Time filter

Source Type

Cuernavaca, Mexico

Dolci P.C.,University of Sol | Macada A.C.G.,Grande Rio University | Grant G.G.,Carleton University
Journal of Enterprise Information Management | Year: 2014

Purpose – The purpose of this paper is to analyze some Brazilian companies’ use of the information technology portfolio management (ITPM) technique as an aid to their information technology (IT) investments management. Design/methodology/approach – It was carried out in five case studies in different Brazilian companies from several economic sectors which were using ITPM or were in the initial implementation phase. Eight interviews were conducted. The persons interviewed were high-level executives working in the IT department in the studied companies. Findings – Different levels of ITPM use was found with respect to IT investment management (planning, control and evaluation). It was observed, in the analyzed cases, that ITPM is used most frequently in IT investment planning, which is the process most discussed and used in analyzed companies. The ITPM technique is used more frequently in Company 2 than in the other cases because the organization of the IT area in the company is structured according to ITPM dimensions. Research limitations/implications – The ITPM technique has received little attention in IT research and research in this area identifying the use and applicability of ITPM in companies is still very limited in the information systems literature. Originality/value – The paper presents IT investment management in different Brazilian companies and how ITPM was used to help companies in this process compose by planning, control and evaluation. © Emerald Group Publishing Limited. Source

Kone A.W.,University dAbobo Adjame | Edoukou E.F.,University dAbobo Adjame | Tondoh J.E.,University of Sol | Gonnety J.T.,Sudan University of Science and Technology | And 2 more authors.
Biology and Fertility of Soils | Year: 2012

In tropical savannas where soils are generally sandy and nutrient poor, organic farming associated with enhanced soil biological activity may result in increased nutrient availability. Therefore, legumes have been introduced in the humid savanna zone of Côte d'Ivoire, owing to their ability to fix atmospheric N and to continually supply soil with great quantity of organic materials in relatively short time. The main objective of this study was to assess the influence of two legume (Cajanus cajan and Lablab purpureus) cultivations on earthworm communities and P and N availability. Trials were carried out under farmers' field conditions; C. cajan was planted on savanna soils (trial 1) while L. purpureus was established on new Chromolaena odorata-dominated fallow soils (trial 2). Native vegetations were considered as controls. Changes in soil properties (earthworm abundance and diversity, microbial biomass carbon (MBC), and plant available P and N) were assessed using the biosequential sampling. After 1 year, both the legume stands showed a significantly higher density of earthworms, compared with the respective controls. This trend was linked to an increase in the abundance of the detritivores Dichogaster baeri Sciacchitano 1952 and Dichogaster saliens Beddard 1893, and the polyhumic Stuhlmannia zielae Omodeo 1963. Equally, legume had beneficial impacts on the average number of earthworm species, the Shannon-Weaver index of diversity and MBC in savanna (trial 1). Available P and ammonium significantly increased under both legume cultivations and were significantly and concurrently linked to litter quality and earthworm activities as shown by multiple regressions. As a result, legumes could improve nutrient availability in the sandy soils of central Côte d'Ivoire by positively affecting soil biological activity and this could bring farmers to cultivate crops on savanna lands. © 2011 Springer-Verlag. Source

Diouf A.,University of Sol | Barbier N.,IRD Montpellier | Lykke A.M.,University of Aarhus | Couteron P.,IRD Montpellier | And 6 more authors.
Applied Vegetation Science | Year: 2012

Question: What are the relationships between edaphic factors, fire regime and woody vegetation structure and composition in savannas at landscape to regional scales? Location: The Transboundary 'W' Regional Park, Niger, West Africa. Methods: We focused on a protected savanna ecosystem with rainfall of 700 mm yr -1, where rainfall is not expected to be a strong limiting factor for tree cover, and with historically low grazer and browser densities. A burned area history map was created over 7 yr using the high temporal resolution Aqua MODIS space-borne sensor. In the field, the composition and structural parameters of the woody layer, as well as soil samples, were acquired in 137 plots of 0.09 ha each, based on a stratified random sampling approach to sampling the fire regime (seasonality and frequency). Using classical multivariate methods, we analysed the correlations between woody cover characteristics, fire regime and soil and geomorphological factors. Results: In spite of management practices aimed at generalizing early fire every year, the fire regime created a diverse spatial structure, with some vegetation less prone to burning (fire-free) and other types that burned very frequently. These diverse fire histories showed correlations with gradients of both structure and composition of the woody layer. Soil variables had a higher explanatory power for vegetation structure and composition than fire. Conclusions: Among the plausible causal chains between fire regime, soil factors and woody vegetation structure and composition, our results showed better agreement with a model in which fire regime is more a consequence than a cause of the other factors. This contrasts with bottleneck/perturbation theories as well as management practices, but meets the common sense opinions of field practitioners. Although our regional approach should be complemented by controlled experiments at a local scale, it does appear that investments in annual efforts to organize early fire campaigns in many protected areas may need to be reassessed. Untangling cause-and-effect relationships between fire, soil and savanna vegetation dynamics requires combining scales and disciplines. Here we propose a regional approach in the semi-arid transboundary W Regional Park in Niger, using MODIS derived fire regime maps and an extensive field data set, and evidence a strong apparent sensitivity of the fire regime to substratum and vegetation structure characteristics. © 2012 International Association for Vegetation Science. Source

Shutcha M.N.,University of Lubumbashi | Mubemba M.M.,SOL REPUBLIC | Faucon M.-P.,Free University of Colombia | Luhembwe M.N.,University of Lubumbashi | And 3 more authors.
International Journal of Phytoremediation | Year: 2010

This study evaluates the feasibility of using the grass species Rendlia altera, Monocymbium ceresiiforme, Cynodon dactylon, and amendments (compost and lime) for the phytostabilisation of soils contaminated by Cu in the province of Katanga (Democratic Republic of Congo). Species were grown on control and Cu-contaminated plots (artificially contaminated with 2,500 mg kg-1 Cu) unamended (NA), amended with 4.5 kg compost m-2 or 0.2 kg lime m-2. R. altera was also grown on contaminated plots amended with 22.5 kg compost m-2 or 1 kg lime m-2. Plant survival, growth, and reproduction were monitored for two years. Cu-concentration in leaves of R. altera and M. ceresiiforme were analysed. pH and extractable Cu (0.01 M CaCl2) in soil were analysed in April 2007 and 2008. Results showed that R. altera seems to be the best candidate because of its highest survival on NA, followed by M. ceresiiforme, while liming was necessary to ensure survival of C. dactylon. Lime increased plant reproduction and reduced Cu accumulation in leaves compared to compost. However, higher survival and number of spikes of R. altera obtained in experiment 2 with 22.5 kg compost m-2 suggest that lime x compost interactions should be investigated in further studies. © Taylor & Francis Group, LLC. Source

Edmond Ghanem M.,Catholic University of Louvain | Han R.-M.,Catholic University of Louvain | Classen B.,University of Kiel | Quetin-Leclerq J.,Catholic University of Louvain | And 5 more authors.
Journal of Plant Physiology | Year: 2010

Mucilage is thought to play a role in salinity tolerance in certain halophytic species by regulating water ascent and ion transport. The localization and composition of mucilage in the halophyte Kosteletzkya virginica was therefore investigated. Plants were grown in a hydroponic system in the presence or absence of 100 mM NaCl and regularly harvested for growth parameter assessment and mucilage analysis with the gas liquid chromatography method. NaCl treatment stimulated shoot growth and biomass accumulation, had little effect on shoot and root water content, and reduced leaf water potential (Ψw), osmotic potential (Ψs) as well as stomatal conductance (gs). Mucilage increased in shoot, stems and roots in response to salt stress. Furthermore, changes were also observed in neutral monosaccharide components. Levels of rhamnose and uronic acid increased with salinity. Staining with a 0.5% alcian blue solution revealed the presence of mucopolyssacharides in xylem vessels and salt-induced mucilaginous precipitates on the leaf abaxial surface. Determination of ion concentrations showed that a significant increase of Na+ and a decrease of K+ and Ca2+ simultaneously occurred in tissues and in mucilage under salt stress. Considering the high proportion of rhamnose and uronic acid in stem mucilage, we suggest that the pectic polysaccharide could be involved in Na+ fixation, though only a minor fraction of accumulated sodium appeared to be firmly bound to mucilage. © 2009 Elsevier GmbH. All rights reserved. Source

Discover hidden collaborations