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Item Prédétermination des débits de crue par différentes méthodes. Cas du bassin versant d’El Kébir Ouest à Ain-Charchar (Nord-Est algérien)(Synthèse: Revue des Sciences et de la Technologie, 2017-01-29) Tarek DAIFALLAHAbstract To combat flooding, a long series of flow measurement is necessary, which is not the case unfortunately in most of the time.The interruption of the hydrometric station of Ain Charchar controlling the watershed of Oued El Kebir West Ain-Charchar on an area of 1130 km2 poses a serious data problem. To overcome this handicap, we used the values of maximum flows recorded over a period of 14 years, from 1985 to 1999, which fit well to the law of Gumbel. From the adjustment line, the probable flood values for different return periods were determined, 200 m3 / s for a return period of 10 years and 300 m3 / s for T equal to 100 years.To achieve our second objective, which is the possibility of reconstructing flood flows using empirical formulas based on precipitation, it has verified the correlation rain-flow rate by the Hydrolab software and the GR 1 model. The two methods have shown the existence of a simple linear relationship with correlation coefficients of 0.82 and 0.69, respectively. The two formulas for determining flood flows (formula of Turazza and that of Skolvoski) have led to similar results to those measured in the gauging station.Item Water resources and their management under impact of climate change and users pressures in Kebir-West River basin (North-Eastern Algeria), using the WEAP model(researchgate, 2017) Tarek DAIFALLAH; Halimi SamiaAbstract Water is the factor of the humanity development, this resource of life threatened by human pressure and the effects of the nature to know the future climate change put the man in face of challenges for a rational management. The objective of this paper is to examine the likely impacts of a climate change on the water supply and demand and the resulting socioeconomic implications in the watershed of El Kebir West located in the northeast of Algeria under different scenarios applying the WEAP model. or an optimistic scenario of reference, the water resources of the basin could perfectly cover the requirements of different users. To that taking into account the impacts of climate change on these reserves, and the augment in the demand induced by the increase of populations and their activities, the region will suffer from water stress from the Horizon 2030, when demand exceeds 80 MCM of water and reach more than 136 MCM in 2050. Whereas, the supply will decrease from 70.8 actually to 66 MCM (million cubic meter) in 2050. This could be caused by a possible decrease in the storage of water. This stress could be avoided if we decide to a policy for the demand management, or may establish a state of balance of supply and demand by various tools of water management.Item Assessment of groundwater salinity and risk of soil degradation in Quaternary aquifer system. Example: Annaba plain, Algeria N-E(JOURNAL OF WATER AND LAND DEVELOPMENT, 2018) Tarek DAIFALLAH; Samia HALIMIAbstract Quality of water resources in Annaba plain (North East) of Algeria is facing a serious challenge due to industrialisation and excessive exploitation of water. Therefore, 29 groundwater samples were collected from this area to assess their hydrogeochemistry and suitability for irrigation purposes. The groundwater samples were analysed for distribution of chemical elements Ca2+, Mg2+, Na+, K+, HCO3 −, Cl−, and SO4 2−. It also includes pH, electrical conductivity. The hydrochimical study has shown that the facieses are changing between a pole calcium-chloride-sulphate and sodium-chloride types. The results also showed that the salinity is the major problem with water for irrigation use (58% of samples fall into C3S1 class). As a result, the quality of the groundwater is not suitable for sustainable crop production and soil health without appropriate remediation.Item Characterization of groundwater mineralization: Hydrochemical methods Livre(amazon, 2021-09-21) Miyada Ouanes; Belgacem HouhaThe main objective of this study is to diagnose the quality of groundwater and the impact of the F'kirina gas turbine power plant on it.10 samples were taken from boreholes and wells in the aquifer exploited in the region and used for human consumption. The results obtained showed that the water is polluted, particularly in terms of conductivity, total hardness and the concentration of minor elements. The study of the pollution parameters showed that there was an excess in the concentration of nitrates as well as sodium and sulphate. This may probably be due to the proximity of agricultural land as well as the gas turbine power plant in the case of some boreholes. To this end, ongoing assessment of water quality is deemed necessary and treatment to reduce water quality deterioration and eliminate health problems may be requiredItem Biological diversity and patrimony evaluation of the fauna and flora of a wetland of "Sebkhet el mahmel" in the arid region of Khenchela in the North-east of Algeria(Journal of Biodiversity and Environmental Sciences, 2022-04-30) Ounes Miada; Khabtane AbdelhamidAbstract The objective of our work is to determine the floristic and faunistic biological diversity and the patrimonial evaluation of the wetland of sebkhet El Mahmel in the arid zone of Khenchela located in the north east of Algeria, in order to allow the decision makers to take adequate measures for the protection and the preservation of this wetland. The results of the study reveal a remarkable floristic, faunistic and patrimonial value richness, where we inventoried 78 plant species, divided into 23 families, the majority of which are herbaceous forms including a protected species and two endemic species. As we counted 21 species of migratory water birds, divided into 6 orders grouping 8 families; dominated by the family of anatidae, all of which are protected. For the terrestrial birds we noted the presence of 35 species, divided in 07 orders containing 19 families dominated by the order of passeriformes with 11 families. For us we report the presence of 98 species; divided into 16 orders containing 44 families dominated by the order of Coleoptera with 13 families, of which 09 species are protected. As we note the presence of an order of amphibians with two families and two orders of reptiles with 05 families and 12 species, the majority of which are protected. For the mammals we noticed the presence of 14 species grouped in 06 orders containing 09 families, we point out that the area is frequented by species of important patrimonial value such as the striped hyena.Item The impact of the factory of the exploitation of the baryta deposits on the quality of the waters of the township of ain Mimoun province of Khenchela N-E of Algeria(Journal of Biodiversity and Environmental Sciences, 2022-06-15) Ouanes Miyada; Houha Belgacem; Aouidane Laiche; Khabthane AbdelhamidAbstract Our work is intended as a contribution to the analysis of the effect of barium factory discharges in the region of Ain Mimoun in the province of Khenchela, the latter has a semi-arid climate, the sampling of the groundwater was carried out on quaternary and cretaceous formations for the purpose of physicochemical analysis. The hydrochemical study revealed that the concentrations of barium and sulphate are high, particularly in the samples taken near the production unit. This means that the discharge of this barite unit has a pollution impact on the groundwater of our study area.Item IMPROVEMENT OF SALT TOLERANCE IN DURUM WHEAT BY ASCORBIC ACID APPLICATION(Journal of Stress Physiology & Biochemistry, 2011-01-07) Azzedine FerchaThe main objective of this study is to examine whether exogenously applied Ascorbic acid (AsA) may enhance the salt tolerance in durum wheat (Triticum durum Desf. var. Waha). Two weeks old seedling, grown in plastic pots of 1kg, were subjected to salt stress by adding 25ml of NaCl (150mm), and treated or not with the addition of ascorbic acid (0.7 mM). Two weeks after salt stress, plants were harvested and the various measures were recorded. The effects of salt stress, in the presence and absence of vitamin C, on the leaf growth, leaf area (LA) and some physiological and biochemical changes were investigated. It was established that the application of vitamin C mitigate to variable extent the adverse effect of salt stress on plant growth, may be due, in part, to increased leaf area, improved chlorophyll and carotenoid contents, enhanced proline accumulation and decreased H2O2 content. In conclusion, we can say that treatment with ascorbic acid improve salt tolerance in durum wheat through the enhancement of multiple processes.Item To study ways to add a phosphorus on vegetative growth of wheat plants growing under conditions of Algeria(AGRICULTURE AND BIOLOGY JOURNAL OF NORTH AMERICA, 2013) Azzedine FerchaABSTRACT Then a field experiment in two consecutive seasons on a farm in the Division lead to study the effectiveness of the added phosphorus spraying on the leaves and compare them added to the ground on the vegetative growth of wheat plants under conditions of Algeria, where you use three factors for phosphorus P0 - Ps - Pr (without adding phosphorus - affixed to the ground - added spray), respectively. and massage at 50 parts / million P2O5 on the image of super phosphate, and then added in two 3 / 2 amount by the Agriculture mixing with the soil and 3 / 1 the remainder after 15 days of agriculture, was also used phosphorus spraying on the leaves concentration of 1% of the sodium phosphate mono NaHPO4 three periods after 30 - 35 - 40 days of agriculture, and selected two types of soil differ in physical and chemical characteristics, results showed the following: Increased the dry weight of shoot significantly by adding phosphorus to any of the methods for the treatment of comparison, regardless of the type of soil The addition of phosphorus in any of the methods to increase the number of leaves and the back in both two soil in the two phases of growth. The addition of phosphorus to the ground to the significant increase in total dry weight of roots and surpassed the values of dry weight of both shoots and roots in the soil of the first region than those in the soil of Talha. - The mutual influence between the two variables is statistically significantIncreased the total content of phosphorus in shoot dry any of the methods although the added Ground surpassed Added spraying on the leaves, but the same trend was observed for the dry weight of roots.Item Gel-free proteomics reveal potential biomarkers of priming-induced salt tolerance in durum wheat(elsevier, 2013-08-12) Azzedine FerchaSeed priming has been successfully demonstrated to be an efficient method to improve crop productivity under stressful conditions. As a first step toward better understanding of the mechanisms underlying the priming-induced salt stress tolerance in durum wheat, and to overcomethe limitations of the gel-based approach, a comparative gel-free proteomic analysis was conducted with durum wheat seed samples of varying vigor as generated by hydro- and ascorbate-priming treatments. Results indicate that hydro-priming was accompanied by significant changes of 72 proteins,most ofwhich are involved in proteolysis, protein synthesis, metabolismand disease/defense response. Ascorbate-primingwas, however, accompanied by significant changes of 83 proteins, which are mainly involved in protein metabolism, antioxidant protection, repair processes and, interestingly, inmethionine-relatedmetabolism. The present study provides new information for understanding how ‘priming-memory’ invokes seed stress tolerance. Biological significance The current work describes the first study in which gel-free shotgun proteomics were used to investigate the metabolic seed protein fraction in durum wheat. A combined approach of protein fractionation, hydrogel nanoparticle enrichment technique, and gel-free shotgun proteomic analysis allowed us to identify over 380 proteins exhibiting greater molecular weight diversity (ranging from7 to 258 kDa). Accordingly, we propose that this approach could be useful to acquire a wider perspective and a better understanding of the seed proteome. In the present work, we employed this method to investigate the potential biomarkers of priming-induced salt tolerance in durum wheat. In this way, we identified several previously unrecognized proteins which were never been reported before, particularly for the ascorbate-priming treatment. These findings could provide new avenues for improving crop productivity, particularly under unfavorable environmental conditions.Item differential response of durum wheat genotypes to salinity A. Fercha1*, H. Gherroucha2(Journal of Applied Botany and Food Quality, 2013) Azzedine FerchaSummary This study aims to investigate the importance of accumulation of osmoprotectants and activities of some key antioxidant enzymes in genotypic variation (GV) observed among durum wheat genotypes in response to increasing NaCl salinity (0-200 mmol/L) at seedling stage. Germination and seedling growth traits of all the genotypes were significantly decreased by salinity. Mohamed Ben Bachir, the more salt-tolerant genotype, exhibited the lowest reduction in final germination percentage (FGP, <18%) and seedling growth (<60%, based on dry biomass), the lowest increase in proline (PRO) and water soluble carbohydrates contents but the highest increase in catalase (CAT) and ascorbate peroxidase (APX) activities. Correlation and principal components analysis revealed that the most important variables distinguishing salt tolerant vs. salt non-tolerant genotypes were root to shoot ratio (R/S, 36.1%), CAT (30.6%), APX (12.5%) and FGP (5.74%). Although PRO and WSC could play a key role in salt tolerance by mediating osmotic adjustment, these compounds do not seem to be significantly involved in genotypic variation (GV) for salinity tolerance in durum wheat.Item Comparative analysis of metabolic proteome variation in ascorbate-primed and unprimed wheat seeds during germination under salt stress(elsevier, 2014-05-21) Azzedine FerchaSeed priming with ascorbic acid improves salt tolerance in durum wheat. For understanding the potential mechanisms underlying this priming effect a gel-free shotgun proteomic analysis was performed comparing unprimed to ascorbate-primed wheat seed during germination under saline and non-saline conditions. Since seed germination is the result of interplay or cross-talk between embryo and embryo-surrounding tissues, we studied the variation of metabolic proteome in both tissues separately. 167 of 697 identified and 69 of 471 identified proteins increase or decrease in abundance significantly in response to priming and/or salinity compared to untreated, unstressed control in embryo and embryo-surrounding tissues, respectively. In untreated wheat embryo salt stress was accompanied by change in 129 proteins, most of which are belonging to metabolism, energy, disease/defense, protein destination and storage categories. Ascorbate pretreatment prevents and counteracts the effects of salinity upon most of these proteins and changes specifically the abundance of 35 others proteins, most of which are involved in metabolism, protein destination and storage categories. Hierarchical clustering analysis revealed three and two major clusters of protein expression in embryo and embryosurrounding tissues, respectively. This study opens promising new avenues to understand priming-induced salt tolerance in plants. Biological significance To clearly understand how ascorbate-priming enhance the salt tolerance of durum wheat during germination, we performed for the first time a comparative shotgun proteomic analysis between unprimed and ascorbate-primed wheat seeds during germination under saline and non-saline conditions. Furthermore, since seed germination is the result ofItem Shotgun proteomic analysis of soybean embryonic axes during germination under salt stress(Proteomics, 2016-03-08) Azzedine FerchaSeed imbibition and radicle emergence are generally less affected by salinity in soybean than in other crop plants. In order to unveil the mechanisms underlying this remarkable salt tolerance of soybean at seed germination, a comparative label-free shotgun proteomic analysis of embryonic axes exposed to salinity during germination sensu stricto (GSS) was conducted. The results revealed that the application of 100 and 200 mmol/L NaCl stress was accompanied by significant changes (>2-fold, P<0.05) of 97 and 75 proteins, respectively. Most of these salt-responsive proteins (70%) were classified into three major functional categories: disease/defense response, protein destination and storage and primarymetabolism. The involvement of these proteins in salt tolerance of soybean was discussed, and some of them were suggested to be potential salttolerant proteins. Furthermore, our results suggest that the cross-protection against aldehydes, oxidative as well as osmotic stress, is the major adaptive response to salinity in soybean.Item ANALYSEMULTIVARIÉE DES TRAITS ASSOCIÉS À LA VIGUEUR DES SEMENCES DE BLÉ DUR SOUS CONDITIONS SALINES(Lebanese Science Journal, 2018) Azzedine FerchaABSTRACT Azzedine Fercha, Ayache Laabassi, Tarek Aissani, Chouki Sahraoui, Mahmoud Ghaoui. 2018. Multivariate analysis of traits associated with durum wheat seed vigor under saline conditions. Lebanese Science Journal, 19(2): 123-134. In this study, the ability of germination, seedlings emergence and salt stress tolerance in durum wheat (Triticum durum Desf.) were evaluated by multivariate analysis using eight cultivars collected from different regions of Algeria. Two-way ANOVA indicated significant effects of "salt stress" and "genotype" on all the attributes of germination and seedlings growth. The principal component analysis indicated that the first and second components accounted for about 64.5 % of the variation among the traits analyzed. The second component included the coleoptiles length, seedlings length and vigor index, and accounted for nearly 60 % of the variation. This component represented the ability of wheat seedlings to grow under salt stress conditions. The hierarchical cluster analysis classified the eight genotypes into two groups. Results obtained suggested that selection for high values of the traits such as "coleoptiles length", ‘seedlings length’ and "seeds vigor" did improve salt tolerance of durum wheat. In addition, the cross between the genotypes classified in groups I and II may increase the genetic diversity in this species, and enable efficient selection among the progeny obtained from these crosses. RÉSUMÉ Azzedine Fercha, Ayache Laabassi, Tarek Aissani, Chouki Sahraoui, Mahmoud Ghaoui. 2018. Analyse multivariée des traits associés à la vigueur des semences de blé dur sous conditions salines. Journal Scientifique Libanais, 19(2): 123-134. La variabilité génétique de la tolérance à la salinité au stade germination/levée de huit génotypes de blé dur (Triticum durum Desf.) a été évaluée à l’aide d’une analyse multivariée. L’ANOVA a indiqué des effets significatifs des facteurs « stress salin » et « génotype » sur tous les attributs de germination et d’établissement des semis. L’analyse en composantes principales a indiqué que les deux premières composantes représentent environ 64.5 % de la variation totale. La deuxième composante comprend la longueur des coléoptiles, la longueur des plantules et l’indice de vigueur des semences avec ~60 % de contribution. Cette composante représente la capacité d’émergence des plantules sous stress salin. L’analyse hiérarchique a permis de classer les huit variétés en deux groupes. Ces résultats suggèrent que la sélection pour des valeurs élevées des traits comme ‘longueur des coléoptiles’, ‘longueur des plantules’ et ‘vigueur des semences’ va améliorer la tolérance à la salinité chez le blé dur. Ceci indique que les croisements entre les génotypes des deux groupes peuvent augmenter la diversité génétique de cette espèce et permettre une sélection efficace dans la progéniture obtenue à partir de ces croisements.Item Chemical Composition and Antibacterial Activity of Berries Essential Oil of Algerian Juniperus thurifera (Var. aurasiaca)(Pharmaceutical Sciences, 2018-09-23) Azzedine Fercha; Azzeddine ZeraibA B S T R A C T Background: Over the past decade, most antibiotic research programs have focused on finding new compounds with antimicrobial activity. This study aims to investigate the chemical composition and antibacterial activity of the essential oil (EO) extracted from ripe berries of Algerian Juniperus thurifera var. aurasiaca. Methods: The chemical composition of J. thurifera EO extracted by hydrodistillation was analyzed by using the GC-MS technique. Antibacterial activity of EO alone and in combination with three conventional antibiotics was assessed by using disc diffusion method against four bacterial strains. Results: Thirty-five components were identified, representing ~87 % of the oil. The main components were m-mentha-6,8-diene (15.43 %), β-pinene (10.59 %), elemol (8.31 %) and terpinene-4-ol (7.44 %). The essential oil showed strong antibacterial activity against S. aureus and E. coli, but no activity against P. aeruginosa and B. subtilis. Synergistic effects were observed because of the combined application of EO with gentamicin against all strains tested, and with amoxicillin against B. subtilis. Furthermore, the combination of EO/cefazolin demonstrated an additive effect against B. subtilis. In contrast, the combination of EO with amoxicillin and céfazoline revealed antagonistic effects against S. aureus, E. coli, and P. aeruginosa. Conclusion: This is the first report on the chemical composition and antibacterial activity of Algerian juniper berries’ essential oil. The results indicate that the studied EO may be a promising source of antibacterial compounds that could be useful for pharmaceutical applications especially in combination with conventional antibiotics.Item Chemical composition and biological activities of Algerian Santolina africana essential oil(elsevier, 2019-05-20) Azzedine Fercha; Azzeddine Zeraiba b s t r a c t The chemical composition and the biological activities of the essential oil (EO) extracted by hydrodistillation from the aerial parts of Algerian population of Santolina africana have been studied. S. Africana EO was chemically characterized by means of GC–MS. Forty-six compounds were identified representing ∼92% of the total oil. β-pinene (11.65%), ger- macrene (10.33%), 1,8-Cineole (9.46%) and sabinene (7.18%) were the major components. The EO antioxidant activity was evaluated by DPPH assay. All EO concentrations showed considerable scavenging ability on DPPH radicals (IC 50 < 1.13 mg.mL −1 ). The antibacterial screening of EO alone and in combination with three conventional antibiotics (ABs) was made by way of disc diffusion against four standard strains. The interactive effects be- tween EO and ABs were evaluated using the One-way ANOVA analysis. The results showed a remarkable antibacterial activity of S. africana EO against Staphylococcus aureus (29 mm), Escherichia coli (29.27 mm) and Bacillus subtilis (15 mm). Excluding the antagonistic effect observed with cefazolin, the combined application of S. africana EO with the other two antibiotics led to synergistic and additive effects. These findings show the potential use of S. africana EO as an interesting source of potent antioxidant and antibiotic components useful for medicine.Item Synergistic effects of Ruta montana (Clus.) L. essential oil and antibiotics against some pathogenic bacteria(Journal of Phytology, 2021-08-31) Azzedine Ferchaa; Azzeddine Zeraib; Khaled RahalABSTRACT Antibiotic resistance has been called one of the world’s most pressing public health threats. The combination of essential oils with conventional antibiotics is one of the emerging approaches that could help prevent this problem. In light of this, the present study aimed to investigate the impact of the combination of Ruta montana essential oil with conventional antibiotics on some pathogenic bacteria. The essential oil isolated by hydrodistillation was first analyzed using GC-MS then tested alone and in combination with five recommended antibiotics against three bacterial strains by the agar disc diffusion and broth micro-dilution methods. Out of forty-nine peaks, thirty-eight components were identified representing 98.17% of the total oil composition. The major components were 2-Undecanone (63.39%), 2-Nonanone (5.65%), 2-Acetoxytetradecane (4.94%), 2-Decanone (4.47%) and 2-Dodecanone (3.35%). While R. montana essential oil showed only weak antibacterial activity compared to the antibiotics tested alone, unexpectedly, the combination of RM essential oil with antibiotics remarkably increased the antibacterial activity of the antibiotics through synergistic effects in up to 70% of cases. These results suggest that combining antibiotics with essential oils, even those with low antibacterial activity, may be effective in overcoming problems caused by increasing bacterial resistance.Item Are diurnal time-budgets andlactivity patterns density-dependent inlthelShelduck (Tadorna tadorna) wintering inlAlgeria? Anlanalysis acrosslmultiple temporal scales(Avian Research, 2019) DjamellBensizeraraAbstract Background: The Shelduck (Tadorna tadorna) is a characteristic waterbird species of inland wetlands in northeastern Algeria. Its wintering behavior in relation to changes of local abundances and foraging group density is poorly known. Objectives: This study aims at monitoring patterns of diurnal activities and the variation of behavioral time-budgets in relation to numbers of wintering Shelducks. We investigate temporal variations of diurnal activities across multiple- time scales and consider their interrelationships. Methods: Assessments of local population abundance were weekly surveyed during two wintering seasons (2010- 2012), whereas diurnal activities (feeding, sleeping, swimming, preening, loafing, flying, courtship, and antagonism) were studied three times a month during seven hours (08:00-16:00) using the Scan method. Time budget variations of each behavioral activity were tested using nested ANOVAs following multiple time scales. Generalized linear mixed- effects models (GLMM) tested whether variations in diurnal activities were density-dependent. Results: During the wintering season, Shelduck's numbers followed a bell-shaped trend, which indicated that the species was typically a wintering migrant in Sabkha Djendli. The first individuals arrived onsite in October-November then numbers reached a peak in January (up to 2400 individuals in 2012) with steady density during December-Feb- ruary, afterward individuals left the site progressively until late April when the site is deserted. During both wintering seasons, diurnal activities were dominated by feeding (60%), followed by sleeping (12%) then swimming and preen- ing with 9% and 8%, respectively. The rest of the activities (loafing, flying, courtship and antagonistic behaviors) had low proportions of time budget. ANOVAs showed that activity time budgets varied significantly following multiple time scales (year, season, month, day, semi-hour). Time budgets of diurnal activities during each wintering season were significantly interrelated. Correlations patterns between the two seasons were similar. GLMMs revealed that the variations of diurnal activities were not density-dependent, except for preening and swimming. Conclusion: During the wintering season, habitats of Sabkha Djendli are important for waterbirds, including the Shelduck that used the lake mainly for food-foraging and resting. The 2400 individuals censused in mid-winter are important locally and at the North African scale. This stresses the need to strengthen the protection status of this wetland and mitigate degradation sources that threaten wintering waterfowl.Item Assessment of soil metallic contamination in several sites from Northeast Algeria by use of terrestrial gastropod: Cornu aspersum (O.F. Müller, 1774) (Helicidae)(researchgate, 2023-06-26) Rabah LarbaABSTRACT The study aimed to determine concentrations of some trace elements (Fe, Mn, and Pb) in soils of five sites in Northeast Algeria (Sidi Ammar, Drean, Chatt, Besbes, and El-Kala) during the spring and autumn of 2019. All of the sites were chosen due to their proximity to industrial factories. In addition, the activity of glutathione S-transferase (GST) and acetylcholinesterase (AChE), indicators of oxidative stress and neurotoxicity respectively, were measured in land snail Cornu aspersum (O.F. Müller, 1774) (Mollusca Gastropoda Helicidae) collected from all studied sites. The concentration of heavy metals in these soils decreases as follows: Fe > Mn > Pb. GST and AChE activities were found to vary between sites and by season. The highest levels of GST activity were registered during the spring at sites closest to potential sources of pollution. AChE values showed inhibition in spring as compared to autumn. In addition, the highest inhibition values were recorded at the Sidi Ammar site. These increased levels of bioindication stress responses correlated significantly with increasing metal concentration in soil samples collected at each site. The differences recorded between the sites studied are related to their level of pollution, while the seasonal variations were due to the effect of heavy metals leaching in autumn.Item Use of the land snail Helix aspersa for monitoring heavy metal soil contamination in Northeast Algeria(researchgate, 2014-04) Rabah LarbaaAbstract The objective of this study was to investigate the impact of anthropogenic activities on soil quality using the land snail Helix aspersa as a bioindicator. Soil samples and snails were collected from several sites in Northeast Algeria during the summer and winter of 2010. All of the sites were chosen due to their proximity to industrial factories – a potential source of soil pollution via heavy metal contamination. The concentration of heavy metals (Pb, Cd, Mn, and Fe) in soil samples was analyzed using atomic absorption spectrophotometry. Activity levels of glutathione S-transferase (GST) and acetylcholinesterase (AChE), indicators of oxidative stress and neurotoxicity respectively, were measured in snails collected from each site. GST and AChE activity were found to vary between sites and by season. The highest levels of GST activity were registered during the summer at sites closest to potential sources of pollution. AChE activity levels also peaked during the summer with the highest values recorded at the site in El Hadjar. These increased levels of bioindicative stress response correlated with increasing metal concentration in soil samples collected at each site.Item Diversity of the terrestrial gastropods in the Northeast Algeria: Spatial and temporal distribution(researchgate, 2013) Rabah LarbaaABSTRACT A survey of terrestrial gastropods was carried out monthly in three sites located in the Northeast Algeria (El Hadjar, Sidi Kaci, El Kala) during the period of February 2010 January 2011. The sites were chosen according to their proximity of factories and other potential sources of pollution. Totally 8463 individuals were collected and 14 species identified (12 species of snails and 2 species of slugs) belonging to six families: Milacidae, Helicidae, Subulinidae, Cochlicellidae, Enidae and Hygromiidae. Among the species identified 4 are constant: Helix aspersa (Müller, 1774), Otala lactea (Müller, 1774), Trochoidea elegans (Gmelin, 1791), Rumina decollate (Linnaeus, 1758), 3 are accessory: Helix aperta (Born, 1778), Helicella virgata (Da Costa, 1780) and Theba pisana (Müller, 1774), and 7 are accidental: Cepaea vendobonensis (Ferussac, 1821), Zebrina detrita (Müller, 1774), Dupotetia A zonata (Pallary, 1926), Cochlicella barbara (Linnaeus, 1758), Milax gagates (Draparnaud, 1801), Milax nigricans (Phillipi, 1836), Cepaea nemoralis (Linnaeus, 1758). The specific richness of the gastropod species was found to vary between sites and by season. General seasonal peak was recorded during Spring and Winter while the lowest abundance observed during Summer. Helix aspersa is the most abundant species in all prospected sites and will be used as a bioindicator of soil pollution.