No inherent left and right side in human ‘mental number line': evidence from right brain damage

Spatial reasoning has a relevant role in mathematics and helps daily computational activities. It is widely assumed that in cultures with left-to-right reading, numbers are organized along the mental equivalent of a ruler, the mental number line, with small magnitudes located to the left of larger ones. Patients with right brain damage can disregard smaller numbers while mentally setting the midpoint of number intervals. This has been interpreted as a sign of spatial neglect for numbers on the left side of the mental number line and taken as a strong argument for the intrinsic left-to-right organization of the mental number line. Here, we put forward the understanding of this cognitive disability by discovering that patients with right brain damage disregard smaller numbers both when these are mapped on the left side of the mental number line and on the right side of an imagined clock face. This shows that the right hemisphere supports the representation of small numerical magnitudes independently from their mapping on the left or the right side of a spatial-mental layout. In addition, the study of the anatomical correlates through voxel-based lesion-symptom mapping and the mapping of lesion peaks on the diffusion tensor imaging-based reconstruction of white matter pathways showed that the rightward bias in the imagined clock-face was correlated with lesions of high-level middle temporal visual areas that code stimuli in object-centred spatial coordinates, i.e. stimuli that, like a clock face, have an inherent left and right side. In contrast, bias towards higher numbers on the mental number line was linked to white matter damage in the frontal component of the parietal-frontal number network. These anatomical findings show that the human brain does not represent the mental number line as an object with an inherent left and right side. We conclude that the bias towards higher numbers in the mental bisection of number intervals does not depend on left side spatial, imagery or object-centred neglect and that it rather depends on disruption of an abstract non-spatial representation of small numerical magnitude

Monitoring of SARS-CoV-2 in wastewater: what normalisation for improved understanding of epidemic trends?

SARS-CoV-2 RNA quantification in wastewater has emerged as a relevant additional means to monitor the COVID-19 pandemic. However, the concentration can be affected by black water dilution factors or movements of the sewer shed population, leading to misinterpretation of measurement results. The aim of this study was to evaluate the performance of different indicators to accurately interpret SARS-CoV-2 in wastewater. Weekly/bi-weekly measurements from three cities in France were analysed from February to September 2021. The concentrations of SARS-CoV-2 gene copies were normalised to the faecal-contributing population using simple sewage component indicators. To reduce the measurement error, a composite index was created to combine simultaneously the information carried by the simple indicators. The results showed that the regularity (mean absolute difference between observation and the smoothed curve) of the simple indicators substantially varied across sampling points. The composite index consistently showed better regularity compared to the other indicators and was associated to the lowest variation in correlation coefficient across sampling points. These findings suggest the recommendation for the use of a composite index in wastewater-based epidemiology to compensate for variability in measurement results

COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

Sensorimotor plasticity and spatial cognition : generalization of prism adaptation after-effects

L’adaptation des fonctions motrices permet l’optimisation des interactions avec l’environnement et ses modifications. Une des grandes questions posées à ce sujet concerne la spécificité des modifications implémentées. Dans la littérature traditionnelle sur l’adaptation visuo-manuelle au port de prismes, on retrouve une généralisation de l’adaptation à des positions spatiales non-apprises, mais un très faible transfert de l’adaptation aux autres effecteurs moteurs. Par contraste, les résultats thérapeutiques acquis chez le patient négligent depuis 12 ans suggèrent que l’adaptation visuo-manuelle peut produire des effets à tous les niveaux affectés par cette pathologie. Cette opposition apparente pose la question de la validité du modèle pathologique pour explorer l’adaptation sensori-motrice, et une façon d’y répondre est d’explorer les effets de l’adaptation sur les fonctions perturbées par la négligence chez le sujet normal. Ces trois volets de la littérature apportent des éclairages complémentaires sur la question de la généralisation des adaptations. Par la mise en évidence d’une généralisation des effets consécutifs de l’adaptation prismatique, notamment à un niveau transmodal, non impliqué dans la procédure d’adaptation per se, ce travail de thèse apporte des éléments pertinents en terme de niveau d’action et d’organisation des réseaux impliqués, laissant suggérer un effet de restructuration sur des représentations spatiales de haut niveau, permettant d’élargir l’orientation des stratégies de réhabilitation, par la mise en évidence d’une activation dynamique de fonctions et de réseaux liés à l’intégration multi-sensorielle, nécessaire aux représentations spatialesAdaptation of motor functions allows optimization of interactions with environment and its alterations. One major question concerns specificity of implemented modifications. Classical data about visuo-manual adaptation to prisms reveal generalization of adaptation to non learned spatial locations, but a very poor transfer to others motor effectors. By contrast, therapeutic results obtained in neglect patients since 12 years suggest that visuo-manual adaptation could produce effects at various levels affected by neglect. This apparent opposition raises the question of validity of pathologic model to explore sensori-motor adaptation, and one way to answer is to explore effects of prism adaptation on disturbed functions by neglect in normal subject. These three sections of review bring out complementary lightings about question of adaptations generalization. By underlying generalization of after-effects of prism adaptation, in particular at a transmodal level, non implicated in adaptative procedure per se, these results bring some relevant arguments in terms of level of action and implicated networks organization, suggesting a restructuring effect on high level spatial representations, allowing to enlarge orientation of rehabilitative strategies. These results bring out a dynamic activation of functions and networks linked to multisensory integration, appropriate to spatial representation

CREATION DE BANQUES D'ADN DE MICRO-ORGANISMES TELLURIQUES SANS ETAPE PREALABLE DE CULTURE IN-VITRO

LYON1-BU.Sciences (692662101) / SudocSudocFranceF

La connaissance par les patients des facteurs de risque cardiovasculaire (l'hypertension artérielle)

LE KREMLIN-B.- PARIS 11-BU Méd (940432101) / SudocSudocFranceF

Influence de la négligence spatiale unilatérale sur le contrôle intentionnel de l'action (analyse cinématique 3D de mouvements de préhension)

LYON1-BU Santé (693882101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF