Data Compression for Space Missions

For many space missions , the ability of spacecraft sensors to acquire meaningful data may surpass to a considerable extent the ability of the telemetry system to transmit this data to earth. It is often possible , however, to receive at the Earth a large portion of the sensed data by preprocessing or compressing the data before transmission in order to remove redundancy or useless information. This paper discusses data compression as applied to space missions. Since the usefulness and form of data compression is dependent to some extent on the particular space mission under consideration, certain general classifications of space missions are considered in light of their amenability to data compression. Some basic compression techniques are applied to example sets of data, and the results show that a rather small increase in onboard data processing can result in a severalfold increase in the amount of data transmitted to Earth. The compression procedures used are limited to those easily implemented by the unsophisticated but highly reliable data processing equipment likely to be present on future spacecraft. Curves are developed showing the compression ratio of various techniques as a function of allowable approximation error and complexity of mechanization. Data compression relationships as functions of reliability are also presented, where reliability is related to the loss of data per bit error in transmission. This analysis shows that certain tradeoffs exist since , in general , higher compression ratios are obtained at the expense of less accurate data representation, more complex implementation, and higher loss of data per bit error in transmission

Changing Autonomy in Operative Experience Through UK General Surgery Training:A National Cohort Study

Objectives:To determine the operative experience of UK general surgery trainees and assess the changing procedural supervision and acquisition of competency assessments through the course of training.Background Summary Data: Competency assessment is changing with concepts of trainee autonomy decisions (termed entrustment decisions) being introduced to surgical training.Methods: Data from the Intercollegiate Surgical Curriculum Programme (ISCP) and the eLogbook databases for all UK General Surgery trainees registered from 1st August 2007 who had completed training were used. Total and index procedures (IP) were counted and variation by year of training assessed. Recorded supervision codes and competency assessment outcomes for IPs were assessed by year of training.Results: We identified 311 trainees with complete data. Appendicectomy was the most frequently undertaken IP during first year of training (mean procedures (mp) = 26) and emergency laparotomy during final year of training (mp = 27). The proportion of all IPs recorded as unsupervised increased through training (

Time Out of General Surgery Specialty training in the UK:A National Database Study

ObjectiveGeneral surgery specialty training in the United Kingdom takes 6 years and allows trainees to take time out of training. Studies from the United States have highlighted an increasing trend for taking time out of surgical training for research. This study aimed to evaluate trends in time out of training and the impact on the duration of UK general surgical specialty training.Design, setting, and participantsA cohort study using routinely collected surgical training data from the Intercollegiate Surgical Curriculum Program database for General surgery trainees registered from August 1, 2007. Trainees were classified as Completed Training or In-Training. Out of training periods were identified and time in training calculated (both unadjusted and adjusted for out of training periods) with a predicted time in training for those In-Training.ResultsOf the trainees still In-Training (n = 994), a greater proportion had taken time out of training compared with those who had completed training (n = 360; 54.5% vs 45.9%, p < 0.01). A greater proportion of the In-Training group had undertaken a formal research period compared with the Completed Training group (35.1% vs 6.1%, p < 0.01). Total unadjusted training time in the Completed Training group was a median 6.0 (interquartile range 6.0-7.0) years compared with a predicted unadjusted training time in the In-Training group, with an out of training period recorded, of a median 8.0 (interquartile range 7.0-9.0) years.ConclusionsTrainees are increasingly taking time out of surgical training, particularly for research, with a subsequent increase in total time of training. This should be considered when redesigning surgical training programs and planning the future surgical workforce

Can Action Research Strengthen District Health Management and Improve Health Workforce Performance? A Research Protocol.

The single biggest barrier for countries in sub-Saharan Africa (SSA) to scale up the necessary health services for addressing the three health-related Millennium Development Goals and achieving Universal Health Coverage is the lack of an adequate and well-performing health workforce. This deficit needs to be addressed both by training more new health personnel and by improving the performance of the existing and future health workforce. However, efforts have mostly been focused on training new staff and less on improving the performance of the existing health workforce. The purpose of this paper is to disseminate the protocol for the PERFORM project and reflect on the key challenges encountered during the development of this methodology and how they are being overcome. The overall aim of the PERFORM project is to identify ways of strengthening district management in order to address health workforce inadequacies by improving health workforce performance in SSA. The study will take place in three districts each in Ghana, Tanzania and Uganda using an action research approach. With the support of the country research teams, the district health management teams (DHMTs) will lead on planning, implementation, observation, reflection and redefinition of the activities in the study. Taking into account the national and local human resource (HR) and health systems (HS) policies and practices already in place, 'bundles' of HR/HS strategies that are feasible within the context and affordable within the districts' budget will be developed by the DHMTs to strengthen priority areas of health workforce performance. A comparative analysis of the findings from the three districts in each country will add new knowledge on the effects of these HR/HS bundles on DHMT management and workforce performance and the impact of an action research approach on improving the effectiveness of the DHMTs in implementing these interventions. Different challenges were faced during the development of the methodology. These include the changing context in the study districts, competing with other projects and duties for the time of district managers, complexity of the study design, maintaining the anonymity and confidentiality of study participants as well as how to record the processes during the study. We also discuss how these challenges are being addressed. The dissemination of this research protocol is intended to generate interest in the PERFORM project and also stimulate discussion on the use of action research in complex studies such as this on strengthening district health management to improve health workforce performance

Cross-sections for heavy atmospheres: H₂O continuum

Most of the exoplanets detected up to now transit in front of their host stars, allowing for the generation of transmission spectra; the study of exoplanet atmospheres relies heavily upon accurate analysis of these spectra. Recent discoveries mean that the study of atmospheric signals from low-mass, temperate worlds are becoming increasingly common. The observed transit depth in these planets is small and more difficult to analyze. Analysis of simulated transmission spectra for two small, temperate planets (GJ 1214 b and K2-18 b) is presented, giving evidence for significant differences in simulated transit depth when the water vapor continuum is accounted for when compared to models omitting it. These models use cross-sections from the CAVIAR lab experiment for the water self-continuum up to 10,000 cm−1; these cross-sections exhibit an inverse relationship with temperature, hence lower-temperature atmospheres are the most significantly impacted. Including the water continuum strongly affects transit depths, increasing values by up to 60 ppm, with the differences for both planets being detectable with the future space missions Ariel and JWST. It is imperative that models of exoplanet spectra move toward adaptive cross-sections, increasingly optimized for H2O-rich atmospheres. This necessitates including absorption contribution from the water vapor continuum into atmospheric simulations

Effects of a Novel Ground-Based Movement Training Program on Functional Movement, Flexibility, Strength and Endurance

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Lessons from Laparoscopic Liver Surgery: A Nine-Year Case Series

Objective. This series describes a developing experience in laparoscopic liver surgery presenting results from 40 procedures including right hemihepatectomy, left lateral lobectomy, and microwave ablation therapy. Methods. Forty patients undergoing laparoscopic liver surgery between September 1997 and November 2006 were included. The data set includes: operative procedure and duration, intraoperative blood loss, conversion to open operation rates, length of hospital stay, complications, mortality, histology of lesions/resection margins, and disease recurrence. Results. Mean age of patient: 59 years, 17/40 male, 23/40 female, 23/40 of lesions were benign, and 17/40 malignant. Operations included: laparoscopic anatomical resections n = 15, nonanatomical resections n = 11, microwave ablations n = 8 and deroofing of cysts n = 7. Median anaesthetic time: 120 minutes (range 40–240), mean blood loss 78 mL and 1/40 conversions to open. Median resection margins were 10 mm (range 1–14) and median length of stay 3 days (range 1–10). Operative and 30-day mortality were zero with no local disease recurrence. Conclusion. Laparoscopic liver surgery appears safe and effective and is associated with reduced hospital stay. Larger studies are required to confirm it is oncologically sound

Improving the quality of care of children in community clinics: an intervention and evaluation in Bangladesh.

Community health care providers (CHCPs) in 40 rural community clinics of Comilla district, Bangladesh, were trained using a newly developed case-management job aid based on the World Health Organization Integrated Management of Childhood Illness and a communication guide.To assess 1) the change in knowledge of the CHCPs after training; 2) the absolute quality of care provided by the CHCPs (determined as the proportion of children aged <5 years [under-fives] correctly diagnosed, treated and referred); and 3) the consultation behaviour of the CHCPs.Change in knowledge was assessed by tests pre-and post-training. The quality of care was determined by reassessments at the clinic exit by a medical officer, without a baseline comparison. Consultation behaviour was assessed through direct observation. The study was performed during 2014-2015.The mean standard knowledge score of the CH-CPs increased from 19 to 25 (P < 0.001). Of 1490 under-fives examined, 91% were correctly diagnosed, 86% were correctly treated and 99.5% received a correct referral decision. The CHCPs performed well on most of the measures of good communication, although one third did not explain the diagnosis and treatment to patients.The training was effective in changing knowledge. The CHCPs applied the knowledge gained and provided good quality care. Following these results, the Bangladesh Ministry of Health and Family Welfare has scaled up the training nationwide. The lessons learnt should be useful for other countries

Time out of general surgery specialty training in the UK: a national database study

Objective:General surgery specialty training in the UK takes 6 years and allows trainees to take time out of training. Studies from the USA have highlighted an increasing trend for taking time out of surgical training for research. This study aimed to evaluate trends in time out of training and the impact on the duration of UK general surgical specialty training. Design, setting and participants: A cohort study using routinely collected surgical training data from the Intercollegiate Surgical Curriculum Programme (ISCP) database for General Surgery trainees registered from 1st August 2007. Trainees were classified as Completed Training or In-Training. Out of training periods were identified and time in training calculated (both unadjusted and adjusted for out of training periods) with a predicted time in training for those In-Training. Results: Of the trainees still In-Training (n=994), a greater proportion had taken time out of training compared with those who had completed training (n=360) (54.5% vs 45.9%, p<0.01). A greater proportion of the In-Training group had undertaken a formal research period compared to the Completed Training group (35.1% vs 6.1%, p<0.01). Total unadjusted training time in the Completed Training group was a median 6.0 (IQR 6.0- 7.0) years compared with a predicted unadjusted training time in the In-Training group, with an out of training period recorded, of a median 8.0 (IQR 7.0- 9.0) years. Conclusions: Trainees are increasingly taking time out of surgical training, particularly for research, with a subsequent increase in total time of training. This should be considered when redesigning surgical training programmes and planning the future surgical workforce