Análisis de la coordinación motora por Índice de Masa Corporal y sexo en escolares de Chile

La investigación tuvo como objetivo analizar la relación entre la Coordinación Motora (CM) con el Índice de Masa Corporal en escolares chilenos de entre 7 y 9 años. El estudio fue observacional de corte transversal, con características descriptivas y correlacionales. Se evaluarona 180 escolares (90 mujeres de 8.4 ± 0.9 años y 90 hombres de 8.5± 0.9 años). Se midieron variables antropométricas de peso y talla. Se calculó el Índice de Masa Corporal (IMC). La coordinación motora (CM) se evaluó utilizando la batería de Körperkoordinationstest Für Kinder (KTK). Los resultados mostraron que en las mujeres el grupo Normopeso tenía un mejor desempeño en la transposición lateral que los grupos Sobrepeso y Obesidad (p˂0.05). En los hombres, el grupo Normopeso superó al grupo Obesidad en los saltos monopedales (p˂0.05). Además, al analizar las diferencias entre sexos, se determinó que las mujeres registraron mayor puntaje que los hombres en el equilibrio a la retaguardia (p<0.05), por su parte, los hombres registraron mejores rendimientos en saltos laterales, transposición lateral y el puntaje total del KTK (p<0.05). Se concluye que existe menor índice de CM en los escolares con elevado IMC, y que existen diferencias significativas entre hombres y mujeres en el equilibrio, saltos laterales, transposición lateral y el puntaje total del test KTK

Desarrollo de nuevos loci de microsatélites para Geoffroea decorticans (Gillies ex Hook. & Arn.) Burkart

Background and aims: One of the few tree species adapted to the ecologically limiting conditions of the Atacama Desert is Geoffroea decorticans, known as chañar. It is a valuable multipurpose resource used as a food and medicinal product. However, for the purpose of genetic studies, codominant DNA markers specific for this species have not yet been developed. The objective of this work is to develop and validate microsatellite markers (SSR) for G. decorticans, in order to perform future studies of genetic diversity and genetic structure of populations. M&amp;M: SSR markers were searched in the G. decorticans genome using the Next-Generation Sequencing (NGS) method, and they were validated through thirty individuals distributed in different localities in northern Chile. Results: A total of ~ 144,117 microsatellite loci were identified and a set of 41 primer pairs was used for validation. The amplified fragments ranged from 106 bp to 225 bp, the number of alleles ranged from 2 to 9, and the PIC value of the 41 SSR loci ranged between 0.32 and 0.86, with an average of 0.64. Conclusions: For the first time, putative neutral SSR markers specific to the G. decorticans species have been developed in order to promote genetic studies for the conservation of the species. The present study provides a set of 38 new polymorphic SSR markers, which could serve as an effective tool to estimate genetic diversity, genetic structure and to be used in breeding programs.Introducción y objetivos: Una de las pocas especies de árboles adaptados a las condiciones ecológicamente limitantes del desierto de Atacama es Geoffroea decorticans, conocido como chañar. Es un valioso recurso multipropósito utilizado como alimento y producto medicinal. Sin embargo, aún no se han desarrollado marcadores de ADN codominantes específicos para esta especie que permitan realizar estudios genéticos en la especie. El objetivo del presente trabajo fue desarrollar y validar marcadores microsatélites (SSR) para G. decorticans, con el fin de analizar en el futuro su diversidad genética y estructura genética poblacional. M&amp;M: Se buscaron marcadores SSR en el genoma de G. decorticans a partir del método Next-Generation Sequencing (NGS), y se validaron a través de treinta individuos distribuidos en diferentes localidades del norte de Chile. Resultados: Se identificó un total de ~144.117 loci de microsatélites y de ellos se usó un grupo de 41 pares de cebadores para la validación. Los fragmentos amplificados variaron de 106 pb a 225 pb, el número de alelos varió de 2 a 9, y el valor PIC de los 41 loci SSR osciló entre 0,32 y 0,86, con un promedio de 0,64. Conclusiones: Por primera vez se desarrollaron marcadores SSR putativamente neutros específicos de la especie G. decorticans con el fin de promover estudios genéticos para la conservación de la especie. El presente estudio provee 38 nuevos marcadores SSR polimórficos, los cuales podrían servir como una herramienta efectiva para estimar la diversidad genética, estructura genética y para ser empleados en programas de mejora

Emotional attribution of 6th grade students in Physical Education and Health

Esta investigación tiene como objetivo determinar la atribución causal de las emociones de escolares de sexto año básico en un proceso de desarrollo de la condición física en las clases de Educación Física y Salud. El estudio es cualitativo, de tipo descriptivo y con un diseño de investigación-acción. Los/as participantes son treinta escolares en el rango de edad comprendido entre los once a trece años. Los resultados indican que los(as) escolares atribuyen sus emociones positivas a la superación del cansancio, al logro de las metas, al beneficio corporal y al entretenimiento con las actividades de la sesión. En cuanto a las emociones negativas, son atribuidas a las expectativas, al pensamiento pesimista, a las burlas, a la envidia, a los problemas de salud, al sedentarismo, a las consecuencias académicas y a la ausencia de logro en las metas de superación de la condición física. Se concluye que las atribuciones emocionales identificadas deben ser comprendidas desde el quehacer didáctico, para favorecer la creación de estrategias de aprendizajes que propicien el bienestar subjetivo y el desarrollo de hábitos de vida activa desde una perspectiva psicosocial.This research aims to determine the causal attribution of emotions in sixth grade primary school children in a process of development of physical condition in the classes of Physical Education and Health. The study is qualitative, descriptive and with a design of action research. The participants are thirty students in the age range between eleven to thirteen years old. The results indicate that students attribute their positive emotions to the fatigue overcoming, to the achievement of goals, to body benefits and to the entertainment with session activities. As for the negative emotions, these are attributed to expectations, pessimistic thinking, ridicule, envy, and health problems, physical inactivity, the academic consequences and lack of achievement of goals in the overcoming of the physical condition. In conclusion, the identified emotional attributions must be understood from the teaching work, to encourage the creation of learning strategies that promote subjective well-being and development of active lifestyle habits from a psychosocial perspective.Facultad de Humanidades y Ciencias de la Educació

Emotional attribution of 6th grade students in Physical Education and Health

Esta investigación tiene como objetivo determinar la atribución causal de las emociones de escolares de sexto año básico en un proceso de desarrollo de la condición física en las clases de Educación Física y Salud. El estudio es cualitativo, de tipo descriptivo y con un diseño de investigación-acción. Los/as participantes son treinta escolares en el rango de edad comprendido entre los once a trece años. Los resultados indican que los(as) escolares atribuyen sus emociones positivas a la superación del cansancio, al logro de las metas, al beneficio corporal y al entretenimiento con las actividades de la sesión. En cuanto a las emociones negativas, son atribuidas a las expectativas, al pensamiento pesimista, a las burlas, a la envidia, a los problemas de salud, al sedentarismo, a las consecuencias académicas y a la ausencia de logro en las metas de superación de la condición física. Se concluye que las atribuciones emocionales identificadas deben ser comprendidas desde el quehacer didáctico, para favorecer la creación de estrategias de aprendizajes que propicien el bienestar subjetivo y el desarrollo de hábitos de vida activa desde una perspectiva psicosocial.This research aims to determine the causal attribution of emotions in sixth grade primary school children in a process of development of physical condition in the classes of Physical Education and Health. The study is qualitative, descriptive and with a design of action research. The participants are thirty students in the age range between eleven to thirteen years old. The results indicate that students attribute their positive emotions to the fatigue overcoming, to the achievement of goals, to body benefits and to the entertainment with session activities. As for the negative emotions, these are attributed to expectations, pessimistic thinking, ridicule, envy, and health problems, physical inactivity, the academic consequences and lack of achievement of goals in the overcoming of the physical condition. In conclusion, the identified emotional attributions must be understood from the teaching work, to encourage the creation of learning strategies that promote subjective well-being and development of active lifestyle habits from a psychosocial perspective.Facultad de Humanidades y Ciencias de la Educació

Above- and belowground biodiversity jointly tighten the P cycle in agricultural grasslands

Experiments showed that biodiversity increases grassland productivity and nutrient exploitation, potentially reducing fertiliser needs. Enhancing biodiversity could improve P-use efficiency of grasslands, which is beneficial given that rock-derived P fertilisers are expected to become scarce in the future. Here, we show in a biodiversity experiment that more diverse plant communities were able to exploit P resources more completely than less diverse ones. In the agricultural grasslands that we studied, management effects either overruled or modified the driving role of plant diversity observed in the biodiversity experiment. Nevertheless, we show that greater above- (plants) and belowground (mycorrhizal fungi) biodiversity contributed to tightening the P cycle in agricultural grasslands, as reduced management intensity and the associated increased biodiversity fostered the exploitation of P resources. Our results demonstrate that promoting a high above- and belowground biodiversity has ecological (biodiversity protection) and economical (fertiliser savings) benefits. Such win-win situations for farmers and biodiversity are crucial to convince farmers of the benefits of biodiversity and thus counteract global biodiversity loss

Sorption and desorption of organic matter in soils as affected by phosphate

The contribution of different adsorption processes to soil organic matter (SOM) stabilization and the consequences of the intensification of land use on the adsorption of SOM are not yet fully understood. Therefore, this study aimed to explore the adsorption of dissolved organic carbon (DOC) in soils as well as desorption of organic carbon (OC) caused by phosphate addition. We conducted desorption and sorption experiments with DOC, phosphate (Na2HPO4), and chloride (KCl) in topsoil and subsoil samples from a Ferralsol, an Andosol, and a Podzol. Furthermore, we quantified the size of DOC by size-exclusion chromatography.We found that phosphate addition caused a strong increase in the DOC concentration in all soils. The DOC concentration was elevated by up to a factor of 4.5 compared to a control (water only) within five minutes after phosphate addition and kept increasing further with time, particularly in the Ferralsol. After 10 days, the DOC concentrations in the P addition treatment were between 5.5 and 18.0 times higher than in the control treatment. In contrast, chloride addition did not lead to increased DOC concentrations compared to the control (water only). Phosphate addition led mostly to desorption of organic matter of medium molecular size (10-100 and 100-1000 kDa) in the Ferralsol and the Andosol and of large molecular size (>1000 kDa) in the Podzol. In contrast, potassium chloride addition shifted the size distribution of DOC in the soil solution towards small compounds (<10 kDa), likely because KCl addition affected the aggregation of DOC compounds, in contrast to Na2HPO4 addition. Furthermore, phosphate addition also decreased subsequent sorption of DOC in the Ferralsol and the Andosol by a factor of up to 2.9 and 2.1, respectively.Our results have far-reaching implications because they show that phosphate addition can lead to desorption, and thus to destabilization of SOM, particularly in Ferralsols, and can also prevent further sorption of organic matter in soils. Our study provides a mechanistic explanation of why phosphate addition can decrease soil organic carbon sequestration and stabilization. This mechanism should be considered in the analysis of land-use and tillage effects on SOM sequestration in the future. Furthermore, our study indicates that also medium and large molecular size organic matter is stabilized through adsorption in soils

Development of SSR loci in Prosopis tamarugo Phillipi and assessment of their transferability to species of the Strombocarpa section

Aims of the study: Phreatophyte species of the Prosopis genus are very important to natural ecosystems in Africa, South America and Asia due to their uses as food and seed sources and in agroforestry. In this research, through next-generation sequencing, we sought to search for and develop SSR markers in Prosopis tamarugo, in addition to assessing their transferability to other species in the Strombocarpa section.Area of study: The study was carried out in species of the Strombocarpa section collected in the “Pampa del Tamarugal”, located in the Atacama Desert (Chile); which is considered the driest and oldest desert on Earth.Materials and methods: The next-generation sequencing for the development of simple sequence repeat (SSR) or microsatellite loci for genetic research in P. tamarugo and their transferability in Prosopis burkartii and Prosopis strombulifera was used.Main results: A total of ~90.000 microsatellite loci in P. tamarugo were found, and a set of 43 primer pairs was used for validating SSR locus amplification. We found a large difference in the percentage of amplified SSR markers between species of the Strombocarpa and Algarobia sections.Research highlights: The present study provides for the first time 24 polymorphic SSR markers for species in the Strombocarpa section, which could be a useful tool for estimating genetic structure, developing breeding programs, quantifying genetic diversity and performing population studies.Keywords: Strombocarpa section; Prosopis tamarugo; Atacama Desert; microsatellites; NGS

La geografía en la historiografía helenística. El concepto de oikoumene en las Historias de Polibio

The development of geography during the hellenistic period, on one hand, was determined by the conquests of Alexander that expanded the horizons of the oikoumene towards territories unknown to the Greek world, and on the other, by a geographical tradition that related elements of other disciplines, such as: literature, philosophy, techné and history. Traditionally the concept of oikoumene is understood as the space where the greek culture expands and develops. Throughout the II century BC, in its search for universal dominion, Rome managed to dominate the Greek space politically, but integrated itself into the greek oikoumene. The present work proposes to consider that the hellenistic historiography used resources of the greek geographical tradition to manage to configure a new space, composed by the greco-hellenistic world and the territories incorporated to Roman domain of the western Mediterranean basin. For this, an analysis of the Histories of Polybius will be carried out, a work that, with a universalist objective, integrated the elements of hellenistic geography to construct a new oikoumene concept.El desarrollo de la geografía durante el período helenístico, por un lado, estuvo determinado por las conquistas de Alejandro que expandieron los horizontes de la oikoumene hacia territorios desconocidos para el mundo griego, y por otro, por una tradición geográfica que relacionó elementos de otras disciplinas, tales como: la literatura, la filosofía, la techné y la historia. Tradicionalmente el concepto de oikoumene se entiende como el espacio donde se expande y desarrolla la cultura griega. A lo largo del siglo II a.C., en su búsqueda de dominio universal, Roma logró dominar políticamente el espacio griego, pero integrándose a su vez a la oikoumene griega. El presente trabajo propone considerar que la historiografía helenística utilizó recursos de la tradición geográfica griega para lograr configurar un nuevo espacio, compuesto por el mundo greco-helenístico y los territorios incorporados a dominio romanos de la cuenca mediterránea occidental. Para ello se realizará un análisis de las Historias de Polibio, obra que con un objetivo universalista, integró los elementos de la geografía helenística para construir un nuevo concepto de oikoumene

Design of a Hydro Bicycle for the Junin, Huancayo Region

The objective of this study was the design of a hydraulic bicycle and the assembly of a floating structure, steering and propulsion to be able to navigate. To this end, a variety of studies have been conducted. A study on the selection of the most suitable materials for the marine environment was also conducted, where a detailed analysis of each component of the power transmission was carried out, where the Shigley-McGrawhill mechanical engineering design book of machine elements was also used. The study of the structural part was carried out to ensure the integrity of the user, also a study of the transmission of pedaling power to the propeller and the pontoons to be able to withstand a maximum load of 120 kg and stability to ensure buoyancy

Water deficit synchronizes berry color development in Crimson seedless table grapes

Crimson Seedless is one of the most important table grape cultivars in the world, but often exhibits uneven berry color when grown in warm climates. Deficit irrigation is used extensively by growers during the ripening phase to advance fruit maturity and color, but there is a lack of information about the relationship between irrigation practices and fruit ripening variability. We imposed deficit irrigation in a commercial Crimson Seedless vineyard in the Maipo Valley, Chile, from veraison to harvest in two consecutive seasons. The fruit was tested for uniformity of Brix, firmness, and the color parameters “L”, “a”, “b”, and the Color Index of Red Grapes using analysis of variance on absolute residuals (Levene’s test). Postveraison water stress increased water productivity, Brix, and slightly improved berry coloration, but did not affect berry weight, size, or firmness. Moderate levels of water stress imp