Subduction interfaces exhibit a variety of slip behaviors, including megathrust and slow earthquakes. Field observations are consistent with crack‐seal deformation, in which tensile cracks are sealed by fluid‐transported solute. However, there are few constraints on the mass fluxes and length and time scales of such deformation and attendant increases in cohesion within the seismogenic zone. Here, we present a systematic geochemical investigation of mass transport associated with development of crack‐seal veins in the Shimanto Belt—an accretionary complex that preserves a record of plate boundary slip behavior at temperatures relevant to the seismogenic zone: 150–350°C. These mélanges show evidence for shear across decameter‐scale zones of deformation dominated by anastomosing scaly fabrics and pervasive veins. We use meso‐ and microstructural observations with geochemical observations of scaly fabrics and crack‐seal veins to evaluate the role of silica redistribution in healing fracture porosity along the plate interface and modulating slip behavior. Crack‐seal veins contain primarily quartz with albite and calcite, and vein textures provide evidence for partial sealing. Bulk rock analyses determined that the amount of phyllosilicates, specifically illite and chlorite, increases with temperature. A simple mass‐balance model based on the immobile chemical component TiO2 shows a systematic trend in mobility for all three mélanges and increased element mobility as a function of temperature. Scaly fabrics and veins show compositional evidence for locally sourced mineral redistribution. This study supports a model where development of scaly slip surfaces and fracture healing through temperature‐dependent mineral redistribution can impact slip behavior and fluid flow along the subduction plate interface.

There has been an expansion in the use of x-ray imaging during the last 20 years. Effective arrangements for justification of exposures as well as for optimisation of protection are crucial. The amount of effort put into the latter, the way in which it is organised and the groups carrying this out vary across the globe. A simple survey of organisational arrangements relating to performance testing of x-ray equipment, management of patient dose and other aspects of implementing optimisation has been undertaken. A total of 137 completed survey forms were received from medical physicists in 48 countries. Results for individual countries from which more responses were received, or for groups of neighbouring ones, are compared to portray variations. Some performance testing of x-ray equipment was mandated in most countries (more than 90%), with the tests being performed primarily by hospital or private medical physicists, although other groups are involved. Testing of equipment prior to clinical use was generally high for most regions, but the frequency was lower in Latin America. There was considerable variation in the frequency and regularity of subsequent testing. The prevalence of patient dose surveys was high in Europe, but lower in other continents. Organisational arrangements for testing performance of x-ray equipment, patient dose surveys and implementing optimisation of protection in medical exposures across the globe can be divided into five main groups. Hospital medical physicists take the lead in western Europe and Australia with the involvement of radiographers. Private medical physicists test equipment in Brazil, the USA and New Zealand, and have some responsibility for optimisation in Brazil. University personnel have significant involvement, together with medical physicists in eastern Europe, but the extent of the coverage is uncertain. Government personnel and service engineers carry out equipment testing in many countries of Africa and Asia, while radiographers have a significant role in Thailand and other countries where the number of medical physicists is limited. In order for dose surveys to have an impact, action must be taken upon the findings, but there must be an effective link between surveyors and radiology facility staff to ensure that this is done.

Biological Dosimetry is a necessary support for national radiation protection programmes and emergency response schemes. The Latin American Biological Dosimetry Network (LBDNet) was formally founded in 2007 to provide early biological dosimetry assistance in case of radiation emergencies in the Latin American Region. Here are presented the main topics considered in the foundational document of the network, which comprise: mission, partners, concept of operation, including the mechanism to request support for biological dosimetry assistance in the region, and the network capabilities. The process for network activation and the role of the coordinating laboratory during biological dosimetry emergency response is also presented. This information is preceded by historical remarks on biological dosimetry cooperation in Latin America. A summary of the main experimental and practical results already obtained by the LBDNet is also included.

To better prepare student-EMTs to respond and manage a disaster scene, MERT is implementing a tabletop exercise module to ensure that MERT members are fluent in the Incident Command System (ICS), familiar with the MERT MCI operating guidelines, and able to size-up a scene appropriately. Unlike the fast-paced MCI drill, the tabletop exercise is an environment for members to ask clarifying questions, learn the ICS thought process, and make mistakes at their own pace. The tabletop scenario presents a potential MCI scenario to a small group overseen by a facilitator and evaluator. The facilitator presents information to the group and questions members' decision-making. Program Evaluation: Concurrently, the evaluator tracks progress using a rubric MERT adapted from FEMA and NIMS standards. This tabletop rubric parallels the rubric used for the MCI drill. Both highlight often-forgotten MERT operating guidelines and parts of the incident command structure (e.g. prioritizing areas of the scene). After the exercise is completed, all of those involved debrief and complete feedback forms. Discussion/Conclusion: Our hope is that members will apply what they have learned during the tabletop to an MCI drill and, thus, show improvement in the fluidity of the simulated response.

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