Gauge Consistent Wilson Renormalization Group I: Abelian Case

A version of the Wilson Renormalization Group Equation consistent with gauge symmetry is presented. A perturbative renormalizability proof is established. A wilsonian derivation of the Callan-Symanzik equation is given.Comment: Latex2e, 39 pages, 3 eps figures. Revised version to appear in Int. J. Mod. Phy

Artificial neural networks for 3D cell shape recognition from confocal images

We present a dual-stage neural network architecture for analyzing fine shape details from microscopy recordings in 3D. The system, tested on red blood cells, uses training data from both healthy donors and patients with a congenital blood disease. Characteristic shape features are revealed from the spherical harmonics spectrum of each cell and are automatically processed to create a reproducible and unbiased shape recognition and classification for diagnostic and theragnostic use.Comment: 17 pages, 8 figure

Plantio cruzado na cultura da soja em uma cultivar de tipo de crescimento indeterminado.

O objetivo desse trabalho foi avaliar a produtividade de grãos e o acamamento de plantas na cultivar de soja de hábito de crescimento indeterminado BRS 359 RR, em diferentes arranjos espaciais de plantas, constituídos por densidades de semeadura, espaçamentos entre fileiras e forma de plantio (cruzado e não cruzado)

On the path of plumes of the Río de La Plata Estuary main tributaries and their mixing scales

With a length of 300 km and a width that narrows from 220 km at its mouth to 40 km at its upper end, the Rio de la Plata is one of the largest estuaries of the world. Its three main tributaries -contributing to a total mean runoff of22,000 m3 s’1- have different properties and are object of diverse environmental impact due to dissimilar development conditions on their shores. The knowledge of the paths of the plumes of those tributaries along the estuary and their mixing scales is necessary for management purposes. In this paper, advection-diffusion equations for passive tracers are coupled to the three-dimensional Hamburg Shelf Ocean Model and validated by means of a case study. Then, simulations in which each tributary is characterized by a different dye tracer are done for scenarios resulting of the combination of diverse characteristic atmospheric forcing and runoff conditions. The impact of bathymetry and Earth’s rotation on plumes paths and mixing is also evaluated. Results indicate that, for mean to low discharge conditions, the path of the waters of the tributaries is in the form of two main plumes. The different water speeds of both tributaries, the presence of a bend immediately after their confluence and the varying geometry and bathymetry of the estuary favor a rapid mixing between the Uruguay and Paraná Guazú-Bravo waters, which then flow along the northern portion of the upper estuary channel. The Paraná de las Palmas waters, instead, occupy the southern shallow region of Playa Honda in the upper estuary and then flow following the southern coast. Downstream Colonia, at the intermediate estuary, the occurrence of another large bend and a change in bathymetric features force the flow to concentrate in the central part of the estuary and favor further mixing between the plumes. For high discharge conditions the northern part of the upper estuary is divided into two regions, one with a larger concentration of Uruguay waters between Oyarvide and Martín Garcia islands and the coast and another with a larger concentration of Paraná Guazú-Bravo waters south of the islands. In this case there is a much larger concentration of Uruguay waters along the northern coast, which might be enhanced if a peak runoff occurs for the Uruguay but not for the Paraná River. These conclusions are consistent with what can be inferred from the conductivity field observed at the intermediate estuary, the bottom sediments distribution and satellite images. Results indicate that even though strong winds can favor the mixing of the plumes, especially along Argentinean coast, they preserve their pattern and the effect of the storms only persists for a few days. For mean runoff, the elapsed time to the arrival of the leading edge of the Paraná de las Palmas, Paraná Guazú- Bravo and Uruguay tracer clouds at Buenos Aires is of around 3, 5 and 7 days, respectively. The elapsed time to the peak concentration of the tracer cloud for a typical mean runoff scenario is of around 20 days at Buenos Aires. For that condition, the flushing times of the upper and upper intermediate estuary are of around 10 and 60 days, respectively. Nevertheless, mixing scales can be half (twice) those valúes for high (low) runoff conditions.Con una extensión de 300 km y un ancho que varía entre 220 km en su boca y 40 km en su parte superior, el Río de la Plata es uno de los mayores estuarios del mundo. Sus tres tributarios -que contribuyen con una descarga media total de 22.000 m3s_1- tienen diferentes propiedades y son objeto de distinto impacto medioambiental debido a condiciones disímiles de desarrollo en sus costas. El conocimiento del camino de las plumas de esos tributarios y sus escalas de mezcla es necesario para propósitos de gestión. En este trabajo, se acoplan ecuaciones de advección-diíusión para trazadores pasivos al modelo tridimensional Hamburg Shelf Ocean Model y se las valida por medio de un estudio de casos. Luego se realizan simulaciones en las cuales cada tributario es caracterizado por un trazador diferente para escenarios que resultan de combinar las diversas condiciones características del forzante atmosférico y la descarga. El impacto de la batimetría y la rotación de la Tierra en el camino de las plumas y su mezcla también es evaluado. Los resultados indican que, para condiciones de descarga media a baja el camino de las aguas de los tributarios es en la forma de dos plumas principales. La diferente velocidad del agua en ambos tributarios, la presencia de una curva inmediatamente después de su confluencia y la geometría y batimetría variables del estuario favorecen una rápida mezcla entre las aguas del Uruguay y el Paraná Guazú-Bravo, que luego fluyen a lo largo de la parte norte del estuario superior. Las aguas del Paraná de las Palmas, en cambio, ocupan la región somera de Playa Honda en la porción sur del estuario superior y luego fluyen a lo largo de la costa sur. Aguas abajo de Colonia, en el estuario medio, la ocurrencia de una gran curva y un cambio en las características batimétricas fuerzan al flujo a concentrarse en la parte central del estuario y favorece mayor mezcla entre las plumas. Para condiciones de descarga alta la porción norte del estuario se divide en dos regiones, una con mayor concentración de aguas del Uruguay entre las islas Oyarvide y Martín García y la costa, y otra con mayor concentración del Paraná Guazú-Bravo al sur de dichas islas. En este caso, hay una concentración mucho mayor de aguas del Uruguay a lo largo de la costa norte, característica que podría incrementarse si un pico de descarga ocurre en el Río Uruguay pero no en el Paraná. Estas conclusiones son consistentes que lo que puede inferirse del campo de conductividad observado en el estuario intermedio, con la distribución de sedimentos de fondo y con imágenes satelitales. Los resultados indican que aunque vientos fuertes pueden favorecer la mezcla de las plumas, especialmente a lo largo de la costa argentina, ellas mantienen su estructura y el efecto de las tormentas sólo persiste unos pocos días. Para descarga media, el tiempo de arribo del borde de las nubes de trazadores de los ríos Paraná de las Palmas, Paraná Guazú-Bravo y Uruguay a Buenos Aires es de aproximadamente 3, 5 y 7 días, respectivamente. El tiempo hasta el alcance de la concentración pico de la nube de trazadores para un escenario típico de descarga media es de alrededor de 20 días para Buenos Aires y 60 días para el estuario medio. Para esa condición, el tiempo de lavado en el estuario superior y medio superior es de alrededor de 10 y 60 días. No obstante, las escalas de mezcla pueden ser la mitad (el doble) de esos valores para condiciones de descarga alta (baja).Asociación Argentina de Geofísicos y Geodesta

About the vertical structure of currents in the intermediate Rio de la Plata: observational study

The Río de la Plata is one of the most important estuarine systems of the world and the most developed basin of eastern South America. Water levels and currents have been measured at many locations of the river and a number of depth-integrated (2-D) models have been applied to determine its circulation. Nevertheless, the three-dimensional characteristics of the currents have been never analyzed neither by means of direct observations nor by means of 3-D models. In this work current data measured using an Acoustic Doppler Current Profiler are presented to show the vertical structure of currents in the intermediate Rio de la Plata. In February 2-3 2000, a transect of approximately 16 Km long was repeated eleven times during 25 hours obtaining 1972 current profiles. After applying a specific processing, sinusoids with M2 (12.42 hours) period was fitted to the data series using least squares fitting method. The M2 amplitudes and phases of the EW and NS components of the current and both components corresponding to the mean flow (residuals) were obtained along the transversal section of the transect. Results showed that currents present strong vertical gradients not only in the phases of the semidiurnal constituent but also in the mean flux in the intermediate zone of the Rio de la Plata. Although the intermediate Rio de la Plata is a very shallow basin results reveal that the current from upper to bottom layers can rotate more than 90°. These results indicate that currents respond strongly to the local winds but their effects are mainly manifested at the upper layer. Finally, results indicate that 3-D baroclinic models (including temperature and salinity fields and a realistic atmospheric forcing) should be used in order to obtain a reliable and complete representation of currents especially at the intermediate and outer zone of the Rio de la Plata.El Rio de la Plata es uno de los sistemas fluviales más importantes del mundo y la cuenca más desarrollada del sudeste sudamericano. Los niveles del agua y las corrientes han sido medidos en un gran número de sitios del río y, por otro lado, diversos modelos integrados en la vertical (2-D) han sido aplicados para determinar su circulación. Sin embargo, hasta el momento, las características tridimensionales de las corrientes no han sido descriptas ni mediante observaciones directas ni por medio de modelos 3-D. En este trabajo los datos de corrientes medidos con un Perfilador de Corrientes Acústico Doppler (del inglés ADCP) son presentados para mostrar la compleja estructura vertical de las corrientes en el Río de la Plata intermedio. Entre el 2 y 3 de febrero de 2000 se repitió once veces durante 25 horas una transecta de aproximadamente 16 Km de longitud obteniéndose un total de 1972 perfiles de corriente. Después de aplicar un procesamiento específico las series fueron ajustadas a sinusoides con periodo correspondiente a la componente de marea M2 (12.42 horas) utilizando el método de mínimos cuadrados. Se obtuvo así las amplitudes y fases de las componentes EW y NS de la corriente correspondientes a la M2 y las dos componentes para el flujo medio (residuos) a lo largo de la transecta estudiada. Los resultados muestran que las corrientes en la zona intermedia del Río de la Plata presentan intensos gradientes verticales no solo en las fases de las componentes semidiurnas sino también en las del flujo medio. Aunque el Río de la Plata intermedio es una cuenca muy somera los resultados revelan que las corrientes pueden variar su dirección en más de 90° entre las capas superior e inferior de la columna de agua. Estos resultados indican que las corrientes responden fuertemente a los vientos locales, pero sus efectos son principalmente manifestados en la capa superior. Finalmente, los resultados indican que para obtener una representación confiable y completa de las corrientes especialmente en las zonas intermedia y exterior del Río de la Plata deberían implementarse modelos baroclínicos 3- D que incluyan tanto los campos térmicos y salinos como así también forzantes atmosféricos realistas.Asociación Argentina de Geofísicos y Geodesta

Plantio cruzado em cultivar de soja de tipo de crescimento determinado.

O objetivo desse trabalho foi avaliar a produtividade de grãos e o acamamento de plantas no cultivar de soja de tipo determinado BRS 295 RR, cultivada em diferentes arranjos espaciais de plantas, incluindo o plantio cruzado

Follow-Up of Coiled Cerebral Aneurysms at 3T: Comparison of 3D Time-of-Flight MR Angiography and Contrast-Enhanced MR Angiography

BACKGROUND AND PURPOSE: Our aim was to compare contrast-enhanced MR angiography (CE-MRA) and 3D time-of-flight (TOF) MRA at 3T for follow-up of coiled cerebral aneurysms. MATERIALS AND METHODS: Fifty-two patients treated with Guglielmi detachable coils for 54 cerebral aneurysms were evaluated at 3T MRA. 3D TOF MRA (TR/TE = 23/3.5; SENSE factor = 2.5) and CE-MRA by using a 3D ultrafast gradient-echo sequence (TR/TE = 5.9/1.8; SENSE factor = 3) enhanced with 0.1-mmol/kg gadobenate dimeglumine were performed in the same session. Source images, 3D maximum intensity projection, 3D shaded surface display, and/or 3D volume-rendered reconstructions were evaluated in terms of aneurysm occlusion/patency and artifact presence. RESULTS: In terms of clinical classification, the 2 MRA sequences were equivalent for 53 of the 54 treated aneurysms: 21 were considered fully occluded, whereas 16 were considered to have a residual neck and 16 were considered residually patent at follow-up MRA. The remaining aneurysm appeared fully occluded at TOF MRA but had a residual patent neck at CE-MRA. Visualization of residual aneurysm patency was significantly ( P = .001) better with CE-MRA compared with TOF MRA for 10 (31.3%) of the 32 treated aneurysms considered residually patent with both sequences. Coil artifacts were present in 5 cases at TOF MRA but in none at CE-MRA. No relationship was apparent between the visualization of patency and either the size of the aneurysm or the interval between embolization and follow-up. CONCLUSION: At follow-up MRA at 3T, unenhanced TOF and CE-MRA sequences are similarly effective at classifying coiled aneurysms as occluded or residually patent. However, CE-MRA is superior to TOF MRA for visualization of residual patency and is associated with fewer artifacts