Social factors affecting seasonal variation in bovine trypanosomiasis on the Jos Plateau, Nigeria

BACKGROUND: African Animal Trypanosomiasis (AAT) is a widespread disease of livestock in Nigeria and presents a major constraint to rural economic development. The Jos Plateau was considered free from tsetse flies and the trypanosomes they transmit due to its high altitude and this trypanosomiasis free status attracted large numbers of cattle-keeping pastoralists to the area. The Jos Plateau now plays a major role in the national cattle industry in Nigeria, accommodating approximately 7% of the national herd, supporting 300,000 pastoralists and over one million cattle. During the past two decades tsetse flies have invaded the Jos Plateau and animal trypanosomiasis has become a significant problem for livestock keepers. Here we investigate the epidemiology of trypanosomiasis as a re-emerging disease on the Plateau, examining the social factors that influence prevalence and seasonal variation of bovine trypanosomiasis. METHODS: In 2008 a longitudinal two-stage cluster survey was undertaken on the Jos Plateau. Cattle were sampled in the dry, early wet and late wet seasons. Parasite identification was undertaken using species-specific polymerase chain reactions to determine the prevalence and distribution of bovine trypanosomiasis. Participatory rural appraisal was also conducted to determine knowledge, attitudes and practices concerning animal husbandry and disease control. RESULTS: Significant seasonal variation between the dry season and late wet season was recorded across the Jos Plateau, consistent with expected variation in tsetse populations. However, marked seasonal variations were also observed at village level to create 3 distinct groups: Group 1 in which 50% of villages followed the general pattern of low prevalence in the dry season and high prevalence in the wet season; Group 2 in which 16.7% of villages showed no seasonal variation and Group 3 in which 33.3% of villages showed greater disease prevalence in the dry season than in the wet season. CONCLUSIONS: There was high seasonal variation at the village level determined by management as well as climatic factors. The growing influence of management factors on the epidemiology of trypanosomiasis highlights the impact of recent changes in land use and natural resource competition on animal husbandry decisions in the extensive pastoral production system

A longitudinal survey of African animal trypanosomiasis in domestic cattle on the Jos Plateau, Nigeria:prevalence, distribution and risk factors

BACKGROUND: Trypanosomiasis is a widespread disease of livestock in Nigeria and a major constraint to the rural economy. The Jos Plateau, Nigeria was free from tsetse flies and the trypanosomes they transmit due to its high altitude and the absence of animal trypanosomiasis attracted large numbers of cattle-keeping pastoralists to inhabit the plateau. The Jos Plateau now plays a significant role in the national cattle industry, accommodating approximately 7% of the national herd and supporting 300,000 pastoralists and over one million cattle. However, during the past two decades tsetse flies have invaded the Jos Plateau and animal trypanosomiasis has become a significant problem for livestock keepers. METHODS: In 2008 a longitudinal two-stage cluster survey on the Jos Plateau. Cattle were sampled in the dry, early wet and late wet seasons. Parasite identification was undertaken using species-specific polymerase chain reactions to determine the prevalence and distribution bovine trypanosomiasis. Logistic regression was performed to determine risk factors for disease. RESULTS: The prevalence of bovine trypanosomiasis (Trypanosoma brucei brucei, Trypanosoma congolense savannah, Trypanosoma vivax) across the Jos Plateau was found to be high at 46.8% (39.0 – 54.5%) and significant, seasonal variation was observed between the dry season and the end of the wet season. T. b. brucei was observed at a prevalence of 3.2% (1% – 5.5%); T. congolense at 27.7% (21.8% - 33.6%) and T. vivax at 26.7% (18.2% - 35.3%). High individual variation was observed in trypanosomiasis prevalence between individual villages on the Plateau, ranging from 8.8% to 95.6%. Altitude was found to be a significant risk factor for trypanosomiasis whilst migration also influenced risk for animal trypanosomiasis. CONCLUSIONS: Trypanosomiasis is now endemic on the Jos Plateau showing high prevalence in cattle and is influenced by seasonality, altitude and migration practices. Attempts to successfully control animal trypanosomiasis on the Plateau will need to take into account the large variability in trypanosomiasis infection rates between villages, the influence of land use, and husbandry and management practices of the pastoralists, all of which affect the epidemiology of the disease

Effects of taurine supplementation on bone mineral density in ovariectomized rats fed calcium deficient diet

Taurine supplementation has been shown to have a beneficial effect on femur bone mineral content in ovariectomized rats. It therefore seemed desirable to find out whether the beneficial effect of taurine on ovariectomized rats fed calcium deficient diet could also be reproduced. Forty female Sprague-Dawley rats were divided into two groups. One group was OVX and the other group received sham operation (SHAM), and received either control diet or a taurine supplemented diet for 6 weeks. All rats were fed on calcium deficient diet (AIN-93: 50% level of calcium) and deionized water. Bone mineral density (BMD) and bone mineral content (BMC) were measured in spine and femur. The serum and urine concentrations of calcium and phosphorus were determined. Bone formation was measured by serum osteocalcin and alkaline phosphatase (ALP) concentrations. Bone resorption rate was measured by deoxypyridinoline (DPD) crosslinks immunoassay and corrected for creatinine. Urinary calcium and phosphorus excretion, osteocalcin in blood and cross link value were not significantly different among the groups. Within the OVX group, the taurine supplemented group had not higher femur bone mineral content than the control group. This study established the need for a study on the taurine effect on bone with different calcium levels

Maternal and child health interventions in Nigeria: a systematic review of published studies from 1990 to 2014

BACKGROUND: Poor maternal and child health indicators have been reported in Nigeria since the 1990s. Many interventions have been instituted to reverse the trend and ensure that Nigeria is on track to achieve the Millennium Development Goals. This systematic review aims at describing and indirectly measuring the effect of the Maternal, Newborn, and Child Health (MNCH) interventions implemented in Nigeria from 1990 to 2014. METHODS: PubMed and ISI Web of Knowledge were searched from 1990 to April 2014 whereas POPLINE® was searched until 16 February 2015 to identify reports of interventions targeting Maternal, Newborn, and Child Health in Nigeria. Narrative and graphical synthesis was done by integrating the results of extracted studies with trends of maternal mortality ratio (MMR) and under five mortality (U5MR) derived from a joint point regression analysis using Nigeria Demographic and Health Survey data (1990-2013). This was supplemented by document analysis of policies, guidelines and strategies of the Federal Ministry of Health developed for Nigeria during the same period. RESULTS: We identified 66 eligible studies from 2,662 studies. Three interventions were deployed nationwide and the remainder at the regional level. Multiple study designs were employed in the enrolled studies: pre- and post-intervention or quasi-experimental (n = 40; 61%); clinical trials (n = 6;9%); cohort study or longitudinal evaluation (n = 3;5%); process/output/outcome evaluation (n = 17;26%). The national MMR shows a consistent reduction (Annual Percentage Change (APC) = -3.10%, 95% CI: -5.20 to -1.00 %) with marked decrease in the slope observed in the period with a cluster of published studies (2004-2014). Fifteen intervention studies specifically targeting under-five children were published during the 24 years of observation. A statistically insignificant downward trend in the U5MR was observed (APC = -1.25%, 95% CI: -4.70 to 2.40%) coinciding with publication of most of the studies and development of MNCH policies. CONCLUSIONS: The development of MNCH policies, implementation and publication of interventions corresponds with the downward trend of maternal and child mortality in Nigeria. This systematic review has also shown that more MNCH intervention research and publications of findings is required to generate local and relevant evidence

'Vernacular Voices: Black British Poetry'

ABSTRACT Black British poetry is the province of experimenting with voice and recording rhythms beyond the iambic pentameter. Not only in performance poetry and through the spoken word, but also on the page, black British poetry constitutes and preserves a sound archive of distinct linguistic varieties. In Slave Song (1984) and Coolie Odyssey (1988), David Dabydeen employs a form of Guyanese Creole in order to linguistically render and thus commemorate the experience of slaves and indentured labourers, respectively, with the earlier collection providing annotated translations into Standard English. James Berry, Louise Bennett, and Valerie Bloom adapt Jamaican Patois to celebrate Jamaican folk culture and at times to represent and record experiences and linguistic interactions in the postcolonial metropolis. Grace Nichols and John Agard use modified forms of Guyanese Creole, with Nichols frequently constructing gendered voices whilst Agard often celebrates linguistic playfulness. The borders between linguistic varieties are by no means absolute or static, as the emergence and marked growth of ‘London Jamaican’ (Mark Sebba) indicates. Asian British writer Daljit Nagra takes liberties with English for different reasons. Rather than having recourse to established Creole languages, and blending them with Standard English, his heteroglot poems frequently emulate ‘Punglish’, the English of migrants whose first language is Punjabi. Whilst it is the language prestige of London Jamaican that has been significantly enhanced since the 1990s, a fact not only confirmed by linguistic research but also by its transethnic uses both in the streets and on the page, Nagra’s substantial success and the mainstream attention he receives also indicate the clout of vernacular voices in poetry. They have the potential to connect with oral traditions and cultural memories, to record linguistic varieties, and to endow ‘street cred’ to authors and texts. In this chapter, these double-voiced poetic languages are also read as signs of resistance against residual monologic ideologies of Englishness. © Book proposal (02/2016): The Cambridge History of Black and Asian British Writing p. 27 of 4

Forging connections: anthologies, arts collectives, and the politics of inclusion

The changing social and political landscape of twentieth-century Britain catalysed a remarkable rise in collaborative activity by artists and activists of black and Asian heritage. Creative communities began to gather in both local and regional contexts, with the aim of sharing resources and securing an audience. This chapter records some of these many activities, tracing the groups’ genesis, manifest objectives, and key contributions. It argues that anthologising should be understood as a specifically motivated activity. Literary anthologies of poetry and fiction served to showcase the diversity of contemporary writing, while also suggesting its coherence. Drawing on the concept of “strategic essentialism” elucidated by Gayatri Chakravorty Spivak, I show that the anthology acts to ensure the visibility of a group, bannered as a unified and singly-titled selection of texts, while also insisting on the differences within: the heterogeneous multiplicity of black and Asian British experiences and creative practices

Carbon cycle processes in tropical savannas of far North Queensland, Australia

Tropical savannas represent a diverse range of heterogenous ecosystems that play an important role in the global carbon cycle as they occupy approximately one fifth of the land surface. Despite their significance, there remains a paucity of studies that quantify the carbon stocks and uxes of these dynamic ecosystems, particularly within Australia (Chapter 1). This study contributes to the field of tropical savanna carbon cycle dynamics by quantifying the carbon stocks and fluxes at three study sites in northern Queensland and placing them in the context of climate change and the global carbon cycle. Chapter 2 presents a review of the ecology and carbon dynamics of tropical savannas. The chapter addresses uncertainty regarding the definition and extent of tropical savannas, and the state of knowledge surrounding the drivers behind the extent of tropical savannas. In particular, stochastic disturbances such as fire play a crucial role in these ecosystems. Tropical savannas are also unique in that they consist of a mix of distinct and competing vegetation in the form of trees and grasses, that generally utilise contrasting photosynthetic strategies. As these photosynthetic pathways respond differently to atmospheric CO₂ and temperature, how these ecosystems will respond to climate change is also a matter of some uncertainty. Chapter 3 presents a detailed description of the three sites used in this study; two of the sites (Davies Creek and Koombooloomba) are located near the rainforest-savanna boundary in a high rainfall zone (mean annual precipitation (MAP) ~1500mm) while the third site (Brooklyn Station) is both more arid (MAP ~900mm) and more seasonal. In Chapter 4, aboveground biomass (AGB) and aboveground net primary productivity (ANPP) is quantified using an inventory-based assessment. These sites are some of the more densely wooded tropical savannas in Australia and basal area remained unchanged at all sites over the sample interval. While the carbon stocks in the AGB (40, 75, and 87 t C ha⁻¹ for Brooklyn Station, Davies Creek, and Koombooloomba, respectively) were dominated by the tree component, the grassy understorey was a significant contributor to ANPP (4.1, 5.1, and 9.2 t C ha⁻¹ y⁻¹ for Brooklyn Station, Davies Creek, and Koombooloomba, respectively) at all sites, consisting of almost three quarters of the total. The woody carbon stock was sensitive to disturbance with high mortality at two sites attributed to damage caused by fire and Tropical Cyclone (TC) Yasi. These results highlight the sensitivity of the carbon storage potential of tropical savannas to stochastic disturbance and their vulnerability to substantial shifts in both structure and composition as a result of climate change. Chapter 5 presents data on soil carbon and nitrogen, as well as their stable isotopes. Soil carbon stocks (0-30cm) were 114 ± 25, 41 ± 14, and 38 ± 19 t C ha⁻¹ at Koombooloomba, Davies Creek, and Brooklyn Station, respectively. The carbon isotopes were used to partition the soil carbon into C3 and C4 sources; the grassy understorey contributed approximately half of the soil carbon at two of the sites (Brooklyn Station and Koombooloomba), but contributed only 27% at the third site. Soil carbon displayed a high level of spatial arrangement at the two wettest sites with higher soil carbon in areas adjacent to trees, but not at the driest site and redistribution of carbon inputs by termites may be responsible. Although considerable quantities of soil carbon are stored at these sites for now, climate change may result in vegetation shifts, changes to _re regimes, and exacerbated erosion that could result in the loss of soil carbon from these sites. Chapter 6 provides the most comprehensive dataset of soil respiration in tropical savannas in Australia. Soil respiration was measured monthly for two years at the three sites. Soil respiration was temporally controlled by temperature and moisture availability, with high respiration rates (~4-8 μmol m⁻² s⁻¹) during the wet season (November - April) when plant growth is high, and low respiration rates (~1-4 μmol m⁻² s⁻¹) during the dry season (May - October) when plant growth slows. Soil respiration was spatially variable and controlled by proximity to woody vegetation with high soil respiration rates near trees and low soil respiration rates in open areas dominated by grasses. Soil respiration in these tropical savanna environments is thus both temporally and spatially heterogeneous suggesting that more complex models may be required to accurately estimate the soil respiration in such systems. In Chapter 7, an experimental drought was created at Davies Creek over two years in order to examine the effects of drought on soil respiration and soil chemistry. The drought successfully reduced soil moisture without impacting significantly on other environmental variables. The drought delayed the growing season of the grasses in the first year and killed them in the second year. Soil respiration was correspondingly reduced in the first wet season and then increased in the second wet season, likely as a result of these changes to plant biomass availability. Higher soil carbon in the drought experiment suggests that there were additional carbon inputs, presumably due to the death of the grass and subsequent recolonisation of the soil by neighbouring grasses. Extended droughts could see shifts in species and ecosystems potentially accompanied by an increase in soil respiration before ecosystem stability is reached. This study presents the first comprehensive assessment of carbon cycle dynamics in tropical savannas in Queensland. Furthermore, this is the first study in Australia to examine transition zone savannas that occur at the rainforest-savanna boundary and the first study in Australia to attempt to simulate drought in tropical savannas

Spatial heterogeneity of soil-derived CO2 efflux in three tropical Australian savannas

[Extract]\ud •Soil-derived CO₂ efflux is one of the largest fluxes in the global C cycle and tropical savannah ecosystems are estimated to cover 20% of the land surface and account for up to 30% of Primary Production.\ud •These ecosystems are characterised by highly seasonal rainfall and consist of a mix of trees and grasses that leads to local heterogeneity in soil properties