This project seeks to develop new statistical methodologies for problems in human development and to apply existing methodologies to those problems in novel ways. Work continues in two areas: (1) statistical modeling of the distribution of birthweights in human populations, and (2) statistical modeling of developmental trajectories of reproductive hormones in children through puberty. Development of a satisfactory statistical model for the distribution of birthweights in a population will facilitate a refined understanding of the relationship of birthweight to infant mortality. Having developed a model and a method for fitting the model to data that allow us to measure selected features of birthweight distributions, we are applying our technique to U.S. birthweight and perinatal mortality data to assess how well mortality rates are predicted by features of birthweight distributions that our technique measures. Serum levels of gonadotropins and gonadal hormones change as children develop through puberty. We have developed parsimonious descriptions of hormonal development through puberty by fitting certain nonlinear regression models to the logarithm of hormone level as a function of either testis volume or Tanner stage and have compared developmental trajectories of FSH, LH, and inhibin between boys and girls. Boys exhibit a steep rise in log LH early in puberty whereas in girls this early rise is more gradual.
| Rowland, Andrew S; Skipper, Betty; Rabiner, David L et al. (2008) The shifting subtypes of ADHD: classification depends on how symptom reports are combined. J Abnorm Child Psychol 36:731-43 |
| Kamel, Freya; Umbach, David M; Stallone, Lillian et al. (2008) Association of lead exposure with survival in amyotrophic lateral sclerosis. Environ Health Perspect 116:943-7 |
| Chen, Honglei; Richard, Marie; Sandler, Dale P et al. (2007) Head injury and amyotrophic lateral sclerosis. Am J Epidemiol 166:810-6 |
| Rowland, Andrew S; Umbach, David M; Bohlig, E Michael et al. (2007) Modifying the response labels of an ADHD teacher rating scale: psychometric and epidemiologic implications. J Atten Disord 11:384-97 |
| Kamel, F; Tanner, Cm; Umbach, Dm et al. (2007) Pesticide exposure and self-reported Parkinson's disease in the agricultural health study. Am J Epidemiol 165:364-74 |
| Rozman, Karl K; Bhatia, Jatinder; Calafat, Antonia M et al. (2006) NTP-CERHR expert panel report on the reproductive and developmental toxicity of soy formula. Birth Defects Res B Dev Reprod Toxicol 77:280-397 |
| Rozman, Karl K; Bhatia, Jatinder; Calafat, Antonia M et al. (2006) NTP-CERHR expert panel report on the reproductive and developmental toxicity of genistein. Birth Defects Res B Dev Reprod Toxicol 77:485-638 |
| Terry, Paul D; Kamel, Freya; Umbach, David M et al. (2004) VEGF promoter haplotype and amyotrophic lateral sclerosis (ALS). J Neurogenet 18:429-34 |
| Kamel, Freya; Umbach, David M; Lehman, Teresa A et al. (2003) Amyotrophic lateral sclerosis, lead, and genetic susceptibility: polymorphisms in the delta-aminolevulinic acid dehydratase and vitamin D receptor genes. Environ Health Perspect 111:1335-9 |
| Rowland, Andrew S; Umbach, David M; Stallone, Lil et al. (2002) Prevalence of medication treatment for attention deficit-hyperactivity disorder among elementary school children in Johnston County, North Carolina. Am J Public Health 92:231-4 |
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