137 research outputs found

    PMS29 BAYESIAN COST-EFFECTIVENESS ANALYSIS OF TREATMENT OF ANKYLOSING SPONDYLITIS

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    International Specialization in Services: Insights from a New Theoretical Taxonomy.

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    commerce international de services; spécialisation pays; international trade in services; country specialization;

    The impacts of herbivores and humans on the utilisation of woody resources in conserved versus non-conserved land in Maputaland, northern KwaZulu-Natal, South Africa

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    This study presents an exploration of the structure, dynamics and utilisation of woody plants in vegetation units of northern Maputaland. Animal (in Tembe Elephant Park) and human (in the rural community of Manqakulane) utilisation of woody plants were compared against a control area (Tshanini Community Conservation Area) where animals were extirpated and people were precluded through tribal rules. The tree assemblages of the unique Sand Forest were explored, and compared with previous studies. A new classification was proposed and a new subcommunity was established. Contrary to previous studies, a gradient from Short to Intermediate to Tall Sand Forest was defined, and it was suggested that structurally different Sand Forest subcommunities represent a mosaic of different evolutionary states, rather than stationary states as perceived currently. Animal utilisation appeared to have transformed Sand Forest in conserved land to such an extent that it no longer resembled Sand Forest outside conserved areas. The structure of Sand Forest and woodlands of the region was evaluated at the vegetation unit level (21 vegetation units), through a size and height class distribution analysis of woody plants. Humans and animals had clearly modified the woodlands and appeared to force succession from closed woodland to open woodland. The Sand Forest appeared to benefit from low intensity animal utilisation, with increased diversity, and possibly enhanced dynamics. However, signs that current animal utilisation have negative effects were perceived. The size class distribution of Sand Forest and woodland woody species was presented and an analysis of species grain was performed. The grain concept was successfully applied to woodland species for the first time. It appeared that nearly all vegetation units were fine-grained, and therefore governed by small-scale dynamics. Frequent small disturbances are necessary to maintain diversity. There was cause for concern that current animal and human utilisation threaten such fine-scale dynamics. The utilisation level by the browsing mammals guild in Tembe Elephant Park and by small browsers and people in Manqakulane Rural Community were evaluated over two periods. Small to medium browsers utilised more woody species and height classes than any other agent, but with short-term effects. However, utilisation marks linked to elephants and people were accumulating significantly, and the long-term effects of these agents were threatening the dynamics of Maputaland vegetation. The case of woody species utilisation by elephants was evaluated further and compared with a previous study. Overall utilisation by elephants reached 100% of individuals for several woody species, while other species’ regeneration potential was severely threatened. Woody species preferred in 1994 were nearly extirpated. Utilisation of woody species by elephants throughout Tembe Elephant Park appeared correlated with distance to permanent water points during a dry spell. In conclusion, it appeared clear that policies in favour of high animal numbers in formally conserved areas were not suited for northern Maputaland and this result should be considered when the expansion of the South African protected areas of Maputaland into Mozambique becomes effective. Community-based conservation appeared promising, but novel ways of generating income should be investigated.Thesis (PhD (Wildlife Management))--University of Pretoria, 2008.Animal and Wildlife Sciencesunrestricte

    A step closer to local carbon calculations : growth timescales and linear relationships for sand forest and woodland tree species in Maputaland, South Africa

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    In Africa, information on time required for plants to develop from seed to mean size and maximum size is scarce. There is also a lack of information regarding accurate relationships between stem diameter, height and canopy dimensions. This type of information is however becoming a real necessity to allow the accurate measurement of carbon stocks and carbon stocks change to qualify for the UNFCCC’s REDD+ mechanism. We evaluated these parameters for 22 Sand Forest and woodland tree species of South Africa’s Maputaland. Results indicated that it takes approximately 66 and 35 years for current dynamics of Sand Forests and woodlands to occur respectively. Based on diameter and growth rates, larger trees of the forests can be older than 600 years, while large woodland trees can reach ages of 900 years. Our evaluation of linear relationships between stem diameter, height and canopy dimensions showed extremely robust results allowing the use of stem diameter to calculate height and canopy dimensions. The results are of interest for carbon related investigations and reconstructing stands dynamics.The University of Pretoria and the South African National Research Foundation under Grant Number 2053522.http://www.scirp.org/journal/ojfam201

    Herbivore and human impacts on woody species dynamics in Maputaland, South Africa

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    Maputaland’s woodlands are under utilization pressure inside and outside conserved areas due to mounting densities of mammals in the former and increasing human utilization of vegetation in the latter. Conservation of this biodiversity hotspot requires a better understanding of vegetation dynamics. To this purpose, woodland vegetation structure was evaluated at three sites through size class distribution analysis and grain determination, a forestry concept here applied to woodlands. The three sites represented animal disturbance/utilization, human disturbance/utilization and no disturbance/utilization regimes for comparable periods. Common species occurrence patterns differed between sites. The woodlands of all three sites were mostly fine-grained forest-like vegetation units and followed fine-grained forest dynamics closely. The grain model performed successfully for the region’s woodlands and proved a good tool to improve vegetation dynamics understanding. In general, people and herbivores led to local extirpation of species and threatened both ecological structure and function of Maputaland’s woodlands. However, the fine grain status was considered positive, as it facilitated future management options by reducing time frames and scale of management actions to be applied.The South African National Research Foundation under Grant Number 2053522 and the University of Pretoria.http://forestry.oxfordjournals.org/hb201

    Is the present Brackenridgea Nature Reserve large enough to ensure the survival of Brackenridgea zanguebarica Oliv.?

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    The Brackenridgea Nature Reserve is a 110 ha protected area established by the provincial Limpopo Department of Economic Development, Environment and Tourism as a way of protecting the population of Brackenridgea zanguebarica, a species classified as critically endangered in South Africa. In the whole of South Africa, the species is found in only one small area around Thengwe–Mafukani in Venda. It is threatened with extirpation due to high demand for its medicinal bark. This study investigated the adequacy of the reserve to conserve the species using a method established in 2001 by Burgman et al. This method involves 12 steps to quantify the risk of the decline or possible extinction of the species and takes current human activities, disturbances and the viability of the population into consideration for setting a conservation target. From the results, it was clear that more area is needed for the current population to survive beyond 50 years. Assuming the status quo, it will require 410 ha to maintain the population, whereas a 50% reduction in human-related activities, such as cultivation, harvesting and livestock grazing, will lower the required potential habitat to 203 ha and a conservation option, which allows for bark harvesting, will require 179 ha. CONSERVATION IMPLICATIONS: The results of this study will have conservation implication on management of viable species population within a nature reserve. It will require managers to take into consideration the reserve size in relation to potential habitats for the development of species under their management.http://www.koedoe.co.zaam201

    Woody vegetation utilisation in Tembe Elephant Park, Kwazulu-Natal, South Africa

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    A survey of woody plant species utilisation by large (excluding elephants), medium and small browsers,man and “natural damage”, was conducted in nine vegetation units of Tembe Elephant Park, KwaZulu-Natal, South Africa. Woody species use and canopy removal were evaluated within two age ranges, (a) recent, ≤ 12 months prior to study and (b) old, > 12 months prior to the study. The results show that recent canopy removal by medium and small browsers was intensive and generally represented one third of height classes available to the agents which were consistently used within all vegetation types. The overall utilisation pattern indicated that medium and small browsers may be removing the regeneration class of the woody plants layer. Natural damage was found to be considerable and it was hypothesized that it may be linked and possibly amplified by prior elephant utilisation. In conclusion, it is possible to suggest that the regular use of the sapling level by small and medium browsers could promote woodland to grassland retrogression, as was found in east Africa under high densities of animals.http://www.ccsenet.org/journal/index.php/ijbhb201

    Floristic and phytogeographycal analysis of coastal and subcoastal vegetation in the Kouilou Department (Republic of Congo)

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    The zone of study is located north of Pointe noire town, in the Department of Kouilou, in Republic of Congo. In order to better understand the floristic richness and chorology of the study site of interest, an analysis on a flora, of the autoecological and phytogeographycal spectra of species was undertaken. This analysis is based on the floristic material from different botanical surveys carried out in 2012, and deposited at the National Herbarium of the Congo (IEC). Over a study area of 202’700 ha investigated through 243 phytosociological plots, a matrix of 580 specific and subspecific taxa, distributed in 386 genus and 119 families, were inventoried. Seven species, of which one for the science, were new for the flora of Republic of Congo. The families of Fabaceae, Poaceae, Rubiaceae, Euphorbiaceae, of Malavaceae and Annonaceae and are the most diversified in species. The ecological spectrum highlights the strong preponderance of the phanerophytes, sarcochores and mesophiles, thereby confirming the dominance of the forest biodiversity compared to grasslands. From a phytogeographical perspective, the preponderance of the base element identified as well as three families and eleven genus of endemic nature integrate the flora within the Guineo-Congolian centre of endemism.La zone d’étude est située au nord de Pointe noire, dans le Département du Kouilou, en République du Congo. Pour mieux connaître la richesse floristique et la position chorologique du site d’intérêt, une analyse sur la flore, des spectres autoécologiques et phytogéographiques des espèces a été entreprise. Cette analyse est basée sur le matériel floristique issu de différentes prospections botaniques effectuées en 2012, et déposé à l’Herbier National du Congo (IEC). Sur une superficie de 202.700 hectares prospectée, au travers de 243 relevés phytosociologiques, une matrice floristique de 580 espèces et taxons infra spécifiques réparties en 386 genres et en 119 familles, a été retenue. Sept nouvelles espèces, dont une nouvelle pour la science, sont des ajouts à la flore du Congo. Les familles des Fabaceae, des Poaceae, des Rubiaceae, des Euphorbiaceae, des Malavaceae et des Annonaceae et sont les plus diversifiées en espèces. Les spectres écologiques mettent en relief la forte représentativité des phanérophytes, des sarcochores et des mésophylles, confirmant de facto la prépondérance de la biodiversité forestière par rapport aux formations herbacées. Sur le plan phytogéographique, la prépondérance de l’élément base décelé ainsi que la présence de trois familles et de onze genres endémiques, intègrent bien cette flore au Centre d’endémisme guinéo-congolais.http://www.ijias.issr-journals.org/am2017Centre for Wildlife Managemen

    Floristic composition, diversity and structure of the forest communities in the Kouilou DĂ©partement, Republic of Congo

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    The objectives of the study were to classify, describe and map the forest communities in the study area and to investigate possible gradients in plant diversity. The study area comprised approximately 166 000 ha in the Kouilou Département, Republic of Congo, a section of land targeted for extensive future development. In total 156 forest sample sites were surveyed using the Braun-Blanquet method of phytosociology. Diversity of each plant community was expressed in terms of species richness; Shannon-Wiener index; exponent of Shannon-Wiener index; evenness; Fisher's alpha; Simpson’s index; and inverse Simpson index. Eleven plant communities were described and mapped at a much finer scale than has been done previously. The communities were arranged along two gradients: a degraded – relatively intact gradient and a wet – dry gradient. The least degraded communities, and consequently those with the highest conservation value, were the swamp forests and the okoumé forest. Overall, the values reported for the diversity parameters in the current study were within the range reported for other tropical forests in Central Africa. The study revealed a gradient between the coast (west) and the Mayombe mountain range (east) in plant diversity linked to topography and climate with plant diversity lowest at the coast. Furthermore, plant diversity was negatively related to the distance to human infrastructure. The forest communities appear to be fairly resilient to past anthropogenic disturbances, however, there is no historical analogue to the more severe types of forest destruction associated with some of the future developments anticipated, such as mechanized logging or mining.http://journals.cambridge.org/action/displayJournal?jid=TRO2017-06-30hb2017Centre for Wildlife ManagementPlant Scienc

    Comprehensive evaluation of genetic variation in S100A7 suggests an association with the occurrence of allergic rhinitis

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    <p>Abstract</p> <p>Background</p> <p>S100A7 is a calcium-binding protein with chemotactic and antimicrobial properties. S100A7 protein levels are decreased in nasal lavage fluid from individuals with ongoing allergic rhinitis, suggesting a role for S100A7 in allergic airway inflammation. The aims of this study were to describe genetic variation in <it>S100A7 </it>and search for associations between this variation and allergic rhinitis.</p> <p>Methods</p> <p>Peripheral blood was collected from 184 atopic patients with a history of pollen-induced allergic rhinitis and 378 non-atopic individuals, all of Swedish origin. DNA was extracted and the <it>S100A7 </it>gene was resequenced in a subset of 47 randomly selected atopic individuals. Nine polymorphisms were genotyped in 184 atopic and 378 non-atopic individuals and subsequently investigated for associations with allergic rhinitis as well as skin prick test results. Haplotypes were estimated and compared in the two groups.</p> <p>Results</p> <p>Thirteen polymorphisms were identified in <it>S100A7</it>, of which 7 were previously undescribed. rs3014837 (G/C), which gives rise to an Asp → Glu amino acid shift, had significantly increased minor allele frequency in atopic individuals. The major haplotype, containing the major allele at all sites, was more common in non-atopic individuals, while the haplotype containing the minor allele at rs3014837 was equally more common among the atopic individuals. Additionally, heterozygotes at this site had significantly higher scores in skin prick tests for 9 out of 11 tested allergens, compared to homozygotes.</p> <p>Conclusion</p> <p>This is the first study describing genetic variation, associated with allergy, in <it>S100A7</it>. The results indicate that rs3014837 is linked to allergic rhinitis in our Swedish population and render S100A7 a strong candidate for further investigations regarding its role in allergic inflammation.</p
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