Conceptualising neuroscience-based leadership behaviour

This thesis primarily focuses on conceptualising Neuroscience Based Leadership (NSBL) by providing a working definition of NSBL, describing the foundational concepts and core behaviours of neuroscience-based leadership (NSBL), and presenting a conceptual framework that integrates interdisciplinary perspectives on leadership behaviour. This was achieved by: 1. Reviewing existing relevant scientific literature and highlighting current knowledge gaps in the conceptualisations of NSBL using Leadership Behaviour, Social Cognitive Neuroscience (SCN), and Neuropsychotherapy (NP) 2. Conducting a small-scale research project using semi-structured, in-depth interviews with three neuroscientists who have employed neuroscience-based diagnostics in leadership development within a corporate context. This study’s key findings reveal key conceptual themes with the following theoretical propositions that underpin NSBL key behaviours: social safety is a primary operating principle; conscious thinking and nonconscious processes drive behaviour; nature-nurture dynamics influence behaviour; experienced-based neuroplasticity drives change; and overlapping large-scale brain networks enable information processing in the brain. 3. Designing and implementing a qualitative Delphi study involving 33 experienced professionals in NSBL to explore how NSBL is defined, conceptualise NSBL as a different domain of leadership behaviour, and provide descriptors of NSBL key behaviours 4. Adopting a case study approach involving an organisational psychologist experienced in Neuropsychotherapy and drawing on his views and experiences to produce a single-case study of NSBL within the context of organisational psychology and applied organisational neuroscience (AONS). 5. Undertaking a reflective and critical review of the four pieces of research and proposing a theoretical framework of NSBL, specifically within formal organisations, to inform, support, foster and develop future NSBL-based behaviour. The contribution of this study is broad in that it offers a working definition of neuroscience-based leadership and an interdisciplinary conceptual framework to guide practitioners and further research. This conceptual framework integrates theoretical propositions regarding leadership behaviour from Leadership Behaviour theory, Social Cognitive and Affective Neuroscience, and Neuropsychotherapy. The theoretical framework of NSBL addresses gaps in the literature by differentiating four domains of NSBL: stress resilience-focused core behaviours, affect and emotional-focused core behaviours, relationship-focused core behaviours, and task-focused core behaviours. It also provides neuroscientific concepts that underpin behaviour. The contribution to practice is that this study advances the understanding of how formal organisations can apply a neuroscientific lens to inform the design of leadership development interventions. This integrative, interdisciplinary theoretical framework can be used for leadership coaching at an individual level. At the group level, it can facilitate team building. It can provide a neuroscientific language for mental experience at an organisational level, thereby enhancing the explanatory power of concepts in leadership and organisational behaviour

Design and optimisation of a composite space frame chassis including experimental and computational analysis.

Masters Degree. University of KwaZulu-Natal, Durban.Composites are used in lightweight structural designs. In this dissertation, a robust carbon fibre reinforced polymer (CFRP) space frame chassis for a lightweight electric tricycle is produced. In large, most composite research is directed toward flat laminates rather than closed sections. This dissertation addresses the complexities of stresses at joints and buckling (local and global). The space frame design consists of two segments of iterations. The second and more important segment is based on optimisation using NX Nastran finite element analysis (FEA). The final design incorporates the use of steel sleeves to address stress concentrations at joins and local buckling. The design and execution of a new test method was developed to validate FEA results. The test method involves applying compressive stress on tubes fabricated using unidirectional (UD) fibre set at 35°, to induce compressive and shear stresses along the primary fibres. In this way, four major failure criteria were compared: Tsai-Wu, Hoffman, Hill and Maximum Strain. The Hoffman and Tsai-Wu criteria were shown to be accurate and conservative. The Hill criteria showed inaccuracy by having incorrectly high strength ratios, while the Maximum Strain criteria had the highest strength ratio, proving to be the least conservative and most inaccurate. This dissertation shows that certain failure criteria may be used confidently in applications such as filament winding and continuous pulComposites are used in lightweight structural designs. In this dissertation, a robust carbon fibre reinforced polymer (CFRP) space frame chassis for a lightweight electric tricycle is produced. In large, most composite research is directed toward flat laminates rather than closed sections. This dissertation addresses the complexities of stresses at joints and buckling (local and global). The space frame design consists of two segments of iterations. The second and more important segment is based on optimisation using NX Nastran finite element analysis (FEA). The final design incorporates the use of steel sleeves to address stress concentrations at joins and local buckling. The design and execution of a new test method was developed to validate FEA results. The test method involves applying compressive stress on tubes fabricated using unidirectional (UD) fibre set at 35°, to induce compressive and shear stresses along the primary fibres. In this way, four major failure criteria were compared: Tsai-Wu, Hoffman, Hill and Maximum Strain. The Hoffman and Tsai-Wu criteria were shown to be accurate and conservative. The Hill criteria showed inaccuracy by having incorrectly high strength ratios, while the Maximum Strain criteria had the highest strength ratio, proving to be the least conservative and most inaccurate. This dissertation shows that certain failure criteria may be used confidently in applications such as filament winding and continuous pultrusion methods, which are widely used in producing closed sections.trusion methods, which are widely used in producing closed sections

Common and distinct organ and stress responsive transcriptomic patterns in Oryza sativa and Arabidopsis thaliana

<p>Abstract</p> <p>Background</p> <p><it>Arabidopsis thaliana </it>is clearly established as the model plant species. Given the ever-growing demand for food, there is a need to translate the knowledge learned in Arabidopsis to agronomically important species, such as rice (<it>Oryza sativa</it>). To gain a comparative insight into the similarities and differences into how organs are built and how plants respond to stress, the transcriptomes of Arabidopsis and rice were compared at the level of gene orthology and functional categorisation.</p> <p>Results</p> <p>Organ specific transcripts in rice and Arabidopsis display less overlap in terms of gene orthology compared to the orthology observed between both genomes. Although greater overlap in terms of functional classification was observed between root specific transcripts in rice and Arabidopsis, this did not extend to flower, leaf or seed specific transcripts. In contrast, the overall abiotic stress response transcriptome displayed a significantly greater overlap in terms of gene orthology compared to the orthology observed between both genomes. However, ~50% or less of these orthologues responded in a similar manner in both species. In fact, under cold and heat treatments as many or more orthologous genes responded in an opposite manner or were unchanged in one species compared to the other. Examples of transcripts that responded oppositely include several genes encoding proteins involved in stress and redox responses and non-symbiotic hemoglobins that play central roles in stress signalling pathways. The differences observed in the abiotic transcriptomes were mirrored in the presence of <it>cis</it>-acting regulatory elements in the promoter regions of stress responsive genes and the transcription factors that potentially bind these regulatory elements. Thus, both the abiotic transcriptome and its regulation differ between rice and Arabidopsis.</p> <p>Conclusions</p> <p>These results reveal significant divergence between Arabidopsis and rice, in terms of the abiotic stress response and its regulation. Both plants are shown to employ unique combinations of genes to achieve growth and stress responses. Comparison of these networks provides a more rational approach to translational studies that is based on the response observed in these two diverse plant models.</p

Applying machine learning to predict patient-specific current CD4 cell count in order to determine the progression of human immunodeficiency virus (HIV) infection

This work shows the application of machine learning to predict current CD4 cell count of an HIV-positive patient using genome sequences, viral load and time. A regression model predicting actual CD4 cell counts and a classification model predicting if a patient’s CD4 cell count is less than 200 was built using a support vector machine and neural network. The most accurate regression and classification model took as input the viral load, time, and genome and produced a correlation of co-efficient of 0.9 and an accuracy of 95%, respectively, proving that a CD4 cell count measure may be accurately predicted using machine learning on genotype, viral load and time.Keywords: Human immunodeficiency virus (HIV), antigens, CD4, computational biology, artificial intelligence, data mining, pattern recognition.African Journal of Biotechnology Vol. 12(23), pp. 3724-373

Defining reference genes in Oryza sativa using organ, development, biotic and abiotic transcriptome datasets

<p>Abstract</p> <p>Background</p> <p>Reference genes are widely used to normalise transcript abundance data determined by quantitative RT-PCR and microarrays. However, the approaches taken to define reference genes can be variable. Although <it>Oryza sativa </it>(rice) is a widely used model plant and important crop specie, there has been no comprehensive analysis carried out to define superior reference genes.</p> <p>Results</p> <p>Analysis of 136 Affymetrix transcriptome datasets comprising of 373 genome microarrays from studies in rice that encompass tissue, developmental, abiotic, biotic and hormonal transcriptome datasets identified 151 genes whose expression was considered relatively stable under all conditions. A sub-set of 12 of these genes were validated by quantitative RT-PCR and were seen to be stable under a number of conditions. All except one gene that has been previously proposed as a stably expressed gene for rice, were observed to change significantly under some treatment.</p> <p>Conclusion</p> <p>A new set of reference genes that are stable across tissue, development, stress and hormonal treatments have been identified in rice. This provides a superior set of reference genes for future studies in rice. It confirms the approach of mining large scale datasets as a robust method to define reference genes, but cautions against using gene orthology or counterparts of reference genes in other plant species as a means of defining reference genes.</p

Radioactive iodine in the management of thyrotoxicosis.

Thesis (M.Med.)-University of KwaZulu-Natal, Durban, 2011.Objective : An audit of the use and outcomes of Radioactive Iodine (RAI) therapy in the definitive management of thyrotoxicosis at Inkosi Albert Luthuli Central Hospital (IALCH), KwaZulu-Natal, South Africa. Methods : The clinical records of all new patients with thyrotoxicosis, referred in a 4 year period between 01/01/2003 and 31/12/2006, were analysed. Response to RAI was monitored using biochemical parameters (namely, Thyroid Stimulating Hormone and Free T4 levels). Rates of euthyroidism (cure), hypothyroidism and hyperthyroidism (treatment failure) were correlated to dose of RAI. Patients were followed-up for at least 2 years or until the onset of hypothyroidism. The follow-up period was until 31/12/2007. Results : One hundred and fourteen patients (37.7%), of a cohort of 302 new thyrotoxic patients treated with RAI, met the inclusion criteria. Ninety-six patients (84.2%) had Graves Disease (GD) whilst 18 had Toxic Nodular Disease (TND). At 2 year follow-up, 91 patients (79.8%) were hypothyroid, 10 (8.8%) were euthyroid and 13 (11.4%) were hyperthyroid. The average dose of RAI to achieve euthyroidism was 10mCi and hypothyroidism, 9.7mCi. The average time to achieve euthyroidism was 5.9 months and 10.1 months to become hypothyroid. Thirty-one patients (27.2%) remained persistently hyperthyroid after one dose of RAI. Patients with GD (88.5%) were more likely to become hypothyroid (p < 0.001) whilst 38.9% of TND patients remained hyperthyroid (p = .001). Baseline TFT values were significant in terms of outcomes correlated with the prescribed RAI dose i.e Low Dose (9mCi)(TSH p = 0.05; FT4 p = 0.003; FT3 p = 0.001). Conclusion : The majority of patients became hypothyroid over time, in keeping with reported data. In the public health sector, where early access to RAI (in terms of waiting times for appointments for RAI) and follow-up are major problems, early cure is essential to minimize the morbidity of thyrotoxicosis and this may be achieved with an initial high dose of RAI

The relationship between personal meaning, sense of coherence and organisational commitment

The present study aimed to investigate the relationships between, personal meaning, sense of coherence, organisational commitment and selected biographical variables, specifically age, tenure and occupational level. It was found that mostly significant positive relationships exist between personal meaning and sense of coherence. Personal meaning and sense of coherence exhibit predictive value for organisational commitment. It was established that self-transcendence plays a significant role in the development of affective and normative organisational commitment. Some significant differences were found between management and non-management employees in the manifestation of personal meaning. Management approximate more personal meaning to achievement, self-acceptance, and fair treatment. On sense of coherence and organisational commitment there were no significant differences between management and non-management employees. It was recommended that the relationship between personal meaning and other positive psychology variables be researched in order to determine the significance of such relationships so as to add to this relatively new body of research.Industrial and Organisational PsychologyM.Comm

Mitochondrial signalling is critical for acclimation and adaptation to flooding in Arabidopsis thaliana

Mitochondria have critical functions in the acclimation to abiotic and biotic stresses. Adverse environmental conditions lead to increased demands in energy supply and metabolic intermediates, which are provided by mitochondrial ATP production and the tricarboxylic acid (TCA) cycle. Mitochondria also play a role as stress sensors to adjust nuclear gene expression via retrograde signalling with the transcription factor (TF) ANAC017 and the kinase CDKE1 key components to integrate various signals into this pathway. To determine the importance of mitochondria as sensors of stress and their contribution in the tolerance to adverse growth conditions, a comparative phenotypical, physiological and transcriptomic characterisation of Arabidopsis mitochondrial signalling mutants (cdke1/rao1andanac017/rao2) and a set of contrasting accessions was performed after applying the complex compound stress of submergence. Our results showed that impaired mitochondrial retrograde signalling leads to increased sensitivity to the stress treatments. The multi-factorial approach identified a network of 702 co-expressed genes, including several WRKY TFs, overlapping in the transcriptional responses in the mitochondrial signalling mutants and stress-sensitive accessions. Functional characterisation of two WRKY TFs (WRKY40andWRKY45), using both knockout and overexpressing lines, confirmed their role in conferring tolerance to submergence. Together, the results revealed that acclimation to submergence is dependent on mitochondrial retrograde signalling, and underlying transcriptional re-programming is used as an adaptation mechanism

Evidence of neutral transcriptome evolution in plants

The transcriptome of an organism is its set of gene transcripts (mRNAs) at a defined spatial and temporal locus. Because gene expression is affected markedly by environmental and developmental perturbations, it is widely assumed that transcriptome divergence among taxa represents adaptive phenotypic selection. This assumption has been challenged by neutral theories which propose that stochastic processes drive transcriptome evolution. To test for evidence of neutral transcriptome evolution in plants, we quantified 18 494 gene transcripts in nonsenescent leaves of 14 taxa of Brassicaceae using robust cross-species transcriptomics which includes a two-step physical and in silicobased normalization procedure based on DNA similarity among taxa. Transcriptome divergence correlates positively with evolutionary distance between taxa and with variation in gene expression among samples. Results are similar for pseudogenes and chloroplast genes evolving at different rates. Remarkably, variation in transcript abundance among root-cell samples correlates positively with transcriptome divergence among root tissues and among taxa. Because neutral processes affect transcriptome evolution in plants, many differences in gene expression among or within taxa may be nonfunctional, reflecting ancestral plasticity and founder effects. Appropriate null models are required when comparing transcriptomes in space and time

ANAC017 coordinates organellar functions and stress responses by reprogramming retrograde signaling

Mitochondria adjust their activities in response to external and internal stimuli to optimize growth via the mitochondrial retrograde response (MRR) signaling pathway. The Arabidopsis (Arabidopsis thaliana) NAC domain transcription factor ANAC017 has previously been identified as a regulator of the MRR. We show here that overexpression of ANAC017 in Arabidopsis leads to growth retardation, altered leaf development with decreased cell size and viability, and early leaf senescence. RNA-seq analyses revealed increased ANAC017 expression leads to higher expression of genes related to mitochondrial stress, cell death/autophagy, and leaf senescence under non-limiting growth conditions, as well as extensive repression of chloroplast function. Gene regulatory network analysis indicated that a complex hierarchy of transcription factors exists downstream of ANAC017. These involve a set of up-regulated ANAC and WRKY transcription factors associated with organellar signaling and senescence. The network also includes a number of ethylene- and gibberellic acid-related transcription factors with established function in stress responses and growth regulation, which down-regulate their target genes. A number of BASIC LEUCINE-ZIPPER MOTIF transcription factors involved in the endoplasmic reticulum unfolded protein response or balancing of energy homeostasis via the SNF1-RELATED PROTEIN KINASE1 were also down-regulated by ANAC017 overexpression. Our results show that the endoplasmic reticulum membrane-tethering of the constitutively expressed ANAC017, and its controlled release, are crucial to fine-tune a fast reactive but potentially harmful signaling cascade. Thus, ANAC017 is a master regulator of cellular responses with mitochondria acting as central sensors