Jacques Demongeot

Jacques Demongeot
Université Grenoble Alpes · Faculty of Medicine

Professor

About

546
Publications
64,654
Reads
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7,974
Citations
Additional affiliations
September 2015 - present
Université Grenoble Alpes
Position
  • Professor Emeritus
January 2010 - December 2011
Le laboratoire AGIM
Le laboratoire AGIM
January 2007 - December 2011
French National Centre for Scientific Research
Position
  • Centre national de la recherche scientifique

Publications

Publications (546)
Article
We discuss the influence of positive and negative feedback on the stability of a system, which is not clear-cut, and involves complex, mathematical problems. We show in particular that positive feedback can have a stabilising effect on some systems. We also point out the role that positive feedback plays in the digital treatment of signals required...
Article
Full-text available
The impacts of COVID-19 outbreak on socio-economic status of countries across the globe cannot be overemphasized as we examine the role it played in various countries. A lot of people were out of jobs, many households were careful of their spending and a greater social fracture of the population in fourteen different countries has emerged. We consi...
Article
Full-text available
Linear functional analysis historically founded by Fourier and Legendre played a significant role to provide a unified vision of mathematical transformations between vector spaces. The possibility of extending this approach is explored when basis of vector spaces is built Tailored to the Problem Specificity (TPS) and not from the convenience or eff...
Preprint
Full-text available
During an epidemic, the infectiousness of infected individuals is known to depend on the time since the individual was infected, that is called the age of infection. Here we study the parameter identifiability of the Kermack-McKendrick model with age of infection which takes into account this dependency. By considering a single cohort of individual...
Article
Full-text available
The end of the acute phase of the COVID-19 pandemic is near in some countries as declared by World Health Organization (WHO) in January 2022 based on some studies in Europe and South Africa despite unequal distribution of vaccines to combat the disease spread globally. The heterogeneity in individual age and the reaction to biological and environme...
Preprint
Full-text available
In automata networks, it is well known that the way entities update their states over time has a major impact on their dynamics. In particular, depending on the chosen update schedule, the underlying dynamical systems may exhibit more or less asymptotic dynamical behaviours such as fixed points or limit cycles. Since such mathematical models have b...
Preprint
Full-text available
Our daily social and political life is more and more impacted by social networks. The functioning of our living bodies is deeply dependent on biological regulation networks such as neural, genetic, and protein networks. And the physical world in which we evolve, is also structured by systems of interacting particles. Interaction networks can be see...
Article
Full-text available
The revisiting of the classical model by Ross and McKendrick, the Suceptible-Infected-Recovered (SIR) model used to formalize the COVID-19 epidemic, requires improvements which will be the subject of this article. The heterogeneity in age of the populations concerned leads to consider models in age groups with specific susceptibilities, which makes...
Article
Full-text available
In this article we study the efficacy of vaccination in epidemiological reconstructions of COVID-19 epidemics from reported cases data. Given an epidemiological model, we developed in previous studies a method that allowed the computation of an instantaneous transmission rate that produced an exact fit of reported cases data of the COVID-19 outbrea...
Article
Full-text available
The dynamics of COVID-19 pandemic varies across countries and it is important as researchers to study different kind of phenomena observed at different stages of the waves during the epidemic period. Our interest in this paper is not to model what happened during the endemic state but during the epidemic state. We proposed a continuous formulation...
Article
Full-text available
In this paper we use the technique of functional data analysis to model daily hospitalized, deceased, Intensive Care Unit (ICU) cases and return home patient numbers along the COVID-19 outbreak, considered as functional data across different departments in France while our response variables are numbers of vaccinations, deaths, infected, recovered...
Preprint
Full-text available
This article aims to study the COVID-19 data for New York City. We use both the daily number of second does vaccination and the daily number of reported cases for New York City. This article provides a method to combine an epidemic model and such data. We explore the influence of vaccine efficacy on our results.
Article
Full-text available
The first COVID 19 case of Kuwait was announced on 24th February, 2020 and the daily new cases increases exponentially since then until May, 2020 when the first wave started to decline. The same exponential dynamics has been observed between January and March, 2021. The forecast of new cases and death recorded daily is crucial so that health expert...
Article
Full-text available
This article focuses on the application of deep learning and spectral analysis to epidemiology time series data, which has recently piqued the interest of some researchers. The COVID-19 virus is still mutating, particularly the delta and omicron variants, which are known for their high level of contagiousness, but policymakers and governments are r...
Article
Full-text available
The COVID-19 pandemic continues to spread and already shows a recurrence in many countries, despite several social distancing and vaccination measures implemented all around the world. Epidemiological data are available, and we use the Auto-Regressive Integrated Moving Average (ARIMA) model to analyze incidence pattern and to generate short-term fo...
Article
Full-text available
(1) Background: The estimation of daily reproduction numbers throughout the contagiousness period is rarely considered and only their sum R0 is calculated to quantify the contagiousness level of an infectious disease; (2) Methods: We give the equation of the discrete dynamics of epidemic growth and obtain an estimation of the daily reproduction nu...
Preprint
Full-text available
The impacts of COVID-19 outbreak on socio-economic status of countries across the globe cannot be overemphasized as we examine the role it played in various countries. A lot of people were out of jobs, many households were careful of their spending and a greater social fracture of the population in fourteen different countries has emerged. We consi...
Preprint
Full-text available
In this paper we use the technique of functional data analysis to model daily hospitalized, deceased, ICU cases and return home patient numbers along the COVID-19 outbreak, considered as functional data across different departments in France while our response variables are numbers of vaccinations, deaths, infected, recovered and tests in France. T...
Article
Full-text available
1) Background: Impact and severity of coronavirus pandemic on health infrastructure vary across countries. We examine the role percentage health expenditure plays in various countries in terms of their preparedness and see how countries improved their public health policy in the first and second wave of the coronavirus pandemic; (2) Methods: We con...
Preprint
Full-text available
(1) Background: Impact and severity of coronavirus pandemic on health infrastructure vary across countries. We examine the role percentage health expenditure plays in various countries in terms of their preparedness and see how countries improved their public health policy in the first and second wave of the coronavirus pandemic; (2) Methods: We co...
Preprint
Full-text available
The first COVID 19 case of Kuwait was announced on 24th February, 2020 and the daily new cases increases exponentially since then until May, 2020 when the first wave started to decline. The same exponential dynamics has been observed between January and March, 2021. The forecast of new cases and death recorded daily is crucial so that health expert...
Article
Full-text available
We provide a new method to analyze the COVID-19 cumulative reported cases data based on a two-step process: first we regularize the data by using a phenomenological model which takes into account the endemic or epidemic nature of the time period, then we use a mathematical model which reproduces the epidemic exactly. This allows us to derive new in...
Article
Full-text available
We present spread parameters for first and second waves of the COVID-19 pandemic for USA states, and for consecutive nonoverlapping periods of 20 days for the USA and 51 countries across the globe. We studied spread rates in the USA states and 51 countries, and analyzed associations between spread rates at different periods, and with temperature, e...
Preprint
Full-text available
Background: The COVID-19 epidemic, which started in late December 2019 and rapidly spread throughout the world, was accompanied by an unprecedented release of reported case data. Our objective is to propose a fresh look at this data by coupling a phenomenological description to the epidemiological dynamics. Methods: We use a phenomenological model...
Article
Full-text available
The purpose of this study is to develop a new method that allows calculating the characteristics of tourist paths, favoring the understanding of visitor behavior. Changes and complexities are considered between a first phase of quasi-random "search" of attractions and tourist sites to visit, and a second phase of direct access to places of interest...
Conference Paper
We propose a panorama of already known Covid-19 determinants and some other new factors depending on three families of variables, i.e., geoclimatic (like temperature or elevation), demographic (like population density or median age) and socio-economic (like Gini' index or health expenditures as percentage of GDP) parameters. The influence of these...
Preprint
Full-text available
We provide a new method to analyze the COVID-19 cumulative reported cases data based on a two-step process: first we regularize the data by using a phenomenological model which takes into account the endemic or epidemic nature of the time period, then we use a mathematical model which reproduces the epidemic exactly. This allows us to derive new in...
Article
Full-text available
Background The objective of this study was to better understand the factors associated with the heterogeneity of in-hospital COVID-19 morbidity and mortality across France, one of the countries most affected by COVID-19 in the early months of the pandemic. Methods This geo-epidemiological analysis was based on data publicly available on government...
Article
Full-text available
Background Understanding the social mechanisms of the circadian rhythms of activity represents a major issue in better managing the mechanisms of age-related diseases occurring over time in the elderly population. The automated analysis of call detail records (CDRs) provided by modern phone technologies can help meet such an objective. At this stag...
Preprint
Full-text available
(1) Background The estimation of daily reproduction rates throughout the infectivity period is rarely considered and only their sum R o is calculated to quantify the level of virulence of an infectious agent; (2) Methods We give the equation of the discrete dynamics of epidemic growth and we obtain an estimation of the daily reproduction rates, by...
Article
The COVID-19 outbreak, which started in late December 2019 and rapidly spread around the world, has been accompanied by an unprecedented release of data on reported cases. Our objective is to offer a fresh look at these data by coupling a phenomenological description to the epidemiological dynamics. We use a phenomenological model to describe and r...
Article
Full-text available
How circadian rhythms of activity manifest themselves in social life of humans remains one of the most intriguing questions in chronobiology and a major issue for personalized medicine. Over the past years, substantial advances have been made in understanding the personal nature and the robustness—i.e. the persistence—of the circadian rhythms of so...
Article
Full-text available
The article is devoted to the parameters identification in the SI model. We consider several methods, starting with an exponential fit to the early cumulative data of SARS-CoV2 in mainland China. The present methodology provides a way to compute the parameters at the early stage of the epidemic. Next, we establish an identifiability result. Then we...
Article
Theoretical minimal RNA rings are candidate primordial genes evolved for non-redundant coding of the genetic code's 22 coding signals (one codon per biogenic amino acid, a start and a stop codon) over the shortest possible length: 29520, exactly 22-nucleotide-long RNA rings solve this min-max constraint. Numerous RNA ring properties are reminiscent...
Preprint
Full-text available
The article is devoted to the parameters identification in the SI model. We consider several methods, starting with an exponential fit of the early cumulative data of Sars-CoV2 in mainland China. The present methodology provides a way to compute the parameters at the early stage of the epidemic. Next, we establish an identifiability result. Then we...
Article
We extend the classical approach in supervised classification based on the local likelihood estimation to the functional covariates case. The estimation procedure of the functional parameter (slope parameter) in the linear model when the covariate is of functional kind is investigated. We show, on simulated as well on real data, that classification...
Article
(1) Background: RNA viruses and especially coronaviruses could act inside host cells not only by building their own proteins, but also by perturbing the cell metabolism. We show the possibility of miRNA-like inhibitions by the SARS-CoV-2 concerning for example the hemoglobin and type I interferons syntheses, hence highly perturbing oxygen distribut...
Article
Genetic code codon-amino acid assignments evolve for 15 (AAA, AGA, AGG, ATA, CGG, CTA, CTG. CTC, CTT, TAA, TAG, TCA, TCG, TGA and TTA (GNN codons notably absent)) among 64 codons (23.4 %) across the 31 genetic codes (NCBI list completed with recently suggested green algal mitochondrial genetic codes). Their usage in 25 theoretical minimal RNA rings...
Article
Full-text available
The management of public health and the preparedness for health emergencies partly rely on the collection and analysis of surveillance data, which become crucial in the context of an emergency such as the pandemic caused by COVID-19. For COVID-19, typically, numerous national and global initiatives have been set up from this perspective. Here, we p...
Preprint
Full-text available
Like in many countries and regions, spread of the COVID 19 pandemic has exhibited important spatial heterogeneity across France, one of the most affected countries so far. To better understand factors associated with incidence, mortality and lethality heterogeneity across the 96 administrative departments of metropolitan France, we thus conducted a...
Article
: (1) Background: RNA viruses and especially coronaviruses could act inside host cells not only by building their own proteins, but also by perturbing the cell metabolism. We show the possibility of miRNA-like inhibitions by the Covid-19 concerning for example the hemoglobin and type I interferons syntheses, hence highly perturbing oxygen distribut...
Preprint
Full-text available
We present spread parameters for first and second waves of the COVID-19 pandemy for USA states, and third wave for 32 regions (19 countries and 13 states of the USA) detected beginning of August 2020. USA first/second wave spreads increase/decrease with population density, are uncorrelated with temperature and median population age. Pooling all 32...
Preprint
Full-text available
This description of contagiosity of SARS-COVID-19 third wave is currently submitted for publication. We post the preprint because of its potential importance for public health and decisions.
Article
Full-text available
1) Background: Here, we characterize COVID-19's waves, following a study presenting negative associations between first wave COVID-19 spread parameters and temperature. (2) Methods: Visual examinations of daily increases in confirmed COVID-19 cases in 124 countries, determined first and second waves in 28 countries. (3) Results: The first wave spre...
Preprint
Full-text available
(1) Background: RNA viruses and especially coronaviruses could act inside host cells not only by building their own proteins, but also by perturbing the cell metabolism. We show the possibility of miRNA-like inhibitions by the SARS-CoV-2 concerning for example the hemoglobin and type I interferons syntheses, hence highly perturbing oxygen distribut...
Preprint
BACKGROUND Understanding the social mechanisms of the circadian rhythms of activity represents a major issue in better managing the mechanisms of age-related diseases occurring over time in the elderly population. The automated analysis of call detail records (CDRs) provided by modern phone technologies can help meet such an objective. At this stag...
Preprint
The COVID-19 epidemic continues to spread outside of China and has some recurrence inside China, despite several social distancing measures implemented by the Chinese government. Limited epidemiological data are available, and recent changes in case definition and reporting further complicate our understanding of the impact of the epidemic, particu...
Preprint
Full-text available
(1) Background: Here, we characterize COVID-19 2nd waves, following a study presenting negative associations between 1st wave COVID-19 spread parameters and temperature; (2) Methods: Visual examinations of daily increase in confirmed COVID-19 cases in 124 countries, determined 1st and 2nd waves in 28 countries; (3) Results: 1st wave spread rate inc...
Preprint
Full-text available
This manuscript is under review at Biology (Basel), we post a preprint because of its potential relevancy in regard of the current coronavirus pandemy.
Article
Nucleotide affinities for noncovalent interactions with amino acids produce associations between mRNAs and cognate peptides, potentially regulating ribosomal translation. Correlations between nucleotide affinities and residue hydrophobicity are explored for 25 theoretical minimal RNA rings, 22 nucleotide-long RNAs designed in silico to code for eac...
Article
Full-text available
Ribosomal RNAs are complex structures that presumably evolved by tRNA accretions. Statistical properties of tRNA secondary structures correlate with genetic code integration orders of their cognate amino acids. Ribosomal RNA secondary structures resemble those of tRNAs with recent cognates. Hence, rRNAs presumably evolved from ancestral tRNAs. Here...
Article
Full-text available
1) Background: The virulence of coronavirus diseases due to viruses like SARS-CoV or MERS-CoV decreases in humid and hot weather. The putative temperature dependence of infectivity by the new coronavirus SARS-CoV-2 or covid-19 has a high predictive medical interest. (2) Methods: External temperature and new covid-19 cases in 21 countries and in the...
Article
Full-text available
(1) Background: Previous experimental observations and theoretical hypotheses have been providing insight into a hypothetical world where an RNA hairpin or ring may have debuted as the primary informational and functional molecule. We propose a model revisiting the architecture of RNA-peptide interactions at the origin of life through the evolution...
Preprint
Full-text available
This manuscript is currently under review in Biology MDPI. We make it here available because of its potential importance in relation to the ongoing pandemy. 1) Background: The virulence of coronavirus diseases due to viruses like SRASS-CoV or 16 MERS-CoV decreases in humid and hot weather. Putative temperature dependence of infectivity by 17 the n...
Article
Full-text available
In automata networks, it is well known that the way entities update their states over time has a major impact on their dynamics. In particular, depending on the chosen update schedule, the underlying dynamical systems may exhibit more or less asymptotic dynamical behaviours such as fixed points or limit cycles. Since such mathematical models have b...
Article
Full-text available
The natural circular code consists of 20 codons (X0) overrepresented in the coding frame of protein-coding genes as compared to remaining noncoding frames, and X1 and X2 (N1N2N3 → N3N1N2 and N1N2N3 → N2N3N1 permutations of X0, overrepresented in + 1 and - 1 frames of protein-coding genes, not self-complementary). X0, X1 and X2 detect ribosomal, + 1...