Investigation of gene action for resistance to early leaf spot of groundnut

Groundnut (Arachishypogaea L.) is an important global oilseed crop and a major source of protein and vitamins in many rural areas of Africa. In Zambia, the production of groundnut is limited by several factors, among which Early Leaf Spot (ELS) caused by Cercosporaarachidicola Hori, is a major destructive disease. Development of resistant varieties to ELS remains the most viable disease management strategy. The objective of this study was to investigate the type of gene action conditioning resistance to C. arachidicolain order to generate information for breeding of ELS resistant groundnut varieties in Zambia. The field work was conducted at Chitedze Research Station in Malawi which is a known hot spot for groundnut foliar diseases. A recombinant inbred line (RIL) population developed from a biparental cross (Robut 33-1, susceptible and ICGV-SM 95714, resistant) and consisting of 110 F8 RILs was used in the study. Data for analysis was generated by phenotyping of the RIL population and this was conducted during the 2013/14 season under field conditions supplemented by irrigation. To ensure that there was disease infection in the experimental field, diseased debris was used as primary inoculums. The nature of gene action was established by generating a distribution curve while the Chi-square test was used to confirm the generation level of the population. These were done using the area under disease progress curves (AUDPCs) and the results suggested additive gene action. The study thus concluded that the gene action conditioning resistance to ELS was additive and breeding schemes such as pedigree and single seed decent can be used in breeding for resistance to Cercosporaarachidicola

Development of a species-specific coproantigen ELISA for human taenia solium taeniasis

Taenia solium causes human neurocysticercosis and is endemic in underdeveloped countries where backyard pig keeping is common. Microscopic fecal diagnostic methods for human T. solium taeniasis are not very sensitive, and Taenia saginata and Taenia solium eggs are indistinguishable under the light microscope. Coproantigen (CoAg) ELISA methods are very sensitive, but currently only genus (Taenia) specific. This paper describes the development of a highly species-specific coproantigen ELISA test to detect T. solium intestinal taeniasis. Sensitivity was maintained using a capture antibody of rabbit IgG against T. solium adult whole worm somatic extract, whereas species specificity was achieved by utilization of an enzyme-conjugated rabbit IgG against T. solium adult excretory-secretory (ES) antigen. A known panel of positive and negative human fecal samples was tested with this hybrid sandwich ELISA. The ELISA test gave 100% specificity and 96.4% sensitivity for T. solium tapeworm carriers (N = 28), with a J index of 0.96. This simple ELISA incorporating anti-adult somatic and anti-adult ES antibodies provides the first potentially species-specific coproantigen test for human T. solium taeniasis

The dynamics of adult neurogenesis in human hippocampus

The phenomenon of adult neurogenesis is now an accepted occurrence in mammals and also in humans. At least two discrete places house stem cells for generation of neurons in adult brain. These are olfactory system and the hippocampus. In animals, newly generated neurons have been directly or indirectly demonstrated to generate a significant amount of new neurons to have a functional role. However, the data in humans on the extent of this process is still scanty and such as difficult to comprehend its functional role in humans. This paper explores the available data on as extent of adult hippocampal neurogenesis in humans and makes comparison to animal data

Evaluation for stable resistance to Stenocarpella maydis in tropical maize (Zea mays L.)

Maize ear rots caused by Stenocarpella maydis cause reduction in yield and quality of the maize due to the mycotoxins produced by the pathogen. Breeding for resistance is the most feasible option in managing ear rots. However, to obtain stable resistance to S. maydis has been a challenge partly due to effect of the environment and availability of different isolates. The objective of this research was therefore, to determine the effect of multiple isolate inoculations in breeding for resistance to S. maydis and to identify genotypes with stable resistance. Seven inbred lines were crosses in a 7 x 7 full diallel without reciprocals. The resultant crosses (21) and their parents (7) were planted and evaluated at two sites, Lusaka and Mpongwe, during the 2015/16 cropping season. The experiment was laid out as a randomized complete block design with 3 replications. Treatments were: (1) single inoculation with isolate A, (2) single inoculation with isolate B and (3) a multiple inoculation of two isolates AB and (4) control with no inoculation at all. The mean genotypic scores were found to be 5.52, 4.96, 5.50 and 1 for treatment 1, 2, 3 and 4 respectively. The t-test analysis revealed that treatment 1 had a higher mean disease severity score (5.52) as compared to treatment 2 (4.96) (P < 0.01). Equally mean for treatment 2 (4.96) and 3 (5.50) were significantly different (P < 0.01). However, there were no significant differences between mean disease severity score for treatment 1 and 3. This indicated that multiple isolate inoculations could give rise to inappropriate genetic information due to the possibility of antagonistic effect between isolates. The genotypes (P2 x P4) and (P3 x P6) crosses were found to have stable resistance to S. maydis. These exhibited consistent significant negative SCA effects (P< 0.05) in both locations

Access to groundwater and link to the impact on quality of life: A look at the past, present and future public health needs in Mzimba District, Malawi

Imagine a world where you have to get up at 4am to walk for two hours in the dark to fetch water. This remains true in Malawi, where it is said that the Millennium Development Goals have been met. This research aimed at understanding the impact access to groundwater has on people\u27s ‘Being’, ‘Belonging’ and ‘Becoming,’ as well as on people\u27s capabilities and on their quality of life in Mzimba District, Malawi. Being, Belonging and Becoming define three life domains. Being reveals ‘who one is,’ Belonging reflects ‘connections with one\u27s environments’ and Becoming relates to ‘achieving personal goals, hopes and aspirations.’ The study comprised of 210 households, four treatment groups based on communities consisting of households with access to a hand pump and compared to four control group communities, where households had no access to a hand pump. Results showed current awareness of environmental issues is linked to recognising future (5 years in advance) environmental challenges. There is a need to create awareness of water quality within the communities and point-of-use household water treatment. Both the treatment- and control group had a gap in sanitation facilities, with up to 27 people (5–6 households) sharing a single pit latrine. Polygamous marriages had implications on self-respect and led to neglect on the first wives. Focus group discussions revealed HIV, disabilities and mental health issues, including the use of drugs and alcohol, affect freedom, and created a burden, not only for affected individuals, but also for their extended families. Focus groups highlighted safe and clean drinking water, improved sanitation facilities, better hygiene, and accessible public health services as pressing needs. The implications of this study demonstrate, rural individuals ‘Being’, ‘Belonging’ and ‘Becoming’ need to be considered when addressing pressing public health needs, as Malawi works toward the Sustainable Development Goals for water supply

Bioactivity of common pesticidal plants on fall armyworm larvae (spodoptera frugiperda)

The fall armyworm (FAW), Spodoptera frugiperda (Lepidoptera: Noctuidae) is a recent invasive pest species that has successfully established across sub‐Saharan Africa where it continues to disrupt agriculture, particularly smallholder cereal production. Management of FAW in its native range in the Americas has led to the development of resistance to many commercial pesticides before its arrival in Africa. Pesticide use may therefore be ineffective for FAW control in Africa, so new and more sustainable approaches to pest management are required that can help reduce the impact of this exotic pest. Pesticidal plants provide an effective and established approach to pest management in African smallholder farming and recent research has shown that their use can be cost‐beneficial and sustainable. In order to optimize the use of botanical extracts for FAW control, we initially screened ten commonly used plant species. In laboratory trials, contact toxicity and feeding bioassays showed differential effects. Some plant species had little to no effect when compared to untreated controls; thus, only the five most promising plant species were selected for more detailed study. In contact toxicity tests, the highest larval mortality was obtained from Nicotiana tabacum (66%) and Lippia javanica (66%). Similarly, in a feeding bioassay L. javanica (62%) and N. tabacum (60%) exhibited high larval mortality at the highest concentration evaluated (10% w/v). Feeding deterrence was evaluated using glass‐fibre discs treated with plant extracts, which showed that Cymbopogon citratus (36%) and Azadirachta indica (20%) were the most potent feeding deterrents among the pesticidal plants evaluated. In a screenhouse experiment where living maize plants infested with fall armyworm larvae were treated with plant extracts, N. tabacum and L. javanica were the most potent species at reducing foliar damage compared to the untreated control whilst the synthetic pesticide chlorpyrifos was the most effective in reducing fall armyworm foliar damage. Further field trial evaluation is recommended, particularly involving smallholder maize fields to assess effectiveness across a range of contexts

Investigating the suitability and cost-benefit of copper tailings as partial replacement of sand in concrete in Zambia: An exploratory study

Purpose: This study investigated the suitability and cost-benefit of using copper tailings as partial replacement of sand in concrete production. The study was motivated by the accumulation and non- utilisation of Copper Tailings in dams among them Tailing Dam 25 also known as TD 25 in Kitwe city of the Copperbelt province in Zambia that take up approximately 111 hectares of unutilised land. Design/methodology/approach: Laboratory experimental approach of concrete production based on water/cement ratios of 0.3 and 0.5 was used because this was an exploratory study designed to establish the primary performance of .concrete. 30 concrete cubes were cast based on the two water-cement ratios. 0% to 30% partial sand replacement with copper tailings was used in both mixes with the 0% copper tailings replacement being the control mix and reference point. Other concrete tests included workability, density, compressive strength and element composition analysis. Findings: Results revealed that copper tailings from TD 25 were suitable for partial replacement of sand in concrete. 30% of sand replacement with copper tailings was established as the maximum replacement amount in order to produce optimum compressive strength values from both mixes. The drier mix of 0.3 water-cement ratio produced higher compressive strength results of 23 MPa at 28 days of concrete curing with 2.34% as optimum concrete cost reduction. Originality/Value: The study provides guidance on optimum concrete grade produced and cost reduction details of copper tailing-based concrete to support for local authorities in suitable land wand waste management using real data

Anatomical variations and morphometric properties of the circulus arteriosus cerebri in a cadaveric Malawian population

Background: Knowledge of the anatomy of the circulus arteriosus cerebri (CAC) is important in understanding its role as an arterial anastomotic structure involved in collateral perfusion and equalization of pressure, and may explain observed variations in neurovascular disease prevalences across populations. This study was aimed at understanding the anatomical configuration and morphometric properties of the CAC in Malawian population. Materials and methods: Brains were collected from 24 recently-deceased black Malawian human cadavers during medico-legal autopsies. Photographs of the CACs were taken using a camera placed at a 30 cm height from the base of the brain. Whole-circle properties and segmental vessel parameters were analyzed using the OSIRIS computer program, paying attention to completeness, typicality, symmetry, and segmental vessel diameters and lengths. Results: 69.57 % of the CACs exhibited the complete-circle configuration. Of these, 37.5 % were typical, representing an overall typicality prevalence of 26.09 %. Vessel asymmetry was observed in 30.43 % of cases. There were 7 cases of vessel aplasia and 12 cases of vessel hypoplasia. The posterior communicating artery (PcoA) was the most variable (with 12 variations), widest (7.67 mm) and longest (27.7 mm) vessel while the anterior communicating artery (AcoA) was the shortest (0.78mm). Both the AcoA and the PcoA were the narrowest vessels (0.67 mm) in this study. CAC variations in Malawian populations appeared to be similar to those observed in diverse populations. Conclusions: Anatomical variations of the circulus arteriosus cerebri exist in Malawian population and should be taken into consideration in clinical practice

Impact of targeted counseling on reported vaginal hygiene practices and bacterial vaginosis: the HIV Prevention Trials Network 035 study

We describe the impact of intense counseling to reduce vaginal hygiene practices and its effect on bacterial vaginosis (BV)