57 research outputs found
Application de la notion de cadre aux énoncés de positionnement et de référence
Projet DIALOGUECe rapport prĂ©sente un ensemble de recherches dont l'objectif est de mettre en oeuvre des systĂšmes de dialogue homme-machine possĂ©dant un comportement aussi naturel que possible. Il s'inscrit dans le cadre du traitement automatique des informations linguistiques concernant l'espace, en vue de dĂ©finir et d'implĂ©menter sur machine des modĂšles formels simulant le raisonnement spatial exprimĂ© en français. La premiĂšre partie de ce rapport dĂ©montre la difficultĂ© qu'il y a de modĂ©liser l'espace en langage naturel, les outils comme la gĂ©omĂ©trie ou la logique pure demeurant insuffisants. Dans la seconde partie, nous dĂ©montrons la nĂ©cessitĂ© d'adjoindre Ă ces modĂšles la notion de cadre, notion qui semble suffisamment gĂ©nĂ©rale pour rendre compte de bien des phĂ©nomĂšnes liĂ©s Ă la modĂ©lisation de l'espace en langage naturel. La troisiĂšme partie s'intĂ©resse au problĂšme de la rĂ©fĂ©rence en gĂ©nĂ©ral puis Ă la rĂ©fĂ©rence spatiale. L'analyse de plusieurs systĂšmes de traitement de la rĂ©fĂ©rence spatiale en IA nous conduit Ă proposer notre propre modĂšle qui s'applique Ă un systĂšme graphique de multifenĂȘtrage. La quatriĂšme partie pose le problĂšme concomitant de la rĂ©fĂ©rence~: celui du positionnement. Nous proposons un modĂšle cognitif des Ă©noncĂ©s de positionnement que nous validons sur un corpus de dialogue qui a Ă©tĂ© recueilli dans notre Ă©quipe. Au terme de cette Ă©tude, nous esquissons le modĂšle de CAO qui constitue la premiĂšre partie de notre maquette informatique visant Ă la validation de la notion de cadre pour les Ă©noncĂ©s de rĂ©fĂ©rence et de positionnement
Deep Learning for scalp High Frequency Oscillations Identification
Since last 2 decades, High Frequency Oscillations (HFOs) are studied as a
promising biomarker to localize the epileptogenic zone of patients with
refractory focal epilepsy. As HFOs visual detection is time consuming and
subjective, automatization of HFO detection is required. Most HFO detectors
were developed on invasive electroencephalograms (iEEG) whereas scalp
electroencephalograms (EEG) are used in clinical routine. In order HFO
detection can benefit to more patients, scalp HFO detectors has to be
developed. However, HFOs identification in scalp EEG is more challenging than
in iEEG since scalp HFOs are of lower rate, lower amplitude and more likely to
be corrupted by several sources of artifacts than iEEG HFOs. The main goal of
this study is to explore the ability of deep learning architecture to identify
scalp HFOs from the remaining EEG signal. Hence, a binary classification
Convolutional Neural Network (CNN) is learned to analyze High Density
Electroencephalograms (HD-EEG). EEG signals are first mapped into a 2D
time-frequency image, several color definitions are then used as an input for
the CNN. Experimental results show that deep learning allows simple end-to-end
learning of preprocessing, feature extraction and classification modules while
reaching competitive performance
Comparaison d'estimateurs de fréquence à complexité algorithmique réduite
De nombreux algorithmes, basés sur une modélisation Auto Régressive du signal, ont été proposés pour des problÚmes d'estimation de fréquence de signaux périodiques. Nous nous intéressons ici aux performances statistiques de tels estimateurs, et proposons des formules approchées du biais et de la variance des estimées. Les résultats obtenus permettent de mettre en évidence l'influence de la fréquence recherchée, du rapport signal sur bruit et du nombre de points sur les performances de l'estimateur
Structural basis for potency differences between GDF8 and GDF11.
BACKGROUND: Growth/differentiation factor 8 (GDF8) and GDF11 are two highly similar members of the transforming growth factor ÎČ (TGFÎČ) family. While GDF8 has been recognized as a negative regulator of muscle growth and differentiation, there are conflicting studies on the function of GDF11 and whether GDF11 has beneficial effects on age-related dysfunction. To address whether GDF8 and GDF11 are functionally identical, we compared their signaling and structural properties. RESULTS: Here we show that, despite their high similarity, GDF11 is a more potent activator of SMAD2/3 and signals more effectively through the type I activin-like receptor kinase receptors ALK4/5/7 than GDF8. Resolution of the GDF11:FS288 complex, apo-GDF8, and apo-GDF11 crystal structures reveals unique properties of both ligands, specifically in the type I receptor binding site. Lastly, substitution of GDF11 residues into GDF8 confers enhanced activity to GDF8. CONCLUSIONS: These studies identify distinctive structural features of GDF11 that enhance its potency, relative to GDF8; however, the biological consequences of these differences remain to be determined
Progesterone Receptor induces bcl-x expression through intragenic binding sites favoring RNA Polymerase II elongation
Steroid receptors were classically described for regulating transcription by binding to target gene promoters. However, genome-wide studies reveal that steroid receptors-binding sites are mainly located at intragenic regions. To determine the role of these sites, we examined the effect of pro- gestins on the transcription of the bcl-x gene, where only intragenic progesterone receptor-binding sites (PRbs) were identified. We found that in response to hormone treatment, the PR is recruited to these sites along with two histone acetyltransferases CREB-binding protein (CBP) and GCN5, leading to an increase in histone H3 and H4 acetylation and to the binding of the SWI/SNF complex. Concomitant, a more relaxed chromatin was detected along bcl-x gene mainly in the regions sur- rounding the intragenic PRbs. PR also mediated the recruitment of the positive elongation factor pTEFb, favoring RNA polymerase II (Pol II) elongation activity. Together these events promoted the re-dis- tribution of the active Pol II toward the 30-end of the gene and a decrease in the ratio between proximal and distal transcription. These results suggest a novel mechanism by which PR regulates gene ex- pression by facilitating the proper passage of the polymerase along hormone-dependent genes.Fil: Bertucci, Paola Yanina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FisiologĂa, BiologĂa Molecular y Neurociencias; ArgentinaFil: Nacht, Ana Silvina. Universitat Pompeu Fabra; España. Centro de RegulaciĂłn GenĂłmica; EspañaFil: AllĂł, Mariano. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FisiologĂa, BiologĂa Molecular y Neurociencias; ArgentinaFil: Rocha Viegas, Luciana. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FisiologĂa, BiologĂa Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de FisiologĂa, BiologĂa Molecular y Celular; ArgentinaFil: BallarĂ©, Cecilia. Universitat Pompeu Fabra; España. Centro de RegulaciĂłn GenĂłmica; EspañaFil: Soronellas, Daniel. Centro de RegulaciĂłn GenĂłmica; España. Universitat Pompeu Fabra; EspañaFil: Castellano, Giancarlo. Centro de RegulaciĂłn GenĂłmica; España. Universitat Pompeu Fabra; EspañaFil: Zaurin, Roser. Centro de RegulaciĂłn GenĂłmica; España. Universitat Pompeu Fabra; EspañaFil: Kornblihtt, Alberto Rodolfo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FisiologĂa, BiologĂa Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de FisiologĂa, BiologĂa Molecular y Celular; ArgentinaFil: Beato, Miguel. Centro de RegulaciĂłn GenĂłmica; España. Universitat Pompeu Fabra; EspañaFil: Vicent, Guillermo. Centro de RegulaciĂłn GenĂłmica; España. Universitat Pompeu Fabra; EspañaFil: Pecci, Adali. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FisiologĂa, BiologĂa Molecular y Neurociencias; Argentin
Inhibition of Lassa Virus Glycoprotein Cleavage and Multicycle Replication by Site 1 Protease-Adapted α1-Antitrypsin Variants
The virus family Arenaviridae includes several hemorrhagic fever causing agents such as Lassa, Guanarito, Junin, Machupo, and Sabia virus that pose a major public health concern to the human population in West African and South American countries. Current treatment options to control fatal outcome of disease are limited to the ribonucleoside analogue ribavirin, although its use has some significant limitations. The lack of effective treatment alternatives emphasizes the need for novel antiviral therapeutics to counteract these life-threatening infections. Maturation cleavage of the viral envelope glycoprotein by the host cell proprotein convertase site 1 protease (S1P) is critical for infectious virion production of several pathogenic arenaviruses. This finding makes this protease an attractive target for the development of novel anti-arenaviral therapeutics. We demonstrate here that highly selective S1P-adapted α1-antitrypsins have the potential to efficiently inhibit glycoprotein processing, which resulted in reduced Lassa virus replication. Our findings suggest that S1P should be considered as an antiviral target and that further optimization of modified α1-antitrypsins could lead to potent and specific S1P inhibitors with the potential for treatment of certain viral hemorrhagic fevers
A planetary health model for reducing exposure to faecal contamination in urban informal settlements: Baseline findings from Makassar, Indonesia
Daniel Reidpath - ORCID: 0000-0002-8796-0420 https://orcid.org/0000-0002-8796-0420Background
The intense interactions between people, animals and environmental systems in urban informal settlements compromise human and environmental health. Inadequate water and sanitation services, compounded by exposure to flooding and climate change risks, expose inhabitants to environmental contamination causing poor health and wellbeing and degrading ecosystems. However, the exact nature and full scope of risks and exposure pathways between human health and the environment in informal settlements are uncertain. Existing models are limited to microbiological linkages related to faecal-oral exposures at the individual level, and do not account for a broader range of human-environmental variables and interactions that affect population health and wellbeing.
Methods
We undertook a 12-month health and environmental assessment in 12 flood-prone informal settlements in Makassar, Indonesia. We obtained caregiver-reported health data, anthropometric measurements, stool and blood samples from children < 5 years, and health and wellbeing data for children 5â14 years and adult respondents. We collected environmental data including temperature, mosquito and rat species abundance, and water and sediment samples. Demographic, built environment and household asset data were also collected. We combined our data with existing literature to generate a novel planetary health model of health and environment in informal settlements.
Results
Across the 12 settlements, 593 households and 2764 participants were enrolled. Two-thirds (64·1%) of all houses (26·3â82·7% per settlement) had formal land tenure documentation. Cough, fever and diarrhoea in the week prior to the survey were reported among an average of 34.3%, 26.9% and 9.7% of children aged < 5 years, respectively; although proportions varied over time, prevalence among these youngest children was consistently higher than among children 5â14 years or adult respondents. Among children < 5 years, 44·3% experienced stunting, 41·1% underweight, 12.4% wasting, and 26.5% were anaemic. There was self- or carer-reported poor mental health among 16.6% of children aged 5â14 years and 13.9% of adult respondents. Rates of potential risky exposures from swimming in waterways, eating uncooked produce, and eating soil or dirt were high, as were exposures to flooding and livestock. Just over one third of households (35.3%) had access to municipal water, and contamination of well water with E. coli and nitrogen species was common. Most (79·5%) houses had an in-house toilet, but no houses were connected to a piped sewer network or safe, properly constructed septic tank. Median monthly settlement outdoor temperatures ranged from 26·2 °C to 29.3 °C, and were on average, 1·1 °C warmer inside houses than outside. Mosquito density varied over time, with Culex quinquefasciatus accounting for 94·7% of species. Framed by a planetary health lens, our model includes four thematic domains: (1) the physical/built environment; (2) the ecological environment; (3) human health; and (4) socio-economic wellbeing, and is structured at individual, household, settlement, and city/beyond spatial scales.
Conclusions
Our planetary health model includes key risk factors and faecal-oral exposure pathways but extends beyond conventional microbiological faecal-oral enteropathogen exposure pathways to comprehensively account for a wider range of variables affecting health in urban informal settlements. It includes broader ecological interconnections and planetary health-related variables at the household, settlement and city levels. It proposes a composite framework of markers to assess water and sanitation challenges and flood risks in urban informal settlements for optimal design and monitoring of interventions.https://doi.org/10.1016/j.envint.2021.106679155pubpu
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Study design, rationale and methods of the Revitalising Informal Settlements and their Environments (RISE) study: a cluster randomised controlled trial to evaluate environmental and human health impacts of a water-sensitive intervention in informal settlements in Indonesia and Fiji
Introduction: Increasing urban populations have led to the growth of informal settlements, with contaminated environments linked to poor human health through a range of interlinked pathways. Here, we describe the design and methods for the Revitalising Informal Settlements and their Environments (RISE) study, a transdisciplinary randomised trial evaluating impacts of an intervention to upgrade urban informal settlements in two Asia-Pacific countries. Methods and analysis: RISE is a cluster randomised controlled trial among 12 settlements in Makassar, Indonesia, and 12 in Suva, Fiji. Six settlements in each country have been randomised to receive the intervention at the outset; the remainder will serve as controls and be offered intervention delivery after trial completion. The intervention involves a water-sensitive approach, delivering site-specific, modular, decentralised infrastructure primarily aimed at improving health by decreasing exposure to environmental faecal contamination. Consenting households within each informal settlement site have been enrolled, with longitudinal assessment to involve health and well-being surveys, and human and environmental sampling. Primary outcomes will be evaluated in children under 5 years of age and include prevalence and diversity of gastrointestinal pathogens, abundance and diversity of antimicrobial resistance (AMR) genes in gastrointestinal microorganisms and markers of gastrointestinal inflammation. Diverse secondary outcomes include changes in microbial contamination; abundance and diversity of pathogens and AMR genes in environmental samples; impacts on ecological biodiversity and microclimates; mosquito vector abundance; anthropometric assessments, nutrition markers and systemic inflammation in children; caregiver-reported and self-reported health symptoms and healthcare utilisation; and measures of individual and community psychological, emotional and economic well-being. The study aims to provide proof-of-concept evidence to inform policies on upgrading of informal settlements to improve environments and human health and well-being. Ethics: Study protocols have been approved by ethics boards at Monash University, Fiji National University and Hasanuddin University. Trial registration number: ACTRN12618000633280; Pre-results
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