The Elaborate Postural Display of Courting Drosophila persimilis Flies Produces Substrate-Borne Vibratory Signals.

Sexual selection has led to the evolution of extraordinary and elaborate male courtship behaviors across taxa, including mammals and birds, as well as some species of flies. Drosophila persimilis flies perform complex courtship behaviors found in most Drosophila species, which consist of visual, air-borne, gustatory and olfactory cues. In addition, Drosophila persimilis courting males also perform an elaborate postural display that is not found in most other Drosophila species. This postural display includes an upwards contortion of their abdomen, specialized movements of the head and forelegs, raising both wings into a "wing-posture" and, most remarkably, the males proffer the female a regurgitated droplet. Here, we use high-resolution imaging, laser vibrometry and air-borne acoustic recordings to analyse this postural display to ask which signals may promote copulation. Surprisingly, we find that no air-borne signals are generated during the display. We show, however, that the abdomen tremulates to generate substrate-borne vibratory signals, which correlate with the female's immobility before she feeds onto the droplet and accepts copulation.This work was supported by the Wellcome Trust Investigator Awards to P. A. Lawrence WT096645MA and WT107060AIA.This is the final version of the article. It first appeared from Springer at http://dx.doi.org/10.1007/s10905-016-9579-8

Triggers of the Postural Display of Courtship in Drosophila persimilis Flies.

D. persimilis courtship shows some flexibility and courting males sometimes perform an elaborate postural display in addition to the standard courtship behaviours shared by most Drosophila species. This postural display includes the acrobatic contortion and tremulation of their abdomen, accompanied by the generation of substrate-borne vibrations, and they proffer a nutritional droplet to the female. Here, we use courtship and choice assays to ask what triggers this display and what advantages males may gain from it during courtship. In pair assays, we found no differences in the courtship duration and copulation success between displaying and non-displaying males. In trio assays, however, the female always mated with the male who performed the display. To investigate what promotes the male display, we varied the level of receptivity of the female and studied the impact of a second male. We found that rejection by the female does not induce the male to display, contrary to what was previously suggested. We present evidence that the male display is in fact promoted by the presence of an attentive and sexually receptive female and the absence of male competition, with the greatest exhibition rate obtained if the courted female is starved. These findings provide valuable information about the social ecology of flies, and how internal and external cues influence sexual behaviours and mate choice

Effect of Tocilizumab vs Usual Care in Adults Hospitalized With COVID-19 and Moderate or Severe Pneumonia

International audienceImportance Severe pneumonia with hyperinflammation and elevated interleukin-6 is a common presentation of coronavirus disease 2019 (COVID-19).Objective To determine whether tocilizumab (TCZ) improves outcomes of patients hospitalized with moderate-to-severe COVID-19 pneumonia.Design, Setting, and Particpants This cohort-embedded, investigator-initiated, multicenter, open-label, bayesian randomized clinical trial investigating patients with COVID-19 and moderate or severe pneumonia requiring at least 3 L/min of oxygen but without ventilation or admission to the intensive care unit was conducted between March 31, 2020, to April 18, 2020, with follow-up through 28 days. Patients were recruited from 9 university hospitals in France. Analyses were performed on an intention-to-treat basis with no correction for multiplicity for secondary outcomes.Interventions Patients were randomly assigned to receive TCZ, 8 mg/kg, intravenously plus usual care on day 1 and on day 3 if clinically indicated (TCZ group) or to receive usual care alone (UC group). Usual care included antibiotic agents, antiviral agents, corticosteroids, vasopressor support, and anticoagulants.Main Outcomes and Measures Primary outcomes were scores higher than 5 on the World Health Organization 10-point Clinical Progression Scale (WHO-CPS) on day 4 and survival without need of ventilation (including noninvasive ventilation) at day 14. Secondary outcomes were clinical status assessed with the WHO-CPS scores at day 7 and day 14, overall survival, time to discharge, time to oxygen supply independency, biological factors such as C-reactive protein level, and adverse events.Results Of 131 patients, 64 patients were randomly assigned to the TCZ group and 67 to UC group; 1 patient in the TCZ group withdrew consent and was not included in the analysis. Of the 130 patients, 42 were women (32%), and median (interquartile range) age was 64 (57.1-74.3) years. In the TCZ group, 12 patients had a WHO-CPS score greater than 5 at day 4 vs 19 in the UC group (median posterior absolute risk difference [ARD] −9.0%; 90% credible interval [CrI], −21.0 to 3.1), with a posterior probability of negative ARD of 89.0% not achieving the 95% predefined efficacy threshold. At day 14, 12% (95% CI −28% to 4%) fewer patients needed noninvasive ventilation (NIV) or mechanical ventilation (MV) or died in the TCZ group than in the UC group (24% vs 36%, median posterior hazard ratio [HR] 0.58; 90% CrI, 0.33-1.00), with a posterior probability of HR less than 1 of 95.0%, achieving the predefined efficacy threshold. The HR for MV or death was 0.58 (90% CrI, 0.30 to 1.09). At day 28, 7 patients had died in the TCZ group and 8 in the UC group (adjusted HR, 0.92; 95% CI 0.33-2.53). Serious adverse events occurred in 20 (32%) patients in the TCZ group and 29 (43%) in the UC group (P = .21).Conclusions and Relevance In this randomized clinical trial of patients with COVID-19 and pneumonia requiring oxygen support but not admitted to the intensive care unit, TCZ did not reduce WHO-CPS scores lower than 5 at day 4 but might have reduced the risk of NIV, MV, or death by day 14. No difference on day 28 mortality was found. Further studies are necessary for confirming these preliminary results.Trial Registration ClinicalTrials.gov Identifier: NCT0433180

Effect of anakinra versus usual care in adults in hospital with COVID-19 and mild-to-moderate pneumonia (CORIMUNO-ANA-1): a randomised controlled trial

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Sarilumab in adults hospitalised with moderate-to-severe COVID-19 pneumonia (CORIMUNO-SARI-1): An open-label randomised controlled trial

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The value of open-source clinical science in pandemic response: lessons from ISARIC

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At-admission prediction of mortality and pulmonary embolism in an international cohort of hospitalised patients with COVID-19 using statistical and machine learning methods

By September 2022, more than 600 million cases of SARS-CoV-2 infection have been reported globally, resulting in over 6.5 million deaths. COVID-19 mortality risk estimators are often, however, developed with small unrepresentative samples and with methodological limitations. It is highly important to develop predictive tools for pulmonary embolism (PE) in COVID-19 patients as one of the most severe preventable complications of COVID-19. Early recognition can help provide life-saving targeted anti-coagulation therapy right at admission. Using a dataset of more than 800,000 COVID-19 patients from an international cohort, we propose a cost-sensitive gradient-boosted machine learning model that predicts occurrence of PE and death at admission. Logistic regression, Cox proportional hazards models, and Shapley values were used to identify key predictors for PE and death. Our prediction model had a test AUROC of 75.9% and 74.2%, and sensitivities of 67.5% and 72.7% for PE and all-cause mortality respectively on a highly diverse and held-out test set. The PE prediction model was also evaluated on patients in UK and Spain separately with test results of 74.5% AUROC, 63.5% sensitivity and 78.9% AUROC, 95.7% sensitivity. Age, sex, region of admission, comorbidities (chronic cardiac and pulmonary disease, dementia, diabetes, hypertension, cancer, obesity, smoking), and symptoms (any, confusion, chest pain, fatigue, headache, fever, muscle or joint pain, shortness of breath) were the most important clinical predictors at admission. Age, overall presence of symptoms, shortness of breath, and hypertension were found to be key predictors for PE using our extreme gradient boosted model. This analysis based on the, until now, largest global dataset for this set of problems can inform hospital prioritisation policy and guide long term clinical research and decision-making for COVID-19 patients globally. Our machine learning model developed from an international cohort can serve to better regulate hospital risk prioritisation of at-risk patients