Induced Subgraphs of Johnson Graphs

The Johnson graph J(n,N) is defined as the graph whose vertices are the n-subsets of the set {1,2,...,N}, where two vertices are adjacent if they share exactly n - 1 elements. Unlike Johnson graphs, induced subgraphs of Johnson graphs (JIS for short) do not seem to have been studied before. We give some necessary conditions and some sufficient conditions for a graph to be JIS, including: in a JIS graph, any two maximal cliques share at most two vertices; all trees, cycles, and complete graphs are JIS; disjoint unions and Cartesian products of JIS graphs are JIS; every JIS graph of order n is an induced subgraph of J(m,2n) for some m <= n. This last result gives an algorithm for deciding if a graph is JIS. We also show that all JIS graphs are edge move distance graphs, but not vice versa.Comment: 12 pages, 4 figure

Verifying data for the implementation of the water release module of the WAS program

Published ArticleThe Water Administration System (WAS) is designed to be a management tool for irrigation schemes and water control offices that want to manage their water accounts and supply water to clients through canal networks, pipelines and rivers. The ultimate aim of WAS is to optimise irrigation water management and minimise management-related distribution losses in irrigation canals. This research projects focused on the implementation of the water release module of the WAS program at the Vaalharts irrigation scheme. The WAS consists of four modules that are integrated into a single program that can be used on a single PC or a multi-user environment. The four modules are an administration module, a water release module, water accounts module and a water request module. The first three modules are already implemented at Vaalharts, while module four is implemented only partially. This module links with the water request module and calculated water releases for the main canal and all its branches allowing for lag times and any water losses and accruals. To precisely calculate this water release, accurate data is needed to ensure that the correct volume of water is released into the canal network. This can be done by verifying existing data with field data. To optimise the management of the irrigation scheme the fully implemented WAS program need to be installed and running at the scheme. A series of data and calculation verifications need to be executed. The exercise will show the adequacy and correctness of the available database WAS uses to do the release calculation from. This will ensure improved management of the irrigation scheme, catchment and water resource sustainability. It is planned that the information generated from this project will be used in the compilation of integrated catchment management information system, currently underway at the Central university of Technology, Free State, South Africa. It is for this reason that all data should be verified, as trustworthy results and service through management can then be offered to the community and irrigation area

South African seed oils are safe for human consumption

Objectives: A diet that is high in fat and low in carbohydrates is advocated in the recently published The Real Meal Revolution. A suggestion was made in this publication that seed oils are toxic. The authors stated that available seed oils on the South African market were high in trans-fatty acid (TFA), as well as being genetically modified, and thus should be avoided. We compared three oils, i.e. canola, sunflower and olive oil, against internationally accepted standards, to determine the quality of these oils using gaschromatographic analysis, to determine whether or not there was any foundation to the statement pertaining to the toxicity of South African seed oils. Reported parameters included the fatty acid profile, TFA content, peroxide level and conjugated diene (CD) content.Design: Samples were purchased from local retail stores. Two independent researchers de-identified the oils, and stored them in numbered containers under nitrogen until commencement of the analysis. Hence, a blind sample of oils was received.Outcome measures: Twelve (n = 12) olive oil, 15 (n = 15) canola oil and 7 (n = 7) sunflower oil samples were subjected to analysis. CD and peroxide levels were conducted spectrophotometrically, and fatty acid content determined by gas liquid chromatography.Results: The total TFA content of the three types of sampled oils was below 0.5%, and the peroxide (meq O2/kg) and CD levels (μmol/g) were within allowable limits, as described in the Codex Standard for Named Vegetable Oils, as well as previous publications.Conclusion: The results demonstrated that the South African seed oils included in this analysis contained a negligible amount of TFA, adhered to international recommendations with respect to fatty acid content, and were well within the safe range for oxidation products. Therefore, the statement that South African seed oils are toxic is inaccurate, unscientific and without merit.Keywords: South Africa, seed oils, canola, sunflower, olive, fatty acid profile, TFA content, peroxide, conjugated diene conten

A church after God’s heart : discerning a missional ecclesiology for the Dutch Reformed Church in South Africa

The research wants to contribute to the development of a missional ecclesiology for the Dutch Reformed Church (DRC) in South Africa. This was done by answering the following two questions: what does the current context of the DRC look like, and is the missional ecclesiology of the church sufficient to guide the church in being a sign, instrument and foretaste of the Kingdom? The research was framed by an analysis of philosophical influences on the development of the DRC, as well as the changes in context since the Reformation. A theological framework was developed that describe the contours of a missional ecclesiology. The framework was formed by analysing the broad ecumenical missional literature; the historical and missiological development of the DRC’s theology; and the fresh expressions movement. This framework was used in evaluating the decisions of the General Synod of the DRC on missional ecclesiology from 1990 until 2013. The research was hermeneutical, correlational, critical and theological, using a literature study as well as a qualitative deductive analysis. This research contributes to the field of missional ecclesiology by: adding a fifth wave of missionary revival to Saayman’s four waves model; developing a theological framework for a missional ecclesiology; evaluating the fresh expressions movement from a Reformed perspective; evaluating the decisions of the General Synod of the DRC on missional ecclesiology; and lastly, suggesting some contours of a missional ecclesiology for the DRC. Although the research is focused on a missional ecclesiology for the DRC, the results may have broader implications for other denominations as well.Thesis(PhD)--University of Pretoria, 2019.Science of Religion and MissiologyPhDUnrestricte

The targeting of nutritionally at-risk children attending a primary health care facility in the Western Cape Province of South Africa

AIM: The aim of this study was to determine the practices of primary health care (PHC) nurses in targeting nutritionally at-risk infants and children for intervention at a PHC facility in a peri-urban area of the Western Cape Province of South Africa. METHODOLOGY: Nutritional risk status of infants and children <6 years of age was based on criteria specified in standardised nutrition case management guidelines developed for PHC facilities in the province. Children were identified as being nutritionally at-risk if their weight was below the 3rd centile, their birth weight was less than 2500 g, and their growth curve showed flattening or dropping off for at least two consecutive monthly visits. The study assessed the practices of nurses in identifying children who were nutritionally at-risk and the entry of these children into the food supplementation programme (formerly the Protein-Energy Malnutrition Scheme) of the health facility. Structured interviews were conducted with nurses to determine their knowledge of the case management guidelines; interviews were also conducted with caregivers to determine their sociodemographic status. RESULTS: One hundred and thirty-four children were enrolled in the study. The mean age of their caregivers was 29.5 (standard deviation 7.5) years and only 47 (38%) were married. Of the caregivers, 77% were unemployed, 46% had poor household food security and 40% were financially dependent on non-family members. Significantly more children were nutritionally at-risk if the caregiver was unemployed (54%) compared with employed (32%) (P=0.04) and when there was household food insecurity (63%) compared with household food security (37%) (P<0.004). Significantly more children were found not to be nutritionally at-risk if the caregiver was financially self-supporting or supported by their partners (61%) compared with those who were financially dependent on non-family members (35%) (P=0.003). The weight results of the nurses and the researcher differed significantly (P<0.001), which was largely due to the different scales used and weighing methods. The researcher's weight measurements were consistently higher than the nurses' (P<0.00). The researcher identified 67 (50%) infants and children as being nutritionally at-risk compared with 14 (10%) by the nurses. The nurses' poor detection and targeting of nutritionally at-risk children were largely a result of failure to plot weights on the weight-for-age chart (55%) and poor utilisation of the Road to Health Chart. CONCLUSIONS: Problems identified in the practices of PHC nurses must be addressed in targeting children at nutritional risk so that appropriate intervention and support can be provided. More attention must be given to socio-economic criteria in identifying children who are nutritionally at-risk to ensure their access to adequate social security networks

Primary health care facility infrastructure and services and the nutritional status of children 0 to 71 months old and their caregivers attending these facilities in four rural districts in the Eastern Cape and KwaZulu-Natal provinces, South Africa

Objective: To assess primary health care (PHC) facility infrastructure and services, and the nutritional status of 0 to 71-month-old children and their caregivers attending PHC facilities in the Eastern Cape (EC) and KwaZulu-Natal (KZN) provinces in South Africa. Design: Cross-sectional survey. Setting: Rural districts in the EC (OR Tambo and Alfred Nzo) and KZN (Umkhanyakude and Zululand). Subjects: PHC facilities and nurses (EC: n = 20; KZN: n = 20), and 0 to 71-month-old children and their caregivers (EC: n = 994; KZN: n = 992). Methods: Structured interviewer-administered questionnaires and anthropometric survey. Results: Of the 40 PHC facilities, 14 had been built or renovated after 1994. The PHC facilities had access to the following: safe drinking water (EC: 20%; KZN: 25%); electricity (EC: 45%; KZN: 85%); flush toilets (EC: 40%; KZN: 75%); and operational telephones (EC: 20%; KZN: 5%). According to more than 80% of the nurses, problems with basic resources and existing cultural practices influenced the quality of services. Home births were common (EC: 41%; KZN: 25%). Social grants were reported as a main source of income (EC: 33%; KZN: 28%). Few households reported that they had enough food at all times (EC: 15%; KZN: 7%). The reported prevalence of diarrhoea was high (EC: 34%; KZN: 38%). Undernutrition in 0 to younger than 6 month-olds was low; thereafter, however, stunting in children aged 6 to 59 months (EC: 22%; KZN: 24%) and 60 to 71 months (EC: 26%; KZN: 31%) was medium to high. Overweight and obese adults (EC: 49%; KZN: 42%) coexisted. Conclusion: Problems regarding infrastructure, basic resources and services adversely affected PHC service delivery and the well-being of rural people, and therefore need urgent attention.Keywords: primary health care facilities; nutritional status; children; caregivers’ rural; South Afric

The symbiotic relationship of vulnerability and resilience in Nursing

Background: Whilst the terms vulnerability and resilience are commonly used within professional nursing discourses, they are often poorly understood. Vulnerability is often framed negatively and linked to being at risk of harm, whilst resilience is often perceived as the ability to withstand challenges. Aim: The aim of this paper is to explore resilience and vulnerability; re-positioning them within the context of contemporary professional nursing practice. Design: Discussion paper. Method: Drawing upon historical and contemporary international literature, both concepts are de-constructed and then re-constructed, examining them from the position of patient care as well as from the perspective of nurses and the nursing profession. Conclusion: Resilience and vulnerability have an interdependent relationship as resilience comes into play in situations of vulnerability. Yet, contrary to the popular discourse they are multi-faceted, complex phenomena based on factors such as individual circumstances, supports and resources

Efficacy of NVX-CoV2373 Covid-19 Vaccine against the B.1.351 Variant.

BACKGROUND: The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants threatens progress toward control of the coronavirus disease 2019 (Covid-19) pandemic. In a phase 1-2 trial involving healthy adults, the NVX-CoV2373 nanoparticle vaccine had an acceptable safety profile and was associated with strong neutralizing-antibody and antigen-specific polyfunctional CD4+ T-cell responses. Evaluation of vaccine efficacy was needed in a setting of ongoing SARS-CoV-2 transmission. METHODS: In this phase 2a-b trial in South Africa, we randomly assigned human immunodeficiency virus (HIV)-negative adults between the ages of 18 and 84 years or medically stable HIV-positive participants between the ages of 18 and 64 years in a 1:1 ratio to receive two doses of either the NVX-CoV2373 vaccine (5 μg of recombinant spike protein with 50 μg of Matrix-M1 adjuvant) or placebo. The primary end points were safety and vaccine efficacy against laboratory-confirmed symptomatic Covid-19 at 7 days or more after the second dose among participants without previous SARS-CoV-2 infection. RESULTS: Of 6324 participants who underwent screening, 4387 received at least one injection of vaccine or placebo. Approximately 30% of the participants were seropositive for SARS-CoV-2 at baseline. Among 2684 baseline seronegative participants (94% HIV-negative and 6% HIV-positive), predominantly mild-to-moderate Covid-19 developed in 15 participants in the vaccine group and in 29 in the placebo group (vaccine efficacy, 49.4%; 95% confidence interval [CI], 6.1 to 72.8). Vaccine efficacy among HIV-negative participants was 60.1% (95% CI, 19.9 to 80.1). Of 41 sequenced isolates, 38 (92.7%) were the B.1.351 variant. Post hoc vaccine efficacy against B.1.351 was 51.0% (95% CI, -0.6 to 76.2) among the HIV-negative participants. Preliminary local and systemic reactogenicity events were more common in the vaccine group; serious adverse events were rare in both groups. CONCLUSIONS: The NVX-CoV2373 vaccine was efficacious in preventing Covid-19, with higher vaccine efficacy observed among HIV-negative participants. Most infections were caused by the B.1.351 variant. (Funded by Novavax and the Bill and Melinda Gates Foundation; ClinicalTrials.gov number, NCT04533399.)