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Theory in Biosciences, Theorie in Den Biowissenschaften

Mohammad Reza Parsaei, Reza Javidan, Narges Shayegh Kargar, Hassan Saberi Nik
In this paper, we study the global properties of a computer virus propagation model. It is, interesting to note that the classical method of Lyapunov functions combined with the Volterra-Lyapunov matrix properties, can lead to the proof of the endemic global stability of the dynamical model characterizing the spread of computer viruses over the Internet. The analysis and results presented in this paper make building blocks towards a comprehensive study and deeper understanding of the fundamental mechanism in computer virus propagation model...
August 3, 2017: Theory in Biosciences, Theorie in Den Biowissenschaften
Nicolas Glade, Olivier Bastien, Pascal Ballet
Cellular automata are often used to explore the numerous possible scenarios of what could have occurred at the origins of life and before, during the prebiotic ages, when very simple molecules started to assemble and organise into larger catalytic or informative structures, or to simulate ecosystems. Artificial self-maintained spatial structures emerge in cellular automata and are often used to represent molecules or living organisms. They converge generally towards homogeneous stationary soups of still-life creatures...
July 18, 2017: Theory in Biosciences, Theorie in Den Biowissenschaften
Pavle Krsmanovic
Discussions of the survival determinism concept have previously focused on its primary role in the evolution of early unicellular organisms in the light of findings which have been reported on a number of diseases. The rationale for such parallel was in the view according to which multicellular organisms could be regarded as sophisticated colonies of semi-autonomous, single-celled entities, whereby various diseases were described as conditions arising upon the activation of the respective survival mechanisms in a milieu unsuitable for such robust stress response...
June 19, 2017: Theory in Biosciences, Theorie in Den Biowissenschaften
Shihong Liu, Yan Yang, Fang Wei, Jifa Duan, Janeen Braynen, Baoming Tian, Gangqiang Cao, Gongyao Shi, Jiachen Yuan
Polyploidy is a widespread feature of plant genomes. As a typical model of polyploidy, autopolyploidy has been postulated evolutionary dead ends and received little attention compared with allopolyploidy. For the limited data available so far, the evolutionary outcome of genome diversity in autopolyploids remains controversial in comparison with its diploid ancestors. In the present study, the effects of autopolyploidy on genome diversity were revealed at a genome-wide scale by comparative analyses of polymorphism between Arabidopsis autopolyploids (autotetraploids and autotriploids) and related diploids within the first ten successive inbred generations using amplified fragment length polymorphism...
June 13, 2017: Theory in Biosciences, Theorie in Den Biowissenschaften
Jeffrey K McKee
Hominin evolution in the African Pliocene and Pleistocene was accompanied and mediated by changes in the abiotic and biotic spheres. It has been hypothesized that such environmental changes were catalysts of hominin morphological evolution and speciations. Whereas there is little doubt that ecological changes were relevant to shaping the trajectories of mammalian evolution, testing specific hypotheses with data from the fossil record has yielded ambiguous results regarding environmental disruption as a primary catalyst...
June 9, 2017: Theory in Biosciences, Theorie in Den Biowissenschaften
Robert Beyer
In response to the computational limitations of individual leaf-based tree growth models, this article presents a new approach for the efficient characterisation of the spatial distribution of foliage in monolayered trees in terms of 2D foliage surfaces. Much like the recently introduced 3D leaf area density, this concept accommodates local crown plasticity, which is a common weak point in large-scale growth models. Recognizing phototropism as the predominant driver of spatial crown expansion, we define the local light gradient on foliage surfaces...
June 3, 2017: Theory in Biosciences, Theorie in Den Biowissenschaften
Jürgen Jost
In biological classification, a character is a property of a taxon that can distinguish it from other taxa. Characters are not independent, and the relations between characters can arise from structural constraints, developmental pathways or functional constraints. That has lead to famous controversies in the history of biology. In addition, a character as a tool of data analysis has some subjective aspects. In this contribution, I develop algebraic and geometric schemes to address these issues in a mathematical framework...
June 2017: Theory in Biosciences, Theorie in Den Biowissenschaften
Jürgen Jost
We investigate the basic principles of structural knowledge. Structural knowledge underlies cognition, and it organizes, selects and assigns meaning to information. It is the result of evolutionary, cultural and developmental processes. Because of its own constraints, it needs to discover and exploit regularities and thereby achieve a complexity reduction.
June 2017: Theory in Biosciences, Theorie in Den Biowissenschaften
Jürgen Jost
No abstract text is available yet for this article.
May 19, 2017: Theory in Biosciences, Theorie in Den Biowissenschaften
Anderson A Eduardo, Ricardo Carmo
The concept of biological diversity has inspired important discussions throughout the history of ecology. Although its meaning and usefulness have been questioned, it is currently one of the key artifacts of ecology. One way to try to understand why such a concept has undergone so many discussions is to examine its emergence and history from the epistemology perspective. In the present work, we investigated how the emergence of mechanical objectivity (as an epistemic virtue) and trained judgment affected how ecologists address the concept of biological diversity...
May 11, 2017: Theory in Biosciences, Theorie in Den Biowissenschaften
Ľudmila Lacková, Vladimír Matlach, Dan Faltýnek
Arbitrariness in the genetic code is one of the main reasons for a linguistic approach to molecular biology: the genetic code is usually understood as an arbitrary relation between amino acids and nucleobases. However, from a semiotic point of view, arbitrariness should not be the only condition for definition of a code, consequently it is not completely correct to talk about "code" in this case. Yet we suppose that there exist a code in the process of protein synthesis, but on a higher level than the nucleic bases chains...
May 9, 2017: Theory in Biosciences, Theorie in Den Biowissenschaften
Hidekazu Yoshioka
A simple game-theoretic model for upstream fish migration, which is a key element in life history of diadromous fishes, is proposed. Foundation of the model is a minimization problem on the cost of migration with the swimming speed and school size as the variables to be simultaneously optimized. Finding the optimizer ultimately reduces to solving a self-consistency equation without explicit solutions. Mathematical analytical results lead to the sufficient condition that the self-consistency equation has a unique solution, which turns out to be identified with the condition where the unique optimizer exists...
May 3, 2017: Theory in Biosciences, Theorie in Den Biowissenschaften
Lennart Olsson, Georgy S Levit, Uwe Hoßfeld
150 years ago, in 1866, Ernst Haeckel published a book in two volumes called "Generelle Morphologie der Organismen" (General Morphology of Organisms) in which he formulated his biogenetic law, famously stating that ontogeny recapitulates phylogeny. Here we describe Haeckel's original idea and follow its development in the thinking of two scientists inspired by Haeckel, Alexei Sewertzoff and Adolf Naef. Sewertzoff and Naef initially approached the problem of reformulating Haeckel's law in similar ways, and formulated comparable hypotheses at a purely descriptive level...
February 21, 2017: Theory in Biosciences, Theorie in Den Biowissenschaften
R Wiff, M A Barrientos, A M Segura, A C Milessi
The amount of biomass production per unit of food consumed (P/Q) represents an important quantity in ecosystem functioning, because it indicates how efficient a population transforms ingested food into biomass. Several investigations have noticed that P/Q remains relatively constant (or invariant) across fish population that feed at the same food-type level (carnivorous/herbivorous). Nevertheless, theoretical explanation for this invariant is still lacking. In this paper, we demonstrate that P/Q remains invariant across fish populations with stable-age distribution...
February 3, 2017: Theory in Biosciences, Theorie in Den Biowissenschaften
Francesco Catania, Ulrich Krohs, Marco Chittò, Diana Ferro, Kevin Ferro, Gildas Lepennetier, Hans-Dieter Görtz, Rebecca S Schreiber, Joachim Kurtz, Jürgen Gadau
Are we in the midst of a paradigm change in biology and have animals and plants lost their individuality, i.e., are even so-called 'typical' organisms no longer organisms in their own right? Is the study of the holobiont-host plus its symbiotic microorganisms-no longer optional, but rather an obligatory path that must be taken for a comprehensive understanding of the ecology and evolution of the individual components that make up a holobiont? Or are associated microbes merely a component of their host's environment, and the holobiont concept is just a beautiful idea that does not add much or anything to our understanding of evolution? This article explores different aspects of the concept of the holobiont...
December 19, 2016: Theory in Biosciences, Theorie in Den Biowissenschaften
David C Krakauer, Lydia Müller, Sonja J Prohaska, Peter F Stadler
A critical feature of all cellular processes is the ability to control the rate of gene or protein expression and metabolic flux in changing environments through regulatory feedback. We review the many ways that regulation is represented through causal, logical, and dynamical components. Formalizing the nature of these components promotes effective comparison among distinct regulatory networks and provides a common framework for the potential design and control of regulatory systems in synthetic biology.
December 2016: Theory in Biosciences, Theorie in Den Biowissenschaften
Elham Shamsara, Jamal Shamsara, Zahra Afsharnezhad
In this paper, we consider a four dimensional model of the human immunodeficiency virus-1 (HIV-1) with delay, which is an extension of some three dimensional models. We approach the treatment problem by adding two controllers to the system for inhibiting viral production. The optimal controller [Formula: see text] is considered for vaccine and [Formula: see text] for the drug. The Pontryagin maximum principle with delay is used to characterize these optimal controls. At the end, numerical results are presented to illustrate the optimal solutions...
December 2016: Theory in Biosciences, Theorie in Den Biowissenschaften
N Grosjean, T Huillet, G Rollet
After an introduction to the general topic of models for a given locus of a diploid population whose quadratic dynamics is determined by a fitness landscape, we consider more specifically the models that can be treated using genetic (or train) algebras. In this setup, any quadratic offspring interaction can produce any type of offspring and after the use of specific changes of basis, we study the evolution and possible stability of some examples. We also consider some examples that cannot be treated using the framework of genetic algebras...
December 2016: Theory in Biosciences, Theorie in Den Biowissenschaften
Jônata Tyska Carvalho, Stefano Nolfi
In this paper, we show how the development of plastic behaviours, i.e., behaviour displaying a modular organisation characterised by behavioural subunits that are alternated in a context-dependent manner, can enable evolving robots to solve their adaptive task more efficiently also when it does not require the accomplishment of multiple conflicting functions. The comparison of the results obtained in different experimental conditions indicates that the most important prerequisites for the evolution of behavioural plasticity are: the possibility to generate and perceive affordances (i...
December 2016: Theory in Biosciences, Theorie in Den Biowissenschaften
Elizabeth Watts, Uwe Hossfeld, Irina Tolstikova, Georgy S Levit
This paper provides a detailed look at how creationism originated in the United States and then explores how this evangelical trend was exported to Russia by American missionaries following the fall of the USSR. The comparison between these two countries is particularly interesting since the rivalry between the US and the USSR during the race to space caused both countries to revamp their science education. Yet, while political interests led both governments to focus on science education, creationist activities were simultaneously focused on diminishing the coverage of evolution in science classrooms...
October 20, 2016: Theory in Biosciences, Theorie in Den Biowissenschaften
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