Optimal Multi-Modes Switching Problem in Infinite Horizon

This paper studies the problem of the deterministic version of the Verification Theorem for the optimal m-states switching in infinite horizon under Markovian framework with arbitrary switching cost functions. The problem is formulated as an extended impulse control problem and solved by means of probabilistic tools such as the Snell envelop of processes and reflected backward stochastic differential equations. A viscosity solutions approach is employed to carry out a finne analysis on the associated system of m variational inequalities with inter-connected obstacles. We show that the vector of value functions of the optimal problem is the unique viscosity solution to the system. This problem is in relation with the valuation of firms in a financial market

Transient mutism after anterior transcallosal approach

Postoperative mutism is an infrequent complication of brain surgery. We report a third ventricular astrocytoma in a 16-year-old boy. The tumor was totally removed via anterior transcallosal approach. The operation was uneventful. On the second postoperative day he became mute. He could follow verbal commands, and write and read. Histopathological examination revealed a pilocystic astrocytoma. Four days postoperatively, he began to say simple words, and two weeks later he could talk normally. The possible cause and pathophysiological mechanism of mutism in the lesions of this region are discussed in this paperKey words: Mutism; Third ventricle; Corpus callosum; Transcallosal approac

Les metastases meningees solitaires prevalentes

Objectif Intérêt d’avoir une confirmation histologique, en présence d’un processus leptoméningée solitaire dont le diagnostic de méningiome bénin est souvent évoqué en premier. Introduction Les métastases méningées sont observées de plus en plus fréquemment chez les patients connus porteur d’une néoplasie, du fait de l’allongement de la survie des patients et l’amélioration des moyens diagnostiques ; elles représentent environ 8 % des métastases du système nerveux central.Observation Nous rapportons deux observations originales de patients sans histoire néoplasique, opérés pour un processus leptomeningé solitaire dont le diagnostic préopératoire était celui d’un méningiome. L’étude histologique révélait la nature néoplasique métastatique de la lésion, alors que le bilan radiologique a permis de détecter la localisation primitive méconnue. Conclusion et discussion La découverte à l’occasion d’une imagerie cérébrale (TDM et/ou IRM) chez un patient, sans histoire néoplasique, d’une ou plusieurs lésions leptoméningées, pose un problème diagnostique. Lorsque lalocalisation est unique, le diagnostic de méningiome est évoqué en premier ; alors que les lésions inflammatoires et secondaires des hémopathies malignes représentent un diagnostic différentiel lorsque les lésions sont diffuses. Seront discutées à lumière de ces observations et d’une revue de la littérature, les aspects physiopathologiques, cliniques, paracliniques, thérapeutiques et évolutifs de cette pathologie

Viscosity solutions of systems of PDEs with interconnected obstacles and Multi modes switching problems

This paper deals with existence and uniqueness, in viscosity sense, of a solution for a system of m variational partial differential inequalities with inter-connected obstacles. A particular case of this system is the deterministic version of the Verification Theorem of the Markovian optimal m-states switching problem. The switching cost functions are arbitrary. This problem is connected with the valuation of a power plant in the energy market. The main tool is the notion of systems of reflected BSDEs with oblique reflection.Comment: 36 page

Prospective Observational Study on acute Appendicitis Worldwide (POSAW)

Acute appendicitis (AA) is the most common surgical disease, and appendectomy is the treatment of choice in the majority of cases. A correct diagnosis is key for decreasing the negative appendectomy rate. The management can become difficult in case of complicated appendicitis. The aim of this study is to describe the worldwide clinical and diagnostic work-up and management of AA in surgical departments.info:eu-repo/semantics/publishedVersio

Faux anévrisme artériel traumatique intracrânien

Nous rapportons un cas d'anévrysme post-traumatique de l'artère carotide interne chez un enfant de 11 ans, ayant présenté une ophtalmoplégie droite. Un faux anévrisme de la carotide interne droite a été diagnostiqué par angiographie cérébrale. Le malade a bénéficié d'un traitement endovasculaire et l'évolution fut favorable. Malgré leur rareté, le diagnostic des anévrysmes post traumatiques devrait être évoqué chez tout traumatisé crânien en cas d'aggravation clinique secondaire, afin de réaliser une exploration  angiographique avant d'envisager un traitement radical soit chirurgical soit par voie endovasculaire

Relativistic elastic scattering of a muon neutrino by an electron in an elliptically polarized laser field

Within the framework of electroweak theory, we investigate the elastic scattering process e−+νμ→e−+νμ in the presence of an intense elliptically polarized laser field. We derive an analytical expression for the spin-unpolarized differential cross section using the first Born approximation and the Dirac-Volkov states to describe the incident and scattered electrons. Our results generalize those found for the linearly polarized field by Bai et al. (2012) [24] and for the circularly polarized field by El Asri et al. (2021) [23]. We find that the differential cross section is significantly enhanced for linear polarization and reduced for circular and elliptical polarizations