Data sharing practices and data availability upon request differ across scientific disciplines.

Data sharing is one of the cornerstones of modern science that enables large-scale analyses and reproducibility. We evaluated data availability in research articles across nine disciplines in Nature and Science magazines and recorded corresponding authors' concerns, requests and reasons for declining data sharing. Although data sharing has improved in the last decade and particularly in recent years, data availability and willingness to share data still differ greatly among disciplines.

Linear X-wave generation by means of cross-phase modulation in Kerr media.

We exploit cross-phase modulation by a strong driving pulse onto a weaker probe pulse at a different wavelength to induce the formation of an X wave possessing the typical nondispersive and nondiffractive propagation properties.