A study of time concepts found in primary reading materials

Thesis (Ed.M.)--Boston Universit

A study of time concepts found in primary reading materials

Thesis (Ed.M.)--Boston Universit

\u3ci\u3eAnoplophora Glabripennis\u3c/i\u3e Within-Tree Distribution, Seasonal Development, and Host Suitability in China and Chicago

Established populations of the Asian longhorned beetle, Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), were first reported in the United States in New York in 1996, Illinois in 1998, and New Jersey in 2002. A federal quarantine and an eradication program were implemented in 1997, involving tree surveys and removal of infested trees. We recorded the number of A. glabripennis life stages found at several locations along the main trunk and major branches of naturally infested trees in China (species of Populus, Salix, and Ulmus) and Chicago, Illinois (species of Acer, Fraxinus, and Ulmus) during 1999 to 2002. Typically, A. glabripennis initiated attack near the crown base along both the trunk and main branches. The one exception to this pattern was on Populus trees in China that had branches along the entire trunk, in which case A. glabripennis initiated attack along the lower trunk. Larvae were the dominant overwintering stage in both countries. A host suitability index for A. glabripennis was calculated for each tree with the formula: (number of living life stages + number of exit holes) / number of oviposition pits. The mean host suitability index was higher on Populus and Salix than Ulmus in China, and generally higher on Acer and Ulmus than Fraxinus in Chicago. Eleven genera of trees (N = 1465 trees) were infested by A. glabripennis in Chicago; in decreasing order of tree frequency they included Acer, Ulmus, Fraxinus, Aesculus, Betula, Salix, Celtis, Malus, Pyrus, Sorbus, and Tilia. When the proportion of each genus of infested street trees (N = 958 trees in 7 genera) was compared to its proportion of all Chicago street trees based on a 2003 inventory (N = 539,613 trees in 45 genera), A. glabripennis showed a significant preference to infest the genera Acer and Ulmus. Based on our results, inspectors should focus their efforts on upper trunks and lower branches of Acer and Ulmus trees

Design iteration timing in new product development

Thesis (Ph. D.)--Massachusetts Institute of Technology, Sloan School of Management, 2008.Includes bibliographical references (p. 288-290).As companies compete to gain market share, increase profits and affect growth they often turn to concurrent engineering in an effort to bring new products to the market more quickly. Despite many anecdotal success stories, implementation of concurrent engineering can often prove difficult. As the pressure to bring new products to market increases, companies often compress their design iteration cycle times in an effort to develop products more quickly. In many cases, design cycles may overlap creating situations where learning opportunities (e.g. through testing) are missed and/or ignored. More perversely, compressing design iteration cycles can cause the creation of "phantom errors" and unnecessary rework as concurrent design activities iterate at different speeds. In this research, I use a system dynamics approach to develop a stylized simulation model of the design-build-test iteration cycle to explore the effects of cycle timing on learning. Specifically, I look at the frequency and timing of integration (build) test events and their effect on new product delivery time, quality, and development cost. This research adds to the existing literature in new product development, concurrent engineering, and system dynamics. Ultimately, the results serve to inform new product development project managers of the implications of design iteration timing on project performance and assist in the scheduling of integration events.by Daniel J. McCarthy.Ph.D

Predicting Medical Student Success on Licensure Exams

Many schools seek to predict performance on national exams required for medical school graduation using prematriculation and medical school performance data. The need for targeted intervention strategies for at-risk students has led much of this interest. Assumptions that preadmission data and high stakes in-house medical exams correlate strongly with national standardized exam performance needs to be examined. Looking at prematriculation data for predicting USMLE Step 1 performance, we found that MCAT exam totals and math-science GPA had the best prediction from a set of prematriculation values (adjusted R 2 = 11.7 %) for step 1. The addition of scores from the first medical school exam improved our predictive capabilities with a linear model to 27.9 %. As we added data to the model, we increased our predictive values as expected. However, it was not until we added data from year 2 exams that we started to get step 1 prediction values that exceeded 50 %. Stepwise addition of more exams in year two resulted in much higher predictive values but also led to the exclusion of many early variables. Therefore, our best step 1 predictive value of around 76.7 % consisted of three variables from a total of 37. These data suggest that the preadmission information is a relatively poor predictor of licensure exam performance and that including class exam scores allows for much more accurate determination of students who ultimately proved to be at risk for performance on their licensure exams. The continuous use of this data, as it becomes available, for assisting at-risk students is discussed (251)

A parsimonious explanation for intersecting perinatal mortality curves: understanding the effects of race and of maternal smoking

BACKGROUND: Neonatal mortality rates among black infants are lower than neonatal mortality rates among white infants at birth weights <3000 g, whereas white infants have a survival advantage at higher birth weights. This finding is also observed when birth weight-specific neonatal mortality rates are compared between infants of smokers and non-smokers. We provide a parsimonious explanation for this paradoxical phenomenon. METHODS: We used data on births in the United States in 1997 after excluding those with a birth weight <500 g or a gestational age <22 weeks. Birth weight- and gestational age-specific perinatal mortality rates were calculated per convention (using total live births at each birth weight/gestational age as the denominator) and also using the fetuses at risk of death at each gestational age. RESULTS: Perinatal mortality rates (calculated per convention) were lower among blacks than whites at lower birth weights and at preterm gestational ages, while blacks had higher mortality rates at higher birth weights and later gestational ages. With the fetuses-at-risk approach, mortality curves did not intersect; blacks had higher mortality rates at all gestational ages. Increases in birth rates and (especially) growth-restriction rates presaged gestational age-dependent increases in perinatal mortality. Similar findings were obtained in comparisons of smokers versus nonsmokers. CONCLUSIONS: Formulating perinatal risk based on the fetuses-at-risk approach solves the intersecting perinatal mortality curves paradox; blacks have higher perinatal mortality rates than whites and smokers have higher perinatal mortality rates than nonsmokers at all gestational ages and birth weights

The Ursinus Weekly, April 10, 1975

How to Succeed is Spring production • New Who\u27s who in religion lists Williamson • S.F.A.R.C. studies U.C. campus issues • Computer careers night a big success • Newman Society sponsors mass • Travelin\u27 VIII concert showcase for talent • Letters to the editor • Alarmed by alarms • Education at Ursinus • Casino Night success: Union production a big hit; Gamblers parley thousands into big prizes • Phils win East, Dodgers win West; Oakland repeats, Yanks win East • Preview of \u2775 Wings • Record review: Song for America, Kansas • Come out: See them!https://digitalcommons.ursinus.edu/weekly/1034/thumbnail.jp

Novel cyclic di-GMP effectors of the YajQ protein family control bacterial virulence

Bis-(3 ',5 ') cyclic di-guanylate (cyclic di-GMP) is a key bacterial second messenger that is implicated in the regulation of many critical processes that include motility, biofilm formation and virulence. Cyclic di-GMP influences diverse functions through interaction with a range of effectors. Our knowledge of these effectors and their different regulatory actions is far from complete, however. Here we have used an affinity pull-down assay using cyclic di-GMP-coupled magnetic beads to identify cyclic di-GMP binding proteins in the plant pathogen Xanthomonas campestris pv. campestris (Xcc). This analysis identified XC_3703, a protein of the YajQ family, as a potential cyclic di-GMP receptor. Isothermal titration calorimetry showed that the purified XC_3703 protein bound cyclic di-GMP with a high affinity (K-d similar to 2 mu M). Mutation of XC_3703 led to reduced virulence of Xcc to plants and alteration in biofilm formation. Yeast two-hybrid and far-western analyses showed that XC_3703 was able to interact with XC_2801, a transcription factor of the LysR family. Mutation of XC_2801 and XC_3703 had partially overlapping effects on the transcriptome of Xcc, and both affected virulence. Electromobility shift assays showed that XC_3703 positively affected the binding of XC_2801 to the promoters of target virulence genes, an effect that was reversed by cyclic di-GMP. Genetic and functional analysis of YajQ family members from the human pathogens Pseudomonas aeruginosa and Stenotrophomonas maltophilia showed that they also specifically bound cyclic di-GMP and contributed to virulence in model systems. The findings thus identify a new class of cyclic di-GMP effector that regulates bacterial virulence

In vitro dissolution models for the prediction of in vivo performance of an oral mesoporous silica formulation

Drug release from mesoporous silica systems has been widely investigated in vitro using USP Type II (paddle) dissolution apparatus. However, it is not clear if the observed enhanced in vitro dissolution can forecast drug bioavailability in vivo. In this study, the ability of different in vitro dissolution models to predict in vivo oral bioavailability in a pig model was examined. The fenofibrate-loaded mesoporous silica formulation was compared directly to a commercial reference product, Lipantil Supra®. Three in vitro dissolution methods were considered; USP Type II (paddle) apparatus, USP Type IV (flow-through cell) apparatus and a USP IV Transfer model (incorporating a SGF to FaSSIF-V2 media transfer). In silico modelling, using a physiologically based pharmacokinetic modelling and simulation software package (Gastroplus™), to generate in vitro/in vivo relationships was also investigated. The study demonstrates that the in vitro dissolution performance of a mesoporous silica formulation varies depending on the dissolution apparatus utilised and experimental design. The findings show that the USP IV transfer model was the best predictor of in vivo bioavailability. The USP Type II (paddle) apparatus was not effective at forecasting in vivo behaviour. This observation is likely due to hydrodynamic differences between the two apparatus and the ability of the transfer model to better simulate gastrointestinal transit. The transfer model is advantageous in forecasting in vivo behaviour for formulations which promote drug supersaturation and as a result are prone to precipitation to a more energetically favourable, less soluble form. The USP IV transfer model could prove useful in future mesoporous silica formulation development. In silico modelling has the potential to assist in this process. However, further investigation is required to overcome the limitations of the model for solubility enhancing formulations