CHARACTERIZATION AND COMPARISON OF SUBHUMAN PRIMATE AND HUMAN TYPE C RETROVIRAL GENE PRODUCTS

The viral specific precursor polyproteins of simian sarcoma/simian associated virus (SiSV/SiAV), baboon endogenous viruses (BaEV), and three human isolate retroviruses, have been analyzed by radioimmunoprecipitation and tryptic peptide mapping. Cells infected with the BaEV isolates are characterized by identical precursor polyproteins: gPr80-85('env), Pr70-71('gag), and Pr65-67('gag). By tryptic digest mapping, m7-BaEV and 455K-BaEV were shown to be highly related. By comparison, mapping studies showed that BILN-BaEV was less highly related to m7-BaEV than was 455K-BaEV. Chase-incubated cells infected with BaEV also contained a stable, p28-related polyprotein termed P72('gag). This polyprotein appeared to arise by posttranslational modification of Pr70-71('gag). Tryptic digest mapping of BaEV and HL23V precursor polyproteins suggested that the BaEV-like component of HL23V was more closely related to m7-BaEV than to 455K-BaEV or BILN-BaEV.^ The intracellular precursor polyproteins of SiSV(SiAV) and gibbon ape leukemia virus (GaLV) were compared to the intracellular proteins of the human retrovirus isolates, HL23V, HEL12V, and A1476V. Cells infected with SiSV(SiAV) were characterized by polyproteins Pr200('gag-pol), gPr80('env), Pr80('gag), pr60('gag), and Pr40('gag). We have found that the human isolates are identical to true SiAV with regard to the size and structure of their precursor polyproteins. Both gPr80('env) and Pr60('gag) of SiAV were identical by tryptic peptide mapping to the respective proteins from the three human retroviral isolates examined. We have also shown that these viruses differ significantly from each of the GaLV isolates studied. Since SiAV differs substantially from any known GaLV isolate, we feel that it is unlikely that SiAV is a subtype of GaLV which exists today in the gibbon gene pool. The experimental evidence suggests that SiAV may be an exogenous human retrovirus that was transmitted originally into the human gene pool in the distant past by cross-species infection with GaLV(,SF) or with the GaLV(,SF) progenitor virus. It is, therefore, quite possible that SiAV expression in the pet woolly monkey arose from a recent infection of that monkey with SiAV from humans.^

Predictors of weight stability in women and men: The aerobic center longitudinal study, 1987--1995

It is estimated that more than half the U.S. adult population is overweight or obese as classified by a body mass index of 25.0–29.9 or ≥30 kg/m 2, respectively. Since the current treatment approaches for long-term maintenance of weight loss are lacking, the National Institutes of Health state that an effective approach may be to focus on weight gain prevention. There is a limited body of literature describing how adults maintain a stable weight as they age. It is hypothesized that weight stability is the result of a balance between energy consumption and energy expenditure as influenced by diet, lifestyle, behavior, genetics and environment. The purpose of this research was to examine the dietary intake and behaviors, lifestyle habits, and risk factors for weight change that predict weight stability in a cohort of 2101 men and 389 women aged 20 to 8 7 years in the Aerobic Center Longitudinal Study regardless of body weight at baseline. At baseline, participants completed a maximal exercise treadmill test to determine cardiorespiratory fitness, a medical history questionnaire, which included self-reported measures of weight, dietary behaviors, lifestyle habits, and risk factors for weight change, a three-day diet record, and a mail-back version of the medical history questionnaire in 1990 or 1995. All analyses were performed separately for men and women. Results from multivariate regression analyses indicated that the strongest predictor of follow-up weight for men and women was previous weight, accounting for 87.0% and 81.9% of the variance, respectively. Age, length of follow-up and eating habits were also significant predictors of follow-up weight in men, though these variables only explained 3% of the variance. For women, length of follow-up and currently being on a diet were significantly associated with follow-up weight but these variables explained only an additional 2% of the variance. Understanding the factors that influence weight change has tremendous public health importance for developing effective methods to prevent weight gain. Since current weight was the strongest predictor of previous weight, preventing initial weight gain by maintaining a stable weight may be the most effective method to combat the increasing prevalence of overweight and obesity. ^

Traditional linkage analysis in admixed families

Currently there is no general method to study the impact of population admixture within families on the assumptions of random mating and consequently, Hardy-Weinberg equilibrium (HWE) and linkage equilibrium (LE) and on the inference obtained from traditional linkage analysis. ^ First, through simulation, the effect of admixture of two populations on the log of the odds (LOD) score was assessed, using Prostate Cancer as the typical disease model. Comparisons between simulated mixed and homogeneous families were performed. LOD scores under both models of admixture (within families and within a data set of homogeneous families) were closest to the homogeneous family scores of the population having the highest mixing proportion. Random sampling of families or ascertainment of families with disease affection status did not affect this observation, nor did the mode of inheritance (dominant/recessive) or sample size. ^ Second, after establishing the effect of admixture on the LOD score and inference for linkage, the presence of induced disequilibria by population admixture within families was studied and an adjustment procedure was developed. The adjustment did not force all disequilibria to disappear but because the families were adjusted for the population admixture, those replicates where the disequilibria exist are no longer affected by the disequilibria in terms of maximization for linkage. Furthermore, the adjustment was able to exclude uninformative families or families that had such a high departure from HWE and/or LE that their LOD scores were not reliable. ^ Together these observations imply that the presence of families of mixed population ancestry impacts linkage analysis in terms of the LOD score and the estimate of the recombination fraction. ^

Multiple imputation for missing continuous and dichotomous data: The effects of patterns of missingness and variable correlations on type I error with small samples

The purpose of this study is to investigate the effects of predictor variable correlations and patterns of missingness with dichotomous and/or continuous data in small samples when missing data is multiply imputed. Missing data of predictor variables is multiply imputed under three different multivariate models: the multivariate normal model for continuous data, the multinomial model for dichotomous data and the general location model for mixed dichotomous and continuous data. Subsequent to the multiple imputation process, Type I error rates of the regression coefficients obtained with logistic regression analysis are estimated under various conditions of correlation structure, sample size, type of data and patterns of missing data. The distributional properties of average mean, variance and correlations among the predictor variables are assessed after the multiple imputation process. ^ For continuous predictor data under the multivariate normal model, Type I error rates are generally within the nominal values with samples of size n = 100. Smaller samples of size n = 50 resulted in more conservative estimates (i.e., lower than the nominal value). Correlation and variance estimates of the original data are retained after multiple imputation with less than 50% missing continuous predictor data. For dichotomous predictor data under the multinomial model, Type I error rates are generally conservative, which in part is due to the sparseness of the data. The correlation structure for the predictor variables is not well retained on multiply-imputed data from small samples with more than 50% missing data with this model. For mixed continuous and dichotomous predictor data, the results are similar to those found under the multivariate normal model for continuous data and under the multinomial model for dichotomous data. With all data types, a fully-observed variable included with variables subject to missingness in the multiple imputation process and subsequent statistical analysis provided liberal (larger than nominal values) Type I error rates under a specific pattern of missing data. It is suggested that future studies focus on the effects of multiple imputation in multivariate settings with more realistic data characteristics and a variety of multivariate analyses, assessing both Type I error and power. ^

Volume 13, Number 2: April/May 2007

Page 2 – The Vice Provost for University Libraries reflects upon the strides made in the last year. Page 3 - Ornithologist David Sibley’s Edwin Way Teale lecture is featured. Page 5 - In a guest column on diversity issues, Professor Hedley Freake examines what UConn is doing to engender cultural understanding in students. Page 6 - Staff anniversaries and awards. Page 7 - Finding articles, images, and music easier with new database locator.

Volume 11, Number 2: April/May 2005

Page 2 – The Vice Provost cites 2004/2005 as a year of significant accomplishments for the Libraries. • The Dodd Research Center and the Human Rights Institute plan a conference on economic human rights for October. Page 3 - Researcher Bill V. Mullen talks about the work of avant garde musician, composer, and author Fred Ho, whose archive is in Archives & Special Collections. Page 4 - Students tell us why they come to the library. • The Dodd Research Center commissions two students to create a logo for its 10th anniversary celebration. • Fragile pamphlets are given new life in the Conservation Lab. Page 5 - The library sponsors a national symposium to explore new technology. • Our newest digital project can lead you to everything you ever wanted to know about Connecticut. • A new Pharmacy Library will open its doors in June. Page 6 - Staff News: service anniversaries and new faces. Page 7 - The Class of 1955 is raising $50,000 for an undergraduate instruction classroom in the library.

Volume 10, Number 3: September/October 2004

Page 2 - Users tell us what they think about library service, and library director Brinley Franklin explains why he thinks the library is a good investment. Page 3 - Pulitzer Prize-winning music critic Tim Page, once the beneficiary of the library’s music collections, is now a patron of the Music & Dramatic Arts Library. Page 4 - Donors to the Libraries during FY 2004 Page 5 - Remembering Theora Whetten, long-time Friend of the Libraries; welcoming new Friends, the Class of ‘55. Page 6 - Beach Society members include the Libraries in their estate plans. Stamford honors Estelle Feinstein. Page 7 - Jack & Virginia Stephens donate a collection of Connecticut town histories.

Volume 13, Number 1: February/March 2007

Page 2 – The Vice Provost for University Libraries examines how the libraries are responding to 21st century student learning. Page 3 - Children’s author and donor to the Northeast Children’s Literature Collection Susan Bivin Aller is featured. Page 5 - In a guest column on diversity issues, Theo. Van Alst describes the events sponsored by Native American Cultural Society Office.

Volume 11, Number 3: September/October 2005

Page 2 – The University and its Libraries celebrate 125 years of growth and service to the citizens of Connecticut. • UConn joins the Center for Research Libraries, the nation’s oldest and most significant library consortium. Page 3 - A profile of Stanley Israelite recounts his civic contributions and his role as a creator of the Dodd Research Center. Page 4 - The Thomas J. Dodd Research Center celebrates its 10th anniversary with a series of special events. • The Pharmacy Library occupies new quarters in UConn’s new Pharmacy/Biology Building. Page 5 - The 2005 Connecticut Children’s Book Fair features a great lineup of authors and illustrators. Page 6 - Staff News • The Wharton Data Research Service is now available for financial research. Page 7 - Donors to the University Libraries, January 1 – June 30, 2005

Volume 11, Number 4: November/December 2005

Page 2 - The vice provost for University Libraries writes about the many efforts underway to archive electronic resources for future use. • The director of the Tri-Campus Libraries comments on freedom of speech & the academic library. Page 3 - Manuscripts from Archives & Special Collections record the recollections of a Civil War nurse, a Connecticut naturalist, and a prosecutor at the Nuremberg Trials. Page 4 - A WPA mural by James Daugherty is rescued and installed in the Jeremy Richard Library. • Access Services finds new ways to improve services for library users. Page 5 - A renovated UConn Health Center Library is transformed from a warehouse for print into an information commons. Page 6 - Staff news