74 research outputs found
The Consequences of Voluntary Information Disclosure on Firm Value: Case of Tunisian listed firms
The aim of this paper is to examine the impact of voluntary information disclosure on firm value for a sample of Tunisian firms listed on the Tunis Stock Exchange between 2005 and 2007. The results of the study have shown that, in the Tunisian context, (1) Voluntary corporate disclosure has an effect on income smoothing since an increased level of voluntary disclosure allows a detection of income smoothing. (2) Voluntary corporate disclosure has an effect on firm value via income smoothing. Actually, the more the Tunisian companies voluntarily disclose information, the less chance will be for managers to smooth earnings since the information needed to detect any income smoothing is held by investors, which entails an amplified firm value. This finding contributes to the relevant literature, particularly in an emerging market context characterized by a scarcity of studies regarding how the marketplace perceives voluntary disclosure. The paper evaluates comprehensively the value relevance of overall voluntary disclosure to the market participants. Finally, this finding might be accepted as a signal to corporations to disclose more information to the stakeholders. Since an increased level of voluntary disclosure will enhance the firm value. Keywords: voluntary disclosure, income smoothing, firm value, emerging market, income
A Typology of Temporal Data Imperfection
International audienceTemporal data may be subject to several types of imperfection (e.g., uncertainty, imprecision..). In this context, several typologies of data imperfections have been already proposed. However, these typologies cannot be applied to temporal data because of the complexity of this type of data and the specificity that it contains. Besides, to the best of our knowledge, there is no typology of temporal data imperfections. In this paper, we propose a typology of temporal data imperfections. Our typology is divided into direct imperfections of both numeric temporal data and natural language based temporal data, indirect imperfections that can be deduced from the direct ones and granularity (i.e., context - dependent temporal data) which is related to several factors that can interfer in specifying the imperfection type such as personâs profile and multiculturalism. We finish by representing an example of imprecise temporal data in PersonLink ontology
Knowledge Management and Total Quality Management Impact on Employee Effectiveness in Emerging Industries: Case of Tunisian Small and Medium Enterprises
Employee effectiveness is highly important for all economic activities. Several factors
can affect its degree, either positively or negatively. In this vein, this work aims to examine the
impact of knowledge management and total quality management on employee effectiveness in the
industry of emerging countries. For that, Tunisian small and medium enterprises were taken as
an example. The proposed methodology consists first of providing a research model linking the
correlation between knowledge management elements, total quality management practices, and
employee effectiveness. Then, a survey was designed and broadcast to more than 3000 Tunisian small
and medium enterprises. Hence, 206 responses were collected from several industrial fields, and
collected data analysis was achieved by SPSS software. For testing research hypotheses, multiple
regression analysis, factor analysis, and structural equation modeling were employed. The finding
points out that total quality management and knowledge management have a positive impact on
staff effectiveness. This impact is highlighted through the roles of knowledge management elements
and total quality management practices on human resources behavior and their ability enhancement.
Consequently, a significant increase in productivity can be seen in the operational processes of the
company. This work is one of the first studies to research total quality management and knowledge
management impact on staff effectiveness in Tunisian small and medium enterprises. Besides, it
reflects the maturity and the awareness of respondent companiesâ managers to the practice of these
concepts in emerging economies.info:eu-repo/semantics/publishedVersio
Oxidative Stress and Cardiovascular Diseases: The Role of Mitochondria
The redox status is determined by the balance between the production of reactive oxygen species (ROS) and their removal by the antioxidant defense system. Mitochondria, the center of oxidative metabolism and the principal site of ROS production, are crucial in health and also in the pathogenesis of many diseases. Mitochondrial dysfunction, resulting in a vicious cycle contributing to cellular damage and consequent cell death, has been proven to play a critical role in the pathogenesis of cardiovascular diseases. Previous studies have shown that mitochondrial transfer in cells plays a crucial role in regulating cardiovascular system development and maintaining normal tissue homeostasis. We review and evaluate in this chapter the evidence for mitochondrial dysfunction as a consequence of stress exposure and a contributing factor to cardiovascular diseases
Representing Imprecise Time Intervals in OWL 2
International audienceRepresenting and reasoning on imprecise temporal information is a common requirement in the field of Semantic Web. Many works exist to represent and reason on precise temporal information in OWL; however, to the best of our knowledge, none of these works is devoted to imprecise temporal time intervals. To address this problem, we propose two approaches: a crisp-based approach and a fuzzy-based approach. (1) The first approach uses only crisp standards and tools and is modelled in OWL 2. We extend the 4D-fluents model, with new crisp components, to represent imprecise time intervals and qualitative crisp interval relations. Then, we extend the Allenâs interval algebra to compare imprecise time intervals in a crisp way and inferences are done via a set of SWRL rules. (2) The second approach is based on fuzzy sets theory and fuzzy tools and is modelled in Fuzzy-OWL 2. The 4D-fluents approach is extended, with new fuzzy components, in order to represent imprecise time intervals and qualitative fuzzy interval relations. The Allenâs interval algebra is extended in order to compare imprecise time intervals in a fuzzy gradual personalized way. Inferences are done via a set of Mamdani IF-THEN rules
Comparative Analysis of WRKY Genes Potentially Involved in Salt Stress Responses in Triticum turgidum L. ssp. durum
WRKY transcription factors are involved in multiple aspects of plant growth, development and responses to biotic stresses. Although they have been found to play roles in regulating plant responses to environmental stresses, these roles still need to be explored, especially those pertaining to crops. Durum wheat is the second most widely produced cereal in the world. Complex, large and unsequenced genomes, in addition to a lack of genomic resources, hinder the molecular characterization of tolerance mechanisms. This paper describes the isolation and characterization of five TdWRKY genes from durum wheat(TriticumturgidumL.ssp.durum).APCR-based screening of aT.turgidum BAC genomic library using primers within the conserved region of WRKY genes resulted in the isolation of five BAC clones. Following sequencing fully the five BACs, fine annotation through Triannot pipeline revealed 74.6% of the entire sequences as transposable elements and a 3.2% gene content with genes organized as islands with in oceans of TEs. Each BAC clone harbored a TdWRKY gene .The study showed a very extensive conservation of genomic structure between TdWRKYs and their orthologs from Brachypodium, barley, and T. aestivum. The structural features of TdWRKY proteins suggested that they are novel members of the WRKY family in durum wheat. TdWRKY1/2/4 , TdWRKY3, and TdWRKY5 belong to the group Ia, IIa, andIIc, respectively. Enrichmentofcis- regulatory elements related to stress responses in the promoters of some TdWRKY genes indicated their potential roles inmediating plant responses to a wide variety of environmental stresses. TdWRKY genes displayed different expression patterns in response to salt stress that distinguishes two durum wheat genotypes with contrasting salt stress tolerance phenotypes. TdWRKY genes tended to react earlier with a down-regulation in sensitive genotype leaves and with an up-regulation intolerant genotype leaves. The TdWRKY transcripts levels in roots increased intolerant genotype compared to sensitive genotype. The present results indicate that these genes might play some functional role in the salt tolerance in durum wheat
TdERF1, an ethylene response factor associated with dehydration responses in durum wheat (Triticum turgidum L. subsp. durum)
Water deficit and increasing salinization reduce productivity of wheat, the leading crop for human diet. While the complete genome sequence of this crop has not been deciphered, a BAC library screening allowed the isolation of TdERF1, the first ethylene response factor gene from durum wheat. This gene is putatively involved in mediating salt stress tolerance and its characterization provides clues towards understanding the mechanisms underlyning the adaptation/tolerance of durum wheat to suboptimal growth conditions. TdERF1 expression is differentially induced by high salt treatment in two durum wheat varieties, the salt-tolerant Grecale (GR) and the salt-sensitive Om Rabiaa (OR). To further extend these findings, we show here that the expression of this ERF is correlated with physiological parameters, such as the accumulation of osmo-regulators and membrane integrity, that discriminate between the two contrasted wheat genotypes. The data confirm that GR and OR are two contrasted wheat genotypes with regard to salt-stress and show that TdERF1 is also induced by water stress with an expression pattern clearly discriminating between the twogenotypes. These findings suggest that TdERF1 might be involved in responses to salt and water stress providing a potential genetic marker discriminating between tolerant and sensitive wheat varieties
Panniculite au cours dâun traitement dâune dermatomyosite par du mĂ©thotrexate
La panniculite est une manifestation rare au cours des dermatomyosites (DM). Lâapparition dâune panniculite au cours dâun traitement par du mĂ©thotrexate (MTX) est exceptionnelle et nâa Ă©tĂ© dĂ©crite que dans 3 cas. Nous rapportons lâobservation dâune patiente ĂągĂ©e de 50 ans atteinte dâune DM diagnostiquĂ©e en 1997 et traitĂ©e par une corticothĂ©rapie avec une Ă©volution favorable aux plans clinique et biologique. A lâoccasion dâune rechute 2 ans plus tard, la corticothĂ©rapie a Ă©tĂ© majorĂ©e et du mĂ©thotrexate Ă une dose hebdomadaire de 7,5 mg a Ă©tĂ© rajoutĂ©. LâĂ©volution Ă©tait rapidement favorable. Dix huit mois plus tard, la patiente prĂ©sentait de multiples nodules sous cutanĂ©s siĂ©geant aux 4 membres et aux fesses, dont lâexamen anatomopthologique concluait Ă une panniculite. Il nâexistait aucun signe dâĂ©volutivitĂ© de la DM. La dose de prĂ©dnisone a Ă©tĂ© augmentĂ©e Ă 0,5 mg/kg/j toujours en association au MTX mais sans aucune amĂ©lioration. Le MTX a Ă©tĂ© arrĂȘtĂ© et les lĂ©sions cutanĂ©es ont complĂštement disparu en 2 mois sans aucune rĂ©cidive avec un recul actuel de 42 mois. Notre observation est particuliĂšre par la survenue dâune panniculite chez une patiente ayant une DM traitĂ©e par du MTX et illustre la difficultĂ© diagnostique. Cette entitĂ© doit ĂȘtre connue malgrĂ© son caractĂšre exceptionnel puisque lâarrĂȘt du MTX induit en gĂ©nĂ©ral la disparition des nodules sous cutanĂ©s.Pan African Medical Journal 2016; 2
Influence of treatments on the dielectric properties of sugar palm fiber reinforced phenolic composites
The dielectric properties of sugar palm fiber (SPF) reinforced-phenolic (PF) composites have been studied in terms of bonding between fiber and matrix. The paper aims to investigate the effect of alkaline treatment and sea water treatment on SPF composite using the dielectric relaxation spectroscopy in the frequency range from 0.1âŻHz to 0.1âŻMHz and temperature range from 80âŻÂ°C to 200âŻÂ°C. The results were discussed in terms of dynamic molecular and interfacial process. Our analysis suggests that interfacial adhesion in the case of alkaline treated composite is higher than those of untreated and sea water treated composites
Smart graphical dialogue, based on an ontology, for a memory prosthesis
Dans le cadre de cette thĂšse, nous proposons une prothĂšse de mĂ©moire « intelligente », appelĂ©e CAPTAIN MEMO, destinĂ©e aux malades dâAlzheimer, pour pallier leurs problĂšmes mnĂ©siques. Cette prothĂšse est basĂ©e sur lâontologie temporelle, floue et multilingue appelĂ©e MemoFuzzyOnto.Cette prothĂšse offre des interfaces accessibles Ă cette classe particuliĂšre dâutilisateurs. Nous proposons, pour mettre en Ćuvre ces interfaces, une mĂ©thodologie de conception appelĂ©e InterfaceToAlz pour concevoir des interfaces accessibles aux malades dâAlzheimer, et qui offre un guide de 146 bonnes pratiques ergonomiques. De plus, nous proposons un outil de visualisation dâontologies appelĂ© Memo Graph qui gĂ©nĂšre un graphe dont la visualisation et la manipulation sont accessibles aux malades dâAlzheimer. Cette proposition est motivĂ©e par le fait que CAPTAIN MEMO a besoin de gĂ©nĂ©rer et dâĂ©diter le graphe de la famille et de lâentourage du patient, Ă partir de lâontologie MemoFuzzyOnto qui structure sa base de connaissances. Memo Graph est fondĂ© sur notre guide de bonnes pratiques ergonomiques et notre approche, appelĂ©e Incremental Key-Instances Extraction and Visualisation, qui permet une extraction et une visualisation incrĂ©mentale du rĂ©sumĂ© des assertions ABox de lâontologie. Il supporte Ă©galement la visualisation des donnĂ©es ouvertes liĂ©es (Linked Data) et le passage Ă lâĂ©chelle. Par ailleurs, nous proposons, dans le cadre de cette thĂšse, une typologie de lâimperfection des donnĂ©es saisies (principalement due Ă la discordance mnĂ©sique provoquĂ©e par la maladie), et une mĂ©thodologie pour permettre Ă CAPTAIN MEMO dâĂȘtre tolĂ©rante Ă la saisie des donnĂ©es fausses. Nous proposons un modĂšle dâĂ©valuation de la crĂ©dibilitĂ© et une approche, nommĂ©e Data Believability Estimation for Applications to Alzheimer Patients, permettant dâestimer qualitativement et quantitativement la crĂ©dibilitĂ© de chaque donnĂ©e saisie. Enfin, pour que CAPTAIN MEMO soit tolĂ©rante Ă la saisie des intervalles temporels imprĂ©cis nous proposons deux approches : lâune basĂ©e sur un environnement prĂ©cis et lâautre basĂ©e sur un environnement flou. Dans chacune des deux approches, nous Ă©tendons lâapproche 4D-fluents pour reprĂ©senter les intervalles temporels imprĂ©cis et les relations temporelles qualitatives, puis nous Ă©tendons lâalgĂšbre dâAllen pour prendre en compte les intervalles imprĂ©cis dans le cadre de notre ontologie MemoFuzzyOnto. Nos contributions sont implĂ©mentĂ©es et Ă©valuĂ©es. Nous avons Ă©valuĂ© lâaccessibilitĂ© de ses interfaces utilisateurs, le service de CAPTAIN MEMO qui a pour but de stimuler la mĂ©moire du patient, notre approche pour lâestimation quantitative de la crĂ©dibilitĂ© des donnĂ©es saisies ainsi que la visualisation du graphe gĂ©nĂ©rĂ©e Ă lâaide de Memo Graph. Nous avons Ă©galement Ă©valuĂ© la performance de Memo Graph et son utilisabilitĂ© par des experts du domaine.In the context of this thesis, we propose a âsmartâ memory prosthesis, called CAPTAIN MEMO, to help Alzheimerâs disease patients to palliate mnesic problems. It is based on a temporal, fuzzy and multilingual ontology named MemoFuzzyOnto. It provides accessible user interfaces to this demographic. To design these interfaces, we propose a methodology named InterfaceToAlz which serves as an information base for guiding and evaluating the design of user interfaces for Alzheimerâs disease patients. It identifies 146 design guidelines.Besides, we propose an ontology visualization tool called Memo Graph which offers an accessible and understandable visualization to Alzheimerâs disease patients. In fact, in the context of CAPTAIN MEMO, there is a need to generate the patient entourage/family tree from its personal data structured according to MemoFuzzyOnto. Memo Graph is based on our design guidelines and our approach, named Incremental Key-Instances Extraction and Visualisation, to extract and visualize descriptive instance summarizations from a given ontology and generate âsummary instance graphsâ from the most important data. It supports Linked Data visualization and scaling.Furthermore, we propose a typology of the imperfection of the data entered (mainly due to the memory discordance caused by this disease), and a methodology to allow false data entry. We propose a believability model and an approach called Data Believability Estimation for Applications to Alzheimer Patients to estimate qualitatively and quantitatively the believability of each data entered. Finally, CAPTAIN MEMO allows imprecise time intervals entry. We propose two approaches: a crisp-based approach and a fuzzy-based approach. The first one uses only crisp standards and tools and is modeled in OWL 2. The second approach is based on fuzzy sets theory and fuzzy tools and is modeled in Fuzzy-OWL 2. For the two approaches, we extend the 4D-fluents model to represent imprecise time intervals and qualitative interval relations. Then, we extend the Allenâs interval algebra to compare imprecise time interval in the context of MemoFuzzyOnto. Our contributions are implemented and evaluated. We evaluated the service of CAPTAIN MEMO which has the aim to stimulate the patientâs memory, the accessibility of its user interfaces, the efficiency of our approach to estimate quantitatively the believability of each data entered and the visualization generated with Memo Graph. We also evaluated Memo Graph with domain expert users
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