This study of boys with fragile X syndrome describes: service delivery; parents' satisfaction with services; early interventionists' perceptions of services needed; and the relationship between service intensity, developmental status, and demographic characteristics. Participants were 50 boys with fragile X syndrome, their parents, and teachers. Early intervention started on average at 21.6 months. There was a steady increase in the amount of early intervention across age periods. The intensity of speech-language and occupational therapies, however, remained constant. By the age of 60 months, the number of children receiving physical therapy and the intensity of physical therapy both decreased. Although parents reported satisfaction with services, most said they would have preferred more services. Early interventionists and teachers seemed more concerned about behavior than cognitive delays. No statistically significant patterns emerged regarding the relationship between developmental status, service intensity, and demographic characteristics.

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Plant nitrogen acquisition requires carbon to be allocated belowground to build roots and sustain microbial associations. This carbon cost to acquire nitrogen varies by nitrogen acquisition strategy; however, the degree to which these costs vary due to nitrogen availability or demand has not been well tested under controlled conditions. We grew a species capable of forming associations with nitrogen-fixing bacteria (Glycine max) and a species not capable of forming such associations (Gossypium hirsutum) under four soil nitrogen levels to manipulate nitrogen availability and four light levels to manipulate nitrogen demand in a full-factorial greenhouse experiment. We quantified carbon costs to acquire nitrogen as the ratio of total root carbon to whole-plant nitrogen within each treatment combination. In both species, light availability increased carbon costs due to a larger increase in root carbon than whole-plant nitrogen, while nitrogen fertilization generally decreased carbon costs due to a larger increase in whole-plant nitrogen than root carbon. Nodulation data indicated that G. max shifted relative carbon allocation from nitrogen fixation to direct uptake with increased nitrogen fertilization. These findings suggest that carbon costs to acquire nitrogen are modified by changes in light and nitrogen availability in species with and without associations with nitrogen-fixing bacteria.