343 research outputs found

    Oea

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    Oea, aujourd’hui Tripoli, capitale de la Libye – arabe Ayas puis Ṭarābulus al-Gharb (Tripoli de l’Ouest) –, fut, avec Lepcis Magna et Sabratha, l’une des trois grandes cités de la Tripolitaine romaine. Le toponyme Oea, dérivé du néopunique Wy’t, Wayat ou Vat/ Oyat, renvoie à une origine préromaine dont le site, remarquable port naturel doublé d’une importante oasis, a livré quelques attestations matérielles. Certes, occupée en permanence, de l’antiquité à nos jours, Oea, comparativement à ses..

    Effect of tillage practices on the soil carbon dioxide flux during fall and spring seasons in a Mediterranean Vertisol

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    In this study, we assessed the effect of conventional tillage (CT), reduced (RT) and no tillage (NT) practices on the soil CO2 flux of a Mediterranean Vertisol in semi-arid Morocco. The measurements focused on the short term (0 to 96 h) soil CO2 fluxes measured directly after tillage during the fall and spring period. Soil temperature, moisture and soil strength were measured congruently to study their effect on the soil CO2 flux magnitude. Immediately after fall tillage, the CT showed the highest CO2 flux (4.9 g m-2 h-1); RT exhibited an intermediate value (2.1 g m-2 h-1) whereas the lowest flux (0.7 g m-2 h-1) was reported under NT. After spring tillage, similar but smaller impacts of the tillage practices on soil CO2 flux were reported with fluxes ranging from 1.8 g CO2 m-2 h-1 (CT) to less than 0.1 g CO2 m-2 h-1 (NT). Soil strength was significantly correlated with soil CO2 emission; whereas surface soil temperature and moisture were low correlated to the soil CO2 flux. The intensity of rainfall events before fall and spring tillage practices could explain the seasonal CO2 flux trends. The findings promote conservation tillage and more specifically no tillage practices to reduce CO2 losses within these Mediterranean agroecosystems. (Résumé d'auteur

    A survey of IoT security based on a layered architecture of sensing and data analysis

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    The Internet of Things (IoT) is leading today’s digital transformation. Relying on a combination of technologies, protocols, and devices such as wireless sensors and newly developed wearable and implanted sensors, IoT is changing every aspect of daily life, especially recent applications in digital healthcare. IoT incorporates various kinds of hardware, communication protocols, and services. This IoT diversity can be viewed as a double-edged sword that provides comfort to users but can lead also to a large number of security threats and attacks. In this survey paper, a new compacted and optimized architecture for IoT is proposed based on five layers. Likewise, we propose a new classification of security threats and attacks based on new IoT architecture. The IoT architecture involves a physical perception layer, a network and protocol layer, a transport layer, an application layer, and a data and cloud services layer. First, the physical sensing layer incorporates the basic hardware used by IoT. Second, we highlight the various network and protocol technologies employed by IoT, and review the security threats and solutions. Transport protocols are exhibited and the security threats against them are discussed while providing common solutions. Then, the application layer involves application protocols and lightweight encryption algorithms for IoT. Finally, in the data and cloud services layer, the main important security features of IoT cloud platforms are addressed, involving confidentiality, integrity, authorization, authentication, and encryption protocols. The paper is concluded by presenting the open research issues and future directions towards securing IoT, including the lack of standardized lightweight encryption algorithms, the use of machine-learning algorithms to enhance security and the related challenges, the use of Blockchain to address security challenges in IoT, and the implications of IoT deployment in 5G and beyond

    Conservation agriculture in the dry Mediterranean climate

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    The objective of this article is to review: (a) the concepts and principles that underpin Conservation Agriculture (CA) ecologically and operationally; (b) the potential benefits that can be harnessed through CA systems in the dry Mediterranean climates; (c) current status of adoption and spread of CA in the dry Mediterranean climate countries; and (d) opportunities for CA in the Central and West Asia and North Africa (CWANA) region. CA, comprising minimum mechanical soil disturbance and no-tillage seeding, organic mulch cover, and crop diversification is now practised on some 125 million ha, corresponding to about 9% of the global arable cropped land. Globally, the area under CA is spread across all continents and all agro-ecologies, including the dryland climates in the Mediterranean basin region as well as in the Mediterranean climates elsewhere in the world. Worldwide empirical and scientific evidence is available to show that significant productivity, economic, social and environmental benefits exist that can be harnessed through the adoption of CA principles for sustainable production intensification in the dry Mediterranean climates, including those in the CWANA region. The benefits include: fundamental change for the better in the sustainability of production systems and ecosystem services; higher stable yields and incomes; climate change adaptation and reduced vulnerability to the highly erratic rainfall distribution; and reduced greenhouse gas emissions. CA has taken off globally and is now spreading in several Mediterranean climates outside the Mediterranean basin particularly in South America, South Africa and Australia. In the dry Mediterranean climates in the CWANA region, CA is perceived to be a powerful tool of land management but CA has not yet taken off. Research on CA in the CWANA region has shown that there are opportunities for CA adoption in rainfed and irrigated farming systems involving arable and perennial crops as well as livestock

    Étude de l'effet du compost des déchets ménagers sur l’amélioration du rendement de Maïs et de la Laitue

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    La valorisation agronomique des ordures ménagères par compostage constitue la filière la plus prometteuse par comparaison avec d’autres voies d’élimination comme l’incinération. En effet, les composts  constituent de bons engrais qui permettent une augmentation des récoltes des plantes cultivées, et améliorent les propriétés physicochimiques du sol. Dans cette optique, le présent travail a pour objectif de déterminer la valeur agronomique du compost, issu d’un dispositif de fermentation installé à la faculté des sciences de Kénitra, sur deux cultures maraîchères : maïs et laitue. Le compost mur obtenu après une phase de fermentation aérobique de 6 mois est caractérisé par une humidité comprise entre 30 et 50 %, un pH de 7.8, un rapport C/N égale à 10, et une absence totale des germes indicateurs de contamination fécale : coliformes fécaux et streptocoques fécaux. Les tests agronomiques, montrent que la teneur satisfaisante en éléments nutritifs fait du compost final un amendement organique intéressant. En effet, l’amélioration des rendements des deux cultures : laitue et maïs est proportionnellement liées à la dose du compost. L’incorporation d’une dose de 75 % s’avère satisfaisante pour atteindre le meilleur rendement.Mots-clés : compost, déchets ménagers, valorisation agronomique, cultures maraichères, Kénitra, Maroc

    Factors Affecting Electronic Commerce Acceptance and Usage in Libyan ICT Organizations

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    Studying how individuals accept new Informatics systems such as E-commerce is one of the main issues in information systems research. Libya needs to develop and implement E-commerce systems successfully; Libya has fallen far behind other similar states in the region with regard to internet and E-commerce uptake. Successful implementation of any system depends on its acceptance and use by potential users. This thesis investigates how managers make their decisions towards E-commerce systems. This investigation is conducted over two culturally similar countries, namely Libya and Tunisia to attempt to identify factors that differ between the two communities in terms of technology acceptance. The study is undertaken using the well-accepted Technology Acceptance model (TAM), but extends this by incorporating new factors, which have both direct and indirect influences on a managers' decision to use E-commerce technology. The thesis seeks to answer the research question “What factors affect a managers' decisions to accept and use E-commerce systems in Libyan and Tunisian companies?” This research adds more constructs to the original technology acceptance model, which are adapted from the theory of reasoned action and the theory of planned behaviour. This research adopts action research, case study and questionnaire survey methods to test the 18 hypotheses. The results confirm the value of the new extended technology acceptance model and hence represent a contribution to the literature of computer systems adoption. The contribution of this research is developing the Technology Acceptance Model and testing it on the Usage of E-commerce in Libyan and Tunisian companies, the Extended Technology Acceptance Model appropriate to E-commerce (E-COMTAM) was based on the critical analysis of the TAM, with eight additional and new items. The dissertation has seven chapters; Chapter One was the concepts of E-commerce, Chapter Two: Theoretical Literature Review of Technology Acceptance Model, the third chapter covers research aims and objectives, Chapter Four: covers the research methodology , Chapter Five research variables and hypotheses, Chapter Six: covers the data analysis and the research results. Finally, Chapter Seven is the conclusion and recommendations

    Dietary fat intake as a risk factor for the development of diabetes. Multinational, multicenter study of the Mediterranean Group for the Study of Diabetes (MGDS)

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    In the context of the Multinational MGSD Nutrition Study, three groups of subjects were studied: 204 subjects with recently diagnosed diabetes(RDM),42subjectswithundiagnoseddiabetes(UDM)(AmericanDiabetesAssociation criteria—fasting plasma glucose [FPG] 126 mg/dl), and 55 subjects with impaired fasting glucose(IFG)(FPG 110and126mg/dl).Eachgroupwascomparedwithacontrolgroupof nondiabetic subjects, matched one by one for center, sex, age, and BMI. Nutritional habits were evaluated by a dietary history method, validated against the 3-day diet diary. In RDM, the questionnaire referred to the nutritional habits before the diagnosis of diabetes. Demographic data were collected, and anthropometrical and biochemical measurements were taken. RESULTS— Compared with control subjects, RDM more frequently had a family history of diabetes(49.0vs.14.2%;P0.001),exercisedless(exerciseindex53.5vs.64.4;P0.01),and more frequently had sedentary professions (47.5 vs. 27.4%; P 0.001). Carbohydrates contributed less to their energy intake (53.5 vs. 55.1%; P 0.05), whereas total fat (30.2 0.5 vs. 27.8 0.5%; P 0.001) and animal fat (12.2 0.3 vs. 10.8 0.3%; P 0.01) contributed moreandtheplant-to-animalfatratiowaslower(1.50.1vs.1.80.1;P0.01).UDMmore frequentlyhadafamilyhistoryofdiabetes(38.1vs.19.0%;P0.05)andsedentaryprofessions (58.5vs.34.1%;P0.05),carbohydratescontributedlesstotheirenergyintake(47.61.7vs. 52.81.4%;P0.05),totalfat(34.71.5vs.30.41.2%;P0.05)andanimalfat(14.2 0.9 vs. 10.6 0.7%; P 0.05) contributed more, and the plant-to-animal fat ratio was lower (1.6 0.2 vs. 2.3 0.4; P 0.05). IFG differed only in the prevalence of family history of diabetes (32.7 vs. 16.4%; P 0.05). CONCLUSIONS— Our data support the view that increased animal fat intake is associated with the presence of diabetes

    Measuring the Effect of Healthcare Service Quality Dimensions on Patient’s Satisfaction in The Algerian Private Sector

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    There is a gap in marketing literature related to impact of service quality dimensions on perceived service quality and patient satisfaction, in the private healthcare industry. The healthcare system is responsible for improving the general population’s health in a country. To differentiate from competitors, the quality of service is mainly considered a critical success factor for hospitals (Azmit et al., 2017). Therefore, competition is essential for improving quality and patient satisfaction in healthcare institutions (Kitapci et al., 2014). This article aims to determine the relationship between health service quality dimensions and patient satisfaction in the healthcare sector. Specifically, the paper seeks to find out the most critical dimensions of service quality, which is used to evaluate the characteristics of private healthcare service quality as perceived by patients. A field study was carried out on a sample of 208 patients in Tlemcen city in Algeria. The questionnaire developed for this study was based on a SERVQUAL model specifically, based on Parasuraman, Zeithaml, and Berry, (1985) variables that identified the influence of five dimensions (i.e., reliability, tangibility, assurance, responsibility, and empathy) in healthcare service environments on patient satisfaction. The results have found after the application of structural equation modelling that: reliability, tangibility, assurance, responsibility was more significant in contributing to patient satisfaction, while empathy was not significant. This indicates that patients tend to have a positive perception about the health service if they consider the perceived quality of the health service to be credible, reliable, tangible, and responsive, even though they may feel that the health provider does not empathize with them. Hence, healthcare industry practitioners can consider this model as an instrument to assess healthcare and help improve their service quality. Therefore, service provider managers can use this instrument to assess private hospital service quality in Algeria and other African countries

    Tillage system affects soil organic carbon storage and quality in Central Morocco

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    Stabilizing or improving soil organic carbon content is essential for sustainable crop production under changing climate conditions. Therefore, soil organic carbon research is gaining momentum in the Mediterranean basin. Our objective is to quantify effects of no tillage (NT) and conventional tillage (CT) on soil organic carbon stock (SOCs) in three soil types (Vertisol, Cambisol, and Luvisol) within Central Morocco. Chemical analyses were used to determine how tillage affected various humic substances. Our results showed that, after 5 years, surface horizon (0–30 cm) SOC stocks varied between tillage systems and with soil type. The SOCs was significantly higher in NT compared to CT (10% more in Vertisol and 8% more in Cambisol), but no significant difference was observed in the Luvisol. Average SOCs within the 0–30 cm depth was 29.35 and 27.36 Mg ha−1 under NT and CT, respectively. The highest SOCs (31.89 Mg ha−1) was found in Vertisols under NT. A comparison of humic substances showed that humic acids and humin were significantly higher under NT compared to CT, but fulvic acid concentrations were significantly lower. These studies confirm that NT does have beneficial effects on SOCs and quality in these soils

    Optimization of NPK levels of Clementine Sidi Aissa (Citrus reticulata Blanco) trees grafted on different citrus rootstocks

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    Received: August 15th, 2023 ; Accepted: October 18th, 2023 ; Published: November 5th, 2023 ; Correspondence: [email protected] present study aims to investigate the impact of various nitrogen concentrations on young Clementine Sidi Aissa citrus trees (Citrus reticulata Blanco), grafted on five citrus rootstocks namely Moroccan Carrizo citrange, French Carrizo citrange, Troyer citrange, Citrus macrophylla, and sour orange (Citrus aurantium L.). The experiment took place in greenhouses at the Experimental station of El Menzeh INRA-Morocco, with the young trees grown in containers. We applied five different nitrogen treatments (expressed as mg L-1 of N-P2O5-K2O): (0–0–0), (0–25–50), (25–25–50), (50–25–50), and (100–25–50). The split-plot experimental design was used with three replications. The findings demonstrate that the nitrogen enrichment resulted in enhanced plant growth, marked by increased plant height, rootstock and scion stem diameters, diameter and shoot length, relative water content (RWC), as well as leaf chlorophyll and proline content. Optimal growth of the Clementine Sidi Aissa trees was observed under the 100–25–50 (mg L-1 of N-P2O5-K2O) treatment. The study also found that leaf nitrogen concentration increased in line with the quantity of nitrogen added, whereas the percentages of phosphorous and potassium in the leaves decreased. The most significant growth increase across the majority of the studied parameters was noted in Clementine Sidi Aissa trees grafted on Moroccan Carrizo citrange and Troyer citrange rootstocks
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