Intersubband electronic Raman scattering in narrow GaAs single quantum wells dominated by single-particle excitations

We measured resonant Raman scattering by intersubband electronic excitations in GaAs/AlAs single quantum wells (QWs) with well widths ranging from 8.5 to 18 nm. In narrow (less than 10 nm) QWs with sufficiently high electron concentrations, only single-particle excitations (SPEs) were observed in intersubband Raman scattering, which was confirmed by the well-width dependence of Raman spectra. We found characteristic variations in Raman shift and line shape for SPEs with incident photon energy in the narrow QWs.Comment: 5 pages including 4 figure

Generalization and Transfer Learning in Neural Networks Performing Shape, Size, and Color Classification

We investigated neural networks’ ability to generalize during visual object recognition. In three experiments, we show that while basic multilayer neural networks easily learn to classify the objects on which they are trained, they show serious difficulties transferring that knowledge to novel items. However, our experiments also show that when the previously trained networks are then trained on the novel items, they learn to respond correctly to the novel items much faster than untrained networks. This shows that these networks are learning abstract representations that go beyond the simple items on which they were trained. We argue that this demonstrates that regarding abstract rule learning, the problem with neural networks is not their inability to learn abstractions, but their ability to apply that knowledge when classifying new objects

Bioresponsive pseudoGlucosinolates (psGSLs) release Isothiocyanates (ITCs) in the Presence of Nitroreductases

Glucosinolates (GSLs) are secondary metabolites produced as part of an herbivore defence system in plants of the order Brassicales. GSLs release isothiocyanates (ITCs) upon activation by the myrosinase. Beyond their herbivore feeding deterrent properties, these ITCs have multiple interesting bioactivities. However, their release is limited by the presence of myrosinase. Here, we report the concept of pseudoglucosinolates (psGSLs) hijacking the natural release mechanism of GSLs for the release of ITCs and adapting it to nitroreductase as triggering enzymes. We provide the proof-of-concept for nitroreductase-responsive psGSLs and demonstrate their potential for peptide labelling and ITC-prodrug approaches