42 research outputs found
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Predictive modeling to de-risk bio-based manufacturing by adapting to variability in lignocellulosic biomass supply.
Commercial-scale bio-refineries are designed to process 2000tons/day of single lignocellulosic biomass. Several geographical areas in the United States generate diverse feedstocks that, when combined, can be substantial for bio-based manufacturing. Blending multiple feedstocks is a strategy being investigated to expand bio-based manufacturing outside Corn Belt. In this study, we developed a model to predict continuous envelopes of biomass blends that are optimal for a given pretreatment condition to achieve a predetermined sugar yield or vice versa. For example, our model predicted more than 60% glucose yield can be achieved by treating an equal part blend of energy cane, corn stover, and switchgrass with alkali pretreatment at 120°C for 14.8h. By using ionic liquid to pretreat an equal part blend of the biomass feedstocks at 160°C for 2.2h, we achieved 87.6% glucose yield. Such a predictive model can potentially overcome dependence on a single feedstock
A Study of the Birth WeightâObesity Relation Using a Longitudinal Cohort and Sibling and Twin Pairs
Sibling and twin study designs provide control for confounding factors that are typically unmeasured in traditional cohort studies. Using nationally representative data from the National Longitudinal Study of Adolescent Health collected at 3 visits during 1994â2002, the authors evaluated the longitudinal association between birth weight and later obesity in a traditional cohort study (n = 13,763; ages 11â21 years at baseline), controlling for sex, age, race/ethnicity, and parental education. Among persons with a nonobese mother, high birth weight (>4 kg) participants were more likely than normal birth weight (â„2.5ââ€4 kg) participants to become obese later in life (incidence rate ratio = 1.46, 95% confidence interval: 1.28, 1.67). In a matched sibling pair sample (full siblings: n = 513; monozygotic twins: n = 207; dizygotic twins: n = 189), the authors examined longitudinal within-pair differences. Birth weight difference was positively associated with body mass index difference later in life for female monozygotic pairs only (ÎČ = 2.67, 95% confidence interval: 0.99, 4.35). Given the null associations observed in the sibling sample, the commonly observed positive association between birth weight and later obesity from cohort analyses may be attributed to confounding by maternal characteristics. Further research is needed to identify specific factors that contribute to the birth weightâobesity relation