Geometric Approach to Pontryagin's Maximum Principle

Since the second half of the 20th century, Pontryagin's Maximum Principle has been widely discussed and used as a method to solve optimal control problems in medicine, robotics, finance, engineering, astronomy. Here, we focus on the proof and on the understanding of this Principle, using as much geometric ideas and geometric tools as possible. This approach provides a better and clearer understanding of the Principle and, in particular, of the role of the abnormal extremals. These extremals are interesting because they do not depend on the cost function, but only on the control system. Moreover, they were discarded as solutions until the nineties, when examples of strict abnormal optimal curves were found. In order to give a detailed exposition of the proof, the paper is mostly self\textendash{}contained, which forces us to consider different areas in mathematics such as algebra, analysis, geometry.Comment: Final version. Minors changes have been made. 56 page

Saturation of a spin 1/2 particle by generalized Local control

We show how to apply a generalization of Local control design to the problem of saturation of a spin 1/2 particle by magnetic fields in Nuclear Magnetic Resonance. The generalization of local or Lyapunov control arises from the fact that the derivative of the Lyapunov function does not depend explicitly on the control field. The second derivative is used to determine the local control field. We compare the efficiency of this approach with respect to the time-optimal solution which has been recently derived using geometric methods.Comment: 12 pages, 4 figures, submitted to new journal of physics (2011

Paraphrastic Reformulations in Spoken Corpora

International audienceOur work addresses the automatic detection of paraphrastic reformulation in French spoken corpora. The proposed approach is syn-tagmatic. It is based on specific markers and the specificities of the spoken language. Manual multi-dimensional annotation performed by two annotators provides fine-grained reference data. An automatic method is proposed in order to decide whether sentences contain or not paraphras-tic relations. The obtained results show up to 66.4% precision. Analysis of the manual annotations indicates that few paraphrastic segments show morphological modifications (inflection, derivation or compounding) and that the syntactic equivalence between the segments is seldom respected, as these usually belong to different syntactic categories

CLAPI, une base de données multimodale pour la parole en interaction : apports et dilemmes

Dans cette contribution, nous présentons la base CLAPI développée au laboratoire ICAR dans le contexte de l’évolution des bases de données de langues parlées en France au cours des trente dernières années. Nous détaillons les deux composantes de CLAPI, l’archive de corpus de langue parlée en interaction audio et vidéo enregistrés dans des situations sociales naturelles variées, et la plateforme d’outils.L’usage et l’apport de CLAPI sont illustrés par deux études. L’une décrit comment la base peut être utilisée pour des travaux de linguistique interactionnelle intégrant la multimodalité (« oh là là ») ; l’autre concerne une recherche combinant données et métadonnées (« trop »). L’article est aussi l’occasion d’un bilan plus général. La mise en perspective montre en effet qu’après la période des questions est venue celle des dilemmes. La période des questions, choix et décisions à toutes sortes de niveaux a accompagné la mise en place des bases de données. L’expérience permet maintenant de mesurer leurs indéniables apports en termes non seulement de quantité de données disponibles (et traitables grâce aux outils), mais aussi de qualité (comme conséquence des exigences de standardisation liées au partage des données). La période des dilemmes nous conduit à nous interroger sur les meilleurs choix à opérer aujourd’hui dans les relations entre la poursuite des recherches sur des corpus variés (et parfois sensibles) et les exigences des bases de données ouvertes.In this contribution, we present the development of the CLAPI by the ICAR Lab in the context of the evolution of the databases of spoken languages in France during the last thirty years. We describe the two components of CLAPI, the archive of corpus of spoken languages in interaction, audio and video, recorded in varied naturally-occurring social situations, and the plateform of tools.The use and the support of CLAPI the research are shown out of two studies. One illustrates how the database can be used for working in an interactional linguistic perspective, including multimodality (“oh là là”); the other concerns a research combining data and metadata (“trop”).The article is also the occasion of a more general assessment. The perspective on the last thirty years shows that after a period of questions came that of dilemmas. The period of questions, choices and decisions at various levels accompanied the implementation of the databases. The experience enables now to measure their undeniable contributions in terms not only of quantity of available data (and possibly dealt with supported by the tools), but also of quality of the data (as a consequence of the requirements of standardization linked to the needs of sharing the data). The period of the dilemmas leads us to wonder about the best choices to be operated today among continuing research on varied corpuses (sometimes delicate) and the requirements of the databases

Outcome of alimentary tract duplications operated on by minimally invasive surgery: a retrospective multicenter study by the GECI (Groupe d'Etude en Coeliochirurgie Infantile).

BACKGROUND: Alimentary tract duplications (ATD) are a rare cause of intestinal obstruction in childhood. There are many case reports but few series about laparoscopy or thoracoscopy for ATD. The aim of our study was to report the outcome of minimally invasive surgery (MIS) for ATD. METHODS: This was a retrospective multicenter study from the GECI (Groupe d\u27Etude en Coeliochirurgie Infantile). We reviewed the charts of 114 patients operated on by MIS for ATD from 1994 to 2009. RESULTS: Sixty-two patients (54 %) had a prenatal diagnosis. Forty-nine patients (43 %) were symptomatic before surgery: 33 of those patients (63 %) with postnatal diagnosis compared to 16 (25 %) with prenatal diagnosis (P < 0.01). In this last group, the median age at onset of symptoms was 16 days (range = 0-972). One hundred and two patients had laparoscopy (esophageal to rectal duplications) and 12 patients had thoracoscopy for esophageal duplications. The mean operative time was 90 min (range = 82-98). There were 32 (28 %) resection anastomoses, 55 (48 %) enucleations, and 27 (24 %) unroofings. The conversion rate was 32 %, and in a multivariate analysis, it was significantly higher, up to 41 % for patients weighing <10 kg (P < 0.01). Ten patients (8 %) had unintentional perioperative opening of the digestive tract during the dissection. Eight patients had nine postoperative complications, including six small bowel obstructions. The median length of hospital stay was 4 days (range = 1-21) without conversion and 6 days (range = 1-27) with conversion (P = 0.01). The median follow-up was 3 months (range = 1-120). Eighteen of the 27 patients who underwent partial surgery had an ultrasound examination during follow-up. Five (18 %) of them had macroscopic residue. CONCLUSION: This study showed that MIS for ATD is feasible with a low rate of complications. Patients with prenatal diagnosis should have prompt surgery to prevent symptoms, despite a high rate of conversion in small infants

De novo mutations in SMCHD1 cause Bosma arhinia microphthalmia syndrome and abrogate nasal development

Bosma arhinia microphthalmia syndrome (BAMS) is an extremely rare and striking condition characterized by complete absence of the nose with or without ocular defects. We report here that missense mutations in the epigenetic regulator SMCHD1 mapping to the extended ATPase domain of the encoded protein cause BAMS in all 14 cases studied. All mutations were de novo where parental DNA was available. Biochemical tests and in vivo assays in Xenopus laevis embryos suggest that these mutations may behave as gain-of-function alleles. This finding is in contrast to the loss-of-function mutations in SMCHD1 that have been associated with facioscapulohumeral muscular dystrophy (FSHD) type 2. Our results establish SMCHD1 as a key player in nasal development and provide biochemical insight into its enzymatic function that may be exploited for development of therapeutics for FSHD

Shape polarization in the tin isotopes near N=60N=60 from precision gg-factor measurements on short-lived 11/2−11/2^- isomers

The $g$ factors of $11/2^-$ isomers in semimagic $^{109}$Sn and $^{111}$Sn (isomeric lifetimes $\tau = 2.9(3)$ ns and $\tau = 14.4(7)$ ns, respectively) were measured by an extension of the Time Differential Perturbed Angular Distribution technique, which uses \LaBr detectors and the hyperfine fields of a gadolinium host to achieve precise measurements in a new regime of short-lived isomers. The results, $g(11/2^-; {^{109}\textrm{Sn}}) = -0.186(8)$ and $g(11/2^-; {^{111}\textrm{Sn}}) = -0.214(4)$, are significantly lower in magnitude than those of the $11/2^-$ isomers in the heavier isotopes and depart from the value expected for a near pure neutron $h_{11/2}$ configuration. Broken-symmetry density functional theory calculations applied to the sequence of $11/2^-$ states reproduce the magnitude and location of this deviation. The $g(11/2^-)$ values are affected by shape core polarization; the odd $0h_{11/2}$ neutron couples to $J^{\pi}=2^+,4^+,6^+...$ configurations in the weakly-deformed effective core, causing a decrease in the $g$-factor magnitudes.Comment: 8 pages, 7 figures. Accepted in Physics Letters

Esophageal atresia: data from a national cohort

PURPOSE: A prospective national register was established in 2008 to record all new cases of live-birth newborns with esophageal atresia (EA). This epidemiological survey was recommended as part of a national rare diseases plan. METHODS: All 38 national centers treating EA participated by completing for each patient at first discharge a questionnaire validated by a national committee of experts. Data were centralized by the national reference center for esophageal anomalies. Quantitative and qualitative analyses were performed, with P-values of less than 0.05 considered statistically significant. Results of the 2008-2009 data collection are presented in this report. RESULTS: Three hundred seven new living cases of EA were recorded between January 1, 2008, and December 31, 2009. The male/female sex ratio was 1.3, and the live-birth prevalence of EA was 1.8 per 10,000 births. Major characteristics were comparable to those reported in the literature. Survival was 95%, and no correlation with caseload was noted. CONCLUSIONS: Epidemiologic surveys of congenital anomalies such as EA, which is a rare disease, provide valuable data for public health authorities and fulfill one important mission of reference centers. When compared with previous epidemiological data, this national population-based registry suggests that the incidence of EA remains stable