485 research outputs found
Influence of overliming vineyard acid soils on the macro-nutritional status of grapevines
[EN] Aim of study: The main aim of this study was to evaluate the effect of overliming with dolomitic lime on the topsoil and grapevine macro-nutritional levels (both petiole and grape tissues), as well as on berry weight and must quality properties in grapevines growing on an acid soil.Area of study: The study was carried out in the viticultural region of El Bierzo (Spain), one of the main wine protected designation of origin in the northwest of Spain.Material and methods: The effects of overliming were studied in soil parameters, petiole and grape tissues, as well as in must quality during three years (2014-2016). Data analysis was performed using factorial ANOVA (both parametric and non-parametric tests have been used).Main results: The results found on the soil levels of magnesium and phosphorus were mirrored by those shown in petiole and grape tissues. Data suggest that insufficient Mg supply in vineyard acid soils could lead to a lower P vascular movement in vines. Additionally, our findings suggest that a great decrease of K levels in vine tissues as a consequence of overliming, could lead to changes in harvest quality.Research highlights: Overliming with dolomitic limestone in large quantities decreased soil exchangeable K, as well as improved supply of exchangeable Mg and available P. Additionally Mg and P levels in both petiole and grape tissues were significantly affected by overliming.SIWe are especially grateful to “Losada Vinos de Finca, SA”, for its assistance in the research project
A comparative study of experimental configurations in synchrotron pair distribution function
The identification and quantification of amorphous components and nanocrystalline phases
with very small crystal sizes, smaller than ~3 nm, within samples containing crystalline phases is
very challenging. However, this is important as there are several types of systems that contain these
matrices: building materials, glass-ceramics, some alloys, etc. The total scattering synchrotron pair
distribution function (PDF) can be used to characterize the local atomic order of the nanocrystalline
components and to carry out quantitative analyses in complex mixtures. Although the resolution in
momentum transfer space has been widely discussed, the resolution in the interatomic distance space
has not been discussed to the best of our knowledge. Here, we report synchrotron PDF data collected at
three beamlines in different experimental configurations and X-ray detectors. We not only discuss the
effect of the resolution in Q-space, Qmax ins of the recorded data and Qmax of the processed data, but we
also discuss the resolution in the interatomic distance (real) space. A thorough study of single-phase
crystalline nickel used as standard was carried out. Then, selected cement-related samples including
anhydrous tricalcium and dicalcium silicates, and pastes derived from the hydration of tricalcium
silicate and ye’elimite with bassanite were analyzed.This work is part of the PhD of Mr. Jesus D. Zea-Garcia. This work was supported by Spanish MINECO and FEDER [BIA2017-82391-R research project and I3 [IEDI-2016-0079] program]
The growth threshold conjecture: a theoretical framework for understanding T-cell tolerance
Adaptive immune responses depend on the capacity of T cells to target specific antigens. As similar antigens can be expressed by pathogens and host cells, the question naturally arises of how can T cells discriminate friends from foes. In this work, we suggest that T cells tolerate cells whose proliferation rates remain below a permitted threshold. Our proposal relies on well-established facts about T-cell dynamics during acute infections: T-cell populations are elastic (they expand and contract) and they display inertia (contraction is delayed relative to antigen removal). By modelling inertia and elasticity, we show that tolerance to slow-growing populations can emerge as a population-scale feature of T cells. This result suggests a theoretical framework to understand immune tolerance that goes beyond the self versus non-self dichotomy.M.A.H. has been partially supported by MINECO grant no. MTM2014-53156. The rest of the authors have not received any particular financial support for this work
Review of current classifications for diverticular disease and a translation into clinical practice
RGNNV and SJNNV reassortants produce mortality and replicate in gilthead seabream larvae
Nervous Necrosis Virus (NNV) is one of the most challenging pathogens for aquaculture development nowadays, mainly affecting marine teleost fish of major interest to the aquaculture industry and causing great economic losses. NNV consist in four genotypes, which seem to have a tropism for certain teleost fish species. Among them, gilthead seabream (Sparus aurata) has been considered as a non-susceptible species to the disease produced by traditional NNV genotypes. However, there are some evidences that indicate seabream is able to develop the disease in the presence of certain reassortant strains of NNV, called RGNNV/SJNNV, which possesses the RNA1 segment of the RGNNV genotype and the RNA2 segment of the
SJNNV genotype, which may cause a new threat to aquaculture.
Therefore, the main objective of this study was to evaluate the susceptibility of gilthead seabream larvae to the reassortant strains RGNNV/SJNNV and SJNNV/RGNNV. For this purpose, larvae were exposed to 104 TCDI50/mL in triplicate tanks with the reassortant strains. Samples of 5 individual larvae were collected at different days post-infection and used for gene expression and infective NNV isolation. Our data show that both reassortants produced mortalities, although the RGNNV/SJNNV was the one which produced the highest mortality and viral gene transcription, which significantly increased from 1 to 7 days post-infection.
In conclusion, our study demonstrate that seabream larvae are susceptible to both RGNNV/SJNNV and SJNNV/RGNNV reassortants under laboratory conditions. Further studies should be performed to understand the pathogenicity of the NNV reassortant strains to prevent and control future outbreaks in aquaculture farms
Profile of Innate Immunity in Gilthead Seabream Larvae Reflects Mortality upon Betanodavirus Reassortant Infection and Replication
Historically, gilthead seabream (Sparus aurata) has been considered a fish species resistant
to nervous necrosis virus (NNV) disease. Nevertheless, mortality in seabream hatcheries, associated
with typical clinical signs of the viral encephalopathy and retinopathy (VER) disease has been
confirmed to be caused by RGNNV/SJNNV reassortants. Because of this, seabream larvae at 37 and
86 days post-hatching (dph) were infected by immersion with RGNNV/SJNNV and
SJNNV/RGNNV reassortants under laboratory conditions, and mortality, viral replication and
immunity were evaluated. Our results show that gilthead seabream larvae, mainly those at 37 dph,
are susceptible to infection with both NNV reassortant genotypes, with the highest impact from the
RGNNV/SJNNV reassortant. In addition, viral replication occurs at both ages (37 and 86 dph) but
the recovery of infective particles was only confirmed in 37 dph larvae,; this value was also highest
with the RGNNV/SJNNV reassortant. Larvae immunity, including the expression of antiviral,
inflammatory and cell-mediated cytotoxicity genes, was affected by NNV infection. Levels of the
natural killer lysin (Nkl) peptide were increased in SJNNV/RGNNV-infected larvae of 37 dph,
though hepcidin was not. Our results demonstrate that the seabream larvae are susceptible to both
NNV reassortants, though mainly to RGNNV/SJNNV, in an age-dependent manner.Versión del editor2,46
Recent studies of cements and concretes by synchrotron radiation crystallographic and cognate methods
The portfolio of available synchrotron radiation techniques is increasing notably for cements
and pastes. Furthermore, sometimes the terminology is confusing and an overall picture highlighting
similarities and differences of related techniques was lacking. Therefore, the main
objective of this work is to review recent advances in synchrotron techniques providing a
comprehensive overview. This work is not intended to gather all publications in cement chemistry
but to give a unified picture through selected examples. Crystallographic techniques are
used for structure determination, quantitative phase analyses and microstructure characterization.
These studies are not only carried out in standard conditions but synchrotron techniques
are especially suited to non-ambient conditions: high temperatures and pressures, hydration,
etc., and combinations. Related crystallographic techniques, like Pair Distribution Function,
are being used for the analysis of ill-crystalline phase(s). Furthermore, crystallographic tools
are also employed in imaging techniques including scanning diffraction microscopy and
tomography and coherent diffraction imaging. Other synchrotron techniques are also reviewed
including X-rays absorption spectroscopy for local structure and speciation characterizations;
small angle X-ray scattering for microstructure analysis and several imaging techniques for
microstructure quantification: full-field soft and hard X-ray nano-tomographies; scanning
infrared spectro-microscopy; scanning transmission and fluorescence X-ray tomographies.
Finally, a personal outlook is provided.I am grateful to all my coauthors, collaborators, colleagues and PhD students, for all our work together
during more than two decades. I thank the University of Malaga and ALBA Synchrotron Light Source
for the support and the stirring environments. I acknowledge the Spanish science funding agencies (they
change the name quite often) for funding my studentship, to do the PhD and the three summer research
stays at Oxford University, to the last ongoing research project. To all synchrotrons I have been allowed to
enjoy carrying out experiments: SRS, ESRF, Max-Lab, DLS, APS, SLS and ALBA. Finally, this work has
been supported by the Spanish MINECO through the BIA2014-57658-C2-1-R research grant
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