Scatterometer Data Analysis program Final report, 1 Jun. 1968 - 31 May 1969

Evaluation and processing of scatterometer data for use in NASA Earth Resources Progra

The effect of dynamical Bloch oscillations on optical-field-induced current in a wide gap dielectric

We consider the motion of charge carriers in a bulk wide-gap dielectric interacting with a few-cycle laser pulse. A semiclassical model based on Bloch equations is applied to describe the emerging time-dependent macroscopic currents for laser intensities approaching the damage threshold. At such laser intensities, electrons can reach edges of the first Brillouin zone even for electron-phonon scattering rates as high as those known for SiO_2. We find that, whenever this happens, Brag-like reflections of electron waves, also known as Bloch oscillations, affect the dependence of the charge displaced by the laser pulse on its carrier-envelope phase.Comment: This version corrects a mistake in the paper published by the New Journal of Physics: panel (a) of Fig. 9 depicts -s(t_0=0) rather than s(t_0=0

In regions with many local governments, some services are provided the least in poorer communities where they are needed the most

There are nearly 90,000 local governments in the U.S.; each one with its own fiscal and administrative responsibilities. This ‘market’ for local governments means that individuals are often able to base their choice of where to live on differing regimes of tax and service provision, and to exercise their voice to ensure that their government responds to their service needs. But does the voice of the poor matter as much as the voice of the rich in determining service levels in the local public market? Using data for municipal governments in the U.S., Benedict S. Jimenez compares the municipal budgetary choices in poor and affluent municipalities, and shows that in highly fragmented regions some services are provided the least in poorer communities, where they are needed the most

Face and voice attractiveness judgments change during adolescence

Attractivenessjudgments are thought to underpin adaptive mate choice decisions. We investigated how these judgmentschange during adolescence when mate choice is becoming relevant. Adolescents aged 11–15 evaluated faces and voices manipulated along dimensions that affect adults' judgments of attractiveness and that are thought to cue mate value. Facial stimuli consisted of pairs of faces that were more or less average, more or less feminine, or more or less symmetric. The adolescents selected the more average, symmetric, and feminine faces as more attractive more often than chance, but judgments of some facial traits differed significantly with rater age and sex, indicating a role of development in judgments of facial cues. Vocal stimuli consisted of pairs of voices manipulated to raise or lower perceived pitch. The older but not younger girls selected the lower-pitched male voices as more attractive at rates above chance, while the younger but not older boys selected the higher-pitched female voices as more attractive. Controlling for rater age, increased pubertal development was associated with increased selection of lower-pitched boys' voices by girls and decreased selection of feminized male faces by boys. Our results are the first to demonstrate that adolescents show somewhat similar attractivenessjudgments to adults in age-matched stimuli and that age, sex, and pubertal development have measurable effects on adolescents' attractivenessjudgments. They suggest that attractivenessjudgments in humans, at least for some traits, are facultatively calibrated to the individual's life stage, only reaching adult values upon sexual maturity when mate choice decisions become relevant

Voice pitch preferences of adolescents: Do changes across time indicate a shift towards potentially adaptive adult-like preferences?

An evolutionary approach to attractiveness judgments emphasises that many human trait preferences exist in order to assist adaptive mate choice. Here we test an adaptive development hypothesis, whereby voice pitch preferences indicating potential mate quality might arise or strengthen significantly during adolescence (when mate choice becomes adaptive). We used a longitudinal study of 250 adolescents to investigate changes in preference for voice pitch, a proposed marker of mate quality. We found significantly stronger preferences for lower-pitched opposite-sex voices in the older age group compared with the younger age group (using different sets of age-matched stimuli), and marginally increased preferences for lower-pitched opposite-sex voices comparing within-participant preferences for the same set of stimuli over the course of 1 year. We also found stability in individual differences in preferences across adolescence: controlling for age, the raters who had stronger preferences than their peers for lower pitched voices when first tested, retained stronger preferences for lower-pitched voices relative to their peers about 1 year later. Adolescence provides a useful arena for evaluating adaptive hypotheses and testing the cues that might give rise to adaptive behaviour