3,405 research outputs found
Residual effect of natural and synthetic zinc chelates on zinc in a soil solution of a waterlogged acidic soil. Evolution of the pH and redox potential.
Zinc chelates have been widely used to correct deficiencies in this micronutrient in different soil types and under different moisture conditions. The aging of the metal in soil could cause a change in its availability. Over time the most labile forms of Zn could decrease in activity and extractability and change to more stable forms. Various soil parameters, such as redox conditions, time, soil type and moisture conditions, affect the aging process and modify the solubility of the metal. In general, redox conditions influence pH and also the chemical forms dissolved in the soil solution. Soil pH also affects Zn solubility; at high pH values, most of the Zn is present in forms that are not bioavailable to plants. The objective of this study was to determine the changes in Zn over time in a soil solution in a waterlogged acidic soil to which synthetic and natural chelates were applie
Modulating osteoclasts with nanoparticles: A path for osteoporosis management?
Osteoclasts are the cells responsible for the bone resorption process during bone
remodeling. In a healthy situation, this process results from an equilibrium
between new matrix formation by osteoblast and matrix resorption by osteoclast.
Osteoporosis (OP) is a systemic bone disease characterized by a decreased bone
mass density and alterations in bone microarchitecture, increasing fracture pre disposition. Despite the variety of available therapies for OP management there is
a growing gap in its treatment associated to the low patients´ adherence owing to
concerns related with long-term efficacy or safety. This makes the development
of new and safe treatments necessary. Among the newly developed strategies, the
use of synthetic and natural nanoparticles to modulate osteoclasts differentiation,
activity, apoptosis or crosstalk with osteoblasts have arisen. Synthetic
nanoparticles exert their therapeutic effect either by loading antiresorptive drugs
or including molecules for osteoclasts gene regulation. Moreover, this control
over osteoclasts can be improved by their targeting to bone extracellular matrix
or osteoclast membranes. Furthermore, natural nanoparticles, also known as
extracellular vesicles, have been identified to play a key role in bone homeostasis.
Consequently, these systems have been widely studied to control osteoblasts and
osteoclasts under variable environments. Additionally, the ability to bioengineer
extracellular vesicles has allowed to obtain biomimetic systems with desirable
characteristics as drug carriers for osteoclasts. The analyzed information reveals
the possibility of modulating osteoclasts by different mechanisms through nanoparticles decreasing bone resorption. These findings suggest that controlling
osteoclast activity using nanoparticles has the potential to improve osteoporosis
management. This article is categorized under: Implantable Materials and Surgical Technologies > Nanomaterials and Implants Implantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and Replacement Nanotechnology Approaches to Biology > Nanoscale Systems in BiologyPatricia García-García acknowledges the University of La Laguna for the action “Recualificación de personal universitario: Margarita Salas para la formación de jóvenes doctores”. Helena Rouco acknowledges the University of Santiago de Compostela for the action “Recualificación de personal universitario: Margarita Salas para la formación de jóvenes doctores”. This work was funded by MCIN/AEI/10.13039/501100011033/FEDER, UE, (PID2021-127493OA-C22)S
El aprendizaje de la Historia mediante el Aprendizaje Basado en Proyectos.
El presente Trabajo de Fin de Grado pone en relieve la importancia de enseñar Historia de un modo adecuado, atendiendo a la adquisición de conceptos temporales por parte del niño que le permitan entender de un modo más claro los contenidos históricos. Se hace hincapié en la necesidad de utilizar metodologías activas que fomenten un aprendizaje significativo y con las que el alumnado sea el centro del proceso de enseñanza. Para ello se muestra una propuesta de intervención basada en la metodología de Aprendizaje Basada en Proyectos con la que el alumnado adquiere conocimientos y habilidades mediante la realización de diversas actividades.Grado en Educación Primari
Acto de habla total en la situación de habla total: dimensión deóntica
Trabajo de Fin de Máster en Investigación en Lógica y Filosofía de la Ciencia, curso 2014-2015[ES] Este trabajo examina la dimensión deóntica de la interacción comunicativa desde el enfoque de la Pragmática Interaccionista, del caso real de Erri De Luca, con el objetivo de contribuir al estudio de la noción austiniana de Acto de Habla Total en la Situación de Habla Total, para ello se siguen dos vías: (i) desarrollo teórico de la noción de marco situacional con especial atención a los aspectos sobre los que la Pragmática Interaccionista ha focalizado la atribución de responsabilidad: agentes, actividad en el proceso, contenido ilocucionario, fuerza ilocucionaria y consecuencias y, (ii) análisis de la limitación de alcance del aspecto cooperativo de la Pragmática Interaccionista para dar cuenta de los casos de atribución de responsabilidad conflictivos.[EN] This paper examines the deontic dimension of communicative interaction from the perspective of the Interactionist Pragmatic approach, of the actualy case of Erri De Luca, with the aim of contributing to the study of the Austinian notion of the total speech act in the total speech situation. Two main points will be addressed: (i) The theoretical development of the concept of situational framework, with particular attention to the aspects in which Interactionist Pragmatic has focused the attribution of responsibility: agents, activity in the process, illocutionary force, locutionary content, illocutionary force and consequences. (ii) A critical analysis of the limited scope of the cooperative aspect of the Pragmatic Interactionist approach in accounting for the cases of attribution of conflicting responsibility
Nanoparticle-mediated selective Sfrp-1 silencing enhances bone density in osteoporotic mice
Osteoporosis (OP) is characterized by a loss in bone mass and mineral density. The stimulation of the canonical Wnt/?-catenin pathway has been reported to promote bone formation, this pathway is controlled by several regulators as secreted frizzled-related protein-1 (Sfrp-1), antagonist of the pathway. Thus, Sfrp-1 silencing therapies could be suitable for enhancing bone growth. However, the systemic stimulation of Wnt/?-catenin has been correlated with side effects. This work hypothesizes the administration of lipid-polymer NPs (LPNPs) functionalized with a MSC specific aptamer (Apt) and carrying a SFRP1 silencing GapmeR, could favor bone formation in OP with minimal undesired effects. Suitable SFRP1 GapmeR-loaded Apt-LPNPs (Apt-LPNPs-SFRP1) were administered in osteoporotic mice and their biodistribution, toxicity and bone induction capacity were evaluated. The aptamer functionalization of the NPs modified their biodistribution profile showing a four-fold increase in the bone accumulation and a ten-fold decrease in the hepatic accumulation compared to naked LPNPs. Moreover, the histological evaluation revealed evident changes in bone structure observing a more compact trabecular bone and a cortical bone thickness increase in the Apt-LPNPs-SFRP1 treated mice with no toxic effects. Therefore, these LPNPs showed suitable properties and biodistribution profiles leading to an enhancement on the bone density of osteoporotic mice.Funding: This work is part of the project RTI2018-097324-B-100 funded by MCIN/AEI/10.13039/501100011033 and by ERDF “A way of making Europe”. Patricia García-García thanks the University of La Laguna for her research grant (M-ULL)
Multiple Intelligences and Videogames: Intervention Proposal for Learning Disabilities
In recent years, there has been much research into the possibilities offered by digital tools for intervention in learning disabilities. The most recent studies have found that these tools can have positive effects on diverse aspects of learning, such as the acquisition of reading, writing, vocabulary and mathematics, as well as improvement of executive functioning and behavioural control skills. Despite the results showing the positive effects of using digital tools for students with learning disabilities, it remains necessary to widen their use in areas such as identification, assessment and intervention as early as possible. Within the current chapter, the application of the conceptual framework of multiple intelligences to the design of educational video games is proposed to facilitate diagnosis and improve intervention success in cases of learning disability. In this regard, a proposed novel tool is presented that may be used for the evaluation and intervention for students with learning disabilities
Sustainability dimensions: A source to enhance corporate reputation
ABSTRACT: The aim of this paper is to enhance our understanding of the relationship between sustainability and corporate image and reputation according to the legitimacy theory framework since the current academic literature does not have an understanding of how sustainability and corporate image and reputation interact. Authors conducted a survey to test the hypotheses. The study was tested using data collected from a sample of 382 Spanish consumers. The proposed hypotheses were analyzed through a structural equation model showing that sustainability plays a vital role as antecedent of both corporate image and reputation. Findings suggest that the economic, social and environmental domains of sustainability present a direct and positive relationship with both corporate image and reputation
Intellectual capital and relational capital: The role of sustainability in developing corporate reputation
Purpose: Intellectual capital offers a potential source of sustainable competitive advantage and is believed to be the source from which economic growth may sprout. However, not many papers analyze the effect of sustainability in the elements involving intellectual capital. This paper seeks to highlight the key role played by corporate sustainability on corporate reputation as one of the key components of relational capital based on the knowledge-based theory. In order to fulfill this objective we consider economic, social and environmental dimensions of corporate sustainability. Design/methodology/approach: Authors develop a structural equation model to test the hypothesis. The study was tested using data collected from a sample of 400 Spanish consumers. Findings: The structural equation model shows that sustainability plays a vital role as antecedent of corporate reputation and relational capital. Findings suggest that economic, social and environmental domains of sustainability have a positive direct effect on corporate reputation. Additionally, this study shows that economic sustainability is considered to be the most important dimension to enhance corporate reputation. Research limitations/implications: Relational capital involves several dimensions which have not been incorporated to this study. Thus, future studies may analyze the role of corporate reputation and sustainability in the formation and development of the different relationships that conform relational capital. Finally, the complicated economic environment currently experienced worldwide may affect the perceptions of Spanish consumers and their ratings. The crosscutting nature of this research inhibits an understanding of the variations in the perceptions of the customers surveyed over time, suggesting that this research could be expanded by a longitudinal study. Secondly, the current study has been conducted with consumers of hotel companies in Spain and it is not clear in how far the findings can be generalized to other industries, stakeholders or countries. Practical implications: This research allows managers to identify the activities in which companies can devote resources to in order to increase firm's reputation. By knowing these specific economic, social and environmental activities, companies can understand, analyze and make decisions in a better way about its sector and about the stakeholders that assess these initiatives. Originality/value: To our knowledge, in any case it has been studied simultaneously the influence of sustainability dimensions on corporate reputation, which is a knowledge gap in the academic literatur
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