Moving in extreme environments:what’s extreme and who decides?

Humans work, rest and play in immensely varied extreme environments. The term ‘extreme’ typically refers to insufficiency or excess of one or more stressors, such as thermal energy or gravity. Individuals’ behavioural and physiological capacity to endure and enjoy such environments varies immensely. Adverse effects of acute exposure to these environments are readily identifiable (e.g. heat stroke or bone fracture), whereas adverse effects of chronic exposure (e.g. stress fractures or osteoporosis) may be as important but much less discernable. Modern societies have increasingly sought to protect people from such stressors and, in that way, minimise their adverse effects. Regulations are thus established, and advice is provided on what is ‘acceptable’ exposure. Examples include work/rest cycles in the heat, hydration regimes, rates of ascent to and duration of stay at altitude and diving depth. While usually valuable and well intentioned, it is important to realise the breadth and importance of limitations associated with such guidelines. Regulations and advisories leave less room for self-determination, learning and perhaps adaptation. Regulations based on stress (e.g. work/rest cycles relative to WBGT) are more practical but less direct than those based on strain (e.g. core temperature), but even the latter can be substantively limited (e.g. by lack of criterion validation and allowance for behavioural regulation in the research on which they are based). Extreme Physiology & Medicine is publishing a series of reviews aimed at critically examining the issues involved with self- versus regulation-controlled human movement acutely and chronically in extreme environments. These papers, arising from a research symposium in 2013, are about the impact of people engaging in such environments and the effect of rules and guidelines on their safety, enjoyment, autonomy and productivity. The reviews will cover occupational heat stress, sporting heat stress, hydration, diving, extreme loading, chronic unloading and high altitude. Ramifications include factors such as health and safety, productivity, enjoyment and autonomy, acute and chronic protection and optimising adaptation

Challenges and Feasibility of Applying Reasoning and Decision Making for a Lifeguard Undertaking a Rescue

ABSTRACT: In areas where lifeguard services operate, less than 6% of all rescued persons need medical attention and require CPR. In contrast, among areas where no lifeguard services are provided almost 30% require CPR. This difference indicates in importance of the lifeguard. Lifeguard work requires effective problem identification, diagnostic strategies and management decisions to be made in high-risk environments, where time is of the essence. The purpose of this investigation was to assess all variables involved in lifeguard work related to a water rescue, and how the information obtained could inform lifeguard training and therefore performance. Methods: By using the drowning timeline, the authors explored all variables involved in a single rescue event by inviting 12 lifeguards to complete a survey of their professional role using a three-round Delphi survey technique. The total potential number of decisions for each phase and sub-phases, the number of variables, the probability of a single event repeating, the duration of each sub-phase and amount of variables demanded per minute were measured. Each sub-phase was presented as predominantly rational (if less than 1 variable per/min) or intuitive (if more than 1/min). Results: The variables identified in sub-phases were: “preparation to work” (8 variables and 0.0001 variables/min) and “prevent” (22 variables; 0.03 variables/min); these sub-phases were predominately considered to lead to rational decisions. The variables identified during “rescue” (27 variables and 2.7 variables/min) and “first-aid” (7 variables and 1.7 variables) were predominantly considered intuitive processes. Conclusion: This study demonstrates the complexity of a decision-making process during the quick, physically and mentally stressful moments of rescuing someone. The authors propose better decision-making processes can be achieved by reducing the time interval between identification of a problem and making a decision. Understanding this complex mechanism may allow more efficient training resulting, in faster and more reliable decision-makers, with the overall benefit of more lives save

Local Residential Sorting and Public Goods Provision: A Classroom Demonstration

This classroom exercise illustrates the Tiebout (1956) hypothesis that residential sorting across multiple jurisdictions leads to a more efficient allocation of local public goods. The exercise places students with heterogeneous preferences over a public good into a single classroom community. A simple voting mechanism determines the level of public good provision in the community. Next the classroom is divided in two, and students may choose to move between the two smaller communities, sorting themselves according to their preferences for public goods. The exercise places a cost on movement at first, then allows for costless sorting. Students have the opportunity to observe how social welfare rises through successive rounds of the exercise, as sorting becomes more complete. One may also observe how immobile individuals can become worse off because of incomplete sorting when the Tiebout assumptions do not hold perfectly.classroom experiments, public goods, residential sorting, Tiebout hypothesis.

Investigation of the Building M6-794 Roofing Fatality, Type A Mishap

The Building M6-794 Roofing Fatality Mishap Investigation Board (Board) was commissioned to gather information; analyze the facts; identify the proximate causes, root causes, and contributing factors relating to the mishap; and recommend appropriate actions to prevent a similar mishap from occurring in the future. During the investigation of this mishap, the Board also examined the fall protection policies of other NASA Centers and operating locations to gain an understanding of how those entities conduct fall protection, as well as the degree to which fall protection is standardized across the Agency

Results for the 2016 VIMS Industry Cooperative Surveys of the Mid-Atlantic, Nantucket Lightship Closed Area, and Closed Area II Resource Areas

Virginia Institute of Marine Scienc

Spindle assembly checkpoint robustness requires Tpr-mediated regulation of Mad1/Mad2 proteostasis

Tpr is a conserved nuclear pore complex (NPC) protein implicated in the spindle assembly checkpoint (SAC) by an unknown mechanism. Here, we show that Tpr is required for normal SAC response by stabilizing Mad1 and Mad2 before mitosis. Tpr coimmunoprecipitated with Mad1 and Mad2 (hereafter designated as Tpr/Mad1/Mad2 or TM2 complex) during interphase and mitosis, and is required for Mad1–c-Mad2 recruitment to NPCs. Interestingly, Tpr was normally undetectable at kinetochores and dispensable for Mad1, but not for Mad2, kinetochore localization, which suggests that SAC robustness depends on Mad2 levels at kinetochores. Protein half-life measurements demonstrate that Tpr stabilizes Mad1 and Mad2, ensuring normal Mad1–c-Mad2 production in an mRNA- and kinetochore-independent manner. Overexpression of GFP-Mad2 restored normal SAC response and Mad2 kinetochore levels in Tpr-depleted cells. Mechanistically, we provide evidence that Tpr might spatially regulate SAC proteostasis through the SUMO-isopeptidases SENP1 and SENP2 at NPCs. Thus, Tpr is a kinetochore-independent, rate-limiting factor required to mount and sustain a robust SAC response