
Activity Data ◽  
Eddy Simulation ◽  
Large Scale Flow ◽  
Insight Into

&lt;p&gt;Climate regulations and satellite monitoring on increasingly high resolution creates a demand for an insight into emissions on an urban scale. The aim of the Ruisdael Observatory (www.ruisdaelobservatory.nl) is to provide just that: detailed and high-resolution modelling and measurements of weather and air quality in a domain covering the Netherlands.&lt;/p&gt;&lt;p&gt;The Ruisdael Observatory created a renewed impulse in the developments of the DALES Large-eddy simulation (LES) model (Heus et al., 2010, Ouwersloot et al. 2016) to find and push the limits of atmospheric modelling. Typical simulations with DALES will use a spatial resolution in the order of 100m in domain sizes spanning over 100x100 km. This high resolution justifies the complexity and the multitude of emission sources and resulting transport of pollutants in the atmospheric boundary layer.&lt;/p&gt;&lt;p&gt;The combination of high resolution and large domain sizes allows us to investigate how emissions disperse in a turbulent environment which is forced by large-scale flow at the same time. Parameterizations are no longer needed to calculate horizontal or vertical transport in the boundary-layer. This way, we can provide new insight into the transport of emissions in the boundary layer and the detrainment of gases out of the boundary layer into the free atmosphere.&lt;/p&gt;&lt;p&gt;We will discuss the construction of our emission database for the Netherlands with a 100-meter and 1-hourly resolution. For this, we started from the official E-PRTR reported emission inventories (www.emissieregistratie.nl) and enriched with high resolution activity data from mostly open-source datasets. Moreover, large emissions sources (accounting for e.g. &gt;80% of CO2 emissions) are subject to mandatory registration and their locations are known exactly. Emissions from different source categories can be tracked individually and compared to measurements from the Ruisdael Observatory measurement sites. Examples of simulations of fair-weather summer days will be compared to surface measurements and showcase the data richness of our new model and combination to measurements from our network.&lt;/p&gt;

scholarly journals Beyond duty hours: leveraging large-scale paging data to monitor resident workload

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Amit Kaushal ◽  
Laurence Katznelson ◽  
Robert A. Harrington
Keyword(s):  
Data Streams ◽  
Data Stream ◽  
Large Scale ◽  
Digital Data ◽  
Internal Medicine Residency Program ◽  
Duty Hours ◽  
Individual Level ◽  
Hospital Operations ◽  
The Individual ◽  
Insight Into

Abstract Monitoring and managing resident workload is a cornerstone of policy in graduate medical education, and the duty hours metric is the backbone of current regulations. While the duty hours metric measures hours worked, it does not capture differences in intensity of work completed during those hours, which may independently contribute to fatigue and burnout. Few such metrics exist. Digital data streams generated during the usual course of hospital operations can serve as a novel source of insight into workload intensity by providing high-resolution, minute-by-minute data at the individual level; however, study and use of these data streams for workload monitoring has been limited to date. Paging data is one such data stream. In this work, we analyze over 500,000 pages—two full years of pages in an academic internal medicine residency program—to characterize paging patterns among housestaff. We demonstrate technical feasibility, validity, and utility of paging burden as a metric to provide insight into resident workload beyond duty hours alone, and illustrate a general framework for evaluation and incorporation of novel digital data streams into resident workload monitoring.

scholarly journals Brain Network Organization During Mindful Acceptance of Emotions

2020 ◽  
Author(s):  
Matthew Luke Dixon ◽  
Manesh Girn ◽  
Kalina Christoff
Keyword(s):  
Information Flow ◽  
Large Scale ◽  
Network Connectivity ◽  
Brain Network ◽  
Global Network ◽  
Default Network ◽  
Present Moment ◽  
Network Organization ◽  
Attentional Scope ◽  
Narrative Evaluation

AbstractIndividuals use various strategies to cope with challenging emotions such as anxiety. Mindful acceptance involves broadening attentional scope and fully experiencing present moment sensory feelings (whether pleasant or unpleasant) without judgment or elaboration. In contrast, narrative-evaluation involves focusing on a narrow band of sensory experience and generating an elaborate narrative about the meaning and desirability of one’s emotional feelings. The current study examined brain network organization during these strategies using graph theoretic analyses. We used a naturalistic task paradigm in which participants reflected on an anxiety-provoking issue from their personal lives and adopted each strategy in different blocks. Compared to narrative-evaluation, mindful acceptance was associated with: (i) increased global network connectivity; (ii) greater integration of interoceptive regions (mid and posterior insula) into large-scale networks; (iii) reorganization of motivational circuits including a shift in the striatum’s network assignment from the default network to the salience network; and (iv) a shift from default network to frontoparietal control network (FPCN) regions as central hubs that coordinate information flow. Functional connectivity patterns within the left FPCN were associated with acceptance reports. Thus, broadening attentional scope during mindful acceptance is supported by a more globally interconnected neural landscape, as well as greater information flow through FPCN regions that underlie metacognitive awareness and cognitive control.

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