Acute disseminated encephalomyelitis mimicking late CNS relapse of acute lymphoblastic leukaemia: case report

BACKGROUND: Acute encephalomyelopathy occurring after an allogeneic bone marrow transplant for leukaemia is a diagnostic emergency. The diagnosis can be challenging since there is a wide set of alternative diagnoses, including opportunistic infections and relapse of the leukaemia. CASE PRESENTATION: A 13-year old girl presented with a severe acute myelopathy and encephalopathy. She was in prolonged remission from a central nervous system and bone marrow relapse of an acute lymphoblastic leukaemia, treated with allogeneic bone marrow transplantation. Neuroimaging showed multifocal grey and white matter lesions of demyelinating appearance in the brain and entire spine. Immunophenotyping and cytogenetic investigations of the girl's cerebrospinal fluid lymphocytosis excluded a late central nervous system relapse of her leukaemia. The diagnosis was acute disseminated encephalomyelitis. With standard immunosuppressive therapy, the girl had early cerebral recovery but a prolonged period of recovery from her myelopathy. CONCLUSION: Acute disseminated encephalomyelitis should be considered in the differential diagnosis of acute encephalomyelopathy after bone marrow transplantation for leukaemia. Demyelinating syndromes such as acute disseminated encephalomyelitis may be late sequelae of bone marrow transplantation

Foraging and Nutritional Ecology of Eastern Australian White Sharks (Carcharodon carcharias)

Understanding and predicting foraging requires considering animals’ intrinsic (physiological) state, extrinsic (environmental/ecological) context, and the reciprocal interplays between these that shape feeding and behaviour. In particular, interactions between nutritional requirements (macronutrient balance) and ecological context are key determinants of foraging. Understanding these dynamics is especially critical in trophic keystone species, like marine top predators. Yet challenges in spatiotemporal observation and insufficient information on marine prey nutritional variability have limited knowledge of marine predator nutritional ecology so far. Here I explore the intrinsic and extrinsic drivers and outcomes of foraging in the white shark (Carcharodon carcharias), an ecologically important, threatened top predator that epitomizes the research challenges above. Using stomach contents, I provide the first diet assessment for white sharks in eastern Australia, identifying differences in prey use from other populations (South Africa) and size-based nutritional niche variation. I develop and apply a new framework leveraging stable isotopes to establish time-integrated nutritional niches and reveal how individual white sharks may specialise on functionally different (benthic or pelagic) but nutritionally complementary prey mixes to achieve similar nutritional goals. Using biologging I identify new functional bases for fine-scale white shark behaviour and recovery following capture and release, offering critical information for conservation and management. Finally, I quantify interspecific and spatiotemporal variation in prey proximate compositions to examine the nutritional landscape of eastern Australian white sharks and suggest new links to prey preference and movement. My thesis advances our understanding of the nutritional and ecological aspects of white shark foraging and develops new adaptable frameworks to enhance field studies in nutritional ecology generally

Purchasing a personality : a case study of cellular phone consumption by South African students at the University of KwaZulu-Natal.

Thesis (M.A.)-University of KwaZulu-Natal, Durban, 2009.This dissertation examines youth consumer culture in South Africa through a case study of cellular phone consumption. The hypothesis is that it is possible to draw some conclusions about identity formation, particularly among young people, by examining how they use cellular phones. Two methods were employed to understand three key research questions regarding the youth (aged 18-25). They were: Why do youth use cellular phones and what gratifications do they experience? From a marketing perspective, what web promotions are in place to target this youth market? How do the youth respond to these messages? The first method utilised a questionnaire investigating young people‟s perceptions, sampled from a group of students at the University of KwaZulu-Natal (UKZN). This objective was to reveal why young people have cellular phones and how they respond to marketed messages encouraging cellular phone consumption. The second method applied a semiotic analysis of the South African oligopolistic cellular networks' websites. This showed how marketers perceive their youth segment and how they harness the Internet as a marketing medium. Significant findings that foster consumption were presented regarding this youth sample. One such finding is that self expression is articulated through consumption. This is particularly evident in the purchasing of cellular phones and airtime and how the purchasing decision reflects the individualisation of self. Further, the importance of social institutions emerged with family instilling or attempting to instil discernment regarding diligent and necessary spending. The opposite is evident with peer pressure influencing unnecessary consumption. Lastly, advertising emerged as a central driver in creating brand awareness and stimulating the consumption of cellular phones and packages amongst this youth segment. Against the research results discussed, relevant literature gave support and further insights into youth consumer culture. This dissertation provides, and concludes with, a deeper understanding into the dynamics of youth and their cellular phone consumption in South Africa, particularly in an area where there has been very little research

Immune modulation by parasitic nematodes

Almost 2 billion people world-wide are infected with parasitic helminths. These complex multicellular eukaryotic organisms are capable of establishing long-term infections even in the face of an intact immune response. Typically, in these settings regulatory components of the immune response, such as Foxp3+ T regulatory cells (Tregs), become dominant, limiting protective effector responses towards the parasite. Helminths are thought to have evolved mechanisms, including release of immunomodulatory molecules termed excretory-secretory products (ES), to sway the balance between the regulatory and effector arms of the immune response to favour their persistence. In this thesis both the development of a protective immune response toward, and the potential manipulation of the immune response by, the rodent gastrointestinal nematode Heligmosomoides polygyrus have been studied. Firstly, the effects of H. polygyrus ES (HES) on bone-marrow derived dendritic cells (DCs) were analysed. Although HES did not alter the phenotype of the DC it was found to be able to suppress the ability of the DC to respond to inflammatory stimuli. This activity was lost when HES was heat-inactivated (hiHES). After adoptive transfer, HES-pulsed DCs were able to induce a HESspecific T helper (Th)2-type response even if co-treated with an inflammatory stimulus. Th2-type responses are protective against H. polygyrus infection. Surprisingly, the ability of HES to generate a Th2-response in a co-treatment situation was not related to its anti-inflammatory properties; DCs co-treated with hiHES and an inflammatory stimulus were able to drive an equivalent Th2-response to HES in this situation. Next, making use of mouse strains with different susceptibility phenotypes to primary H. polygyrus infection, potential mechanisms of resistance were characterised. Development of granulomas in the gut wall were found to be associated with reduced worm burdens. Furthermore, in highly susceptible C57BL/6 mice, production of IL-23 was shown to be counter-regulatory to this process, as mice on the same background but deficient in this cytokine have increased numbers of granulomas and dramatically enhanced resistance. Susceptibility to H. polygyrus was also considered at the level of epigenetic regulation. A protein that binds specifically to methylated DNA, methyl-CpG binding domain protein (MBD)2, was found to affect the proportion of Foxp3+ Tregs within the CD4+ T cell population in vivo. Additionally, in vitro induction of Foxp3 in response to TGF-β was enhanced in MBD2-/- CD4+ T cells. MBD2-/- mice had a trend towards increased worm burdens when infected with H. polygyrus, suggesting that the difference in proportion of Tregs may limit generation of an effector response. Finally, the ability of HES to directly affect the regulatory arm of the immune response was focussed upon. It was found that HES was able to induce Foxp3 expression in naïve peripheral T cells, and that this was mediated by stimulation of the TGF-β pathway. The TGF-β mimic was of parasite origin as a pan-vertebrate TGF-β antibody was unable to block its effects but sera from H. polygyrus infected animals was competent to do this. Activity of this type was not limited to HES as ES from the ovine helminth Haemonchus contortus was found to have the same property. These data imply that some helminth parasites have evolved mechanisms to support generation of Foxp3+ Tregs, thus favouring the regulatory arm of the immune response and hence their own persistence

Curiosity and an Entrepreneurial Mindset: Views from Fellows of the University

Generally, people will associate the term ‘entrepreneurship’ with starting a business. It is this, certainly, but really entrepreneurship covers a wide spectrum of activities – it is a way of behaving. This booklet discusses entrepreneurial behaviour – and the mindset that drives this – in terms of finding opportunities to create value for others, whilst (ideally) doing something a person enjoys and can do well. There is an implicit realisation that there will always be challenge, uncertainty and risk involved. The booklet draws upon interviews with successful people who all have an association with the University; and, because the underlying message is relevant for every student across the University, the booklet sets out to encourage and enable readers to reflect upon their own capabilities and ambitions

Masked priming and ERPs dissociate maturation of orthographic and semantic components of visual word recognition in children

This study examined the time-course of reading single words in children and adults using masked repetition priming and the recording of event-related potentials. The N250 and N400 repetition priming effects were used to characterize form- and meaning-level processing, respectively. Children had larger amplitude N250 effects than adults for both shorter and longer duration primes. Children did not differ from adults on the N400 effect. The difference on the N250 suggests that automaticity for form processing is still maturing in children relative to adults, while the lack of differentiation on the N400 effect suggests that meaning processing is relatively mature by late childhood. The overall similarity in the children's repetition priming effects to adults' effects is in line with theories of reading acquisition, according to which children rapidly transition to an orthographic strategy for fast access to semantic information from print.Ellison Medical FoundationF32HD06118

Quantifying the checks and balances of collaborative governance systems for adaptive carnivore management

Recovering or threatened carnivore populations are often harvested to minimise their impact on human activities, such as livestock farming or game hunting. Increasingly, harvest quota decisions involve a set of scientific, administrative and political institutions operating at national and sub-national levels whose interactions and collective decision-making aim to increase the legitimacy of management and ensure population targets are met. In practice, however, assessments of how quota decisions change between these different actors and what consequences these changes have on population trends are rare. We combine a state-space population modelling approach with an analysis of quota decisions taken at both regional and national levels between 2007 and 2018 to build a set of decision-making models that together predict annual harvest quota values for Eurasian lynx (Lynx lynx) in Norway. We reveal a tendency for administrative decision-makers to compensate for consistent quota increases by political actors, particularly when the lynx population size estimate is above the regional target. Using population forecasts based on the ensemble of decision-making models, we show that such buffering of political biases ensures lynx population size remains close to regional and national targets in the long term. Our results go beyond the usual qualitative assessment of collaborative governance systems for carnivore management, revealing a system of checks and balances that, in the case of lynx in Norway, ensures both multi-stakeholder participation and sustainable harvest quotas. Nevertheless, we highlight important inter-regional differences in decision-making and population forecasts, the socio-ecological drivers of which need to be better understood to prevent future population declines. Synthesis and applications. Our work analyses the sequence of decisions leading to yearly quotas for lynx harvest in Norway, highlighting the collaborative and structural processes that together shape harvest sustainability. In doing so, we provide a predictive framework to evaluate participatory decision-making processes in wildlife management, paving the way for scientists and decision-makers to collaborate more widely in identifying where decision biases might lie and how institutional arrangements can be optimised to minimise them. We emphasise, however, that this is only possible if wildlife management decisions are documented and transparent