52 research outputs found

    Effects Of The Internet Of Things (IoT): A Systematic Review Of The Benefits And Risks

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    The Internet of Things (IoT) might yield many benefits and can be transformative in nature, yet has been given scant attention in e-commerce literature. The IoT describes a situation whereby physical objects are connected to the Internet and are able to communicate with, and identify themselves to other devices. These devices generate a huge amount of data. When it is possible to combine data from devices and other systems, new insights may be created which may provide important benefits to e-commerce. The duality of technology predicts that the accomplishment of benefits might also cause risks. In this paper we conduct a systematic review of literature to create an overview of perceived benefits and risks of IoT. The results confirm the duality that IoT has a variety of expected political, strategic, tactical and operational benefits as well as interrelated risks attached to its adoption. However, risks regarding the adoption of IoT also occur at all levels. Accomplishment of benefits requires that possible risks need to be mitigated in concert

    Modélisation de cultures mixtes de levures pour leur mise en oeuvre optimale dans les bioprocédés

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    Les potentialitĂ©s liĂ©es aux cultures mixtes de micro-organismes sont immenses et ouvrent de vastes possibilitĂ©s pour l’innovation dans les bioprocĂ©dĂ©s. Cependant, Ă©tant donnĂ© la complexitĂ© des phĂ©nomĂšnes rĂ©gulant la physiologie d’un seul micro-organisme, leur mise en oeuvre en culture mixte est d’autant plus difficile Ă  maĂźtriser que des interactions entre ces micro-organismes viennent s’ajouter. Le travail prĂ©sentĂ© dans ce manuscrit est une Ă©tude d'un couple de levures oenologiques constituĂ© de Saccharomyces cerevisiae et de Torulaspora delbrueckii. Son objectif est d'acquĂ©rir des informations expĂ©rimentales afin d’analyser et in fine modĂ©liser l'Ă©volution des cultures pures et des cultures mixtes. L'analyse des donnĂ©es expĂ©rimentales acquises lors des cultures pures de chaque levure a permis de quantifier l'effet favorable de la concentration initiale d'azote assimilable sur la croissance et la vitesse de fermentation des deux levures. Elle a aussi mis en Ă©vidence une prolongation de la phase de latence de T. delbrueckii induite par une augmentation des facteurs anaĂ©robies. Les cultures mixtes ont Ă©tĂ© rĂ©alisĂ©es en prĂ©sence et en absence de membrane de sĂ©paration permettant ainsi d'observer les effets du contact physique sur l'Ă©volution des cocultures. Le contact physique influence la dynamique des populations. En culture mixte, S. cerevisiae domine T. delbrueckii dans un milieu synthĂ©tique classique. Une augmentation de la concentration initiale de facteurs anaĂ©robies inverse complĂštement cette domination. L'analyse des rĂ©sultats expĂ©rimentaux nous a orientĂ© vers le dĂ©veloppement d'un modĂšle «stoechio-cinĂ©tique» structurĂ© dans lequel l'azote assimilĂ© par la levure se rĂ©partit en deux compartiments: le compartiment constitutif et le compartiment de stockage. Ce modĂšle a permis une reprĂ©sentation fidĂšle des cinĂ©tiques observĂ©es en culture pure. La prise en compte des interactions s'est faite en intĂ©grant la compĂ©tition pour les substrats, les interactions indirectes et les interactions directes. L'ensemble des hypothĂšses Ă©mises lors de ce travail de modĂ©lisation souligne la nĂ©cessitĂ© d'approfondir les connaissances scientifiques concernant le mĂ©tabolisme deT. delbrueckii en anaĂ©robiose stricte et l'effet des facteurs anaĂ©robies sur les interactions microbiennes

    Etude comparĂ©e de l’efficacitĂ© des extraits aqueux de feuilles d’eucalyptus (Eucalyptus camaldulensis) et des graines de neem (Azadirachta indica Juss) contre les principaux ravageurs de chou

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    Cette Ă©tude a Ă©tĂ© conduite afin d’évaluer ’efficacitĂ© des extraits aqueux de feuilles d’eucalyptus (Eucalyptus camaldulensis) et des graines de neem (Azadirachta indica Juss) contre les principaux ravageurs de chou. A cet effet, une parcelle disposĂ©e en 3 blocs complets, randomisĂ©s et Ă©quilibrĂ©s constituĂ©s de 4 parcelles Ă©lĂ©mentaires correspondant Ă  3 traitements et 1 tĂ©moin sans traitement a servi de dispositif expĂ©rimental. AprĂšs analyse des rĂ©sultats, il ressort que l’extrait de graines de neem a un effet significatif sur tous les ravageurs ciblĂ©s. L’extrait de feuilles d’eucalyptus s’est montrĂ© inefficace sur Plutella xylostella et Brevicoryne brassicae. L’insecticide de synthĂšse a eu un effet immĂ©diat sur Brevicoryne brassicae, un effet remarquable sur Spodoptera littoralis, mais s’est montrĂ© moins efficace sur Hellula undalis et Plutella xylostella. Les meilleurs rendements ont Ă©tĂ© obtenus sur les parcelles Ă©lĂ©mentaires (PE) traitĂ©es avec l’extrait aqueux de graines de neem et la solution aqueuse de K-OPTIMAL. Des extraits aqueux de grains neem et des feuilles d’Eucalyptus camaldulensis ont Ă©tĂ© prĂ©parĂ©s sĂ©parĂ©ment en introduisant respectivement 40 g dans 0,5litre d’eau et 22,5 g dans 0,5 litre d’eau, puis appliquĂ©s sur des cultures de chou en comparaison avec deux tĂ©moins dont un insecticide de synthĂšse le K-OPTIMAL dosĂ© Ă  2ml/l et un tĂ©moin sans traitement. Contrairement aux extraits aqueux de feuilles d’Eucalyptus camaldulensis, les extraits de graines de neem, ont Ă©tĂ© efficace sur la plupart des ravageurs. Ces extraits peuvent donc ĂȘtre utilisĂ©s dans un programme de lutte intĂ©grĂ©e contre les ravageurs majeurs du chou

    The Destructive Effect of Corruption on Economic Growth in Mali : a Nonlinear Model Analysis

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    A growing body of empirical work has raised awareness of the destructive effect of corruption on economic development, although no existing study has considered the threshold value at which corruption impedes economic growth. This study assesses the effect of corruption on economic growth by adopting a non-linear approach to determining the corruption threshold. By analyzing the effect of corruption on economic growth in Mali over the period 1988 to 2021, this study examines whether there is evidence of an inverted U-shaped relationship between economic growth and corruption. The threshold effect of corruption is assessed using an augmented quadratic model. The results confirm the existence of an inverted U-shaped relationship between corruption and economic growth on the one hand and show the existence of a long-run relationship between these variables on the other hand, thus validating our initial hypothesis. Furthermore, the results show that economic growth peaks when the corruption perception index reaches 0.07 points. The main lessons to be drawn from these results are that below this threshold, corruption becomes a lubricant for economic growth, while above this threshold, it constitutes a brake on economic growth in Mali

    Mixed culture fermentation using Torulaspora delbrueckii and Saccharomyces cerevisiae with direct and indirect contact: impact of anaerobic growth factors

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    The role of the initial concentration of anaerobic growth factors (AGF) on interactions between Torulaspora delbrueckii and Saccharomyces cerevisiae was investigated in strict anaerobiosis. Experiments were performed in a synthetic grape must medium in a membrane bioreactor, a special tool designed for studying direct and indirect interactions between microorganisms. In pure culture fermentations, increased AGF concentration had no impact on S. cerevisiae behaviour, whereas it induced an extension of T. delbrueckii latency. Surprisingly, T. delbrueckii used only 75 to 80% of the consumed sugar to produce biomass, glycerol and ethanol. Physical separation influenced the population dynamics of co-fermentations. S.cerevisiae dominated the co-cultures having a single dose of AGF as its presence indirectly induced a decrease in numbers of living T. delbrueckii cells and physical contact with T. delbrueckii stimulated S.cerevisiae growth. Increasing the AGF initial concentration completely upset this domination: S. cerevisiae growth was not stimulated and T. delbrueckii living cells did not decrease. Yeasts incorporate exogenous AGFs, which probably impact their response to competing yeasts. The increase in AGF might have induced changes in the lipid composition of the T. delbrueckii membrane, which would hinder its interaction with S. cerevisiae antimicrobial peptides. The initial concentration of anaerobic growth factors influenced co-culture fermentation population dynamics tremendously, thus highlighting a new way to monitor population evolution and eventually wine organoleptic properties

    Adsorption du benzo(a)pyrĂšne sur du charbon activĂ© Ă  base de coques de coco provenant de CĂŽte d’Ivoire

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    L’accumulation des Hydrocarbures Aromatiques Polycycliques (HAP) dans l’environnement est une prĂ©occupation mondiale du fait de leur persistance et de leur toxicitĂ©. l’Union EuropĂ©enne a ainsi jugĂ© seize HAP comme « prĂ©occupants », parmi lesquels le benzo(a)pyrĂšne est l’un des plus toxiques. La dĂ©pollution du benzo(a)pyrĂšne contenu dans les eaux a ainsi Ă©tĂ© Ă©tudiĂ©e par adsorption sur charbon activĂ© prĂ©parĂ© Ă  partir de coques de noix de coco. La concentration rĂ©siduelle en benzo(a)pyrĂšne et l’influence de la masse de charbon activĂ© Ă©tudiĂ©es par Chromatographie Liquide Ă  Haute Performance (CLHP) ont montrĂ© que la quantitĂ© de benzo(a)pyrĂšne adsorbĂ©e dans l’eau croissait avec la masse de charbon activĂ© introduite. L'adsorption du benzo(a)pyrĂšne a suivi les modĂšles de Freundlich et de Langmuir et a obĂ©it Ă  la cinĂ©tique d’ordre 2; avec une constante thermodynamique (Kad2) de 0,0706 g.ÎŒg-1.min-1. Aussi, le paramĂštre d'Ă©quilibre k infĂ©rieur Ă  1 et le facteur d'hĂ©tĂ©rogĂ©nĂ©itĂ© n compris entre 0,5 et 1 ont indiquĂ© que l'adsorption du benzo(a)pyrĂšne dans l'eau Ă©tait favorable, cependant le charbon Ă©tudiĂ© a prĂ©sentĂ© un pouvoir adsorbant faible pour l’adsorption du benzo(a)pyrĂšne. Ainsi, Le charbon activĂ© Ă  base de coques de coco est donc un moyen limitĂ© de dĂ©pollution du benzo(a)pyrĂšne.© 2015 International Formulae Group. All rights reserved.Mots clĂ©s: Adsorption, charbon activĂ©, benzo(a)pyrĂšne, isotherme, cinĂ©tiqueEnglish Title: Benzo(a)pyrene adsorption on activated coal based on coconut shells from CĂŽte d'IvoireEnglish AbstractPolycyclic Aromatic Hydrocarbons (PAHs) accumulation in environment is a world preoccupation, due to their persistence, toxicity and carcinogenic character for the food chain. The European union judged sixteen thus among them " preoccupying ", among which the benzo(a)pyrene is one of the most toxic. Thus, removal of benzo(a)pyrene from waters has been studied by adsorption on activated carbon prepared from raw coconut cockles. The vestigial concentration in benzo(a)pyrĂšne and the influence of activated carbon mass studied by a High Performance Liquid Chromatography (HPLC), showed that the quantity of benzo(a)pyrene adsorbed in  water grows with carbon mass introduced. Benzo(a)pyrene adsorption follows the Freundlich and Langmuir models and it obeys the kinetics of order 2; with a thermodynamic constant (Kad2) of 0,0706 g.ÎŒg-1.min-1. Also, the balance parameter k lower to 1 and the heterogeneity factor n comprise between 0,5 and 1 indicate that benzo(a)pyrene adsorption in water is favorable, however the studied carbon presents a weak adsorption power for benzo(a)pyrĂšne. So, activated carbon prepared from coconut cockles is therefore a limited method of benzo(a)pyrene removal from waters.© 2015 International Formulae Group. All rights reserved.Keywords: Adsorption, activated carbon, benzo(a)pyrene, isotherm, kinetic

    Aldicarbe et crimidine dans les eaux et les sĂ©diments aux alentours de la dĂ©charge municipale d’AkouĂ©do (Abidjan, CĂŽte d’Ivoire): niveaux et frĂ©quences de contamination

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    En Afrique, plusieurs familles de pesticides, susceptibles de nuire Ă  la santĂ© de l’homme et de l’environnement, sont utilisĂ©es contre les pestes et autres nuisibles. Cependant, la plupart des Ă©tudes menĂ©es se sont focalisĂ©es sur les organochlorĂ©s. La frĂ©quence de dĂ©tection et les concentrations des pesticides aldicarbe et crimidine ont Ă©tĂ© examinĂ©es dans les eaux et les sĂ©diments autour de la dĂ©charge municipale d’AkouĂ©do (CĂŽte d’Ivoire). Les analyses ont Ă©tĂ© effectuĂ©es de juin 2013 Ă  janvier 2014 par chromatographie liquide à haute performance couplĂ©e Ă  la mĂ©thode de dĂ©tection par fluorescence, aprĂšs une extraction liquide/liquide des eaux, et une extraction au soxhlet des sĂ©diments. Les rĂ©sultats ont montrĂ© une contamination significative des sĂ©diments par l’aldicarbe et la crimidine Ă  des frĂ©quences de dĂ©tection trĂšs Ă©levĂ©es, contrairement aux eaux lagunaires et souterraines. Les concentrations ont Ă©tĂ© significativement plus Ă©levĂ©es pendant la saison des crues dans les eaux et pendant la saison des pluies dans les sĂ©diments. Ces rĂ©sultats suggĂšrent que la crimidine est utilisĂ©e ou rejetĂ©e de façon illĂ©gale dans la zone d’étude, et que les niveaux de concentration de la crimidine et de l’aldicarbe dans la baie de M’Badon peuvent causer des risques de santĂ© pour certains organismes aquatiques et les populations.© 2016 International Formulae Group. All rights reserved.Mots clĂ©s: Pesticides; lixiviat, estuaire, lagune EbriĂ©, CĂŽte d’IvoireEnglish Title: Aldicarb and crimidine in waters and sediments in the vicinity of the AkouĂ©do municipal dumping site (Abidjan, Cote d’Ivoire): concentrations and detection frequenciesEnglish AbstractThe impact of pesticides on environmental quality is of great concern in many developing countries. However, data on pesticide contamination levels in African estuaries has mainly focused on organochlorine compounds, although some among other pesticide families are able to persist in water for several days and pose toxicological risks to humans and wildlife. This study assessed the detection frequency and concentration levels of aldicarb and crimidine residues in waters and sediments (from leachate, pits, and M’Badon Bay) around the municipal dumping site of AkouĂ©do (Abidjan, Ivory Coast). Samples were analyzed by the HPLCfluorescence detector method after liquid/liquid and soxhlet extractions of waters and sediments, respectively, from June 2013 to January 2014. The results showed significant contamination of sediments by the aldicarb and the crimidine, with detection frequencies up to 100% during the wet season. The highest pesticide concentrations in waters and sediments were observed during the flooding season and the wet season, respectively. The aldicarb and crimidine concentrations were significantly higher in sediments than waters, although they are highly soluble in water. The results suggest that the crimidine is illegally used or disposed of in Abidjan area, and that aldicarbe and crimidine concentration levels could pose health risks to biota.© 2016 International Formulae Group. All rights reserved.Keywords: Pesticides; leachate, estuary, EbriĂ© Lagoon, Ivory Coas

    Examination of Late Palaeolithic archaeological sites in northern Europe for the preservation of cryptotephra layers

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    We report the first major study of cryptotephra (non-visible volcanic ash layers) on Late Palaeolithic archaeological sites in northern Europe. Examination of 34 sites dating from the Last Termination reveals seven with identifiable cryptotephra layers. Preservation is observed in minerogenic and organic deposits, although tephra is more common in organic sediments. Cryptotephra layers normally occur stratigraphically above or below the archaeology. Nearby off-site palaeoclimate archives (peat bogs and lakes <0.3 km distant) were better locations for detecting tephra. However in most cases the archaeology can only be correlated indirectly with such cryptotephras. Patterns affecting the presence/absence of cryptotephra include geographic position of sites relative to the emitting volcanic centre; the influence of past atmospherics on the quantity, direction and patterns of cryptotephra transport; the nature and timing of local site sedimentation; sampling considerations and subsequent taphonomic processes. Overall, while tephrostratigraphy has the potential to improve significantly the chronology of such sites many limiting factors currently impacts the successful application

    Seasonal and Regional Dynamics of M. ulcerans Transmission in Environmental Context: Deciphering the Role of Water Bugs as Hosts and Vectors

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    Buruli ulcer, caused by Mycobacterium ulcerans, is a devastating skin disease. Most cases of Buruli ulcer occur in poor rural communities. As a result, treatment is frequently sought too late and about 25% of those infected—particularly children—become permanently disabled. Outbreaks of Buruli ulcer have always been associated with swampy areas. However, the route(s) of bacillus transmission is (are) still unclear. This Mycobacterium species resides in water where it colonizes many ecological niches such as aquatic plants, herbivorous animals and predatory/carnivorous insects. For several years the role of water bugs as hosts and vectors of M. ulcerans was suspected and was demonstrated under laboratory conditions. The aim of this work was to further assess the role of water bugs as hosts and vectors of M. ulcerans in environmental context. This work identifies several water bug families as hosts of M. ulcerans in Buruli ulcer endemic area. The detection of bacilli in saliva of human biting insects provides further evidence for their role in M. ulcerans transmission. Interestingly, three of these insects are good flyers, and as such could participate in M. ulcerans dissemination

    Ecology and Transmission of Buruli Ulcer Disease: A Systematic Review

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    Buruli ulcer is a neglected emerging disease that has recently been reported in some countries as the second most frequent mycobacterial disease in humans after tuberculosis. Cases have been reported from at least 32 countries in Africa (mainly west), Australia, Southeast Asia, China, Central and South America, and the Western Pacific. Large lesions often result in scarring, contractual deformities, amputations, and disabilities, and in Africa, most cases of the disease occur in children between the ages of 4–15 years. This environmental mycobacterium, Mycobacterium ulcerans, is found in communities associated with rivers, swamps, wetlands, and human-linked changes in the aquatic environment, particularly those created as a result of environmental disturbance such as deforestation, dam construction, and agriculture. Buruli ulcer disease is often referred to as the “mysterious disease” because the mode of transmission remains unclear, although several hypotheses have been proposed. The above review reveals that various routes of transmission may occur, varying amongst epidemiological setting and geographic region, and that there may be some role for living agents as reservoirs and as vectors of M. ulcerans, in particular aquatic insects, adult mosquitoes or other biting arthropods. We discuss traditional and non-traditional methods for indicting the roles of living agents as biologically significant reservoirs and/or vectors of pathogens, and suggest an intellectual framework for establishing criteria for transmission. The application of these criteria to the transmission of M. ulcerans presents a significant challenge
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