Normal mediastinal lymph nodes: number and size according to American Thoracic Society mapping

CT was used to investigate the number and size of normal mediastinal lymph nodes at 11 intrathoracic nodal stations defined by the American Thoracic Society lymph-node mapping scheme. Nodal size was measured both as short- and long-axis diameters in the transverse plane. Findings for 56 patients show the largest normal mediastinal nodes to be in the subcarinal and right tracheobronchial regions. Upper paratracheal nodes were smaller than lower paratracheal or tracheobronchial nodes, and right-sided tracheobronchial nodes were larger than left-sided ones. From the distributions of node sizes, thresholds were set above which nodes in any region might be considered enlarged. These thresholds, in agreement with a prior investigation of patients with lung cancer, suggest 1.0 cm as the upper limit of normal for the short axis of a mediastinal node in the transverse plane.     

Socioeconomic status,education, and reproduction in modern women: An evolutionary perspective

Although associations between status or resources and reproduction are positive in premodern societies and also in men in modern societies, in modern women the associations are typically negative. We investigated how the association between socioeconomic status and reproductive output varies with the source of status and resources, the woman's education, and her age at reproductive onset (proxied by age at marriage). By using a large sample of US women, we examined the association between a woman's reproductive output and her own and her husband's income and education. Education, income, and age at marriage are negatively associated with a woman's number of children and increase her chances of childlessness. Among the most highly educated two‐thirds of the sample of women, husband's income predicts the number of children. The association between a woman's number of children and her husband's income turns from positive to negative when her education and age at marriage is low (even though her mean offspring number rises at the same time). The association between a woman's own income and her number of children is negative, regardless of education. Rather than maximizing the offspring number, these modern women seem to adjust investment in children based on their family size and resource availability. Striving for resources seems to be part of a modern female reproductive strategy—but, owing to costs of resource acquisition, especially higher education, it may lead to lower birthrates: a possible evolutionary explanation of the demographic transition, and a complement to the human capital theory of net reproductive output. Am. J. Hum. Biol. 22:578–587, 2010. © 2010 Wiley‐Liss, Inc.