303 research outputs found
Motivation to physical loads as a factor in the direction of the development of physical health in modern students
Nowadays, students are engaged not only in
educational activities, but also work independently, and in some
situations, all act as parents [1]. In addition, modern students lack
the notion of a daily regimen as such. All this leads to the fact that
they do not have time for physical activity or simply are not
interested in its implementation [2]. Therefore, it is very important
to identify factors that motivate students to engage in physical labor
in order to further increase the level of students’ interest in
physical activity
Estudio de una escultura con inscripción ibérica procedente del santuario del Cerro de los Santos
La línea de trabajo sobre imagen en la cultura ibérica ha aportado a la arqueología ibérica excelentes resultados, tanto desde el punto de vista de la dinamización teórica de la disciplina, como en su aplicación concreta al estudio y la interpretación de determinados programas iconográficos en sus contextos arqueológicos (OLMOS 1992, 1996; ARANEGUI 1997, entre otros). Uno de los sujetos de investigación de especial relevancia de esta línea ha sido la religiosidad y sus diversas manifestaciones. En este sentido, los exvotos ibéricos labrados en caliza y bronce (RUIZ BREMÓN 1989a; PRADOS1992), sin olvidar aquellos elaborados en terracota, representan un material de estudio privilegiado
Motivation to physical loads as a factor in the direction of the development of physical health in modern students
Nowadays, students are engaged not only in
educational activities, but also work independently, and in some
situations, all act as parents [1]. In addition, modern students lack
the notion of a daily regimen as such. All this leads to the fact that
they do not have time for physical activity or simply are not
interested in its implementation [2]. Therefore, it is very important
to identify factors that motivate students to engage in physical labor
in order to further increase the level of students’ interest in
physical activity
A systematic fitting scheme for caustic-crossing microlensing events
We outline a method for fitting binary-lens caustic-crossing microlensing
events based on the alternative model parameterisation proposed and detailed in
Cassan (2008). As an illustration of our methodology, we present an analysis of
OGLE-2007-BLG-472, a double-peaked Galactic microlensing event with a source
crossing the whole caustic structure in less than three days. In order to
identify all possible models we conduct an extensive search of the parameter
space, followed by a refinement of the parameters with a Markov Chain-Monte
Carlo algorithm. We find a number of low-chi2 regions in the parameter space,
which lead to several distinct competitive best models. We examine the
parameters for each of them, and estimate their physical properties. We find
that our fitting strategy locates several minima that are difficult to find
with other modelling strategies and is therefore a more appropriate method to
fit this type of events.Comment: 12 pages, 11 figure
Experimental evidence that livestock grazing intensity affects cyclic vole population regulation processes
Peer reviewedPublisher PD
Interpretation of Strong Short-Term Central Perturbations in the Light Curves of Moderate-Magnification Microlensing Events
To improve the planet detection efficiency, current planetary microlensing
experiments are focused on high-magnification events searching for planetary
signals near the peak of lensing light curves. However, it is known that
central perturbations can also be produced by binary companions and thus it is
important to distinguish planetary signals from those induced by binary
companions. In this paper, we analyze the light curves of microlensing events
OGLE-2007-BLG-137/MOA-2007-BLG-091, OGLE-2007-BLG-355/MOA-2007-BLG-278, and
MOA-2007-BLG-199/OGLE-2007-BLG-419, for all of which exhibit short-term
perturbations near the peaks of the light curves. From detailed modeling of the
light curves, we find that the perturbations of the events are caused by binary
companions rather than planets. From close examination of the light curves
combined with the underlying physical geometry of the lens system obtained from
modeling, we find that the short time-scale caustic-crossing feature occurring
at a low or a moderate base magnification with an additional secondary
perturbation is a typical feature of binary-lens events and thus can be used
for the discrimination between the binary and planetary interpretations.Comment: 17 pages, 4 figures, 1 tabl
I. Flux and color variations of the quadruply imaged quasar HE 0435-1223
aims: We present VRi photometric observations of the quadruply imaged quasar
HE 0435-1223, carried out with the Danish 1.54m telescope at the La Silla
Observatory. Our aim was to monitor and study the magnitudes and colors of each
lensed component as a function of time. methods: We monitored the object during
two seasons (2008 and 2009) in the VRi spectral bands, and reduced the data
with two independent techniques: difference imaging and PSF (Point Spread
Function) fitting.results: Between these two seasons, our results show an
evident decrease in flux by ~0.2-0.4 magnitudes of the four lensed components
in the three filters. We also found a significant increase (~0.05-0.015) in
their V-R and R-i color indices. conclusions: These flux and color variations
are very likely caused by intrinsic variations of the quasar between the
observed epochs. Microlensing effects probably also affect the brightest "A"
lensed component.Comment: 10 pages, 8 figure
Binary microlensing event OGLE-2009-BLG-020 gives a verifiable mass, distance and orbit predictions
We present the first example of binary microlensing for which the parameter
measurements can be verified (or contradicted) by future Doppler observations.
This test is made possible by a confluence of two relatively unusual
circumstances. First, the binary lens is bright enough (I=15.6) to permit
Doppler measurements. Second, we measure not only the usual 7 binary-lens
parameters, but also the 'microlens parallax' (which yields the binary mass)
and two components of the instantaneous orbital velocity. Thus we measure,
effectively, 6 'Kepler+1' parameters (two instantaneous positions, two
instantaneous velocities, the binary total mass, and the mass ratio). Since
Doppler observations of the brighter binary component determine 5 Kepler
parameters (period, velocity amplitude, eccentricity, phase, and position of
periapsis), while the same spectroscopy yields the mass of the primary, the
combined Doppler + microlensing observations would be overconstrained by 6 + (5
+ 1) - (7 + 1) = 4 degrees of freedom. This makes possible an extremely strong
test of the microlensing solution. We also introduce a uniform microlensing
notation for single and binary lenses, we define conventions, summarize all
known microlensing degeneracies and extend a set of parameters to describe full
Keplerian motion of the binary lenses.Comment: 51 pages, 8 figures, 2 appendices. Submitted to ApJ. Fortran codes
for Appendix B are attached to this astro-ph submission and are also
available at http://www.astronomy.ohio-state.edu/~jskowron/OGLE-2009-BLG-020
Limb-darkening measurements for a cool red giant in microlensing event OGLE 2004-BLG-482
Aims: We present a detailed analysis of OGLE 2004-BLG-482, a relatively
high-magnification single-lens microlensing event which exhibits clear
extended-source effects. These events are relatively rare, but they potentially
contain unique information on the stellar atmosphere properties of their source
star, as shown in this study. Methods: Our dense photometric coverage of the
overall light curve and a proper microlensing modelling allow us to derive
measurements of the OGLE 2004-BLG-482 source star's linear limb-darkening
coefficients in three bands, including standard Johnson-Cousins I and R, as
well as in a broad clear filter. In particular, we discuss in detail the
problems of multi-band and multi-site modelling on the expected precision of
our results. We also obtained high-resolution UVES spectra as part of a ToO
programme at ESO VLT from which we derive the source star's precise fundamental
parameters. Results: From the high-resolution UVES spectra, we find that OGLE
2004-BLG-482's source star is a red giant of MK type a bit later than M3, with
Teff = 3667 +/- 150 K, log g = 2.1 +/- 1.0 and an assumed solar metallicity.
This is confirmed by an OGLE calibrated colour-magnitude diagram. We then
obtain from a detailed microlensing modelling of the light curve linear
limb-darkening coefficients that we compare to model-atmosphere predictions
available in the literature, and find a very good agreement for the I and R
bands. In addition, we perform a similar analysis using an alternative
description of limb darkening based on a principal component analysis of ATLAS
limb-darkening profiles, and also find a very good agreement between
measurements and model predictions.Comment: Accepted in A&
Extreme Magnification Microlensing Event OGLE-2008-BLG-279: Strong Limits on Planetary Companions to the Lens Star
We analyze the extreme high-magnification microlensing event
OGLE-2008-BLG-279, which peaked at a maximum magnification of A ~ 1600 on 30
May 2008. The peak of this event exhibits both finite-source effects and
terrestrial parallax, from which we determine the mass of the lens, M_l=0.64
+/- 0.10 M_Sun, and its distance, D_l = 4.0 +/- 0.6. We rule out Jupiter-mass
planetary companions to the lens star for projected separations in the range
0.5-20 AU. More generally, we find that this event was sensitive to planets
with masses as small as 0.2 M_Earth ~= 2 M_Mars with projected separations near
the Einstein ring (~3 AU).Comment: 25 pages, 7 figures, submitted to Ap
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