Dartmouth College

About: Dartmouth College is a education organization based out in Hanover, New Hampshire, United States. It is known for research contribution in the topics: Population & Health care. The organization has 20740 authors who have published 51426 publications receiving 2796969 citations. The organization is also known as: Dartmouth.

Effect of Xylan and Lignin Removal by Batch and Flowthrough Pretreatment on the Enzymatic Digestibility of Corn Stover Cellulose

Abstract: Compared with batch systems, flowthrough and countercurrent reactors have important potential advan- tages for pretreating cellulosic biomass, including higher hemicellulose sugar yields, enhanced cellulose digestibility, and reduced chemical additions. Unfortunately, they suffer from high water and energy use. To better understand these trade-offs, comparative data are reported on xylan and lignin removal and enzymatic digestibility of cellu- lose for corn stover pretreated in batch and flowthrough reactors over a range of flow rates between 160j and 220jC, with water only and also with 0.1 wt% sulfuric acid. Increasing flow with just water enhanced the xylan dissolution rate, more than doubled total lignin removal, and increased cellulose digestibility. Furthermore, adding dilute sulfuric acid increased the rate of xylan removal for both batch and flowthrough systems. Interestingly, adding acid also increased the lignin removal rate with flow, but less lignin was left in solution when acid was added in batch. Although the enzymatic hydrolysis of pretreated cellulose was related to xylan removal, as others have shown, the digestibility was much better for flowthrough compared with batch systems, for the same degree of xylan removal. Cellulose digestibility for flowthrough reactors was related to lignin removal as well. These results suggest that altering lignin also affects the enzymatic digestibility of corn stover. B 2004 Wiley Periodicals, Inc.

Four-Year Follow-Up of Trastuzumab Plus Adjuvant Chemotherapy for Operable Human Epidermal Growth Factor Receptor 2–Positive Breast Cancer: Joint Analysis of Data From NCCTG N9831 and NSABP B-31

Abstract: Purpose Trastuzumab is a humanized monoclonal antibody against the human epidermal growth factor receptor 2 (HER2). The clinical benefits of adjuvant trastuzumab have been demonstrated in interim analyses of four large trials. Initial data of the combined analysis of the North Central Cancer Treatment Group (NCCTG) N9831 Intergroup trial and National Surgical Adjuvant Breast and Bowel Project (NSABP) B-31 trial were reported in 2005. Long-term follow-up results on disease-free survival (DFS) and overall survival (OS) have been awaited. Patients and Methods Patients with HER2-positive operable breast cancer were randomly assigned to doxorubicin plus cyclophosphamide followed by paclitaxel with or without trastuzumab in the NCCTG N9831 and NSABP B-31 trials. The similar design of both trials allowed data from the control and trastuzumab-containing arms to be combined in a joint analysis. Results At 3.9 years of median follow-up, there continues to be a highly statistically significant reduction in DFS event...

Legislators and Interest Groups: How Unorganized Interests Get Represented

Abstract: This paper derives a supply price for public policy using a constrained maximization model. In the model, three sets of agents each have preferences over outcomes: organized interest groups offer campaign contributions to improve their own wealth, voters offer votes to obtain outcomes closer to their most preferred outcomes, and legislators seek both campaign contributions and votes to obtain reelection. A given legislator's supply price for policy is shown to depend on the productivity of his effort, as determined by committee assignments, priority and ability, and by the preferences of his unorganized constituency in the home district. Two extreme assumptions about the effectiveness of campaign spending in eliciting votes are used to illustrate the comparative statics properties of the model. The prediction of the model is that interest groups will, in general, seek out legislators whose voters are indifferent to the policy the interest group seeks. Thus, voters who do have preferences over policy are in effect represented, even though they are not organized.

Multifactor Explanations of Asset Pricing Anomalies

Abstract: Previous work shows that average returns on common stocks are related to firm characteristics like size, earnings/price, cashflow/price, book-to-market equity, past sales growth, long-term past return, and short term past return. Because these patterns in average returns apparently are not explained by the CAPM, they are called anomalies. We find that, except for the continuation of short-term returns, the anomalies largely disappear in a three-factor model. Our results are consistent with rational ICAPM or APT asset pricing, but we also consider irrational pricing and data problems as possible explanations.