Coastal Aquifer Salinization in Semi-Arid Regions: The Case of Grombalia (Tunisia)

Groundwater resources are facing increasing pressure especially in semi-arid regions where they often represent the main freshwater resource to sustain human needs. Several aquifers in the Mediterranean basin suffer from salinization and quality degradation. This study provides an assessment of Grombalia coastal aquifer (Tunisia) based on multidisciplinary approach that combines chemical and isotopic (δ2H, δ18O, 3H, 14C and δ13C) methods to characterize the relation between groundwater quality variation and aquifer recharge. The results indicate that total dissolved solids exceed 1000 mg/L in the most of samples excepting the recharge area. In addition to water–rock interaction, evaporation and nitrate pollution contributing to groundwater mineralization, the reverse cation exchange process constitute an important mechanism controlling groundwater mineralization with enhancing risk of saltwater intrusion. Environmental isotope tracers reveal that groundwater is evolving within an open system to close system. A significant component of recent water that is recharging Grombalia aquifer system is confirmed by applying correction models based on the δ13C values and 14C activities and tritium contents. However, this recharge, which is mainly associated to the return flow of irrigation water, contributes to the groundwater salinization, especially for the shallow aquifer

Hydrochemical Investigation and Quality Assessment of Groundwater in the BouHafna-Haffouz Unconfined Aquifers, Central Tunisia

Multivariate statistical techniques were applied to improve the understanding of the aquifers hydrodynamic and to identify the natural and anthropogenic processes that control the BouHafna and Haffouz groundwater quality. Some other parameters, such as sodium adsorption ratio (SAR), percent sodium (%Na), residual sodium carbonate (RSC), and permeability index (PI), were used to examine the suitability of groundwater for irrigation applications. Groundwater samples are classified into Ca-Mg-HCO3 and Ca-Mg-SO4 water-type. The statistical investigation permits to identify three different groups. The first group reflects the influence of water-rock interaction in relation with the dissolution of evaporatic minerals, the cation exchange process with phyllosilicates and the dedolomitization. The second and third groups, including the weakly mineralized groundwater samples, suggest, firstly, that the return flow of irrigation waters has a small, but not negligible contribution to the groundwater contamination, and secondly, the reduction of nitrate (NO3) to nitrogen gas (N2). Furthermore, it has been demonstrated that the majority of the groundwater samples are suitable for irrigation uses

Change of Diet, Plasma Lipids, Lipoproteins, and Fatty Acids during Ramadan: A Controversial Association of the Considered Ramadan Model with Atherosclerosis Risk

Different Islamic populations have different alimentary habits, notably during Ramadan. The paper reports the change of diet, lipids, and lipoproteins produced during Ramadan in one Tunisian population. During Ramadan, the study subjects consumed more proteins, cholesterol, vitamin E (p<0.01), and polyunsaturated fatty acids (p<0.05). At the same time, they exhibited an increase in total cholesterol, low-density lipoprotein-cholesterol (p<0.01) and apoprotein B (p<0.05) and a decrease in the ratio of apoprotein AI to apoprotein B (p<0.01). All assayed saturated fatty acids were unaffected by Ramadan fasting while three unsaturated fatty acids (C18:1cis9, C18:2n-6, and C30:4n-6) increased significantly. A return to the habitual diet for a four-week period was not sufficient to restore the pre-fasting patterns. For the study subjects, Ramadan was clearly associated with a change of diet and biochemical profile but its effective impact on atherosclerosis risk was unclear, perhaps, because other non-alimentary changes ought to be considered too. Future studies considering the non-alimentary factors, such as sleep and physical activity, would be useful to clarify the contribution of dietary change in the observed modification of biological profile

The analgesic effect of clonidine as an adjuvant in dorsal penile nerve block

Introduction: Dorsal penile nerve block (DPNB) is a commonly performed regional anesthetic technique for male circumcision. The aim of this study was to assess the analgesic effect of the adjunction of clonidine to bupivacaine 0.5% in this block. Methods: It was a prospective randomized double-blind clinical trial including 40 ASA1 boys aged from 1 to 4 years undergoing elective circumcision. Dorsal penile nerve block was performed under general Anesthesia. Patients were randomized in two groups: Group 1 (G1) : received 0.1 ml/Kg of bupivacaine 0.5 %with 1μg/kg of clonidine in each side. Group 2 (G2): received 0.1 ml/kg of bupivacaine 0.5 % with placebo in each side. The failure of the DNPB was defined by the increase of heart rate by more than 25% comparing to baseline and in his case an intravenous injection of 20 μg/kg of alfentanyl was given. Post-operative pain was assessed by CHEOPS score. Results: A total of 40 patients were enrolled. Demographic parameters were similar in both groups. We noted no case of DNPB failure in this study. The supply for additional analgesia was seen in 12 patients in group 2 versus 3 cases in group 1. CHEOPS (Children's Hospital of Eastern Ontario Pain Scale) was significantly lower in group 1 from 2nd post operative hour until the 24th hour. Conclusion: Clonidine can be used in dorsal penile nerve block to improve and to prolong its analgesic effects after male circumcision.Pan African Medical Journal 2016; 2

HOLOCENE ENVIRONMENT CHANGES IN THE HACHICHINA WETLAND (GULF OF GABES, TUNISIA) EVIDENCED BY FORAMINIFERA AND OSTRACODA, GEOCHEMICAL PROXIES AND SEDIMENTOLOGICAL ANALYSES

Four sediment cores, drilled at Younga and Ouadrane Sebkhas (Hachichina wetland), were selected for micropalaeontological, sedimentological, geochronological and geochemical investigation coupled to hierarchical cluster and correspondence analysis. Our research aimed at reconstructing the past biodiversity, the Holocene palaeoenvironmental evolution and the responsible forcing. Subsurface sediments record four major phases: i) the first one is characterized by poorly to very poorly sorted silts, the dominance of the lagoonal/estuarine ostracod and the lagoonal/marine foraminifera and high values of terrestrial geochemical element ratios, such as K/Al and Fe/Al, which indicate an estuarine lagoon; ii) two major marine transgressions, TR1 and TR2, allowing the settlement of widely opened lagoons towards 7160-8680 and 5070-5520 cal yr BP, are marked by the enhancement of the marine/brackish ostracods and marine foraminifera, the improvement of species number, individuals number and H and E index values and of the marine element ratios such as Cl/Al and Sr/Al; iii) the opening of the lagoon is hampered by the action of drift currents allowing the genesis of sand spit and the settlement of a closed lagoon, towards 2610-3610 cal yr BP, characterized by the enhancement of lagoonal/estuarine ostracods and lagoonal/marine foraminifera and the increase of the individuals number; iv) the dominance of the lagoonal/estuarine ostracods and the lagoonal/marine foraminifera and the decline of the species number and density mark a brackish lagoon, also characterized by very poorly sorted silts transported by uniform suspension, which evolves to the actual sebkha. This evolution, within a global climate alteration context, from an estuarine environment to the present sebkha passing by an opened lagoon, is linked to the complex hydrographic setting of the sebkhas and of the Ouadrane Wadi outlet discharging in the Hachichina wetland

Change of Diet, Plasma Lipids, Lipoproteins, and Fatty Acids during Ramadan: A Controversial Association of the Considered Ramadan Model with Atherosclerosis Risk

Different Islamic populations have different alimentary habits, notably during Ramadan. The paper reports the change of diet, lipids, and lipoproteins produced during Ramadan in one Tunisian population. During Ramadan, the study subjects consumed more proteins, cholesterol, vitamin E (p&lt;0.01), and polyunsaturated fatty acids (p&lt;0.05). At the same time, they exhibited an increase in total cholesterol, low-density lipoprotein-cholesterol (p&lt;0.01) and apoprotein B (p&lt;0.05) and a decrease in the ratio of apoprotein AI to apoprotein B (p&lt;0.01). All assayed saturated fatty acids were unaffected by Ramadan fasting while three unsaturated fatty acids (C18:1cis9, C18:2n-6, and C30:4n-6) increased significantly. A return to the habitual diet for a four-week period was not sufficient to restore the pre-fasting patterns. For the study subjects, Ramadan was clearly associated with a change of diet and biochemical profile but its effective impact on atherosclerosis risk was unclear, perhaps, because other non-alimentary changes ought to be considered too. Future studies considering the non-alimentary factors, such as sleep and physical activity, would be useful to clarify the contribution of dietary change in the observed modification of biological profile

Développement d’une nouvelle saucisse de dromadaire : Effet de l’incorporation d’éleusine (Eleusine coracana L.) sur la qualité sensorielle et la stabilité

L’objectif de cette étude est de formuler une saucisse à base de viande de dromadaire qui s’aligne avec la tendance des « allégations santé » visant à réduire la consommation de viandes rouges conventionnelles et de graisses animales. Par ailleurs, l’effet de la substitution de la fécule de pomme de terre, couramment utilisé en tant qu’agent liant dans les produits charcutiers, par la farine intégrale d’éleusine (Eleusine coracana L.) sur la qualité de la saucisse a été étudié. L’éleusine est cultivée dans l’oasis de Chenini-Gabès, située dans le sud-est de la Tunisie. L’analyse de sa composition révèle une teneur 70,19% en carbohydrates, dont 11,5% sont des fibres alimentaires, 13,53% de protéines, 2,75% de cendres, 1,81% de lipides et 0,25% de composés phénoliques. Sa capacité de rétention d’eau atteint 150 g d’eau/100 g. Par ailleurs, l’activité anti-DPPH• de l’extrait eau/éthanol révèle une valeur de CI50 de 60 µg/ml. Ensuite, la stabilité de la saucisse de dromadaire a été suivie pendant 21 j de stockage réfrigéré. L’introduction de la farine d’éleusine n’a pas altéré la qualité sensorielle, et a réussi à maintenir les caractéristiques texturales, à stabiliser la couleur et les pigments héminiques, et à limiter l’oxydation des lipides. Les résultats de cette étude suggèrent que la farine d’éleusine se positionne comme un substitut prometteur de la fécule de pomme de terre dans la fabrication de saucisses. Il est intéressant d’approfondir les recherches dans ce domaine afin d’explorer davantage les applications potentielles de la farine d’éleusine dans l’industrie alimentaire

Management and protection of Mediterranean groundwater-related coastal wetlands and their service

In the framework of the GEF/UNEP-MAP Strategic Partnership for the Mediterranean Sea Large Marine Ecosystem, UNESCO-IHP executed a component on “Management of coastal aquifers and groundwater”, which included an activity on “Implementation of eco-hydrogeology applications for management and protection of coastal wetlands”. The aim of the activity was to reverse degradation trends in coastal aquifers and groundwater-related coastal wetlands and enhance human wellbeing, namely by providing appropriate capacities for the integration of an ecosystem services approach into groundwater and wetlands assessment and management. To this end, UNESCO-IHP sought the cooperation of experts in order to design and carry out actions aiming to generate a new conceptual framework integrating hydrogeological, ecosystem, and management considerations in the management of Mediterranean groundwater-related coastal wetlands. Among key actions, a background document was prepared, detailing the basic aspects to be considered for an improved management of Mediterranean groundwater-related coastal wetlands through the assessment of the interlinkages between groundwater ows, wetlands services, and human wellbeing. This book sets forth the conceptual and empirical aspects that must be examined and followed to better understand the relationships between groundwater-associated wetlands, geology, hydrology, and services to human well-being. It also presents methods for inventorying the basic information needed to characterize wetlands and aquifer functioning and to assess wetlands’ contribution to human well-being. Finally, it proposes guidelines and recommendations for the evaluation and integrated management of Mediterranean groundwater-related coastal wetlands in order to preserve the sustaining role of groundwater in relation the many environmental services that wetlands provide.Global Environmental Facility (GEF) United Nations Environmental Programme/Mediterranean Action Plan (UNEP/MAP

Hydrogeochemical and stable isotope data of groundwater of a multi-aquifer system: Northern Gafsa basin – Central Tunisia

The hydrodynamic of the multi-aquifer system (the Continental Intercalaire “ C.I ” and the Complex Terminal “ C.T ”) of the North Gafsa basin is largely determined by tectonics (Tebessa - Gafsa fault). The composition of groundwater is controlled by complex reactions at gas-liquid-solid “mineralogical composition of associated rocks” interfaces, which depend on the natural surrounding and potential anthropogenic impact. The hydrochemical data (major ion geochemistry) indicate that these groundwaters are characterized by the dominance a Ca-Mg-HCO3/SO4 and Na-Cl-NO3 water types. Geochemical pattern is mainly controlled by the dissolution of halite, gypsum and/or anhydrite as well as by the incongruent dissolution of carbonate minerals. The pH of these samples range from 6.54 to 8.89, supporting the conclusion that the H2CO3/HCO3 couple control pH buffering. Oxygen-18 (δ18O‰SMOW) and deuterium (dD‰SMOW) isotopic data show the exchange between the groundwater and the rock (water-rock interaction) and the evaporation effect. The isotopic content of the boreholes waters is of mixed Mediterranean - Atlantic origin and is opposite to the quantity of rainwater distribution, both in space and time in the study area. This is due to its geographical situation in the southern and south-western of the Mediterranean Sea and between the Atlas area and the Sahara Platform. The concentrations of the isotopic composition of the groundwater are significantly higher than the rainwater. This is indicative of the dissolution of salts and other processes modifying the rainwater geochemical composition during infiltration into the vadose zone. The hydraulic interconnection of these components of the system has led to the evolution of these interesting groundwater types