@article{KretschmannVockLuedtke2014,
  author    = {Kretschmann, Julia and Vock, Miriam and Luedtke, Oliver},
  title     = {Acceleration in elementary school: using propensity score matching to estimate the effects on academic achievement},
  series = {The journal of educational psychology},
  volume    = {106},
  journal   = {The journal of educational psychology},
  number    = {4},
  publisher = {American Psychological Association},
  address   = {Washington},
  issn      = {0022-0663},
  doi       = {10.1037/a0036631},
  pages     = {1080 -- 1095},
  year      = {2014},
  abstract  = {Using German data, we examined the effects of one specific type of acceleration-grade skipping-on academic performance. Prior research on the effects of acceleration has suffered from methodological restrictions, especially due to a lack of appropriate comparison groups and a priori measurements. For this reason, propensity score matching was applied in this analysis to minimize selection bias due to observed confounding variables. Various types of matching were attempted, and, in consideration of balancing the covariates, full matching was the final choice. We used data from the Berlin ELEMENT Study, analyzing, after matching, the information of 81 students who had skipped a grade over the course of elementary school and up to 1,668 nonaccelerated students who attended the same grade level as the accelerated students. Measurements took place 3 times between the 4th and 6th grades, including the assessment of reading, spelling, and mathematics performance. After matching, the results of between-group comparisons regarding performance indices showed no significant effects of skipping a grade, other than a small positive effect found on spelling performance. Theoretical implications and methodological limitations are discussed.},
  language  = {en}
}
@article{GronostajWernerBochowetal.2016,
  author    = {Gronostaj, Anna and Werner, Elise and Bochow, Eric and Vock, Miriam},
  title     = {Gifted Grade-Skippers in Germany},
  series = {The gifted child quarterly},
  volume    = {60},
  journal   = {The gifted child quarterly},
  publisher = {Sage Publ.},
  address   = {Thousand Oaks},
  issn      = {0016-9862},
  doi       = {10.1177/0016986215609999},
  pages     = {31 -- 46},
  year      = {2016},
  abstract  = {Skipping a grade, one specific form of acceleration, is an intervention used for gifted students. Quantitative research has shown acceleration to be a highly successful intervention regarding academic achievement, but less is known about the social-emotional outcomes of grade-skipping. In the present study, the authors used the grounded theory approach to examine the experiences of seven gifted students aged 8 to 16 years who skipped a grade. The interviewees perceived their "feeling of being in the wrong place" before the grade-skipping as strongly influenced by their teachers, who generally did not respond adequately to their needs. We observed a close interrelationship between the gifted students' intellectual fit and their social situation in class. Findings showed that the grade-skipping in most of the cases bettered the situation in school intellectually as well as socially, but soon further interventions, for instance, a specialized and demanding class- or subject-specific acceleration were added to provide sufficiently challenging learning opportunities.},
  language  = {en}
}
@article{CervantesShpritsAseevetal.2019,
  author    = {Cervantes, Sebastian and Shprits, Yuri Y. and Aseev, Nikita and Drozdov, Alexander and Castillo Tibocha, Angelica Maria and Stolle, Claudia},
  title     = {Identifying radiation belt electron source and loss processes by assimilating spacecraft data in a three-dimensional diffusion model},
  series = {Journal of geophysical research : Space physics},
  volume    = {125},
  journal   = {Journal of geophysical research : Space physics},
  number    = {1},
  publisher = {American Geophysical Union},
  address   = {Washington},
  issn      = {2169-9380},
  doi       = {10.1029/2019JA027514},
  pages     = {16},
  year      = {2019},
  abstract  = {Data assimilation aims to blend incomplete and inaccurate data with physics-based dynamical models. In the Earth's radiation belts, it is used to reconstruct electron phase space density, and it has become an increasingly important tool in validating our current understanding of radiation belt dynamics, identifying new physical processes, and predicting the near-Earth hazardous radiation environment. In this study, we perform reanalysis of the sparse measurements from four spacecraft using the three-dimensional Versatile Electron Radiation Belt diffusion model and a split-operator Kalman filter over a 6-month period from 1 October 2012 to 1 April 2013. In comparison to previous works, our 3-D model accounts for more physical processes, namely, mixed pitch angle-energy diffusion, scattering by Electromagnetic Ion Cyclotron waves, and magnetopause shadowing. We describe how data assimilation, by means of the innovation vector, can be used to account for missing physics in the model. We use this method to identify the radial distances from the Earth and the geomagnetic conditions where our model is inconsistent with the measured phase space density for different values of the invariants mu and K. As a result, the Kalman filter adjusts the predictions in order to match the observations, and we interpret this as evidence of where and when additional source or loss processes are active. The current work demonstrates that 3-D data assimilation provides a comprehensive picture of the radiation belt electrons and is a crucial step toward performing reanalysis using measurements from ongoing and future missions.},
  language  = {en}
}
@article{WangShprits2019,
  author    = {Wang, Dedong and Shprits, Yuri Y.},
  title     = {On How High-Latitude Chorus Waves Tip the Balance Between Acceleration and Loss of Relativistic Electrons},
  series = {Geophysical research letters},
  volume    = {46},
  journal   = {Geophysical research letters},
  number    = {14},
  publisher = {American Geophysical Union},
  address   = {Washington},
  issn      = {0094-8276},
  doi       = {10.1029/2019GL082681},
  pages     = {7945 -- 7954},
  year      = {2019},
  abstract  = {Modeling and observations have shown that energy diffusion by chorus waves is an important source of acceleration of electrons to relativistic energies. By performing long-term simulations using the three-dimensional Versatile Electron Radiation Belt code, in this study, we test how the latitudinal dependence of chorus waves can affect the dynamics of the radiation belt electrons. Results show that the variability of chorus waves at high latitudes is critical for modeling of megaelectron volt (MeV) electrons. We show that, depending on the latitudinal distribution of chorus waves under different geomagnetic conditions, they cannot only produce a net acceleration but also a net loss of MeV electrons. Decrease in high-latitude chorus waves can tip the balance between acceleration and loss toward acceleration, or alternatively, the increase in high-latitude waves can result in a net loss of MeV electrons. Variations in high-latitude chorus may account for some of the variability of MeV electrons.},
  language  = {en}
}