Early growth and survival of Acacia galpinii after planting in a semi-arid environment in Zimbabwe: research note

Acacia galpinii grows naturally on the riverbanks and smaller drainage lines in semi-arid areas of Southern Africa. Trial planting of the species as a decorative tree commenced in 1993 along urban roads in Bulawayo, Zimbabwe. Early growth and survival of the species after planting was investigated in order to assess its suitability for afforestation in semi-arid environments. Growth and survival of trees were measured 3 to 9 years after planting. A significant positive correlation between crown height and stem diameter was observed in all the trial plantings. Growth rate was fast with trees reaching a mean diameter of 10 cm and height of 3 m over 3 years and a diameter of 16 cm and height of 5 m over 9 years. Such growth rates were reached under frequent drought conditions. Average stem height growth was 0.6 m year-1 and diameter growth (at 30 cm above ground) was 2 cm year-1. Survival of A. galpinii was more than 86 percent. Foliage transparency was in excess of 80% for all age groups while crown dieback and stem damage was below 5%. A. galpinii was found to be suitable for dry-zone afforestation. Key Words: Indigenous tree planting; Acacia galpinii; Growth rate; Survival rate; Tree health Southern African Forestry Journal Issue 202 2004: 61-6

Business Management 1A

Exam paper for Business Managemen

Three-dimensional Finite Element Modelling of Composite Slabs for High Speed Rails

Currently precast steel-concrete composite slabs are being considered on railway bridges as a viable alternative replacement for timber sleepers. However, due to their nature and the loading conditions, their behaviour is often complex. Present knowledge of the behaviour of precast steel-concrete composite slabs subjected to rail loading is limited. FEA is an important tool used to simulate real life behaviour and is widely accepted in many disciples of engineering as an alternative to experimental test methods, which are often costly and time consuming. This paper seeks to detail FEM of precast steel-concrete slabs subjected to standard in-service loading in high-speed rail with focus on the importance of accurately defining material properties, element type, mesh size, contacts, interactions and boundary conditions that will give results representative of real life behaviour. Initial finite element model show very good results, confirming the accuracy of the modelling procedure

Does the type of treatment supporter influence tuberculosis treatment outcomes in Zimbabwe? [Short communication]

Zimbabwe is one of the world’s 22 high tuberculosis(TB) burden countries, and ⩾60% of its TB patients are infected with the human immunodeficiency virus (HIV).1 In 2010, the treatment success rate for new sputum smear-positive TB patients was 81%, lower than the 90% rate recommended by the new Global Plan to Stop TB.The World Health Organization’s (WHO’s) Stop TB strategy recommends supervised treatment and support,including direct observation of treatment (DOT), ensuring that every dose of medication is swallowed under observation. The Zimbabwean National TB Guidelines recommend that DOT should be provided, in order of priority, by a health facility-based worker, a trained community worker or a family member/relative as a last resort, with the belief that untrained family members/relatives might not be the best people to perform DOT. However, health facility-based DOT may be challenging due to distances travelled by patients,time spent away from home/work and transport costs.Studies in Thailand, Nepal, Malawi and Tanzania have shown that family- or community-based DOT is associated with good treatment outcomes.There is no published information on whether TB treatment outcomes are infl uenced by different types of DOT supporter in Zimbabwe. We therefore conducted this study in a district of Zimbabwe to describe 1) the number and proportions of registered TB patients receiving different types of DOT in relation to baseline characteristics and 2) the association of different types of DOT with TB treatment outcomes

Macavirus latency-associated protein evades immune detection through regulation of protein synthesis in cis depending upon its glycin/glutamate-rich domain

Alcelaphine herpesvirus 1 (AlHV-1) is a γ-herpesvirus (γ-HV) belonging to the macavirus genus that persistently infects its natural host, the wildebeest, without inducing any clinical sign. However, cross-transmission to other ruminant species causes a deadly lymphoproliferative disease named malignant catarrhal fever (MCF). AlHV-1 ORF73 encodes the latency-associated nuclear antigen (LANA)-homolog protein (aLANA). Recently, aLANA has been shown to be essential for viral persistence in vivo and induction of MCF, suggesting that aLANA shares key properties of other γ-HV genome maintenance proteins. Here we have investigated the evasion of the immune response by aLANA. We found that a glycin/glutamate (GE)-rich repeat domain was sufficient to inhibit in cis the presentation of an epitope linked to aLANA. Although antigen presentation in absence of GE was dependent upon proteasomal degradation of aLANA, a lack of GE did not affect protein turnover. However, protein self-synthesis de novo was downregulated by aLANA GE, a mechanism directly associated with reduced antigen presentation in vitro. Importantly, codon-modification of aLANA GE resulted in increased antigen presentation in vitro and enhanced induction of antigen-specific CD8+ T cell responses in vivo, indicating that mRNA constraints in GE rather than peptidic sequence are responsible for cis-limitation of antigen presentation. Nonetheless, GE-mediated limitation of antigen presentation in cis of aLANA was dispensable during MCF as rabbits developed the disease after virus infection irrespective of the expression of full-length or GE-deficient aLANA. Altogether, we provide evidence that inhibition in cis of protein synthesis through GE is likely involved in long-term immune evasion of AlHV-1 latent persistence in the wildebeest natural host, but dispensable in MCF pathogenesis