ABC, 123: Can you text me now? The Impact of a Mobile Phone Literacy Program on Educational Outcomes.

We report the short-term results from a randomized evaluation of a mobile phone literacy and numeracy program (Project ABC) in Niger, in which adult literacy students learned how to use mobile phones as part of a literacy and numeracy class. Students in ABC villages showed substantial gains in numeracy exam scores. There is also evidence of heterogeneity in program effects across regions, suggesting the impact is context dependent. These results were stronger in one region, for women and for participants younger than 45. There was also evidence of persistent impacts: six months after the end of the first year of classes, students in ABC villages retained what they had learned better than the non-ABC students. These effects do not appear to be driven by differences in teacher quality and motivation, nor student attendance.Education; literacy; information technology; program evaluation; Nigeria

ABC, 123: The Impact of a Mobile Phone Literacy Program on Educational Outcomes

CGD non-resident fellow Jenny Aker and co-authors report on the results from a randomized evaluation of a mobile phone education program (Project ABC) in Niger, in which adult students learned how to use mobile phones as part of a literacy and numeracy class. Overall, students demonstrated substantial improvements in literacy and numeracy test scores. There is also evidence of persistent impacts: six months after the end of the first year of classes, students in the program retained what they had learned better than others. The effects do not appear to be driven by differences in teacher quality or in teacher and student attendance. The results suggest that simple and relatively cheap information and communication technology can serve as an effective and sustainable learning tool for rural populations.Education

Viscous stabilization of 2D drainage displacements with trapping

We investigate the stabilization mechanisms due to viscous forces in the invasion front during drainage displacement in two-dimensional porous media using a network simulator. We find that in horizontal displacement the capillary pressure difference between two different points along the front varies almost linearly as function of height separation in the direction of the displacement. The numerical result supports arguments taking into account the loopless displacement pattern where nonwetting fluid flow in separate strands (paths). As a consequence, we show that existing theories developed for viscous stabilization, are not compatible with drainage when loopless strands dominate the displacement process.Comment: The manuscript has been substantially revised. Accepted in Phys. Rev. Let

An extensible multilingual open source lemmatizer

We present GATE DictLemmatizer, a multilingual open source lemmatizer for the GATE NLP framework that currently supports English, German, Italian, French, Dutch, and Spanish, and is easily extensible to other languages. The software is freely available under the LGPL license. The lemmatization is based on the Helsinki Finite-State Transducer Technology (HFST) and lemma dictionaries automatically created from Wiktionary. We evaluate the performance of the lemmatizers against TreeTagger, which is only freely available for research purposes. Our evaluation shows that DictLemmatizer achieves similar or even better results than TreeTagger for languages where there is support from HFST. The performance drops when there is no support from HFST and the entire lemmatization process is based on lemma dictionaries. However, the results are still satisfactory given the fact that DictLemmatizer isopen-source and can be easily extended to other languages. The software for extending the lemmatizer by creating word lists from Wiktionary dictionaries is also freely available as open-source software

Analysis methods for the first KATRIN neutrino-mass measurement

We report on the dataset, data handling, and detailed analysis techniques of the first neutrino-mass measurement by the Karlsruhe Tritium Neutrino (KATRIN) experiment, which probes the absolute neutrino-mass scale via the β-decay kinematics of molecular tritium. The source is highly pure, cryogenic T2 gas. The β electrons are guided along magnetic field lines toward a high-resolution, integrating spectrometer for energy analysis. A silicon detector counts β electrons above the energy threshold of the spectrometer, so that a scan of the thresholds produces a precise measurement of the high-energy spectral tail. After detailed theoretical studies, simulations, and commissioning measurements, extending from the molecular final-state distribution to inelastic scattering in the source to subtleties of the electromagnetic fields, our independent, blind analyses allow us to set an upper limit of 1.1 eV on the neutrino-mass scale at a 90% confidence level. This first result, based on a few weeks of running at a reduced source intensity and dominated by statistical uncertainty, improves on prior limits by nearly a factor of two. This result establishes an analysis framework for future KATRIN measurements, and provides important input to both particle theory and cosmolog

Borders, Ethnicity And Trade

This paper uses unique high-frequency data on prices of two agricultural goods to examine the additional costs incurred in cross-border trade between Niger and Nigeria, as well as trade between ethnically distinct markets within Niger. We find a sharp and significant conditional price change of about 20 to 25% between markets immediately across the national border. This price change is significantly lower when markets on either side of the border share a common ethnicity. Within Niger, trade between ethnically distinct regions exhibits an ethnic border effect that is comparable, in its magnitude, to the national border effect between Niger and Nigeria. Our results suggest that having a common ethnicity may reduce the transaction costs associated with agricultural trade, especially the costs associated with communicating and providing credit. (C) 2013 Elsevier B.V. All rights reserved

First operation of the KATRIN experiment with tritium

Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UA