Sex differences in verbal and performance IQ's of children undergoing open-heart surgery

Boys with congenital heart defects had essentially normal Verbal and Performnance IQ's on preoperative and postoperative tests; but girls' Verbal IQ's were significantly lower than those of boys, and significantly lower than girls' own Performance IQ's. This sex difference among congenital heart cases reverses the usual finding that girls excel on Verbal tests.     

Low (Sub-1-volt) halfwave voltage polymeric electro-optic modulators achieved by controlling chromophore shape

Electro-optic (EO) modulators encode electrical signals onto fiber optic transmissions. High drive voltages limit gain and noise levels. Typical polymeric and lithium niobate modulators operate with halfwave voltages of 5 volts. Sterically modified organic chromophores have been used to reduce the attenuation of electric field poling-induced electro-optic activity caused by strong intermolecular electrostatic interactions. Such modified chromophores, incorporated into polymer hosts, were used to fabricate EO modulators with halfwave voltages of 0.8 volts (at a telecommunications wavelength of 1318 nanometers) and to achieve a halfwave voltage-interaction length product of 2.2 volt-centimeters. Optical push-pull poling and driving were also used to reduce halfwave voltage. This study, together with recent demonstrations of exceptional bandwidths (more than 110 gigahertz) and ease of integration (with very large scale integration semiconductor circuitry and ultra-low-loss passive optical circuitry) demonstrates the potential of polymeric materials for next generation telecommunications, information processing, and radio frequency distribution.