Search results for "Huxley"
showing 10 items of 13 documents
Topology of multiplex heterogeneous networks of Hodgkin-Huxley-type of models with bistability leading to stabilization stable equilibrium
2021
The dynamics of a multiplex heterogeneous networks of oscillators is studied. Two types of very similar models based on the Hodgkin-Huxley formalism are used as the basic elements of the network: the first one demonstrates bursting oscillations; the second one manifests bistability between bursting oscillations and stable equilibrium. Multiplex networks were developed and investigated, assuming more active communication between models with bistability. Different topologies of the networks are studied. It is shown that in this case it is enough to have one element with bistability in the subnetworks in order to stabilize the equilibrium state in the entire network.
The response of calcareous nannoplankton to sea surface variability at Ceara Rise during the early Pleistocene glacial-interglacial cycles
2019
The Ceara Rise lies just beyond the edge of the Amazon River Fan and sediments from this site may record the complex interplay of different climatic systems and processes, including past changes in southern America monsoon activity, Intertropical Convergence Zone setting, different Atlantic Meridional Overturning Circulation (AMOC) strength and phytoplankton blooming triggered by Amazon River plumes. Here we investigate early Pleistocene calcareous nannoplankton at Ceara Rise, between about 1150 and 850 kiloyears ago. Our investigation shows abrupt variations in water column dynamics across glacial/interglacial cycles or, even better, linked with different AMOC modes. Dominant placoliths in…
Believing in Victorian Times, octobre 2012.
2013
International audience; Those articles deals with several notable aspects of beliefs in Victorian England
Decline in coccolithophore diversity and impact on coccolith morphogenesis along a natural CO2 gradient
2014
A natural pH gradient caused by marine CO2 seeps off Vulcano Island (Italy) was used to assess the effects of ocean acidification on coccolithophores, which are abundant planktonic unicellular calcifiers. Such seeps are used as natural laboratories to study the effects of ocean acidification on marine ecosystems, since they cause long-term changes in seawater carbonate chemistry and pH, exposing the organisms to elevated CO2 concentrations and therefore mimicking future scenarios. Previous work at CO2 seeps has focused exclusively on benthic organisms. Here we show progressive depletion of 27 coccolithophore species, in terms of cell concentrations and diversity, along a calcite saturation …
«Was not the labour problem the same everywhere». «Homo ad laborem nascitur et avis ad volatum»! (Prolegomena per uno studio del diritto del lavoro t…
2019
The purpose of this research is to catalogue the biblical texts - notably in a first phase those which are in the first (or old) testament of the Christian Bible - which contain both prescriptive structures and pathways designed to protect the position of social weakness of the "worker", understood in its broadest sense and in its various and diverse facets: worker, salaried employee, servant, even slave, and so on. The starting point and most immediate objective of this work is therefore to find the biblical sources - and to get ready one first critical apparatus - which refer, directly or indirectly, to work in a broad sense, that is a personal relationship in which one of the two subject…
Ewolucja ludzkości według Hoene-Wrońskiego
2017
The aim of this article is to recall and, at the same time, to update, the theory of the evolution of humanity by Josef Hoëné-Wronski. I am trying to show that the author of Metapolitics (Métapolitique messianique) and of other philosophical and mathematical works was much ahead of his contemporaries concerning his ideas about evolution and these ideas, although expressed in a somewhat archaic and obscure language, are still valid for us today. Hoëné-Wronski has boldly challenged the deterministic picture of the world emerging from modern science and has derived human evolution from the moral and rational development of human beings. He divided it into seven stages. My interpretation of Hoë…
« Traduction des miracles et miracle de la traduction: Thomas H. Huxley, traducteur engagé »
2021
Thomas H. Huxley n’est guère connu comme traducteur mais L’Histoire de la translation des bienheureux martyrs S. Marcellin et S. Pierre d’Éginhard, qu’il traduit partiellement en anglais mérite un examen. Publié dans Nineteenth Century l’article « The Value of Witness to the Miraculous » (1889), s’inscrit dans un débat fondamental sur le caractère révélé de la religion chrétienne que mène Huxley en partie contre le monde religieux. Partielle, s’appuyant sur la traduction en français de Toulet et inscrite dans l’éthique de la croyance de W.K. Clifford, elle permet à Huxley d’invalider la valeur du témoignage d’Éginhard. Toujours commentée, sa traduction sert également de couverture au vérita…
Ergodicity for a stochastic Hodgkin–Huxley model driven by Ornstein–Uhlenbeck type input
2013
We consider a model describing a neuron and the input it receives from its dendritic tree when this input is a random perturbation of a periodic deterministic signal, driven by an Ornstein-Uhlenbeck process. The neuron itself is modeled by a variant of the classical Hodgkin-Huxley model. Using the existence of an accessible point where the weak Hoermander condition holds and the fact that the coefficients of the system are analytic, we show that the system is non-degenerate. The existence of a Lyapunov function allows to deduce the existence of (at most a finite number of) extremal invariant measures for the process. As a consequence, the complexity of the system is drastically reduced in c…
Primary productivity variability on the Atlantic Iberian Margin over the last 70,000 years: Evidence from coccolithophores and fossil organic compoun…
2010
[1] This study analyzes coccolithophore abundance fluctuations (e.g., Emiliania huxleyi, Gephyrocapsa specimens, and Florisphaera profunda) in core MD01-2444 sediment strata retrieved at the Iberian Margin, northeastern Atlantic Ocean. Coccolithophores are calcareous nannofossils, a major component of the oceanic phytoplankton, which provide information about past ecological and climatological variability. Results are supported by data on fossil organic compounds (sea surface temperatures, alkenones, and n-hexacosan-1-ol index) and geochemical analyses (benthic δ13Ccc and planktonic δ18Occ isotopes). Three scenarios are taken into account for this location at centennial-scale resolution ove…
Lake zooplankton delta13C values are strongly correlated with the delta13C values of distinct phytoplankton taxa
2016
Article