scholarly journals Gibsonian Information: an agent-based paradigm for quantitative information

2021 ◽  
Author(s):  
Bradly Alicea ◽  
daniela cialfi ◽  
Anson Lim ◽  
Jesse Parent
Keyword(s):  
Channel Model ◽  
Random Noise ◽  
Quantitative Information ◽  
Nervous Systems ◽  
Collective Behaviors ◽  
Environmental Signals ◽  
Cognitive Behaviors ◽  
Agent Interactions ◽  
Cognitive Information

We propose a new way to quantitatively characterize information: Gibsonian Information (GI). This framework is relevant to both the study of cognitive agents and single cell systems that exhibit cognitive behaviors. GI provides a means to characterize how agents extract information from direct perceptual signals. This differs from existing information theories in two ways. The first involves an emphasis on sensory processing, engagement in collective behaviors, and the dynamic evolution of such interactions. GI is useful for understanding information in terms of agent interactions with naturalistic contexts, and also allows us to distinguish the role of first-order sensory inputs in the context of higher-order representations. This allows us to extend GI to cybernetic and other types of symbolic systems representations. As an alternate way to look at information in nervous systems, GI also emphasizes the role of information content in the relationship between ecology and nervous systems. Along with direct sensory input and simple internal representations, statistical affordances are an important component of transforming environmental signals into GI. Statistical affordances, defined as clustered information that is spatiotemporally dependent perceptual input, facilitates the extraction of GI from the environment. Quantitatively accounting for perceptual information, GI provides a means to measure spatial concentration in addition to being a generalized indicator of nervous system input. To better understand GI as a measurable phenomenon, we characterize three model scenarios: disjoint distributions, contingent action, and coherent movement. All of these cases provide a means to create a differential system between both motion (information) and random noise/stasis (non-information) and between the active sensory channel and information derived from mental representations. By applying this framework to a variety of specific contexts, including a four-channel model of multisensory embodiment, we demonstrate how GI is essential to understanding the full scope of cognitive information processing.

POLÍTICAS DE ESCALA E A CONFORMAÇÃO DE ESTRATÉGIAS-REDE DAS AÇÕES COLETIVAS NO ESPAÇO SISALEIRO DA BAHIA

GEOgraphia ◽  
2018 ◽  
Vol 19 (41) ◽  
pp. 39
Author(s):  
Agripino Souza Coelho Neto
Keyword(s):  
Political Action ◽  
Spatial Scales ◽  
Spatial Behavior ◽  
Collective Actions ◽  
Collective Behaviors ◽  
Rural Workers ◽  
Scale Levels ◽  
Scale Network ◽  
Comme Point

Resumo: O presente texto pretende analisar o papel das ações coletivas (associações, cooperativas e sindicatos de agricultores) no acionamento e na ativação das escalas geográficas para o desenvolvimento de suas atividades. O estudo foi realizado no Espaço Sisaleiro da Bahia (Brasil), onde um conjunto significativo de associações e cooperativas de agricultores e sindicatos de trabalhadores rurais tem se organizado em torno das escalas espaciais para viabilizar sua ação político-institucional e econômico-produtiva. A ação desses coletivos organizados em rede tem permitido a conformação e o fortalecimento de novas escalas de ação política, como no caso da criação do conselho territorial para viabilização da implantação de políticas de governo. Cooperativas, associações e sindicatos se apoiam nas escalas para compor organizações em diferentes níveis escalares (escala local, escala regional, escala do estado federado e escala nacional), buscando fortalecer seus propósitos e ampliar seu poder de barganha e influência. Analisando o comportamento espacial dessas variadas modalidades de ações coletivas, é possível considerar que elas desenvolvem políticas de escala, ou seja, a escala passa a significar muito mais que uma categoria de análise, mas se torna uma categoria da prática social e política. Nesse sentido, parte-se do pressuposto de que os grupos humanos produzem e tornam efetivas suas próprias escalas visando a alcançar suas metas e organizar seus comportamentos coletivos. Palavras-chave: Escala. Rede. Cooperativismo. Associativismo. Sindicalismo. Espaço Sisaleiro da Bahia. SCALE POLICIES AND THE DEVELOPMENT OF NETWORK STRATEGIES OF COLLECTIVE ACTIONS IN THE SISAL REGION OF BAHIA (BRAZIL)Abstract: This paper aims to analyze the role of collective initiatives of associations, cooperatives and farmers’ unions in the mobilization and activation of geographical scales for the development of their activities. The study was conducted in the Sisal Region of Bahia (Brazil), where a significant number of farmers associations and cooperatives and rural workers’ unions have been organizing their actions around spatial scales to enable their political-institutional and economic-productive influence. The gathering and action of these organized groups in a network have allowed the establishment and strengthening of new scales of political action, as seem in the case of the creation of a territorial council to facilitate the implementation of government policies. Cooperatives, associations, and unions rely on scales to form organizations at different scale levels (local, regional, federal and national scales), seeking to strengthen their performance and increase their bargaining power and influence. After analyzing the spatial behavior of these various forms of collective actions, it’s reasonable to say that they develop scale policies, which means the scale becomes more than a category of analysis, but also a category of social and political practice. In this sense, it’s assumed that human groups produce and utilize the scales in order to reach their goals and organize their own collective behaviors. Keywords: Scale. Network. Cooperativism. Associativism. Syndicalism. Sisal Region of Bahia. POLITIQUES D’ÉCHELLE ET FORMATION DES STRATÉGIES-RÉSEAU DES ACTIONS COLLECTIVES DANS LA RÉGION DU SISAL DE L’ÉTAT DE BAHIA Resumé: Cet article analyse le rôle des actions collectives (associations, coopératives et syndicats d’agriculteurs) dans la prise en compte et l’utilisation des échelles géographiques pour le développement de leurs activités. L’étude a été menée dans la région du sisal à Bahia (Brésil), où un ensemble important d’associations et de coopératives d’agriculteurs et de syndicats de travailleurs ruraux se sont organisés autour d’échelles spatiales pour que puisse être mise en place leur action politique et institutionnelle, économique et productive. L’action de ces groupements organisés en réseaux a permis la conformation et le renforcement de nouvelles échelles d’action politique, comme lors de la création du conseil territorial, pour permettre la mise en œuvre des politiques gouvernementales. Les coopératives, les associations et les syndicats prennent les échelles comme point de départ pour former des organisations à différents niveaux scalaires (échelle locale, échelle régionale, échelle fédérée et échelle nationale), dans le but de renforcer leurs objectifs et d’accroître leur pouvoir de négociation et d’influence. Si nous analysons le comportement spatial de ces diverses formes d’action collective il est possible de considérer qu’ils développent des politiques d’échelle, à savoir l’échelle vient signifier bien plus qu’une catégorie d’analyse, puisqu’elle devient une catégorie de la pratique sociale et politique. En ce sens, on suppose que les groupes humains produisent et rendent efficaces leurs propres échelles pour atteindre leurs objectifs et organiser leurs comportements collectifs. Mots-clés: Échelle. Réseau. Coopérativisme. Associations. Syndicalisme. Région du sisal de l’État de Bahia.

scholarly journals The MarR-Type Regulator PA3458 Is Involved in Osmoadaptation Control in Pseudomonas aeruginosa

2021 ◽  
Vol 22 (8) ◽  
pp. 3982
Author(s):  
Karolina Kotecka ◽  
Adam Kawalek ◽  
Kamil Kobylecki ◽  
Aneta Agnieszka Bartosik
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Binding Sites ◽  
Transcriptional Profiling ◽  
Mrna Level ◽  
Transcriptional Regulators ◽  
Resistance Mechanisms ◽  
Chronic Infections ◽  
Environmental Signals ◽  
Regulatory Systems

Pseudomonas aeruginosa is a facultative human pathogen, causing acute and chronic infections that are especially dangerous for immunocompromised patients. The eradication of P. aeruginosa is difficult due to its intrinsic antibiotic resistance mechanisms, high adaptability, and genetic plasticity. The bacterium possesses multilevel regulatory systems engaging a huge repertoire of transcriptional regulators (TRs). Among these, the MarR family encompasses a number of proteins, mainly acting as repressors, which are involved in response to various environmental signals. In this work, we aimed to decipher the role of PA3458, a putative MarR-type TR from P. aeruginosa. Transcriptional profiling of P. aeruginosa PAO1161 overexpressing PA3458 showed changes in the mRNA level of 133 genes; among them, 100 were down-regulated, suggesting the repressor function of PA3458. Concomitantly, ChIP-seq analysis identified more than 300 PA3458 binding sites in P. aeruginosa. The PA3458 regulon encompasses genes involved in stress response, including the PA3459–PA3461 operon, which is divergent to PA3458. This operon encodes an asparagine synthase, a GNAT-family acetyltransferase, and a glutamyl aminopeptidase engaged in the production of N-acetylglutaminylglutamine amide (NAGGN), which is a potent bacterial osmoprotectant. We showed that PA3458-mediated control of PA3459–PA3461 expression is required for the adaptation of P. aeruginosa growth in high osmolarity. Overall, our data indicate that PA3458 plays a role in osmoadaptation control in P. aeruginosa.

scholarly journals Portraits of Undergraduate Discipline-Specific Thinking: Guiding Students from Novice to Proficient Learner

2020 ◽  
Vol 20 (2) ◽  
Author(s):  
Patricia Stovey ◽  
Tiffany Trimmer
Keyword(s):  
Undergraduate Students ◽  
Habits Of Mind ◽  
College Level ◽  
Student Centered ◽  
Cognitive Behaviors ◽  
Second Nature ◽  
Historical Methods ◽  
First Time

This case study presents our experiences, insights, and the pedagogical techniques used to guide undergraduate students toward discipline-specific thinking. It demonstrates the role of student-centered practices in moving students from what we categorize as novice to proficient, a common goal in rite-of-passage courses across the disciplines. Our study follows two semesters of students in undergraduate college-level Historiography and Historical Methods courses to identify common stumbling blocks encountered when learning contextualization (our discipline-specific thinking skill). We analyze students’ habits of mind, cognitive behaviors, and assumptions when learning to think differently. We present a qualitative portrait demonstrating the range of student cognitive behaviors as they attempt to move towards proficiency. As experts immersed in our fields of study and its practices, we can sometimes forget that what comes second-nature to us is far from natural to our students—regardless of their enthusiasm. We may overestimate the background knowledge that our students have, and underestimate the brain bandwidth required when trying—for the first time—to think differently.

scholarly journals Endospores and other lysis-resistant bacteria comprise a widely shared core community within the human microbiota

2017 ◽  
Author(s):  
Sean M. Kearney ◽  
Sean M. Gibbons ◽  
Mathilde Poyet ◽  
Thomas Gurry ◽  
Kevin Bullock ◽  
...  
Keyword(s):  
Dietary Fatty Acids ◽  
Resistant Bacteria ◽  
Human Gut ◽  
Environmental Signals ◽  
Human Microbiota ◽  
Disease States ◽  
Culture Independent ◽  
Health And Disease ◽  
Over Time

AbstractEndospore-formers in the human microbiota are well adapted for host-to-host transmission, and an emerging consensus points to their role in determining health and disease states in the gut. The human gut, more than any other environment, encourages the maintenance of endospore formation, with recent culture-based work suggesting that over 50% of genera in the microbiome carry genes attributed to this trait. However, there has been limited work on the ecological role of endospores and other stress-resistant cellular states in the human gut. In fact, there is no data to indicate whether organisms with the genetic potential to form endospores actually form endosporesin situand how sporulation varies across individuals and over time. Here, we applied a culture-independent protocol to enrich for endospores and other stress-resistant cells in human feces to identify variation in these states across people and within an individual over time. We see that cells with resistant states are more likely than those without to be shared among multiple individuals, which suggests that these resistant states are particularly adapted for cross-host dissemination. Furthermore, we use untargeted fecal metabolomics in 24 individuals and within a person over time to show that these organisms respond to shared environmental signals, and in particular, dietary fatty acids, that likely mediate colonization of recently disturbed human guts.

Modulated adhesion: a proposal for the role of myelin-associated glycoprotein in myelin wrapping.

1989 ◽  
Vol 35 (5) ◽  
pp. 717-720 ◽  
Author(s):  
J Attia ◽  
M Tropak ◽  
P W Johnson ◽  
W Newerly-Abranow ◽  
T Pawson ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Schwann Cells ◽  
Clinical Findings ◽  
Membrane Glycoprotein ◽  
Nervous Systems ◽  
Phosphorylation State ◽  
Phosphatase Activities ◽  
Cell Assays ◽  
Myelin Associated Glycoprotein

Abstract Myelin-associated glycoprotein (MAG) is a 100-kDa integral membrane glycoprotein expressed by oligodendrocytes and Schwann cells in the central and peripheral nervous systems, respectively. It is found first in loosely wrapped myelin and then periaxonally after compaction. Clinical findings, structural analysis, and cell assays indicate a role for MAG in adhesion. We propose that the phosphorylation state of MAG modulates its adhesion and that a minimum spatial requirement for the separation of the kinase and phosphatase activities postulated by this model may explain the correlation between axon size and myelination state.

scholarly journals Flow interactions between uncoordinated flapping swimmers give rise to group cohesion

2019 ◽  
Vol 116 (7) ◽  
pp. 2419-2424 ◽  
Author(s):  
Joel W. Newbolt ◽  
Jun Zhang ◽  
Leif Ristroph
Keyword(s):  
Group Cohesion ◽  
Wake Flow ◽  
Dynamical Models ◽  
Collective Behaviors ◽  
Reduced Order ◽  
Fluid Forces ◽  
Flow Interactions ◽  
Remarkable Agreement ◽  
Control Locomotion

Many species of fish and birds travel in groups, yet the role of fluid-mediated interactions in schools and flocks is not fully understood. Previous fluid-dynamical models of these collective behaviors assume that all individuals flap identically, whereas animal groups involve variations across members as well as active modifications of wing or fin motions. To study the roles of flapping kinematics and flow interactions, we design a minimal robotic “school” of two hydrofoils swimming in tandem. The flapping kinematics of each foil are independently prescribed and systematically varied, while the forward swimming motions are free and result from the fluid forces. Surprisingly, a pair of uncoordinated foils with dissimilar kinematics can swim together cohesively—without separating or colliding—due to the interaction of the follower with the wake left by the leader. For equal flapping frequencies, the follower experiences stable positions in the leader’s wake, with locations that can be controlled by flapping amplitude and phase. Further, a follower with lower flapping speed can defy expectation and keep up with the leader, whereas a faster-flapping follower can be buffered from collision and oscillate in the leader’s wake. We formulate a reduced-order model which produces remarkable agreement with all experimentally observed modes by relating the follower’s thrust to its flapping speed relative to the wake flow. These results show how flapping kinematics can be used to control locomotion within wakes, and that flow interactions provide a mechanism which promotes group cohesion.

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