405 research outputs found
Motionless of snail Hydrobia ulvae (Pennant) as response to sediment toxicity and its consequences for the post-exposure feeding
Post-exposure feeding and motionless may be useful endpoints for assessing toxicity. The present study aimed to examine (i) the immobility of the estuarine snail Hydrobia ulvae resulting from short-term exposure to copper-spiked sediment, and subsequently, (ii) the potential application of post-exposure feeding (indirectly measured as pellets excreted) as an ecotoxicological response associated with motionlessness. Mobility and post-exposure feeding were influenced by copper contamination. Motionless was noticeable above the concentration of 200 μg Cu g-1, where 40% of the organisms were inactive. Practically all the organisms remained active at the two lowest concentrations: 40 (control) and 60 μg Cu g-1. For 400 and 800 μg Cu g-1 the motionless was generally higher than 50%. Mortality higher than 25% was observed at 200, 400 and 800 μg Cu g-1, with values of 27, 40 and 60%, respectively. The feeding inhibition values showed an increasing inhibition from 20% at the lowest concentration (60 μg Cu g-1), up to 59% at 400 μg Cu g-1; at concentration of 800 μg Cu g-1, although the physical activity inhibition had reached 67%, the post-exposure feeding was 1.5 higher in relation to the control. Probably, the starvation period due to motionless during exposure seems to increase the post-exposure feeding and egestion when food was provided; alternatively, increased pellet production could also indicate a detoxification process
Products released from surgical face masks can provoke cytotoxicity in the marine diatom Phaeodactylum tricornutum
Surgical face masks are more present than ever as personal protective equipment due to the COVID-19 pandemic. In
this work, we show that the contents of regular surgical masks: i) polypropylene microfibres and ii) some added metals
such as: Al, Fe, Cu, Mn, Zn and Ba, may be toxic to some marine life. This work has got two objectives: i) to study the
release rate of the products from face masks in marine water and ii) to assess the toxicity in Phaeodactylum tricornutum
of these by-products. To achieve these two objectives, we performed release kinetic experiments by adding masks in
different stages of fragmentation to marine water (i.e. whole face masks and fragments of them 1.52 ± 0.86 mm). Released microfibres were found after one month in shaking marine water; 0.33 ± 0.24 and 21.13 ± 13.19 fibres·mL−1
were collected from the whole and fragmented face masks, respectively. Significant amounts of dissolved metals such
as Mn, Zn and Ni, as well as functional groups only in the water containing the face mask fragments were detected.
Water from both treatments was employed to study its toxicity on the marine diatom. Only the water from the face
mask fragments showed a significant, dose-dependent, decrease in cell density in P. tricornutum; 53.09 % lower than
in the controls. Although the water from the face mask fragments showed greater effects on the microalgae population
than the water from the whole face mask, the latter treatment did show significant changes in the photosynthetic apparatus and intrinsic properties of the cells. These results indicate that during fragmentation and degradation face
masks a significant chemical print can be observed in the marine environment.Marta Sendra wishes to acknowledge her contract Juan de la Cierva Incorporación (IJC2020-043162-I) funded by MCIN/AEI/10.13039/ 501100011033 and European Union NextGenerationEU/PRTR. Dr. Araceli Rodríguez-Romero is supported by the Spanish grant Juan de la Cierva Incorporación referenced as IJC2018–037545-I
Temporal variations in metallothionein concentration and subcellular distribution of metals in gills and digestive glands of the oyster <i>Crassostrea angulata</i>
Educación inclusiva. Creando culturas
En este trabajo se desarrolla el concepto de inclusión basándonos en dos pilares fundamentales: aceptación de la integración como algo positivo que se puede convertir en oportunidades de aprendizajes y la comunidad, entendida como un apoyo total de todos los miembros que forman parte del centro, desde alumnos a otras instituciones. En él se tratan aspectos teóricos en los que posteriormente me basaré para analizar, a través del Index (índice de inclusión) de Ainscow y Booth, la dimensión más social y cultural de un centro, que se caracteriza por su carácter inclusivo. Con este instrumento intentaré valorar el grado de inclusividad del mismo y cómo da respuesta a las necesidades que presentan los alumnos
In vivo immunomodulatory and antioxidant properties of nanoceria (nCeO2) in the marine mussel Mytilus galloprovincialis
Cerium nanoparticles (nCeO2) are increasingly utilized in a wide variety of industrial, environmental and biomedical applications, and are therefore expected to be released in the aquatic environment. Due to its peculiar redox properties, nCeO2 may present unique hazards to environmental and human health. Previous data showed that in the hemocytes of the marine bivalve Mytilus galloprovincialis, in vitro exposure to a particular type of nCeO2 (9 nm, characterized by negative ζ-potential, high H2O2 scavenging capacity and Ce3+/Ce4+ surface ratio) reduced basal ROS production, lysosomal membrane stability and phagocytic activity in the presence of hemolymph serum; the effects observed were partly ascribed to the formation of a SOD-protein corona in the hemolymph. In this work, the in vivo effects of this type of nCeO2 were investigated in mussels exposed to 100 μg/L nCeO2 for 96 h; several lysosomal, immune, inflammatory and antioxidant biomarkers were measured at cellular (hemocytes) and tissue (gills, digestive gland) level. Molecular responses were evaluated in hemocytes and digestive gland by determining expression of 11 selected genes related to known biological functions. The results show specific immunomodulatory and antioxidant effects of nCeO2 at different levels of biological organization in the absence of Cerium tissue accumulation. These data further support the redox mechanisms at the basis of the physiological effects of nCeO2. Finally, in order to evaluate the possible impact at the whole organism level, the effects of nCeO2 were evaluated in the 48 h embryotoxicity assay in a wide concentration range. However, nCeO2 exposure resulted in a small reduction in normal embryo development. Overall, the results demonstrate that in mussels nCeO2 can selectively modulate different physiological processes at different levels of biological organization
Explotación en ciclo cerrado para 120 vacas nodrizas en Naval (Huesca)
Se trata de la ampliación de una explotación, ya existente, de vacuno de carne hasta 120 vacas nodrizas de raza pirenaica en el municipio de Naval (Huesca). En la parcela donde se ubica la explotación ya existe un cebadero de terneros para 90 cabezas y un henil, además de 60 vacas nodrizas criadas en un sistema de explotación completamente extensivo. El objetivo del promotor es la crianza de terneros con vacas nodrizas, para su posterior cebo y venta para sacrificio. Por todo ello, se hacen necesarias las siguientes construcciones: una nave para alojar 120 vacas con todos los terneros que puedan tener, 4 toros y 18 novillas, un nuevo henil con capacidad para todo el forraje de la explotación, un estercolero dimensionado para todas las cabezas de la explotación, un lazareto dimensionado para todas las cabezas de la explotación, una nueva fosa de cadáveres y un badén de desinfección. Además en este proyecto se ha abordado todo lo referente al nuevo manejo que se seguirá en la explotación con 120 vacas. El presente proyecto contará con los siguientes documentos: Memoria y anejos a la memoria, Planos, Pliego de condiciones, Presupuesto y Estudio de Seguridad y salud
Feminismo en democracia. El activismo del Frente Feminista(Zaragoza, 1977-1988)
El Frente Feminista fue una de las organizaciones aragonesas más importantes de los años setenta y ochenta en defensa de los derechos de la mujer. Tras cuarenta años de dictadura, donde la mujer estuvo relegada al hogar en su papel de "buena madre y esposa", la ciudadanía democrática trajo consigo la oportunidad de acceso a lo público para la mujer y dio voz a esta parte de infravalorada y silenciada de la sociedad en pro de nuevos derechos hasta entonces negados tales como el derecho al divorcio, el aborto, el acceso a la educación superior y al mercado laboral, la desigualdad salarial, la libertad sexual o la coeducación ,entre otros
Improving the WFD purposes by the incorporation of ecotoxicity tests
Trabajo presentado en la 4th SCARCE International Conference (Towards a better understanding of the links between stressors, hazard assessment and ecosystem services under water scarcity), celebrada en Cádiz el 25 y 26 de noviembre de 2013.The approval of the European Water Framework Dir ective (WFD) supposed a big step regarding aquatic ecosystems protection. According to this Directive, assessment of ecological status is based on three quality elements: biological, physicoc hemical and hydromorphological, but ecotoxicological status is still not included. Some studies have observed that biol ogical status is not always in coherence with physicochemical status, maybe due to the adaptati on mechanisms of aquatic organisms under chronic chemical exposure. In these situations, ecotoxicity t ests could be useful to obtain a better characterisation of these specific ecosystems.
The general aim of this work is to add a battery of
ecotoxicity tests to the
current analyses defined by
WFD in order to obtain a better ecological characteriza
tion of freshwater systems. The specific aims of
this work are: (1) to compare the
effectiveness and viability of differen
t ecotoxicity tests performed with
freshwater sediments (directly and with pore water) ta
king as target organisms different aquatic species,
and (2) to evaluate the relationship between stream
pollutants concentrations (organic pollutants and
metals), biological and hydromorphological status and
sediments ecotoxicity. For this purpose, thirteen
sampling sites within the Ebro river watershed were
selected. Data about priority pollutants in water,
sediment and fish as well as biological and hydromor
phological status of each sampling point will be
achieved. Moreover, in each sampling reach, composite
samples of sediment were collected by using a
Van Veen grab. Sediment samples were stored
at 4ºC prior to the ecotoxicity analysesThe ecotoxicity of pore water was evaluated by different bioassays (
Vibrio fischeri, Pseudokirshneriella
subcapitata
and
Daphnia magna
) while the ecotoxicity of wh
ole sediment was evaluated in
Vibrio
fischeri, Nitzschia palea
and
Chironomus riparius
In addition, the concentration of total heavy metals and
metal bioavailability was calculated by a sequential
extraction according to the Community Bureau of
Reference (BCR) method. To distinguish the potentially
toxic fraction associated to heavy metals burden
of sediments, an analysis of acid-volatile sulphide
(AVS) and simultaneously extracted metals (SEM) was
performed. Complementary sediment variables as humi
dity, porosity, percentages of fines (<63 μm)
organic carbon and organic
matter were determined.
This study expect to demonstrate that the integr
ation of chemical, biological and ecotoxicological
analyses could be crucial to unde
rstand the hazard of pollutants in
aquatic ecosystems, especially, in
freshwater sediments. Future research in this area is
needed in order to obtain more data and be able to
establish a tree decision of freshwater analyses ev
aluation. The poster will present the methodology
purposed for this study as well as the first prelim
inary results obtained from ecotoxicity tests.Authors would like to thank the Spanish Ministry of Economy and Competitiveness for its financial support through the project
SCARCE (Consolider-Ingenio 2010 CSD2009-00065Peer Reviewe
Enhanced Performance of Zn/Br Flow Battery Using N-Methyl-N-Propylmorpholinium Bromide as Complexing Agent
Redox flow batteries (RFB) are one of the most interesting technologies in the field of energy storage, since they allow the decoupling of power and capacity. Zinc–bromine flow batteries (ZBFB) are a type of hybrid RFB, as the capacity depends on the effective area of the negative electrode (anode), on which metallic zinc is deposited during the charging process. Gaseous bromine is generated at the positive electrode (cathode) during the charging process, so the use of bromine complexing agents (BCA) is very important. These BCAs are quaternary amines capable of complexation with bromine and generating an organic phase, immiscible with the aqueous electrolyte. One of the most commonly used BCAs in RFB technology is 4-methylethylmorpholinium bromide (MEM-Br). In this work, an alternative quaternary amine 4-methylpropylmorpholinium bromide (MPM-Br) was studied. MPM-Br was integrated into the electrolyte, and 200 charge–discharge cycles were performed on the resulting ZBFBs. The obtained results were compared with those when MEM-Br was used, and it was observed that the electrolyte with MPM-Br displays a higher resistance in voltage and higher energy efficiency, making it a promising alternative to MEM-Br
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