The Relative Effectiveness of Teachers and Learning Software: Evidence from a Field Experiment in El Salvador

This study provides novel evidence on the relative effectiveness of computer-assisted learning (CAL) software and traditional teaching. Based on a randomized controlled trial in Salvadoran primary schools, we evaluate three interventions that aim to improve learning outcomes in mathematics: (i) teacher-led classes, (ii) CAL classes monitored by a technical supervisor, and (iii) CAL classes instructed by a teacher. As all three interventions involve the same amount of additional mathematics lessons, we can directly compare the productivity of the three teaching methods. CAL lessons lead to larger improvements in students' mathematics skills than traditional teacher-centered classes. In addition, teachers add little to the effectiveness of learning software. Overall, our results highlight the value of CAL approaches in an environment with poorly qualified teachers

PocketOptimizer 2.0 : A modular framework for computer‐aided ligand‐binding design

The ability to design customized proteins to perform specific tasks is of great interest. We are particularly interested in the design of sensitive and specific small molecule ligand‐binding proteins for biotechnological or biomedical applications. Computational methods can narrow down the immense combinatorial space to find the best solution and thus provide starting points for experimental procedures. However, success rates strongly depend on accurate modeling and energetic evaluation. Not only intra‐ but also intermolecular interactions have to be considered. To address this problem, we developed PocketOptimizer, a modular computational protein design pipeline, that predicts mutations in the binding pockets of proteins to increase affinity for a specific ligand. Its modularity enables users to compare different combinations of force fields, rotamer libraries, and scoring functions. Here, we present a much‐improved version––PocketOptimizer 2.0. We implemented a cleaner user interface, an extended architecture with more supported tools, such as force fields and scoring functions, a backbone‐dependent rotamer library, as well as different improvements in the underlying algorithms. Version 2.0 was tested against a benchmark of design cases and assessed in comparison to the first version. Our results show how newly implemented features such as the new rotamer library can lead to improved prediction accuracy. Therefore, we believe that PocketOptimizer 2.0, with its many new and improved functionalities, provides a robust and versatile environment for the design of small molecule‐binding pockets in proteins. It is widely applicable and extendible due to its modular framework. PocketOptimizer 2.0 can be downloaded at https://github.com/Hoecker-Lab/pocketoptimizer

Contrasting offspring responses to variation in salinity and temperature among populations of a coastal crab: A maladaptive ecological surprise?

Current understanding of species capacities to respond to climate change is limited by the amount of information available about intraspecific variation in the responses. Therefore, we quantified between- and within- population variation in larval performance (survival, development, and growth to metamorphosis) of the shore crab Carcinus maenas in response to key environmental drivers (temperature, salinity) in 2 populations from regions with contrasting salinities (32-33 PSU: Helgoland, North Sea; 16-20 PSU: Kerteminde, Baltic Sea). We also accounted for the effect(s) of salinity experienced during embryogenesis, which differs between populations. We found contrasting patterns between populations and embryonic salinity conditions. In the Helgoland population, we observed a strong thermal mitigation of low salinity stress (TMLS) for all performance indicators, when embryos were kept in seawater. The negative effects of low salinity on survival were mitigated at increased temperatures; only at high temperatures were larvae exposed to low salinity able to sustain high growth rates and reduced developmental time, thereby metamorphosing with comparable levels of carbon and nitrogen to those reared in seawater. By contrast, larvae from the Kerteminde population showed a detrimental effect of low salinity, consistent with a maladaptive response and a weak TMLS. Low salinity experienced during embryogenesis pre-empted the development of TMLS in both populations, and reduced survival for the Kerteminde population, which is exposed to low salinity. Our study emphasises the importance of evaluating species responses to variation in temperature and salinity across populations; the existence of maladaptive responses and the importance of the maternal habitat should not be underestimated