Some Statistical Aspects for Algerian Earthquake Catalogue

The scope of this study is to analyze some aspects of the Algerian earthquake catalogue between 1980 and 2009.Seismicity analysis is based on reliable compilation of earthquake catalogs obtained from different agencies.All intensities and magnitudes were converted to Ms magnitude using appropriate relationships.Dependent events were removed using adapted time and space windows.In addition,the completeness of the catalogue as a function of magnitude was determined from the standard deviation of occurrence rate plots,using the Stepp’s methodology.The remaining 2,016 independent earthquakes with Ms 2.2 were used to obtain various parameters(b-value,z-value)to characterize the temporal and spatial seismic activity for the entire northern part of Algeria.Finally,the obtained results are discussed to explain parameters variability.

Floristic composition of the halophilic and salt-resistant plant population in Hammam-Boughrara (Oran-Algeria)

This phyto-ecological study is on halophilic and salt-resistant vegetation of Oran region. The semiarid and sometimes arid climate has been defined and confirmed from a bioclimatic point of view. The pedological approach used shows a soil with sandy to silty-sandy texture, favoring regression of the vegetation and a halophilic vegetation set up. In this study, we analyze the floristic composition of the northern region of Hammam Boughrara using multiple floristic surveys conducted at three stations along the Tafna wadi. Dominated by Mediterranean and Saharo-Sindian elements, the relatively poor flora (88 species in total) is biologically characterized by a clear dominance of therophytes (>33%) and chamaephytes (>19%) to the detriment of phanerophytes.

Estimation of soil erosion and sediment yield in Wadi El Hachem watershed(Algeria)using the RUSLE-SDR approach

One of the most common types of soil degradation is water erosion.It reduces soil quality at the erosion site and may cause sedimentation issues at the deposition site.This phenomenon is estimated using a variety of models.The Revised Universal Soil Loss Equation(RUSLE)model is the most often used,due to its consistence and low data requirement.It is useful for estimating annual soil loss at the watershed scale.To investigate the relationship between soil erosion and sediment deposition,the combined RUSLE and Sediment Delivery Ratio(SDR)models are used.The Wadi El Hachem watershed is a coastal and mountainous Mediterranean basin with rugged topography and high degree of climatic aggressiveness.Both of these characteristics can have an immediate effect on soil erosion and sediment yield.This research includes estimating the Average Annual Soil Loss(A)and Sediment Yield(SY)in the Wadi El Hachem watershed,mapping different RUSLE factors as well as A and SY,and studying the influence of rainfall erosivity(R)on A and SY in dry and rainy years.The A results vary from 0 to 410 t·ha^(-1)·yr^(-1)with an annual average of 52 t·ha^(-1)·yr^(-1).The Renfro's SDR model was selected as the best model for estimating SY,with standard error,standard deviation,coefficient of variation,and Nash–Sutcliffe efficiency(NSE)values of 0.38%,0.02,0.07%,and 1.00,respectively.The average SY throughout the whole watershed is around 27 t·ha^(-1)·yr^(-1).The SY map for the entire Wadi El Hachem watershed revealed that sediment production zones are mainly concentrated in the Northeast of the basin,at the basin’s outlet,and in the tributaries of the dam.The simulation results of soil loss and sediment yield in dry and rainy years revealed that R is one of the main factors affecting soil erosion and sediment deposition in the Wadi El Hachem watershed.The mean difference in R factor between dry year and rainy year is 671 MJ·mm·ha^(-1)·h^(-1)·yr^(-1).As a result of this fluctuation,the soil loss and sediment yield have increased by 15 and 8 t·ha^(-1)·yr^(-1),respectively.The results of this research can be used to provide scientific and technical support for conservation and management strategies of the Wadi El Hachem watershed.

Some Anthropic Aspects in Meridional Region of Sebdou (Oran-Algeria)

Relying essentially on human data (social structure, demography, population repartitions, migratory movements, agro-pastural activities), the authors, from their studies, note that these regions are an extension of hamlets and other groups. Highlands gather a small population that seems to settle. Responsible human disturbance (clearings, cultures, urbanization, etc.) modified a large part of the actual state of vegetation structures. The results also show that most of the population is concentrated in the main towns. This concentration causes consumption of pre-forest land and rangelands. The average annual extension can sometimes reach 2.4 Ha. Hamlets, home grouping seem to impose a lifestyle approaching that of centers located in the North. At the bioclimatic level, the results show that the cold thermal variations promote contact between woody vegetation and steppe formations with thermal determinism (formation often in xerophytes thorny pads). Droughts often advocate regressive dynamics of these plant formations which are quite degraded. On the other hand, stressing continuity issues related to human actions, the authors present the floristic composition, detailing the botanical plant species including biological and morphological types. The therophyte type predominates in all areas explored and their percentage can reach 73% in the steppe and 49% in Beni-Snous.

Germination Behaviour of a Perennial Amaranthaceae of North Western Algeria(Oran):Arthrocnemum glaucum(Del.)Ung.Respectively Submitted to Thermal Factor and Salt Stress

In light of the importance of seeds germinative phase in the progress of later stages of development of any particular plant species in semi-arid and arid area, it is essential to study the germinative behavior and to evaluate the tolerance of a perennial halophyte of Amaranthacaea family, Arthrocnemum glaucum (Del.) Ung. during this crucial phase. A study is devoted to this species seeds germination, which although it’s a mandatory halophyte, it’s less tolerant to salt stress in germination’ phase. Germinative tests are carried out in laboratory, on seeds putted in Petri dishes placed at different temperatures. They enable us to determine the optimal germination temperature, which is 40&#176C while the cold one (5&#176C) completely inhibits it. The seeds of Arthrocnemum glaucum show an optimum germination of 44% in distilled water (NaCl 0 mm) similar to glycophytes but they differ in their ability to germinate at higher salinities. Beyond 300 mM germination is completely inhibited. Prior to break dormancy seeds, a cold treatment at 5&#176C has been achieved;the germination capacity of the seeds increases with the duration of the cold treatment. It increases from 30% after 2 weeks of treatment to 80% after a treatment of 27 weeks.

非洲公路项目施工过程关键技术分析--以阿尔及利亚贝佳亚连接线为例

随着中国对非洲援助的不断深入,国内的设计和施工队伍也不断走向非洲。由于所属地区的不同,非洲本地的实际情况、现场环境以及所采取的规范均有所不同,若不对本土情况进行了解,很容易造成工程项目的质量型问题出现。本文以阿尔及利亚贝佳亚连接线为例,该项目是连接贝佳亚港口-东西高速公路哈尼夫互通的关键性项目,项目所在处情况复杂,采用规范与国内均不同,为保证施工过程的稳定进行,对其在该公路项目施工过程的路基、桥涵的关键性技术进行分析。拟为相关类似工程提供参考。

Prevalence of type 2 diabetes in Algerian patients with hepatitis C virus infection

AIM:To investigate the prevalence of,and risk factors for,diabetes mellitus(DM) in Algerian patients with chronic hepatitis C virus(HCV) infection and in a control group.METHODS:A cross-sectional study was undertaken.A total of 416 consecutive patients with viral chronic hepatitis attending the Internal Medicine Department of the University Hospital Center Touhami Benflis in Batna [290 HCV-infected and 126 hepatitis B virus(HBV)-infected patients] were prospectively recruited.RESULTS:The prevalence of DM was higher in HCV-infected patients in comparison with HBV-infected patients(39.1% vs 5%,P < 0.0001).Among patients without cirrhosis,diabetes was more prevalent in HCV-infected patients than in HBV-infected patients(33.5% vs 4.3%,P < 0.0001).Among patients with cirrhosis,diabetes was more prevalent in HCV-infected patients,but the difference was not significant(67.4% vs 20%,P = 0.058).The logistic regression analysis showed that HCV infection [odds ratio(OR) 4.73,95% CI:1.7-13.2],metabolic syndrome(OR 12.35,95% CI:6.18-24.67),family history of diabetes(OR 3.2,95% CI:1.67-6.13) and increased hepatic enzymes(OR 2.22,95% CI:1.1-4.5) were independently related to DM in these patients.CONCLUSION:The high prevalence of diabetes in HCV-infected patients,and its occurrence at early stages of hepatic disease,suggest that screening for glucose abnormalities should be indicated in these patients.

Soil characteristics and plant distribution in saline wetlands of Oued Righ, northeastern Algeria

Saline wetlands are rare ecosystems in Saharan areas, which are important for conservation of many endemic and rare plant species. In this study, we investigated five saline wetland sites of the Oued Righ region, located in the northeastern Algeria, to determine the environmental factors controlling the composition and distribution of plant communities. We established a total of 20 transects to measure the vegetation parameters （density and cover） and soil characteristics （electrical conductivity, moisture, pH, CaSO4, CaCO3, organic matter, Na＋, K＋, Mg2＋, Ca2＋, SO42 , CI-, NO3- and HCO3-）. A total of 17 plant species belonging to seven families were identified. The natural vegetation was composed of halophytic and hydro-halophytic plant communities, presented specially by the species of Amaranthaceae family. Soils in the studied wetlands were moist, gypsiferous, alkaline, salty to very salty with dominance of chloride and calcium. Results of the Canonical Correspondence Analysis （CCA） showed that community structure and species distribution patterns of vegetation were mainly dependent on soil characteristics, mainly being soil salinity （CaSO4, K＋, Ca2＋ and CI-） and moisture. The distribution of plant species was found to follow a specific zonal pattern. Halocnemum strobilaceum was observed to grow in highly salt-affected soils, thus being the more salt-tolerant species. Phragmites communis plants were widely distributed in the study area with a high density at the edges of accumulated water body. Juncus maritimus, Tamarix gallica and Saficornia fructicosa grew in soils that are partially or completely flooded in winter. Suaeda fructicosa, Traganum nudatum, Arthrocnemum glaucum, Aeluropus littoralis, Cressa cretica and Cynodon dactylon were distributed in salty and moist soils away from the open water body. Plants of Zygophyllum album, Limonastrirum guyonianum, Cornulaca monacantha, Cistanche tinctoria, Mollugo nudicaulis and Sonchus maritimus were found in soils with less salty and moisture. They constituted the outermost belt of vegetation in the studied wetlands. This study will provide a reference on introducing the salt-tolerant plant species as a fodder resource in saline habitats and regenerating the degraded saline wetlands.

NOD2/CARD15 gene mutations in North Algerian patients with inflammatory bowel disease

AIM: To analyse allelic frequency of NOD2 gene variantsand to assess their correlation with inflammatory bowel disease(IBD) in Algeria.METHODS: We studied 132 unrelated patients diagnosed with IBD, 86 with Crohn's disease(CD) and 46 with ulcerative colitis(UC). Data was prospectively collected between January 2011 and December 2013. The demographic and clinical characteristics were recorded for all the patients. A group of 114 healthy unrelated individuals were selected as controls. All groups studied originated from different regions of North Algeria and confirmed the Algerian origin of their parents and grandparents. Informed and written consent was obtained from each of the participants. All individuals were genotyped for the three CDassociated NOD2 variants(p.Arg702 Trp, p.Gly908 Arg and p.Leu1007 fsins C mutations) using the polymerase chain reaction-restriction fragment length polymorphism method. Allele and genotype frequencies in patients and control subjects were compared by χ2 test and Fisher's exact test where appropriate. Odds ratios(OR) and 95% confidence intervals(95%CI) were also estimated. Association analyses were performed to study the influence of these variants on IBD and on clinical phenotypes.RESULTS: The p.Arg702 Trp mutation showed the highest frequency in CD patients(8%) compared to UC patients(2%)(P = 0.09, OR = 3.67, 95%CI: 0.48-4.87) and controls(5%)(P = 0.4, OR = 1.47, 95%CI: 0.65-3.31). In CD patients allelic frequencies of p.Gly908 Arg and p.Leu1007 fsins C variants compared to HC were 3% vs 2%(P = 0.5, OR = 1.67, 95%CI: 0.44-6.34); 2% vs 1%(P = 0.4 OR = 2.69 95%CI: 0.48-14.87 respectively). In UC patients, allelic frequencies of p.Gly908 Arg and p.Leu1007 fsins C variants compared to HC were 1% vs 2%(P = 1, OR = 1.62, 95%CI: 0.17-4.74) and 2% vs 1%(P = 0.32, OR = 0.39, 95%CI: 0.05-2.87). The total frequency of the mutated NOD2 chromosomes was higher in CD(13%), than in HC(8%) and UC(5%). In addition, NOD2 variants were linked to a particular clinical sub-phenotype in CD in this Algerian cohort. As expected, the three NOD2 variants showed a significant association with CD but did not reach statistical significance, despite the fact that the allele frequency of NOD2 variants was in the range found in most of the European populations. This might be due to the non-exposure of the NOD2 carriers to environmental factors, required for the expression of the disease.CONCLUSION: Further analyses are necessary to study genetic and environmental factors in IBD in the Algerian population, using larger patient groups.

Algeria某油田低电阻率油气层的机理分析及测井解释

针对Algeria某油田油气层具有地层水矿化度高[（1．5～5）×10^5mg／L]电阻率低等特点，对储层非均质性，粘土矿物的附加导电作用及高矿化度地层水对油气层电阻率的影响进行了初步机理分析。根据实验数据得到不同岩性和不同地层水矿化度的m、n和b值的变化规律。实践证明用可变m、n和b值法计算储层的含水饱和度值比用固定的m、n和b值有明显改善。

Geochemical assessment, mixing behavior and environmental impact of thermal waters in the Guelma geothermal system,Algeria

A study of thirteen geothermal springs located in the geothermal field of Guelma,northeastern Algeria,was conducted.Samples were collected during the period between January 2014 and February 2016.Geochemical processes responsible for the chemical composition of thermal and mineralized water were evaluated.The hydrochemical analysis shows that the thermal waters are characterized by the presence of two different chemical facies,the first type SO4-Ca in the east,west and south of Guelma,the second type HCO3-Ca in the south.This analysis also attributed to sodium,chlorides,and sulfates to an evaporitic terrigenous origin by the molar ratio Sr2+/Ca2+.The thermal spring waters from Guelma geothermal system have a meteoric origin,and all samples are immature with strong mixing between hot and shallow waters with 19-38.5%rate of mixing.The silica geothermometer shows that these thermal waters have a temperature varying from 84 to 122℃and that the water came from a depth of 2100-3000 m through a fault system that limits the pullapart basin of Guelma.Potential environmental effluent from thermal spas could pollute in both the irrigation and drinking waters,and which imposes danger on the health of the inhabitants of the region.

Using a GIS to Assessment the Load-Carrying Capacity of Soil Case of Berhoum Area, Hodna Basin, (Eastern Algeria)

The concept of load-carrying capacity of the soil can be evaluated by two main components: permissible stress and permissible depth;and therefore, running it begins its assessment that allows an outline of exploitation. Nevertheless, the assessment of the load-carrying capacity made the object of several works of research and many models, based on the multi-criteria analysis, have been established. This work examines the contribution of GIS approach to assessment load-carrying capacity of the soil. This one has been finished in two practicums: 1) Assessment of the capacity of soil by a multi-criteria approach, using the Weighted Sum Model (WSM);2) It brought to use the GIS approach to evaluate and spatialize degree of soil bearing stresses resulting from the buildings, as well as load distribution. The method has been applied to the Berhoum area of Hodna Basin, in eastern Algeria, where each is characterized by its various natural properties and density of equipment. Final results are better in the classification of the degree of load-carrying capacity possible in each site. This results in allowing exploiters to program their optimal designs for the rational management of the area.

Qualitative and Comparative Study of Different Methods of Interpolation for the Mapping of Groundwater Salinity: Case Study of Thermal Waters Used for Irrigation in Northeastern Algeria

Faced with the scarcity of surface water accentuated by climate change, particularly in many arid and semi-arid countries, the quality of groundwater used for irrigation is a concern to agronomists and hydrogeologists. When these waters are of deep origin, they may have high mineralization and chemical compositions unsuitable for irrigation;in particular, they may alter soils and crops. It is therefore important to optimize the spatial estimation of the salinity of these waters and contribute to better knowledge of their quality, through an adapted and robust statistical and geostatistical approach. In the case of north-eastern Algeria, the objective of this study is to characterize the quality of deep waters and to test two interpolation methods (Inverse distance weight and ordinary Kriging) of their electrical conductivity (EC) as an indicator of their salinity and of the risk of damaging irrigated soils. 51 groundwater samples were taken in this region where there are many thermal springs, the water of which is used for irrigation and often is highly mineralized (EC between 0.6 and 26.6 dS/m). The geology is composed of karstic rocks crossed by large faults that allow deep water to rise. Based on major elements contents, analysis of the hydrochemical facies of these waters shows that the main facies are hyperchlorinated sodium (38%) and sulfated calcium (32%). The RSC (Residual Sodium Carbonate) and SAR (Irrigation water salt) indexes were used to assess the water quality. The results indicate that the majority of the sampled groundwater present a risk for soils irrigated with these waters (almost 1/3 presents a strong risk). The risk for the soils seems to be explained by the positive value of the residual alkalinity, and the high risks of sodization and alkalinization. The geostatistical analysis reveals strong heterogeneity in electrical conductivity (salinity). The maps based on this analysis allow the identification of risk areas. The comparison of Inverse distance weight and ordinary Kriging methods indicates similar results being obtained through both methods. However, ordinary kriging appears to be more accurate, less biased, and seemingly better represents the organization of the groundwater resources, as NE-SW alignments are visible. With the proposed approach, it is possible to calculate the surface areas of the different salinity thresholds and then optimize the use of deep groundwater for irrigation.

Physico-Chemical Complex of Matorral Soils of the North Western Region of Algeria

The objective of this study is to determine the influence of soil physico-chemical factors on the spatial distribution of matorrals in the plain from Remchi to Béni-Saf located in the western region of Algeria. This study informs us of the relationships that soil can have on the diversity of matorrals. On the bioclimatic level, the region is characterized by semi-aridity accentuating the phenomena of thérophysation. Soil analyzes carried out using known methods (Stokes Particle Size Method, Electrometric Method for pH, 1/5 Extract Method for Electrical Conductivity, Bernard Calcium Method for CaCO3, Anne Method for Organic Carbon). The results show a textural diversity;sandy-muddy “Remchi”, sandy “Rachgoun 1 and Rechgoun 2”, not far from Béni-Saf. The low clay content (Remchi: Profile 1: Horizon 1: Clays 10%, Profile 2: Horizon 1: Clays 16%, Profile 3: Horizon 1: Clays 5%, Rechgoun: Profile 1: Horizon 1: Clays 3%, Profile 3: Horizon 1: 2% Clays and Horizon 2: 3% Clays) leads to poor structural stability leading to degradation of the soil surface through erosion. The latter is revealed by the presence of small erosion claws visible on these rough slopes or almost.

A hydrochemical study of the Hammam Righa geothermal waters in north-central Algeria

This study focuses on the hydrochemical characteristics of 47 water samples collected from thermal and cold springs that emerge from the Hammam Righa geothermal ?eld, located in north-central Algeria. The aquifer that feeds these springs is mainly situated in the deeply fractured Jurassic limestone and dolomite of the Zaccar Mount. Measured discharge temperatures of the cold waters range from 16.0 to 26.5 °C and the hot waters from 32.1 to 68.2 °C. All waters exhibited a near-neutral p H of 6.0–7.6. The thermal waters had a high total dissolved solids(TDS) content of up to 2527 mg/l, while the TDS for cold waters was 659.0–852.0 mg/l. Chemical analyses suggest that two main types of water exist: hot waters in the up?ow area of the Ca–Na–SO_4type(Hammam Righa) and cold waters in the recharge zone of the Ca–Na–HCO_3type(Zaccar Mount). Reservoir temperatures were estimated using silica geothermometers and?uid/mineral equilibria at 78, 92, and 95 °C for HR4, HR2,and HR1, respectively. Stable isotopic analyses of the δ^(18)O and δD composition of the waters suggest that the thermal waters of Hammam Righa are of meteoric origin. We conclude that meteoric recharge in?ltrates through the fractured dolomitic limestones of the Zaccar Mount and is conductively heated at a depth of 2.1–2.2 km. The hot waters then interact at depth with Triassic evaporites located in the hydrothermal conduit(fault), giving rise to the Ca–Na–SO_4water type. As they ascend to the surface,the thermal waters mix with shallower Mg-rich groundwater, resulting in waters that plot in the immature water?eld in the Na–K–Mg diagram. The mixing trend between cold groundwaters from the recharge zone area(Zaccar Mount) and hot waters in the up?ow area(Hammam Righa) is apparent via a chloride-enthalpy diagram that shows a mixing ratio of 22.6 \ R \ 29.2 %. We summarize these results with a geothermal conceptual model of the Hammam Righa geothermal ?eld.

Aetiological factors of Budd-Chiari syndrome in Algeria

AIM: To study the clinical presentation of Budd-Chiari syndrome(BCS) and identify the aetiologies of this disease in Algeria. METHODS: Patients with BCS, hospitalised in our unit from January 2004 until June 2010 were included and the aetiological factors were assessed. Patients presenting a BCS in the setting of advanced-stage cirrhosis or a liver transplantation were excluded from the study. The diagnosis was established when an obstruction of hepatic venous outflow(thrombosis, stenosis or compression) was demonstrated. We diagnosed myeloproliferative disease(MPD) by bone marrow biopsy and V617 F JAK2 mutation. Anti-phospholipid syndrome(APLS) was detected by the presence of anticardiolipin antibodies, anti-β2 glycoprotein antibodies and Lupus anticoagulant. We also detected paroxysmal nocturnal haemoglobinuria(PNH) by flow cytometry. Celiac disease and Behcet disease were systematically investigated in our patients. Hereditary anticoagulant protein deficiencies were also assessed. We tested our patients for the G20210 A mutation at Beaujon Hospital. Imaging procedures were performed to determine a local cause of BCS, such as a hydatid cyst or a liver tumour.RESULTS: One hundred and fifteen patients were included. Mean follow up: 32.12 mo. Mean age: 34.41 years, M/F = 0.64. Chronic presentation was frequent:63.5%. The revealing symptoms for the BCS were ascites(74.8%) and abdominal pain(42.6%). The most common site of thrombosis was the hepatic veins(72.2%). Involvement of the inferior vena cava alone was observed in 3 patients. According to the radiological investigations, BCS was primary in 94.7% of the cases(n = 109) and secondary in 5.2%(n = 6). An aetiology was identified in 77.4% of the patients(n = 89); it was multifactorial in 27%(n = 31). The predominant aetiology of BCS in our patients was a myeloproliferative disease, observed in 34.6% of cases. APLS was found in 21.7% and celiac disease in 11.4%. Other acquired conditions were: PNH(n = 4), systemic disease(n = 6) and inflammatory bowel disease(n = 5). Anticoagulant protein deficiency was diagnosed in 28% of the patients(n = 18), dominated by protein C deficiency(n = 13). Secondary BCS was caused by a compressing hydatic cyst(n = 5) and hepatocellular carcinoma(n = 1). CONCLUSION: The main aetiologic factor of BCS in Algeria is MPD. The frequency of celiac disease justifies its consideration when BCS is diagnosed in our region.

Chemical Mobility and Mineralogical Variability in Edough Massif Micaschists(Annaba,Northeast Algeria)

The Edough massif is the easternmost crystalline massif of the Maghrebides which represent the southeastern part of the West Mediterranean orogen.It occurs below the greenschist-facies Tellian units that represent the thrusted Mesozoic to Eocene passive paleomargin of northern Africa deposited on thinned continental crust.The upper unit of the Edough massif is characterized by metasedimentary rocks affected