444 research outputs found

    Memetic Pareto Evolutionary Artificial Neural Networks for the determination of growth limits of Listeria Monocytogenes

    Get PDF
    The main objective of this work is to automatically design neural network models with sigmoidal basis units for classification tasks, so that classifiers are obtained in the most balanced way possible in terms of CCR and Sensitivity (given by the lowest percentage of examples correctly predicted to belong to each class). We present a Memetic Pareto Evolutionary NSGA2 (MPENSGA2) approach based on the Pareto-NSGAII evolution (PNSGAII) algorithm. We propose to augmente it with a local search using the improved Rprop—IRprop algorithm for the prediction of growth/no growth of L. monocytogenes as a function of the storage temperature, pH, citric (CA) and ascorbic acid (AA). The results obtained show that the generalization ability can be more efficiently improved within a framework that is multi-objective instead of a within a single-objective one

    Effectiveness of XP-endo finisher in the reduction of bacterial load in oval-shaped root canals

    Get PDF
    This study investigated the effectiveness of XP-Endo Finisher (XPF) associated with XP-Endo Shaper (XPS) or Reciproc Blue (RB) files in reducing bacterial load in oval-shaped root canals (RC) during chemomechanical preparation (CMP) using 0.9% saline solution (NaCl) or 2.5% sodium hypochlorite (NaOCl). Eighty mandibular incisors with single oval-shaped RC were contaminated with Enterococcus faecalis. The teeth were randomly assigned to eight experimental groups (n = 10) according to the CMP, as follows: G1: XPS, G2: XPS + XPF, G3: RB, and G4: RB + XPF. CMP was performed with NaCl or NaOCl. The reduction of bacterial load was assessed by colony-forming unit count before (S1) and after (S2) CMP. Data normality was verified by using Shapiro-Wilk test. ANOVA, Tukey's test, and Bonferroni post-hoc test were used at a 5% significance level. Culturable bacteria were present in all S1 samples (p>0.05). All instrumentation techniques were effective in reducing bacterial load, irrespective of the irrigating solution (p < 0.05). With the use of NaCl, RB was more effective than XPS (p = 0.035). With the use of NaOCl, XPS and RB presented similar effectiveness (p = 0.779). XPF enhanced the bacterial reduction of both systems tested (p < 0.05). The use of NaOCl improved the CMP, irrespective of the instrumentation technique used (p < 0.05). In conclusion, XPS and RB files are effective in reducing bacterial levels in oval-shaped RC. The use of XPF as a method of agitation of the irrigating solution improved the cleaning efficiency of both file systems tested. Mechanical preparation performed with saline solution decreased culturable bacteria from the root canal, but antimicrobial substances such as NaOCl should be used to achieve a significantly better disinfection33CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP308162/2014-5não tem2015/23479-

    Anomalous tag diffusion in the asymmetric exclusion model with particles of arbitrary sizes

    Full text link
    Anomalous behavior of correlation functions of tagged particles are studied in generalizations of the one dimensional asymmetric exclusion problem. In these generalized models the range of the hard-core interactions are changed and the restriction of relative ordering of the particles is partially brocken. The models probing these effects are those of biased diffusion of particles having size S=0,1,2,..., or an effective negative "size" S=-1,-2,..., in units of lattice space. Our numerical simulations show that irrespective of the range of the hard-core potential, as long some relative ordering of particles are kept, we find suitable sliding-tag correlation functions whose fluctuations growth with time anomalously slow (t1/3t^{{1/3}}), when compared with the normal diffusive behavior (t1/2t^{{1/2}}). These results indicate that the critical behavior of these stochastic models are in the Kardar-Parisi-Zhang (KPZ) universality class. Moreover a previous Bethe-ansatz calculation of the dynamical critical exponent zz, for size S0S \geq 0 particles is extended to the case S<0S<0 and the KPZ result z=3/2z=3/2 is predicted for all values of SZS \in {Z}.Comment: 4 pages, 3 figure

    Biological attributes of the kissing bug Triatoma rubrofasciata from Vietnam

    Get PDF
    Background Triatoma rubrofasciata is the only kissing bug species distributed globally. In the Americas, this species transmits the parasite Trypanosoma cruzi, responsible for Chagas disease. The presence of T. rubrofasciata in several Asian countries has greatly increased recently. In Vietnam, it is found in large numbers, closely associated with human environments. Although T. rubrofasciata from Asia is not infected with Tryp. cruzi, it carries other parasites such as Trypanosoma lewisi and Trypanosoma conorhini. Reports of bites by T. rubrofasciata have increased significantly in several places of Vietnam, becoming a public health problem as it produces severe anaphylactic reactions. Methods Specimens of T. rubrofasciata were collected from seven provinces in central Vietnam. We analyzed different biological attributes (life-cycle, starvation resistance, feeding and reproductive capacities) and genetic characteristics (chromosomes and DNA sequences) of T. rubrofasciata from Vietnam and compared them with Brazilian specimens. Natural infection with Tryp. conorhini and Tryp. lewisi were analyzed in a sample of 100 collected insects. Results Species identification of T. rubrofasciata from central Vietnam was corroborated by genetic markers. Cytogenetic analyses showed that T. rubrofasciata from central Vietnam share the same chromosomal characteristics with individuals from Brazil and Hanoi. DNA sequence analyses of a mitochondrial cytochrome b gene fragment showed little variation between Old and New World specimens. Our study sample, compared with Brazilian individuals, showed a higher survival capacity revealed by a higher hatching rate (98% compared with 80.5%), a larger amount of blood taken in single meal and long-term starvation resistance. Furthermore, this species had a high natural rate of infection with Tryp. conorhini (46%) and Tryp. lewisi (27%). Conclusions For T. rubrofasciata of Vietnam, a high rate of fecundity throughout the year, a high capacity for starvation, and its occurrence in synanthropic environments of urban areas with a high availability of food sources are risk factors to be taken into account by vector control campaigns. The several allergic reactions caused by their bites and their high infection with Tryp. lewisi highlight the need to implement specific control programmes for T. rubrofasciata in Vietnam

    The evolution of mobile bed tests: a step towards the future of coastal engineering

    Get PDF
    Coastal Engineering still presents significant levels of uncertainty, much larger for sediment transport and morphodynamics than for the driving hydrodynamics. Because of that there is still a need for experimental research that addresses the water and sediment fluxes occurring at multiple scales in the near shore and for some of which there are still not universally accepted equations or closure sub-models. Large scale bed tests offer the possibility to obtain undistorted results under controlled conditions that may look at sediment transport and associated bed evolution under a variety of wave and mean water level conditions. The present limitations in conventional observation equipment preclude a clear advancement in knowledge or model calibration. However the new developments in opto-acoustic equipment should allow such an advancement to take place provided the new experimental equipment becomes more robust in parallel with a protocol for deployment and data processing. This paper will present the experimental approach to erosive and accretive beach dynamics, with emphasis on the accretive experiments. These accretive tests still present further uncertainties and sometimes cannot be explained with the present state of the art. Following this there is a presentation of the novel development of an acoustic bed form and suspended sediment imager, able to monitor bed forms near bed sediment transport and their corresponding dynamics. The next section deals with an acoustic high resolution concentration and velocity profiler that is able to infer even the elusive bed level, together with the near bed concentrated sediment transport and the details of fluxes on the stoss and lee sides of moving bed forms. This is followed by a discussion on the merits of novel optic techniques, using structured and unstructured light sources. There is also some remarks on new approaches. Illustrated by the use of ferro-fluids to obtain directly the shear stresses acting on a wall even under the presence of “some” sediment. The paper ends with some conclusions on the use of such mobile bed tests in present and future Coastal Engineering.Postprint (published version

    Quantum electromagnetic field in a three dimensional oscillating cavity

    Full text link
    We compute the photon creation inside a perfectly conducting, three dimensional oscillating cavity, taking the polarization of the electromagnetic field into account. As the boundary conditions for this field are both of Dirichlet and (generalized) Neumann type, we analyze as a preliminary step the dynamical Casimir effect for a scalar field satisfying generalized Neumann boundary conditions. We show that particle production is enhanced with respect to the case of Dirichlet boundary conditions. Then we consider the transverse electric and transverse magnetic polarizations of the electromagnetic field. For resonant frequencies, the total number of photons grows exponentially in time for both polarizations, the rate being greater for transverse magnetic modes.Comment: 11 pages, 1 figur

    Evolución del contenido en vitamina C en brócoli mínimamente procesado en fresco desinfectado con agua electrolizada y con recubrimientos comestibles

    Get PDF
    Tradicionalmente, los recubrimientos comestibles se han empleado con el fin de retrasar la senescencia del producto vegetal, estableciendo una protección natural. En este trabajo, se estudió el efecto de la aplicación de dos recubrimientos comestibles sobre la calidad y el contenido de vitamina C durante la vida comercial de brócoli “Parthenon” mínimamente procesado en fresco. El broccoli fue desinfectado con agua electrolizada neutra (AEN) (ORP= 830 mV; 5 ºC; pH=7; tiempo de contacto= 2 min). Posteriormente, se aplicaron dos recubrimientos comestibles: Naturcover® (5% de sucroesteres) y alginato de sodio (2 g/100 mL), empleando glicerol como plastificante (1,5 g/100 mL) y aceite de girasol como emulsionante. El producto fue almacenado bajo condiciones de atmosfera modificada (AM) durante 15 días a 5 ºC. Brócoli lavado con agua corriente a 5ºC fue considerado como testigo. Se estudió la calidad sensorial, la carga microbiana (mesófilos, enterobacterias y hongos y levaduras) y el contenido de vitamina C (ácido ascórbico y dehidroascórbico) de los floretes de brócoli ‘Parthenon’. La AM de equilibrio se alcanzó a los 3‐4 días de conservación y fue de 10‐ 12 kPa CO2 y 5‐11 kPa O2. La carga microbiana para los tres tipos de microrganismos estudiados estuvo situada entre 4 y 7 UFC g‐1 durante el almacenamiento refrigerado. El contenido de vitamina C el día inicial varió entre los 914.74 mg/kg materia fresca del tratamiento NEW y los 555.96 del tratamiento testigo. Como conclusión principal, el brócoli ‘Parthenon’ MPF tratado con NEW y Naturcover® mostraron una mejor calidad durante la vida comercial conservando el contenido de vitamina C inicial.Agradecer a la empresa Sakata SEEDS S.L.U. por la financiación necesaria para la elaboración de esta investigación, y a la Cooperativa Agrícola de Producción SACOJE por la donación del material vegetal

    Latitudinal Variation in the Toxicity and Sexual Compatibility of Alexandrium catenella Strains from Southern Chile

    Get PDF
    The bloom-forming toxic dinoflagellate Alexandrium catenella was first detected in southern Chile (39.5–55° S) 50 years ago and is responsible for most of the area’s cases of paralytic shellfish poisoning (PSP). Given the complex life history of A. catenella, which includes benthic sexual cysts, in this study, we examined the potential link between latitude, toxicity, and sexual compatibility. Nine clones isolated from Chilean Patagonia were used in self- and out-crosses in all possible combinations (n = 45). The effect of latitude on toxicity, reproductive success indexes, and cyst production was also determined. Using the toxin profiles for all strains, consisting of C1, C2, GTX4, GTX1, GTX3, and NeoSTX, a latitudinal gradient was determined for their proportions (%) and content per cell (pg cell−1), with the more toxic strains occurring in the north (−40.6° S). Reproductive success also showed a latitudinal tendency and was lower in the north. None of the self-crosses yielded resting cysts. Rather, the production of resting cysts was highest in pairings of clones separated by distances of 1000–1650 km. Our results contribute to a better understanding of PSP outbreaks in the region and demonstrate the importance of resting cysts in fueling new toxic events. They also provide additional evidence that the introduction of strains from neighboring regions is a cause for concern.En prens

    Effect of postharvest LED lighting in the phenolic content and scavenging free radicals in broccoli sprouts

    Get PDF
    [SPA] El objetivo fue evaluar el contenido de compuestos fitoquímicos en brotes de brócoli mínimamente procesados iluminados durante 15 días a 5ºC con LEDs blancas, azules, verdes, rojas y rojas lejanas. Se utilizaron tratamientos de oscuridad y luz Fluorescente como controles. Los germinados bajo iluminación LED blanca, azul, verde, roja y roja lejana mejoraron la capturación de radicales libres tras 8 días a 5ºC en un 61, 58, 54, 68 y 36%, respectivamente, en comparación con la oscuridad. Todos los tratamientos LED mantuvieron dichos incrementos en el porcentaje de captación de radicales tras 15 días a 5ºC. Estos resultados están en concordancia con el aumento de los compuestos fenólicos, en los que los brotes iluminados con LEDs durante 15 días a 5ºC mostraron un aumento respecto a la luz fluorescente y la oscuridad. En conclusión, nuestros resultados sugieren que los germinados mínimamente procesados pueden beneficiarse de la iluminación LED durante su vida útil en términos de sus compuestos nutracéuticos, especialmente bajo iluminación roja. [ENG] The objective was to evaluate phytochemical content changes in minimally processed broccoli sprouts illuminated for 15 days at 5ºC with white, blue, green, red and far red LEDs. darkness and fluorescent light (FL) were used as controls. Sprouts under white, blue, green, red, and far red LED lighting improved the free radical scavenging after 8 days at 5ºC by 61, 58, 54, 68, and 36%, respectively, compared to darkness. All LED treatments maintained these increases in the percentage of radical scavenging after 15 days at 5ºC. Such results agree with the increase in phenolic compounds, where sprouts illuminated with LEDs for 15 days at 5ºC showed an increase compared to FL and darkness. In conclusion, our results suggest that minimally processed sprouts can benefit from LED illumination during their shelf life in terms of their nutraceutical compounds, especially under red illumination.Se agradece la financiación a la Comunidad Autónoma de la Región de Murcia a través del Programa Regional de Fomento de la Investigación Científica y Técnica de la Fundación Séneca-Agencia de Ciencia y Tecnología de la Región de Murcia (Proyecto Ref 20849/PI/18) y al Ministerio de Economía y Competitividad la concesión de un contrato predoctoral a Noelia Castillejo (FPU/04763)

    Seismic structure of the northern continental margin of Spain from ESCIN deep seismic profiles

    Get PDF
    By the end of the Carboniferous, the crust of the continental shelf in northwestern Spain was made up of deeply rooted structures related to the Variscan collision. From Permian to Triassic times the tectonic setting had changed to mainly extensional and the northern Iberian continental margin underwent rifting during Late Jurassic-Early Cretaceous times, along with sea-floor spreading and the opening of the Bay of Biscay until the Late Cretaceous. Subsequently, the northern Iberian margin was active during the north-south convergence of Eurasia and Iberia in the Tertiary. A multichannel seismic experiment, consisting of two profiles, one north-south (ESCIN-4) crossing the platform margin offshore Asturias, and another (ESCIN-3) crossing the platform margin to the northwest of Galicia, was designed to study the structure of the northern Iberian margin. The ESCIN-4 stacked section reveals inverted structures in the upper crust within the Le Danois Basin. North of the steep continental slope, ESCIN-4 shows a thick sedimentary package from 6 to 9.5 s, two-way travel time (TWT). Within this latter package, a 40-km-long, north-tapering wedge of inclined, mainly south-dipping reflections is thought to represent a buried, Alpine-age accretionary prism. In the north western part of the ESCIN-3 (ESCIN-3-1) stacked section, horizontal reflections from 6.5 to 8.5 s correspond to an undisturbed package of sediments lying above oceanic-type basement. In this part of the line, a few kilometres long, strong horizontal reflection at 11.2 s within the basement may represent an oceanic Moho reflection. Also, a band of reflections dips gently towards the southeast, from the base of the gently dipping continental slope. The part of ESCIN-3 line that runs parallel to the NW-Galicia coast (ESCIN-3-2), is characterized by bright, continuous lower crustal reflections from 8 to 10 s. Beneath the lower crustal reflectivity, a band of strong reflections dips gently toward the southwest from 10 to 13.5 s. The part of ESCIN-3 that parallels the northern margin (ESCIN 3-3), shows good reflectivity in all levels. Upper crustal reflections image the sedimentary fill of probable Mesozoic to recent basins. Mid-crustal reflectivity is characterized by dipping reflections until 8 s that are probably related to compressional Variscan features. The lower crustal level shows 'layered' reflections between 8 and 12 s. Dipping reflections are found below the continental Moho.J. Alvarez-Marrón held a post-doc research grant from the Ministry of Education and Science of Spain. The ESCI-N program was sponsored by the Spanish agencies CICYT (project GEO 90-0660) and FICYT, and STRIDE Program of the EU.Peer Reviewe
    corecore