119 research outputs found

    Sand plain fynbos conservation : the Kenilworth Racecourse case study

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    Bibliography: pages 114-122.The current extent of Sand Plain Fynbos and threats to its survival are examined, with a view to proposing effective means of managing areas of high conservation priority. Extensive depletion of Sand Plain Fynbos has resulted from agricultural development, urbanisation and its susceptibility to invasion by introduced woody plant species. The need to conserve this veld type is apparent in that only 0.05% of the original Cape Flats Sand Plain Fynbos still survives within scattered refugia. A mere 3.8% of this already minute fraction is represented in proclaimed nature reserves, clearly illustrating the neglected conservation status of this veld type. The majority of the remaining habitat owes its survival, albeit in various stages of degradation, to low impact land uses not related to conservation per se. The in-fields of the three racecourses on the Cape Flats in total comprise the land use supporting the largest area of Sand Plain Fynbos. This suggests the potential compatibility of such a land use with conservation in the longer term. Of the three racecourses, Kenilworth is the most important in terms of area, diversity and unprecedented numbers of threatened flora and fauna of the fynbos it supports. This provides a case study on which to base an assessment of the trends in species survival on small remnants. A historical backdrop to the isolation and degradation of the Kenilworth Racecourse and neighbouring remnants is provided. The predictions of conservation theory for the long-term viability of such small and isolated remnants are then reviewed. To determine the effects of recent events and processes on the conservation merits of Kenilworth Racecourse, species extinctions and turnover from 1950 to the present are determined for the flora and avifauna respectively. Past and current species checklists form the basis of this analysis. Causes of species loss are investigated by comparing the physical attributes and habitat preferences of the species present with those which have apparently become extinct locally. The influence of private landownership on the conservation security of Kenilworth Racecourse is of fundamental importance to its future conservation. In this respect, the likelihood of change in land use of the in-field fynbos, as well as the Racecourse area as a whole, is a crucial factor addressed in this study. The present and future operating requirements of the Racecourse Management are also determined and their likely effects on the natural system are assessed. The study establishes a need for conservation management at Kenilworth Racecourse. The approach adopted to achieve the ongoing conservation of the area is through the development of a Conservation Management Plan. The latter has been derived through reasoned and personal interaction with the Racecourse Management and is aimed towards integrating the needs of the Management with the ecological requirements for the natural system under its control. The creation of corridors to facilitate migration of biota, as well as the reintroduction of those species which have become extinct locally, are described as an adjunct to these proposals. The implementation of an organised burn programme is proposed as a management procedure to counteract species loss. Evaluation of initial success resulting from the Management Plan reveals that there is now an improved communication channel with the Management. This encompasses moral obligations for eradication of alien vegetation, abstention from further drainage of wetlands, prevention of future encroachment of parking within the natural system and an agreement to cease indiscriminate dumping of refuse material. A major constraint facing the conservation of the area is the reluctance of the Management to allow public interest groups direct involvement with monitoring and implementation of proposals presented within the Management Plan. The research findings and conservation management approach generated by the study are important because they have potential for promoting the long term conservation of analogous remnants, not only within the fynbos biome, but in other similar systems further afield. Although threats exist to the ongoing survival of Sand Plain Fynbos remnants, these should not prejudice their selection as areas worthy of sound conservation management. Remnants have inherent value as refugia. They are also of potential importance as sites for reintroduction of species that have become extinct locally, as educational resources and as relatively low-maintenance open spaces within the urban landscape

    Crystallographic and magnetic identification of secondary phase in orientated Bi5Fe0.5Co0.5Ti3O15 ceramics

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    Oxide materials which exhibit both ferroelectricity and ferromagnetism are of great interest for sensors and memory applications. Layered bismuth titanates with an Aurivillius structure, (BiFeO3)nBi4Ti3O12, can possess ferroelectric and ferromagnetic order parameters simultaneously. It has recently been demonstrated that one such example, Bi5Fe0.5Co0.5Ti3O15,where n = 1 with half the Fe3+ sites substituted by Co3+ ions, exhibits both ferroelectric and ferromagnetic properties at room temperature. Here we report the fabrication of highly-oriented polycrystalline ceramics of this material, prepared via molten salt synthesis and uniaxial pressing of high aspect ratio platelets. Electron backscatter images showed that there is a secondary phase within the ceramic matrix which is rich in cobalt and iron, hence this secondary phase could contribute in the main phase ferromagnetic property. The concentration of the secondary phase obtained from secondary electron microscopy is estimated at less than 2.5 %, below the detection limit of XRD. TEM was used to identify the crystallographic structure of the secondary phase, which was shown to be cobalt ferrite, CoFe2O4. It is inferred from the data that the resultant ferromagnetic response identified using VSM measurements was due to the presence of the minor secondary phase. The Remanent magnetization at room temperature was Mr ≈ 76 memu/g which dropped down to almost zero (Mr ≈ 0.8 memu/g) at 460 oC, far lower than the anticipated for CoFe2O4

    A large scale hearing loss screen reveals an extensive unexplored genetic landscape for auditory dysfunction

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    The developmental and physiological complexity of the auditory system is likely reflected in the underlying set of genes involved in auditory function. In humans, over 150 non-syndromic loci have been identified, and there are more than 400 human genetic syndromes with a hearing loss component. Over 100 non-syndromic hearing loss genes have been identified in mouse and human, but we remain ignorant of the full extent of the genetic landscape involved in auditory dysfunction. As part of the International Mouse Phenotyping Consortium, we undertook a hearing loss screen in a cohort of 3006 mouse knockout strains. In total, we identify 67 candidate hearing loss genes. We detect known hearing loss genes, but the vast majority, 52, of the candidate genes were novel. Our analysis reveals a large and unexplored genetic landscape involved with auditory function

    Comparative Analysis of Fecal Microbiota in Infants with and without Eczema

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    Eczema is a chronic form of childhood disorder that is gaining in prevalence in affluent societies. Previous studies hypothesized that the development of eczema is correlated with changes in microbial profile and composition of early life endemic microbiota, but contradictory conclusions were obtained, possibly due to the lack of minimization of apparent non-health related confounders (e.g., age, antibiotic consumption, diet and mode of delivery). In this study, we recruited seven caesarean-delivered and total formula-fed infants, and comparatively examined the early-life endemic microbiota in these infants with and without eczema. Using 16S pyrosequencing, infants' fecal microbiota were observed to comprise Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes as the four main phyla, and the presence and absence of specific populations within these four phyla are primarily mediated by ageing. Quantitative analysis of bacterial targets on a larger sample size (n = 36 at 1, 3, and 12 months of age) revealed that the abundances of Bifidobacterium and Enterobacteriaceae were different among caesarean-delivered infants with and without eczema, and the bacterial targets may be potential biomarkers that can correlate to the health status of these infants. Our overall findings suggest that the minimization of possible confounders is essential prior to comparative evaluation and correlation of fecal microbiota to health status, and that stool samples collected from caesarean-delivered infants at less than 1 year of age may represent a good cohort to study for potential biomarkers that can distinguish infants with eczema from those without. These findings would greatly facilitate future efforts in understanding the possible pathogenesis behind certain bacterial targets, and may lead to a timely intervention that reduces the occurrence of early life eczema and possibly allergic disorders in later life

    B Cell: T Cell Interactions Occur within Hepatic Granulomas during Experimental Visceral Leishmaniasis

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    Hepatic resistance to Leishmania donovani infection in mice is associated with the development of granulomas, in which a variety of lymphoid and non-lymphoid populations accumulate. Although previous studies have identified B cells in hepatic granulomas and functional studies in B cell-deficient mice have suggested a role for B cells in the control of experimental visceral leishmaniasis, little is known about the behaviour of B cells in the granuloma microenvironment. Here, we first compared the hepatic B cell population in infected mice, where ≈60% of B cells are located within granulomas, with that of naïve mice. In infected mice, there was a small increase in mIgMlomIgD+ mature B2 cells, but no enrichment of B cells with regulatory phenotype or function compared to the naïve hepatic B cell population, as assessed by CD1d and CD5 expression and by IL-10 production. Using 2-photon microscopy to quantify the entire intra-granuloma B cell population, in conjunction with the adoptive transfer of polyclonal and HEL-specific BCR-transgenic B cells isolated from L. donovani-infected mice, we demonstrated that B cells accumulate in granulomas over time in an antigen-independent manner. Intra-vital dynamic imaging was used to demonstrate that within the polyclonal B cell population obtained from L. donovani-infected mice, the frequency of B cells that made multiple long contacts with endogenous T cells was greater than that observed using HEL-specific B cells obtained from the same inflammatory environment. These data indicate, therefore, that a subset of this polyclonal B cell population is capable of making cognate interactions with T cells within this unique environment, and provide the first insights into the dynamics of B cells within an inflammatory site

    A large scale hearing loss screen reveals an extensive unexplored genetic landscape for auditory dysfunction.

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    The developmental and physiological complexity of the auditory system is likely reflected in the underlying set of genes involved in auditory function. In humans, over 150 non-syndromic loci have been identified, and there are more than 400 human genetic syndromes with a hearing loss component. Over 100 non-syndromic hearing loss genes have been identified in mouse and human, but we remain ignorant of the full extent of the genetic landscape involved in auditory dysfunction. As part of the International Mouse Phenotyping Consortium, we undertook a hearing loss screen in a cohort of 3006 mouse knockout strains. In total, we identify 67 candidate hearing loss genes. We detect known hearing loss genes, but the vast majority, 52, of the candidate genes were novel. Our analysis reveals a large and unexplored genetic landscape involved with auditory function.The full extent of the genetic basis for hearing impairment is unknown. Here, as part of the International Mouse Phenotyping Consortium, the authors perform a hearing loss screen in 3006 mouse knockout strains and identify 52 new candidate genes for genetic hearing loss

    Identification of genetic elements in metabolism by high-throughput mouse phenotyping.

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    Metabolic diseases are a worldwide problem but the underlying genetic factors and their relevance to metabolic disease remain incompletely understood. Genome-wide research is needed to characterize so-far unannotated mammalian metabolic genes. Here, we generate and analyze metabolic phenotypic data of 2016 knockout mouse strains under the aegis of the International Mouse Phenotyping Consortium (IMPC) and find 974 gene knockouts with strong metabolic phenotypes. 429 of those had no previous link to metabolism and 51 genes remain functionally completely unannotated. We compared human orthologues of these uncharacterized genes in five GWAS consortia and indeed 23 candidate genes are associated with metabolic disease. We further identify common regulatory elements in promoters of candidate genes. As each regulatory element is composed of several transcription factor binding sites, our data reveal an extensive metabolic phenotype-associated network of co-regulated genes. Our systematic mouse phenotype analysis thus paves the way for full functional annotation of the genome

    Delivery of maternal health care in Indigenous primary care services: baseline data for an ongoing quality improvement initiative

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    Extent: 10p.BACKGROUND: Australia's Aboriginal and Torres Strait Islander (Indigenous) populations have disproportionately high rates of adverse perinatal outcomes relative to other Australians. Poorer access to good quality maternal health care is a key driver of this disparity. The aim of this study was to describe patterns of delivery of maternity care and service gaps in primary care services in Australian Indigenous communities. METHODS: We undertook a cross-sectional baseline audit for a quality improvement intervention. Medical records of 535 women from 34 Indigenous community health centres in five regions (Top End of Northern Territory 13, Central Australia 2, Far West New South Wales 6, Western Australia 9, and North Queensland 4) were audited. The main outcome measures included: adherence to recommended protocols and procedures in the antenatal and postnatal periods including: clinical, laboratory and ultrasound investigations; screening for gestational diabetes and Group B Streptococcus; brief intervention/advice on health-related behaviours and risks; and follow up of identified health problems. RESULTS: The proportion of women presenting for their first antenatal visit in the first trimester ranged from 34% to 49% between regions; consequently, documentation of care early in pregnancy was poor. Overall, documentation of routine antenatal investigations and brief interventions/advice regarding health behaviours varied, and generally indicated that these services were underutilised. For example, 46% of known smokers received smoking cessation advice/counselling; 52% of all women received antenatal education and 51% had investigation for gestational diabetes. Overall, there was relatively good documentation of follow up of identified problems related to hypertension or diabetes, with over 70% of identified women being referred to a GP/Obstetrician. CONCLUSION: Participating services had both strengths and weaknesses in the delivery of maternal health care. Increasing access to evidence-based screening and health information (most notably around smoking cessation) were consistently identified as opportunities for improvement across services.Alice R. Rumbold, Ross S. Bailie, Damin Si, Michelle C. Dowden, Catherine M. Kennedy, Rhonda J. Cox, Lynette O’Donoghue, Helen E. Liddle, Ru K. Kwedza, Sandra C. Thompson, Hugh P. Burke, Alex D. H. Brown, Tarun Weeramanthri and Christine M. Connor

    The Australasian Resuscitation In Sepsis Evaluation : fluids or vasopressors in emergency department sepsis (ARISE FLUIDS), a multi-centre observational study describing current practice in Australia and New Zealand

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    Objectives: To describe haemodynamic resuscitation practices in ED patients with suspected sepsis and hypotension. Methods: This was a prospective, multicentre, observational study conducted in 70 hospitals in Australia and New Zealand between September 2018 and January 2019. Consecutive adults presenting to the ED during a 30-day period at each site, with suspected sepsis and hypotension (systolic blood pressure <100 mmHg) despite at least 1000 mL fluid resuscitation, were eligible. Data included baseline demographics, clinical and laboratory variables and intravenous fluid volume administered, vasopressor administration at baseline and 6- and 24-h post-enrolment, time to antimicrobial administration, intensive care admission, organ support and in-hospital mortality. Results: A total of 4477 patients were screened and 591 were included with a mean (standard deviation) age of 62 (19) years, Acute Physiology and Chronic Health Evaluation II score 15.2 (6.6) and a median (interquartile range) systolic blood pressure of 94 mmHg (87–100). Median time to first intravenous antimicrobials was 77 min (42–148). A vasopressor infusion was commenced within 24 h in 177 (30.2%) patients, with noradrenaline the most frequently used (n = 138, 78%). A median of 2000 mL (1500–3000) of intravenous fluids was administered prior to commencing vasopressors. The total volume of fluid administered from pre-enrolment to 24 h was 4200 mL (3000–5661), with a range from 1000 to 12 200 mL. Two hundred and eighteen patients (37.1%) were admitted to an intensive care unit. Overall in-hospital mortality was 6.2% (95% confidence interval 4.4–8.5%). Conclusion: Current resuscitation practice in patients with sepsis and hypotension varies widely and occupies the spectrum between a restricted volume/earlier vasopressor and liberal fluid/later vasopressor strategy
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