Letter Regarding "Impact of the COVID-19 Pandemic on Training and Well-Being of Nephrology Residents in France and Belgium".

International audienc

Dynamics of collective motion across time and species

Most studies of collective animal behaviour rely on short-term observations, and comparisons of collective behaviour across different species and contexts are rare. We therefore have a limited understanding of intra- and interspecific variation in collective behaviour over time, which is crucial if we are to understand the ecological and evolutionary processes that shape collective behaviour. Here, we study the collective motion of four species: shoals of stickleback fish (Gasterosteus aculeatus), flocks of homing pigeons (Columba livia), a herd of goats (Capra aegagrus hircus) and a troop of chacma baboons (Papio ursinus). First, we describe how local patterns (inter-neighbour distances and positions), and group patterns (group shape, speed and polarization) during collective motion differ across each system. Based on these, we place data from each species within a ‘swarm space’, affording comparisons and generating predictions about the collective motion across species and contexts. We encourage researchers to add their own data to update the ‘swarm space’ for future comparative work. Second, we investigate intraspecific variation in collective motion over time and provide guidance for researchers on when observations made over different time scales can result in confident inferences regarding species collective motion. This article is part of a discussion meeting issue ‘Collective behaviour through time’

Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.

RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)

The Comet Interceptor Mission

Here we describe the novel, multi-point Comet Interceptor mission. It is dedicated to the exploration of a little-processed long-period comet, possibly entering the inner Solar System for the first time, or to encounter an interstellar object originating at another star. The objectives of the mission are to address the following questions: What are the surface composition, shape, morphology, and structure of the target object? What is the composition of the gas and dust in the coma, its connection to the nucleus, and the nature of its interaction with the solar wind? The mission was proposed to the European Space Agency in 2018, and formally adopted by the agency in June 2022, for launch in 2029 together with the Ariel mission. Comet Interceptor will take advantage of the opportunity presented by ESA’s F-Class call for fast, flexible, low-cost missions to which it was proposed. The call required a launch to a halo orbit around the Sun-Earth L2 point. The mission can take advantage of this placement to wait for the discovery of a suitable comet reachable with its minimum ΔV capability of 600 ms−1. Comet Interceptor will be unique in encountering and studying, at a nominal closest approach distance of 1000 km, a comet that represents a near-pristine sample of material from the formation of the Solar System. It will also add a capability that no previous cometary mission has had, which is to deploy two sub-probes – B1, provided by the Japanese space agency, JAXA, and B2 – that will follow different trajectories through the coma. While the main probe passes at a nominal 1000 km distance, probes B1 and B2 will follow different chords through the coma at distances of 850 km and 400 km, respectively. The result will be unique, simultaneous, spatially resolved information of the 3-dimensional properties of the target comet and its interaction with the space environment. We present the mission’s science background leading to these objectives, as well as an overview of the scientific instruments, mission design, and schedule

Development of a field test to evaluate colostral immunity transfer in young calves

Failure of transfer of immunity from dam’s colostrum generates a negative effect on calves’ health leading to increased morbidity and mortality (De Nise et al., 1989; Wittum and Perino, 1995). Unawareness of the colostral quality and variation in the calf’s capability to efficiently absorb immunoglobulins (IgG) supports the need for specific evaluation of the immunity transfer at a herd level. The aim of the study was to evaluate the performances of a field test for passive immunity transfer (PIT) in calves

Development of a field test to evaluate colostrum quality (IgG) in cattle

Failure of transfer of immunity from dam’s colostrum generates a negative effect on calves’ health leading to increased morbidity and mortality (De Nise et al., 1989; Wittum and Perino, 1995). Immunoglobulins (IgG) content of colostrum is highly variable and cannot be predicted. Distinguishing good from poor quality colostrum allows to adapt the volume administered or to initiate ancillary procedures for a sufficient transfer of IgG. The aim of the study was to evaluate the performances of a field test for colostrum quality determination

Strong chemical evidence for high Fe(II)-colloids and low As-bearing colloids (200 nm–10 kDa) contents in groundwater and flooded paddy fields in Bangladesh: A size fractionation approach

International audienceArsenic speciation in groundwater and interstitial waters from soil irrigated with As-rich groundwater in Bangladesh was investigated through a size fractionation approach performed in the field and under con-ditions that allowed the preservation of natural anoxic conditions. Based on a simple chemical character-ization, the presence of Fe(II) in the colloidal fraction (10 kDa) in anoxic groundwaters and soil waters of flooded paddy fields was assessed. Arsenic was found to be present mainly as a ''solute'' oxy-anion as indicated by the small amount of As associated with the 200 nm–10 kDa colloidal fraction (most of the time, less than 10 ± 5% of total As). When As-colloids were observed, they were linked to high Fe concentration and the As-colloid percentage was relatively well correlated with the total Fe concentra-tion in solution. This study underlined that under natural anoxic conditions, there was no impact of PO 3À 4 , SiO 4À 4 and Mn on the As-bearing colloids, which is not in agreement with results obtained under laboratory controlled conditions. Therefore, it is suspected that the impact of other naturally occurring ligands, such as organic matter, could modify Fe(II) speciation, and, in turn, As speciation. To assess the complexation of Fe(II) by organic matter, the WinHumicV model was used to calculate Fe(II) specia-tion. Using the standard parameters to describe organic matter reactivity, results showed that organi-cally-bound Fe(II) ranges from 5% to 100% and 30% to 100%, for groundwater and soil water, respectively, depending on the pH and the Fe(II) and DOC contents. Evidence for independent speciation of Fe and As under natural anoxic conditions is of great importance for predictive modelling of the mobil-ity, the availability and then the bioavailability of As in As-affected areas

Effects of intraoperative high versus low inspiratory oxygen fraction (FiO2) on patient's outcome: A systematic review of evidence from the last 20 years

International audienceDespite numerous studies, controversies about the best intraoperative FiO2 remain. In 2016, the WHO recommended that adult patients undergoing general anaesthesia should be ventilated intraoperatively with an 80% FiO2 to reduce surgical site infection (SSI). However, several data suggest that hyperoxia could have adverse effects. In order to determine the potential effect of FiO2 on SSI, we included in this systematic review 23 studies (among which 21 randomized controlled trials [RCT]) published between 1999 and 2020, comparing intraoperative high versus low FiO2. Results were heterogeneous but the most recent studies on one hand, and the largest RCTs on the other hand, reported no difference on the incidence of SSI regarding to intraoperative FiO2 during general anaesthesia. There was also no difference in the incidence of SSI depending of intraoperative FiO2 in patients receiving regional anaesthesia. The review on secondary endpoints (respiratory and cardiovascular adverse events, postoperative nausea and vomiting, postoperative length-of-stay and mortality) also failed to support the use of high FiO2. On the opposite, some data from follow-up analyses and registry studies suggested a possible negative effect of high intraoperative FiO2 on long-term outcomes. In conclusion, the systematic administration of a high intraoperative FiO2 in order to decrease SSI or improve other perioperative outcomes seems unjustified in the light of the evidence currently available in the literature