16 research outputs found
The distribution of the dwarf succulent genus <i>Conophytum</i> N.E.Br. (Aizoaceae) in southern Africa
Background: The dwarf succulent genus Conophytum N.E.Br. is one of the most species rich in the Aizoceae. The genus is most closely associated with a region of high floral endemism and biodiversity, the Succulent Karoo biome in south-western Africa.
Objectives: To examine the distribution of Conophytum in south-western Namibia and in the Northern and Western Cape Provinces of South Africa.
Method: A database comprising 2798 locality records representing all known species and subspecies of the genus Conophytum has been constructed.
Results: The genus is primarily restricted to the arid winter-rainfall region of the Northern and Western Cape Provinces of South Africa and south-western Namibia, within the Greater Cape Floristic Region. Whilst taxa are found across all the main biomes in the region (the Succulent Karoo, Nama Karoo, Desert and Fynbos biomes), 94% of Conophytum taxa are found only in the Succulent Karoo biome and predominantly (88% of taxa) within South Africa. Endemism within specific bioregions is a feature of the genus and ~60% of taxa are endemic to the Succulent Karoo. Approximately 28% of all taxa could be considered point endemics. Whilst the genus has a relatively wide geographical range, we identify a pronounced centre of endemism in the southern Richtersveld.
Conclusion: The genus Conophytum can be used as a good botanical model for studying patterns of diversity and speciation in the Succulent Karoo biome, the effects of climate change on dwarf succulents, and for informing conservation planning efforts
Application of Landsat-derived vegetation trends over South Africa: Potential for monitoring land degradation and restoration
Monitoring vegetation change is important because the nature, extent and rate of change in key measures, such as plant biomass, cover and species composition, provides critical insight into broader environmental and land use drivers and leads to the development of appropriate policy. We used Landsat data between 1984 and 2018 to produce a map of Enhanced Vegetation Index (EVI) change over South Africa at 30 m resolution and an interactive web application to make the analysis both globally applicable and locally meaningful. We found an increase in EVI of 0.37 ± 0.59% yr−1 (mean ± standard deviation), confirming global vegetation greening trends observed with lower-resolution satellites. Mesic, productive biomes including the Albany Thicket and Savanna, exhibited the largest greening trends while browning trends were dominant in more arid biomes, such as the Succulent Karoo and Desert. Although overall EVI trends correspond to vegetation index trends derived from the Advanced Very-High-Resolution Radiometer (8 km resolution), the relative scarcity of Landsat data availability during the 1980 s is a potential source of error. Using repeat very-high-resolution satellite (ca. 3 m resolution) imagery and ground-based photography as reference, we found good correspondence with EVI trends, revealing patterns of degradation (e.g. woody plant encroachment, desertification), and restoration (e.g. increased rangeland productivity, alien clearing) over selected landscapes. The utility of the EVI trend layer to government and industry for monitoring ecosystem changes will be enhanced by the ability to distinguish climatic from anthropogenic drivers of change. This may be partially achieved though interactive exploration of the EVI trends using the application found here: http://evitrend.zsv.co.zaacceptedVersio
Application of Landsat-derived vegetation trends over South Africa: Potential for monitoring land degradation and restoration
Monitoring vegetation change is important because the nature, extent and rate of change in key measures, such as plant biomass, cover and species composition, provides critical insight into broader environmental and land use drivers and leads to the development of appropriate policy. We used Landsat data between 1984 and 2018 to produce a map of Enhanced Vegetation Index (EVI) change over South Africa at 30 m resolution and an interactive web application to make the analysis both globally applicable and locally meaningful. We found an increase in EVI of 0.37 ± 0.59% yr−1 (mean ± standard deviation), confirming global vegetation greening trends observed with lower-resolution satellites. Mesic, productive biomes including the Albany Thicket and Savanna, exhibited the largest greening trends while browning trends were dominant in more arid biomes, such as the Succulent Karoo and Desert. Although overall EVI trends correspond to vegetation index trends derived from the Advanced Very-High-Resolution Radiometer (8 km resolution), the relative scarcity of Landsat data availability during the 1980 s is a potential source of error. Using repeat very-high-resolution satellite (ca. 3 m resolution) imagery and ground-based photography as reference, we found good correspondence with EVI trends, revealing patterns of degradation (e.g. woody plant encroachment, desertification), and restoration (e.g. increased rangeland productivity, alien clearing) over selected landscapes. The utility of the EVI trend layer to government and industry for monitoring ecosystem changes will be enhanced by the ability to distinguish climatic from anthropogenic drivers of change. This may be partially achieved though interactive exploration of the EVI trends using the application found here: http://evitrend.zsv.co.z
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Impact of anticoagulation levels on outcomes in patients undergoing elective percutaneous coronary intervention: insights from the STEEPLE trial
Aims To determine the relationship between anticoagulation levels during percutaneous coronary intervention, and ischaemic events and bleeding.
Methods and results A sub-analysis from the STEEPLE trial was conducted. Pre-defined target anticoagulation levels were achieved in 86% of patients receiving enoxaparin, compared with 20% receiving unfractionated heparin (UFH) (P 0.9 IU/mL and covariate-adjusted rate of non-coronary artery bypass graft-related major and minor bleeding [odds ratio (OR) 1.6, 95% CI 1.0-2.5 for each unit of anti-Xa; P = 0.03]; anti-Xa levels and covariate-adjusted incidence of death, myocardial infarction, or revascularization showed no significance (P = 0.47). Major bleeding increased significantly with an activated clotting time (ACT) > 325 s (OR 1.6, 95% CI 1.1-2.2 per 100 s; P = 0.04). A significant relationship with increasing ischaemic events was observed when ACT was < 325 s (OR 0.7, 95% CI 0.2-0.8 per 100 s; P = 0.006) indicating a narrow therapeutic window.
Conclusion Target anticoagulation levels were achieved more readily in patients receiving enoxaparin. An anti-Xa level of up to 0.9 IU/mL has a good safety and efficacy profile; poor achievement of target ACT with UFH makes assessing the optimal range difficult
Improving the key biodiversity areas approach for effective conservation planning
The key biodiversity areas (KBA) approach aims to identify globally important areas for species conservation. Although a similar methodology has been used successfully to identify Important Bird Areas, we have identified five limitations that may apply when considering other taxa: The KBA approach is overly prescriptive in identifying important conservation features, is inflexible when dealing with landscape connectivity, creates errors by applying global criteria without input from local experts, relies on post hoc consideration of implementation opportunities and constraints, and fails to automatically involve implementation agencies in the assessment process. We suggest three modifications to the present approach: (1) Provide training in regional conservation planning for local stakeholders, (2) expand the Alliance for Zero Extinction program to include a broader range of threatened species, and (3) allow local stakeholders to nominate KBAs on the basis of their own regional conservation assessments. These modifications would build on the expertise of those promoting the KBA approach and help maintain the diversity of methods that are needed to conserve biodiversity effectively
Standardizing nomenclature in regional anesthesia : an ASRA-ESRA Delphi consensus study of upper and lower limb nerve blocks
Abstract: BackgroundInconsistent nomenclature and anatomical descriptions of regional anesthetic techniques hinder scientific communication and engender confusion; this in turn has implications for research, education and clinical implementation of regional anesthesia. Having produced standardized nomenclature for abdominal wall, paraspinal and chest wall regional anesthetic techniques, we aimed to similarly do so for upper and lower limb peripheral nerve blocks.MethodsWe performed a three-round Delphi international consensus study to generate standardized names and anatomical descriptions of upper and lower limb regional anesthetic techniques. A long list of names and anatomical description of blocks of upper and lower extremities was produced by the members of the steering committee. Subsequently, two rounds of anonymized voting and commenting were followed by a third virtual round table to secure consensus for items that remained outstanding after the first and second rounds. As with previous methodology, strong consensus was defined as >= 75% agreement and weak consensus as 50%-74% agreement.ResultsA total of 94, 91 and 65 collaborators participated in the first, second and third rounds, respectively. We achieved strong consensus for 38 names and 33 anatomical descriptions, and weak consensus for five anatomical descriptions. We agreed on a template for naming peripheral nerve blocks based on the name of the nerve and the anatomical location of the blockade and identified several areas for future research.ConclusionsWe achieved consensus on nomenclature and anatomical descriptions of regional anesthetic techniques for upper and lower limb nerve blocks, and recommend using this framework in clinical and academic practice. This should improve research, teaching and learning of regional anesthesia to eventually improve patient care