The Use of Rank Histograms and MVL Diagrams to Characterize Ensemble Evolution in Weather Forecasting

13 páginas, 9 figuras.-- El pdf del artículo es la versión pre-print.Rank Histograms are suitable tools to assess the quality of ensembles within an ensemble prediction system or framework. By counting the rank of a given variable in the ensemble, we are basically making a sample analysis, which does not allow us to distinguish if the origin of its variability is external noise or comes from chaotic sources. The recently introduced Mean to Variance Logarithmic (MVL) Diagram accounts for the spatial variability, being very sensitive to the spatial localization produced by infinitesimal perturbations of spatiotemporal chaotic systems. By using as a benchmark a simple model subject to noise, we show the distinct information given by Rank Histograms and MVL Diagrams. Hence, the main effects of the external noise can be visualized in a graphic. From the MVL diagram we clearly observe a reduction of the amplitude growth rate and of the spatial localization (chaos suppression), while from the Rank Histogram we observe changes in the reliability of the ensemble. We conclude that in a complex framework including spatiotemporal chaos and noise, both provide a more complete forecasting picture.We acknowledge financial support from MEC, Spain, through Grant No. CGL2007- 64387/CLI, and also thank the AECID, Spain, for support through projects A/013666/07 and A/018685/08. JAR thanks the MEC, Spain, for the award of a Juan de la Cierva fellowship. HSW thanks to the European Commission for the award of a Marie Curie Chair during part of the development of this work.Peer reviewe

In vitro dynamics of HIV-1 BF intersubtype recombinants genomic regions involved in the regulation of gene expression

HIV-1 intersubtype recombination is a very common phenomenon that has been shown to frequently affect different viral genomic regions. Vpr and Tat are viral proteins known to interact with viral promoter (LTR) during the replication cycle. This interaction is mainly involved in the regulation of viral gene expression, so, any structural changes in the LTR and/or these regulatory proteins may have an important impact on viral replication and spread. It has been reported that these genetic structures underwent recombination in BF variants widely spread in South America. To gain more insight of the consequences of the BF intersubtype recombination phenomenon on these different but functionally related genomic regions we designed and performed and in vitro study that allowed the detection and recovery of intersubtype recombinants sequences and its subsequent analysis. Our results indicate that recombination affects differentially these regions, showing evidence of a time-space relationship between the changes observed in the viral promoter and the ones observed in the Vpr/Tat coding region. This supports the idea of intersubtype recombination as a mechanism that promotes biological adaptation and compensates fitness variations

Efectos de las condiciones del pretratamiento osmótico en la capacidad antioxidante de frambuesas variedad heritage

Se determinó el efecto de las condiciones del pretratamiento osmótico en soluciones de sacarosa al 40% y 60% p/v, a diferentes temperaturas y tiempos sobre la capacidad antioxidantes en frambuesas. Se observó que ninguna de las combinaciones de las condiciones de los tratamientos osmóticos presentó influencia significativa sobre la capacidad antioxidante de las muestras tratadas.Facultad de IngenieríaCentro de Investigación y Desarrollo en Criotecnología de Alimento

Guinea-pig interpubic joint (symphysis pubica) relaxation at parturition: Underlying cellular processes that resemble an inflammatory response

BACKGROUND: At term, cervical ripening in coordination with uterine contractions becomes a prerequisite for a normal vaginal delivery. Currently, cervical ripening is considered to occur independently from uterine contractions. Many evidences suggest that cervical ripening resembles an inflammatory process. Comparatively little attention has been paid to the increased flexibility of the pelvic symphysis that occurs in many species to enable safe delivery. The aim of this study was to investigate whether the guinea-pig interpubic joint relaxation process observed during late pregnancy and parturition resembles an inflammatory process. METHODS: Samples of pubic symphysis were taken from pregnant guinea-pigs sacrificed along gestation, parturition and postpartum. Serial sections of paraffin-embedded tissues were used to measure the interpubic distance on digitalized images, stained with Giemsa to quantify leukocyte infiltration and to describe the vascular area changes, or studied by the picrosirius-polarization method to evaluate collagen remodeling. P4 and E2 serum levels were measured by a sequential immunometric assay. RESULTS: Data showed that the pubic relaxation is associated with an increase in collagen remodeling. In addition, a positive correlation between E2 serum levels and the increase in the interpubic distance was found. On the other hand, a leukocyte infiltration in the interpubic tissue around parturition was described, with the presence of almost all inflammatory cells types. At the same time, histological images show an increase in vascular area (angiogenesis). Eosinophils reached their highest level immediately before parturition; whereas for the neutrophilic and mononuclear infiltration higher values were recorded one day after parturition. Correlation analysis showed that eosinophils and mononuclear cells were positively correlated with E2 levels, but only eosinophilic infiltration was associated with collagen remodeling. Additionally, we observed typical histological images of dissolution of the connective tissue matrix around eosinophils. CONCLUSION: The present study shows that a timely regulated influx of infiltrating leukocytes is associated with an extensive collagen remodeling process that allows the pubic separation for a normal delivery in guinea-pig. Thus, the findings in this study support the hypothesis that the guinea-pig pubic symphyseal relaxation at parturition resembles an inflammatory process

Cinética de deshidratación osmótica de ciruelas D´Enté (<i>Prunus doméstica</i> L.)

El propósito del presente trabajo fue estudiar la cinética de deshidratación osmótica de ciruelas D´Enté (Prunus doméstica L.) evaluando el efecto de la concentración de la solución osmótica, el tipo de soluto, la temperatura, la relación fruta/solución y el tiempo de procesamiento sobre la humedad y el contenido de sólidos solubles. Fueron utilizadas para la deshidratación soluciones hipertónicas de jarabe de glucosa y sorbitol al 40 y 60% p/p durante 2 h a temperaturas de 25 y 40°C y con relaciones de fruta a agente osmótico de 1/4 y 1/10. El análisis de la varianza indicó que a diferencia de la temperatura del tratamiento osmótico, todas las variables ejercieron un efecto significativo sobre la humedad y el contenido de sólidos solubles de las ciruelas.Centro de Investigación y Desarrollo en Criotecnología de AlimentosFacultad de Ingenierí

Dehydration of nectaries (Prunus persica var. nectarina) by combined methods

La deshidratación se presenta como una alternativa para la conservación de frutos estacionales como las frutas de carozo, que permite proveer el producto durante todo el año, para el consumo directo como fruta seca o como ingrediente de otros productos alimenticios. Durante el desarrollo de este trabajo se deshidrataron pelones de la variedad Caldesi por métodos combinados de deshidratación osmótica (DO) y secado por aire caliente (SAC) bajo diferentes condiciones. En una primera etapa, mediante la inmersión de las frutas en soluciones concentradas de azúcares, se logró la reducción de su contenido de humedad y el incremento del contenido de sólidos solubles, obteniéndose un producto poco estable para su conservación; a posteriori, la segunda etapa de secado con aire caliente permitió obtener un producto final estable de buena calidad organoléptica. Los pelones se seleccionaron y se lavaron con agua a temperatura ambiente, luego se pelaron y se cortaron manualmente en porciones de 1/16 (~3,2 g). En la DO las muestras se sumergieron en soluciones hipertónicas de distintos agentes osmóticos (AO) tales como jarabe de glucosa y sorbitol en concentraciones del 40% p/p durante 2 h a temperaturas (TDO) de 25 y 40 °C ± 0,5°C. La deshidratación se llevó adelante mediante agitación continua a 331 rpm y utilizando relaciones de fruta a agente osmótico (FR-AO) de 1:4 y 1:10. Los pelones osmodeshidratados se secaron por aire caliente a distintas temperaturas (TSAC) de 60, 70 y 80 ºC ± 0,5°C durante 5 h en una estufa de convección forzada. Durante la deshidratación osmótica y el secado por aire caliente, a intervalos regulares las muestras fueron evaluadas en peso (balanza analítica, precisión ± 0,0001 g), contenido de humedad (M) y contenido de sólidos solubles (SS). Mediante un análisis de varianza (ANDEVA) con un 95% de confianza se evaluó el efecto de las distintas variables del proceso sobre la pérdida de agua (WL), la ganancia de sólidos solubles (SG), la razón de humedad (MR= M/Mo) y la razón de sólidos solubles (SR= SS/SSo) para la DO, y sobre la razón de humedad para el SAC. En la DO, la interacción (AO*FR-AO) presentó diferencias significativas para todas las variables estudiadas. El tiempo de tratamiento (TPO) sólo fue significativo para MR y SR. Las variables WL y SG fueron influenciadas significativamente por el (AO), la relación (FR-AO), la (TDO) y sus combinaciones. En el secado por aire caliente, la variable MR fue significativamente influenciada por el tiempo de tratamiento (TPO), el (AO), la relación (FR-AO), la (TSAC) y las interacciones (TPO*TSAC), (AO*FR-AO), (AO*TSAC) y (TDO*TSAC).Dehydration is an alternative for the preservation of seasonal stone fruits, because allows providing the product for direct consumption along the year and supplies dried fruit as an ingredient in other foodstuffs. In this work, nectarines of the Caldesi variety were dehydrated by combined methods based on osmotic dehydration (DO) and hot-air drying (SAC) under different conditions. In a first step, by immersing the fruit in concentrated sugar solutions, their moisture content was reduced and their content of soluble solids increased, yielding a poorly stable product for preservation; after then, the second stage of hot-air drying allows to obtain a very stable end-product with good organoleptic quality. The nectarines were selected and washed in water at room temperature; then, were manually peeled and cut into pieces of 1/16 (~3,2 g). During DO, samples were immersed in hypertonic solutions of different osmotic agents (AO) such as glucose syrup and sorbitol in concentrations of about 40% w/w for 2 hours at different temperatures (TDO) of 25 and 40°C ± 0.5°C. Dehydration was carried out at continuous agitation of 331 rpm and using relationships between fruit and osmotic agent (FR-AO) of 1:4 and 1:10. The osmodehydrated nectarines were dried by hot air at different temperatures (TSAC) of 60, 70 and 80ºC ± 0,5°C for 5 h in a forced convection oven. During osmotic dehydration and hot-air drying, at regular intervals, samples were evaluated in weight (analytical balance, precision ± 0,0001 g), moisture content (M) and total soluble solids (SS). An analysis of variance (ANOVA) with 95% of confidence was used to analyze the effect of different process variables on water loss (WL), soluble solids gain (SG), moisture ratio (MR = M/Mo) and the ratio of soluble solids (SR = SS/SSo) for DO, and on the moisture ratio for SAC. In the osmodehydration process, the interaction (FR-AO*AO) demonstrated significant differences for all variables studied. The treatment time (TPO) was only significant for MR and SR. The variables WL and SG were significantly influenced by the (AO), the ratio (FR-AO), the (TDO) and their combinations. In hot-air drying, the variable MR was significantly influenced by treatment time (TPO), the (AO), the ratio (FR-AO), the (TSAC) and the interactions (TPO*TSAC), (AO*FR-AO), (AO*TSAC) and (TDO*TSAC).Centro de Investigación y Desarrollo en Criotecnología de AlimentosFacultad de Ingenierí

Evaluating students' perception of Scrum through a learning game

Games for learning help students and professionals to incorporate new knowledge through a playful experience. With the popularization of virtual education (partially due to COVID-19), there is a need for new tools that complement virtual educational environments. To deal with this need, we present Scrum Game, a mobile application game that aims to support the Scrum software methodology teaching and training. Scrum Game offers 42 activities grouped in levels with specific learning goals. This paper reports on a controlled experiment that evaluates Scrum Game in a course with more than 160 students. We assessed Scrum Game's effectiveness in terms of (i) user performance (i.e., students' marks and number of levels/activities completed) and (ii) user experience (i.e., usability). We found that students who used Scrum Game outperformed those who did not use it. We also found that students think that Scrum Game exhibits an enjoyable user experience.Sociedad Argentina de Informática e Investigación Operativ

Characterization of Oct4-GFP transgenic mice as a model to study the effect of environmental estrogens on the maturation of male germ cells by using flow cytometry

Oct4 is involved in regulation of pluripotency during normal development and is down-regulated during formation of postnatal reservoir of germ cells. We propose thatOct4/GFP transgenic mouse, which mimics the endogenous expression pattern of Oct4, could be used as a mammalian model to study the effects of environmental estrogens on the development of male germ cells. Oct4/GFP maturation profile was assessed during postnatal days -PND- 3, 5, 7, 10, 14 and 80, using flow cytometry. Then, we exposed pregnant mothers to 17a-ethinylestradiol (EE2) from day post coitum (dpc) 5 to PND7. Percentage of Oct4/GFP-expressing cells and levels of expression of Oct4/GPF were increased in PND7 after EE2 exposure. These observations were confirmed by analysis of GFP and endogenous Oct4 protein in the seminiferous tubules and by a reduction in epididymal sperm count in adult mice. We introduced Oct4/ GFP mouse together with flow cytometry as a tool to evaluate changes in male germ cells development.Agencia Nacional de Investigación e InnovaciónFONCyT (Fondo para la InvestigaciónCientífica y Tecnológica de la Agencia Nacional de PromociónCientífica y Tecnológica, ANPCyT, Argentina)FOCEM (MERCOSUR Structural Convergence Fund), COF 03/11CONICET (becas doctoral y postdoctoral

Magnetocaloric properties of rapidly solidified Dy3Co alloy ribbons

"The magnetic and magnetocaloric (MC) properties of melt-spun ribbons of the Dy3Co intermetallic compound were investigated. Samples were fabricated in an Ar environment using a homemade melt spinner system at a linear speed of the rotating copper wheel of 40 ms(-1). X-ray diffraction analysis shows that ribbons crystallize into a single-phase with the Fe3C-type orthorhombic crystal structure. The M(T) curve measured at 5mT reveals the occurrence of a transition at 32K from a first to a second antiferromagnetic (AFM) state and an AFM-to-paramagnetic transition at T-N = 43 K. Furthermore, a metamagnetic transition is observed below T-N, but the magnetization change Delta M is well below the one reported for bulk alloys. Below 12 K, large inverse MC effect and hysteresis losses are observed. This behavior is related to the metamagnetic transition. For a magnetic field change of 5 T (2 T) applied along the ribbon length, the produced ribbons show a peak value of the magnetic entropy change Delta S-M(peak) of -6.5 (-2.1) Jkg(-1) K-1 occurring close to TN with a full-width at half-maximum delta T-FWHM of 53 (37) K, and refrigerant capacity RC = 364 (83) Jkg(-1) (estimated from the product vertical bar Delta S-M(peak)vertical bar x delta T-FWHM).