536 research outputs found
Perceptions and expectations of learning in young university
[EN] This article raises the importance of
the teaching-learning process from the
perspective of students. The objective
was to analyze the perceptions and
expectations about learning scenario by
students of the Universidad Veracruzana
in Mexico. The research is qualitative
comprised of 20 students in four focus
groups in two work centers: Veracruz and
Xalapa. For data collection interviews
each session is recorded and transcribed
into digital format for content analysis
using the lite version Qda Miner software.
The study results indicate the attitude
and credentials as a key factor in the
learning process, while the routines
of study, teacher-student interaction
encourage learning by students. Notably,
no significant differences were found
in the dimensions of perception and
expectations of learning scenarios
school level. Finally university students
emphasize the need to change the role of
the teacher as a companion in the process
of teaching and learning, which allows to
point to the demands of students improve
response aspects of attitude, use of new
technologies; also stresses the need to
articulate the final assessment throughout
the course and not only take into account
the written exam.[ES] Este artículo plantea un esbozo de perfil del estudiante universitario considerando algunos aspectos inherentes al proceso de enseñanza-aprendizaje. El objetivo fue analizar la percepción y las expectativas acerca del escenario de aprendizaje por parte del alumnado de la Universidad Veracruzana en México. El tipo de investigación es cualitativo y está conformado por 20 estudiantes distribuidos en cuatro grupos focales pertenecientes a dos regiones: Veracruz y Xalapa. Para la recolección de datos se grabaron las entrevistas de cada sesión y se transcribieron en formato digital para el analisis de contenido utilizando el software Qda Miner versión lite. Los resultados del estudio señalan la actitud y actualización docente como factor clave para el proceso de enseñanza, en tanto que las rutinas de estudio, la interacción docente-alumnos fomentan el aprendizaje por parte de los estudiantes. Cabe destacar que no se encontraron diferencias significativas en las dimensiones de percepción y expectativas de los escenarios de aprendizaje a nivel de centro educativo. Finalmente los jóvenes universitarios enfatizan la necesidad de modificar el rol del docente como un acompañante en el proceso de enseñanza-aprendizaje, el cual permita dar respuesta puntual a las demandas de los estudiantes mejorando los aspectos de actitud, uso de nuevas tecnologías; asimismo destaca la necesidad de articular la evaluación final a lo largo del curso y no solamente tomar en cuenta el examen escrito.
Guardar / Salir Siguiente >Soto Ortiz, JL.; Torres Gastelú, CA. (2016). Percepciones y expectativas del aprendizaje en jóvenes universitarios. REDU. Revista de Docencia Universitaria. 14(1):51-68. doi:10.4995/redu.2016.5797.SWORD516814
NGC1600 - Cluster or Field Elliptical?
A study of the galaxy distribution in the field of the elliptical galaxy
NGC1600 has been undertaken. Although this galaxy is often classified as a
member of a loose group, all the neighbouring galaxies are much fainter and
could be taken as satellites of NGC1600. The number density profile of galaxies
in the field of this galaxy shows a decline with radius, with evidence of a
background at approximately 1.3 Mpc. The density and number density profile are
consistent with that found for other isolated early-type galaxies. NGC1600
appears as an extended source in X-rays, and the center of the X-ray emission
seems not to coincide with the center of the galaxy. The velocity distribution
of neighbouring galaxies has been measured from optical spectroscopic
observations and shows that the mean radial velocity is approximately 85 km/s
less than that of NGC1600, indicating that the centre of mass could lie outside
the galaxy. The velocity dispersion of the `group' is estimated at 429 km/s.
The inferred mass of the system is therefore of the order of 10^14 solar
masses, a value that corresponds to a large group. NGC1600 therefore shares
some similarities, but is not identical to, the `fossil clusters' detected in
X-ray surveys. Implications of this result for studies of isolated early-type
galaxies are briefly discussed.Comment: 8 pages, 5 figures and 2 table, accepted for publication in the Ap
Generalized Casimir forces in non-equilibrium systems
In the present work we propose a method to determine fluctuation induced
forces in non equilibrium systems. These forces are the analogue of the well
known Casimir forces, which were originally introduced in Quantum Field theory
and later extended to the area of Critical Phenomena. The procedure starts from
the observation that many non equilibrium systems exhibit long-range
correlations and the associated structure factors diverge in the long
wavelength limit. The introduction of external bodies into such systems in
general modifies the spectrum of these fluctuations and leads to the appearance
of a net force between these bodies. The mechanism is illustrated by means of a
simple example: a reaction diffusion equation with random noises.Comment: Submitted to Europhysics Letters. 7 pages, 2 figure
Identification of Biologically Active Ganoderma lucidum Compounds and Synthesis of Improved Derivatives That Confer Anti-cancer Activities in vitro
We previously reported that Ganoderma lucidum extract (GLE) demonstrate significant anti-cancer activity against triple negative inflammatory breast cancer models. Herein, we aimed to elucidate the bioactive compounds of GLE responsible for this anti-cancer activity. We performed NMR, X-ray crystallography and analog derivatization as well as anti-cancer activity studies to elucidate and test the compounds. We report the structures of the seven most abundant GLE compounds and their selective efficacy against triple negative (TNBC) and inflammatory breast cancers (IBC) and other human cancer cell types (solid and blood malignancies) to illustrate their potential as anti-cancer agents. Three of the seven compounds (ergosterol, 5,6-dehydroergosterol and ergosterol peroxide) exhibited significant in vitro anti-cancer activities, while we report for the first time the structure elucidation of 5,6-dehydroergosterol from Ganoderma lucidum. We also show for the first time in TNBC/IBC cells that ergosterol peroxide (EP) displays anti-proliferative effects through G1 phase cell cycle arrest, apoptosis induction via caspase 3/7 activation, and PARP cleavage. EP decreased migratory and invasive effects of cancer cells while inhibiting the expression of total AKT1, AKT2, BCL-XL, Cyclin D1 and c-Myc in the tested IBC cells. Our investigation also indicates that these compounds induce reactive oxygen species, compromising cell fate. Furthermore, we generated a superior derivative, ergosterol peroxide sulfonamide, with improved potency in IBC cells and ample therapeutic index (TI > 10) compared to normal cells. The combined studies indicate that EP from Ganoderma lucidum extract is a promising molecular scaffold for further exploration as an anti-cancer agent
Measuring Baryon Acoustic Oscillations along the line of sight with photometric redshifs: the PAU survey
Baryon Acoustic Oscillations (BAO) provide a standard ruler of known physical
length, making it a promising probe of the nature of dark energy. The detection
of BAO requires measuring galaxy positions and redshifts. "Transversal"
(angular distance) BAO measure the angular size of this scale, while
"line-of-sight" (or "radial") BAO require precise redshifts, but provide a
direct measurement of the Hubble parameter at different redshifts, a more
sensitive probe of dark energy. The main goal of this paper is to show that a
precision of sigma_z ~0.003(1 + z) is sufficient to measure BAO in the radial
direction. This precision can be achieved for bright, red galaxies, by using a
filter system comprising about 40 filters, each with a width of ~100 A, from ~
4000 A to ~ 8000 A, supplemented by two broad-band filters. We describe a
practical implementation, a new galaxy survey, PAU, to be carried out with a
telescope/camera combination with an etendue of about 20 m^2deg^2, and covering
8000 sq. deg. in the sky in four years. We expect to measure positions and
redshifts for over 14 million red, early-type galaxies with L > L* and i_AB <
22.5 in the interval 0.1 < z < 0.9, with sigma_z < 0.003(1 + z). This
population has a number density n > 10^-3 Mpc^-3 h^3 within the 9 (Gpc/h)^3
volume of the survey, ensuring that the error in the determination of the BAO
scale is not limited by shot-noise. By itself, such a survey will deliver
precisions of order 5% in the dark-energy equation of state parameter w, if
assumed constant, and can determine its time derivative when combined with
future CMB measurements. In addition, PAU will yield high-quality redshift and
low-resolution spectroscopy for hundreds of millions of other galaxies.Comment: 56 pages, 18 figures. Version 4 fixes figures 5 and 9 to 14 that had
been erroneously uploaded in v2 and v3. The figures were however correct in
version
Latin American Consensus: Children Born Small for Gestational Age
72-87Cuatrimestra
Microorganisms and spatial distribution of the sinkholes of the Yucatan Peninsula, underestimated biotechnological potential?
Investigación basada en el potencial bio-tecnológico de las micro-especies que habitan los cenotes de la Península de YucatánAbstract Objective: To detect the spatial distribution of the sinkholes of the Peninsula of Yucatan (SPY) and identify those cenotes where microorganisms have been registered. Methods: The geographic coordinates of the SPYs were obtained from various databases, as well as from scientific publications relating to the terminology ‘sinkholes’, ‘karst systems’ and ‘cenotes’. All coordinates were transformed into the Universal Transverse Mercator reference system (UTM) with datum WGS84. An infrared composite image was created with 432 RGB bands from the Landsat 8 satellite. The points with the location of the cenotes were imported into the Software TerrSet. Results: Total 1026 coordinates of sinkholes were recorded in the Yucatan Peninsula. In 18 sinkholes (<2%), microorganisms have been recovered and identified in various taxonomic levels, and only 6 sinkholes (<0.6%) has their biotechnological potential been evaluated. Conclusions: The microorganisms that inhabit the sinkholes of the Yucatan Peninsula are a reservoir with practically unexplored biotechnological potential.CONACY
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