scholarly journals Characterizing the interplay between multiple levels of organization within bacterial sigma factor regulatory networks

2013 ◽  
Vol 4 (1) ◽  
Author(s):  
Yu Qiu ◽  
Harish Nagarajan ◽  
Mallory Embree ◽  
Wendy Shieu ◽  
Elisa Abate ◽  
...  
Keyword(s):  
Sigma Factor ◽  
Regulatory Networks ◽  
Levels Of Organization ◽  
Multiple Levels

scholarly journals Considering the role of ecology on individual differentiation

2016 ◽  
Vol 39 ◽  
Author(s):  
Tomás Cabeza de Baca ◽  
Rafael Antonio Garcia ◽  
Michael Anthony Woodley of Menie ◽  
Aurelio José Figueredo
Keyword(s):  
Social Roles ◽  
Social Systems ◽  
Character Displacement ◽  
Complex Societies ◽  
Levels Of Organization ◽  
Multiple Levels ◽  
Individual Differentiation ◽  
Strategic Differentiation ◽  
Integration Effort

AbstractOur commentary articulates some of the commonalities between Baumeister et al.'s theory of socially differentiated roles and Strategic Differentiation-Integration Effort. We expand upon the target article's position by arguing that differentiating social roles is contextual and driven by varying ecological pressures, producing character displacement not only among individuals within complex societies, but also across social systems and multiple levels of organization.

Empirical Research on Populations of Adaptive Individuals

2020 ◽  
pp. 141-153
Keyword(s):  
Empirical Research ◽  
Empirical Studies ◽  
Theory Development ◽  
Organization Change ◽  
Laboratory Studies ◽  
Design Studies ◽  
Entire Process ◽  
Levels Of Organization ◽  
Model Based ◽  
Multiple Levels

This chapter studies how modeling supports empirical research. The benefit of integrating modeling and empirical research has long been recognized: theorists and modelers pose hypotheses that empirical researchers then design studies to test, and empirical research informs the development of new hypotheses. Such integration may be particularly valuable in frameworks that include multiple levels of organization, from individuals to populations to communities. But does working across levels of organization change the relationships of theory, modeling, and empirical research? What kinds of field and laboratory studies do we need, and at what levels of organization, to support modeling? The chapter assesses these questions. Thinking about the relation between modeling and empirical research requires one to address the entire process of model-based research, which is usefully characterized as a modeling cycle. The chapter then explores how the kind of modeling and theory development presented in this book can contribute to empirical studies and research.

Synthetic approaches to cognitive neuroscience

2000 ◽  
Vol 23 (4) ◽  
pp. 548-549 ◽  
Author(s):  
Olaf Sporns
Keyword(s):  
Cognitive Neuroscience ◽  
Computational Approaches ◽  
Levels Of Organization ◽  
Neural Processes ◽  
Multiple Levels ◽  
Organizational Levels ◽  
Synthetic Approaches ◽  
And Behavior ◽  
Theoretical Foundations

Cognition and behavior are the result of neural processes occurring at multiple levels of organization. Synthetic computational approaches are capable of bridging the gaps between multiple organizational levels and contribute to our understanding of how neural structures give rise to specific dynamical states. Such approaches are indispensable for formulating the theoretical foundations of cognitive neuroscience.

The Companion Modelling Approach: Dealing with Multiple Scales and Multiple Levels of Organization

2013 ◽  
pp. 263-290
Author(s):  
Raphaèle Ducrot ◽  
Aurélie Botta ◽  
Patrick d’Aquino ◽  
Martine Antona ◽  
Géraldine Abrami ◽  
...  
Keyword(s):  
Multiple Scales ◽  
Levels Of Organization ◽  
Multiple Levels ◽  
Modelling Approach

scholarly journals Involvement of AlgQ in Transcriptional Regulation of Pyoverdine Genes in Pseudomonas aeruginosa PAO1

2005 ◽  
Vol 187 (15) ◽  
pp. 5097-5107 ◽  
Author(s):  
Cecilia Ambrosi ◽  
Federica Tiburzi ◽  
Francesco Imperi ◽  
Lorenza Putignani ◽  
Paolo Visca
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Sigma Factor ◽  
Transcription Initiation ◽  
Regulatory Networks ◽  
Regulatory Protein ◽  
Single Copy ◽  
Virulence Determinants ◽  
Iron Starvation ◽  
Inorganic Polyphosphate ◽  
E Coli

ABSTRACT In response to iron limitation, Pseudomonas aeruginosa produces the fluorescent siderophore pyoverdine. Transcription of pyoverdine biosynthetic (pvd) genes is driven by the iron starvation sigma factor PvdS, which is negatively regulated by the Fur-Fe(II) holorepressor. We studied the effect of AlgQ, the Escherichia coli Rsd orthologue, on pyoverdine production by P. aeruginosa PAO1. AlgQ is a global regulatory protein which activates alginate, ppGpp, and inorganic polyphosphate synthesis through a cascade involving nucleoside diphosphate kinase (Ndk). AlgQ is also capable of interacting with region 4 of RpoD. In a reconstituted E. coli system, PvdS-dependent transcription from the pvdA promoter was doubled by the multicopy algQ gene. The P. aeruginosa ΔalgQ mutant exhibited a moderate but reproducible reduction in pyoverdine production compared with wild-type PAO1, as a result of a decline in transcription of pvd genes. PvdS expression was not affected by the algQ mutation. Single-copy algQ fully restored pyoverdine production and expression of pvd genes in the ΔalgQ mutant, while ndk did not. An increased intracellular concentration of RpoD mimicked the ΔalgQ phenotype, whereas PvdS overexpression suppressed the algQ mutation. E. coli rsd could partially substitute for algQ in transcriptional modulation of pvd genes. We propose that AlgQ acts as an anti-sigma factor for RpoD, eliciting core RNA polymerase recruitment by PvdS and transcription initiation at pvd promoters. AlgQ provides a link between the pyoverdine and alginate regulatory networks. These systems have similarities in responsiveness and physiological function: both depend on alternative sigma factors, respond to nutrient starvation, and act as virulence determinants for P. aeruginosa.

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