Parks and Gardens as a learning resource in Primary Education

En el presente trabajo se propone una metodología y secuenciación de actividades en relación a la utilización de espacios verdes urbanos, tales como parques y jardines, como recurso didáctico en la etapa de Educación Primaria con dos finalidades fundamentales: aumentar el nivel de conocimiento sobre los seres vivos y la biodiversidad mediante la experimentación y la construcción del propio aprendizaje e incidir positivamente sobre actitudes, hábitos y comportamientos responsables con el medio natural y su conservación. Asimismo, esta propuesta didáctica trata de familiarizar al alumnado de esta etapa educativa con la metodología científica y fomentar el trabajo en equipo.In the present study it is proposed a methodology and sequencing of activities related to the use of urban green spaces, such as parks and gardens, as a didactic resource in the stage of Primary Education with two fundamental purposes: to increase the level of knowledge about beings living and biodiversity through experimentation and the construction of the own learning and have a positive impact on attitudes, habits and responsible behaviors with the natural environment and its conservation. Also, this didactic proposal tries to familiarize the students with the scientific methodology while encouraging cooperative work

The pollen grain and its identification: teaching material in Experimental Sciences

En este trabajo se presenta una guía básica para la identificación de granos de polen procedentes de diversas especies vegetales en función de las características morfológicas observables con el miscroscopio óptico. Se hará especial énfasis en dos características principales: ornamentación externa y sistema de aperturas. Además, se expone una propuesta metodológica para que el alumnado de educación superior que curse materias relacionadas con las ciencias experimentales (también de utilidad para estudiantes que cursen el bachillerato de ciencias) ponga en práctica habilidades y destrezas propias de la ciencia y pueda utilizar este material didáctico.This paper presents a basic guide for the identification of pollen grains from different plant species depending on the morphological characteristics observable with the optical microscope and that are usually used for that purpose. Special emphasis will be placed on two main characteristics: external ornamentation and opening system. In addition, a methodological proposal is exposed so that the students of higher education in experimental sciences (also useful for students who study the baccalaureate of sciences) put into practice skills of the science and can use this didactic material

Las nuevas formas de escribir de las juventudes mediadas por las tecnologías

Luego del proceso de confinamiento en la educación uno de los grandes temas debatidos es el uso de las herramientas digitales en el aula, así como la problemática de la escritura. Esto pasó a ser un tema que preocupa a toda la comunidad educativa. Muchos autores trataron este asunto evidenciando la gran relevancia de los medios digitales en la actualidad como eje temático educativo con la escritura como factor protagonista. Sáez (2021) plantea la gran importancia que tiene en la actualidad el uso de las plataformas digitales en los jóvenes y de qué manera esto influye en la escritura y lectura de los estudiantes de las nuevas generaciones. La presente investigación intenta hallar las voces de los protagonistas respecto a los cambios que existen en la escritura mediada por las herramientas digitales, qué aspectos han variado y cuáles son los factores que se ponen en juego a la hora de hablar de una educación digital, todo esto contextualizado en una escuela pública y técnica de la ciudad de San Luis. Para lograr los objetivos, se realizaron entrevistas a docentes y estudiantes y luego encuestas a otro grupo de profesores del primer año de la secundaria donde se encontraron diferentes miradas, se pudo entrever un cambio de la escritura mediada por el uso y la dinámica áulica, así como el factor sociopolítico que atraviesa este proceso

Pollinators, biodiversity and conservation: a didactic proposal

La polinización, proceso de transferencia de los granos de polen desde las anteras hasta el estigma de las flores, garantiza el éxito reproductivo de las plantas angiospermas. El transporte de los granos de polen lo pueden realizar diferentes agentes externos denominados vectores de polinización de entre los que destacan los insectos. La presente propuesta didáctica tiene entre sus objetivos reconocer el valor del papel de los polinizadores en los ecosistemas y fomentar la motivación por la conservación de la biodiversidad. Dicha propuesta didáctica consta de dos actividades complementarias entre sí, las cuales permitirán que el alumnado logre los objetivos marcados.Pollination, the process of transferring pollen grains from the anthers to the stigma of the flowers, guarantees the reproductive success of the angiosperm plants. The transport of pollen grains can be done by different external agents called pollination vectors, mainly insects are. The aim of this didactic proposal is to recognize the value of the role of pollinators within ecosystems and to encourage motivation for promoting the conservation of biodiversity. This didactic proposal consists of two complementary activities, which will allow the students to achieve the objectives set

Dexamethasone-doped nanoparticles improve mineralization, crystallinity and collagen structure of human dentin

zation. This study aims to evaluate bonding ability and both mechanical and chemical behavior of demineralized dentin infiltrated with polymeric nanoparticles doped with dexamethasone (Dex-NPs). Methods: Dentin conditioned surfaces were infiltrated with NPs, Dex-NPs or Dex-Zn-NPs. Bonded interfaces were also created and stored for 24 h or 21d, and then submitted to microtensile bond strength testing. Dentin remineralization was analyzed by Nanohardness, Young’s modulus and Raman analysis. Results: At 21d of storage, dentin treated with undoped-NPs attained the lowest nanohardness and Young’s modulus. Dex-NPs and Zn-Dex-NPs increased dentin nanohardness and Young’s modulus after 21d Raman analysis showed high remineralization, crystallinity, crosslinking and better structure of collagen when functionalized Dex-NPs were present at the dentin interface. Conclusions: Infiltration of dentin with Dex-NPs promoted functional remineralization as proved by nanomechanical and morpho-chemical evaluation tests. Dexamethasone in dentin facilitated crystallographic maturity, crystallinity and improved maturity and secondary structure of dentin collagen. Clinical significance: Using dexamethasone-functionalized NPs before resin infiltration is a clear option to obtain dentin remineralization, as these NPs produce the reinforcement of the dentin structure, which will lead to the improvement of the longevity of resin restorationsGrant PID2020-114694RB-I00 funded by MCIN/AEI 10.13039/501100011033Funding for open access charge: Universidad de Granada / CBUA

Ultra-structure characterization of self-etching treated cementum surfaces

Objectives: to evaluate the effect of different conditioning treatments on surface roughness and topography of dental cementum. Study Design: Extracted human canines were used for the present study. The mesial surface from the cervical third of the roots were ground flat with wet 600-grit silicon carbide paper. They were polished (up to 1/4 µm diamond paste) and treated as follows: 1) No treatment, 2) 35% H3PO4 during 15 s, 3) Clearfil SE Bond primer (SEB), 4) One-Up Bond F (OUB). The adhesive systems were applied following manufacturer?s instructions. SEB primer and OUB were removed from surfaces by washing and ultrasonic agitation with ascending ethanol solutions. Digital images of treated surfaces (5x5 and 15x15 µm) were obtained by means of an atomic force microscope (AFM) analysis. The average surface roughness (Ra nanometers) of the scanned areas was assessed. Data were analyzed by ANOVA and SNK multiple comparisons tests (p<0.05). Results: phosphoric acid treatment produced the highest mean roughness value, at all scan sizes. At 5x5 µm AFM images, for self-etch adhesive systems no differences in roughness were detected. At 15x15 µm, when One-Up Bond F was employed the lowest value was obtained. Conclusions: When phosphoric acid treatment was applied, cementum surface roughness increased and a strong demineralization with exposed collagen fibers could be observed

Estudio de la Producción Polínica del olivo (Olea europaea L.)

Las plantas anemófilas han tenido que desarrollar diferentes estrategias reproductoras para asegurar la fecundación debido al elevado grado de imprecisión del vector polinizante, como por ejemplo aumentar la tasa de producción polínica, determinada principalmente por el número de granos de polen que produce cada antera y por del número total de flores producidas por la planta.Existen diversos estudios realizados sobre producción polínica en diferentes especies vegetales, tanto en gimnospermas (Allison, T.D, 1990, Ecology, 71:516-522) como en angiospermas (Gómez-Casero et al., 2004, Grana, 43: 1-9; Rovira, M & Tous, J., Producción y viabilidad del polen, en : Variedades del olivo en España, 1ª Ed. 2005, Ed. Junta de Andalucía, Ministerio de Agricultura, Pesca y Alimentación y Ediciones Mundi-Prensa, España, pp 295-300), que demuestran que los diferentes procesos fisiológicos relacionados con la biología floral, como es el caso de la producción de polen, son de gran importancia en el buen desarrollo de la cosecha final en plantas cultivadas, y que esta capacidad se encuentra condicionada por factores genéticos y fisiológicos, además de por factores meteorológicos, que influyen tanto en la duración de la floración como en la tasa de producción de polen (Fornaciari et al., 1997, Agr. Med, 127: 134-137; Galán et al, 2008, Agr. Journal, 100: 98-104). El presente trabajo está basado en el estudio de la producción polínica del olivo (Olea europaea L.), especie cultivada de gran importancia para la economía y ampliamente distribuida en la provincia de Jaén. Las observaciones fueron realizadas sobre árboles localizados en zonas con diferente altitud con el fin de comprobar si existe influencia por parte de ésta en el proceso de producción de polen.Los resultados obtenidos arrojan evidencias de la existencia de una producción neta diferencial de flores y polen en función de la altitud, siendo los olivos localizados a mayor altitud los que presentan una mayor tasa de producción polínica, ya que, a pesar de ser los que producen menos cantidad de polen por antera y flor, compensan éste hecho con una mayor producción de brotes, racimos y flores

Wetting ability of an acetone/based etch rinse adhesive after NaOCl-treatment

Objectives: to evaluate the effect of sodium hypochlorite (NaOCl) treatment on surface dentin roughness (Ra) and contact angle (CA) when using Prime and Bond NT adhesive (PB NT). Study Design: Extracted human third molars were sectioned to expose flat, superficial and deep dentin surfaces. CA and Ra were measured (1) before and (2) after 35% H 3 PO 4 etching, and (3) H 3 PO 4 etching + 5% NaOCl treated for 2 minutes before the application of PB NT. CA was measured by the Axisymmetric Drop Shape Analysis Technique using distilled and deionized water and PB NT. Roughness was evaluated with a profilometer, twelve radial measurements were performed in each treatment surface. Data were analyzed with two-way ANOVA and Newman-Keuls multiple comparison test procedures. Results: CA values decreased after acid etching and even more after NaOCl treatment on deep dentin when water was tested. With resin, there were not differences on CA results after H 3 PO 4 neither after NaOCl treatment, in both dentin surfaces. Etching and NaOCl treatment resulted in surface roughness increase. Conclusions: In spite of the higher roughness after NaOCl treatment on superficial and deep dentin, the use of 5% NaOCl for 2 min after dentin demineralization when PB NT was employed did not improved the wettability of dentin, probably due to nanofiller content and/or hydrogen-bonding interactions with residues of the organic matrix on collagen-depleted denti

Bonding efficacy of an acetone/based etch-and-rinse adhesive after dentin deproteinization

Objectives: to evaluate the effect of sodium hypochlorite (NaOCl) treatment on dentin bonding by means of shear bond strength (SBS) measurements when using Prime and Bond NT (PB NT) adhesive. Ultrastructure of the interfaces was examined by scanning electron microscopy (SEM). Study design: Extracted human third molars were sectioned and ground to expose flat surfaces of superficial or deep dentin. Specimens were randomly assigned to two equal groups, and bonded as follows: (1) according to the manufacturers? directions, after 35% H 3 PO 4 etching, (2) 5% NaOCl treated for 2 minutes, after 35% H 3 PO 4 etching. Each sample was embedded in a Watanabe shear test assembly for a single plane lap shear. After PB NT bonding, specimens were stored in water for 24 h at 37ºC and thermocycled (500x). Samples were tested in shear to failure using a universal testing machine at 0.75 mm/ min. Data were analyzed with ANOVA and Newman-Keuls multiple comparison test procedures. Two samples of each group were randomly selected to investigate the morphologic aspect of the resin/dentin interface with SEM. Results: After etching and after aqueous sodium hypochlorite (NaOCl aq ) application, SBS values were similar on superficial than deep dentin (p>0.05). SEM findings shows for H 3 PO 4 etching conditioned samples a detectable hybrid layer and long resin tags; for NaOCl treated specimens, it may be observed a non apparent hybrid layer, and the adhesive contact directly with the neck of the cylindrical resin tags. Conclusions: The use of 5% NaOCl for 2 min after dentin demineralization when PB NT was employed did not improve the bond strength to dentin, probably due to nanofiller content and/or oxidative changes on collagen-depleted denti

Biochemical assessment of nanostructures in human trabecular bone: Proposal of a Raman microspectroscopy based measurements protocol

Background: Improvements to the understating of the compositional contributions of bone mineral and organic components to the competence of trabecular bone are crucial. The purpose of this study was to propose a protocol to study biochemical composition of trabecular bone, based on two combined Raman analysis methodologies. Material and Methods: Both cluster and single point Raman mappings were obtained, in order to assess bone degeneration associated with aging, disease, or injury, and to help in the evaluation and development of successful therapies. In this study, human trabecular bone has been analysed throughout a) Raman cluster analysis: bone mineral content, carbonate-to-phosphate ratio (both from the mineral components), the crosslinking and nature/secondary structure of collagen (both from the organic components); and b) Single point Raman spectra, where Raman points related to the minerals and organic components were also obtained, both techniques were employed in spectra attained at 400 to 1700 cm- 1. Results: Multivariate analysis confirmed: 1) the different spectral composition, 2) the existence of centroids grouped by chemical affinity of the various components of the trabecular bone, and 3) the several traces of centroids and distribution of chemical compositional clusters. Conclusions: This study is important, because it delivers a study protocol that provides molecular variations information in both mineral and collagen structure of trabecular bone tissue. This will enable clinicians to benefit knowing the microstructural differences in the bone subjected to degeneration of their patients.Project MAT2017-85999-P supported by the Ministry of Economy and Competitiveness (MINECO) of Spanish Government and European Regional Development Fund (ERDF)