Case report: viral shedding for 120 days in an allergic child with Covid 19

Since it was first detected in Dec 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread through the planet causing the novel coronavirus disease, Covid-19. Here, we report the case of a 9-year-old girl with persistent viral shedding based on RT-PCR detection. Her first positive (Ct=36) dated from March 4 2021, came in a preoperative physical examination (scheduled tonsillectomy), with no apparent symptoms. Her father fell ill and tested positive soon after that casual finding. Surgery was postponed. The patient came positive again on July 1 2021 (Ct=33) and on July 29 2021 (Ct=29). She had a persistent cough, which was also compatible with her allergic condition. Her surgery could not be postponed any longer and was operated on July 30 2021. Excised adenoids and tonsils were extensively rubbed with a swab to test whether the material detected resulted infectious or not, on Vero E6 cell cultures. Based on the absence of any cytopathic effect, we found it was not infective, even upon an intended amplification by a second passage. RT-PCR was negative when performed on the last supernatant. The histological pattern of her tonsillar and adenoid tissue was analyzed through H&E staining and immune cell populations were examined by FACS. Both aspects were compatible with her hyperplastic condition and also with a viral infection. We tested the anti-Spike specific response by ELISA on serum samples taken on Aug 6 2021 (IgM=1.34, cut off=0.584 and IgG=3.27, cut off=0.364). Finally, we determined the neutralizing antibodies titer on the same serum, using the wild type SARS-CoV-2 (titre=32, the mean of infected adults is 64). We concluded that, albeit the long period the genetic material of the virus was detected on her swabs, the patient does not seem to have a major immunological deficiency and could mount an appropriate immune response against the virus. Importantly, we demonstrated she was not able to transmit virus at the time of the surgery.Fil: Paletta, Ana Luz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Puyssegur, Juliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Husain, Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Gallo Vaulet, Lucía. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Rodríguez Fermepin, Marcelo. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Cabral, Cecilia. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Paoli, Bibiana Patricia. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Ceballos, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Arana, Eloisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; ArgentinaAnnual Meeting of Bioscience Societies 2021: LXVI Annual Meeting of Sociedad Argentina de Investigación Clínica (SAIC), LXIX Annual Meeting of Sociedad Argentina de Inmunología(SAI), LIII Annual Meeting of Asociación Argentina de Farmacología Experimental (AAFE), XI Annual Meeting of Asociación Argentina de Nanomedicinas (NANOMED-Ar)ArgentinaSociedad Argentina de Investigación ClínicaSociedad Argentina de InmunologíaAsociación Argentina de Farmacología ExperimentalAsociación Argentina de Nanomedicin

Multiscale InSAR Time Series (MInTS) analysis of surface deformation

We present a new approach to extracting spatially and temporally continuous ground deformation fields from interferometric synthetic aperture radar (InSAR) data. We focus on unwrapped interferograms from a single viewing geometry, estimating ground deformation along the line-of-sight. Our approach is based on a wavelet decomposition in space and a general parametrization in time. We refer to this approach as MInTS (Multiscale InSAR Time Series). The wavelet decomposition efficiently deals with commonly seen spatial covariances in repeat-pass InSAR measurements, since the coefficients of the wavelets are essentially spatially uncorrelated. Our time-dependent parametrization is capable of capturing both recognized and unrecognized processes, and is not arbitrarily tied to the times of the SAR acquisitions. We estimate deformation in the wavelet-domain, using a cross-validated, regularized least squares inversion. We include a model-resolution-based regularization, in order to more heavily damp the model during periods of sparse SAR acquisitions, compared to during times of dense acquisitions. To illustrate the application of MInTS, we consider a catalog of 92 ERS and Envisat interferograms, spanning 16 years, in the Long Valley caldera, CA, region. MInTS analysis captures the ground deformation with high spatial density over the Long Valley region

Compensation du délai de phase atmosphérique en interférométrie radar et inversion de vitesses tectoniques

Cette étude propose un filtre de la composante troposphérique eninterférométrie différentielle d'images satellites radar (DInSAR) et uneméthode d'exploitation de séries d'interférogrammes pour l'étude desdéformations tectoniques lentes (inter et post sismiques). La contributioncohérente de l'atmosphère et le bruit résultant de la perte de cohérencetemporelle sont deux limites majeures de l'interférométrie. La composanteatmosphérique est variable spatialement et temporellement et son amplitudede l'ordre du signal tectonique. Le délai atmosphérique est la somme dudélai ionosphérique, qui n'a pas été étudié dans cette thèse, et du délaitroposphérique. Le délai troposphérique radar dépend des pressions totale etpartielle en vapeur d'eau, de la température, du contenu en eau des nuageset des précipitations. Il est estimé grâce au modèle météorologiqueméso-échelle MM5. Dans le cas des images ENVISAT/ASAR, nous exploitonségalement des images multispectrales ENVISAT/MERIS acquises simultanémentaux images ASAR. Ces images fournissent une estimée du contenu total envapeur d'eau de l'atmosphère, exploitée conjointement aux simulations MM5pour calculer le délai troposphérique. Testé sur un ensembled'interférogrammes, le filtre atmosphérique proposé est plus performant queceux fondés sur des modèles statiques de l'atmosphère et le signalatmosphérique est réduit de 43% en moyenne. Le deuxième volet concernel'exploitation de séries d'interférogrammes pour l'estimation des paramètrestectoniques. Des études précédentes exploitent des séries déroulées ainsique des séries enroulées mais restreintes à des zones peu étendues et detrès bonne cohérence ; c'est le cas de la méthode des diffuseurs permanents.Nous généralisons ces méthodes au cas des déformations spatialement étenduescaractéristiques des déformations tectoniques. A partir du graphe des datesreliées par des interférogrammes, la phase propre enroulée est estimée pourchaque date relativement à une même date de référence. Les paramètres dumodèle tectonique sont ensuite inversés dans le plan complexe à partir del'ensemble des mesures. Les méthodes ont été appliquées à des sériesinter-sismique (10 ans pour le cas du Liban, vitesse de déformationconstante), post-sismique (2 ans pour le séisme de Bam, Iran, 2003, vitessede déformation exponentiellement décroissante) et le filtre météorologique apermis une comparaison de corrections atmosphériques en GPS (données GPScontinues du LDG au Népal). La vitesse de déformation intersismique au Libanest inférieure au seuil de détection d'environ 1 à 2 millimètres par an, letemps de relaxation postsismique pour Bam est d'environ 229 jours (rapportsignal sur bruit égal à 7) et l'estimation des distances entre stations GPSdépend pour moins d'une fraction de centimètre du modèle atmosphériquePARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Sci.Terre recherche (751052114) / SudocSudocFranceF

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Wrapped Interferograms Enhanced By MuLSAR Method: Applications And Comparison To Other Methods

International audienceSAR interferometry (InSAR) is a powerful technique to monitor surface displacements. However, InSAR suffers from numerous noise sources such as temporal and geometric decorrelation of images. In this study, we apply the MuLSAR method [1] to produce robust denoised wrapped phase time series from the combination of wrapped interferograms, using the redundancy of interferograms. It is particularly efficient in high temporal decorrelation areas. Our method has been applied to ENVISAT time series suffering from diverse temporal decorrelation in three regions: the Himalaya, the Levantine Fault in Lebanon and Western Pakistan. The interferograms are efficiently enhanced for every time series. First, we show that a criterion called colinearity is more efficient than the coherence to quantify wrapped phase quality. The performance of MuLSAR method is demonstrated as it enhances post-processing steps (DEM residual compensation, unwrapping). It is finally compared to another method of wrapped time series enhancement, SqueeSAR [2]

Wrapped Interferograms Enhanced By MuLSAR Method: Applications And Comparison To Other Methods

International audienceSAR interferometry (InSAR) is a powerful technique to monitor surface displacements. However, InSAR suffers from numerous noise sources such as temporal and geometric decorrelation of images. In this study, we apply the MuLSAR method [1] to produce robust denoised wrapped phase time series from the combination of wrapped interferograms, using the redundancy of interferograms. It is particularly efficient in high temporal decorrelation areas. Our method has been applied to ENVISAT time series suffering from diverse temporal decorrelation in three regions: the Himalaya, the Levantine Fault in Lebanon and Western Pakistan. The interferograms are efficiently enhanced for every time series. First, we show that a criterion called colinearity is more efficient than the coherence to quantify wrapped phase quality. The performance of MuLSAR method is demonstrated as it enhances post-processing steps (DEM residual compensation, unwrapping). It is finally compared to another method of wrapped time series enhancement, SqueeSAR [2]

Wrapped Interferograms Enhanced By MuLSAR Method: Applications And Comparison To Other Methods

International audienceSAR interferometry (InSAR) is a powerful technique to monitor surface displacements. However, InSAR suffers from numerous noise sources such as temporal and geometric decorrelation of images. In this study, we apply the MuLSAR method [1] to produce robust denoised wrapped phase time series from the combination of wrapped interferograms, using the redundancy of interferograms. It is particularly efficient in high temporal decorrelation areas. Our method has been applied to ENVISAT time series suffering from diverse temporal decorrelation in three regions: the Himalaya, the Levantine Fault in Lebanon and Western Pakistan. The interferograms are efficiently enhanced for every time series. First, we show that a criterion called colinearity is more efficient than the coherence to quantify wrapped phase quality. The performance of MuLSAR method is demonstrated as it enhances post-processing steps (DEM residual compensation, unwrapping). It is finally compared to another method of wrapped time series enhancement, SqueeSAR [2]

Wrapped Interferograms Enhanced By MuLSAR Method: Applications And Comparison To Other Methods

International audienceSAR interferometry (InSAR) is a powerful technique to monitor surface displacements. However, InSAR suffers from numerous noise sources such as temporal and geometric decorrelation of images. In this study, we apply the MuLSAR method [1] to produce robust denoised wrapped phase time series from the combination of wrapped interferograms, using the redundancy of interferograms. It is particularly efficient in high temporal decorrelation areas. Our method has been applied to ENVISAT time series suffering from diverse temporal decorrelation in three regions: the Himalaya, the Levantine Fault in Lebanon and Western Pakistan. The interferograms are efficiently enhanced for every time series. First, we show that a criterion called colinearity is more efficient than the coherence to quantify wrapped phase quality. The performance of MuLSAR method is demonstrated as it enhances post-processing steps (DEM residual compensation, unwrapping). It is finally compared to another method of wrapped time series enhancement, SqueeSAR [2]

EXPERIMENTAL COMPARISON OF REGISTRATION METHODS FOR MULTISENSOR SAR-OPTICAL DATA

Synthetic aperture radar (SAR) and optical satellite image registration is a field that developed in the last decades and gave rise to a great number of approaches. The registration process is composed of several steps: feature definition, feature comparison and optimization of a geometric transformation between the images. Feature definition can be done using simple traditional filtering or more complex deep learning (DL) methods. In this paper, two traditional approaches and a DL approach are compared. One can then wonder if the complexity of DL is worth to address the registration task. The aim of this paper is to quantitatively compare approaches rooted in distinct methodological areas on two common datasets with different resolutions. The comparison suggests that, although more complex, the DL approach is more precise than traditional methods

Role of germinal center and CD39ʰⁱᵍʰCD73⁺ B cells in the age-related tonsillar involution

Background The tonsils operate as a protection ring of mucosa at the gates of the upper aero-digestive tract. They show similarities with lymph nodes and participate as inductive organs of systemic and mucosal immunity. Based on the reduction of their size since puberty, they are thought to experience involution in adulthood. In this context, we have used tonsillar mononuclear cells (TMC) isolated from patients at different stages of life, to study the effect of ageing and the concomitant persistent inflammation on these immune cells. Results We found an age-dependent reduction in the proportion of germinal center B cell population (BGC) and its T cell counterpart (T follicular helper germinal center cells, TfhGC). Also, we demonstrated an increment in the percentage of local memory B cells and mantle zone T follicular helper cells (mTfh). Furthermore, younger tonsils rendered higher proportion of proliferative immune cells within the freshly isolated TMC fraction than those from older ones. We demonstrated the accumulation of a B cell subset (CD20⁺CD39ʰⁱᵍʰCD73⁺ cells) metabolically adapted to catabolize adenosine triphosphate (ATP) as patients get older. To finish, tonsillar B cells from patients at different ages did not show differences in their proliferative response to stimulation ex vivo, in bulk TMC cultures. Conclusions This paper sheds light on the changing aspects of the immune cellular landscape, over the course of time and constant exposure, at the entrance of the respiratory and digestive systems. Our findings support the notion that there is a re-modelling of the immune functionality of the excised tonsils over time. They are indicative of a transition from an effector type of immune response, typically oriented to reduce pathogen burden early in life, to the development of an immunosuppressive microenvironment at later stages, when tissue damage control gets critical provided the time passed under immune attack. Noteworthy, when isolated from such histologic microenvironment, older tonsillar B cells seem to level their proliferation capacity with the younger ones. Understanding these features will not only contribute to comprehend the differences in susceptibility to pathogens among children and adults but would also impact on vaccine developments intended to target these relevant mucosal sites.Instituto de Estudios Inmunológicos y Fisiopatológico