199 research outputs found
Application of Biochar for the Restoration of Metal(loid)s Contaminated Soils
Funding: The work has been supported by funds from the Spanish Ministry of Economy, Industry and Competitiveness through the Project “CTM2017-86504-R”, and by Ministry of Science, Innovation and Universitiesam trought Research Project “RTI2018-094327-B-I00”.Biochar has recently aroused great interest for the restoration of contaminated soils since
it improves soil properties and induces the immobilization of pollutants. This study evaluates the
use of biochar from plant pruning, applied as an amendment, for immobilizing metal(loid)s in a
highly contaminated soil as well as for reducing the phytotoxicity of these pollutants by promoting
natural revegetation. For this purpose, a bioassay with Trifolium pratense L. was used to test the
effectiveness of the soil amendment in greenhouse conditions. Three treatments were carried out
including soil contaminated with metal(loid)s (RA), and this soil was amended with biochar at
different dosage: 4% (RA4B) and 8% (RA8B). A non-contaminated soil (NC) from a nearby area not
affected by contamination was used as a control. The results show that biochar increased soil pH
by several units depending on the dose used, 8% being the most effective one. Biochar treatments
also reduced soluble and bioavailable forms of Zn and Cu. Likewise, phytotoxicity was significantly
reduced, promoting seed germination and biomass with plant growth values similar to the non-polluted soil. In light of the results obtained, the evaluation of the bioremediation potential of biochar
under field conditions can be considered.Ministry of Science, Innovation and Universitiesam trought Research Project
RTI2018-094327-B-I00Ministerio de Economía, Industria y Competitividad, Gobierno de España
CTM2017-86504-
Comprensión del concepto de serie numérica a través del modelo de Pirie y Kieren
Diversas investigaciones han dado cuenta de las dificultades que tienen los estudiantes para la adquisición y comprensión del concepto de serie numérica. Los conceptos de límite e infinito, así como la diferenciación entre la serie y la sucesión de sumas parciales, son algunos de los obstáculos que han de superar. En este artículo, se analiza el proceso que sigue un grupo de estudiantes cuando resuelve una actividad sobre el cálculo de la altura y el volumen de una torre que involucra el trabajo con series armónicas mediante el modelo de Pirie y Kieren. Comenzando desde el nivel Image Making, los alumnos realizan conexiones entre diferentes elementos matemáticos del concepto de serie numérica. Las interacciones entre ellos les permiten avanzar entre los diferentes niveles del modelo para lograr la comprensión del concepto recurriendo al mecanismo de folding back.Several research studies have realized the difficulties faced by students for the acquisition and understanding of the concept of numerical series. The concepts of limits, infinity and the difference between the series and the sequence of partial sums are some obstacles to be overcome. This article analyzes the process that follows a group of students solving the activity about the calculi of the height and volume of a tower that involves working with harmonic series in the light of Pirie and Kieren model. Starting from Image Making level the students link different elements of the mathematical concept of numerical series. The interactions between them allow to advance between the different levels of the model to develop an understanding of the concept using the folding back mechanism
Inhibition of PTEN by peroxynitrite activates the phosphoinositide-3-kinase/Akt neuroprotective signaling pathway
El derivado del óxido nítrico, peroxinitrito, activa una cascada de señalización de supervivencia en neuronas. El mecanismo implica la oxidación de la fosfatasa PTEN, que permite incrementar la forma fosforilada (neuroprotectora) de akt.Peroxynitrite is usually considered as a neurotoxic nitric oxidederivative. However, an increasing body of evidence suggests that, at low concentrations, peroxynitrite affords transient cytoprotection, both in vitro and in vivo. Here, we addressed the signaling mechanism responsible for this effect, and found that rat cortical neurons in primary culture acutely exposed to peroxynitrite (0.1 mmol/L) rapidly elicited Akt-Ser473 phosphorylation. Inhibition of phosphoinositide-3-kinase (PI3K)/Akt pathway with wortmannin or Akt small hairpin RNA (shRNA) abolished the ability of peroxynitrite to prevent etoposide-induced apoptotic death. Endogenous peroxynitrite formation by short-term incubation of neurons with glutamate stimulated Akt-Ser473 phosphorylation, whereas Akt shRNA enhanced the vulnerability of neurons against glutamate. We further show that Akt-Ser473 phosphorylation was consequence of the oxidizing, but not the nitrating properties of peroxynitrite. Peroxynitrite failed to nitrate or phosphorylate neurotrophin tyrosine kinase receptors (Trks), and it did not modify the ability of brain-derived neurotrophic factor (BDNF), to phosphorylate its cognate receptor, TrkB; however, peroxynitrite enhanced BDNF-mediated Akt-Ser473 phosphorylation. Finally, we found that peroxynitrite-stimulated Akt-Ser473 phosphorylation was associated with an increased proportion of oxidized phosphoinositide phosphatase, PTEN, in neurons. Moreover, peroxynitrite prevented the increase of apoptotic neuronal death caused by over-expression of PTEN. Thus, peroxynitrite exerts neuroprotection by inhibiting PTEN, hence activating the anti-apoptotic PI3K/Akt pathway in primary neurons
“Materiales y Recursos Didácticos e Informáticos para la Enseñanza de las Matemáticas” en la titulación de Grado en Maestro de Educación Primaria a través de la plataforma virtual Studium
Memoria ID12-0175. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2012-2013
La enseñanza basada en proyectos interdisciplinares en ciencias y matemáticas en el Grado de Educación Primaria
Memoria ID-0170. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2017-2018
https://doi.org/10.1016/j.chemosphere.2023.140364
The fate of the antibiotic sulfamethoxazole in amended soils remains unclear, moreover in basic soils. This work aimed to assess the adsorption, leaching, and biodegradation of sulfamethoxazole in unamended and biochar from holm oak pruning (BC)- and green compost from urban pruning (CG)-amended basic soil. Adsorption properties of the organic amendments and soil were determined by adsorption isotherms of sulfamethoxazole. The leachability of this antibiotic from unamended (Soil) and BC- (Soil + BC) and GC- (Soil + GC) amended soil was determined by leaching columns using water as solvent up to 250 mL. Finally, Soil, Soil + BC, and Soil + GC were spiked with sulfamethoxazole and incubated for 42 days. The degradation rate and microbial activity were periodically monitored. Adsorption isotherms showed poor adsorption of sulfamethoxazole in unamended basic soil. BC and CG showed good adsorption capacity. Soil + BC and Soil + GC increased the sulfamethoxazole adsorption capacity of the soil. The low sulfamethoxazole adsorption of Soil produced quick and intense sulfamethoxazole leaching. Soil + BC reduced the sulfamethoxazole leaching, unlike to Soil + GC which enhanced it concerning Soil. The pH of adsorption isotherms and leachates indicate that the anion of sulfamethoxazole was the major specie in unamended and amended soil. CG enhanced the microbial activity of the soil and promoted the degradability of sulfamethoxazole. In contrast, the high adsorption and low biostimulation effect of BC in soil reduced the degradation of sulfamethoxazole. The half-life of sulfamethoxazole was 2.6, 6.9, and 11.9 days for Soil + GC, Soil, and Soil + BC, respectively. This work shows the benefits and risks of two organic amendments, BC and GC, for the environmental fate of sulfamethoxazole. The different nature of the organic carbon of the amendments was responsible for the different effects on the soilPDC 2021-120744-I0
La biodiversidad como herramienta en la gestión y certificación forestal : zonas de alto valor de conservación en montes madereros del suroeste peninsular
Este artículo presenta un estudio sobre la
biodiversidad y el estado de ocho Zonas de Alto
Valor de Conservación en la provincia de Huelva
(localizada en el suroeste de la Península Ibérica),
colindantes a plantaciones de especies de
crecimiento rápido (Eucalyptus globulus). El estudio
se incluye en el marco de un proceso de certificación
forestal.
Se han evaluado algunos parámetros de
biodiversidad –riqueza, diversidad alfa, diversidad
beta- y estado –regeneración, cobertura, densidaden
143 parcelas de comunidades leñosas. Se han
registrado un alto número de taxones animales y
vegetales, algunos de los cuales son especies
amenazadas o endémicas.
El uso de los índices de diversidad ha sido esencial;
son simples abstracciones de la estructura altamente
compleja de las comunidades, muy útiles para hacer
comparaciones. Han mostrado la alta diversidad de
las zonas estudiadas mediante datos cuantificables.
Este tipo de estudios son muy importantes e útiles
para conocer el estado de ecosistemas forestales y
abordar su seguimiento, y por lo tanto para la
gestión forestal.____________________________________This paper presents a study about the biodiversity
and the status of eight Zones of High Conservation
Value within the province of Huelva (located in the
southwest of the Iberian Peninsula), near plantations
of fast growing species (Eucalyptus globulus). The
study is in the framework of a forest certification
process.
Some parameters of biodiversity –species richness,
diversity alpha, diversity beta– and status –
regeneration, cover, density– have been evaluated in
143 plots of woody communities. A high number of
vegetal and animal species have been recorded;
some of them are endangered or endemic species.
The use of diversity indices has been essential; they
are simple abstractions of the highly complex
structure of communities, very useful for
comparisons. They have shown the high biodiversity
of the study areas using quantifiable data.
Such studies are very important and useful to know
the status of forest ecosystems and to address the
monitoring of these ones, and therefore for forest
management
Diseño e implementación de metodologías activas vinculadas a las asignaturas de matemáticas del Grado de Maestro en Educación Primaria e Infantil para contextualizar su enseñanza
Memoria ID-0321. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2014-2015
Effects and Risk Assessment of the Polycyclic Musk Compounds Galaxolide (R) and Tonalide (R) on Marine Microalgae, Invertebrates, and Fish
The current research investigated the potential environmental risk of the polycyclic musk compounds, Galaxolide (R) (HHCB) and Tonalide (R) (AHTN), in the marine environments. These substances are lipophilic, bioaccumulated, and potentially biomagnified in aquatic organisms. To understand the toxicity of HHCB and AHTN, acute toxicity tests were performed by exposing marine microalgae (Phaeodactylum tricornutum, Tretraselmis chuii, and Isochrysis galbana), crustaceans (Artemia franciscana), echinoderms (Paracentrotus lividus), bivalves (Mytilus galloprovincialis), fish (Sparus aurata), and a candidate freshwater microalga (Raphidocelis subcapitata) to environmentally relevant concentrations (0.005-5 mu g/L) following standardized protocols (US EPA, Environment Canada and OECD). P. tricornutum and I. galbana were sensitive to both substances and for P. tricornutum exposed to HHCB and AHTN, the IC10 values (the inhibition concentration at which 10% microalgae growth inhibition was observed) were 0.127 and 0.002 mu g/L, respectively, while IC10 values calculated for I. galbana were 5.22 mu g/L (a little higher than the highest concentration) and 0.328 mu g/L, for HHCB and AHTN, respectively. Significant (p < 0.01) concentration dependent responses were measured in P. lividus and M. galloprovincialis larvae developments, as well as S. aurata mortality tested with HHCB. The effect of HHCB on P. lividus larvae development was the most sensitive endpoint recorded, producing an EC50 value (the effect concentration at which 50% effect was observed) of 4.063 mu g/L. Considering the risk quotients both substances seem to represent high environmental risk to P. tricornutum and M. galloprovincialis in marine environments
The aryl hydrocarbon receptor ligand FICZ improves left ventricular remodeling and cardiac function at the onset of pressure overload-Induced heart failure in mice
Adverse ventricular remodeling is the heart’s response to damaging stimuli and is linked to heart failure and poor prognosis. Formyl-indolo [3,2-b] carbazole (FICZ) is an endogenous ligand for the aryl hydrocarbon receptor (AhR), through which it exerts pleiotropic effects including protection against inflammation, fibrosis, and oxidative stress. We evaluated the effect of AhR activation by FICZ on the adverse ventricular remodeling that occurs in the early phase of pressure overload in the murine heart induced by transverse aortic constriction (TAC). Cardiac structure and function were evaluated by cardiac magnetic resonance imaging (CMRI) before and 3 days after Sham or TAC surgery in mice treated with FICZ or with vehicle, and cardiac tissue was used for biochemical studies. CMRI analysis revealed that FICZ improved cardiac function and attenuated cardiac hypertrophy. These beneficial effects involved the inhibition of the hypertrophic calcineurin/NFAT pathway, transcriptional reduction in pro-fibrotic genes, and antioxidant effects mediated by the NRF2/NQO1 pathway. Overall, our findings provide new insight into the role of cardiac AhR signaling in the injured heart.This research was supported by Grants SAF2017-84777-R, funded by the Ministry of Economy and Competitiveness (MINECO) of Spain, PID2020-113238RB-I00 funded by the Ministry of Science and Innovation (MCIN)/AEI/ 10.13039/501100011033 of Spain and the “European Union Next GenerationEU/PRTR”; PI20/01482-1 funded by the Instituto de Salud Carlos III, CB16/11/00222 funded by the Centro de Investigación Biomédica en Red en Enfermedades Cardiovasculares (CIBERCV) and a Grant (Proyectos 2021) financed by the Universidad Francisco de Vitoria
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