32 research outputs found
A generic tilt-rotor simulation model with parallel implementation
The unique capabilities of the tilt-rotor configuration are generally accepted to provide
significant potential when applied to numerous civil and military operations. A vital
stage in the development of any tilt-rotor design is the simulation of its basic flying
qualities which are essentially defined by the vehicle's response to a range of control
inputs and the trim states it adopts. In order to carry out this simulation satisfactorily,
an accurate generic mathematical model is required, however, the author is unaware of
any existing tilt-rotor simulations which utilise the latest modelling techniques. A
generic tilt-rotor simulation model (GTILT) which includes individual blade modelling
to describe the behaviour of the rotor has been developed during this research.
One of the most significant attributes of individual blade models is that they
portray the oscillatory nature of the forces and moments produced by a lifting rotor.
The resulting trimmed flight path of the vehicle is periodic rather than steady in nature
and consequently existing trimming algorithms, formulated for use with rotor disc
representations, are inappropriate when applied to individual blade simulations. A
specialised trimming algorithm capable of rapidly trimming rotorcraft simulations to a
specified periodic trim state has been developed and incorporated into the GTILT
model.
Individual blade modelling provides a higher level of fidelity than is
possible when using a rotor disc representation but this benefit is obtained at the
expense of computational burden. Hence, most sequential computing facilities are
unable to provide the performance necessary to make such models practical. In order to
reduce computational run-times to an acceptable level GTILT has been parallelised and
implemented on a custom designed transputer network.
GTILT has been configured using XV-IS data in order to investigate the
fidelity of its predicted trim states and vehicle response to a range of control inputs.
During the course of this investigation, the trim algorithm is shown to be robust and
capable of producing rapid convergence to a wide range of trim states. Longitudinal
trims predicted by GTILT are verified against those of the similarly configured Bell
C81 for a range of nacelle incidences and good correlation obtained in all cases. A
qualitative verification of the trim states adopted in turning flight reveals no anomalies
and the results obtained are very encouraging. The dynamic response of the vehicle is
demonstrated to be qualitatively valid when a range of control inputs are applied at
various nacelle incidences with the behaviour of the vehicle being explicable in all
cases
Sleep, stress and compensatory behaviors in Australian nurses and midwives
OBJECTIVE: To describe sleep, stress and compensatory behaviors in nurses and midwives. METHODS: The study included 41 midwives and 21 nurses working in Australian hospitals between 2005 and 2009. Participation was voluntary. All participants recorded on a daily basis their work and sleep hours, levels of stress and exhaustion, caffeine intake and use of sleep aids for a month (1,736 days, 1,002 work shifts). RESULTS: Participants reported moderate to high levels of stress and exhaustion on 20-40% of work days; experienced sleep disruption on more than 50% of work days; struggled to remain awake on 27% of work days; and suffered extreme drowsiness or experienced a near accident while travelling home on 9% of workdays. Age, perceived sleep duration and work hours were significant predictors of caffeine intake. About 60% of participants reported using sleep aids (about 20% reported taking prescription medications and 44% of nurses and 9% of midwives reported alcohol use as a sleep aid at least once during the study). Stress and workdays were significant predictors of sedative use. Overall, 22% reported being indifferent or mildly dissatisfied with their job. CONCLUSIONS: Sleep problems, high levels of stress and exhaustion and low job satisfaction are prevalent among nurses and midwives. The use of alcohol and sleeping pills as sleep aids, and the use of caffeine to help maintain alertness is also common. Nurses and midwives may use caffeine to compensate for reduced sleep, especially on workdays, and sleeping pills to cope with their daily work-related stress
Declining Sleep Quality among Nurses: A Population-Based Four-Year Longitudinal Study on the Transition from Nursing Education to Working Life
Background: Several studies have established impaired sleep is a common problem among nurses. Overworked, fatigued and stressed nurses are at a higher risk of making mistakes that threaten patient safety as well as their own health. The aim of the present study was to longitudinally monitor the development of sleep quality in nurses, starting from the last semester at the university, with three subsequent annual follow-ups once the nurses had entered working life. Methodology/Principal Findings: Nationwide, longitudinal questionnaire study of nursing students and newly qualified nurses in Sweden. The results imply a continuous decline in sleep quality among nurses during the three years of follow-up, starting from their last semester of nursing education and continuing for three years into their working life. The most pronounced short-term decline in sleep quality seems to occur in the transition between student life and working life. Conclusion/Significance: This finding is important since it may affect the quality of care and the health of nurses negatively
Visualization and Identification of IL-7 Producing Cells in Reporter Mice
Interleukin-7 (IL-7) is required for lymphocyte development and homeostasis although the actual sites of IL-7 production have never been clearly identified. We produced a bacterial artificial chromosome (BAC) transgenic mouse expressing ECFP in the Il7 locus. The construct lacked a signal peptide and ECFP (enhanced cyan fluorescent protein ) accumulated inside IL-7-producing stromal cells in thoracic thymus, cervical thymus and bone marrow. In thymus, an extensive reticular network of IL-7-containing processes extended from cortical and medullary epithelial cells, closely contacting thymocytes. Central memory CD8 T cells, which require IL-7 and home to bone marrow, physically associated with IL-7-producing cells as we demonstrate by intravital imaging
Visualization and Identification of IL-7 Producing Cells in Reporter Mice
Interleukin-7 (IL-7) is required for lymphocyte development and homeostasis although the actual sites of IL-7 production have never been clearly identified. We produced a bacterial artificial chromosome (BAC) transgenic mouse expressing ECFP in the Il7 locus. The construct lacked a signal peptide and ECFP (enhanced cyan fluorescent protein ) accumulated inside IL-7-producing stromal cells in thoracic thymus, cervical thymus and bone marrow. In thymus, an extensive reticular network of IL-7-containing processes extended from cortical and medullary epithelial cells, closely contacting thymocytes. Central memory CD8 T cells, which require IL-7 and home to bone marrow, physically associated with IL-7-producing cells as we demonstrate by intravital imaging
Localized-Statistical Quantification of Human Serum Proteome Associated with Type 2 Diabetes
BACKGROUND: Recent advances in proteomics have shed light to discover serum proteins or peptides as biomarkers for tracking the progression of diabetes as well as understanding molecular mechanisms of the disease. RESULTS: In this work, human serum of non-diabetic and diabetic cohorts was analyzed by proteomic approach. To analyze total 1377 high-confident serum-proteins, we developed a computing strategy called localized statistics of protein abundance distribution (LSPAD) to calculate a significant bias of a particular protein-abundance between these two cohorts. As a result, 68 proteins were found significantly over-represented in the diabetic serum (p<0.01). In addition, a pathway-associated analysis was developed to obtain the overall pathway bias associated with type 2 diabetes, from which the significant over-representation of complement system associated with type 2 diabetes was uncovered. Moreover, an up-stream activator of complement pathway, ficolin-3, was observed over-represented in the serum of type 2 diabetic patients, which was further validated with statistic significance (p = 0.012) with more clinical samples. CONCLUSIONS: The developed LSPAD approach is well fit for analyzing proteomic data derived from biological complex systems such as plasma proteome. With LSPAD, we disclosed the comprehensive distribution of the proteins associated with diabetes in different abundance levels and the involvement of ficolin-related complement activation in diabetes
Reading Bronson from deep on the inside: An exploration of prisoners watching prison films
This chapter reports on a small scale project screening contemporary British prison films to people serving sentences in British prisons. In particular, this will focus on one of the films, Bronson (UK 2008, Dir. Nicolas Winding Refn), a stylized biography of notorious British prisoner, Charles Bronson. The chapter will set out the theoretical groundwork regarding the representation of prisons in the media and its effects upon society and individuals. It will go on to explain the methodology of the study and summarise the narrative of the film before exploring the responses of the audience. The responses particularly focus on issues of power, resistance and hope. The chapter concludes with a discussion of the consumption of prison media by prisoners and its implications for individuals and social control