scholarly journals African genomes illuminate the early history and transition to selfing in Arabidopsis thaliana

2017 ◽  
Vol 114 (20) ◽  
pp. 5213-5218 ◽  
Author(s):  
Arun Durvasula ◽  
Andrea Fulgione ◽  
Rafal M. Gutaker ◽  
Selen Irez Alacakaptan ◽  
Pádraic J. Flood ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Large Scale ◽  
Molecular Model ◽  
Genomic Analysis ◽  
Geographic Region ◽  
Early History ◽  
Sub Saharan Africa ◽  
Last Interglacial ◽  
Wide Range ◽  
History Of

Over the past 20 y, many studies have examined the history of the plant ecological and molecular model, Arabidopsis thaliana, in Europe and North America. Although these studies informed us about the recent history of the species, the early history has remained elusive. In a large-scale genomic analysis of African A. thaliana, we sequenced the genomes of 78 modern and herbarium samples from Africa and analyzed these together with over 1,000 previously sequenced Eurasian samples. In striking contrast to expectations, we find that all African individuals sampled are native to this continent, including those from sub-Saharan Africa. Moreover, we show that Africa harbors the greatest variation and represents the deepest history in the A. thaliana lineage. Our results also reveal evidence that selfing, a major defining characteristic of the species, evolved in a single geographic region, best represented today within Africa. Demographic inference supports a model in which the ancestral A. thaliana population began to split by 120–90 kya, during the last interglacial and Abbassia pluvial, and Eurasian populations subsequently separated from one another at around 40 kya. This bears striking similarities to the patterns observed for diverse species, including humans, implying a key role for climatic events during interglacial and pluvial periods in shaping the histories and current distributions of a wide range of species.

Ivan Kavaleridze`s dramaturgy on the Sumy stage

2021 ◽  
Author(s):  
D.V. Budianskyi
Keyword(s):  
Large Scale ◽  
Musical Comedy ◽  
Historical Figures ◽  
Wide Range ◽  
Socialist Realist ◽  
History Of ◽  
Characteristic Features ◽  
Old Men ◽  
The Impact ◽  
First Time

The characteristic features of I. Kavaleridze’s drama is considered in the article. It is noted that there are signs of the artist’s individuality, attraction to expressionist forms, artistic techniques characteristic for the art of sculpture: symbolism, monumentality, hyperbole. I. Kavaleridze was well versed in the drama laws, understood the specifics of the stage events construction, had a large arsenal of literary means, thanks to which the characters’ monologues and dialogues were extremely expressive and colorful. In his work, he implemented original solutions that were ahead of time. Therefore, many of the artist’s ideas and achievements received due recognition only after his death. I. Kavaleridze’s creative heritage covers a wide range of both purely artistic and general philosophical problems. Among them the formation of the era of modernism and its features in the Ukrainian art of the early XX century, the impact of revolutionary ideas on the work of the 1920s, the role of spiritual leaders of the Ukrainian people T. Shevchenko and G. Skovoroda in the formation of national consciousness, political and ideological pressure on figurative art language and the formation of a socialist-realist canon, etc. The analysis of the productions of I. Kavalerizde’s plays “The First Furrow” and “Gregory and Paraskeva” on the stage of the Mykhailo Shchepkin Sumy Theater of Drama and Musical Comedy in 1970-1972. The article notes that these plays were staged in Sumy for the first time in the history of Ukrainian theater. The premiere of “The First Furrow” (the play was called “Old Men”) took place on March 19, 1970. The figure of the national genius Hryhoriy Skov oroda was als o embodied for the first time on t he stage in Sumy in th e play “Hryhoriy and Paraskeva”. It premiered on October 21, 1972. I. Rybchynsky, Honored Artist of the USSR, performed the production. Creating generalized historical outlines of people’s life, features of life at that time, depicting psychological portraits of people in various, sometimes-dramatic collisions, in the productions of I. Kavaleridze’s plays on the Sumy stage the emphasis was on universal values such as virtue, love. The main character was the Ukrainian people, who nurtured such large-scale historical figures, gave them strength and wisdom for great achievements. Based on publications in periodicals of that time, memoirs of Ukrainian directors, the peculiarities of the director’s interpretation, stenographic and musical design of these plays on the Sumy stage are considered. Considerable attention is paid to the analysis of acting works in I. Kavaleridze’s plays. In particular, the peculiarities of the actor’s embodiment of the image of the national genius Hryhoriy Skovoroda on the stage are presented. It is noted that I. Kavaleridze’s plays, created in a difficult political, social and ideological context, are rightly considered to be highly artistic works of Ukrainian drama. Their staging was carried out on various theatrical stages, including Mykhailo Shchepkin Sumy Theater of Drama and Musical Comedy is an important page of national theatrical art.

scholarly journals On the Shoulders of Giants: Continuing the Legacy of Large-Scale Ecosystem Manipulation Experiments in Puerto Rico

Forests ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 210 ◽  
Author(s):  
Tana Wood ◽  
Grizelle González ◽  
Whendee Silver ◽  
Sasha Reed ◽  
Molly Cavaleri
Keyword(s):  
Puerto Rico ◽  
Tropical Forests ◽  
Large Scale ◽  
Field Experiments ◽  
Management Strategies ◽  
Luquillo Experimental Forest ◽  
Hurricane Disturbance ◽  
Wide Range ◽  
History Of ◽  
Forest Function

There is a long history of experimental research in the Luquillo Experimental Forest in Puerto Rico. These experiments have addressed questions about biotic thresholds, assessed why communities vary along natural gradients, and have explored forest responses to a range of both anthropogenic and non-anthropogenic disturbances. Combined, these studies cover many of the major disturbances that affect tropical forests around the world and span a wide range of topics, including the effects of forest thinning, ionizing radiation, hurricane disturbance, nitrogen deposition, drought, and global warming. These invaluable studies have greatly enhanced our understanding of tropical forest function under different disturbance regimes and informed the development of management strategies. Here we summarize the major field experiments that have occurred within the Luquillo Experimental Forest. Taken together, results from the major experiments conducted in the Luquillo Experimental Forest demonstrate a high resilience of Puerto Rico’s tropical forests to a variety of stressors.

The Origin, Formation and Early History of the Chikunda of South Central Africa

1972 ◽  
Vol 13 (3) ◽  
pp. 443-461 ◽  
Author(s):  
Allen Isaacman
Keyword(s):  
Nineteenth Century ◽  
Historical Linguistic ◽  
Cultural Differences ◽  
Ethnic Groups ◽  
Large Scale ◽  
Central Africa ◽  
Military History ◽  
Early History ◽  
South Central ◽  
History Of

Although historians have examined the process of pre-colonial political integration, little attention has been paid to the complementary patterns of ethnic and cultural assimilation. The Chikunda, who were initially slaves on the Zambezi prazos, provide an excellent example of this phenomenon. Over the course of several generations, captives from more than twenty ethnic groups submerged their historical, linguistic, and cultural differences to develop a new set of institutions and a common identity. The decline of the prazo system during the first half of the nineteenth century generated large scale migrations of Chikunda outside of the lower Zambezi valley. They settled in Zumbo, the Luangwa valley and scattered regions of Malawi where they played an important role in the nineteenth-century political and military history of south central Africa.

Place Names as an Historical Source: An Introduction with Examples from Southern Senegambia and Germany

1992 ◽  
Vol 19 ◽  
pp. 45-101 ◽  
Author(s):  
Stephan Bühnen
Keyword(s):  
Fifteenth Century ◽  
Oral Tradition ◽  
Sub Saharan Africa ◽  
Place Names ◽  
Research Experience ◽  
Wide Range ◽  
History Of ◽  
Egg Shells ◽  
Sub Saharan ◽  
Written Sources

Written sources for the history of sub-Saharan Africa (with the exception of East Africa) only begin to appear with the inception of Arabic records from the ninth century onwards, and these are restricted to the Sahel and the northern part of the savanna belt. European sources begin in the mid-fifteenth century, first for Senegambia. They, in turn, confine themselves to the coast and its immediate hinterland, as well as the navigable courses of rivers, with few, and often vague, references to the interior. For the time before the early written sources and for those extensive areas which only much later entered the horizon of writing witnesses, other sources illuminating the past have to be traced and tapped. Among such non-written sources are the findings of anthropology and archeology, of research in oral tradition and place names. Because of their interdependence, working with different source types contributes to the reliability of results.So far little systematic use has been made of place names as a source for African history. Houis' 1958 dictum, “la toponymie ouest-africaine n'est pas encore sortie de l'oeuf,” has not yet been proven obsolete. In this paper I hope to stimulate the process of shedding the egg shells. It is intended as a short introduction to the potential historical treasures place names may yield, into their characteristics, and into some principles guiding their interpretation. With the aim at illustrating my arguments, I add examples of place names. These I have chosen from two areas which, at first sight, seem to have been selected rather randomly; southern Senegambia and Germany. In fact both areas share few features, both geographically and historically. Two reasons have led me to select them. First, they simply are the regions I know best. Secondly, the recourse to German place names is instructive, as research on place names has been undertaken there for more than a century, leading to a wide range of data and to the accumulation of rich research experience.

French officials and the insecurities of change in sub-Saharan Africa: Dakar, 19 August 1960 revisited

2013 ◽  
pp. 44-58 ◽  
Author(s):  
Alexander Keese
Keyword(s):  
Decision Making ◽  
Armed Forces ◽  
Early History ◽  
Sub Saharan Africa ◽  
French Military ◽  
Military Commanders ◽  
History Of ◽  
Sub Saharan ◽  
New Interpretation ◽  
New Situation

How would French services operating on the ground, charged with ‘decolonizing’ African territories, adapt to the new situation? This question is posed by Alexander Keese with regard to a dramatic incident in the decolonization process, the August 1960 stand-off between Senegalese and Soudanese politicians and officials in Dakar, an event that led to the end of the short-lived Federation of Mali between Soudan (present-day Mali) and Senegal. French military commanders were still in charge of the vast majority of the armed forces in these former colonial territories. These commanders were faced with an unfamiliar process of decision-making. Keese analyses the behaviour of these remaining French representatives on the ground, and comes to a new interpretation of a crucial event in the early history of Franco-African networks.

scholarly journals Sir George Gabriel Stokes, Bart (1819–1903): his impact on science and scientists

2020 ◽  
Vol 378 (2174) ◽  
pp. 20190524
Author(s):  
Paul Ranford
Keyword(s):  
Royal Society ◽  
Large Scale ◽  
Stokes Equations ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Victorian Era ◽  
Wide Range ◽  
History Of ◽  
And Mathematics ◽  
Lord Kelvin

Lucasian Professor Sir George Gabriel Stokes was appointed joint-Secretary of the Royal Society in 1854, a post he held for the unprecedented period of 31 years, relinquishing the role when he succeeded T.H. Huxley as President in 1885. An eminent scientist of the Victorian era, Stokes explained fluorescence (he also coined the word) and his hydrodynamical formulae (the ‘Navier–Stokes equations’) remain ubiquitous today in the physics of any phenomenon involving fluid flows, from pipelines to glaciers to large-scale atmospheric perturbations. He also made seminal advances in optics and mathematics, and formulae that bear his name remain widely used today. The historiography however appears to understate Stokes's significant impact on science as unacknowledged collaborator on a wide range of scientific developments. His scientific peers regarded him as a mentor, advisor, designer of crucial experiments and, as editor of the Royal Society's scientific journals, arbiter of the standards of excellence in scientific communication to be attained before publication would be considered. Three brief case studies on Stokes's correspondence with Lord Kelvin, Sir William Crookes and the chemist Arthur Smithells exemplify how his impact was conveyed through the work of other scientists. This paper also begins consideration of why the character and worldview of Stokes led him to eschew personal reputation and profit for the sake of science and the Royal Society, and of how the development of the discipline of history of science has impacted on historiography relating to Stokes and others. This article is part of the theme issue ‘Stokes at 200 (Part 1)’.

Introduction

2018 ◽  
Author(s):  
Clive Holes
Keyword(s):  
Social Factors ◽  
Large Scale ◽  
Early History ◽  
Small Scale ◽  
Linguistic Change ◽  
The Social ◽  
History Of ◽  
Arabic Dialects ◽  
Early Occurrence

This chapter outlines the scholarly background of the study of Arabic historical dialectology, and addresses the following issues: the early history of Arabic: myth and reality; the definition and exemplification of ‘Middle Arabic’ and ‘Mixed Arabic through history’; evidence for the early occurrence of certain Arabic dialectal features; examples of substrates and borrowing in Arabic dialects; the dialect geography of Arabic and its typology, especially the ‘sedentary’ and ‘bedouin’ divide; how and why dialects have undergone change, large-scale and small-scale, and the causative social factors; a classification of the typology of internal linguistic change in Arabic; causes of the social indexicalization of dialectal features of Arabic; examples of the pidginization and creolization of Arabic, and the reasons for the apparent rarity of this phenomenon.

Local Lives, Parallel Histories

2020 ◽  
Author(s):  
Marcel Thomas
Keyword(s):  
Social Change ◽  
Life Histories ◽  
Large Scale ◽  
Postwar Germany ◽  
Wide Range ◽  
History Of ◽  
Local Meaning ◽  
Economic Developments ◽  
The Cold War ◽  
Oral History Interviews

The division of Germany separated a nation, divided communities, and inevitably shaped the life histories of those growing up in the socialist dictatorship of the East and the liberal democracy of the West. This peculiarly German experience of the Cold War has so far mostly been seen through the lens of the divided Berlin or other border communities. What has been much less explored, however, is what division meant to the millions of Germans in East and West who lived far away from the Wall and the centres of political power. This book is the first comparative study to examine how villagers in both Germanies dealt with the imposition of two very different systems in their everyday lives. Focusing on two villages, Neukirch (Lausitz) in Saxony and Ebersbach (Fils) in Baden-Württemberg, it explores how local residents experienced and navigated social change in their localities in the postwar era. Based on a wide range of archival sources as well as oral history interviews, the book argues that there are parallel histories of responses to social change among villagers in postwar Germany. Despite the different social, political, and economic developments, the residents of both localities desired rural modernization, lamented the loss of ‘community’, and became politically active to control the transformation of their localities. The book thereby offers a bottom-up history of the divided Germany which shows how individuals on both sides of the Wall gave local meaning to large-scale processes of change.

Ribosomal RNA Sequences and the Early History of the Metazoa

1988 ◽  
Vol 1 ◽  
pp. 63-74
Author(s):  
Rudolf A. Raff
Keyword(s):  
Ribosomal Rna ◽  
Fossil Record ◽  
Comparative Anatomy ◽  
Early History ◽  
Rna Sequences ◽  
Ribosomal Rna Sequences ◽  
Wide Range ◽  
Animal Phyla ◽  
History Of ◽  
Fossil Records

The problems of resolving phylogenetic relationships change with increasing evolutionary distance: very widely separated organisms, which share few phylogenetically helpful morphological features pose the greatest difficulties. Thus, the resolution of relationships between animal phyla and classes present some of the most challenging problems in systematic zoology and paleontology. Traditionally, relationships have been inferred on the basis of comparative anatomy, embryology, and the paleontological record. However, phyla are established on the basis of the unique features of their body plans, and have few shared derived characters to unite them. Even when similar features are available, homology can still be uncertain. The fossil record has been largely unavailable to provide the needed continuity of structure to establish such homologies between phyla and most classes. Generally, the best data for connecting major groups have come from detailed embryological data. But, even there, many ambiguous situations and conflicts of interpretation remain, and these problems are pervasive over a wide range of animal groups, both with and without extensive fossil records.

scholarly journals Image-based methods for phenotyping growth dynamics and fitness components in Arabidopsis thaliana

2017 ◽  
Author(s):  
François Vasseur ◽  
George Wang ◽  
Justine Bresson ◽  
Rebecca Schwab ◽  
Detlef Weigel
Keyword(s):  
Growth Rate ◽  
Arabidopsis Thaliana ◽  
Relative Growth Rate ◽  
Large Scale ◽  
Growth Dynamics ◽  
Dry Mass ◽  
Relative Growth ◽  
Fruit Number ◽  
Wide Range ◽  
Plant Dry Mass

AbstractBackgroundThe model species Arabidopsis thaliana has extensive resources to investigate intraspecific trait variability and the genetic bases of ecologically relevant traits. However, the cost of equipment and software required for high-throughput phenotyping is often a bottleneck for large-scale studies, such as mutant screening or quantitative genetics analyses. Simple tools are needed for the measurement of fitness-related traits, like relative growth rate and fruit production, without investment in expensive infrastructures. Here, we describe methods that enable the estimation of biomass accumulation and fruit number from the analysis of rosette and inflorescence images taken with a regular camera.ResultsWe developed two models to predict plant dry mass and fruit number from the parameters extracted with the analysis of rosette and inflorescence images. Predictive models were trained by sacrificing growing individuals for dry mass estimation, and manually measuring a fraction of individuals for fruit number at maturity. Using a cross-validation approach, we showed that quantitative parameters extracted from image analysis predicts more 90% of both plant dry mass and fruit number. When used on 451 natural accessions, the method allowed modelling growth dynamics, including relative growth rate, throughout the life cycle of various ecotypes. Estimated growth-related traits had high heritability (0.65 < H2 < 0.93), as well as estimated fruit number (H2 = 0.68). In addition, we validated the method for estimating fruit number with rev5, a mutant with increased flower abortion.ConclusionsThe method we propose here is based on the automated computerization of plant images with ImageJ, and subsequent statistical modelling in R. It allows plant biologists to measure growth dynamics and fruit number in hundreds of individuals with simple computing steps that can be repeated and adjusted to a wide range of laboratory conditions. It is thus a flexible toolkit for the measurement of fitness-related traits in large plant populations.

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