The impact of fire on habitat use by the short-snouted elephant shrew ('Elephantulus brachyrhynchus') in North West Province, South Africa

Several studies have investigated the response of small mammal populations to fire, but few have investigated behavioural responses to habitat modification. In this study we investigated the impact of fire on home range, habitat use and activity patterns of the short-snouted elephant shrew (Elephantulus brachyrhynchus) by radio-tracking individuals before and after a fire event. All animals survived the passage of fire in termite mound refugia. Before the fire, grassland was used more than thickets, but habitat utilization shifted to thickets after fire had removed the grass cover. Thickets were an important refuge both pre- and post-fire, but the proportion of thicket within the home range was greater post-fire. We conclude that fire-induced habitat modification resulted in a restriction of E. brachyrhynchus movements to patches of unburned vegetation. This may be a behavioural response to an increase in predation pressure associated with a reduction in cover, rather than a lack of food. This study highlights the importance of considering the landscape mosaic in fire management and allowing sufficient island patches to remain post-fire ensures the persistence of the small mammal fauna

OPTIMIZATION METHODOLOGIES OF MIXED ELECTRICAL GENERATORS IN ALGERIA BASED ON RENEWABLE APPLICATION TO TELECOMMUNICATIONS SYSTEMS

<p>This article deals of the optimization of renewable energy electric generators, for the alimentation of radio telecommunication systems. The principals’ interests of this system are the independence production, and the supplying of electric energy in isolated localities.</p><p>Have at one’s the energetic and economic models, and simulation tools, we effected an optimization study based on mixed productions. For this approach, the energetic resources of sites where are implanted telecommunications systems and their consumption are supposed known. Then the problem is the optimization of electric generators using these resources, enable to have an optimal type system for the powering of telecommunications equipments in rural site of Algeria. Next it is quite possible to command these optimized generators by a control circuit. This circuit make possible to have according to availability of resources, one of mixed systems found, then telecommunications system be always supplied in any possible case, and without any shortage.</p

STUDY AND REALIZATION OF DEVICE OF SOLAR SENSITIVE TRACKING FOR A PROTOTYPE OF CYLINDRO-PARABOLIC CONCENTRATOR

<p>After the realization of a new prototype of concentrator through, we have study the realization of a sun tracking system in order to assure the best system efficiency throughout the day. We started in the first step by the blind sun tracking where we have acquired the good results. In this paper we try to speak about the realization of a new system of sun tracking who is the sensitive sun tracking. In this sort of tracking we have used a special telescope, like a sensitive element in for the detection of sun position. An electronic Card based PIC microcontroller is realized to pilot the mechanic system of the san tracking. In order to controlled the prototype we have put on a chain of data acquisition. The results were compared with the results of the blind sun tracking system and the stationary position, it was noted that the results were better this time and the efficiency is very important.</p

Phylogeography and genetic diversity of Psammophis schokari (Serpentes) in North Africa based on mitochondrial DNA sequences

The snake Psammophis schokari has a widespread distribution across North Africa, and in Morocco/Western Sahara is represented by three different morphotypes: striped, unicoloured and the Western-Sahara morph. ND4 mitochondrial DNA sequences from 28 specimens comprising 20 P. shokari, two P. aegyptius, one P. elegans, two P. sibilans, one P. condanarus and two outgroups were analysed. Within P. schokari we identified four genetic lineages (Morocco/ Western Sahara,  Mauritania, Algeria and Israel) with a genetic divergence ranging from 4–5%, less than that typically found between different species. Surprisingly, Moroccan/WesternSahara and Algerian lineages are the most divergent ones. This geographic  substructuring may be due to severe climate changes in the Sahara desert between the Miocene and Pleistocene associated with expansion/contraction phases of this desert. Psammophis aegyptius is the sister-taxon of Psammophis schokari with a high level of genetic divergence between them (10.7%) supporting the recognition of P. aegyptius as a distinct species. The three Moroccan/ Western Sahara colour  morphotypes form one genetic lineage, indicating that colour pattern does not reflect a different phylogenetic history, and is probably an ecological adaptation to the local environment.Key words: Psammophis schokari, North Africa, phylogeny, ND4 sequence, colour pattern

Climate change and peripheral populations: predictions for a relict Mediterranean viper

Ecological niche-based models were developed in peripheral populations of <em>Vipera latastei</em> North Africa to: 1) identify environmental factors related to species occurrence; 2) identify present suitable areas; 3) estimate future areas according to forecasted scenarios of climate change; and 4) quantify habitat suitability changes between present and future climatic scenarios. Field observations were combined with environmental factors to derive an ensemble of predictions of species occurrence. The resulting models were projected to the future North African environmental scenarios. Species occurrence was most related to precipitation variation. Present suitable habitats were fragmented and ranged from coastal to mountain habitats, and the overall fragmented range suggests a relict distribution from wider past ranges. Future projections suggest a progressive decrease in suitable areas. The relationship with precipitation supports the current unsuitability of most North Africa for the species and predicts future increased extinction risk. Monitoring of population trends and full protection of mountain forests are key-targets for long-term conservation of African populations of this viper. Predicted trends may give indications about other peripheral populations of Palearctic vertebrates in North Africa which should be assessed in detail

Genetic variation among spiny-footed lizards in the Acanthodactylus pardalis group from North Africa

The systematics of the genus Acanthodactylus was classically based on external morphological traits, osteological characters and morphology of the hemipenes. Although the identification of species complexes is relatively easy, the distinction within some groups is difficult due to a high variability of the external morphology. Partial mitochondrial (12S and 16S rRNA) sequences (371 and 499 base pairs, respectively) were analysed from 32 specimens of the A. pardalis group from northern Africa including the described species A. busacki, A. maculatus, A. mechriguensis and A. pardalis. Several highly distinct genetic units were resolved, but with little support for relationships between them. These units did not coincide with current taxonomic units, but showed geographic structuring. Although the A. pardalis group displays significant variation, the present taxonomy of the group must be considered unsatisfactory since it is not supported by genetic evidence. For some forms, such as A. mechriguensis there is no support and it is suggested that it should be synonymized with A. maculatus. More data are clearly needed for other forms. Complex microevolutionary patterns due to the recent contraction/ expansion phases of the Sahara Desert probably are related with the phylogenetic patterns observed.Key words: Acanthodactylus pardalis, phylogeny, North Africa, mitochondrial DNA

The new Algerian Digital Seismic Network (ADSN): towards an earthquake early-warning system

Seismic monitoring in Algeria has seen great changes since the Boumerdes earthquake of 21 May 2003. Indeed, the installation of a new digital seismic network has resulted in a significant upgrade of the previous analog telemetry network. <br><br> During the last four years, the number of stations in operation has increased substantially from 25 to 69, and 20 of these are broadband, 2 are very broadband, 47 are short period. 21 are equipped with accelerometers. They are all managed by Antelope software from Kinemetrics (US Cie), and they are all connected in real time and use various modes of transmission (e.g., satellite, internet, mobile phone). The spatial repartition of the stations now cover most of northern Algeria. In addition, 70 GPS stations have recently been added to this seismological network, most of them collocated with the seismological stations. <br><br> Since the installation of the network, the records of local or distant events have improved significantly. The automatic processing of the data in a few minutes allows alert messages to be distributed to Civil Defense and other national authorities to react promptly to any emergency. The current strategy is to improve the data quality, to increase the density of the network by adding about 50 new stations, to reduce the processing time, and to reduce the time needed to send out an alert message. The result should be greatly improved network performance, which will lead to an effective early-warning system