132 research outputs found
Evolution of the upper proterozoic continental deposits from «La Serena», (Southern Central Iberian Zone) Badajoz, Spain
[Resumen] Se describen por primera vez afloramientos, recientemente descubiertos, del Alcudiense Superior, en «La Serena», Badajoz. Se demuestra el carácter continental de la parte basal de varias secuencias, y se esboza un esquema paleogeográfico, que implica una línea de,costa hacia el Oeste, y la diferenciación de tres ciclos sedimentarios.[Abstract] Sorne recently discovered Upper Alcudian outcrops, from «La Serena» region in
Badajoz province, are described in this paper for the first time. The basal pan of most of the studied logs shows continental characteristics here depicted; a paleogeographical scheme is also submitted. This latter implies moving the suggested coast line westward for the first cycle. Three local sedimentary cycles are here proposed and correlated with those from well known areas
Two-step magnetization reversal FORC fingerprint of coupled bi-segmented Ni/Co magnetic nanowire arrays
First Order Reversal Curve (FORC) analysis has been established as an appropriate method to investigate the magnetic interactions among complex ferromagnetic nanostructures. In this work, the magnetization reversal mechanism of bi-segmented nanowires composed by long Co and Ni segments contacted at one side was investigated, as a model system to identify and understand the FORC fingerprint of a two-step magnetization reversal process. The resulting hysteresis loop of the bi-segmented nanowire array exhibits a completely different magnetic behavior than the one expected for the magnetization reversal process corresponding to each respective Co and Ni nanowire arrays, individually. Based on the FORC analysis, two possible magnetization reversal processes can be distinguished as a consequence of the ferromagnetic coupling at the interface between the Ni and Co segments. Depending on the relative difference between the magnetization switching fields of each segment, the softer magnetic phase induces the switching of the harder one through the injection and propagation of a magnetic domain wall when both switching fields are comparable. On the other hand, if the switching fields values differ enough, the antiparallel magnetic configuration of nanowires is also possible but energetically unfavorable, thus resulting in an unstable magnetic configuration. Making use of the different temperature dependence of the magnetic properties for each nanowire segment with different composition, one of the two types of magnetization reversal is favored, as demonstrated by FORC analyses
Reconocimiento geológico y métodos de estabilización de taludes rocosos en formaciones volcánicas del sur de Gran Canaria y Fuerteventura, Islas Canarias.
El relieve natural de las islas volcánicas montañosas tiene profundos barrancos taludes rocosos de pronunciadas pendientes y elevados acantilados costeros. Las formaciones geológicas de origen volcánico incluyen materiales rocosos y suelos muy heterogéneos en cuanto a su disposición espacial y comportamiento geomecánico. Además, en las zonas del sur de Gran Canaria y Fuerteventura, con frecuencia las construcciones civiles y de edificación muestran altos taludes practicados en el terreno y, como resultado en diversos puntos se ven afectados por desprendimientos de rocas y deslizamientos En el presente trabajo se muestran dos casos de estudio: 1) Estudio del riesgo de desprendimientos de rocas y métodos de estabilización aplicados en el talud de Los Teques, T.M. de Mogán, sur de Gran Canaria, y 2) Estudio geológico-geotécnico para el proyecto de construcción del paseo peatonal en el acantilado costero de Morro Jable T.M. de Pájara, sur de Fuerteventura. La variación espacial de las formaciones volcamcas, su grado de soldadura y alteración variables y la dificultad de establecer familias de fracturas características, han hecho que los métodos clásicos de clasificación geomecanica resultaran poco eficaces. En estos casos, el reconocimiento geológico detallado y una estimación del comportamiento geomecánico de los materiales ha sido el método empleado para definir y evaluar las zonas inestables en los taludes y para establecer los métodos de estabilización más convenientes
Pain expressions and inhibitory control in patients with fibromyalgia: behavioral and neural correlates
Fibromyalgia (FM) is a generalized chronic pain condition associated with a variety of symptoms, including altered cognitive and emotional processing. It has been proposed that FM patients show a preferential allocation of attention to information related to the symptoms of the disease, particularly to pain cues. However, the existing literature does not provide conclusive evidence on the presence of this attentional bias, and its effect on cognitive functions such as inhibitory control. To clarify this issue, we recorded the electroencephalographic activity of 31 women diagnosed with FM and 28 healthy women, while performing an emotional Go/NoGo task with micro-videos of pain, happy, and neutral facial expressions. We analyzed behavioral data, performed EEG time-frequency analyses, and obtained the event-related potentials (ERPs) N2 and P3 components in NoGo trials. A series of self-reports was also administered to evaluate catastrophic thinking and the main symptoms of fibromyalgia. Pain expressions were associated with longer reaction times and more errors, as well as with higher theta and delta power, and P3 amplitude to NoGo stimuli. Thus, behavioral and psychophysiological data suggest that increased attention to pain expressions impairs the performance of an inhibitory task, although this effect was similar in FM patients and healthy controls. N2 amplitude was modulated by type of facial expression (larger to pain faces), but only for the control group. This finding suggests that the presentation of pain faces might represent a smaller conflict for the patients, more used to encounter pain stimuli. No main group effects were found significant for N2 or P3 amplitudes, nor for time-frequency data. Using stimuli with greater ecological validity than in previous studies, we could not confirm a greater effect of attentional bias toward negative stimuli over inhibitory performance in patients with FM. Studying these effects allow us to better understand the mechanisms that maintain pain and develop intervention strategies to modify them.Galician
Government (Consellería de Cultura, Educación e Ordenación
Universitaria; axudas para a consolidación e estruturación
de unidades de investigación competitivas do Sistema
Universitario de Galicia [grant number GPC2014/047] and
funding from the Spanish Government (Ministerio de Economía
y Competitividad) [grant number PSI2013-45818-R]. AG-V was
supported by a grant from the Deputación da Coruña (Bolsas de
investigación en ciencias da saúde 2017) and Xunta de Galici
Monocrystalline Heusler Co2FeSi alloy glass-coated microwires: Fabrication and magneto-structural characterization
Singularity resolution depends on the clock
We study the quantum cosmology of a flat Friedmann–Lemaître–Robertson–Walker Universe filled with a (free) massless scalar field and a perfect fluid that represents radiation or a cosmological constant whose value is not fixed by the action, as in unimodular gravity. We study two versions of the quantum theory: the first is based on a time coordinate conjugate to the radiation/dark energy matter component, i.e., conformal time (for radiation) or unimodular time. As shown by Gryb and Thébault, this quantum theory achieves a type of singularity resolution; we illustrate this and other properties of this theory. The theory is then contrasted with a second type of quantisation in which the logarithm of the scale factor serves as time, which has been studied in the context of the 'perfect bounce' for quantum cosmology. Unlike the first quantum theory, the second one contains semiclassical states that follow classical trajectories and evolve into the singularity without obstruction, thus showing no singularity resolution. We discuss how a complex scale factor best describes the semiclassical dynamics. This cosmological model serves as an illustration of the problem of time in quantum cosmology
Water seepage beneath dams on soluble evaporite deposits: a laboratory and field study (Caspe Dam, Spain)
The paper presents analytical methods and results for assessing the variation in the concentration of sulphate (and other ions) over space and time in groundwater flowing through a soluble evaporite terrain beneath a dam. The influence of effective porosity, groundwater flow velocity and the specific rate of dissolution (K′) are considered. The theoretical analysis was tested in a scale model simulating a dam constructed on heavily karstified bedrock. A simple and useful method for assessing how much material is lost through dissolution and how the rate of dissolution changes over time is considered in the context of the Caspe Dam, Spain
Las sucesiones estratigráficas del Paleozoico Inferior y Medio
p. 31-43Ya se ha visto que la formación del Macizo Ibérico,
donde aflora el basamento de la Península Ibérica, está
íntimamente ligada al desarrollo de la orogenia Varisca
del Paleozoico Superior. La consecuencia fue el acortamiento
y deformación intensa de los sedimentos marinos
depositados previamente a lo largo de los extensos
márgenes continentales de Gondwana durante el
Paleozoico Inferior y Medio. El Macizo Ibérico contiene
los afloramientos más extensos y fosilíferos de cuantos
componen la Cadena Varisca europea. Sus distintas zonas
estructurales y paleogeográficas albergan importantes
sucesiones estratigráficas de los períodos
Cámbrico a Devónico (García-Cortés et al., 2000,
2001; Gutiérrez-Marco, 2006), que configuran uno de
los contextos geológicos clave para conocer la evolución
fini-precámbrica y paleozoica de la Península
Ibérica y de Europa Occidental, y en donde se registran
numerosos eventos geológicos y biológicos de alcance
global
Whole-genome sequencing to determine origin of multinational outbreak of Sarocladium kiliense bloodstream infections
We used whole-genome sequence typing (WGST) to investigate an outbreak of Sarocladium kiliense bloodstream infections (BSI) associated with receipt of contaminated antinausea medication among oncology patients in Colombia and Chile during 2013-2014. Twenty-five outbreak isolates (18 from patients and 7 from medication vials) and 11 control isolates unrelated to this outbreak were subjected to WGST to elucidate a source of infection. All outbreak isolates were nearly indistinguishable (≤5 single-nucleotide polymorphisms), and >21,000 single-nucleotide polymorphisms were identified from unrelated control isolates, suggesting a point source for this outbreak. S. kiliense has been previously implicated in healthcare-related infections; however, the lack of available typing methods has precluded the ability to substantiate point sources. WGST for outbreak investigation caused by eukaryotic pathogens without reference genomes or existing genotyping methods enables accurate source identification to guide implementation of appropriate control and prevention measures. © 2016, Centers for Disease Control and Prevention (CDC). All rights reserved
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