Voice Loops as Coordination Aids in Space Shuttle Mission Control

Voice loops, an auditory groupware technology, are essential coordination support tools for experienced practitioners in domains such as air traffic management, aircraft carrier operations and space shuttle mission control. They support synchronous communication on multiple channels among groups of people who are spatially distributed. In this paper, we suggest reasons for why the voice loop system is a successful medium for supporting coordination in space shuttle mission control based on over 130 hours of direct observation. Voice loops allow practitioners to listen in on relevant communications without disrupting their own activities or the activities of others. In addition, the voice loop system is structured around the mission control organization, and therefore directly supports the demands of the domain. By understanding how voice loops meet the particular demands of the mission control environment, insight can be gained for the design of groupware tools to support cooperative activity in other event-driven domains.     

Cerebral arterial inflow assessment with F-FDG PET: Methodology and feasibility

Positron emission tomography (PET) with ¹⁸fluorodeoxyglucose (¹⁸F-FDG) is increasingly used in neurology. The measurement of cerebral arterial inflow (QA) using ¹⁸F-FDG complements the information provided by standard brain PET imaging. Here, injections were performed after the beginning of dynamic acquisitions and the time to arrival (t0) of activity in the gantry's field of view was computed. We performed a phantom study using a branched tube (internal diameter: 4 mm) and a ¹⁸F-FDG solution injected at 240 mL/min. Data processing consisted of (i) reconstruction of the first 3 s after t0, (ii) vascular signal enhancement and (iii) clustering. This method was then applied in four subjects. We measured the volumes of the tubes or vascular trees and calculated the corresponding flows. In the phantom, the flow was calculated to be 244.2 mL/min. In each subject, our QA value was compared with that obtained by quantitative cine-phase contrast magnetic resonance imaging; the mean QA value of 581.4 ± 217.5 mL/min calculated with ¹⁸F-FDG PET was consistent with the mean value of 593.3 ± 205.8 mL/min calculated with quantitative cine-phase contrast magnetic resonance imaging. Our ¹⁸F-FDG PET method constitutes a novel, fully automatic means of measuring QA.     

A Relational Turbulence Model of Military Service Members' Relational Communication During Reintegration

This study employed the relational turbulence model to examine features of relational communication and dimensions of relational inferences during the postdeployment transition for military service members. We surveyed 220 military personnel who had recently returned home from deployment about their romantic relationship. Results of a structural equation model indicated that relational uncertainty and interference from partners predicted openness and aggressiveness, which in turn predicted appraisals of affiliation and dominance in the relationship. The results imply that the transition from deployment to reunion corresponds with upheaval in how service members communicate with a romantic partner and make judgments about their relationship.     

Metals in female scalp hair globally and its impact on perceived hair health

Globally, billions of individuals wash their hair in water, which acts as an exogenous metal source. Many studies which measure the metal levels found on human hair specifically aim to remove exogenous materials prior to analysis. Although this is needed when using hair analysis to probe the impact of the local environment on endogenous metal levels, it is not relevant for understanding exactly what is on hair as a result of contact with its daily environment. Understanding these levels are important, as the presence of redox active metals, such as copper and iron, can impact fibre health, either as a result of UV irradiation, or during the hair colouring process. A global hair sampling study of over 300 individuals from nine countries has been performed, and the combined endogenous and exogenous metals analysed. The levels measured vary widely, even within the narrow geography of each hair sampling location. The levels of calcium, magnesium, copper and iron were not correlated, and within each location, there are expected to be individuals with high metal levels. Levels increased from hair root to tip for calcium, magnesium and copper, attributed to hair contact with the environment showing the impact of exogenous metals in the overall levels on hair. Levels of redox metals were comparable between individuals who coloured or did not colour their hair, although water hardness ions were statistically significantly higher for hair colouring individuals. Individuals who perceived their hair health as poor had higher metal levels on their hair. Controlling metals on hair, either by preventing their binding during environmental contact, or through controlling their ability to cause hair damage, should lead to improved consumer perceived hair health.     

Subjective and behavioral presence measurement and interactivity in the collaborative augmented reality game TimeWarp

Presence is usually assessed via a variety of subjective and objective measures. However, constraints often result in subjective measurements using questionnaires as a key method of data collection. In this paper we present a study of 44 participants of a collaborative augmented reality game known as TimeWarp which used both subjective and objective behavioral measures. Behavior as coded from video recordings of one scene of the game and self-reports about feelings of presence were compared. Our findings indicate that pointing behavior and verbal responses to the virtual content are correlated negatively to sense of presence. We further investigated the influence of subjectively perceived interactivity on perceived presence. We found that the interaction possibilities perceived by the participants predicted their experience of social presence with the virtual characters in the game. Furthermore, playing together with another person did not result in decreased social presence of the virtual characters. Implications for presence research are discussed.     

Metal Fabrication by Additive Manufacturing Using Laser and Electron Beam Melting Technologies

Selective laser melting (SLM) and electron beam melting (EBM) are relatively new rapid, additive manufac- turing technologies which can allow for the fabrication of complex, multi-functional metal or alloy monoliths by CAD-directed, selective melting of precursor powder beds. By altering the beam parameters and scan strategies, new and unusual, even non-equilibrium microstructures can be produced; including controlled microstructural architectures which ideally extend the contemporary materials science and engineering paradigm relating structure-properties-processing-performance. In this study, comparative examples for SLM and EBM fabricated components from pre-alloyed, atomized precursor powders are presented. These include Cu, Ti–6Al–4V, alloy 625 (a Ni-base superalloy), a Co-base superalloy, and 17-4 PH stainless steel. These systems are characterized by optical metallography, scanning and transmission electron microscopy, and X-ray diffraction.     

System among the corticosteroids: specificity and molecular dynamics

Understanding how structural features determine specific biological activities has often proved elusive. With over 161 000 steroid structures described, an algorithm able to predict activity from structural attributes would provide manifest benefits. Molecular simulations of a range of 35 corticosteroids show striking correlations between conformational mobility and biological specificity. Thus steroid ring A is important for glucocorticoid action, and is rigid in the most specific (and potent) examples, such as dexamethasone. By contrast, ring C conformation is important for the mineralocorticoids, and is rigid in aldosterone. Other steroids that are less specific, or have mixed functions, or none at all, are more flexible. One unexpected example is 11-deoxycorticosterone, which the methods predict (and our activity studies confirm) is not only a specific mineralocorticoid, but also has significant glucocorticoid activity. These methods may guide the design of new corticosteroid agonists and antagonists. They will also have application in other examples of ligand–receptor interactions.