UV light exposure versus vitamin D supplementation: A comparison of health benefits and vitamin D metabolism in a pig model.

There is limited data on the effect of UV light exposure versus orally ingested vitamin D on vitamin D metabolism and health. A 4-week study with 16 pigs (as a model for human physiology) was conducted. The pigs were either supplemented with 20 µg/d vitamin D or exposed to UV light for 19 min/d to standardize plasma 25-hydroxyvitamin D levels.

Visualizing the NIOSH Pocket Guide: Open-source web application for accessing and exploring the NIOSH Pocket Guide to Chemical Hazards.

The NIOSH Pocket Guide to Chemical Hazards is a trusted resource that displays key information for a collection of chemicals commonly encountered in the workplace. Entries contain chemical structures-occupational exposure limit information ranging from limits based on full-shift time-weighted averages to acute limits such as short-term exposure limits and immediately dangerous to life or health values, as well as a variety of other data such as chemical-physical properties and symptoms of exposure. The NIOSH Pocket Guide (NPG) is available as a printed, hardcopy book, a PDF version, an electronic database, and a downloadable application for mobile phones.

Impact of Organism Allocations on Potency Estimates from Ceriodaphnia dubia Reproduction Tests.

In aquatic toxicology experiments, organisms are randomly assigned to an exposure group that receives a particular concentration level of a toxicant (including a control group with no exposure), and their survival, growth, or reproduction outcomes are recorded. Standard experiments use equal numbers of organisms in each exposure group. In the present study, we explored the potential benefits of modifying the current design of aquatic toxicology experiments when it is of interest to estimate the concentration associated with a specific level of decrease from control reproduction responses.

ToxicR: A computational platform in R for computational toxicology and dose-response analyses.

The need to analyze the complex relationships observed in high-throughput toxicogenomic and other omic platforms has resulted in an explosion of methodological advances in computational toxicology. However, advancements in the literature often outpace the development of software researchers can implement in their pipelines, and existing software is frequently based on pre-specified workflows built from well-vetted assumptions that may not be optimal for novel research questions. Accordingly, there is a need for a stable platform and open-source codebase attached to a programming language that allows users to program new algorithms.

Mobile Digital Health Intervention to Promote Nutrition and Physical Activity Behaviors Among Long-term Unemployed in Rural Areas: Protocol for a Randomized Controlled Trial.

Background: Long-term unemployed have poor nutritional and physical activity statuses, and, therefore, special health promotion needs. Particularly in rural areas, however, they often do not have access to health promotion service. Thus, new promising strategies to improve the health of long-term unemployed are needed.

UVB-exposed wheat germ oil increases serum 25-hydroxyvitamin D without improving overall vitamin D status: a randomized controlled trial.

Purpose: This study investigated whether UVB-exposed wheat germ oil (WGO) is capable to improving the vitamin D status in healthy volunteers.

Methods: A randomized controlled human-intervention trial in parallel design was conducted in Jena (Germany) between February and April. Ultimately, 46 healthy males and females with low mean 25-hydroxyvitamin D (25(OH)D) levels (34.

Identifying sensitive windows of airborne lead exposure associated with behavioral outcomes at age 12.

Unlabelled: Despite the precipitous decline of airborne lead concentrations following the removal of lead in gasoline, lead is still detectable in ambient air in most urban areas. Few studies, however, have examined the health effects of contemporary airborne lead concentrations in children.

Methods: We estimated monthly air lead exposure among 263 children (Cincinnati Childhood Allergy and Air Pollution Study; Cincinnati, OH; 2001-2005) using temporally scaled predictions from a validated land use model and assessed neurobehavioral outcomes at age 12 years using the parent-completed Behavioral Assessment System for Children, 2nd edition.

Supporting Advanced Practice Providers Through the Development and Implementation of an Advanced Practice Provider Professional Advancement Program.

As the number of Advanced Practice Providers (APPs) has increased across health care settings, institutions have identified the need to provide opportunities for the advancement, growth, and development of APPs. An APP Professional Advancement Program was developed and implemented at our freestanding, pediatric academic medical center that employs over 700 APPs. This program was designed to support all APPs regardless of their role and practice setting by recognizing their accomplishments and providing the tools and resources needed to pursue opportunities to further their professional development and leadership.

Roles of Registered Nurses in Pediatric Preventive Care Delivery: A Pilot Study on Between-office Variation and Within-office Role Overlap.

Purpose: Registered nurses (RN) participate in delivery of routine pediatric preventive care. This pilot study characterized variation in RN roles and overlap with other team roles.

Methods: We conducted a pilot cross-sectional survey of RNs from an urban/suburban pediatric primary care network.

Quantal Risk Assessment Database: A Database for Exploring Patterns in Quantal Dose-Response Data in Risk Assessment and its Application to Develop Priors for Bayesian Dose-Response Analysis.

Quantitative risk assessments for physical, chemical, biological, occupational, or environmental agents rely on scientific studies to support their conclusions. These studies often include relatively few observations, and, as a result, models used to characterize the risk may include large amounts of uncertainty. The motivation, development, and assessment of new methods for risk assessment is facilitated by the availability of a set of experimental studies that span a range of dose-response patterns that are observed in practice.

On the impact of sample size on median lethal concentration estimation in acute fish toxicity testing: Is n = 7/group enough?

The fish acute toxicity test method is foundational to aquatic toxicity testing strategies, yet the literature lacks a concise sample size assessment. Although various sources address sample size, historical precedent seems to play a larger role than objective measures. We present a novel and comprehensive quantification of the effect of sample size on estimation of the median lethal concentration (LC50), covering a wide range of scenarios.

Bayesian Quantile Impairment Threshold Benchmark Dose Estimation for Continuous Endpoints.

Quantitative risk assessment often begins with an estimate of the exposure or dose associated with a particular risk level from which exposure levels posing low risk to populations can be extrapolated. For continuous exposures, this value, the benchmark dose, is often defined by a specified increase (or decrease) from the median or mean response at no exposure. This method of calculating the benchmark dose does not take into account the response distribution and, consequently, cannot be interpreted based upon probability statements of the target population.

Historical Context and Recent Advances in Exposure-Response Estimation for Deriving Occupational Exposure Limits.

Virtually no occupational exposure standards specify the level of risk for the prescribed exposure, and most occupational exposure limits are not based on quantitative risk assessment (QRA) at all. Wider use of QRA could improve understanding of occupational risks while increasing focus on identifying exposure concentrations conferring acceptably low levels of risk to workers. Exposure-response modeling between a defined hazard and the biological response of interest is necessary to provide a quantitative foundation for risk-based occupational exposure limits; and there has been considerable work devoted to establishing reliable methods quantifying the exposure-response relationship including methods of extrapolation below the observed responses.

Selecting the best design for nonstandard toxicology experiments.

Although many experiments in environmental toxicology use standard statistical experimental designs, there are situations that arise where no such standard design is natural or applicable because of logistical constraints. For example, the layout of a laboratory may suggest that each shelf serve as a block, with the number of experimental units per shelf either greater than or less than the number of treatments in a way that precludes the use of a typical block design. In such cases, an effective and powerful alternative is to employ optimal experimental design principles, a strategy that produces designs with precise statistical estimates.

An empirical comparison of low-dose extrapolation from points of departure (PoD) compared to extrapolations based upon methods that account for model uncertainty.

Experiments with relatively high doses are often used to predict risks at appreciably lower doses. A point of departure (PoD) can be calculated as the dose associated with a specified moderate response level that is often in the range of experimental doses considered. A linear extrapolation to lower doses often follows.

Impact of exchanges and client-therapist alliance in online-text psychotherapy.

The impact of exchanges and client-therapist alliance of online therapy text exchanges were compared to previously published results in face-to-face therapy, and the moderating effects of four participant factors found significant in previously published face-to-face studies were investigated using statistical mixed-effect modeling analytic techniques. Therapists (N=30) and clients (N=30) engaged in online therapy were recruited from private practitioner sites, e-clinics, online counseling centers, and mental-health-related discussion boards. In a naturalistic design, they each visited an online site weekly and completed the standard impact and alliance questionnaires for at least 6 weeks.

Estimating infectivity rates and attack windows for two viruses.

Cells exist in an environment in which they are simultaneously exposed to a number of viral challenges. In some cases, infection by one virus may preclude infection by other viruses. Under the assumption of independent times until infection by two viruses, a procedure is presented to estimate the infectivity rates along with the time window during which a cell might be susceptible to infection by multiple viruses.

Bayesian approach to potency estimation for aquatic toxicology experiments when a toxicant affects both fecundity and survival.

Chemicals in aquatic systems may impact a variety of endpoints including mortality, growth, or reproduction. Clearly, growth or reproduction will only be observed in organisms that survive. Because it is common to observe mortality in studies focusing on the reproduction of organisms, especially in higher concentration conditions, the resulting observed numbers of young become a mixture of zeroes and positive counts.

Risk factors of falls in community-dwelling older adults: logistic regression tree analysis.

Purpose Of The Study: A novel logistic regression tree-based method was applied to identify fall risk factors and possible interaction effects of those risk factors.

Design And Methods: A nationally representative sample of American older adults aged 65 years and older (N = 9,592) in the Health and Retirement Study 2004 and 2006 modules was used. Logistic Tree with Unbiased Selection, a computer algorithm for tree-based modeling, recursively split the entire group in the data set into mutually exclusive subgroups and fit a logistic regression model in each subgroup to generate an easily interpreted tree diagram.

Bayesian approach to estimating reproductive inhibition potency in aquatic toxicity testing.

Effectively and accurately assessing the toxicity of chemicals and their impact on the environment continues to be an important concern in ecotoxicology. Single experiments conducted by a particular laboratory commonly serve as the basis of toxicity risk assessment. These laboratories often have a long history of conducting experiments using particular protocols.

Monotonic Bayesian semiparametric benchmark dose analysis.

Quantitative risk assessment proceeds by first estimating a dose-response model and then inverting this model to estimate the dose that corresponds to some prespecified level of response. The parametric form of the dose-response model often plays a large role in determining this dose. Consequently, the choice of the proper model is a major source of uncertainty when estimating such endpoints.

Baseline characteristics and statistical implications for the OECD 210 fish early-life stage chronic toxicity test.

The fish toxicity assay most commonly used to establish chronic effects is the Organisation for Economic Co-operation and Development (OECD) 210, fish early-life stage test. However, the authors are not aware of any systematic analysis of the experimental design or statistical characteristics of the test since the test guideline was adopted nearly 20 years ago. Here, the authors report the results of an analysis of data compiled from OECD 210 tests conducted by industry labs.

Fall risk factors in community-dwelling elderly who receive Medicaid-supported home- and community-based care services.

Objective: This study identifies fall risk factors in an understudied population of older people who receive community-based care services.

Method: Data were collected from enrollees of Ohio's Medicaid home- and community-based waiver program (preadmission screening system providing options and resources today [PASSPORT]). A total of 23,182 participants receiving PASSPORT services in 2005/2006 was classified as fallers and nonfallers, and a variety of risk factors for falling was analyzed using logistic regressions.

Comparing weighted and unweighted analyses applied to data with a mix of pooled and individual observations.

Smaller organisms may have too little tissue to allow assaying as individuals. To get a sufficient sample for assaying, a collection of smaller individual organisms is pooled together to produce a simple observation for modeling and analysis. When a dataset contains a mix of pooled and individual organisms, the variances of the observations are not equal.

Comparing methods for analyzing overdispersed count data in aquatic toxicology.

Endpoints in aquatic toxicity tests can be measured using a variety of measurement scales including dichotomous (survival), continuous (growth) and count (number of young). A distribution is assumed for an endpoint and analyses proceed accordingly. In certain situations, the assumed distribution may be incorrect and this may lead to incorrect statistical inference.