34 research outputs found
THREE ESSAYS ON INTERNATIONAL ASSET PRICING
No full textThe common thread running through my research is to explore the asset price dynamics across countries and across asset classes. In the first chapter of this thesis, I apply Newton's law of universal gravitation to investigate the determinants of the bilateral relationships in returns. Examining the gravity effect in a large set of countries, I find that the size of economies and geographical distance are significant determinants of the contemporaneous as well as the lead-lag correlation patterns observed in stock returns across countries. In addition, decomposing stock market returns into cash-flow and discount-rate news shows that the international transmission of country specific news is more pronounced through discount-rate news, and that the size of economies and geographical distance are significant determinants for both components of returns.
In the second chapter, based on a joint work with Redouane Elkamhi and Mikhail Simutin, we propose a diversification approach that exploits the global connectedness of developed countries to gain exposure to emerging countries' overall economies rather than their shallow equity markets. In doing so, we demonstrate that developed markets still offer substantial diversification benefits beyond those available through equity indices, contrary to a large body of literature claiming that the benefits of international diversification via developed markets have dramatically declined. Our results also suggest that relying on equity indices to assess diversification benefits understates diversification gains.
The third chapter explores the potential risk of investing in global markets. Specifically, my co-author Redouane Elkamhi and I study the two widely-known speculation strategies in the FX market, carry and momentum trades, and provide a risk-based explanation for the excess returns. We construct a common factor that drives correlation across international equity markets and show that the cross-sectional variations in the average excess returns across carry and momentum portfolios can be explained by different sensitivities to our correlation factor. By using a factor constructed from the equity market to explain abnormal return in the FX market, these findings shed light on the important linkage across the two markets through equity correlations as a main instrument of the aggregate risk.Ph.D
THREE ESSAYS ON INTERNATIONAL ASSET PRICING
No full textThe common thread running through my research is to explore the asset price dynamics across countries and across asset classes. In the first chapter of this thesis, I apply Newton's law of universal gravitation to investigate the determinants of the bilateral relationships in returns. Examining the gravity effect in a large set of countries, I find that the size of economies and geographical distance are significant determinants of the contemporaneous as well as the lead-lag correlation patterns observed in stock returns across countries. In addition, decomposing stock market returns into cash-flow and discount-rate news shows that the international transmission of country specific news is more pronounced through discount-rate news, and that the size of economies and geographical distance are significant determinants for both components of returns.
In the second chapter, based on a joint work with Redouane Elkamhi and Mikhail Simutin, we propose a diversification approach that exploits the global connectedness of developed countries to gain exposure to emerging countries' overall economies rather than their shallow equity markets. In doing so, we demonstrate that developed markets still offer substantial diversification benefits beyond those available through equity indices, contrary to a large body of literature claiming that the benefits of international diversification via developed markets have dramatically declined. Our results also suggest that relying on equity indices to assess diversification benefits understates diversification gains.
The third chapter explores the potential risk of investing in global markets. Specifically, my co-author Redouane Elkamhi and I study the two widely-known speculation strategies in the FX market, carry and momentum trades, and provide a risk-based explanation for the excess returns. We construct a common factor that drives correlation across international equity markets and show that the cross-sectional variations in the average excess returns across carry and momentum portfolios can be explained by different sensitivities to our correlation factor. By using a factor constructed from the equity market to explain abnormal return in the FX market, these findings shed light on the important linkage across the two markets through equity correlations as a main instrument of the aggregate risk.Ph.D
Évaluation de la qualité de vie des transplantés cardiaques par questionnaires standardisés : étapes préliminaires à leur intégration dans un registre national français de greffe d'organes
No full textHeart transplantation (HTx) remains the gold standard treatment for end-stage heart failure when all other options have been exhausted. Although HTx survival has dramatically improved, with a median survival of 12 years, these advances have underscored the importance of addressing long-term outcomes and quality of life (QoL) for recipients. The 2022-2026 ministerial transplant plan recommends that the Agence de la biomedicine implement post-transplant QoL measurement tools and develop QoL surveys for patients.These Patient-Reported Outcome Measures (PROMs) will complement the objective clinical data already available in the national transplant registry (CRISTAL)The objective of the thesis is therefore to evaluate the prerequisites and conditions for implementing systematic health-related quality of life (HRQoL) follow-up in a registry of heart transplant recipients.Initially, we conducted a thorough and comprehensive inventory of all currently available instruments used to measure QoL in HTx recipients. These tools demonstrate significant diversity in the number of items, assessed domains, scale types, and psychometric properties. We identified 19 generic instruments, 71 domain-specific instruments, 9 heart disease-specific tools, and 16 instruments specifically designed for immunosuppressant treatment or HTx. Despite the many tools available, there is no consensus on the most appropriate tool to use. Some have yet to be validated in this population group and in the French language.In a second step, to help select appropriate questionnaires, a qualitative study using semi-structured interviews was conducted with 14 recipients to complement the quantitative data from the literature review. This approach enabled an in-depth exploration of HTx recipients' lived experiences and identified key dimensions affecting their QoL. Fatigue, anxiety, and depression, as well as immunosuppressive medication side effects, were found to have a significant impact. In addition, social support, coping strategies, and autonomy proved to be important elements to consider.Third, we asked patients about their opinions on QoL questionnaires, focusing on administration and usage modalities, particularly length, data collection frequency, and questionnaire content. A sample of 34 HTx patients was then randomly assigned to three groups, each receiving a different mode of questionnaire access: email, tablet, or QR code. Our results showed that patients preferred brief questionnaires, administered annually, and completed at their annual transplant clinic appointments. No significant preference was observed between the three tested administration methods.Finally, based on our findings, we established recommendations for implementing a QoL assessment tool within the national CRISTAL registry.A key limitation of existing QoL questionnaires is their focus on specific dimensions, potentially overlooking the full spectrum of HTx recipients' QoL. It is recommended to regularly administer a generic questionnaire along with a specific questionnaire that alternately targets an important and specific aspect of heart transplantation. Although more complex to implement, this strategy allows for capturing both the general and specific aspects of the experience of heart transplant patients.La greffe cardiaque reste le traitement de dernier recours en cas de défaillance terminale du coeur. L'amélioration significative des taux de survie au cours des dernières décennies (survie médiane de 12 ans) a apporté de nouveaux défis en termes de résultats à long terme et de qualité de vie (Qdv) des patients greffés. Le plan ministériel 2022-2026 portant sur la greffe recommande à l’Agence de la biomédecine de mettre en place des outils de mesure de la Qdv post-greffe et de développer des enquêtes sur la Qdv auprès des patients. Ces mesures de résultats rapportés par les patients (PROMs) viendront compléter les données cliniques objectives déjà disponibles dans le registre national de transplantation (CRISTAL). L’objectif de la thèse est donc d’évaluer les prérequis et les conditions de mise en place d’un suivi systématique de la qualité de vie liée à la santé (QVLS) dans un registre de patients ayant reçu une greffe cardiaque.Dans un premier temps, nous avons réalisé un inventaire de tous les instruments actuellement disponibles et utilisés pour mesurer la Qdv chez les transplantés cardiaques. Ces outils présentent une grande diversité en termes de nombre d’items, de domaines évalués, de types d’échelles utilisés et de propriétés psychométriques. Nous avons identifié 19 instruments génériques, 71 instruments spécifiques à un domaine, 9 outils spécifiques aux maladies cardiaques et 16 instruments spécifiquement conçus pour le traitement immunosuppresseur ou la transplantation cardiaque. Malgré les nombreux outils disponibles, il n'existe aucun consensus sur le choix de l'outil le plus approprié. Certains doivent encore être validés dans cette catégorie de population et en langue française.Dans un deuxième temps, nous avons complété les données quantitatives issues de la revue de littérature par une étude qualitative basée sur des entretiens semi-directifs auprès de 14 patients, visant à explorer en profondeur l’expérience vécue par les transplantés cardiaques et à identifier les dimensions clés contribuant à leur Qdv.La fatigue, l’anxiété et la dépression, ainsi que les effets secondaires des médicaments immunosuppresseurs, semblent avoir un impact important. De plus, le soutien social, les stratégies d'adaptation et l'autonomie se révèlent être des éléments importants à prendre en compte.Dans un troisième temps, nous avons également interrogé les patients afin de connaître leurs opinions sur ces questionnaires, en nous concentrant sur leurs modalités d’administration et d’utilisation, notamment leur longueur, la fréquence de collecte des données et le contenu des questionnaires. Ensuite, un échantillon de 34 de patients transplantés cardiaques a été répartie aléatoirement en trois groupes, chacun recevant un mode d’accès différent aux questionnaires : par e-mail, sur tablette ou via un QR code. Aucune préférence significative n'a été observée entre les trois modes d'administration testés. Nos résultats ont montré que les patients préféraient un questionnaire court, administré annuellement dans un cadre hospitalier.Finalement, nous avons élaboré un ensemble de recommandations visant à faciliter l'intégration d’un outil de recueil de la Qdv au sein du registre national CRISTAL.Des défis spécifiques seront à relever, notamment en raison des contraintes propres à ce cadre, telles que la charge administrative supplémentaire, la compatibilité des outils avec les pratiques existantes et l’interprétation des données recueillies. Il est préconisé d’administrer à la fois un questionnaire générique de façon régulière et un questionnaire spécifique, ciblant à tour de rôle, un élément important et spécifique à la transplantation cardiaque. Bien que plus complexe à mettre en oeuvre, cette stratégie permet de saisir à la fois les aspects généraux et spécifiques de l’expérience des patients transplantés cardiaques
Quality of Life Assessment in Heart Transplant Recipients Using Standardized Questionnaires : Preliminary Steps for Integration into a French National Transplant Registry
No full textLa greffe cardiaque reste le traitement de dernier recours en cas de défaillance terminale du coeur. L'amélioration significative des taux de survie au cours des dernières décennies (survie médiane de 12 ans) a apporté de nouveaux défis en termes de résultats à long terme et de qualité de vie (Qdv) des patients greffés. Le plan ministériel 2022-2026 portant sur la greffe recommande à l’Agence de la biomédecine de mettre en place des outils de mesure de la Qdv post-greffe et de développer des enquêtes sur la Qdv auprès des patients. Ces mesures de résultats rapportés par les patients (PROMs) viendront compléter les données cliniques objectives déjà disponibles dans le registre national de transplantation (CRISTAL). L’objectif de la thèse est donc d’évaluer les prérequis et les conditions de mise en place d’un suivi systématique de la qualité de vie liée à la santé (QVLS) dans un registre de patients ayant reçu une greffe cardiaque.Dans un premier temps, nous avons réalisé un inventaire de tous les instruments actuellement disponibles et utilisés pour mesurer la Qdv chez les transplantés cardiaques. Ces outils présentent une grande diversité en termes de nombre d’items, de domaines évalués, de types d’échelles utilisés et de propriétés psychométriques. Nous avons identifié 19 instruments génériques, 71 instruments spécifiques à un domaine, 9 outils spécifiques aux maladies cardiaques et 16 instruments spécifiquement conçus pour le traitement immunosuppresseur ou la transplantation cardiaque. Malgré les nombreux outils disponibles, il n'existe aucun consensus sur le choix de l'outil le plus approprié. Certains doivent encore être validés dans cette catégorie de population et en langue française.Dans un deuxième temps, nous avons complété les données quantitatives issues de la revue de littérature par une étude qualitative basée sur des entretiens semi-directifs auprès de 14 patients, visant à explorer en profondeur l’expérience vécue par les transplantés cardiaques et à identifier les dimensions clés contribuant à leur Qdv.La fatigue, l’anxiété et la dépression, ainsi que les effets secondaires des médicaments immunosuppresseurs, semblent avoir un impact important. De plus, le soutien social, les stratégies d'adaptation et l'autonomie se révèlent être des éléments importants à prendre en compte.Dans un troisième temps, nous avons également interrogé les patients afin de connaître leurs opinions sur ces questionnaires, en nous concentrant sur leurs modalités d’administration et d’utilisation, notamment leur longueur, la fréquence de collecte des données et le contenu des questionnaires. Ensuite, un échantillon de 34 de patients transplantés cardiaques a été répartie aléatoirement en trois groupes, chacun recevant un mode d’accès différent aux questionnaires : par e-mail, sur tablette ou via un QR code. Aucune préférence significative n'a été observée entre les trois modes d'administration testés. Nos résultats ont montré que les patients préféraient un questionnaire court, administré annuellement dans un cadre hospitalier.Finalement, nous avons élaboré un ensemble de recommandations visant à faciliter l'intégration d’un outil de recueil de la Qdv au sein du registre national CRISTAL.Des défis spécifiques seront à relever, notamment en raison des contraintes propres à ce cadre, telles que la charge administrative supplémentaire, la compatibilité des outils avec les pratiques existantes et l’interprétation des données recueillies. Il est préconisé d’administrer à la fois un questionnaire générique de façon régulière et un questionnaire spécifique, ciblant à tour de rôle, un élément important et spécifique à la transplantation cardiaque. Bien que plus complexe à mettre en oeuvre, cette stratégie permet de saisir à la fois les aspects généraux et spécifiques de l’expérience des patients transplantés cardiaques.Heart transplantation (HTx) remains the gold standard treatment for end-stage heart failure when all other options have been exhausted. Although HTx survival has dramatically improved, with a median survival of 12 years, these advances have underscored the importance of addressing long-term outcomes and quality of life (QoL) for recipients. The 2022-2026 ministerial transplant plan recommends that the Agence de la biomedicine implement post-transplant QoL measurement tools and develop QoL surveys for patients.These Patient-Reported Outcome Measures (PROMs) will complement the objective clinical data already available in the national transplant registry (CRISTAL)The objective of the thesis is therefore to evaluate the prerequisites and conditions for implementing systematic health-related quality of life (HRQoL) follow-up in a registry of heart transplant recipients.Initially, we conducted a thorough and comprehensive inventory of all currently available instruments used to measure QoL in HTx recipients. These tools demonstrate significant diversity in the number of items, assessed domains, scale types, and psychometric properties. We identified 19 generic instruments, 71 domain-specific instruments, 9 heart disease-specific tools, and 16 instruments specifically designed for immunosuppressant treatment or HTx. Despite the many tools available, there is no consensus on the most appropriate tool to use. Some have yet to be validated in this population group and in the French language.In a second step, to help select appropriate questionnaires, a qualitative study using semi-structured interviews was conducted with 14 recipients to complement the quantitative data from the literature review. This approach enabled an in-depth exploration of HTx recipients' lived experiences and identified key dimensions affecting their QoL. Fatigue, anxiety, and depression, as well as immunosuppressive medication side effects, were found to have a significant impact. In addition, social support, coping strategies, and autonomy proved to be important elements to consider.Third, we asked patients about their opinions on QoL questionnaires, focusing on administration and usage modalities, particularly length, data collection frequency, and questionnaire content. A sample of 34 HTx patients was then randomly assigned to three groups, each receiving a different mode of questionnaire access: email, tablet, or QR code. Our results showed that patients preferred brief questionnaires, administered annually, and completed at their annual transplant clinic appointments. No significant preference was observed between the three tested administration methods.Finally, based on our findings, we established recommendations for implementing a QoL assessment tool within the national CRISTAL registry.A key limitation of existing QoL questionnaires is their focus on specific dimensions, potentially overlooking the full spectrum of HTx recipients' QoL. It is recommended to regularly administer a generic questionnaire along with a specific questionnaire that alternately targets an important and specific aspect of heart transplantation. Although more complex to implement, this strategy allows for capturing both the general and specific aspects of the experience of heart transplant patients
Corrigendum to: Enhanced Long-term Stability and Carbon Resistance of Ni/MnxOy-Al2O3 Catalyst in Near-equilibrium CO2 Reforming of Methane for Syngas Production [15(2), 2020, 331-347]
No full textAccording to Authors request (10th December 2020), Corrigendum to: Djebarri, B., Touahra, F., Aider, N., Bali, F., Sehailia, M., Chebout, R., Bachari, K., Halliche, D. (2020). Bulletin of Chemical Reaction Engineering & Catalysis, 15(2), 2020, 331-347 (doi:10.9767/bcrec.15.2.6983.331-347). First Author (Baya Djebarri) is added as member of Corresponding Author because of his largest contribution in the article and his expertise.
Correction:
The Authors Names were corrected to:
Baya Djebarri1,*, Fouzia Touahra2,*, Nadia Aider4, Ferroudja Bali3, Moussa Sehailia2, Redouane Chebout2, Khaldoun Bachari2, Djamila Halliche3
The information detail of Corresponding Authors was corrected to:
* Corresponding Authors.
Email: [email protected] (F. Touahra); [email protected] (B. Djebarri)
Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Temps et fonctionnement textuel chez Rachid Mimouni
No full textTime and Textual Functioning at Rachid Mimouni
The temporal dimension is a variable as important as space, and it is far from lacking in interest in the work of Rachid Mimouni. In fact, the issue of time considered as a structuring factor of the event representations which punctuate the story (1) is at the very heart of his romantic enterprise. To show how temporality exercises a locating and regulating function in the Mimounian text, we distinguish four temporal aspects to which the author focuses in his writing universe: romantic time, lived time, historical time and social time
Predicting Remaining Useful Life of Engines Using SVR and CNN
No full text43p.Engines’ Remaining Useful Life (RUL) prediction is a considerable issue to
realize Prognostics and Health Management (PHM) that is being widely applied in many
industrial systems to ensure high system availability over their life cycles. This work
presents a data-driven method of RUL prediction based on two Machine Learning (ML)
techniques, mainly Support Vector Machine (SVM) for Regression or Support Vector
Regression (SVR) and Convolutional Neural Network (CNN). These techniques are
applied on the NASA C-MAPSS turbofan engine dataset. To extract the input features,
the dataset was analyzed with the help of plots and a filter-based feature selection
technique known as Mutual Information (MI). the resulting features are then fed to both
models. Although SVM and CNN algorithms are mostly used in classification problems,
their effectiveness in estimating the RUL, which is a regression problem, is demonstrated
and compared to some state-of-the-art methods. The results show that the SVR and CNN
models provide approximately similar performance in predicting the RUL for the used
dataset.Université M’hamed Bougara de Boumerdes : Institut de Genie Electrique et Electroniqu
A novel high power factor PWM rectifier with push-pull control for harmonic reduction in industrial areas networks of smart grid
No full text
