scholarly journals A structure-function substrate of memory for spatial configurations in medial and lateral temporal cortices

2020 ◽  
Author(s):  
Shahin Tavakol ◽  
Qiongling Li ◽  
Jessica Royer ◽  
Reinder Vos de Wael ◽  
Sara Larivière ◽  
...  
Keyword(s):  
Spatial Memory ◽  
Structure Function ◽  
Functional Mri ◽  
Ad Hoc ◽  
Meta Analysis ◽  
Spatial Relations ◽  
Structural Mri ◽  
Spatial Task ◽  
Separation Performance ◽  
New Paradigm

AbstractPrior research has shown that structures of the mesiotemporal lobe, particularly the hippocampal-parahippocampal complex, are engaged in different forms of spatial cognition. Here, we developed a new paradigm, the Conformational Shift Spatial task (CSST), which examines the ability to encode and retrieve spatial relations between three unrelated items. This task is short, uses symbolic cues, and incorporates two difficulty levels and can be administered inside and outside the scanner. A cohort of 48 healthy young adults underwent the CSST, together with a set of validated behavioral measures and multimodal magnetic resonance imaging (MRI). Interindividual differences in CSST performance correlated with scores on an established spatial memory paradigm, but neither with episodic memory nor pattern separation performance, highlighting the specificity of the new measure. Analyzing high resolution structural MRI data, individuals with better spatial memory showed thicker medial as well as lateral temporal cortices. Functional relevance of these findings was supported by task-based functional MRI analysis in the same participants and ad hoc meta-analysis. Exploratory resting-state functional MRI analyses centered on clusters of morphological effects revealed additional modulation of intrinsic network integration, particularly between lateral and medial temporal structures. Our work presents a novel spatial memory paradigm and supports an integrated structure-function substrate in the human temporal lobe. Task paradigms are programmed in python and made open access.

Diagnostic test accuracy for use of machine learning in diagnosis of autism spectrum disorder: A Systematic Review and Meta-Analysis (Preprint)

2019 ◽  
Author(s):  
Sun Jae Moon ◽  
Jin Seub Hwang ◽  
Rajesh Kana ◽  
John Torous ◽  
Jung Won Kim
Keyword(s):  
Machine Learning ◽  
Systematic Review ◽  
Autism Spectrum Disorder ◽  
Meta Analysis ◽  
Learning Algorithms ◽  
Structural Mri ◽  
Autism Spectrum ◽  
Machine Learning Algorithms ◽  
Spectrum Disorder ◽  
Test Accuracy

BACKGROUND Over the recent years, machine learning algorithms have been more widely and increasingly applied in biomedical fields. In particular, its application has been drawing more attention in the field of psychiatry, for instance, as diagnostic tests/tools for autism spectrum disorder. However, given its complexity and potential clinical implications, there is ongoing need for further research on its accuracy. OBJECTIVE The current study aims to summarize the evidence for the accuracy of use of machine learning algorithms in diagnosing autism spectrum disorder (ASD) through systematic review and meta-analysis. METHODS MEDLINE, Embase, CINAHL Complete (with OpenDissertations), PsyINFO and IEEE Xplore Digital Library databases were searched on November 28th, 2018. Studies, which used a machine learning algorithm partially or fully in classifying ASD from controls and provided accuracy measures, were included in our analysis. Bivariate random effects model was applied to the pooled data in meta-analysis. Subgroup analysis was used to investigate and resolve the source of heterogeneity between studies. True-positive, false-positive, false negative and true-negative values from individual studies were used to calculate the pooled sensitivity and specificity values, draw SROC curves, and obtain area under the curve (AUC) and partial AUC. RESULTS A total of 43 studies were included for the final analysis, of which meta-analysis was performed on 40 studies (53 samples with 12,128 participants). A structural MRI subgroup meta-analysis (12 samples with 1,776 participants) showed the sensitivity at 0.83 (95% CI-0.76 to 0.89), specificity at 0.84 (95% CI -0.74 to 0.91), and AUC/pAUC at 0.90/0.83. An fMRI/deep neural network (DNN) subgroup meta-analysis (five samples with 1,345 participants) showed the sensitivity at 0.69 (95% CI- 0.62 to 0.75), the specificity at 0.66 (95% CI -0.61 to 0.70), and AUC/pAUC at 0.71/0.67. CONCLUSIONS Machine learning algorithms that used structural MRI features in diagnosis of ASD were shown to have accuracy that is similar to currently used diagnostic tools.

scholarly journals Network-based approaches to quantify multicellular development

2017 ◽  
Vol 14 (135) ◽  
pp. 20170484 ◽  
Author(s):  
Matthew D. B. Jackson ◽  
Salva Duran-Nebreda ◽  
George W. Bassel
Keyword(s):  
Structure Function ◽  
Spatial Relations ◽  
Higher Order ◽  
Cellular Interaction ◽  
Cellular Organization ◽  
Multicellular Development ◽  
Cell Organization ◽  
Function Relationship ◽  
And Function ◽  
The Relationship

Multicellularity and cellular cooperation confer novel functions on organs following a structure–function relationship. How regulated cell migration, division and differentiation events generate cellular arrangements has been investigated, providing insight into the regulation of genetically encoded patterning processes. Much less is known about the higher-order properties of cellular organization within organs, and how their functional coordination through global spatial relations shape and constrain organ function. Key questions to be addressed include: why are cells organized in the way they are? What is the significance of the patterns of cellular organization selected for by evolution? What other configurations are possible? These may be addressed through a combination of global cellular interaction mapping and network science to uncover the relationship between organ structure and function. Using this approach, global cellular organization can be discretized and analysed, providing a quantitative framework to explore developmental processes. Each of the local and global properties of integrated multicellular systems can be analysed and compared across different tissues and models in discrete terms. Advances in high-resolution microscopy and image analysis continue to make cellular interaction mapping possible in an increasing variety of biological systems and tissues, broadening the further potential application of this approach. Understanding the higher-order properties of complex cellular assemblies provides the opportunity to explore the evolution and constraints of cell organization, establishing structure–function relationships that can guide future organ design.

The human hippocampus is not sexually-dimorphic: Meta-analysis of structural MRI volumes

NeuroImage ◽  
2016 ◽  
Vol 124 ◽  
pp. 350-366 ◽  
Author(s):  
Anh Tan ◽  
Wenli Ma ◽  
Amit Vira ◽  
Dhruv Marwha ◽  
Lise Eliot
Keyword(s):  
Meta Analysis ◽  
Structural Mri ◽  
Sexually Dimorphic ◽  
Human Hippocampus

scholarly journals Neuroimaging Anomalies in Community-Dwelling Asymptomatic Adults With Very Early-Stage White Matter Hyperintensity

2021 ◽  
Vol 13 ◽  
Author(s):  
Shuai Guan ◽  
Xiangyu Kong ◽  
Shifei Duan ◽  
Qingguo Ren ◽  
Zhaodi Huang ◽  
...  
Keyword(s):  
White Matter ◽  
Functional Mri ◽  
Resting State ◽  
Early Stage ◽  
Structural Mri ◽  
Resting State Fmri ◽  
Community Dwelling ◽  
White Matter Hyperintensity ◽  
Age Related ◽  
Comparative Results

White matter hyperintensity (WMH) is common in healthy adults in their 60s and can be seen as early as in their 30s and 40s. Alterations in the brain structural and functional profiles in adults with WMH have been repeatedly studied but with a focus on late-stage WMH. To date, structural and functional MRI profiles during the very early stage of WMH remain largely unexplored. To address this, we investigated multimodal MRI (structural, diffusion, and resting-state functional MRI) profiles of community-dwelling asymptomatic adults with very early-stage WMH relative to age-, sex-, and education-matched non-WMH controls. The comparative results showed significant age-related and age-independent changes in structural MRI-based morphometric measures and resting-state fMRI-based measures in a set of specific gray matter (GM) regions but no global white matter changes. The observed structural and functional anomalies in specific GM regions in community-dwelling asymptomatic adults with very early-stage WMH provide novel data regarding very early-stage WMH and enhance understanding of the pathogenesis of WMH.

scholarly journals Simulation of Cryptographic Algorithms in IPSec on Ad-Hoc Networks

2017 ◽  
Vol 28 (1) ◽  
pp. 31-46
Author(s):  
A.A. Adas A.A. Adas
Keyword(s):  
Ad Hoc Networks ◽  
Ad Hoc Network ◽  
Ad Hoc ◽  
Data Communication ◽  
Secure Routing ◽  
Security Model ◽  
Mobile Nodes ◽  
New Paradigm ◽  
Hoc Networks ◽  
Ipsec Protocol

This paper focuses on secure data communication between nodes in Ad-Hoc networks by employing IPSec (Internet Protocol Security). In wireless communication, Ad-Hoc network is a new paradigm since, which is used for highly sensitive and emergency operations. Ad-Hoc network is considered a number of mobile nodes that are connected through wireless interfaces and moves arbitrarily. Ensuring security is one of the main issues due to its infrastructure less solutions. This research aims for IPSec protocol that provides security for an Ad-Hoc networking in a various applications. IPSec incorporates security model, i.e. AES (Advanced Encryption Standard) into its framework. In this work, we consider the problem of incorporating security mechanisms to securing data communication for Ad-Hoc networks. We look at AODV routing protocol (Ad-Hoc On-Demand Distance Vector) in detail and it is used for secure routing. Simulation of IPSec protocol is simulated using NS-3 simulator. Results from NS-3 simulator is compared with AH, ESP, and AES in terms of Quality of Service parameters throughput, average processing time and average end-to-end delay.

Can Preoperative Mapping with Functional MRI Reduce Morbidity in Brain Tumor Resection? A Systematic Review and Meta-Analysis of 68 Observational Studies

Radiology ◽  
2021 ◽  
pp. 204723
Author(s):  
Licia P. Luna ◽  
Farzaneh Ghazi Sherbaf ◽  
Haris I. Sair ◽  
Debraj Mukherjee ◽  
Isabella Bezerra Oliveira ◽  
...  
Keyword(s):  
Systematic Review ◽  
Brain Tumor ◽  
Functional Mri ◽  
Observational Studies ◽  
Meta Analysis ◽  
Tumor Resection ◽  
Preoperative Mapping ◽  
Brain Tumor Resection

scholarly journals Tactile direction discrimination in humans after stroke

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Linda C Lundblad ◽  
Håkan Olausson ◽  
Pontus Wasling ◽  
Katarina Jood ◽  
Anna Wysocka ◽  
...  
Keyword(s):  
White Matter ◽  
Functional Mri ◽  
Sensory System ◽  
Insular Cortex ◽  
Structural Mri ◽  
Skin Surface ◽  
Direction Discrimination ◽  
Healthy Humans ◽  
Tactile Stimuli ◽  
Hands And Feet

Abstract Sensing movements across the skin surface is a complex task for the tactile sensory system, relying on sophisticated cortical processing. Functional MRI has shown that judgements of the direction of tactile stimuli moving across the skin are processed in distributed cortical areas in healthy humans. To further study which brain areas are important for tactile direction discrimination, we performed a lesion study, examining a group of patients with first-time stroke. We measured tactile direction discrimination in 44 patients, bilaterally on the dorsum of the hands and feet, within 2 weeks (acute), and again in 28 patients 3 months after stroke. The 3-month follow-up also included a structural MRI scan for lesion delineation. Fifty-nine healthy participants were examined for normative direction discrimination values. We found abnormal tactile direction discrimination in 29/44 patients in the acute phase, and in 21/28 3 months after stroke. Lesions that included the opercular parietal area 1 of the secondary somatosensory cortex, the dorsolateral prefrontal cortex or the insular cortex were always associated with abnormal tactile direction discrimination, consistent with previous functional MRI results. Abnormal tactile direction discrimination was also present with lesions including white matter and subcortical regions. We have thus delineated cortical, subcortical and white matter areas important for tactile direction discrimination function. The findings also suggest that tactile dysfunction is common following stroke.

THE INNOVATION OF VULNERABLE FISHERIES USING ECOSYSTEM-BASED FISHERY MANAGEMENT APPROACH: A TEST CASE IN KARIMUNJAWA ECOSYSTEM, CENTRAL JAVA, INDONESIA

2016 ◽  
Vol 78 (4-2) ◽  
Author(s):  
Mayanggita Kirana ◽  
Indah Susilowati ◽  
Kuperan Viswanathan
Keyword(s):  
Fisheries Management ◽  
Fishery Management ◽  
Meta Analysis ◽  
Marine Ecosystem ◽  
Primary Data ◽  
Management Approach ◽  
New Paradigm ◽  
Initial Finding ◽  
Central Java ◽  
The Government

The sustainability of marine ecosystem has become a major concern the government; however, the implementation of sustainability-based fisheries management has not been fully carried out and well controlled. Therefore, having a concept of ecosystem-based fisheries management (EBFM) is essential in protecting it preserved. The aim of this study was to analyze the implementation of EBFM in Karimunjawa ecosystem, Central Java, Indonesia. The analysis of this study was based on the primary data collected from fishermen and stakeholders using in-depth interviews, and the secondary data gathered from stakeholders of Karimunjawa documentation. Meta-analysis with triangulation was invoked in this study. The result showed that the vulnerability of marine ecosystem, particularly fisheries’ resource in the pilot project is in progress. The conventional approach has not yet succeeded in managing fisheries’ resource in terms of sustainability attributes. Moreover, the EBFM has not yet proven to be a suitable approach for some reasons; although, this concept is very promising in encouraging a new paradigm for sustainable management in Indonesia with a protocol concept. This initial finding needs to be furthered in order to explore other aspects of development. 

Statistical methods for detecting outlying and influential studies in meta-analysis of diagnostic test accuracy studies

2019 ◽  
Vol 29 (4) ◽  
pp. 1227-1242 ◽  
Author(s):  
Zelalem F Negeri ◽  
Joseph Beyene
Keyword(s):  
Diagnostic Test ◽  
Random Effects ◽  
Ad Hoc ◽  
Meta Analysis ◽  
Analysis Data ◽  
Diagnostic Test Accuracy ◽  
Statistical Reasoning ◽  
Test Accuracy ◽  
Analysis Tool ◽  
Random Effects Models

Bivariate random-effects models are currently widely used to synthesize pairs of test sensitivity and specificity across studies. Inferences drawn based on these models may be distorted in the presence of outlying or influential studies. Currently, subjective methods such as inspection of forest plots are used to identify outlying studies in meta-analysis of diagnostic test accuracy studies. We proposed objective methods based on solid statistical reasoning for identifying outlying and/or influential studies. The proposed methods have been validated using simulation study and illustrated on two published meta-analysis data. Our methods outperform and neglect the subjectivity of the currently used ad hoc methods. The proposed methods can be used as a sensitivity analysis tool concurrently with the current bivariate random-effects models or as a preliminary analysis tool for robust models that accommodate outlying and/or influential studies in meta-analysis of diagnostic test accuracy studies.

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