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A biosecurity panel met, expecting to approve recommendations, but myriad concerns complicated the proceedings. A biosecurity panel met, expecting to approve recommendations, but myriad concerns complicated the proceedings. Credit: Patrick Semansky/AP/Shutterstock A sign on the door of a Biosafety Level 4 laboratory at the U.S. Army Medical Research Institute of Infectious Diseases.

This study conducted human factors risk analyses of a doffing protocol for Ebola-level personal protective equipment to identify and quantify the risk of errors made by healthcare workers, marked with surrogate viruses, while doffing and to predict rates of self-contamination.

This paper is a transcription of the texts read by three commentators appointed by the scientific committee to open the first debate session convened in June 2020 as a continuation of the virtual QSN conference held a month before. It should be noted that, for practical reasons as well as time constraints (there were researchers from countries with different time zones), the comments did not address presentations in the order in which they appeared in the conference program.

In aero-engine containment tests, titanium alloy blades exploding and flying off generate a large amount of titanium fire, affecting the capture and recording of the blade flyoff process. To solve the problem of titanium fire interference caused by the shaped charge cutting process, this study innovatively proposed a barrier layer protection technique based on the analysis of the titanium fire mechanism of explosive flyoff, and prepared and used aluminosilicate materials as barrier layers for experiments. The results show that the use of aluminosilicate materials as a barrier layer can significantly reduce the generation of titanium fire, with a suppression effect of 75%. The study confirmed that the barrier layer technique can effectively inhibit the generation of titanium fire by precisely utilizing the speed difference between the metal jet and the detonation products to isolate the titanium alloy from direct contact with the detonation products in a short period of time, thereby providing an effective protection solution for observation systems in aero-engine containment tests.

The serious threats posed by drug-resistant bacterial infections and recent developments in synthetic biology have fueled a growing interest in genetically engineered phages with therapeutic potential. To date, many investigations on engineered phages have been limited to proof of concept or fundamental studies using phages with relatively small genomes or commercially available “phage display kits”. Moreover, safeguards supporting efficient translation for practical use have not been implemented. Here, we developed a cell-free phage engineering and rebooting platform. We successfully assembled natural, designer, and chemically synthesized genomes and rebooted functional phages infecting gram-negative bacteria and acid-fast mycobacteria. Furthermore, we demonstrated the creation of biologically contained phages for the treatment of bacterial infections. These synthetic biocontained phages exhibited similar properties to those of a parent phage against lethal sepsis in vivo. This efficient, flexible, and rational approach will serve to accelerate phage biology studies and can be used for many practical applications, including phage therapy.

In simulations of Ebola-level personal protective equipment doffing with experienced healthcare workers, hands, inner gloves, and scrubs are contaminated with nonenveloped viruses and, infrequently, with enveloped viruses.

Fluorescent lamps are estimated to annually release 11 of mercury into the air in the United States: transport of used lamps may play an important role in these emissions. In 1999, the U.S. Environmental Protection Agency added lamps to the universal waste rule to encourage recycling by allowing shipment to recycling facilities by common carrier. The rules required that lamp packaging must be structurally sound and adequate to prevent breakage but did not address vapor release. In 2005, a requirement was added that packaging must be designed to prevent the escape of mercury into the environment, but this change does not apply to fluorescent lamps. The goal of this research was to compare mercury vapor containment among different packaging configurations. In 10 replicate experiments of 5 different packages containing 40 broken, used, low-mercury lamps, two 6-hr samples of airborne mercury vapor concentrations were taken in a well-mixed sealed chamber held at 83 2 F. Average chamber concentrations ranged from 0.977 mg/m3 for a single cardboard box to 0.004 mg/m3 for a double cardboard box with a plastic-foil laminate bag sandwiched between the boxes. In comparison to the single cardboard box, a single box with an unsealed thin plastic liner lowered mercury concentrations in the chamber by 52%, single or double boxes with a thicker tape-sealed plastic bag lowered concentrations by 90-92%, and a double box with a ziplock plastic-foil laminate bag lowered concentrations by 99.7%. The latter was the only configuration capable of maintaining airborne concentrations below all occupational exposure levels. Standards more specific to mercury containment are needed for packages used to ship fluorescent lamps to recyclers. Results from this study suggest that an effective packaging design should minimize the effect of cuts from broken glass while also preventing the release of mercury vapor from broken lamps.

The ongoing Ebola outbreak poses an alarming risk to the countries of West Africa and beyond. To assess the effectiveness of containment strategies, we developed a stochastic model of Ebola transmission between and within the general community, hospitals, and funerals, calibrated to incidence data from Liberia. We find that a combined approach of case isolation, contact-tracing with quarantine, and sanitary funeral practices must be implemented with utmost urgency in order to reverse the growth of the outbreak. As of 19 September, under status quo, our model predicts that the epidemic will continue to spread, generating a predicted 224 (134 to 358) daily cases by 1 December, 280 (184 to 441) by 15 December, and 348 (249 to 545) by 30 December.

The integrity of containment buildings in nuclear power plants is crucial for preventing the release of radioactive materials during severe accidents. This study investigates the effect of the uncertainty in temperature-dependent strength of concrete on the internal pressure capacity of prestressed concrete containment vessel (PCCV). To this end, a high-fidelity finite element model is developed and the uncertainty in concrete material properties due to temperature variations is taken into account for a finite element analysis with internal pressure and temperature histories. In addition, two limit states of PCCV, such as onset of leakage and functional failure, are defined to investigate internal pressure capacity depending on the different damages to PCCV. The results provide insights into the behavior of PCCV under severe accident conditions and the impact of the uncertainty in the concrete material due to temperature on their performance, in terms of the leakage of PCCV. This research enhances the understanding of PCCV’s response to internal pressure and temperature and contributes to the safety assessment of nuclear power plants.

BackgroundStand-replacing wildfires and eastern spruce budworm outbreaks (Choristoneura fumiferana; SBW) are important disturbances in the boreal forest. SBW defoliation can affect fire behaviour by altering fuel loads and connectivity, thereby promoting the transition of low-activity surface fires into crown fires. However, little is known about how these altered fuels impact the effectiveness of fire suppression.AimsTo assess key drivers of initial attack (IA) success in Ontario’s boreal forest and determine if incorporating SBW defoliation data improves predictive models.MethodsWe developed random forest models of fire containment using established predictors including fire weather, fire size at IA and region. We then evaluated if the inclusion of time since SBW defoliation improved model performance.Key resultsFire size at IA was the most influential variable for determining whether a fire escaped containment. Contrary to our hypothesis, we did not find evidence that SBW defoliation greatly improved model performance.Conclusions and implicationsThe size of the fire at IA was the most important variable in determining successful containment. Although budworm defoliation has been shown to affect other aspects of fire hazard, we were unable to identify an influence on IA success. Future work could benefit from focused investigation into how historical SBW defoliation affects fire behaviour.