Modular structure in C. elegans neural network and its response to external localized stimuli

Synchronization plays a key role in information processing in neuronal networks. Response of specific groups of neurons are triggered by external stimuli, such as visual, tactile or olfactory inputs. Neurons, however, can be divided into several categories, such as by physical location, functional role or topological clustering properties. Here we study the response of the electric junction C. elegans network to external stimuli using the partially forced Kuramoto model and applying the force to specific groups of neurons. Stimuli were applied to topological modules, obtained by the ModuLand procedure, to a ganglion, specified by its anatomical localization, and to the functional group composed of all sensory neurons. We found that topological modules do not contain purely anatomical groups or functional classes, corroborating previous results, and that stimulating different classes of neurons lead to very different responses, measured in terms of synchronization and phase velocity correlations. In all cases, however, the modular structure hindered full synchronization, protecting the system from seizures. More importantly, the responses to stimuli applied to topological and functional modules showed pronounced patterns of correlation or anti-correlation with other modules that were not observed when the stimulus was applied to ganglia.Comment: 23 pages, 6 figure

Isolation of Bovine Milk-Derived Exosomes via a Polyester Capillary- Channeled Polymer (C-CP) Fiber Stationary Phase

https://tigerprints.clemson.edu/csrp/1004/thumbnail.jp

Faculty Scholarship Celebration 2017

Program for Western Carolina University's annual Faculty Scholarship Celebration

Faculty Scholarship Celebration 2018

Program for Western Carolina University's annual Faculty Scholarship Celebration

Environmental sensitivity analysis of environments affected by the oil spill on the Brazilian coast

The crude oil spill that occurred in 2019 at the Northeast Brazilian Coast is considered one of the most severe disasters recorded in tropical coastal regions. In order to contribute to the understanding of the impact generated by the disaster, this work linked oil sightings by the Brazilian Institute of the Environment and Renewable Natural Resources (IBAMA) with the Coastal Sensitivity Index (CSI) of the Environmental Sensitivity to Oil Spills Maps (Carta SAO), generating an overview of the types of coastal environments affected by the oil. This crossing was carried out through the public vector bases in the Geographic Information System. The results show that intermediate beaches, mangroves and Salt Marshes, reefs and tidal flats recorded more than 50% of sightings with oil residues. At the end of this analysis, the environments that still had oil records were mangroves and Salt Marshes, and intermediate, dissipative and gravel beaches. The analysis allowed us to understand the main environments affected by the spill along the coast, also indicating the need to adopt mechanisms that integrate public data to assist in the structuring of oil combat mechanisms, with actions to combat oil arising from any spills on the Brazilian coast becoming more effective.O derramamento de óleo cru que ocorreu no litoral do Nordeste do Brasil em 2019 é considerado um dos desastres mais severos registrados em regiões costeiras tropicais. Para contribuir para a compreensão do impacto gerado pelo desastre, este trabalho relacionou as avistagens de óleo do Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis (IBAMA) com o Índice de Sensibilidade do Litoral (ISL) das Cartas de Sensibilidade Ambiental a Derramamentos de Óleo (SAO), gerando um panorama dos tipos de ambientes costeiros atingidos pelo óleo. Este cruzamento foi realizado por meio da sobreposição de bases vetoriais públicas em sistema de informação geográfica. Os resultados demonstram que as praias intermediárias, manguezais e marismas, recifes e planícies de maré registraram mais de 50% de avistagens com resíduos de óleo. Ao fim desta análise, os ambientes que ainda apresentaram registros de óleo foram os manguezais e marismas e as praias intermediárias, dissipativas e de cascalho. A análise permitiu compreender os principais ambientes afetados pelo derramamento ao longo da costa, indicando também a necessidade de adotar mecanismos de integração dos dados públicos para auxiliar na estruturação de mecanismos de combate ao óleo, tornando mais eficazes as ações de combate em eventuais derramamentos na costa brasileira

Binary Dynamics On Star Networks Under External Perturbations.

We study a binary dynamical process that is a representation of the voter model with two candidates and opinion makers. The voters are represented by nodes of a network of social contacts with internal states labeled 0 or 1 and nodes that are connected can influence each other. The network is also perturbed by opinion makers, a set of external nodes whose states are frozen in 0 or 1 and that can influence all nodes of the network. The quantity of interest is the probability of finding m nodes in state 1 at time t. Here we study this process on star networks, which are simple representations of hubs found in complex systems, and compare the results with those obtained for networks that are fully connected. In both cases a transition from disordered to ordered equilibrium states is observed as the number of external nodes becomes small. For fully connected networks the probability distribution becomes uniform at the critical point. For star networks, on the other hand, we show that the equilibrium distribution splits in two peaks, reflecting the two possible states of the central node. We obtain approximate analytical solutions for the equilibrium distribution that clarify the role of the central node in the process. We show that the network topology also affects the time scale of oscillations in single realizations of the dynamics, which are much faster for the star network. Finally, extending the analysis to two stars we compare our results with simulations in simple scale-free networks.9204281

Finns det bara en väg till ett personligt uttryck?

Syftet med vår studie är att undersöka hur fyra sångpedagoger beskriver hur de förhåller sig till och arbetar med personligt uttryck, härmning och förebildning samt genrekunskap och hur deras syn påverkar samverkan mellan begreppen och metoderna. Studien är av kvalitativ art och vi har använt oss av semistrukturerade frågor för att fånga pedagogernas tankar och åsikter. Sångpedagogerna säger sig ofta koncentrera sig på arbetet med ett personligt uttryck, ofta utifrån tolkning av texten. Däremot uppger pedagogerna ofta att de hyser stor försiktighet när det kommer till förebildning eftersom de ofta upplever en risk att påverka eleven. I sina beskrivningar betonar pedagogerna inte heller arbetet med genrekunskap i större utsträckning. Vår tolkning av resultaten är att fokuseringen på arbetet med elevers personliga uttryck, ofta utifrån texttolkning, prioriteras högre än fördjupade genrekunskaper och härmning av stilistiska förlagor. Utifrån resultaten gör vi slutsatsen att sångpedagoger möjligen skulle vinna på att i större utsträckning prioritera genrekunskap, exempelvis genom härmning av deras förebildning, för att på så sätt möjliggöra för eleven att utveckla ett personligt uttryck även från dessa utgångspunkter.The purpose of our study is to investigate how vocal teachers describe how they relate to and work with personal expression, imitation, demonstration, knowledge about genre and how their views affect the interaction between these concepts and methods. The study is qualitative in nature and we have used semi-structured questions to capture the teachers’ thoughts and opinions. The vocal teachers say they often concentrate on the work with and towards a personal expression, often based on the interpretation of the text. In contrast the vocal teachers often state that they have great caution when it comes to demonstration, as they often experience a risk to influence the student. In their descriptions the teachers do not emphasize the work with knowledge about genre to a greater extent. Our reading of the results is that the focus on the work of students’ personal expression, often based on textual interpretation, has higher priority than deeper knowledge about genre and imitation of stylistic models. Based on the results we conclude that vocal teachers could possibly gain from making the knowledge about genre a greater priority, for example through imitation of role models, to thus enable the student to develop a personal expression also from these starting points