Data for guidance.

Thesis (M.S.

Space Station Freedom automation and robotics: An assessment of the potential for increased productivity

This report presents the results of a study performed in support of the Space Station Freedom Advanced Development Program, under the sponsorship of the Space Station Engineering (Code MT), Office of Space Flight. The study consisted of the collection, compilation, and analysis of lessons learned, crew time requirements, and other factors influencing the application of advanced automation and robotics, with emphasis on potential improvements in productivity. The lessons learned data collected were based primarily on Skylab, Spacelab, and other Space Shuttle experiences, consisting principally of interviews with current and former crew members and other NASA personnel with relevant experience. The objectives of this report are to present a summary of this data and its analysis, and to present conclusions regarding promising areas for the application of advanced automation and robotics technology to the Space Station Freedom and the potential benefits in terms of increased productivity. In this study, primary emphasis was placed on advanced automation technology because of its fairly extensive utilization within private industry including the aerospace sector. In contrast, other than the Remote Manipulator System (RMS), there has been relatively limited experience with advanced robotics technology applicable to the Space Station. This report should be used as a guide and is not intended to be used as a substitute for official Astronaut Office crew positions on specific issues

Statistical analysis of congestion in road traffic at an intersection

The problem considered is that of delays caused to vehicles on a major two-lane road at its intersection with a minor road. There are no traffic lights or policemen at the intersection and delays are assumed to occur purely as a result of right-turning traffic (where left-hand-drive is the convention observed). A survey of literature relevant to this problem is made in Chapter 1. In Chapters 2, 3, 4 mathematical models of increasing complexity are proposed as idealisations of the actual situation. These models are constructed with the aims of simplicity and realism in view, so that a valid mathematical analysis of the steady-state behaviouir of each may be made. The models are based on such simplifications as the replacement of vehicles by geometrical points, the generation of vehicle arrivals by a Poisson process, and rules for the interaction of vehicles at the intersection which, although probably unrealistic in model I, may provide a reasonable picture of actual behaviour in model III. The distributions of delay to vehicles is determined under the assumptions of each of models I - III, and programmes were constructed to calculate numerical values for certain aspects of these distributions. Chapter 5 is concerned with the assessment of these models, particularly model III, against observations. The observations are described and their limitations discussed. The parameters defining model III are estimated, and the goodness-of-fit of model III to the data is considered. A comparison of model III with model I is attempted. The tentative conclusion is reached that on the basis of the data available model III may provide an adequately realistic picture of vehicle behaviour. In a final chapter some practical applications of the work are briefly considered, and further related problems are described

Probing the Evaporation Dynamics of Ethanol/Gasoline Biofuel Blends Using Single Droplet Manipulation Techniques

Peer reviewedPublisher PD

Learning from microarray interlaboratory studies: measures of precision for gene expression

<p>Abstract</p> <p>Background</p> <p>The ability to demonstrate the reproducibility of gene expression microarray results is a critical consideration for the use of microarray technology in clinical applications. While studies have asserted that microarray data can be "highly reproducible" under given conditions, there is little ability to quantitatively compare amongst the various metrics and terminology used to characterize and express measurement performance. Use of standardized conceptual tools can greatly facilitate communication among the user, developer, and regulator stakeholders of the microarray community. While shaped by less highly multiplexed systems, measurement science (metrology) is devoted to establishing a coherent and internationally recognized vocabulary and quantitative practice for the characterization of measurement processes.</p> <p>Results</p> <p>The two independent aspects of the metrological concept of "accuracy" are "trueness" (closeness of a measurement to an accepted reference value) and "precision" (the closeness of measurement results to each other). A carefully designed collaborative study enables estimation of a variety of gene expression measurement precision metrics: repeatability, several flavors of intermediate precision, and reproducibility. The three 2004 Expression Analysis Pilot Proficiency Test collaborative studies, each with 13 to 16 participants, provide triplicate microarray measurements on each of two reference RNA pools. Using and modestly extending the consensus ISO 5725 documentary standard, we evaluate the metrological precision figures of merit for individual microarray signal measurement, building from calculations appropriate to single measurement processes, such as technical replicate expression values for individual probes on a microarray, to the estimation and display of precision functions representing all of the probes in a given platform.</p> <p>Conclusion</p> <p>With only modest extensions, the established metrological framework can be fruitfully used to characterize the measurement performance of microarray and other highly multiplexed systems. Precision functions, summarizing routine precision metrics estimated from appropriately repeated measurements of one or more reference materials as functions of signal level, are demonstrated and merit further development for characterizing measurement platforms, monitoring changes in measurement system performance, and comparing performance among laboratories or analysts.</p

Response of angina and ischemia to long-term treatment in patients with chronic stable angina: A double-blind randomised individualized dosing trial of nifedipine, propranolol and their combination

AbstractSeventy-four patients with chronic stable mild angina, mild coronary artery disease (83% had one- or two-vessel disease) and normal left ventricular function were studied to measure the response of treadmill exercise performance and painful and silent ischemia in the ambulatory setting to randomly assigned treatment with nifedipine or propranolol and their combination; titration to maximal tolerated dosages was performed in doubleblind manner.At 3 months both nifedipine and propranolol reduced the weekly angina rate (p < 0.05); during treadmill exercise testing, increases (p < 0.05) were noted in time to angina and total exercise time and decreases in maximal ST depression at the end of exercise. There were no differences between the responses to nifedipine and propranolol and no significant additional changes were seen after another 3 months of therapy. The combination of nifedipine and propranolol reduced the number of patients with angina on exercise treadmill testing from 64% to 38% (p < 0.05).During ambulatory electrocardiographic monitoring before treatment, there were 1.4 ± 2.4 (mean ± SD) episodes/24 h of painful ischemia and a very low silent ischemia frequency: mean 1.1 ± 2.7 episodes/24 h, mean duration 16 ± 25 min/24 h. Treatment with propranolol and nifedipine resulted in reduction of episodes and duration of painful and painless ischemia; approximately 77% of patients were free of all ischemic episodes.It is concluded that patients with chronic stable mild angina have a low incidence of silent ischemia. Nifedipine or propranolol alone, titrated to individualized maximally tolerated dosages, are equally effective in long-term control of painful and painless ischemia, anginal episodes and exercise-induced ischemia. Combination therapy further reduced only exercise-induced angina and maximal exercise-induced ST depression

Places and people: the perceptions of men who have sex with men concerning STI testing: a qualitative study.

OBJECTIVES: To explore the experiences and views of men who have sex with men (MSM) on attending clinical sexual health services and their preferences regarding service characteristics in the context of the disproportionate burden of STIs experienced by this group. The wider study aim was to develop a risk assessment tool for use in sexual health clinics. METHODS: Qualitative study comprising eight focus group discussions with 61 MSM in four English cities. Topics included: experience of attending sexual health services, perceptions of norms of attendance among MSM, knowledge of, and attitudes towards, STIs and views on 'being researched.' Discussions were audio-recorded and transcribed and a thematic data analysis conducted. RESULTS: Attending sexual health services for STI testing was described as embarrassing by some and some clinic procedures were thought to compromise confidentiality. Young men seeking STI testing were particularly sensitive to feelings of awkwardness and self-consciousness. Black and ethnic minority men were concerned about being exposed in their communities. The personal qualities of staff were seen as key features of sexual health services. Participants wanted staff to be friendly, professional, discreet, knowledgeable and non-judgemental. CONCLUSIONS: A range of opinion on the type of STI service men preferred was expressed with some favouring generic sexual and reproductive health clinics and others favouring specialist community-based services. There was consensus on the qualities they would like to see in healthcare staff. The knowledge, conduct and demeanour of staff could exacerbate or ameliorate unease associated with attending for STI testing

The Acceptability and Feasibility of Implementing a Bio-Behavioral Enhanced Surveillance Tool for Sexually Transmitted Infections in England: Mixed-Methods Study.

BACKGROUND: Sexually transmitted infection (STI) surveillance is vital for tracking the scale and pattern of epidemics; however, it often lacks data on the underlying drivers of STIs. OBJECTIVE: This study aimed to assess the acceptability and feasibility of implementing a bio-behavioral enhanced surveillance tool, comprising a self-administered Web-based survey among sexual health clinic attendees, as well as linking this to their electronic health records (EHR) held in England's national STI surveillance system. METHODS: Staff from 19 purposively selected sexual health clinics across England and men who have sex with men and black Caribbeans, because of high STI burden among these groups, were interviewed to assess the acceptability of the proposed bio-behavioral enhanced surveillance tool. Subsequently, sexual health clinic staff invited all attendees to complete a Web-based survey on drivers of STI risk using a study tablet or participants' own digital device. They recorded the number of attendees invited and participants' clinic numbers, which were used to link survey data to the EHR. Participants' online consent was obtained, separately for survey participation and linkage. In postimplementation phase, sexual health clinic staff were reinterviewed to assess the feasibility of implementing the bio-behavioral enhanced surveillance tool. Acceptability and feasibility of implementing the bio-behavioral enhanced surveillance tool were assessed by analyzing these qualitative and quantitative data. RESULTS: Prior to implementation of the bio-behavioral enhanced surveillance tool, sexual health clinic staff and attendees emphasized the importance of free internet/Wi-Fi access, confidentiality, and anonymity for increasing the acceptability of the bio-behavioral enhanced surveillance tool among attendees. Implementation of the bio-behavioral enhanced surveillance tool across sexual health clinics varied considerably and was influenced by sexual health clinics' culture of prioritization of research and innovation and availability of resources for implementing the surveys. Of the 7367 attendees invited, 85.28% (6283) agreed to participate. Of these, 72.97% (4585/6283) consented to participate in the survey, and 70.62% (4437/6283) were eligible and completed it. Of these, 91.19% (4046/4437) consented to EHR linkage, which did not differ by age or gender but was higher among gay/bisexual men than heterosexual men (95.50%, 722/756 vs 88.31%, 1073/1215; P<.003) and lower among black Caribbeans than white participants (87.25%, 568/651 vs 93.89%, 2181/2323; P<.002). Linkage was achieved for 88.88% (3596/4046) of consenting participants. CONCLUSIONS: Implementing a bio-behavioral enhanced surveillance tool in sexual health clinics was feasible and acceptable to staff and groups at STI risk; however, ensuring participants' confidentiality and anonymity and availability of resources is vital. Bio-behavioral enhanced surveillance tools could enable timely collection of detailed behavioral data for effective commissioning of sexual health services

Transient and steady state creep response of ice I and magnesium sulfate hydrate eutectic aggregates

Using uniaxial compression creep experiments, we characterized the transient and steady state deformation behaviors of eutectic aggregates of system ice I and MgSO4 • 11H2O (MS11; meridianiite), which has significance because of its likely presence on moons of the outer solar system. Synthetic samples of eutectic liquid bulk composition, which produce eutectic colonies containing 0.35–0.50 volume fraction MS11, were tested as functions of colony size and lamellar spacing, temperature (230–250 K), and confining pressure (0.1 and 50 MPa) to strains ≤ 0.2. Up to a differential stress of 6 MPa, the ice I‐MS11 aggregates display an order of magnitude higher effective viscosity and higher stress sensitivity than do aggregates of pure polycrystalline ice at the same conditions. The creep data and associated microstructural observations demonstrate, however, that the aggregates are additionally more brittle than pure ice, approaching rate‐independent plasticity that includes rupture of the hydrate phase at 6–8 MPa, depending on the scale of the microstructure. Microstructures of deformed samples reveal forms of semibrittle flow in which the hydrate phase fractures while the ice phase deforms plastically. Semibrittle flow in the icy shell of a planetary body would truncate the lithospheric strength envelope and thereby decrease the depth to the brittle‐ductile transition by 55% and reduce the failure limit for compressional surface features from 10 to ∼6 MPa. A constitutive equation that includes eutectic colony boundary sliding and intracolony flow is used to describe the steady state rheology of the eutectic aggregates