ABSTRACT
Exploring planets requires cooperative robotics technologies that make it possible to act independently of human influence. So-called multi-robot teams, consisting of different and synchronized robots, can solve problems that cannot be handled by a single robot. The PRO-ACT (Planetary RObots deployed for Assembly and Construction Tasks) project aimed to develop and demonstrate key technologies for robot collaboration in the construction of future ISRU (In-Situ Resource Utilization) facilities on the Moon. To this end, the following robots were used: Veles-a rover with six wheels and a 7-DoF (Degree of Freedom) arm, Mantis-a six-legged walking system, and a mobile gantry that can be used for payload manipulation or 3D printing. The project further developed existing software and hardware developed in previous space robotics projects and integrated them into the robotic systems involved. The software enables collaborative tasks such as transportation, mapping and navigation. Due to the Covid-19 situation, the final demonstration was performed remotely for defined mission scenarios. The intensive remote test campaigns provided valuable lessons learned that are directly applicable to future space missions. In addition, PRO-ACT opens a new way for multi-robot collaboration. The paper describes the developed robotic software and hardware as well as the final mission scenarios performed in lunar analogues with Mantis tested in the test field with granules in the DFKI Space Hall in Bremen, Germany, with Veles tested in Warsaw, Poland and with the mobile gantry tested in Elgoibar, Spain. In addition one mission scenario, manipulation tasks with two robotic systems, was performed with two Panda robotic arms in Toulouse, France. The paper concludes with the results of the final demonstration of the multi-robotics team. © 2021 International Astronautical Federation, IAF. All rights reserved.
ABSTRACT
This article presents the evolution of SARS-CoV-2 RNA in the water and sludge treatment lines of Seine Valenton - Syndicat interdépartemental pour l'assainissement de l'agglomération parisienne (Siaap) - Sival Wastewater Treatment Plant (WWTP). This article aims to contribute to the improvement of the knowledge on the fate of the genetic material of the virus responsible for the Covid-19 pandemic in WWTPs. From water and sludge samples taken at different treatment stages of the Valenton WWTP, the N1 and N2 genes of the virus were measured by RT-qPCR after RNA extraction and the F-specific RNA bacteriophages were enumerated. Results confirm that there is a link between the amount of SARS-CoV-2 in the wastewater and the dynamics of the epidemic. The results also indicate that the WWTP with a complete treatment of nitrogen also allows a reduction of 2.5 to 3 log for the N1 and N2 genes of SARS-CoV-2. The genetic material is logically found in fresh sludge, with RNA levels in the same order of magnitude as the levels observed in raw water. The sludge treatment steps also show an efficiency to reduce the concentration levels of SARSCoV- 2 RNA with removals observed during the drying step. In conclusion, this study shows that the concentration levels of SARS-CoV-2 genetic material are below the limits of quantification at the WWTP discharge and are either low or below the limits of quantification for dried sludge. © 2021 Assoc. Generale des Hygienistes et Techniciens Municipaux. All rights reserved.
ABSTRACT
SARS-CoV-2 wastewater-based epidemiology (WBE) has been advanced as a relevant indicator of distribution of COVID-19 in communities, supporting classical testing and tracing epidemiological approaches. An extensive sampling campaign, including ten municipal wastewater treatment plants, has been conducted in different cities of France over a 20-week period, encompassing the second peak of COVID-19 outbreak in France. A well-recognised ultrafiltration - RNA extraction - RT-qPCR protocol was used and qualified, showing 5.5 +/- 0.5% recovery yield on heat-inactivated SARS-CoV-2. Importantly the whole, solid and liquid, fraction of wastewater was used for virus concentration in this study. Campaign results showed medium- to strong- correlation between SARS-CoV-2 WBE data and COVID-19 prevalence. To go further, statistical relationships between WWTP inlet flow rate and rainfall were studied and taken into account for each WWTP in order to calculate contextualized SARS-CoV-2 loads. This metric presented improved correlation strengths with COVID-19 prevalence for WWTP particularly submitted and sensitive to rain. Such findings highlighted that SARS-CoV-2 WBE data ultimately require to be contextualized for relevant interpretation.
Subject(s)
COVID-19 , Wastewater , Cities , France , Humans , SARS-CoV-2ABSTRACT
Introduction: During the COVID-19 pandemic, hospitals implemented infection prevention strategies to reduce nosocomial transmission. Nevertheless, these strategies sometimes failed and determination of risk factors of transmission is crucial. Objectives: Our main objective was to determine the risk factors of nosocomial Covid-19 at Grenoble Alpes University hospital (CHUGA). Methods: A case-control study was conducted at CHUGA. A retrospective data collection was performed between 01/09/2020 and 31/01/2021. Adults patients hospitalized in medicine or surgery units were included. Infants or patients hospitalized in ICU were excluded. Case patients were patients with a nosocomial Covid-19 (clinical symptoms and positive PCR for SARS-CoV-2 or positive PCR for SARSCoV- 2 ≤ 28CT);control patients were patients without infection (negative PCR for SARS-CoV-2). They were matched by their length of stay and their period of admission. Bivariate and multivariate analysis were performed with a conditional logistic regression by Stata 12.0. Results: A total of 1393 patients with Covid-19 were hospitalized;722 patients were included in the case-control analysis ( ncase = 281;ncontrol = 441). In bivariate analysis, case patients were significantly older (OR:1.25;CI95% [1.12;1.40]), had more often a roommate (OR:1.74;CI95% [1.23;2.43]), more often a co-infection (OR:1.73;CI95% [1.26;2.36]), more often a severity risk factor of Covid-19 (OR:2.06;CI95% [1.14;3.71]) and a higher Charlson comorbidity index (OR:1,09;CI95% [1,01;1,20] than control patients. In an adjusted model that included the admission in the emergency room and the existence of a severity risk factor, the risk factors of nosocomial Covid-19 were: older age (aOR:1.24 per 10 years;CI95% [1.08;4.41]), having a roommate (aOR:1.63;CI95% [1.14;2.33]), and having a co-infection (aOR:1.62;CI95% [1.17;2.26]). Conclusion: Older patients with co-infection hospitalized in a multiple room were more susceptible to nosocomial Covid-19. These preliminary results need to be consolidated taking into account exposition to contagious healthcare workers or contagious patients.