Characterization of a small helicopter UAV’s main rotor blade through Image Processing

Abstract: Image processing is applied to the task of characterizing the response of a miniature helicopter’s main rotor to collective control inputs under static conditions. The objective is to measure the pitch of the main rotor blade in relation to collective control inputs and deduce a transfer function model from the data..

Assessing a portable, real-time display handheld meter with UV-A and UV-B sensors for potential application in personal sun exposure studies

BACKGROUND : Observing accurate real-time measurements of solar ultraviolet radiation (UVR) levels is important since personal excess sun exposure is associated with skin cancers. Handheld measurement devices may be helpful but their accuracy is unknown. We compare a portable, science-grade solar UVR monitoring device against two fixed, science-grade solar UVR instruments. METHODS : Instruments were (1) a fixed Solar Light 501 UV-B biometer to measure UV-B; (2) a fixed Kipp and Zonen radiometer used to measure UV-A and UV-B; and (3) Goldilux ultraviolet probes which are commercially available portable devices. Two different probes were used, one measured UV-A and the other UV-B radiation. The Goldilux probes were levelled and secured next to the UV-B biometer. Between 10:00 and 14:40 UTC+2, the UV-B biometer was set to record at 10-minute intervals and measurements by the Goldilux probes were manually taken simultaneously. Results were compared for all data and by solar zenith angle (SZA) ranges. RESULTS : The Goldilux UV-B probe measured UV-B relatively well in its diurnal pattern, however, its readings were ~77% higher than those made by the UV-B biometer. While UV-A measurements from the Goldilux UV-A probe and those from the radiometer were in relatively good agreement in pattern, the radiometer read ~47% higher than the Goldilux UV-A probe. UV-B data from Goldilux UV-B probe had a moderately strong correlation with UV-B biometer data for small SZAs; conversely, for UV-A, the Goldilux UV-A probe had a strong correlation with the UV-A radiometer data for large SZAs. CONCLUSION : Handheld devices may be useful to provide real-time readings of solar UVR patterns, however, to achieve synchronicity in the magnitude of readings to those made by science-grade fixed instruments, devices may need to be used during certain times of the day and in clear-sky conditions which may not be practical in personal exposure studies.Dr Wright receives funding support from the South African Medical Research Council and the National Research Foundation of South Africa.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1600-08462019-11-01hj2019Geography, Geoinformatics and Meteorolog

Enforcement and effectiveness of consumer law in South Africa

This chapter discusses and evaluates the enforcement and effectiveness of Consumer Law in South Africa. It first provides the principal legal and policy framework, including the legislation and common law and consumer policy and strategic plans of the governmental authorities and enforcement agencies. It sets out details and some statistics regarding enforcement by specialised enforcement agencies, such as the National Consumer Commission, the National Credit Regulator and provincial consumer protection authorities. Alternative dispute resolution actors are discussed, including ombuds enforcing the Consumer Protection Act and ombuds in the financial services sector. Thereafter enforcement by the courts are considered, as well as enforcement through collective redress. The role of consumer organisations and private regulation are discussed, as well as sanctions for breaches of consumer law. External relations and cooperation of the State, enforcers and consumer organisations with bodies external to South Africa are considered. Finally, the effectiveness of the enforcement mechanisms is critically evaluated and some proposals for reform made

Inequalities in early marriage, childbearing and sexual debut among adolescents in sub-Saharan Africa

Background: Adolescent sexual and reproductive health (ASRH) is a major public health concern in sub-Saharan Africa (SSA). However, inequalities in ASRH have received less attention than many other public health priority areas, in part due to limited data. In this study, we examine inequalities in key ASRH indicators. Methods: We analyzed national household surveys from 37 countries in SSA, conducted during 1990–2018, to exam- ine trends and inequalities in adolescent behaviors related to early marriage, childbearing and sexual debut among adolescents using data from respondents 15–24 years. Survival analyses were conducted on each survey to obtain estimates for the ASRH indicators. Multilevel linear regression modelling was used to obtain estimates for 2000 and 2015 in four subregions of SSA for all indicators, disaggregated by sex, age, household wealth, urban–rural residence and educational status (primary or less versus secondary or higher education). Results: In 2015, 28% of adolescent girls in SSA were married before age 18, declined at an average annual rate of 1.5% during 2000–2015, while 47% of girls gave birth before age 20, declining at 0.6% per year. Child marriage was rare for boys (2.5%). About 54% and 43% of girls and boys, respectively, had their sexual debut before 18. The declines were greater for the indicators of early adolescence (10–14 years). Large differences in marriage and childbearing were observed between adolescent girls from rural versus urban areas and the poorest versus richest households, with much greater inequalities observed in West and Central Africa where the prevalence was highest. The urban– rural and wealth-related inequalities remained stagnant or widened during 2000–2015, as the decline was relatively slower among rural and the poorest compared to urban and the richest girls. The prevalence of the ASRH indicators did not decline or increase in either education categories. Conclusion: Early marriage, childbearing and sexual debut declined in SSA but the 2015 levels were still high, especially in Central and West Africa, and inequalities persisted or became larger. In particular, rural, less educated and poorest adolescent girls continued to face higher ASRH risks and vulnerabilities. Greater attention to disparities in ASRH is needed for better targeting of interventions and monitoring of progress

The impact of health programmes to prevent vertical transmission of HIV. Advances, emerging health challenges and research priorities for children exposed to or living with HIV: Perspectives from South Africa

Over the past three decades, tremendous global progress in preventing and treating paediatric HIV infection has been achieved. This paper highlights the emerging health challenges of HIV-exposed uninfected (HEU) children and the ageing population of children living with HIV (CLHIV), summarises programmatic opportunities for care, and highlights currently conducted research and remaining research priorities in high HIV-prevalence settings such as South Africa. Emerging health challenges amongst HEU children and CLHIV include preterm delivery, suboptimal growth, neurodevelopmental delay, mental health challenges, infectious disease morbidity and mortality, and acute and chronic respiratory illnesses including tuberculosis, pneumonia, bronchiectasis and lymphocytic interstitial pneumonitis. CLHIV and HEU children require three different categories of care: (i) optimal routine child health services applicable to all children; (ii) routine care currently provided to all HEU children and CLHIV, such as HIV testing or viral load monitoring, respectively, and (iii) additional care for CLHIV and HEU children who may have growth, neurodevelopmental, behavioural, cognitive or other deficits such as chronic lung disease, and require varying degrees of specialised care. However, the translation thereof into practice has been hampered by various systemic challenges, including shortages of trained healthcare staff, suboptimal use of the patient-held child’s Road to Health book for screening and referral purposes, inadequate numbers and distribution of therapeutic staff, and shortages of assistive/diagnostic devices, where required. Additionally, in low-middle-income high HIV-prevalence settings, there is a lack of evidence-based solutions/models of care to optimise health amongst HEU and CLHIV. Current research priorities include understanding the mechanisms of preterm birth in women living with HIV to optimise preventive interventions; establishing pregnancy pharmacovigilance systems to understand the short-, medium- and long-term impact of in utero ART and HIV exposure; understanding the role of preconception maternal ART on HEU child infectious morbidity and long-term growth and neurodevelopmental trajectories in HEU children and CLHIV, understanding mental health outcomes and support required in HEU children and CLHIV through childhood and adolescence; monitoring HEU child morbidity and mortality compared with HIV-unexposed children; monitoring outcomes of CLHIV who initiated ART very early in life, sometimes with suboptimal ART regimens owing to medication formulation and registration issues; and testing sustainable models of care for HEU children and CLHIV including later reproductive care and support

Conservation laws for vacuum tetrad gravity

Ten conservation laws in useful polynomial form are derived from a Cartan form and Exterior Differential System (EDS) for the tetrad equations of vacuum relativity. The Noether construction of conservation laws for well posed EDS is introduced first, and an illustration given, deriving 15 conservation laws of the free field Maxwell Equations from symmetries of its EDS. The Maxwell EDS and tetrad gravity EDS have parallel structures, with their numbers of dependent variables, numbers of generating 2-forms and generating 3-forms, and Cartan character tables all in the ratio of 1 to 4. They have 10 corresponding symmetries with the same Lorentz algebra, and 10 corresponding conservation laws.Comment: Final version with additional reference

The practices of apartheid as a war crime: a critical analysis

The human suffering caused by the political ideology of apartheid in South Africa during the Apartheid era (1948-1994) prompted worldwide condemnation and a variety of diplomatic and legal responses. Amongst these responses was the attempt to have apartheid recognised both as a crime against humanity in the 1973 Apartheid Convention as well as a war crime in Article 85(4)(c) of Additional Protocol I. This article examines the origins, nature and current status of the practices of apartheid as a war crime and its possible application to the Israeli-Palestinian conflict

Programmable medicine: Autonomous, ingestible, deployable hydrogel patch and plug for stomach ulcer therapy

Gastric ulcer is a chronic and complex (and often complete) erosion of the stomach wall that happens as a complication of a previous chronic, inflammatory process. It represents a catastrophic situation in which the patient is critical and its conditions need to be treated fast. This study presents a remotely navigatable and deployable ingestible patch and plug for gastric ulcer treatment. The patch/plug structure is made of agarose hydrogel that can change rigidity through hydration and dehydration. When dehydrated, it is rigid and can maintain a folded configuration so it can be ingested as a “pill”. This can be guided to the targeted location by a magnetic field, and be deployed instantly by hydration, namely by supplying water from the mouth. Due to the deployable origami design, it exhibits an expansion of 10 times its initial surface area, making the device suitable for the use of dressing a surface as a patch, and filling a hole as a plug