Publications by authors named "Colas J"

Article Synopsis
  • Limited evidence exists about how much wheezing in young children is linked to respiratory syncytial virus (RSV) infections in their early years.
  • A study tracked 2-year-olds in 8 countries until they turned six, assessing wheeze occurrences and calculating the population attributable risk (PAR) for those with previous RSV lower respiratory tract infections.
  • Results showed that children with RSV-LRTI had significantly higher incidences of wheezing, suggesting that preventing RSV infections in early childhood could reduce wheezing episodes in later years.
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Active reinforcement learning enables dynamic prediction and control, where one should not only maximize rewards but also minimize costs such as of inference, decisions, actions, and time. For an embodied agent such as a human, decisions are also shaped by physical aspects of actions. Beyond the effects of reward outcomes on learning processes, to what extent can modeling of behavior in a reinforcement-learning task be complicated by other sources of variance in sequential action choices? What of the effects of action bias (for actions per se) and action hysteresis determined by the history of actions chosen previously? The present study addressed these questions with incremental assembly of models for the sequential choice data from a task with hierarchical structure for additional complexity in learning.

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Parabolic equations are among the most popular numerical techniques in many fields of physics. This article considers extra-wide-angle parabolic equations, wide-angle parabolic equations, and narrow-angle parabolic equations (EWAPEs, WAPEs, and NAPEs, respectively) for sound propagation in moving inhomogeneous media with arbitrarily large variations in the sound speed and Mach number of the (subsonic) wind speed. Within their ranges of applicability, these parabolic equations exactly describe the phase of the sound waves and are, thus, termed the phase-preserving EWAPE, WAPE, and NAPE.

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Noise generated by wind turbines is significantly impacted by its propagation in the atmosphere. Hence, for annoyance issues, an accurate prediction of sound propagation is critical to determine noise levels around wind turbines. This study presents a method to predict wind turbine sound propagation based on linearized Euler equations.

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Heuristics can inform human decision making in complex environments through a reduction of computational requirements (accuracy-resource trade-off) and a robustness to overparameterisation (less-is-more). However, tasks capturing the efficiency of heuristics typically ignore action proficiency in determining rewards. The requisite movement parameterisation in sensorimotor control questions whether heuristics preserve efficiency when actions are nontrivial.

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Lipids, especially lysophosphatidylcholine LPC16:0, have been shown to be involved in chronic joint pain through the activation of acid-sensing ion channels (ASIC3). The aim of the present study was to investigate the lipid contents of the synovial fluids from controls and patients suffering from chronic joint pain in order to identify characteristic lipid signatures associated with specific joint diseases. For this purpose, lipids were extracted from the synovial fluids and analyzed by mass spectrometry.

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Cystic fibrosis is a disease caused by a mutation on the CFTR gene coding for a chloride channel. The dominant mutation F508del eliminates the CFTR protein at the surface of epithelial cells, causing an accumulation of viscous mucus in the airways. In advanced stages of the disease, respiratory failure is associated with cellular hypoxia.

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The evaluation of single substances or environmental samples for their genotoxic or estrogenic potential is highly relevant for human- and environment-related risk assessment. To examine the effects on a mechanism-specific level, standardized cell-based in vitro methods are widely applied. However, these methods include animal-derived components like fetal bovine serum (FBS) or rat-derived liver homogenate fractions (S9-mixes), which are a source of variability, reduced assay reproducibility and ethical concerns.

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Pulmonary veno-occlusive disease (PVOD) is a rare form of pulmonary arterial hypertension (PAH) occurring in a heritable form (hPVOD) due to biallelic inactivating mutations of (encoding GCN2, general control nonderepressible 2) or in a sporadic form in older age (sPVOD), following exposure to chemotherapy or organic solvents. In contrast to PAH, PVOD is characterized by a particular remodeling of the pulmonary venous system and the obliteration of small pulmonary veins by fibrous intimal thickening and patchy capillary proliferation. The pathobiological knowledge of PVOD is poor, explaining the absence of medical therapy for PVOD.

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The model-free algorithms of "reinforcement learning" (RL) have gained clout across disciplines, but so too have model-based alternatives. The present study emphasizes other dimensions of this model space in consideration of associative or discriminative generalization across states and actions. This "generalized reinforcement learning" (GRL) model, a frugal extension of RL, parsimoniously retains the single reward-prediction error (RPE), but the scope of learning goes beyond the experienced state and action.

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Background: Monoclonal antibodies acting on the calcitonin gene-related peptide or its receptor (CGRP-mabs) are novel drugs for resistant migraine prophylaxis. As CGRP-mabs cause inhibition of vasodilatation, their use is reserved to patients with no recent history of cardiovascular diseases. We report a case of myocardial infarction associated with erenumab.

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Article Synopsis
  • Researchers found that DNA double-strand breaks (DSBs) increased due to the A-amyloid peptide but decreased with all-trans retinoic acid (RA) in Alzheimer's disease models.
  • In mutated cells, DSBs were less responsive to RA treatment compared to normal cells, indicating a malfunction in the repair mechanisms.
  • The study suggests a compensatory neuroprotective mechanism involving increased BRCA1 and BARD1 proteins that helps lower DSB levels in mutant cells, which may be crucial in fighting Alzheimer's disease.
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The balance within phospholipids (PLs) between saturated fatty acids and monounsaturated or polyunsaturated fatty acids is known to regulate the biophysical properties of cellular membranes. As a consequence, in many cell types, perturbing this balance alters crucial cellular processes, such as vesicular budding and the trafficking/function of membrane-anchored proteins. The worldwide spread of the Western diet, which is highly enriched in saturated fats, has been clearly correlated with the emergence of a complex syndrome known as metabolic syndrome (MetS).

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Article Synopsis
  • The study explores the neuroprotective effects of all--retinoic acid (RA) against amyloid-beta (A)-induced DNA double-strand breaks (DSBs) in neuronal and astrocytic cell lines, and murine brain tissues.
  • Findings indicate that RA not only repairs existing DSBs but also prevents their formation independent of other antioxidants like vitamin C, suggesting a complex mechanism involving PPAR/ and antiamyloidogenic proteins.
  • The research concludes that RA operates through the RAR// and PPAR/ receptors, proposing that RA's pathways could serve as a preventive strategy to protect memory in Alzheimer’s disease and aging.
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The present work investigates paper-paper friction dynamics by pulling a slider over a substrate. It focuses on the transition between stick-slip and inertial regimes. Although the device is classical, probing solid friction with the fewest contact damage requires that the applied load should be small.

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Background: Intravenous immunoglobulin (IVIG) is a fractionated plasma product used to treat a range of autoimmune or inflammatory conditions, as well as immunodeficiency. Demand for this high-cost product is increasing worldwide. Understanding historical changes in IVIG use is important for inventory management and demand forecasting as well as for the development of initiatives aimed at optimizing blood product use.

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Background: Reduction in postpartum length of stay has been advocated within a context of reducing health care system costs and maintaining quality of care. We assessed trends in postpartum length of stay for vaginal and cesarean deliveries at an academic hospital, The Ottawa Hospital, before and after the implementation in 2014 of a novel community-based postpartum outpatient clinic, the Monarch Centre.

Methods: The Monarch Centre model of postpartum care consists of prebooked appointments at the postpartum clinic, scheduled within 48 hours of hospital discharge.

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Decision making in any brain is imperfect and costly in terms of time and energy. Operating under such constraints, an organism could be in a position to improve performance if an opportunity arose to exploit informative patterns in the environment being searched. Such an improvement of performance could entail both faster and more accurate (i.

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In principle, formal dynamical models of decision making hold the potential to represent fundamental computations underpinning value-based (i.e., preferential) decisions in addition to perceptual decisions.

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Prediction-error signals consistent with formal models of "reinforcement learning" (RL) have repeatedly been found within dopaminergic nuclei of the midbrain and dopaminoceptive areas of the striatum. However, the precise form of the RL algorithms implemented in the human brain is not yet well determined. Here, we created a novel paradigm optimized to dissociate the subtypes of reward-prediction errors that function as the key computational signatures of two distinct classes of RL models-namely, "actor/critic" models and action-value-learning models (e.

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Background: Transfusion data for obstetric patients are scarce. Identifying characteristics associated with red blood cell transfusion (RBCT) is of importance to better identify patients who would benefit from blood conservation strategies as the risk of alloimmunization from RBCT has the potential to affect the fetus and newborn.

Study Design And Methods: We conducted a retrospective cohort study using hospital administrative data to identify trends and risk factors of RBCT in obstetric patients.

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Background: Exposure to blood products during pregnancy carries a potential risk of transfusion transmission of infectious agents. Blood agencies have historically sought optimal deferral and testing strategies to protect blood supplies in part to ensure the protection of pregnant women and their unborn infants. The Zika virus outbreak of 2016 has heightened attention to these concerns.

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With the ever-increasing volume of polymer wastes and their associated detrimental impacts on the environment, the plastic life cycle has drawn increasing attention. Here, eight commercial polymers selected from biodegradable to environmentally persistent materials, all formulated under a credit card format, were incubated in an outdoor compost to evaluate their fate over time and to profile the microbial communities colonizing their surfaces. After 450 days in compost, the samples were all colonized by multispecies biofilms, these latest displaying different amounts of adhered microbial biomass and significantly distinct bacterial and fungal community compositions depending on the substrate.

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Article Synopsis
  • BARD1δ is a special version of a protein that is linked to how aggressive tumors can be and how they grow.
  • When BARD1δ is present, it can stop normal cells from dividing, which is called cell cycle arrest.
  • It messes with important parts of the cells, like chromosomes and telomeres, making it possible for some cancer cells to keep growing even when they have problems because of BARD1δ.
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