Genetic variability, stability and heritability for quality and yield characteristics in provitamin A cassava varieties

Open Access Article; Published online: 25 Jan 2020Cassava is widely consumed in many areas of Africa, including Ghana, and is a major part of most household diets. These areas are characterized by rampant malnutrition, because the tuberous roots are low in nutritional value. Provitamin A biofortified cassava varieties have been developed by the International Institute for Tropical Agriculture, but adoption of these varieties in Ghana will largely depend on their agronomic performance, including fresh root yield, dry matter content, resistance to major pests and diseases, mealiness, starch content and the stability of these traits. Eight provitamin A varieties with two white checks were planted in three environments for two seasons to determine stability and variability among the varieties for important traits. There were significant variations in performance between varieties and between environments for cassava mosaic disease, root number, fresh root yield and starch content. High broad-sense heritability and genetic advance were observed in all traits, except for storage root number, and could be exploited through improvement programs. This study identified the best performing enhanced provitamin A varieties for traits that are key drivers of variety adoption in Ghana. In view of this, some varieties can be recommended for varietal release after on-farm testing. The study also showed the possibility of tapping heterosis after careful selection of parents

The Effects of Strategic Nitrogen Fertiliser Application During the Cool Season on the Composition of a Perennial Ryegrass-White Clover Pasture in the Western Cape Province of South Africa

Application of fertiliser N to stimulate DM production of perennial ryegrass-white clover pastures during the cool season can be an important management tool. Application of fertiliser N should however maintain clover contents between 30 and 50 percent (Martin, 1960; Harris, 1994). The aim of the study was to develop a better understanding of the effect of a strategic N fertiliser application during the cool season on the grass-clover balance and to identify possible management guidelines that would maximise dry matter production without suppressing clover content to values lower than required to maintain the benefit of clover in the pasture

From implementation to revising simulation integration into undergraduate physiotherapy training

Background. Careful consideration of an increasingly underprepared tertiary student population, the limited use of simulation in South African (SA) healthcare education and a changing healthcare education milieu is required from SA educators when implementing, evaluating and revising simulation integration. Objectives. To develop a conceptual framework for the integration of simulation in the SA undergraduate physiotherapy programme. Methods. A non-experimental descriptive research design was used. A purposive sample of 15 healthcare educationalists from SA and abroad were approached to participate in a modified Delphi survey, informed by the results obtained from a systematic review identifying simulation integration framework elements. Data were analysed as percentages, with feedback provided to panel members following each round. Results. Data saturation was achieved after round 3, with a response rate of 73.3% (n=11). The main findings suggested that student preparation prior to simulation-based learning experiences (SBLEs) should include orientation to SBLE logistics and expectations (73%), and could include informal assessment of theory (64%). Inclusion of the feedback/debriefing process (82%), methods (100%) and timing (85%) as part of student and educator preparation were also deemed essential. Panel members agreed that programme evaluation in line with stakeholder feedback (92%) is vital for guiding adjustments to the programme that is integrating simulation. Conclusion. The developed conceptual framework indicates the necessity of student and educator preparation to ensure optimal SBLE participation and outcome achievement. Programme sustainability should be ensured through programme evaluation and adjustment, in line with stakeholder feedback, best practice and accrediting professional body guidelines

How to plan for simulation integration into undergraduate physiotherapy training

Background. The benefits of simulation in healthcare education are undeniable, and in the current healthcare climate, a drastic change in delivering healthcare training is critical. Therefore, integration of simulation is essential, and necessitates detailed planning and well-trained educators. Objectives. To develop a conceptual framework for the integration of simulation in South African (SA) undergraduate physiotherapy programmes. Methods. A non-experimental descriptive research design using a modified Delphi survey was conducted. Results from a systematic review identifying simulation integration framework elements informed the Delphi survey. A purposive sample of 15 healthcare educationalists from SA and abroad were approached to participate. Data were analysed as percentages, and feedback was provided to panel members following each round. Results. A response rate of 73.3% (n=11) was achieved. Planning was explored as one of the themes. Both institutional- and discipline-specific needs analyses were identified as essential (93%), and societal needs were useful to consider (64%). Resource identification and sharing (84%) were regarded as vital, and expert collaboration in curriculum development (79%) with scaffolded skills integration (75%) was advised. The necessity for trained facilitators (93%) and educator role identification (71%) was evident. Statements related to mastery learning/deliberate practice and the use of simulation for assessment purposes yielded the least consensus. Conclusion. A constructively aligned curriculum based on both student and institutional needs and resource availability in guiding simulation integration was regarded as essential. Educator competency in both the development and delivery of the programme, especially debriefing methods, is vital for optimising student learning

Spatial variation of epoxyscillirosidine concentrations in Moraea pallida (yellow tulp) in South Africa

Moraea pallida (yellow tulp) poisoning is economically the most important intoxication of livestock in South Africa. Poisoning varies according to locality, climatic conditions and growth stage of the plant. The primary objective of this study was to determine the concentration of the toxic principle, epoxyscillirosidine, in yellow tulp leaves and to ascertain the variability of epoxyscillirosidine concentrations within and between different locations. A secondary objective was to utilise Geographic Information Systems in an attempt to explain the variability in toxicity. Flowering yellow tulp plants were collected at 26 sampling points across 20 districts of South Africa. The leaves of five plants per sampling point were extracted and submitted for liquid chromatography/mass spectrometry analysis. A large variation in mean epoxyscillirosidine concentrations, ranging from 3.32 μg/g – 238.27 μg/g, occurred between different geographical regions. The epoxyscillirosidine concentrations also varied tremendously between individual plants (n= 5) collected at the same sampling point, with up to a 24 times difference between the lowest and highest concentration detected. No generalised correlation between epoxyscillirosidine concentrations and soil elemental concentrations could be established. However, samples obtained from the north-eastern part of the sampling region tended to have higher epoxyscillirosidine concentrations compared to samples obtained from the south-western part of the sampling region. Higher toxin concentrations in the northeast were associated with statistically significant higher soil concentrations of iron, bismuth, bromide, cadmium, chromium, rubidium, tellurium, thallium, titanium and zinc, whilst soil concentrations of strontium and soil pH, were significantly lower. This study corroborated the contention that epoxyscillirosidine concentration in yellow tulp fluctuates and may explain the variability in toxicity

Micromanipulation at an infertility centre

Aim. Human in vitro fertilisation (IVF) and gamete intrafallopian transfer have been used in the management of various forms of infertility. In cases of severe male-factor infertility, fertilisation can be a factor. In this study micromanipulation was used to increase fertilisation in such cases.Methods. Two micromanipulation techniques, subzonal sperm injection (SUZI) and partial zona dissection (PZD), were used to assist fertilisation in patients with abnorTl)al semen parameters. Ten couples with severe oligo-, teratoand asthenozoospermia participated in the SUZI programme. Seventy-three oocytes were obtained from these 10 patients. PZD was used on day 1 oocytes in cases of male infertility as well as a rescue attempt on day 2 oocytes when fertilisation had failed after routine insemination.Results. The SUZI technique had a fertilisation rate of 37,7%. In this group, a biochemical pregnancy was achieved. Differences between the fertilisation rate of conventionallVF (33,3%) and PZD (56,3%) in cases of male infertility, were not statistically significant although a clinical difference could be detected. PZD was statistically effective in facilitating fertilisation (37,5% v. 8,3%) in couples where this procedure was introduced to reinseminate 24-hour-old unfertilised oocytes. Four patients received PZD reinseminated embryos. An average of 1,45 PZD embryos were replaced and 1 implantation pregnancy was confirmed.Conclusion. The micromanipulation results are encouraging arid seemed to increase the efficiency of IVF in humans. Furthermore, our data support the conclusion that micromanipulation procedures can bring about pregnancies

Continuous measurements of greenhouse gases and atmospheric oxygen at the Namib Desert atmospheric observatory

A new coastal background site has been established for observations of greenhouse gases (GHGs) in the central Namib Desert at Gobabeb, Namibia. The location of the site was chosen to provide observations for a data-poor region in the global sampling network for GHGs. Semi-automated continuous measurements of carbon dioxide, methane, nitrous oxide, carbon monoxide, atmospheric oxygen, and basic meteorology are made at a height of 21 m a.g.l., 50 km from the coast at the northern border of the Namib Sand Sea. Atmospheric oxygen is measured with a differential fuel cell analyzer (DFCA). Carbon dioxide and methane are measured with an early-model cavity ring-down spectrometer (CRDS); nitrous oxide and carbon monoxide are measured with an off-axis integrated cavity output spectrometer (OA-ICOS). Instrument-specific water corrections are employed for both the CRDS and OA-ICOS instruments in lieu of drying. The performance and measurement uncertainties are discussed in detail. As the station is located in a remote desert environment, there are some particular challenges, namely fine dust, high diurnal temperature variability, and minimal infrastructure. The gas handling system and calibration scheme were tailored to best fit the conditions of the site. The CRDS and DFCA provide data of acceptable quality when base requirements for operation are met, specifically adequate temperature control in the laboratory and regular supply of electricity. In the case of the OA-ICOS instrument, performance is significantly improved through the implementation of a drift correction through frequent measurements of a reference cylinder

How to plan for simulation integration into undergraduate physiotherapy training

Background. The benefits of simulation in healthcare education are undeniable, and in the current healthcare climate, a drastic change in delivering healthcare training is critical. Therefore, integration of simulation is essential, and necessitates detailed planning and well-trained educators. Objectives. To develop a conceptual framework for the integration of simulation in South African (SA) undergraduate physiotherapy programmes. Methods. A non-experimental descriptive research design using a modified Delphi survey was conducted. Results from a systematic review identifying simulation integration framework elements informed the Delphi survey. A purposive sample of 15 healthcare educationalists from SA and abroad were approached to participate. Data were analysed as percentages, and feedback was provided to panel members following each round. Results. A response rate of 73.3% (n=11) was achieved. Planning was explored as one of the themes. Both institutional- and discipline-specific needs analyses were identified as essential (93%), and societal needs were useful to consider (64%). Resource identification and sharing (84%) were regarded as vital, and expert collaboration in curriculum development (79%) with scaffolded skills integration (75%) was advised. The necessity for trained facilitators (93%) and educator role identification (71%) was evident. Statements related to mastery learning/deliberate practice and the use of simulation for assessment purposes yielded the least consensus. Conclusion. A constructively aligned curriculum based on both student and institutional needs and resource availability in guiding simulation integration was regarded as essential. Educator competency in both the development and delivery of the programme, especially debriefing methods, is vital for optimising student learning

Long-term evidence for ecological intensification as a pathway to sustainable agriculture

Ecological intensification (EI) could help return agriculture into a ‘safe operating space’ for humanity. Using a novel application of meta-analysis to data from 30 long-term experiments from Europe and Africa (comprising 25,565 yield records), we investigated how field-scale EI practices interact with each other, and with N fertilizer and tillage, in their effects on long-term crop yields. Here we confirmed that EI practices (specifically, increasing crop diversity and adding fertility crops and organic matter) have generally positive effects on the yield of staple crops. However, we show that EI practices have a largely substitutive interaction with N fertilizer, so that EI practices substantially increase yield at low N fertilizer doses but have minimal or no effect on yield at high N fertilizer doses. EI practices had comparable effects across different tillage intensities, and reducing tillage did not strongly affect yields

Clinical and cost-effectiveness of contingency management for cannabis use in early psychosis: the CIRCLE randomised clinical trial

Cannabis is the most commonly used illicit substance amongst people with psychosis. Continued cannabis use following the onset of psychosis is associated with poorer functional and clinical outcomes. However, finding effective ways of intervening has been very challenging. We examined the clinical and cost-effectiveness of adjunctive contingency management (CM), which involves incentives for abstinence from cannabis use, in people with a recent diagnosis of psychosis. CIRCLE was a pragmatic multi-centre randomised controlled trial. Participants were recruited via Early Intervention in Psychosis (EIP) services across the Midlands and South East of England. They had had at least one episode of clinically diagnosed psychosis (affective or non-affective); were aged 18 to 36; reported cannabis use in at least 12 out of the previous 24 weeks; and were not currently receiving treatment for cannabis misuse, or subject to a legal requirement for cannabis testing. Participants were randomised via a secure web-based service 1:1 to either an experimental arm, involving 12 weeks of CM plus a six-session psychoeducation package, or a control arm receiving the psychoeducation package only. The total potential voucher reward in the CM intervention was £240. The primary outcome was time to acute psychiatric care, operationalised as admission to an acute mental health service (including community alternatives to admission). Primary outcome data were collected from patient records at 18 months post-consent by assessors masked to allocation. The trial was registered with the ISRCTN registry, number ISRCTN33576045. Five hundred fifty-one participants were recruited between June 2012 and April 2016. Primary outcome data were obtained for 272 (98%) in the CM (experimental) group and 259 (95%) in the control group. There was no statistically significant difference in time to acute psychiatric care (the primary outcome) (HR 1.03, 95% CI 0.76, 1.40) between groups. By 18 months, 90 (33%) of participants in the CM group, and 85 (30%) of the control groups had been admitted at least once to an acute psychiatric service. Amongst those who had experienced an acute psychiatric admission, the median time to admission was 196 days (IQR 82, 364) in the CM group and 245 days (IQR 99, 382) in the control group. Cost-effectiveness analyses suggest that there is an 81% likelihood that the intervention was cost-effective, mainly resulting from higher mean inpatient costs for the control group compared with the CM group; however, the cost difference between groups was not statistically significant. There were 58 adverse events, 27 in the CM group and 31 in the control group. Overall, these results suggest that CM is not an effective intervention for improving the time to acute psychiatric admission or reducing cannabis use in psychosis, at least at the level of voucher reward offered