weak connectivity
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2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Victor M. Vergara ◽  
Martin Norgaard ◽  
Robyn Miller ◽  
Roger E. Beaty ◽  
Kiran Dhakal ◽  
...  

AbstractOne of the most complex forms of creativity is musical improvisation where new music is produced in real time. Brain behavior during music production has several dimensions depending on the conditions of the performance. The expression of creativity is suspected to be different whether novel ideas must be externalized using a musical instrument or can be imagined internally. This study explores whole brain functional network connectivity from fMRI data during jazz music improvisation compared against a baseline of prelearned score performance. Given that creativity might be affected by external execution, another dimension where musicians imagine or vocalize the music was also tested. We found improvisation was associated with a state of weak connectivity necessary for attenuated executive control network recruitment associated with a feeling of “flow” allowing unhindered musical creation. In addition, elicited connectivity for sensorimotor and executive control networks is not different whether musicians imagine or externalize (through vocalization) musical performance.


2021 ◽  
Vol 0 (0) ◽  
pp. 0
Author(s):  
Pierre Roux ◽  
Delphine Salort

<p style='text-indent:20px;'>The Nonlinear Noisy Leaky Integrate and Fire (NNLIF) model is widely used to describe the dynamics of neural networks after a diffusive approximation of the mean-field limit of a stochastic differential equation. In previous works, many qualitative results were obtained: global existence in the inhibitory case, finite-time blow-up in the excitatory case, convergence towards stationary states in the weak connectivity regime. In this article, we refine some of these results in order to foster the understanding of the model. We prove with deterministic tools that blow-up is systematic in highly connected excitatory networks. Then, we show that a relatively weak control on the firing rate suffices to obtain global-in-time existence of classical solutions.</p>


Author(s):  
Evelyn Valencia ◽  
Erika Meerhoff ◽  
Ernesto Díaz‐Cabrera ◽  
Felipe Guerrero ◽  
Noemi Roja‐Hernández ◽  
...  

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Lu Liu ◽  
Lichuan Zhang ◽  
Shuo Zhang ◽  
Sheng Cao

In this paper, a multi-unmanned underwater vehicle (UUV) cooperative dynamic maneuver decision-making algorithm is proposed based on the combination of game theory and intuitionistic fuzzy sets. Underwater environments with weak connectivity, underwater noise, and dynamic uncertainties are fully considered through intuitionistic fuzzy sets, which solves one of the main problems in making decisions underwater. Subsequently, the intuitionistic fuzzy multiattribute evaluation of a UUV maneuver strategy is conducted, and the intuitionistic fuzzy payment matrix of the cooperative dynamic maneuver game is obtained. Thereafter, the Nash equilibrium condition is proposed to satisfy the intuitionistic fuzzy total order, and the Nash equilibrium maneuver decision-making model under a dynamic underwater environment is established. Meanwhile, the modified particle swarm optimization method is presented to solve the established problem and find the optimal strategy. Finally, an example is used to verify the superiority of the proposed cooperative dynamic maneuver decision-making algorithm.


2020 ◽  
Author(s):  
Qian Wang ◽  
Lu Luo ◽  
Na Xu ◽  
Jing Wang ◽  
Yayue Gao ◽  
...  

ABSTRACTThe human auditory sensory area, which includes primary and non-primary auditory cortices, has been considered to locate in the supra-temporal lobe for more than a century. Recently, accumulating evidence shows that the posterior part of insula responses to sounds under non-task states with relevant short latencies. However, whether posterior insula (InsP) contribute to forming auditory sensation remains unclear. Here we addressed this issue by recording and stimulation directly on the supra-temporal and insular areas via intracranial electrodes from 53 epileptic patients. During passive listening to a non-speech sound, the high-γ (60-140 Hz) active rate of InsP (68.8%) was approximate to the non-primary auditory areas (72.4% and 79.0%). Moreover, we could not distinguish InsP from supra-temporal subareas by either activation, latency, temporal pattern or lateral dominance of sound induce high-γ. On the contrary, direct electrical stimulation evoked auditory sensations effectively on supra-temporal subareas (> 65%), while sparsely on InsP (9.49%). The results of cortico-cortical evoked potentials (CCEPs) showed strong bidirectional connectivity within supra-temporal areas, but weak connectivity between supra-temporal areas and InsP. These findings suggest that even the InsP has similar basic auditory response properties to the primary or non-primary cortex, it may not directly participate in the formation of auditory perception.


2020 ◽  
Vol 8 (1) ◽  
pp. 5-16
Author(s):  
Fraidoon Rashid ◽  
Devan O. Hussein ◽  
Hawar A. Zangana

The Tertiary rocks of Khurmala Formation in the Taq Taq oil field have been studied using wireline log analysis, drilling cutting descriptions with integration of mud logging report, and test results for understanding reservoir potentiality and fluid distribution. The formation comprised dolostone and dolomitic limestone with an intercalation of clay layers between the recognized beds. The formation has variable thickness throughout the field, 99.8 m from the northeastern limb and 109 m in the southeastern plunge. The calculated shale volume in the studied interval shows a high rate of the clay contents which in some points the gamma ray has 100% of shale. The corrected log-derived bulk porosity subdivided the Khurmala Formation into 5 porosity units from the top to the bottom including (Kh-1, Kh-2, Kh-3, Kh-4, and Kh-5). The first (Kh-1), third (Kh-3), and fifth (Kh-5) porosity units have the average porosity ≥0.10 (10%) that can be considered as good reservoir unit in terms of porosity, whereas the shale contents reduced the reservoir quality of these units. However, well hydrocarbon entrapment through interconnected fractures and fault in the other Tertiary reservoir was recorded in Taq Taq field , but the weak connectivity of the pores in the Khurmala Formation caused this rock interval remains as water bearing zone.


The Condor ◽  
2019 ◽  
Vol 121 (3) ◽  
Author(s):  
Ellis L Smith ◽  
Matthew W Reudink ◽  
Peter P Marra ◽  
Ann E Mckellar ◽  
Steven L Van Wilgenburg

ABSTRACT Populations of Vaux’s Swift (Chaetura vauxi), like those of many aerial insectivores, are rapidly declining. Determining when and where populations are limited across the annual cycle is important for their conservation. Establishing the linkages between wintering and breeding sites and the strength of the connections between them is a necessary first step. In this study, we analyzed 3 stable isotopes (δ13C, δ15N, δ2H) from feathers collected during spring migration from Vaux’s Swifts that perished during a stopover on Vancouver Island, British Columbia, Canada. We previously analyzed claw tissue (grown during winter) from the same individuals, revealing that the swifts likely wintered in 2 or 3 locations/habitats. Here, we used stable isotope analysis of flight feathers presumed to have been grown on, or near, the breeding grounds to determine the likely previous breeding locations and presumed destinations for the swifts. Stable isotope values (δ13C, δ15N, δ2H) showed no meaningful variation between age classes, sexes, or with body size. Surprisingly, ~26% of the birds sampled had feather isotope values that were not consistent with growth on their breeding grounds. For the remaining birds, assigned breeding origins appeared most consistent with molt origins on Vancouver Island. Overall, migratory connectivity of this population was relatively weak (rM = 0.07). However, the degree of connectivity depended on how many winter clusters were analyzed; the 2-cluster solution suggested no significant connectivity, but the 3-cluster solution suggested weak connectivity. It is still unclear whether low migratory connectivity observed for Vaux’s Swift and other aerial insectivores may make their populations more or less vulnerable to habitat loss; therefore, further efforts should be directed to assessing whether aerial insectivores may be habitat limited throughout the annual cycle.


2018 ◽  
Vol 115 (14) ◽  
pp. E3192-E3200 ◽  
Author(s):  
Gunnar R. Kramer ◽  
David E. Andersen ◽  
David A. Buehler ◽  
Petra B. Wood ◽  
Sean M. Peterson ◽  
...  

Migratory species can experience limiting factors at different locations and during different periods of their annual cycle. In migratory birds, these factors may even occur in different hemispheres. Therefore, identifying the distribution of populations throughout their annual cycle (i.e., migratory connectivity) can reveal the complex ecological and evolutionary relationships that link species and ecosystems across the globe and illuminate where and how limiting factors influence population trends. A growing body of literature continues to identify species that exhibit weak connectivity wherein individuals from distinct breeding areas co-occur during the nonbreeding period. A detailed account of a broadly distributed species exhibiting strong migratory connectivity in which nonbreeding isolation of populations is associated with differential population trends remains undescribed. Here, we present a range-wide assessment of the nonbreeding distribution and migratory connectivity of two broadly dispersed Nearctic-Neotropical migratory songbirds. We used geolocators to track the movements of 70Vermivorawarblers from sites spanning their breeding distribution in eastern North America and identified links between breeding populations and nonbreeding areas. Unlike blue-winged warblers (Vermivora cyanoptera), breeding populations of golden-winged warblers (Vermivora chrysoptera) exhibited strong migratory connectivity, which was associated with historical trends in breeding populations: stable for populations that winter in Central America and declining for those that winter in northern South America.


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