Las aplicaciones de inteligencia de negocio utilizan de manera más frecuente técnicas de inteligencia artificial para realizar predicciones, manejar la incertidumbre e incidir en la toma de ...decisiones organizacionales. El sistema ejecutivo para el seguimiento a estrategias organizacionales - BIMAS, es una solución informática para la gestión del desempeño e inteligencia empresarial, desarrollada y comercializada por la empresa cubana DESOFT que evalúa los indicadores claves de rendimiento de la empresa de manera rígida a través de rangos definidos por los usuarios. Esta evaluación de indicadores en el tiempo ha presentado resultados que en ocasiones no se ajustan a la realidad; al ser una evaluación dirigida por el usuario, no se han considerado intervalos de tiempo para la misma y lo que para algunos, un indicador puede resultar "bajo", para otros pudiera considerarse "medio" e incluso "alto". De ahí que el objetivo de este trabajo radique en implementar un modelo de inferencia borroso que tome en consideración aspectos objetivos y subjetivos que caracterizan el desempeño de los procesos en las organizaciones, eligiendo en este caso como términos para el análisis, el porciento de cumplimiento y el período de evaluación de cada indicador. Se pretende demostrar que con este modelo se obtienen evaluaciones flexibles y cercanas a la realidad, brindando a los decisores información confiable respecto a sus organizaciones.
Abstract
Early childhood education and care (ECEC) institutions are considered contexts wherein physical activity (PA) can be effectively promoted. Some approaches have been used in the early ...childhood setting to identify how teachers incorporate movement opportunities into the ECEC curriculum. However, studies are still scarce regarding pedagogical content knowledge (PCK) of structured and non-structured movement possibilities in toddler education (1–3 years old). Taking into account that working with toddlers requires specific training and sensitivity, the aim of the study was to assess ECEC educators’ and student teachers’ perceptions of what they know, how they transmit it, what kind of curricular practices they execute, and the didactic implications of movement opportunities in toddler education. This was an exploratory qualitative research study, in which open-ended, semi-structured qualitative interviews, plus qualitative content analysis of a written questionnaire, were conducted with 14 educators and 20 student teachers. Our results show that educators and students distinguish PCK in the different curricular practices related to movement, identifying differences between structured PA opportunities and free play opportunities. Educators and student teachers identified different sources of knowledge, barriers, and facilitators of structured movement opportunities in the ECEC toddler context, and they recognized that PA is important to young children’s development; however, little knowledge of PA guidelines to promote it was evident. Our findings contribute to understanding educators’ perceptions regarding movement as a curricular practice for children aged 1 to 3 years. Educators and public administration could find structured PA to be a complement to a harmonious development from a young age.
In this study we parameterize the textural attributes of plagioclase phenocrysts and microlites from nineteen pyroclasts ejected during mild to violent explosions at Stromboli over a timespan of ...∼18 years, from 2003 to 2021. By allying kinetic and crystal size distribution principles, we document that the morphological stability of large-sized, euhedral phenocrysts is superimposed on an internal textural heterogeneity due to growth-dissolution phenomena associated with the input rate of hot, H2O-rich recharge magmas rising from depth. As a result, the volumetric plagioclase proportion, dominant size, and number of phenocrysts per unit volume decrease from mild to violent explosions responding to a more efficient magma mixing process via sustained injections of mafic magmas into the shallow reservoir. On the other hand, the crystallization of anhedral plagioclase microlites is controlled by fast growth kinetics taking place in the uppermost part of the conduit during magma acceleration towards the surface. Under such highly dynamic crystallization conditions, the microlite number density closely depends on the increase of melt liquidus temperature via magma decompression and H2O exsolution. This mutualism allows to model the degassing rate and ascent velocity of magma under open-conduit flow regimes for the different eruptive styles, thereby supporting the idea that violent explosions at Stromboli are driven by sustained influxes of recharge magmas favoring strong acceleration (∼12–27 m/s), decompression (∼0.25–0.49 MPa/s), and H2O exsolution (∼0.005–0.01 wt%/s) before magma discharge at the vent.
•Plagioclase crystallization dominates scoria clasts erupted at Stromboli.•Plagioclase textural attributes markedly change as a function of the eruptive style.•Phenocrysts record the renewal rate of the shallow magmatic reservoir.•Microlites reflect conduit dynamics before magma discharge at the vent.
Petrological studies of active volcanoes typically focus on eruptive phenomena occurring over long timescales of the order of days to years, aiming at identifying major changes in the ...physico-chemical state of magma during ascent towards the surface. Exceptionally, we present results from an integrated petrological and statistical approach based on the compilation of ∼5300 major and trace element data for glass and crystals, in combination with volcanological data on eruptive events occurred over timescales of minutes at Stromboli volcano (Sicily). On May 11, 2019, we had the rare opportunity to collect individual fresh fallout ash products from eighteen mostly consecutive explosions, erupted in a 2-h time span and, at the same time, to acquire continuous high frequency (50 Hz) infrared thermal data of the same explosions. Through video analysis, we observe that explosions were more frequent and ash-dominated at the southwestern crater area (SCA, 8–10 events/h) than at the northeastern crater area (NCA, 3–5 events/h), where coarser material was ejected. The statistical analysis of glass and plagioclase compositions reveals differences in the products erupted from the two crater areas. SCA explosions tapped less differentiated magmas (Mg#∼42–46, ∼257–365 LaN, ∼0.7–0.9 Eu/Eu*) in equilibrium with more anorthitic plagioclase cores (An∼72–88), whereas NCA area explosions are more differentiated (Mg#∼40–44, ∼286–387 LaN, ∼0.6–0.8 Eu/Eu*) and in equilibrium with less anorthitic plagioclase cores (An∼68–82). Thermometric calculations based on major and trace element clinopyroxene-plagioclase-melt equilibrium modeling highlight that the SCA explosions were statistically fed by hotter magmas in comparison to NCA explosions. Plagioclase-based diffusion modeling also indicates longer timescales for the dynamic ascent of NCA magmas, leading to preferential groundmass crystallization at the conduit walls and transition from sideromelane to tachylite groundmass textures. The final emerging picture is that in May 2019, concurrent normal eruptions from different crater areas at Stromboli were heralds of compositionally and thermally diverse magmas rising at different rates within the uppermost branched part of the conduit region. High frequency petrological investigations aided by statistical treatment of data have the potential to constrain dynamic conduit processes related to transient, explosive eruptions in persistently active volcanoes, thereby offering new insights on the interplay between magma dynamics, ascent timescales, and eruptive behavior.
•High-frequency eruption sampling at Stromboli reveals subtle chemical changes.•Sample compositions and textures differ between the two crater areas.•Thermal and compositional gradients are reconstructed in the shallow mush system.•Crystallization is promoted by slower magma ascent rates at the conduit walls.
Gomesa bifolia (Orchidaceae, Cymbidieae, Oncidiinae) is an epiphytic orchid that presents showy yellow flowers with brown markings on sepals and petals, fragranceless and with oil as reward. The ...floral biology of this species was studied in cultivated individuals to describe phenology, flower longevity, reproductive system (using manipulative treatment of cross-pollination vs. self-pollination) and floral pollinators. Moreover, direct observations were made on plants exposed outdoors to identify pollinators, describing their foraging behavior and the duration of visits. The results showed that G. bifolia is a mainly self-incompatible, non-autogamous and pollinator-dependent species. The fruit set in manually cross-pollination flowers (100%) was higher than the manually self-pollinated flowers (30.8%), whereas the control flowers did not set fruits. Females of Centris trigonoides (Apidae, Centridini) were the exclusive pollinators, and the visit rate was low. Several Neotropical orchids of the subtribe Oncidiinae offer floral oils to the pollinators, like the Malpighiaceae familiy. Our results allow inferring that both groups of plants would be part of a guild of species pollinated by oil-collecting bees and that the deceit/pollination syndrome should not be applied to all Oncidiinae flowers. Gomesa bifolia (Orchidaceae, Cymbidieae, Oncidiinae) es una orquídea epífita que presenta vistosas flores amarillas con marcas marrones en los sépalos y pétalos, carentes de fragancia y con aceite como recompensa. La biología floral de esta especie fue estudiada en individuos cultivados para describir la fenología, longevidad floral, conocer el sistema reproductivo (mediante tratamientos manipulativos de auto-polinización vs. polinización cruzada) y sus polinizadores. Además, se realizaron observaciones directas sobre plantas expuestas al aire libre para identificar a los polinizadores, describiendo su comportamiento de forraje y la duración de las visitas. Los resultados obtenidos revelan que G. bifolia es una especie principalmente auto-incompatible, no autógama y dependiente de sus polinizadores. La formación de frutos en flores tratadas con polinización cruzada manual (100%) fue superior a las flores manualmente auto-polinizadas (30,8%); mientras que las flores no tratadas no formaron frutos. Los únicos polinizadores observados fueron hembras de Centris trigonoides (Apidae, Centridini), y la tasa de visitas fue baja. Numerosas orquídeas Neotropicales de la subtribu Oncidiinae ofrecen aceites florales a sus polinizadores, como lo hacen los representantes de la familia Malpighiaceae. Los resultados obtenidos también permiten inferir que ambos grupos de plantas estarían formando parte de un gremio de especies polinizadas por abejas colectoras de aceites y que el síndrome de polinización por engaño no es verdadero para todas las especies de Oncidiinae.
The resuspension of volcanic ash by wind is a significant source of hazard during and after volcanic eruptions. Parameterizing and modeling ash resuspension requires direct measurement of the minimum ...wind shear stress required to move particles, usually expressed as the threshold friction velocity U⁎th, a parameter that, for volcanic ash, has been measured only scarcely and always in the laboratory. Here, we report the first field measurements of U⁎th for volcanic ash, with a portable wind tunnel specifically developed, calibrated, and tested. Field measurements, performed on natural reworked ash deposits from Sakurajima (Japan) and Cordón Caulle (Chile) volcanoes, agree well with our laboratory determinations on ash from the same deposits, with values of U⁎th ranging from 0.13 to 0.38 m/s. Our results show that the median grain size of the deposit and particle shape have a stronger control on U⁎th than the local substratum nature and deposit texture.
•We measured wind erosion threshold friction velocity of volcanic ash in the field.•Field measurements are efficient, cheap, fast, and congruent with laboratory ones.•Shape and median grain size of particles exert first order control on resuspension.•Ash resuspension is controlled secondarily by local substratum and deposit textures.
Early childhood education and care (ECEC) is an environment where binary discourses produce gendered bodies. Following a qualitative approach, this study has two major aims: (a) to analyze ECEC ...educators' and parents' perception regarding gender as a correlate for explaining toddlers' physical activity (PA) and (b) to discuss from a critical perspective how these perceptions could impact PA promotion from a very young age. The major findings were as follows: while some educators perceive no differences in PA patterns between girls and boys, others consider that girls are less active than boys and attribute this tendency to a greater propensity for symbolic play and biological determinants; and families perceive that their daughters are physically active and with natural predisposition to movement. In conclusion, despite the fact that some teachers' perceptions of young children continue to be encouraged into binary gendered practices, families show resistance and alternative ways to interpret the emphasized femininity.
Coronavirus disease 2019 (COVID-19) is perceived as the worst modern-times pandemic. This entirely new health situation entailed a new challenge to the education system. To our knowledge, the impact ...of alternative teaching methods derived from the social distancing imposed by COVID-19 on university student perception in teacher education has not been investigated. The aim of this study was to analyse an educative experience developed in a Faculty of Teaching from March 2020 to July 2020 in order to overcome the challenge imposed by COVID-19. A qualitative approach was used for data collection and analysis using four information sources: (a) The final written documents developed by the working groups (b) The online oral presentation of their work (c) The semi-structured interviews conducted through videoconferencing during the lockdown and, (d) The focus groups meetings. We have identified 8 major categories. Our results show that: (a) students find videoconferences are a tool that offsets the issues of social distancing; (b) intrinsic motivation is essential to overcome the perceived barriers; (c) the move to a virtual environment allowed students to deepen their methodological skills; (d) students now see themselves more competent regarding academic information research; e) the constant interaction among group members and the teacher is a key element to achieve a positive experience during social isolation; (f) new logistic and operational dynamics for cooperative working were constructed as a result of using videoconferences. We highlighted the barriers and facilitators perceived by students during the implementation of a tutorial action during the COVID-19 pandemic.
We present the results of laboratory experiments that quantify the physical controls on the thickness of the falling film of liquid around a Taylor bubble, when liquid-gas interfacial tension can be ...neglected. We find that the dimensionless film thickness λ′ (the ratio of the film thickness to the pipe radius) is a function only of the dimensionless parameter , where ρ is the liquid density, g the gravitational acceleration, D the pipe diameter and μ the dynamic viscosity of the liquid. For , the dimensionless film thickness is independent of Nf with value λ′ 0.33; in the interval , λ′ decreases with increasing Nf; for film thickness is, again, independent of Nf with value λ′ 0.08. We synthesize existing models for films falling down a plane surface and around a Taylor bubble, and develop a theoretical model for film thickness that encompasses the viscous, inertial and turbulent regimes. Based on our data, we also propose a single empirical correlation for λ′(Nf), which is valid in the range 10−1<Nf<105. Finally, we consider the thickness of the falling film when interfacial tension cannot be neglected, and find that film thickness decreases as interfacial tension becomes more important.
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