142 research outputs found

    Measuring fish activities as additional environmental data during a hydrographic survey with a multi-beam echo sounder

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    International audienceThe modern multi-beam echo sounders (MBES) are advanced instrumentation for active underwater acoustic surveys that can be boarded on oceanic vessels as well on light crafts. Although their versatility allows scientists to perform various environmental studies, their potential is seldom fully exploited. A single data acquisition cruise is not only able to display the seabed backscatter, but also provide an estimation of the fish activities from an underwater site thanks to water column imagery. This work is aiming at developing some (automatic) signal processing techniques to detect, analyse and classify objects observed in the water column with a focus on fish activities to provide fish accumulation and classification but also some comparative analyses along with the seafloor classification

    A New Family of Receptor Tyrosine Kinases with a Venus Flytrap Binding Domain in Insects and Other Invertebrates Activated by Aminoacids

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    Background: Tyrosine kinase receptors (RTKs) comprise a large family of membrane receptors that regulate various cellular processes in cell biology of diverse organisms. We previously described an atypical RTK in the platyhelminth parasite Schistosoma mansoni, composed of an extracellular Venus flytrap module (VFT) linked through a single transmembrane domain to an intracellular tyrosine kinase domain similar to that of the insulin receptor. Methods and Findings: Here we show that this receptor is a member of a new family of RTKs found in invertebrates, and particularly in insects. Sixteen new members of this family, named Venus Kinase Receptor (VKR), were identified in many insects. Structural and phylogenetic studies performed on VFT and TK domains showed that VKR sequences formed monophyletic groups, the VFT group being close to that of GABA receptors and the TK one being close to that of insulin receptors. We show that a recombinant VKR is able to autophosphorylate on tyrosine residues, and report that it can be activated by L-arginine. This is in agreement with the high degree of conservation of the alpha amino acid binding residues found in many amino acid binding VFTs. The presence of high levels of vkr transcripts in larval forms and in female gonads indicates a putative function of VKR in reproduction and/or development. Conclusion: The identification of RTKs specific for parasites and insect vectors raises new perspectives for the control of human parasitic and infectious diseases

    Diversite Phlebotomienne Dans Trois Villages De La Commune De Bouake (Cîte D’ivoire) Durant La Periode De Mars A Juin 2019

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    La leishmaniose cutanĂ©e est une parasitose due Ă  des protozoaires du genre Leishmania et rĂ©pandue dans le monde. Une enquĂȘte mĂ©dicale rĂ©alisĂ©e dans trois villages de la ville de BouakĂ©, autour de cas suspects de leishmaniose cutanĂ©e, a permis de confirmer la prĂ©sence de cette pathologie dans ces villages. Dans le cadre de l’identification des acteurs du cycle Ă©pidĂ©miologique de la leishmaniose cutanĂ©e, une Ă©tude entomologique a Ă©tĂ© conduite dans ces villages afin d’identifier les phlĂ©botomes potentiels vecteurs de leishmanies. Les piĂšges huileux et les piĂšges lumineux CDC, ont Ă©tĂ© posĂ©s entre mars et juin 2019, suivant une mĂ©thode de rotation entre les sites de piĂ©geage. Ils ont Ă©tĂ© posĂ©s entre 17h et 18h et relevĂ©s le lendemain matin entre 7h et 8h. La diversitĂ© spĂ©cifique des espĂšces identifiĂ©es a Ă©tĂ© dĂ©terminĂ©e Ă  partir des indices Ă©cologiques d’équitabilitĂ© et de Hill. Ces piĂšges ont permis la capture de 135 phlĂ©botomes, dont 78 ont Ă©tĂ© morphologiquement identifiĂ©s. Le genre Sergentomyia constituait 91% de nos rĂ©coltes contre 9% pour le genre Phlebotomus. Ph. bergeroti, Ph. rodhaini et Ph. sergenti Ă©taient les espĂšces du genre Phlebotomus, capturĂ©es dans ces sites. Des travaux approfondis portant sur l’identification du parasite Ă  la fois chez les phlĂ©botomes et chez l’homme doivent ĂȘtre effectuĂ©s, afin d’identifier les phlĂ©botomes incriminĂ©s dans la transmission des leishmanies Ă  BouakĂ©. Cutaneous leishmaniasis is a parasitosis caused by protozoa of the genus Leishmania and is widespread worldwide. A medical survey carried out in three villages of the city of BouakĂ©, around suspected cases of cutaneous leishmaniasis, confirmed the presence of this pathology in these villages. As part of the identification of the actors of the epidemiological cycle of cutaneous leishmaniasis, an entomological study was conducted in these villages in order to identify potential phlebotomus vectors of leishmaniasis. Oil traps and CDC light traps were set between March and June 2019, following a rotation method between trapping sites. They were set between 5:00 pm and 6:00 pm and were collected the next morning between 7:00 am and 8:00 am. The specific diversity of the identified species was determined from the ecological indices of equitability and Hill's ecological indices. These traps allowed the capture of 135 sandfish, 78 of which were morphologically identified. The genus Sergentomyia constituted 91% of our harvests against 9% for the genus Phlebotomus. Ph. bergeroti, Ph. rodhaini and Ph. sergenti were the species of the genus Phlebotomus caught at these sites. Further work on the identification of the parasite in both sandflies and humans should be carried out in order to identify the sandflies incriminated in the transmission of leishmania in BouakĂ©

    Rapport d\u27analyse ­ EnquĂȘte : Les donnĂ©es de la recherche Ă  l\u27universitĂ© ParisSaclay, panorama et perspectives

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    Cette enquĂȘte, proposĂ©e par l’ensemble du rĂ©seau des bibliothĂšques et centres de documentation et le ComitĂ© de pilotage de la Science Ouverte de l’UniversitĂ© Paris-Saclay en 2021, s’inscrit dans un contexte dynamique de Science Ouverte prĂŽnant l’obligation de publication des donnĂ©es de la recherche selon les principes FAIR (Facilement trouvable, Accessible, InteropĂ©rable, RĂ©utilisable)

    Reversible transitions between noradrenergic and mesenchymal tumor identities define cell plasticity in neuroblastoma

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    Noradrenergic and mesenchymal identities have been characterized in neuroblastoma cell lines according to their epigenetic landscapes and core regulatory circuitries. However, their relationship and relative contribution in patient tumors remain poorly defined. We now document spontaneous and reversible plasticity between the two identities, associated with epigenetic reprogramming, in several neuroblastoma models. Interestingly, xenografts with cells from each identity eventually harbor a noradrenergic phenotype suggesting that the microenvironment provides a powerful pressure towards this phenotype. Accordingly, such a noradrenergic cell identity is systematically observed in single-cell RNA-seq of 18 tumor biopsies and 15 PDX models. Yet, a subpopulation of these noradrenergic tumor cells presents with mesenchymal features that are shared with plasticity models, indicating that the plasticity described in these models has relevance in neuroblastoma patients. This work therefore emphasizes that intrinsic plasticity properties of neuroblastoma cells are dependent upon external cues of the environment to drive cell identity

    T Cells Contribute to Tumor Progression by Favoring Pro-Tumoral Properties of Intra-Tumoral Myeloid Cells in a Mouse Model for Spontaneous Melanoma

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    Tumors affect myelopoeisis and induce the expansion of myeloid cells with immunosuppressive activity. In the MT/ret model of spontaneous metastatic melanoma, myeloid cells are the most abundant tumor infiltrating hematopoietic population and their proportion is highest in the most aggressive cutaneous metastasis. Our data suggest that the tumor microenvironment favors polarization of myeloid cells into type 2 cells characterized by F4/80 expression, a weak capacity to secrete IL-12 and a high production of arginase. Myeloid cells from tumor and spleen of MT/ret mice inhibit T cell proliferation and IFNÎł secretion. Interestingly, T cells play a role in type 2 polarization of myeloid cells. Indeed, intra-tumoral myeloid cells from MT/ret mice lacking T cells are not only less suppressive towards T cells than corresponding cells from wild-type MT/ret mice, but they also inhibit more efficiently melanoma cell proliferation. Thus, our data support the existence of a vicious circle, in which T cells may favor cancer development by establishing an environment that is likely to skew myeloid cell immunity toward a tumor promoting response that, in turn, suppresses immune effector cell functions

    A united statement of the global chiropractic research community against the pseudoscientific claim that chiropractic care boosts immunity.

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    BACKGROUND: In the midst of the coronavirus pandemic, the International Chiropractors Association (ICA) posted reports claiming that chiropractic care can impact the immune system. These claims clash with recommendations from the World Health Organization and World Federation of Chiropractic. We discuss the scientific validity of the claims made in these ICA reports. MAIN BODY: We reviewed the two reports posted by the ICA on their website on March 20 and March 28, 2020. We explored the method used to develop the claim that chiropractic adjustments impact the immune system and discuss the scientific merit of that claim. We provide a response to the ICA reports and explain why this claim lacks scientific credibility and is dangerous to the public. More than 150 researchers from 11 countries reviewed and endorsed our response. CONCLUSION: In their reports, the ICA provided no valid clinical scientific evidence that chiropractic care can impact the immune system. We call on regulatory authorities and professional leaders to take robust political and regulatory action against those claiming that chiropractic adjustments have a clinical impact on the immune system

    Vaccine breakthrough hypoxemic COVID-19 pneumonia in patients with auto-Abs neutralizing type I IFNs

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    Life-threatening `breakthrough' cases of critical COVID-19 are attributed to poor or waning antibody response to the SARS- CoV-2 vaccine in individuals already at risk. Pre-existing autoantibodies (auto-Abs) neutralizing type I IFNs underlie at least 15% of critical COVID-19 pneumonia cases in unvaccinated individuals; however, their contribution to hypoxemic breakthrough cases in vaccinated people remains unknown. Here, we studied a cohort of 48 individuals ( age 20-86 years) who received 2 doses of an mRNA vaccine and developed a breakthrough infection with hypoxemic COVID-19 pneumonia 2 weeks to 4 months later. Antibody levels to the vaccine, neutralization of the virus, and auto- Abs to type I IFNs were measured in the plasma. Forty-two individuals had no known deficiency of B cell immunity and a normal antibody response to the vaccine. Among them, ten (24%) had auto-Abs neutralizing type I IFNs (aged 43-86 years). Eight of these ten patients had auto-Abs neutralizing both IFN-a2 and IFN-., while two neutralized IFN-omega only. No patient neutralized IFN-ss. Seven neutralized 10 ng/mL of type I IFNs, and three 100 pg/mL only. Seven patients neutralized SARS-CoV-2 D614G and the Delta variant (B.1.617.2) efficiently, while one patient neutralized Delta slightly less efficiently. Two of the three patients neutralizing only 100 pg/mL of type I IFNs neutralized both D61G and Delta less efficiently. Despite two mRNA vaccine inoculations and the presence of circulating antibodies capable of neutralizing SARS-CoV-2, auto-Abs neutralizing type I IFNs may underlie a significant proportion of hypoxemic COVID-19 pneumonia cases, highlighting the importance of this particularly vulnerable population

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

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    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
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