1,549 research outputs found

    Exploration of Boston start-up formation

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    Thesis (S.M. in Engineering and Management)--Massachusetts Institute of Technology, Engineering Systems Division, 2010.Cataloged from PDF version of thesis.Includes bibliographical references.Boston, specifically Kendall Square, has a high concentration of technology startups. This concentration provides the opportunity to study the connection between the founding conditions and the outcome of the entrepreneurial effort in a relatively controlled environment. Through case studies including deep research and founder interviews we explore the role of people and places in the founding of four Cambridge technology start-ups. The findings indicate maturity of ideation, team size, experience - in startups in general and in the specific sector, understanding of the local entrepreneurial ecosystem, passion for the mission and ability to communicate are key factors in the success of a startup. Connectors - people and places - are best engaged to assist in completing a founding team who have a defined focus and to provide investor leads to a founding team post-ideation, but founders with the ability to make first-degree connections may be more successful than those who use connectors.by Carrie L. Stalder.S.M.in Engineering and Managemen

    Sky Variability in the y Band at the LSST Site

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    We have measured spatial and temporal variability in the y band sky brightness over the course of four nights above Cerro Tololo near Cerro Pachon, Chile, the planned site for the Large Synoptic Survey Telescope (LSST). Our wide-angle camera lens provided a 41 deg field of view and a 145 arcsec pixel scale. We minimized potential system throughput differences by deploying a deep depletion CCD and a filter that matches the proposed LSST y_3 band (970 nm-1030 nm). Images of the sky exhibited coherent wave structure, attributable to atmospheric gravity waves at 90 km altitude, creating 3%-4% rms spatial sky flux variability on scales of about 2 degrees and larger. Over the course of a full night the y_3 band additionally showed highly coherent temporal variability of up to a factor of 2 in flux. We estimate the mean absolute sky level to be approximately y_3 = 17.8 mag (Vega), or y_3 = 18.3 mag (AB). While our observations were made through a y_3 filter, the relative sky brightness variability should hold for all proposed y bands, whereas the absolute levels should more strongly depend on spectral response. The spatial variability presents a challenge to wide-field cameras that require illumination correction strategies that make use of stacked sky flats. The temporal variability may warrant an adaptive y band imaging strategy for LSST, to take advantage of times when the sky is darkest.Comment: 8 pages, 5 figures, accepted to PASP. Minor changes from referee report and editor's revisions

    Selection for Intramuscular Fat in Duroc Swine – An Update

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    Long-term progress or improvement in many economically important traits is ultimately the responsibility of the seedstock supplier. If selection progress is to be made in traits of economic importance, the trait must: 1) be accurately measurable, 2) show sufficient heritability, and 3) display an adequate level of variation. For such reasons, tremendous progress has been made in the swine industry toward increasing lean meat percentage over the past quarter century. However, in more recent years, meat quality traits have received more attention and have become more important in breeding programs as producers and processors try to meet consumer demands for high quality, nutritious products

    Selection for Intramuscular Fat in Duroc Swine

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    Today’s U.S. pork industry is experiencing phenomenal growth as it continues to meet consumer demand and pork is the most widely eaten meat worldwide. Pork has proven to be a valuable protein source as Americans consume 66 lbs/person/year on a carcass disappearance basis (USDA, 2002 Agricultural Statistics). Pork production in the United States is also a vital part of the economy. Nearly 19 billion pounds of pork, with a retail value of 38billion,wasprocessedfromabout97millionhogsin2001.TheU.S.porkindustryisresponsibleforover38 billion, was processed from about 97 million hogs in 2001. The U.S. pork industry is responsible for over 72 billion in total domestic economic activity. In addition, the pork industry adds over $27 billion of value to basic production inputs such as corn and soybeans (NPPC, 2003)

    Effect of Inorganic and Organic Trace Mineral Supplementation on the Performance, Carcass Characteristics, and Fecal Mineral Excretion of Phase-fed, Grow-finish Swine

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    Concentrated livestock production has led to soil nutrient accumulation concerns. To reduce the environmental impact, it is necessary to understand current recommended livestock feeding practices. Two experiments were conducted to compare the effects of trace mineral supplementation on performance, carcass composition, and fecal mineral excretion of phase-fed, grow-finish pigs. Crossbred pigs (Experiment 1 (Exp. 1), (n = 528); Experiment 2 (Exp. 2), (n = 560)) were housed in totally-slatted, confinement barns, blocked by weight, penned by sex, and randomly assigned to pens at approximately 18 kg BW. Treatments were allocated in a randomized complete block design (12 replicate pens per treatment) with 9 to 12 pigs per pen throughout the grow-finish period. In Exp. 1, the control diet (Io100) contained Cu as CuSO4, Fe as FeSO4, and Zn (of which 25% was ZnO and 75% was ZnO4) at concentrations of 63 and 378 mg/kg, respectively. Treatment 2 (O100) contained supplemental Cu, Fe, and Zn from organic sources (Bioplex, Alltech Inc., Nicholasville, KY) at concentrations of 19, 131, and 91 mg/kg, respectively, which are the commercially recommended dietary inclusion levels for these organic trace minerals. Organic Cu, Fe, and Zn concentrations from O100 were reduced by 25% and 50% to form treatments 3 (O75) and 4 (O50-1), respectively. In Exp. 2, treatment 5 (Io25) contained 25% of the Cu, Fe, and Zn (inorganic sources) concentrations found in Io100. Treatment 6 (O50-2) was identical to the O50-1 diet from Exp. 1. Treatment 7 (O25) contained the experimental microminerals reduced by 75% from concentrations found in O100. Treatment 8 (O0) contained no trace mineral supplementation and served as a negative control for Exp. 2. In Exp. 1, tenth-rib backfat, loin muscle area and ADG did not differ (p\u3e0.05) between treatments. Pigs fed the control diet (Io100) consumed less feed (p\u3c0.01) compared to pigs fed diets containing organic trace minerals, thus, G:F was greater (p = 0.03). In Exp. 2, there were no differences among treatment means for loin muscle area, but pigs fed the reduced organic trace mineral diets consumed less (p\u3c0.05) feed and tended (p = 0.10) to have less tenth-rib backfat compared to pigs fed the reduced inorganic trace mineral diet. Considering that performance and feed intake of pigs was not affected by lower dietary trace mineral inclusion, mineral excretion could be reduced during the grow-finish phase by reducing dietary trace mineral concentration
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