L'utilisation des réseaux de neurones artificiels en finance.

Depuis le début de la décennie 1990, les réseaux de neurones artificiels habituellement utilisés en physique appliquée font leur entrée dans les sciences de gestion en tant que méthode quantitative de prévision, à côté des méthodes statistiques classiques. Ils sont en particulier utilisés en finance, mais d’autres champs de la gestion sont aussi concernés. L’objet du présent article est d’abord de présenter succinctement l’architecture et le mode de fonctionnement de la classe de réseaux les plus couramment utilisés en finances : les réseaux à couches. Il est ensuite de montrer l’intérêt de cet outil pour les applications de finance, face aux méthodes statistiques classiques, à travers un balayage des champs d’application déjà explorés. Enfin, la dernière partie de l’article s’attache à recenser les imperfections dont souffre encore cet outil, aujourd’hui en plein développement.réseaux de neurones artificiels, finance, prévisions, méthodes de prévisions

DE L'INFORMATION A LA CONNAISSANCE

document de recherche du Laboratoire Orléanais de GestionDans un monde de compétitivité accrûe, l'un des défis majeurs que l'entreprise doit affronter est le management de la connaissance. Celle-ci naît des apprentissages internes ou externes à l'organisation, mais aussi de sa capacité à combiner et à transformer des informations en provenance de son environnement. La première partie de l'article montre que le développement sans précédent des technologies de l'information et de la communication rend de plus en plus facile l'accès à l'information et augmente la rapidité de son traitement. Mais, la technologie ne constitue qu'un moyen, elle ne produit pas de la connaissance par elle-même. La seconde partie de l'article s'efforce de faire le lien entre le développement de ces outils et la production de connaissances

Acute generalized exanthematous pustulosis due to an iodinated contrast radiodiagnostic agent.

peer reviewedIodinated contrast agents are frequently involved in delayed polymorphic adverse skin reactions. Acute generalized exanthematous pustulosis following administration of iodinated contrast agents is a rare but severe form of such reactions. The disease is characterized by the sudden occurrence of an erosive and pustular erythroderma with fever, leukocytosis and sometimes peripheral adenopathies and liver involvement. This condition is considered as an immunologic reaction, primarily involving T lymphocytes. The overall mortality reaches about 1%. Elucidating the differential diagnosis with other acute paroxysmal drug eruptions (toxic epidermal necrolysis, Steven-Johnson syndrome and drug hypersensitivity syndrome) is of paramount importance for establishing the adequate treatment of PEAG

Drug of month. Topical tacrolimus (Protopic).

peer reviewedTacrolimus is a potent inhibitor of immune mechanisms. It belongs to the macrolactam group. It inhibits the release of both Th1 and Th2 cytokines. It proves to be efficacious after topical application in the treatment of atopic dermatitis. In this indication, tacrolimus challenges topical corticosteroids. Irritation risks are present. The local immuno-depression can boost disseminated infections including herpes. The risk to promote photocarcinogenesis on the long term, and that bound to chronic resorption remain theoretical concerns that have not been assessed so far

International Epidemic Intelligence at the Institut de Veille Sanitaire, France

The French Institute for Public Health Surveillance monitors health events of potential international importance occurring worldwide to provide timely warning to French health authorities. We reviewed the nature and place of occurrence of the last 200 events. From an individual country’s perspective, the need for multiple sources is emphasized

Redirecting splicing with bifunctional oligonucleotides

Abstract: Ectopic modulators of alternative splicing are important tools to study the function of splice variants and for correcting mis-splicing events that cause human diseases. Such modulators can be bifunctional oligonucleotides made of an antisense portion that determines target specificity, and a nonhybridizing tail that recruits proteins or RNA/protein complexes that affect splice site selection (TOSS and TOES, respectively, for targeted oligonucleotide silencer of splicing and targeted oligonucleotide enhancer of splicing). The use of TOSS and TOES has been restricted to a handful of targets. To generalize the applicability and demonstrate the robustness of TOSS, we have tested this approach on more than 50 alternative splicing events. Moreover, we have developed an algorithm that can design active TOSS with a success rate of 80%. To produce bifunctional oligonucleotides capable of stimulating splicing, we built on the observation that binding sites for TDP-43 can stimulate splicing and improve U1 snRNP binding when inserted downstream from 50 splice sites. A TOES designed to recruit TDP-43 improved exon 7 inclusion in SMN2. Overall, our study shows that bifunctional oligonucleotides can redirect splicing on a variety of genes, justifying their inclusion in the molecular arsenal that aims to alter the production of splice variants

Cyanoacrylate Skin Surface Stripping and the 3S-Biokit Advent in Tropical Dermatology: A Look from Liège

In the dermatopathology field, some simple available laboratory tests require minimum equipment for establishing a diagnosis. Among them, the cyanoacrylate skin surface stripping (CSSS), formerly named skin surface biopsy or follicular biopsy, represents a convenient low cost procedure. It is a minimally invasive method collecting a continuous sheet of stratum corneum and horny follicular casts. In the vast majority of cases, it is painless and is unassociated with adverse events. CSSS can be performed in subjects of any age. The method has a number of applications in diagnostic dermatopathology and cosmetology, as well as in experimental dermatology settings. A series of derived analytic procedures include xerosis grading, comedometry, corneofungimetry, corneodynamics of stratum corneum renewal, corneomelametry, corneosurfametry, and corneoxenometry

A CATT Negative Result after Treatment for Human African Trypanosomiasis Is No Indication for Cure

The 2 year follow-up period required after treatment of human African trypanosomiasis (HAT) patients is a major challenge for patients and control programmes alike. The patient should return every 6 months for lumbar puncture and cerebrospinal fluid examination since, so far, no markers for cure have been identified in blood. The Card Agglutination Test for Trypanosomiasis (CATT) is a simple, rapid test for trypanosome-specific antibody detection in blood that is extensively used in endemic areas to screen for HAT. We examined the value of a normalising CATT as a marker for treatment outcome. We observed that CATT titres decreased after treatment both in patients who experienced treatment failure as well as in cured patients. We conclude that CATT, though a good screening test, is unreliable for monitoring treatment outcome. We also showed that the sensitivity of CATT in relapse cases was as low as 78%, and as a consequence some relapse cases might be missed in screening programs if they have no clinical signs yet