Learning from Cochrane systematic reviews: what improvements do these suggest for the design of trials?

Grant information: The study was funded by the Health Research Board (grant ‘Capacity Building for Evidence Synthesis – Evidence Synthesis Ireland 2018’) as part of Trial Forge (http://trialforge.org), a non-commercial research initiative led by ST. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

Initial Active Interrogation Experiments at The University of Michigan Linear Accelerator Laboratory

To support the mission of the Countering Weapons of Mass Destruction Office of the Department of Homeland Security, the Detection for Nuclear Nonproliferation group is researching active interrogation techniques and the development of new detection algorithms for fast neutron spectroscopy. The Countering Weapons of Mass Destruction Officehas loaned us a Varian M9 linear accelerator (linac), helium-3 detectors, boron-coated straw detectors, and perfluorocarbondetectors as part of this research, providing a variety of tools to conduct our experiments.In the summer of 2018, a thorough licensing process concluded, and preliminary experiments commenced. Later in the year, the facility was approved to possess and irradiate depleted uranium, which enabledus to conduct active interrogation experiments.In the fall of 2018, we conducted our first active interrogation measurements using the linac facility. The measurements used the linac to irradiate depleted uranium,lead, and tungsten targets to induce photonuclear reactions to emit fast neutrons. The neutrons were then detected using a simple helium-3 detector. Simulations were developed using MCNPX-PoliMi and MCNP 6.1 to validate the measured results. The simulations showed close agreement for depleted uranium but indicated that additional investigation is required for the lead and tungsten data. The facility will be indispensable as the researchprogressesbyproviding a mixed-radiation field consisting of fast neutrons and photons, which is similar to the radiation environment encountered in active interrogation scenarios.Additionally, the facility is involved inresearch related toradiation damage, dosimetry, and radiation-oncology.Future activities will involve characterization of photonuclear properties of various materials, and collaborations with other university researchers

Multiplicity counting using organic scintillators to distinguish neutron sources: An advanced teaching laboratory

In this advanced instructional laboratory, students explore complex detection systems and nondestructive assay techniques used in the field of nuclear physics. After setting up and calibrating a neutron detection system, students carry out timing and energy deposition analyses of radiation signals. Through the timing of prompt fission neutron signals, multiplicity counting is used to carry out a special nuclear material (SNM) nondestructive assay. Our experimental setup is comprised of eight trans-stilbene organic scintillation detectors in a well-counter configuration, and measurements are taken on a spontaneous fission source as well as two ({\alpha},n) sources. By comparing each source's measured multiplicity distribution, the resulting measurements of the ({\alpha},n) sources can be distinguished from that of the spontaneous fission source. Such comparisons prevent the spoofing, i.e., intentional imitation, of a fission source by an ({\alpha},n) neutron source. This instructional laboratory is designed for nuclear engineering and physics students interested in organic scintillators, neutron sources, and nonproliferation radiation measurement techniques.Comment: 29 pages, 17 figures, pre-proof accepted to AJP, AJP number AJP22-AR-01524R2 (DOI: 10.1119/5.0139531

A DevOps Capability - The IVI DevOps Effectiveness Assessment

The DevOps Effectiveness Assessment (DEA) is a new IVI assessment drawing on the IT Capability Maturity Framework (IT-CMF). The assessment provides a holistic analysis of an organization’s DevOps maturity, and identifies the key relevant IT-CMF Critical Capabilities (CCs) to aid improvement. DevOps refers to a set of technical, architectural, and cultural practices aimed at increasing the efficiency and effectiveness of delivering business needs into production, through improved communication and collaboration between business, development, and IT operations. The DEA is based on rigorous academic research and collaboration with experts from leading organizations. This paper outlines the key insights from this research, which have informed the development of the DEA

Origin of Madagascan Scarabaeini dung beetles (Coleoptera : Scarabaeidae) : dispersal from Africa

Madagascar, the world’s fourth largest island, has a long history of isolation (160 MY) and a wide range of climates and ecosystems which have in turn resulted in high levels of endemism across different taxonomic levels. Although Madagascar has a rich dung beetle fauna that belongs to various tribes only three species of the Scarabaeini are found there, namely Scarabaeus viettei, S. radama and S. sevoistra. These three species are superficially quite distinctive and have, consequently, had a relatively tortured taxonomic history since the first was described in1896. The morpholgical differences between these species resulted in them being placed in different genera at different times. However, currently, based on cladistic analysis, they are all classified in the genus Scarabaeus. In this study, two of the species, S. viettei and S. radama, were included in a phylogenetic analysis based on two mitochondrial gene regions - cytochrome oxidase I (COI) and 16S rRNA - and a 247 morphological and behavioural dataset of 23 members of the Scarabaeinae. A Bayesian phylogram supports the monophyly of the genus Scarabaeus, with the two species from Madagascar appearing sister to three species of Scarabaeus from southwest Africa. Estimated times of divergence based on published mutation rates of 0.012 and 0.0075 for COI indicate that a shared African/Madagascan origin occurred around 15.18 or 24.15 MYA, respectively. This study is another example in support of Madagascan fauna having an African origin with colonisation having occurred via dispersal as opposed to ancient vicariant events.http://www.brill.nl/iseab201

Monte Carlo Simulation for LINAC Standoff Interrogation of Nuclear Material

The development of new techniques for the interrogation of shielded nuclear materials relies on the use of Monte Carlo codes to accurately simulate the entire system, including the interrogation source, the fissile target and the detection environment. The objective of this modeling effort is to develop analysis tools and methods-based on a relevant scenario-which may be applied to the design of future systems for active interrogation at a standoff. For the specific scenario considered here, the analysis will focus on providing the information needed to determine the type and optimum position of the detectors. This report describes the results of simulations for a detection system employing gamma rays to interrogate fissile and nonfissile targets. The simulations were performed using specialized versions of the codes MCNPX and MCNP-PoliMi. Both prompt neutron and gamma ray and delayed neutron fluxes have been mapped in three dimensions. The time dependence of the prompt neutrons in the system has also been characterized For this particular scenario, the flux maps generated with the Monte Carlo model indicate that the detectors should be placed approximately 50 cm behind the exit of the accelerator, 40 cm away from the vehicle, and 150 cm above the ground. This position minimizes the number of neutrons coming from the accelerator structure and also receives the maximum flux of prompt neutrons coming from the source. The lead shielding around the accelerator minimizes the gamma-ray background from the accelerator in this area. The number of delayed neutrons emitted from the target is approximately seven orders of magnitude less than the prompt neutrons emitted from the system. Therefore, in order to possibly detect the delayed neutrons, the detectors should be active only after all prompt neutrons have scattered out of the system. Preliminary results have shown this time to be greater than 5 ?s after the accelerator pulse. This type of system is illustrative of a host of real-world scenarios of interest to nonproliferation and homeland security. Due to the multistep procedure of the MCNPX/MCNP-PoliMi code system, the analysis of somewhat modular - meaning that changing details such as the detector type, position, or surroundings does not require a re-calculation of the source-target interactions. This feature allows for efficient parametric analysis of numerous system parameters without recomputing the constant source-target behavior. Such efficient analysis mechanisms could prove invaluable in the design and future deployment of an active interrogation detection system