The Effect of Eight-Week Functional Core Training on Core Stability in Young Rhythmic Gymnasts: A Randomized Clinical Trial

All data files are available from the figshare database: https://doi.org/10.6084/m9.figshare.16810885.v1 (accessed on 29 January 2022)[Abstract] It is suggested that core stability (CS) might improve rhythmic gymnasts' performance. Nevertheless, the effect of core stability training (CST) in CS performance is not clear. Purpose: Evaluating the effect of an eight-week functional CST on young rhythmics gymnasts' CS performance. Method: A sample of 45 young female rhythmic gymnasts from a competitive team (age = 10.5 ± 1.8 years, height = 144.1 ± 10.6 cm, weight 38.2 ± 8.9 kg, peak height velocity (PHV) = 12.2 ± 0.6 years) participated in the study. The participants were randomly allocated into the control group (CG) and experimental group (EG) and completed pre-tests and post-tests of specific CS tests using a pressure biofeedback unit (PBU). The CS was assessed by the bent knee fall out (BKFO), the active straight leg raise (ASLR) tests and the pelvic tilt test, all performed on the right and left sides. The EG (n = 23) performed an eight-week functional CST program based on rhythmic gymnastics (RG) technical requirements added to the traditional RG training sessions. Meanwhile, the CG (n = 22) received the traditional RG training sessions. Results: Mixed model analysis showed non-significant interaction effects; however, the ANOVA omnibus test showed a time effect (p < 0.05) in right BKFO (F1,42 = 4.60; p = 0.038) and both pelvic tilt tests (right F1,42 = 22.01, p < 0.001; left F1,42 = 19.13, p < 0.001). There were non-significant interaction effects. The fixed effects estimated parameters for right BKFO showed that both groups had less pressure variation after intervention compared with pre-intervention (β = -1.85 mmHg, 95%CI = [-3.54 to -0.16], t42 = -2.14, p = 0.038). Furthermore, the left pelvic tilt (β = 37.0 s, 95%CI = [20.4 to 53.6], t42 = 4.37, p < 0.001) improved 8.9 s more than the right pelvic tilt (β = 28.1 s, 95%CI = [16.3 to 39.8], t42 = 4.69, p < 0.001) considering both groups together. Conclusions: Adding a functional CST to regular training showed a trend in improving the performance of CS-related variables, which could help improve RG-specific performance. Coaches working with rhythmic gymnasts should consider adding a functional CST to regular training to improve CS performance leading to increased specific RG performance.https://doi.org/10.6084/m9.figshare.16810885.v

Local adaptation of Ruellia nudiflora (Acanthaceae) to biotic counterparts: complex scenarios revealed when two herbivore guilds are considered

This study evaluated whether the herb Ruellia nudiflora is locally adapted to a specialist insect seed predator (SP) and insect folivores, and if plant local adaptation (LA) to the former is more likely. A reciprocal transplant experiment was conducted using three sites in Yucatan (Mexico) (n = 864 plants). A third of the plants of each origin were placed at each site, and we recorded the following during a 9-month period: fruit number, leaf damage, and fruits attacked by SP. Results indicated lack of plant LA for all the variables measured. Instead, seed predation was c. 100% greater for native plants at one study site, suggesting insect LA or plant maladaptation; folivory was homo- geneous across sites ⁄ origins. Based on these results, we discuss differences in the potential each herbivore guild has to promote plant LA, as well as divergent evolutionary outcomes of plant–herbivore interactions across sites.Peer reviewe

Selection and pemanence at higher education: the case of Autonomous University of Yucatán

En la actualidad, la demanda para ingresar a las Instituciones de Educación Superior supera en mucho a la oferta de espacios disponibles. Por lo que se utilizan pruebas nacionales estandarizadas a gran escala diseñadas para apoyar la selección de los alumnos de nuevo ingreso. En el presente trabajo se presentan los resultados obtenidos por los estudiantes seleccionados en el curso 2005-2006 de la Universidad Autónoma de Yucatán. La prueba usada es conocida como EXANI II y fue diseñada por el Centro Nacional de Evaluación para la Educación Superior, A.C. (CENEVAL). Los resultados en el EXANI-II fueron correlacionados con el desempeño y riesgo escolar en los primeros cuatro periodos, para determinar en qué medida el examen de selección se asocia a la trayectoria escolar. Se encontraron relaciones entre los resultados de ciertas áreas del examen y las variables de desempeño escolar y riesgo de abandono de los estudios. Para el campus de Ciencias de la salud, no se encontró correlación entre el desempeño en el EXANI-II y el desempeño escolar hasta el cuarto semestre. En los campus de Ciencias sociales, Ciencias Biológicas y Agropecuarias y Ciencias Exactas e Ingenierías se encontraron relaciones significativas entre el desempeño en el EXANI-II y el desempeño escolar hasta el cuarto semestre, en áreas diferentes del exame

Influence of multiple factors on plant local adaptation: soil type and folivore effects in Ruellia nudiflora (Acanthaceae)

Different environmental factors can have contrasting effects on the extent of plant local adaptation (LA). Here we evaluate the influence of folivory and soil type on LA in Ruellia nudiflora by performing reciprocal transplants at two sites in Yucatan (Mexico) while controlling for soil source and folivory level. Soil samples were collected at each site and half of the plants of each source at each site were grown with one soil source and half with the other. After transplanting, we reduced folivory by using an insecticide applied to half of the plants of each population source grown on each soil at each site. This resulted in a fully-crossed design with site, population source, soil source and folivory as main effects. We evaluated LA by means of a significant site 9 origin interaction showing a home-site advantage of native plants. Additionally, to test for an effect of soil source and folivores on LA, we estimated the three-way interactions of site 9 origin 9 soil source and site 9 origin 9 folivory. We recorded fruit number and survival throughout an 8-month period. For survival, we found evidence of home-site advantage at one site, while for fecundity we found no evidence of LA and at one site even observed evidence of lower fecundity for local relative to foreign plants. Importantly, folivory had no influence on the degree of home-site advantage for either response variable, while soil source influenced the degree of home-site advantage in fecundity at one site (suggesting some degree of spe- cialization to soil characteristics in R. nudiflora). Our results emphasize the need for simultaneously evaluating multiple factors of influence in tests of LA.Peer reviewe

NMR Structural Study of the Prototropic Equilibrium in Solution of Schiff Bases as Model Compounds

An NMR titration method has been used to simultaneously measure the acid dissociation constant (pKa) and the intramolecular NHO prototropic constant ΔKNHO on a set of Schiff bases. The model compounds were synthesized from benzylamine and substituted ortho-hydroxyaldehydes, appropriately substituted with electron-donating and electron-withdrawing groups to modulate the acidity of the intramolecular NHO hydrogen bond. The structure in solution was established by 1H-, 13C- and 15N-NMR spectroscopy. The physicochemical parameters of the intramolecular NHO hydrogen bond (pKa, ΔKNHO and ΔΔG°) were obtained from 1H-NMR titration data and pH measurements. The Henderson–Hasselbalch data analysis indicated that the systems are weakly acidic, and the predominant NHO equilibrium was established using Polster–Lachmann δ-diagram analysis and Perrin model data linearization

Environmental Factors That Affect the Sanitary and Nutritional Variability of Raw Milk in Dual Purpose Livestock Systems of Colombian Orinoquia

Milk is the natural food with the highest biological quality for the human population and its production can be affected by several sanitary factors and management conditions. With the objective of identifying influence factors on milk compositional and sanitary quality in a region with wide productive potential in the Colombian Orinoquia, an experiment was carried out in two contrasting climatic seasons. For the milk compositional analysis, samples of daily production from 30 dual-purpose systems were analyzed. Similarly, the udder sanitary status of 300 cows was studied using the California Mastitis Test (CMT). Data analysis included mixed models, Pearson correlations, frequency tables, and the Kruskal–Wallis test. The results showed that the total daily milk production of the farm and the season influenced the milk compositional quality. The farms with milk productions lower than 100 kg/day presented the highest levels of protein, lactose, solid non-fat (SNF), and density, while in the rainy season, the milk quality was higher compared to the dry season. The CMT test indicated that only 7.6% of the evaluated mammary quarters presented two or more degrees of positivity. There is an opportunity to improve the milk compositional quality by improving the nutritional offer for animals during the year. The low CMT positivity indicates that, in the calf-at-foot milking system, the presence of subclinical mastitis is not a determining variable in milk production

Plant Microbial Fuel Cells–Based Energy Harvester System for Self-powered IoT Applications

The emergence of modern technologies, such as Wireless Sensor Networks (WSNs), the Internet-of-Things (IoT), and Machine-to-Machine (M2M) communications, involves the use of batteries, which pose a serious environmental risk, with billions of batteries disposed of every year. However, the combination of sensors and wireless communication devices is extremely power-hungry. Energy Harvesting (EH) is fundamental in enabling the use of low-power electronic devices that derive their energy from external sources, such as Microbial Fuel Cells (MFC), solar power, thermal and kinetic energy, among others. Plant Microbial Fuel Cell (PMFC) is a prominent clean energy source and a step towards the development of self-powered systems in indoor and outdoor environments. One of the main challenges with PMFCs is the dynamic power supply, dynamic charging rates and low-energy supply. In this paper, a PMFC-based energy harvester system is proposed for the implementation of autonomous self-powered sensor nodes with IoT and cloud-based service communication protocols. The PMFC design is specifically adapted with the proposed EH circuit for the implementation of IoT-WSN based applications. The PMFC-EH system has a maximum power point at 0.71 V, a current density of 5 mA cm − 2 , and a power density of 3.5 mW cm − 2 with a single plant. Considering a sensor node with a current consumption of 0.35 mA, the PMFC-EH green energy system allows a power autonomy for real-time data processing of IoT-based low-power WSN systems