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Publisher: Springer-Verlag   (Total: 2341 journals)

 Acta Biotheoretica   [SJR: 0.419]   [H-I: 25]   [5 followers]  Follow         Hybrid journal (It can contain Open Access articles)    ISSN (Print) 1572-8358 - ISSN (Online) 0001-5342    Published by Springer-Verlag  [2341 journals]
• The Role of Hyalomma Truncatum on the Dynamics of Rift Valley Fever:
Insights from a Mathematical Epidemic Model
• Authors: Sansao A. Pedro; Shirley Abelman; Henri E. Z. Tonnang
Pages: 1 - 36
Abstract: Abstract To date, our knowledge of Rift Valley fever (RVF) disease spread and maintenance is still limited, as flooding, humid weather and presence of biting insects such as mosquitoes, have not completely explained RVF outbreaks. We propose a model that includes livestock, mosquitoes and ticks compartments structured according to their questing and feeding behaviour in order to study the possible role of ticks on the dynamics of RVF. To quantify disease transmission at the initial stage of the epidemic, we derive an explicit formula of the basic reproductive number, $$R_0$$ . Using the concept of Metzler matrix, we state necessary conditions for global asymptotic stability of the disease-free equilibrium. Results suggest that although host-ticks interactions may serve as disease reservoirs or disease amplifiers, the Aedes reproductive number should be kept under unity if disease post-epizootics activities are to be controlled. Results of both local and global sensitivity analysis of selected model parameters indicate that $$R_0$$ is more sensitive to the ticks attachment and detachment rates, probability of transmission from ticks to host and from host to ticks, length of infection in livestock and ticks death rate. Furthermore, when comparing the mean value of $$R_0$$ with that from previous studies which did not include ticks we found that our $$R_0$$ is very much larger resulting in an increase in the exponential phase of an outbreak. These findings suggest that if ticks are capable of transmitting the virus, they may be contributing to disease outbreaks and endemicity.
PubDate: 2017-03-01
DOI: 10.1007/s10441-016-9285-0
Issue No: Vol. 65, No. 1 (2017)

• SMT and TOFT Integrable After All: A Reply to Bizzarri and Cucina
• Authors: Baptiste Bedessem; Stphanie Ruphy
Pages: 81 - 85
Abstract: Abstract In a previous paper recently published in this journal, we argue that the two main theories of carcinogenesis (SMT and TOFT) should be considered as compatible, at the metaphysical, epistemological and biological levels. In a reply to our contribution, Bizzarri and Cucina claim we are wrong since SMT and TOFT are opposite and incompatible paradigms. Here, we show that their arguments are not satisfactory. Indeed, the authors go through the same mistakes that we already addressed. In particular, they confuse reductionism, as an ontological frame, and genetic determinism, as a causal pathway. Beside, they make an inadequate use of the Kuhnian notion of paradigm shift. Finally, we confirm our previous conclusion: there is no strong argument to totally abandon the somatic mutation theory. It describes a partial causal pathway, compatible with the one proposed by TOFT.
PubDate: 2017-03-01
DOI: 10.1007/s10441-016-9286-z
Issue No: Vol. 65, No. 1 (2017)

• Skewed Exposure to Environmental Antigens Complements Hygiene Hypothesis
in Explaining the Rise of Allergy
• Authors: Wilfried Allaerts; Tse Wen Chang
Abstract: Abstract The Hygiene Hypothesis has been recognized as an important cornerstone to explain the sudden increase in the prevalence of asthma and allergic diseases in modernized culture. The recent epidemic of allergic diseases is in contrast with the gradual implementation of Homo sapiens sapiens to the present-day forms of civilization. This civilization forms a gradual process with cumulative effects on the human immune system, which co-developed with parasitic and commensal Helminths. The clinical manifestation of this epidemic, however, became only visible in the second half of the twentieth century. In order to explain these clinical effects in terms of the underlying IgE-mediated reactions to innocuous environmental antigens, the low biodiversity of antigens in the domestic environment plays a pivotal role. The skewing of antigen exposure as a cumulative effect of reducing biodiversity in the immediate human environment as well as in changing food habits, provides a sufficient and parsimonious explanation for the rise in allergic diseases in a highly developed and helminth-free modernized culture. Socio-economic tendencies that incline towards a further reduction of environmental biodiversity may provide serious concern for future health. This article explains that the “Hygiene Hypothesis”, the “Old Friends Hypothesis”, and the “Skewed Antigen Exposure Hypothesis” are required to more fully explain the rise of allergy in modern societies.
PubDate: 2017-03-24
DOI: 10.1007/s10441-017-9306-7

• Stability of a Stochastic Model of an SIR Epidemic with Vaccination
• Authors: P. J. Witbooi
Abstract: Abstract We prove almost sure exponential stability for the disease-free equilibrium of a stochastic differential equations model of an SIR epidemic with vaccination. The model allows for vertical transmission. The stochastic perturbation is associated with the force of infection and is such that the total population size remains constant in time. We prove almost sure positivity of solutions. The main result concerns especially the smaller values of the diffusion parameter, and describes the stability in terms of an analogue $$\mathcal{R}_\sigma$$ of the basic reproduction number $$\mathcal{R}_0$$ of the underlying deterministic model, with $$\mathcal{R}_\sigma \le \mathcal{R}_0$$ . We prove that the disease-free equilibrium is almost sure exponentially stable if $$\mathcal{R}_\sigma <1$$ .
PubDate: 2017-03-21
DOI: 10.1007/s10441-017-9308-5

• External Noise and External Signal Induced Transition of Gene Switch and
Coherence Resonance in the Genetic Regulatory System
• Authors: Jian-Cheng Shi; Min Luo; Tao Dong; Chu-Sheng Huang
Abstract: Abstract The transition of gene switch induced by external noises (multiplicative external noise and additive external noise) and external signals is investigated in the genetic regulatory system. Results show that the state-to-state transition of gene switch as well as resonant behaviors, such as the explicit coherence resonance (ECR), implicit coherence resonance (ICR) and control parameter coherence biresonance (CPCBR), can appear when noises are injected into the genetic regulatory system. The ECR is increased with the increase of the control parameter value when starting from the supercritical Hopf bifurcation parameter point, and there exists a critical control parameter value for the occurrence of ECR. However, the ICR is decreased as the control parameter value is increased when starting from the subcritical Hopf bifurcation point. In particular, the coherence of ECR is higher and more sensitive to noise than that of ICR. When an external signal is introduced into the system, the enhancement or suppression of the CPCBR and the number of peaks strongly depend on the frequency and amplitude of the external signal. Furthermore, the gene regulation system can selectively enhance or decrease the noise-induced oscillation signals at preferred frequency and amplitude of an external signal.
PubDate: 2017-03-17
DOI: 10.1007/s10441-017-9307-6

• Mapping Biological Transmission: An Empirical, Dynamical, and Evolutionary
Approach
• Authors: Francesca Merlin; Livio Riboli-Sasco
Abstract: Abstract The current debate over extending inheritance and its evolutionary impact has focused on adding new categories of non-genetic factors to the classical transmission of DNA, and on trying to redefine inheritance. Transmitted factors have been mainly characterized by their directions of transmission (vertical, horizontal, or both) and the way they store variations. In this paper, we leave aside the issue of defining inheritance. We rather try to build an evolutionary conceptual framework that allows for tracing most, if not all forms of transmission and makes sense of their different tempos and modes. We discuss three key distinctions that should in particular be the targets of theoretical and empirical investigation, and try to assess the interplay among them and evolutionary dynamics. We distinguish two channels of transmission (channel 1 and channel 2), two measurements of the temporal dynamics of transmission, respectively across and within generations (durability and residency), and two types of transmitted factors according to their evolutionary relevance (selectively relevant and neutral stable factors). By implementing these three distinctions we can then map different forms of transmission over a continuous space describing the combination of their varying dynamical features. While our aim is not to provide yet another model of inheritance, putting together these distinctions and crossing them, we manage to offer an inclusive conceptual framework of transmission, grounded in empirical observation, and coherent with evolutionary theory. This interestingly opens possibilities for qualitative and quantitative analyses, and is a necessary step, we argue, in order to question the interplay between the dynamics of evolution and the dynamics of multiple forms of transmission.
PubDate: 2017-02-14
DOI: 10.1007/s10441-017-9305-8

• Erratum to: Exploring Darwinian Worlds: From Darwin to the Extended
Synthesis
• Authors: Elena Casetta; Andrea Borghini
PubDate: 2017-02-06
DOI: 10.1007/s10441-017-9304-9

• Dual Causality and the Autonomy of Biology
• Authors: Walter J. Bock
Abstract: Abstract Ernst Mayr’s concept of dual causality in biology with the two forms of causes (proximate and ultimate) continues to provide an essential foundation for the philosophy of biology. They are equivalent to functional (=proximate) and evolutionary (=ultimate) causes with both required for full biological explanations. The natural sciences can be classified into nomological, historical nomological and historical dual causality, the last including only biology. Because evolutionary causality is unique to biology and must be included for all complete biological explanations, biology is autonomous from the physical sciences.
PubDate: 2017-01-02
DOI: 10.1007/s10441-016-9303-2

• On the Role of Imitation on Adolescence Methamphetamine Abuse Dynamics
• Authors: J. Mushanyu; F. Nyabadza; G. Muchatibaya; A. G. R. Stewart
Abstract: Abstract Adolescence methamphetamine use is an issue of considerable concern due to its correlation with later delinquency, divorce, unemployment and health problems. Understanding how adolescents initiate methamphetamine abuse is important in developing effective prevention programs. We formulate a mathematical model for the spread of methamphetamine abuse using nonlinear ordinary differential equations. It is assumed that susceptibles are recruited into methamphetamine use through imitation. An epidemic threshold value, $${\mathcal {R}}_a$$ , termed the abuse reproduction number, is proposed and defined herein in the drug-using context. The model is shown to exhibit the phenomenon of backward bifurcation. This means that methamphetamine problems may persist in the population even if $${\mathcal {R}}_a$$ is less than one. Sensitivity analysis of $${\mathcal {R}}_a$$ was performed to determine the relative importance of different parameters in methamphetamine abuse initiation. The model is then fitted to data on methamphetamine users less than 20 years old reporting methamphetamine as their primary substance of abuse in the treatment centres of Cape Town and parameter values that give the best fit are chosen. Results show that the proportion of methamphetamine users less than 20 years old reporting methamphetamine as their primary substance of abuse will continue to decrease in Cape Town of South Africa. The results suggest that intervention programs targeted at reducing adolescence methamphetamine abuse, are positively impacting methamphetamine abuse.
PubDate: 2016-12-18
DOI: 10.1007/s10441-016-9302-3

• Discrete Mesh Approach in Morphogenesis Modelling: the Example of
Gastrulation
• Abstract: Abstract Morphogenesis is a general concept in biology including all the processes which generate tissue shapes and cellular organizations in a living organism. Many hybrid formalizations (i.e., with both discrete and continuous parts) have been proposed for modelling morphogenesis in embryonic or adult animals, like gastrulation. We propose first to study the ventral furrow invagination as the initial step of gastrulation, early stage of embryogenesis. We focus on the study of the connection between the apical constriction of the ventral cells and the initiation of the invagination. For that, we have created a 3D biomechanical model of the embryo of the Drosophila melanogaster based on the finite element method. Each cell is modelled by an elastic hexahedron contour and is firmly attached to its neighbouring cells. A uniform initial distribution of elastic and contractile forces is applied to cells along the model. Numerical simulations show that invagination starts at ventral curved extremities of the embryo and then propagates to the ventral medial layer. Then, this observation already made in some experiments can be attributed uniquely to the specific shape of the embryo and we provide mechanical evidence to support it. Results of the simulations of the “pill-shaped” geometry of the Drosophila melanogaster embryo are compared with those of a spherical geometry corresponding to the Xenopus lævis embryo. Eventually, we propose to study the influence of cell proliferation on the end of the process of invagination represented by the closure of the ventral furrow.
PubDate: 2016-11-16
DOI: 10.1007/s10441-016-9301-4

• Interactions Between the Cross-Shore Structure of Small Pelagic Fish
Population, Offshore Industrial Fisheries and Near Shore Artisanal
Fisheries: A Mathematical Approach
• Authors: Rachid Mchich; Timothée Brochier; Pierre Auger; Patrice Brehmer
Abstract: Abstract This work presents a mathematical model describing the interactions between the cross-shore structure of small pelagic fish population an their exploitation by coastal and offshore fisheries. The complete model is a system of seven ODE’s governing three stocks of small pelagic fish population moving and growing between three zones. Two types of fishing fleets are inter-acting with the fish population, industrial boats, constrained to offshore area, and artisanal boats, operating from the shore. Two time scales were considered and we use aggregation methods that allow us to reduce the dimension of the model and to obtain an aggregated model, which is a four dimension one. The analysis of the aggregated model is performed. We discuss the possible equilibriums and their meaning in terms of fishery management. An interesting equilibrium state can be obtained for which we can expect coexistence and a stable equilibrium state between fish stocks and fishing efforts. Some identification parameters are also given in the discussion part of the model.
PubDate: 2016-10-26
DOI: 10.1007/s10441-016-9299-7

• Effects of Behavioural Strategy on the Exploitative Competition Dynamics
• Authors: Doanh Nguyen-Ngoc; Thuy Nguyen-Phuong
Abstract: Abstract We investigate a system of two species exploiting a common resource. We consider both abiotic (i.e. with a constant resource supply rate) and biotic (i.e. with resource reproduction and self-limitation) resources. We are interested in the asymmetric competition where a given consumer is the locally superior resource exploiter (LSE) and the other is the locally inferior resource exploiter (LIE). They also interact directly via interference competition in the sense that LIE individuals can use two opposite strategies to compete with LSE individuals: we assume, in the first case, that LIE uses an avoiding strategy, i.e. LIE individuals go to a non-competition patch to avoids competition with LSE individuals, and in the second one, LIE uses an aggressive strategy, i.e. being very aggressive so that LSE individuals have to go to a non-competition patch. We further assume that there is no resource in the non-competition patch so that individuals have to come back to the competition patch for their maintenance, and the migration process acts on a fast time scale in comparison with demography and competition processes. The models show that being aggressive is efficient for LIE’s survival and even provoke global extinction of the LSE and this result does not depend on the nature of resource.
PubDate: 2016-10-21
DOI: 10.1007/s10441-016-9297-9

• Basin of Attraction of Solutions with Pattern Formation in Slow–Fast
Reaction–Diffusion Systems
• Authors: B. Ambrosio; M. A. Aziz-Alaoui
Abstract: Abstract This article is devoted to the characterization of the basin of attraction of pattern solutions for some slow–fast reaction–diffusion systems with a symmetric property and an underlying oscillatory reaction part. We characterize some subsets of initial conditions that prevent the dynamical system to evolve asymptotically toward solutions which are homogeneous in space. We also perform numerical simulations that illustrate theoretical results and give rise to symmetric and non-symmetric pattern solutions. We obtain these last solutions by choosing particular random initial conditions.
PubDate: 2016-10-21
DOI: 10.1007/s10441-016-9294-z

• A Greedy Algorithm for Brain MRI’s Registration
• Authors: Clément Chesseboeuf
Abstract: Abstract This document presents a non-rigid registration algorithm for the use of brain magnetic resonance (MR) images comparison. More precisely, we want to compare pre-operative and post-operative MR images in order to assess the deformation due to a surgical removal. The proposed algorithm has been studied in Chesseboeuf et al. ((Non-rigid registration of magnetic resonance imaging of brain. IEEE, 385–390. doi:10.1109/IPTA.2015.7367172, 2015), following ideas of Trouvé (An infinite dimensional group approach for physics based models in patterns recognition. Technical Report DMI Ecole Normale Supérieure, Cachan, 1995), in which the author introduces the algorithm within a very general framework. Here we recalled this theory from a practical point of view. The emphasis is on illustrations and description of the numerical procedure. Our version of the algorithm is associated with a particular matching criterion. Then, a section is devoted to the description of this object. In the last section we focus on the construction of a statistical method of evaluation.
PubDate: 2016-10-19
DOI: 10.1007/s10441-016-9296-x

• Recursive Model Identification for the Evaluation of Baroreflex
Sensitivity
• Authors: Virginie Le Rolle; Alain Beuchée; Jean-Paul Praud; Nathalie Samson; Patrick Pladys; Alfredo I. Hernández
Abstract: Abstract A method for the recursive identification of physiological models of the cardiovascular baroreflex is proposed and applied to the time-varying analysis of vagal and sympathetic activities. The proposed method was evaluated with data from five newborn lambs, which were acquired during injection of vasodilator and vasoconstrictors and the results show a close match between experimental and simulated signals. The model-based estimation of vagal and sympathetic contributions were consistent with physiological knowledge and the obtained estimators of vagal and sympathetic activities were compared to traditional markers associated with baroreflex sensitivity. High correlations were observed between traditional markers and model-based indices.
PubDate: 2016-10-18
DOI: 10.1007/s10441-016-9295-y

• A Mathematical Model for Alternation of Polygamy and Parthenogenesis:
Stability Versus Efficiency and Analogy with Parasitism
• Authors: Evariste Sanchez-Palencia; Philippe Lherminier; Jean-Pierre Françoise
Abstract: Abstract The present work is a contribution to the understanding of the sempiternal problem of the “burden of factor two” implied by sexual reproduction versus asexual one, as males are energy consumers not contributing to the production of offspring. We construct a deterministic mathematical model in population dynamics where a species enjoys both sexual and parthenogenetic capabilities of reproduction and lives on a limited resource. We then show how polygamy implies instability of a parthenogenetic population with a small number of sexually born males. This instability implies evolution of the system towards an attractor involving both (sexual and asexual) populations (which does not imply optimality of the population). We also exhibit the analogy with a parasite/host system.
PubDate: 2016-10-13
DOI: 10.1007/s10441-016-9293-0

• Influence of Antithrombin on the Regimes of Blood Coagulation: Insights
from the Mathematical Model
• Authors: Anass Bouchnita; Tatiana Galochkina; Vitaly Volpert
Abstract: Abstract Blood coagulation is regulated through a complex network of biochemical reactions of blood factors. The main acting enzyme is thrombin whose propagation in blood plasma leads to fibrin clot formation. Spontaneous clot formation is normally controlled through the action of different plasma inhibitors, in particular, through the thrombin binding by antithrombin. In the current study we develop a mathematical model of clot formation both in quiescent plasma and in blood flow and determine the analytical conditions on the antithrombin concentration corresponding to different regimes of blood coagulation.
PubDate: 2016-10-07
DOI: 10.1007/s10441-016-9291-2

• Exploring Darwinian Worlds: From Darwin to the Extended Synthesis
• PubDate: 2016-10-03
DOI: 10.1007/s10441-016-9289-9

• The Poitiers School of Mathematical and Theoretical Biology:
Besson–Gavaudan–Schützenberger’s Conjectures on Genetic Code and
RNA Structures
• Authors: J. Demongeot; H. Hazgui
Abstract: Abstract The French school of theoretical biology has been mainly initiated in Poitiers during the sixties by scientists like J. Besson, G. Bouligand, P. Gavaudan, M. P. Schützenberger and R. Thom, launching many new research domains on the fractal dimension, the combinatorial properties of the genetic code and related amino-acids as well as on the genetic regulation of the biological processes. Presently, the biological science knows that RNA molecules are often involved in the regulation of complex genetic networks as effectors, e.g., activators (small RNAs as transcription factors), inhibitors (micro-RNAs) or hybrids (circular RNAs). Examples of such networks will be given showing that (1) there exist RNA “relics” that have played an important role during evolution and have survived in many genomes, whose probability distribution of their sub-sequences is quantified by the Shannon entropy, and (2) the robustness of the dynamics of the networks they regulate can be characterized by the Kolmogorov–Sinaï dynamic entropy and attractor entropy.
PubDate: 2016-09-03
DOI: 10.1007/s10441-016-9287-y

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