Search results for " Africa"

Diagnostic des virus des gastroentérites aiguës de l'adulte dans les pays en voie de développement:intérêt et stratégie.

2009

L'Oscillation de Madden-Julian et la variabilité pluviométrique régionale en Afrique Subsaharienne

2007

The role of the Madden-Julian Oscillation ("MJO") on rainfall variability in Sub-Saharan Africa is examined, based on daily rain-gauge records and the NCEP-DOE AMIP-II reanalyses. The convective and dynamical signal associated with the MJO is extracted using two differing methodologies, the BMRC daily indices (Wheeler & Hendon 2004) on the one hand, and a Local Mode Analysis ("LMA", Goulet & Duvel 2000) on the other hand. The temporal variability of the MJO (in terms of period, amplitude, seasonality and location of the convective anomalies) is first analysed. Though the overall amplitude of the signal is not related to El Niño, the oscillations occurring under El Niño (La Niña) conditions …

Pluviométrie et circulation atmosphérique simulées par le modèle régional WRF en Afrique australe : sensibilité à la physique et variabilité interne

2011

This study evaluates the capability of the regional climate model WRF to simulate Southern African rainfall and associated atmospheric circulation, particularly over South Africa, a country covered by a dense network of in situ observations. Three sets of simulations are performed at a 35km horizontal resolution during the core of the austral rainy season (December to February: DJF) with 6-hourly forcings provided by ERA40 reanalysis. The first set quantifies sensitivity of the simulated climate to the parameterizations of atmospheric convection, planetary boundary layer and microphysics. The retained case study (DJF 1993-1994: DJF94) is representative of the South African rainfall climatol…

Urbanization and forest degradation in east Africa - a case study around Dar es Salaam, Tanzania

2016

In this paper we examine the impact of the growing urbanization of Dar es Salaam, Tanzania, on the forest areas around the city. Since 1990 the city has seen an annual population growth rate of over 4%. We document the expansion of the city over the last 30 using the Global Human Settlement Layers, derived from the global Landsat archive. At the same time we show the depletion, of the surrounding forests that has occurred to meet the growing demand for agricultural land, fuel wood and construction material over the same period. The impact on these forests as a result of the demand from an expanding urban conglomeration is higher than would be expected from a dispersed population increase. T…

Phytotoxic effects of Lantana camara, Eucalyptus camaldulensis and Eriocephalus africanus essential oils in weeds of Mediterranean summer crops

2009

Abstract The essential oil composition of Lantana camara , Eucalyptus camaldulensis and Eriocephalus africanus was analyzed by means of GC and GC–MS and bioassayed in order to determine their activity against Amaranthus hybridus and Portulaca oleracea . E. camaldulensis essential oil, with spathulenol as the main compound, was the most effective, completely inhibiting germination and seedling growth on both weeds. The essential oil of E. africanus , rich in artemisia ketone, showed activity similar to that of E. camaldulensis on A. hybridus , but it was not so effective against P. oleracea , and L. camara essential oil, with high percentages in sesquiterpene hydrocarbons, also showed higher…

Pachydema lopadusanorum n.sp. (Coleoptera Melolonthidae) from Lampedusa Island (Sicily Channel, Central Metditerranean Sea, Italy)

2018

In this paper the populations of Pachydema Castelnau, 1832 (Coleoptera Melolonthidae) living in Lampedusa Island (Sicily Channel, Central Mediterranean Sea, Italy), so far attributed to P. hirticollis (Fabricius, 1787) of North Africa, are examined. The comparison of the main morphological characters between these two populations allowed to attribute those of Lampedusa to a new species that is described in the present work. Faunistic and biological observations on these species are provided.

Types of names of Orobanche taxa described from North Africa

2013

In the framework of the revision of the genus Orobanche (including Phelipaea) in the Mediterranean area, the original material for 31 names of new taxa described from North Africa by Ball, Battandier, Forsska°l, Maire (partly with Emberger and Jahandiez), Persoon, Poiret and Pomel has been analysed. Typification is discussed, and where necessary types are designated. Accepted names and synonyms of the recognized taxa are given. Three species are illustrated, and one new combination (O. inexspectata) is proposed.

Where are you from, stranger? The enigmatic biogeography of North African pond turtles (Emys orbicularis)

2014

Abstract The European pond turtle (Emys orbicularis) is a Nearctic element in the African fauna and thought to have invaded North Africa from the Iberian Peninsula. All North African populations are currently identified with the subspecies E. o. occidentalis. However, a nearly range-wide sampling in North Africa used for analyses of mitochondrial and microsatellite DNA provides evidence that only Moroccan populations belong to this taxon, while eastern Algerian and Tunisian pond turtles represent an undescribed distinct subspecies. These two taxa are most closely related to E. o. galloitalica with a native distribution along the Mediterranean coast of northern Spain through southern France …

Chemical composition of the essential oils fromEriocephalus africanus L. var.africanus populations growing in Spain

2007

Essential oils from the aerial parts of three Eriocephalus africanus L. var. africanus populations were analysed by means of GC–FID and GC–MS. Sixty-one constituents were identified, representing more than 96% of the total oil composition. Artemisia ketone (56.46–56.58%), intermedeol (9.19–11.63%) and γ-eudesmol (4.26–5.64%) were the main compounds. Application of the Pearson correlation coefficient showed high similarity between the nine samples analysed. Copyright © 2007 John Wiley & Sons, Ltd.

Annotated Check-List of Orthoptera of Libya

2009

Abstract A list of Libyan Orthoptera is presented based on specimens preserved in Museums, incorporating all (previously published or unpublished) label information. Overall, 141 species are included, of which four are new records for the country. Given within “species inquirendae” are another six species, with the reasons for confirming their presence. Libya's orthopteran fauna is probably not rich, but our knowledge of it is far from exhaustive.