Analysis of Soil Profile Water Storage under Sunflower × Cowpea Intercrop in the Limpopo Province of South Africa

Sunflower (Helianthus annuus L.) is the most important oilseed crop in South Africa. Its production in semi-arid area is limited by low rainfall exacerbated by high temperatures that deplete soil moisture. Cowpea (Vigna unguiculta) intercropped in sunflower could reduce evaporation of soil moisture by increasing soil cover. A field study was carried out 2007/2008 and 2008/2009 seasons in the Limpopo Province (South Africa) to compare (i) the changes in soil profile water storage, (ii) water use efficiency, and (iii) productivity of the sunflower–cowpea cropping systems. Extraction patterns by layers showed no significant differences in all cropping systems in the 0–300, 300–600, and 600–900 mm during 2007/2008 and 2008/2009 seasons. Sole sunflower (SS) significantly extracted more soil water than sole cowpea and the intercrop from the 1200- to 1500-mm layer after 56 days after planting (DAP) during 2007/2008 season. There were no significant differences in soil water extraction by cropping systems in the whole profile during both cropping seasons. Intercropping of sunflower resulted in grain yield reduction of sunflower of up to 50 and 30% of cowpea during 2007/2008 and 2008/2009, respectively. Water use and water use efficiency by SS were significantly greater than other cropping systems during the second cropping season

Effects of tillage on runoff from a bare clayey soil on a semi-arid ecotope in the Limpopo Province of South Africa

Runoff constitutes one of the major water losses from agricultural fields in semi-arid areas. However, by adopting appropriate soil management practices, the runoff can be harnessed for improving crop yields. The main objective of this study was to quantify rainfall-runoff relationships under in-field rainwater harvesting (IRWH) using simulated rainfall, and tocompare these results to those obtained with annually tilled conventional tillage (CON) (control). IRWH is a special type of no-till (NT) crop production practice that promotes runoff from a crusted runoff strip into basins where the water infiltrates beyond evaporation but is available for crop use. Runoff was related to time to runoff, total runoff, final runoff rate and runoff coefficient. This experiment demonstrated that by adopting IRWH production technique smallholder farmers could harness an additional 45.54 m3·ha-1 of water compared to the CON system. The extra water harvested could meet about 1% of maize water requirements

Risk Assessment of Sunflower Production Using In-Field Rainwater Harvesting on Semi-Arid Ecotope in South Africa

Risk assessment of sunflower production was carried out using an empirical model. The crop yield prediction for semi-arid areas (CYP-SA) was used to simulate sunflower yield using 26 years (1984–2010) climatic data. Scenarios of crop yield simulation included production techniques associated with in-field rainwater harvesting (IRWH), and conventional tillage (CT). IRWH is a no-till (NT) crop production practice that promotes runoff from a crusted runoff strip into basins where water infiltrates beyond evaporation. The study focused on the effect of initial soil water content at planting viz. empty profile (water content near the lower limit of plant available water (LL)); half profile (water content between LL and the drained upper limit (DUL)); full profile (water content near DUL) and planting dates (November, December and January). Yield difference at 80% probability was 74% higher under IRWH compared to CT with empty initial soil water content at planting. Results indicated that IRWH is more sustainable compared to the CT

An analysis of the attitudes and perceptions of church leaders towards their perceived leadership roles in HIV prevention in the Matabeleland Province of Zimbabwe

This study investigated the attitudes of church leaders towards their perceived leadership roles in HIV prevention, using a sample of 85 clergy and lay leaders. Working from the premise that churches concentrate on care and support instead of HIV prevention, data were collected from Lutheran church leaders in Zimbabwe, using a questionnaire based on the constructs of the theory of reasoned action. The findings of this study suggest that the church is a potential source for HIV prevention. However, the capability to lead in HIV prevention was limited by barriers due to self-efficacy and cultural constraints, differences between communicator and audience, experiences and perceptions of the communicator and to some extent, institutional constraints. Programmers should focus on removing the barriers faced by the church leaders to improve their ability to lead in HIV prevention and strengthen prevention efforts.SociologyM.A. (Social Behaviour Studies in HIV/AIDS

Synthesis and evaluation of 7-substituted 3-propargylamine coumarin derivatives as multifunctional monoamine oxidase and cholinesterase inhibitors for Alzheimer’s Disease treatme

>Magister Scientiae - MScAlzheimer’s Disease (AD) is a neurodegenerative disease which results from the irreversible loss of neurons in the brain. The disease is characterized by progressive cognitive impairment with recurrent short-term memory loss. AD is the leading cause of dementia and 4th leading cause of death in the elderly. Success in the treatment of AD has been limited, with drugs only treating it at a symptomatic level due to its pathology being complex and poorly understood. However, it is known that the cholinesterase and MAO-B enzymes play an important role in the disease through their association with production of amyloid plaques and oxidative stress respectively, two mechanisms associated with cell death and the symptoms seen in AD

Transparent Microelectrode Arrays Fabricated by Ion Beam Assisted Deposition for Neuronal Cell In Vitro Recordings

Microelectrode array (MEA) is a tool used for recording bioelectric signals from electrically active cells in vitro. In this paper, ion beam assisted electron beam deposition (IBAD) has been used for depositing indium tin oxide (ITO) and titanium nitride (TiN) thin films which are applied as transparent track and electrode materials in MEAs. In the first version, both tracks and electrodes were made of ITO to guarantee full transparency and thus optimal imaging capability. In the second version, very thin (20 nm) ITO electrodes were coated with a thin (40 nm) TiN layer to decrease the impedance of Ø30 µm electrodes to one third (1200 kΩ → 320 kΩ) while maintaining (partial) transparency. The third version was also composed of transparent ITO tracks, but the measurement properties were optimized by using thick (200 nm) opaque TiN electrodes. In addition to the impedance, the optical transmission and electric noise levels of all three versions were characterized and the functionality of the MEAs was successfully demonstrated using human pluripotent stem cell-derived neuronal cells. To understand more thoroughly the factors contributing to the impedance, MEAs with higher IBAD ITO thickness as well as commercial sputter-deposited and highly conductive ITO were fabricated for comparison. Even if the sheet-resistance of our IBAD ITO thin films is very high compared to the sputtered one, the impedances of the MEAs of each ITO grade were found to be practically equal (e.g., 300–370 kΩ for Ø30 µm electrodes with 40 nm TiN coating). This implies that the increased resistance of the tracks, either caused by lower thickness or lower conductivity, has hardly any contribution to the impedance of the MEA electrodes. The impedance is almost completely defined by the double-layer interface between the electrode top layer and the medium including cells

Pastoral and Bio-medical Responses to HIV and AIDS by the Lutheran Communion in Southern Africa (LUCSA): Case Study of the Thusanang HIV & AIDS Project and Manama Mission Hospital in Zimbabwe

This article is an exposition of the Pastoral and Biomedical Responses to HIV and AIDS programming by LUCSA. This was done through engaging with members and workers of the church regarding their experiences of Home Based Care (HBC) training as a way of managing and holistically responding to the HIV and AIDS epidemic. This study explores the impact of the training for caregivers, nursing staff and pastors in HIV and AIDS management through a case study of the Thusanang HIV & AIDS project and Manama Mission Hospital of the Western Diocese of the Evangelical Lutheran Church in Zimbabwe (ELCZ) in Gwanda South. The study concludes that skills training in HBC and Palliative Care have made a positive and remarkable impact on the lives and work of HBC givers and pastors and that such training has contributed to the retention of caregivers

Design, synthesis, and evaluation of 3,7-substituted coumarin derivatives as multifunctional Alzheimer’s disease agents

Multitarget directed ligands (MTDLs) are emerging as promising treatment options for Alzheimer’s disease (AD). Coumarin derivatives serve as a good starting point for designing MTDLs due to their inherent inhibition of monoamine oxidase (MAO) and cholinesterase enzymes, which are complicit in AD’s complex pathophysiology. A preliminary series of 3,7-substituted coumarin derivatives were synthesised and evaluated for enzyme inhibitory activity, cytotoxicity as well as neuroprotective ability. The results indicated that the compounds are weak cholinesterase inhibitors with five compounds demonstrating relatively potent inhibition and selectivity towards MAO-B with IC50 values between 0.014 and 0.498 hx00B5;mM. Significant neuroprotective effects towards MPPþ-compromised SH-SY5Y neuroblastoma cells were also observed, with no inherent cytotoxicity at 10 mM for all compounds. The overall results demonstrated that substitution of the phenylethyloxy moiety at the 7-position imparted superior general activity to the derivatives, with the propargylamine substitution at the 3-position, in particular, displaying the best MAO-B selectivity and neuroprotection

Determination of regional emission factors for the power sector in Southern Africa

The generation of power within Southern Africa is reviewed. A study is described in which the emission factors for CO2 and NOx were determined experimentally across a wide range of power stations and technologies, and compared to the IPCC default factors. It was found that the CO2 emission factors tended to be at the upper end of the IPCC default range, whereas the NOx emission factors were generally below the low end. The results from South Africa tend to dominate the regional picture at present, but this is likely to change in the near future, as Botswana has announced plans to introduce over 4 000 MWe of coal-fired power stations