2,254 research outputs found
Development and analysis of a modular approach to payload specialist training
A modular training approach for Spacelab payload crews is described. Representative missions are defined for training requirements analysis, training hardware, and simulations. Training times are projected for each experiment of each representative flight. A parametric analysis of the various flights defines resource requirements for a modular training facility at different flight frequencies. The modular approach is believed to be more flexible, time saving, and economical than previous single high fidelity trainer concepts. Block diagrams of training programs are shown
Renaissance Fun: The machines behind the scenes
Renaissance Fun is about the technology of Renaissance entertainments in stage machinery and theatrical special effects; in gardens and fountains; and in the automata and self-playing musical instruments that were installed in garden grottoes. How did the machines behind these shows work? How exactly were chariots filled with singers let down onto the stage? How were flaming dragons made to fly across the sky? How were seas created on stage? How did mechanical birds imitate real birdsong? What was ‘artificial music’, three centuries before Edison and the phonograph? How could pipe organs be driven and made to play themselves by waterpower alone? And who were the architects, engineers, and craftsmen who created these wonders? All these questions are answered. At the end of the book we visit the lost ‘garden of marvels’ at Pratolino with its many grottoes, automata and water jokes; and we attend the performance of Mercury and Mars in Parma in 1628, with its spectacular stage effects and its music by Claudio Monteverdi – one of the places where opera was born. Renaissance Fun is offered as an entertainment in itself. But behind the show is a more serious scholarly argument, centred on the enormous influence of two ancient writers on these subjects, Vitruvius and Hero. Vitruvius’s Ten Books on Architecture were widely studied by Renaissance theatre designers. Hero of Alexandria wrote the Pneumatics, a collection of designs for surprising and entertaining devices that were the models for sixteenth and seventeenth century automata. A second book by Hero On Automata-Making – much less well known, then and now – describes two miniature theatres that presented plays without human intervention. One of these, it is argued, provided the model for the type of proscenium theatre introduced from the mid-sixteenth century, the generic design which is still built today. As the influence of Vitruvius waned, the influence of Hero grew
Life course building epidemiology: An alternative approach to the collection and analysis of carbon emission data
Developing policy for the reduction of the carbon emissions due to buildings requires models for energy usage that incorporate social, behavioural, and environmental factors in addition to the physical properties and technical specifications of the buildings. Marked parallels exist with some of the more intractable public health issues, such as rising levels of obesity. Recently, health researchers have recognized the importance of taking a broader life-course approach to epidemiology in order to examine the degree that long-term health outcomes are set in early life and the extent that these may be mediated or mitigated by subsequent growth and development, as well as by intervention strategies. Life course epidemiology as applied in building science, where energy usage is treated as analogous to poor health outcomes, provides an alternative approach for the construction of causal models that allow for complex interactions between social and technical factors as well as long term effects. It can provide a useful framework for the successful management and analysis of longitudinal studies and may prove particularly effective in identifying the type, timing, and targeting of intervention strategies to produce optimal outcomes in terms of absolute reductions of carbon emissions and resilience of building performance to external stresses, such as those imposed by climate change. An example based on a study in Milton Keynes (London), which is currently in progress, is used to illustrate the way causal models may help elucidate the complex interactions between factors that influence energy usage
The effect of spinal cord injury on sexual function.
Spinal cord injury (SCI) causes severe neurological impairment with widespread motor, autonomic and sensory deficits, leading to a substantial quality of life impairment. The number of individuals with SCI increases by approximately 12,500 annually, and over 80% of individuals with SCI are males. SCI individuals rate sexual function as a top priority quality of life issue, and men with SCI likely suffer from sexual dysfunction, such as erectile and ejaculatory dysfunction, as well as infertility. Regardless of the high status of importance of sexual function, limited numbers of experimental studies in SCI animal models have focused on sexual function after SCI. Interestingly, human clinical research participants with SCI undergoing daily locomotor treadmill training have reported changes in sexual function. To advance targeted recovery of sexual function after SCI, a better understanding of the post-injury neural circuitry is necessary. The objective of this project was to determine the effect of activity-based training (ABT) on sexual function in a rat model of SCI and examine the effects of a contusion SCI on sexual function using improved quantifiable measures. Two well-established measures of sexual function were used to determine the effects of ABT on sexual function after SCI: the penile dorsiflexion reflex (PDFR) and bulbospongiosus electromyography. The second and third studies focused on determining the effect of a clinically relevant contusion injury of varying severities using kinematic analysis of the PDFR and real-time intracavernosal pressure recordings from the penis of rats undergoing mating behavior testing. ABT was shown to positively affect sexual function after SCI, where task-specific stepping and/or hindlimb loading impacts the local spinal cord circuitry responsible for sexual function. ABT may strengthen the residual fibers crossing the lesion epicenter, providing better coordination of supraspinal influences on the spinal cord sexual circuitry. Sexual function after SCI was determined to be correlated with the percent of white matter spared (a measure of injury severity), further supporting the disruption of spinobulbospinal coordination as the cause of sexual dysfunction after SCI. Kinematic analysis of the penile dorsiflexion reflex and telemetric recording of intracavernosal pressure may provide improved quantifiable measures for examining sexual function after SCI
Changes in neuronal representations of consonants in the ascending auditory system and their role in speech recognition
A fundamental task of the ascending auditory system is to produce representations that facilitate the recognition of complex sounds. This is particularly challenging in the context of acoustic variability, such as that between different talkers producing the same phoneme. These representations are transformed as information is propagated throughout the ascending auditory system from the inner ear to the auditory cortex (AI). Investigating these transformations and their role in speech recognition is key to understanding hearing impairment and the development of future clinical interventions. Here, we obtained neural responses to an extensive set of natural vowel-consonant-vowel phoneme sequences, each produced by multiple talkers, in three stages of the auditory processing pathway. Auditory nerve (AN) representations were simulated using a model of the peripheral auditory system and extracellular neuronal activity was recorded in the inferior colliculus (IC) and primary auditory cortex (AI) of anaesthetized guinea pigs. A classifier was developed to examine the efficacy of these representations for recognizing the speech sounds. Individual neurons convey progressively less information from AN to AI. Nonetheless, at the population level, representations are sufficiently rich to facilitate recognition of consonants with a high degree of accuracy at all stages indicating a progression from a dense, redundant representation to a sparse, distributed one. We examined the timescale of the neural code for consonant recognition and found that optimal timescales increase throughout the ascending auditory system from a few milliseconds in the periphery to several tens of milliseconds in the cortex. Despite these longer timescales, we found little evidence to suggest that representations up to the level of AI become increasingly invariant to across-talker differences. Instead, our results support the idea that the role of the subcortical auditory system is one of dimensionality expansion, which could provide a basis for flexible classification of arbitrary speech sounds
Spacelab mission dependent training parametric resource requirements study
Training flows were developed for typical missions, resource relationships analyzed, and scheduling optimization algorithms defined. Parametric analyses were performed to study the effect of potential changes in mission model, mission complexity and training time required on the resource quantities required to support training of payload or mission specialists. Typical results of these analyses are presented both in graphic and tabular form
Patello-femoral cartilage damage: patients with grade 4 chondral defects of the patella have increased disability
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