Tunisian Area Research Articles

Little owls (Athene noctua) shift their diet towards nocturnal beetles in an arid North African area

AbstractUrban life is associated with dietary shifts in opportunistic predators, such as raptors. This is presumably true in food‐poor environments, such as drylands. We investigated this issue in little owls (Athene noctua) inhabiting an arid southern Tunisian area. Using pellet data, we found that coleopterans accounted for 69% of ingested food items. Controlling for prey availability, this coleopteran‐based diet was more notable in the urban environment compared to rural areas. We suggest that habitat conditions in the urban areas have increased the catchability of nocturnal coleopterans which were then more exposed to predation by little owls than in rural areas.

The Short-Term Effect of Olive Mill Wastewater Application on Humic Acid in Subsurface Soil Layers of the Arid Region of Tunisia

ABSTRACT Few studies have assessed the changes in soil quality based on humic acids (HA) in relation to the fresh olive mill wastewater (OMW) application. Qualitative changes to soil organic matter (SOM) under the application of OMW in real conditions have been little investigated. To make a contribution in this context, an experimental field was established in an arid Tunisian area, which included a control soil, a soil treated with 10 L m˗ 2 OMW and another amended with 10 kg m˗ 2 manure. Soil samples were collected from soil depths: 0–20 cm, 20–40 cm and 40–60 cm on the first day of OMW and manure application (day 0) and after 4 months (120 days). Results revealed that soil treated with OMW had the highest SOM content (1.42 ± 0.13%), cation exchange capacity (CEC) (3.03 ± 0.51 (cmol(c) kg−1)) and soil pH value. OMW mineralization supplied soluble ions which enhanced the electrical conductivity (EC) (1.44 ± 0.34 dS m−1). Infrared (IR) spectroscopy showed higher aliphatic, aromatic and phenolic groups in OMW amended soil than the manured soil for initial and final dates. Spreading OMW on soils provides a favorable environment for improving soil humic acids (HAs), recycling organic matter (OM) and enhancing soil properties by transferring aromatic and aliphatic structures into deeper horizons, which in turn increased the sequestration of soil organic carbon (SOC).

Patterns of vertebrate road-kills in a pre-Saharan Tunisian area

Understanding spatio-temporal patterns of animal-vehicle collisions is a crucial step for the implementation of efficient mitigation measures of this worldwide threat against biodiversity. In this study we investigated vertebrate road-kills in a pre-Saharan area in southern Tunisia. In particular, we assessed how road mortality varied according to land cover and season. From February 2019 to January 2020, a road section crossing three land cover types (desert, oasis and urban areas) was monitored twice a week for the survey of road-killed vertebrates. There was about one animal killed per 10 km and per day. Birds were the vertebrate class most affected by road-kills. Mammals constituted a non-negligible part of recorded road-kills and were mainly represented by stray cats and dogs. The highest rate of vertebrate road-kill was recorded in oases, which was expected given the higher abundance of animals in these densely-vegetated areas compared to desert and urban areas. The peak road mortality was recorded in spring and early summer for birds, but in winter for mammals. In sum, our results reveal that vertebrate classes have different patterns of road mortality in the area studied. They also stress the need for urgent mitigation measures, especially inside oases.

Heat stress effect assessment on milk yield in dairy herds of the Tunisian northern west area

Dairy herds are raised under dry climate in Tunisia which make them subject to heat stress which is known to considerably decline their milk yield. This paper aimed to evaluate heat stress impact on the dairy performances of the Tunisian North West cows. We used 4789 test-day recorded between 2008 and 2011 on 585 Holstein cows in their first three parities, calved between 2007 and 2011 and belong to 10 herds from the Tunisian North-West area. Temperature and humidity data were associated to each test-day and Thermal Humidity Indexes (THI) were calculated. First, the effect of temperature and humidity factors were assessed separately, then the effect of their interaction and finally the effect of their THI using three statistical models. For model 2 and 3, all fixed factors were significant (P<0.001) while for model 1 the humidity didn’t show a significant on the milk performances. The highest milk yield was 51 kg and was found to be reached during the lowest daily temperature and the highest humidity; corresponding to the lowest THI index. The lowest milk yield was 1 kg and was found to be recorded during the hottest temperature and the lowest humidity; resulting in the highest THI; which have significantly exceeded the THIThreshold. Our analysis has showed that Tunisian dairy cows in the North West area undergo moderate heat stress during one third of the year and that the average milk yield decline is about 5 kg/day.

Study of the Effects of Two Crop Systems and Best Management Practices on Soil and Water Conservation in Tunisian Semi-arid Area

In Tunisia, water erosion is one of the most important processes affecting around 25% of arable land, generating a potential loss of soil productivity due to a decrease of hydraulically and chemical stocks. To control water erosion on lands of average slopes (less than 10%) best management practices (crop rotation, organic fertilization, etc.) have to be developed especially in Tunisian semiarid area, where rainfall irregularity and aggressivity enhance water erosion. Thus, conservative techniques for soil and water protection are required and have to be implemented at the level of the agricultural parcel to maintain or improve the productive potential of soils on average slopes in rain-fed lands, located in Tunisian semi arid area. In this context the article is presented. It is a synthesis of some experimental works on plots of 1 to 4 m2 in the experimental field station of the ESA Mograne, for the study of the effects of different kinds of crop-rotation (fallow long duration- chick pea) and organic fertilizers (row olive mills waste water) on the fertility of the soil and its potential yield. Results showed that long fallow-chickpea rotation and use of 50 m3/ha of row olive mills waste water improve soil fertility (water retention and C/N). This improvement in water and soil chemical properties increases the components of performance of chickpea (rate of dry matter) and weight of 1000 grains and plant biodiversity for 50 m3/ha spreading of row olive mills waste water. These results can be valued for the development of strips crops on average slope lands in Tunisian semiarid area for soil and water conservation.

Temporal and spatial changes of the submarine Cretaceous paleoslope in Northern Tunisia, inferred from slump folds analysis

This paper presents the first comprehensive, non-exhaustive, study of the genetic relationship between slump folds and the synsedimentary paleoslope during Cretaceous time in northern Tunisia. Slump folds occur mainly in the Cretaceous marl-dominated lithofacies, which exposes numerous slump folds structures. In addition, fault kinematic analysis is conducted to define the paleostress fields and the stress states characterizing the Cretaceous extension that triggers soft-sediment deformation and slumping. The MAM and the APM methods are used to deduce the paleoslope in several localities. The calculated values of paleoslope trend derived from MAM and APM methods precise the variation of the paleoslope trend during Cretaceous times in northern Tunisia. This paleoslope is ∼NW-dipping during Berriasian, ∼SSW-dipping during Valanginian, ∼NW-dipping during the Barremian and ∼N- to ∼NNE or ∼S- to ∼SSW-dipping during Aptian–Albian period. The results of the back-tilted fault diagram show a ∼North to ∼Northeast-trending tectonics extension. The back-tilting of Cenomanian slump axis and poles of axial planes (MAM and APM methods) give close results with ∼Southward or ∼Northward-dipping paleoslope. The restored fault diagrams show ∼North to ∼Northeast-trending extension during Cenomanian times. Coniacian-Santonian marls deposits seal all the gravity-driven deformation structures. North Tunisian area exposes evidences for abundant soft-sediment deformation and slumping atop a northward facing submarine slope, which was probably dominant from the Early Cretaceous to Santonian with ∼North-South tectonic extension related to the Southern Tethyan rifted continental margin evolution.

Methodology for Tracing a Coastal Flood Risk Card in the Coastal Area of Hammam Lif

Hammam lif is a Tunisian coastal area threatened by the flooding for years, it underwent exceptional meteorological events which are manifested in 4 major storms 1931, 1981,2003 and 2012. From the study of the anthropogenic and natural damage resulting from each storm, one can deduce the parameters generating the flood in Hammam Lif and generally in each coastal zone threatened by the risk of flooding. The parameters are: rainfall, wave run-up, urbanization and infrastructure. How to highlight the generating parameters of the coastal flood with the aim of mapping a map with detailed flood risk areas that will serve as a flood risk prevention plan for the Hammam Lif area ? and what census methods and tools to use ?

New Archaeomagnetic Data from Tunisia: Dating of Two Kilns and New Archaeointensities from Three Ceramic Artifacts

Two isolated kilns of unknown age and three well‐dated artifacts from Tunisia have been investigated using archaeomagnetic techniques. Dating has been attempted for the kilns and archaeomagnetic intensities have been obtained for the artifacts. The kilns lack datable artifacts although one of them (Sidi Zahruni) could be related to a nearby late Roman site. Comparison with the SCHA.DIF.3K regional geomagnetic model suggests for both kilns two possible periods of last use, either Roman or Medieval. Three archaeomagnetic intensities were obtained for the well‐dated ceramic artifacts adding to scarce archaeomagnetic data from Africa. The new data along with recently published archaeointensities from other Tunisian sites have been compared with the regional model SCHA.DIF.3K, its updated version, and the global ARCH3k.1 geomagnetic model. The models show relatively good agreement with the new archaeointensities and with previously published intensities. The uncertainty of the experimental data tends to increase for older artifacts, and their agreement with the geomagnetic models diminishes. The observed trend of the intensity models to underestimate values in the Tunisian area for the Roman period could be overcome by adding new data from well‐dated artifacts from North African, particularly from pre‐Roman and Roman sites.

Improvement of Fruit Yield and Quality by Iron Chelates Addition

A field study was carried out to evaluate the effects of supplying iron chelates on fruit yield and quality of two peach varieties (Elegant lady and Carnival) in Tunisian area. Results showed that EDDHA-Fe improved fruit quality parameters for both varieties and 20 and 40 g/tree doses enhanced significantly the total sugar rate (°Brix) of juice in the Elegant Lady variety. However, iron chelates increased the weight of five fruits and firmness by 20, 40 and 60 g/trees the both varieties. Fruit diameter and growth of peaches were improved by the EDDHA-Fe addition. Nevertheless, no significant differences were observed between the different treatments.

Submarine allochthonous salt sheets: Gravity-driven deformation of North African Cretaceous passive margin in Tunisia – Bled Dogra case study and nearby salt structures

We used structural, stratigraphic and sedimentologic data, together with a comparison of nearby structures and a Bouguer gravity map, to evaluate the evolution of the Bled Dogra salt structure (northern Tunisia) during the Cretaceous. Triassic salt sheets are recognized in the northwestern region of the Tunisian Atlas. These salt sheets are the result of Cretaceous thick and/or thin-skinned extension along the south Tethyan margin. The Bled Dogra salt structure is one of these submarine allochthonous salt sheets, which was emplaced during the Early Cretaceous. The geologic framework, during this period, produces conditions for a predominantly gravity-driven deformation: extension has produced space for the salt to rise; vigorous differential sedimentation created differential loading that resulted in the emplacement and extrusion of a large volume of Triassic salt and formation of large submarine salt sheets. Geologic field data suggest an interlayered Triassic salt sheet within Albian sequences. Salt was extruded at the sea floor during the Early–Middle Albian and was initially buried by Middle–Late Albian strata. The Coniacian corresponds to a second transgressive cover onto the salt sheet after the gliding of the first salt cover (Late Albian–Turonian). In addition, this northwest Tunisian area exposes evidences for salt flow and abundant slump features at the base of a northward facing submarine slope, which was probably dominant from the Early Cretaceous to Santonian. Two gravity deformation processes are recognized: gravity gliding and gravity spreading. Acting concurrently, these two processes appear indistinguishable in this geologic context. Like the present-day salt-involved passive margins – such as the northern Gulf of Mexico, the Atlantic margin of Morocco, the Brazilian Santos basin, the Angola margin, Cadiz in western Iberia, and the Red Sea – the North African Cretaceous passive margin in Tunisia provides evidences that deformation in a passive-margin salt basin is predominantly gravity-driven deformation.

Disinfection of Wastewater by Infiltration-Percolation Coupled to UV Irradiation in an Arid Tunisian Area

This paper aimed to the study of microbiological quality of wastewater effluents issued from a sand filter system used as a secondary treatment; this sand filter was coupled to UV irradiation system as a tertiary treatment to assume their possible application as alternatives to chemical disinfection of municipal wastewater before agronomic utilization. For that reason, an infiltration basin of 100 m² of area equipped with two wells of sampling, in the center and in the periphery, has been constructed on the irrigated perimeter of Dissa in Gabes (south east of Tunisia). A comparative study was undertaken concerning the quality of effluents obtained from the sand filter as secondary effluent and from the UV irradiation disinfection system as a tertiary municipal wastewater treatment. Both the combined systems gave effluent of excellent microbiological quality (almost total absence of E. coli, faecal coliforms and P. aeruginosa). However, if the microbiological quality of effluent remained constant in the case of a sand filter system which depends only on the quality of the influent, while with the UV-disinfection process, microbiological quality of tertiary effluent was shown to depend on the quality of secondary effluent. The monitoring of the UV irradiation device using a UV dose of around 96 mW.s.cm-2 and corresponding to an exposure time of 16 sec, for the secondary effluent at the outlet of Sand Filter, showed that the average bacterial inactivation rate was around 3 U-Log for E. coli, faecal coliforms and P. aeruginosa, respectively. Therefore, the average concentration remaining in the effluent at the output of the UV reactor, was less than a 100 cfu/ 100 ml for E. coli and faecal coliforms, and less than a 100 bacteria/ 100 ml for P. aeruginosa. These values coincided with the range recommended by several standardized international guidelines.

A New Raw-Starch-Digesting α-Amylase: Production Under Solid-State Fermentation on Crude Millet and Biochemical Characterization

A new Bacillus strain degrading starch, named Bacillus sp. UEB-S, was isolated from a southern Tunisian area. Amylase production using solid-state fermentation on millet, an inexpensive and available agro-resource, was investigated. Response surface methodology was applied to establish the relationship between enzyme production and four variables: inoculum size, moisture-to-millet ratio, temperature, and fermentation duration. The maximum enzyme activity recovered was 680 U/g of dry substrate when using 1.38 × 10(9) CFU/g as inoculation level, 5.6:1 (ml/g) as moisture ratio (86%), for 4 days of cultivation at 37 degrees C, which was in perfect agreement with the predicted model value. Amylase was purified by Q-Sepharose anion-exchange and Sephacryl S-200 gel filtration chromatography with a 14-fold increase in specific activity. Its molecular mass was estimated at 130 kDa. The enzyme showed maximal activity at pH 5 and 70 degrees C, and efficiently hydrolyzed starch to yield glucose and maltose as end products. The enzyme proved its efficiency for digesting raw cereal below gelatinization temperature and, hence, its potentiality to be used in industrial processes.

P02-89 Suicidal attempts in primary care: Prevalence and correlates in a Tunisian area

Aims:This study aimed to determine prevalence and correlates of suicidal attempts in an adult primary care population in Sousse (Tunisia).Method:Sampling followed a stratified multistage probability cluster design from witch a representative sample of adult primary care population of Sousse was obtained. The sample was composed of 1249 subjects aged 18 years or more. Subjects were interviewed by trained clinicians using the Tunisian version of Composite International Diagnostic Interview 2.1.General and clinical characteristics of subjects who had reported previous suicidal attempts were compared with those of the remainder using t test and Chi-2 test.Results:Mean age in our sample was 43.4 ± 17.62 years, with female gender (70.9%) and urban residency (67.8%) predominance. 62.3% of participants were married, 27.3% celibates and 10.4% divorced or widowed. 68.4% of them had low educational level and 70% were out of work during the last 12 months. Suicidal attempts were found in 2.9% of participants. They were correlated to less than 40 years age (p=0.036) and to the diagnosis of major depressive episodes (p< 10-3), recurrent major depressive disorder (p=0.005) and dysthymic disorder (p< 10-3). Among major depressive episodes, only severe ones were associated to higher prevalence of suicidal attempts (p< 10-3).Conclusion:Prevalence of suicidal attempts in Sousse primary care population was 2.9%. It was correlated to low age and to depressive disorders.

Characterization of Volatiles in Virgin Olive Oil Produced in the Tunisian Area of Tataouine

The Tataouine province in southern Tunisia is well known for its severe pedoclimatic conditions. Using solid phase microextraction (SPME) and gas chromatography (GC), coupled to flame ionization and mass spectrometer detectors, we characterized virgin olive oils from Chemlali Tataouine, Fakhari Douirat, Zarrazi Douirat, and Dhokar Douirat varieties, which grow in the harsh arid region of Tataouine. Significant differences in the proportions of volatile constituents from oils of different varieties were detected. The results showed that lipoxygenase products were generally the major metabolites of the volatile fraction, and (E)-Hex-2-enal was the principal compound characterizing the olive oil headspace for most samples, though the absolute levels varied greatly, never exceeding 76.45 and 32.16%, respectively. The C5 compounds were unusually abundant, comprising 42.97% of the total lipoxygenase products and a remarkably high level of penten dimers. Each autochthonous variety could thus be differentiated according to the percentage of each metabolite.

Assessment of the genetic diversity ofFrankiamicrosymbionts ofElaeagnus angustifoliaL. plants growing in a Tunisian date-palm oasis by analysis of PCR amplifiednifD-Kintergenic spacer

Diversity of Frankia microsymbionts of non-native Elaeagnus angustifolia L. plants spontaneously growing in a Tunisian desertic retreat area, the date-palm oasis of Tozeur, was investigated by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and PCR-sequencing techniques targeting the nifD-K intergenic spacer. Three PCR-RFLP haplotypes (I, II, and III) were detected among collected nodules. Haplotype I was detected at all five sampling sites and dominated the other haplotypes present at these sites. This haplotype was also exhibited by strain BMG5.10, which was isolated by a plant-capturing assay in 1998 from soil collected in the same locality, qualifying it to be the most competitive haplotype in the edapho-climatic condition of the studied desertic date-palm oasis. nifD-K sequences of the three haplotypes formed a closely related phylogenetic subgroup. These results suggest that Frankia variability is constrained by severe edapho-climatic conditions of retreated desert in Tunisian area.

Corporate Governance in Tunisian's Law

In this survey, we examine the legal system of Tunisian' firms as well as their working modality in the setting of the new reform undertaken on corporate governance. In what follows, the reader will find a general overview of firms operating in the Tunisian area. In this sense, he will be able to distinguish the legal form of firms and permit to foreign investors to get an overview in Tunisian legislation more clearly before investing in such country.