Testimoni de premsa, ràdio i televisió

Testimoni de premsa, ràdio i televisi

Relationship among acceleration, change of direction ability and horizontal jump performance in young athletes.

The aim of this study was to analyze the relationship among the straight acceleration capacity, the change of direction ability (CODA) and the horizontal jumping (HJ) performance in young athletes. This study involved a total of 264 young athletes aged between 8 and 16 years (10.2 ± 2.6 years; 37.5 ± 11.7 kg, 1.4 ± 0.1 m, 17.7 ± 2.4 kg·m-2). The 5 and 15 m straight acceleration capacity, the CODA in the 505 test (505) and modified agility test (MAT), the horizontal counter movement jump (HCMJ) and the horizontal arm swing counter movement jump (HCMJAS) were assessed. The relationship between acceleration capacity in 5 m and CODA (505: r = 0.54, p 0.05) were more consistent than the association among 15 m test and CODA or HJ. The association between MAT test and HJ (HCMJ: r = -0.73, p <0.01; HCMJAS: r = -0.74, p <0.01) was higher than the relationship between 505 test and HCMJ (r = -0.63, p <0.01) or 505 test and HCMJAS (r = -0.61, p <0.01). The type, the duration and the nature of these field tests determine the associations among different motor skills. KEY WORDS: athletic, training, motor skills, agility, strengthEl objetivo de este estudio fue analizar la asociación existente entre la capacidad de aceleración en línea recta, la capacidad de cambiar de dirección (CODA) y la capacidad de salto horizontal (SH) en jóvenes atletas. En este estudio participaron un total de 264 jóvenes atletas de entre 8 y 16 años (10,2 ± 2,6 años; 37,5 ± 11,7 kg; 1,4 ± 0,1 m, 17,7 ± 2,4 kg·m-2). Se evaluó la capacidad de aceleración en línea recta en los test de 5 y 15 m, la CODA en el test 505 (505) y en el modified agility test (MAT) y la capacidad de SH con contra movimiento (HCMJ) y manos libres (HCMJAS). La asociación entre la capacidad de aceleración en 5 m y los test de CODA (505: r = 0,54, p 0,05) fue más consistente que la asociación entre la aceleración en 15 m y los test de CODA o SH. La asociación entre el test MAT y el SH (HCMJ: r = -0,73, p < 0,01 y HCMJAS: r = -0,74, p < 0,01) fue mayor que la relación observada entre el 505 y el HCMJ (r = -0,63, p < 0,01) o el HCMJAS (r = -0,61, p < 0,01). El tipo, la duración y la naturaleza de los test de campo utilizados, condicionan las asociaciones observadas entre las distintas habilidades motoras

Prioritizing bona fide bacterial small RNAs with machine learning classifiers

Bacterial small (sRNAs) are involved in the control of several cellular processes. Hundreds of putative sRNAs have been identified in many bacterial species through RNA sequencing. The existence of putative sRNAs is usually validated by Northern blot analysis. However, the large amount of novel putative sRNAs reported in the literature makes it impractical to validate each of them in the wet lab. In this work, we applied five machine learning approaches to construct twenty models to discriminate bona fide sRNAs from random genomic sequences in five bacterial species. Sequences were represented using seven features including free energy of their predicted secondary structure, their distances to the closest predicted promoter site and Rho-independent terminator, and their distance to the closest open reading frames (ORFs). To automatically calculate these features, we developed an sRNA Characterization Pipeline (sRNACharP). All seven features used in the classification task contributed positively to the performance of the predictive models. The best performing model obtained a median precision of 100% at 10% recall and of 64% at 40% recall across all five bacterial species, and it outperformed previous published approaches on two benchmark datasets in terms of precision and recall. Our results indicate that even though there is limited sRNA sequence conservation across different bacterial species, there are intrinsic features in the genomic context of sRNAs that are conserved across taxa. We show that these features are utilized by machine learning approaches to learn a species-independent model to prioritize bona fide bacterial sRNAs

Summer drought and spring frost, but not their interaction, constrain European beech and Silver fir growth in their southern distribution limits

Climate warming has lengthened the growing season by advancing leaf unfolding in many temperate tree species. However, an earlier leaf unfolding increases also the risk of frost damage in spring which may reduce tree radial growth. In equatorward populations of temperate tree species, both late frosts and summer droughts impose two constraints to tree growth, but their effects on growth are understudied. We used a tree-ring network of 71 forests to evaluate the potential influence of late frosts and summer droughts on growth in two tree species that reach their southern distribution limits in north-eastern Spain: the deciduous European beech (Fagus sylvatica L.) and the evergreen Silver fir (Abies alba Mill). The occurrence of late frost events and summer drought was quantified by using a high-resolution daily temperature and precipitation dataset considering the period 1950 2012. Late frosts were defined as days with average temperature below 0 °C in the site-specific frost-free period, whereas drought was quantified using the 18 month-long August Standardized Precipitation Evapotranspiration Index (SPEI). The growth of European beech and Silver fir was reduced by the occurrence of both late frost events and summer drought. However, we did not find a significant interaction on growth of these two climate extremes. Beech was more negatively impacted by late frosts, whereas Silver fir was more impacted by summer drought. Further studies could use remote-sensing information or in situ phenological records to refine our frost index and better elucidate how late frosts affect growth, whether they interact with drought to constrain growth, and how resilience mechanisms related to post-frost refoliation operate in beech. © 2019 Elsevier B.V

Development of a dairy fouling model to assess the efficacy of cleaning procedures using alkaline and enzymatic products

Dairy fouling is defined as the accumulation of thermally insulating materials or deposits from process fluids which are especially formed on heat transfer surfaces. The selection of suitable cleaning strategies to remove dairy fouling requires the understanding of its composition and the relationships with the surfaces where it is formed. For the industry, the development of novel strategies to test cleaning products, as well reducing water and energy consumption during the dairy processing operations is of enormous interest. The results showed the development of a laboratory-milk fouling model (MFM) with an average content of 52.8 mg/cm2 of fouling in the test coupons. Seven different cleaners were tested with a fouling removal effectiveness of between 55% and 97%. Additionally, for evaluating the cleaning process of the model, the turbidity of the cleaning solutions was assessed. We presented an enzymatic alternative to the use of traditional cleaning products, with a similar efficacy against the dairy fouling. 78% of fouling removal after the use of enzymatic solution, in comparison to the 72% of fouling removal after the use of alkaline cleaning products. A reduction in water (−33.3%) and temperature (−28.5%), as well as shorter cleaning times (−33%) than its chemical alternative, was observed.info:eu-repo/semantics/acceptedVersio

Chatbots and messaging platforms in the classroom: An analysis from the teacher’s perspective

Messaging platforms are applications, generally mediated by an app, desktop program or the web, mainly used for synchronous communication among users. As such, they have been widely adopted officially by higher education establishments, after little or no study of their impact and perception by the teachers. We think that the introduction of these new tools and the opportunities and challenges they have needs to be studied carefully in order to adopt the model, as well as the tool, that is the most adequate for all parties involved. We already studied the perception of these tools by students, in this paper we examine the teachers’ experiences and perceptions through a survey that we validated with peers, and what they think these tools should make or serve so that it enhances students learning and helps them achieve their learning objectives. The survey has been distributed among tertiary education teachers, both in universitary and other kind of tertiary establishments, based in Spain (mainly) and Spanish-speaking countries. We have focused on collecting teachers’ preferences and opinions on the introduction of messaging platforms in their day-to-day work, as well as other services attached to them, such as chatbots. What we intend with this survey is to understand their needs and to gather information about the various educational use cases where these tools could be valuable. In addition, an analysis of how and when teachers’ opinions towards the use of these tools varies across gender, experience, and their discipline of specialization is presented. The key findings of this study highlight the factors that can contribute to the advancement of the adoption of messaging platforms and chatbots in higher education institutions to achieve the desired learning outcomes

Optimization of the efficiency in an induction machine drive by algorithm based on the interior point method

[EN] This work optimizes the efficiency of the squirrel cage type Inverter-Induction Machine (IM) system, using an algorithm based on the Interior Point Method (IPM), where the input variables are the electromagnetic torque and the rotor speed at steady state,and as outputs the optimal efficiency and slip values are obtained. The optimum rotor flux value is calculated, which is used as a reference in the flux control loop, in the direct control vector method of the IM. Simulation results are obtained where the increase in efficiency is observed in low load states. The experimental installation used in the implementation of the vector control with maximum system efficiency is described, and the experimental results obtained are shown. A discussion is carried out on the results and the use of the Interior Point Optimization Method.[ES] En este trabajo se realiza la optimización de la eficiencia del sistema  Inversor-Máquina de Inducción (MI) del tipo jaula de ardilla, utilizando un algoritmo basado en el Método de Punto Interior (MPI), donde las variables de entrada son el par electromagnético y la velocidad del rotor en estado estacionario, y como salidas se obtienen los valores de la eficiencia óptima y del deslizamiento. Se calcula el valor del flujo óptimo del rotor que se utiliza como referencia en el lazo de control del flujo, en el control vectorial método directo de la MI. Se obtienen resultados de simulación donde se observa el incremento de la eficiencia en estados de baja carga. Se describe la instalación experimental usada en la implementación del control vectorial con máxima eficiencia del sistema, y se muestran los resultados experimentales obtenidos. 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First modern human settlement recorded in the Iberian hinterland occurred during Heinrich Stadial 2 within harsh environmental conditions

As the south-westernmost region of Europe, the Iberian Peninsula stands as a key area for understanding the process of modern human dispersal into Eurasia. However, the precise timing, ecological setting and cultural context of this process remains controversial concerning its spatiotemporal distribution within the different regions of the peninsula. While traditional models assumed that the whole Iberian hinterland was avoided by modern humans due to ecological factors until the retreat of the Last Glacial Maximum, recent research has demonstrated that hunter-gatherers entered the Iberian interior at least during Solutrean times. We provide a multi-proxy geoarchaeological, chronometric and paleoecological study on human–environment interactions based on the key site of Peña Capón (Guadalajara, Spain). Results show (1) that this site hosts the oldest modern human presence recorded to date in central Iberia, associated to pre-Solutrean cultural traditions around 26, 000 years ago, and (2) that this presence occurred during Heinrich Stadial 2 within harsh environmental conditions. These findings demonstrate that this area of the Iberian hinterland was recurrently occupied regardless of climate and environmental variability, thus challenging the widely accepted hypothesis that ecological risk hampered the human settlement of the Iberian interior highlands since the first arrival of modern humans to Southwest Europe. © 2021, The Author(s)

Producción de ovino de carne en medio semiárido

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