The bii4africa dataset of faunal and floral population intactness estimates across Africa's major land uses.

Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species' population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate 'intactness scores': the remaining proportion of an 'intact' reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the region's major land uses (urban, cropland, rangeland, plantation, protected, etc.

Rediscovery of the lost skink Proscelotes aenea and implications for conservation.

Biodiversity loss is recognized as a grand challenge of the twenty-first century but ascertaining when a species is "lost" can be incredibly difficult-since the absence of evidence is not evidence of absence. This may be a relatively easy task for large and conspicuous animals, but extremely difficult for those living hidden lives or at low population sizes. We showcase this challenge by focusing on Africa's montane skink, Proscelotes aenea (Barbour & Loveridge 1928).

A new forest dwelling button spider from South Africa (Araneae, Theridiidae, Latrodectus).

The medically important spider genus Latrodectus Walckenaer 1805, commonly referred to as "button spiders" in South Africa, is represented by six species in the country. Using morphology and the COI barcoding gene we describe a new forest dwelling species, Latrodectus umbukwane n. sp.

A new Reed Frog (Hyperoliidae: Hyperolius) from coastal northeastern Mozambique.

A new species of African reed frog (genus Hyperolius Rapp, 1842) is described from the Coastal Forests of the Eastern Africa Biodiversity Hotspot in northeastern Mozambique. It is currently only known from less than ten localities associated with the Mozambican coastal pans system, but may also occur in the southeastern corner of Tanzania. Phylogenetic reconstructions using the mitochondrial 16S marker revealed that it is the sister taxon of Hyperolius mitchelli (>5.

Duncan F. Gregory, William Walton and the development of British algebra: 'algebraical geometry', 'geometrical algebra', abstraction.

This paper provides a detailed account of the period of the complex history of British algebra and geometry between the publication of George Peacock's Treatise on Algebra in 1830 and William Rowan Hamilton's paper on quaternions of 1843. During these years, Duncan Farquharson Gregory and William Walton published several contributions on 'algebraical geometry' and 'geometrical algebra' in the Cambridge Mathematical Journal. These contributions enabled them not only to generalize Peacock's symbolical algebra on the basis of geometrical considerations, but also to initiate the attempts to question the status of Euclidean space as the arbiter of valid geometrical interpretations.