Wake Forest University

About: Wake Forest University is a education organization based out in Winston-Salem, North Carolina, United States. It is known for research contribution in the topics: Population & Diabetes mellitus. The organization has 21499 authors who have published 48731 publications receiving 2246027 citations. The organization is also known as: Wake Forest College.

Dementia and Alzheimer's disease incidence in relationship to cardiovascular disease in the cardiovascular health study cohort

Abstract: Objectives: To determine whether coronary artery disease, peripheral arterial disease (PAD), or noninvasive markers of cardiovascular disease (CVD) predict the onset of dementia and Alzheimer's disease (AD). Design: Longitudinal cohort study. Setting: Four U.S. communities. Participants: Men and women (N=3,602) with a brain magnetic resonance imaging (MRI) scan but no dementia were followed for 5.4 years. Participants with stroke were excluded. Measurements: Neurologists and psychiatrists classified incident cases of dementia and subtype using neuropsychological tests, examination, medical records and informant interviews. CVD was defined at the time of the MRI scan. Noninvasive tests of CVD were assessed within 1 year of the MRI. Apolipoprotein E allele status, age, race, sex, education, Mini-Mental State Examination score, and income were assessed as potential confounders. Results: The incidence of dementia was higher in those with prevalent CVD, particularly in the subgroup with PAD. The rate of AD was 34.4 per 1,000 person-years for those with a history of CVD, versus 22.2 per 1,000 person-years without a history of CVD (adjusted hazard ratio (HR)=1.3, 95% confidence interval (CI)=1.0–1.7). Rates of AD were highest in those with PAD (57.4 vs 23.7 per 100 person-years, adjusted HR=2.4, 95% CI=1.4–4.2). Results were similar with further exclusion of those with vascular dementia from the AD group. A gradient of increasing risk was noted with the extent of vascular disease. Conclusion: Older adults with CVD other than stroke had a higher risk of dementia and AD than did those without CVD. The risk was highest in people with PAD, suggesting that extensive peripheral atherosclerosis is a risk factor for AD.

Demixed principal component analysis of neural population data

Abstract: Neurons in higher cortical areas, such as the prefrontal cortex, are often tuned to a variety of sensory and motor variables, and are therefore said to display mixed selectivity. This complexity of single neuron responses can obscure what information these areas represent and how it is represented. Here we demonstrate the advantages of a new dimensionality reduction technique, demixed principal component analysis (dPCA), that decomposes population activity into a few components. In addition to systematically capturing the majority of the variance of the data, dPCA also exposes the dependence of the neural representation on task parameters such as stimuli, decisions, or rewards. To illustrate our method we reanalyze population data from four datasets comprising different species, different cortical areas and different experimental tasks. In each case, dPCA provides a concise way of visualizing the data that summarizes the task-dependent features of the population response in a single figure.

Mid-trimester endovaginal sonography in women at high risk for spontaneous preterm birth.

Abstract: ContextAlthough shortened cervical length has been consistently associated with spontaneous preterm birth, it is not known when in gestation this risk factor becomes apparent.ObjectiveTo determine whether sonographic cervical findings between 16 weeks' and 18 weeks 6 days' gestation predict spontaneous preterm birth and whether serial evaluations up to 23 weeks 6 days' gestation improve prediction in high-risk women.Design, Setting, and ParticipantsBlinded observational study performed between March 1997 and November 1999 at 9 university-affiliated medical centers in the United States in 183 women with singleton gestations who previously had experienced a spontaneous birth before 32 weeks' gestation.ObservationCertified sonologists performed 590 endovaginal sonographic examinations at 2-week intervals. Cervical length was measured from the external os to the functional internal os along a closed endocervical canal. Funneling and dynamic cervical shortening were also recorded.Main Outcome MeasureSpontaneous preterm birth before 35 weeks' gestation, analyzed by selected cutoff values of cervical length.ResultsForty-eight women (26%) experienced spontaneous preterm birth before 35 weeks' gestation. A cervical length of less than 25 mm at the initial sonographic examination was associated with a relative risk (RR) for spontaneous preterm birth of 3.3 (95% confidence interval [CI], 2.1-5.0; sensitivity = 19%; specificity = 98%; positive predictive value = 75%). After controlling for cervical length, neither funneling (P = .24) nor dynamic shortening (P = .054) were significant independent predictors of spontaneous preterm birth. However, using the shortest ever observed cervical length on serial evaluations, after any dynamic shortening, the RR of a cervical length of less than 25 mm for spontaneous preterm birth increased to 4.5 (95% CI, 2.7-7.6; sensitivity = 69%; specificity = 80%; positive predictive value = 55%). Compared with a single cervical measurement at 16 weeks' to 18 weeks 6 days' gestation, serial measurements at up to 23 weeks 6 days significantly improved the prediction of spontaneous preterm birth in a receiver operating characteristic curve analysis (P = .03).ConclusionsCervical length assessed by endovaginal sonography between 16 weeks' and 18 weeks 6 days' gestation, augmented by serial evaluations, predicts spontaneous preterm birth before 35 weeks' gestation in high-risk women.

A methodology for construct development in MIS research

Abstract: This paper presents a comprehensive methodology for developing constructs in MIS research. It is applicable to both individual and organizational levels of analysis, depending on the nature of the concept under study. The methodology is presented as a research guide progressing through three stages: (1) domain definition, (2) instrument construction, and (3) evaluation of measurement properties. The methodology addresses six key measurement properties (content validity, factorial validity, reliability, convergent validity, discriminant validity, nomological validity), which are discussed in detail. An assessment of the proposed methodology indicates that its adoption in MIS research would greatly improve the rigor of construct development projects. This is evidenced by the wide range of quality publications that have used its techniques and its performance when compared to a number of prominent standards for assessing construct development research.

The relationship between early age of onset of initial substance use and engaging in multiple health risk behaviors among young adolescents

Abstract: BACKGROUND: Previous research based on problem-behavior theory has found that early age of onset of substance use is associated with engaging in multiple health risk behaviors among high school students It is unknown whether these relationships begin during early adolescence OBJECTIVE: To examine the relationships between early age of onset of cigarette, alcohol, marijuana, and cocaine use and engaging in multiple risk behaviors among middle school students METHODS: A modified version of the Centers for Disease Control and Prevention Youth Risk Behavior Survey was administered to 2227 sixth through eighth grade students attending 53 randomly selected middle schools in North Carolina A Health Risk Behavior Scale was constructed from 16 behaviors, including indicators of violence and weapon carrying; current substance use; nonuse of helmets when biking, in-line skating or skateboarding; not wearing a seat belt; riding with a driver who had been drinking; and suicide plans Among this sample of middle school students, the scale had a mean (SD) of 41 (27) (range=O-15), and had a high internal reliability coefficient (alpha(=074) The independent variables included first time use of cigarettes, alcohol, marijuana, and cocaine at age 11 years or earlier; actual age of onset of each substance; race and ethnicity; family composition; sex; school grade; academic ranking; and older age for school grade These data were analyzed with analysis of variance, Spearman r, and multiple linear regression RESULTS: All the independent variables were found to be associated (P Language: en