Search results for " Connectivity"
showing 10 items of 167 documents
Questions and controversies in the study of time-varying functional connectivity in resting fMRI.
2020
The brain is a complex, multiscale dynamical system composed of many interacting regions. Knowledge of the spatiotemporal organization of these interactions is critical for establishing a solid understanding of the brain’s functional architecture and the relationship between neural dynamics and cognition in health and disease. The possibility of studying these dynamics through careful analysis of neuroimaging data has catalyzed substantial interest in methods that estimate time-resolved fluctuations in functional connectivity (often referred to as “dynamic” or time-varying functional connectivity; TVFC). At the same time, debates have emerged regarding the application of TVFC analyses to re…
Invasive crayfish increase habitat connectivity
2012
Several studies have shown that distinct compartments of lake ecosystems are coupled via transportation of organic matter, nutrients and energy across habitat boundaries. Here we evaluate the potential of the invasive signal crayfish (Pacifastacus leniusculus (Dana)) to modify energy pathways in large boreal lakes. Using a stable isotope mixing model and calculation of the isotopic niches we estimated the contribution of different food sources to the diets of crayfish captured from different habitats, and from that inferred their potential to transport energy across the littoral-profundal gradient. The crayfish caught from the littoral area utilized mainly littoral food sources, whereas the…
Effects of Transcranial Direct Current Stimulation on Brain Networks Related to Creative Thinking
2020
AbstractHuman creative thinking is unique and capable of generating novel and valuable ideas. Recent research has clarified the contribution of different brain networks (default mode network, DN; executive control network; salience network) to creative thinking. However, the effects of brain stimulation on brain networks during creative thinking and on creative performance have not been clarified. The present study was designed to examine the changes in functional connectivity (FC) and effective connectivity (EC) of the large-scale brain network, and the ensuing changes in creative performance, induced by transcranial direct current stimulation (tDCS). Fourteen healthy male students underwe…
SUGGESTIONS OF SCENARIOS FOR RESTORING LONGITUDINAL CONNECTIVITY TO SUSTAIN FISH FAUNA MIGRATION UPSTREAM AND DOWNSTREAM OF APAHIDA BOTTOM SILL
2016
Rivers and their corridors form complex ecosystems that include adjacent land, flora and fauna and the actual courses of water. Given the ecological criteria for prioritizing the rehabilitation of longitudinal continuity of watercourses recommended by the International Commission for Protection of the Danube River (ICPDR) (Appendix 1) and starting from the analysis of the Management Plan to ensure longitudinal continuity of watercourses in Some?-Tisa River Area (Annex 9.17.a in BMP – Basin Management Plan) there have been proposed several scenarios in order to facilitate fish species migration above the bottom sill from Apahida. The selected case study is focused on the mentioned discharge …
DEFAULT MODE NETWORK AND WORKING MEMORY NETWORK DURING AN FMRI WORKING MEMORY TASK: DIFFERENCES AND CORRELATIONS WITH BEHAVIORAL PERFORMANCE
2013
INTRODUCTION Previous neuroimaging studies have shown that working memory load has marked effects on regional neural activation[1-5]. However, the mechanism through which working memory load modulates brain connectivity is still unclear. During a working memory task, two of the most involved networks are the default mode network (DMN) and the working memory network (WMN)[6-7]: the selective focus on these networks can be useful in better understanding the load effects. Spatial independent component analysis (ICA)[8] has becomes a reliable technique to investigate the networks involved during an fMRI task, as it extracts spatiotemporal patterns of neural activity maximizing spatial independe…
Dissociable Functional Brain Networks Associated With Apathy in Subcortical Ischemic Vascular Disease and Alzheimer’s Disease
2021
Few studies have investigated differences in functional connectivity (FC) between patients with subcortical ischemic vascular disease (SIVD) and Alzheimer’s disease (AD), especially in relation to apathy. Therefore, the aim of this study was to compare apathy-related FC changes among patients with SIVD, AD, and cognitively normal subjects. The SIVD group had the highest level of apathy as measured using the Apathy Evaluation Scale-clinician version (AES). Dementia staging, volume of white matter hyperintensities (WMH), and the Beck Depression Inventory were the most significant clinical predictors for apathy. Group-wise comparisons revealed that the SIVD patients had the worst level of “Ini…
Analysing gene flow in heterogeneous landscapes: why and how to use genetic graphs?
2019
International audience; In heterogeneous landscapes, when species occupy discrete habitat patches, ecological connectivity is influenced by populations’ topology. Graph-theoretic methods constitute a relevant tool to reveal this topology and better analyse gene flow. Despite growing interest in genetic graphs, a better understanding of when and how to use them is lacking.To fill this gap, we simulated gene flow between 50 populations in different landscape configurations and constructed genetic graphs using various genetic distances and pruning (link selection) methods. We then compared metrics derived from these graphs to analogous metrics describing the topology and connectivity of the di…
Morphological characterization of calanchi (badland) hillslope connectivity
2017
Calanchi, a type of Italian badlands created by a combination of water erosion processes and local geomorphological and tectonic controls, is a striking example of long-term landscape evolution. In small temporal/spatial scales, the calanchi exhibit many of the geomorphic processes and landforms that may be observed in fluvial landscapes, hence they may be considered as micro-basins where geomorphic dynamics and landscape features can be related. The goal of this research is testing the use of simple morphometric variables for assessing sediment connectivity of calanchi landforms. In order to detect the morphological characteristics controlling the landscape connectivity of calanchi basins,…
Environmental mitigation hierarchy and biodiversity offsets revisited through habitat connectivity modelling.
2020
International audience; Biodiversity loss is accelerating because of unceasing human activity and land clearing for development projects (urbanisation, transport infrastructure, mining and quarrying …). Environmental policy-makers and managers in different countries worldwide have proposed the mitigation hierarchy to ensure the goal of “no net loss (NNL) of biodiversity” and have included this principle in environmental impact assessment processes. However, spatial configuration is hardly ever taken into account in the mitigation hierarchy even though it would greatly benefit from recent developments in habitat connectivity modelling incorporating landscape graphs. Meanwhile, national, Euro…
The Importance of Air Connectivity and the Impact on Romanian Airports
2019
In a world where passenger air travel is set to keep a positive growth rate over the years, airports all over the world are striving to increase their connectivity rate by attracting different airline companies, either for point to point connections or hub connectivity to wider the number of destinations reached from the airport to all over the world via a hub. From an airport perspective, creating a strategy to increase the connectivity performance index requires a lot of market analysis, following latest developments of hub connections from all over Europe, as hub connectivity tends to change on a yearly basis. Airport connectivity performance is directly linked to growth, studies (ACI Eu…