9,800 research outputs found
The use and misuse of computers in education : evidence from a randomized experiment in Colombia
This paper presents the evaluation of the program Computers for Education. The program aims to integrate computers, donated by the private sector, into the teaching of language in public schools. The authors conduct a two-year randomized evaluation of the program using a sample of 97 schools and 5,201 children. Overall, the program seems to have had little effect on students'test scores and other outcomes. These results are consistent across grade levels, subjects, and gender. The main reason for these results seems to be the failure to incorporate the computers into the educational process. Although the program increased the number of computers in the treatment schools and provided training to the teachers on how to use the computers in their classrooms, surveys of both teachers and students suggest that teachers did not incorporate the computers into their curriculum.Tertiary Education,Primary Education,Secondary Education,Teaching and Learning,Education For All
Effect of Isothiocyanates and Selenium on Antioxidant Enzyme Expression and DNA Methylation in Colon Cancer Cells in vitro
Grazing by the Antarctic fish Notothenia coriiceps evidence for selective feeding on macroalgae
Conditional cash transfers in education : design features, peer and sibling effects evidence from a randomized experiment in Colombia
This paper presents an evaluation of multiple variants of a commonly used intervention to boost education in developing countries - the conditional cash transfer - with a student level randomization that allows the authors to generate intra-family and peer-network variation. The analysis tests three treatments: a basic conditional cash transfer treatment based on school attendance, a savings treatment that postpones a bulk of the cash transfer due to good attendance to just before children have to re-enroll, and a tertiary treatment where some of the transfers are conditional on students'graduation and tertiary enrollment rather than attendance. On average, the combined incentives increase attendance, pass rates, enrollment, graduation rates, and matriculation to tertiary institutions. Changing the timing of the payments does not change attendance rates relative to the basic treatment but does significantly increase enrollment rates at both the secondary and tertiary levels. Incentives for graduation and matriculation are particularly effective, increasing attendance and enrollment at secondary and tertiary levels more than the basic treatment. There is some evidence that the subsidies can cause a reallocation of responsibilities within the household. Siblings (particularly sisters) of treated students work more and attend school less than students in families that received no treatment. In addition, indirect peer influences are relatively strong in attendance decisions with the average magnitude similar to that of the direct effect.Tertiary Education,Access to Finance,Primary Education,Secondary Education,Economics of Education
Magnetic field detection in the B2Vn star HR 7355
The B2Vn star HR 7355 is found to be a He-rich magnetic star.
Spectropolarimetric data were obtained with FORS1 at UT2 on Paranal observatory
to measure the disk-averaged longitudinal magnetic field at various phases of
the presumed 0.52 d cycle. A variable magnetic field with strengths between B_z
= -2200 and +3200G was found, with confidence limits of 100 to 130G. The field
topology is that of an oblique dipole, while the star itself is seen about
equator-on. In the intensity spectra the HeI-lines show the typical equivalent
width variability of He-strong stars, usually attributed to surface abundance
spots. The amplitudes of the equivalent width variability of the HeI lines are
extraordinarily strong compared to other cases. These results not only put HR
7355 unambiguously among the early-type magnetic stars, but confirm its
outstanding nature: With v sin i = 320 km/s the parameter space in which
He-strong stars are known to exist has doubled in terms of rotational velocity.Comment: 6 pages, 5 figures, 1 Table. Accepted for publication in MNRAS
Letter
The (B0+?)+O6 system FN CMa: A case for tidal-pulsational interaction?
FN CMa is visually double with a separation of about 0.6arcsec. Sixty
high-cadence VLT/UVES spectra permit the A and B components to be disentangled,
as the relative contribution of each star to the total light entering the
spectrograph fluctuates between exposures due to changes in seeing. Component A
exhibits rapid line-profile variations, leading us to attribute the photometric
variability seen by HIPPARCOS (with a derived P=0.08866d) to this component.
From a total of 122 archival and new echelle spectra it is shown that component
A is an SB1 binary with an orbital period of 117.55 days. The eccentricity of
0.6 may result in tidal modulation of the pulsation(s) of component Aa.Comment: 2 pages, 1 figure, IAUS 272 - Active OB Stars: Structure, Evolution,
Mass Loss and Critical Limit
Constant of Motion for several one-dimensional systems and outlining the problem associated with getting their Hamiltonians
The constants of motion of the following systems are deduced: a relativistic
particle with linear dissipation, a no-relativistic particle with a time
explicitly depending force, a no-relativistic particle with a constant force
and time depending mass, and a relativistic particle under a conservative force
with position depending mass. The problem of getting the Hamiltonian for these
systems is determined by getting the velocity as an explicit function of
position and generalized linear momentum, and this problem can be solved a
first approximation for the first above system.Comment: 15 pages, Te
La vivencia de la esclavitud: nota bibliogrĂĄfica sobre testimonios y autobiografias de esclavos afroamericanos.
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The Use and Misuse of Computers in Education: Evidence from a Randomized Experiment in Colombia
This paper presents the evaluation of the program Computers for Education. The program aims to integrate computers, donated by the private sector, into the teaching of language in public schools. The authors conduct a two-year randomized evaluation of the program using a sample of 97 schools and 5,201 children. Overall, the program seems to have had little effect on students' test scores and other outcomes. These results are consistent across grade levels, subjects, and gender. The main reason for these results seems to be the failure to incorporate the computers into the educational process. Although the program increased the number of computers in the treatment schools and provided training to the teachers on how to use the computers in their classrooms, surveys of both teachers and students suggest that teachers did not incorporate the computers into their curriculum
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