Optical Emission Spectroscopy of High Voltage Cold Atmospheric Plasma Generated Using Dielectric Barrier Discharges

While numerous experiments have demonstrated the efficacy of high voltage cold atmospheric pressure plasmas for extending food shelf-life and sterilizing medical instrumentation in sealed packages, the influence of the packaging material and gas composition on the reactive gas species generated by the high voltage atmospheric cold plasma is poorly understood. This study elucidates the impact of these parameters on plasma generation in sealed packages for four gases (ambient air, commercial grade compressed air, and high purity helium and nitrogen) placed in commercially available transparent plastic containers and bags. After adequate gas flushing, we observed that the container and bag individually reduced signal intensity by 63% and 45% across the measured wavelengths of 200 nm to 1100 nm, demonstrating that they acted as broadband absorbers. Neither the container nor bag influenced the wavelengths of the peak emissions, only the amplitude, indicating no significant effect on the types of species generated. Lissajous diagrams showed that the power dissipated by the nitrogen and ambient air plasma generated at 72 3.7 kV RMS were comparable to the compressed dry air discharge generated at 80 3.7 kV RMS. The helium discharge at 37 3.7 kV RMS absorbed approximately 92% more power than these gases. We observed translational temperatures ranging from 1088 K for nitrogen to 1421 K for compressed air and rotational temperatures ranging from 285 K for helium to 479 K for compressed air. These results indicate that packaging materials have minimal effect on the most dominant peaks although further studies are required to elucidate the impact on less intense peaks observed

Perceptions of Women's Opportunities in the FederalRepublic of Gennany and the UnitedKingdom

This study assesses the impact ofsocio-economic status and family life on perceptions of women's opportunities among German and British women and men. Our theoretical framework links national characteristics to individual characteristics and perceptions. We hypothesize that the influence of work-family status on perceptions of women's opportunities varies by gender and country because of crossnational differences in ideology and policy. Separate multiple regression analyses for women and men in eacb country' indicate important variations in the effects of labor force participation. family income, age, and family status on perceptions ofwomen's opportunities for education and employment

Patterns in Family Policy Preferences in the European Union

This study empirically examines the relationship between national content and individual preferences for national policy priorities related to improving family life within the European Union. Using data from the Eurobarometer survey, logistic regression models indicate that public opinion about nine potential priorities (housing, economic prospects, education, flexible work hours, childcare, tax advantages, child allowances, parental leave, and contraception) parallels and ideological subscription to traditional gender roles, the level of economic prosperity, and the degree and type of state support for families with children. We also find that women are more concerned about policies that enhance the reconciliation of work and family, while men are more concerned about policies that support their traditional breadwinner duties

Modeling slope failure in the Jones Creek Watershed, Acme, Washington

Mountain watersheds in the Pacific Northwest are particularly susceptible to shallow landslides and debris flows during periods of intense precipitation. The Jones Creek watershed near Acme, WA, is a 6.7 km2 basin that hosts several active landslides. Shallow mass wasting on the unvegetated landslide toes, and deep-seated rotational slide movement can lead to landslide dam outburst floods and debris flows. There are approximately 100 buildings constructed on a 0.75 km2 alluvial fan deposited by debris flows sourced in the watershed. Predicting the occurrence of mass wasting and deep-seated movement events as they relate to the duration and intensity of antecedent precipitation conditions is important for land-use planning and emergency preparedness in the surrounding Acme community. The Distributed-Hydrology-Soil-Vegetation Model (DSHVM) simulates a water and energy balance at the pixel scale of a digital elevation model (DEM). I use DHSVM hydrology simulations, coupled with an infinite-slope failure model, to determine the probability of shallow mass-wasting events for a variety of historical precipitation scenarios. The infinite slope model uses a stochastic approach to predict the probability of slope failure on a cell-by-cell basis. Following the methods of Godt (2004), I use the simulated failure probabilities, paired with antecedent precipitation and intensity, to define a series of predictive antecedent precipitation thresholds for slope failure probability in the Jones Creek watershed. Although basin hydrology is not well-constrained in this study, the failure probability thresholds compare favorably with similar, more rigorous studies performed in the Pacific Northwest. Timber harvest can increase the rate of slope failure in steep basins due to reduced evapotranspiration and root strength loss. In order to supplement current logging prescriptions in the Jones Creek basin, I use DHSVM to model slope failure probability for a design storm event under a number of hypothetical harvest scenarios. DHSVM simulations suggest that root strength is the most important factor for the stabilization of slopes in the Jones Creek basin, and that a total basin harvest would significantly increase the susceptibility to slope failure. Based on the results of this study, I recommend expansion of the current logging prescriptions to include more harvest-restricted area. I also use RocScience SLIDE© version 6.0 software to model the influence of groundwater and soil mechanical properties on deep-seated slope stability for four deep-seated landslides in the Jones Creek watershed. Slide uses a comprehensive suite of tools for probabilistic modeling of complex failures, and incorporates a standalone finite element model for groundwater flow. SLIDE results indicate that the transition from unconsolidated material to weak bedrock on the toes of the deep seated landslides is likely to occur at a depth of less than two meters, which agrees with observed conditions in the basin

Development of Hollow Fiber-Based Bioreactor Systems for 3D Dynamic Neuronal Cell Cultures

Adult central nervous system tissue does not retain the ability to regenerate and restore functional tissue lost to disease or trauma. The peripheral nervous system only has the capacity to regenerate when tissue damage is minor. Most in vitro research investigating the neurobiological mechanisms relevant for enhancing nerve regeneration has focused on culture of neuronal cells on a 2D surface under static conditions. We have performed studies enabling development of an advanced in vitro culture model based on hollow fiber-based bioreactors to allow high density neuronal cell networking with directed axonal outgrowth.The model neuronal-like PC12 cell line was initially used to compare neurite outgrowth after nerve growth factor stimulation between cultures under either static or dynamic conditions with 2D or 3D configurations. High density PC12 cell cultures with extensive neurite outgrowth in three dimensional collagen gels were only possible under the dynamically perfused conditions of a hollow fiber-based bioreactor. Analysis of neurite networking within cultures demonstrated enhanced active synapsin I+ synaptic vesicle clustering among PC12 cells cultured within the 3D dynamic bioreactor compared to cells cultured statically on a 2D surface. We further used two different hollow fiber-based bioreactor designs to investigate primary mouse neural stem cell differentiation within different injectable extracellular matrix hydrogel scaffolds cultured under dynamic conditions. HyStem, a cross-linked hyaluronan hydrogel, allowed structure formation with improved neuronal differentiation compared to collagen and Matrigel hydrogels.We have made further developments in order to create a new hollow fiber-based bioreactor device for controlling directed axonal growth. Excimer laser modification was utilized to fabricate hollow fiber scaffolds allowing control over axonal outgrowth from neurons within a 3D space. Incorporation of these scaffolds into a novel hollow fiber-based bioreactor design will produce a device for high density neuronal tissue formation with axonal outgrowth in a 3D configuration. Such a device will provide an advanced research tool for more accurate evaluation of neurobiological events and development of therapeutic strategies useful for enhancing nerve regeneration