587 research outputs found
Complex, Dynamic Combination of Physical, Chemical and Nutritional Variables Controls Spatio-Temporal Variation of Sandy Beach Community Structure
Sandy beach ecological theory states that physical features of the beach control macrobenthic community structure on all but the most dissipative beaches. However, few studies have simultaneously evaluated the relative importance of physical, chemical and biological factors as potential explanatory variables for meso-scale spatio-temporal patterns of intertidal community structure in these systems. Here, we investigate macroinfaunal community structure of a micro-tidal sandy beach that is located on an oligotrophic subtropical coast and is influenced by seasonal estuarine input. We repeatedly sampled biological and environmental variables at a series of beach transects arranged at increasing distances from the estuary mouth. Sampling took place over a period of five months, corresponding with the transition between the dry and wet season. This allowed assessment of biological-physical relationships across chemical and nutritional gradients associated with a range of estuarine inputs. Physical, chemical, and biological response variables, as well as measures of community structure, showed significant spatio-temporal patterns. In general, bivariate relationships between biological and environmental variables were rare and weak. However, multivariate correlation approaches identified a variety of environmental variables (i.e., sampling session, the C:N ratio of particulate organic matter, dissolved inorganic nutrient concentrations, various size fractions of photopigment concentrations, salinity and, to a lesser extent, beach width and sediment kurtosis) that either alone or combined provided significant explanatory power for spatio-temporal patterns of macroinfaunal community structure. Overall, these results showed that the macrobenthic community on Mtunzini Beach was not structured primarily by physical factors, but instead by a complex and dynamic blend of nutritional, chemical and physical drivers. This emphasises the need to recognise ocean-exposed sandy beaches as functional ecosystems in their own right
Usable pasts forum: critically engaging food security
In this inaugural Usable Pasts Forum, we make the case that archaeology has a critical role to play in reframing approaches to food security in the African continent
Cretaceous fossils from the Orapa Diamond Mine
Main articleThe Orapa kimberlite pipe, situated in north-central Botswana, is well-known for its rich reserves
of diamonds. It is indeed one of the largest and richest diamond mines in the world. The kimberlite
magma transporting the diamonds from the upper mantle erupted through a sequence ofKaroo-aged
rocks before the deposition ofthe Kalahari Sands. This eruption has been radiometrically dated at
early Late Cretaceous (Cenomanian-Coniacian). When volcanism ceased, a succession of epiclastic
crater lake sediments was deposited above the kimberlite plug. Analysis of these sediments, which
mostly comprise the results of mudflows and debris flows and fmer sediments during quiescenttimes,
suggests that most of the sediments within the crater were deposited rapidly as mass flows, and were
therefore mobilised soon after the volcanic eruption. Buried within the fine-grained sediments is a
unique assemblage of fossils including flowering plants and many whole-bodied insects. The fossils
are commonly exquisitely preserved in extremely fine-grained mudstone. Interpretation of the
sedimentary facies and fossils is that the mid-Cretaceous climate of central Botswana was temperate,
seasonal and wet, and the area surrounding the crater was forested. The fossils represent the recovery
of the biota of the area after the violent eruptions of Orapa and other nearby kimberlite fissures and
pipes. The fossils have contributed considerably to our understanding of mid-Cretaceous insects and
flowering plants and suggest intimate relationships between the two at an early stage in the radiation
of flowering plants. It seems that southern Gondwana (including southern Africa) was a centre of
diversification for both insects and angiosperms in the mid-Cretaceous.Friends of the Museum,
Gaborone; Debswana (Orapa); University of the Witwatersrand;
South African Foundation for Research Developmen
Implementation of a science-action partnership to manage a threatened ecosystem in an urban context
Abstract: The gap between scientific knowledge and implementation of such knowledge in the fields of biodiversity conservation, environmental management and climate change adaptation, is widely recognized. The state of knowledge of urban ecosystems is generally quite poor, and there is a shortage of human capacity to implement scientifically-sound management practices at the local level, especially within institutions having the mandate of regulating land use planning. The need to bridge the science-action gap to improve decision-making for local land use planning and management, and thereby reduce the impacts of urbanization on ecosystems, has been recognized by eThekwini Municipality in the city of Durban, South Africa..
Climate Velocity Can Inform Conservation in a Warming World
Climate change is shifting the ranges of species. Simple predictive metrics of range shifts such as climate velocity, that do not require extensive knowledge or data on individual species, could help to guide conservation. We review research on climate velocity, describing the theory underpinning the concept and its assumptions. We highlight how climate velocity has already been applied in conservation-related research, including climate residence time, climate refugia, endemism, historic and projected range shifts, exposure to climate change, and climate connectivity. Finally, we discuss ways to enhance the use of climate velocity in conservation through tailoring it to be more biologically meaningful, informing design of protected areas, conserving ocean biodiversity in 3D, and informing conservation actions
Post-tuberculosis lung health: perspectives from the first International symposium
Tuberculosis, although curable, frequently leaves the individual with chronic physical and psycho-social impairment, yet these consequences have to-date been largely neglected. The 1st International Post-Tuberculosis Symposium was devoted entirely to impairment after tuberculosis, and covered a number of multi-disciplinary topics. Using the Delphi process, consensus was achieved for the terms “post-tuberculosis”, “post-tuberculosis lung disease/s (PTLD)”, and “post-tuberculosis economic, social and psychological well-being” (Post-TB ESP)”, to overcome the historical challenge of varied terminology in the literature. A minimum case-definition was proposed by consensus for PTLD in adults and children. Lack of sufficient evidence hampered definitive recommendations in most domains, including prevention and treatment of PTLD, but highlighted the dire need for research and priorities were identified. The heterogeneity of respiratory outcomes and previously employed research methodologies complicates the accurate estimation of disease burden. However, consensus was reached proposing a toolkit for future PTLD measurement, and on PTLD patterns to be considered. The importance of extra-pulmonary consequences and progressive impairment throughout the life-course was identified, including tuberculosis recurrence and increased mortality. Patient advocates emphasised the need for addressing the psychological and social impacts post tuberculosis, and called for clinical guidance. Increased awareness and more research addressing post-tuberculosis complications is urgently needed
Australasia
Observed changes and impacts
Ongoing climate trends have exacerbated many extreme events (very high confidence). The Australian trends include further warming and sea level rise sea level rise (SLR), with more hot days and heatwaves, less snow, more rainfall in the north, less April–October rainfall in the southwest and southeast and more extreme fire weather days in the south and east. The New Zealand trends include further warming and sea level rise (SLR), more hot days and heatwaves, less snow, more rainfall in the south, less rainfall in the north and more extreme fire weather in the east. There have been fewer tropical cyclones and cold days in the region. Extreme events include Australia’s hottest and driest year in 2019 with a record-breaking number of days over 39°C, New Zealand’s hottest year in 2016, three widespread marine heatwaves during 2016–2020, Category 4 Cyclone Debbie in 2017, seven major hailstorms over eastern Australia and two over New Zealand from 2014–2020, three major floods in eastern Australia and three over New Zealand during 2019–2021 and major fires in southern and eastern Australia during 2019–2020
Standardized Methods for Enhanced Quality and Comparability of Tuberculous Meningitis Studies
Tuberculous meningitis (TBM) remains a major cause of death and disability in tuberculosis-endemic areas, especially in young children and immunocompromised adults. Research aimed at improving outcomes is hampered by poor standardization, which limits study comparison and the generalizability of results. We propose standardized methods for the conduct of TBM clinical research that were drafted at an international tuberculous meningitis research meeting organized by the Oxford University Clinical Research Unit in Vietnam. We propose a core dataset including demographic and clinical information to be collected at study enrollment, important aspects related to patient management and monitoring, and standardized reporting of patient outcomes. The criteria proposed for the conduct of observational and intervention TBM studies should improve the quality of future research outputs, can facilitate multicenter studies and meta-analyses of pooled data, and could provide the foundation for a global TBM data repository
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