RESUMEN
Atmospheric remote sensing has played a pivotal role in the increasingly sophisticated representation of clouds in the numerical models used to assess global and regional climate change. This has been accomplished because the underlying bulk cloud properties can be derived from a statistical analysis of the returned microwave signals scattered by a diverse ensemble comprised of numerous cloud hydrometeors. A new Doppler radar, previously used to track small debris particles shed from the NASA space shuttle during launch, is shown to also have the capacity to detect individual cloud hydrometeors in the free atmosphere. Similar to the traces left behind on film by subatomic particles, larger cloud particles were observed to leave a well-defined radar signature (or streak), which could be analyzed to infer the underlying particle properties. We examine the unique radar and environmental conditions leading to the formation of the radar streaks and develop a theoretical framework which reveals the regulating role of the background radar reflectivity on their observed characteristics. This main expectation from theory is examined through an analysis of the drop properties inferred from radar and in situ aircraft measurements obtained in two contrasting regions of an observed multicellular storm system. The observations are placed in context of the parent storm circulation through the use of the radar's unique high-resolution waveforms, which allow the bulk and individual hydrometeor properties to be inferred at the same time.
RESUMEN
The current study tested a psychosocial mediation model of the association between subjective social status (SSS) and academic achievement for youth. The sample included 430 high school students from diverse racial/ethnic and socioeconomic backgrounds. Those who perceived themselves to be at higher social status levels had higher GPAs. As predicted by the model, most of the relationship was mediated by emotional distress and study skills and habits. The lower SSS students had more depressive symptoms, which led to less effective studying and lower GPA. The model held across different racial/ethnic groups, was tested against alternative models, and results remained stable controlling for objective socioeconomic status. Implications for identity-based intervention are discussed.
Asunto(s)
Clase Social , Estrés Psicológico , Adolescente , Evaluación Educacional , Escolaridad , Femenino , Humanos , Masculino , Medio Oeste de Estados Unidos , Modelos Teóricos , Motivación , Encuestas y CuestionariosRESUMEN
This study assessed 1500 adolescents from the National Longitudinal Study of Youth to test the hypothesis that African American mothers differentially socialize their girls and boys. The results showed that later-born boys had fewer chores, argued more with their mothers, lived in less cognitively stimulating homes, and were not allowed to make the same decisions as were the girls or firstborn boys at the same age. The later-born boys were also lowest in achievement and highest in externalizing behaviors. Parenting differences accounted for the achievement differences but not for the externalizing behavior differences. It was concluded that the later-born boys would achieve at the same rates as their siblings if they were socialized in the same manner as their siblings.