Solar ultraviolet radiation exposure, and incidence of childhood acute lymphocytic leukaemia and non-Hodgkin lymphoma in a US population-based dataset

Background: Acute lymphocytic leukaemia (ALL) and non-Hodgkin lymphoma (NHL) are among the commonest types of childhood cancer. Some previous studies suggested that elevated ultraviolet radiation (UVR) exposures increase ALL risk; many more indicate NHL risk is reduced. Methods: We assessed age&lt;20 ALL/NHL incidence in Surveillance, Epidemiology and End Results data using AVGLO-derived UVR irradiance/cumulative radiant exposure measures, using quasi-likelihood models accounting for underdispersion, adjusted for age, sex, racial/ethnic group and other county-level socioeconomic variables. Results: There were 30,349 cases of ALL and 8062 of NHL, with significant increasing trends of ALL with UVR irradiance (relative risk (RR) = 1.200/mW/cm2 (95% CI 1.060, 1.359, p = 0.0040)), but significant decreasing trends for NHL (RR = 0.646/mW/cm2 (95% CI 0.512, 0.816, p = 0.0002)). There was a borderline-significant increasing trend of ALL with UVR cumulative radiant exposure (RR = 1.444/MJ/cm2 (95% CI 0.949, 2.197, p = 0.0865)), and significant decreasing trends for NHL (RR = 0.284/MJ/cm2 (95% CI 0.166, 0.485, p &lt; 0.0001)). ALL and NHL trend RR is substantially increased among those aged 0–3. All-age trend RRs are most extreme (increasing for ALL, decreasing for NHL) for Hispanics for both UVR measures. Conclusions:Our more novel finding, of excess UVR-related ALL risk, is consistent with some previous studies, but is not clear-cut, and in need of replication.</p

Neighborhood deprivation and association with neonatal intensive care unit mortality and morbidity for extremely premature infants

IMPORTANCE: Socioeconomic status affects pregnancy and neurodevelopment, but its association with hospital outcomes among premature infants is unknown. The Area Deprivation Index (ADI) is a validated measure of neighborhood disadvantage that uses US Census Bureau data on income, educational level, employment, and housing quality. OBJECTIVE: To determine whether ADI is associated with neonatal intensive care unit (NICU) mortality and morbidity in extremely premature infants. DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study was performed at 4 level IV NICUs in the US Northeast, Mid-Atlantic, Midwest, and South regions. Non-Hispanic White and Black infants with gestational age of less than 29 weeks and born between January 1, 2012, and December 31, 2020, were included in the analysis. Addresses were converted to census blocks, identified by Federal Information Processing Series codes, to link residences to national ADI percentiles. EXPOSURES: ADI, race, birth weight, sex, and outborn status. MAIN OUTCOMES AND MEASURES: In the primary outcome, the association between ADI and NICU mortality was analyzed using bayesian logistic regression adjusted for race, birth weight, outborn status, and sex. Risk factors were considered significant if the 95% credible intervals excluded zero. In the secondary outcome, the association between ADI and NICU morbidities, including late-onset sepsis, necrotizing enterocolitis (NEC), and severe intraventricular hemorrhage (IVH), were also analyzed. RESULTS: A total of 2765 infants with a mean (SD) gestational age of 25.6 (1.7) weeks and mean (SD) birth weight of 805 (241) g were included in the analysis. Of these, 1391 (50.3%) were boys, 1325 (47.9%) reported Black maternal race, 498 (18.0%) died before NICU discharge, 692 (25.0%) developed sepsis or NEC, and 353 (12.8%) had severe IVH. In univariate analysis, higher median ADI was found among Black compared with White infants (77 [IQR, 45-93] vs 57 [IQR, 32-77]; P \u3c .001), those who died before NICU discharge vs survived (71 [IQR, 45-89] vs 64 [IQR, 36-86]), those with late-onset sepsis or NEC vs those without (68 [IQR, 41-88] vs 64 [IQR, 35-86]), and those with severe IVH vs those without (69 [IQR, 44-90] vs 64 [IQR, 36-86]). In a multivariable bayesian logistic regression model, lower birth weight, higher ADI, and male sex were risk factors for mortality (95% credible intervals excluded zero), while Black race and outborn status were not. The ADI was also identified as a risk factor for sepsis or NEC and severe IVH. CONCLUSIONS AND RELEVANCE: The findings of this cohort study of extremely preterm infants admitted to 4 NICUs in different US geographic regions suggest that ADI was a risk factor for mortality and morbidity after adjusting for multiple covariates

Solar ultraviolet radiation exposure, and incidence of childhood acute lymphocytic leukaemia and non-Hodgkin lymphoma in a US population-based dataset

Background: Acute lymphocytic leukaemia (ALL) and non-Hodgkin lymphoma (NHL) are among the commonest types of childhood cancer. Some previous studies suggested that elevated ultraviolet radiation (UVR) exposures increase ALL risk; many more indicate NHL risk is reduced. Methods: We assessed age<20 ALL/NHL incidence in Surveillance, Epidemiology and End Results data using AVGLO-derived UVR irradiance/cumulative radiant exposure measures, using quasi-likelihood models accounting for underdispersion, adjusted for age, sex, racial/ethnic group and other county-level socioeconomic variables. Results: There were 30,349 cases of ALL and 8062 of NHL, with significant increasing trends of ALL with UVR irradiance (relative risk (RR) = 1.200/mW/cm2 (95% CI 1.060, 1.359, p = 0.0040)), but significant decreasing trends for NHL (RR = 0.646/mW/cm2 (95% CI 0.512, 0.816, p = 0.0002)). There was a borderline-significant increasing trend of ALL with UVR cumulative radiant exposure (RR = 1.444/MJ/cm2 (95% CI 0.949, 2.197, p = 0.0865)), and significant decreasing trends for NHL (RR = 0.284/MJ/cm2 (95% CI 0.166, 0.485, p  Conclusions: Our more novel finding, of excess UVR-related ALL risk, is consistent with some previous studies, but is not clear-cut, and in need of replication

On the analysis of event-related potential and electroencephalographic data: Spatio-temporal modeling, variography, and simulation

National awareness of Traumatic Brain Injuries (TBI) has recently increased due to higher incidence among military personnel, as well as to high profile lawsuits and rule-changes in North American professional sports. TBI affect both short-term and long-term brain and behavior mechanisms associated with cognitive deficits which are commonly measured using Event-Related Potential (ERP) data. Unfortunately, sophisticated methodology for ERP data analysis has not yet been established. In this dissertation, I present novel approaches to modeling ERP data in the context of spatio-temporal Gaussian random fields with the purpose of aiding TBI diagnosis in college athletes. First, I employ a flexible, non-separable sum-metric spatio-temporal model to represent ERP assessments collected during a working memory task, and utilize the estimated parameters to classify athletes as either being healthy or suffering from TBI. Results indicate that parameter estimates provide a promising basis for accurate ERP classification when applied to the Match condition of the memory task. Next, I develop a novel measure of dissimilarity between two spatio-temporal variogram surfaces. In addition, I detail a method of generating ERP data in the spatio-temporal domain for both healthy subjects and subjecs suffering from TBI. Classification accuracy of the proposed measure is examined for both simulated ERP data and ERP collected from college athletes. Results indicate that the proposed measure of dissimilarity successfully separates two populations of ERP assessments - for both real and simulated data - that are different only according to their variance-covariance matrices. Lastly, I present a method of approximating the ML and REML likelihood functions in the context of parameter estimation for moderately large, non-stationary spatial data. Partial Singular Value Decomposition (SVD) is used to approximate the spatial variance-covariance matrix in order to increase speed of convergence. Approximated parameter estimates are subsequently examined for presence, degree, and direction of estimation bias through the use of a simulation. Results suggest that spatial process parameter estimates are generally downward biased, whereas spatial trend parameter estimates remain unbiased. As expected, partial SVD approximation resulted in a significant increase in speed of computation for both ML and REML-based models

Measuring Peer Socialization for Adolescent Substance Use:A Comparison of Perceived and Actual Friends’ Substance Use Effects

Objective: There has been an increase in the use of social network analysis in studies of peer socialization effects on adolescent substance use. Some researchers argue that social network analyses provide more accurate measures of peer substance use, that the alternate strategy of assessing perceptions of friends’ drug use is biased, and that perceptions of peer use and actual peer use represent different constructs. However, there has been little research directly comparing the two effects, and little is known about the extent to which the measures differ in the magnitude of their influence on adolescent substance use, as well as how these two effects may be redundant or separate constructs. Method: Using Waves I and II of the National Longitudinal Study of Adolescent Health (Add Health) saturated subsample, we directly compared effects of perception of friends’ use (PFU) and actual friends’ use (AFU) on alcohol, cigarette, and marijuana initiation and persistence of use 1 year later. We also examined potential moderating effects of friendship quality and individual use on the relationship between perceived and actual friends’ substance use and outcomes. Results: Results indicated that, overall, PFU effects were larger than AFU effects; however, these effects did not significantly differ in magnitude for most models. In addition, interaction effects differed for different substances and usage outcomes, indicating the meaning of PFU and AFU constructs (and thus, different types of peer socialization) may change based on substance and type of use. Conclusions: These results highlight the multifaceted nature of peer influence on substance use and the importance of assessing multiple aspects of peer socialization while accounting for distinct contexts related to specific substances and use outcomes

Impact of altitude on COVID-19 infection and death in the United States: A modeling and observational study.

BackgroundCOVID-19, the disease caused by SARS-CoV-2, has caused a pandemic, sparing few regions. However, limited reports suggest differing infection and death rates across geographic areas including populations that reside at higher elevations (HE). We aimed to determine if COVID-19 infection, death, and case mortality rates differed in higher versus low elevation (LE) U.S. counties.MethodsUsing publicly available geographic and COVID-19 data, we calculated per capita infection and death rates and case mortality in population density matched HE and LE U.S. counties. We also performed population-scale regression analysis to investigate the association between county elevation and COVID-19 infection rates.FindingsPopulation density matching of LA (2133m, n = 58) counties yielded significantly lower COVID-19 cases at HE versus LE (615 versus 905, p = 0.034). HE per capita deaths were significantly lower than LE (9.4 versus 19.5, p = 0.017). However, case mortality did not differ between HE and LE (1.78% versus 1.46%, p = 0.27). Regression analysis, adjusted for relevant covariates, demonstrated decreased COVID-19 infection rates by 12.82%, 12.01%, and 11.72% per 495m of county centroid elevation, for cases recorded over the previous 30, 90, and 120 days, respectively.ConclusionsThis population-adjusted, controlled analysis suggests that higher elevation attenuates infection and death. Ongoing work from our group aims to identify the environmental, biological, and social factors of residence at HE that impact infection, transmission, and pathogenesis of COVID-19 in an effort to harness these mechanisms for future public health and/or treatment interventions

Natural Hydrocarbon Samples Classification by Topological Analysis Method

Nowadays material science involves powerful 3D imaging techniques such as X-ray computed tomography that generates high-resolution images of different structures. These methods are widely used to reveal information about the internal structure of geological cores; therefore, there is a need to develop modern approaches for quantitative analysis of the obtained images, their comparison, and classification. Topological persistence is a useful technique for characterizing the internal structure of 3D images. We show how persistent data analysis provides a useful tool for the classification of porous media structure from 3D images of hydrocarbon reservoirs obtained using computed tomography. We propose a methodology of 3D structure classification based on geometry-topology analysis via persistent homology

Dataset for: Correlated Poisson Models for Age-Period-Cohort Analysis

Age-period-cohort (APC) models are widely used to analyze population-level rates, particularly cancer incidence and mortality. These models are used for descriptive epidemiology, comparative risk analysis, and extrapolating future disease burden. Traditional APC models have two major limitations: 1) they lack parsimony because they require estimation of deviations from linear trends for each level of age, period, and cohort; and 2) rates observed at similar ages, periods, and cohorts are treated as independent, ignoring any correlations between them that may lead to biased parameter estimates and inefficient standard errors. We propose a novel approach to estimation of APC models using a spatially-correlated Poisson model that accounts for over-dispersion and correlations in age, period, and cohort, simultaneously. We treat the outcome of interest as event rates occurring over a grid defined by values of age, period, and cohort. Rates defined in this manner lend themselves to well-established approaches from spatial statistics in which correlation among proximate observations may be modeled using a spatial random effect. Through simulations, we show that in the presence of spatial dependence and over-dispersion: 1) the correlated Poisson model attains lower AIC; 2) the traditional APC model produces biased trend parameter estimates; and 3) the correlated Poisson model corrects most of this bias. We illustrate our approach using brain and breast cancer incidence rates from the Surveillance Epidemiology and End Results Program of the United States. Our approach can be easily extended to accommodate comparative risk analyses and interpolation of cells in the Lexis with sparse data

Perioperative systemic blood pressure parameters and clinical outcomes following 27g vitrectomy for diabetic tractional detachment repair

Background Extremes in perioperative blood pressures are known risk factors for adverse outcomes after surgical interventions. There is scarce literature studying these parameters as predictors of outcomes after ocular surgery.Methods This was a retrospective single-centre interventional cohort analysis to evaluate the relationship between perioperative (preoperative and intraoperative) blood pressure value and variability and postoperative visual and anatomic outcomes. Included were patients who underwent primary 27-gauge (27g) vitrectomy for repair of diabetic tractional retinal detachment (DM-TRD) with at least 6 months of follow-up. Univariate analyses were conducted via independent two-sided t-tests and Pearson’s χ2 tests. Multivariate analyses were conducted via generalised estimating equations.Results 71 eyes of 57 patients were included in the study. Higher preprocedure mean arterial pressure (MAP) was associated with fewer Snellen lines of improvement at postoperative month 6 (POM6) (p&lt;0.01). Higher mean intraoperative systolic blood pressure (SBP), diastolic blood pressure and MAP were associated with visual acuity 20/200 or worse at POM6 (p&lt;0.05). Patients with sustained intraoperative hypertension had 1.77 times the risk of visual acuity 20/200 or worse at POM6 compared with those without sustained intraoperative hypertension (p=0.006). Higher SBP variability was associated with worse visual outcomes at POM6 (p&lt;0.05). Blood pressure was not associated with macular detachment at POM6 (p&gt;0.10).Conclusions Higher average perioperative blood pressure and blood pressure variability are associated with worse visual outcomes in patients undergoing 27g vitrectomy for DM-TRD repair. Patients with sustained intraoperative hypertension were approximately twice as likely to have visual acuity 20/200 or worse at POM6 compared to those without sustained intraoperative hypertension