Copy and paste: the impact of a new non-L1 retroposon on the gonosomal heterochromatin of Microtus agrestis

2002 ◽  
Vol 96 (1-4) ◽  
pp. 179-185 ◽  
Author(s):  
H. Neitzel ◽  
V. Kalscheuer ◽  
A.P. Singh ◽  
S. Henschel ◽  
K. Sperling
Keyword(s):  
Microtus Agrestis ◽  
Copy And Paste ◽  
The Impact

An Investigation into the Impact of Software Licenses on Copy-and-paste Reuse among OSS Projects

2011 ◽  
Author(s):  
Yu Kashima ◽  
Yasuhiro Hayase ◽  
Norihiro Yoshida ◽  
Yuki Manabe ◽  
Katsuro Inoue
Keyword(s):  
Software Licenses ◽  
Copy And Paste ◽  
The Impact

English in Flemish adolescents’ computer-mediated discourse

2012 ◽  
Vol 33 (3) ◽  
pp. 321-352 ◽  
Author(s):  
Benny De Decker ◽  
Reinhild Vandekerckhove
Keyword(s):  
Native Language ◽  
Electronic Media ◽  
Target Language ◽  
Socialization Process ◽  
Representative Case ◽  
Computer Mediated ◽  
Mediated Discourse ◽  
Copy And Paste ◽  
The Impact

The paper focuses on the presence of English in a written chat corpus produced by Flemish teenagers whose native language is (a variety of) Dutch: it deals with the relative presence of several lexemes and word categories, with the effect on the target language and with the way the loans are integrated into teenager chatspeak, i.e. with (g)localisation processes. In quantitative terms, the impact of English on the informal “speech” of Flemish teenagers appears to be considerable, but the borrowing process is not a copy-and-paste practice. In many cases the teenagers transform the English words graphemically, morphologically and/or semantically. By using an extensive and reliable corpus and by quantifying and categorizing the English tokens in several ways, this paper aims at describing a representative case study for the appropriation of English by a generation the socialization process of which partly proceeds via electronic media.

scholarly journals Stochastic Effects in Retrotransposon Dynamics Revealed by Modeling under Competition for Cellular Resources

Life ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1209
Author(s):  
Sergey Pavlov ◽  
Vitaly V. Gursky ◽  
Maria Samsonova ◽  
Alexander Kanapin ◽  
Anastasia Samsonova
Keyword(s):  
Stochastic Effects ◽  
Alu Elements ◽  
Predator Prey ◽  
Available Energy ◽  
A Cell ◽  
Multiple Cell ◽  
Competition Process ◽  
Copy And Paste ◽  
Transposon Activity ◽  
The Impact

Transposons are genomic elements that can relocate within a host genome using a ‘cut’- or ‘copy-and-paste’ mechanism. They make up a significant part of many genomes, serve as a driving force for genome evolution, and are linked with Mendelian diseases and cancers. Interactions between two specific retrotransposon types, autonomous (e.g., LINE1/L1) and nonautonomous (e.g., Alu), may lead to fluctuations in the number of these transposons in the genome over multiple cell generations. We developed and examined a simple model of retrotransposon dynamics under conditions where transposon replication machinery competed for cellular resources: namely, free ribosomes and available energy (i.e., ATP molecules). Such competition is likely to occur in stress conditions that a malfunctioning cell may experience as a result of a malignant transformation. The modeling revealed that the number of actively replicating LINE1 and Alu elements in a cell decreases with the increasing competition for resources; however, stochastic effects interfere with this simple trend. We stochastically simulated the transposon dynamics in a cell population and showed that the population splits into pools with drastically different transposon behaviors. The early extinction of active Alu elements resulted in a larger number of LINE1 copies occurring in the first pool, as there was no competition between the two types of transposons in this pool. In the other pool, the competition process remained and the number of L1 copies was kept small. As the level of available resources reached a critical value, both types of dynamics demonstrated an increase in noise levels, and both the period and the amplitude of predator–prey oscillations rose in one of the cell pools. We hypothesized that the presented dynamical effects associated with the impact of the competition for cellular resources inflicted on the dynamics of retrotransposable elements could be used as a characteristic feature to assess a cell state, or to control the transposon activity.

Retrotransposons: Metaparasites and Agents of Genome Evolution

2006 ◽  
Vol 52 (3-4) ◽  
pp. 319-330 ◽  
Author(s):  
François Sabot ◽  
Ruslan Kalendar ◽  
Marko Jääskeläinen ◽  
Chang Wei ◽  
Jaakko Tanskanen ◽  
...  
Keyword(s):  
Life Cycle ◽  
Genome Evolution ◽  
Selfish Dna ◽  
Higher Plant ◽  
Defective Interfering Particles ◽  
Cellular Genes ◽  
Copy And Paste ◽  
Set Up ◽  
Cis And Trans ◽  
The Impact

Transposable elements comprise the bulk of higher plant genomes. The majority of these elements are the Class I LTR retrotransposons, which transpose via an RNA intermediate in a "Copy-and-Paste" mechanism. Because retrotransposons use cellular resources and their own enzymes to replicate independently of the genome as a whole, and have thereby become in many cases more predominant than the cellular genes, they have been considered "selfish DNA" and nuclear parasites. They are thought to share many features of the internal life cycle of retroviruses such as HIV (lentiviruses). However, whereas at least some of the retroviruses arriving in an organism during an infection must be functional in order for the infection to proceed, some LTR retrotransposon families appear to completely lack active members even though they remain mobile. Furthermore, the process of retrotransposition is inherently error-prone and mutagenic, giving rise to "pseudospecies," or clusters of imperfect copies. The non-autonomous retrotransposons are able to cis- and trans-parasitize host retrotransposons to gain mobility, much as do defective interfering particles of RNA viruses. Hence, a complex dynamic is set up, whereby the impact of retrotransposons on genomes can be under selection on the organismal level; the impact of non-autonomous retrotransposons on autonomous ones can likewise be under selection if there is selection on the autonomous elements themselves. We are exploring the retrotransposon life cycle and the causes and possible consequences of non-autonomy at each stage regarding genome evolution.

scholarly journals The impact of experimentally elevated energy expenditure on oxidative stress and lifespan in the short-tailed field vole Microtus agrestis

2008 ◽  
Vol 275 (1645) ◽  
pp. 1907-1916 ◽  
Author(s):  
Colin Selman ◽  
Jane S McLaren ◽  
Andrew R Collins ◽  
Garry G Duthie ◽  
John R Speakman
Keyword(s):  
Oxidative Stress ◽  
Energy Expenditure ◽  
Microtus Agrestis ◽  
Field Vole ◽  
The Impact

scholarly journals Bacterial adaptation by a transposition burst of an invading IS element

2020 ◽  
Author(s):  
Scott R. Miller ◽  
Heidi E. Abresch ◽  
Nikea J. Ulrich ◽  
Emiko B. Sano ◽  
Andrew H. Demaree ◽  
...  
Keyword(s):  
Adaptive Evolution ◽  
Carbon Fixation ◽  
Single Copy ◽  
Beneficial Mutations ◽  
Is Element ◽  
General Importance ◽  
Carbon Concentrating Mechanisms ◽  
Acaryochloris Marina ◽  
Copy And Paste ◽  
The Impact

AbstractThe impact of transposable elements on host fitness range from highly deleterious to beneficial, but their general importance for adaptive evolution remains debated. Here, we investigated whether IS elements are a major source of beneficial mutations during 400 generations of laboratory evolution of the cyanobacterium Acaryochloris marina strain CCMEE 5410, which has experienced a recent or on-going IS element expansion. The dynamics of adaptive evolution were highly repeatable among eight independent experimental populations and included beneficial mutations related to exopolysaccharide production and inorganic carbon concentrating mechanisms for photosynthetic carbon fixation. Most detected mutations were IS transposition events, but, surprisingly, the majority of these involved the copy-and-paste activity of only a single copy of an unclassified element (ISAm1) that has recently invaded the genome of A. marina strain CCMEE 5410. Our study reveals that the activity of a single transposase can fuel adaptation for at least several hundred generations.Impact statementA single transposable element can fuel adaptation to a novel environment for hundreds of generations without an apparent accumulation of a deleterious mutational load.

Formation of Lunar Craters and Bright Rays as a Result of Meteorite Impacts

1962 ◽  
Vol 14 ◽  
pp. 415-418
Author(s):  
K. P. Stanyukovich ◽  
V. A. Bronshten
Keyword(s):  
Explosive Charge ◽  
The Moon ◽  
Meteorite Impacts ◽  
The Earth ◽  
Lunar Craters ◽  
The Impact

The phenomena accompanying the impact of large meteorites on the surface of the Moon or of the Earth can be examined on the basis of the theory of explosive phenomena if we assume that, instead of an exploding meteorite moving inside the rock, we have an explosive charge (equivalent in energy), situated at a certain distance under the surface.

The Geosciences Applied to Lunar Exploration

1962 ◽  
Vol 14 ◽  
pp. 169-257 ◽  
Author(s):  
J. Green
Keyword(s):  
Lunar Surface ◽  
Probable Mechanism ◽  
Point Of View ◽  
Lunar Exploration ◽  
Geological Model ◽  
Apply Geophysics ◽  
Surface Features ◽  
The Impact

The term geo-sciences has been used here to include the disciplines geology, geophysics and geochemistry. However, in order to apply geophysics and geochemistry effectively one must begin with a geological model. Therefore, the science of geology should be used as the basis for lunar exploration. From an astronomical point of view, a lunar terrain heavily impacted with meteors appears the more reasonable; although from a geological standpoint, volcanism seems the more probable mechanism. A surface liberally marked with volcanic features has been advocated by such geologists as Bülow, Dana, Suess, von Wolff, Shaler, Spurr, and Kuno. In this paper, both the impact and volcanic hypotheses are considered in the application of the geo-sciences to manned lunar exploration. However, more emphasis is placed on the volcanic, or more correctly the defluidization, hypothesis to account for lunar surface features.

Asteroid and Comet Impact Speeds upon Mars: Significance for Panspermia and the Supply of Organics

1997 ◽  
Vol 161 ◽  
pp. 197-201 ◽  
Author(s):  
Duncan Steel
Keyword(s):  
Probability Distributions ◽  
Regions Of Interest ◽  
Significant Fraction ◽  
Organic Chemicals ◽  
Impact Speed ◽  
The Mean ◽  
The Impact

AbstractWhilst lithopanspermia depends upon massive impacts occurring at a speed above some limit, the intact delivery of organic chemicals or other volatiles to a planet requires the impact speed to be below some other limit such that a significant fraction of that material escapes destruction. Thus the two opposite ends of the impact speed distributions are the regions of interest in the bioastronomical context, whereas much modelling work on impacts delivers, or makes use of, only the mean speed. Here the probability distributions of impact speeds upon Mars are calculated for (i) the orbital distribution of known asteroids; and (ii) the expected distribution of near-parabolic cometary orbits. It is found that cometary impacts are far more likely to eject rocks from Mars (over 99 percent of the cometary impacts are at speeds above 20 km/sec, but at most 5 percent of the asteroidal impacts); paradoxically, the objects impacting at speeds low enough to make organic/volatile survival possible (the asteroids) are those which are depleted in such species.

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