Manganese and zinc in acidic agricultural soils from Central Spain: Distribution and phytoavailability prediction with chemical extraction tests

The extractability and distribution of manganese (Mn) and zinc (Zn) were evaluated in acidic agricultural soils from Central Spain. Both single (0.1 M hydrochloride [HCl] and 0.05 M ethylenediaminetetraacetate [EDTA]) and sequential extraction procedures (SEP) (modified Tessier procedure and Community Bureau of Reference [BCR] protocol) were applied to 29 representative soils that belong to the Alfisol, Inceptisol, and Entisol orders. Average relative Mn extractabilities with respect to the total content (16.6% for HCl and 31.9% for EDTA) were higher than those of Zn (7.7% for HCl and 6.5% for EDTA). Manganese was mainly released in the oxide-bound phase of both SEP (33.1% for modified Tessier and 48.9% for BCR), whereas Zn was predominantly found in the residual fraction (49.1% for modified Tessier and 31.4% for BCR). Significant correlations were only found between the amounts of extractable Zn and the oxide-bound fraction in both SEP. Few relationships were established between Zn fractions extracted by the BCR procedure and those obtained with the Tessier method. Both metal concentrations in spring barley (Hordeum vulgare L., cv Beka) grown in 11 selected soils and the calculated soil/plant transfer coefficients (soil/plant concentration factor (CF), mean values of 31.2 for Mn and 196 for Zn) were poorly (or not at all) correlated with the different extracted soil fractions (single and sequential). A number of empirical equations have been obtained by regression analyses to predict the Mn and Zn uptake by barley, with soil metal forms and some soil characteristics as components (pH for Mn and organic matter for Zn). Values of R2 in the equations were relatively low (<68%). Single-extraction techniques produced worse results than SEP for the evaluation of Mn phytoavailability. The modified Tessier procedure provided better predictions of Zn uptake by plants than BCR, but not better than those obtained with the HCl extraction method

Deficiencia de zinc en los cultivos y correctores de carencia del micronutriente

Una gran cantidad de cultivos estan afectados por la deficiencia de zinc, siendo algunos de ellos los siguientes: cereales, leguminosas, algodón y tabaco. Debido a esta deficiencia se pueden tener perdidas de hasta un 30% en la producción de cereales de grano como el maiz, el trigo o el arroz sin la aparicion de síntomas visibles de estrés en la planta. Las deficiencias mas acusadas, manifestadas con sintomas en las hojas, pueden provocar mayores pérdidas en los cultivos, e incluso pueden llevar a la pérdida total de los mismos. La aplicación al suelo de productos fertilizantes que contienen distintas formas de zinc es una práctica habitual que tiene por objeto corregir dichas deficiencias. La efectividad de estos productos depende de numerosos factores, tales como el tipo de suelo y el tipo de cultivo

Histological differences in the adherence of connective tissue to laser-treated abutments and standard abutments for dental implants. An experimental pilot study in humans

The goal of the current study is to assess the difference in connective tissue adherence to laser microtextured versus machined titanium abutments. Six patients were selected and each of them received 2 implants, one combined with a laser treated abutment and one with a machined abutment. After three months, the abutments were retrieved together with their surrounding gingival tissue for histological analysis. Qualitative and quantitative evaluation of microscopical images was performed to assess the presence or absence of adherence between the soft tissues and the abutment, and the percentage of soft tissue adhered to the two different surfaces. Intimate adherence between connective tissue and the laser treated abutments, while on machined abutments no adherence was detected. A significant difference was found in the percentage of surface in contact with soft tissue between both implant abutments p=0.03. Within the limitation of the current study, it can be concluded that connective tissues show enhanced adherence to microtextured abutments compared to machined abutments

Emotion, Psychological Well-Being and Their Influence on Resilience. A Study with Semi-Professional Athletes

The objective of the present study is to analyze the influence of coaches on emotional intelligence and on levels of anxiety, motivation, self-esteem, and resilience among athletes. Five-hundred forty-seven semi-professional athletes between the ages of 16 and 19 participated in this study. Various statistical analyses were conducted which explain the causal relationships between the variables. The results, obtained using a structural equations model, find that while autonomy support positively predicts emotional intelligence, perceived control predicts it negatively. Moreover, emotional intelligence positively predicts self-esteem and self-determined motivation, but negatively predicts anxiety. Other results show that self-esteem positively predicts self-determined motivation, whereas anxiety predicts it negatively. Finally, self-determined motivation positively predicts resilience. Indeed, the study demonstrates the influence and the importance of coaches in relation to the emotional intelligence, psychological well-being, and motivational processes of adolescent athletes when the latter engage in their respective sports. These results help to better understand how different behavioral, emotional, and social aspects belonging to the athlete interrelate with one another during competition

Influence of Physical Education Teachers on Motivation, Embarrassment and the Intention of Being Physically Active During Adolescence

According to a WHO report (2018), more than 80% of adolescents do not do enough physical activity. Physical Education (PE) classes should be aimed at solving this problem. The present study aims to analyze the influence teachers have on motivation, embarrassment and intention to be physically active among their students. A total of 604 secondary school students participated in the study. Various statistical analyses were carried out to explain the causal relationships between the variables. The results revealed a positive relation between the autonomy support and the satisfaction of basic psychological needs (BPN), and a negative relation with the frustration of BPN. In contrast, perceived control revealed a positive relation with frustration of BPN, and a negative relation with the satisfaction of BPN. Satisfaction of BPN was negatively related to embarrassment and positively related to self-determined motivation. On the other hand, frustration of BPN was positively related to embarrassment and negatively with self-determined motivation. Embarrassment was negatively related to self-determined motivation, and the latter was positively related to intention to be physically active. Indeed, the study demonstrates the influence and the importance of PE teachers and of the motivational and emotional processes of adolescents during PE classes and the role they play in acquiring the habits of an active lifestyle

Criteria for assessing dairy farm types

In Galicia and in the rest of Spain, dairy barns are going through a transition to implement the latest technologies, improve labour efficiency, and increase size. Barns with capacity for more cows are required due to the new market demands. Such barns must be perfectly defined, so that the construction of new buildings may entail reduced investment and operating costs. A wrong decision in the design phase can lead to serious financial trouble, even to the extent of making the farm economically non-viable. This study focuses in determining the factors that most strongly affect the construction costs of dairy housing, based on the most common barn designs in Galicia. Such factors are determined by implementing different indices that analyse the shape of the building. The implemented indices concern the design of the building –mainly its shape– and consider in all cases the relation of the design to the total cost and cost per item of the different constructions. Among these indices, the ‘ratio of area to perimeter squared’ or shape index (dimensionless), and elongation (ratio between the length and the width of the building), enable the determination of the shapes that are more convenient from the economic perspective. The cost of the building envelope per square meter varies as the barn area increases. The relation between the variation in the cost of the building envelope and both indices is studied for the different design options considered. With the data obtained, some guidelines are suggested in order to help project designers find the most appropriate result for their design work

Biochar and vermicompost as peat replacement for ornamental-plant production

Poster presentado en el Understanding Biochar Mechanisms for Practical Implementation. Final Meeting EU-COST Actions Biochar & 76Biochar is a by-product of the C-negative pyrolysis technology for production of bio-energy from organic materials. Containerized plant production in floriculture primarily utilizes soilless substrates such as peat moss. Environmental concerns about draining peat bogs have enhanced interests in research on complementary products that can be added to peat. Thus, a comparative study was conducted to assess the suitability of a biochar (B) and vermicompost (V) mix as a partial substitute for peat-based growing media for ornamental plant production.This work was partially supported by the project CTQ 2013-46804-C2-1-R of the Spanish Ministry of Economy and Competitiveness and the European Regional Development Funds (ERDF). The authors wish to thank the Horticultural Department and Carbon Sequestration and Management Center of Ohio State University for providing materials and facilities for this investigation, also he is deeply grateful to Mrs. Loewe and Dr. J. Altland from Application Technology Research Unit at Wooster OSU campus for their laboratory assistance in determining substrates mixes physical properties.Peer reviewe