William L. Harkness

Abruptio placentae and perinatal death: A prospective study

Abruptio placentae caused 3.96 perinatal deaths per 1,000 births in a large prospective study. Intrapartum but not prepartum maternal hypertension was observed in the fatal cases. Decidual necrosis at the placental margin and large placental infarcts were the most characteristic placental abnormalities. The decidual necrosis was correlated with maternal cigarette smoking and low pregnancy weight gains in the abruption placentae cases. The fetuses and neonates who died had a pattern of growth retardation characteristic of antenatal undernutrition, indicating that poor maternal nutrition during pregnancy may have contributed to the genesis of the abruptio placentae.

What to Consider When Conducting a Cost-Effectiveness Analysis in a Clinical Setting

More data are needed providing strong evidence that nutrition services are cost-effective. Economic evaluations, such as cost-effectiveness analyses, are excellent practice-based research projects. We conducted a cost-effectiveness analysis in a clinical setting to compare the cost-effectiveness of lipid-lowering medications plus diet therapy (medication + diet) with diet therapy alone (diet alone) for treating patients with hypercholesterolemia. Twenty-five adults with hypercholesterolemia (13 receiving medication + diet, 12 receiving diet alone) either participated in an 8-week, home-based, step 1 intervention or were counseled about diet and lifestyle by their care provider. Diet, cost, and laboratory data were collected at baseline, at 9 months, and at 19 months after participation in the intervention (follow-up). Cost per unit change in outcome was evaluated for each group. The diet-alone group made only small changes in dietary intake, changes that were smaller in magnitude than those made by the medication + diet group. Nevertheless, at 9 months, costs per unit change in total serum cholesterol level and low-density lipoprotein cholesterol (LDL-C) level were approximately

A Sequential Sampling Scheme for Detecting Infestation Levels of Tracheal Mites (Heterostigmata: Tarsonemidae) in Honey Bee (Hymenoptera: Apidae) Colonies

24 and

Inequalities for tail probabilities for the multivariate normal distribution

83 less, respectively, for the diet-alone group. At follow-up, however, the cost per unit change in LDL-C level was approximately

Penn State University Department of Statistics

17 less for the medication + diet group, which can be explained by the medication + diet groups greater decrease in LDL-C level. The following elements should be considered when conducting a cost-effectiveness analysis of medical nutrition therapy: effectiveness of the nutrition intervention, adequate sample size, confounding variables, compliance with diet and drug therapy, direct and indirect costs of care, and follow-up evaluation.

Examination of Preservice and In-service Secondary Science Teachers' Beliefs about Science-Technology-Society Interactions.

Abstract The introduction of parasitic honey bee mites, the tracheal mite, Acarapis woodi (Rennie) in 1984 and the Varroa mite, Varroa jacobsoni, in 1987, has dramatically increased the winter mortality of honey bee, Apis mellifera L., colonies in many areas of the United States. Some beekeepers have minimized their losses by routinely treating their colonies with menthol, currently the only Environmental Protection Agency-approved and available chemical for tracheal mite control. Menthol is also expensive and can interfere with honey harvesting. Because of inadequate sampling techniques and a lack of information concerning treatment, this routine treatment strategy has increased the possibility that tracheal mites will develop resistance to menthol. It is important to establish economic thresholds and treat colonies with menthol only when treatment is warranted rather than treating all colonies regardless of infestation level. The use of sequential sampling may reduce the amount of time and effort expended in examining individual colonies and determining if treatment is necessary. Sequential sampling also allows statistically based estimates of the percentage of bees in standard Langstroth hives infested with mites while controlling for the possibility of incorrectly assessing the amount of infestation. On the average, sequential sampling plans require fewer observations (bees) to reach a decision for specified probabilities of type I and type II errors than are required for fixed sampling plans, especially when the proportion of infested bees is either very low or very high. We developed a sequential sampling decision plan to allow the user to choose specific economic injury levels and the probability of making type I and type II errors which can result inconsiderable savings in time, labor and expense.

Patterns of instructional-design factors prompting reflective thinking in middle-school and college level problem-based learning environments

Inequalities for tail probabilities of the multivariate normal distribution are obtained, as a generalization of those given by Feller (1966). Upper and lower bounds are given in the equi-correlated case. For an arbitrary correlation matrix R, an upper bound is obtained, using a result of Slepian (1962) which asserts that certain multivariate normal probabilities are a non-decreasing function of correlations.

Views about science — technology — society interactions held by college students in general education physics and sts courses

If this chapter were being written by a writer for the New York Times, the headline might well have proclaimed “New Department of Statistics Created by Non-Statisticians at Penn State University” and it could easily have been defended as the truth. The writer would have elaborated as follows: “The Department of Statistics was created on July 1, 1968, with James B. Bartoo as its first head. Questions have been asked about how it came about and why. Who were the moving forces leading to its creation? What was their motivation? In this story answers to these questions are provided!” Our story may be typical of how other statistics departments were created. Regardless, these are the facts the writer could have cited to back up our story.