Search results for " African"
showing 10 items of 198 documents
Data from: Moving in the Anthropocene: global reductions in terrestrial mammalian movements
2019
Animal movement is fundamental for ecosystem functioning and species survival, yet the effects of the anthropogenic footprint on animal movements have not been estimated across species. Using a unique GPS-tracking database of 803 individuals across 57 species, we found that movements of mammals in areas with a comparatively high human footprint were on average one-half to one-third the extent of their movements in areas with a low human footprint. We attribute this reduction to behavioral changes of individual animals and to the exclusion of species with long-range movements from areas with higher human impact. Global loss of vagility alters a key ecological trait of animals that affects no…
Karthago provinciae nostrae magistra venerabilis. Uno sguardo su Cartagine: i Florida di Apuleio
2023
This paper proposes a focus on the city of Carthage through Florida: Apuleius lavishes continuous and extraordinary praise on Carthage and its citizens. It becomes clear how the city, in Apuleius' time, was by then an established and ‘Romanised’ cultural centre. In Apuleius' words, Carthage appears as the only city capable of competing with Rome.
Guenon Radiation is Enriched by a New Species that Demonstrates an Evolutionary Complexity with Which we are yet to Become Familiar
2012
th September described this discovery to the scientific community (1). As is becoming increasingly frequent these days, given the high number of scientific articles, the media news reached us faster than the scientific information. The area known as TL2, a few hundred km as the crow flies south- west from the city of Kisangani, famous for its manufacturing, and important port on the Zaire river, is still uncontaminated and houses several important endemisms. This new species, studied in the area since 2007, on the basis of first sightings by the inhabitants of the zone and local hunters, has been named Cercopithecus lomamiensis. C.lomamiensis (CLO) is a tree-dweller and has been described i…
Chemical characterization of organic residues on Late Roman amphorae from shipwrecks off the coast of Marsala (Trapani, Italy)
2021
Abstract Organic residues were extracted from thirty-three different types of Roman and Late Antique amphorae retrieved from underwater contexts in the custody of the Archaeological Museum “Baglio Anselmi” of Marsala in Sicily. The samples were analysed using GC-MS and 1H NMR, finding biomarkers of plant oils (including saturated and unsaturated fatty acids, alcohols and alkanes present in plant waxes) were identified in seven samples. The biomarkers for Pinaceae spp., used for making pitch, were identified in one sample. The results obtained shed light on the function of different types of North African amphorae, traditionally interpreted as containers for olive oil, wine and fish sauce, p…
XRF and LA-ICP-MS studies of gold and silver artefacts from a 12–13th century CE tumulus in Senegal: Implications for the medieval African gold trade
2019
Abstract Silver and gold artefacts from a 12–13th c. CE tumulus in Senegal were recently analysed by means of XRF and LA-ICP-MS. The identification of major, minor and trace elements allowed gaining a rare insight into the composition of precious metals circulating in that part of Africa in medieval times. The results show that all objects were made of polymetallic alloys. Comparisons with analyses from other West African as well as North African and European silver and gold artefacts suggest that the metal from the studied objects most probably originate from outside West Africa. At least in the case of the gold artefacts, this is quite surprising, as we expected to come across pure West A…
Monsoon Multidisciplinary Analysis (AMMA) : an integrated project for understanding of the West African climate system and its human dimension
2011
International audience; The intraseasonal time scale is critical in West Africa where resources are highly rainfall dependent. Three main modes of variability have been identified, two with a mean periodicity of 15 days and one with a mean periodicity around 40 days. These modes have a regional scale and can strongly influence precipitation and convective activity. They are mainly controlled by atmospheric dynamics and land-surface interactions. They can also modulate the very specific phase of the African summer monsoon onset. A better knowledge of the mechanisms controlling this scale is necessary to improve its predictability.
Quasi-decadal signals of Sahel rainfall and West African monsoon since the mid-twentieth century
2013
[1] Sahel rainfall shows pronounced decadal variability and a negative trend between wet conditions in the 1950s–1960s and dry ones in the 1970s–1980s. Using continuous wavelet transform, the quasi-decadal variability (QDV) of rainfall reveals zonal contrasts. The highest QDV is identified in the 1950s–1960s over western Sahel and in the 1970s–1980s over eastern Sahel. The quasi-decadal atmospheric anomalies have been reconstructed using Fourier transform for the 1950s–1960s and the 1970s–1980s, respectively, and assessed by the composite analysis of the QDV phases for the periods before and after 1968. Over western Sahel, the rainfall QDV in the 1950s–1960s is related to the North Atlantic…
Interannual and decadal SST-forced responses of the West African monsoon
2010
International audience; We review the studies carried out during the African Monsoon Multidisciplinary Analysis (AMMA)-EU on the changes of interannual sea surface temperature (SST)-West African monsoon (WAM) covariability at multidecadal timescales, together with the influence of global warming (GW). The results obtained in the AMMA-EU suggest the importance of the background state, modulated by natural and anthropogenic variability, in the appearance of different interannual modes. The lack of reliability of current coupled models in giving a realistic assessment for WAM in the future is also stated.
Sea Surface Temperature Fields Associated with West African Rainfall Anomaly Types
1996
Abstract Four West African rainfall anomaly types are defined in relation to the northern summer rainfall departure signs in the Sahel and in the Guinean region in order to investigate the statistical links between interannual variability of West African rainfall and sea surface temperature (SST) through the period 1950–90. Composite analysis depicts the setup of four different mean SST anomaly fields. Drought over all of West Africa is associated with the growth of positive SST anomalies in the eastern Pacific and in the Indian Ocean, and negative SST anomalies in the northern Atlantic and in the Gulf of Guinea. In contrast, drought limited to the Sahel corresponds mostly to a northward ex…
Chemical composition of modern and fossil hippopotamid teeth and implications for paleoenvironmental reconstructions and enamel formation – Part 2: A…
2012
Abstract. For reconstructing environmental change in terrestrial realms the geochemistry of fossil bioapatite in bones and teeth is among the most promising applications. This study demonstrates that alkaline earth elements in enamel of Hippopotamids, in particular Ba and Sr are tracers for water provenance and hydrochemistry. The studied specimens are molar teeth from Hippopotamids found in modern and fossil lacustrine settings of the Western Branch of the East African Rift system (Lake Kikorongo, Lake Albert, and Lake Malawi) and from modern fluvial environments of the Nile River. Concentrations in enamel vary by ca. two orders of magnitude for Ba (120–9336 μg g−1) as well as for Sr (9–21…