1,183 research outputs found
Oor die koninkryk van God
As Johannes die Doper spreek van die koninkryk van God wat naby gekom het (Matt. 3 : 12) en Jesus dat die koninkryk inderdaad gekom het (Matt. 12 : 28; Luk. 11 : 20; 17 : 21), spreek hulle oor ’n saak wat eers ver was en nou naby is, en wat eers nie was nie of elders was en nou gekom het
A forced-gradient tracer test on the Hansrivier Dyke : Beaufort West, South Africa
A field-scale pumping test and uranin tracer test was carried out at Hansrivier Farm in Beaufort West to determine the hydraulic properties of the Hansrivier Dyke/Karoo sedimentary rock aquifer. Analysis of borehole images and pumping test results reveal that the fractured-rock aquifer is highly transmissive due to the influence of the Hansrivier Dyke; however its influence is concentrated on extremely limited conductive zones. Results of the tracer test show that chemical transport can take place via multiple flow paths with differing hydraulic properties, such as fracture aperture, connectivity and permeability. Furthermore, diffusion of a tracer into fractures and rock matrix has a universal retardatory travel time due to the various flow paths. In order to interpret the tracer test data, the Single Fissure Dispersion Model (SFDM) was used for inverse modelling of the breakthrough curves. The resulting effective diffusion coefficients are comparable with laboratory-derived values, and are therefore considered to be representative of the investigated part of the aquifer.Water Research Commission and the Institute for Groundwater Studies.http://www.wrc.org.z
Case Studies: Unusual phaeochromocytomas in African families: the importance of genetic testing
No AbstractKeywords: phaeochromocytomas; genetic testing; Von Hippel-Lindau syndrome; familial cancer; genetic counsellin
Ultrasonic Investigation of Tensile Fatigue Overloads in Fatigue Cracks
The growth of a fatigue crack is generally modeled in terms of empirical rules such as the Paris law [1] which states that da/dN = A(ΔK)m where a is the crack length, N is the number of fatigue cycles at a particular stress intensity range ΔK and A and m are material constants. Recently, evidence has accumulated that establishes that the full excursion of the applied load or the full stress intensity range does not drive the crack tip forward due to a variety of phenomena often referred to as crack tip shielding [2,3]. This shielding arises as a consequence of the formation of contacting asperities between the surfaces of the fatigue crack. Since these contacting asperities bear a portion of the load, they modify the stress intensity at the tip, thereby altering the growth rate
Determining the effect of three- dimensional printing orientation on the bending strength of sand moulds and cores when using a voxeljet additive manufacturing machine
Abstract: Advances made in Additive Manufacturing (AM) or 3D printing led to the 3D printing of sand moulds and cores used in the foundry industry. Ideally, the mechanical properties of the 3D printed moulds and cores should be uniform throughout the 3D printed part. This will ensure that the casting produced from the 3D printed mould has uniform properties throughout the mould. The following study investigated the effect of the printing location and part orientation in the AM machine used to produce the 3D Printed mould on the bending strength property of sand parts. Several printing orientations and angles were considered in the investigation. Descriptive statistics was used to assess and interpret the results
Experiences of support by unsuppressed adolescents living with HIV and their caregivers in Windhoek, Namibia: a qualitative study
BackgroundAdolescents living with HIV (ALHIV) lag behind younger children and adults in the achievement of HIV care and treatment targets for HIV epidemic control. Treatment outcomes for adolescents may be influenced by their experiences with the support provided in HIV programs. We report on the experiences of virally unsuppressed adolescents and their caregivers with the current support in primary healthcare settings in Namibia.MethodsA qualitative descriptive and exploratory study was conducted in 13 public primary healthcare facilities in Windhoek, Namibia. A total of 25 in-depth interviews were conducted with unsuppressed adolescents (n = 14) and their caregivers (n = 11) between August and September 2023. The audio-recorded interviews were transcribed verbatim, and uploaded into ATLAS.ti software, and subjected to thematic content analysis.FindingsThree main support domains for the unsuppressed adolescents emerged from our analysis, namely: psychosocial, clinical and care, and socioeconomic support. The psychosocial support was delivered through peer support (teen clubs and treatment supporters) and enhanced adherence counselling mostly. The clinical and care support included implementing adolescent-friendly HIV services, differentiated service delivery approaches, and caregivers and healthcare worker care support for improved ART adherence, clinic attendance and continuous engagement in care. Socioeconomic support was provided for nutritional support, transport to access clinics, and school supplies, as well as income-generating projects.ConclusionPsychosocial, clinical and care, and socioeconomic support are key elements in addressing the needs of adolescents challenged with achieving viral suppression. Health systems may benefit from whole-of-society and whole-of-government approaches to meet the needs of ALHIV that are beyond the scope of health service delivery such as nutritional, education and socioeconomic influences on both the health and well-being of ALHIV
Relationship between tumour PTEN/Akt/COX-2 expression, inflammatory response and survival in patients with colorectal cancer
In patients with colorectal cancer (CRC), local and systemic inflammatory responses have been extensively reported to associate with cancer survival. However, the specific signalling pathways responsible for inflammatory responses are not clear. The PTEN/Akt pathway is a plausible candidate as it may play a role in mediating inflammation via COX-2, and has been associated with cancer progression. This study therefore examined the relationship between tumour PTEN/Akt/COX-2 expression, inflammatory responses and survival in CRC patients using a tissue microarray.
In 201 CRC patients, activation of tumour-specific PTEN/Akt significantly associated with poorer CSS (12.0yrs v 7.3yrs, P=0.032), poorer differentiation (P=0.032), venous invasion (P=0.008) and peritoneal involvement (P=0.004). Patients were stratified for peri-nuclear expression of COX-2 to examine associations with inflammatory responses. In patients with absent peri-nuclear COX-2 expression, activation of tumour-specific PTEN/Akt significantly associated with poorer CSS (11.9yrs v 5.4yrs, P=0.001), poorer differentiation (P=0.018), venous invasion (P=0.003) and peritoneal involvement (P=0.001). However, no associations were seen with either the local or systemic inflammatory responses.
In CRC patients, tumour-specific PTEN/Akt pathway activation was significantly associated with poorer CSS, particularly when peri-nuclear COX-2 expression was absent. However, activation of the PTEN/Akt pathway appears not to be responsible for the regulation of inflammatory responses
The effects of teen clubs on retention in HIV care among adolescents in Windhoek, Namibia
Adolescents living with HIV (ALHIV) are notably underserved by the national HIV programmes globally because of their unique needs. Of particular concern is limited access to and availability of adolescent-friendly antiretroviral therapy (ART) services, which contribute to poor retention in care in many sub-Saharan African countries. A Teen Club intervention was introduced in 2010 in Windhoek, Namibia, to improve retention in care among ALHIV through psychosocial support in a peer-group environment. Objectives: To compare the effects of the Teen Club intervention against standard care on retention in HIV care amongst adolescents at a Paediatric ART clinic. Method: A retrospective cohort analysis of adolescents aged 10-19 years receiving ART between July 2015 and June 2017 was conducted. Routine patient data were extracted from an electronic database and patient registers. A sample of 385 participants was analysed: 78 in the Teen Club and 307 in standard care. Retention was measured by assessing attendance to prescribed clinic visits up to 24 months. Comparisons were assessed with the Chi-square test, and Kaplan-Meier survival analysis was conducted to analyse differences in retention rates. Results: The overall retention rate at 24 months among all adolescents was 90.1%, with no statistically significant difference between those in Teen Club (91%) and those in standard care (89%) (p = 0.956). Younger adolescents (10-14 years) had better retention rates at 24 months compared to older adolescents (15-19 years) (94% vs. 86%; p = 0.016)
Determinants and rates of retention in HIV care among adolescents receiving antiretroviral therapy in Windhoek, Namibia: A baseline cohort analysis
Long-term engagement in HIV care is essential to achieving and maintaining viral suppression.
Adolescents living with HIV (ALHIV) experience many barriers to remaining engaged in care and treatment programs.
Higher attrition among adolescents compared to adults remains a huge concern due to unique psychosocial and
health systems challenges adolescents face, and recently the COVID-19 pandemic effects. We report on determinants
and rates of retention in care in adolescents aged 10–19 years enrolled on antiretroviral therapy (ART) in Windhoek,
Namibia. A retrospective cohort analysis of routine clinical data of 695 adolescents aged 10–19 years enrolled for
ART at 13 Windhoek district public healthcare facilities, between January 2019 and December 2021 was conducted.
Anonymized patient data were extracted from an electronic database and registers. Bivariate and Cox proportional
hazards analysis were performed to determine factors associated with retention in care among ALHIV at 6, 12, 18, 24
and 36 months. Retention in care trends were also described using the Kaplan-Meier survival analysis
The effect of carbohydrate dose and timing on timed effort and time to exhaustion within a simulated cycle race in male professional cyclists
A key performance limitation affecting professional endurance cycling is carbohydrate storage and utilisation (Pöchmüller, Schwingshack, Colombani & Hoffmann, 2016, Journal of the International Society of Sports Nutrition, 13). Muscle glycogen stores alone are inefficient at maintaining optimal blood glucose levels beyond two hours of exercise; consequently, exogenous CHO is commonly used to counteract this (Jeukendrup, 2011, Journal of Sports Sciences, 21, 91-99). High concentrations of CHO can cause drops in blood glucose, excessive glycogen utilisation and gastrointestinal discomfort (GID) (Jeukendrup, 2011). Therefore, the aim of this study was to determine if frequent, smaller CHO feedings would be preferable to large, bolus CHO feedings on time trial cycling performance. With institutional ethics approval, 5 professional cyclists completed a 4h simulated cycle ride with 3 timed efforts in a randomised, cross-over, double blind design study. Each timed effort occurred in the last 10 min of each hour (TE1, TE2, TE3); participants were asked to cycle with maximum effort for this time. There was also a final effort at the end of the 4th hour to replicate a sprint finish. This was measured as time to exhaustion (TTE). Two interventions were used; a frequent feed (F) where participants drank 20g maltodextrin in 300ml flavoured water solution 3 times per hour and a bolus feed (B) where participants drank 60g maltodextrin solution once per hour. Heart rate, power output, GID, perceived exertion (RPE), blood lactate and blood glucose were recorded before and after TE1, TE2, TE3 and TTE. Wilcoxen signed rank test and Cohen’s D was performed to study differences between interventions and effect sizes.In the F intervention, average watts were significantly higher at TE2 (P<0.05 d=0.75) and TE3 (P<0.05 d=1.21) and the RPE was lower TE1 (P≥0.05 d=1.12), TE2 (P<0.05, d=1.12) and TTE (P≥0.05 d=1.12) compared to B. There was no significant difference between any other variables. The results suggest that despite power output being higher, RPE was lower in the F intervention. Gut absorption of CHO is limited to 1g/h (Jeukendrup, 2011), which may help explain these findings. This is one of the first studies to look at concentration and timing of CHO consumption in endurance cycling. Regular feeds of 20g CHO may be more beneficial on power output and RPE in endurance cycling compared to hourly 60g feeds
- …