Quantitative method of viral pollution determination for large volume of water using ferric hydroxide gel impregnated on the surface of glassfibre cartridge

Quantitative method of viral pollution determination for large volume of water using ferric hydroxide gel impregnated on the surface of glassfibre cartridge filter. The use of ferric hydroxide gel, impregnated on the surface of glassfibre cartridge filter enable us to recover 62.5% of virus (Poliomylitis type I, Lsc strain) exsogeneously added to 400 liters of tap-water. The virus concentrator system consists of four cartridge filters, in which the three first one are clarifiers, where the contaminants are removed physically, without significant virus loss at this stage. The last cartridge filter is impregnated with ferric hydroxide gel, where the virus is adsorbed. After the required volume of water has been processed, the last filter is removed from the system and the viruses are recovered from the gel, using 1 liter of glycine/NaOH buffer, at pH 11. Immediately the eluate is clarified through series of cellulose acetate membranes mounted in a 142mm Millipore filter. For the second step of virus concentration, HC1 1N is added slowly to the eluate to achieve pH 3.5-4. MgC1, is added to give a final concentration of 0.05M and the viruses are readsorbed on a 0.45 , porosity (HA) cellulose acetate membrane, mounted in a 90 mm Millipore filter. The viruses are recovered using the same eluent plus 10% of fetal calf serum, to a final volume of 3 ml. In this way, it was possible to concentrate virus from 400 liters of tap-water, into 1 liter in the first stage of virus concentration and just to 3 ml of final volume in a second step. The efficiency, simplicity and low operational cost, provded by the method, make it feasible to study viral pollution of recreational and tap-water sources.

Metodología de diseño de filtros CRF/SCF basada en modelos de resonadores BAW acoplados acústicamente

La creixent utilització de sistemes de comunicacions mòbils ha impulsat la demanda de filtres passabanda miniaturitzats d'elevades prestacions operant en el rang de freqüències de microones. Els Film Bulk Acoustic Resonators (FBAR) estan esdevenint la principal alternativa als filtres basats en ressonadors Surface Acoustic Wave (SAW) o als basats en ressonadors ceràmics. Els Stacked Crystal Filters (SCF) i els Coupled Resonator Filters (CRF) són configuracions FBAR que permeten assolir una excel·lent atenuació en la banda de refús. Aquest treball presenta un innovador circuit equivalent elèctric que modela el CRF. Llavors, es desenvolupa una metodologia de síntesi de filtres per al SCF i per al CRF utilitzant els seus circuits equivalents elèctrics. La metodologia de disseny presentada permet obtenir les dimensions de l'estructura del filtre acústic partint de les especificacions del filtre i de les restriccions pròpies de la tecnologia. S'han implementat diferents respostes de Chebyshev per a sistemes de comunicacions reals per tal de validar el procediment de disseny dels filtres obtenint els resultats esperats.

Análisis y diseño de filtros apilados basados en resonadores acústicos

Durant els últims anys la demanda de filtres pas banda de ràdio freqüència, de reduïdes dimensions, lleugers i d'elevades prestacions destinats a sistemes de comunicacions inalàmbriques s'ha incrementat de forma significativa. Aquests sistemes principalment són els sistemes de telefonia mòbil de tercera generació UMTS y el sistema de navegació GPS. Els filtres actuals, basats en ressonadors SAW (Surface Acoustic Wave), tenen unes dimensions reduïdes però estan limitats en freqüència (3 GHz) i la seva tecnologia no és compatible amb les tecnologies estàndards de circuits integrats. Per aquestes raons s'espera que els filtres basats en ressonadors BAW (Bulk Acoustic Wave) substitueixin als SAW. Els dos tenen dimensions similars, però els filtres BAW poden funcionar a freqüències superiors a 3 GHz, poden treballar amb nivells de potència majors, i és important destacar el fet que la seva tecnologia és compatible amb les tecnologies estàndards de circuits integrats. La investigació en l'àmbit dels filtres BAW s'ha centrat en millorar els processos tecnològics i la qualitat dels materials, però s'ha treballat poc en l'adaptació de les tècniques sistemàtiques de disseny de filtres a les particularitats d'aquesta tecnologia, per tant el principal objectiu d'aquest treball és presentar mètodes sistemàtics per al disseny de filtres BAW, centrant-se en l'estudi d’estructures apilades.

Development of CBCT-based prostate setup correction strategies and impact of rectal distension.

BACKGROUND: Cone-beam computed tomography (CBCT) image-guided radiotherapy (IGRT) systems are widely used tools to verify and correct the target position before each fraction, allowing to maximize treatment accuracy and precision. In this study, we evaluate automatic three-dimensional intensity-based rigid registration (RR) methods for prostate setup correction using CBCT scans and study the impact of rectal distension on registration quality. METHODS: We retrospectively analyzed 115 CBCT scans of 10 prostate patients. CT-to-CBCT registration was performed using (a) global RR, (b) bony RR, or (c) bony RR refined by a local prostate RR using the CT clinical target volume (CTV) expanded with 1-to-20-mm varying margins. After propagation of the manual CT contours, automatic CBCT contours were generated. For evaluation, a radiation oncologist manually delineated the CTV on the CBCT scans. The propagated and manual CBCT contours were compared using the Dice similarity and a measure based on the bidirectional local distance (BLD). We also conducted a blind visual assessment of the quality of the propagated segmentations. Moreover, we automatically quantified rectal distension between the CT and CBCT scans without using the manual CBCT contours and we investigated its correlation with the registration failures. To improve the registration quality, the air in the rectum was replaced with soft tissue using a filter. The results with and without filtering were compared. RESULTS: The statistical analysis of the Dice coefficients and the BLD values resulted in highly significant differences (p<10(-6)) for the 5-mm and 8-mm local RRs vs the global, bony and 1-mm local RRs. The 8-mm local RR provided the best compromise between accuracy and robustness (Dice median of 0.814 and 97% of success with filtering the air in the rectum). We observed that all failures were due to high rectal distension. Moreover, the visual assessment confirmed the superiority of the 8-mm local RR over the bony RR. CONCLUSION: The most successful CT-to-CBCT RR method proved to be the 8-mm local RR. We have shown the correlation between its registration failures and rectal distension. Furthermore, we have provided a simple (easily applicable in routine) and automatic method to quantify rectal distension and to predict registration failure using only the manual CT contours.

Differential effect of long versus short wavelength light exposure on pupillary re-dilation in patients with outer retinal disease.

BACKGROUND: In patients with outer retinal degeneration, a differential pupil response to long wavelength (red) versus short wavelength (blue) light stimulation has been previously observed. The goal of this study was to quantify differences in the pupillary re-dilation following exposure to red versus blue light in patients with outer retinal disease and compare them with patients with optic neuropathy and with healthy subjects. DESIGN: Prospective comparative cohort study. PARTICIPANTS: Twenty-three patients with outer retinal disease, 13 patients with optic neuropathy and 14 normal subjects. METHODS: Subjects were tested using continuous red and blue light stimulation at three intensities (1, 10 and 100 cd/m2) for 13 s per intensity. Pupillary re-dilation dynamics following the brightest intensity was analysed and compared between the three groups. MAIN OUTCOME MEASURES: The parameters of pupil re-dilation used in this study were: time to recover 90% of baseline size; mean pupil size at early and late phases of re-dilation; and differential re-dilation time for blue versus red light. RESULTS: Patients with outer retinal disease showed a pupil that tended to stay smaller after light termination and thus had a longer time to recovery. The differential re-dilation time was significantly greater in patients with outer retinal disease (median = 28.0 s, P < 0.0001) compared with controls and patients with optic neuropathy. CONCLUSIONS: A differential response of pupil re-dilation following red versus blue light stimulation is present in patients with outer retinal disease but is not found in normal eyes or among patients with visual loss from optic neuropathy.

Nivells de radó en exterior i recintes tancats a la marjal càrstica de Peníscola

S’ha portat a terme un mostreig de diferents punts de la Marjal de Peníscola i 7 instal·lacions properes amb la finalitat de determinar les concentracions de 222Rn en aire exterior i interior. Les anàlisis en els punts exteriors obtenen unes concentracions de 222Rn elevades, superiors a 50 Bq·m-3 en alguns punts. El fet que el sòl de la marjal tingui altes concentracions de 226Ra i elevades concentracions de 226Ra i 222Rn en l’aigua salobre poden justificar aquests valors. L’alta activitat de l’aigua, les característiques de l’edifici i mala gestió del sistema de clavegueram de Peníscola són els responsables de les elevades concentracions de 222Rn en l’aire interior de la depuradora, amb concentracions màximes de més de 70000 Bq·m-3. Un sistema de ventilació adequat com un extractor de PVC evitaria l’acumulació del 222Rn a l’interior de la instal·lació.

Biodiversity of amoebae and amoebae-resisting bacteria in a drinking water treatment plant

The complex ecology of free-living amoebae (FLA) and their role in spreading pathogenic microorganisms through water systems have recently raised considerable interest. In this study, we investigated the presence of FLA and amoebae-resisting bacteria (ARB) at various stages of a drinking water plant fed with river water. We isolated various amoebal species from the river and from several points within the plant, mostly at early steps of water treatment. Echinamoeba- and Hartmannella-related amoebae were mainly recovered in the drinking water plant whereas Acanthamoeba- and Naegleria-related amoebae were recovered from the river water and the sand filtration units. Some FLA isolates were recovered immediately after the ozonation step, thus suggesting resistance of these microorganisms to this disinfection procedure. A bacterial isolate related to Mycobacterium mucogenicum was recovered from an Echinamoeba-related amoeba isolated from ozone-treated water. Various other ARB were recovered using co-culture with axenic Acanthamoeba castellanii, including mycobacteria, legionella, Chlamydia-like organisms and various proteobacteria. Noteworthy, a new Parachlamydia acanthamoebae strain was recovered from river water and from granular activated carbon (GAC) biofilm. As amoebae mainly multiply in sand and GAC filters, optimization of filter backwash procedures probably offers a possibility to better control these protists and the risk associated with their intracellular hosts

Monitor EMG con conexión inalámbrica

El sistema desarrollado en este trabajo permite la detección de fatiga del músculo de un paciente. Las señales electromiográficas generadas por el músculo son detectadas mediante electrodos superficiales, que sirven de entrada al circuito hacia los diferentes canales de entrada. Tras una primera etapa de amplificación, las señales son filtradas por un filtro pasabanda. Las señales acondicionadas se digitalizan mediante un conversor analógico digital que está conectado a un microcontrolador. Éste establece la comunicación con el PC enviándole los datos a través del puerto serie. Finalmente, mediante un programa implementado en Labview se procesan los datos y se determina la existencia o no de fatiga muscular.

Gestor d'avaluació online

Aquesta memòria tracta sobre el desenvolupament d’una aplicació web, amb tecnologia Ajax, per la gestió d’avaluacions de manera online. L’aplicació està destinada a facilitar la creació i correcció de proves i lliuraments per part dels usuaris professors i per automatitzar el procés de realització d’una prova i lliurament per part de l’alumne.

Procesamiento de imágenes biológicas

Este proyecto se ha desarrollado a petición del CSIC. El proyecto consiste en crear una aplicación que automatice la localización y obtención de la intensidad de unos puntos luminosos en las células que aparecen en el vídeo. También se desea identificar en qué estadio celular se encuentran las células y si los puntos hallados están en la zona del septim ring. Para ello, se ha hecho un estudio y probado dos métodos para la localización de los puntos y se ha realizado un filtro mediante Adaboost para la localización de las células. También se ha realizado una interfaz gráfica para el usuario final.

Padrões distributivos e zoogeografia dos moluscos da plataforma continental brasileira: Parte III. Comissão Oceanográfica Espiríto Santo I

One hundred senventy-five species of marine mollusks have been identified in the Expedition Espírito Santo I. Standing out the species Margarites olivaceus (Brown, 1827); Cyclostremiscus caraboboensis Weishord, 1962; Balcis gibba Folin, 1867; Triphora compsa (Dall, 1927); Henrya af. goldmani Bartsh, 1947 and Limaea subovata Jeffreys, 1876 as they have not been previously assigned to Brazil. The analysis of the geographical distribution patterns points out the dominance of the species with thermophiles affinities. This situation evidences the importance of the Brazilian Current in the maintanance of the biogeographical structure of the studied region. However, it is the analysis of the cryophiles species that shows the Cabo Frio region as an ecological filter quite more permeable to the species with thermophile affinities than to the cryophiles ones. The existence of this barrier and the endemism rate (4.27%) characterize the region that extends from the south of Cabo Frio as a transition between the two patterns cited above. Therefore they do not corroborate in malacological parameters the proposition made by Palacio (1982) for the individualization of the Paulista Province.

Long-term fluctuation of relative afferent pupillary defect in subjects with normal visual function.

PURPOSE: To determine whether the relative afferent pupillary defect (RAPD) remains constant over time in normal subjects. METHODS: Seventeen normal subjects were tested with infrared pupillography and automated perimetry in four sessions over 3 years. The changes in RAPD and visual field asymmetry between testing sessions were compared. RESULTS: The range of RAPD was 0.0 to 0.3 log unit, and the difference in the mean deviation between the eyes on automated static perimetry was 0 to 3 dB. Eight subjects repeatedly had an RAPD in the same eye. There was no correlation between the RAPD and the visual field asymmetry at the same visit. Changes in the magnitude of the RAPD between any two sessions were typically small (median, 0.08 log unit; 25th percentile, 0.04 log unit; 75th percentile, 0.15 log unit). CONCLUSIONS: Some normal subjects may show a persistent but small RAPD in the absence of detectable pathologic disease. Therefore, an isolated RAPD in the range of 0.3 log unit that is not associated with any other significant historical or clinical finding should probably be considered benign.

Oxidative potential for fine/ultrafine particles in occupational situations

Introduction : The redox properties of fine/ultrafine particles as well as nanoparticles (NP) are suggested to be important to explain their biological activity and could constitute a novel and promising metric for hazard evaluation. The acellular in vitro dithiothreitol (DTT) assay allows measuring this property. Objectives : (1) to evaluate sampling requirements for fine/ultrafine particle allowing measurement of their oxidative potential (2) to apply the methodology to occupational situations where particle from combustion sources are generated. Material and method : Sampling parameters (type of filters and loaded amount) and storage duration affecting the DTT measurements were evaluated. Based on these results, a methodological approach was defined and applied in two occupational situations where diesel and other combustion particles are present (toll station in a tunnel and mechanical yard for bus reparation). Results : Teflon filters loaded with diesel particles were found more suitable for the DTT assay, due to their better chemical inertness compared to quartz filters: after storage durations larger than 150 hours, an increased reactivity toward DTT was observed only with quartz filters. Reactivity was linearly correlated to the loaded mass until about 1000 μg/filter. Different redox reactivities were determined in both working places, with the mechanical yard presenting a higher DTT consumption rate. Discussion and conclusions : These results demonstrate the feasibility of this method to determine the oxidative potential of fine/ultrafine particles in occupational situations. We propose to include this approach for hazard assessment of work places with exposure to manufactured and other NP.

Reconocimiento de objetos multi-clase basado en descriptores de forma

Este trabajo presenta un sistema para detectar y clasificar objetos binarios según la forma de éstos. En el primer paso del procedimiento, se aplica un filtrado para extraer el contorno del objeto. Con la información de los puntos de forma se obtiene un descriptor BSM con características altamente descriptivas, universales e invariantes. En la segunda fase del sistema se aprende y se clasifica la información del descriptor mediante Adaboost y Códigos Correctores de Errores. Se han usado bases de datos públicas, tanto en escala de grises como en color, para validar la implementación del sistema diseñado. Además, el sistema emplea una interfaz interactiva en la que diferentes métodos de procesamiento de imágenes pueden ser aplicados.

Large Time-Varying Parameter VARs

In this paper we develop methods for estimation and forecasting in large timevarying parameter vector autoregressive models (TVP-VARs). To overcome computational constraints with likelihood-based estimation of large systems, we rely on Kalman filter estimation with forgetting factors. We also draw on ideas from the dynamic model averaging literature and extend the TVP-VAR so that its dimension can change over time. A final extension lies in the development of a new method for estimating, in a time-varying manner, the parameter(s) of the shrinkage priors commonly-used with large VARs. These extensions are operationalized through the use of forgetting factor methods and are, thus, computationally simple. An empirical application involving forecasting inflation, real output, and interest rates demonstrates the feasibility and usefulness of our approach.