Monetary information arrivals and intraday exchange rate volatility : a comparison of the GARCH and the EGARCH models

In this article, we examine the intradaily Euro-dollar exchange rate volatility persistence result from the dissymmetric impact of monetary policy signals stemming from the ECB Council and the FOMC. A model is constructed by extending the AR(1)-GARCH (1,1) to an exponential process EGARCH (1,1), using high-frequency data (five minutes frequency) which integrates a polynomials structure depending on signal variables, starting from the deseasonalized exchange rate returns series. It is found that, unlike the equity market, the best volatility predictions are derived from the EGARCH(1,1) process.Exchange rate, official intervention, monetary policy, GARCH models.

Monetary information arrivals and intraday exchange rate volatility : a comparison of the GARCH and the EGARCH models

URL des Documents de travail :http://ces.univ-paris1.fr/cesdp/CESFramDP2007.htmDocuments de travail du Centre d'Economie de la Sorbonne 2007.35 - ISSN : 1955-611XIn this article, we examine the intradaily Euro-dollar exchange rate volatility persistence result from the dissymmetric impact of monetary policy signals stemming from the ECB Council and the FOMC. A model is constructed by extending the AR(1)-GARCH (1,1) to an exponential process EGARCH (1,1), using high-frequency data (five minutes frequency) which integrates a polynomials structure depending on signal variables, starting from the deseasonalized exchange rate returns series. It is found that, unlike the equity market, the best volatility predictions are derived from the EGARCH(1,1) process.Dans cet article, nous examinons la persistance de la volatilité intra-journalière du taux de charge euro-dollar résultant de l'impact dissymétrique des signaux de politique monétaire issus des réunions du Conseil de la BCE et du FOMC. Pour ce faire, et à partir de la série désaisonnalisée de rendements du taux de change utilisant des données à haute fréquence (fréquence de cinq minutes), nous développons le modèle AR(1)-GARCH (1.1) en un processus exponentiel EGARCH (1.1) qui incorpore une structure polynomiale, elle même fonction des variables de signal. Les résultats montrent que, malgré l'efficience des marchés, les meilleures prévisions de volatilité sont dérivées du processus EGARCH(1,1)

Kupershmidt operators on Hom-Malcev algebras and their deformation

The main feature of Hom-algebras is that the identities defining the structures are twisted by linear maps. The purpose of this paper is to introduce and study a Hom-type generalization of pre-Malcev algebras, called Hom-pre-Malcev algebras. We also introduce the notion of Kupershmidt operators of Hom-Malcev and Hom-pre-Malcev algebras and show the connections between Hom-Malcev and Hom-pre-Malcev algebras using Kupershmidt operators. Hom-pre-Malcev algebras generalize Hom-pre-Lie algebras to the Hom-alternative setting and fit into a bigger framework with a close relationship with Hom-pre-alternative algebras. Finally, we establish a deformation theory of Kupershmidt operators on a Hom-Malcev algebra in consistence with the general principles of deformation theories and introduce the notion of Nijenhuis elements.Comment: arXiv admin note: substantial text overlap with arXiv:2105.00606; text overlap with arXiv:1803.09287 by other author

An unusual etiology of posttraumatic Collet–Sicard Syndrome: a case report

Posttraumatic Unilateral paralysis of the last four cranial nerves (IX-XI), known as collet-Sicard syndrome, is rare following closed head injury. A 21-year-old man presented with slurred speech, hoarseness voice and difficulty swallowing his saliva following closed head trauma. The cranial nerve examination revealed left sided severe dysfunction of cranial nerves VII, IX, X, XI, and XII.A CT-Scan of the neck was performed demonstrating a fracture of the left styloid process at the base of the skull.The Magnetic Resonance Imaging showed unusually well seen lower cranial nerves due to nerve edema. The patient was managed conservatively with steroids and regular sessions of neuromuscular and orthophonic rehabilitation.The nutrition had to be administered by gastrostomy since he was unable to swallow.Six months after the injury a total neurological recovery was noted.We present the exceptional case of Collet-Sicard Syndrome caused by styloid process fracture.Pan African Medical Journal 2016; 2

The Causal Links between Economic Growth, Renewable Energy, Financial Development and Foreign Trade in Gulf Cooperation Council Countries

This paper examines the causal relationship between renewable energy consumption, real GDP, trade and financial development for the GCC countries during the period 1980-2012. Compared to the previous studies, our models are extended by including the financial development as macroeconomic factor. The results indicate bidirectional causality in both short and long-run between output and exports. While, there is no evidence of causality in the short-run between output and renewable energy consumption or private sector credit and between exports and renewable energy consumption or private sector credit. Moreover, the long-run estimated results indicate that there is evidence of a statistically significant impact of renewable energy consumption, exports and private sector credit on output. Our finding indicates that renewable energy use and exports are able to increase the economic growth for the GCC countries. Nevertheless, we find negative impact of the financial development on economic growth related to the deflationary monetary policy of the considered countries. Keywords: Granger Causality, Panel Cointegration, Renewable Energy Consumption, Economic Growth, Financial Development; Trade; GCC Countries JEL Classifications: C33; O24; Q4

Carcinome adenoide kystique sous-glottique

Introduction: Laryngeal adenoid cystic carcinoma (ACC) is unusual. It accounts for 0.25% of all malignant tumors in the larynx, and only about 120 cases have been reported in the literature until now.Purpose: We report a case of subglottic ACC and examine the clinical, diagnostic, histological and therapeutic features and the outcome of this tumor in this location.Case report: A 75-year-old man, presented with a laryngeal dyspnea. The computed tomography of the larynx showed a posterior subglottic tumor. The panendoscopy revealed a large nonulcerated submucosal tumor in the posterior wall of the subglottic area. Biopsies made the diagnosis of laryngeal ACC. The patient had total laryngectomy with total thyroidectomyand bilateral lateral neck dissection. Histological examination didn't find neck metastases. The surgery was followed by a postoperative radiotherapy. There were no local recurrence or distant metastases during one year and half of follow-up.Conclusions: ACC shows a very slow growth pattern. Its diagnosis is often delayed and its treatment is based on surgery and postoperative radiotherapy. This tumor is characterized by the occurrence of local recurrence and distant metastases often several years after treatment of the primary tumor.Keywords: adenoid cystic carcinoma, subglottic, surgery, postoperative radiotherapy, survival

Adénome pléomorphe de l’espace parapharyngé

Les tumeurs de l’espace parapharyngé sont rares, elles représentent 0,5% de l’ensemble des tumeurs de la tête et du cou. elles sont bénignes dans 70 à 80 % des cas selon les séries. elles ont pour origine les glandes salivaires dans 40 à 50% des cas, dominés par les adénomes pléomorphes. Nous rapportons un cas d’adénome pléomorphe de l’espace parapharyngé chez une femme âgée de 38 ans. La patiente a été opérée par voie trans-orale avec exérèse complète de la tumeur. L’examen anatomopathologique définitif a conclu à un adénome pléomorphe. Les suites opératoires étaient simples. on n’a pas noté de récidive après un recul de 2 ans.Mots clés : tumeur para pharyngé, glandes salivaires, adénome pléomorphe

Carcinome parathyroidien

Parathyroid cancer is uncommon and its etiology is largely unknown. It is difficult to diagnose. The preoperative syndrome is unusually severe primary hyperparathyroidism. Intraoperatively, many characteristics of the tumor may be highly suggestive. Confirmation requires pathological analysis of the operative specimens and the diagnosis is strengthened in the presence of associated Shantz and Castelman criteria. Specific immunohistochemical techniques have been shown to be contributive. The diagnosis can be further supported by the clinical course of local recurrence or metastatic spread.Treatment of this tumor is primarly surgical. In some cases, postoperative radiotherapy may improve locoregional control of the tumor. The disease control can be monitored by regula assay of serum calcium and the parathormone. We report a case of parathyroid carcinoma, with special emphasis on the diagnostic modalities of this tumor, its treatmentand its prognosis.Keywords: Hypercalcemia, Primary Hyperparathyroidism, Parathyroid carcinoma, Surgery

Decompression of Facial Nerve after Temporal Bone Fracture: about 20 Cases

Background: Seven to ten percent of facial nerve paralysis occurs in patients with temporal bone fracture. It has become increasingly common due to the development of human activity. One of the main topics of discussion is facial nerve injury management resulting from temporal bone trauma. The purpose of this study is to report the paralysis of facial nerve after temporal bone fractures. Aim: In this study, our goal was to record the facial profile of rhinoplasty applicants in Shiraz. Methods: This retrospective study analyzed 20 cases of traumatic paralysis of facial nerve, which underwent facial nerve decompression. Results: Recovery rate was correlated to the delay of surgery. 83.3% of patients who underwent decompression surgery within the first 2 weeks after trauma had an excellent therapeutic outcome (HB grading I-II) and the difference was statistically significant (p=0.000). Conclusion: Facial nerve paralysis surgical management after bone fracture is controversial. The decision must be taken according to the type of paralysis and the radiological electrophysiological and evolutionary data

Teratome mature de la parotide : a propos d’une observation

Le tératome de la parotide est une malformation tumorale vestigiale rare contenant des dérivés plus ou moins différenciés, des trois feuillets embryonnaires. A la lumière d’une nouvelle observation et des données de la littérature, on se propose de mettre l’accent sur les aspects cliniques, histologiques et thérapeutiques de cette affection exceptionnelle dans cette localisation.Mots-clés : tératome, glande parotide, chirurgie, matureTeratoma of the parotid is a rare remnant malformation tumor containing undifferenciated derivatives of three germ layers. Through a new observation and literature review, authors proposed to focus on the clinical, histological and treatment of this lesion in this exceptionallocation.Key-words : teratoma, parotid gland, sugery, matur