Trinocular stereovision using figural continuity, dealing with curved objects

A method to build a dense and reliable 3-D description of a scene from three digital images by means of passive stereovision is presented. This method uses figural continuity to improve the results of a previously developed algorithm. In particular, it copes much better with curved objects and produces results which are organized as 3-D chains of segments

In-situ pulsed laser induced growth of CdS nanoparticles on ZnO nanorods surfaces

Herein we present a process for the in-situ growth of CdS nanoparticles using a pulsed laser irradiation. A Nd-YAG laser was applied to ZnO nanorods previously submerged in an aqueous precursor solution containing cadmium chloride and thiourea. For optimum values of the laser fluence, around 40 mJ/cm2 it was possible to fabricate a highly homogeneous film of CdS nanoparticles covering the ZnO nanorods surface. Cathodoluminescence measurements of the ZnO/CdS structure show the quenching of the ZnO yellow and green luminescence, indicating the ZnO surface defects passivation by CdS nanostructures. Although lasers have been already used for inducing growth in solution, this work presents new evidence of in-situ growth on the surface of nanostructured materials. The laser based technique presented is simple, easy to implement, scalable and it could be applied in the fabrication of nanostructured solar cells and other devices

Effect of prevention measures on incidence of human listeriosis, France, 1987-1997.

To assess the impact of preventive measures by the food industry, we analyzed food monitoring data as well as trends in the incidence of listeriosis estimated through three independent sources: the National Reference Center of Listeriosis; a laboratory-based active surveillance network; and two consecutive nationwide surveys of public hospital laboratories. From 1987 to 1997, the incidence of listeriosis decreased by an estimated 68%. A substantial reduction in the proportion of Listeria monocytogenes-contaminated products was observed at the retail level. The temporal relationship between prevention measures by the food industry, reduction in L. monocytogenes-contaminated foodstuffs, and reduction in listeriosis incidence suggests a causal relationship and indicates that a substantial part of the reduction in illness is related to prevention efforts

Efecto antifúngico de cuatro mezclas de monoterpenos como alternativa para el control de Rhizoctonia solani Kün.

Rhizoctonia solani Kühn, es un patógeno de suelo, que causa enfermedades en un amplio rango de hospedantes de cultivos agrícolas. Las necesidades de reducir el uso indiscriminado de fungicidas químicos conllevan al estudio de otras alternativas menos agresivas al medio ambiente. Los monoterpenos presentes en los aceites esenciales de plantas, presentan una marcada actividad biocida y son compuestos que resultan menos perjudiciales desde el punto de vista ambiental. Se prepararon cuatro mezclas de monoterpenos (timol-mentol, timolalcanfor, timol-citronelal y timol-1,8 cineol) con el objetivo de evaluar la actividad antifúngica in vitro sobre R. solani, mediante su efecto sinérgico. Se empleó el método de adición al medio de cultivo de cada una de las mezclas a concentraciones de: 0,5; 0,1; 0,05; 0,03 y 0,01%, partiendo de una solución madre al 10% en dimetilsufóxido (DMSO) al 5%. Se calcularon los porcentajes de inhibición y los resultados se analizaron estadísticamente. Se determinaron las dosis inhibitorias medias y se clasificaron la toxicidad de cada una de las mezclas en: inocua, ligera, moderada y tóxica a cada concentración. Las cuatro mezclas mostraron 100% de inhibición a las concentraciones de: 0, 5; 0, 1; 0,05 y 0,03%. A la menor concentración las mezclas de timol-mentol y timol-cineol fueron las de mayor efecto inhibitorio del crecimiento micelial de R. solani

Steroid modulation of neurogenesis: Focus on radial glial cells in zebrafish

International audienc

Robust iso-surface tracking for interactive character skinning

International audienceWe present a novel approach to interactive character skinning, which is robust to extreme character movements, handles skin contacts and produces the effect of skin elasticity (sliding). Our approach builds on the idea of implicit skinning in which the character is approximated by a 3D scalar field and mesh-vertices are appropriately re-projected. Instead of being bound by an initial skinning solution used to initialize the shape at each time step, we use the skin mesh to directly track iso-surfaces of the field over time. Technical problems are two-fold: firstly, all contact surfaces generated between skin parts should be captured as iso-surfaces of the implicit field; secondly, the tracking method should capture elastic skin effects when the joints bend, and as the character returns to its rest shape, so the skin must follow. Our solutions include: new composition operators enabling blending effects and local self-contact between implicit surfaces, as well as a tangential relaxation scheme derived from the as-rigid-as possible energy to solve the tracking problem

Detección de Fusarium semitectum en vainas de plantas de Moringa (Moringa oleifera Lam)

Se analizaron muestras de Moringa oleifera procedentes de la provincia Habana, Cuba con el objetivo de determinar el agente causal de los daños.Las plantas presentaban afectaciones en las vainas, tallo y follaje iniciadas por insecto seguida por síntomas típicos de hongos fitopatógenos. Lasmuestras fueron procesadas y se determinó que el agente causal es el hongo fitopatógeno Fusarium semitectum. Este hongo se asocia a Fusicladium sp causando daños severos en la planta. En Cuba seha aislado fundamentalmente en lotes de semillas de moringa

Evaluación de la actividad antifúngica de extractos liquénicos e identificación de sus metabolitos

Los líquenes son los hongos que establecen una relación simbiótica con un alga o cianobacteria. En esta simbiosis se producen por parte del hongo, una serie de metabolitos secundarios conocidos como sustancias liquénicas; las cuales presentan una marcada actividad antibiótica. En Cuba no se tienen antecedentes sobre estudios de metabolitos liquénicos por lo que se propone; evaluar el efecto fungicida de extractos liquénicos producidos por especies cubanas así como identificar sus metabolitos. Se emplearon líquenes de diferentes zonas del país (Parmotrema dilatatum, P. tinctorum, P. praesorediosum P. cristiferum, Ramalina americana, Cladonia ceratophylla y Cladonia portentosa spp. pacífica), a los cuales se les extrajo con acetona, las sustancias liquénicas almacenadas en el talo. Los extractos fueron probados contra los hongos fitopatógenos Rhizoctonia solani y Phythophtora nicotianae; por el método de envenenamiento del medio de cultivo agar papa dextrosa a concentraciones de: 0,01%; 0,03% y 0,07%. Se utilizó un control negativo de dimetilsufóxido al 0,07% y se determinaron los porcentajes de inhibición, cuyos resultados fueron analizados estadísticamente. Los metabolitos secundarios presentes en los extractos se identificaron por cromatografía de capa fina (TLC). Exceptuando el extracto liquénico de P. cristiferum, todos los demás mostraron más de un 50% de inhibición del crecimiento de ambos hongos a la concentración de 0,07%, mientras que a las restantes concentraciones los valores fueron variados con diferencias significativas con respecto al control. Se lograron identificar tres metabolitos liquénicos: metil 2‘-O- metilmicrofilinato, 4-O-Demetilmicrofilinico y el ácido ramaniloico

Lack of correlation of stem cell markers in breast cancer stem cells

BACKGROUND: Various markers are used to identify the unique sub-population of breast cancer cells with stem cell properties. Whether these markers are expressed in all breast cancers, identify the same population of cells, or equate to therapeutic response is controversial. METHODS: We investigated the expression of multiple cancer stem cell markers in human breast cancer samples and cell lines in vitro and in vivo, comparing across and within samples and relating expression with growth and therapeutic response to doxorubicin, docetaxol and radiotherapy. RESULTS: CD24, CD44, ALDH and SOX2 expression, the ability to form mammospheres and side-population cells are variably present in human cancers and cell lines. Each marker identifies a unique rather than common population of cancer cells. In vivo, cells expressing these markers are not specifically localized to the presumptive stem cell niche at the tumour/stroma interface. Repeated therapy does not consistently enrich cells expressing these markers, although ER-negative cells accumulate. CONCLUSIONS: Commonly employed methods identify different cancer cell sub-populations with no consistent therapeutic implications, rather than a single population of cells. The relationships of breast cancer stem cells to clinical parameters will require identification of specific markers or panels for the individual cancer

Statistical M-Estimation and Consistency in Large Deformable Models for Image Warping

The problem of defining appropriate distances between shapes or images and modeling the variability of natural images by group transformations is at the heart of modern image analysis. A current trend is the study of probabilistic and statistical aspects of deformation models, and the development of consistent statistical procedure for the estimation of template images. In this paper, we consider a set of images randomly warped from a mean template which has to be recovered. For this, we define an appropriate statistical parametric model to generate random diffeomorphic deformations in two-dimensions. Then, we focus on the problem of estimating the mean pattern when the images are observed with noise. This problem is challenging both from a theoretical and a practical point of view. M-estimation theory enables us to build an estimator defined as a minimizer of a well-tailored empirical criterion. We prove the convergence of this estimator and propose a gradient descent algorithm to compute this M-estimator in practice. Simulations of template extraction and an application to image clustering and classification are also provided