97 research outputs found
Evaluation of soil salinity indexes based on bulk electrical conductivity
[SPA] Los sensores del suelo que miden conductividad eléctrica (CE) y humedad desempeñan un papel esencial en el control de la salinidad del suelo. Sin embargo, la interpretación precisa de la salinidad del suelo depende del desarrollo de Índices de Salinidad (IS) adecuados. Este trabajo se enfoca en el estudio del potencial de varios IS basados en la CE del medio (ECb), utilizando análisis de regresión para conocer cómo estos IS representan la salinidad del suelo. Los resultados indican que el ECb es un IS eficiente siempre que se mida a humedad constante. Además, la precisión de esta medida aumenta con la humedad del sustrato. La pendiente del ajuste de regresión lineal humedad-ECb se propone como un IS nuevo y fiable.
[ENG] Soil sensors that measure electrical conductivity (EC) and moisture play an essential role in monitoring soil salinity. However, the accurate understanding of salinity depends on the development of suitable sensor-based Salinity Indices (SI). This work studied the potential of several SIs based on bulk EC (ECb), which is the only EC directly measured by sensors. Regression studies were performed to know how these SIs describe soil salinity. The results indicate that ECb is an efficient SI as long as humidity is constant. Moreover, its accuracy increases with substrate moisture. The slope of the linear regression fit moisture-ECb is proposed as a novel and reliable SIEsta investigación ha sido financiada por el Ministerio de Ciencia, Innovación y Universidades de España, el Fondo Europeo de Desarrollo Regional, subvención número RTI2018-093997-B-I00, y por la AEI española (subvención número PCI 2019-103608) bajo el programa PRIMA en el marco del proyecto PRECIMED
Estudio de la marcha en pacientes tratados ortopédicamente de fractura unilateral del calcáneo
Veinticinco pacientes afectos de fractura unilateral desplazada articular de calcá-
neo fueron tratados mediante inmovilización con yeso, siendo los resultados a los 6 años (rango:
3-10), excelentes en 5 pacientes, buenos en 4, regulares en 7 y malos en 9. De este grupo se excluyeron
los afectos de patología local o general asociada, siendo útiles para el estudio de la marcha
12 pacientes a los que se les hizo deambular sobre plataformas dinamométricas para registrar
la fuerza de reacción al suelo, demostrando una disminución de la fuerza vertical de apoyo y
despegue (F1 y F3) y un aumento estadísticamente significativo del tiempo de apoyo total durante
la marcha. Abogamos por la restitución anatómica del calcáneo como medio para mejorar la
capacidad funcional del paciente.Twenty-five patients with unilateral displaced joint calcaneus fracture were treated
by cast being the results after 6 years (range: 3-10), excellent in 5 patients, good in 4 patients,
poor in 7 and bad in 9. We excluded for the study the patients with associated local or general
pathology being useful for our study 12 patients. These patients walked on a dynamometric platform
in order to analyse floor reaction forces, proving a diminuí ion of vertical support and takeoff
forces (Fl and F2), and statistically significant a increase of total support phase during gait
Evidence for a mixed mass composition at the `ankle' in the cosmic-ray spectrum
We report a first measurement for ultra-high energy cosmic rays of the
correlation between the depth of shower maximum and the signal in the water
Cherenkov stations of air-showers registered simultaneously by the fluorescence
and the surface detectors of the Pierre Auger Observatory. Such a correlation
measurement is a unique feature of a hybrid air-shower observatory with
sensitivity to both the electromagnetic and muonic components. It allows an
accurate determination of the spread of primary masses in the cosmic-ray flux.
Up till now, constraints on the spread of primary masses have been dominated by
systematic uncertainties. The present correlation measurement is not affected
by systematics in the measurement of the depth of shower maximum or the signal
in the water Cherenkov stations. The analysis relies on general characteristics
of air showers and is thus robust also with respect to uncertainties in
hadronic event generators. The observed correlation in the energy range around
the `ankle' at differs significantly from
expectations for pure primary cosmic-ray compositions. A light composition made
up of proton and helium only is equally inconsistent with observations. The
data are explained well by a mixed composition including nuclei with mass . Scenarios such as the proton dip model, with almost pure compositions, are
thus disfavoured as the sole explanation of the ultrahigh-energy cosmic-ray
flux at Earth.Comment: Published version. Added journal reference and DOI. Added Report
Numbe
Atmospheric effects on extensive air showers observed with the Surface Detector of the Pierre Auger Observatory
Atmospheric parameters, such as pressure (P), temperature (T) and density,
affect the development of extensive air showers initiated by energetic cosmic
rays. We have studied the impact of atmospheric variations on extensive air
showers by means of the surface detector of the Pierre Auger Observatory. The
rate of events shows a ~10% seasonal modulation and ~2% diurnal one. We find
that the observed behaviour is explained by a model including the effects
associated with the variations of pressure and density. The former affects the
longitudinal development of air showers while the latter influences the Moliere
radius and hence the lateral distribution of the shower particles. The model is
validated with full simulations of extensive air showers using atmospheric
profiles measured at the site of the Pierre Auger Observatory.Comment: 24 pages, 9 figures, accepted for publication in Astroparticle
Physic
Deep-sequencing reveals broad subtype-specific HCV resistance mutations associated with treatment failure
A percentage of hepatitis C virus (HCV)-infected patients fail direct acting antiviral (DAA)-based treatment regimens, often because of drug resistance-associated substitutions (RAS). The aim of this study was to characterize the resistance profile of a large cohort of patients failing DAA-based treatments, and investigate the relationship between HCV subtype and failure, as an aid to optimizing management of these patients. A new, standardized HCV-RAS testing protocol based on deep sequencing was designed and applied to 220 previously subtyped samples from patients failing DAA treatment, collected in 39 Spanish hospitals. The majority had received DAA-based interferon (IFN) a-free regimens; 79% had failed sofosbuvir-containing therapy. Genomic regions encoding the nonstructural protein (NS) 3, NS5A, and NS5B (DAA target regions) were analyzed using subtype-specific primers. Viral subtype distribution was as follows: genotype (G) 1, 62.7%; G3a, 21.4%; G4d, 12.3%; G2, 1.8%; and mixed infections 1.8%. Overall, 88.6% of patients carried at least 1 RAS, and 19% carried RAS at frequencies below 20% in the mutant spectrum. There were no differences in RAS selection between treatments with and without ribavirin. Regardless of the treatment received, each HCV subtype showed specific types of RAS. Of note, no RAS were detected in the target proteins of 18.6% of patients failing treatment, and 30.4% of patients had RAS in proteins that were not targets of the inhibitors they received. HCV patients failing DAA therapy showed a high diversity of RAS. Ribavirin use did not influence the type or number of RAS at failure. The subtype-specific pattern of RAS emergence underscores the importance of accurate HCV subtyping. The frequency of “extra-target” RAS suggests the need for RAS screening in all three DAA target regions
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Gaia Early Data Release 3: The celestial reference frame (Gaia-CRF3)
Context. Gaia-CRF3 is the celestial reference frame for positions and proper motions in the third release of data from the Gaia mission, Gaia DR3 (and for the early third release, Gaia EDR3, which contains identical astrometric results). The reference frame is defined by the positions and proper motions at epoch 2016.0 for a specific set of extragalactic sources in the (E)DR3 catalogue. Aims. We describe the construction of Gaia-CRF3 and its properties in terms of the distributions in magnitude, colour, and astrometric quality. Methods. Compact extragalactic sources in Gaia DR3 were identified by positional cross-matching with 17 external catalogues of quasi-stellar objects (QSO) and active galactic nuclei (AGN), followed by astrometric filtering designed to remove stellar contaminants. Selecting a clean sample was favoured over including a higher number of extragalactic sources. For the final sample, the random and systematic errors in the proper motions are analysed, as well as the radio-optical offsets in position for sources in the third realisation of the International Celestial Reference Frame (ICRF3). Results. Gaia-CRF3 comprises about 1.6 million QSO-like sources, of which 1.2 million have five-parameter astrometric solutions in Gaia DR3 and 0.4 million have six-parameter solutions. The sources span the magnitude range G = 13-21 with a peak density at 20.6 mag, at which the typical positional uncertainty is about 1 mas. The proper motions show systematic errors on the level of 12 μas yr-1 on angular scales greater than 15 deg. For the 3142 optical counterparts of ICRF3 sources in the S/X frequency bands, the median offset from the radio positions is about 0.5 mas, but it exceeds 4 mas in either coordinate for 127 sources. We outline the future of Gaia-CRF in the next Gaia data releases. Appendices give further details on the external catalogues used, how to extract information about the Gaia-CRF3 sources, potential (Galactic) confusion sources, and the estimation of the spin and orientation of an astrometric solution
Medidas para reducir la exposición de los ciclistas a los principales contaminantes atmosféricos urbanos
Recoge los principales resultados generados durante la realización del proyecto LIFE+RESPIRA, llevado a cabo en la ciudad de Pamplona (Navarra, España) por un equipo interdisciplinar constituido por más de 30 investigadores pertenecientes a la Universidad de Navarra, el Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT) y Gestión Ambiental de Navarra (GAN-NIK). El libro, que se ha publicado en castellano y en inglés, se ha dividido en 7 capítulos: 1. ¿Ciudades sostenibles? 2. Exposición de los ciudadanos a la contaminación atmosférica 3. Papel de la vegetación urbana en la calidad del aire 4. Modelos de alta resolución para evaluar la calidad del aire 5. Impactos de la contaminación urbana 6. Movilidad y sostenibilidad urbanas 7. Comunicación y educación ambiental. Este libro pretende ser una guía de utilidad para científicos, gestores y ciudadanos, aportando un conjunto de herramientas que permitan mejorar la calidad de vida de nuestras ciudades. Además, quiere rendir un homenaje a todos los voluntarios ciclistas que han participado en dicho proyecto y que son los verdaderos artífices del mismo, ya que gracias a su dedicación incondicional durante más de dos años, han proporcionado una cantidad ingente de datos sobre la calidad del aire de la ciudad de Pamplona
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