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

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

Приклади завдань для позакласної роботи з інформатики у початковій школі

У статті коротко описана методика проведення позакласної роботи з інформатики у початковій школі

Four New Bat Species (Rhinolophus hildebrandtii Complex) Reflect Plio-Pleistocene Divergence of Dwarfs and Giants across an Afromontane Archipelago

The original publication is available at http://www.plosone.orgGigantism and dwarfism evolve in vertebrates restricted to islands. We describe four new species in the Rhinolophus hildebrandtii species-complex of horseshoe bats, whose evolution has entailed adaptive shifts in body size. We postulate that vicissitudes of palaeoenvironments resulted in gigantism and dwarfism in habitat islands fragmented across eastern and southern Africa. Mitochondrial and nuclear DNA sequences recovered two clades of R. hildebrandtii senso lato which are paraphyletic with respect to a third lineage (R. eloquens). Lineages differ by 7.7 to 9.0% in cytochrome b sequences. Clade 1 includes R. hildebrandtii sensu stricto from the east African highlands and three additional vicariants that speciated across an Afromontane archipelago through the Plio-Pleistocene, extending from the Kenyan Highlands through the Eastern Arc, northern Mozambique and the Zambezi Escarpment to the eastern Great Escarpment of South Africa. Clade 2 comprises one species confined to lowland savanna habitats (Mozambique and Zimbabwe). A third clade comprises R. eloquens from East Africa. Speciation within Clade 1 is associated with fixed differences in echolocation call frequency, and cranial shape and size in populations isolated since the late Pliocene (ca 3.74 Mya). Relative to the intermediate-sized savanna population (Clade 2), these island-populations within Clade 1 are characterised by either gigantism (South African eastern Great Escarpment and Mts Mabu and Inago in Mozambique) or dwarfism (Lutope-Ngolangola Gorge, Zimbabwe and Soutpansberg Mountains, South Africa). Sympatry between divergent clades (Clade 1 and Clade 2) at Lutope-Ngolangola Gorge (NW Zimbabwe) is attributed to recent range expansions. We propose an ‘‘Allometric Speciation Hypothesis’’, which attributes the evolution of this species complex of bats to divergence in constant frequency (CF) sonar calls. The origin of species-specific peak frequencies (overall range = 32 to 46 kHz) represents the allometric effect of adaptive divergence in skull size, represented in the evolution of gigantism and dwarfism in habitat islands.Publisher's versio

Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

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..