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1.
J Neuromuscul Dis ; 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38701156

RESUMO

Medical acts, such as imaging, lead to the production of various medical text reports that describe the relevant findings. This induces multimodality in patient data by combining image data with free-text and consequently, multimodal data have become central to drive research and improve diagnoses. However, the exploitation of patient data is problematic as the ecosystem of analysis tools is fragmented according to the type of data (images, text, genetics), the task (processing, exploration) and domain of interest (clinical phenotype, histology). To address the challenges, we developed IMPatienT (Integrated digital Multimodal PATIENt daTa), a simple, flexible and open-source web application to digitize, process and explore multimodal patient data. IMPatienT has a modular architecture allowing to: (i) create a standard vocabulary for a domain, (ii) digitize and process free-text data, (iii) annotate images and perform image segmentation, (iv) generate a visualization dashboard and provide diagnosis decision support. To demonstrate the advantages of IMPatienT, we present a use case on a corpus of 40 simulated muscle biopsy reports of congenital myopathy patients. As IMPatienT provides users with the ability to design their own vocabulary, it can be adapted to any research domain and can be used as a patient registry for exploratory data analysis. A demo instance of the application is available at https://impatient.lbgi.fr/.

2.
PLoS Comput Biol ; 19(9): e1011429, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37721943

RESUMO

Addressing global environmental crises such as anthropogenic climate change requires the consistent adoption of proenvironmental behavior by a large part of a population. Here, we develop a mathematical model of a simple behavior-environment feedback loop to ask how the individual assessment of the environmental state combines with social interactions to influence the consistent adoption of proenvironmental behavior, and how this feeds back to the perceived environmental state. In this stochastic individual-based model, individuals can switch between two behaviors, 'active' (or actively proenvironmental) and 'baseline', differing in their perceived cost (higher for the active behavior) and environmental impact (lower for the active behavior). We show that the deterministic dynamics and the stochastic fluctuations of the system can be approximated by ordinary differential equations and a Ornstein-Uhlenbeck type process. By definition, the proenvironmental behavior is adopted consistently when, at population stationary state, its frequency is high and random fluctuations in frequency are small. We find that the combination of social and environmental feedbacks can promote the spread of costly proenvironmental behavior when neither, operating in isolation, would. To be adopted consistently, strong social pressure for proenvironmental action is necessary but not sufficient-social interactions must occur on a faster timescale compared to individual assessment, and the difference in environmental impact must be small. This simple model suggests a scenario to achieve large reductions in environmental impact, which involves incrementally more active and potentially more costly behavior being consistently adopted under increasing social pressure for proenvironmentalism.


Assuntos
Meio Ambiente , Modelos Teóricos , Humanos , Retroalimentação , Relações Interpessoais , Interação Social
3.
BMC Bioinformatics ; 22(1): 561, 2021 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-34814826

RESUMO

BACKGROUND: Ab initio prediction of splice sites is an essential step in eukaryotic genome annotation. Recent predictors have exploited Deep Learning algorithms and reliable gene structures from model organisms. However, Deep Learning methods for non-model organisms are lacking. RESULTS: We developed Spliceator to predict splice sites in a wide range of species, including model and non-model organisms. Spliceator uses a convolutional neural network and is trained on carefully validated data from over 100 organisms. We show that Spliceator achieves consistently high accuracy (89-92%) compared to existing methods on independent benchmarks from human, fish, fly, worm, plant and protist organisms. CONCLUSIONS: Spliceator is a new Deep Learning method trained on high-quality data, which can be used to predict splice sites in diverse organisms, ranging from human to protists, with consistently high accuracy.


Assuntos
Algoritmos , Redes Neurais de Computação , Animais , Genoma , Humanos
4.
BMC Bioinformatics ; 21(1): 513, 2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-33172385

RESUMO

BACKGROUND: Recent advances in sequencing technologies have led to an explosion in the number of genomes available, but accurate genome annotation remains a major challenge. The prediction of protein-coding genes in eukaryotic genomes is especially problematic, due to their complex exon-intron structures. Even the best eukaryotic gene prediction algorithms can make serious errors that will significantly affect subsequent analyses. RESULTS: We first investigated the prevalence of gene prediction errors in a large set of 176,478 proteins from ten primate proteomes available in public databases. Using the well-studied human proteins as a reference, a total of 82,305 potential errors were detected, including 44,001 deletions, 27,289 insertions and 11,015 mismatched segments where part of the correct protein sequence is replaced with an alternative erroneous sequence. We then focused on the mismatched sequence errors that cause particular problems for downstream applications. A detailed characterization allowed us to identify the potential causes for the gene misprediction in approximately half (5446) of these cases. As a proof-of-concept, we also developed a simple method which allowed us to propose improved sequences for 603 primate proteins. CONCLUSIONS: Gene prediction errors in primate proteomes affect up to 50% of the sequences. Major causes of errors include undetermined genome regions, genome sequencing or assembly issues, and limitations in the models used to represent gene exon-intron structures. Nevertheless, existing genome sequences can still be exploited to improve protein sequence quality. Perspectives of the work include the characterization of other types of gene prediction errors, as well as the development of a more comprehensive algorithm for protein sequence error correction.


Assuntos
Fases de Leitura Aberta/genética , Primatas/metabolismo , Proteoma , Sequência de Aminoácidos , Animais , Bases de Dados de Proteínas , Deleção de Genes , Humanos , Mutagênese Insercional , Proteínas Tirosina Fosfatases Semelhantes a Receptores/química , Proteínas Tirosina Fosfatases Semelhantes a Receptores/genética , Proteínas Tirosina Fosfatases Semelhantes a Receptores/metabolismo , Alinhamento de Sequência
5.
Sci Total Environ ; 743: 140700, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32758829

RESUMO

In life cycle assessment (LCA), temporal considerations are usually lost during the life cycle inventory calculation, resulting in an aggregated "snapshot" of potential impacts. Disregarding such temporal considerations has previously been underlined as an important source of uncertainty, but a growing number of approaches have been developed to tackle this issue. Nevertheless, their adoption by LCA practitioners is still uncommon, which raises concerns about the representativeness of current LCA results. Furthermore, a lack of consistency can be observed in the used terms for discussions on temporal considerations. The purpose of this review is thus to search for common ground and to identify the current implementation challenges while also proposing development pathways. This paper introduces a glossary of the most frequently used terms related to temporal considerations in LCA to build a common understanding of key concepts and to facilitate discussions. A review is also performed on current solutions for temporal considerations in different LCA phases (goal and scope definition, life cycle inventory analysis and life cycle impact assessment), analysing each temporal consideration for its relevant conceptual developments in LCA and its level of operationalisation. We then present a potential stepwise approach and development pathways to address the current challenges of implementation for dynamic LCA (DLCA). Three key focal areas for integrating temporal considerations within the LCA framework are discussed: i) define the temporal scope over which temporal distributions of emissions are occurring, ii) use calendar-specific information to model systems and associated impacts, and iii) select the appropriate level of temporal resolution to describe the variations of flows and characterisation factors. Addressing more temporal considerations within a DLCA framework is expected to reduce uncertainties and increase the representativeness of results, but possible trade-offs between additional data collection efforts and the increased value of results from DLCAs should be kept in mind.

6.
BMC Genomics ; 21(1): 293, 2020 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-32272892

RESUMO

BACKGROUND: The draft genome assemblies produced by new sequencing technologies present important challenges for automatic gene prediction pipelines, leading to less accurate gene models. New benchmark methods are needed to evaluate the accuracy of gene prediction methods in the face of incomplete genome assemblies, low genome coverage and quality, complex gene structures, or a lack of suitable sequences for evidence-based annotations. RESULTS: We describe the construction of a new benchmark, called G3PO (benchmark for Gene and Protein Prediction PrOgrams), designed to represent many of the typical challenges faced by current genome annotation projects. The benchmark is based on a carefully validated and curated set of real eukaryotic genes from 147 phylogenetically disperse organisms, and a number of test sets are defined to evaluate the effects of different features, including genome sequence quality, gene structure complexity, protein length, etc. We used the benchmark to perform an independent comparative analysis of the most widely used ab initio gene prediction programs and identified the main strengths and weaknesses of the programs. More importantly, we highlight a number of features that could be exploited in order to improve the accuracy of current prediction tools. CONCLUSIONS: The experiments showed that ab initio gene structure prediction is a very challenging task, which should be further investigated. We believe that the baseline results associated with the complex gene test sets in G3PO provide useful guidelines for future studies.


Assuntos
Biologia Computacional/métodos , Eucariotos/genética , Anotação de Sequência Molecular/métodos , Animais , Curadoria de Dados , Evolução Molecular , Humanos , Filogenia
7.
Sci Total Environ ; 718: 135278, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-31839321

RESUMO

Low carbon strategies recently focus on soil organic carbon (SOC) sequestration potentials from agriculture and forestry, while Life Cycle Assessment (LCA) increasingly becomes the framework of choice to estimate the environmental impacts of these activities. Classic LCA is limited to static carbon neutral approaches, disregarding dynamic SOC flows and their time-dependent GHG contributions. To overcome such limitation, the purpose of this study is to model SOC flows associated with agricultural land use (LU) and the provision of agricultural substrates to transport biofuels, thus generating dynamic inventories and comparatively assessing energy policy scenarios and their climate consequences in the context of dynamic LCA. The proposed framework allows computing SOC from annual and perennial species under specific management practices (e.g. residue removal rates, organic fertiliser use). The results associated with the implementation of three energy policies and two accounting philosophies (C-neutral and C-complete) show that shifting energy pathways towards advanced biofuels reduces overall resource consumption, LU and GHG emissions. The French 2015 Energy Transition for Green Growth Act (LTECV) leads towards higher mitigation targets compared with business-as-usual (BAU) and intermediate (15BIO) policy constraints. C-neutral results show reduced radiative forcing effects by 10% and 34% for 15BIO and LTECV respectively, with respect to BAU. C-complete (i.e. dynamic assessment of all biogenic- and fossil-sourced C flows) results reveal further mitigation potentials across policies, whereof 50%-65% can be attributed to temporal C sequestration in perennial rhizomes. A sensitivity analysis suggests important SOC variations due to temperature increase (+2°C) and changes in residue removal rates. Both parameters affect mitigation and the latter also LU, by a factor of -0.56 to + 5. This article highlights the importance of SOC modelling in the context of LU in LCA, which is usually disregarded, as SOC is considered only in the context of land use change (LUC).


Assuntos
Solo , Agricultura , Carbono , Sequestro de Carbono , Produtos Agrícolas , França
8.
Phys Rev E ; 100(4-1): 042608, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31771015

RESUMO

To account for the possibility of an externally driven taxis in active systems, we develop a model of a guided active drift which relies on the presence of an external guiding field and a vectorial coupling between the mechanical degrees of freedom and a chemical reaction. To characterize the ability of guided active particles to carry cargo, we generalize the notion of Stokes efficiency extending it to the case of stall conditions. To show the generality of the proposed mechanism, we discuss guided electric circuits capable of turning fluctuations into a directed current without a source of voltage.

9.
Data Brief ; 23: 103841, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31372468

RESUMO

The data and analyses presented support the research article entitled "Coupling partial-equilibrium and dynamic biogenic carbon models to assess future transport scenarios in France" (Albers et al., 2019). Carbon sequestration and storage in forestry products (e.g. transport fuels) is sought as a climate change mitigation option. The data presented support and inform dynamic modelling approaches to predict biomass growth and carbon fixation dynamics, of a tree or forest stand, over specific rotation lengths. Data consists of species-specific yield tables, parameters for non-linear growth models and allometric equations. Non-linear growth models and allometric equations are listed and described. National statistics and surveys of the wood supply chain serve to identify main tree species, standing wood volumes and distributions within specific geographies; here corresponding to managed forests in France. All necessary data and methods for the computation of the annual fixation flows are presented.

10.
J Med Syst ; 42(1): 1, 2017 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-29159559

RESUMO

Cohort Study Platforms (CSP) are emerging as a key tool for collecting patient information, providing new research data, and supporting family and patient associations. However they pose new ethics and regulatory challenges since they cross the gap between patients and medical practitioners. One of the critical issues for CSP is to enforce a strict control on access privileges whilst allowing the users to take advantage of the breadth of the available data. We propose Cerberus, a new access control scheme spanning the whole life-cycle of access right management: design, implementation, deployment and maintenance, operations. Cerberus enables switching from a dual world, where CSP data can be accessed either from the users who entered it or fully de-identified, to an access-when-required world, where patients, practitioners and researchers can access focused medical data through explicit authorisation by the data owner. Efficient access control requires application-specific access rights, as well as the ability to restrict these rights when they are not used. Cerberus is implemented and evaluated in the context of the GENIDA project, an international CSP for Genetically determined Intellectual Disabilities and Autism Spectrum Disorders. As a result of this study, the software is made available for the community, and validated specifications for CSPs are given.


Assuntos
Transtorno do Espectro Autista/genética , Estudos de Coortes , Segurança Computacional/normas , Troca de Informação em Saúde/normas , Deficiência Intelectual/genética , Anonimização de Dados , Registros Eletrônicos de Saúde/normas , Pesquisa Empírica , Ética em Pesquisa , Troca de Informação em Saúde/ética , Humanos , Estudos Longitudinais , Pesquisa Qualitativa
11.
J Theor Biol ; 411: 48-58, 2016 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-27742260

RESUMO

Horizontal transfer (HT) of heritable information or 'traits' (carried by genetic elements, plasmids, endosymbionts, or culture) is widespread among living organisms. Yet current ecological and evolutionary theory addressing HT is scant. We present a modeling framework for the dynamics of two populations that compete for resources and horizontally exchange (transfer) an otherwise vertically inherited trait. Competition influences individual demographics, thereby affecting population size, which feeds back on the dynamics of transfer. This feedback is captured in a stochastic individual-based model, from which we derive a general model for the contact rate, with frequency-dependent (FD) and density-dependent (DD) rates as special cases. Taking a large-population limit on the stochastic individual-level model yields a deterministic Lotka-Volterra competition system with additional terms accounting for HT. The stability analysis of this system shows that HT can revert the direction of selection: HT can drive invasion of a deleterious trait, or prevent invasion of an advantageous trait. Due to HT, invasion does not necessarily imply fixation. Two trait values may coexist in a stable polymorphism even if their invasion fitnesses have opposite signs, or both are negative. Addressing the question of how the stochasticity of individual processes influences population fluctuations, we identify conditions on competition and mode of transfer (FD versus DD) under which the stochasticity of transfer events overwhelms demographic stochasticity. Assuming that one trait is initially rare, we derive invasion and fixation probabilities and time. In the case of costly plasmids, which are transfered unilaterally, invasion is always possible if the transfer rate is large enough; under DD and for intermediate values of the transfer rate, maintenance of the plasmid in a polymorphic population is possible. In conclusion, HT interacts with ecology (competition) in non-trivial ways. Our model provides a basis to model the influence of HT on evolutionary adaptation.


Assuntos
Algoritmos , Transferência Genética Horizontal/genética , Modelos Genéticos , Polimorfismo Genético/genética , Adaptação Fisiológica/genética , Animais , Comportamento Competitivo , Ecossistema , Evolução Molecular , Genética Populacional , Fenótipo , Densidade Demográfica , Dinâmica Populacional , Probabilidade , Processos Estocásticos , Fatores de Tempo
12.
J Math Biol ; 67(3): 569-607, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22821207

RESUMO

Adaptive dynamics (AD) so far has been put on a rigorous footing only for clonal inheritance. We extend this to sexually reproducing diploids, although admittedly still under the restriction of an unstructured population with Lotka-Volterra-like dynamics and single locus genetics (as in Kimura's in Proc Natl Acad Sci USA 54: 731-736, 1965 infinite allele model). We prove under the usual smoothness assumptions, starting from a stochastic birth and death process model, that, when advantageous mutations are rare and mutational steps are not too large, the population behaves on the mutational time scale (the 'long' time scale of the literature on the genetical foundations of ESS theory) as a jump process moving between homozygous states (the trait substitution sequence of the adaptive dynamics literature). Essential technical ingredients are a rigorous estimate for the probability of invasion in a dynamic diploid population, a rigorous, geometric singular perturbation theory based, invasion implies substitution theorem, and the use of the Skorohod M 1 topology to arrive at a functional convergence result. In the small mutational steps limit this process in turn gives rise to a differential equation in allele or in phenotype space of a type referred to in the adaptive dynamics literature as 'canonical equation'.


Assuntos
Diploide , Evolução Molecular , Modelos Genéticos , Mutação , Fenótipo , Característica Quantitativa Herdável , Seleção Genética
13.
Phys Chem Chem Phys ; 13(10): 4674-8, 2011 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-21283845

RESUMO

Evolutionary algorithms have proved to be efficient for solving complicated optimization problems. On the other hand, the many-core architecture in graphical cards "General Purpose Graphic Processing Unit" (GPGPU) offers one of the most attractive cost/performance ratio. Using such hardware, the manuscript shows how an efficiently implemented genetic algorithm with a simple fitness function allows boosting the determination of zeolite structures. A case study is presented.

14.
Bioresour Technol ; 102(1): 207-14, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20674343

RESUMO

Due to resource depletion and climate change, lipid-based algal biofuel has been pointed out as an interesting alternative because of the high productivity of algae per hectare and per year and its ability to recycle CO(2) from flue gas. Another option for taking advantage of the energy content of the microalgae is to directly carry out anaerobic digestion of raw algae in order to produce methane and recycle nutrients (N, P and K). In this study, a life-cycle assessment (LCA) of biogas production from the microalgae Chlorella vulgaris is performed and the results are compared to algal biodiesel and to first generation biodiesels. These results suggest that the impacts generated by the production of methane from microalgae are strongly correlated with the electric consumption. Progresses can be achieved by decreasing the mixing costs and circulation between different production steps, or by improving the efficiency of the anaerobic process under controlled conditions. This new bioenergy generating process strongly competes with others biofuel productions.


Assuntos
Biocombustíveis , Chlorella vulgaris/crescimento & desenvolvimento , Meio Ambiente , Anaerobiose , Animais , Dióxido de Carbono/metabolismo , Conservação dos Recursos Naturais , Eletricidade , Fontes Geradoras de Energia , Etanol/economia , Fermentação , Alimentos/economia , Gases , Estágios do Ciclo de Vida , Lipídeos/análise , Metano/metabolismo
15.
Phys Rev E Stat Nonlin Soft Matter Phys ; 81(3 Pt 1): 031109, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20365699

RESUMO

We investigate the stationary state of a model system evolving according to a modified focusing truncated nonlinear Schrödinger equation used to describe the envelope of Langmuir waves in a plasma. We restrict the system to have a finite number of normal modes each of which is in contact with a Langevin heat bath at temperature T . Arbitrarily large realizations of the field are prevented by restricting each mode to a maximum amplitude. We consider a simple modeling of wave breaking in which each mode is set equal to zero when it reaches its maximum amplitude. Without wave breaking the stationary state is given by a Gibbs measure. With wave breaking the system attains a nonequilibrium stationary state which is the unique invariant measure of the time evolution. A mean-field analysis shows that the system exhibits a transition from a regime of low-field values at small |lambda| , to a regime of higher-field values at large |lambda| , where lambda<0 specifies the strength of the nonlinearity in the focusing case. Field values at large |lambda| are significantly smaller with wave breaking than without wave breaking.


Assuntos
Algoritmos , Modelos Químicos , Dinâmica não Linear , Processos Estocásticos , Simulação por Computador , Teoria Quântica
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