Helix Explorer : une nouvelle base de données de structures de protéines

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal

Morphological variability of Mauritanian date-palm (Phoenix dactylifera L.) cultivars as revealed by vegetative traits

The aim of this study was to use morphological markers to characterize twelve Mauritanian date-palm ecotypes currently grown by farmers. Eighteen phenotypic traits describing the vegetative systems were measured in the field in Atar Oasis. The data set was analyzed by principal components analysis (PCA) and UPGMA clustering. PCA revealed a great variability among the cultivars. Fourteen out of the 18 characters studied showed a high discriminating power suggesting their possible uses in the establishment of a Mauritanian date-palm catalogue. UPGMA Clustering revealed association between cultivars with similar fruit characteristics indicating that these ecotypes are morphologically related. Results also showed that individuals belonging to the Ahmar cultivar were morphologically distinct, suggesting it is likely a polyclonal variety

Snake Venom Peptides: Promising Molecules with Anti-Tumor Effects

International audienc

MISE EN PLACE D’UN MODÈLE QUALITATIF POUR LA CARTOGRAPHIE DES ZONES À RISQUE D'ÉROSION HYDRIQUE DANS LA CHAÎNE ATLASIQUE: CAS DU BASSIN VERSANT DE LA TESSAOUTE AMONT. (HAUT ATLAS CENTRAL, MAROC)

The catchment areas of the Atlas chain are threatened by water erosion phenomena that can degrade soil quality and cause siltation of potential dams. The objective of this current study is to develop a methodology using remote sensing and geographic information systems (GIS). This serves to map areas at risk of water erosion in the watershed upstream Tessaoute (High Atlas of Morocco). In addition to produce potential erosion risk map that can be used as a tool for land planning. To conduct this study, we’ve chosen to apply on our watershed qualitative model, based on the model proposed by the Bissonnais (2002) and amended by Abaoui et al (2005), as it is applied in the region High Atlas by Bachaoui et al (2007) and Maimouni et al (2012). Through this model the sensitivity of land to erosion is assessed from the sum of the features attributed to classes of three parameters: the land, the friability of materials and the degree of slope. The methodology presented is to integrate in a GIS environment, the three main factors controlling the erosion which enables the establishment of a qualitative model for mapping soil sensitivity to water erosion. The potential erosion risk map derived therefrom shows four areas of vulnerability to water erosion: low, medium, high and very high

Analysis of Tunisian date palm germplasm using simple sequence repeat primers

Inter Simple Sequence Repeat (ISSR) markers involve polymerase chain reaction (PCR) amplification of DNA using a single primer composed of a microsatellite sequence. ISSR technology rapidly reveals high polymorphic fingerprints and determines genetic diversity. We used genetic markers generated from selected ISSR primers to assess genetic diversity among a set of Tunisian date palm varieties. Seven primers were used to cluster 12 date palm varieties and 77 polymorphic markers were sufficient to identify all of the varieties. These discrete molecular markers were used to estimate genetic distances among the 12 accessions and to examine their genetic relationships. Data analysis identified phenetic groups that were in agreement with those obtained according to agronomic traits and random amplified polymorphic DNA (RAPD) markers. Among the 12 simple sequence repeat (SSR) motifs tested, the most abundant were AG. Key Words: Genetic diversity; ISSR polymorphisms; date palm; Pheonix dactylifera. African Journal of Biotechnology Vol. 3 (4), 2004: 215-21

Structure génétique des cécidomyies des céréales en Tunisie

Genetic structure of Hessian flies in Tunisia. The genetic structure of M. destructor and M. hordei was investigated by sampling 21 fields of cereals in 14 localities of central and southern Tunisia. As previously shown, there was no strict association between the cereal species (wheat, barley and oat) and the Mayetiola species. M. destructor males displayed no heterozygosity at the Pgm3 locus, indicating that they were hemizygous as is the PGM locus in North America. In M. hordei, heterozygous males were observed at all loci, but strong heterozygote deficits were found at two loci (Mdh2 et Hk). Since no such deficit was observed in females, the population structure of M. hordei was studied only in females. Although heterozygosity was two fold higher in M. hordei than in M. destructor, the two species were similar for other genetic characteristics, including a low (Fst < 0.05) but significant (P < 0.05) genetic differentiation, no isolation by distance, and similar rates of gene flow (5.7 ≤ Nm ≤ 9.6). These results are discussed in relation to their consequences in the event of controlling Tunisian Hessian flies using wheat cultivars that are resistant to a M. destructor biotype

Isolated anti-Ro/SSA thrombocytopenia: a rare feature of neonatal lupus

We report a rare case of isolated thrombocytopenia related to anti-Ro/SSA antibodies. The mother was  followed for unlabeled familial thrombocytopenia. The mother had positive anti-Ro/SSA antibodies. She was asymptomatic without skin lesions or other criteria neither of systemic lupus erythematosus nor other  connective tissue disease. Pregnancy was uneventful. The postnatal examination was normal. On the first day of life, blood cells count showed thrombocytopenia at 40 x 109/L. Within the second day of life, platelet level  dropped to 20 x 109/L. The management of thrombocytopenia included platelet transfusion and human  immunoglobulin infusion. On the fifth day of life, there has been a drop in platelet count to 10 x 109/L requiring renewed platelet transfusion and human immunoglobulin infusion. On the 10th of life platelets rate was stable around 60 x 109/L. The infant had no evidence of cardiac, dermatologic or hepatobilary involvement initially or throughout follow up.Key words: Neonatal lupus erythematosus, thrombocytopenia, anti-Ro/SS

MISE EN PLACE D’UN MODÈLE QUALITATIF POUR LA CARTOGRAPHIE DES ZONES À RISQUE D'ÉROSION HYDRIQUE DANS LA CHAÎNE ATLASIQUE: CAS DU BASSIN VERSANT DE LA TESSAOUTE AMONT. (HAUT ATLAS CENTRAL, MAROC)

The catchment areas of the Atlas chain are threatened by water erosion phenomena that can degrade soil quality and cause siltation of potential dams. The objective of this current study is to develop a methodology using remote sensing and geographic information systems (GIS). This serves to map areas at risk of water erosion in the watershed upstream Tessaoute (High Atlas of Morocco). In addition to produce potential erosion risk map that can be used as a tool for land planning. To conduct this study, we’ve chosen to apply on our watershed qualitative model, based on the model proposed by the Bissonnais (2002) and amended by Abaoui et al (2005), as it is applied in the region High Atlas by Bachaoui et al (2007) and Maimouni et al (2012). Through this model the sensitivity of land to erosion is assessed from the sum of the features attributed to classes of three parameters: the land, the friability of materials and the degree of slope. The methodology presented is to integrate in a GIS environment, the three main factors controlling the erosion which enables the establishment of a qualitative model for mapping soil sensitivity to water erosion. The potential erosion risk map derived therefrom shows four areas of vulnerability to water erosion: low, medium, high and very high