DYNAMICS OF RODENT ASSEMBLAGES INHABITING ABANDONED PETROLEUM LANDFARMS IN OKLAHOMA

Studies on the effects of anthropogenic contamination on wildlife have largely been focused at the individual level. Biomarkers have been used to monitor changes in the health of individuals exposed to contaminants; however, little attention has been given to the effects of chronic exposure at the population or community levels. We studied rodent assemblages from uncontaminated (reference) sites (n 5 5) and abandoned petrochemical landfarms (n 5 5) in Oklahoma to investigate potential alterations in community structure and composition. Rodent assemblages inhabiting landfarms had lower species diversity, lower richness, and a more even distribution of individuals across species. Reference sites showed typical rodent assemblage structure dominated by hispid cotton rats (Sigmodon hispidus) and fulvous harvest mice (Reithrodontomys fulvescens). Assemblages inhabiting landfarms also were dominated by cotton rats; however, harvest mice were replaced by deer mice (Peromyscus maniculatus) on two landfarms. Contaminated sites also were characterized by an increase in house mice (Mus musculus) and an absence of voles (Microtus spp.). Although landfarms tended to have lower cotton rat densities, we could not separate the effects of contamination from increased bare ground associated with landfarms. The results of this study suggest that rodent assemblages were different on landfarms, when compared with reference sites. However, no direct link between site contamination and rodent community structure could be established

Selenium interactions with algae: Chemical processes at biological uptake sites, bioaccumulation, and intracellular metabolism

Selenium (Se) uptake by primary producers is the most variable and important step in determining Se concentrations at higher trophic levels in aquatic food webs. We gathered data available about the Se bioaccumulation at the base of aquatic food webs and analyzed its relationship with Se concentrations in water. This important dataset was separated into lotic and lentic systems to provide a reliable model to estimate Se in primary producers from aqueous exposure. We observed that lentic systems had higher organic selenium and selenite concentrations than in lotic systems and selenate concentrations were higher in lotic environments. Selenium uptake by algae is mostly driven by Se concentrations, speciation and competition with other anions, and is as well influenced by pH. Based on Se species uptake by algae in the laboratory, we proposed an accurate mechanistic model of competition between sulfate and inorganic Se species at algal uptake sites. Intracellular Se transformations and incorporation into selenoproteins as well as the mechanisms through which Se can induce toxicity in algae has also been reviewed. We provided a new tool for risk assessment strategies to better predict accumulation in primary consumers and consequently to higher trophic levels, and we identified some research needs that could fill knowledge gaps

Infection Prevention and the Protective Effects of Unidirectional Displacement Flow Ventilation in the Turbulent Spaces of the Operating Room

Background: Unidirectional displacement flow (UDF) ventilation systems in operating rooms are characterized by a uniformity of velocity 80% and protect patients and operating room personnel against exposure to hazardous substances. However, the air below the surgical lights and in the surrounding zone is turbulent, which impairs the ventilation system’s effect. Aim: We first used the recovery time (RT) as specified in International Organization for Standardization 14644 to determine the particle reduction capacity in the turbulent spaces of an operating room with a UDF system. Methods: The uniformity of velocity was analyzed by comfort-level probe grid measurements in the protected area below a hemispherical closed-shaped and a semi-open column-shaped surgical light (tilt angles: 0/15/30) and in the surrounding zone of a research operating room. Thereafter, RTs were calculated. Results: At a supply air volume of 10,500 m3/h, the velocity, reported as average uniformity+standard deviation, was uniform in the protected area without lights (95.8% + 1.7%), but locally turbulent below the hemispherical closedshaped (69.3% + 14.6%), the semi-open column-shaped light (66.9% + 10.9%), and in the surrounding zone (51.5%+17.6%). The RTs ranged between 1.1 and 1.7 min below the lights and 3.5+0.28 min in the surrounding zone and depended exponentially on the volume flow rate. Conclusions: Compared to an RT of 20 min as required for operating rooms with mixed dilution flow, particles here were eliminated 12–18 times more quickly from below the surgical lights and 5.7 times from the surrounding zone. Thus, the effect of the lights was negligible and the UDF’s retained its strong protective effect

Previous Experiences with Epilepsy and Effectiveness of Information to Change Public Perception of Epilepsy

Differences with regard to the effectiveness of health information and attitude change are suggested between people with direct, behavioral experiences with a health topic and people with indirect, nonbehavioral experiences. The effects of three different methods of health education about epilepsy, frequently used in health education practice, are assessed in a pretest posttest design with control groups, controlling for experiences with epilepsy. Subjects were 132 students from teacher-training colleges. After all treatments, attitudes, and knowledge about epilepsy were changed in a positive way. Treatments were found to be equally effective. Before treatment, direct behavioral experiences were related to knowledge and a more positive attitude towards epilepsy. After treatment, subjects with direct behavioral experiences with epilepsy showed less change of attitude and knowledge as compared with subjects with indirect experiences. Direct experiences appear to restrain the processing of new information and attitude change

Tracking of TV and video gaming during childhood: Iowa Bone Development Study

<p>Abstract</p> <p>Background</p> <p>Tracking studies determine the stability and predictability of specific phenomena. This study examined tracking of TV viewing (TV) and video game use (VG) from middle childhood through early adolescence after adjusting for moderate and vigorous physical activity (MVPA), percentage of body fat (% BF), and maturity.</p> <p>Methods</p> <p>TV viewing and VG use were measured at ages 5, 8, 11, and 13 (n = 434) via parental- and self-report. MVPA was measured using the Actigraph, % BF using dual-energy x-ray absorptiometry, and maturity via Mirwald predictive equations. Generalized Estimating Equations (GEE) were used to assess stability and logistic regression was used to predict children "at risk" for maintaining sedentary behaviors. Additional models examined tracking only in overfat children (boys ≥ 25% BF; girls ≥ 32% BF). Data were collected from 1998 to 2007 and analyzed in 2010.</p> <p>Results</p> <p>The adjusted stability coefficients (GEE) for TV viewing were 0.35 (95% CI = 0.26, 0.44) for boys, 0.32 (0.23, 0.40) for girls, and 0.45 (0.27, 0.64) for overfat. For VG use, the adjusted stability coefficients were 0.14 (0.05, 0.24) for boys, 0.24 (0.10, 0.38) for girls, and 0.29 (0.08, 0.50) for overfat. The adjusted odds ratios (OR) for TV viewing were 3.2 (2.0, 5.2) for boys, 2.9 (1.9, 4.6) for girls, and 6.2 (2.2, 17.2) for overfat. For VG use, the OR were 1.8 (1.1, 3.1) for boys, 3.5 (2.1, 5.8) for girls, and 1.9 (0.6, 6.1) for overfat.</p> <p>Conclusions</p> <p>TV viewing and VG use are moderately stable throughout childhood and predictive of later behavior. TV viewing appears to be more stable in younger children than VG use and more predictive of later behavior. Since habitual patterns of sedentarism in young children tend to continue to adolescence, early intervention strategies, particularly to reduce TV viewing, are warranted.</p

Performance robustness analysis in machine-assisted design of photonic devices

Machine-assisted design of integrated photonic devices (e.g. through optimization and inverse design methods) is opening the possibility of exploring very large design spaces, novel functionalities and non-intuitive geometries. These methods are generally used to optimize performance figures-of-merit. On the other hand, the effect of manufacturing variability remains a fundamental challenge since small fabrication errors can have a significant impact on light propagation, especially in high-index-contrast platforms. Brute-force analysis of these variabilities during the main optimization process can become prohibitive, since a large number of simulations would be required. To this purpose, efficient stochastic techniques integrated in the design cycle allow to quickly assess the performance robustness and the expected fabrication yield of each tentative device generated by the optimization. In this invited talk we present an overview of the recent advances in the implementation of stochastic techniques in photonics, focusing in particular on stochastic spectral methods that have been regarded as a promising alternative to the classical Monte Carlo method. Polynomial chaos expansion techniques generate so called surrogate models by means of an orthogonal set of polynomials to efficiently represent the dependence of a function to statistical variabilities. They achieve a considerable reduction of the simulation time compared to Monte Carlo, at least for mid-scale problems, making feasible the incorporation of tolerance analysis and yield optimization within the photonic design flow