scholarly journals Paternal leakage of organelles can improve adaptation to changing environments

2020 ◽  
Author(s):  
Arunas Radzvilavicius ◽  
Iain G. Johnston

AbstractSexual eukaryotes have diverse mechanisms preventing the biparental inheritance of mitochondria and plastids, and reducing the coexistence of dissimilar organelle DNA (heteroplasmy). Nevertheless, paternal leakage often occurs in plants, fungi, protists and animals, and this leaves the possibility that heteroplasmy can in some contexts be advantageous. Theoretical models developed in the past revealed that maternal inheritance improves selection against deleterious mitochondrial mutations, but none of them have explained the observed variation in the extent of paternal leakage. Here we show that paternal leakage regulated by nuclear loci can evolve to maintain advantageous organelle diversity in fluctuating environments. Strict maternal inheritance reduces organelle variance within the cell, but this loss of diversity can be detrimental when environments are shifting rapidly. Our model reveals that high levels of paternal leakage can evolve in these types of rapidly changing environments and that strict maternal inheritance evolves only when the environment is changing slowly.DataMatlab/Octave implementation of the model is available at Https://github.com/StochasticBiology/PaternalLeakageEvolution.

Author(s):  
Lauren Stewart ◽  
Katharina von Kriegstein ◽  
Simone Dalla Bella ◽  
Jason D. Warren ◽  
Timothy D. Griffiths

This article presents an overview of case studies of acquired disorders of musical listening. Like any cognitive faculty, music is multifaceted, and the identification of the neural basis of any complex faculty must proceed, hand in hand, with an elucidation of its cognitive architecture. The past decade has seen an evolution in the theoretical models of musical processing, allowing the development of theoretically motivated instruments for the systematic evaluation of musical disorders. Such developments have allowed reports of musical disorders to evolve from historical anecdotes to systematic, verifiable accounts that can play a critical role in contributing to our understanding of the cognitive neuroscience of music.


Sociologija ◽  
2010 ◽  
Vol 52 (3) ◽  
pp. 285-306
Author(s):  
Milan Cakic

The main topic of this article are the motives that led to the adoption of lustration laws in the Czech Republic, Poland, and Serbia, and their social functions. In the opening section, lustration is placed in the wider framework of dealing with the past and two possible approaches to the phenomenon are discussed: to take it as part of the broader process of decommunization, or a measure of transitional justice. In the next section an attempt at defining the concept of lustration is made, with a view to eliminating some ambiguities surrounding it. Subsequently, two partially complementary theoretical models explaining the occurrence, form and severity of dealing with the past and lustration are presented. After that comes the description of the socio-political context at the time of the adoption of lustration laws in the three countries and identification of political and ideological forces that have supported or challenged it. Finally, the article attempts to answer the question whether lustration is a legitimate measure of settling historical justice, overcoming the legacies of socialism, a way to strengthen liberal democracy, or merely a tool in political struggles for power.


2021 ◽  
Author(s):  
◽  
Elspeth Hocking

<p>Public history and academic history have been viewed both as opposites, two practices related only by their concern with sharing the past, as well as conceptualised as similar fields with close connections to each other. Museum history exhibitions are an obvious example of public history in action. However, is the history that exhibitions present all that different from what is produced in the academy, or is this history academia in another form? Initially this dissertation aimed to explore the relationships between academic and public histories as discipline and practice, assuming a relationship rather than divide between the two fields as suggested in some of the literature. However, the eventual results of the research were different than expected, and suggested that in fact public histories manifest very differently to academic histories within a museum context. Using an adapted ethnographic research methodology, this dissertation traces the development of a single history exhibition, "Te Ahi Kā Roa, Te Ahi Kātoro Taranaki War 1860–2010: Our Legacy – Our Challenge", from its concept development to opening day and onwards to public programmes. This exhibition opened at Puke Ariki in New Plymouth in March 2010, and was a provocative display not only of the history of the wars themselves, but of the legacy of warfare in the Taranaki community. Other methods include partially structured interviews which were conducted with ten people involved in creating this exhibition, who outlined their roles in its production and provided their views on its development, and also a brief analysis of the broader social and historical context in which the exhibition was staged. Through tracing the creation of this history, the findings suggested that the history produced at Puke Ariki is a history in its own right, with noticeable differences from academic histories. The strongest correlation between public and academic history in this instance was the shared aspiration to be rigorous in conducting research and, as far as possible, to create an accurate portrayal of the past. Otherwise the history created by Puke Ariki through the exhibition proved to be different in that it was deliberately designed to be very accessible, and it utilised a number of presentation modes, including objects, text, audiovisual and sound. It was interactive, and had a clear aim of enabling the audience to participate in a discussion about the history being presented. Finally, it was a highly politicised history, in that decision making had to be negotiated with source communities in a collaborative fashion, and issues of censorship worked through with the council, a major funding source. The dissertation concludes that producing history in a museum context is a dynamic and flexible process, and one that can be successful despite not necessarily following theoretical models of exhibition development.</p>


2021 ◽  
Author(s):  
Jiayi Ji ◽  
Donavan J. Jackson ◽  
Adam D. Leaché ◽  
Ziheng Yang

In the past two decades genomic data have been widely used to detect historical gene flow between species in a variety of plants and animals. The Tamias quadrivittatus group of North America chipmunks, which originated through a series of rapid speciation events, are known to undergo massive amounts of mitochondrial introgression. Yet in a recent analysis of targeted nuclear loci from the group, no evidence for cross-species introgression was detected, indicating widespread cytonuclear discordance. The study used heuristic methods that analyze summaries of the multilocus sequence data to detect gene flow, which may suffer from low power. Here we use the full likelihood method implemented in the Bayesian program BPP to reanalyze these data. We take a stepwise approach to constructing an introgression model by adding introgression events onto a well-supported binary species tree. The analysis detected robust evidence for multiple ancient introgression events affecting the nuclear genome, with introgression probabilities reaching 65%. We estimate population parameters and highlight the fact that species divergence times may be seriously underestimated if ancient cross-species gene flow is ignored in the analysis. Our analyses highlight the importance of using adequate statistical methods to reach reliable biological conclusions concerning cross-species gene flow.


Author(s):  
Gennaro Pellone

<span>The place of the computer in the classroom especially within TAFE Colleges has increased dramatically over the past decade. This paper attempts to describe the role of computers in TAFE education providing some understanding of the principal theoretical models of learning and their relationship with the computer as an educational aid.</span>


1975 ◽  
Vol 69 (2) ◽  
pp. 49-61
Author(s):  
Leslie L. Clark

This overview of the past, present, and future of research and development related to severely visually impaired persons covers the following subjects: documentation, creation of an armamentarium of aids (including both ordinary and highly sophisticated devices), the financing of R&D, the problem of technology transfer, dealing with change, the need for better theoretical models, and new definitions of the reality in which severely visually impaired individuals and those who work with them and for their benefit find themselves.


Philosophia ◽  
2018 ◽  
Vol 47 (4) ◽  
pp. 1011-1021
Author(s):  
Giacomo Andreoletti ◽  
Giuliano Torrengo

2018 ◽  
Vol 17 (1) ◽  
pp. 133-144 ◽  
Author(s):  
Moshe Farjoun

This essay broadens the conversation on the state of organizational contradictions and paradox research by turning to dialectics—a time-honored, living perspective on social processes and relations, which continues to influence our understanding of the past, present, and future. Dialectics distinctive relational process worldview sets it apart from approaches stressing equilibrium, linearity, and coherence, making it highly relevant to a world in flux. I propose that dialectics is already present in strategy research and in contemporary business, and can become even more central to strategy, addressing core questions in the field and propelling it in new directions. Strategy scholars can draw on dialectics principles as a generative tool kit to construct new theories and managerial tools. Dialectics can also be used as a theoretical lens to understand emerging empirical phenomena such as the rapid advent of artificial intelligence. Finally, dialectics critical stance and philosophical grounding makes it a particularly attractive perspective for challenging existing theoretical models and for considering alternatives.


2019 ◽  
Vol 2019 (255) ◽  
pp. 109-131 ◽  
Author(s):  
Judith Purkarthofer ◽  
Guri Bordal Steien

Abstract In this article, we examine how parents explain their choices of transmitting certain languages to their children, a key element of family language policies (FLP), in light of their dynamic linguistic repertoires and biographic experiences. Contributing to the framework of FLP, we focus in particular on parents’ memories, their narratives of multilingual upbringing in the past, and how these are used to construct present FLP. We analyze conversations where six multilingual parents in Norway talk about their experiences and intentions regarding FLP, and in particular, their reasons for the transmission of (some of their) languages to their children. The parents of three of the families are from the Democratic Republic of Congo (DRC), and in three others at least one of the parents migrated from Germany. We find that the parents align their decisions with both prior and new experiences. They relate to their language(s), their past and their current family life, and express the wish for continuity across the lifespan. At the same time, they demonstrate a certain flexibility and willingness to adapt to the constantly changing environments that they and their children experience and in which they navigate. Through their complex accounts, their memories and lived language experiences, we can understand parents’ manifold positions as regards their children’s linguistic repertoires.


2018 ◽  
Vol 2018 ◽  
pp. 1-31 ◽  
Author(s):  
M. G. Dainotti ◽  
R. Del Vecchio ◽  
M. Tarnopolski

The mechanism responsible for the prompt emission of gamma-ray bursts (GRBs) is still a debated issue. The prompt phase-related GRB correlations can allow discriminating among the most plausible theoretical models explaining this emission. We present an overview of the observational two-parameter correlations, their physical interpretations, and their use as redshift estimators and possibly as cosmological tools. The nowadays challenge is to make GRBs, the farthest stellar-scaled objects observed (up to redshift z=9.4), standard candles through well established and robust correlations. However, GRBs spanning several orders of magnitude in their energetics are far from being standard candles. We describe the advances in the prompt correlation research in the past decades, with particular focus paid to the discoveries in the last 20 years.


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