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Ghardaia, Algeria

Sadine S.E.,University of Ouargla | Sadine S.E.,University of Ghardaia | Bissati S.,University of Ouargla | Lourenco W.R.,French Natural History Museum
Comptes Rendus - Biologies | Year: 2016

Since the early 2000s, the genus Buthus Leach, 1815 (family Buthidae) has been the subject of an important number of studies. These concerned particularly the species belonging to the 'Buthus occitanus' complex. A number of populations previously considered as subspecies or varieties of B. occitanus Leach were raised to the rank of species, but also many new species have been described. Most of the species considered in these studies come from North Africa, in particular from Morocco, Mauritania, Chad, Sudan and Egypt, but only two new species were recorded from Algeria. At present, one more new species of Buthus is described from the Algerian Saharan Desert, raising the number of confirmed Buthus in Algeria to five. Since most Buthus species from North Africa, and in particular those from Algeria, inhabit more mesic environments than the Saharan Central compartment, the new species appears as the first true deserticolous species found in this country. © 2015 Academie des sciences.

Bouderba H.,University of Ghardaia | Beddiaf R.,University of Batna
Modern Physics Letters B | Year: 2014

In the present work, based on first-principles calculations, we show that it is possible to obtain a new high pressure polymorph of the CaSi2 compound with a Laves structure. It corresponds to the MgCu2-type (C15) which is one of the three most important Laves phases. We also show that the two other structures, MgNi2- and MgZn2-types are very competitive energetically and are possible candidates for finite temperature investigations. © 2014 World Scientific Publishing Company.

Oulad-Naoui S.,University of Ghardaia | Cherroun H.,University of Laghouat | Ziadi D.,CNRS Informatics Systems Laboratory
DATA 2015 - 4th International Conference on Data Management Technologies and Applications, Proceedings | Year: 2015

It is well-known that developing a unifying theory is one of the most important issues in Data Mining research. In the last two decades, a great deal has been devoted to the algorithmic aspects of the Frequent Itemset (FI) Mining problem. We are motivated by the need of formal modeling in the field. Thus, we introduce and analyze, in this theoretical study, a new model for the FI mining task. Indeed, we encode the itemsets as words over an ordered alphabet, and state this problem by a formal series over the counting semiring (ℕ,+,×,0,1), whose the range constitutes the itemsets and the coefficients their supports. This formalism offers many advantages in both fundamental and practical aspects: The introduction of a clear and unified theoretical framework through which we can express the main FI-approaches, the possibility of their generalization to mine other more complex objects, and their incrementalization and/or parallelization; in practice, we explain how this problem can be seen as that of word recognition by an automaton, allowing an efficient implementation in O(|Q|) space and O(|FL||Q||) time, where Q is the set of states of the automaton used for representing the data, and FL the set of prefixial maximal FI.

Ganghoffer J.-F.,LEMTA ENSEM | Kabouya N.,University of Ghardaia | Mefti N.,Enitec
Journal of Biomechanics | Year: 2010

Models of the adhesion of a population of cells in a plane flow are developed, considering the dilute regime. Cells considered as rigid punctual entities are virtually injected at regular times within a plane channel limited by two fixed planes. The pressure profile is supposed to be triangular (constant gradient), in accordance with the assumptions of a Poiseuille flow. The cell adherence to the channel wall is governed by the balance of forces, accounting for gravity, non-specific physical interactions, such as electrostatic effects (repulsive) and Van der Waals forces (attractive), specific adhesive forces representing the ligand-receptor interactions, and friction between cells and the fluid in the vicinity of the endothelium wall. The spatial distribution of the adhesion molecules along the wall is supposed to be a random event, accounted for by a stochastic spatial variability of the dipolar moments of those molecules, according to a Gaussian process. Experimental trends reported for the rate of aggregation of L-selectin mediated leukocytes under shear flow are in qualitative accordance with the evolution versus time of adhering cells obtained by the present simulations. The effect of the maximal injection pressure on those kinetics is assessed. © 2009 Elsevier Ltd. All rights reserved.

Aouiche A.,Laboratoire Of Biologie Des Systemes Microbiens Lbsm | Aouiche A.,University El Bachir El Ibrahimi | Bouras N.,Laboratoire Of Biologie Des Systemes Microbiens Lbsm | Bouras N.,University of Ghardaia | And 6 more authors.
Antonie van Leeuwenhoek, International Journal of General and Molecular Microbiology | Year: 2015

A novel actinomycete strain, designated PAL84, was isolated from a Saharan soil sample collected from Béni-Isguen, Ghardaïa (South of Algeria). This strain was studied for its taxonomic position using a polyphasic approach and was identified as a member of the genus Actinokineospora. Phylogenetic analysis showed that strain PAL84 had 16S rRNA gene sequence similarities with members of the genus Actinokineospora ranging from 96.2 % (Actinokineospora inagensis DSM 44258T) to 97.8 % (Actinokineosporabaliensis NBRC 104211T). The strain was observed to produce pinkish-purple aerial mycelium and purplish red substrate mycelium, which fragmented readily into chains of non-motile elements. The optimum growth temperature and pH were found to be 25–30 °C and 5.0–7.0, respectively. The cell-wall hydrolysate of strain PAL84 was found to contain meso-diaminopimelic acid and the diagnostic whole-cell sugars were identified as arabinose and galactose. The predominant menaquinone was identified as MK-9 (H4). The major fatty acids were found to be iso-C16:0, iso-C15:0, iso-C16:1 H and iso-C16:0 2OH. The diagnostic phospholipid detected was phosphatidylethanolamine. The genotypic and phenotypic data show that the strain represents a novel species of the genus Actinokineospora, for which the name Actinokineosporamzabensis sp. nov. is proposed, with the type strain PAL84T (=DSM 45961T = CECT 8578T). © 2014, Springer International Publishing Switzerland.

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