2,166 research outputs found
Contrôle moléculaire de la remontée de floraison chez le rosier
Rose is a polycarpic plant which presents the ability to flower several times during the year (reccurent blooming. Continuous flowering is due to a mutation of RoKSN a floral repressor homolog to TERMINAL FLOWER 1. In spring, after blooming in once-flowering rose, RoKSN transcripts increase and inhibit nex bloomings. Moreover, the exogenous application of gibberellins (GA) inhibits flowering in spring in once-flowering rose and has no effect on continuous flowering roses. This link between GA and TFL1 was never found before. The main objectives of this study are to understand the function and the regulation of RoKSN and to study the link between RoKSN and GA. By overexpression of RoKSN in Arabidopsis tfl1 mutant we validate floral repressor function of RoKSN. Roses that express ectopically RoKSN, never bloom after few months in greenhouse. In spring exogenous application of GA during floral transition induces RoKSN transcription. The accumulation of RoKSN transcripts correlated with floral inhibition. GA also induces RoFD and Rolfy in a RoKSN-I independent way. To understand the mode of action of RoKS we demonstrate that RoKSN interacted with RoFD. Moreover, there was a competition between RoFT (homologue of FT) and RoKSN FOR RoFD. The consequences of this competition on flowering are still unknow. This study proposed a model for the control of flowering in rose in link with Ga and RoKSN. Other factors as vernalization are under investigation
Diode-pumped, mechanically-flexible polymer DFB laser encapsulated by glass membranes
A diode-pumped, mechanically-flexible organic distributed-feedback laser that is fully encapsulated with ultra-thin glass is reported. The organic laser is excited by 450nm laser diode and emits at 537 nm with an oscillation threshold of 290 W/cm2. The encapsulation format of the device results in a photostability that is improved by two orders of magnitude compared to a non-encapsulated reference device while maintaining mechanical flexibility thanks to an overall device thickness below 105 μm. The laser is also wavelength-tunable between 535 nm and 545 nm by bending the ultra-thin glass structure
RGB and white-emitting organic lasers on flexible glass
Two formats of multiwavelength red, green and blue (RGB) laser on mechanically-flexible glass are demonstrated. In both cases, three all-organic, vertically-emitting distributed feedback (DFB) lasers are assembled onto a common ultra-thin glass membrane substrate and fully encapsulated by a thin polymer overlayer and an additional 50µm-thick glass membrane in order to improve the performance. The first device format has the three DFB lasers sitting next to each other on the glass substrate. The DFB lasers are simultaneously excited by a single overlapping optical pump, emitting spatially separated red, green and blue laser output with individual thresholds of, respectively, 28 µJ/cm2, 11 µJ/cm2 and 32 µJ/cm2 (for 5 ns pump pulses). The second device format has the three DFB lasers, respectively the red, green and blue laser, vertically stacked onto the flexible glass. This device format emits a white laser output for an optical pump fluence above 42 µJ/cm2
Health, production and economic indicators for assessing the performance of small ruminant herds in Africa
Les auteurs présentent un ensemble d'indicateurs zootechniques, d'échange économique et financiers permettant de comparer les performances des troupeaux de petits ruminants et d'établir un diagnostic sur le fonctionnement des systèmes d'élevage. les indicateurs zootechniques retenus sont les tauxde fertilité, de fécondité, de mortalité avant 3 mois et le poids à 90j. Les paramètres d'échanges économiques sont la variation de l'effectifdes femelles reproductrices, le taux d'introduction d'animaux, d'achat,d'exploitation et de vente. Les taux utilisés sont des taux vrais. les indicateurs financiers sont calculés sur une base annuelle : ce sont les produits économiques, les produits monétaires, les charges économiques et les charges monétaires. Ils peuvent être ramenés en unités monétaires par tête ou servir en l'état au calcul du compte d'exploitation. Un exemple est présenté sur un jeu de données recueillies de juillet 1995 à juin 1996 dans la région de Kaolack (Sénégal central). L'ensemble d'indicateurs et les modes de calculs proposés ont été choisis afin d'être utilisables dans une large gamme d'enquêtes et de situations zoo-économiques
Ensayo de una metodología innovadora para la detección de masas polimetálicas profundas: modelo geológico y exploración geotérmica preliminares de la Masa Valverde (Huelva).
Se presentan los resultados provisionales de los trabajos iniciales realizados para el Proyecto Innovative Geothermal Methodology to detect deep blind Polymetallic Ore Bodies, financiado por la CE Y co-financiado por DGICYT y organizaciones participantes. Los principales objetivos de este Proyecto son la cuantificación de los efectos térmicos "in situ" de masas polimetálicas profundas a fin de desarrollar nuevos métodos geotérmicos específicos que puedan detectar depósitos no aflorantes. Dichos métodos deberían proporcionar, previsiblemente, un procedimiento rápido y barato para la detección superficial de cuerpos profundos, midiendo perfiles térmicos en sondeos cortos. La exploración geotérmica permite, a diferencia de otros métodos (por ejemplo gravimetría), discriminar anomalías significativas. Para detectar pequeñas anomalías de temperatura (teniendo en cuenta que el efecto térmico decrece rápidamente hacia la superficie), la resolución térmica medida debe ser del orden de O,001ºC. Se han calibrado nuevos termistores muy sensibles en el Laboratoire National d'Essais (LNE) de París para obtener la máxima sensibilidad en el intervalo de temperaturas considerado (lO a 60ºC). Se miden conductividades térmicas sobre testigos con una precisión del 5% y una reproductibilidad del 2%, que permiten determinar las anomalías del gradiente de temperatura relacionadas con las litologías. Para poner a punto el método, se modelizarán las medidas y se compararán con la realidad de cuerpos conocidos, a fin de establecer un modelo fiable y de aplicación general. Esta metodología se ensaya en primer lugar en la MV (Masa Valverde, Huelva), descubierta y reconocida mediante sondeos por la E.N. Adaro, a fin de partir de un modelo suficientemente preciso para la modelización geotérmica. Los trabajos geológicos realizados integran observaciones de campo, examen y desmuestres de testigos de sondeos, geoquímica, geología estructural y estudio de testigos por diversas técnicas como petrografía, microscopía de menas, DRX, MEB, Microsonda Electrónica, etc. A pesar de la profundidad (en torno a los 600 m.l y de la complejidad de la estructura de MV puesta de manifiesto por el presente estudio, los resultados del primer año de investigación geológica -objeto de esta comunicación-, conducen a un modelo provisional que sirve de base a la interpretación de los datos térmicos. Dicho modelo difiere de los anteriormente conocidos en aspectos como: la posición, definición e interpretación de ciertos tramos litológicos; la demostración de muy frecuentes contactos tectónicos acompañados de procesos de deformación dúctil a veces muy intensa; la identificación de fallas o cabalgamientos que definen unidades independientes, entre las cuales los tramos litológicos, incluidos los cuerpos mineralizados, no son correlaciona bies; la estructura del cuerpo mineralizado, caracterizada por una superposición de escamas imbricadas con geometría antiformal, resultado de procesos tectónicos relacionados con la Tectónica de cabalgamientos de la región y recientemente demostrados -ITGE- en la parte española de la FPI (Faja Pirítica Ibérica). Los resultados provisionales arrojan, pues, un resultado coherente desde las diversas perspectivas de trabajo, particularmente por lo que respecta a los modelos geotérmico y geológico - geométrico, y permiten albergar fundadas esperanzas en una rápida puesta a punto del método, para su aplicación en exploración
Weak radiative hyperon decays, Hara's theorem and the diquark
Weak radiative hyperon decays are discussed in the diquark-level approach. It
is pointed out that in the general diquark formalism one may reproduce the
experimentally suggested pattern of asymmetries, while maintaining Hara's
theorem in the SU(3) limit. At present, however, no detailed quark-based model
of parity-violating diquark-photon coupling exists that would have the
necessary properties.Comment: 10 pages, LaTe
Separation between coherent and turbulent fluctuations. What can we learn from the Empirical Mode Decomposition?
The performances of a new data processing technique, namely the Empirical
Mode Decomposition, are evaluated on a fully developed turbulent velocity
signal perturbed by a numerical forcing which mimics a long-period flapping.
First, we introduce a "resemblance" criterion to discriminate between the
polluted and the unpolluted modes extracted from the perturbed velocity signal
by means of the Empirical Mode Decomposition algorithm. A rejection procedure,
playing, somehow, the role of a high-pass filter, is then designed in order to
infer the original velocity signal from the perturbed one. The quality of this
recovering procedure is extensively evaluated in the case of a "mono-component"
perturbation (sine wave) by varying both the amplitude and the frequency of the
perturbation. An excellent agreement between the recovered and the reference
velocity signals is found, even though some discrepancies are observed when the
perturbation frequency overlaps the frequency range corresponding to the
energy-containing eddies as emphasized by both the energy spectrum and the
structure functions. Finally, our recovering procedure is successfully
performed on a time-dependent perturbation (linear chirp) covering a broad
range of frequencies.Comment: 23 pages, 13 figures, submitted to Experiments in Fluid
Curative pelvic exenteration for recurrent cervical carcinoma in the era of concurrent chemotherapy and radiation therapy. A systematic review
International audienceOBJECTIVE: Pelvic exenteration requires complete resection of the tumor with negative margins to be considered a curative surgery. The purpose of this review is to assess the optimal preoperative evaluation and surgical approach in patients with recurrent cervical cancer to increase the chances of achieving a curative surgery with decreased morbidity and mortality in the era of concurrent chemoradiotherapy. METHODS: Review of English publications pertaining to cervical cancer within the last 25 years were included using PubMed and Cochrane Library searches. RESULTS: Modern imaging (MRI and PET-CT) does not accurately identify local extension of microscopic disease and is inadequate for preoperative planning of extent of resection. Today, only half of pelvic exenteration procedures obtain uninvolved surgical margins. CONCLUSION: Clear margins are required for curative pelvic exenterations, but are poorly predictable by pre-operative assessment. More extensive surgery, i.e. the infra-elevator exenteration with vulvectomy, is a logical surgical choice to increase the rate of clear margins and to improve patient survival following surgery for recurrent cervical carcinoma
Impact of the method of exposure in total hip arthroplasty on balancing ability in response to sudden unidirectional perturbation in the first six months of the postoperative period
Application des recommandations dans la prise en charge du cancer de l’endomètre en pratique clinique. Étude rétrospective bretonne
National audienceObjective - To assess the use of French Cancer Institute recommendations for the diagnosis and treatment of endometrial cancer. Methods - Retrospective observational study involving 137 patients with endometrial cancer between 2011 and 2013. Results - Both MRI and pathological assessment with correct report as recommended were used for 66.4% of patients with endometrial cancer. For patients with correct preoperative assessment, 44.9% of patients were uncorrectly classified and upgraded on final pathological analysis of hysterectomy concerning lymph node involvement risk. These patients did not have confident surgical assessment, according this risk. Conclusion - To improve relevance of preoperative assessment in endometrial cancer, radiological and pathological expertise is required. However, even performed optimally, preoperative assessment does not allow correct risk stratification of lymph node involvement in endometrial cancer. This ineffective stratification leads to propose sentinel lymph node biopsy with hysterectomy in case of preoperative low risk endometrial cancer assessment
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