377 research outputs found
Assessing microplastic ingestion and occurrence of bisphenols and phthalates in bivalves, fish and holothurians from a Mediterranean marine protected area
Microplastic (MP) ingestion, along with accumulated plasticizers such as bisphenol A (BPA), bisphenol F (BPF), and bisphenol S (BPS), and phthalates represented by diethyl phthalate (DEP), dibutyl phthalate (DBP) and bis (2-ethylhexyl) phthalate (DEHP), were quantified in bivalves, fish, and holothurians collected from a coastal pristine area at the western Mediterranean Sea. MP ingestion in sediment-feeders holothurians (mean value 12.67 ± 7.31 MPs/individual) was statistically higher than ingestion in bivalves and fish (mean 4.83 ± 5.35 and 3 ± 4.44 MPs/individual, respectively). The main ingested polymers were polyethylene, polypropylene, and polystyrene. The levels of BPS, BPF, and DEHP were highest in bivalves' soft tissue; BPA and DBP had the highest levels in the holothuriansâ muscle. In addition, the levels of all plasticizers assessed were lowest in fish muscle; only BPA levels in fish were higher than in bivalves, with intermediate values between those of bivalves and holothurians. This study provides data on exposure to MPs and plasticizers of different species inhabiting Cabrera Marine Protected Area (MPA) and highlights the differences in MP ingestion and levels of plasticizers between species with different ecological characteristics and feeding strategies.En prensa3,39
Study of carbon-doped Mn3Ga thin films with enhanced magnetization
Carbon-doped Mn3Ga thin films were grown on Si/SiO2 substrates using rf magnetron sputtering technique and they present an enhancement of their magnetization. In this work we focus on the structural stress, theoretical calculations and magnetization analysis (using both Bloch's and Kneller's laws). The residual stress component has been calculated by means of x-ray diffraction in gracing incidence, using the ? method for multiple crystallographic reflections. We have observed an increase of the cell volume or positive (tensile) strain, which is higher near the surface of the film. The existence of induced magnetism in Mn3GaC0.25, with C entering in interstitial positions has been investigated by first-principles calculations, using the projector-augmented-wave method, within the generalized gradient approximation. Spin charge distributions and magnetic moments associated with each ion, were analyzed by performing a Bader charge analysis. Noteworthily, in spite of being a thin film, the magnetic behavior of the sample can be well described considering it formed by magnetic nanoparticles. Magnetic field and temperature dependence of the magnetization measurements were used to evaluate the Bloch and Kneller exponents, showing that dipolar interactions take place between Mn3GaC0.25 nanoparticle
The Milky Way Bulge: Observed properties and a comparison to external galaxies
The Milky Way bulge offers a unique opportunity to investigate in detail the
role that different processes such as dynamical instabilities, hierarchical
merging, and dissipational collapse may have played in the history of the
Galaxy formation and evolution based on its resolved stellar population
properties. Large observation programmes and surveys of the bulge are providing
for the first time a look into the global view of the Milky Way bulge that can
be compared with the bulges of other galaxies, and be used as a template for
detailed comparison with models. The Milky Way has been shown to have a
box/peanut (B/P) bulge and recent evidence seems to suggest the presence of an
additional spheroidal component. In this review we summarise the global
chemical abundances, kinematics and structural properties that allow us to
disentangle these multiple components and provide constraints to understand
their origin. The investigation of both detailed and global properties of the
bulge now provide us with the opportunity to characterise the bulge as observed
in models, and to place the mixed component bulge scenario in the general
context of external galaxies. When writing this review, we considered the
perspectives of researchers working with the Milky Way and researchers working
with external galaxies. It is an attempt to approach both communities for a
fruitful exchange of ideas.Comment: Review article to appear in "Galactic Bulges", Editors: Laurikainen
E., Peletier R., Gadotti D., Springer Publishing. 36 pages, 10 figure
Contrasting growth and water use efficiency after thinning in mixed Abies pinsapoâPinus pinasterâPinus sylvestris forests
Foresters frequently lack sufficient information about thinning intensity effects to optimize semi-natural forest management and their effects and interaction with climate are still poorly understood. In an Abies pinsapoâPinus pinasterâPinus sylvestris forest with three thinning intensities, a dendrochronologial approach was used to evaluate the short-term responses of basal area increment (BAI), carbon isotope (ÎŽ13C) and water use efficiency (iWUE) to thinning intensity and climate. Thinning generally increased BAI in all species, except for the heavy thinning in P. sylvestris. Across all the plots, thinning increased 13C-derived water-use efficiency on average by 14.49% for A. pinsapo, 9.78% for P. sylvestris and 6.68% for P. pinaster, but through different ecophysiological mechanisms. Our findings provide a robust mean of predicting water use efficiency responses from three coniferous species exposed to different thinning strategies which have been modulated by climatic conditions over time
A solution scan of societal options to reduce transmission and spread of respiratory viruses: SARS-CoV-2 as a case study
Societal biosecurity â measures built into everyday society to minimize risks from pests and diseases â is an important aspect of managing epidemics and pandemics. We aimed to identify societal options for reducing the transmission and spread of respiratory viruses. We used SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) as a case study to meet the immediate need to manage the COVID-19 pandemic and eventually transition to more normal societal conditions, and to catalog options for managing similar pandemics in the future. We used a âsolution scanningâ approach. We read the literature; consulted psychology, public health, medical, and solution scanning experts; crowd-sourced options using social media; and collated comments on a preprint. Here, we present a list of 519 possible measures to reduce SARS-CoV-2 transmission and spread. We provide a long list of options for policymakers and businesses to consider when designing biosecurity plans to combat SARS-CoV-2 and similar pathogens in the future. We also developed an online application to help with this process. We encourage testing of actions, documentation of outcomes, revisions to the current list, and the addition of further options.</p
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