They called having an oxygen toxicity attack "getting a Pete".In the decade following World War II, Lambertsen et al. made further discoveries on the effects of breathing oxygen under pressure and methods of prevention. Their work on intermittent exposures for extension of oxygen tolerance and on a model for prediction of pulmonary oxygen toxicity based on pulmonary function are key documents in the development of standard operating procedures when breathing increased pressures of oxygen. Lambertsens work showing the effect of carbon dioxide in decreasing time to onset of central nervous system symptoms has influenced work from current exposure guidelines to future breathing apparatus design.Retinopathy of prematurity was not observed before World War II, but with the availability of supplemental oxygen in the decade following, it rapidly became one of the principal causes of infant blindness in developed countries. By 1960 the use of oxygen had become identified as a risk factor and its administration restricted. The resulting fall in retinopathy of prematurity was accompanied by a rise in infant mortality and hypoxia-related complications. Since then, more sophisticated monitoring and diagnosis have established protocols for oxygen use which aim to balance between hypoxic conditions and problems of retinopathy of prematurity.Bronchopulmonary dysplasia was first described by Northway in 1967, who outlined the conditions that would lead to the diagnosis. This was later expanded by Bancalari and in 1988 by Shennan, who suggested the need for supplemental oxygen at 36 weeks could predict long-term outcomes. Nevertheless, Palta et al.
The greater degree to which a persons pupils mirror another predicts a persons greater score on empathy. In disorders such as autism and psychopathy, facial expressions that represent sadness may be subtle, which may show a need for a more non-linguistic situation to affect their level of empathy. Vocal expression
According to DIPR scientist Swati Johar,: VII  sadness is an emotion "identified by current speech dialogue and processing systems". : 12  Measurements to distinguish sadness from other emotions in the human voice include root mean square (RMS) energy, inter-word silence and speaking rate. It is communicated mostly by lowering the mean and variability of the fundamental frequency (f0), besides being associated with lower vocal intensity, and with decreases in f0 over time. Johar argues that, "when someone is sad, slow, low pitched speech with weak high audio frequency energy is produced". Likewise, "low energy state of sadness attributes to slow tempo, lower speech rate and mean pitch". : 10, 13 Sadness is, as stated by Klaus Scherer, one of the "best-recognized emotions in the human voice", although its "generally somewhat lower than that of facial expression". In a study by Scherer, it was found that in Western countries sadness had 79% of accuracy for facial recognition and 71% for vocal, while in Non-Western countries the results were of 74% and 58%, respectively.