HIV dynamics and natural history studies: Joint modeling with doubly interval-censored event time and infrequent longitudinal data

Hepatitis C virus (HCV) coinfection has become one of the most challenging clinical situations to manage in HIV-infected patients. Recently the effect of HCV coinfection on HIV dynamics following initiation of highly active antiretroviral therapy (HAART) has drawn considerable attention. Post-HAART HIV dynamics are commonly studied in short-term clinical trials with frequent data collection design. For example, the elimination process of plasma virus during treatment is closely monitored with daily assessments in viral dynamics studies of AIDS clinical trials. In this article instead we use infrequent cohort data from long-term natural history studies and develop a model for characterizing post-HAART HIV dynamics and their associations with HCV coinfection. Specifically, we propose a joint model for doubly interval-censored data for the time between HAART initiation and viral suppression, and the longitudinal CD4 count measurements relative to the viral suppression. Inference is accomplished using a fully Bayesian approach. Doubly interval-censored data are modeled semiparametrically by Dirichlet process priors and Bayesian penalized splines are used for modeling population-level and individual-level mean CD4 count profiles. We use the proposed methods and data from the HIV Epidemiology Research Study (HERS) to investigate the effect of HCV coinfection on the response to HAART.Comment: Published in at http://dx.doi.org/10.1214/10-AOAS391 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

Topic Grids for Homogeneous Data Visualization

We propose the topic grids to detect anomaly and analyze the behavior based on the access log content. Content-based behavioral risk is quantified in the high dimensional space where the topics are generated from the log. The topics are being projected homogeneously into a space that is perception- and interaction-friendly to the human experts

Comparison of Compliance with Cervical Cancer Screening among Women aged 18 and above in Arkansas and the United States

Introduction: Cervical cancer preys on women without access to preventative screening. Any woman who has developed an invasive case of cervical cancer should be regarded as a failure of screening. Disparities in access to screening, triage, and treatment fuel an uneven distribution in the burden of cervical cancer within the United States; weighing unusually heavy on the Southern States like Arkansas. The purpose of this study was to evaluate demographic and behavioral risk factors for cervical cancer and identify potential barriers which may influence the likelihood of complying with current Pap test recommendations on a state level, in Arkansas, and also a national scale, in the United States. Materials and Methods: National data from the 2014 Behavioral Risk Factor Survey System (BRFSS) was used to collect demographic characteristics and behavioral risk factors among females aged 18 and above in Arkansas and the United States. BFRSS data included a total of 1,587 women in Arkansas and 162,222 in the United States who were aged 18 and above and eligible to receive Pap tests. Women with a medical history of hysterectomy that included the removal of the cervix were excluded from analysis because they are not considered to be medically eligible to receive Pap tests. Results: Socioeconomic status, age, race, and health insurance were significantly associated with likelihood to comply with current screening recommendations among women in both Arkansas and the United States. Arkansan women who had less than a 12-year education (Odds Ratio (OR) = 1.41, 95% Confidence Interval (CI) = 1.04, 1.64) and were without health insurance (OR = 3.56, 95% CI = 1.66, 7.66) were more likely to be non-compliant with Pap testing, which is similar to the finding on the national level. The prevalence of Pap test compliance was significantly lower among women in Arkansas when compared to US average in every sociodemographic sector. Discussion: According to US Census data collected in 2013, Arkansas had the highest cervical cancer incidence of 10.6 per 100,000 person-years, while the national average was 7.7 per 100,000 person-years. Therefore, future population-based cervical cancer interventions in Arkansas should target the promotion of Pap test compliance among the most vulnerable subpopulations (i.e., low socioeconomic status, minority, medically under or uninsured). Organized screening interventions might include offering free or reduced cost Pap testing in both urban and rural locations

Robotic distal ureterectomy with psoas hitch and ureteroneocystostomy: Surgical technique and outcomes

AbstractUse of the da Vinci® surgical robotic system has expanded to numerous upper and lower urinary tract procedures. We describe our surgical technique and perioperative outcome of robotic distal ureterectomy with psoas hitch and ureteroneocystostomy for distal ureteral pathologies. Eight patients with a median age of 69.5 years old underwent robotic distal ureterectomy with psoas hitch and ureteroneocystostomy between April 2009 and August 2014. The entirety of all cases was performed robotically by a single surgeon at a tertiary academic medical center. Median operative time was 285 min (range: 210–360 min), estimated blood loss was 50 mL (range: 50–75 mL) and median length of hospital stay was 2.5 days (range: 1–6 days). There was one post-operative complication, a readmission for dehydration (Clavien I). It suggests that robotic distal ureterectomy with psoas hitch and ureteroneocystostomy is a safe and effective minimally invasive alternative for patients with distal ureteral pathology

Pricing of foreign exchange rate and interest rate risks using short to long horizon returns

Copyright © 2021 The Author(s). In this paper, we test whether foreign exchange (FX) rate and interest rate (IR) risks are priced at short to long return horizons. We also test whether the associated risk premia relate to certain stock characteristics. Our new evidence indicates that risk premia increase with the length of the return horizon and that the risk premium signs depend on the sign of the corresponding exposure beta. Thus, for our longest return horizon of 950 days, positive (negative) FX rate premia increase in absolute value to 2.642% (–2.050%), whereas positive (negative) IR premia increase to 1.039% (–1.151%). Zero exposure betas have zero risk premia. We find that, depending on the level of profitability, Size, book-to-market-ratio (B/M) and sales-to-stock price ratio (S/P) explain most of the variation in exposure betas and risk premia. Our results imply that investors view exposure betas and risk premia as important factors affecting portfolio returns

How Different Are Young Adults From Older Adults When It Comes to Information Privacy Attitudes & Policies?

Media reports teem with stories of young people posting salacious photos online, writing about alcohol-fueled misdeeds on social networking sites, and publicizing other ill-considered escapades that may haunt them in the future. These anecdotes are interpreted as representing a generation-wide shift in attitude toward information privacy. Many commentators therefore claim that young people “are less concerned with maintaining privacy than older people are.” Surprisingly, though, few empirical investigations have explored the privacy attitudes of young adults. This report is among the first quantitative studies evaluating young adults’ attitudes. It demonstrates that the picture is more nuanced than portrayed in the popular media. In this telephonic (wireline and wireless) survey of internet using Americans (N=1000), we found that large percentages of young adults (those 18-24 years) are in harmony with older Americans regarding concerns about online privacy, norms, and policy suggestions. In several cases, there are no statistically significant differences between young adults and older age categories on these topics. Where there were differences, over half of the young adult-respondents did answer in the direction of older adults. There clearly is social significance in that large numbers of young adults agree with older Americans on issues of information privacy. A gap in privacy knowledge provides one explanation for the apparent license with which the young behave online. 42 percent of young Americans answered all of our five online privacy questions incorrectly. 88 percent answered only two or fewer correctly. The problem is even more pronounced when presented with offline privacy issues – post hoc analysis showed that young Americans were more likely to answer no questions correctly than any other age group. We conclude then that that young-adult Americans have an aspiration for increased privacy even while they participate in an online reality that is optimized to increase their revelation of personal data

Shareholders wealth and mergers and acquisitions (M&AS)

We re-examine the abnormal returns (ARs) around merger announcements using a large sample of 8,945 announcements. We estimate the ARs using the Carhart (1997) fourfactor model under the standard ordinary least square (OLS) method and the Glosten et al.'s (1993) asymmetric GARCH specification (hereafter, GJR-GARCH). Under the OLS method, acquirers do not generate significant cumulative ARs (CARs) in line with prior work. Our new results, however, show that under the GJR-GARCH estimation, acquirers generate positive and significant cumulative CARs. We attribute the gains to the use of the GJR-GARCH estimation method, as the GJR-GARCH method is more effective in capturing conditional volatility and asymmetry in the excess returns