Search results for: Northwestern of Tunisia

Authors: Chokri Slim

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The objective of this research is attempting to respond to this question: Is there a significant difference between the regression model and statistical learning models in predicting credit risk management? A Multiple Linear Regression (MLR) model was compared with neural networks including Multi-Layer Perceptron (MLP), and a Support vector regression (SVR). The population of this study includes 50 listed Banks in Tunis Stock Exchange (TSE) market from 2000 to 2016. Firstly, we show the factors that have significant effect on the quality of loan portfolios of banks in Tunisia. Secondly, it attempts to establish that the systematic use of objective techniques and methods designed to apprehend and assess risk when considering applications for granting credit, has a positive effect on the quality of loan portfolios of banks and their future collectability. Finally, we will try to show that the bank governance has an impact on the choice of methods and techniques for analyzing and measuring the risks inherent in the banking business, including the risk of non-repayment. The results of empirical tests confirm our claims.

Keywords: credit risk management, multiple linear regression, principal components analysis, artificial neural networks, support vector machines

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Authors: Rim Khemiri, Mariam Dammak

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The aim of this study is to trace the historical evolution of Tunisian higher accounting education and to understand and highlight the circumstances of its birth and its development. A documentary study (archival documents, official documents, public speeches, etc.), as well as semi-directive interviews with key actors, were carried out as part of this research work. These interviews aim to fill a lack of information on this subject and to confirm events addressed by other sources, but for which it lacks the elements necessary for a good understanding. After having put forward the specificities of the Tunisian context, we will, first of all, proceed to a review of the literature related to our theme in various contexts of the world. Then, we will present the evolution of the accounting curriculum by highlighting the circumstances of its birth and those of the successive reforms led by the Tunisian government. The study of higher accounting education in Tunisia and its evolution has several interests. The first lies in understanding the circumstances of its birth and its evolution in relation to the historical, socio-economic, and political context of the country. The second is to propose a reading grid that allows an understanding of the reforms that led to the university accountancy accounting course as we know it today. And, the third, aims to complete the literature on the processes of evolution of higher education accounting, by treating a different context, in order to provide additional knowledge necessary to compare experiences in this area around the world.

Keywords: accounting history, higher accounting education, socio-economic and political context, Tunisian context

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Authors: Nadia Elouaer

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Tax revenue is the main state resource and one of the important variables in tax policy. Nevertheless, this resource is continually decreasing, so it is important to focus on the reasons for this decline. Several studies show that the taxpayer is reluctant to pay taxes, especially in countries at risk or in countries in transition, including Tunisia. This study focuses on the tax evasion behavior of a Tunisian taxpayer under the influence of his political beliefs, as well as the influence of different tax compliance variables. Using a questionnaire, a sample of 500 Tunisian taxpayers is used to examine the relationship between political beliefs and taxpayer affiliations and tax compliance variables, as well as the study of the causal link between political beliefs and fraudulent behavior. The data were examined using correlation, factor, and regression analysis and found a positive and statistically significant relationship between the different tax compliance variables and the tax evasion behavior. There is also a positive and statistically significant relationship between tax evasion and political beliefs and affiliations. The study of the relationship between political beliefs and compliance variables shows that they are closely related. The conclusion is to admit that tax evasion and political beliefs are closely linked, and the government should update its tax policy and modernize its administration in order to strengthen the credibility and disclosure of information in order to restore a relationship of trust between public authorities and the taxpayer.

Keywords: fiscal policy, political beliefs, tax evasion, taxpayer behavior

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Authors: Emna Benmohamed, Hela Ltifi, Mounir Ben Ayed

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Bayesian Network (BN) is one of the most efficient classification methods. It is widely used in several fields (i.e., medical diagnostics, risk analysis, bioinformatics research). The BN is defined as a probabilistic graphical model that represents a formalism for reasoning under uncertainty. This classification method has a high-performance rate in the extraction of new knowledge from data. The construction of this model consists of two phases for structure learning and parameter learning. For solving this problem, the K2 algorithm is one of the representative data-driven algorithms, which is based on score and search approach. In addition, the integration of the expert's knowledge in the structure learning process allows the obtainment of the highest accuracy. In this paper, we propose a hybrid approach combining the improvement of the K2 algorithm called K2 algorithm for Parents and Children search (K2PC) and the expert-driven method for learning the structure of BN. The evaluation of the experimental results, using the well-known benchmarks, proves that our K2PC algorithm has better performance in terms of correct structure detection. The real application of our model shows its efficiency in the analysis of the phosphate laundry effluents' impact on the watershed in the Gafsa area (southwestern Tunisia).

Keywords: Bayesian network, classification, expert knowledge, structure learning, surface water analysis

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Authors: Mohamed Amine Helali, Walid Oueslati, Ayed Added

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Sedimentation rates and total fluxes of heavy metals (Fe, Mn, Pb, Zn and Cu) was measured in three different depths (10m, 20m and 40m) during March and August 2012, offshore of the Mejerda River outlet (Gulf of Tunis, Tunisia). The sedimentation rates are estimated from the fluxes of the suspended particulate matter at 7.32, 5.45 and 4.39 mm y⁻¹ respectively at 10m, 20m and 40m depth. Heavy metals sequestration in sediments was determined by chemical speciation and the total metal contents in each core collected from 10, 20 and 40m depth. Heavy metals intake to the sediment was measured also from the suspended particulate matter, while the fluxes from the sediment to the water column was determined using the benthic chambers technique and from the diffusive fluxes in the pore water. Results shown that iron is the only metal for which the balance transfer between intake/uptake (45 to 117 / 1.8 to 5.8 g m² y⁻¹) and sequestration (277 to 378 g m² y⁻¹) was negative, at the opposite of the Lead which intake fluxes (360 to 480 mg m² y⁻¹) are more than sequestration fluxes (50 to 92 mg m² y⁻¹). The balance transfer is neutral for Mn, Zn, and Cu. These clearly indicate that the contributions of Mejerda have consistently varied over time, probably due to the migration of the River mouth and to the changes in the mining activity in the Mejerda catchment and the recent human activities which affect the delta area.

Keywords: delta, fluxes, heavy metals, sediments, sedimentation rates

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Authors: Hamed Hedayatnia, Nathan Van Den Bossche

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Understanding the ways in which climate change accelerates or slows down the process of material deterioration is the first step towards assessing adaptive approaches for the conservation of historical heritage. Analysis of the climate change effects on the degradation risk assessment parameters like freeze-thaw cycles and wind erosion is also a key parameter when considering mitigating actions. Due to the vulnerability of cultural heritage to climate change, the impact of this phenomenon on material degradation criteria with the focus on brick masonry walls in Timurid heritage, located in Iran, was studied. The Timurids were the final great dynasty to emerge from the Central Asian steppe. Through their patronage, the eastern Islamic world in northwestern of Iran, especially in Mashhad and Herat, became a prominent cultural center. Goharshad Mosque is a mosque in Mashhad of the Razavi Khorasan Province, Iran. It was built by order of Empress Goharshad, the wife of Shah Rukh of the Timurid dynasty in 1418 CE. Choosing an appropriate regional climate model was the first step. The outputs of two different climate model: the 'ALARO-0' and 'REMO,' were analyzed to find out which model is more adopted to the area. For validating the quality of the models, a comparison between model data and observations was done in 4 different climate zones in Iran for a period of 30 years. The impacts of the projected climate change were evaluated until 2100. To determine the material specification of Timurid bricks, standard brick samples from a Timurid mosque were studied. Determination of water absorption coefficient, defining the diffusion properties and determination of real density, and total porosity tests were performed to characterize the specifications of brick masonry walls, which is needed for running HAM-simulations. Results from the analysis showed that the threatening factors in each climate zone are almost different, but the most effective factor around Iran is the extreme temperature increase and erosion. In the north-western region of Iran, one of the key factors is wind erosion. In the north, rainfall erosion and mold growth risk are the key factors. In the north-eastern part, in which our case study is located, the important parameter is wind erosion.

Keywords: brick, climate change, degradation criteria, heritage, Timurid period

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Authors: H. Moalla, A. Frikha

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Multi-criteria decision aid methods consider decision problems where numerous alternatives are evaluated on several criteria. These methods are used to deal with perfect information. However, in practice, it is obvious that this information requirement is too much strict. In fact, the imperfect data provided by more or less reliable decision makers usually affect decision results since any decision is closely linked to the quality and availability of information. In this paper, a PROMETHEE-BELIEF approach is proposed to help multi-criteria decisions based on incomplete information. This approach solves problems with incomplete decision matrix and unknown weights within PROMETHEE method. On the base of belief function theory, our approach first determines the distributions of belief masses based on PROMETHEE’s net flows and then calculates weights. Subsequently, it aggregates the distribution masses associated to each criterion using Murphy’s modified combination rule in order to infer a global belief structure. The final action ranking is obtained via pignistic probability transformation. A case study of real-world application concerning the location of a waste treatment center from healthcare activities with infectious risk in the center of Tunisia is studied to illustrate the detailed process of the BELIEF-PROMETHEE approach.

Keywords: belief function theory, incomplete information, multiple criteria analysis, PROMETHEE method

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Authors: Imed Mezghani, Yousra Ben Salah, Mohamed Chaieb

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Tricholaena teneriffae L. is a xerophytic perennial herb that belongs to the Poaceae family likely to be used for ecological restoration programs. It's a dominant and economically important species widely distributed in the Bou-Hedma National Park, Tunisia. Reintroduction and expansion of T. teneriffae depend solely on sexual reproduction. This makes the understanding of its germination requirements vital for conservation and management. To provide basic information for its conservation and reintroduction, we studied the influence of environmental factors on seed germination patterns. The germination responses of seeds were determined over a wide range of constant temperatures (15–35°C), polyethylene glycol solutions of different osmotic potentials (0 to −2 MPa) and salt solution (0 to 150 mM of NaCl). Results indicated that the optimum temperature germination was attained at 25°C which corresponds to temperatures prevailing during mid spring season in the Mediterranean area. Seeds germinated in Polyethylene Glycol solutions exhibited significantly lower germination than control especially when water potential fell below -0.6 MPa. Germination percentage and rate decreased with an increase NaCl concentration. Seeds germination was substantially delayed and reduced with an increase in NaCl to levels above 50 mM. T. teneriffae is moderately salt tolerant at germination stage.

Keywords: germination, temperature, Tricholaena teneriffae L., salt stress, water stress, rehabilitation

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Authors: Ghassen Kharroubi, Ines Cherif, Leila Bouabid, Adel Gharbi, Aicha Boukthir, Margaret McCarron, Nissaf Ben Alaya, Afif Ben Salah, Jihene Bettaieb

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Influenza vaccination (IV) is recommended for elderly persons, especially those with underlying conditions. In countries where IV rates in the elderly remain unsatisfactory, exploring attitudes of older persons toward the flu vaccine could be useful to identify barriers and facilitators to IV. The aim of this study was to determine the reasons for IV acceptance or decline in the Tunisian elderly. A national cross-sectional study was conducted in 2019, among persons aged 60 years and over with chronic disease. Data were collected using a standard administered questionnaire. Of the 1191 older persons included, 19.4% received the influenza vaccine in the 2018-2019 flu season. The two main reasons that may lead to refusal of vaccination were concerns that the vaccine could cause side effects (71.5%) and a belief that the vaccine was ineffective (33.9%). The main reason that may lead to accepting vaccination was a doctor’s recommendation (41.1%). Doctors were by far the most trusted source for information regarding influenza vaccine (91.5%) followed by pharmacists (17.6%). Our results highlighted the important role that doctors could play in promoting IV among the Tunisian elderly. Physicians should correct misconceptions about adverse events and the efficiency of the vaccine. In fact, influenza vaccines are generally effective and safe among older persons.

Keywords: attitudes, influenza vaccination, older persons, Tunisia

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Authors: Wenqian Bai

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Background: In response to the post-pandemic directives of Xi Jinping concerning the new era of ecological civilization, China has embarked on ecological restoration projects across its territorial spaces. This initiative faces challenges such as complex evaluation metrics and subpar informatization standards. Methodology: This research focuses on Mianzhu City, Sichuan Province, to assess its resource and environmental carrying capacities and the appropriateness of land use for development from ecological, agricultural, and urban perspectives. The study incorporates a range of spatial data to evaluate factors like ecosystem services (including water conservation, soil retention, and biodiversity), ecological vulnerability (addressing issues like soil erosion and desertification), and resilience. Utilizing the Minimum Cumulative Resistance model along with the ‘Three Zones and Three Lines’ strategy, the research maps out ecological corridors and significant ecological networks. These frameworks support the ecological restoration and environmental enhancement of the area. Results: The study identifies critical ecological zones in Mianzhu City's northwestern region, highlighting areas essential for protection and particularly crucial for water conservation. The southeastern region is categorized as a generally protected ecological zone with respective ratings for water conservation functionality and ecosystem resilience. The research also explores the spatial challenges of three ecological functions and underscores the substantial impact of human activities, such as mining and agricultural expansion, on the ecological baseline. The proposed spatial arrangement for ecological restoration, termed ‘One Mountain, One Belt, Four Rivers, Five Zones, and Multiple Corridors’, strategically divides the city into eight major restoration zones, each with specific tasks and projects. Conclusion: With its significant ‘mountain-plain’ geography, Mianzhu City acts as a crucial ecological buffer for the Yangtze River's upper reaches. Future development should focus on enhancing ecological corridors in agriculture and urban areas, controlling soil erosion, and converting farmlands back to forests and grasslands to foster ecosystem rehabilitation.

Keywords: ecological restoration, resource and environmental carrying capacity, land development suitability, ecosystem services, ecological vulnerability, ecological networks

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Authors: Mejbri Sami, Zhani Khalifa, Zarzoum Kamel, Ben Bacha Habib, Koschikowski Joachim, Pfeifle Daniel

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Many places worldwide, especially arid and semi-arid remote regions, are suffering from the lack of drinkable water and the situation will be aggravated in the near future. Furthermore, remote areas are characterised by lack of conventional energy sources, skilled personnel and maintenance facilities. Therefore, the development of small to medium size, stand-alone and robust solar desalination systems is needed to provide independent fresh water supply in remote areas. This paper is focused on experimental studies on compact membrane distillation (MD) solar desalination prototype located at the Mechanical Engineering Department site, Kairouan University, Kairouan, Tunisia. The pilot system is designed and manufactured as a part of a research and development project funded by the MESRS/BMBF. The pilot system is totally autonomous. The electrical energy required to operate the unit is generated through a field of 4 m² of photovoltaic panels, and the heating of feed water is provided by a field of 6 m² of solar collectors. The Kairouan plant performance of the first few months of operation is presented. The highest freshwater production of 150 L/d is obtained on a sunny day in July of 633 W/m²d.

Keywords: experimental, membrane distillation, solar desalination, Permeat gap

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Authors: Bruno Tassin, Robin Treilles, Cleo Stratmann, Minh Trang Nguyen, Sam Azimi, Vincent Rocher, Rachid Dris, Johnny Gasperi

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Microplastics (<5mm) in the environment and in hydro systems is one of the major present environmental issues. Over the last five years a research programme was conducted in order to assess the behavior of microplastics in the Seine river catchment, in a Man-Land-Sea continuum approach. Results show that microplastic concentration varies at the seasonal scale, but also at much smaller scales, during flood events and with tides in the estuary for instance. Moreover, microplastic sampling and characterization issues emerged throughout this work. The Seine river is a 750km long river flowing in Northwestern France. It crosses the Paris megacity (12 millions inhabitants) and reaches the English Channel after a 170 km long estuary. This site is a very relevant one to assess the effect of anthropogenic pollution as the mean river flow is low (mean flow around 350m³/s) while the human presence and activities are very intense. Monthly monitoring of the microplastic concentration took place over a 19-month period and showed significant temporal variations at all sampling stations but no significant upstream-downstream increase, indicating a possible major sink to the sediment. At the scale of a major flood event (winter and spring 2018), microplastic concentration shows an evolution similar to the well-known suspended solids concentration, with an increase during the increase of the flow and a decrease during the decrease of the flow. Assessing the position of the concentration peak in relation to the flow peak was unfortunately impossible. In the estuary, concentrations vary with time in connection with tides movements and in the water column in relation to the salinity and the turbidity. Although major gains of knowledge on the microplastic dynamics in the Seine river have been obtained over the last years, major gaps remain to deal mostly with the interaction with the dynamics of the suspended solids, the selling processes in the water column and the resuspension by navigation or shear stress increase. Moreover, the development of efficient chemical characterization techniques during the 5 year period of this pluriannual research programme led to the improvement of the sampling techniques in order to access smaller microplastics (>10µm) as well as larger but rare ones (>500µm).

Keywords: microplastics, Paris megacity, seine river, suspended solids

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Authors: Christina Van Wingerden

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This paper focuses on a sense of belonging, isolation, and the use of a learning management system as a “third space” for connection and community. Given student use of learning management systems (LMS) for courses on campuses, moderate to high use of social media and hand-held devices, the author explores the possibilities of LMS as a third space. The COVID-19 pandemic has exacerbated student experiences of isolation, and research indicates that students who experience a sense of belonging have a greater likelihood for academic retention and success. The impacts on students of an LMS designed for student employee orientation and training were examined through a mixed methods approach, including a survey, individual interviews, and focus groups. The sample involved 250-450 undergraduate student employees at a US northwestern university. The goal of the study was to find out the efficiency and effectiveness of the orientation information for a wide range of student employees from multiple student affairs departments. And unexpected finding emerged within the study in 2015 and was noted again as a finding in the 2017 study. Students reported feeling like they individually connected to the department, and further to the university because of the LMS orientation. They stated they could see themselves as part of the university community and like they belonged. The orientation, through the LMS, was designed for and occurred online (asynchronous), prior to students traveling and beginning university life for the academic year. The students indicated connection and belonging resulting from some of the design features. With the onset of COVID-19 and prolonged sheltering in place in North America, as well as other parts of the world, students have been precluded from physically gathering to educate and learn. COVID-19 essentially paused face-to-face education in 2020. Media, governments, and higher education outlets have been reporting on widespread college student stress, isolation, loneliness, and sadness. In this context, the author conducted a current mixed methods study (online survey, online interviews) of students in advanced degree programs, like Ph.D. and Ed.D. specifically investigating isolation and sense of belonging. As a part of the study a prototype of a Canvas site was experienced by student interviewees for their reaction of this Canvas site prototype as a “third” space. Some preliminary findings of this study are presented. Doctoral students in the study affirmed the potential of LMS as a third space for community and social academic connection.

Keywords: COVID-19, isolation, learning management system, sense of belonging

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Authors: Khawla Hlel

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Purpose: This study aims to examine whether critical audit matters (CAM) affect financial information quality. We also investigate the moderating role of the audit committee on the association between CAM and financial information quality. Design/Methodology/Approach: The analysis is based on GLS and GMM regressions explaining the absolute value of discretionary accruals by using 52 Tunisian listed firms on the Tunisia Stock Exchange (TSE) for the period 2017-2020. Findings: We find evidence that managers react to the CAM by increasing the quality of financial disclosures. This study provides insights into how a change in the auditor’s report model might impact the quality of financial information. It suggests that external auditors and audit committees serve as a beneficial mechanism for enhancing financial information quality by reducing information asymmetry. In addition, our results indicate that CAM is an efficient monitoring mechanism that increases financial reporting quality and supervises managers. Originality: This study is important for potential investors who should assess CAM when evaluating firms. Furthermore, the authors expect the findings to be interesting to firms, as this study highlights the effectiveness of the auditor in reducing managerial opportunistic behavior and improving information quality. The results could encourage audit regulators to ameliorate the standards, as this research reinforces the role of the auditor in increasing the quality of financial disclosure by offering the required information for shareholders.

Keywords: critical audit matters, audit committee, information quality, Tunisian firms

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Authors: L. Khalfa, M. Bagane, M. L. Cervera, S. Najjar

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The aim of this work is to present a low cost adsorbent for removing toxic heavy metals from aqueous solutions. Therefore, we are interested to investigate the efficiency of natural clay minerals collected from south Tunisia and their modified form using sulfuric acid in the removal of toxic metal ions: Zn(II) and Pb(II) from synthetic waste water solutions. The obtained results indicate that metal uptake is pH-dependent and maximum removal was detected to occur at pH 6. Adsorption equilibrium is very rapid and it was achieved after 90 min for both metal ions studied. The kinetics results show that the pseudo-second-order model describes the adsorption and the intraparticle diffusion models are the limiting step. The treatment of natural clay with sulfuric acid creates more active sites and increases the surface area, so it showed an increase of the adsorbed quantities of lead and zinc in single and binary systems. The competitive adsorption study showed that the uptake of lead was inhibited in the presence of 10 mg/L of zinc. An antagonistic binary adsorption mechanism was observed. These results revealed that clay is an effective natural material for removing lead and zinc in single and binary systems from aqueous solution.

Keywords: heavy metal, activated clay, kinetic study, competitive adsorption, modeling

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Authors: Bahlous Afef, Bouzid Kahena, Bardkis Ahlem, Mrad Mehdi, Kalai Eya, Sonia Bahri, Abdelmoula Jaouida

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Diabetic nephropathy is the first cause of chronic renal failure and hemodialysis use in several countries including Tunisia. The role of hypertension (HT) as major risk factor for nephropathy is undeniable. The aim of our study was to determine the relationship between blood pressure and nephropathy in a population of diabetic type 2 recently discovered. Materials and methods: We conducted a prospective study focused on 60 patients with type 2 diabetes recently discovered (<5 years). Each patient have benefited from: -a full clinical examination with measurement of blood pressure - exploring a blood-glucose control and renal function -urinary exploration with the determination of proteinuria microalbuminumie of 24 hours with a immunoturbidimetric method using Architect (ABBOTT CI 8200). Results and discussion: Hypertension was present in 46.7% of cases. Twenty patients, 35% of the study population showed nephropathy. Four of these patients (6.66% of cases) had proteinuria, while 16 (26.6% of patients) had microalbuminuria (> 30mg/24 hours). Systolic blood pressure was significantly (p < 0.05) associated with the presence of nephropathy (139 +19.44) vs. for the group with normal renal function (128.65 +15.12 mmHg). Conclusion: The etiology of diabetic nephropathy is multifactorial. However, systolic blood pressure and glycemic control remains the major risk factors. Better glycemic control and treatment of hypertension allowed preventing and slowing the progression of diabetic nephropathy.

Keywords: hypertension, nephropathy, hemodialysis, diabetes

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Authors: Sihem Salmi Laouar, Khoudair Chabane, Rabah Laouar, Adrian J. Boyce et Anthony E. Fallick

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The solid mass of Essouabaa belongs paléogéography to the field téthysian and belonged to the area of the Mounts of Mellègue. This area was not saved by the oceanic-2 event anoxic (EAO-2) which was announced, over one short period, around the limit cénomanian-turonian. In the solid mass of Essouabba, the dominant sediments, pertaining to this period, are generally fine, dark, laminated and sometimes rolled deposits. They contain a rather rich planktonic microfaune, pyrite, and grains of phosphate, thus translating an environment rather deep and reducing rather deep and reducing. For targeting well the passage Cénomanian-Turonian (C-T) in the solid mass of Essouabaa, of the studies lithological and biostratigraphic were combined with the data of the isotopic analyses carbon and oxygen like with the contents of CaCO3. The got results indicate that this passage is marked by a biological event translated by the appearance of the "filaments" like by a positive excursion of the δ13C and δ18O. The cénomanian-turonian passage in the solid mass of Essouabaa represents a good example where during the oceanic event anoxic a facies with organic matter with contents of COT which can reach 1.36%. C E massive presents biostratigraphic and isotopic similarities with those obtained as well in the areas bordering (ex: Tunisia and Morocco) that throughout the world.

Keywords: limit cénomanian-turonian (C-T), COT, filaments, event anoxic 2 (EAO-2), stable isotopes, mounts of Mellègue, Algeria

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Authors: Maphuti Georgina Kwata

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Coal mining in Mpumalanga Province is known of contributing to the atmospheric pollution from various activities. Gold mining in North-West Province is known of also contributing to the atmospheric pollution especially with the production of radon gas. In this research directional dust deposition gauge was used to measure source of direction and meteorological data was used to determine the wind rose blowing and the influence of the seasonal changes. Fourteen months of dust collection was undertaken in Witbank Area and Carletonville Area. The results shows that the sources of direction for Ericson Dam its East in February 2010 and Tip Area shows that the source of direction its West in October 2010. In the East direction there were mining operations, power stations which contributed to the East to be the sources of direction. In the West direction there were smelters, power stations and agricultural activities which contributed for the source of direction to be the West direction for Driefontein Mine: East Recreational Village Club. The East of Leslie Williams hospital is the source of direction which also indicated that there dust generating activities such as mining operation, agricultural activities. The meteorological results for Emalahleni Area in summer and winter the wind rose blow with wind speed of 5-10 ms-1 from the East sector. Annual average for the wind rose blow its East South eastern sector with 20 ms-1 and day time the wind rose from northwestern sector with excess of 20 ms-1. The night time wind direction East-eastern direction with a maximum wind speed of 20 ms-1. The meteorogical results for Driefontein Mine show that North-western sector and north-eastern sector wind rose is blowing with 5-10 ms-1 win speed. Day time wind blows from the West sector and night time wind blows from the north sector. In summer the wind blows North-east sector with 5-10 ms-1 and winter wind blows from North-west and it’s also predominant. In spring wind blows from north-east. The conclusion is that not only mining operation where the directional dust deposit gauge were installed contributed to the source of direction also the power stations, smelters, and other activities nearby the mining operation contributed. The recommendations are the dust suppressant for unpaved roads should be used on a regular basis and there should be monitoring of the weather conditions (the wind speed and direction prior to blasting to ensure minimal emissions).

Keywords: directional dust deposition gauge, BS part 5 1747 dust deposit gauge, wind rose, wind blowing

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Authors: Gannouni Sonia, Hammami Asma, Saidi Salwa, Rebai Noamen

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Water resources in Tunisia have experienced quantitative and qualitative degradation, especially when talking about wetlands and Sbekhas. Indeed, the objective of this work is to study the spatio-temporal evolution of salinity for 29 years (from 1987 to 2016). A study of the connection between surface water and groundwater is necessary to know the degree of influence of the Sebkha brines on the water table. The evolution of surface salinity is determined by remote sensing based on Landsat TM and OLI/TIRS satellite images of the years 1987, 2007, 2010, and 2016. The processing of these images allowed us to determine the NDVI(Normalized Difference Vegetation Index), the salinity index, and the surface temperature around Sebkha. In addition, through a geographic information system(GIS), we could establish a map of the distribution of salinity in the subsurface of the water table of Chott Mariem and Hergla/SidiBouAli/Kondar. The results of image processing and the calculation of the index and surface temperature show an increase in salinity downstream of in addition to the sebkha and the development of vegetation cover upstream and the western part of the sebkha. This richness may be due both to contamination by seawater infiltration from the barrier beach of Hergla as well as the passage of groundwater to the sebkha.

Keywords: spatio-temporal monitoring, salinity, satellite images, NDVI, sebkha

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Authors: Hajer Chaker Ben Hadj Kacem, Thouraya Slama, Néjiba El Yetim Zribi

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This paper analyzes the effects of gender, affiliation, prior work experience, social work, and vicarious learning through family role models on entrepreneurial skills development by students when they have learned through the entrepreneurship method in Tunisia. Authors suggest that these variables enhance the development of students’ entrepreneurial skills when combined with teaching through entrepreneurship. The article assesses the impact of these combinations by comparing their effects on the development of thirteen students’ entrepreneurial competencies, namely entrepreneurial mindset, core self-evaluation, entrepreneurial attitude, entrepreneurial knowledge, creativity, financial literacy, managing ambiguity, marshaling of resources, planning, teaching methods, entrepreneurial teachers, innovative employee, and Entrepreneurial intention. Authors use a two-sample independent t-test to make the comparison, and the results indicate that, when combined with teaching through the entrepreneurship method, students with prior work experience developed better six entrepreneurial skills; students with social work developed better three entrepreneurial skills, men developed better four entrepreneurial skills than women. However, all students developed their entrepreneurial skills through this practical method regardless of their affiliation and their vicarious learning through family role models.

Keywords: affiliation, entrepreneurial skills, gender, role models, social work, teaching through entrepreneurship, vicarious learning, work experience

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Authors: Yuqing Zou, Chunrui Zou, Yichong Cao

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Previous research has revealed relationships between self-efficacy (SE), engagement, and academic achievement among students in Western countries, but these relationships remain unknown in college math courses among college students in China. In addition, previous research has shown that test anxiety has a direct effect on engagement and academic achievement. However, how test anxiety affects the relationships between SE, engagement, and academic achievement is still unknown. In this study, the authors aimed to explore the mediating roles of behavioral engagement (BE), emotional engagement (EE), and cognitive engagement (CE) in the association between SE and academic achievement and the moderating role of test anxiety in college math courses. Our hypotheses are that the association between SE and academic achievement was mediated by engagement and that test anxiety played a moderating role in the association. To explore the research questions, the authors collected data through self-reported surveys among 147 students at a northwestern university in China. Self-reported surveys were used to collect data. The motivated strategies for learning questionnaire (MSLQ) (Pintrich, 1991), the metacognitive strategies questionnaire (Wolters, 2004), and the engagement versus disaffection with learning scale (Skinner et al., 2008) were used to assess SE, CE, and BE and EE, respectively. R software was used to analyze the data. The main analyses used were reliability and validity analysis of scales, descriptive statistics analysis of measured variables, correlation analysis, regression analysis, and structural equation modeling (SEM) analysis and moderated mediation analysis to look at the structural relationships between variables at the same time. The SEM analysis indicated that student SE was positively related to BE, EE, and CE and academic achievement. BE, EE, and CE were all positively associated with academic achievement. That is, as the authors expected, higher levels of SE led to higher levels of BE, EE, and CE, and greater academic achievement. Higher levels of BE, EE, and CE led to greater academic achievement. In addition, the moderated mediation analysis found that the path of SE to academic achievement in the model was as significant as expected, as was the moderating effect of test anxiety in the SE-Achievement association. Specifically, test anxiety was found to moderate the association between SE and BE, the association between SE and CE, and the association between EE and Achievement. The authors investigated possible mediating effects of BE, EE, and CE in the associations between SE and academic achievement, and all indirect effects were found to be significant. As for the magnitude of mediations, behavioral engagement was the most important mediator in the SE-Achievement association. This study has implications for college teachers, educators, and students in China regarding ways to promote academic achievement in college math courses, including increasing self-efficacy and engagement and lessening test anxiety toward math.

Keywords: academic engagement, self-efficacy, test anxiety, academic achievement, college math courses, behavioral engagement, cognitive engagement, emotional engagement

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Authors: Mohamed Dhaoui, Hakim Gabtni

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The migration of hydrocarbons is a fairly complicated process that depends on several parameters, both structural and sedimentological. In this study, we will try to determine secondary migration paths which convey hydrocarbon from their main source rock to the largest reservoir of the Paleozoic petroleum system of the Tunisian part of Ghadames basin. In fact, The Silurian source rock is the main source rock of the Paleozoic petroleum system of the Ghadames basin. However, the most solicited reservoir in this area is the Triassic reservoir TAGI (Trias Argilo-Gréseux Inférieur). Several geochemical studies have confirmed that oil products TAGI come mainly from the Tannezuft Silurian source rock. That being said that secondary migration occurs through the fault system which affects the post-Silurian series. Our study is based on analysis and interpretation of gravity data. The gravity modeling was conducted in the northern part of Ghadames basin and the Telemzane uplift. We noted that there is a close relationship between the location of producing oil fields and gravity gradients which separate the positive and negative gravity anomalies. In fact, the analysis and transformation of the Bouguer anomaly map, and the residual gravity map allowed as understanding the architecture of the Precambrian in the study area, thereafter gravimetric models were established allowed to determine the probable migration path.

Keywords: basement, Ghadames, gravity, hydrocarbon, migration path

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Authors: T. Tommasi, E. Batuecas, G. Mancini, G. Saracco, D. Fino

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Extra virgin olive-oil (EVO) production is an important economic activity for several countries, especially in the Mediterranean area such as Spain, Italy, Greece and Tunisia. The two major by-products from olive oil production, solid-liquid Olive Pomace (OP) and the Olive Mill Waste Waters (OMWW), are still mainly disposed on soil, in spite of the existence of legislation which already limits this practice. The present study compares the environmental impacts associated with two different scenarios for the management of waste from olive oil production through a comparative Life Cycle Assessment (LCA). The two alternative scenarios are: (I) Anaerobic Digestion and (II) current Disposal on soil. The analysis was performed through SimaPro software and the assessment of the impact categories was based on International Life Cycle Data and Cumulative Energy Demand methods. Both the scenarios are mostly related to the cultivation and harvesting phase and are highly dependent on the irrigation practice and related energy demand. Results from the present study clearly show that as the waste disposal on soil causes the worst environmental performance of all the impact categories here considered. Important environmental benefits have been identified when anaerobic digestion is instead chosen as the final treatment. It was consequently demonstrated that anaerobic digestion should be considered a feasible alternative for olive mills, to produce biogas from common olive oil residues, reducing the environmental burden and adding value to the olive oil production chain.

Keywords: anaerobic digestion, waste management, agro-food waste, biogas

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Authors: Hamdi Omar Omar, Hela Fakhfakh, Chokri Yaich

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This work reflects the integration of different techniques, such as field sampling and observations, magnetic susceptibility measurement, cyclostratigaraphy and sequence stratigraphy. The combination of these results allows us to reconstruct the environmental evolution of the Sidi Khalif Formation in the North-South Axis (NOSA), aged of Upper Tithonian, Berriasian and Lower Valanginian. Six sedimentary facies were identified and are primarily influenced by open marine sedimentation receiving increasing terrigenous influx. Spectral analysis, based on MS variation (for the outcropped section) and wireline logging gamma ray (GR) variation (for the sub-area section) show a pervasive dominance of 405-kyr eccentricity cycles with the expression of 100-kyr eccentricity, obliquity and precession. This study provides (for the first time) a precise duration of 2.4 myr for the outcropped Sidi Khalif Formation with a sedimentation rate of 5.4 cm/kyr and the sub-area section to 3.24 myr with a sedimentation rate of 7.64 cm/kyr. We outlined 27 5th-order depositional sequences, 8 Milankovitch depositional sequences and 2 major 3rd-order cycles for the outcropping section, controlled by the long eccentricity (405 kyr) cycles and the precession index cycles. This study has demonstrated the potential of MS and GR to be used as proxies to develop an astronomically calibrated time-scale for the Mesozoic era.

Keywords: Berriasian, magnetic susceptibility, orbital tuning, Sidi Khalif Formation

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Authors: Zelalem Teshager

Abstract:

The Choke Mountains have several endangered and endemic wildlife species and provide important ecosystem services. Despite their environmental importance, the Choke Mountains are found in dangerous conditions. This raised the need for an evaluation of the community's perception of deforestation and its major drivers and suggested possible solutions in the Choke Mountains of northwestern Ethiopia. For this purpose, household surveys, key informant interviews, and focus group discussions were used. A total sample of 102 informants was used for this survey. A purposive sampling technique was applied to select the participants for in-depth interviews and focus group discussions. Both qualitative and quantitative data analyses were used. Computation of descriptive statistics such as mean, percentages, frequency, tables, figures, and graphs was applied to organize, analyze, and interpret the study. This study assessed smallholder agricultural land expansion, Fuel wood collection, population growth; encroachment, free grazing, high demand of construction wood, unplanned resettlement, unemployment, border conflict, lack of a strong forest protecting system, and drought were the serious causes of forest depletion reported by local communities. Loss of land productivity, Soil erosion, soil fertility decline, increasing wind velocity, rising temperature, and frequency of drought were the most perceived impacts of deforestation. Most of the farmers have a holistic understanding of forest cover change. Strengthening forest protection, improving soil and water conservation, enrichment planting, awareness creation, payment for ecosystem services, and zero grazing campaigns were mentioned as possible solutions to the current state of deforestation. Applications of Intervention measures, such as animal fattening, beekeeping, and fruit production can contribute to decreasing the deforestation causes and improve communities’ livelihood. In addition, concerted efforts of conservation will ensure that the forests’ ecosystems contribute to increased ecosystem services. The major drivers of deforestation should be addressed with government intervention to change dependency on forest resources, income sources of the people, and institutional set-up of the forestry sector. Overall, further reduction in anthropogenic pressure is urgent and crucial for the recovery of the afro-alpine vegetation and the interrelated endangered wildlife in the Choke Mountains.

Keywords: choke afro-alpine, deforestation, drivers, intervention measures, perceptions

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Authors: Lobna Mnif Fakhfakh, Mohamed Chaieb

Abstract:

Most ecological studies in North Africa reveal a process of continuous degradation of pastoral ecosystems as a result of overgrazing. This degradation appears across the depletion of perennial grass species. Indeed, the majority of steppic ecosystems are characterized by a low density of perennial grasses. This phenomenon reveals a drop in food value of rangelands, which is now estimated at less than 100 UF.ha -1. -1 Year in all North African steppes. However, for ecological restoration initiatives, some species such the genus of Stipagrostis and Stipa can be considered a good candidates species for effective pastoral improvement under arid bioclimate. The present work concerns Stipagrostis ciliata (Desf.) De Winter, perennial grasses, abundant in ecosystems characterized by the high content of gypsum (CaSO4)2H2O in the southern Tunisia. This tufted species with C4 biochemical photosynthesis type is able to grow and develop under high temperature and low annual rainfall, where the minimum water potential (ψmd), can reach -4 MPa during the summer season with a phenological growth maintained throughout the season unfavorable. At this point in the early autumn rains, S. ciliata begins its growth, especially with a heading which occurs 2-3 weeks after the first autumn rains. From the foregoing, it can be concluded that Stipagrostis ciliata is an excellent promising pastoral species for the ecological restoration, and enhancement of ecosystems biological productivity in arid bioclimate of North Africa.

Keywords: Stipagrostis ciliata, pastoral species, ecological restoration, arid bioclimate

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Authors: Naresh Kumar, Radhika Sharma, A. K. Singh

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Granites from Khanak and Devsar areas, a part of Malani Igneous Suite (MIS) were investigated for their geochemical characteristics to understand the petrogenetic aspect of the research area. Neoproterozoic rocks of MIS are well exposed in Jhunjhunu, Jodhpur, Pali, Barmer, Jalor, Jaisalmer districts of Rajasthan and Bhiwani district of Haryana and also occur at Kirana hills of Pakistan. The MIS predominantly consists of acidic volcanic with acidic plutonic (granite of various types), mafic volcanic, mafic intrusive and minor amount of pyroclasts. Based on the field and petrographical studies, 28 samples were selected and analyzed for geochemical analysis of major, trace and rare earth elements at the Wadia Institute of Himalayan Geology, Dehradun by X-Ray Fluorescence Spectrometer (XRF) and ICP-MS (Inductively Coupled Plasma- Mass Spectrometry). Granites from the studied areas are categorized as grey, green and pink. Khanak granites consist of quartz, k-feldspar, plagioclase, and biotite as essential minerals and hematite, zircon, annite, monazite & rutile as accessory minerals. In Devsar granites, plagioclase is replaced by perthite and occurs as dominantly. Geochemically, granites from Khanak and Devsar areas exhibit typical A-type granites characteristics with their enrichment in SiO2, Na2O+K2O, Fe/Mg, Rb, Zr, Y, Th, U, REE (except Eu) and significant depletion in MgO, CaO, Sr, P, Ti, Ni, Cr, V and Eu suggested about A-type affinities in Northwestern Peninsular India. The amount of heat production (HP) in green and grey granites of Devsar area varies upto 9.68 & 11.70 μWm-3 and total heat generation unit (HGU) i.e. 23.04 & 27.86 respectively. Pink granites of Khanak area display a higher enrichment of HP (16.53 μWm-3) and HGU (39.37) than the granites from Devsar area. Overall, they have much higher values of HP and HGU than the average value of continental crust (3.8 HGU), which imply a possible linear relationship among the surface heat flow and crustal heat generation in the rocks of MIS. Chondrite-normalized REE patterns show enriched LREE, moderate to strong negative Eu anomalies and more or less flat heavy REE. In primitive mantle-normalized multi-element variation diagrams, the granites show pronounced depletions in the high-field-strength elements (HFSE) Nb, Zr, Sr, P, and Ti. Geochemical characteristics (major, trace and REE) along with the use of various discrimination schemes revealed their probable correspondence to magma derived from the crustal origin by a different degree of partial melting.

Keywords: A-type granite, neoproterozoic, Malani igneous suite, Khanak, Devsar

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Authors: Clara Tramuta, Floris Irene, Daniela Manila Bianchi, Monica Pitti, Giulia Federica Cazzaniga, Lucia Decastelli

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This work presents the results obtained by the Regional Reference Centre for Salmonella Typing (CeRTiS) in a retrospective study aimed to investigate, through Pulsed-field Gel Electrophoresis (PFGE) analysis, the genetic relatedness of emerging Salmonella serotypes of human origin circulating in North-West of Italy. Furthermore, the goal of this work was to create a Regional database to facilitate foodborne outbreak investigation and to monitor them at an earlier stage. A total of 112 strains, isolated from 2016 to 2018 in hospital laboratories, were included in this study. The isolates were previously identified as Salmonella according to standard microbiological techniques and serotyping was performed according to ISO 6579-3 and the Kaufmann-White scheme using O and H antisera (Statens Serum Institut®). All strains were characterized by PFGE: analysis was conducted according to a standardized PulseNet protocol. The restriction enzyme XbaI was used to generate several distinguishable genomic fragments on the agarose gel. PFGE was performed on a CHEF Mapper system, separating large fragments and generating comparable genetic patterns. The agarose gel was then stained with GelRed® and photographed under ultraviolet transillumination. The PFGE patterns obtained from the 112 strains were compared using Bionumerics version 7.6 software with the Dice coefficient with 2% band tolerance and 2% optimization. For each serotype, the data obtained with the PFGE were compared according to the geographical origin and the year in which they were isolated. Salmonella strains were identified as follow: S. Derby n. 34; S. Infantis n. 38; S. Napoli n. 40. All the isolates had appreciable restricted digestion patterns ranging from approximately 40 to 1100 kb. In general, a fairly heterogeneous distribution of pulsotypes has emerged in the different provinces. Cluster analysis indicated high genetic similarity (≥ 83%) among strains of S. Derby (n. 30; 88%), S. Infantis (n. 36; 95%) and S. Napoli (n. 38; 95%) circulating in north-western Italy. The study underlines the genomic similarities shared by the emerging Salmonella strains in Northwest Italy and allowed to create a database to detect outbreaks in an early stage. Therefore, the results confirmed that PFGE is a powerful and discriminatory tool to investigate the genetic relationships among strains in order to monitoring and control Salmonellosis outbreak spread. Pulsed-field gel electrophoresis (PFGE) still represents one of the most suitable approaches to characterize strains, in particular for the laboratories for which NGS techniques are not available.

Keywords: emerging Salmonella serotypes, genetic characterization, human strains, PFGE

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Authors: Nouira Mariem, Ben Rayana Hazem, Ennigrou Samir

Abstract:

Background and aim: During the past decade, the frequency of extrapulmonary forms of tuberculosis has increased. These forms are under-diagnosed using conventional tests. The aim of this study was to evaluate the performance of the Tuberculin Skin Test (TST) for the diagnosis of tuberculosis, using the ROC curve and Fagan’s Nomogram methodology. Methods: This was a case-control, multicenter study in 11 anti-tuberculosis centers in Tunisia, during the period from June to November2014. The cases were adults aged between 18 and 55 years with confirmed tuberculosis. Controls were free from tuberculosis. A data collection sheet was filled out and a TST was performed for each participant. Diagnostic accuracy measures of TST were estimated using ROC curve and Area Under Curve to estimate sensitivity and specificity of a determined cut-off point. Fagan’s nomogram was used to estimate its predictive values. Results: Overall, 1053 patients were enrolled, composed of 339 cases (sex-ratio (M/F)=0.87) and 714 controls (sex-ratio (M/F)=0.99). The mean age was 38.3±11.8 years for cases and 33.6±11 years for controls. The mean diameter of the TST induration was significantly higher among cases than controls (13.7mm vs.6.2mm;p=10-6). Area Under Curve was 0.789 [95% CI: 0.758-0.819; p=0.01], corresponding to a moderate discriminating power for this test. The most discriminative cut-off value of the TST, which were associated with the best sensitivity (73.7%) and specificity (76.6%) couple was about 11 mm with a Youden index of 0.503. Positive and Negative predictive values were 3.11% and 99.52%, respectively. Conclusion: In view of these results, we can conclude that the TST can be used for tuberculosis diagnosis with a good sensitivity and specificity. However, the skin induration measurement and its interpretation is operator dependent and remains difficult and subjective. The combination of the TST with another test such as the Quantiferon test would be a good alternative.

Keywords: tuberculosis, tuberculin skin test, ROC curve, cut-off

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Authors: Mariem Saadi, Sabri Kanzari, Adel Zghibi

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In semi-arid areas like the Kairouan region, the constant irrigation with saline water and the overuse of groundwater resources, soils and aquifers salinization has become an increasing concern. In this study, a methodology has been developed to evaluate the groundwater contamination risk based on the unsaturated zone hydraulic properties. Two soil profiles with different ranges of salinity, one located in the north of the plain and another one in the south of plain (each 30 m deep) and both characterized by direct recharge of the aquifer were chosen. Simulations were conducted with Hydrus-1D code using measured precipitation data for the period 1998-2003 and calculated evapotranspiration for both chosen profiles. Four combinations of initial conditions of water content and salt concentration were used for the simulation process in order to find the best match between simulated and measured values. The success of the calibration of Hydrus-1D allowed the investigation of some scenarios in order to assess the contamination risk under different natural conditions. The aquifer risk contamination is related to the natural conditions where it increased while facing climate change and temperature increase and decreased in the presence of a clay layer in the unsaturated zone. Hydrus-1D was a useful tool to predict the groundwater level and quality in the case of a direct recharge and in the absence of any information related to the soil layers except for the texture.

Keywords: Hydrus-1D, Kairouan, salinization, semi-arid region, solute transport, unsaturated zone

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