7,526 research outputs found
Dispositivo impactador de laboratorio para la determinación de la firmeza en fruta: una nueva versión.
Se ha desarrollado una nueva versión de un dispositivo impactador para obtener un sistema versátil y de fácil manejo. La resolución, la precisión y la relación señal-ruido son mayores en el nuevo sistema que en prototipos anteriores. Se ha realizado un diseño de experimentos con diferentes materiales usando el nuevo y el antiguo impactador para comprobar las mejoras conseguidas
Influencia del estiramiento en el calentamiento para el salto y la velocidad
The purpose of the study is to determine the influence of passive stretchings included as part of warm up in explosive strength performance, in this case in several vertical jump tests: Squat Jump (SJ), Countermouvement Jump (CMJ) and Reactive Jump (RJ); and also in a 30 meters speed test with 5 meters start flying.Sample was composed by 9 male Málaga Football Club soccerplayers (18.22 ± 0.44 years) performed 2 warm up protocols in they free day in two consecutive weeks. The soccer players use the passive stretching in warm up and the kind of effort during the activity has a high component of explosive ballistic strength, movements executed by great intensity and short duration, for example shoot the ball, sprints, way changes, jumps, etc.Were observed decreases in SJ, RJ and speed tests performance, with statistic significant differences (p<0.05) in power and flight time of RJ test, also in speed test. As for the CMJ test, benefits have been obtained though the differences have not been significant. Therefore, passive stretching included in warm up had a negative influence in explosive strength and speed in trained soccer players group.El objetivo del estudio es determinar si la realización de estiramientos pasivos, incluidos como parte del calentamiento, influyen en el rendimiento de la fuerza explosiva, en este caso en varios tests de salto vertical: Squat Jump (SJ), Countermouvement Jump (CMJ) y Reactive Jump (RJ); y también en un test de velocidad de 30 metros (mts.) con salida lanzada de 5 mts. Para ello, 9 jugadores del Málaga Club de Fútbol de categoría juvenil (18,22 ± 0,441 años) realizaron 2 protocolos de calentamiento en dos semanas consecutivas en su día de recuperación. Los jugadores de fútbol utilizan los estiramientos pasivos en su calentamiento y el tipo de esfuerzo al que se someten durante su actividad tiene un alto componente de fuerza explosiva de tipo balístico, movimientos que se ejecutan con gran intensidad y corta duración, tales como golpear el balón, sprints, cambios de dirección, saltos, etc. Se han encontrado disminuciones en el rendimiento de los test de SJ y RJ, así como también en el test de velocidad, obteniéndose valores significativos (p<0,05) tanto para la potencia y el tiempo de vuelo del test RJ, como también para el test de velocidad. En cuanto al test CMJ, se han obtenido beneficios aunque las diferencias no han sido significativas. Por tanto, la realización de estiramientos pasivos influye de forma negativa en el rendimiento de la fuerza explosiva y la velocidad en una muestra de futbolistas entrenados
Analysis of Li-ion battery degradation using self-organizing maps
This paper proposes a new methodology to identify the different degradation processes of Li-Ion battery cells. The goal of this study is to determine if different degradation factors can be separated by waveform analysis from aged cells with similar remaining capacity. In contrast to other works, the proposed method identifies the past operating conditions in the cell, regardless of the actual State of Health. The methodology is based on a data-driven approach by using a SOM (Self-organizing map), an unsupervised neural network. To verify the hypothesis a SOM has been trained with laboratory data from whole data cycles, to classify cells concerning their degradation path and according to their discharge voltage patterns. Additionally, this new methodology based on the SOM allows discriminating groups of cells with different cycling conditions (based on depth of discharge, ambient temperature and discharge current). This research line is very promising for classification of used cells, not only depending on their current static parameters (capacity, impedance), but also the battery use in their past life. This will allow making predictions of the Remaining Useful Life (RUL) of a battery with greater precision
Aislamiento, propagación y crecimiento de hongos comestibles nativos en residuos agroindustriales
La investigación tuvo como objetivo aislar el micelio secundario de Auricularia spp y Pleurotus spp procedente de tres áreas naturales de la región San Martín, así como evaluar el crecimiento en medio agar papa dextrosa y en sustratos estériles a base de residuos agroindustriales. Se obtuvieron 10 aislamientos de micelios secundarios a través de carpóforos desinfectados de Pleurotus spp y otros 10 aislamientos de carpóforos desinfectados de Auricularia spp. La mayor velocidad de crecimiento en Auricularia spp fue de 62,5 µm h-1 (A1) y de 75 µm h-1 (B10) para Pleurotus spp. En una segunda parte del experimento se produjo semilla de las cepas nativas más veloces en granos de maíz esterilizado durante un periodo de incubación de 40 días. La semilla fue inoculada en sustratos estériles a base de residuos agroindustriales. Las cepas A1 de Auricularia spp y B10 de Pleurotus spp desarrollaron mejor en sustrato a base de residuos de pulpa de café, logrando una eficiencia biológica de 30,33% y 18,20%, respectivamente. Se concluye que las cepas nativas A1 y B10 de hongos comestibles pueden ser utilizadas en la propagación de semilla y producción de hongos comestibles, brindando al agricultor una alternativa complementaria de alto valor nutritivo
Los sistemas de pago por servicios ambientales entre la adicionalidad y la subsidiariedad: aplicación a la belleza escénica en el pantano de San Juan, Madrid, España
A payment for environmental services (PES) based on the beauty of the San Juan dam landscape is proposed containing two innovative aspect in regard to previous PES systems: the elaboration of a diagnosis oriented to obtain a shared vision of the area based in a participative process including all relevant local stakeholders, and the integration of the PES mechanism into the regional public environmental policy. The proposed system also identifies the offer and the demand of the environmental service. It shows the main problems associated to the preservation of the service and proposes management plans oriented to its conservation. Finally, the economic viability of the system is studied comparing three different scenarios according to the grade of integration of the PES model into the regional conservation public policy. This paper shows how a PES system can be used to guarantee public investments in nature conservation through a private management.Se plantea un sistema de pago por servicios ambientales (PSA) basado en la valoración de la belleza escénica en la
zona del pantano de San Juan, Madrid, con dos aspectos novedosos respecto a estudios PSA previos: la elaboración de un diagnóstico basado en un proceso participativo que involucra a todos los actores sociales locales y cuyo fin es el de obtener una visión compartida sobre el área, y la integración del mecanismo PSA en la gestión pública regional de la conservación de la naturaleza. El sistema propuesto además identifica los oferentes y demandantes del servicio ambiental, muestra los principales problemas asociados a la conservación del servicio y plantea programas de gestión orientados a contribuir a su conservación. Se estudia, por último, la viabilidad económica del sistema comparando tres escenarios hipotéticos en función del grado de integración del sistema PSA en las políticas públicas de conservación de la naturaleza regionales. El trabajo muestra como un sistema PSA puede servir para garantizar las inversiones públicas en conservación a través de la gestión privada
Renal angiotensin II up-regulation and myofibroblast activation in human membranous nephropathy
Renal angiotensin II up-regulation and myofibroblast activation in human membranous nephropathy.BackgroundThe molecular mechanisms of renal injury and fibrosis in proteinuric nephropathies are not completely elucidated but the renin-angiotensin system (RAS) is involved. Idiopathic membranous nephropathy (MN), a proteinuric disease, may progress to renal failure. Our aim was to investigate the localization of RAS components in MN and their correlation with profibrotic parameters and renal injury.MethodsRenal biopsies from 20 patients with MN (11 with progressive disease) were studied for the expression of RAS components [angiotensin-converting enzyme (ACE) and angiotensin II (Ang II)] by immunohistochemistry. Transforming growth factor-β (TGF-β) and platelet-derived growth factor (PDGF)-BB were studied by by in situ hybridization, and myofibroblast transdifferentiation by α-smooth muscle actin (α-SMA) staining.ResultsACE immunostaining was elevated in tubular cells and appeared in interstitial cells colocalized in α-actin–positive cells in progressive disease. Elevated levels of Ang II were observed in tubules and infiltrating interstitial cells. TGF-β and PDGF mRNAs were up-regulated mainly in cortical tubular epithelial cells in progressive disease (P < 0.01) and correlated with the myofibroblast transdifferentiation (r = 0.8, P < 0.01 for TGF-β; r = 0.6, P < 0.01 for PDGF). Moreover, in serial sections of progressive cases, the ACE and Ang II over-expression was associated with the tubular expression of these pro-fibrogenic factors, and with the interstitial infiltration and myofibroblast activation.ConclusionIntrarenal RAS is selectively activated in progressive MN. De novo expression of ACE at sites of tubulointerstitial injury suggests that the in situ Ang II generation could participate in tubular TGF-β up-regulation, epithelial-myofibroblast transdifferentiation, and disease progression. These results suggest a novel role of Ang II in human tubulointerstitial injury
Impact of vulvovaginal atrophy of menopause in Spanish women: prevalence and symptoms according to the EVES Study
Introduction: The prevalence of menopausal women with confirmed vulvovaginal atrophy (VVA) oscillates between 67e98%. Aim: To assess the prevalence of postmenopausal women with VVA confirmed by gynecologic clinical assessment among all women attending menopause centers in Spain, as well as to describe the impact of VVA on quality of life and sexual functioning. Methods: Women aged 45e75 years old with the last menstrual period >12 months before were included in a cross-sectional study. Main Outcome Measures: Women with 1 VVA symptoms filled out a number of questionnaires, including EuroQoL, Day-to-Day Impact of Vaginal Aging, Female Sexual Function Index, and Female Sexual Distress Scale-revised. A gynecologic examination was performed to confirm diagnosis. Results: 1,177 evaluable patients were included. VVA was confirmed in 87.3% of the patients. Almost 80% of women who acknowledged being sexually active (n ¼ 717) presented pain during intercourse. As compared with patients without confirmed VVA (n ¼ 66), patients with confirmed VVA (n ¼ 1,028) were significantly older (P < .0001), had lower rates of sexual activity (P < .05), and used more VVA treatments (P < .05). Severe vaginal atrophy and severe vulvar atrophy were more prevalent in VVA-confirmed women (P < .0001, in both cases). No differences regarding the confirmation of VVA were observed for EuroQoL andDay-to-Day Impact of Vaginal Aging quality-oflife questionnaires. Sexual function measured through the Female Sexual Function Index score was significantly reduced in sexually-active patients with confirmed VVA (P < .05). Conclusion: VVA signs and symptoms are highly prevalent in Spanish postmenopausal women. Confirmation of VVA diagnosis was associated with impaired sexual function. The early recognition of VVA symptoms should be actively promoted in medical practice, instead of waiting until signs appear to exclude other reasons for VVA and to manage treatment effectively
The Mass-Metallicity relation explored with CALIFA: I. Is there a dependence on the star formation rate?
We present the results on the study of the global and local M-Z relation
based on the first data available from the CALIFA survey (150 galaxies). This
survey provides integral field spectroscopy of the complete optical extent of
each galaxy (up to 2-3 effective radii), with enough resolution to separate
individual HII regions and/or aggregations. Nearly 3000 individual HII
regions have been detected. The spectra cover the wavelength range between
[OII]3727 and [SII]6731, with a sufficient signal-to-noise to derive the oxygen
abundance and star-formation rate associated with each region. In addition, we
have computed the integrated and spatially resolved stellar masses (and surface
densities), based on SDSS photometric data. We explore the relations between
the stellar mass, oxygen abundance and star-formation rate using this dataset.
We derive a tight relation between the integrated stellar mass and the
gas-phase abundance, with a dispersion smaller than the one already reported in
the literature (0.07 dex). Indeed, this
dispersion is only slightly larger than the typical error derived for our
oxygen abundances. However, we do not find any secondary relation with the
star-formation rate, other than the one induced due to the primary relation of
this quantity with the stellar mass. We confirm the result using the 3000
individual HII regions, for the corresponding local relations.
Our results agree with the scenario in which gas recycling in galaxies, both
locally and globally, is much faster than other typical timescales, like that
of gas accretion by inflow and/or metal loss due to outflows. In essence,
late-type/disk dominated galaxies seem to be in a quasi-steady situation, with
a behavior similar to the one expected from an instantaneous
recycling/closed-box model.Comment: 19 Pages, 8 figures, Accepted for Publishing in Astronomy and
Astrophysics (A&A
The cosmic gamma-ray background in the MeV range
The -ray background from supernovae is calculated on the basis of the
reconstructed efficiency of supernova explosions from star formation at various
redshifts. The calculations presented here show how Type Ia SN rates compatible
with the results of optical supernova searches give a background emission in
the MeV range that can explain the extragalactic emission measured by COMPTEL
and SMM. Star formation histories reaching maximum values of 0.3-0.4
M yr Mpc at z 1.5 (and/or possibly keeping that
value to higher z) give a -ray background compatible with observations
while they also predict the observed supernova rates per comoving volume. The
-ray background in the MeV range is mostly sensitive to the star
formation rate at z 1-2, but the activity in forming stars at even higher
z has an influence as well on the absolute level of the cosmic -ray
background: the time elapsed by the SNe Ia progenitors until they explode has a
broad distribution and the rates of SNe Ia at z 1.5-2 depend on the
formation frequencies of their progenitor stars at earlier epochs.
The mutual consistency of predictions of optical rates and integrated
emission in the -ray domain place in a firm ground the Type Ia
supernova identification as the astrophysical source responsible for this
cosmic backgroundComment: 52 pages, 15 figures, ApJ (in press
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