5,622 research outputs found
ENOBIO - First tests of a dry electrophysiology electrode using carbon nanotubes
We describe the development and first tests of Enobio, a dry electrode sensor
concept for biopotential applications. In the proposed electrodes, the tip of
the electrode is covered with a forest of multi-walled CNTs that can be coated
with Ag/AgCl to provide ionic-electronic transduction. The CNT brush-like
structure is to penetrate the outer layers of the skin improving electrical
contact as well as increae the contact surface area. In this paper, we report
the results of the first tests of this concept -- immersion on saline solution
and pig skin signal detection. These indicate performance on a par with state
of the art research-oriented wet electrodes.Comment: Submitted and accepted at the 28th IEEE EMBS International
Conference, New York City, August 31st-September 3rd, 2006. Figures updated
with proper filtering and averagin
Inicio de una investigación de diseño sobre el desarrollo de competencias numéricas con niños de 4 años
En esta investigación de diseño sobre el desarrollo de competencias numéricas, describimos el comienzo de un taller de resolución de problemas con niños de 4 y 5 años. Aspiramos a lograr una complementariedad metodológica al incorporar, dentro de la investigación de diseño, el uso del Test de Competencia Matemática Básica (TEMA-3). Con él pretendemos evaluar el desarrollo de las competencias numéricas de los niños durante el curso. Además, dado que uno de los objetivos de la investigación es el desarrollo del currículo de Educación Infantil, a través de la elaboración del taller, deseamos valorar la idoneidad del TEMA-3 para un posible estudio posterior sobre la eficiencia de la intervención a través del taller
Percepción de la violencia en niños y niñas de 4to., 5to. y 6to. grado de primaria que asisten a la Escuela Oficial Urbana Mixta Tipo Federación No. 2, 17 de abril de 1763, Villa Nueva.
Interpretó la percepción que tienen los niños y niñas de nivel primario de la violencia. Implementó un programa de prevención de la violencia, se logró promover formas de relación pacíficas y se desarrollar habilidades de comunicación que favorecieron la libre y sana convivencia en la comunidad educativa, se contribuyó en la construcción de una cultura de paz. La investigación fue desarrollada en la Escuela Oficial Urbana Mixta Tipo Federación No.2 “17 de Abril de 1763”, jornada matutina; ubicada en el municipio de Villa Nueva, durante los meses de febrero a junio del año 2014. La muestra estuvo conformada por 46 niños y niñas de 4to., 5to. y 6to. primaria. Para recolectar datos se utilizó la observación participativa, el dibujo técnico, entrevista en profundidad, cuestionario para maestros acerca de percepción de violencia y talleres participativos. Para el análisis estadístico de los resultados se utilizaron: codificación abierta, codificación axial y teorización. Con el programa se logró que, los estudiantes adquirieran conciencia de su realidad y de su responsabilidad, se logró mejores relaciones interpersonales y habilidades sociales asertivas
A Comprehensive X-ray Absorption Model for Atomic Oxygen
An analytical formula is developed to represent accurately the
photoabsorption cross section of O I for all energies of interest in X-ray
spectral modeling. In the vicinity of the Kedge, a Rydberg series expression is
used to fit R-matrix results, including important orbital relaxation effects,
that accurately predict the absorption oscillator strengths below threshold and
merge consistently and continuously to the above-threshold cross section.
Further minor adjustments are made to the threshold energies in order to
reliably align the atomic Rydberg resonances after consideration of both
experimental and observed line positions. At energies far below or above the
K-edge region, the formulation is based on both outer- and inner-shell direct
photoionization, including significant shake-up and shake-off processes that
result in photoionization-excitation and double photoionization contributions
to the total cross section. The ultimate purpose for developing a definitive
model for oxygen absorption is to resolve standing discrepancies between the
astronomically observed and laboratory measured line positions, and between the
inferred atomic and molecular oxygen abundances in the interstellar medium from
XSTAR and SPEX spectral models
Accurate and rapid technique for leaf area measurment in medlar (Mespilus germanica L.)
A model to estimate medlar (Mespilus germanica) leaf area across genotypes was obtained by means of linear measurements in 2005-06
Impact of COVID-19 on case reporting for HTLV and HIV-2 in Spain.
The medical demand imposed by COVID-19 has distracted proper care of other illnesses. Herein, we report the impact on new diagnoses of HTLV-1, HTLV-2, and HIV-2 in Spain, where these infections are mostly driven by immigration flows from endemic regions. As expected, case reporting declined for all three retroviral infections with respect to prior years. Furthermore, late presentations were more common. The two major reasons for these observations were significant declines in the arrival of foreigners from endemic regions and a shift in medical resources to prioritize COVID-19
Whetstones from Bronze Age hill forts of North Eastern Italy
A group of Bronze Age whetstones from Protohistoric hill forts, locally called Castellieri, of eastern Friuli Venezia Giulia (north eastern Italy) has been studied using different techniques, including non destructive methods such as X-ray computed micro-tomography and portable X-ray fluorescence, in order to characterize the raw material and define its origin. The obtained results suggest that small pebbles of reddish subarkose and quartz arenites collected from the gravel deposits of river Isonzo, perhaps deriving from Val Gardena Formation outcrops, were exploited for the production of the studied artefacts during the Bronze Age. These data complement our knowledge about the lithic raw materials exploitation strategies during the ancient phase of Castellieri culture, almost exclusively based on local rock type
The Complete Structure of the Core Oligosaccharide from Edwardsiella tarda EIB 202 Lipopolysaccharide
The chemical structure and genomics of the lipopolysaccharide (LPS) core oligosaccharide of pathogenic Edwardsiella tarda strain EIB 202 were studied for the first time. The complete gene assignment for all LPS core biosynthesis gene functions was acquired. The complete structure of core oligosaccharide was investigated by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, electrospray ionization mass spectrometry MSn, and matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry. The following structure of the undecasaccharide was established: The heterogeneous appearance of the core oligosaccharide structure was due to the partial lack of β-d-Galp and the replacement of α-d-GlcpNAcGly by α-d-GlcpNGly. The glycine location was identified by mass spectrometry
IMF - metallicity: a tight local relation revealed by the CALIFA survey
Variations in the stellar initial mass function (IMF) have been invoked to
explain the spectroscopic and dynamical properties of early-type galaxies.
However, no observations have yet been able to disentangle the physical driver.
We analyse here a sample of 24 early-type galaxies drawn from the CALIFA
survey, deriving in a homogeneous way their stellar population and kinematic
properties. We find that the local IMF is tightly related to the local
metallicity, becoming more bottom-heavy towards metal-rich populations. Our
result, combined with the galaxy mass-metallicity relation, naturally explains
previous claims of a galaxy mass-IMF relation, derived from non-IFU spectra. If
we assume that - within the star formation environment of early-type galaxies -
metallicity is the main driver of IMF variations, a significant revision of the
interpretation of galaxy evolution observables is necessary.Comment: Accepted for publication in ApJL. 6 pages, 4 figure
- …