Performance of differenced range data types in Voyager navigation

Voyager radio navigation made use of a differenced rage data type for both Saturn encounters because of the low declination singularity of Doppler data. Nearly simultaneous two-way range from two-station baselines was explicitly differenced to produce this data type. Concurrently, a differential VLBI data type (DDOR), utilizing doubly differenced quasar-spacecraft delays, with potentially higher precision was demonstrated. Performance of these data types is investigated on the Jupiter-to-Saturn leg of Voyager 2. The statistics of performance are presented in terms of actual data noise comparisons and sample orbit estimates. Use of DDOR as a primary data type for navigation to Uranus is discussed

Tracking mortality in near to real time provides essential information about the impact of the COVID-19 pandemic in South Africa in 2020

Background. Producing timely and accurate estimates of the impact of COVID-19 on mortality is challenging for most countries, but impossible for South Africa (SA) from cause-of-death statistics. Objectives. To quantify the excess deaths and likely magnitude of COVID-19 in SA in 2020 and draw conclusions on monitoring the epidemic in 2021. Methods. Basic details of deaths registered on the National Population Register by the Department of Home Affairs (DoHA) are provided to the South African Medical Research Council weekly. Adjustments are made to the numbers of weekly deaths to account for non-registration on the population register, as well as late registration of death with the DoHA. The weekly number of deaths is compared with the number predicted based on the Holt-Winters time-series analysis of past deaths for provinces and metropolitan areas. Excess deaths were calculated for all-causes deaths and natural deaths, using the predicted deaths as a baseline. In addition, an adjustment was made to the baseline for natural deaths to account for the drop in natural deaths due to lockdown. Results. We estimated that just over 550 000 deaths occurred among persons aged ≥1 year during 2020, 13% higher than the 485 000 predicted before the pandemic. A pronounced increase in weekly deaths from natural causes peaked in the middle of July across all ages except <20 years, and across all provinces with slightly different timing. During December, it became clear that SA was experiencing a second wave of COVID-19 that would exceed the death toll of the first wave. In 2020, there were 70 000 - 76 000 excess deaths from natural causes, depending on the base. Using the adjusted base, the excess death rate from natural causes was 122 per 100 000 population, with a male-to-female ratio of 0.78. Deaths from unnatural causes halved for both males and females during the stringent lockdown level 5. The numbers reverted towards the predicted number with some fluctuations as lockdown restrictions varied. Just under 5 000 unnatural deaths were averted. Conclusions. Tracking the weekly numbers of deaths in near to real time has provided important information about the spatiotemporal impact of the pandemic and highlights that the ~28 000 reported COVID-19 deaths during 2020 substantially understate the death toll from COVID-19. There is an urgent need to re-engineer the system of collecting and processing cause-of-death information so that it can be accessed in a timely way to inform public health actions

Issues in public health: Unnatural deaths, alcohol bans and curfews: Evidence from a quasi-natural experiment during COVID-19

Background. Coronavirus disease-19 (COVID-19) restrictions, particularly relating to the sale of alcohol and hours of curfew, have had a marked effect on the temporal pattern of unnatural deaths in South Africa. Methods. Death data were collected over 68 weeks from January 2020 to April 2021, together with information on the nature of restrictions (if any) on the sale of alcohol, and hours of curfew. Data were analysed using a simple ordinary least square (OLS) regression model to estimate the relative contribution of restrictions on the sale of alcohol and hours of curfew to the pattern of excess unnatural deaths. Results. The complete restriction on the sale of alcohol resulted in a statistically significant reduction in unnatural deaths regardless of the length of curfew. To the contrary, periods where no or limited restrictions on alcohol were in force had no significant effect, or resulted in significantly increased unnatural deaths. Conclusion. The present study highlights an association between alcohol availability and the number of unnatural deaths and demonstrates the extent to which those deaths might be averted by disrupting the alcohol supply. While this is not a long-term solution to addressing alcohol-related harm, it further raises the importance of implementing evidence-based alcohol control measures

Need for timely paediatric HIV treatment within primary health care in rural South Africa

<p>Background: In areas where adult HIV prevalence has reached hyperendemic levels, many infants remain at risk of acquiring HIV infection. Timely access to care and treatment for HIV-infected infants and young children remains an important challenge. We explore the extent to which public sector roll-out has met the estimated need for paediatric treatment in a rural South African setting.</p> <p>Methods: Local facility and population-based data were used to compare the number of HIV infected children accessing HAART before 2008, with estimates of those in need of treatment from a deterministic modeling approach. The impact of programmatic improvements on estimated numbers of children in need of treatment was assessed in sensitivity analyses.</p> <p>Findings: In the primary health care programme of HIV treatment 346 children <16 years of age initiated HAART by 2008; 245(70.8%) were aged 10 years or younger, and only 2(<1%) under one year of age. Deterministic modeling predicted 2,561 HIV infected children aged 10 or younger to be alive within the area, of whom at least 521(20.3%) would have required immediate treatment. Were extended PMTCT uptake to reach 100% coverage, the annual number of infected infants could be reduced by 49.2%.</p> <p>Conclusion: Despite progress in delivering decentralized HIV services to a rural sub-district in South Africa, substantial unmet need for treatment remains. In a local setting, very few children were initiated on treatment under 1 year of age and steps have now been taken to successfully improve early diagnosis and referral of infected infants.</p&gt

Pharmacokinetics and safety of rifabutin in young HIV-infected children receiving rifabutin and lopinavir/ritonavir

ObjectivesCo-treatment of HIV and TB in young children is complicated by limited treatment options and complex drug–drug interactions. Rifabutin is an alternative to rifampicin for adults receiving a ritonavir-boosted PI. We aimed to evaluate the short-term safety and pharmacokinetics of rifabutin when given with lopinavir/ritonavir in children.Patients and methodsWe conducted an open-label study of rifabutin dosed at 5 mg/kg three times a week in HIV-infected children ≤5 years of age receiving lopinavir/ritonavir. Intensive steady-state pharmacokinetic sampling was conducted after six doses. The Division of AIDS 2004, clarification 2009, table for grading severity of adverse events was used to classify drug toxicities. The study was registered with ClinicalTrials.gov, number NCT01259219.ResultsSix children completed the study prior to closure by institutional review boards. The median (range) AUC0–48 of rifabutin was 6.91 (3.52–8.67) μg · h/mL, the median (range) Cmax of rifabutin was 0.39 (0.19–0.46) μg/mL, the median (range) AUC0–48 of 25-O-desacetyl rifabutin was 5.73 (2.85–9.13) μg · h/mL and the median (range) Cmax of 25-O-desacetyl rifabutin was 0.17 (0.08–0.32) μg/mL. The neutrophil count declined in all children; two children experienced grade 4 neutropenia, which resolved rapidly without complications. There was strong correlation between AUC0–48 measures and neutrophil counts.ConclusionsRifabutin dosed at 5 mg/kg three times per week resulted in lower AUC0–48, AUC0–24 and Cmax values for rifabutin and 25-O-desacetyl rifabutin compared with adults receiving 150 mg of rifabutin daily, the current recommended dose. We observed high rates of severe transient neutropenia, possibly due to immaturity of CYP3A4 in young children. It remains unclear whether a safe and effective rifabutin dose exists for treatment of TB in children receiving lopinavir/ritonavir

Flexible electronics: The next ubiquitous platform

Thin-film electronics in its myriad forms has underpinned much of the technological innovation in the fields of displays, sensors, and energy conversion over the past four decades. This technology also forms the basis of flexible electronics. Here we review the current status of flexible electronics and attempt to predict the future promise of these pervading technologies in healthcare, environmental monitoring, displays and human-machine interactivity, energy conversion, management and storage, and communication and wireless networks

Managing by design

This editorial written by myself and Marc Gruber of EPFL. It explores the role of design thinking in the management of large organisations, and focuses on how design principles can be applied to the design of the workplace and the nature of work itself. As Head of Service Design at the RCA, my contribution is on how to apply design thinking methods for managers and the 6 key elements described in this approach In the last decade the importance of design and the value of design thinking as a tool for innovation has been recognized by both business and government. Design has become a strategic tool for business helping to translate technological innovation into user value, connecting with consumer needs and creating compelling product and service experiences that create new business value. In this paper we consider a further application of design thinking by considering how managers can apply it to the design of the workplace experience. Many enterprises, especially those in the knowledge economy, are defined by their human resources and their capacity to attract and retain talent. In this competitive environment the design of the employee experience and the services that support them and enable them to deliver value to the clients and colleagues, is a key differentiator. Applying design thinking to the design of work itself, the systems that support it, and the physical and virtual environments in which it takes place can help business and organizational leaders to attract and retain top talent, as well as to enhance productivity and operational effectiveness. In this paper we explore the key factors and principles by which leaders and managers can apply design thinking to transform the workplace experience and we propose 6 key elements for managers to enable that transformation and enhance social capital and business and organisational performance

The epidemiological transition in Antananarivo, Madagascar: an assessment based on death registers (1900–2012)

Background: Madagascar today has one of the highest life expectancies in sub-Saharan Africa, despite being among the poorest countries in the continent. There are relatively few detailed accounts of the epidemiological transition in this country due to the lack of a comprehensive death registration system at the national level. However, in Madagascar's capital city, death registration was established around the start of the 20th century and is now considered virtually complete. Objective: We provide an overview of trends in all-cause and cause-specific mortality in Antananarivo to document the timing and pace of the mortality decline and the changes in the cause-of-death structure. Design: Death registers covering the period 1976–2012 were digitized and the population at risk of dying was estimated from available censuses and surveys. Trends for the period 1900–1976 were partly reconstructed from published sources. Results: The crude death rate stagnated around 30‰ until the 1940s in Antananarivo. Mortality declined rapidly after the World War II and then resurged again in the 1980s as a result of the re-emergence of malaria and the collapse of Madagascar's economy. Over the past 30 years, impressive gains in life expectancy have been registered thanks to the unabated decline in child mortality, despite political instability, a lasting economic crisis and the persistence of high rates of chronic malnutrition. Progress in adult survival has been more modest because reductions in infectious diseases and diseases of the respiratory system have been partly offset by increases in cardiovascular diseases, neoplasms, and other diseases, particularly at age 50 years and over. Conclusions: The transition in Antananarivo has been protracted and largely dependent on anti-microbial and anti-parasitic medicine. The capital city now faces a double burden of communicable and non-communicable diseases. The ongoing registration of deaths in the capital generates a unique database to evaluate the performance of the health system and measure intervention impacts