L’avantage concurrentiel dans un contexte d’emergence du marche en Algerie

Cet article analyse l’origine de l’avantage concurrentiel des entreprises dans le contexte particulier d’un  pays en développement. Il s’agit de mesurer simultanément l’impact relatif des facteurs de l’industrie et des facteurs internes sur l’innovation et la performance des entreprises au sein d’un marché faiblement  compétitif. Le secteur des entreprises agroalimentaires émergentes (privées) en Algérie constitue le cadre empirique de la recherche. A partir des deux approches dominant le champ du management  stratégique, le schéma d’analyse porterien et l’approche par les ressources (RBV), un modèle conceptuel composite est proposé. Nous montrons que l’origine de l’avantage concurrentiel des entreprises évoluant sur un marché  émergent est influencée principalement par les facteurs externes et les ressources tangibles. Un échantillon de 31 entreprises agroalimentaires émergentes et la méthode statistique Partial Least Square sont mobilisés pour tester les hypothèses. Les résultats de l’analyse statistique sont ensuite discutés et relativisés à la  lumière des fondements théoriques et des spécificités empiriques de la recherche.Mots clés: Avantage concurrentiel, marché émergent, entreprises agroalimentaires, Algérie

Existence of Super Chaotic Attractors in a General Piecewise Smooth Map of the Plane

In this paper we give some rigorous conditions for the occurrence of super chaotic attractors in a general piecewise smooth map of the plane

Existence of Super Chaotic Attractors in a General Piecewise Smooth Map of the Plane

In this paper we give some rigorous conditions for the occurrence of super chaotic attractors in a general piecewise smooth map of the plane

INCIDENCE, CONTROL AND PROBLEMATIC ISSUES RELATED TO BRUCELLOSIS IN THE MAGHREB

Brucellosis, although eradicated in the developed countries, is still endemic in low income countries with serious consequences for human health and livestock production. In this study, we examine the evidence and knowledge about brucellosis in humans and domestic ruminants in the Maghreb countries over the last decade using a systematic review approach. Our study reveals that the Maghreb countries still record the highest brucellosis incidence rate in the world in both human and animal populations. The overall herd and individual seroprevalence of brucellosis in small ruminants is estimated at 15.11% and 4.31% for sheep and 20, 83%, 4.18% for goats, respectively. Brucellosis in cattle revealed a herd and individual seroprevalence of 17% and 6.60%, respectively. In humans, the annual incidence rate per million populations is evaluated at 143.65 cases. This data is much more underestimated due to passive collection and under-reporting cases. Control measures, including vaccination and testing and slaughter measures implemented for decades, have not yet made real incidence mitigation. Husbandry systems related to mixed species breeding and animal movement as well as weak breeders’ involvement make brucellosis difficult to eradicate. Given the low financial resources of these countries and the complexity of test and slaughter programs, the application of vaccination for all livestock is the best choice for decreasing the disease burden. 

STUDY OF THE EFFECT OF TWO SURFACTANTS ON SPRAY RETENTION BY BARLEY LEAVES

Surfactants are nowadays very useful additives to improve the effectiveness of phytosanitary treatments. They contribute to change the types of impact and thus the amount of spray retained by the leaves of the treated plant. We performed tests of retention on whole barley plants on BBCH 12 stage and small pieces of barley leaves at the same stage of growth. Spraying was done in three ways: water without surfactant, water with Break-Thru S240 and water with Li700. The three slurries of fluorescein contained in an amount of 0.2 g / l. Fluorescein retained by the leaves in both cases is then measured by a spectrofluoremeter. The retention tests on whole plants show that it is tripled by the first surfactant and doubled by the second. By cons on small pieces of barley leaves, the amount was increased by the use of surfactants but not to the same scale. This study concluded that the use of surfactants in spray pesticides may increase the amount of retention as a function of leaf area and the surfactant used

CcMP-II Metalloproteinase from Cerastes Cerastes Snake Venom Acts both on Blood Vessel ECM and Platelets

Background: Snake venoms contain various metalloproteinases that are highly toxic, inducing in severe bleeding by interfering with the blood coagulation and degrading the basement membrane or extracellular matrix (ECM) components. It has been suggested that hemorrhagic metalloproteinases interact in a specific way with platelet surface proteins resulting in an alteration of platelet function.  Hemorrhage and tissue necrosis are common manifestations of viperid envenomations in humans, largely due to the actions of prominent metalloproteinases. CcMP-II a weakly hemorrhagic metalloproteinase purified from Cerastes cerastes venom, as already described it belongs to the class P-II snake venom metalloproteinase. Methods: In this study, we characterized the biological effects of CcMP-II, including the ability of the enzyme to hydrolyze extracellular matrix components and plasma proteins, as well as its histopathological effects induced in capillaries. Then a study of the anti-aggregating activity was carried out and controlled for 10 min using a Chronolog aggregometer (ServiBIO) (USTHB, Faculty of Biological Sciences, BP 32, El-Alia Bab Ezzouar, 16111, Algiers, Algeria in 2019). The histopathological changes induced by CcMP-II were also analyzed and the 1 µm semi-thin sections are then stained with Toluidine Blue and the observation of these sections was realized using a photomicroscope. Toluidine Blue, magnification: 100x. Results: Obtained results showed that CcMP-II metalloproteinase hydrolyzed selectively the A α-chain of fibrinogen. This enzyme hydrolyzed also laminin and type IV collagen in time- and dose-dependent manner. CcMP-II inhibits collagen-induced platelet aggregation of human PRP with an IC50 value of 0.11 nM.  Pathological changes induced by CcMP-II after intramuscular injection in mice gastrocnemius were also studied. Histological study showed that the main morphological alterations in capillary vessels are characterized by a separation of endothelial cells from the surrounding basement membrane and reduction in the width of these cells, together with loss of basement membrane in some areas, through which erythrocytes and plasma are extravasated. Conclusion: In conclusion, CcMP-II, as a member of the P-II class of SVMPs, presents a selective specificity toward fibrinogen, laminin and type IV collagen. It was an α- fibrinogenase metalloproteinase, which inhibits collagen-stimulated platelet aggregation. This study will contribute to understanding better the functional mechanisms of the metalloproteinases that may be useful in the development of therapeutic agents related to thrombotic disorders

Studies of ion electroadsorption in supercapacitor electrodes

Electrochemical capacitors, now often termed supercapacitors, are high power electrochemical energy storage devices that complement or replace high power batteries in applications ranging from wind turbines to hybrid engines to uninterruptable power supplies to electronic devices. My dissertation explores the applications of relatively uncommon techniques for both supercapacitor material syntheses and gaining better mechanistic understanding of factors impacting electrochemical performance of supercapacitors. From fundamental ion electroadsorption studies made possible by using small angle neutron scattering (SANS), to the systematic investigations of coating thickness and microstructure in metal oxide / carbon nanocomposite electrodes realized through the novel use of the atomic layer deposition (ALD) technique, new avenues of material characterization and fabrication have been studied. In this dissertation I first present the motivation to expand the knowledge of supercapacitor science and technology, and follow with an in-depth literature review of the state of the art. The literature review covers different types of supercapacitors, the materials used in the construction of commercial and exploratory devices, an exploration of the numerous factors which affect supercapacitor performance, and an overview of relevant materials synthesis and characterization techniques The technical objectives for the work performed in this dissertation are then presented, followed by the contributions that I made in this field in my two primary research thrusts: advances to the understanding of ion electroadsorption theory in both aqueous and organic electrolytes through the development of a SANS-based methodology, and advances to metal-oxide carbon nanocomposites as electrodes through the use of ALD. The understanding of ion electro-adsorption on the surface of microporous (pores < 2 nm) solids is largely hindered by the lack of experimental techniques capable of identifying the sites of ion adsorption and the concentration of ions at the nanoscale. In the first research thrust of my dissertation, I harness the high penetrating power and sensitivity of neutron scattering to isotope substitution to directly observe changes in the ion concentration as a function of the applied potential and the pore size. I have conducted initial studies in selected aqueous and organic electrolytes and outlined the guidelines for conducting such experiments for the broad range of electrode-ions-solvent combinations. I unambiguously demonstrate that depending on the solvent properties and the solvent-pore wall interactions, either enhanced or reduced ion electro-adsorption may take place in sub-nanometer pores. More importantly, for the first time I demonstrate the route to identify the critical pore size below which either enhanced or reduced electrosorption of ions takes place. My studies experimentally demonstrate that poor electrolyte wetting in the smallest pores may indeed limit device performance. The proposed methodology opens new avenues for systematic in-situ studies of complex structure-property relationships governing adsorption of ions under applied potential, critical for rational optimization of device performance. In addition to enhancing our understanding of ion sorption, there is a critical need to develop novel supercapacitor electrode materials with improved high-energy and high-power characteristics. The formation of carbon-transition metal oxide nanocomposites may offer unique benefits for such applications. Broadly available transition metal oxides, such as vanadium oxide, offer high ion storage capabilities due to the broad range of their oxidation states, but suffer from high resistivities. Carbon nanomaterials, such as carbon nanotubes (CNT), in contrast are not capable to store high ion content, but offer high and readily accessible surface area and high electrical conductivity. In the second research thrust of my thesis, by exploiting the ability of atomic layer deposition (ALD) to produce uniform coatings of metal oxides on CNT electrodes, I demonstrated an effective way to produce high power supercapacitor electrodes with ultra-high energy capability. The electrodes I developed showed stable performance with excellent capacitance retention at high current densities and sweep rates. Electrochemical performance of the oxide layers were found to strongly depend on the coating thickness. Decreasing the vanadium oxide coating thickness to ~10 nm resulted in some of the highest values of capacitance reported to date (~1550 F·g⁻¹VOx at 1 A·g⁻¹ current density). Similar methodology was utilized for the deposition of thin vanadium oxide coatings on other substrates, such as aluminum (Al) nanowires. In this case the VOₓ coated Al nanowire electrodes with 30-50% of the pore volume available for electrolyte access show volumetric capacitance of 1390-1950 F cc⁻¹, which exceeds the volumetric capacitance of porous carbons and many carbon-metal oxide composites by more than an order of magnitude. These results indicated the importance of electrode uniformity and precise control over conformity and thickness for the optimization of supercapacitor electrodes.Ph.D

LSTM deep learning method for network intrusion detection system

The security of the network has become a primary concern for organizations. Attackers use different means to disrupt services or steal information, these various attacks push to think of a new way to block them all in one manner. In addition, these intrusions can change and penetrate the devices of security. To solve these issues, we suggest, in this paper, a new idea for Network Intrusion Detection System (NIDS) based on Long Short-TermMemory (LSTM) to recognize menaces and to obtain a long-term memory on them, inorder to stop the new attacks that are like the existing ones, and at the sametime, to have a single mean to block intrusions. According to the results of the experiments of detections that we have carried out, the Accuracy reaches upto 99.98 % and 99.93 % for respectively the classification of two classes and several classes, Also the False Positive Rate (FPR) reaches up to only 0,068 % and 0,023 % for respectively the classification of two classes and several classes, which proves that the proposed model is very effective, it has a great ability to memorize and differentiate between normal traffic and attack traffic and its identification is more accurate than other Machine Learning classifiers

الدلالات السيكوسوسيولوجية لبعض سلوكات العنف خلال ممارسة النشاط البدني والرياضي التربوي من وجهة نظر الأستاذ والتلميذ - دراسة ميدانية بثانويات مدينة باتنة -

This study aimes to know the forms and behaviors of violence which is deployed during school sport activity. or what we call it in the title of the study sports violence in school. in hight school in batna. and to know the degree of its appearance and legitimacy from the point of view of the teacher and the student. and between the student in effect of sex detreminants, education level, and between the three institutions. then to extract the psycosocial sign of each behavior according to the interpretation of both teacher and the student. for the reasons of its occurrence. The sample of the study was in the teacher of physical education teachers (30 teachers) 55.55% of the study population (city of batna ). And 217 students from the three high schools and by estimated rate 12.52% of the study population as well . we reached through the application of search tools (note, observation, and the interview) to the following results: * The spread of several forms of violence before, during and after practice sport activities * Each behavior of the symbols of the psycosocial according to the interpretation of both the teacher and the student for the reason of occurrenc