3,180 research outputs found

    Sleep Environment Recommendations for Future Spaceflight Vehicles

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    Current evidence demonstrates that astronauts experience sleep loss and circadian desynchronization during spaceflight. Ground-based evidence demonstrates that these conditions lead to reduced performance, increased risk of injuries and accidents, and short and long-term health consequences. Many of the factors contributing to these conditions relate to the habitability of the sleep environment. Noise, inadequate temperature and airflow, and inappropriate lighting and light pollution have each been associated with sleep loss and circadian misalignment during spaceflight operations and on Earth. As NASA prepares to send astronauts on long-duration, deep space missions, it is critical that the habitability of the sleep environment provide adequate mitigations for potential sleep disruptors. We conducted a comprehensive literature review summarizing optimal sleep hygiene parameters for lighting, temperature, airflow, humidity, comfort, intermittent and erratic sounds, and privacy and security in the sleep environment. We reviewed the design and use of sleep environments in a wide range of cohorts including among aquanauts, expeditioners, pilots, military personnel and ship operators. We also reviewed the specifications and sleep quality data arising from every NASA spaceflight mission, beginning with Gemini. Finally, we conducted structured interviews with individuals experienced sleeping in non-traditional spaces including oil rig workers, Navy personnel, astronauts, and expeditioners. We also interviewed the engineers responsible for the design of the sleeping quarters presently deployed on the International Space Station. We found that the optimal sleep environment is cool, dark, quiet, and is perceived as safe and private. There are wide individual differences in the preferred sleep environment; therefore modifiable sleeping compartments are necessary to ensure all crewmembers are able to select personalized configurations for optimal sleep. A sub-optimal sleep environment is tolerable for only a limited time, therefore individual sleeping quarters should be designed for long-duration missions. In a confined space, the sleep environment serves a dual purpose as a place to sleep, but also as a place for storing personal items and as a place for privacy during non-sleep times. This need for privacy during sleep and wake appears to be critically important to the psychological well-being of crewmembers on long-duration missions

    Birds and people in Europe

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    At a regional scale, species richness and human population size are frequently positively correlated across space. Such patterns may arise because both species richness and human density increase with energy availability. If the species-energy relationship is generated through the 'more individuals' hypothesis, then the prediction is that areas with high human densities will also support greater numbers of individuals from other taxa. We use the unique data available for the breeding birds in Europe to test this prediction. Overall regional densities of bird species are higher in areas with more people; species of conservation concern exhibit the same pattern. Avian density also increases faster with human density than does avian biomass, indicating that areas with a higher human density have a higher proportion of small-bodied individuals. The analyses also underline the low numbers of breeding birds in Europe relative to humans, with a median of just three individual birds per person, and 4 g of bird for every kilogram of human

    Establishing a Virtual Makerspace for an Online Graduate Course: A Design Case

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    This design case discusses key steps taken to establish a virtual makerspace for students enrolled in an online graduate course on informal learning. Two key design decisions are elaborated around (a) the selection of appropriate projects and packaged materials that distance education students can receive by mail to participate in making, and (b) the choice of an online platform for distance education students to document their design processes for assessment purposes and peer interaction and learning. This design case is relevant to a variety of online communities who may wish to engage in maker activities as well as isolated face-to-face communities or individuals who may not have local mentors to support informal making and could, therefore, benefit from online connectivity to an expert or peer support. To promote replication of the design, materials and community tools to support making among geographically dispersed makers are detailed

    Sleep Environment Recommendations for Future Spaceflight Vehicles

    Get PDF
    Evidence from spaceflight and ground-based missions demonstrate that sleep loss and circadian desynchronization occur among astronauts, leading to reduced performance and, increased risk of injuries and accidents. We conducted a comprehensive literature review to determine the optimal sleep environment for lighting, temperature, airflow, humidity, comfort, intermittent and erratic sounds, privacy and security in the sleep environment. We reviewed the design and use of sleep environments in a wide range of cohorts including among aquanauts, expeditioners, pilots, military personnel, and ship operators. We also reviewed the specifications and sleep quality data arising from every NASA spaceflight mission, beginning with Gemini. We found that the optimal sleep environment is cool, dark, quiet, and is perceived as safe and private. There are wide individual differences in the preferred sleep environment; therefore modifiable sleeping compartments are necessary to ensure all crewmembers are able to select personalized configurations for optimal sleep

    Arterial hypoxaemia and its impact on coagulation:significance of altered redox homeostasis

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    AimsArterial hypoxaemia stimulates free radical formation. Cellular studies suggest this may be implicated in coagulation activation though human evidence is lacking. To examine this, an observational study was designed to explore relationships between systemic oxidative stress and haemostatic responses in healthy participants exposed to inspiratory hypoxia.ResultsActivated partial thromboplastin time and international normalised ratio were measured as routine clinical biomarkers of coagulation and ascorbate free radical (A•−) as a direct global biomarker of free radical flux. Six hours of hypoxia activated coagulation, and increased formation of A•−, with inverse correlations observed against oxyhaemoglobin saturation.ConclusionsThis is the first study to address the link between free radical formation and coagulation in vivo. This ‘proof-of-concept’ study demonstrated functional associations between hypoxaemia and coagulation that may be subject to redox activation of the intrinsic pathway. Further studies are required to identify precisely which intrinsic factors are subject to redox activation.</jats:sec

    Assembly, Secretory Pathway Trafficking, and Surface Delivery of Kainate Receptors Is Regulated by Neuronal Activity

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    Summary: Ionotropic glutamate receptor (iGluR) trafficking and function underpin excitatory synaptic transmission and plasticity and shape neuronal networks. It is well established that the transcription, translation, and endocytosis/recycling of iGluRs are all regulated by neuronal activity, but much less is known about the activity dependence of iGluR transport through the secretory pathway. Here, we use the kainate receptor subunit GluK2 as a model iGluR cargo to show that the assembly, early secretory pathway trafficking, and surface delivery of iGluRs are all controlled by neuronal activity. We show that the delivery of de novo kainate receptors is differentially regulated by modulation of GluK2 Q/R editing, PKC phosphorylation, and PDZ ligand interactions. These findings reveal that, in addition to short-term regulation of iGluRs by recycling/endocytosis and long-term modulation by altered transcription/translation, the trafficking of iGluRs through the secretory pathway is under tight activity-dependent control to determine the numbers and properties of surface-expressed iGluRs. : Evans et al. show that secretory pathway trafficking of KARs is highly activity-dependent. This medium-term regulatory mechanism demonstrates how neuronal excitability and network activity are regulated at multiple levels over a range of time courses. Keywords: kainate receptor, retention using selective hooks, RUSH, secretory pathway, ER exit sites, Golgi outposts, AMPA receptors, scaling, Q/R editing, ADAR2, PDZ ligan
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