Fighting climate change with bamboo in Africa: The case of Kyela, Rungwe and Mufindi districts – Tanzania

Responding to the African Forest Landscape Restoration Initiative (AFR100), 32 countries have committed to restoring more than 100 million hectares of land across Africa by 2030. Bamboo is being discussed as one of the nature-based solutions to achieve this ambitious target in the face of climate change. Major advantages are that it is a fast-growing versatile woody grass that can prosper in degraded lands. So far, landscape restoration strategies are driven by climate policy debates where bamboo is largely neglected. Most empirical research on the potential of bamboo for fighting climate change has been conducted in Asia, leaving open questions on the transferability of results to the African context. In this paper, we contribute to the debate by investigating how bamboo can contribute to climate change mitigation, especially in degraded ecosystems. Taking Tanzania as an example, we lay a special focus on bamboo carbon sequestration and storage potential and assess the dynamics of carbon stocks: (i) across an elevation gradient, (ii) between indigenous and exotic bamboo species, and (iii) between intensively and extensively managed bamboo ecosystems. We collected data from 60 destructive sample plots and estimated biomass carbon stocks in the aboveground carbon pool. The weighted average biomass, carbon stocks, and sequestration rates obtained were 52.4 t ha-1, 26.2 t C ha-1, and 19 t C ha-1yr-1, respectively. The ANOVA revealed a significant variation in carbon stocks across an elevation gradient and between bamboo species (P< 0.05), which explained 22% and 11% of the total variation. We also observed a significant two-way-factors interaction between elevation versus species and silvicultural management options (P< 0.05), explaining 12% and 5% of the total variation, respectively. Similarly, a three-way interaction between all factors was significant, accounting for 4% of the total aboveground carbon variation. Our results contribute to developing a more nuanced picture of the advantages and disadvantages of incorporating bamboo in landscape restoration efforts. The novel findings may be a first step toward unlocking future climate finance in Africa

Investigating the structural diversity within a committee of classifiers and their generalization performance

This study investigates the measures of diversity within ensembles of classifiers. The use of neural networks is carried out in measuring ensemble diversity by the use of statistical and ecological methods and to some extent information theory. A new way of looking at ensemble diversity is proposed. This ensemble diversity is called ensemble structural diversity, for this study is concerned with the diversity within the structure of the individual classifiers forming an ensemble and not via the outcomes of the individual classifiers. Ensemble structural diversity was also induced within the ensemble by varying the structural parameters (learning parameters) of the artificial machines (classifiers). The importance or the use of these measures was judged by comparing the measure of structural diversity and the ensemble generalization performance. This was done so that comparisons can be made on the robustness of the idea of structural diversity and its relationship with ensemble generalization performance. It was found that diversity could be induced by having ensembles with different structural and implicit (e.g learning) parameters and that this diversity does influence the predictive ability of the ensemble. This was concurrent with literature even though within literature ensemble diversity was viewed from the output as opposed to the structure of the individual classifiers. As the structural diversity increased so did the generalization performance. However there was a point where structural diversity decreased the generalization performance of the ensemble, where from that point onwards as the structural diversity increased the generalization performance decreased. This makes sense because too much of diversity within the ensemble might mean no consensus is reached at all. The disadvantages of comparing structural diversity and the generalization performance (accuracy) of the ensemble are that: an ensemble can be structurally diverse even though all the classifiers within the ensemble approximate the same function which means in this case structural diversity is meaningless in terms of improving the accuracy of the ensemble. The use of ensemble structural diversity measures in developing efficient ensembles still remains to be explored. This study, however, has also shown that diversity can be measured from the structural parameters and moreover reducing the abstractness of diversity by being able to quantify structural diversity making it possible to map a relationship between structural diversity and accuracy. It was observed that structural diversity does improve the accuracy of the ensemble, however, within a limited region of structural diversity

Design and Development of Novel Electric Drives for Synchronous Reluctance and PM Synchronous Machines

Permanent magnet synchronous machines (PMSMs) with rare-earth magnets are widely used by the hybrid electric and electric vehicle industry due to their high torque density and efficiency. However the increasing fluctuating prices of the rare earth magnets have triggered the search for other alternative electrical machines such as the induction machine (IM), synchronous reluctance machine (SynRM) and a variable flux machine (VFM). The SynRM and the variable flux machine have been identified as potential PMSMs replacement. This is because the control strategy for the SynRM is closer to the PMSM and that the VFM is a PMSM. Therefore the same hardware used for the PMSM drive can be used for the SynRM and the VFM. There has also been an increasing demand for higher dc bus voltage on the electric drive train for better performance. A three level inverter has been identified as the best candidate to meet this demand. Hence the thesis presents a three level inverter neutral point clamped SynRM drive for traction applications. A new space vector modulation scheme is also proposed for the three level inverter SynRM drive. A comparison between a three and two level inverter SynRM drives was also conducted. Due to high cost associated with EV/HEVs, a low cost high resolution position sensor is proposed for the SynRM and the variable flux machine drives. The low cost position sensor is also compared to the position sensor used in electric power steering (EPS) machine. The EPS machines are predominantly used in vehicles and the low cost position sensor is proposed as a best alternative for the position sensor used in the EPS machine due to their simpler algorithm for position information, higher resolution and cost reduction benefits. The effect of the three level inverter supply on the core losses of the SynRM was also conducted. The SynRM experienced lower core losses when supplied from a three level inverter. The reduction in the core losses is more significant in the stator tooth which is harder to cool as compared to the stator yoke. Hence the additional benefit of a three level inverter SynRM drive is that the burden of the cooling system will be reduced and hence a reduction in the cost associated with machine cooling. The thesis also presents a novel control strategy for a variable flux machine (VFM) which uses low cost aluminum-nickel-cobalt (AlNiCo) permanent magnets (PMs). The strategy implements field weakening for speed extension and takes into account the demagnetization characteristics of the AlNiCo magnets. The magnet flux is reduced from the armature current pulses thus eliminating the additional copper losses associated with the flux weakening current in conventional rare earth PMSMs. The performance of the core losses on the VFM are also evaluated and quantified

When a child has cancer : the constructed experiences of mothers of children with cancer

When a child is diagnosed with cancer, the roles and responsibilities of family members change to accommodate the demands of the illness. The current study aimed to explore the experiences of mothers of children with cancer, focusing on their constructed roles within the family context and their social support. A case study design within the qualitative research approach was employed, underpinned by social constructionism as a theoretical framework. Three mothers were selected, using a combination of purposive and snowball sample techniques. Rich descriptive data were collected from three mothers through semi-structured interviews and reflective essays, and analysed using thematic analysis techniques. Results showed that although mothers of children with cancer experience some common themes, there are contextual differences influencing how they construct their stories. The following main themes were identified in the comparative analysis: events leading to the diagnosis, emotions, life changes, the effect of the illness and coping.PsychologyM.A. (Psychology

The Role Of Glutaminase In Cancer

Increased glutamine metabolism (glutaminolysis) is a hallmark of cancer and is recognised as a key metabolic change in cancer cells. As a heterogeneous disease with different morpholog- ical and molecular subtypes and response to therapy, breast cancer cells are known to rewire glutamine metabolism to support survival and proliferation. Glutaminase isoenzymes (GLS and GLS2) are key enzymes for glutamine metabolism. Interestingly, GLS and GLS2 display contrasting functions in tumourigenesis. In this review, we explore the role of glutaminase in cancer, primarily focussing on breast cancer, address the role played by oncogenes and tu- mour suppressor genes in regulating glutaminase, and discuss current therapeutic approaches in targeting glutaminase

The solute carrier SLC7A8 is a marker of favourable prognosis in ER-positive low proliferative invasive breast cancer

Purpose: Breast cancer (BC) is a heterogeneous disease consisting of various subtypes, withdifferent prognostic and therapeutic outcomes. The amino acid transporter, SLC7A8, is over expressed in estrogen receptor positive BC. However the consequences of this overexpression, it terms of disease prognosis, is still obscure. This study aimed to evaluate the biological and prognostic value of SLC7A8 in BC with emphasis on the intrinsic molecular subtypes.Methods: SLC7A8 was assessed at the genomic, using METABRIC data (n=1,980), and proteomic, using immunohistochemistry and TMA (n=1,562), levels in well-characterised primary BC cohorts. SLC7A8 expression was examined with clinicopathological parameters, molecular subtypes, and patient outcome.Results: SLC7A8 mRNA and SLC7A8 protein expression were strongly associated with good prognostic features, including small tumour size, low tumour grade and good Nottingham Prognostic Index (NPI) (all

PPFIA1 expression associates with poor response to endocrine treatment in luminal breast cancer

BackgroundPPFIA1 is an important regulator of cell migration and invasion, regulating focal adhesion signalling and disassembly. PPFIA1 is frequently amplified in breast cancer, and recent functional studies indicate that PPFIA1 is an important promoter of migration and invasion in breast cancer. This study aims to evaluate the utility of PPFIA1 expression in the luminal breast cancer as a prognostic marker to predict the response to endocrine therapy.MethodsLarge, well-characterised cohorts of primary luminal breast cancer patients with long-term follow-up was assessed for the clinical impact of PPFIA1 expression at the transcriptomic and proteomic levels. Prognostic significance of PPFIA1 and its relationship with clinical outcome and benefit of endocrine therapy were analysed. In addition, its association with other related-genes was analysed.ResultsThere was significant association between PPFIA1 expression and a member of the liprin family that involves in cell invasion (PPFIBPI), and the cell cycle regulator (CCND1), whereas a negative association was observed with the tumour suppressor gene (CD82). Patients with high PPFIA1 expression were associated with high risk of recurrence, distant metastasis and death from breast cancer (P< 0.05). Importantly, high PPFIA1 expression predicted relapse in a subset of patients who were subject to endocrine treatment alone, and was an independent prognostic marker of unfavourable outcome in these patients (P< 0.05).ConclusionsThese findings support the proposed role for PPFIA1 as a regulator of cell migration in breast cancer and provides definitive evidence for the clinical utility of PPFIA1 expression in patients with luminal breast cancer. Most importantly, our data suggests that PPFIA1 might be a potential predictive marker for poor benefit from endocrine therapy

CDC20 expression in oestrogen receptor positive breast cancer predicts poor prognosis and lack of response to endocrine therapy

PurposeEndocrine therapy is the standard treatment for oestrogen receptor positive (ER+) breast cancer. Despite its efficacy, around half of patients will develop resistance to this treatment and eventually relapse. Identification of effective and reliable biomarkers to predict the efficacy of endocrine therapy is of crucial importance in the management of ER+ breast cancer. Emerging evidence has revealed that the cell division regulator CDC20 exhibits an oncogenic function and plays important roles in tumourigenesis and progression of solid tumours. In this study, we investigated the prognostic and predictive role of CDC20 in early ER+ breast cancer patients.MethodsThe biological and clinical impact of CDC20 expression was assessed in large clinical annotated cohort of ER+ breast cancer with long-term follow-up at the mRNA level, using METABRIC and KM-Plotter datasets, and the protein level using immunohistochemistry on patients presenting at Nottingham. CDC20 expression was correlated with clinico-pathological parameters, molecular subtypes, clinical outcome and efficacy of endocrine therapy.ResultsHigh CDC20 mRNA expression was associated with poor clinico-pathological parameters including large tumour size and high tumour grade (P