372 research outputs found
A Quantitative Cross-Regional Analysis of the Spanish VET Systems From a Systemic Approach: From a Regional Comparative VET Research Perspective
Purpose: The aim of this paper is to analyse comparatively, at regional level, the current state of a wide range of indicators of Vocational Education and Training (VET) at regional level in Spain. This will make it possible to characterise and better understand the existence of a variety of regional VET systems, including the Initial VET and Continuous VET subsystems within Spain, doing so under a multidimensional approach examining VET supply and demand.
Methods: Systemic analysis of Spanish VET indicators leads to a selection of 54 indicators, which are then compared at regional level using k-means clustering. This approach identifies similarities and differences (clusters) across all of Spain's 17 autonomous communities (Spanish regions). The correlation between the variables is then analysed to examine the interaction between the VET system's supply and demand dimensions.
Findings: The results show that 19 indicators explain the main differences between autonomous communities, which form two distinct clusters. Both VET supply and VET environment and demand influence cluster formation and inter-cluster differences. In the set of indicators that differentiate the two clusters of autonomous communities, close interaction is detected between certain indicators of VET supply and demand, especially those referring to the STEM occupational group, which confirms the correlation between these dimensions, albeit to a limited extent.
Conclusions: While it is necessary to analyse the differences between clusters in greater depth, the results suggest that Spain’s regions are split into two distinct groups (clusters) in which the respective VET systems are developing and advancing differently. Moreover, there is evidence of a small number of significant interrelations between indicators of VET supply and demand, which point to both the VET system's specialisation and its inclusive nature
Co-occurrence patterns of fish species in two aquatic habitats of the Arauca River floodplain, Venezuela
The study of co-occurrence patterns has been extensively applied to propose assembly rules for community organization. Recently, a new interest has grown in the effect of gradients on these patterns and to analyze them through new approximations such as co-occurrence networks, through which keystone species can be identified. Neotropical floodplains represent interesting systems to study such patterns, because of their spatial heterogeneity, temporal variability and their high fish species richness. With this in mind, our goal was to study the co-occurrence patterns of fish in a segment of the Arauca River’s floodplain and the influence of the spatial and temporal variability on them. One stream and one floodplain lake were sampled with gill nets during 2014 – 2015 across a hydrological cycle and 5 matrices for each 5 sampled months in each water body were prepared to explore the co-occurrence patterns in each water body across months and 2 for the entire period, through a probabilistic pair-wise analysis of species co-occurrence that identified aggregated and segregated species pairs. With the observed cooccurrences × water body × month, the species weighted degrees and betweenness were calculated, and co-occurrence networks were constructed. The networks structures, in terms of the degrees of every species, were compared spatially and temporally through a generalized linear model. The stream showed the highest numbers of aggregated species pairs, and in general showed the most complex networks in terms of nodes, edges and degrees. The habitat type and the hydrological phases significantly influenced the structure of the fish co-occurrence networks. Two species, Loricariichthys brunneus and Pygocentrus cariba were identified as the core of the fish communities of the floodplain and as keystone species because they contribute to the connection of the networks by having a series of links with less frequent species
U Geminorum: a test case for orbital parameters determination
High-resolution spectroscopy of U Gem was obtained during quiescence. We did
not find a hot spot or gas stream around the outer boundaries of the accretion
disk. Instead, we detected a strong narrow emission near the location of the
secondary star. We measured the radial velocity curve from the wings of the
double-peaked H emission line, and obtained a semi-amplitude value that
is in excellent agreement with the obtained from observations in the
ultraviolet spectral region by Sion et al. (1998). We present also a new method
to obtain K_2, which enhances the detection of absorption or emission features
arising in the late-type companion. Our results are compared with published
values derived from the near-infrared NaI line doublet. From a comparison of
the TiO band with those of late type M stars, we find that a best fit is
obtained for a M6V star, contributing 5 percent of the total light at that
spectral region. Assuming that the radial velocity semi-amplitudes reflect
accurately the motion of the binary components, then from our results: K_em =
107+/-2 km/s; K_abs = 310+/-5 km/s, and using the inclination angle given by
Zhang & Robinson(1987); i = 69.7+/-0.7, the system parameters become: M_WD =
1.20+/-0.05 M_sun,; M_RD = 0.42+/-0.04 M_sun; and a = 1.55+/- 0.02 R_sun. Based
on the separation of the double emission peaks, we calculate an outer disk
radius of R_out/a ~0.61, close to the distance of the inner Lagrangian point
L_1/a~0.63. Therefore we suggest that, at the time of observations, the
accretion disk was filling the Roche-Lobe of the primary, and that the matter
leaving the L_1 point was colliding with the disc directly, producing the hot
spot at this location.Comment: 36 pages, 14 figures, ccepted for publication in A
Efecto de la adición de proteÃnas solubles recuperadas del agua de lavado de surimi de Pacific Whiting sobre las propiedades funcionales y mecánicas de surimi de Alaska pollock grado FA
Soluble proteins from surimi wash water (SWW) can be insolubilized by complexing with chitosan-alginate allowing its recovery and the reduction of the organic matter in the processing water discharged from surimi processing plants. The objective of this work was to evaluate the effect of adding soluble proteins recovered from Pacific whiting SWW on the mechanical and functional properties of commercial Alaska Pollock surimi grade FA. Levels evaluated were 0 (control), 10, 30 and 50 g insolubilized SWW solids/kg Alaska Pollock grade FA surimi. The mechanical and functional properties of Alaska Pollock surimi pastes and gels were characterized by texture profile analysis (TPA), puncture test, expressible water (EW) and color attributes. TPA and puncture test parameters increased significantly (P≤0.05) when 10–30 g/kg of soluble proteins from Pacific whiting SWW were added. EW values increased also, indicating a decrease of the water holding capacity. Color parameters showed that all surimi gels increased in redness, an undesirable effect in the production of Alaska Pollock grade FA surimiLas proteÃnas solubles del agua de lavado del surimi (ALS) pueden ser insolubilizadas por medio de la formación de complejos con quitosano y alginato. Su recuperación por este método permite reducir la materia orgánica en el agua de proceso. El objetivo de este trabajo fue evaluar el efecto de la adición de proteÃna soluble recuperada del ALS de Pacific whiting sobre las propiedades mecánicas y funcionales de surimi comercial de Alaska Pollock de grado FA. Los niveles de adición evaluados fueron 0 (control), 10, 30 y 50 g sólidos insolubilizados de ALS/kg de surimi de Alaska Pollock de grade FA. Las propiedades mecánicas y funcionales se caracterizaron por medio del análisis de perfil de textura (TPA), prueba de punción, agua extraÃble y atributos de color. Los valores de los parámetros de TPA y prueba de punción incrementaron significativamente (P≤0.05) cuando se adicionaron de 10 a 30 g/kg de proteÃnas solubles de ALS de Pacific whiting. El agua extraÃble también se incrementó, indicando un descenso de la capacidad de retención de agua. Los atributos de color indicaron que todos los geles de surimi incrementaron su color rojo, lo cual podrÃa ser desfavorable para la producción de surimi de Alaska Pollock grado FAThis work was partially supported by Grant no. NA
16RG 1039 (Project no. R/SF-29) from the National Oceanic
and Atmospheric Administration to the Sea Grant College
Program at Oregon State University, and appropriations
made by the Oregon State Legislature. Part of this study
was supported by Grant no. TAMPS-2003-C02-14, FOMIXCONACYT,
MéxicoS
Cyclic brightening in the short-period WZ Sge-type cataclysmic variable SDSS J080434.20+510349.2
We have observed a new cataclysmic variable (CV) SDSS J080434.20+510349.2 and
study the origin of a long-term variability found in its light curve.
Multi-longitude time-resolved photometric observations were carried out to
analyze the uncommon behavior also found recently in two newly discovered CVs.
This study of SDSS J080434.20+510349.2 mainly concerns the understanding of the
nature of the observed double-humped light curve and its relation to a cyclic
brightening occurring during quiescence. The observations were obtained early
in 2007, when the object was at about V~17.1, 0.4 mag brighter than the
pre-outburst magnitude. The light curve shows a sinusoidal variability with an
amplitude of about 0.07 mag and a periodicity of 42.48 min, which is half of
the orbital period of the system. In addition, we have observed two
"mini-outbursts" of the system up to 0.6 mag, with a duration of about 4 days
each. The "mini-outburst" had a symmetric profile and repeated in about 32
days. Subsequent monitoring of the system shows a cyclical behaviour of such
"mini-outbursts" with a similar recurrence period. The origin of the
double-humped light curve and the periodic brightening is discussed in the
light of the evolutionary state of SDSS J080434.20+510349.2.Comment: 7 pages, 6 figures, Accepted by A&A, typos added, figure correcte
Experiencias de metodologÃa CDIO en IngenierÃa de Minas y en IngenierÃa Civil
A menudo, los alumnos creen, que los estudios de ingenierÃa son demasiado difÃciles, o hace falta poseer una inteligencia o preparación muy especial para acometerlos con éxito. EIT – Raw Materials, procurando futuros profesionales adaptados a los nuevos entornos actuales, desarrolla proyectos educativos implementando la iniciativa CDIO (Concebir – Diseñar – Implementar – Operar), que potencia el aprendizaje, ayudando a los alumnos a aprender disfrutando. La idea es despertar su interés, proponiéndoles el desarrollo completo de proyectos creativos, explicándoles la metodologÃa CDIO, acompañados por un tutor. La metodologÃa CDIO, hace hincapié en el fundamento de la ingenierÃa para resolver problemas. En este estudio se presentan, como antecedentes, experiencias desde 2001, para centrarse en las actuales, asociadas a un Proyecto de innovación educativa que está terminando de desarrollarse en el momento en que se escribe este estudio, constatando que la metodologÃa mejora el interés de los alumnos, y el aprendizaje. La experiencia que se presenta, se hace sin ayuda material de ningún tipo, ni facilitando material, ni laboratorio alguno. Aún asÃ, los alumnos, consiguen, presentar soluciones muy interesantes, de todo tipo, incluso de software, robóticas u otras. Se constata que los estudiantes prefieren actividades prácticas que complejos cálculos matemáticos
The Expanding Nebular Remnant of the Recurrent Nova RS Ophiuchi (2006): II. Modeling of Combined Hubble Space Telescope Imaging and Ground-based Spectroscopy
We report Hubble Space Telescope imaging, obtained 155 and 449 days after the
2006 outburst of the recurrent nova RS Ophiuchi, together with ground-based
spectroscopic observations, obtained from the Observatorio Astron\'omico
Nacional en San Pedro M\'artir, Baja California, M\'exico and at the
Observatorio Astrof\'isico Guillermo Haro, at Cananea, Sonora, M\'exico. The
observations at the first epoch were used as inputs to model the geometry and
kinematic structure of the evolving RS Oph nebular remnant. We find that the
modeled remnant comprises two distinct co-aligned bipolar components; a
low-velocity, high-density innermost (hour glass) region and a more extended,
high-velocity (dumbbell) structure. This overall structure is in agreement with
that deduced from radio observations and optical interferometry at earlier
epochs. We find that the asymmetry observed in the west lobe is an instrumental
effect caused by the profile of the HST filter and hence demonstrate that this
lobe is approaching the observer. We then conclude that the system has an
inclination to the line of sight of 39 degrees. This is in
agreement with the inclination of the binary orbit and lends support to the
proposal that this morphology is due to the interaction of the outburst ejecta
with either an accretion disk around the central white dwarf and/or a
pre-existing red giant wind that is significantly denser in the equatorial
regions of the binary than at the poles. The second epoch HST observation was
also modeled. However, as no spectra were taken at this epoch, it is more
difficult to constrain any model. Nevertheless, we demonstrate that between the
two HST epochs the outer dumbbell structure seems to have expanded linearly.Comment: 33 pages, 9 figures, 1 table, accepted for publication in Ap
Recursos educativos para niños y jóvenes en las páginas web de los museos y centros de ciencia
Los Museos y Centros de Ciencia, conscientes de la importancia de la comunicación y la divulgación cientÃfica a través de Internet, especialmente en el ámbito educativo, han creado sus propias páginas web en las que se encuentran actividades muy adecuadas para niños y jóvenes asà como recursos didácticos que tanto padres y madres como el profesorado pueden utilizar para el desarrollo de su labor educativa. En este trabajo se analizan algunas de esas páginas asà como sus posibilidades didácticas
Utilización del museo de ciencias como recurso didáctico en educación social
Las investigaciones realizadas en los últimos años en los museos y centros de ciencia presentan a éstos como contextos de aprendizaje no formales, en los cuales la interactividad juega un papel importante. Entre los aspectos más investigados podemos citar los factores que favorecen el aprendizaje en dichos centros, como son la preparación de la visita, el personal de apoyo o las estrategias de comunicación, entre otros. Para comparar estos resultados con los obtenidos en el Miramón Kutxaespacio de la Ciencia de San Sebastián, se ha realizado un pequeño estudio con los estudiantes de la diplomatura de Educación Social que realizaron una visita al citado museo
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