Faculty Opinions recommendation of Faster than neutral evolution of constrained sequences: the complex interplay of mutational biases and weak selection.

2011 ◽  
Author(s):  
Nicolas Galtier ◽  
Julien Dutheil
Keyword(s):  
Neutral Evolution ◽  
Weak Selection ◽  
Complex Interplay

scholarly journals The role of weak selection and high mutation rates in nearly neutral evolution

2009 ◽  
Vol 257 (4) ◽  
pp. 696-703 ◽  
Author(s):  
Daniel John Lawson ◽  
Henrik Jeldtoft Jensen
Keyword(s):  
Neutral Evolution ◽  
Mutation Rates ◽  
Weak Selection

scholarly journals Both Epistasis and Diversifying Selection Drive the Structural Evolution of the Ebola Virus Glycoprotein Mucin-Like Domain

2016 ◽  
Vol 90 (11) ◽  
pp. 5475-5484 ◽  
Author(s):  
Neke Ibeh ◽  
Jean Claude Nshogozabahizi ◽  
Stéphane Aris-Brosou
Keyword(s):  
Ebola Virus ◽  
Mechanistic Model ◽  
Central Africa ◽  
Structural Evolution ◽  
Dimensional Structure ◽  
Structural Constraints ◽  
Weak Selection ◽  
Complex Interplay ◽  
Correlated Evolution ◽  
Diversifying Selection

ABSTRACTThroughout the last 3 decades, Ebola virus (EBOV) outbreaks have been confined to isolated areas within Central Africa; however, the 2014 variant reached unprecedented transmission and mortality rates. While the outbreak was still under way, it was reported that the variant leading up to this outbreak evolved faster than previous EBOV variants, but evidence for diversifying selection was undetermined. Here, we test this selection hypothesis and show that while previous EBOV outbreaks were preceded by bursts of diversification, evidence for site-specific diversifying selection during the emergence of the 2014 EBOV clade is weak. However, we show strong evidence supporting an interplay between selection and correlated evolution (epistasis), particularly in the mucin-like domain (MLD) of the EBOV glycoprotein. By reconstructing ancestral structures of the MLD, we further propose a structural mechanism explaining how the substitutions that accumulated between 1918 and 1969 distorted the MLD, while more recent epistatic substitutions restored part of the structure, with the most recent substitution being adaptive. We suggest that it is this complex interplay between weak selection, epistasis, and structural constraints that has shaped the evolution of the 2014 EBOV variant.IMPORTANCEThe role that selection plays in the emergence of viral epidemics remains debated, particularly in the context of the 2014 EBOV outbreak. Most critically, should such evidence exist, it is generally unclear how this relates to function and increased virulence. Here, we show that the viral lineage leading up to the 2014 outbreak underwent a complex interplay between selection and correlated evolution (epistasis) in a protein region that is critical for immune evasion. We then reconstructed the three-dimensional structure of this domain and showed that the initial mutations in this lineage deformed the structure, while subsequent mutations restored part of the structure. Along this mutational path, the first and last mutations were adaptive, while the intervening ones were epistatic. Altogether, we provide a mechanistic model that explains how selection and epistasis acted on the structural constraints that materialized during the 2014 EBOV outbreak.

‘Nothing is simply one thing’: Woolf, Deleuze and Difference

2013 ◽  
Vol 7 (4) ◽  
pp. 456-474
Author(s):  
Beatrice Monaco
Keyword(s):  
Virginia Woolf ◽  
Prose Poetry ◽  
Close Reading ◽  
Similar Model ◽  
Complex Interplay ◽  
To The Lighthouse

This paper explores some key texts of Virginia Woolf in the context of Deleuzian concepts. Using a close reading style, it shows how the prose poetry in Mrs Dalloway engages a complex interplay of repetition and difference, resulting in a remarkably similar model of the three syntheses of time as Deleuze understands them. It subsequently explores Woolf's technical processes in a key passage from To the Lighthouse, showing how the prose-poetic technique systematically undoes the structures of logical fact and rationality inscribed in both language and everyday speech to an extremely precise level.

Introduction: Exploring Russian nationalisms

2018 ◽  
Author(s):  
Pål Kolstø ◽  
Helge Blakkisrud
Keyword(s):  
The State ◽  
Complex Interplay ◽  
Recent Developments ◽  
Part Structure

Russian societal nationalism comes in various guises, both ethnic and imperialist. Also Putin’s rhetoric is marked by the tensions between ethnic and state-focused, imperialist thinking. Noting the complex interplay of state nationalism and societal nationalism, this introductory chapter examines the mental framework within which Russian politicians were acting prior to the decision to annex Crimea. The chapter develops a typology of Russian nationalisms, surveys recent developments, and presents the three-part structure of this book: official nationalism, radical and other societal nationalisms, and identities/otherings. It concludes that after the annexation of Crimea, when the state took over the agenda of both ethnic and imperialist nationalists in Russia, societal nationalism finds itself at low ebb.

Cellulose Separators with Integrated Carbon Nanotube Interlayers for Lithium-Sulfur Batteries: An Investigation into the Complex Interplay Between Cell Components

2019 ◽  
Author(s):  
Yu-Chuan Chien ◽  
Ruijun Pan ◽  
Ming-Tao Lee ◽  
Leif Nyholm ◽  
Daniel Brandell ◽  
...  
Keyword(s):  
Coulombic Efficiency ◽  
Solid Electrolyte Interphase ◽  
Holistic Approach ◽  
Cycle Life ◽  
Complex Interplay ◽  
Positive Electrodes ◽  
Lithium Sulfur Batteries ◽  
Cell Components ◽  
Redox Shuttle ◽  
Lithium Sulfur

This work aims to address two major roadblocks in the development of lithium-sulfur (Li-S) batteries: the inefficient deposition of Li on the metallic Li electrode and the parasitic "polysulfide redox shuttle". These roadblocks are here approached, respectively, by the combination of a cellulose separator with a cathode-facing conductive porous carbon interlayer, based on their previously reported individual benefits. The cellulose separator increases cycle life by 33%, and the interlayer by a further 25%, in test cells with positive electrodes with practically relevant specifications and a relatively low electrolyte/sulfur (E/S) ratio. Despite the prolonged cycle life, the combination of the interlayer and cellulose separator increases the polysulfide shuttle current, leading to reduced Coulombic efficiency. Based on XPS analyses, the latter is ascribed to a change in the composition of the solid electrolyte interphase (SEI) on Li. Meanwhile, electrolyte decomposition is found to be slower in cells with cellulose-based separators, which explains their longer cycle life. These counterintuitive observations demonstrate the complicated interactions between the cell components in the Li-S system and how strategies aiming to mitigate one unwanted process may exacerbate another. This study demonstrates the value of a holistic approach to the development of Li-S chemistry.<br>

Thermodynamics of Flowing Systems: with Internal Microstructure

1994 ◽  
Author(s):  
Antony N. Beris ◽  
Brian J. Edwards
Keyword(s):  
Free Energy ◽  
Theoretical Study ◽  
Flow Behavior ◽  
Irreversible Thermodynamics ◽  
Hamiltonian Mechanics ◽  
Complex Interplay ◽  
Microscopic Models ◽  
Flow Phenomena ◽  
The Subject ◽  
The Continuum

This much-needed monograph presents a systematic, step-by-step approach to the continuum modeling of flow phenomena exhibited within materials endowed with a complex internal microstructure, such as polymers and liquid crystals. By combining the principles of Hamiltonian mechanics with those of irreversible thermodynamics, Antony N. Beris and Brian J. Edwards, renowned authorities on the subject, expertly describe the complex interplay between conservative and dissipative processes. Throughout the book, the authors emphasize the evaluation of the free energy--largely based on ideas from statistical mechanics--and how to fit the values of the phenomenological parameters against those of microscopic models. With Thermodynamics of Flowing Systems in hand, mathematicians, engineers, and physicists involved with the theoretical study of flow behavior in structurally complex media now have a superb, self-contained theoretical framework on which to base their modeling efforts.

Greek Slave Systems in their Eastern Mediterranean Context, c.800-146 BC

2018 ◽  
Author(s):  
David M. Lewis
Keyword(s):  
Recent Work ◽  
Eastern Mediterranean ◽  
Demographic Variables ◽  
Archaic Period ◽  
Ancient World ◽  
Complex Interplay ◽  
Cultural Economic ◽  
Early Archaic ◽  
Mediterranean World ◽  
Orthodox View

The orthodox view of ancient Mediterranean slavery holds that Greece and Rome were the only ‘genuine slave societies’ of the ancient world, that is, societies in which slave labour contributed significantly to the economy and underpinned the wealth of elites. Other societies, labelled as ‘societies with slaves’, apparently made little use of slave labour, and have therefore been largely ignored in recent work. Greek Slave Systems in their Eastern Mediterranean Context, c.800–146 BC presents a radically different view. Slavery was indeed particularly highly developed in Greece and Rome; but it was also highly developed in Carthage and other parts of the Eastern Mediterranean, and played a not insignificant role in the affairs of elites in Assyria, Babylonia, and Persia. This new study portrays the Eastern Mediterranean world as a patchwork of regional slave systems. In Greece, diversity was the rule: from the early archaic period onwards, differing historical trajectories in various regions shaped the institution of slavery in manifold ways, producing very different slave systems in regions such as Sparta, Crete, and Attica. In the wider Eastern Mediterranean world, we find a similar level of diversity. Slavery was exploited to different degrees across all of these regions, and was the outcome of a complex interplay between cultural, economic, political, geographic, and demographic variables.

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